JPH06478B2 - Liquid crystal display for vehicle - Google Patents

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly to a liquid crystal display device suitable for use in vehicles. [Prior Art] Conventionally, in a liquid crystal display device of this type, for example, a normal information pattern display unit for displaying normal information such as the traveling speed of a vehicle and an abnormal state of a headlight, oil, a door, and various other actuating devices A liquid crystal panel having a centralized warning information pattern display unit for displaying warning information is disposed on an instrument panel of a vehicle, and a plate-shaped prism is superposed on the back surface of the liquid crystal panel, and the centralized warning information pattern display unit of the liquid crystal panel is arranged. A through hole is formed in the portion of the prism corresponding to, and a reflective surface (by white printing, grain, etc.) is formed on the back surface of the prism, an opaque substrate is superposed on the reflective surface, and the concentrated warning is given to the opaque substrate. Inserting a plurality of guide tubes provided corresponding to each warning information pattern display portion of the information pattern display portion into the through hole of the prism,
Each color lens is mounted in each of the guide tubes in a state of being superposed on the reflecting surface, and a main lamp is arranged on the side of the prism, and when the dimming circuit is not operating, the main lamp is connected to the prism. A predetermined amount of light is incident on the side of the prism, and when the dimming circuit is activated, the amount of light incident from the main lamp into the prism is reduced to be smaller than the predetermined amount of incident light. A lamp is disposed in each of the guide tubes, and when the concentrated warning information is displayed when the dimming circuit is not operating or is operating, the auxiliary lamps pass through the guide tubes and the color lenses of the liquid crystal panel. Light is incident on the back surface at the predetermined incident amount. Therefore, in such a configuration, the normal information is displayed on the normal information pattern display unit with a predetermined brightness while the liquid crystal panel receives light from the prism at the predetermined incident amount. Then, the same display is performed by making it darker than the predetermined brightness in the state where the light is received from the prism at the reduced incident amount, and the light is emitted at the predetermined incident amount from the color lens in each of the guide tubes. When the light is received, the concentration warning information is displayed with the predetermined brightness on the concentration warning information pattern display unit regardless of whether the dimming circuit is activated or deactivated. [Problems to be Solved by the Invention] However, in such a liquid crystal display device, light incident on the prism is hampered by the guide tubes regardless of whether the auxiliary lamps are turned on or off. Since the light is distributed in the prism in a non-uniform state, the display content of the liquid crystal panel has a bright portion and a dark portion, which hinders visibility. Further, when the auxiliary lamps are not lit while the main lamp is lit, the cross-sectional shape of the guide tubes and the shade of the color lenses are formed in the concentrated warning information pattern display section of the liquid crystal panel, which impairs the appearance. . [Object of the Invention] In order to cope with such a situation, the present invention makes the brightness of the entire display surface of the liquid crystal panel of the vehicle liquid crystal display device as uniform as possible and improves the appearance of the entire display surface. It is something that tries to improve. [Means for Solving the Problems] In solving the above problems, in the present invention, a normal information pattern display unit and a centralized unit which are arranged on an instrument panel of a vehicle and respectively display normal information and warning information about the vehicle. A liquid crystal panel having a warning information pattern display section, a light guide plate superposed on the back surface of the liquid crystal panel, a light source arranged laterally of the light guide plate, and a dimming circuit for limiting the light amount of the light source. And a reflection surface that reflects light incident on the light guide plate on the back surface of the light guide plate toward the back surface of the liquid crystal panel within the light guide plate, and when the dimming circuit is not operating, A predetermined incident amount of light is made incident on the light guide plate, and a reduced incident amount of light is made incident on the light guide plate when the dimming circuit is operated, and the liquid crystal panel is made to make the predetermined incident amount or the decrease from the light guide plate. Entering In the liquid crystal display device configured to display the normal information on the normal information pattern display unit in response to a radiant amount of light and to display the warning information on the concentrated warning information pattern display unit, the concentration of the liquid crystal panel A notch that is formed at a predetermined depth on the back surface of the light guide plate corresponding to the back of the warning information pattern display portion and that opens to the side of the remaining side of the light guide plate, and an inner peripheral surface of the notch of the light guide plate. A reflective surface continuously superposed on the reflective surface superposed on the back surface, an auxiliary light guide plate fitted through a partition having a through hole in the notch, and an auxiliary light guide plate superposed on the back surface of the auxiliary light guide plate to assist the auxiliary light guide plate. An auxiliary reflection surface for reflecting the light incident on the light guide plate toward the back surface of the concentrated warning information pattern display section of the liquid crystal panel in the auxiliary light guide plate, and arranged on the remaining side of the auxiliary light guide plate. Warning information table for the LCD panel At the time of showing, an auxiliary light source for making light incident at a predetermined incident amount is provided in the auxiliary light guide plate. [Effects of the Invention] With the above configuration of the present invention, however, the light incident from the light source into the light guide plate is uniformly distributed over the entire light guide plate, and the back surface of the liquid crystal panel is displayed. As a result, the liquid crystal panel can always secure a uniform brightness over the entire surface thereof, which leads to an improvement in its visibility. Further, as in the above-mentioned configuration, since the partition wall is located in the notch of the light guide plate and the auxiliary light source is located on the side of the remaining part of the light guide plate, the conductive light is guided to the display surface of the liquid crystal panel. Undesirable shadows such as the shape of the auxiliary light source or the shape of the through hole at the time of non-light emission are not formed through the light plate, which leads to improvement of appearance beauty on the surface of the liquid crystal panel. In addition, as described above, the light from the auxiliary light source is made to enter the auxiliary light guide plate from the side, and the incident light is passed through the through hole of the partition wall based on the reflection effect of the auxiliary reflection surface. Since the light is reflected toward the plate, even if the concentrated warning information pattern display portion of the liquid crystal panel covers a large area, it is only necessary to provide each single auxiliary light guide plate, auxiliary light source and auxiliary reflection surface. The warning information by the concentrated warning information pattern display section of the liquid crystal panel can be clearly displayed with uniform brightness. [Embodiment] An embodiment of the present invention will be described below with reference to the drawings.
FIG. 2 and FIG. 2 show an example of a vehicle liquid crystal display device according to the present invention, and this liquid crystal display device is mounted on an instrument panel (not shown) in the vehicle compartment of the vehicle. The liquid crystal display device has a cover 10 fixed to the inside of the instrument panel. In the cover 10, the liquid crystal panel 20 exposes its display surface 20a through the opening 11 of the cover 10 to the interior of the vehicle. It is installed. The liquid crystal panel 20 includes a traveling speed pattern display unit 21, a left turn pattern display unit 22, a right turn pattern display unit 23, a fuel remaining amount pattern display unit 24, and a temperature pattern display unit 25, which form a normal information pattern display unit. Cage,
Further, it has a concentrated warning information pattern display section 26.
Here, a plate-shaped prism 30 which is a light guide plate described later
Also, receiving light from the plate-shaped prism 70 that is an auxiliary light guide plate, the display units 21 to 26 display the traveling speed of the vehicle, the left turn display, the right turn display, the remaining fuel amount display, the engine temperature display, and the concentrated warning information. Display selectively or together. Here, the concentrated warning information pattern display portion 26 of the liquid crystal panel 20 is configured by arranging ten rectangular warning information pattern display portions 26a to 26j in a quadrangular shape (see FIG. 2). Information pattern display portions 26a, 2
6b, 26c, 26d, 26e, 26f, 26g, 26
h, 26i, and 26j correspond to respective abnormal states of the headlight, brake, oil, alternator, door, choke, hazard switch, transmission, and air conditioner rear differential mode and rear fog mode of the vehicle. The prism 30, which is a light guide plate, is an opaque U-shaped frame plate 40 (fixed to the instrument panel).
It is mounted inside and overlaps with the back surface 20b of the liquid crystal panel 20, and the back surface of the prism 30 has the liquid crystal panel 2
A notch 32 opening from one side 31 of the prism 30 is formed with a predetermined depth in a portion corresponding to the concentration warning information pattern display portion 0 of 0, and the remaining back surface of the prism 30 and the inner periphery of the notch 32. The reflective surface 33 is formed by white printing or graining over the surface (excluding the portion corresponding to the through hole 71a of the partition wall 71 described later). In addition, a lamp 50 serving as a light source is provided near one side 34 of the prism 30.
The base portion of the lamp 50 is fitted to the one side portion 61 of the printed circuit board 60, and the lamp 50 causes the light to enter the prism 30 from the one side 34 when the lamp 50 is turned on. This means that the light that has entered the prism 30 from the lamp 50 is diffused and reflected in the prism 30 by the reflecting surface 33 and is evenly distributed and incident on the entire back surface 20b of the liquid crystal panel 20. However, the lamp 50 emits a first predetermined amount of light when the dimming circuit (not shown) of the liquid crystal display device is inactive, and a second predetermined amount of light (the first predetermined amount of light) when the dimming circuit is operating. It is designed to emit light by striking. That is, the dimming circuit is a circuit provided to limit the current flowing through the lamp to reduce the amount of light emitted from the lamp, and the dimming circuit becomes inoperative during daytime running of the vehicle, and This dimming circuit operates when the vehicle is running in a tunnel or at night. In FIG. 1, reference numeral 62 indicates a rod that supports the printed circuit board 60. In the notch 32 of the prism 30, a prism 70 serving as an auxiliary light guide plate is fitted along the frame plate 40 via a partition wall 71 made of an aluminum plate material, and an auxiliary reflection surface 72 is provided on the back surface of the prism 70. It is formed similarly to the reflecting surface 33. The through hole 71a of the partition wall 71 is formed in a quadrangular shape at a position corresponding to the concentrated warning information pattern display portion 26 of the liquid crystal panel 20, as shown in FIG. As can be easily understood from FIG. 2, it is outside the outline of the concentrated warning information pattern display portion 26. However, the partition wall 71 separates the prisms 30 and 70 from each other except the through hole 71a. One side 73 of the prism 70 (that is, one side 3 of the prism 30)
A lamp 80, which is an auxiliary light source, is disposed in the vicinity of 1) by fitting its base portion to the other side portion 63 of the printed circuit board 60, and the amount of light emitted from the lamp 80 is a concentration warning of the liquid crystal panel 20. When the warning information is displayed by the information pattern display unit 26, the first predetermined light amount is set when the dimming circuit is not operated, and the second predetermined light amount is set when the dimming circuit is operated. In the present embodiment configured as described above, since the dimming circuit is inactive during the daytime running of the vehicle, the lamp 50 is turned on so that the one side 34 in the prism 30 receives the first predetermined light amount. Light from the prism 30
The incident light is uniformly distributed over the entire inside thereof under the diffuse reflection action of the reflecting surface 33, and is made incident on the entire back surface 20b of the liquid crystal panel 20. At this time, the lamp 8
0 also causes the light to enter the prism 70 in the first predetermined light amount by being turned on, and the prism 70 causes the incident light to diffuse through the auxiliary reflection surface 72 so that the through hole 7 of the partition wall 71 is exposed.
It is incident on the prism 30 through 1a. This allows
The display surface 20a during non-display by each of the pattern display portions 21 to 26 of the liquid crystal panel 20 is entirely covered by the first surface.
It is possible to always maintain the uniform brightness determined by the predetermined amount of light. Therefore, when the liquid crystal panel 20 displays the traveling speed of the vehicle, the left turn, the right turn, the remaining fuel amount, the engine temperature, and the concentration warning information on each of the pattern display portions 21 to 26, the respective display contents are displayed. Clearly visible with uniform contrast. When the vehicle is traveling at night or in a tunnel, the lamp 50 causes light to enter the prism 30 from one side 34 thereof at the second predetermined light amount under the operation of the dimming circuit. In the same manner as above, reference numeral 80 makes the second predetermined amount of light enter the prism 30 through the prism 70 and the through holes 71a of the interval 71, and both incident lights applied to the prism 30 are uniformly distributed in the same manner as described above. The light is made incident on the entire back surface 20b. As a result, the brightness determined by the second predetermined light amount over the entire display surface 20a during non-display by the pattern display units 21 to 25 of the liquid crystal panel 20 (that is, the brightness determined by the first predetermined light amount is lower than the brightness determined by the first predetermined light amount). It can always be maintained in dark brightness). In such a case, when the concentration warning information is displayed by the concentration warning information pattern display unit 26 of the liquid crystal panel 20, the lamp 8
0 enters the concentrated warning information pattern display 26 of the liquid crystal panel 20 through the through hole 71a of the prism 70 and the partition 71 at the second predetermined amount of light under the operation of the dimming circuit. The display content of the display unit 26 can be clearly recognized with the brightness corresponding to the first predetermined light amount, despite the above-described dimming illumination of the display surface 20a. Further, as described above, the partition wall 71 is separated from the liquid crystal panel 20 by the prism 30, and the lamp 80 serves as the prism 30.
Since it is located on the remaining side of the liquid crystal panel 20, the outer shape of the lamp 80, the shape of the partition wall 71 and the shapes of the through holes 71a thereof, etc. are irrespective of whether the dimming circuit is operated or not.
Since it is not formed as a shadow on the display surface 20a, it is useful for improving the appearance and visibility of the display surface 20a of the liquid crystal panel 20. Further, as described above, each pattern display portion 26a to 26j of the concentrated warning information pattern display unit 26 of the liquid crystal panel 20.
For each single prism 70, partition 71 and lamp 80
, The light from the lamp 80 is distributed as uniform diffused light in the prism 30 and passes through the through hole 71a of the partition wall 71 and the prism 30 to display each pattern display portion 26a to 26.
Since the light is made to be incident uniformly over the entire j, the lamp 8 is provided corresponding to each of the pattern display portions 26a to 26j.
It is not necessary to separately provide 0, which leads to simplification of the configuration of this type of device. In such a case, by adopting each single prism 70, partition wall 71 and lamp 80, the mutual intervals of the pattern display portions 26a to 26j of the concentrated warning information pattern display unit 26 can be further narrowed. In the above embodiment, the prism 70, the partition 71 and the lamp 80 are provided corresponding to the concentrated warning information pattern display portion 26 of the liquid crystal panel 20, but the invention is not limited to this, and the liquid crystal panel 20 is turned left and right. Pattern display part 2
2, 23, the remaining fuel amount pattern display portion 24, the temperature pattern display portion 25, and other portions of the prism 30 corresponding to the various normal information pattern display portions, respectively, can be implemented in the same manner as in the above embodiment. The effect of can be achieved. In such a case, the surface area and shape of the prism 70 and the size and shape of the through hole 71a of the partition wall 71 may be appropriately changed according to the size of various normal information pattern display portions of the liquid crystal panel 20. Note that this can also be established with respect to the number of pattern display portions forming the concentrated warning information pattern display portion.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part of the device of the present invention, and FIG. 2 is a front view of the same. Explanation of reference numerals 20 ... Liquid crystal panel, 22-25 ... Normal information pattern display section, 26 ... Concentrated warning information pattern display section, 30 ... Light guide plate (prism), 32 ... Notch, 33 ... Reflecting surface, 50 ... Light source (lamp) , 70 ... auxiliary light guide plate (prism), 71 ... partition wall, 71a ... through hole, 72 ... auxiliary reflection surface, 80 ... auxiliary light source (lamp).

Claims (1)

[Claims] 1. A liquid crystal panel which is provided on an instrument panel of a vehicle and has a normal information pattern display section and a centralized warning information pattern display section for displaying normal information and warning information on the vehicle, respectively, and this liquid crystal. A light guide plate superposed on the back surface of the panel, a light source arranged on the side of the light guide plate, a dimming circuit for limiting the light amount of the light source, and a light guide plate superposed on the back surface of the light guide plate and incident on the light guide plate. And a reflection surface that reflects the reflected light toward the back surface of the liquid crystal panel in the light guide plate, and allows a predetermined incident amount of light to enter the light guide plate when the dimming circuit is not operating. When the circuit is in operation, a reduced incident amount of light is made incident on 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 normal information pattern display section is displayed. Display the normal information In the liquid crystal display device for displaying the warning information on the concentrated warning information pattern display section, a predetermined depth is provided on the back surface of the light guide plate corresponding to the back of the concentrated warning information pattern display section of the liquid crystal panel. A notch that is formed in the same light guide plate and opens to the side of the remaining side, a reflective surface that is continuously superposed on a reflective surface that is superposed on the back surface of the light guide plate on the inner peripheral surface of the notch, and the notch. The auxiliary light guide plate fitted through a partition having a through hole therein, and the light which is superposed on the back surface of the auxiliary light guide plate and is incident on the auxiliary light guide plate is concentrated inside the liquid crystal panel within the auxiliary light guide plate. An auxiliary reflection surface that reflects toward the back surface of the warning information pattern display portion and a side of the remaining part of the auxiliary light guide plate are provided, and when the warning information is displayed on the liquid crystal panel, the auxiliary light guide plate has a predetermined incident amount. Auxiliary light source that makes light incident Vehicle liquid crystal display device, wherein a provided.