JP2002336180A - Dishwasher - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dishwasher that can stably continue and complete an operation when power is recovered even if a power failure occurs during the operation. SOLUTION: The dishwasher has a storage section 102, a control means 101 operating by power supplied from a power source, reading a program stored in the storage section and operating each section while controlling them, and a nonvolatile storage means 119 storing the progress of work that the control means 101 executes on the basis of the program, the control means 101 stores work it finishes executing in the nonvolatile storage means 119 during a normal operation, and when power supply is once interrupted and power is supplied again, reads the progress of work stored in the nonvolatile storage means 119 and executes a continuation of finished work recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an operation of a dishwasher which can perform a series of operations based on a program after an operation is interrupted, and more particularly to an improvement of a continuous operation mechanism after an unexpected operation is interrupted.

[0002]

2. Description of the Related Art A dishwasher capable of performing a series of operations by a program or the like can automatically perform a desired operation by setting in advance by a user or the like.
It is commonly used and becoming popular. Such a dishwasher generally reads out a program of an operation to be performed, temporarily stores the program in a RAM or the like, and operates sequentially according to the program. However, in such a form, when an unexpected operation interruption such as a power failure occurs, the RAM
If the operation information stored in the etc. is reset and the operation is interrupted due to a power failure, for example, even if the power is restored, the information on what work was performed and how much has been lost will be lost. Had to start over. For this reason, unnecessary material consumption when the work involves consumption of some material and extra energy consumption due to prolonged operation time cannot be avoided.

[0003] In order to avoid such a problem, a technique disclosed in Japanese Patent Application Laid-Open No. Hei 6-189886 has conventionally existed. The dishwasher disclosed in the above publication is provided with a power failure detection means for detecting a power failure in the dishwasher, and when a power failure is detected by the power failure detection means, the power is temporarily compensated by a capacitor or the like, and the nonvolatile storage is performed. The operating state is stored in the means, and the remaining operation after the stored operating state is executed when the power is restored.

[0004]

However, according to the technique disclosed in the above-mentioned Japanese Patent Application Laid-Open No. Hei 6-189886, when a power failure is detected, the operation of the dishwasher before the power failure is performed while compensating for the power after the power is cut off. Since the state is stored in the non-volatile storage means, the power supply of the control unit is in an unstable state, and when storing the information in the non-volatile storage means, the stored information may be destroyed. If the information actually stored cannot be read due to a possibility of occurrence, the restarted operation is performed from the beginning. In addition, since the power outage time was not measured, if the power outage lasted for a long time during the cleaning process, the inside of the cleaning tank was cooled down, and the cleaning water in a dirty state remained. In such a case, it is considered that a sufficient detergency cannot be obtained.

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above problems, and has as its object to enable each of the completed operations to be stored in a storage means in a state where the control unit is stabilized, and to cause a power failure or the like during the operations. Another object of the present invention is to provide a dishwasher capable of reliably starting the subsequent operation from the state before the power failure when the power is restored again. It is another object of the present invention to provide a dishwasher capable of determining whether a power failure has occurred over a long period of time and selecting whether to continue the operation before the power failure after power recovery or to change to another suitable operation. .

[Means for Solving the Problems]

[0006] A dishwasher according to the present invention is operated by power from a power supply supplied to the dishwasher and stores a program for work performed by the dishwasher, and is stored in the storage unit. Control means for reading out the program, operating while controlling each part of the dishwasher based on the program, and non-volatile storage means for storing the progress of the work performed by the control means based on the program, The control means stores the work that has been completed based on the program in the non-volatile storage means at the time of normal operation of the dishwasher, and when power supplied at least during the operation of the dishwasher is cut off, When power is supplied, the control means reads the progress of the work stored in the nonvolatile storage means, and plays the work following the recorded completed work. Is characterized in that to continue working by executing based on grams. Further, the dishwasher according to the present invention, a washing tank for accommodating tableware,
A water supply valve for controlling the supply of water to the cleaning tank, a cleaning pump for injecting the cleaning water to the dishes contained in the cleaning tank, and a discharge pump for discharging the cleaning water in the cleaning tank to the outside,
Heating means for heating the washing water to be sprayed on the dishes, and temperature measuring means for detecting the temperature of the washing water to be heated; And at least two part programs of a washing step and a rinsing step are stored. When the execution of the part program of each step is completed, the control means stores the completion of the step in the nonvolatile storage means. is there.

In the dishwasher according to the present invention, when the control means operates the dishwasher based on a part program, the timepiece means for measuring an elapsed time from the start of the operation of the step to be executed is provided. The non-volatile storage means stores the process being performed at regular intervals and the elapsed time measured by the timing means. Further, the dishwasher according to the present invention stores the temperature measured by the temperature measuring means in the non-volatile storage means at regular intervals, and at least power supplied during operation of the dishwasher is cut off. When the power is supplied again, the temperature read from the nonvolatile memory means is compared with the temperature actually measured by the temperature measuring means, and the nonvolatile memory is stored in accordance with the temperature difference. Whether to execute the work following the completed work recorded in the means or to change to another work is selected.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a dishwasher according to the present invention will be described in detail using a dishwasher / dryer according to an embodiment of the present invention.

Embodiment 1 FIG. 1 shows a schematic configuration diagram of a dishwasher / dryer according to an embodiment of the present invention. In the figure, reference numeral 100 denotes a control device as a control means constituted by a microcomputer, for example.
Includes a control unit 101, a storage unit 102 for storing a program from a washing step to a drying step, a timer unit 103 for managing the time of each step, and a temperature judging unit 104 for judging the temperature of hot water in the washing tank. It is configured.

The dishwasher according to the present embodiment includes a water supply valve 105 connected to a water tap or the like, and a washing pump 10 for injecting washing water to dishes and the like contained in the washing tank.
6. It has a drain pump 107 for draining washing water, rinsing water, etc. in the washing tank, a blower fan 108 for circulating air in the washing tank, and a heater 109 for heating water injected into the washing tank. ing. Further, the dishwasher according to the present embodiment includes a water supply valve driving unit 110 that drives the water supply valve 105 to open and close, and a cleaning pump driving unit 11 that drives the cleaning pump 106.
1. Drain pump driving means 112 for driving the drain pump 107, blowing fan driving means 113 for driving the blowing fan 108, and heater driving means 114 for driving the heater 109, each driving means for driving each part of the dishwasher, Each of the driving means is controlled by the control unit 10 of the control device 100.
The respective components of the dishwasher are driven based on the control of (1).

