JP3002109B2 - Display unit with backlight - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display unit with a backlight having a reflection surface for guiding light of a backlight provided in a case to a liquid crystal display.

[0002]

2. Description of the Related Art As a display unit with a backlight,
For example, there is an odd trip meter shown in FIG. This odometer is used in automobiles and the like, and has an odometer function and a tripmeter function. This od trip meter is
The case 1 is covered by a flat box-shaped case 1, and one side wall 1 a of the case 1 is constituted by a hard printed wiring board (hereinafter, referred to as HPC) 2. A display window 1b is opened in the front of the case 1, and the liquid crystal display 3 is arranged inside the display window 1b. The liquid crystal display 3 is an HPC 2
While being fixedly connected to the edge of the HPC 2.

A backlight 4 is provided at a position near the rear wall 1c of the case 1 at a position behind the liquid crystal display 3. The backlight 4 is attached to the case 1 via the auxiliary HPC 5. The auxiliary HPC 5 detachably holds the backlight 4 and makes an electrical connection with the backlight 4. The auxiliary HPC 5 is connected to the HPC 2 via the connectors 6 and 7. A push-type switching knob 8 for switching between the odometer and the trip meter and resetting the trip meter is provided on the front of the case 1 so as to protrude. In addition, HP
The C2 is provided with electronic components (not shown) such as an IC for controlling the liquid crystal display 3, the backlight 4, and the like.

In the od trip meter configured as described above, since the liquid crystal display 3 is illuminated from behind by the light of the backlight 4, the display unit is extremely easy to see.

[0005]

By the way, the above-mentioned od
In the trip meter, since the light of the backlight 4 is radiated to the entire inside of the case 1, only a part of the light reaches the liquid crystal display 3 and there is a problem that the lighting efficiency is poor. For this reason, the liquid crystal display 3
It is conceivable to provide a light shielding wall in the case 1 for guiding the light to the other part and preventing the light from leaking to other parts. However, when such a light-shielding wall is provided in the case 1, heat generated from the backlight 4 is trapped in a portion closed by the light-shielding wall, the case 1, the HPC 2, and the like.
There is a disadvantage in that thermal stress is applied to electronic components and the like provided in the HPC 2.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and an object of the present invention is to improve the illumination efficiency of a liquid crystal display and to apply a thermal stress to electronic components on an HPC. An object of the present invention is to provide a display unit with a backlight that can be prevented.

[0007]

In order to achieve the above object, the present invention relates to a case formed in a box shape, and an HPC provided as one constituent surface so as to constitute one side wall of the case. A display unit with a backlight, comprising: a liquid crystal display provided in the HPC; and a backlight provided in the case and illuminating the liquid crystal display, the other side of the case facing the HPC. By forming the wall in a concave shape on the HPC side, an optical path for guiding the light of the backlight to the liquid crystal display side is formed, and a reflecting surface is formed on a side wall of the optical path.

Further, it is preferable that the two side walls in the light path are formed obliquely so that the distance between the side walls gradually increases toward the liquid crystal display.

Further, it is preferable that a diffusion plate for uniformly diffusing the light of the backlight and radiating the light to the liquid crystal display is provided on the back side of the liquid crystal display.

Further, it is preferable that the diffusion plate is formed integrally with the light path and the case by using the same resin.

[0011]

In the display unit with backlight configured as described above, light emitted from the backlight reaches the liquid crystal display through the light path. At this time, the light of the backlight is reflected by the reflection surface formed by the side wall of the light path and reaches the liquid crystal display. Therefore, the illumination efficiency of the liquid crystal display can be improved.

In addition, since the light path is formed by forming a part of the other side wall of the case in a concave shape inside the case, the heat of the backlight located on the light path side is reduced by HP.
Movement to the C side can be prevented. Therefore, it is possible to prevent thermal stress from being applied to electronic components and the like on the HPC.

Further, since the light path is formed by forming a part of the other side wall of the case in a concave shape inward of the case, the part of the light path on the other side wall is opened. Has become. Therefore, since the heat of the backlight does not remain in the light path, it is possible to prevent the liquid crystal display from being subjected to thermal stress.

Also, in the case where the two side walls in the light path are formed obliquely so that the distance between these side walls gradually opens toward the liquid crystal display, the light of the backlight can be reduced. Will be uniformly reflected. Therefore, the liquid crystal display can be illuminated with uniform brightness.

Further, in the case where a diffusion plate for uniformly diffusing the light of the backlight and radiating the light to the liquid crystal display is provided on the back side of the liquid crystal display, the brightness of the liquid crystal display becomes more uniform. Depending on the position where the display unit with the backlight is provided, the opening of the light path may be closed, but even in such a case, the part on the backlight side and the liquid crystal display side are diffused by the diffusion plate. And the liquid crystal display can be prevented from being exposed to high temperature due to the heat of the backlight. That is, it is possible to prevent a thermal stress from being applied to the liquid crystal display.

Further, when the diffusion plate is formed integrally with the light path and the case by the same resin, it is possible to prevent the heat of the backlight from moving to the liquid crystal display side due to air leakage. . That is, it is possible to more sufficiently prevent the temperature of the liquid crystal display from becoming high due to the heat of the backlight. In addition, the number of parts can be reduced and the number of assembling steps can be reduced because the diffusion plate is integrated with the case.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 and 2 show the first embodiment, FIG. 3 shows the second embodiment, and FIG. 4 shows the third embodiment. In each of these embodiments, an example in which the display unit with a backlight according to the present invention is applied to an od trip meter for a vehicle is shown, and the od trip meter is usually housed in a combination meter. ing. However, the relationship between the odd trip meter and the combination meter is not shown in the first and second embodiments, but is shown only in the third embodiment.

First, a first embodiment of the present invention will be described with reference to FIGS. However, elements common to those of the conventional example shown in FIG. 6 are denoted by the same reference numerals, and description thereof will be simplified.

Odd trip meter 1 of the first embodiment
Numeral 0 has the function of an odometer and the function of a trip meter, and is entirely covered by a case 11. The case 11 is formed in a flat box shape (a rectangular parallelepiped shape), and one side wall 11 a of the case 11 is configured by a hard printed wiring board (hereinafter, referred to as HPC) 12. That is, the part of the one side wall 11a of the case 11 is in an open state as a whole,
The HPC 12 is provided so as to cover the opening. This HPC 12 is provided with a locking claw (not shown).
The case 11 is detachably attached to the case 11.

A display window 11c is opened in the front wall 11b of the case 11 orthogonal to the one side wall 11a, and a liquid crystal display 13 is arranged inside the display window 11c. The liquid crystal display 13 is electrically connected to the HPC 12 while being fixedly connected to an edge of the HPC 12.

A backlight 14 is provided on the case 11 on a rear wall 11d at a position directly opposite to the front wall 11b.
Is provided with a mounting hole 11e for detachably mounting. This mounting hole 11e is formed in the back wall 11d.
It is formed at a position substantially corresponding to the center of the liquid crystal display 13. That is, the backlight 14 is located behind the center of the liquid crystal display 13. The electrical connection to the backlight 14 is made by connecting the conductive part 1 for a bulb of a flexible printed circuit board (hereinafter, referred to as FPC) 15.
5a.

The FPC 15 is, as shown in FIG. 5, a meter case 10 of the combination meter 100.
It is provided on one back wall 101a. The back wall 101a is provided with a through hole 101b for inserting and fixing the odd trip meter 10. The valve conductive portion 15a of the FPC 15 is provided along the outer surface of the back wall 11d of the case 11 fixed to the through hole 101b, at a position corresponding to the mounting hole 11e of the back wall 11d. Further, the FPC 15 is bent together with the case 11 into the through hole 101b at a position adjacent to the conductive portion 15a for a valve, and is connected to a connector (not shown) (connector 17 in the third embodiment).
A conductive portion 15b for making an electrical connection with the PC 12 is provided.

