JPH0434422Y2 - - Google Patents

Description

[Detailed explanation of the invention] (A) Industrial application field The present invention relates to a vehicle instrument using a liquid crystal display device, and particularly in the daytime, it is possible to use outside light as illumination light for the liquid crystal display. It is about things.

(a) Conventional technology Conventionally, when using a liquid crystal display device in a vehicle instrument, Japanese Patent Application Laid-open Nos. 53-101995, 56-14281, and 56
- As disclosed in No. 14295, etc., a light source is provided to illuminate the liquid crystal display device, and the light source is turned on all the time or only at night in conjunction with the vehicle's light switch to illuminate the liquid crystal display device. Ta.

By the way, Utility Model No. 50-87892, No. 57-142775
As disclosed in the above publication, there is a known device that uses external light to reflect the display on a liquid crystal display device on a mirror for viewing, and it is being considered to apply this to vehicle instruments.

(C) Problems with the Prior Art When a liquid crystal display device that uses outside light as illumination light is applied to a vehicle instrument, it is necessary to take in outside light during the day and use an illumination light source at night. The front window (windshield) seems to be the most suitable location for letting in outside light due to the location of the instruments, but in order to let in light from the window, the structure must be such that light can pass between the liquid crystal display and the window. Therefore, when the illumination light source is turned on at night, a portion of the illumination light is reflected by the window and is visible to the driver, making it difficult to see in front of the driver, which is dangerous.

(d) Purpose of the invention In view of the above problems, this invention prevents light from leaking toward the window at night, and allows outside light to enter during the day.
The purpose is to configure a vehicle instrument using a liquid crystal display device.

(e) Summary of the invention In order to achieve the above object, the present invention provides a light source that can utilize external light entering the vehicle through the vehicle window as illumination light for a liquid crystal display device, and that also provides a light source for night illumination of the liquid crystal display device. A shutter member having a light-transmitting portion is disposed between the liquid crystal display device and the window of the vehicle, and a shape memory alloy is connected directly or indirectly to the shutter member near the light source. It is characterized by the fact that it is equipped with.

(f) Embodiment FIG. 1 is a sectional view of the main parts showing an embodiment of the present invention. In the figure, reference numeral 1 denotes a meter visor integrated with an instrument panel of a vehicle, and a resin glass 2 is fixed to the meter visor 1 at a position above a liquid crystal display device to be described later. 3 is a liquid crystal display device, which includes a liquid crystal cell 4, a light diffusion plate 5,
It consists of a light guide plate 6, and the light guide plate 6, light diffusing plate 5, and liquid crystal cell 4 are stacked in this order from the top.

Reference numeral 7 denotes a mirror member so that the display displayed on the liquid crystal display device 3 reflected on the mirror member 7 can be viewed by the driver through the opening 8 of the meter visor 1. Reference numeral 9 denotes a circuit board having a display drive circuit, which in this case is disposed below the mirror member 7 and connected to the liquid crystal cell 4 through lead wires 10.

Reference numeral 11 denotes a fixing plate having a plurality of punch holes 12, and a shutter 14 having a plurality of punch holes 13 is disposed below the fixing plate 11. This shutter 14 is held by a holding member 15 attached to the meter visor 1, and is arranged so as to be slidable in the left-right direction in the figure. 16 is a return spring member fixed at both ends to the shutter 14 and the meter visor 1, and 17 is a return spring member fixed at both ends to the shutter 14 and the meter visor 1 in the opposite direction to the return spring member 16. This is a moving spring member made of memory alloy.

Numeral 18 is a light source that allows light to enter the light guide plate 6, and is turned on when the driver closes the vehicle lighting switch at night or the like. This light source 18 is disposed near the moving spring member 17, and is configured so that its heat is transmitted to the moving spring member 17.

Note that 19 is a viewing glass fixed to the opening of the meter visor 1, 20 is a finely uneven surface formed on the upper surface of the light guide plate 6, and 21 is a front window (windshield) of the vehicle.

The operation of the above configuration will be explained.

The liquid crystal display device 3 has an upside-down display because the display is reflected on the mirror member 7 and is visually recognized, and is of a transmission type that transmits light from the rear to the front for display. During the day, the light source 18 is off, so there is no heat generation, and the return spring member 16 pulls the shutter 14 against the moving spring member 17, thereby communicating the hole 12 of the fixed plate 11 with the hole 13 of the shutter 14. let Therefore, light that has mainly passed through the front window 21 of the vehicle is irradiated onto the light guide plate 6 through the holes 12 and 13. This irradiated light reaches the mirror member 7 through the light guide plate 6 of the liquid crystal display device 3, the light diffuser plate 5, and the transparent portion of the liquid crystal cell 4 determined by the display drive circuit, and the mirror member 7 is When viewed through the viewing window glass 19, either a positive or negative display can be seen depending on the transparent and non-transparent portions of the liquid crystal cell 4.

Next, when the light source 18 is turned on at night, the light emitted from the light source 18 enters the light guide plate 6, and the light guide plate 6
It is diffusely reflected by the uneven surface 20 on the top surface and travels to the light diffusing plate 5 and the liquid level cell 4, allowing the driver to see the display as in the case of the daytime, but it is reflected upward from the uneven surface 20 on the top surface of the light guide plate 6. There is also light leaking out. When the light source 18 is turned on, the moving spring member 17 made of a shape memory alloy disposed near the light source 18 is heated and changes to a pre-memorized contracted shape. Then, the return spring member 16 extends without being able to resist the force of the moving spring member 17, the shutter 14 slides, and the hole 12 of the fixed plate 11 and the hole 13 of the shutter 14 do not communicate with each other, and the hole 12 is closed. A portion of the shutter 14 other than the hole 13 is closed, and a portion of the fixed plate 11 other than the hole 12 is closed. Therefore, the light leaking upward from the light guide plate 6 does not reach the front window 21 of the vehicle due to the shutter 14 and the fixed plate 11, and the light reflected on the front window 21 is visible to the driver. This problem can be solved.

FIG. 2 shows another embodiment of the present invention, in which the same components as in FIG. 1 are given the same reference numerals. In this case, the meter visor 1 has a plurality of glasses 2A and a cover 2B that makes the others opaque is fixed to the meter visor 1, and a window glass 19 for viewing the liquid crystal display device 3.
This embodiment differs from the above embodiment in that the light passing through the glass 2A is reflected by the mirror member 7 and becomes transmitted light for illuminating the liquid crystal display device 3, and that a fixing plate is not provided. differ.

During the daytime, the light passing through the glass 2A of the cover 2B is reflected by the mirror member 7 (any material that can reflect light) as described above, and becomes illumination light for the liquid crystal display device 3, and at night, the light passes through the glass 2A of the cover 2B. The light that enters the light guide plate 6 by turning on the light source 18 becomes illumination light for the liquid crystal display device 3 . At this time, from the light guide plate 6 to the mirror member 7
A moving spring member 1 made of a shape memory alloy is used to prevent light leaking to the side from being reflected by the mirror member 7 and reaching the front glass (not shown) through the glass 2A.
7 is arranged near the light source 18, one end of this moving spring member 17 is connected to the visor 2, and the other end is connected to the shutter 1.
It is attached to 4. That is, when the light source 18 is turned off, the hole 13 of the shutter 14 is located at a position that almost corresponds to the glass 2A of the cover 2B, allowing light to pass therethrough, and when the moving spring member 17 receives heat when the light source 18 is turned on, the hole 13 of the cover 2B closes. The position corresponds to the opaque area, preventing light from passing through.

FIG. 3 shows still another embodiment, in which a liquid crystal display device does not use a mirror member and a light guide plate, but instead includes a liquid crystal cell 4 and a reflective diffuser plate 5A at the mirror member arrangement position in the above embodiment. 3, and during the daytime, a cover 2B similar to that shown in the embodiment of FIG. 2 above is provided.
The light that passes through the glass 2A and the hole 13 of the shutter 14 reaches the front surface of the liquid crystal cell 4, passes through the transparent part of the liquid crystal cell 4 determined by the drive circuit of the circuit board 9, is reflected by the reflective diffuser plate 5A, and returns to the liquid crystal. It exits to the front side through the cell 4 and is visible to the driver through the viewing window glass 19.

On the other hand, at night, the light source 18 disposed on the back side of the meter visor 1 emits light to display the same display as in the daytime.
The moving spring member 17 made of a shape memory alloy disposed near 8 contracts against the force of the return spring member 16, and the shutter 14 slides.
The cutout hole 13 and the non-transparent part of the cover 2B overlap to prevent the liquid crystal display device 3 from being seen in the front window (not shown) of the vehicle.

Each of the embodiments described above can also provide the same effects as the embodiment shown in FIG. 1 above.

In the embodiment shown in FIG. 2, as shown in FIG. 4, for example, white printing 31 is applied in a plurality of strips on the surface of the light guide plate 6 on the mirror member 7 side, and black printing 3 is applied on top of the white printing 31.
2 is applied, the shutter 14 is arranged in a layered manner on the mirror member 7 side of the light guide plate 6, and the slide mechanism and the moving spring member 17 change their shapes due to the heat generated by the light emission of the light source 18. The black print 32 and the hole 13 of the shutter 14 may be configured to face each other so that no light passes through. However, the white print 31 is for reflecting the light emitted from the light source 18 toward the liquid crystal cell 4 side, and may be replaced by other means (for example, a finely uneven surface).

In addition, although the shapes of the shape memory alloys have all been described as coil-shaped spring members, other shapes may be used as long as they can function in the same way. 11 and Figure 2,
It is provided as appropriate to match the shape of the glass 2A of the guide 2B in FIG. 3, the black print 32 in FIG. It is sufficient that the shutters are connected directly or indirectly so that the shutters can be moved.

(G) Effect of the invention According to the invention, during the daytime, light incident from outside the vehicle is used as illumination light for the liquid crystal display device,
At night, the light emitted by the light source is used as illumination light for the liquid crystal display device, and the conventional drawback that the light emitted from the light source is reflected on the front window of the vehicle and seen by the driver can be solved. At this time, since the shutter is moved by a shape memory alloy and the heat generated by the light emission of the light source is used to heat the shape memory alloy, there is also the advantage that there is no need to newly provide a shape memory alloy heating element. ing.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing one embodiment of the present invention, FIG. 2 is a diagram showing another embodiment of the present invention, FIG. 3 is a diagram showing still another embodiment of the present invention, and FIG. 4 is a diagram showing another embodiment of the present invention. FIG. 2 is a diagram showing a modification of the embodiment in FIG. 2; 1...Meter visor, 2...Resin glass, 2A
...Glass, 2B...Cover, 3...Liquid crystal display device, 4...Liquid crystal cell, 5...Light diffusion plate, 5A...
Reflection diffuser plate, 6... Light guide plate, 7... Mirror member, 11
... fixed plate, 12 ... hole in fixed plate, 13 ... hole in shutter, 14 ... shutter, 16 ... spring member for return, 17 ... spring member for movement made of shape memory alloy, 18 ... light source , 21...Front window of the vehicle.

Claims (1)

[Scope of utility model registration request] A vehicle that can utilize outside light entering the vehicle through a vehicle window as illumination light for a liquid crystal display device, and has a light source for night illumination of the liquid crystal display device,
A shutter member having a light-transmitting portion is disposed between the liquid crystal display device and the window of the vehicle, and a shape memory alloy is disposed near the light source that is directly or indirectly connected to the shutter member. A vehicle instrument characterized by: