JPS58166379A - Lighting apparatus for liquid crystal display unit - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an illumination device for a liquid crystal display.

Since a liquid crystal display itself does not have a light emitting function, a lighting device is required when using a device having a liquid crystal display in a dark place. Conventionally, when using a device with a liquid crystal display in a dark place, as shown in Figs. A tungsten light bulb 7 for illumination is attached to the side of the liquid crystal display 5 of the device 6 with the liquid crystal display aS attached to the substrate 4, and the liquid Ii &
A method of illuminating the inside of the display device 5 was generally used.

However, tungsten light bulbs have major drawbacks, such as the fact that the filament breaks due to vibration, etc., or the bulb needs to be replaced frequently due to the filament's lifespan, and if the filament of a tungsten light bulb breaks, the display on the liquid crystal display becomes unreadable. ing.

Additionally, in order to make the display easier to read, if a large liquid crystal display is used, the tungsten bulb for illumination must also be of a size commensurate with the display, which requires a large amount of power consumption. becomes.

In addition, many of the portable appliances have a relatively small power supply capacity, and the tungsten bulb for illumination cannot be made very large, so there is a drawback that sufficient illuminance cannot be obtained.

The present invention has been made to eliminate one or more drawbacks, and by applying a light emitting diode conventionally used as an indicator light to an 1IIf1 device of a liquid crystal display, the liquid crystal display can be changed by the disconnection of the conventional tungsten light bulb. To eliminate the disadvantage of not being able to continue displaying the display, and to diffuse and reflect the light from a light emitting diode near a point light source onto the display surface of the liquid crystal display (to further reduce the illuminance of one display area). It is an object of the present invention to provide an illumination device for a liquid crystal display device whose display is uniform and easy to read.

One embodiment of the present invention will be explained in detail below. Figure 3 is a plan view of an illumination device for a liquid crystal display according to an embodiment of the present invention, and Figure 4 shows Figure 83 in the forward direction. FIG. 5 is a plan view of another embodiment of the present invention, and FIG. FIG. 3 is a side view showing a cross section of the main part of Il when viewed from the forward direction.

111 to FIG. 6, the same numbers indicate the same members.

As shown in FIGS. 3 and 4, a lighting device 8 for a liquid crystal display according to an embodiment of the present invention is composed of one or more light emitting diodes 9 and one reflecting plate 10. and 1
One or more light emitting diodes 9 are arranged on the printed circuit board 4K in the device 6 and on the diagonal upper blade of the liquid crystal display device, and the 1 reflection plate 1O is attached to the cover 2 facing the light emitting surface of the light emitting diode 90. ing.

Further, the irradiation angle of the light emitting diode 9 and the angle of reflection @10 are each adjusted so that the illuminance of the display surface of the display device 5 is maximized.

Next, the lighting device 118 of the liquid crystal display having the above configuration
The effect of this will be explained.

When the light switch (not shown) is turned on, the light emitting diode lights up, and a portion of the light emitted from the light emitting diode 9 illuminates the liquid crystal display 5. Other σ) A part of the light hits the reflector 10 and the reflected light illuminates the display surface of the liquid crystal display lamp S. Since the reflected light is greater than 0, the display image of the liquid crystal display l becomes uniform and illumination with less unevenness is achieved. .

The illumination device 11 of the liquid crystal display lamp according to another embodiment of the present invention shown in FIG.
Optical axis rf of one or more light emitting diodes 9 mounted with the optical axis facing upward (cover 〇1) and the light emitting diode 9 mounted on the back side of the cover 2: [Reflectors mounted facing each other so as not to intersect The irradiation angle of the light emitting diode is the light reflected by the reflection plate 12, and the liquid crystal display 6
11) @ The illuminance on the water surface is adjusted to 5 to maximize it. Next, the illumination 1111 of the liquid crystal display having the above configuration
The effect of No. 11 will be explained. When the power switch (not shown) is turned on, the light emitting diode lights up and the light emitted from the light emitting diode 1 is reflected by the reflection 91M and displayed on the liquid crystal display 5.
The display surface is illuminated with almost uniform illuminance.

In this method, since the M projection distance can be substantially increased, the distance between the liquid crystal display 5 and the cover 2 can be shortened, and the thickness of the device 603 case 3 can be reduced.

As described above, the lighting device for a liquid crystal display of the present invention does not use a conventional tungsten bulb, but uses a light emitting diode and a reflector to illuminate the display surface of the liquid crystal display. It is possible to provide an illumination device for a liquid crystal display that can illuminate with almost uniform illuminance, eliminate bulb burnout, which is a drawback when using a tungsten bulb, and consume less power.

[Brief explanation of the drawings] Fig. 1 is a plan view of a conventional display illumination device. Fig. 2 is a plan view of a conventional display lighting device.
Figure 3 is a plan view of one embodiment of the present invention. Figure 4 is a sharp view of the ■ arrow in Figure 3. Figure 5 is a plan view of another embodiment of moxibustion according to the present invention. Fifth
■Arrow view of the figure 1...Window plate, 2...Cover, 3...Case, 4...
... Printed circuit board, 5... Liquid crystal display, 6... Equipment, 8. H...Lighting device for liquid crystal display, A...Light emitting diode, 10.12...Reflector. Patent applicant Shibaura Seisakusho Co., Ltd.

Claims (1)

[Scope of Claims] (1) One or more light emitting diodes that illuminate all of the liquid crystal display devices, and one or more light emitting diodes that diffusely reflect the light of the first and second light diodes to make the illuminance of the display section of the liquid crystal display approximately #t uniform. (2) K11l is attached diagonally above the liquid crystal display. - One or more light emitting diodes and a direct light beam mounted opposite to the front Ie* light diode. A lighting device for a liquid crystal display according to Claims - Clause 1. The wA bright side of the liquid crystal display according to claim 1 is composed of a blue light diode and a direct radiation plate mounted oppositely so as not to be perpendicular to the optical axis of the light emitting diode.