JPS60252324A - Liquid crystal display device for vehicle - Google Patents

Abstract

PURPOSE:To make the brightness of the whole of the display surface of a liquid crystal panel uniform and to improve the beauty of the external appearence of the whole of the display surface by providing a through-hole in a part of a reflective plate corresponding to the rear of the second pattern display part of the liquid crystal panel and arranging an auxiliary light source in the rear of the through-hole. CONSTITUTION:When a vehicle is run in the daytime, a lamp 50 is lit with a first prescribed quantity of light, and the light is made incident on the inside of a prism 30 from one side 32 of the prism 30, and the light is incident on the whole of a rear face 22 of a liquid crystal panel 20 by the diffuse reflection action of a reflective face 31; and when the vehicle is run at night, the lamp 50 is lit with the second prescribed quantity of light, and the light is made incident on the inside of the prism 30 from one side 32 of the prism 30 and is incident on the whole of the rear face 22 of the liquid crystal panel 20. In this case, when left turn is displayed on a pattern display part 21a of the liquid crystal panel 20, the lamp 70 is lit with the first prescribed quantity of light, and the light is made incident on the pattern display part 21a through a guide cylinder 42, a through-hole 41, and the prism 30, and display contents on the display part 21a are distinctly recognized visually in brightness corresponding to the first prescribed quantity of light independently of dimming illumination to a display surface.

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 converts the normal information and/or warning information (excluding left turn information) into the normal information while receiving light from the prism at the predetermined incident amount. The pattern display section and/or the warning information pattern display section (excluding the left turn pattern display section) are displayed at a predetermined brightness, and the predetermined information is displayed while receiving light from the prism at the reduced incident amount. A similar display is performed in a manner darker than the brightness, and when light is received at the predetermined incident amount from the color lens of the guide tube, the left turn pattern display section displays the above information regardless of whether the dimming circuit is activated or not. A left turn is displayed with a predetermined brightness.

However, in such a liquid crystal display device, the light that enters the prism causes the auxiliary lamp to turn on and
Regardless of whether the light is lit or not, the light is obstructed by the guide tube and is distributed unevenly within the prism, so that bright and dark areas appear in the display content of the liquid crystal panel, impeding 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 the above-mentioned problems, and its purpose is to provide a liquid crystal display device for a vehicle.
The purpose is to make the brightness of the entire display surface of the liquid crystal panel as uniform as possible and to improve the appearance of the entire display 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, and when the dimming U path 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 reflector that reflects toward the back surface of the liquid crystal panel within the light guide plate, the liquid crystal panel receiving the predetermined incident amount or the reduced incident amount of light from the light guide plate; (or) The normal information and (or) ! on the second pattern display section. In the liquid crystal display device configured to display blue information, a through hole is provided in a portion of the reflective plate corresponding to the back of the second pattern display section of the liquid crystal panel, and an auxiliary light source is arranged behind the through hole. and when the warning information is displayed on the liquid crystal panel under the operation of the dimming circuit, 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 is incident on the back surface of the liquid crystal panel, and as a result, the liquid crystal panel always displays a uniform display over its entire display surface. This ensures brightness and improves 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. [Example] Hereinafter, an example of the present invention will be described with reference to the drawings.
1 and 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 assembled into an instrument panel (not shown) in the cabin of the vehicle. The liquid crystal display device has a cover 10 fixed inside the instrument panel, and this cover 1
A liquid crystal panel 20 is mounted on the vehicle with its display surface 21 facing into the vehicle interior through the opening 11 of the cover 10.

The liquid crystal panel 20 includes a left turn pattern display section 21a, a right turn pattern display section 21b, a travel speed pattern display section 21c,
Remaining amount pattern display section 21d and temperature pattern display section 21
e, and each display section 218 to 21e receives light from a plate prism 30, which will be described later, to display a left turn indication for the vehicle.
A right turn display, a traveling speed display, a remaining fuel amount display, and an engine temperature display are selectively (or both) displayed.

The prism 30 is mounted inside an opaque U-shaped frame plate 40 (fixed to the instrument panel) and superimposed on the back surface 22 of the liquid crystal panel 20. On the back surface of the prism 30, The reflective surface 31 is formed by white printing or graining except for the portion corresponding to the through hole 41 of the frame plate 400. 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 is uniformly distributed over the entire back surface 22 of the liquid crystal panel 20 and enters the prism 30 . 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 has become. 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 rond supporting the printed circuit board 60. As shown in FIG.

