JP3244122B2 - Display device for vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an instrument and other various display devices mounted on a vehicle.

[0002]

2. Description of the Related Art Conventionally, for example, in a vehicle instrument,
A discharge tube such as a cold cathode tube is used as a light source for irradiating the scale plate.

[0003]

Since the discharge tube is usually formed in a circulatory line, the structure of the instrument light source is often complicated. In order to cope with this, it is conceivable to employ a discharge tube having a straight shape or a shape as close as possible to a straight line. In order to use the light generated from the discharge tube as effectively as possible,
Usually, a reflector is provided near the discharge tube.

Accordingly, there is a strong demand to reliably protect the discharge tube. Therefore, an object of the present invention is to provide a vehicular display device capable of protecting a linear discharge tube in order to deal with such a problem.

[0005]

According to the first to third aspects of the present invention, power supply to a heater provided in a discharge tube is cut off from a power supply by a switch made of a temperature-sensitive material. Done. This prevents an abnormally high temperature of the discharge tube due to heater control by a switch made of a temperature-sensitive material.

Further, since the discharge tube is linear, it has a simple structure as compared with the case where a circline type discharge tube is used.

According to the first to third aspects of the present invention,
A heater (H) provided in the discharge tube for heating the discharge tube by power supply from a power supply (Ba), a temperature detection element (111) for detecting the temperature of the discharge tube, and a temperature detected by the temperature detection element Control means (110) for shutting off the power supply from the power supply to the heater when the discharge tube is at a high temperature in the normal range, whereby the discharge tube can be reliably protected.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIGS. 1 to 4 show a first embodiment of a vehicle display device according to the present invention. As shown in FIGS. 1 and 2, this display device includes a scale plate unit 10 disposed in a vehicle cabin. The scale plate unit 10 includes a flat scale plate 10a and a linear cold cathode fluorescent lamp. 10
b, a light guide plate 10c and an L-shaped reflector 10d (also used as a holder).

The scale plate 10a is an instrument panel disposed in the cabin of the vehicle.
On the black display surface a, an engine speed scale section 11, a vehicle speed scale section 12, an engine water temperature scale section 13, and a fuel amount scale section 14 are formed by punching. In addition,
The black display surface of the scale plate 10 a is covered by a front panel 30 via an annular return plate 20.

The cold cathode tube 10b is, as shown in FIG.
At the upper edge in the width direction of the back surface of the scale plate 10a, the scale plate 1
0a, the cold cathode tube 1
The total length of 0b is a value that can illuminate the engine speed scale section 11, the vehicle speed scale section 12, the engine water temperature scale section 13, and the fuel amount scale section 14. The cold cathode tube 10b includes a string heater H (see FIG. 4).
The heater H is attached to the outer surface of the cold cathode tube 10b along the longitudinal direction.

The light guide plate 10c is made of a light guide material such as a transparent acrylic resin.
It is mounted adjacent to the cold cathode tube 10b on the back surface of the scale plate 10a (see FIG. 2). The incident end face 15 of the light guide plate 10c is located parallel to the axial direction of the cold cathode tube 10b and faces the light emitting surface of the cold cathode tube.
Is formed on the back surface thereof in order to secure a light diffusion action in the light guide plate 10c.

Thus, the light guide plate 1 is moved from the cold cathode tube 10b.
0c from the incident end face 15 is reflected by the reflector 1
Under the reflection of 0d, the light is efficiently guided to irradiate the engine speed scale section 11, the vehicle speed scale section 12, the engine water temperature scale section 13, and the fuel amount scale section 14. The reflector 10d is detachably attached to the scale plate 10a and a casing 60 described later so as to cover the cold cathode tubes 10b.

[0013] The display device further includes respective hands for instructing the rotation speed, the vehicle speed, the water temperature, and the fuel amount, and each driving device for driving each of the hands. In FIGS. 1 and 2, a pointer 40 for indicating the number of rotations and the pointer 40
Is shown only the driving device 50 for driving. The driving device 50 includes a casing 60 mounted on the back surface of the light guide plate 10c.
The driving shaft 50 of the driving device 50
Extends through each through hole of the light guide plate 10c and the scale plate 10a, and supports the pointer 40.

The display device includes a wiring board 70, a connector 80, and a wiring board 90, as shown in FIG. The wiring board 70 is detachably attached to the bottom wall of the reflector 10d from below so as to face the cold cathode tube 10b via the bottom wall.
The cold-cathode tube 10b is connected to a predetermined wiring portion of the “0” at both input terminals T1 and T2.

On the other hand, the wiring board 90 is fastened to the bottom wall of the casing 60 from below by a plurality of screws.
The wiring board 90 is opposed to the wiring board 70 at the left end in FIG. In addition, a high-voltage generation circuit 100 (see FIG. 4), which will be described later , is connected to a predetermined wiring portion of the wiring board 90 through both output terminals 101 and 102.

As shown in FIG. 2, the connector 80 is composed of a terminal holder 81 formed of a flat plate made of an electrically insulating material, and a plurality of connector terminals 82 fitted to the terminal holder 81. The connector 80 is fixed between the wiring boards 70 and 90. The two connector terminals 82 are connected at both ends between both input terminals of the cold-cathode tube 10a and both input terminals of the high-voltage generating circuit 100 via respective wiring portions of both the wiring boards 70 and 90. (See FIG. 4).

Here, an electrical circuit connection configuration for the cold cathode tube 10a will be described with reference to FIG. The high-voltage generating circuit 100 is supplied with power from a battery Ba via an ignition switch IG of the vehicle, and generates a high voltage of several hundred volts to several thousand volts between its two output terminals 101 and 102 at several tens of kilohertz. .

The heater circuit 110 is based on the temperature detection output of the cold-cathode tube 10a by the thermistor 111 and is made of a normally closed polyswitch (Rachem Corp.)
In the closed state of the battery 120, the heater H is driven to generate heat by receiving power from the battery Ba via the ignition switch IG. Thus, the heater H heats the cold cathode tube 10a. When the temperature of the cold-cathode tube 10a is within the normal temperature range, the polyswitch 120 detects this and turns on. When the temperature of the cold cathode tube 10a goes out of the normal range and becomes abnormally high, the poly switch 120 is turned off. In order to increase the on / off accuracy of the poly switch 120, the poly switch 120 is connected to the scale plate 10
a, reflector 10d, light guide plate 10c, and casing 6
It is preferable to arrange it in a place hermetically enclosed by the zero flange portion 61.

Next, the assembling structure of the cold cathode tube 10a, the reflector 10d, the wiring board 70 and the thermistor 111 in the display device will be described in detail. As shown in an exploded perspective view of FIG. 3, each of the cold cathode tubes 10b has a bifurcated shape projecting from both ends of an upper surface of a bottom wall 17 of a reflector 10d by cylindrical holders 16 fitted to both ends thereof. The hooks 17a are detachably fitted to the hooks 17a against the elasticity of the hooks. Thereby, the cold-cathode tube 10b is connected to the reflector 10d.
Is detachably attached along the bottom wall 17.

The wiring board 70 is provided with each claw portion 17 b projecting from the bottom wall 17 back surface of the reflector 10 d in each groove portion 71.
It is detachably fitted to. Thereby, the wiring board 70
Is detachably assembled along the bottom wall 17 of the reflector 10d from the back side thereof. A bifurcated terminal 72 protrudes from the side edge of the wiring board 70, and each terminal H <b> 1 of the heater H is detachably fitted and fixed to each terminal 72. Thereby, the electrical connection of the heater H to the wiring board 70 is achieved.

With the above assembly, the cold cathode fluorescent lamp 1
0b, the reflector 10d and the wiring board 70 are completed as a detachable light source unit U. After the light source unit U is completed as described above, the connector 80 is fitted into the connector portion 74 of the wiring board 70. Thereby, the electrical connection between the wiring board 70 and the connector 80 is achieved.

The thermistor 111 is connected to the wiring portion of the wiring board 70 by soldering at both lead terminals. The cold cathode tube 10b is electrically connected to both sides of the wiring board 70 by soldering at both terminals. In addition, reflector 1
Od is detachably fitted to the flange portion 52 of the casing 50 at each claw portion 17c protruding from the bottom wall 17.
At this time, the side wall 18 of the reflector 10d comes into contact with the outer peripheral edge of the scale plate 10a from the back side at the upper edge.

Thus, the detachable assembly of the light source unit U to the scale plate unit 10 and the casing 50 is completed. In this case, after completing the light source unit U, the bottom wall 17 of the reflector 70 is detachably assembled to the flange portion 61 of the casing 60 as described above, so that the light source unit U is attached to the scale plate unit 10 and the casing 60. Can be assembled. Therefore, the cold cathode tube 10b, the reflector 10d, and the wiring board 70 can be easily and integrally assembled in the display device.

When the cold-cathode tube 10b becomes unusable due to aging or the like, since the light source unit U is outside the casing 60, the light source unit U can be removed without removing extra members. What is necessary is just to remove from 60 and to assemble a new light source unit U. Therefore, maintenance work of the light source of this type of display device is easy.

As described above, the cold cathode tube 10b, the reflector 10d, and the wiring board 70 are connected to the light source unit U.
And the cold cathode tube 10
Objects other than the light source unit U do not directly touch b. For this reason, even if the cold cathode tube 10b is, for example, a tube having a diameter of 300 mm and a diameter of 3 mm and is easily cracked or broken, there is no breakage.

Since the cold-cathode tube 10b is linear, the distance between the two terminals of the heater H is increased. However, both terminals of the heater H are connected to the two terminals 72 of the wiring board 70 as described above. Only the heater H is required, so that the wiring of the heater H can be easily arranged. Further, since the cold-cathode tube 10b is linear, the structure is simpler than that of a circline light source.

FIG. 5 shows a modification of the first embodiment. In this modification, the wiring board 70 described in the first embodiment is eliminated, and both terminals of the cold cathode tube 10b, both terminals of the heater H, and both terminals of the thermistor 111 are provided with a plurality of lead wires L. It is connected to each connector terminal 82 of the connector 80. The thermistor 111
Split-shaped holder 1 fitted in the center of cold-cathode tube 10b
6a. Other configurations are the same as those in the first embodiment.

In this modified example, the cold cathode tube 10b and the reflector 10d excluding the wiring board 70 constitute the light source unit Ub.
According to this, substantially the same operation and effect as described in the first embodiment can be achieved. (Second Embodiment) FIGS. 6 to 8 show a second embodiment of the present invention.

In the second embodiment, the first
Light guide plate 10c and reflector 10 described in the embodiment
d, the light guide plate 1 instead of the casing 60 and the wiring board 70
0e, a casing 10f, a box-shaped reflector 130, and a wiring board 140 are employed. The light guide plate 10e is mounted on the lower surface of the scale plate 10a instead of the light guide plate 10c. The casing 10f is mounted on the lower surface of the scale plate 10a so as to cover the light guide plate 10e and the driving device 50 instead of the reflector 10d and the casing 60.

This casing 10f has a U-shaped cross-section housing portion 19 formed in a longitudinal shape, and this housing portion 19 is formed by a long opening 19a formed in the bottom wall thereof.
At a position corresponding to the V-shaped groove 19b formed on the surface of the light guide plate 10c, it is in contact with the lower surface of the light guide plate 10c. The cold cathode tube 10b described in the first embodiment is housed and supported in the housing portion 19 of the casing 10f by the reflector 130. The cold cathode tube 10b is
0, the light guide plate 10 through the opening 19a.
The portion corresponding to the V-shaped groove 19b on the lower surface of c is irradiated.

The wiring board 140 is detachably mounted on the lower surface of the reflector 130, while the wiring board 90
Is mounted on the bottom wall of the casing 10f by screwing instead of the casing 60. Next, the above-mentioned cold cathode tube 10a, thermistor 111, polyswitch 12
A detailed description will be given of an assembling configuration of the reflector 130 and the wiring board 140 in the display device.

As shown in the exploded perspective view of FIG. 8, the cold cathode tube 10b is
Each of the forked claw portions 1 protruding from both ends of the upper surface of the bottom wall 131
32 is removably fitted against the elasticity of these claws. As a result, the cold cathode tube 10b is
Is detachably attached along the bottom wall 131. The wiring board 140 is provided with the reflector 130 in each groove 141.
Is detachably fitted to each of the claws 133 protruding from the back surface of the bottom wall 131. Thus, the wiring board 140 is detachably assembled along the bottom wall 131 of the reflector 130 from the back side thereof. At this time, the connector portion 142 of the wiring board 140 is located beside the reflector 130.

Thus, both terminals T1 of the cold cathode tube 10b,
T2 passes through the bottom wall 131 of the reflector 130 and the wiring board 1
It is inserted and soldered into both corresponding land holes at the side edge of the connector part 142 on the side of the connector part 142. Further, both terminals H1 of the heater H,
H2, both terminals of the thermistor 111 and poly switch 12
The two terminals 0 are inserted and soldered through the bottom wall of the reflector 130 into both corresponding land holes at the side edge of the wiring board 140 on the connector 142 side.

However, in the second embodiment, the thermistor 111 is fitted to another cut portion of the cut holder 16b fitted to the center of the discharge tube 10b. The thermistor 111 and the polyswitch 120 are housed in the U-shaped housing portions 134a and 134b of the reflector 130, respectively. By the assembling as described above, the cold cathode tube 10b, the reflector 130, and the wiring board 140 are completed as a detachable light source unit Ub.

After completing the light source unit Ub, the connector 142 of the wiring board 140
The connector 80 is fitted. Thereby, the wiring board 14
0 and the connector 80 are electrically connected. Thus, the detachable assembly of the light source unit Ub to the scale plate unit 10 and the casing 10f is completed.

In this case, after the light source unit Ub is completed, each of the claws 135 projecting from the peripheral wall 134 of the reflector 130 is detachably fitted to the upper wall of the housing portion 19 of the casing 10f. The light source unit Ub can be assembled to the scale plate unit 10 and the casing 10f. Therefore, the cold cathode tube 10b, the reflector 130, and the wiring board 140 can be easily and integrally assembled in the display device.

When the cold-cathode tube 10b becomes unusable due to aging or the like, since the light source unit Ub is outside the casing 10f, the light source unit Ub is removed from the casing 10f and a new light source unit Ub is removed.
b may be assembled. Therefore, maintenance work of the light source of this type of display device is easy. Further, as described above, since the cold cathode tube 10b, the reflector 130, and the wiring board 140 are assembled to the casing 10f as the light source unit Ub, objects other than the light source unit Ub do not directly touch the cold cathode tube 10b. Therefore, the cold cathode tube 10b is not damaged. Other configurations, functions, and effects are the same as those in the first embodiment.

In practicing the present invention, the number of the cold cathode tubes 10b is not limited to one, and may be a linear cold cathode tube divided into a plurality of tubes. It may be slightly bent in a curved shape. In practicing the present invention, various discharge tubes such as a xenon tube may be employed instead of the cold cathode tube 10b.

In practicing the present invention, the reflectors 10d and 130 may be detachably assembled to the light guide plates 10c and 10e or the scale plate 10a instead of the casings 60 and 10f. Also, the wiring boards 70 and 140
May be detachably attached to a light guide plate, a casing, or a scale plate, instead of each reflector. In the implementation of the present invention, when the brightness of the discharge tube 10b fluctuates on the left and right, the color of the wire constituting the heater H is changed on the left and right, so that the transmittance of the light guide plate 10c and the scale plate 10a is changed. Variations in the brightness of the discharge tube 10b between left and right may be eliminated.

In practicing the present invention, the present invention may be applied to a vehicle display device or a vehicle digital display device employing a liquid crystal panel, an EL, or the like.

[Brief description of the drawings]

FIG. 1 is a plan view of a scale plate unit in a first embodiment of a vehicle display device according to the present invention.

FIG. 2 is a cross-sectional view of a main part along line 2-2 of FIG.

FIG. 3 is an enlarged exploded perspective view of the light source unit of FIG. 1;

FIG. 4 is a schematic electric circuit configuration diagram of a display device.

FIG. 5 is an exploded perspective view showing a main part of a modification of the first embodiment.

FIG. 6 is a front view showing a main part of a second embodiment of the present invention.

FIG. 7 is a cross-sectional view of a main part along line 7-7 in FIG. 6;

8 is an enlarged exploded perspective view of a light source unit of FIG.

[Explanation of symbols]

10a: Scale plate, 10b: Cold cathode tube, 10c, 10e
... Light guide plate, 10d, 130 ... Reflector, 10f, 60
... casing, 40 ... pointer, 50 ... drive unit, 70, 1
Reference numeral 40 denotes a wiring board, 100 denotes a high voltage generation circuit, 111 denotes a temperature detection element, and 120 denotes a polyswitch.

Claims (3)

(57) [Claims] 1. A scale plate (10a), a light source (10b), and a light source disposed on a back side of the scale plate for receiving light from the light source.
A light guide plate (10c, 10e) for guiding to the scale plate, and a reflection for reflecting light from the light source toward the light guide plate
(10d, 130) and a casing (10f, 6) arranged on the back side of the light guide plate.
0) and a drive mechanism (50) housed in the drive mechanism and extending from the drive mechanism through the light guide plate and the scale plate.
Pointer (40) supported on a rotating shaft (51)
In the display device for a vehicle, the light source may be attached to the reflector so as to be along the light guide plate.
A linear discharge tube that is assembled and installed in the discharge tube;
And the discharge tube is powered by the power supply (Ba).
The heater (H) is heated, and the power supply is turned on in the normal temperature range of the radiator tube, so that the heat source is turned on.
The power is supplied to the heater, and the power is supplied from the normal temperature range.
It will shut off by turning off the abnormally high temperature
Connected between the heater and the power source, and
A switch made of a temperature-sensitive material attached to the reflector
(120) and the temperature of the radiator tube, and
A temperature detecting element (111) attached to the heat radiating pipe, and
At the time of high temperature in the normal temperature range, from the power supply to the heater
Control means (110) for interrupting power supply to the light source, and connected to the light source and assembled to the reflector
And a switch made of the thermosensitive material is connected to the wiring board.
A display device for a vehicle, comprising: 2. The temperature detecting element is connected to the wiring board.
The vehicle display according to claim 1, wherein the display is provided.
apparatus. 3. A scale plate (10a), a light source (10b), and a light source disposed on the back side of the scale plate for receiving light from the light source.
A light guide plate (10c, 10e) for guiding to the scale plate, and a reflection for reflecting light from the light source toward the light guide plate
(10d, 130) and a casing (10f, 6) arranged on the back side of the light guide plate.
0) and a drive mechanism (50) housed in the drive mechanism and extending from the drive mechanism through the light guide plate and the scale plate.
Pointer (40) supported on a rotating shaft (51)
In the display device for a vehicle, the light source may be attached to the reflector so as to be along the light guide plate.
A linear discharge tube that is assembled and installed in the discharge tube;
And the discharge tube is powered by the power supply (Ba).
The heater (H) is heated, and the power supply is turned on in the normal temperature range of the radiator tube, so that the heat source is turned on.
The power is supplied to the heater, and the power is supplied from the normal temperature range.
It will shut off by turning off the abnormally high temperature
Connected between the heater and the power source, and
A switch made of a temperature-sensitive material attached to the reflector
(120) and the temperature of the radiator tube, and
And Tagged temperature detecting element (111), the said heat radiating pipe based on the detected temperature of the temperature detecting element
At the time of high temperature in the normal temperature range, from the power supply to the heater
Control means (110) for cutting off the power supply to the casing, and a high-voltage generating circuit (100) fixed to the casing.
And a wiring board mounted on the reflector and the wiring board.
(70) A display device for a vehicle , comprising: a connector fixed therebetween.