JP2003016823A - Lighting system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate lowering of tansmittance due to a space in between sheet-like components in a lighting system, to efficiently emit light of a light source to a liquid crystal panel, and to facilitate assembling. SOLUTION: This lighting system has a light guide panel 2 for guiding the light from the light source, a reflecting sheet 1 for upwardly reflecting the light incident into the light guide panel 2, and a diffusion sheet 3 for diffusion- transmitting the light or a lens sheet 4 for convegence-transmitting the light, or both of them. They are formed of resin and are overlapped in layers to constitute the lighting system.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lighting device mainly used for a liquid crystal display device.

[0002]

2. Description of the Related Art In recent years, display devices for information devices such as notebook personal computers and word processors, or display devices for video devices such as portable televisions, video movies, car navigation systems, etc.
Liquid crystal display devices have been widely used due to their low power consumption. These liquid crystal display devices
In order to realize a bright display screen, there are many cases in which a built-in illumination unit applies illumination light from behind the display element.

FIG. 2 is a sectional view showing the structure of a liquid crystal display device having a conventional backlight type illuminating device. On the back surface of the light guide plate 2 that has been subjected to equalization so as to effectively use the light of the light source (not shown), the reflection plate 1 for reflecting the light incident on the light guide plate 2 upward is arranged, and the surface of the light guide plate 2 is arranged. A diffuser plate 3 that diffuses and transmits light and a lens sheet 4 that collects and transmits light are layered, and their peripheral portions are fixed with an adhesive 7, respectively, so that the entire peripheral portion is wrapped. It is configured to be held by the housing 5 and the back cover 9. The reflection plate 1, the light guide plate 2, the diffusion plate 3, and the lens sheet 4 are plate-shaped (sheet-shaped) and are formed to have substantially the same shape.

In such an illuminating device, a liquid crystal display panel P is arranged on the irradiation surface side (upper side in the drawing) (for this reason, the illuminating device is also called a backlight device), a metal frame or the like is attached, It becomes a liquid crystal display device. The liquid crystal display panel P displays characters and images. A pair of transparent substrates on which display electrodes are laid face each other at appropriate intervals, a liquid crystal material is injected into the intervals, and the periphery of the transparent substrate is sealed. It is composed of a liquid crystal panel formed by sealing with a material, a plurality of drive circuits arranged around the liquid crystal panel for displaying the liquid crystal panel, a board on which the drive circuits are mounted, and the like.

[0005]

However, in the conventional lighting device, the plate-shaped (sheet-shaped) parts are fixed using the adhesive 7 or the tape, so that the space 8 is formed between the parts. . Due to this space 8, the light transmittance of the light source decreases, and the efficiency of the light emitted to the liquid crystal panel decreases,
Therefore, there is a problem that the brightness of the liquid crystal display device is reduced. In addition, in order to minimize the space 8, it is necessary to take extra care when bonding so that thin sheet-like parts do not wrinkle or sag, and when the bonding fails, do not damage the parts. It was difficult to remove and remove the adhesive. The present invention solves the above problems, and an object of the present invention is to provide a lighting device that efficiently emits light from a light source to a liquid crystal display panel P and can be easily assembled.

[0006]

The invention according to claim 1 of the present invention comprises a light guide plate for guiding the light from the light source and a reflecting plate for reflecting the light incident on the light guide plate upward. Is an illuminating device made of resin and configured to be layered. In the invention according to claim 2 of the present invention, a light guide plate for guiding light from a light source, a reflection plate for reflecting light incident on the light guide plate upward, and a diffusion plate or light for diffusing and transmitting light are provided. An illuminating device that has a lens sheet that collects and transmits light, or both, and that is made of resin and is layered in layers.

According to the present invention, since the plate-shaped (sheet-shaped) parts constituting the lighting device are formed of resin, static electricity is generated between the resin parts, and an adhesive, a tape or the like is applied between the parts. It can be fixed without using. Moreover, even if the components are erroneously placed, they can be easily peeled off and the components can be redone many times.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention.
Will be described with reference to. FIG. 1 is a cross-sectional view of the configuration of a liquid crystal display device having an illuminating device (backlight type) of the present invention. On the back surface of the light guide plate 2 that is uniformized so that the light from the light source (not shown) is effectively used, the reflector plate 1 that reflects the light incident on the light guide plate 2 upward is arranged, and the surface of the light guide plate 2 is arranged. The diffuser plate 3 for diffusing and transmitting the light and the lens sheet 4 for collecting and transmitting the light are stacked in layers, and are held by the housing 5 and the back cover 9 so as to wrap the periphery thereof.

The light guide plate 2 is made of a resin material such as acryl which has the optimum optical characteristics represented by the transmittance and the refractive index required for light transmission. The light guide plate 2 has a dot pattern, a groove pattern (not shown) or the like whose shape is changed according to the distance from the light source on the back surface.

The reflection plate 1 has a role of reflecting the light traveling outward from the back surface of the light guide plate 2 back into the light guide plate 2 and returning the illumination light efficiently from the front surface of the light guide plate 2. It is arranged along the back side. The reflector 1 is made of a white resin film having a high reflectance.

The diffusion plate 3 and the lens sheet 4 are arranged on the surface of the light guide plate 2 and have a role of allowing the light incident from the light guide plate to be efficiently emitted from the surface without being biased, and a resin film is mainly used. Has been done. Depending on the specifications of the device to which the lighting device is attached, the diffuser plate 3 and the lens sheet 4 may not be used, or another optical component may be used. The reflection plate 1, the light guide plate 2, the diffusion plate 3, and the lens sheet 4 are plate-shaped (sheet-shaped) and are formed to have substantially the same shape.

The housing 5 holds a stack of the reflection plate 1, the light guide plate 2, the diffusion plate 3, and the lens sheet 4, and at the same time, together with the back cover 9, a liquid crystal panel (not shown) and a light source (not shown). Also has a role to hold. Examples of the material of the housing 5 include polycarbonate resin. The back cover 9 is often made of metal such as stainless steel or aluminum, but may be made of plastic or other material.

In such an illuminating device, a liquid crystal display panel P is arranged on the front surface side (upper side) thereof, and a metal frame or the like is attached to the liquid crystal display device. Liquid crystal display panel P
Is for displaying characters and images. A pair of transparent substrates on which display electrodes are laid face each other at appropriate intervals, a liquid crystal material is injected into the intervals, and the periphery of the transparent substrates is sealed with a sealing material. And a plurality of driving circuits arranged around the liquid crystal panel for displaying the liquid crystal panel, a board on which the driving circuits are mounted, and the like.

In the illuminating device having the above structure, plate-like (sheet-like) parts and the housing 5 which are stacked in layers.
Are all made of resin or the like. For this reason, static electricity is generated on the contact surface 6 of each component, and due to the static electricity force, they are naturally fixed by simply stacking them when assembling.
Further, even if the position of the component is wrong, it can be easily peeled off and redone. Even after assembly, the plate-shaped (sheet-shaped) parts are not displaced by vibration.

[0016]

As described above, according to the present invention, a plate-shaped (sheet-shaped) component in a lighting device is fixed by using a resin component to generate static electricity between the components. You can At the time of assembly, it is fixed naturally by just stacking the parts, and since it can be redone as many times as necessary, it can be easily assembled without failure.
In addition, since static electricity is generated between the plate-shaped (sheet-shaped) component and the housing, even if vibration is applied after the assembly, it is difficult to shift. In addition, since no adhesives or tapes are used to fix each component, there is no decrease in transmittance due to the adhesives or tapes used in conventional fixing parts, and the light from the light source is effectively incident on the liquid crystal display panel side. The brightness of the display device can be increased. Furthermore, by not using an adhesive or a tape, the step of fixing with an adhesive or a tape becomes unnecessary, and the layer thickness of the entire lighting device becomes thin, so that it is possible to achieve economy, weight reduction, and thickness reduction.

[0017]

[Brief description of drawings]

FIG. 1 is a configuration cross-sectional view of a lighting device according to an embodiment of the present invention.

FIG. 2 is a sectional view showing the structure of a conventional lighting device.

[Explanation of symbols]

1 reflector 2 Light guide plate 3 diffuser 4 lens sheet 5 housing 6 contact surface 7 adhesive 8 spaces 9 Back cover P liquid crystal display panel

Front page continuation (51) Int.Cl. ⁷ Identification code FI theme code (reference) // F21Y 103: 00 F21Y 103: 00

Claims (2)

[Claims] 1. A light guide plate for guiding light from a light source, and a reflection plate for reflecting light incident on the light guide plate upward, which are made of resin and are layered in layers. Lighting equipment. 2. A light guide plate that guides light from a light source, a reflection plate that reflects upward light incident on the light guide plate, a diffuser plate that diffuses and transmits light, or a lens sheet that condenses and transmits light, or the same. An illumination device that has both of them, and is made of resin and is formed by stacking layers.