Further, the dishwasher according to the present embodiment includes a water level detecting means 115 for detecting the level of water or hot water supplied into the cleaning tank, and a temperature measuring means 116 for measuring the temperature of the water or hot water in the cleaning tank. It is possible to detect the state inside the dishwasher. Further, in the dishwasher of the present embodiment, the operation panel 1 which can operate the dishwasher and perform various settings.
The operation and settings performed by the user through the operation panel 117 are input to the control unit 101, and each unit of the dishwasher is operated using the operation and setting information.

FIG. 2 shows a sectional view of a dishwasher / dryer according to an embodiment of the present invention. The dishwasher according to the present embodiment has a door 131 on the front surface of a main body outer shell 130, and a washing tank 121 for storing tableware with an open front surface is provided inside the main body outer shell 130. An operation unit 117 that can perform setting and operation of the main body is provided at a lower part of the front surface of the main body outer shell 130, and the control device 100 is provided adjacent to the operation unit. The control device 100 includes a nonvolatile memory 119.

The water supply valve 105 is connected to the back of the cleaning tank 121 so as to supply cleaning water into the cleaning tank 121, and a hose 122 of the water supply valve 105 is connected to a water tap (not shown). . Further, the washing water supplied into the washing tank 121 is taken in from the lower surface of the washing tank 121 by the washing pump 106, and the tableware 1 stored in the washing tank 121.
The cleaning water is injected to the nozzle 23 by the injection nozzle 124. At the time of drainage, the drainage pump 1
07 to drain outside the device through a drain hose 125.

The cleaning water supplied into the cleaning tank 121 is supplied to a heater 109 serving as a heating means provided on the lower surface of the cleaning tank 121.
The temperature is measured by a temperature detector 106 which is a temperature measuring means, and the signal is sent to the control device 10.
Sent to 0. The water level detecting means 115 is provided for the float 12
6 and a detector 127, the level of the cleaning water supplied into the cleaning tank 121 is measured by the float 126, and the detector 12 for detecting the height of the float 126 is used.
The position of the float is detected by 7, and the detection signal is transmitted to the control device 100. A blower fan 108 is provided at the back of the water level detecting means, and when the washing of the dishes is completed, the wind can be circulated in the washing tank 121 to dry the dishes.

FIG. 3 is a schematic diagram showing an operation panel as an operation unit in the present embodiment. As shown in the figure, a power key 117 for turning on / off the power is provided on the operation panel 117.
a, a start / pause key 117b for starting or suspending a series of operations from washing to rinsing and drying of the dishwasher in the present embodiment, and a light which is turned on when the power is turned on, and the dishwasher operates. A lamp 117c that changes to a red color while the dishwasher is stopped and changes to a green color while the dishwasher is stopped to indicate a power-on state and an operation state of the dishwasher, and that a washing step, a rinsing step, a drying step, etc. are being executed or have been executed Process and
A display unit 117 that displays the remaining time until the work is completed.
d. The information displayed on the display unit 117d is displayed on the display unit 117d via the display driving unit 118 controlled by the control device 100 as shown in FIG.

In the dishwasher according to an embodiment of the present invention having such a configuration, the control unit 101 controls various keys on the operation panel 117, the water level detection unit 115, and the temperature measurement unit 1.
When the respective signals from 16 are input, the water supply valve 105, the cleaning pump 106, the drainage pump 107, the blower fan 108, the heater 109, and the display unit 117d are controlled based on these input signals and the program stored in the storage unit 102. It can be controlled via driving means 110 to 114 and 118, respectively. A feature of the dishwasher of the present invention is that the control device 100 has a nonvolatile memory 119 as a nonvolatile storage means for storing the progress of the work performed based on the program.

As described above, in the dishwasher of the present invention, the storage unit 102 for storing the program of the work performed by the dishwasher.
And a control unit that operates by power from a power supply supplied to the dishwasher, reads a program stored in the storage unit, and controls and operates each unit of the dishwasher based on the program. Apparatus 100
And a non-volatile memory 119 as non-volatile storage means for storing the progress of work performed by the control means based on a program. Then, the control means causes the non-volatile storage means to store the work whose execution has been completed based on the program. For this reason, the power supplied to the dishwasher is cut off due to an unexpected situation, and when power is supplied again to the dishwasher, the control unit reads the progress stored in the nonvolatile storage unit, The work is continued by executing the continued work of the recorded completed work based on the program. In addition, before the power cutoff state such as a power failure, the completed work is recorded when the dishwasher is operating normally, so that information can be stably stored, and power failure detection means and the like can be stored. Since no configuration is required, cost can be reduced.

Hereinafter, the present invention will be described in more detail with reference to a use example of a dishwasher according to an embodiment of the present invention. The dishwasher, which is one embodiment of the dishwasher of the present invention, performs a series of operations from washing to rinsing and drying.
Water supply process for supplying water to the dishwasher, washing process for washing dishes, rinsing process for rinsing, heating rinsing process for heating water and rinsing with hot water, drying process for drying wet tableware, The storage unit 102 divides the water into six steps of a drainage step of draining water, and stores a program such as an operation of the dishwasher performed in each of the steps as a part program configured in units of steps.

When using the dishwasher, the user can combine these steps to form a desired washing method. Combining such processes,
Some cleaning courses corresponding to various needs may be created in advance, and the user may perform a desired cleaning method by selecting a course. Further, there is no problem if the operation of the dishwasher in the process can be finely set by the user. The work performed in this way is part-programmed,
It is possible to more flexibly perform an operation corresponding to the needs of the user, the tableware to be washed, and the degree of contamination.

In the dishwasher as one embodiment of the dishwasher of the present invention, when power is supplied from a power supply, the control device 100 is initialized. Then, the completed work stored in the nonvolatile memory as the nonvolatile storage means is read out. If the completed work read here has completed all steps from washing to rinsing and drying, the dishwasher is in a state of waiting for user input.
If the completed work read from the non-volatile storage means ends in the middle of the program configured by combining the part programs, the dishwasher performs the work following the program. This will be described in detail later.

When power is supplied to the dishwasher and the user waits for an input, the power supply key is turned on by pressing the power supply 117a of the operation panel 117 shown in FIG.
17c and the display unit 117d are turned on. In this state, the user can select a desired dishwasher operation by combining a part program or by selecting a preset washing course by combining the part programs. If the cleaning course is not selected, the previous cleaning course or the standard cleaning course may be selected.
In this embodiment, if a cleaning course is not selected, a cleaning course set in advance as a standard is selected. In such a state, the dishwasher is operated with the start / pause key 1
Waiting for the input of 17b. Then, when the start / pause key 117b is pressed, the dishwasher starts operating.

The operation of the dishwasher when the user presses the start / stop key 117b will be described below. 4 to 7 are flowcharts showing a series of operation examples from washing to rinsing and drying of the dishwasher according to one embodiment of the present invention. The flowchart shown here exemplifies the flow of the operation of the cleaning course which is set in advance by combining part programs in advance.

Start / pause key 11 by user
When the button 7b is pressed, the control unit 101 receives a start input and first starts a water supply process based on a program.
In the water supply 1 step, the control unit 101 outputs a drive signal to the water supply valve driving means 110 and receives the signal.
10 opens the water supply valve (S1). Thereby, water is injected into the cleaning tank.

The water level of the injected water is determined by the water level detecting means 1.
15 to detect whether the water level in the cleaning tank has reached a specified water level (water level for starting cleaning or rinsing) (S2). When the water level injected into the cleaning tank has not reached the specified water level, the water level detection means 115
Does not output a signal to the control unit 101,
Keeps supplying water until the signal of the water level detecting means 115 is received. When the water level injected into the washing tank reaches the specified water level, the water level detection means 115 outputs a detection signal to the control section 101, and the control section 101 which has received this signal outputs a drive stop signal to the water supply valve driving means 115. , Water supply valve driving means 11
5 closes the water supply valve 107. Thus, one step of water supply is completed. When one water supply step by one part program is completed, the control unit 101 writes the completion of one water supply step into the nonvolatile memory 119 (S
3).

When the writing to the non-volatile memory 119 is completed, the execution of the process by the subsequent part program is started. The subsequent step is a washing step. The control unit 101 outputs a drive signal to the cleaning pump driving unit 111 based on the part program of the cleaning process, and the cleaning pump driving unit 111 that has received the signal drives the cleaning pump 106. Further, the control unit 101 outputs a drive signal to the heater drive unit 114, and energizes the heater 109 to start cleaning (S
4).

When the cleaning process starts, the control unit 101 starts the timer unit 103 to start time measurement, and determines whether or not the elapsed time has passed a preset time (S5). If the set time has not elapsed, the flow returns to S4 to continue the cleaning, and if the set time has elapsed, the process proceeds to the subsequent step.

In the following step, it is determined whether or not the water temperature in the washing tank measured by the temperature measuring means 116 has reached a preset temperature (S6).
If the temperature has not reached the set temperature, the process returns to step S4 to continue the cleaning. If the temperature has reached the set temperature, the control unit 101 stops the timer unit 103 and stops counting the time. A driving stop signal is output, and the cleaning pump driving unit 111 and the heater driving unit 114 that have received the signal stop the cleaning pump 106 and the heater 109 to complete the cleaning process. When the cleaning step is completed, as in the first water supply step, the control unit 101 writes in the non-volatile memory 119 that the cleaning step is completed (S7).

Subsequently, one step of drainage is performed. The control unit 101 outputs a drive signal to the drain pump driving unit 112, and the drain pump driving unit 112 drives the drain pump 107 to drain the water in the cleaning tank (S8). When drainage is completed, the control unit 101 outputs a drive stop signal to the drainage pump driving unit 112, and the drainage pump driving unit 112
Is stopped, and one step of drainage is completed. And the control unit 10
1 indicates that one step of drainage is completed in the nonvolatile memory 11.
9 (S9).

In the flow chart, A in FIG.
(Hereinafter, when straddling the drawings on the flowchart, it is assumed that they are connected to the portions described by the same alphabet). When drainage 1 is completed, water supply is started again to perform rinsing. Since the dishwasher according to the present embodiment has a part program for each step, the water supply 2 step (S10) can be performed by the same operation as the above-described water supply 1 step by the part program of the water supply step. . Then, when the specified water level is reached (S1
1) End the two steps of water supply. When the two steps of water supply are completed, the control unit 101 writes the completion of the two steps of water supply into the nonvolatile memory 119 (S12). When the water supply is completed, one rinse step is started. The control unit 101 controls the cleaning pump driving unit 111 based on the part program of the rinsing process.
The cleaning pump driving unit 111 receives the signal and drives the cleaning pump 106 (S1).
3).

When the rinsing step is started, the control unit 1
In step S14, the timer 103 is started to start counting, and it is determined whether the elapsed time has exceeded a preset time (S14). If the set time has not elapsed, the process returns to step S13 to continue the rinsing. If the set time has elapsed, the control unit 101 stops the timer unit 103 to stop timing, and the cleaning pump driving unit 112 stops driving. A signal is output, and the cleaning pump driving unit 111 that has received the signal stops the cleaning pump 106 to complete one rinsing step. When the one rinsing step is completed, the control unit 101 writes the completion of the one rinsing step in the nonvolatile memory 119 (S15).

Subsequently, two steps of drainage are performed. In the drain step, the drain step 2 (S16) can be performed by the part program in the same operation as the drain step 1 described above. When the two drainage processes are completed, the control unit 101 writes in the non-volatile memory 119 that the two drainage processes are completed (S1).
7).

As described above, using the part program of each step, three steps of water supply (S18, S19), two steps of rinsing (S21, S22), three steps of drainage (S24), four steps of water supply (S26, S27), rinsing 3 steps (S29, S3
0), 4 steps of drainage (S32), 5 steps of water supply (S34, S
35), each of the five drainage processes (S41) is performed, and when each process is completed, the completed process is stored in the nonvolatile memory 119 (S20, S23, S25, S2).
8, S31, S33, S36, S42).

In the heating and rinsing step shown in FIG. 7, the control unit 101 outputs a driving signal to the cleaning pump driving means 111 based on a part program of the heating and rinsing step, and the cleaning pump driving means 111 which has received the signal outputs the cleaning signal. The pump 106 is driven. Further, the control unit 101 outputs a drive signal to the heater drive unit 114, and energizes the heater 109 to start rinsing (S37).

When the heating and rinsing step is started, the control unit 10
1 activates the timer unit 103 to start time measurement, and determines whether the elapsed time has exceeded a preset time (S38). If the set time has not elapsed, the process returns to step S37 to continue the heating rinsing, and if the set time has elapsed, proceeds to the subsequent step.

In the following step, it is determined whether or not the water temperature in the cleaning tank measured by the temperature measuring means 116 has reached a preset temperature (S3).
9). If the temperature has not reached the set temperature, the process returns to step S37 to continue the heating and rinsing. If the temperature has reached the set temperature, the control unit 101 stops the timer unit 103 to stop measuring the time, and the cleaning pump driving unit 112 and the heater driving unit 114 The cleaning pump driving unit 111 and the heater driving unit 114 that have received the driving stop signal
06 and the heater 109 are stopped to complete the heating and rinsing step. When the heating and rinsing step is completed, the control unit 101 writes the completion of the heating and rinsing step into the nonvolatile memory 119 (S40). In the heating and rinsing step, the dishwasher operates in the same manner as in the above-described washing step, but there is a great difference in that no detergent is used for washing the dishes.

In the drying step, the control unit 101 controls the blower fan driving means 113 based on a part program of the drying step.
The fan driving means 113 receives the signal and drives the fan 108. The control unit 101 outputs a drive signal to the heater drive unit 114,
The heater 109 is energized. Thereby, warm air is blown and drying is started (S43).

The control unit 101 activates the timer unit 103 to start timing, and determines whether the elapsed time has exceeded a preset time (S44).
If the set time has not elapsed, the process returns to step S43 to continue the drying. If the set time has elapsed, the control unit 101 stops the timer unit 103 and stops measuring the time, and the blowing fan driving unit 113 and the heater driving unit A driving stop signal is output to 114, and the blower fan driving unit 11
3 stops the blower fan 108 and the heater driving means 114 stops the heater 109, respectively, and the drying process is completed. When the drying step is completed, the control unit 101 writes that the drying step is completed in the nonvolatile memory 119 (S45). When a series of operations up to the drying step is completed in this way, the operation of the dishwasher is stopped, and the apparatus is in a state of waiting for user input (S46).

As described above, in the dishwasher according to the present invention, the operation performed by the dishwasher is classified into two or more processes in the storage unit 102, and the classified part programs are stored for each process. The control means is configured to, upon completion of execution of the part program of each step, store the end of the step in the nonvolatile storage means.

With this configuration, even if a power failure occurs during the operation of the dishwasher or an unexpected interruption such as the user accidentally unplugging the dishwasher, initialization is performed after the power is restored. By reading the completed work stored in the non-volatile memory as the non-volatile storage means, even if the control device 100 terminates in the middle of a program configured by combining the part programs, You can start over.

As described above, the operation when power is supplied from the power supply to the dishwasher, which is one embodiment of the dishwasher of the present invention, has been briefly described. The processing procedure in the device will be described in detail. FIG. 8 is a flowchart illustrating an example of processing in the dishwasher from when power is supplied from a power source to the dishwasher according to the embodiment of the present invention until the user operates the dishwasher to start operation. I do.

As shown in the figure, when power is supplied from the power supply (S50), the control device 100 is initialized.
Then, the nonvolatile memory 119 serving as a nonvolatile storage means
The completed work stored in is read out. In the case of the dishwasher / dryer according to the above-described embodiment, if all the series of steps from cleaning to rinsing and drying have been completed, the drying step completion to be finally stored should be written. is there. Therefore, the control device 100 determines whether or not the end of the drying step is written in the completed work written in the nonvolatile memory 119 (S51).

If the read information indicates that the drying step has been completed, the series of steps from cleaning to rinsing and drying have been completed normally. Enter a waiting state. That is, first, the input of the power key 117a on the operation panel is waited (S52), and if the power key 117a is pressed, the input of the start / pause key 117b is subsequently waited (S53).
Becomes When the start / pause key 117b is input, the operation as described with reference to the flowcharts of FIGS. 4 to 7 is started (S54).

On the other hand, when there is no writing of the end of the drying step in the read information, that is, when information other than the completion of the drying step is written, it is determined that the work was interrupted during the operation of the dishwasher, and the operation panel is operated. 117 display section 117d
Next, the process written in the storage means is displayed (S5).
At the same time as 5), the system enters a state of waiting for input of the start / pause key 117b (S56). Then, when the user presses the start / pause key 117b, the operation is started from the step next to the step stored in the nonvolatile memory 119, that is, the step interrupted without completing the operation.

If it is determined that the operation has been interrupted during the operation of the dishwasher without waiting for the input as in S56, the operation is started from the step next to the step stored in the nonvolatile memory 119 as it is. It may be configured to start.

With the above configuration, the dishwasher of the present invention can determine whether a series of operations has been completed normally by reading information written in the nonvolatile storage means, and interrupted halfway. If it has been done, the work after the interruption can be continued as it is. Also,
As described above, by displaying the interruption on the display unit so that the user can recognize the interruption, it is possible to inform the user that the interruption has occurred during the work.

Therefore, even if there is an unexpected interruption of the work, the subsequent work can be continued normally, and the dishwasher / dryer of the embodiment of the present invention described above does not repeat the completed process. In order to prevent waste of water, detergent, and power, the dishwasher of the present invention can prevent waste of resources and energy, thereby greatly improving the usability. In addition, since the configuration can be made without using a detection unit that detects an unexpected power interruption such as a power failure, a backup power supply, or the like, costs can be reduced.

Embodiment 2 FIG. 9 shows a schematic configuration diagram of a dishwasher / dryer which is another embodiment of the dishwasher of the present invention. In the figure, components corresponding to the same components as those in FIG. 1 are denoted by the same reference numerals, and description thereof is omitted.

A dishwasher / dryer as an embodiment of the dishwasher of the present invention shown in FIG. 9 has components 100 to 119 each having the same components as those shown in FIG. . Further, this embodiment also has the same structure as that of the embodiment shown in FIG. 2 and has the operation unit 117 shown in FIG. What is characteristic in the present embodiment is that when the control means 100 operates the dishwasher based on the part program, the second means as a time measuring means for measuring the elapsed time from the start of the operation of the step to be executed. That is, a timer unit 120 is provided.

The present dishwasher measures the time from the start of each process by using the second timer section 120 as the time counting means, and the process in operation and the time counting means as the time counting means each time a predetermined time elapses. The elapsed time measured by the second timer section 120 is stored in the nonvolatile storage means.

As described above with reference to FIGS. 4 to 7, the operation of the dishwasher according to this embodiment is also performed by combining a part program for each process stored in the storage unit. Is what you do. Therefore, how the dishwasher of this embodiment operates in each process will be described, and how the dishwasher of this embodiment performs a series of operations will be described.

FIG. 10 is a flowchart showing an operation example of a water supply step of the dishwasher / dryer as one embodiment of the dishwasher of the present invention shown in FIG. When the part program of the water supply step is started (S60), the control unit 101 outputs a drive signal to the water supply valve driving unit 110, and the water supply valve driving unit 110 that has received the signal opens the water supply valve 105 (S60).
61). Thereby, water is injected into the cleaning tank.

When the process starts, the second timer unit 12
0 is started, and time measurement is started at regular intervals (for example, 30 seconds). The control unit 101 determines whether the second timer unit 120 has passed a predetermined time, for example, 30 seconds (S6).
2) If the fixed time has not elapsed, the flow returns to step S61 to continue the water supply. If the fixed time has elapsed, the control unit 101 determines that the water supply process is operating in the nonvolatile memory 119 and determines from the process start. Is written (S63).

Further, the water level of the injected water is monitored by the water level detecting means 115, and it is detected whether or not the water level in the cleaning tank has reached a prescribed water level (water level for starting cleaning or rinsing) ( S64). Water level detecting means 1 when the water level injected into the washing tank has not reached the specified water level.
15 does not output a signal to the control unit 101,
01 returns to S61 and continues to supply water until the signal of the water level detecting means 115 is received. When the water level injected into the washing tank reaches the specified water level, the water level detection means 115 outputs a detection signal to the control section 101, and the control section 101 which has received this signal outputs a drive stop signal to the water supply valve driving means 115. The water supply valve driving means 115 closes the water supply valve 105. Thus, the water supply step is completed (S65).

As described above, when the water supply process by one part program is completed in S65, the control unit 101
Writes in the nonvolatile memory 119 that the water supply step has been completed. When the writing to the nonvolatile memory 119 is completed, the execution of the process by the subsequent part program is started. Further, during the water supply process or when writing the completion of the water supply process to the nonvolatile memory 119, the water supply process performed in a program of a series of operations such as water supply for cleaning or water supply for rinsing. It is as described in the above-described embodiment that there is a record.

Next, the cleaning step will be described. FIG.
FIG. 9 is a flowchart showing an operation example of a washing process of the dishwasher which is an embodiment of the dishwasher of the present invention shown in FIG. When the control unit 101 starts the process based on the part program of the cleaning process (S70), it outputs a drive signal to the cleaning pump driving unit 111, and the cleaning pump driving unit 111 that has received the signal drives the cleaning pump 106. Further, the control unit 101 outputs a drive signal to the heater drive unit 114, and energizes the heater 109 to start cleaning (S71).

At the start of the process, the control section 101 activates the timer section 103 and the second timer section 120, and the timer section 103 counts whether or not the elapsed time has exceeded a preset time. At 120, time counting is started at regular intervals. Then, the control unit 101 determines whether the second timer unit 120 has passed a predetermined time (S72). If the predetermined time has not passed, the control unit 101 proceeds to S7.
1 and the cleaning is continued. If the predetermined time has elapsed, the control unit 101 writes in the nonvolatile memory 119 that the cleaning process is in operation and the elapsed time from the start of the process (S7).
3). Further, the control unit 101 determines whether or not the elapsed time has exceeded a preset time using the timer unit 103 (S74). If the set time has not elapsed, the flow returns to step S71 to continue the cleaning, and if the set time has elapsed, the process proceeds to the subsequent step.

In the following step, it is determined whether or not the water temperature in the cleaning tank measured by the temperature measuring means 116 has reached a preset temperature (S7).
5). If the temperature has not reached the set temperature, the flow returns to S71 to continue the cleaning, and if the temperature has reached the set temperature, the control unit 101
Stops the timer unit 103 to stop timing, outputs a drive stop signal to the cleaning pump driving unit 112 and the heater driving unit 114, and the cleaning pump driving unit 111 and the heater driving unit 114 receiving the signals stop the cleaning pump 106 and the cleaning pump 106. The heater 109 is stopped to complete the cleaning process. When the cleaning process is completed, the control unit 101 writes the completion of the cleaning process in the nonvolatile memory 119 and starts the next process (S76). In the dishwasher / dryer according to the present embodiment, the heating and rinsing step is performed by the same operation as the above-described washing step, and thus the description is omitted. However, no detergent is used in the heating and rinsing step.

Next, the drainage process will be described. FIG. 12 is a flowchart illustrating an operation example of a drainage process of the dishwasher / dryer according to the embodiment of the dishwasher of the present invention illustrated in FIG. 9. When the control unit 101 starts the process based on the part program of the drainage process (S80), the control unit 101 outputs a drive signal to the drainage pump driving unit 112, and the drainage pump driving unit 112 drives the drainage pump 107, thereby The water is drained (S81). At the start of the process, the control unit 101 starts the timer unit 103 and the second timer unit 120, and the timer unit 103 determines whether the elapsed time has passed a preset time by the second timer unit 120. Start hourly clocking.

Then, the control unit 101 controls the second timer unit 1
It is determined whether or not a predetermined time has elapsed (S82).
If the fixed time has not elapsed, the process returns to step S81 to continue draining. If the fixed time has elapsed, the control unit 101 stores in the nonvolatile memory 119 that the draining process is in operation, The time is written (S83). Further, the control unit 101 determines whether or not the elapsed time has exceeded a preset time using the timer unit 103 (S84). If the set time has not elapsed, the flow returns to S81 to continue draining. If the set time has elapsed, the control unit 101 outputs a drive stop signal to the drain pump driving means 112, and the drain pump driving means 112 The drain pump 107 is stopped, and the drain process ends. Then, the control unit 101 writes in the nonvolatile memory 119 that the drainage process has been completed, and proceeds to the subsequent process (S85).

Next, the rinsing step will be described. FIG. 13 is a flowchart illustrating an operation example of a rinsing step of the dishwasher according to the embodiment of the dishwasher of the present invention illustrated in FIG. 9. When the control unit 101 starts the process based on the part program of the rinsing process (S90), the control unit 101 outputs a drive signal to the cleaning pump driving unit 111, and the cleaning pump driving unit 111 which has received the signal outputs the cleaning pump 106. Is driven (S91).

At the start of the process, the control section 101 starts the timer section 103 and the second timer section 120, and the timer section 103 counts whether or not the elapsed time has passed a preset time. At 120, time counting is started at regular intervals. Then, the control unit 101 determines whether the second timer unit 120 has passed a predetermined time (S92). If the predetermined time has not passed, the control unit 101 proceeds to S9.
The rinsing process returns to 1 and the rinsing is continued. If the predetermined time has elapsed, the control unit 101 writes in the nonvolatile memory 119 that the rinsing process is in operation and the elapsed time from the start of the process (S93).

The control unit 101 determines whether or not the elapsed time has exceeded a preset time by using the timer unit 103 (S94). Then, if the set time has not elapsed, the process returns to S91 to continue the rinsing,
If the set time has elapsed, the control unit 101 stops the timer unit 103 to stop the time measurement, and the cleaning pump driving unit 11
Then, a drive stop signal is output to 2 and the cleaning pump driving means 111 that has received the signal stops the cleaning pump 106 and terminates the rinsing step. Then, the control unit 101 writes in the nonvolatile memory 119 that the rinsing process has been completed,
The process proceeds to the subsequent step (S95).

Finally, the drying step will be described. FIG. 14 is a flowchart illustrating an operation example of a drying process of the dishwasher, which is one embodiment of the dishwasher of the present invention illustrated in FIG. 9. When the control unit 101 starts the process based on the part program of the drying process (S110), it outputs a drive signal to the blower fan drive unit 113, and the blower fan drive unit 113 that has received the signal drives the blower fan 108. Further, the control unit 101 outputs a drive signal to the heater drive unit 114 and supplies electricity to the heater 109. Thereby, warm air is blown and drying is started (S111).

At the start of the process, the control section 101 starts the timer section 103 and the second timer section 120, and the timer section 103 counts whether or not the elapsed time has passed the preset time. At 120, time counting is started at regular intervals. Then, the control unit 101 determines whether the second timer unit 120 has passed a predetermined time (S112).
Returning to step 111, the drying is continued. If the predetermined time has elapsed, the control unit 101 writes in the nonvolatile memory 119 that the drying process is in operation and the elapsed time from the start of the process (S113).

The control unit 101 determines whether or not the elapsed time has exceeded a preset time by using the timer unit 103 (S114). If the set time has not elapsed, the process returns to step S111 to continue the drying. If the set time has elapsed, the control unit 101 stops the timer unit 103 to stop the time measurement, and the blower fan driving unit 113 and the heater drive A driving stop signal is output to the means 114, and the blower fan driving means 113 which has received the signal outputs the blower fan 108, and the heater driving means 114
09 are stopped to complete the drying process. Then, the control unit 101 writes the completion of the drying step in the non-volatile memory 119, and shifts to the subsequent step or ends the operation performed by the dishwasher (S115).

As described above, in the dishwasher according to the present embodiment, the operation performed by the dishwasher is classified into two or more steps in the storage unit 102, and the classified part programs for the respective steps are stored. The control means is configured to store the step being executed and the elapsed time from the start of the execution, or to store the completion of the step in the non-volatile storage means when the execution of the part program of each step is completed.

When the electric power is supplied from the power source after the power supply is stopped, the dishwasher of the present embodiment thus configured operates in the same manner as the embodiment described with reference to FIG. Therefore, detailed description is omitted. However, in the present embodiment, since the work elapsed time of the process is also recorded in the information read from the non-volatile memory 119, even if the dishwasher is interrupted during operation, the recorded elapsed time is not changed. Since the work can be continued by performing the later work, it is not necessary to restart the interrupted process from the beginning as in the embodiment. For this reason, wasteful use of resources and energy can be prevented, and usability is greatly improved.

In addition, as the method of writing the elapsed time described in the present embodiment, even if the elapsed time is counted by the second timer unit 120, the accumulated time itself is used. The recording format may be used, and such a recording method is not particularly limited. Further, the fixed time measured by the second timer unit is not particularly limited, but if the time is too long, in the operation continued after the operation is interrupted, the same repeated operation time increases, and if the time is too short, an extra time is added to the control device. Since a load is applied, 5 seconds to 5 minutes, and more preferably, about 10 seconds to 1 minute.

If it is necessary to repeat each step a plurality of times during execution of a program for a series of operations, a series of steps may be performed during writing of each step or completion of each step in the nonvolatile memory 119. It is preferable to record where the process is performed in the work program. By recording in this way, even if the operation is interrupted during the execution of a series of operations, the subsequent program can be executed suitably after the power is restored. In the present embodiment, a second timer unit different from the timer unit is used to measure the elapsed time from the start of the process.However, it is also possible to configure a single timer unit by substituting the timer unit. is there.

Embodiment 3 As described above, in the dishwasher according to the present invention, even if the work is interrupted during the operation of the dishwasher due to a power failure or the like, the work can be continued from the interrupted process after the power is restored. However, when the power cutoff state such as a power failure has been extended for a long time, the dishwasher according to the embodiment has been heated to water in the washing step and the heating and rinsing step, and the water temperature has cooled. In some cases, it may be preferable to start the process again or start the operation from the beginning. Therefore, an embodiment of the present invention that can deal with such a case will be described.

The configuration of the dishwasher of the third embodiment, which is one embodiment of the dishwasher of the present invention, can be implemented by the same configuration as that of the second embodiment shown in FIG. . What is different from the second embodiment in this embodiment is the washing step, the operation of the dishwasher in the heating and rinsing step, and power is supplied from the power supply, until the user operates and the dishwasher starts operating. In the dishwasher.

Hereinafter, this portion will be described in detail.
FIG. 15 is a flowchart illustrating an operation example of a washing step and a heating rinsing step of the dishwasher / dryer according to the third embodiment of the dishwasher of the present invention. When the control unit 101 starts the process based on the part program of the cleaning process or the heating rinsing process (S120), the cleaning pump driving unit 1
The driving signal is output to 11, and the cleaning pump driving unit 111 that has received the signal drives the cleaning pump 106. Further, the control unit 101 outputs a drive signal to the heater drive unit 114, and energizes the heater 109 to start cleaning or heating rinsing (S121).

At the start of the process, the control section 101 activates the timer section 103 and the second timer section 120, and the timer section 103 counts whether or not the elapsed time has passed a preset time. At 120, time counting is started at regular intervals. Then, the control unit 101 determines whether the second timer unit 120 has passed a predetermined time (S122).
Returning to step 121, washing or heating rinsing is continued. If the fixed time has elapsed, the control unit 101 measures the temperature t in the cleaning tank at that time by the temperature measuring means 116 (S12).
3) Then, together with the measured temperature, the fact that the cleaning or heating rinsing step is in operation and the elapsed time from the start of the step are written in the nonvolatile memory 119 (S124).

The control unit 101 determines whether or not the elapsed time has exceeded a preset time using the timer unit 103 (S125). If the set time has not elapsed, the process returns to step S121 to continue the washing or heating and rinsing, and if the set time has elapsed, the process proceeds to the subsequent step.

In the following step, it is determined whether or not the water temperature in the cleaning tank measured by the temperature measuring means 116 has reached a preset temperature (S12).
6). If the temperature has not reached the set temperature, the process returns to step S121 to continue the washing or heating and rinsing. If the temperature has reached the set temperature, the control unit 101 stops the timer unit 103 to stop timing, and the cleaning pump driving unit 112 and the heater drive A driving stop signal is output to the means 114, and the cleaning pump driving means 111 and the heater driving means 114 receiving the signal.
Stops the cleaning pump 106 and the heater 109 to complete the cleaning or heating rinsing step. When the cleaning or heating rinsing step is completed, the control unit 101 writes the completion of the cleaning or heating rinsing step into the nonvolatile memory 119 and starts the next step (S127). Therefore,
In this embodiment, the operating process and the temperature in the cleaning tank at that time are written in the non-volatile memory 119 every time a predetermined time elapses during the cleaning or heating rinsing process.

In this embodiment, the processing in the dishwasher from when power is supplied from the power source to when the user operates and the dishwasher starts operating is performed as follows. FIG. 16 shows processing in the dishwasher from when power is supplied from a power source to the dishwasher, which is the third embodiment of the dishwasher according to the present invention, until the user operates and the dishwasher starts operating. Is described.

As shown in the figure, when power is supplied from the power supply (S140), the control device 100 is initialized. Then, the nonvolatile memory 1 serving as a nonvolatile storage means
The completed work stored in 19 is read out. For example, FIGS. 4 to 4 described in the dishwasher / dryer according to the first embodiment.
If all the series of steps from cleaning to rinsing and drying described in the flowchart of 7 have been completed, there should be a finally stored note of the completion of the drying step. Therefore, the control device 100 determines whether or not the end of the drying process is written in the completed work written in the nonvolatile memory 119 (S141).

Here, if the read information indicates that the drying step is completed, a series of steps from cleaning to rinsing to drying have been completed normally. Enter a waiting state. That is, first, the input of the power key 117a on the operation panel is waited for (S142), and if the power key 117a is pressed, the input of the start / pause key 117b is subsequently waited for (S14).
3). When the start / pause key 117b is input, the operation as described with reference to the flowcharts of FIGS. 4 to 7 is started (S144).

On the other hand, when there is no write of the end of the drying step in the read information, that is, a series of operations are not completed,
If the operation has been interrupted, the temperature T written in the nonvolatile memory 119 is read out (S14).
5) Then, the current temperature t is measured by the temperature measuring means 116.
Is read (S146), and the two temperatures are compared (S1).
47).

Here, the temperature T written in the non-volatile memory 119 is compared with the current temperature t, the result is classified as shown in FIG. 17, and the operation to be restarted is determined. FIG. 17 is a table summarizing the definition of operation settings selected after the control unit of the dishwasher is initialized according to the compared temperature difference.

When the difference between the temperature T written in the nonvolatile memory 119 and the temperature t in the cleaning tank read immediately after the control unit 101 is initialized is larger than 10 ° C.
Since it is considered that a long time has passed since the cleaning or heating and rinsing was performed or interrupted halfway, the control unit 101 is set to restart a series of programmed operations from the beginning (FIG. 16). , S148).

The difference between the temperature T written in the nonvolatile memory 119 and the temperature t in the cleaning tank read immediately after the control unit 101 is initialized is larger than 3 ° C. and 10 ° C.
In the following cases, it is considered that only a relatively short time has passed since the cleaning or heating and rinsing was performed or interrupted halfway, so the process is terminated based on the information written in the nonvolatile memory 119. Is recorded,
If the process following the process is recorded up to the middle of the process, the controller 101 is set to restart the interrupted process from the beginning (FIG. 16, S149).

Further, when the difference between the temperature T written in the nonvolatile memory 119 and the temperature t in the cleaning tank read immediately after the initialization of the control unit 101 is 3 ° C. or less,
The time that has elapsed since the cleaning or heating rinse was performed or interrupted halfway was extremely short, for example, when the breaker was activated due to the use of other equipment, or the user accidentally unplugged the outlet. Therefore, the control unit 101 is set so as to resume the work subsequent to the information written in the nonvolatile memory 119 (see FIG. 1).
6, S150).

The setting of the operation to be resumed is selected based on the temperature difference between the temperature T written in the nonvolatile memory 119 and the temperature t in the cleaning tank read immediately after the control unit 101 is initialized. After that, as shown in FIG. 16, the fact that the operation of the dishwasher was interrupted during the execution of the work is displayed on the display unit 117d of the operation panel 117 (S151), and the state of waiting for input of the start / pause key 117b ( S15
2). Then, when the start / pause key 117b is pressed by the user, S148 and S14 are respectively performed.
9. The work based on the settings made in S150 is resumed (S
153). If it is determined that the operation has been interrupted during the operation of the dishwasher without being in the state of waiting for input as in S152, S148, S149, S150.
May be configured to start the work based on the settings made in.

With the above-described configuration, even when the operation of the dish washer / dryer of the present embodiment is interrupted due to a power failure or the like, the nonvolatile memory 119 can be stored in the non-volatile memory 119 when the control device is initialized. Read the written process and temperature information, and guess at which process it was interrupted and how long it was interrupted from the difference between the temperature information at the time of initialization, and Since the operation after the power is restored can be changed according to the time spent, sufficient cleaning can be obtained even if the work is interrupted halfway, and resources such as excess water and detergent, power, etc. Energy can be saved, and usability is greatly improved.

Further, in the present invention, the program created by combining the part programs by the user, the course selected by the user (prepared by combining the part programs in advance), and the settings of the dishwasher performed by the user are also included. It is preferable that the information is stored in the nonvolatile storage means. Further, after an unexpected interruption of the operation during the operation, when the power is restored, resetting means or the like for resetting the operation after the interruption to be performed by the dishwasher according to the user's will may be provided.

[0087]

As described above, according to the first aspect of the present invention,
According to the dishwasher described in the above, even if the power supplied during the operation of the dishwasher is cut off, when power is supplied to the dishwasher again, it is possible to continue the interrupted work Become. According to the dishwasher of the second aspect, when the supplied electric power is cut off and the electric power is supplied again, the process in which the operation is completed can be continued without being repeated. Further, according to the dishwasher according to the third aspect, even if the power supplied during the process during the operation is cut off and the operation is interrupted, the completed process is completed when the power is supplied again. Work after the completed work can be continued. Moreover, according to the dishwasher of Claim 4, when the electric power supplied is cut off and it is supplied again,
Suitable work can be restarted by the water temperature in the washing tank.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a dishwasher that is an embodiment of a dishwasher of the present invention.

FIG. 2 is a sectional view of a dishwasher / dryer according to an embodiment of the present invention.

FIG. 3 is a schematic diagram showing an operation panel according to an embodiment of the present invention.

FIG. 4 is a flowchart showing a series of operation examples from washing to rinsing and drying of the dishwasher according to one embodiment of the present invention.

FIG. 5 is a continuation of the flowchart of FIG. 4 showing an example of a series of operations from washing to rinsing and drying of the dishwasher according to an embodiment of the present invention.

FIG. 6 is a flowchart continued from FIG. 5 showing an example of a series of operations from washing to rinsing and drying of the dishwasher according to an embodiment of the present invention.

FIG. 7 is a continuation of the flowchart of FIG. 6 showing an example of a series of operations from washing to rinsing and drying of the dishwasher according to an embodiment of the present invention.

FIG. 8 shows an example of processing in the dishwasher from when power is supplied from a power source to the dishwasher according to an embodiment of the present invention until the user operates and the dishwasher starts operating. It is a flowchart shown.

FIG. 9 is a schematic structural diagram of a dish washer / dryer which is another embodiment of the dish washer of the present invention.

FIG. 10 is a flowchart showing an operation example of a water supply step of the dishwasher / dryer according to the embodiment of the dishwasher of the present invention described in FIG. 9;

FIG. 11 is a flowchart showing an operation example of a washing process of the dishwasher / dryer which is one embodiment of the dishwasher of the present invention described in FIG. 9;

FIG. 12 is a flowchart showing an operation example of a drainage process of the dishwasher which is one embodiment of the dishwasher of the present invention described in FIG. 9;

FIG. 13 is a flowchart illustrating an operation example of a rinsing step of the dishwasher / dryer according to the embodiment of the dishwasher of the present invention described in FIG. 9;

FIG. 14 is a flowchart illustrating an operation example of a drying process of the dishwasher according to the embodiment of the dishwasher of the present invention illustrated in FIG. 9.

FIG. 15 is a flowchart showing an operation example of a washing step and a heating rinsing step of a dishwasher / dryer according to a third embodiment of the dishwasher of the present invention.

FIG. 16 is a tableware washer-dryer according to a third embodiment of the present invention, in which electric power is supplied from a power supply to a dishwasher;
It is a flowchart which shows the process in a dishwasher until a user operates and a dishwasher starts operation | movement.

FIG. 17 is a table summarizing definitions of operation settings selected after the control unit of the dishwasher is initialized according to the compared temperature difference.

[Explanation of symbols]

Reference Signs List 100 control device, 101 control unit, 102 storage unit, 103 timer unit, 104 temperature determination unit,
105 water supply valve, 106 cleaning pump, 107 drainage pump, 108 blower fan, 109 heater,
110 water supply valve driving means, 111 cleaning pump driving means, 112 drainage pump driving means, 113 blower fan driving means, 114 heater driving means, 115
Water level detecting means, 116 temperature measuring means, 117 operating section, 118 display section driving means, 119 non-volatile memory, 120 second timer section.

Claims (4)

[Claims] 1. A storage unit for storing a program of an operation performed by a dishwasher, and a storage unit that operates by power from a power supply supplied to the dishwasher, reads a program stored in the storage unit, and reads the program. Control means for operating while controlling each part of the dishwasher based on the, and a non-volatile storage means for storing the progress of work performed by the control means based on a program, the control means based on a program The work whose execution has been completed is stored in the non-volatile storage means during the normal operation of the dishwasher, and at least when the power supplied during the operation of the dishwasher is cut off, the power is supplied again. The control means reads the progress of the work stored in the nonvolatile storage means, and executes the work following the recorded completed work based on a program. A dishwasher characterized by being able to continue its work. 2. A washing tank for accommodating tableware, a water supply valve for controlling supply of water to the washing tank, a washing pump for injecting washing water to the tableware contained in the washing tank, and a washing tank. A discharge pump for discharging the washing water in the outside to the outside, a heating means for heating the washing water injected into the tableware, and a temperature measuring means for detecting the temperature of the heated washing water; Divides the work performed by the dishwasher into a plurality of steps, and stores at least two part programs of a washing step and a rinsing step. 2. The dishwasher according to claim 1, wherein the means stores the end of the step. 3. When the control means operates the dishwasher based on the part program, the control means has time measuring means for measuring an elapsed time from the start of the operation of the step to be executed, 3. The dishwasher according to claim 2, wherein the non-volatile storage means stores the step and the elapsed time measured by the time measuring means. 4. 4. The non-volatile storage means stores the temperature measured by the temperature measurement means at regular intervals, and when the power supplied at least during the operation of the dishwasher is cut off, the power is reduced again. When supplied, the temperature read from the non-volatile storage means is compared with the temperature actually measured by the temperature measurement means, and the completion recorded in the non-volatile storage means is determined according to the temperature difference. The dishwasher according to any one of claims 2 to 3, wherein it is selected whether to execute the operation following the completed operation or to change to another operation.