FLUSH TOILET APPARATUS

CROSS REFERENCES TO RELATED APPLICATIONS

[0001]The present invention contains subject matter related to Japanese Patent Application No. 2024-204167 filed in the Japan Patent Office on Nov. 22, 2024, the entire contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

[0002]The present invention relates to a flush toilet apparatus and, more particularly, to a siphon jet-type flush toilet apparatus.

2. Description of the Related Art

[0003]When flushing a toilet, a user manually selects from a full flush, a partial flush, or an eco partial flush (a flush using a smaller amount of water than the partial flush) to flush the toilet. The amounts of flush water used in these types of flush are set in consideration of all types and amounts of waste that may be assumed, such that any waste can be discharged. Each of these flush water amounts is always constant and cannot be changed in accordance with the condition of waste during each flush. Consequently, for example, when the amount of waste is less than expected, although the waste can be discharged, there is a possibility that more flush water than necessary will be used.

[0004]In the related art, as described in Japanese Unexamined Patent Application Publication No. 2019-526003 (PTL 1), a flush toilet apparatus is known in which the amount of flush water used in a partial flush is varied depending on whether toilet paper is used. In such a flush toilet apparatus, the amount of flush water used in a partial flush can be reduced when toilet paper is not used.

[0005]In addition, in the related art, as described in Japanese Unexamined Patent Application Publication No. 2021-050983 (PTL 2), a flush toilet apparatus is known that determines the type and amount of waste. In such a flush toilet apparatus, an image of waste that has fallen into or is falling into a bowl is captured, and the captured image is analyzed to determine the type and amount of the waste.

SUMMARY OF THE INVENTION

[0006]Although the flush toilet apparatus described in PTL 1 varies the amount of flush water used in a partial flush depending on toilet paper usage, the flush toilet apparatus is not configured to perform an optimal toilet flush in a full flush based on the type and amount of waste.

[0007]In addition, although the flush toilet apparatus described in PTL 2 determines the type and amount of waste, the flush toilet apparatus is not configured to perform an optimal toilet flush based on the type and amount of waste.

[0008]Accordingly, in the flush toilet apparatuses described in PTL 1 and PTL 2, there is a problem in that, for example, an excessive amount of flush water may be used in the case where the amount of waste is less than expected.

[0009]The present invention has been made to solve the above-described problem in the related art, and it is an object of the present invention to provide a flush toilet apparatus capable of achieving further water saving by performing an optimal toilet flush for each toilet flush while maintaining waste discharge performance.

[0010]To achieve the above-described object, the present invention provides a flush toilet apparatus that is a siphon jet-type flush toilet apparatus, the flush toilet apparatus including a bowl having a waste receiving surface and a rim portion, the waste receiving surface being configured to receive waste, and the rim portion being formed above the waste receiving surface, a drain trap conduit connected to a lower portion of the bowl and configured to discharge waste, a jet water spout port provided at a lower portion of the bowl and configured to eject flush water toward an inlet of the drain trap conduit, a flush water supply device configured to supply flush water to the jet water spout port, a detection unit configured to detect an object fallen into the bowl, and a control unit that is configured to perform a determination of whether the object is solid waste or floating waste based on a detection result obtained by the detection unit and to control the flush water supply device based on a result of the determination. The control unit is configured to control the flush water supply device such that first jet water ejection is performed through the jet water spout port at a first flow rate for inducing siphonage and such that second jet water ejection is subsequently performed through the jet water spout port at a second flow rate lower than the first flow rate. The control unit is configured to control the flush water supply device such that a duration of the first jet water ejection is shorter when the object is determined to be floating waste than when the object is determined to be solid waste.

[0011]According to the present invention configured as described above, since the control unit is configured to control the flush water supply device such that the first jet water ejection is performed through the jet water spout port at the first flow rate for inducing siphonage and such that the second jet water ejection is subsequently performed through the jet water spout port at the second flow rate lower than the first flow rate, siphonage may be induced at an early stage by the first jet water ejection, after which waste may be flushed out by the second jet water ejection. In addition, since the control unit is configured to control the flush water supply device such that the duration of the first jet water ejection is shorter when the object is determined to be floating waste than when the object is determined to be solid waste, the duration of the first jet water ejection that has little effect on discharge of floating waste may be shortened, thereby enabling reduction in the amount of flush water. As a result, further water saving may be achieved while maintaining waste discharge performance by performing optimal toilet flushing for each toilet flush.

[0012]In the present invention, preferably, the control unit is configured to perform a determination of an amount of an object based on a detection result obtained by the detection unit and to control the flush water supply device based on a result of the determination, and the control unit is configured to control the flush water supply device such that, when the object is determined to be floating waste, the duration of the first jet water ejection is substantially constant regardless of the amount of the object.

[0013]According to the present invention configured as described above, since the control unit is configured to perform a determination of an amount of an object based on a detection result obtained by the detection unit and to control the flush water supply device based on a result of the determination, and the control unit is configured to control the flush water supply device such that, when the object is determined to be floating waste, the duration of the first jet water ejection is substantially constant regardless of the amount of the object, the duration of the first jet water ejection, which has little effect on discharge of floating waste, may be set to be substantially constant, thereby enabling reduction in the amount of flush water.

[0014]In addition, in the present invention, preferably, the control unit is configured to control the flush water supply device such that, when the object is determined to be floating waste, the duration of the second jet water ejection increases as the amount of the object increases.

[0015]According to the present invention configured as described above, since the control unit is configured to control the flush water supply device such that, when the object is determined to be solid waste, the duration of the second jet water ejection increases as the amount of the object increases, floating waste remaining in the drain trap conduit may be reliably flushed out by the second jet water ejection when the amount of floating waste is large.

[0016]In the present invention, preferably, the control unit is configured to perform a determination of an amount of an object based on a detection result obtained by the detection unit and to control the flush water supply device based on a result of the determination, and the control unit is configured to control the flush water supply device such that, when the object is determined to be solid waste, the duration of the first jet water ejection increases as the amount of the object increases. According to the present invention configured as described above, since the control unit is configured to perform a determination of an amount of an object based on a detection result obtained by the detection unit and to control the flush water supply device based on a result of the determination, and the control unit is configured to control the flush water supply device such that, when the object is determined to be solid waste, the duration of the first jet water ejection increases as the amount of the object increases, siphonage may be continued for a long time, thereby enabling reliable discharge of solid waste.

[0017]In addition, in the present invention, preferably, the control unit is configured to control the flush water supply device such that, when the object is determined to be solid waste, the duration of the second jet water ejection is substantially constant regardless of the amount of the object.

[0018]According to the present invention configured as described above, since the control unit is configured to control the flush water supply device such that, when the object is determined to be solid waste, the duration of the second jet water ejection is substantially constant regardless of the amount of the object, the duration of the second jet water ejection that has little effect on discharge of solid waste may be set to be substantially constant, thereby enabling reduction in the amount of flush water.

[0019]In the present invention, preferably, the control unit is configured to perform a determination of whether the object is solid waste, floating waste, or an object other than waste based on a detection result obtained by the detection unit and to control the flush water supply device based on a result of the determination, and the control unit is configured to control the flush water supply device such that the duration of the second jet water ejection is shorter when the object is determined to be an object other than waste than when the object is determined to be solid waste and floating waste.

[0020]According to the present invention configured as described above, since the control unit is configured to perform a determination of whether the object is solid waste, floating waste, or an object other than waste based on a detection result obtained by the detection unit and to control the flush water supply device based on a result of the determination, and the control unit is configured to control the flush water supply device such that the duration of the second jet water ejection is shorter when the object is determined to be an object other than waste than when the object is determined to be solid waste and floating waste, the duration of the second jet water ejection that has little effect on discharge of an object other than waste may be shortened, thereby enabling reduction in the amount of flush water.

[0021]To achieve the above-described object, the present invention provides a flush toilet apparatus that is a siphon jet-type flush toilet apparatus, the flush toilet apparatus including a bowl having a waste receiving surface and a rim portion, the waste receiving surface being configured to receive waste, and the rim portion being formed above the waste receiving surface, a drain trap conduit connected to a lower portion of the bowl and configured to discharge waste, a jet water spout port provided at a lower portion of the bowl and configured to eject flush water toward an inlet of the drain trap conduit, a flush water supply device configured to supply flush water to the jet water spout port, a detection unit configured to detect an object fallen into the bowl, and a control unit that is configured to perform a determination of whether the object is solid waste or floating waste based on a detection result obtained by the detection unit and to control the flush water supply device based on a result of the determination. The control unit is configured to control the flush water supply device such that first jet water ejection is performed through the jet water spout port at a first flow rate for inducing siphonage and such that second jet water ejection is subsequently performed through the jet water spout port at a second flow rate lower than the first flow rate. The control unit is configured to control the flush water supply device such that an instantaneous flow rate in the first jet water ejection is higher when the object is determined to be floating waste than when the object is determined to be solid waste.

[0022]According to the present invention configured as described above, since the control unit is configured to control the flush water supply device such that the first jet water ejection is performed through the jet water spout port at the first flow rate for inducing siphonage and such that the second jet water ejection is subsequently performed through the jet water spout port at the second flow rate lower than the first flow rate, siphonage may be induced at an early stage by the first jet water ejection, after which waste may be flushed out by the second jet water ejection. In addition, since the control unit is configured to control the flush water supply device such that the instantaneous flow rate in the first jet water ejection is higher when the object is determined to be floating waste than when the object is determined to be solid waste, siphonage may be induced at an early stage, enabling the discharge of floating waste. As a result, further water saving may be achieved while maintaining waste discharge performance by performing optimal toilet flushing for each toilet flush.

[0023]In the present invention, preferably, the control unit is configured to control the flush water supply device such that the instantaneous flow rate in the second jet water ejection is higher when the object is determined to be floating waste than when the object is determined to be solid waste.

[0024]According to the present invention configured as described above, since the control unit is configured to control the flush water supply device such that the instantaneous flow rate in the second jet water ejection is higher when the object is determined to be floating waste than when the object is determined to be solid waste, floating waste remaining in the drain trap conduit may be reliably flushed out by the second jet water ejection.

[0025]In addition, in the present invention, preferably, the control unit is configured to perform a determination of whether the object is solid waste, floating waste, or an object other than waste based on a detection result obtained by the detection unit and to control the flush water supply device based on a result of the determination, and the control unit is configured to control the flush water supply device such that the instantaneous flow rate in the second jet water ejection is lower when the object is determined to be an object other than waste than when the object is determined to be floating waste.

[0026]According to the present invention configured as described above, since the control unit is configured to perform a determination of whether the object is solid waste, floating waste, or an object other than waste based on a detection result obtained by the detection unit and to control the flush water supply device based on a result of the determination, and the control unit is configured to control the flush water supply device such that the instantaneous flow rate in the second jet water ejection is lower when the object is determined to be an object other than waste than when the object is determined to be floating waste, the instantaneous flow rate in the second jet water ejection that has little effect on discharge of an object other than waste may be reduced, thereby enabling reduction in the amount of flush water.

[0027]To achieve the above-described object, the present invention provides a flush toilet apparatus that is a siphon jet-type flush toilet apparatus, the flush toilet apparatus including a bowl having a waste receiving surface and a rim portion, the waste receiving surface being configured to receive waste, and the rim portion being formed above the waste receiving surface, a drain trap conduit connected to a lower portion of the bowl and configured to discharge waste, a jet water spout port provided at a lower portion of the bowl and configured to eject flush water toward an inlet of the drain trap conduit, a flush water supply device configured to supply flush water to the jet water spout port, a detection unit configured to detect an object fallen into the bowl, and a control unit that is configured to perform a determination of whether the object is solid waste or floating waste based on a detection result obtained by the detection unit and to control the flush water supply device based on a result of the determination. The control unit is configured to control the flush water supply device such that first jet water ejection is performed through the jet water spout port at a first flow rate for inducing siphonage and such that second jet water ejection is subsequently performed through the jet water spout port at a second flow rate lower than the first flow rate. The control unit is configured to control the flush water supply device such that a duration of the second jet water ejection is longer when the object is determined to be floating waste than when the object is determined to be solid waste.

[0028]According to the present invention configured as described above, since the control unit is configured to control the flush water supply device such that the first jet water ejection is performed through the jet water spout port at the first flow rate for inducing siphonage and such that the second jet water ejection is subsequently performed through the jet water spout port at the second flow rate lower than the first flow rate, siphonage may be induced at an early stage by the first jet water ejection, after which waste may be flushed out by the second jet water ejection. In addition, since the control unit is configured to control the flush water supply device such that the duration of the second jet water ejection is longer when the object is determined to be floating waste than when the object is determined to be solid waste, floating waste remaining in the drain trap conduit may be reliably flushed out by the second jet water ejection. As a result, further water saving may be achieved by performing optimal toilet flushing for each toilet flush while maintaining waste discharge performance.

[0029]The flush toilet apparatus according to the present invention can achieve further water saving by performing an optimal toilet flush for each toilet flush while maintaining waste discharge performance.

BRIEF DESCRIPTION OF THE DRAWINGS

[0030]FIG. 1 is a perspective view of a flush toilet apparatus according to an embodiment of the present invention.

[0031]FIG. 2 is an overall configuration diagram of the flush toilet apparatus according to the embodiment of the present invention.

[0032]FIG. 3 is a block diagram illustrating a configuration relating to a control unit of the flush toilet apparatus according to the embodiment of the present invention.

[0033]FIG. 4 is a flowchart illustrating toilet flushing control in the flush toilet apparatus according to the embodiment of the present invention.

[0034]FIG. 5 is a diagram illustrating a flushing sequence of jet water ejection in each jet water ejection pattern of the flush toilet apparatus according to the embodiment of the present invention.

[0035]FIG. 6 is a schematic diagram illustrating how waste or the like is discharged in each jet water ejection pattern of the flush toilet apparatus according to the embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0036]A flush toilet apparatus according to an embodiment of the present invention will be described below with reference to the accompanying drawings.

[0037]First, the overall configuration of the flush toilet apparatus according to the embodiment of the present invention will be described with reference to FIG. 1 to FIG. 3.

[0038]FIG. 1 is a perspective view of the flush toilet apparatus according to the embodiment of the present invention. FIG. 2 is an overall configuration diagram of the flush toilet apparatus according to the embodiment of the present invention. FIG. 3 is a block diagram illustrating a configuration relating to a control unit of the flush toilet apparatus according to the embodiment of the present invention.

[0039]As illustrated in FIG. 1 and FIG. 2, a flush toilet apparatus 1 according to the embodiment of the present invention is a siphon jet-type toilet and includes a toilet main body 2 made of ceramic, a personal washing device 4 disposed on an upper surface of the toilet main body 2, a valve unit 6 that supplies flush water to the toilet main body 2, a water storage tank 8 that stores flush water, and a pressure pump 10 that supplies flush water stored in the water storage tank 8 to the toilet main body 2.

[0040]The toilet main body 2 includes a bowl 15 and a drain trap conduit 16. The bowl 15 has a bowl-shaped waste receiving surface 12 that receives waste and a rim portion 14 that is formed above the waste receiving surface 12. The drain trap conduit 16 is connected to a lower bottom portion of the bowl 15 so as to discharge waste. A rim water conduit 18 is formed inside the rim portion 14, and a rim water spout portion 20 that is a downstream end of the rim water conduit 18 has a rim water spout port 20a through which rim water ejection is performed. The rim water spout port 20a is formed at a front-right portion of the bowl 15 as viewed from the front of the flush toilet apparatus 1, and is configured to eject flush water rearward so as to form a swirling flow along the inner peripheral surface of the rim portion 14.

[0041]In addition, a jet water conduit 22 is formed in a lower portion of the toilet main body 2, and a jet water spout portion 24 that is a downstream end of the jet water conduit 22 has a jet water spout port 24a through which jet water ejection is performed. The jet water spout port 24a is located at the bottom portion of the bowl 15, is oriented substantially horizontally toward an inlet 16a of the drain trap conduit 16, and is configured to eject flush water toward the inlet 16a of the drain trap conduit 16.

[0042]The drain trap conduit 16 includes the inlet 16a, an ascending conduit 16b that extends upward from the inlet 16a, and a descending conduit 16c that extends downward from the ascending conduit 16b. An apex 16d is located between the ascending conduit 16b and the descending conduit 16c. A drain socket 26 is connected to a lower end of the descending conduit 16c of the drain trap conduit 16.

[0043]As illustrated in FIG. 1, the personal washing device 4 includes a main body 4a, a washing nozzle 4b that is provided to be extendable and retractable from the main body 4a, a toilet seat 4c that is pivotably attached to the main body 4a, and a toilet lid 4d that is pivotably attached to the main body 4a so as to cover the toilet seat 4c.

[0044]As illustrated in FIG. 2, the valve unit 6 includes a main water supply conduit 30 through which flush water is supplied from a water pipe 28 that is a water supply source. In the main water supply conduit 30, a constant flow valve 38, a diaphragm-type solenoid on-off valve 40, and a water-supply-conduit switching valve 42 are provided in this order from an upstream side. In addition, in the main water supply conduit 30 located on the upstream side of the valve unit 6, a stop valve 32, a strainer 34, and a branch fitting 36 are provided in this order from the upstream side. The main water supply conduit 30 is formed of a water supply hose that is connected to the water pipe 28 outside the toilet.

[0045]A rim-side water supply conduit 44 for supplying flush water to the rim water spout port 20a and a tank-side water supply conduit 46 for supplying flush water to the water storage tank 8 are connected to the downstream side of the water-supply-conduit switching valve 42. The rim water conduit 18 is connected to the downstream end of the rim-side water supply conduit 44, and flush water is supplied to the rim water spout port 20a by the water supply pressure of a water supply system.

[0046]The constant flow valve 38 is configured to restrict the flow rate of flush water that has flowed therein through the stop valve 32, the strainer 34, and the branch fitting 36 to a predetermined flow rate or less. Flush water that has passed through the constant flow valve 38 flows into the solenoid on-off valve 40, and the flush water that has passed through the solenoid on-off valve 40 is supplied, by the water-supply-conduit switching valve 42, to the rim water spout port 20a through the rim-side water supply conduit 44, which is located on a rim side, or to the water storage tank 8 through the tank-side water supply conduit 46, which is located on a tank side.

[0047]The water-supply-conduit switching valve 42 is a switching valve that is capable of supplying flush water to both the rim-side water supply conduit 44 and the tank-side water supply conduit 46 simultaneously and freely changing the distribution ratio of the amount and flow rate of flush water between the rim-side and the tank-side. The water-supply-conduit switching valve 42 includes a rotor (not illustrated) for changing the distribution ratio of the amount and flow rate of flush water between the rim-side and the tank-side, and the rotor is driven to a desired position by a motor (not illustrated).

[0048]A pump-side water supply conduit 48 is connected to a lower portion of the water storage tank 8, and the pressure pump 10 that includes a pump chamber is connected to the downstream end of the pump-side water supply conduit 48. In addition, the pressure pump 10 and the jet water conduit 22 are connected to each other by a jet-side water supply conduit 50, and the pressure pump 10 is configured to pressurize the flush water stored in the water storage tank 8 so as to supply the flush water to the jet water spout port 24a.

[0049]The pressure pump 10 is configured to pressurize the flush water stored in the water storage tank 8 such that the flush water is ejected from the jet water spout port 24a at a predetermined flow rate. The upstream side of the pressure pump 10 is connected to the pump-side water supply conduit 48, and the downstream side of the pressure pump 10 is connected to the jet-side water supply conduit 50. The pressure pump 10 includes a casing 10a, an impeller 10b that is a vane wheel provided in the casing 10a in such a manner as to be rotatable in both forward and reverse directions, and a motor 10c that causes the impeller 10b to rotate. The pressure pump 10 is a centrifugal pump that pumps the flush water stored in the water storage tank 8 by using centrifugal force generated by rotation of the impeller 10b.

[0050]Note that the pressure pump 10 is an example of a “flush water supply device” in the present invention. In the present embodiment, a pressure pump is used as the flush water supply device. However, instead of a pressure pump, for example, an accumulator-type booster that stores energy of water in the form of pressure or an air compressor that operates using compressed air as driving power may alternatively be used. Alternatively, as the flush water supply device, the above-described water-supply-conduit switching valve or a solenoid on-off valve that can vary a cross-sectional area of a flow passage may be used.

[0051]The rim-side water supply conduit 44 is provided with a vacuum breaker 52 that is a check valve, and the tank-side water supply conduit 46 is provided with a vacuum breaker 54 that is also a check valve. These vacuum breakers 52 and 54 prevent backflow from the rim water spout port 20a and the water storage tank 8. In addition, flush water that overflows from an atmospheric vent portion of the vacuum breaker 52 of the rim-side water supply conduit 44 flows into the water storage tank 8 through a return conduit 55.

[0052]The water storage tank 8 is a sealed-type water storage tank. A ball-type check valve 56 is provided at a portion where the tank-side water supply conduit 46 and the water storage tank 8 are connected to each other, and a ball-type check valve 58 is provided at a portion where the return conduit 55 and the water storage tank 8 are connected to each other. These ball-type check valves 56 and 58 prevent backflow of flush water even if the water storage tank 8 becomes completely full beyond the upper end of an overflow channel 60.

[0053]A drain plug 62 is provided at a bottom portion of the water storage tank 8. The drain plug 62 is located below the pressure pump 10 and is configured such that, by opening the drain plug 62 during maintenance, flush water in the water storage tank 8 and the pressure pump 10 can be discharged.

[0054]An upper float switch 64 and a lower float switch 66 are provided inside the water storage tank 8. The upper float switch 64 switches to an ON state when the water level inside the water storage tank 8 reaches a predetermined level L2 slightly below a maximum water level L3 during normal use. Upon detecting that the upper float switch 64 is in the ON state, a control unit 74 closes the solenoid on-off valve 40. The lower float switch 66 switches to an ON state when the water level inside the water storage tank 8 drops to a minimum water level L1 during normal use. Upon detecting that the lower float switch 66 is in the ON state, the control unit 74 stops the pressure pump 10.

[0055]The overflow channel 60 for discharging overflowed flush water is provided in the water storage tank 8. The upper end of the overflow channel 60 opens into the water storage tank 8, and the lower end of the overflow channel 60 is connected to the jet-side water supply conduit 50. A flapper valve 67 that is a check valve is attached to the overflow channel 60 so that backflow from the jet water spout port 24a can be prevented.

[0056]As illustrated in FIG. 1 and FIG. 2, the flush toilet apparatus 1 includes a seating sensor 68 for detecting a user's seating action, a line sensor 70 for detecting an object that has fallen into the bowl 15 after the user has excreted, and the control unit 74 that controls the pressure pump 10 on the basis of a detection result obtained by the line sensor 70.

[0057]The seating sensor 68 is provided at a rear-left portion of the underside of the toilet seat 4c, which is included in the personal washing device 4. The seating sensor 68 is a load sensor that detects the load of a user. The seating sensor 68 is configured to be capable of detecting a change in load while a user is seated on the toilet seat 4c and detecting a start and end of excretion by the user.

[0058]Note that, although a load sensor is used as the seating sensor 68 in the present embodiment, an infrared distance-measuring sensor or the like may alternatively be used instead of the load sensor.

[0059]The line sensor 70 is provided at the main body 4a of the personal washing device 4 so as to face the interior of the bowl 15 and configured to detect an object that has fallen into the bowl 15. The line sensor 70 includes a plurality of light receiving elements arranged linearly and is configured to acquire one-dimensional data (linear still images) over time at predetermined time intervals. A plurality of one-dimensional data items that have been acquired are arranged in chronological order by the control unit 74 so as to generate a single two-dimensional image, and the single two-dimensional image is used to determine the type and amount of an object corresponding to the single two-dimensional image.

[0060]Note that the line sensor 70 is an example of a “detection unit” in the present invention. In the present embodiment, a line sensor is used as the detection unit. However, instead of a line sensor, a camera that captures an image of an object that has fallen into the bowl 15 or an ultrasonic distance-measuring sensor that measures the level of the water surface in the bowl 15 by using ultrasonic waves may alternatively be used. In addition, although the line sensor 70 is provided at the main body 4a of the personal washing device 4 in the present embodiment, the line sensor 70 may alternatively be provided at the underside of the toilet seat 4c or the underside of the toilet lid 4d.

[0061]As illustrated in FIG. 3, the control unit 74 is electrically connected to the upper float switch 64, the lower float switch 66, the seating sensor 68, the line sensor 70, a toilet flushing switch 76, the solenoid on-off valve 40, the water-supply-conduit switching valve 42, and the pressure pump 10, and is configured to be capable of communicating with the various devices. When the toilet flushing switch 76 is pressed, the control unit 74 sequentially operates the solenoid on-off valve 40, the water-supply-conduit switching valve 42, and the pressure pump 10. As a result, first, flush water is ejected from the rim water spout port 20a. Next, while continuing to eject flush water from the rim water spout port 20a, flush water is ejected from the jet water spout port 24a. Finally, flush water is ejected from the rim water spout port 20a. Note that, although the control unit 74 is connected to each of the various devices via a wired connection in the present embodiment, it may be connected to each of the various devices wirelessly.

[0062]The control unit 74 is configured to generate a single two-dimensional image by arranging a plurality of one-dimensional data items, which are acquired from the line sensor 70, in chronological order and to determine the type and amount of an object that has fallen into the bowl 15. In addition, the control unit 74 is configured to control, for each toilet flush, the pressure pump 10 on the basis of a determination result for the type and amount of an object that has fallen into the bowl 15 and to vary the instantaneous flow rate of flush water ejected from the jet water spout port 24a and the duration of the ejection.

[0063]Next, toilet flushing control in the flush toilet apparatus 1 according to the embodiment of the present invention will be described in detail.

[0064]FIG. 4 is a flowchart illustrating toilet flushing control in the flush toilet apparatus according to the embodiment of the present invention. In FIG. 4, “5” indicates each step.

[0065]First, in S1, it is determined whether a user is seated on the toilet seat 4c. More specifically, when the control unit 74 detects a signal from the seating sensor 68, it determines that a user is seated on the toilet seat 4c, and the process proceeds to S2 (Yes in S1). If the control unit 74 does not detect a signal from the seating sensor 68, it determines that no user is not seated on the toilet seat 4c (No in S1).

[0066]Next, in S2, an object that has fallen into the bowl 15 is detected. More specifically, after the user has excreted, an object falling into the bowl 15 is detected by the line sensor 70. The line sensor 70 acquires one-dimensional data items (linear still images) of the object over time at predetermined time intervals. The plurality of acquired one-dimensional data items are transmitted to the control unit 74 and arranged in chronological order by the control unit 74 so as to generate a single two-dimensional image.

[0067]In S3, it is determined whether the user has finished excretion. More specifically, when a change in the signal from the seating sensor 68 (a change in a seating state) is detected, the control unit 74 determines that the user has finished excretion, and the process proceeds to S4 (Yes in S3). If no change in the signal from the seating sensor 68 is detected, the control unit 74 determines that the user has not yet finished excretion (No in S3).

[0068]Next, in S4, the type and amount of the object that has fallen into the bowl 15 is determined. More specifically, the control unit 74 compares the two-dimensional image generated in S2 with a reference image that is stored beforehand in the control unit 74. In addition, in S4, it is determined whether the type of the object is “solid waste”, “floating waste”, or “toilet paper (object other than waste)”. Furthermore, in S4, it is determined whether the amount of the object is “small”, “medium”, or “large”. In the comparison between the two-dimensional image and the reference image, the brightness, hue, saturation, gradation, and so forth of each of the images are quantified, and the type and amount of the object are determined by comparing the numerical values of the images. Note that, in the case where at least two out of “solid waste”, “floating waste”, and “toilet paper” are present, the control unit 74 determines the type of the one with the largest amount as the type of the object.

[0069]In S5, once the toilet flushing switch 76 has been pressed by the user to start toilet flushing, toilet flushing is executed (S6).

[0070]Next, in S6, the control unit 74 starts toilet flushing by controlling the solenoid on-off valve 40, the water-supply-conduit switching valve 42, and the pressure pump 10.

[0071]First, the control unit 74 opens the solenoid on-off valve 40 and fully opens the water-supply-conduit switching valve 42 toward the rim side. This allows flush water to be ejected from the rim water spout port 20a so as to wash the bowl 15.

[0072]Next, while continuing to eject flush water from the rim water spout port 20a, the control unit 74 drives the pressure pump 10 so as to eject flush water from the jet water spout port 24a. More specifically, the control unit 74 controls the pressure pump 10 such that first jet water ejection is performed at a first flow rate for inducing siphonage, and then controls the pressure pump 10 such that second jet water ejection is performed at a second flow rate that is lower than the first flow rate. In this case, the control unit 74 selects one of nine jet water ejection patterns (described later) on the basis of the type and amount of the object, which have been determined in S4, and controls the pressure pump 10. As a result, flush water is ejected from the jet water spout port 24a in accordance with the selected jet water ejection pattern.

[0073]Subsequently, the control unit 74 stops the pressure pump 10 so as to stop the ejection of flush water from the jet water spout port 24a. Even after the pressure pump 10 has been stopped, flush water continues to be ejected from the rim water spout port 20a, and thus, the water stored in the bowl 15 returns to its original level, completing the toilet flushing (S7).

[0074]Next, selection of one of the above-mentioned jet water ejection patterns according to the type and amount of an object will be described in detail with reference to FIG. 5 and FIG. 6.

[0075]FIG. 5 is a diagram illustrating a flushing sequence of jet water ejection in each of the jet water ejection patterns of the flush toilet apparatus according to the embodiment of the present invention. FIG. 6 is a schematic diagram illustrating how waste and the like are discharged in each of the jet water ejection patterns of the flush toilet apparatus according to the embodiment of the present invention. Note that FIG. 5 illustrates each flushing sequence from the start to the end of ejection of flush water from the jet water spout port 24a. In FIG. 6, section (a) illustrates how waste and the like are discharged by the first jet water ejection, and section (b) illustrates how waste and the like are discharged by the second jet water ejection.

[0076]As illustrated in FIG. 5, the jet water ejection patterns are classified into nine patterns (patterns A1 to A3, patterns B1 to B3, and patterns C1 to C3) based on the types and amounts of objects. The types of object are classified into three categories: “solid waste”, “floating waste”, and “toilet paper”. Here, “solid waste” refers to waste that is heavier than water and that sinks in water, “floating waste” refers to waste (diarrhea) that is lighter than water and floats in water, and “toilet paper” refers to paper that is used after excretion and that dissolves in water. In addition, the amounts of objects are classified into three categories: “small”, “medium”, and “large”. Here, regarding the amount of an object, “small” refers to an amount less than approximately 100 g, “medium” refers to an amount in a range from approximately 100 g to approximately 300 g, and “large” refers to an amount greater than approximately 300 g.

[0077]Note that, although the jet water ejection patterns are classified into nine patterns in the present embodiment, the present invention is not limited to this, and for example, the jet water ejection patterns may be classified into fewer than nine patterns, or may be classified into more than nine patterns. In addition, in the present embodiment, although the types of objects are classified into “solid waste”, “floating waste”, and “toilet paper”, the types of objects may be classified into “solid waste”, “floating waste”, and “object other than waste”.

[0078]In each of the jet water ejection patterns, first, the first jet water ejection is performed at the first flow rate for inducing siphonage, after which the second jet water ejection is performed at the second flow rate, which is lower than the first flow rate. As a result, the first jet water ejection causes the drain trap conduit 16 to become filled with water, thereby inducing siphonage at an early stage. Due to the siphonage, waste and the like are discharged out of the drain trap conduit 16. Subsequently, after the completion of siphonage or immediately before the completion of siphonage, residual matter and water returning from the drain trap conduit 16 are flushed out of the drain trap conduit 16 by the second jet water ejection (blow flow).

[0079]First, when an object is determined to be “solid waste”, one of the patterns A1 to A3 is selected based on the amount of the solid waste, and the jet water ejection of the selected pattern is executed.

[0080]As illustrated in FIG. 5, in the case of “solid waste”, the instantaneous flow rate of flush water ejected from the jet water spout port 24a is the same across the patterns A1 to A3. The instantaneous flow rate in the first jet water ejection is 50 L/min, and the instantaneous flow rate in the second jet water ejection is 35 L/min.

[0081]As illustrated in FIG. 5, in the case of “solid waste”, the duration of the first jet water ejection is set such that the greater the amount of solid waste, the longer the duration. More specifically, the duration of the first jet water ejection is 0.5 seconds when the amount of solid waste is “small”, 0.6 seconds when the amount of solid waste is “medium”, and 0.7 seconds when the amount of solid waste is “large”. The duration of the second jet water ejection is set to be substantially constant (0.7 seconds) regardless of the amount of solid waste. In addition, the amount of flush water ejected from the jet water spout port 24 a is 2.63 L when the amount of solid waste is “small”, 2.80 L when the amount of solid waste is “medium”, and 2.96 L when the amount of solid waste is “large”.

[0082]As illustrated in section (a) of FIG. 6, in the case of “solid waste”, the instantaneous flow rate in the first jet water ejection is set to a relatively high flow rate, and thus, the drain trap conduit 16 becomes filled with water, thereby inducing siphonage at an early stage. In addition, since the duration of the first jet water ejection is set such that the greater the amount of solid waste, the longer the duration, the duration of the siphonage also increases as the amount of solid waste increases. As a result, even when the amount of solid waste is large, the solid waste can be reliably discharged by the first jet water ejection.

[0083]As illustrated in section (b) of FIG. 6, in the case of “solid waste”, the instantaneous flow rate in the second jet water ejection is set to a relatively low flow rate, and thus, residual waste and water returning from the drain trap conduit 16 are flushed out by the second jet water ejection while the amount of flush water has been reduced. Since the duration of the second jet water ejection is set to be substantially constant regardless of the amount of solid waste, the amount of flush water is reduced. Here, even if the amount of solid waste increases, the solid waste is mostly discharged by the first jet water ejection, and thus, the discharge performance for solid waste will not degrade even when the duration of the second jet water ejection is set to be substantially constant.

[0084]Next, when an object is determined to be “floating waste”, one of the patterns B1 to B3 is selected based on the amount of the floating waste, and the jet water ejection of the selected pattern is executed.

[0085]As illustrated in FIG. 5, in the case of “floating waste”, the instantaneous flow rate of flush water ejected from the jet water spout port 24a is the same across the patterns B1 to B3. The instantaneous flow rate in the first jet water ejection is 56 L/min, and the instantaneous flow rate in the second jet water ejection is 40 L/min. As described above, in the case of “floating waste”, the instantaneous flow rate in the first jet water ejection is set to be higher than that in the case of “solid waste” (patterns A1 to A3). Similarly, the instantaneous flow rate in the second jet water ejection is set to be higher than that in the case of “solid waste” (patterns A1 to A3).

[0086]As illustrated in FIG. 5, in the case of “floating waste”, the duration of the first jet water ejection is set to be substantially constant (0.4 seconds) regardless of the amount of floating waste. As described above, in the case of “floating waste”, the duration of the first jet water ejection is set to be shorter than that in the case of “solid waste” (patterns A1 to A3). In addition, the duration of the second jet water ejection is set such that the greater the amount of floating waste, the longer the duration. More specifically, the duration of the second jet water ejection is 0.7 seconds when the amount of floating waste is “small”, 0.8 seconds when the amount of floating waste is “medium”, and 1.2 seconds when the amount of floating waste is “large”. As described above, in the case of “floating waste”, the duration of the second jet water ejection is set to be equal to or longer than that in the case of “solid waste” (patterns A1 to A3). In addition, the amount of flush water ejected from the jet water spout port 24 a is 2.81 L when the amount of floating waste is “small”, 2.94 L when the amount of floating waste is “medium”, and 3.14 L when the amount of floating waste is “large”.

[0087]As illustrated in section (a) of FIG. 6, in the case of “floating waste”, the instantaneous flow rate in the first jet water ejection is set to be higher than that in the case of “solid waste”, and thus, the drain trap conduit 16 becomes filled with water, thereby inducing siphonage at an earlier stage. In addition, the duration of the first jet water ejection is set to be shorter than that in the case of “solid waste” and to be substantially constant regardless of the amount of floating waste, and thus, the amount of flush water can be reduced. Here, even if the amount of floating waste increases, by inducing siphonage at an early stage, most of the floating waste excluding the floating waste remaining in the drain trap conduit 16 (see the portion indicated by X in section (a) of FIG. 6) can be discharged. Therefore, even if the duration of the first jet water ejection is set to be shorter than that in the case of “solid waste” and to be substantially constant, the discharge performance for floating waste will not degrade.

[0088]As illustrated in section (b) of FIG. 6, in the case of “floating waste”, the instantaneous flow rate in the second jet water ejection is set to be higher than that in the case of “solid waste”, and thus, the floating waste remaining in the drain trap conduit 16 (see the portion indicated by X in section (a) of FIG. 6) and water returning from the drain trap conduit 16 are flushed out by the second jet water ejection. In addition, since the duration of the second jet water ejection is set such that the greater the amount of floating waste, the longer the duration, the time taken to flush out the floating waste remaining in the drain trap conduit 16 also increases as the amount of floating waste increases. Therefore, even when the amount of floating waste is large, such remaining floating waste can be reliably discharged by the second jet water ejection.

[0089]Next, when an object is determined to be “toilet paper”, one of the patterns C1 to C3 is selected, and the jet water ejection of the selected pattern is executed.

[0090]As illustrated in FIG. 5, in the case of “toilet paper”, the instantaneous flow rate of flush water ejected from the jet water spout port 24a is the same across the patterns C1 to C3. The instantaneous flow rate in the first jet water ejection is 56 L/min, and the instantaneous flow rate in the second jet water ejection is 35 L/min. As described above, in the case of “toilet paper”, the instantaneous flow rate in the first jet water ejection is set to be higher than that in the case of “solid waste” (patterns A1 to A3). In addition, the instantaneous flow rate in the second jet water ejection is set to be lower than that in the case of “floating waste” (patterns B1 to B3).

[0091]As illustrated in FIG. 5, in the case of “toilet paper”, the duration of the first jet water ejection is set to be substantially constant (0.4 seconds) regardless of the amount of toilet paper. As described above, in the case of “toilet paper”, the duration of the first jet water ejection is set to be shorter than that in the case of “solid waste” (patterns A1 to A3). In addition, the duration of the second jet water ejection is set such that the greater the amount of toilet paper, the longer the duration. More specifically, the duration of the second jet water ejection is 0.1 seconds when the amount of toilet paper is “small”, 0.2 seconds when the amount of toilet paper is “medium”, and 0.4 seconds when the amount of toilet paper is “large”. As described above, in the case of “toilet paper”, the duration of the second jet water ejection is set to be shorter than that in the case of “solid waste” (patterns A1 to A3) and shorter than that in the case of “floating waste” (patterns B1 to B3). In addition, the amount of flush water ejected from the jet water spout port 24a is 2.40 L when the amount of toilet paper is “small”, 2.46 L when the amount of toilet paper is “medium”, and 2.58 L when the amount of toilet paper is “large”.

[0092]As illustrated in section (a) of FIG. 6, in the case of “toilet paper”, the instantaneous flow rate in the first jet water ejection is set to be higher than that in the case of “solid waste”, and thus, the drain trap conduit 16 becomes filled with water, thereby inducing siphonage at an earlier stage. In addition, the duration of the first jet water ejection is set to be shorter than that in the case of “solid waste” and to be substantially constant regardless of the amount of toilet paper, and thus, the amount of flush water can be reduced. Here, even if the amount of toilet paper increases, by inducing siphonage at an early stage, the toilet paper can be discharged because the water-filled state of the drain trap conduit 16 is maintained by the toilet paper. Therefore, even if the duration of the first jet water ejection is set to be shorter than that in the case of “solid waste” and to be substantially constant, the discharge performance for toilet paper will not degrade.

[0093]As illustrated in section (b) of FIG. 6, in the case of “toilet paper”, the instantaneous flow rate in the second jet water ejection is set to be lower than that in the case of “floating waste”, and thus, remaining toilet paper and water returning from the drain trap conduit 16 are flushed out by the second jet water ejection while the amount of flush water has been reduced. In addition, since the duration of the second jet water ejection is set such that the greater the amount of toilet paper, the longer the duration, the time taken to flush out the toilet paper remaining in the drain trap conduit 16 also increases as the amount of toilet paper increases. Therefore, even when the amount of toilet paper is large, such remaining toilet paper can be reliably discharged by the second jet water ejection.

[0094]Next, the operational effects of the flush toilet apparatus 1 according to the above-described embodiment of the present invention will be described.

[0095]First, in the flush toilet apparatus 1 according to the embodiment of the present invention, the control unit 74 is configured to control the pressure pump 10 (flush water supply device) such that the first jet water ejection from the jet water spout port 24a is performed at the first flow rate for inducing siphonage, after which the second jet water ejection from the jet water spout port 24a is performed at the second flow rate lower than the first flow rate. Thus, siphonage can be induced at an early stage by the first jet water ejection, after which waste can be flushed out by the second jet water ejection. In addition, the control unit 74 is configured to control the pressure pump 10 such that the duration of the first jet water ejection is shorter when an object is determined to be floating waste than when the object is determined to be solid waste. Thus, the duration of the first jet water ejection that has little effect on discharge of floating waste can be shortened, thereby enabling reduction in the amount of flush water. As a result, further water saving can be achieved while maintaining waste discharge performance by performing optimal toilet flushing for each toilet flush.

[0096]In the flush toilet apparatus 1 according to the embodiment of the present invention, the control unit 74 is configured to control the pressure pump 10 (flush water supply device) such that, when an object is determined to be floating waste, the duration of the first jet water ejection is substantially constant regardless of the amount of the object. Thus, the duration of the first jet water ejection, which has little effect on discharge of floating waste, can be set to be substantially constant, thereby enabling reduction in the amount of flush water.

[0097]In the flush toilet apparatus 1 according to the embodiment of the present invention, the control unit 74 is configured to control the pressure pump 10 (flush water supply device) such that, when an object is determined to be floating waste, the greater the amount of the object, the longer the duration of the second jet water ejection. Thus, when the amount of floating waste is large, floating waste remaining in the drain trap conduit 16 can be reliably flushed out by the second jet water ejection.

[0098]In the flush toilet apparatus 1 according to the embodiment of the present invention, the control unit 74 is configured to control the pressure pump 10 (flush water supply device) such that, when an object is determined to be solid waste, the greater the amount of the object, the longer the duration of the first jet water ejection. Thus, siphonage can be continued for a long time, thereby enabling reliable discharge of solid waste.

[0099]In the flush toilet apparatus 1 according to the embodiment of the present invention, the control unit 74 is configured to control the pressure pump 10 (flush water supply device) such that, when an object is determined to be solid waste, the duration of the second jet water ejection is substantially constant regardless of the amount of the object. Thus, the duration of the second jet water ejection that has little effect on discharge of solid waste can be set to be substantially constant, thereby enabling reduction in the amount of flush water.

[0100]In the flush toilet apparatus 1 according to the embodiment of the present invention, the control unit 74 is configured to control the pressure pump 10 (flush water supply device) such that the duration of the second jet water ejection is shorter when an object is determined to be toilet paper (object other than waste) than when the object is solid waste or floating waste. Thus, the duration of the second jet water ejection that has little effect on discharge of toilet paper can be shortened, thereby enabling reduction in the amount of flush water.

[0101]In the flush toilet apparatus 1 according to the embodiment of the present invention, the control unit 74 is configured to control the pressure pump 10 (flush water supply device) such that the instantaneous flow rate in the first jet water ejection is higher when an object is determined to be floating waste than when the object is determined to be solid waste. Thus, siphonage can be induced at an early stage, enabling the discharge of floating waste.

[0102]In the flush toilet apparatus 1 according to the embodiment of the present invention, the control unit 74 is configured to control the pressure pump 10 (flush water supply device) such that the instantaneous flow rate in the second jet water ejection is higher when an object is determined to be floating waste than when the object is determined to be solid waste. Thus, floating waste remaining in the drain trap conduit 16 can be reliably flushed out by the second jet water ejection.

[0103]In the flush toilet apparatus 1 according to the embodiment of the present invention, the control unit 74 is configured to control the pressure pump 10 (flush water supply device) such that the instantaneous flow rate in the second jet water ejection is lower when an object is determined to be toilet paper (object other than waste) than when the object is determined to be floating waste. Thus, the instantaneous flow rate in the second jet water ejection that has little effect on discharge of toilet paper can be reduced, thereby enabling reduction in the amount of flush water.

[0104]In the flush toilet apparatus 1 according to the embodiment of the present invention, the control unit 74 is configured to control the pressure pump 10 (flush water supply device) such that the duration of the second jet water ejection is longer when an object is determined to be floating waste than when the object is determined to be solid waste. Thus, floating waste remaining in the drain trap conduit 16 can be reliably flushed out by the second jet water ejection.

[0105]The present invention is not limited to the above-described embodiment, and various changes and modifications can be made therein within the scope of the technical idea described in the claims. In particular, the numerical values of the instantaneous flow rates, durations of water ejection, and amounts of flush water are not limited to those described above, and various changes may be made within the scope of the technical idea described in the claims.