JP2615748B2 - Liquid crystal display - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device used for an electric cooker used in ordinary households.

2. Description of the Related Art Conventionally, this type of liquid crystal display device uses a reflection type liquid crystal display element. However, since those liquid crystal display elements do not emit light, various lighting devices are used. FIG. 4 shows an example of a liquid crystal display device having such illumination.
In FIG. 4, reference numeral 1 denotes a light emitting substrate.
Is mounted on the substrate 2 and connected to the chip-shaped pattern by bonding wires. Reference numeral 4 denotes a diffusing plate for diffusing the light of the LED 3, reference numeral 5 denotes a liquid crystal display element, and reference numeral 6 denotes a printed circuit board on which electronic components are mounted. Since the light from the LED 3 is received from behind via the diffusion plate 4, the display can be easily viewed even in a dark place. In addition, these lighting devices are configured to illuminate the entire surface of the liquid crystal display element 5 when starting operation.

However, in the above-described conventional configuration, when an attempt is made to display various operation modes using a large-sized liquid crystal display element 5, when the operation is started, the entire surface of the liquid crystal display element 5 becomes full. As a result, when the liquid crystal display element 5 is partially used, the display is sometimes difficult to understand.

The present invention has been made to solve the above-described problems, and has as its object to provide a liquid crystal display device capable of illuminating only a display portion.

Means for Solving the Problems In order to solve the above problems, the present invention provides a plurality of selectively operable LED drive elements connected to a microcomputer, and a plurality of drive controllable by the LED drive elements, and the plurality of LED drive elements. A plurality of LEDs each connected to the LED driving element, a box-shaped frame attached to surround the plurality of LEDs, and having an open front surface, and installed in a front opening of the frame. A liquid crystal display device includes a reflective liquid crystal display element and a diffusion plate located between the liquid crystal display element and the plurality of LEDs and disposed on the frame.

Operation According to the above configuration, since the plurality of LEDs mounted on the printed circuit board are driven and controlled by the plurality of LED driving elements connected to the microcomputer, the liquid crystal display element is partially controlled according to the operation mode. In the case of using a liquid crystal display element for display, it is possible to partially illuminate the liquid crystal display element by causing only the LED of that part to emit light by the LED driving element. As a result, even when a large liquid crystal display element is used, The display is very easy to see. Further, the configuration is such that the user can easily understand the current operation mode.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a circuit diagram of a liquid crystal display device according to an embodiment of the present invention, in which 11 is a microcomputer, and 12, 13, 14, and 15 are a plurality of LED driving elements connected to the microcomputer 11 and are constituted by transistors. Have been. Also, 16 and
17,18 and 19,20 and 21,22 and 23 are those LED drive elements 12,13,
It is a plurality of LEDs that are driven and controlled by 14,15. Reference numeral 24 denotes a liquid crystal display element for display connected to the microcomputer 11.

FIG. 2 is a partial cross-sectional view of an electric cooker provided with a liquid crystal display device according to an embodiment of the present invention, and FIG. 3 shows an assembly configuration of the liquid crystal display device. In the main body 25, a printed circuit board 26 on which electronic components and a plurality of diode-type LEDs 16 to 23 are mounted is disposed in front of the inside of the main body 25. 27 is a box-shaped frame with open front and rear faces.
A plurality of locking claws 28 are integrally formed on the upper and lower portions of the rear opening 27, and the locking claws 28 are inserted into holes 29 provided corresponding to the printed circuit board 26 to engage therewith. As a result, the frame 27 is attached to the printed board 26. In this case, the frame 27 is formed in a size that can surround the plurality of diode-type LEDs 16 to 23. Also the frame
A reflection type liquid crystal display (LCD) 24 is installed in the front opening of the LCD 27. The liquid crystal display 24 and a diode type LE
Diffusion plate 30 is installed on frame 27 so as to be located between D16 and D16-23 and on the back side of liquid crystal display element 24. The diffusion plate 30 is formed of a white-colored glass plate or a resin plate. Numeral 31 denotes a glass plate for protecting the liquid crystal display element 24. The glass plate 31 is disposed in the front opening 25a of the electric cooker main body 25 so as to face the liquid crystal display element 24. 32 is a control unit, and 33 is an input switch. The diode type LEDs 16 to 23 are LEDs 16 and 17, 18 and 19, 20 and 21,2.
2 and 23 are arranged as shown in FIG.

Next, the operation of the above configuration will be described. When the diode-type LEDs 16 to 23 mounted on the printed circuit board 26 emit light, the light of the LEDs 16 to 23 can illuminate the liquid crystal display element 24 from behind via the diffusion plate 30. In this case, since the plurality of LED driving elements 12 to 15 are driven according to the operation mode controlled by the microcomputer 11, the LED group arranged behind the liquid crystal display element 24 is such that all the LEDs 16 to 23 emit light. , Only LEDs 16 and 17 emit light,
And 17 and 22 and 23 emit light, so as to illuminate the portion of the liquid crystal display element 24 to be displayed,
LED drive elements 12, 13, 14, 15, LED drive element 12, LED drive element
12 and 15 drive and control the LEDs 16 to 23, the LEDs 16 and 17, the LEDs 16 and 17, and the LEDs 22 and 23, respectively.

Advantageous Effects of the Invention As described above, according to the present invention, a plurality of LED drive elements connected to a microcomputer drive and control a plurality of LEDs mounted on a printed circuit board. When partially used according to the operation mode, only the portion to be displayed can be illuminated, and thereby the operation mode can be emphasized and displayed, so that a display that is easy for the user to understand is obtained. Can be done. Further, even if one of the plurality of LEDs does not light due to a failure, light can be supplemented to some extent by the light emission of the adjacent LED.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a liquid crystal display device showing an embodiment of the present invention, FIG. 2 is a partial sectional view of an electric cooker provided with the liquid crystal display device, and FIG. 3 is an exploded perspective view of the liquid crystal display device. FIG. 4 is an exploded perspective view showing a conventional liquid crystal display device. 11… Microcomputer, 12,13,14,15 …… LED drive element, 16-23 …… LED, 24 …… Liquid crystal display element, 26 ……
Printed circuit board, 27 ... frame, 30 ... diffusion plate.

Continuation of the front page (56) References JP-A-49-134299 (JP, A) JP-A-61-198189 (JP, A) JP-A 62-140571 (JP, U) JP-A 61-182584 (JP, A) , U) Japanese Utility Model Showa 60-140084 (JP, U)

Claims (1)

(57) [Claims] 1. A plurality of selectively operable LED driving elements connected to a microcomputer, and a plurality of LED driving elements driven and controlled by the LED driving elements and connected to the plurality of LED driving elements one by one. An LED, a box-shaped frame attached to surround the plurality of LEDs, and having an open front, a reflective liquid crystal display element installed in a front opening of the frame, and the liquid crystal display element. A liquid crystal display device comprising a diffusion plate located between the plurality of LEDs and disposed on the frame.