As shown in FIG. 2, the through hole 41 of the frame plate 40 has a rectangular shape and is formed at a position corresponding to the left turn pattern display section 21'a of the liquid crystal panel 20. As can be easily understood from FIG. 2, it is located outside the outline of the left turn pattern display section 21a. In addition, the frame board 40 includes
A guide tube 42 that opens directly to the back surface of the prism 30 through the through hole 41 is integrally formed so as to extend to the left in FIG. 1 through the printed circuit board 60. At the lower end in the figure, a lamp 70 is inserted into the lower part of the guide tube 42, and its base is fitted into an intermediate portion of a printed circuit board 70 (fixed to the instrument panel). Thus, the lamp 70 is turned on only when the left turn pattern display section 21a of the liquid crystal panel 20 indicates a left turn of the vehicle under the operation of the dimming circuit, and the lamp 70 illuminates the guide tube 42, the through hole 41, and the like with the first predetermined light amount. Light is made to pass through the prism 30 and enter a portion of the back surface 22 of the liquid crystal panel 20 corresponding to the left turn pattern display section 21a.

In this embodiment configured as described above, since the dimming circuit is inactive when the vehicle is in intermediate running, the lamp 50 is turned on to illuminate the prism 3 with the first predetermined light amount.
0 from one side 32 of the liquid crystal panel 20, and the prism 30 uniformly distributes the incident light throughout its interior under the diffuse reflection effect of the reflective surface 31, thereby covering the entire back surface 22 of the liquid crystal panel 20. It is made incident over a period of time. Thereby, when the pattern display sections 21a to 21e of the liquid crystal panel 20 are not displaying, the entire display surface 21 is always maintained at a uniform brightness corresponding to the first predetermined light amount. Therefore, when the liquid crystal panel 20 displays the traveling speed, left turn, right turn, remaining fuel level, and engine temperature of the vehicle in each pattern display section 21a to zte, these display contents are displayed with uniform contrast. clearly visible.

Further, when the vehicle is running at night or in a tunnel, the lamp 50 causes light to enter the prism 30 from one side 32 at the second predetermined light intensity under the operation of the dimming circuit, and the prism 30 The incident light is uniformly distributed in the same manner as described above and is made to be incident over the entire back surface 22 of the liquid crystal panel 20. As a result, the display surface 21 when each pattern display section 21a to 21e of the liquid crystal panel 20 is not displaying information.
can always be maintained at a brightness corresponding to the second predetermined light amount, that is, a brightness darker than the brightness corresponding to the first predetermined light amount. 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. Since light is incident on the table base 21a, the display contents by the pattern display section 2]a can be clearly displayed at a brightness corresponding to the first predetermined light amount, despite the above-mentioned dimmed illumination for the display surface 21. Visible.

In addition, the through hole 41 of the frame plate 40, the guide tube 42, and the lamp 7
0 is displayed on the liquid crystal panel 2 by the prism 3o as described above.
0, the external shape of the lamp 70 when it is not lit, the shape of the through hole 41 of the frame plate 4o, etc. will be the same as that of the liquid crystal panel 2o, regardless of whether the dimming circuit is activated or not.
The shadows are not formed on the display surface 21 of the liquid crystal panel 20, which helps improve the appearance and visibility of the display surface 21 of the liquid crystal panel 20.

In the above embodiment, the through hole 41, the guide tube 42, and the 7° angle of the opening were provided in the portion of the frame plate 4° corresponding to the left turn pattern display section 21a of the liquid crystal panel 2°. Not only the right turn pattern display section 21b of the liquid crystal panel 20, the remaining amount pattern display section 21C1, the temperature pattern display section 21e, and the parts of the frame plate 40 corresponding to various other warning information pattern display sections also have one through hole and a guide tube. Even if a lamp is provided, the same effects as in the above embodiment can be achieved.

[Brief explanation of drawings]

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. Applicant Nippondenso Co., Ltd. Agent Patent Attorney Teru Hase - 1st J! 1 21st! I n 20 2 no

Claims (1)

[Claims] A liquid crystal panel disposed on an instrument panel of a vehicle and having first and second pattern display sections that respectively display normal information and warning information regarding the vehicle; and a light guide plate superimposed on the back surface of the liquid crystal panel. and is disposed on the side of the light guide plate, so that when the light attenuation circuit is not in operation, light is drawn into the light guide plate from the side at a predetermined amount of incidence, and when the light attenuation circuit is in operation, it is directed into the light guide plate. a light source that reduces the incident amount of light from the predetermined incident 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. the liquid crystal panel receives the predetermined amount of incident light or its reduced amount of light from the light guide plate, and displays the normal information and/or information on the first and/or second pattern display section. ) 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, and an auxiliary light source is provided behind the through hole. A liquid crystal display for a vehicle, characterized in that the liquid crystal display is arranged such that 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 under the operation of the dimming circuit. Display device.