JPH04136623A - Liquid crystal display device for microwave oven - Google Patents

Abstract

PURPOSE:To grasp a heating mode and a state of heating or no-heating clearly from far away, by a method wherein light sources are composed of a plurality of illuminating means having different colors, and a control means whereby the illuminating means is selected corresponding to a cooking mode preset and electricity is fed to the illuminating means, is provided. CONSTITUTION:A cooking menu key and a start button on an operation panel 21 for a microwave oven are pushed. By a microcomputer 27, an operation time corresponding to a cooking menu selected is set in a magnetron drive circuit 22, a timer is started, a momentarily-clocking value and a letters of 'heat' are displayed on a liquid crystal display element 1 and electricity is fed to an LED-lighting circuit 24 for a red color, based on the information stored in a storage 26. A current is applied to five red-diodes 6 through feeding terminals 11, and the whole of a backlight 4 is illuminated in the red color, and the red light thereof transmits the periphery of indicating-segments 2, 3 and enters the eye of a user. By the liquid crystal display element 1 illuminated in red color, the user can easily confirm that the microwave oven is in microwave heating, even if the user is far apart from the microwave oven. When a clocking is ended, the display of the 'heat' disappears, feeding to the LED- lighting circuit for the red color turns into the feeding to a LED-lighting circuit 25 for a green color.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a liquid crystal display device for a microwave oven that allows light from a backlight to pass through a liquid crystal display element to provide clear display.

[Conventional technology]

Conventionally, as this type of liquid crystal display device, the ones shown in FIGS. 4 to 6, for example, are known. This liquid crystal display device 4
0 is located at the top of the operation panel 33 on the front right side of the microwave oven, which has cooking mode (microwave heating, heater heating) setting buttons 31, 32, etc., as shown in FIG. 4, and as shown in FIG. , a light emitting diode 46 is arranged as a backlight on the control board 34 in the operation panel 33, and a liquid crystal display element 41 is arranged so as to cover the front surface thereof. As shown in FIG. 6, the liquid crystal display element 41 includes a number segment 42 that displays a four-digit number and a character segment 43 that displays the set cooking mode, heating level, etc.
It consists of a light emitting diode on the back - 1"46 (see Figure 5)
Both segments 42 and 43 (
The background of the display segment 44) is illuminated to provide contrast for clear display.

[Problem to be solved by the invention]

However, as microwave ovens have recently become more multi-functional and more compact, the conventional liquid crystal display devices are becoming smaller in size, and the display segments 44 are also becoming smaller. Therefore, there is no problem as long as the user is using the microwave in front of them, but if the user frequently leaves the microwave while cooking, it may be difficult to reliably recognize the displayed contents, and it may be difficult to confirm whether the cooking process is currently complete or not. Either that or the problem is that it is difficult to know what cooking mode is currently in during continuous cooking. SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a liquid crystal display device for a microwave oven that allows a user who is far away to clearly recognize the operating status and cooking mode of the microwave oven by devising a backlight structure. It is about providing.

[Means for Solving the Problems] In order to achieve the above object, the liquid crystal display device for a microwave oven of the present invention transmits light from a light source provided on the back side to the liquid crystal display element, and displays segments or backgrounds thereof. In the microwave oven, the light source is constituted by a plurality of lamp means emitting light of different colors, and depending on the cooking mode set on the operation panel of the microwave oven, any one of the lamp means or The present invention is characterized by comprising a control means for selecting two or more combinations and supplying power to the selected lamp means. Further, the lamp means may be a light emitting diode, and the cooking mode may be microwave heating, heater heating, or non-heating.

[Effect]

When the user sets the cooking mode of the microwave oven on the operation panel, the control means selects one or a combination of two or more of the plurality of lamp means that emit light in different colors, depending on the set cooking mode. and supplies power to the selected lamp means. As a result, only the powered lamp means lights up, and the monochromatic or mixed color light specific to the set cooking mode passes through the liquid crystal display element and enters the user's eyes. Therefore, even if the user is far away from the microwave oven, the user can easily and immediately visually recognize the cooking mode by the color of the transmitted light, resulting in a user-friendly microwave oven. Furthermore, since the cooking mode can be omitted from the displayed content, the display segment can be enlarged accordingly, and other display content can be displayed in a larger size. In addition, if the lamp means is a light emitting diode and the cooking mode is specified, it is possible to easily obtain a wide variety of emitted light colors by the control means, and the heating mode, heating, etc. in continuous cooking etc. can be easily obtained.
The unheated state can be clearly seen even from a distance.

【Example】

Hereinafter, the present invention will be explained in detail with reference to illustrated embodiments. FIGS. 1(a), 1(b), and 1(c) are front views showing an embodiment of a liquid crystal display device for a microwave oven according to the present invention, respectively;
They are a longitudinal cross-sectional view and a transverse cross-sectional view. This liquid crystal display device consists of a liquid crystal display element (1) having a number segment 2 for displaying a four-digit time and a character segment 3 for "heating" for displaying the heating state.
(see FIG. 1(a)), and a backlight 4 as a light source arranged on the entire back surface of this element I (see FIG. 1(c)).
Equipped with As shown in FIG. 1(b), the backlights 4 are provided with a resin case 5 that also serves as a reflector and covers the back surface of the liquid crystal display element 1, and five backlights arranged alternately along the bottom of the case 5. Red and green light-emitting diodes 6.7 are lined up in rows as lamp means, and a milky-white, translucent resin 8 is filled in the case 5 to fill these light-emitting diodes 6.7 and diffuses light. Become. The five red and five green light emitting diodes 67 are connected in series by conductive wires 9 and 10, respectively.
Both ends of the conductor wires 9 and 10 each become a pair of power supply terminals 1112 that protrude from the case 5, and the entire resin 8 becomes uniformly red when the power supply terminal 11 is energized and green when the power supply terminal 12 is energized. This light illuminates the liquid crystal display element l in front of it.
It is transparent. FIG. 2 is a schematic block diagram of a control circuit etc. that supplies power to the light emitting diode 6.7. In the same figure, 2
1 is an operation panel having cooking menu keys, etc.; 22 is a magnetron drive circuit that drives a magnetron 23 that generates microwaves; 24 and 25 are LED lighting circuits that light red and green light emitting diodes 6 and 7, respectively; A memory 27 for storing control programs and various information operates the magnetron drive circuit 22 and the liquid crystal display element 1 in response to button operations on the operation panel 21 based on the information stored in the memory 26, and also operates an LED lighting circuit 24 as a control means. This is a microcomputer that selects either one of .25 and supplies power. The micro combi coater 27 is configured to supply power to the red LED lighting circuit 24 when the magnetron drive circuit 22 is in an operating state, and to the green LED lighting circuit 25 when the magnetron drive circuit 22 is in an inactive state. The liquid crystal display device having the above configuration operates as follows. Now, when the user presses a specific cooking menu key and a start button on the operation panel 2I of the microwave oven, the microcomputer 27 sets the operating time according to the pressed cooking menu to the magnetron drive circuit based on the stored information in the memory 26. 22, and starts timing to display the instantaneous time value and the word "heating" on the liquid crystal display element 1, and also starts supplying power to the red LED lighting circuit 24. Then, the red LED lighting circuit 24 turns on the power supply terminal 11 (first
The five red diodes 6 are energized via the backlight 4 (see figure (b)), and the entire backlight 4 glows red, and this red light passes around the display segment 2.3 and enters the user's eyes. Therefore, even if the user is far away from the microwave oven and cannot discern the word "heating," the user can easily and immediately visually tell that microwave heating is in progress by using the liquid crystal display element whose background lights up in red. Recognizable. Next, when the predetermined operating time ends, the microcomputer 27 stops the magnetron drive circuit 22, erases the "heating" display, and changes the power supply from the red to the green LED lighting circuit 25. Then, the five green diodes 7 are energized by the green LED lighting circuit 25 via the power supply terminal 12, and the entire background of the liquid crystal display element 1 similarly lights up in green. Therefore, even a user who is far away from the microwave oven can easily and immediately visually recognize that microwave heating has ended. In this way, the presence or absence of heating, which was conventionally indicated only by the word "heating" in small character segments, is now distinguished by the red and green light emitted from the entire liquid crystal display element 1 by the backlight 4. Even users who are far away from the microwave can easily and instantly know the operating status of the microwave, making the microwave more convenient to use. Fig. 3 is a front view of a modified example of the liquid crystal display device. This modified example 0 indicates the cooking mode (microwave heating, heater heating) from the conventional liquid crystal display element 41 described in FIG.
VEN", "MICRO"HEATER" and the "C00" character display indicating heating is removed.
A backlight 4 having a structure similar to that shown in FIG. 1(b) is used. However, the control program of the microcomputer 27 has been changed so that when the start button is not pressed on the operation panel 21, the green light emitting diode 7 will turn on, and when the microwave heating is selected and the start button is pressed, the red light emitting diode 6 will turn on.
When heater heating is selected and the start button is pressed, power is supplied to both light emitting diodes 6 and 7, respectively. Further, when a continuous cooking mode such as 10 minutes of microwave heating followed by 15 minutes of heater heating is selected on the operation panel 21, the same power supply is performed depending on the time. - Therefore, according to the above modification, the user can see the current cooking state even from a distance by emitting red light during microwave heating, orange light (a mixture of red and green) during heater heating, and green light when not heating. You can accurately grasp the mode,
The microwave oven becomes even more convenient to use. Furthermore, as mentioned above, since the character display of the cooking mode can be eliminated from the liquid crystal display element, the numeric segment 2' etc. can be made larger accordingly, which is convenient for the user. Furthermore, since the liquid crystal display element 1 emits light in three different colors, the design is also progressively innovative. Note that the lamp means of the present invention is not limited to the red and green light emitting diodes of the embodiment, but may also use blue light emitting diodes, or may use these three colors as a single color or a combination of colors depending on the number of cooking modes. Moreover, a tungsten lamp can also be used as the lamp means.

【Effect of the invention】

As is clear from the above description, the liquid crystal display device for a microwave oven of the present invention uses a plurality of lamp means emitting light of different colors from each other as a back light source of the liquid crystal display element, and the control means sets the lamps on the operation panel. Since any one or a combination of two or more of the above-mentioned lamp means is selected according to the cooking mode and power is supplied to the selected lamp means, even a user who is far away from the microwave oven can easily and immediately use the lamp means. You can know the operating status of the microwave oven,
The microwave becomes much easier to use.

[Brief explanation of drawings]

FIG. 1 is a front view, vertical sectional view, and horizontal sectional view showing one embodiment of the liquid crystal display device of the present invention, and FIG. 2 is a schematic block diagram of a control circuit that controls the liquid crystal display device etc. of FIG. 3 is a front view showing a modification of the present invention, FIG. 4 is a front view of a microwave oven, FIG. 5 is a sectional view taken along the line ■-V of FIG. 4 including a conventional liquid crystal display device, and FIG. FIG. 5 is a view taken along the line Vl-Vl in FIG. 5; l...Liquid crystal display element, 2...Numeric segment, 3
・Character segment, 4 ・Backlight, 6...Red light emitting diode, 7...Green light emitting diode, 21...Operation panel, 27
...Microcomputer.

Claims (2)

[Claims] (1) In a microwave oven liquid crystal display device in which light from a light source provided on the back is transmitted through the liquid crystal display element to illuminate display segments or the background thereof, the light source is replaced by a plurality of lamps that emit light of different colors. and any one of the lamp means according to the cooking mode set on the operation panel of the microwave oven.
1. A liquid crystal display device for a microwave oven, comprising control means for selecting one or more combinations and supplying power to the selected lamp means. (2) The liquid crystal display device for a microwave oven according to claim 1, wherein the lamp means is a light emitting diode, and the cooking modes are microwave heating, heater heating, and non-heating.