JP2003344828A - Liquid crystal display means - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize a liquid crystal display part to be used in an operating part of a copying machine, a printer or the like at a low cost. <P>SOLUTION: A liquid crystal display means is provided with: a light emitting means to irradiate a liquid crystal plate from the rear surface side; a mounting means to mount the liquid crystal plate on a substrate and equipped with a reflection plane to reflect part of light emitted from the light emitter to the rear surface of the liquid crystal; and a diffusing means mounted on the rear surface of the liquid crystal plate to diffuse emitted light. The light emitting means and the mounting means are disposed on the substrate identical to the substrate on which the liquid crystal plate is disposed. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to copying, faxing,
In an image forming apparatus using electrophotography such as a printer, particularly relates to a backlight for a liquid crystal display, and particularly to a light emitting body that irradiates a liquid crystal plate, fixing the liquid crystal plate, and light emitted from the light emitting body. Is characterized in that the sheet metal for the purpose of reflecting light and the liquid crystal plate are on the same substrate.

[0002]

2. Description of the Related Art A conventional liquid crystal display backlight technology is a liquid crystal comprising a liquid crystal plate and a backlight module 50 for illuminating the liquid crystal plate from the back so as to bring up characters, pictures and the like displayed on the liquid crystal plate. Display devices are widely used. The liquid crystal display device A includes a liquid crystal plate 101 and a backlight module 50 disposed below the liquid crystal plate 101, as shown in FIG. The backlight 102 is provided. Backlight module 50
In the configuration, the backlight 102 is provided with a plurality of LED chips 104 and the like on the periphery of the substrate 103,
4 is formed by placing a transparent casing 105 on the substrate 103 so as to cover 4. In this transparent casing 105, a reflective film 107 or the like is attached to the upper and side surfaces except a display port 106 for illuminating characters and pictures displayed on the liquid crystal plate 101, and a similar reflective film 107 is further provided on the substrate 10.
The light emitted from the LED chip 104 also passes through the optical path L and is guided to the display opening 106 as scattered light, and irradiates the display opening 106.

Further, in a backlight module 60 as shown in FIG. 6 which is also shown as a conventional example, the LED module 104 is provided in the backlight module 60 not only in the peripheral portion of the substrate 103 but also in the entire surface of the substrate including immediately below the display port 106. It is arranged in multiple. In this case, the housing 105
In some cases, a diffusion film 108 or the like for diffusing the direct light from the LED chip 104 is attached to the portion of the display port 106 in, the back surface of the liquid crystal plate 101, or the like.

[0004]

Since the above-mentioned conventional technique uses the backlight module, in order to configure the liquid crystal display unit, the substrate having the input means, the liquid crystal display unit, and the backlight unit are used. It was necessary to combine many modules with, and there was a problem that the manufacturing cost increased.

Further, in a liquid crystal display backlight such as that shown in FIG. 5, in which the number of LED chips is reduced and reflected light is used, sufficient brightness can be obtained without using high-intensity LED chips. I couldn't get it. Even if a high-brightness LED chip is used, the brightness of the backlight largely depends on the performance of the reflective film attached to the inside of the housing or the substrate, and unless a high-performance reflective film is used, the LED chip emits light. The emitted light cannot be efficiently collected, and the brightness of the backlight may be reduced or the light may be uneven. As a result, even if a high-brightness type LED chip is used in order to reduce the number of LEDs, a reflective film having good performance is used, so that there is little effect on cost reduction. Furthermore, the manufacturing process itself, in which the reflective film is attached to the inside of the housing or the substrate, requires difficulty and precision, which increases the manufacturing cost.

Further, in a liquid crystal display backlight as shown in FIG. 6, a plurality of LED chips and the like are provided immediately below the display port, and most of the light of the backlight is made by direct light. In this case, it is generally difficult to uniformly illuminate the entire area of the display port. In particular, when the liquid crystal plate is a transmissive type in order to efficiently use the light emitted from a light emitting body such as an LED chip and to increase the brightness of the backlight, the LED chip can be seen through the transmissive liquid crystal plate. Will end up.

In order to prevent this, a diffusion film or the like is used. In this case, the haze (the degree of haze of the film) is so high that the light emitting body such as the LED chip cannot be seen through the transmissive liquid crystal plate. However, the constraint that a film having a high light transmittance must be used increases, and needless to say, the cost increases as the film becomes such a film. Further, the use of the diffusion film itself leads to an increase in cost. Note that the above-described light emitting body such as the LED chip is the same even if it is a discrete type. Moreover, the structure of the housing itself is not simple, which leads to an increase in cost and the cost of dies and the like. Further, in the conventional technology, the one for fixing the liquid crystal plate and the one for reflecting the light emitted from the light emitter are separately made and used, so that the mold cost, the parts cost, the manufacturing cost, the management cost, etc. The cost has increased significantly.

[0008]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides a light emitting means for irradiating a liquid crystal plate with light from the back side, and the light emitting body for mounting the liquid crystal plate on a substrate. A mounting means having a reflecting surface for reflecting a part of the light emitted from the liquid crystal toward the back surface of the liquid crystal; and a diffusing means provided on the back surface of the liquid crystal plate for diffusing the emitted light, The light emitting means and the mounting means are arranged on the same substrate as the substrate on which the liquid crystal plate is arranged. As a result, it is possible to eliminate the housing and the reflection film that are generally used in the prior art, and it is possible to significantly reduce the cost.

Further, since the housing itself is eliminated, the manufacturing process which requires the difficulty and precision of attaching the reflection film inside the housing is eliminated, and the manufacturing cost is reduced. Further, unlike the case where a plurality of LED chips or other light emitting bodies are provided directly below the display port and most of the light of the backlight is emitted by direct light, the liquid crystal plate is reflected by reflecting the light emitted from the light emitting bodies. Since the irradiation mechanism is used, it is not necessary to provide a large number of light emitters to cover the area of the liquid crystal plate, the number of light emitters can be reduced, and the cost can be reduced.

Further, by adjusting the distance between the liquid crystal plate and the light emitter, it is possible to prevent the light emitter from being seen through the liquid crystal plate even when a transmissive liquid crystal plate is used.
It is not necessary to use a diffusion film with high haze, and it can be realized with an inexpensive sheet.

Further, in the case of utilizing reflected light as in the present invention, it is generally difficult to obtain sufficient brightness without using a high-luminance type light emitter, but with the mechanism of the present invention Since the number of times is one and the reflection path is not complicated as shown in FIG. 1, light attenuation is small, and sufficient brightness can be obtained without using a high-luminance type light emitter.

Further, by using the sheet metal according to the present invention, it is possible to perform the two functions of fixing the liquid crystal plate and reflecting the light emitted from the light emitting body. Since it is not necessary to separately prepare the one that reflects the light emitted from the light emitter, the cost can be significantly reduced in terms of die cost, parts cost, manufacturing cost and the like.

Further, according to a second aspect of the present invention, since the reflecting surface of the above-mentioned mounting means is subjected to a surface treatment capable of reflecting light while diffusing the light, it is irradiated from the light emitting body. The diffused light is diffused at the same time as it is reflected, and the above-mentioned diffusion film is no longer necessary, and the parts cost, management cost, manufacturing cost, etc. can be greatly reduced.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below with reference to the drawings. In addition, this embodiment is an example,
Various modifications can be considered without departing from the spirit of the present invention. An embodiment of the liquid crystal display means of the present invention will be described with reference to FIG. The liquid crystal display means indicated by B as a whole is
In general, it is composed of an input substrate 3 capable of inputting various kinds of commands to a display unit, a liquid crystal component 1 for displaying various information, and a backlight unit 20 for irradiating the liquid crystal component 1 with light from the back side. Has been done.

Various electrical components including an input switch 22 are attached to the board 3, and when used in a copying machine, various information such as the number of copies and the paper size can be input. The liquid crystal plate 1 is directly attached to the substrate 3 by a metal support 9 at the end portion (left side in FIG. 1) of the substrate 3. Similarly, a plurality of LED chips 4 for irradiating the liquid crystal plate with light from the back side are attached as light emitting means to the end portion of the substrate 3.

The metal support 9 has a structure as shown in FIG. 2, and has a liquid crystal support 29 for supporting the liquid crystal component 1 on its surface,
And a leg portion 30 for attaching the supporting portion to the substrate. A receiving portion 32 for receiving the liquid crystal plate 1 is provided below the liquid crystal support portion 29. This receiving portion 32
Can be formed, for example, by sheet metal processing for bending the liquid crystal support portion 29 made of metal.

On the other hand, on the lower side of the leg portion 30, a protruding portion 34 for mounting in the opening 36 (see FIG. 3) provided in the substrate 3 is formed. The liquid crystal support 29 is
The metal support 9 attached to the substrate 3 is inclined at a predetermined angle θ with respect to the substrate 3.

Further, inside the liquid crystal support portion 29, an irradiation opening 38 for irradiating the backlight light is formed. The opening 38 is formed by bending the reflective surface 10 from the inside of the liquid crystal support 29. Thus, the metal support 9 can be manufactured at a low cost by pressing one metal plate to form the liquid crystal support 29, the legs 30, the liquid crystal receiver 32, and the reflection surface 10.

As shown in FIG. 4, the reflecting surface 10 and the liquid crystal support 29 are bent at an angle of θ '.

In this embodiment, the angles θ and θ ′ described above are formed to be 25 degrees and 32 degrees, respectively, which is the upper surface (about 90 cm to 90 cm or more) of a printer or copying machine which normally uses a liquid crystal display. It is assumed that it is provided at 110 cm), and can be designed in a preferable range as appropriate.

Next, a method of attaching the liquid crystal plate 1 to the metal support 9 will be described with reference to FIGS.
First, a light diffusing film 40 as a light diffusing means is placed so as to cover the opening 38 (see FIG. 2) of the metal support 9, and the light diffusing film 40 is sandwiched between the liquid crystal component 1 and the receiving portion 32 at the lower side. To support the liquid crystal support 29
Paste it on. A known adhesive means such as an adhesive or a double-sided tape is used as the attaching means. Next, the metal support 9 to which the liquid crystal component 1 is bonded in this manner is attached to the substrate 3
It is possible to easily assemble it by inserting it into the opening 36 formed at the predetermined position. In this case, as shown in FIG. 3, by forming the two protrusions 42 and 43 on the leg portion 30 by pressing, the substrate 3 can be positioned between the protrusions 42 and 43, and mounting is extremely easy. Becomes

Next, the backlight for the liquid crystal display section will be described mainly with reference to FIGS. In this embodiment, LEDs are used as the light source for the backlight. Specifically, referring to FIG. 3, light is emitted from LED chips 20 arranged in a line at the end of substrate 3 in a substantially horizontal direction. This illuminating light is once reflected by the reflecting surface 10 arranged at a distance M from the LED chip.
The liquid crystal support portion 2 is passed through the optical path L as shown in (side sectional view).
The light enters the liquid crystal component 1 from the back side through the opening 36 formed in 9. At this time, the action of the light diffusion film 40 causes the LED
The light source is diffused and can be illuminated uniformly. Furthermore,
By appropriately roughening the reflecting surface 10, the LED light can be diffused even on this reflecting surface, and a more uniform light can be obtained.
Can be incident on 1. Alternatively, by increasing the degree of rough surface, it is possible to obtain uniform incident light without using the diffusion film 40.

The liquid crystal display means B described above is used by being incorporated in a display section housing provided on the upper surface of the casing of an image forming apparatus such as a copying machine or a printer. Alternatively, it is also possible to cover the liquid crystal display means B with an appropriate housing and mount it as a liquid crystal display member on a copying machine or a printer for use.

[0024]

As is apparent from the above description, according to the present invention, it is possible to eliminate the case used in the prior art, the die cost is also reduced, and the cost can be significantly reduced. it can. In addition, since there is no housing itself, the difficulty of attaching the reflective film inside the housing and the manufacturing process that requires precision are eliminated, and the manufacturing cost is reduced.
The effect is that it is easy to make. In addition, since the light reflection path is short and the light can be condensed efficiently, it is not necessary to use an expensive high-luminance type light emitter, and the number can be reduced, so the cost of parts can be expected to be greatly reduced. it can. Further, even when the liquid crystal plate is a transmissive type, in the structure of the present invention, it is not necessary to use an expensive diffusion film having a high haze and a high light transmittance, so that the cost can be reduced. In the reflective film, the object itself is unnecessary, which leads to cost reduction. In addition, by using the sheet metal of the present invention, it is possible to perform two functions of fixing the liquid crystal plate and reflecting the light emitted from the light emitting body. Since it is not necessary to separately make the one that reflects the light emitted from the body, it can be expected that the cost can be significantly reduced in terms of die cost, parts cost, manufacturing cost, and the like.

Further, in the above-mentioned sheet metal, the reflecting surface for reflecting the light emitted from the light-emitting body is processed, and surface treatment such as unevenness is applied to reflect the light emitted on the reflecting surface of the sheet metal. At the same time, it can be diffused. As a result, the above-mentioned diffusion film becomes unnecessary, the parts cost of the diffusion film, the management cost, the manufacturing cost, etc. are eliminated, and the cost can be greatly reduced.

[Brief description of drawings]

FIG. 1 is a perspective view showing a specific example of a liquid crystal display means of the present invention.

FIG. 2 is a perspective view showing a configuration of a support metal piece for supporting a liquid crystal plate used in the liquid crystal display means of the present invention.

FIG. 3 is a perspective view of the liquid crystal display unit of FIG. 1 viewed from another angle.

FIG. 4 is a schematic diagram illustrating an irradiation state of backlight light.

FIG. 5 is a diagram showing an example of a conventional backlight.

FIG. 6 is a diagram showing another example of a conventional backlight.

[Explanation of symbols]

1: Liquid crystal parts 3: substrate 4, 20: LED chip 9: Metal support 40: Light diffusion film A: Liquid crystal display device B: Liquid crystal display means

Claims (2)

[Claims] 1. A light emitting means for irradiating a liquid crystal plate with light from the back side, and mounting the liquid crystal plate on a substrate and reflecting a part of light emitted from the light emitting body toward the back surface of the liquid crystal. An attaching means having a reflecting surface and a diffusing means provided on the back surface of the liquid crystal plate for diffusing emitted light are provided, and the light emitting means and the attaching means are the same as the substrate on which the liquid crystal plate is arranged. Liquid crystal display means arranged on a substrate. 2. The liquid crystal display means according to claim 1, wherein the reflecting surface of the mounting means is subjected to a surface treatment capable of reflecting the light while diffusing the light.