JPH11342074A - Electric rice cooker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stop the lighting of a back light when needed. SOLUTION: This electric rice cooker is provided with the various kinds of operation switches (menu switch 41, rice cooking switch 42, heat retaining switch 43, reservation switch 44, time (hour) setting switch 45a, time (minute) setting switch 45b and re-heating switch 47) to be operated so as to execute rice cooking, a liquid crystal display 48 for performing menu display and time display, etc., and a back light 73 for illuminating the liquid crystal display 48. Then, a control means (microcomputer unit 70) for lighting or turning off the back light 73 corresponding to the respective processes of a water absorption process, a cooking process, a steaming process and a heat insulation process at the time of cooking rice is attached and the back light 73 is lighted only in the process in which a user requires it.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric rice cooker having a liquid crystal display.

[0002]

2. Description of the Related Art In a recent electric rice cooker, a heating means is controlled by a microcomputer control circuit, and a rice cooking menu set by various operation switches, a cooking level, a timer set time, and the like are displayed on a liquid crystal display. It has become.

Since the liquid crystal display itself is a light-receiving electronic display element having no self-light source, it has a drawback that contrast on a display surface is poor and that it is very difficult to see in a dark place such as a kitchen or at night.

Therefore, attempts have been made to provide a backlight for illuminating the liquid crystal display to make the display surface easier to see.

[0005]

However, the backlight is required only when the user needs to look at the display surface of the liquid crystal display. However, it is desirable from the viewpoint of energy saving.

The present invention has been made in view of the above points, and has as its object to enable the backlight to be turned off when necessary.

[0007]

According to a first basic configuration of the present invention (invention of claim 1), various operation switches operated to execute rice cooking are provided as means for solving the above problems, In an electric rice cooker equipped with a liquid crystal display for displaying menus, time display, and the like, and a backlight for illuminating the liquid crystal display, the electric rice cooker supports various processes such as a water absorption process, a cooking process, a steaming process, and a heat retention process during cooking. Control means for turning the backlight on or off is provided.

With the above-described structure, the backlight is turned on only in a process required by the user, and power consumption can be reduced.

In this case, as in the second aspect of the present invention, the lighting time of the backlight by the control means is set at the start of the water absorption step and the start of the steaming step, and the lighting time of the backlight by the control means is set to the cooking time. In the case of the start of the raising process and the start of the warming process, the lighting period of the backlight is the time that the user needs most (ie,
Only during the water absorption step and during the steaming step), and the power consumption can be further reduced.

In this case, the lighting time of the backlight by the control means is set at the start of the water absorption step and the start of the steaming step, and the turning off time of the backlight by the control means is set as in the invention of claim 3. When a predetermined time has elapsed after the start of the cooking process and after the start of the heat retaining process, the time when the user needs it most (ie, from the water absorption process to the initial stage of the cooking process and from the steaming process to the initial stage of the heat retaining process). Only power consumption can be further reduced.

In the second basic configuration of the present invention (invention of claim 4), as means for solving the above-mentioned problems, various operation switches operated to execute rice cooking, menu display, time display, etc. Liquid crystal display, a backlight that illuminates the liquid crystal display, and an electric rice cooker including a temperature detecting unit that detects the temperature of the inner pot, wherein the temperature of the inner pot detected by the temperature detecting unit is changed. Control means for turning on or off the backlight.

With the above-described structure, the backlight is turned on only when the temperature of the inner pot is within a predetermined temperature range (for example, a water absorption step, a steaming step, etc.), and power consumption can be reduced.

In a third basic configuration of the present invention (invention of claim 5), as means for solving the above-mentioned problems, various operation switches operated to execute rice cooking, menu display, time display, etc. , A backlight that illuminates the liquid crystal display, and a temperature detector that detects the temperature of the inner pot, in the rice cooker, turns on the backlight when the various operation switches are operated, and starts rice cooking. Control means for turning off the backlight when the temperature of the inner pot detected by the temperature detecting means has risen to a predetermined value is added.

[0014] With the above-described structure, the backlight is turned on only when the inner pot temperature rises to a predetermined temperature after the operation of the various operation switches (for example, a water absorption step in which the user needs to turn on the backlight). Lighting is performed, and power consumption can be reduced.

[0015] In a fourth basic configuration of the present invention (the invention of claim 6), as means for solving the above problems, various operation switches operated to execute rice cooking, menu display, time display and the like are provided. A liquid crystal display, a backlight for illuminating the liquid crystal display, a temperature detecting means for detecting the temperature of the inner pot, and a microcomputer control circuit for executing rice cooking, the electric rice cooker, Control means is provided for turning on the backlight at the time of operation and turning off the backlight when the clock incorporated in the microcomputer control circuit is in an initial state after the backlight is turned on.

With the above-described configuration, the backlight is lit only from the time when the various operation switches are operated to the time when the clock built in the microcomputer control circuit is set to the initial state. Can be reduced.

In this case, when the time from when the backlight is turned on to the initial state of the timepiece is short, the turning-off time of the backlight by the control means is set to the time of the timepiece. When the time is the next initial state, the lighting time of the backlight does not become too short, which is practical.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Some preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

First Embodiment FIGS. 1 to 4 show an electric rice cooker according to a first embodiment of the present invention.

This electric rice cooker serves both for cooking rice and for keeping warm, and as shown in FIG.
The rice cooker main body 1 has a double structure having a space portion 4 in which the rice cooker can be set, and a lid 2 that covers the upper opening of the rice cooker main body 1 so as to be openable and closable.

The rice cooker main body 1 has a bottomed cylindrical outer case 5 made of a synthetic resin constituting a bottom wall and an outer wall, a protective frame 6 constituting an inner peripheral surface, and upper ends of both cases 5, 6. And a shoulder member 7 made of a synthetic resin for coupling the inner pot 3 therein.

The protective frame 6 has a cylindrical portion 6a made of a thin metal plate having an upper end engaged with the shoulder member 7 and provided with a heater 8 at the upper and lower central portions of the outer peripheral surface. 6a, which is made of a synthetic resin dish-shaped portion 6b which engages with the lower end of 6a.
A center sensor 9 is provided at the center of the bottom surface of the dish-shaped portion 6b so as to contact the bottom surface of the inner pot 3.

The center sensor 9 functions as an inner pot temperature detecting means for detecting the temperature of the inner pot 3 and also as an inner pot set detecting means for detecting whether or not the inner pot 3 is set. In addition, a thermistor 10 serving as a temperature detecting unit and an inner pot set detection sensor 11 serving as an inner pot set detecting unit are built in.

The center sensor 9 according to the present embodiment is disposed in a circular storage portion 12 formed at the center of the dish-shaped case 6b, is disposed vertically movably, and has the thermistor 10 built therein. It is provided with a holder 13 and a spring 14 for urging the sensor holder 13 upward (that is, in a direction of contacting the bottom surface of the inner pot 3). In the case of the present embodiment, the upper surface of the sensor holder 13 is a circular flat surface, and a sensor cap 15 that is in contact with the bottom surface of the inner pot 3 is provided.

The inner pot set detection sensor 11
The reed switch 16 and the magnet (not shown) provided at opposing positions on the outer periphery of the sensor holder 13 and the reed switch when the sensor holder 13 is moved downward (in other words, when the inner pot is set). Closure plate 17 inserted between 16 and magnet
And is constituted by.

An annular work coil 18 surrounds the center sensor 9 and extends from the bottom surface of the inner pot 3 to the lower curved portion on the lower surface of the protective frame dish 6b.
Are arranged. The work coil 18 functions as a magnet generating means in the high-frequency electromagnetic induction heating device. Reference numeral 19 denotes a coil table for holding the work coil 18 at a predetermined position, 20 denotes a ferrite core that shuts off the magnetism of the work coil 18 so as not to affect the underlying equipment, 24 denotes a cooling fan, and 27 denotes a cooling fan. This is an air inlet formed at the bottom of the outer case 5.

The lid 2 is composed of an upper plate 29 made of a synthetic resin constituting the upper surface, a lower plate 30 made of a synthetic resin constituting the outer peripheral annular portion on the lower surface, and a radiator for covering an opening in the lower plate 30. The disk 31 has a hollow structure.
The lid 2 is openably and closably attached to one side of the shoulder member 7 via a hinge mechanism 32, and has an open end engaged with a predetermined position of the lid 2. A lock mechanism 33 for keeping the lid 2 closed is provided.
Reference numeral 34 denotes a steam discharge port, and 35 denotes a lid heater. Further, in a front space 4a between the outer case 1 and the protection frame 6, a microcomputer unit for controlling the energization of the work coil 18, the heat retaining heater 8, and the lid heater 35 (FIG. The control board 37 provided with the support housing 36 is accommodated in the support housing 36.

An annular heat insulator 38 is provided outside the cylindrical portion 6a of the protective frame 6, and an annular heat shield plate 39 is provided outside the heat insulator 38.

On the front side of the shoulder member 5, an operation panel section 40 is provided. The operation panel section 40 has a rice cooking menu (for example, white rice, fast-cooked rice, Sushi, cooked, rice, brown rice,
Menu switch 41, rice cooker switch 42, heat switch 43, reservation switch 44, time (hour) setting switch 45a, time (minute) setting switch 45b, cancel switch 46, reheating switch 47, etc. A switch and a liquid crystal display 48 are provided. The liquid crystal display 48 has a steaming time,
The remaining rice cooking time, the timer reservation setting time, the heat retention elapsed time, and the like are displayed. Reference numeral 49a denotes a display time on the display surface of the liquid crystal display 48, and 49b denotes a display time on the liquid crystal display 4.
Menu display portion printed on the outer peripheral portion of the display surface of No. 8, 49c
Reference numeral denotes a display index on the display surface side of the liquid crystal display 48, which is arbitrarily moved in correspondence with the menu display of the designated menu and is displayed oppositely.

On the inner side of the operation panel section 40, the liquid crystal display 48 and the various operation switches (namely, the menu switch 41, the rice cooker switch 42, the warming switch 43, the reservation switch 44, the time (hour) setting switch 45a, An operation board 50 provided with a time (minute) setting switch 45b, a cancel switch 46, and a reheating switch 47) is provided. The operation board 50 includes the control board 37.
It is supported on an inclined support plate 51 integrated with the support housing 36 on the side.

Next, referring to the electric circuit shown in FIG.
The electrical elements in the present embodiment will be described.

Reference numeral 52 denotes an AC power supply for home appliances, 53 denotes a rectifier circuit, 54 denotes a resonance capacitor, 55 denotes a synchronous trigger circuit,
56 is an IGBT (that is, a power transistor), 57 is an IGBT drive circuit, 58 is a pulse width modulation circuit, 59
, A power feedback circuit; 60, a fan motor as a drive source of the cooling fan 24; 61, 62, 63, a triac for controlling energization of the heat retaining heater 8, the lid heater 35 and the fan motor 60; 64, a triac drive circuit; Is a triac drive power supply circuit, 66 is a transformer, 67 is a rectifier circuit, 68 is a stabilized power supply, 69 is a battery,
70 is a microcomputer unit (hereinafter referred to as a microcomputer unit) acting as a microcomputer control circuit, 7
1 is a reset circuit, 72 is a buzzer circuit, 73 is a backlight for illuminating the liquid crystal display 48, 74, 75, 7
Reference numeral 6 denotes light-emitting diodes for cooking, keeping warm, and for reservation, each of which is connected as shown.

The microcomputer unit 70 includes a work coil 18, a heating heater 8, and a lid heater 3 for cooking rice and keeping heat.
5 and control of turning on / off the backlight 73.

Next, with reference to the flow chart shown in FIG. 4, the control of turning on / off the backlight in the electric rice cooker having the above configuration will be described.

The cooking switch 42 at step S ₁ is being turned ON, the rice is started, the backlight 7
3 is turned on, water step of water absorption of the water in the rice is executed in step S _2. When the water absorption step is completed, the backlight 73 is turned off in step S _3.

Next, the determination of the rice amount performed in step S _4, step-up cooking in step S ₅ is executed. When the cooking process is completed, step S
₆ backlight 73 is turned in, step is performed steaming at step S _7.

When the steaming step is completed, step S
_{At 8} , it is determined whether or not the inner pot temperature detected by the center sensor 9 is equal to or lower than 72 ° C., which is the heat retention set temperature. If a negative determination is made, step S ₉
Work coil 18 in to S _11, insulation heater 8 and lid heater 35 is turned OFF, if the determination is positive at step S _8, the work coil 18 is turned ON by the duty ratio of 1/16 in step S _12, step S
_{At 13} , the heater 8 is turned on with a duty ratio of 5/16
Is, lid heater 35 at step S ₁₄ is ON duty ratio 4/16. That is, the heat retention control is executed. Then, the determination inner bowl temperature is whether or not it is 80 ° C. or less in the step S ₁₅ is made, if an affirmative determination, when it returns to step S _8, a negative determination is made, step S ₁₆ backlight 73 is turned off at, and then returns to step S _8. That is, after the end of the steaming process, the inner pot temperature is set
The backlight 73 is turned on until the temperature reaches 0 ° C. (that is, until the heat retaining step is started).

As described above, in this embodiment,
The backlight 73 is turned on at the start of the water absorption step and at the start of the steaming step, and the backlight 73 is turned off at the start of the cooking step and at the start of the warming step. Only when necessary (ie, during the water absorption step and during the steaming step), power consumption can be reduced.

Second Embodiment FIG. 5 shows a flowchart for controlling turning on / off of a backlight in an electric rice cooker according to a second embodiment of the present invention.

In this case, when the rice cooking is started, the backlight 73 is turned off in step S ₁ and step S ₂
In water absorption step is performed, the determination of the cooking amount is made in step S _3, steps are performed up cooking in step S _4. And when the cooking process ends,
In step S ₅ the backlight 73 is lit, steaming process is performed in step S _6. When steaming process is completed, the backlight 7 in step S ₇
3 is blinking inform the user that entered the incubating process, T seconds timer is started in step S _8, incubating process is performed in step S _9. The blinking of the backlight 73 means that the lighting is intermittently performed, and the lighting in the claims includes blinking.

During execution of the heat retaining step, step S ₁₀
The backlight 73 is turned off in step S ₁₁ when T seconds timer is determined to have counted up when and step S ₁₂ the lid 2 is determined to have been operated to open the. That is, the fact that the lid 2 has been opened indicates that the user performs the work of cooking rice, so that the backlight 73 does not need to be turned on, so that the backlight 73 may be turned off. Incidentally, after the backlight 73 is turned off in step S _11, or when T seconds timer is determined not to be counted up in step S _12, the process returns to step S _10.

As described above, the lighting timing of the backlight 73 is defined as the start of the steaming process, and the timing of turning off the backlight 73 is determined for a predetermined time (for example, T
Seconds), only the time that the user needs the most (that is, from the steaming process to the beginning of the warming process) is obtained, and the power consumption can be reduced.

Third Embodiment FIG. 6 shows a flowchart for controlling turning on / off of a backlight in an electric rice cooker according to a third embodiment of the present invention.

In this case, when rice cooking is started, the backlight 73 is turned on in step S ₁ and the step S ₂
, An N-second timer is started. The inner pot temperature determination is made of whether or not a 50 ° C. or less in step S _3, if a negative determination is made here,
Work coil 18 in step S ₄ to S _6, insulation heater 8 and lid heater 35 is turned OFF, if an affirmative determination is made, the work coil 18 is turned ON by the duty ratio of 1/16 at step S _7, step S ₈ insulation heater 8 is turned ON at a duty ratio 5/16 in lid heater 35 is duty ratio in step S ₉ 4/16
Is turned on. That is, the water absorption step is performed.

The determination is made inner bowl temperature is whether a 40 ° C. or less in the step S _10, when a negative determination is made here, the backlight 7 in step S ₁₁
After 3 is turned off, the process proceeds to step S _12, when a positive determination is made, the process proceeds directly to step S12. Then, N seconds timer in step S ₁₂ is performed is discriminated whether counted up, when a negative determination is made here, returns to step S _3, the same control (i.e., water absorption process control) is continued but is the, when an affirmative determination, the determination of the cooking amount is made in step S _13, step is performed up cooking in step S _14, step S
Step steaming at ₁₅ is executed, and the holding step is performed in step S _16. That is, the backlight 73 is turned on from the start of cooking rice until the temperature of the inner pot rises to 40 ° C.

As described above, after the rice cooker has started cooking, the temperature of the inner pot rises to a predetermined temperature (for example, 40 ° C.) (for example, a water absorption step in which the user needs to turn on the backlight 73). Is performed, and power consumption can be reduced.

Fourth Embodiment FIG. 7 shows a flowchart for controlling turning on / off of a backlight in an electric rice cooker according to a fourth embodiment of the present invention.

[0048] In this case, various operation switches (e.g. excluding cancel switch 46 at step S _1, the menu switch 41, cooking switch 42, thermal insulation switch 43, reserved switch 44, the time (hour) setting switch 45a, the time (min) Setting Switch 45b and reheating switch 47)
There determination is made whether or not the ON operation, wherein if the determination is positive, the backlight 73 is turned in the step S _2, which is built in the microcomputer unit 70 which acts as a microcomputer control circuit in step S ₃ The reading of the number of seconds t until the clock (for example, a clock initialized in units of 60 seconds) becomes the initial state is performed.

[0049] Then, made whether the determination has become t <30 in step S _4, when a negative determination is made here, when the number of seconds t is determined to have elapsed in step S _7, step in S ₆ backlight 73 is turned off, and then returns to step S _1.

On the other hand, if a negative determination is made in step S ₄ , if it is determined in step S ₅ that the time obtained by adding 60 seconds to the number of seconds t has elapsed, step S 5 is performed.
₆ backlight 73 is turned off at, and then returns to step S _1.

[0051] When a negative determination is made in step S _1, a determination is made whether the cancel switch 46 has been operated in step S _8, wherein when an affirmative determination is made directly to step S ₆ willing, is turned off the backlight 73, but then returns to step S _1, when a negative determination is made, the routine returns to step S _1.

That is, the backlight 73 illuminated by the ON operation of the various operation switches is connected to the microcomputer unit 7.
When the number of seconds t until the clock built in 0 (for example, a clock initialized in units of 60 seconds) becomes an initial state elapses, the light is turned off, but the number of seconds t is less than 30 seconds. Is turned off when the time obtained by adding 60 seconds to the seconds t elapses. Therefore, the lighting time of the backlight 73 is between 30 seconds and 90 seconds, and the user can clearly see the liquid crystal display 48. Note that when the number of seconds t required for the clock (for example, a clock initialized in units of 60 seconds) built in the microcomputer unit 70 to reach the initial state has elapsed, the backlight 73
May be turned off.

As described above, the backlight 73 is lit only from the time when the various operation switches are operated to the time when the clock built in the microcomputer unit 70 is initialized, so that the power consumption can be reduced. In addition, when the time until the timepiece is in the initial state is short, the turning-off time of the backlight 73 is set to the time point when the timepiece enters the next initial state, so that the lighting time of the backlight 73 becomes too short. And it becomes practical.

[0054]

According to the first basic configuration (the invention of claim 1) of the present invention, various operation switches operated for executing rice cooking, a liquid crystal display for displaying menus, time display, and the like, In an electric rice cooker provided with a backlight for illuminating the liquid crystal display, a control means for turning on or off the backlight in accordance with each step of a water absorption step, a cooking step, a steaming step, a warming step and the like during rice cooking. The backlight is turned on only in the process required by the user,
There is an effect that power consumption can be reduced.

In this case, the lighting time of the backlight by the control means is set to the start of the water absorption step and the start of the steaming step, and the turning off time of the backlight by the control means is set to the cooking time. In the case of the start of the raising process and the start of the warming process, the lighting period of the backlight is the time that the user needs most (ie,
Only during the water absorption step and during the steaming step), and the power consumption can be further reduced.

In this case, the lighting time of the backlight by the control means is defined as the start of the water absorption step and the start of the steaming step, and the timing of turning off the backlight by the control means. When a predetermined time has elapsed after the start of the cooking process and after the start of the heat retaining process, the time when the user needs it most (ie, from the water absorption process to the initial stage of the cooking process and from the steaming process to the initial stage of the heat retaining process). Only power consumption can be further reduced.

According to the second basic configuration of the present invention (invention of claim 4), various operation switches operated to execute rice cooking, a liquid crystal display for displaying a menu, a time display, etc., and the liquid crystal In an electric rice cooker provided with a backlight for illuminating a display and a temperature detecting means for detecting an inner pot temperature, the backlight is turned on or off in accordance with a change in the inner pot temperature detected by the temperature detecting means. A control means is provided to turn on the backlight only when the temperature of the inner pot is within a predetermined temperature range (for example, a water absorption step, a steaming step, etc.), so that power consumption can be reduced. is there.

According to the third basic configuration (the invention of claim 5) of the present invention, various operation switches operated to execute rice cooking, a liquid crystal display for displaying menus, time display, etc., and the liquid crystal In an electric rice cooker provided with a backlight for illuminating a display and a temperature detecting means for detecting an inner pot temperature, the backlight is turned on when the various operation switches are operated, and the temperature is detected by the temperature detecting means after the start of rice cooking. Control means for turning off the backlight at the time when the inner pot temperature rises to a predetermined value,
Since the backlight is turned on only after the operation of the various operation switches while the inner pot temperature rises to a predetermined temperature (for example, a water absorption step that requires the user to turn on the backlight), power consumption is reduced. The effect is that it can be reduced.

According to the fourth basic configuration (the invention of claim 6) of the present invention, various operation switches operated to execute rice cooking, a liquid crystal display for displaying menus, time display, and the like, and the liquid crystal In an electric rice cooker including a backlight for illuminating a display, a temperature detection unit for detecting an inner pot temperature, and a microcomputer control circuit for performing rice cooking, the backlight is turned on when the various operation switches are operated. After the backlight is turned on, a control means for turning off the backlight is provided when a clock built in the microcomputer control circuit is in an initial state, and the control means is built in the microcomputer control circuit from the time of operating various operation switches. The backlight is turned on only until the watch that is set to the initial state, so if power consumption can be reduced There is a cormorant effect.

In this case, when the time from when the backlight is turned on to the initial state of the watch is short, the turning off time of the backlight by the control means is set to the time of the watch. When the time is the next initial state, the lighting time of the backlight does not become too short, which is practical.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an electric rice cooker according to a first embodiment of the present invention.

FIG. 2 is an enlarged front view of an operation panel unit in the electric rice cooker according to the first embodiment of the present invention.

FIG. 3 is a connection diagram of electric elements in the electric rice cooker according to the first embodiment of the present invention.

FIG. 4 is a flowchart showing the content of backlight on / off control in the electric rice cooker according to the first embodiment of the present invention.

FIG. 5 is a flowchart showing the content of a backlight on / off control in the electric rice cooker according to the second embodiment of the present invention.

FIG. 6 is a flowchart showing the content of backlight on / off control in the electric rice cooker according to the third embodiment of the present invention.

FIG. 7 is a flowchart showing the content of backlight on / off control in the electric rice cooker according to the fourth embodiment of the present invention.

[Explanation of symbols]

9 is a temperature detecting means (center sensor), 40 is an operation panel unit, 41 is a menu switch, 42 is a rice cooker switch,
43 is a heat retention switch, 44 is a reservation switch, 45a is a time (hour) setting switch, 45b is a time (minute) setting switch, 47 is a reheating switch, 48 is a liquid crystal display,
70 is a microcomputer control circuit (microcomputer unit), 73 is a backlight.

Claims (7)

[Claims] 1. An electric rice cooker comprising: various operation switches operated to execute rice cooking; a liquid crystal display for displaying a menu, a time display; and a backlight for illuminating the liquid crystal display. An electric rice cooker, further comprising control means for turning on or off the backlight in accordance with each step of a water absorption step, a cooking step, a steaming step, a warming step, and the like during rice cooking. 2. The lighting timing of the backlight by the control means is defined as a start time of a water absorption step and a start time of a steaming step,
2. The electric rice cooker according to claim 1, wherein the backlight is turned off by the control unit at a start of a cooking step and at a start of a heat retention step. 3. 3. The lighting timing of the backlight by the control means is defined as a start time of a water absorption step and a start time of a steaming step,
2. The electric rice cooker according to claim 1, wherein the backlight is turned off by the control unit at a time when a predetermined time has elapsed after the start of the heating step and the start of the heat retention step. 3. 4. An operation switch operated to execute rice cooking, a liquid crystal display for displaying a menu, a time display, etc., a backlight for illuminating the liquid crystal display, and a temperature detecting means for detecting an inner pot temperature. An electric rice cooker comprising: a control unit for turning on or off the backlight in accordance with a change in the temperature of the inner pot detected by the temperature detecting unit. 5. An operation switch operated to execute rice cooking, a liquid crystal display for displaying a menu, a time display, etc., a backlight for illuminating the liquid crystal display, and a temperature detecting means for detecting an inner pot temperature. An electric rice cooker comprising: the backlight is turned on when the various operation switches are operated, and the backlight is turned on when the inner pot temperature detected by the temperature detecting means rises to a predetermined value after the start of rice cooking. An electric rice cooker, further comprising control means for turning off the light. 6. An operation switch operated to execute rice cooking, a liquid crystal display for displaying a menu, a time display, etc., a backlight for illuminating the liquid crystal display, and a temperature detecting means for detecting an inner pot temperature. An electric rice cooker comprising a microcomputer control circuit for executing rice cooking, wherein the backlight is turned on when the various operation switches are operated, and is built in the microcomputer control circuit after the backlight is turned on. An electric rice cooker, further comprising control means for turning off the backlight when the timepiece is in an initial state. 7. When the time from when the backlight is turned on to when the watch is in the initial state is short, the time when the backlight is turned off by the control means is set to the time when the watch enters the next initial state. The electric rice cooker according to claim 6, wherein: