JPS58108340A - Electronic range - Google Patents

Abstract

PURPOSE:To improve the safety by arranging a heater elevation indicating means at positions on an operation panel, etc. which can be seen from the outside in an electronic range having a grill function given by a heater which can be moved up and down. CONSTITUTION:A number of light-emitting diodes LED1'-LED3'... which emit light corresponding to the position of a heater for grill as it is moved up and down are arranged on an operation panel 1. These light-emitting diodes LED1'- LED3'... are connected to a heater driving circuit via a comparator whose reference voltage is determined by a divided resistance. The light-emitting diodes LED1'-LED3'... emit light sequentially with the elevation of the heater, indicating the position of the heater. By this constitution, the position of the heater can be confirmed even from a remote position, and thus the safety can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a microwave oven, and more specifically to a microwave oven that has a grilling function by heating a heater and is equipped with an automatic raising/lowering means for the grill heater. A microwave oven that also has a grill function first performs microwave heating, and then switches to grill heating using a heater.

This transition to grill heating is achieved by energizing the heater and lowering the heater (IM) from the top of the heating chamber to near the top of the food in order to improve the thermal efficiency of the heater. After the grill heating is completed, the power supply to the heater is stopped and the heater is raised to the top of the heating chamber.

When the above-mentioned grill heater is raised and lowered, if you try to open the heating chamber and take out the food, because the heater is being raised and lowered, it is easy to touch the high plate located between the top of the heating chamber and the top of the food. Sometimes the heater approaches and touches Takako while it is moving. In addition, in microwave ovens that automatically determine and correct the lowering end of the heater by detecting the gas generated by the food, the heater moves slowly, and it is difficult to see that the heater is moving just by looking at it. It is difficult to determine whether it is inside or not. Furthermore, when the heater heating starts after the microwave heating ends, the steam and gas generated from the food during microwave heating can be removed from the inner surface of the door inside the heating chamber by stopping the fan blowing into the heating chamber during the heater heating. The transparent part of the door becomes cloudy and the inside of the heating chamber cannot be seen from the outside.Under this situation, the heater is lowered, so the position of the heater can be found from the solution.

The present invention has been developed in view of the above, and an object of the present invention is to provide a microwave oven with improved safety by providing display means for raising and lowering a grill heater in a location visible from the outside, such as an operation panel.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a front view of an operation panel according to an embodiment of the present invention.

The operation panel 1 is designed with a light emitting diode LED 1 that lights up only when the grill heater is going down and a light emitting diode LED 2 that lights up only when the grill heater is going up, so that you can tell at a glance whether the grill heater is going up or down. There is.

FIG. 2 shows a circuit diagram of the embodiment of the present invention described above.

A gas sensor 4 for detecting gas generated by food is connected to a DC power supply VC via a load resistor R1, and a thermistor 5 is connected to a DC power supply VC via a load resistor RL.
and the terminal voltage VT of thermistor 5 are seven independent A-
D converters 12, 13 and input/output interface 14
The signal is then input to the CPU of the microcomputer 15. The microcomputer 15 has a built-in ROM, RAM, and electronic clock for storing programs and the like for the CPU. Key signals on the operation panel 1 are also input to the microcomputer 15 via the interface 14. On the other hand, according to the output command from the CPU, the microwave drive relay R1 and the heater energization relay I are activated.

Heater rising relay R, heater lowering relay R1 are controlled via interface 14 and switching transistors Tr, Tr, Tr, Tr, Tr, respectively. The magnetron 7 for generating microwaves is driven by a commercial AC power source via a microwave driving relay, contacts R and a, a door switch 16, a step-up transformer 17, and the like. The heater 8 is driven from a commercial alternating current power source AC through a heater energizing relay, a contact R-, and a door switch 16. A DC motor 9 for raising or lowering the heater 8 is driven by a DC power supply VCK obtained by a transformer and a rectifier circuit 18, and is connected to a contact Rs of a raising relay R.
When & is on, it rotates in the upward direction and lowering relay R6
When the contact R4a is on, it rotates in the downward direction. The light emitting diode LEDl is connected in parallel to the falling relay R4, and the light emitting diode LED2 is connected in parallel to the rising relay Ra, and falls when an H level signal is sent from the computer 150 CPU to the switching transistor Tr4 or Tr. The relay RJ) or the rising relay operates to lower or raise the DC motor and light up the light emitting diode LEDl or LED2.

In the above-described embodiment of the present invention, the light emitting diode LED1 is turned on only when the grill heater is going down, and the light emitting diode LED2 is turned on only when the grill heater is going up. FIG. 3 shows a front view of the operation panel 1. As shown, it may be replaced with a light emitting guide LED 6 that lights up when the grill heater is lowered or raised, and only the changed part of the circuit diagram in that case is shown in FIG. The switching transistors Tra and Tr4 are connected to the ED light emitting diode 3 via the OR circuit 19, and therefore the light emitting diode L
ED-6 is configured to turn on when the grill heater is raised or lowered.

As shown in the front view of the operation panel 1 in FIG. 5, as the grill heater moves up and down, the light emitting diodes L ED1' light up sequentially corresponding to the position of the grill heater.
, L E D2' , L E'D! l',...
The existing position of the grill heater can also be displayed by arranging a large number of them, and the main part of the circuit diagram is shown in FIG.

When the switching transistor Tr and Tratc parallel [Tr,' and Tr' are connected, and the CPU of the computer 15 outputs a lowering command for the grill heater to Tr as an H level signal, relay 4 is turned on. , the DC motor 9 is driven to lower the grill heater, and the Tr- is also turned on to charge the capacitor C1 via the resistor.

Therefore, the voltage of the capacitor C6 gradually increases from 0 to 0, and the comparator C0M1 of the LED display circuit 20,
It is input to C0M2, C0M3, ---, C0Mn. Comparator COM 1. C0M2゜C0M3
, . . . COM n has a reference voltage determined by a predetermined dividing resistor and follows the voltage from the capacitor C4, and LEDl'.

L; D2', LED3'...LEDn' are lit in sequence, and when the door and grill heater are raised, the 11th light is lit in the same way, and the grill heater is lit on the operation panel shown in Figure 5. It is configured to display its current position according to its movement.

In addition, in a microwave oven in which the lowering end of the grill heater is predetermined by key operation for selecting the type of cooking, each cooking Light-emitting diodes LED4 and LED5 that light up when the grill heater goes up and down are placed at positions corresponding to the lowering end of the grill heater determined by the type of grill heater.
For example, if you press 1 on the grilled fish key or 2 on the gratin key, the light emitting diode L will be activated at the position corresponding to the lowering end of each grill heater.
It is also possible to make the ED4 or LED5 light up when the grill heater goes up and down, and the main part of the circuit diagram is shown in FIG.

The outputs of the switching transistors Tr& and Tr4 are connected to the light emitting diodes LED4 and LE via the OR circuit 19.
When the D5 is connected and the corresponding keys 1 and 2 are pressed, a light emitting diode emitted at the lower end position of the grill heater will light up when the grill heater is raised or lowered.

Furthermore, the present invention can also be applied to a type of microwave oven in which the grill heater is fixed at the top of the heating chamber and does not move. In a microwave oven where the grill heater is fixed at the top of the heating chamber and the shelf on which food is placed is changed depending on the type of cooking, the main part of the circuit diagram is shown in Figure 9.
When you press the key [3, 4, etc.] corresponding to the type of cooking, LED6, LED7, etc. arranged on the operation panel corresponding to the specified shelf position set in advance will light up and the corresponding position will be displayed. It is configured to inform you of the following.

In each of the embodiments of the present invention described above, it is also possible to interpose a known oscillation circuit in front of each light emitting diode and make it blink when the light emitting diode is turned on, or the light emitting diode can be used as other display means. Needless to say, it is okay.

As explained above, according to the present invention, the raising and lowering of the grill heater, which is difficult to discern from the outside, is displayed using a display that can be determined at a glance even from a distance. It is possible to provide a microwave oven with improved safety, such as preventing accidents such as touching, or displaying the lower end setting of the grill heater to prevent contact with food.

[Brief explanation of the drawing]

1, 3, 5, and 7 are respectively front views of the operation panel of the embodiment of the present invention, and FIGS. 2, 4, 6, 8, and 9 are the main views, respectively. FIG. 3 is a circuit diagram of an embodiment of the invention. 7...Macnetron 8...Grill heater 9...DC motor LED...Light emitting diode Patent applicant Sharp Corporation Representative Patent attorney Nishi 1) New

Claims (4)

[Claims] (1) In a microwave oven that has a grill function using heater heating and is equipped with automatic raising and lowering means for the grill heater,
A microwave oven characterized by comprising display means for raising and lowering the grill heater at a location visible from the outside, such as an operation panel. (2) The microwave oven according to claim 1, wherein the display means for raising and lowering the grill heater is a display that lights up only while the grill heater is moving up and down. (3) The microwave oven according to claim 1, wherein the display means for raising and lowering the grill heater is a display group that lights up in accordance with the status of the grill heater. (4) A plurality of indicators that light up only when the grill heater is in the ascending position are arranged in correspondence with the descending end of the grill heater, which is set in advance according to the type of food to be cooked. 3. The microwave oven according to claim 2, wherein only the display body corresponding to the lowering end of the grill heater is turned on depending on the type of food to be cooked.