As shown in FIG. 1, an optical path F extending from the backlight 14 to the liquid crystal display 13 is provided on the other side wall 11 f of the case 11 facing the HPC 12. The light path F is formed by forming a part of the other side wall 11f in a concave shape inside the case 11, and the two side walls F2 rising from the bottom wall F1 of the light path F. The reflection surface R reflects toward the container 13 side. These two side walls F2 are formed obliquely so that the distance between the side walls F2 gradually opens toward the liquid crystal display 13.

The case 11 having the optical path F thus formed is integrally formed of the same resin.
Further, at the end of the light path F on the liquid crystal display 13 side,
A diffusion plate 16 is provided so as to partition the optical path F and face the liquid crystal display 13. The diffusion plate 16 uniformly diffuses the light of the backlight 14 and emits the light to the liquid crystal display 13. The HPC 12 controls electronic components 12 a and 12 such as an IC that controls the liquid crystal display 13, the backlight 14, and the like, and also controls a speedometer 102 and a tachometer 103 of a combination meter 100 described below.
b etc. are provided.

In the odometer 10 configured as described above, light emitted from the backlight 14 reaches the liquid crystal display 13 through the optical path F.
At this time, the light of the backlight 14 is transmitted to the side wall F of the light path F.
The liquid crystal display 1 is reflected by the reflection surface R formed by
3 will be reached. Therefore, the illumination efficiency of the liquid crystal display 13 can be improved.

Further, since the light path F is formed by forming a part of the other side wall 11f of the case 11 in a concave shape inside the case 11, the backlight 14 located on the light path F side is formed. Heat can be prevented from moving to the HPC 12 side. Therefore, it is possible to prevent the electronic components 12a and the like on the HPC 12 from being subjected to thermal stress.

Further, since the light path F is formed by forming a part of the other side wall 11f of the case 11 into a concave shape inside the case 11, the other side wall 1f of the light path F is formed.
The portion on the 1f side is open. Accordingly, since the heat of the backlight 14 does not remain in the optical path F, it is possible to prevent the liquid crystal display 13 from being subjected to thermal stress.

The two side walls F2 in the optical path F
Are formed obliquely so that the distance between these side walls F2 gradually opens toward the liquid crystal display 13, so that the light of the backlight 14 can be uniformly reflected to the liquid crystal display 13 side. . Therefore, the liquid crystal display 13 can be illuminated with uniform brightness.

Further, the position on the back side of the liquid crystal display 13,
That is, since the diffusion plate 16 for uniformly diffusing the light of the backlight 14 and hitting the liquid crystal display 13 is provided at a position facing the liquid crystal display 13 in the light path F, the brightness of the liquid crystal display 13 is increased. It can be uniform. Also,
Depending on the position where the odd trip meter 10 is provided, the opening of the optical path F may be closed. However, even in such a case, since the portion on the backlight 14 side and the portion on the liquid crystal display 13 side are separated by the diffusion plate 16, the liquid crystal display is heated to a high temperature by the heat of the backlight 14. Exposure to conditions can be prevented.

The electric connection of the backlight 14 is F
Since it can be performed through the valve conductive portion 15a of the PC 15, there is no need to provide the auxiliary HPC 5 and the connectors 6 and 7 (see FIG. 6) as conventionally used, so that the number of parts is reduced accordingly. And the number of assembling steps can be reduced.

Next, a second embodiment of the present invention will be described with reference to FIG. However, components common to those of the first embodiment shown in FIGS. 1 and 2 are denoted by the same reference numerals, and description thereof will be simplified. The second embodiment differs from the first embodiment in that a diffusion plate 16 is provided integrally with the case 11 forming the optical path F.

That is, the case 11 is made of a resin forming the diffusion plate 16, and the diffusion plate 16, the light path F, and the other side wall 11 are formed.
f, the entire case 11 including the front wall 11b, the back wall 11d, and the like are integrally formed. The diffusion plate 16 is disposed at a position where the distance between the two side wall portions F2 is the widest, and opposes the liquid crystal display 13 so as to partition the light path F between the backlight 14 and the liquid crystal display 13. It is provided in.

In the od trip meter 10 configured as described above, since the diffusion plate 16 is formed integrally with the case 11, the backlight 14 is caused by air leakage.
Can be more sufficiently prevented from moving to the liquid crystal display 13 side. That is, when the temperature of the liquid crystal display 13 becomes high due to the heat of the backlight 14, the diffusion plate 16
Can be completely prevented as compared with the case where they are configured separately. Moreover, since the diffusion plate 16 is integrated with the case 11, the number of parts can be reduced, and the number of assembly steps can be reduced.

Next, a third embodiment of the present invention will be described with reference to FIGS. However, the first shown in FIGS.
The same reference numerals are given to the same components as those of the embodiment, and the description will be simplified. The main difference between the third embodiment and the first embodiment is that the HPC 12 is located on the upper side of the case 11 in the drawing, and the optical path F is open on the lower side.

That is, as shown in FIG. 4, the HPC 12 is provided so as to constitute one side wall 11a of the case 11, and is pressed against each step portion 11g provided in the case 11 so that each HPC 12 is pressed. It is configured to be locked to the case 11 by being locked to a stop claw 11h. Also, HP
C12 is provided with a connector 17 for connection with the conductive portion 15b (see FIG. 5) of the FPC 15. The connector 17 has a plurality of contact pins 17a that protrude elastically.

The display window 11c of the case 11 is formed so as to open toward the one side wall 11a, and the liquid crystal display 13 is inserted through the opening. Then, a diffusion plate 16 is provided between the liquid crystal display 13 and the end of the light path F on the liquid crystal display 13 side. Further, as shown in FIGS. 4 and 5, the case 11 has a screw 1 on a back wall 101 a of the meter case 101.
A flange 11i is provided for fixing through the flange 8.

On the other hand, the combination meter 100
As shown in FIG. 5, the speedometer 102, the tachometer 103, the fuel gauge 104, the thermometer 105, and the od trip meter 1
0, and an FPC 15 provided on the back side of the back wall 101a of the meter case 10.
And a dial 106 covering the other parts except for the display units of the speedometer 102, the tachometer 103, the fuel meter 104, the thermometer 105, and the odometer 10; and the dial 106
And a front glass 107 provided on the front side of the front glass.

Speedometer 102, tachometer 103, fuel gauge 10
4. The thermometer 105 is fixed to the back wall 101a of the meter case 101 by a conductive screw 108, and is electrically connected to the FPC 15.

The od / trip meter 10 has a through hole 1 formed in a rear wall 101a of the meter case 101.
01b, and is fixed to the back wall 101a with screws 18 via a flange 11i provided on the case 11. Then, the case 11 is connected to the through hole 10 of the back wall 101a.
When inserted into the through hole 1b, the conductive portion 15b of the FPC 15 is pressed by the connector 17 and bent inside the through hole 101b. At this time, each contact pin 17a of the connector 17
Are elastically bent, and each conductive part 15 of the FPC 15 is
b. In addition, the valve conductive portion 15a of the FPC 15 is provided together with the case 11 together with the through hole 10a.
1b, the valve conductive portion 15a can be easily pulled out since the gap between the through hole 101b and the case 11 is large. Then, when the valve conductive portion 15a of the FPC 15 is pulled out from the through hole 101b, the case 11
Is provided along the outer surface of the rear wall 11d so as to coincide with the mounting hole 11e of the rear wall 11d.

The through-hole 107a through which the switching knob 8 of the odometer 10 protrudes is formed in the front glass 107.
Is provided.

In the od trip meter 10 and the combination meter 100 configured as described above, the speedometer 102, the tachometer 103,
Since the fuel gauge 104, the thermometer 105, and the odometer 10 are electrically connected, and the meters are controlled by the HPC 12 provided in the odometer 10, the number of components such as connectors is reduced. Can be reduced, and the number of assembling steps can be reduced.

In each of the above embodiments, an example is shown in which the display unit with a backlight according to the present invention is applied to an odometer. However, the present invention is not limited to this odometer. It goes without saying that the present invention may be applied to other instruments and the like.

[0043]

According to the present invention, since the light of the backlight is reflected by the reflection surface of the side wall of the light path and reaches the liquid crystal display, the illumination efficiency of the liquid crystal display can be improved. .

Furthermore, since the light path is formed by forming a part of the other side wall of the case in a concave shape inside the case, the heat of the backlight located on the light path side is reduced by HP.
Movement to the C side can be prevented. Therefore, it is possible to prevent thermal stress from being applied to electronic components and the like on the HPC.

Further, since the light path is formed by forming a part of the other side wall of the case in a concave shape inside the case, the part of the other side wall of the light path is opened. Has become. Therefore, since the heat of the backlight does not remain in the light path, it is possible to prevent the liquid crystal display from being subjected to thermal stress.

In the case where the two side walls in the light path are formed obliquely so that the distance between these side walls gradually opens toward the liquid crystal display, the light of the backlight is not provided on the liquid crystal display side. Will be uniformly reflected. Therefore, the liquid crystal display can be illuminated with uniform brightness.

Further, in the case where a diffusion plate for uniformly diffusing the light of the backlight and radiating the light to the liquid crystal display is provided on the back side of the liquid crystal display, the brightness of the liquid crystal display becomes more uniform. Also, depending on the position where the display unit with backlight is provided, the opening of the light path may be closed, but even in such a case, the part on the backlight side and the side on the liquid crystal display are And the liquid crystal display can be prevented from being exposed to high temperature due to the heat of the backlight. That is, it is possible to prevent a thermal stress from being applied to the liquid crystal display.

Furthermore, in the case where the diffusion plate is formed integrally with the light path and the case by the same resin, the heat of the backlight is more sufficiently prevented from moving to the liquid crystal display side due to air leakage. be able to. That is,
It is possible to prevent the temperature of the liquid crystal display from becoming high due to the heat of the backlight. In addition, the number of parts can be reduced and the number of assembling steps can be reduced because the diffusion plate is integrated with the case.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of an od trip meter shown as a first embodiment of the present invention.

FIG. 2 is a diagram showing the odd trip meter, and is a cross-sectional view taken along the line II-II of FIG. 1;

FIG. 3 is an exploded perspective view of an od trip meter shown as a second embodiment of the present invention.

FIG. 4 is an exploded perspective view of an od trip meter shown as a third embodiment of the present invention.

FIG. 5 is an exploded perspective view of a combination meter that stores the odd / trip meter.

FIG. 6 is an exploded perspective view of an od trip meter shown as a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Odd trip meter 11 Case 11a One side wall 11f Other side wall 12 HPC (hard printed wiring board) 13 Liquid crystal display 14 Backlight F Optical path F1 Bottom wall F2 Side wall R Reflecting surface

Claims (4)

(57) [Claims] 1. A case formed in a box shape, an HPC provided as one constituent surface so as to constitute one side wall of the case, a liquid crystal display provided in the HPC, and a case inside the case. A backlight unit provided with a backlight for illuminating the liquid crystal display, wherein the other side wall of the case facing the HPC is formed in a concave shape on the HPC side, so that the backlight unit A display unit with a backlight, wherein an optical path for guiding light to a liquid crystal display side is formed, and a reflective surface is formed on a side wall of the optical path. 2. The back according to claim 1, wherein the two side walls in the light path are formed obliquely so that the distance between the side walls gradually opens toward the liquid crystal display. Display unit with light. 3. The liquid crystal display according to claim 1, further comprising a diffuser disposed on the back side of the liquid crystal display for uniformly diffusing the light of the backlight and radiating the light to the liquid crystal display. Display unit with backlight. 4. The display unit with a backlight according to claim 3, wherein the diffusion plate is formed integrally with the light path and the case by the same resin.