JPH0521212B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a liquid crystal display device, and particularly to a liquid crystal display device suitable for use in a vehicle.

[Prior art]

Conventionally, in this type of liquid crystal display device, for example, a liquid crystal panel equipped with a normal information pattern display section that displays normal information such as the traveling speed of the vehicle and a warning information pattern display section that displays warning information such as left turn, etc. A plate-like prism is superimposed on the back surface of the liquid crystal panel, and a through hole is formed in a portion of the prism corresponding to a left turn pattern display part of the warning information pattern display part of the liquid crystal panel. At the same time, a reflective surface (by white printing, graining, etc.) is formed on the back surface of the prism, and the opaque substrate is superimposed on the reflective surface by inserting its guide tube into the through hole of the prism, and the color lens is attached to the reflective surface. The main lamp is installed in the guide tube in a state where it overlaps the reflective surface, and the main lamp is arranged on the side of the prism, and when the dimming circuit is not activated, the main lamp is inserted into the prism from the side in a predetermined direction. The light is incident at an incident amount, and when the dimming circuit is activated, the amount of light incident from the main lamp into the prism is reduced from the predetermined incident amount, and an auxiliary lamp is disposed behind the guide tube. and when the dimmer circuit is not activated or when the left turn indication is activated, light is made to enter the back surface of the liquid crystal panel from the auxiliary lamp through the guide tube and the color lens at the predetermined incident amount. There is.

In such a configuration, the liquid crystal panel displays the normal information and/or the liquid crystal panel while receiving the predetermined amount of light from the prism.
Warning information (excluding left turn information) is displayed at a predetermined brightness on the normal information pattern display section and/or warning information pattern display section (excluding the left turn pattern display section), and the reduced incident amount from the prism is displayed. A similar display is made with the brightness darker than the predetermined brightness when the light is received at Regardless of the operation, the left turn pattern display section displays a left turn with the predetermined brightness.

However, in such a liquid crystal display device, regardless of whether the auxiliary lamp is lit or not, the light that has entered the prism is obstructed by the guide tube and is unevenly distributed within the prism. Therefore, the content displayed on the liquid crystal panel has bright and dark parts, which impairs visibility. Moreover, when the auxiliary lamp is not lit while the main lamp is lit, the cross-sectional shape of the guide tube and the shade of the color lens are formed in the left turn pattern display section of the liquid crystal panel, detracting from the appearance.

[Purpose of the invention]

The present invention has been made in response to these problems, and its purpose is to make the brightness of the entire display surface of the liquid crystal panel as uniform as possible in a liquid crystal display device for a vehicle, and to The purpose is to improve the appearance of the entire surface.

[Structure of the invention]

In achieving this object, the present invention has a structural feature that includes first and second pattern display sections that are disposed on an instrument panel of a vehicle and display normal information and warning information regarding the vehicle, respectively. A liquid crystal panel consisting of a liquid crystal panel, a light guide plate superimposed on the back surface of the liquid crystal panel, and a light guide plate disposed on the side of the light guide plate so that when a dimming circuit is not activated, a predetermined amount of light enters the light guide plate from the side. A light source that allows light to enter the light guide plate and reduces the amount of light incident on the light guide plate from the predetermined amount of light when the light attenuation circuit is activated; a reflecting plate that reflects toward the back surface of the liquid crystal panel within the light guide plate, and the liquid crystal panel receives the predetermined incident amount or the reduced incident amount of light from the light guide plate, and the first and ( or) a liquid crystal display device configured to display the normal information and/or warning information on a second pattern display section,
A through hole is provided in a portion of the reflecting plate corresponding to the back of the second pattern display section of the liquid crystal panel, and an auxiliary light source is disposed behind the through hole, so that the When warning information is displayed on a liquid crystal panel, light is made to enter the light guide plate from the auxiliary light source through the through hole.

〔Effect of the invention〕

Therefore, in the present invention configured in this manner, as described above, the through hole is provided only in the reflecting plate, and the auxiliary light source is disposed behind the through hole, so that the light source is connected to the light source. The light incident on the light guide plate is uniformly distributed throughout the light guide plate and enters the back surface of the liquid crystal panel, so that the liquid crystal panel always has uniform brightness over its entire display surface. This will lead to improved visibility. Further, as described above, since the auxiliary light source is located behind the through hole of the reflection plate, the shape of the auxiliary light source when not emitting light or the shape of the through hole can be changed by passing the light guide plate onto the display surface of the liquid crystal panel. Undesirable shadows, such as shapes, are not formed, leading to an improvement in the appearance of the display surface of the liquid crystal panel.

〔Example〕

Hereinafter, one embodiment of the present invention will be explained with reference to the drawings. Fig. 1 and Fig. 2 show an example of a liquid crystal display device for a vehicle according to the present invention, and this liquid crystal display device is installed in an instrument in a vehicle interior of the vehicle. It is assembled into a maintenance panel (not shown). The liquid crystal display device has a cover 10 fixed to the inside of the instrument panel, and a liquid crystal panel 20 is mounted on the cover 10 so that its display surface 21 faces into the vehicle interior through the opening 11 of the cover 10. has been done. The liquid crystal panel 20 has a left turn pattern display section 2
1a, a right turn pattern display section 21b, a traveling speed pattern display section 21c, a remaining amount pattern display section 21d, and a temperature pattern display section 21e.
1a to 21e selectively (or both) display a left turn, a right turn, a running speed, a remaining amount of fuel, and an engine temperature for the vehicle.

The prism 30 has an opaque U-shaped frame plate 40.
(It is fixed to the instrument panel)
The prism 30 is attached to the inside and superimposed on the back surface 22 of the liquid crystal panel 20.
Except for the portion of the frame plate 40 corresponding to the through hole 41, the reflective surface 31 is formed by white printing or graining. Near one side 32 of this prism 30, a lamp 50 has its base connected to one side 6 of a printed circuit board 60.
When the lamp 50 is turned on, light enters the prism 30 from one side 32 thereof. This means that the light that enters the prism 30 from the lamp 50 is diffusely reflected within the prism 30 by the reflective surface 31 and the liquid crystal panel 2
This means that the light is uniformly distributed and incident over the entire back surface 22 of 0. However, the lamp 50 emits light at a first predetermined amount of light when the dimming circuit of the liquid crystal display device is not activated, and emits light at a second predetermined amount of light (less than the first predetermined amount of light) when the dimming circuit is activated. It's getting old. The dimming circuit is inactive when the vehicle is running during the day, and is activated when the vehicle is running in a tunnel or at night. Further, in FIG. 1, reference numeral 62 indicates a rod that supports the printed circuit board 60.

The through hole 41 of the frame plate 40 has a rectangular shape as shown in FIG. 2, and is formed at a position corresponding to the left turn pattern display section 21a of the liquid crystal panel 20, and the inner circumference of the through hole 41 is as shown in FIG. As can be easily understood from the figure, it is located outside the outline of the left turn pattern display section 21a. The frame plate 40 also includes a guide tube 42 that passes through a through hole 41 and opens directly to the back surface of the prism 30.
is integrally formed so as to pass through the printed circuit board 60 and extend to the left in FIG. This base portion is fitted into the intermediate portion of the printed circuit board 70 (fixed to the instrument panel). Thus, the lamp 70 is illuminated by the left turn pattern display section 21a of the liquid crystal panel 20 under the operation of the dimming circuit.
The light is turned on only when the vehicle is indicating a left turn, and the light is incident on the back surface 22 of the liquid crystal panel 20 corresponding to the left turn pattern display section 21a through the guide tube 42, the through hole 41, and the prism 30 at the first predetermined light intensity. let

In this embodiment configured as described above, since the dimming circuit is inactive when the vehicle is intermediately traveling, the lamp 50 is turned on and the first predetermined amount of light is emitted into the prism 30 from one side 32 thereof. Light is made incident, and the incident light is uniformly distributed throughout the interior of the prism 30 under the diffuse reflection effect of the reflective surface 31, and is made incident over the entire back surface 22 of the liquid crystal panel 20. Thereby, the display surface 21 is always maintained at a uniform brightness corresponding to the first predetermined light amount over the entire display surface 21 when the pattern display sections 21a to 21e of the liquid crystal panel 20 are not displaying information. Therefore, when the liquid crystal panel 20 displays the traveling speed, left turn, right turn, remaining fuel level, and engine temperature of the vehicle on its respective pattern display sections 21a to 21e, these display contents are displayed with uniform contrast. It is clearly visible at the base.

Furthermore, when the vehicle is running at night or in a tunnel, the lamp 5 is turned off under the operation of the dimming circuit.
0 causes light to enter the prism 30 from one side 32 at the second predetermined light intensity, and the prism 30 uniformly distributes the incident light as described above over the entire back surface 22 of the liquid crystal panel 20. Make it incident. As a result, each pattern display section 2 of the liquid crystal panel 20
Display surface 21 during non-display by 1a to 21e
can always be maintained at the brightness corresponding to the second predetermined light amount (that is, the brightness darker than the brightness corresponding to the first predetermined light amount) over the entire area. Therefore, the traveling speed displayed by the pattern display section 21c of the liquid crystal panel 20 can be clearly viewed with uniform contrast. In such a case, when the pattern display section 21a of the liquid crystal panel 20 indicates a left turn, the lamp 70 illuminates to display the pattern on the liquid crystal panel 20 through the guide cylinder 42, through hole 41 and prism 30 of the frame plate 40 with the first predetermined amount of light. Display section 21
Since light is incident on a, this pattern display section 2
Despite the above-mentioned dimmed illumination of the display surface 21, the display contents of 1a can be clearly recognized with brightness corresponding to the first predetermined amount of light.

In addition, since the through hole 41 of the frame plate 40, the guide cylinder 42, and the lamp 70 are isolated from the liquid crystal panel 20 by the prism 30 as described above, the lamp 70 is isolated from the liquid crystal panel 20 by the prism 30. The external shape when not lit, the shape of the through hole 41 of the frame plate 40, etc. are the display surface 21 of the liquid crystal panel 20.
LCD panel 2
This is useful for improving the appearance and visibility of the display surface 21 of 0.

In addition, in the embodiment, the liquid crystal panel 20
A frame board 40 corresponding to the left turn pattern display section 21a of
A through hole 41, a guide tube 42 and a lamp 70 are provided in the section.
However, the present invention is not limited to this, and the frame plate 40 corresponding to the right turn pattern display section 21b, remaining amount pattern display section 21c, temperature pattern display section 21e, and various other warning information pattern display sections of the liquid crystal panel 20 may be provided. Even if the parts are also provided with through holes, guide tubes and lamps, the same effects as in the above embodiment can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part of the apparatus of the present invention, and FIG. 2 is a front view thereof. Explanation of symbols, 20...Liquid crystal panel, 30...Prism, 31...Reflective surface, 40...Frame plate, 41...
...Through hole, 50, 70...Lamp.

Claims (1)

[Claims] 1. A liquid crystal panel disposed on the instrument panel of a vehicle and having first and second pattern display sections that display normal information and warning information regarding the vehicle, respectively, and a conductor polymerized on the back surface of the liquid crystal panel. a light plate, and a light attenuation circuit disposed on the side of the light guide plate to allow light to enter the light guide plate from the side at a predetermined amount when the light attenuation circuit is not in operation, and when the light attenuation circuit is in operation, the light guide plate a light source that reduces the amount of light incident on the liquid crystal panel from the predetermined amount; and a light source that is superimposed on the back surface of the light guide plate and reflects the light that is incident on the light guide plate toward the back surface of the liquid crystal panel within the light guide plate. a reflection plate, the liquid crystal panel receives the predetermined incident amount or its reduced incident amount of light from the light guide plate, and displays the normal information and ( or) in a liquid crystal display device configured to display warning information, a through hole is provided in a portion of the reflective plate corresponding to the back of the second pattern display portion of the liquid crystal panel;
An auxiliary light source is disposed behind the through hole, and light is incident from the auxiliary light source into the light guide plate through the through hole when warning information is displayed on the liquid crystal panel while the dimming circuit is activated. A liquid crystal display device for a vehicle, which is characterized by: