JPS6239422Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a device that displays numerical values and the like using a reflective liquid crystal panel, and particularly relates to a lighting device for a liquid crystal panel.

In general, a reflective liquid crystal panel always requires a predetermined amount of light from in front of the display surface of the liquid crystal panel.

FIG. 3 shows a conventional example of this type of liquid crystal display device 01, in which a liquid crystal panel 02 is disposed on a printed circuit board 04 via conductive rubber 03, one end of which abuts against the front surface of the liquid crystal panel 02 and the other end of which is fixed to the printed circuit board 04 by a panel retainer 05 made of metal or synthetic resin which is attached to the printed circuit board 04.

On the printed circuit board 04 near the liquid crystal panel 02,
An illumination light source 06 is attached, and the light beam of this light source 06 is transmitted to the case (not shown) of the liquid crystal display device 01.
The light is reflected by a reflective surface 07a on the rear surface of the dial 07 located in front of the liquid crystal panel 02 attached to the screen, and illuminates the display surface of the liquid crystal panel 02.

In such a liquid crystal display device 01, depending on the position of the light source 06 attached to the printed circuit board 04, unevenness occurs in the light beam illuminating the display surface of the liquid crystal panel 02.

Moreover, if the wiring of the light source 06 is determined preferentially, restrictions will be imposed on mounting electronic components (not shown) for driving the liquid crystal panel 02 on the printed circuit board 04.

This idea solves these problems by
A panel holder for holding down the liquid crystal panel was formed from a light guiding material, and a light incident part through which the light beam from the light source was incident was formed in a part of this light guiding material.

FIG. 1 shows a liquid crystal display device 1 to which an embodiment of this invention is applied, in which a well-known reflective liquid crystal panel 2 is placed on a printed circuit board 4 via a conductive rubber 3 and fixed by a panel retainer 5. That is,
This panel retainer 5 is made of a light guiding material, for example, acrylic resin, and is formed into a hollow substantially prismatic shape surrounding the side peripheral surface of the liquid crystal panel 2, and one end thereof has a hook 5a that comes into contact with the front surface of the liquid crystal panel 2. A reflective surface 5b is formed at the tip of the hook 5a to reflect a light beam, which will be described later, to the display surface of the liquid crystal panel 2. The other end is in surface contact with the printed circuit board 4, and a portion of the other end has a surface that penetrates the printed circuit board 4. A fastening portion 5c is formed on the rear surface of the printed circuit board 4 to be heat-stamped. Also,
The panel retainer 5 is formed with a light entrance portion 5d that surrounds the illumination light source 6 attached to the printed circuit board 4.

7 is located in front of the liquid crystal panel 2, has a display window 7a through which the display surface of the liquid crystal panel 2 can be viewed, and has a scale part 7b printed with characters, symbols, etc. on the surface. It is a dial plate that can be attached to

In this way, according to this embodiment, the panel retainer 5 for fixing the liquid crystal panel 2 is made of acrylic resin, and by adding the function of guiding the light rays of the illumination light source 6, it is possible to achieve
It can enhance the lighting effect. That is, the light beam from the light source 6 travels from the light entrance part 5d into the inside of the panel holder 5, is guided to the vicinity of the display surface of the liquid crystal panel 2, and is reflected toward the display surface of the liquid crystal panel 2 by the reflective surface 5b at the tip thereof. As shown in the conventional example in Fig. 3,
Compared to a configuration in which illumination is performed by reflection from the rear surface of the dial 07 or the inner surface of the case, a sufficient illumination effect can be obtained with a small light source 6 with a small capacity. Therefore, the liquid crystal panel 2 can be illuminated efficiently.

Further, since the panel retainer 5 has the added function of guiding the light beam of the illumination light source 6, there is an advantage that no additional external structure is required compared to the conventional structure.

Furthermore, since the light entrance portion 5d only needs to be formed in a part of the panel holder 5, the position of the light source 6 attached to the printed circuit board 4 can be set relatively freely.

Further, even if the panel presser 5 is formed of acrylic resin, the ability to fix the liquid crystal panel 2 will not be reduced.

FIG. 2 shows another embodiment of this invention;
Although the structure is similar to that of the illustrated embodiment, a portion of a hook 5a formed at one end of the panel retainer 5 is formed to protrude so as to cover the entire display surface of the liquid crystal panel 2.

According to this embodiment, the same effects as those of the previous embodiments can of course be obtained, but the light source that travels from the light entrance portion 5d into the inside of the panel holder 5 can reach the panel very close to the display surface of the liquid crystal panel 2. Since the light is guided by the hook 5a of the presser 5, the lighting efficiency can be further improved.

In this way, this invention forms the panel holder with a light guide material, one end of which is formed into a hook shape that comes into contact with the liquid crystal panel, and the other end is fixed to the substrate.
By providing a light incident part on a part of the panel holder and forming a reflective surface on the tip of the hook to reflect the light rays to the liquid crystal panel display surface, it is possible to avoid adding expensive separate parts, and The lighting effect of the liquid crystal display device can be increased without reducing the ability to fix the liquid crystal panel.

Furthermore, it is not subject to limitations when arranging the illumination light source,
The degree of freedom in placement increases, making it easier to do artwork on the board. Therefore, the arrangement of the electronic components for driving the liquid crystal panel arranged on the board is not limited, and as a result, it is not only possible to change the design of the case shape of the liquid crystal display device, but also to make it possible to Since it is possible to minimize the influence between the two, it is convenient to use it for vehicle instruments, which are limited in their location.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an embodiment of this invention.
FIG. 2 is a sectional view of another embodiment same as the above. FIG. 3 is a sectional view of a conventional example. 1: Liquid crystal display device, 2: Liquid crystal cell, 4: Printed circuit board, 5: Panel holder, 6: Light source.

Claims (1)

[Scope of utility model registration request] In a liquid crystal display device in which a reflective liquid crystal panel is placed on a substrate via a conductive material and fixed to the substrate by a panel holder, the panel holder is made of a light guide material and a hook is formed at one end to abut the front surface of the liquid crystal panel. A fixing part for fixing the board was formed at the other end, a light entrance part was formed in a part to take in the light from the light source, and a reflective surface was formed on the hook to reflect the incident light to the liquid crystal panel display surface. LCD display device.