JPH0524007Y2 - - Google Patents

Description

[Detailed Description of the Invention] Field of Industrial Application The present invention relates to a vehicle liquid crystal instrument installed as a speedometer in a vehicle such as an automobile, and specifically relates to the structure of a lighting device.

〓Prior art〓 A conventional liquid crystal meter for a vehicle has a structure as shown in Fig. 3, in which a liquid crystal panel 12 is attached to a meter case 11 made of resin, etc. is a light source 14 such as an incandescent light bulb
The light from this light source 14 is uniformly distributed to the liquid crystal panel 1.
A light guide 13 made of transparent resin or the like is provided to diffuse and illuminate the display surface of 2, and a reflector 15 may be attached to the light guide 13 to increase illumination efficiency. be.

Generally, a drive circuit 16 for driving the liquid crystal panel 12 is also provided in the meter case 11, and the whole is sealed as a unit.
It is designed to reduce the number of man-hours required during vehicle manufacturing.

〓Problems to be solved by the invention〓 However, when this liquid crystal instrument is attached to a vehicle, especially a two-wheeled vehicle, and the surroundings are extremely bright during the daytime, the driver who is the viewer of this instrument Because the driver's visibility decreases as the driver adapts to the bright surroundings, the instrument lighting needs to be extremely bright to match the driver's decreased visibility. It is not possible to obtain a light source that is strong enough to correspond to sunlight, and even if one were available, it would not be possible to incorporate it into this type of meter case due to problems such as heat generation. It was impossible to illuminate the area, and it was dark and difficult to read, which created a major problem for the enforcement of safe driving.

〓Means for Solving the Problems〓 The present invention provides a liquid crystal panel, a light source that illuminates the liquid crystal panel from the back, In a vehicle instrument in which a light guide that diffuses the light from the light source as uniform light onto the display surface of the liquid crystal panel is integrated into a meter case, an end of the light guide is provided with lighting for the light source. An outside light lighting section is provided adjacent to the light guide, and the outside light lighting section is formed to have an upward slope with respect to the liquid crystal panel installation surface of the light guide, and the slope has a semi-transparent mirror or the above-mentioned light guide. To provide a liquid crystal meter for a vehicle, characterized in that a wavelength selection filter that does not transmit the main wavelength component of light emitted from a light source is attached and is incorporated so as to face an opening provided in the meter case. This solves the above-mentioned conventional problems.

〓Example〓 Next, the present invention will be explained in detail based on an example shown in the drawings.

What is indicated by the reference numeral 1 in FIG. 1 is a meter case, which is formed into a box shape using an opaque material such as resin. The same shall be incorporated. Further, a light guide 3 made of transparent resin or the like is incorporated on the back side of the liquid crystal panel 2. According to the present invention, an opening 1a is provided in the meter case 1, and the light guide 3 is installed in the opening 1a. 3 is assembled so that the end of one side of 3 becomes a protrusion 3a, and the end face of the protrusion 3a is formed to be an upward slope with respect to the installation surface of the liquid crystal panel 2, as shown in the figure, and this slope A semi-transparent mirror 7 is closely attached to the external light lighting section 3d.
It is said that

What is shown in FIG. 2 is for explaining the operating principle of the external light lighting section 3d.
When the light rays from the light source 4 shown by 2 reach this slope, they will be emitted from the light guide 3 having a high refractive index into the air at a lower level.
The light beam approaches the critical angle and is emitted into the air at an angle close to the slope, but at this time, since the semi-transparent mirror 7 is placed in close contact with the light guide, all the light rays are emitted into the light guide 3. This prevents light from being reflected by the outside light and leaking out from the outside light-collecting section 3d. on the other hand,
Since the external light indicated by the solid arrow SL enters the higher light guide 3 side from the air, which has a lower refractive index, it enters the light guide 3 side regardless of the presence or absence of the semi-transparent mirror 7. Further, the outside light lighting section 3d is configured to face a lighting window 8a provided on the instrument panel 8 of the vehicle, etc., so that the outside light SL
At this time, the other side is provided with a conventional light source 4 and a lighting section 3c, which are arranged side by side with the outside lighting section 3d. Daylighting section 3c, outside daylighting section 3
The light taken in from d is both emitted from the illumination section 3b, and illuminates the liquid crystal panel 2 from the back side. By doing this, the vehicle liquid crystal instrument of the present invention can
During the daytime, when the ambient brightness changes rapidly, by appropriately configuring the shape and dimensions of the external light lighting section 3d, the light will be illuminated with an appropriate brightness proportional to the external light, and the ambient brightness will not change as much. At night when the brightness does not change, it is illuminated by the light source 4 as before, and during this night, the outside light lighting section 3d
The light from the light source 4 does not leak from the light source 4. still,
The same effect can be obtained by replacing the semi-transparent mirror 7 with a mirror such as a dichroic mirror, which has the effect of not transmitting and reflecting the main wavelength component of the light emitted from the light source 4.
It will be effective. Further, when the light emitted from the light source 4 is monochromatic light, it is possible to use a filter that absorbs the color instead of the semi-transparent mirror 7. In this case, the end surface of the protrusion 3a of the light guide 3 can be It is not necessary to form it on a slope.

In addition, in the description of this embodiment, the external light lighting section 3d
Although the explanation has been made assuming that it protrudes from the opening 1a of the meter case 1, in actual implementation,
For example, in order to improve waterproof performance,
d may not protrude, and the opening 1a may be covered with a transparent member.The key point is to provide the light guide 3 with an outside light letting part 3d.

Furthermore, since the light source 4, reflection plate 5, and drive circuit 6 are completely the same as those of the conventional example, detailed explanations thereof will be omitted here.

<Effects of the invention> As explained above, according to the present invention, an LCD instrument for a vehicle is provided with an external light lighting section attached to the lighting section for the light source at the end of the light guide, and the outside light lighting section is provided at the end of the light guide. By incorporating the instrument so that it faces the opening in the meter case, the instrument surface is illuminated with a brightness proportional to the brightness of outside light during the day, making it easy to read at all times. This makes it possible to maintain the instrument surface at a level of brightness that is easy to use, making it possible to transmit information to the driver no matter how the outside light changes. It eliminates leakage and does not cause any hindrance to the driver or oncoming passengers, and is highly effective in encouraging safe driving.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing an embodiment of a liquid crystal meter for a vehicle according to the present invention, FIG. 2 is an explanatory view showing essential parts of the same embodiment, and FIG. 3 is a cross-sectional view showing a conventional example. 1...meter case, 1a...opening, 2...
...Liquid crystal panel, 3...Light guide, 3a...Protrusion, 3b...Lighting part, 3c...Lighting part, 3c...
...External light lighting section, 4...Light source, 5...Reflector, 6...
...Drive circuit, 7...Semi-transparent mirror, 8...Instrument panel, 8a...Lighting window.

Claims (1)

[Scope of utility model registration request] A vehicle meter in which a liquid crystal panel, a light source that illuminates the liquid crystal panel from the back, and a light guide that diffuses the light from the light source as uniform light onto the display surface of the liquid crystal panel are integrated into a meter case. , an external light lighting section is provided at an end of the light guide in conjunction with a lighting section for the light source, and the external light lighting section has an upward slope with respect to the liquid crystal panel installation surface of the light guide. A translucent mirror or a wavelength selection filter that does not transmit the main wavelength component of the light emitted from the light source is attached to this slope, and is incorporated so as to face the opening provided in the meter case. A liquid crystal instrument for vehicles that is characterized by: