JP2003262543A - Display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a combination meter 1 which ensures a sufficient intensity of illumination on a dial 2 and obtains a sufficient space for forming electric circuits on a printed board 3 by contriving the arrangement and shape a light guide body 4 and the arrangement a light emitting diode 5. <P>SOLUTION: A light guide 4 is disposed between a dial 2 and a printed board 3, an incident surface 4b of the light guide body 4 is tightly fitted in a through-hole 3a of the printed board 3, and a light emitting diode 5 is mounted on the backside of the board 3 so as to emit a light on the incident surface 4b through the through-hole 3a. An emitting surface 4a is set to have a larger area S4 than the area S3 of the through-hole 3a. This minimizes the light path from the diode 5 to the dial 2 to ensure a sufficient intensity of illumination on the dial 2 and reduces the area S3 of the through-hole 3a of the board 3 to a minimum essential to realize a combination meter 1 having a sufficient space for forming electric circuits on the printed board 3. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device suitable for use in automobiles and the like.

[0002]

2. Description of the Related Art As a conventional display device, for example, there is an instrument disclosed in Japanese Patent Laid-Open No. 2000-304921. In this instrument, a light guide member and a light source having two reflecting surfaces are arranged on the back surface side of an electric wiring board provided with a through hole, and a light outlet of the light guide member is arranged in the through hole of the electric wiring board. is doing. Then, the light incident on the light guide member from the light source is reflected by both reflecting surfaces and emitted from the light exit of the light guide member toward the dial plate to illuminate the dial plate. With this configuration, the gap between the scale board and the electric wiring board is narrowed to achieve a thin instrument.

[0003]

By the way, in the instrument disclosed in Japanese Patent Laid-Open No. 13-304921, the size of the through hole provided in the electric wiring board depends on the size of the light outlet of the light guide member. The size is set to be almost the same. Therefore, in order to increase the illuminance of the graduation plate in order to improve the visibility of the graduation plate, it is necessary to enlarge the light outlet of the light guide member (widen the area). That is, the size of the through hole provided in the electric wiring board must be increased. When the area of the through hole is increased in this way, there is a problem that the space for forming an electric circuit of the electric wiring board is reduced and the electric circuit configuration of the meter becomes difficult. Further, since the light from the light source is reflected twice inside the light guide, a loss occurs at each reflecting surface. Therefore, in order to compensate for this loss and secure a predetermined illuminance on the scale, it is necessary to use a light source with higher brightness (expensive), which may increase the cost of the instrument.

The present invention has been made in view of the above-mentioned problems, and by devising the arrangement and shape of the light guide member and the arrangement of the light source, an inexpensive light source of general brightness can be used to provide a sufficient scale plate. An object of the present invention is to provide a display device capable of obtaining a wide space for forming an electric circuit on an electric wiring board while ensuring illuminance.

[0005]

In order to achieve the above object, the present invention employs the following technical means.

A display device according to claim 1 of the present invention comprises a through hole provided in an electric wiring board and a light guide arranged between the scale board and the electric wiring board, and the light source comprises: The light guide is mounted on the back surface of the electric wiring board so that light can be emitted toward the dial through the through hole, and the end portion of the light guide body on the electric wiring board side is fitted into the through hole so that light from the light source can enter. The emission surface that emits light from the light source toward the dial is formed at the end on the dial side, and the area of this output surface is set larger than the area of the through hole. did. This allows
Since the path of light from the light source to the scale can be minimized, sufficient illuminance of the scale can be secured even with an inexpensive standard-luminance light source, and the light incident portion on the light guide body can be secured.
That is, it is possible to realize a display device in which the through-hole area of the electric wiring board is reduced and a large space for forming an electric circuit can be obtained on the electric wiring board.

According to the second aspect of the invention, the light source is a light emitting diode, and the light emitting surface and the electrode are arranged on the same surface. Thus, the light source can be arranged on the electric wiring board so as to emit light toward the dial and easily mounted.

According to the third aspect of the present invention, the through hole provided in the electric wiring board and the light guide disposed between the scale board and the electric wiring board are provided, and the light source is the electric wiring board. It is mounted on the back surface so as to emit light in a direction substantially parallel to the electric wiring board, and the end portion of the light guide body on the electric wiring board side is fitted and fixed in the through hole so that light from the light source can enter, and It has a reflective surface that reflects the light from the light source toward the graduation plate, while the end of the light guide body on the graduation plate side emits the light entering the light guide body from the light source toward the graduation plate. A surface is formed, and the area of this emission surface is set to be larger than the area of the through hole. As a result, the number of reflections on the way of the light from the light source to the graduation plate is suppressed to one time to secure sufficient illuminance of the graduation plate, and the degree of freedom of the positional relationship between the light source and the light guide body is improved, and the electric power is improved. The degree of freedom in designing the wiring board can be improved.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION A case where a display device according to the present invention is applied to a combination meter for an automobile will be described below with reference to the drawings.

(First Embodiment) FIG. 1 shows a first embodiment of the present invention.
FIG. 4 is a partially enlarged cross-sectional view of the combination meter 1 which is the display device according to the embodiment of FIG.

FIG. 2 is a front view of the combination meter 1.

FIG. 3 is a sectional view of the combination meter 1, which is a sectional view taken along line III-III of FIG.

The combination meter 1 is arranged in a position in the interior of the automobile in a position visible to the driver in front of the driver's seat to display the traveling speed of the automobile, operating states of various parts of the automobile, etc. to the driver. .

That is, the combination meter 1 is
Pointer shaft 6a according to a vehicle speed signal which is an electric signal from the outside
Is provided with a movement 6 for rotating the pointer 6 supported on the tip of the pointer shaft 6a along the surface of the dial 2 to indicate the traveling speed of the vehicle and to check the operating state of each part of the vehicle. It is instructed by turning on or off each of the indicators 21 to 24.

The graduation plate 2 is made of a transparent material such as polycarbonate resin, and has a graduation portion 2a, a numeral portion 2b and a character portion 2c for instructing the running speed of the automobile, and indicators for instructing the operating state of each portion of the automobile. 21-2
4 are formed. Here, each indicator is a water temperature indicator 21 that indicates the engine cooling water temperature, and a fuel indicator 2 that indicates the remaining fuel amount in the fuel tank.
2, a voltage indicator 23 that indicates the battery voltage, and an oil indicator 24 that indicates the amount of lubricating oil in the engine. Scale part 2a, number part 2b, character part 2
The c and the indicators 21 to 24 are formed of a transparent white printed layer having light transmittance. On the other hand, the scale 2
a, number part 2b, character part 2c and indicator 21 to
The portions other than 24, that is, the ground portion of the dial 2 are formed by a light-shielding black print layer that blocks the transmission of light.
Therefore, the back side of the dial 2 (right side of FIGS. 1 and 3)
When illuminated by the light emitted from the light emitting diode 5 which is the light source arranged at, the scale portion 2a, the numeral portion 2b, the character portion 2
c and the respective indicators 21 to 24 are luminescently displayed.

A printed circuit board 3 which constitutes an electric circuit of the combination meter 1 is arranged on the rear surface side (right side in FIG. 3) of the scale plate 2. The printed board 3 is a board 3b made of an electrically insulating material such as glass epoxy resin.
An electric conductor, for example, a copper foil 3c is attached to the surface of the. In the combination meter 1 according to the first embodiment of the present invention, the copper foil 3c is attached only to the back surface (the front surface on the right side in FIG. 3) of the printed circuit board 3. This copper foil 3c
Accordingly, a light emitting diode 5 which is a light source described later, a terminal (not shown) for connecting to electrodes of the movement 6 and the like, and a wiring portion (not shown) for electrically connecting each terminal to form an electric circuit. ) Is formed. In other words, the electric circuit of the combination meter 1
The printed circuit board 3 is intensively formed on the back surface (front surface on the right side in FIG. 3). Therefore, since the soldering work of various components such as the light emitting diode 5 and the movement 6 on the printed circuit board 3 is completed only on one side, the cost can be reduced as compared with the case where the electric circuits are formed on both sides of the printed circuit board. . Further, the printed board 3 is provided with a through hole 3a, and further, as shown in FIG. 1, a light emitting diode 5 as a light source is provided so as to emit light toward the dial 2 through the through hole 3a. It is implemented. As shown in FIG. 1, the light emitting diode 5 has a light emitting surface 5a for emitting light.
And the electrode 5b are arranged on the same surface. That is,
The size of the through hole 3a is smaller than that of the light emitting diode 5 and is set to be substantially the same as that of the light emitting surface 5a. The electrode 5b and the copper foil 3c of the printed circuit board 3 are electrically connected and fixed by the solder 12.

As shown in FIG. 3, a light guide 4 is arranged between the dial 2 and the printed circuit board 3. Light guide 4
Are arranged corresponding to the scale portion 2a, the numeral portion 2b, the character portion 2c, and the respective indicators 21 to 24. That is, one light guide body 4 is arranged corresponding to each one indicator, and further, corresponding to the scale portion 2a, the numeral portion 2b, and the character portion 2c, they are light-emitted and displayed with uniform brightness. Thus, another light guide 4 is arranged. Light guide 4
Is made of a transparent material such as acrylic resin. An incident surface 4b on which light from the light emitting diode 5 is incident is provided at the end of the light guide 4 on the printed circuit board 3 side. The incident surface 4b is formed to have substantially the same shape as the through hole 3a.
It is fitted to a and fixed to the printed circuit board 3. As a result, almost 100% of the light emitted by the light emitting diode 5 can be made incident into the light guide 4. On the other hand, the light guide 4
At the end on the scale plate 2 side, an emission surface 4a is provided to emit light from the light emitting diode 5 that has entered the light guide 4 from the incident surface 4b toward the scale plate 2. The area S4 of these emission surfaces 4a is set larger than the area S3 of the through holes 3a.

In the conventional instrument, the exit surface of the light guide is arranged in the through hole of the printed circuit board, and in order to increase the exit surface of the light guide in order to increase the illuminance of the dial, the print is performed. It was necessary to make the through holes of the substrate large (widen the area). For this reason, there is a problem that the space for forming an electric circuit on the printed circuit board is reduced and the electric circuit configuration of the instrument becomes difficult. On the other hand, in the combination meter 1 according to the first embodiment of the present invention, the light guide 4 is arranged between the graduation plate 2 and the printed board 3, and the area S4 of the emission surface 4a is equal to the area of the through hole 3a. Since it is set larger than S3, the illuminance of the dial 2 is increased and the area of the incident surface 4b, that is, the area S3 of the through hole 3a is increased.
By making the necessary minimum, it is possible to secure a sufficient electric circuit configuration space on the printed circuit board 3.

Since each light guide 4 is fixed to the printed circuit board 3 by fitting each incident surface 4b into the through hole 3a, the light emitting surface 5a of the light emitting diode 5 and each incident surface 4b are in a positional relationship. Is always maintained with high accuracy, and each light guide 4
It is possible to easily carry out the assembling work of the above to the printed circuit board 3.

On the back side of the dial 2 (right side of FIG. 3), that is, the back side of the printed circuit board 3 (right side of FIG. 3), an electric signal from the outside (in the combination meter 1 according to the first embodiment of the present invention) is used. Is a pointer shaft 6a according to the vehicle speed signal)
A movement 6 for rotating is mounted. A pointer shaft 6a of the movement 6 extends to the front of the dial 2 (on the left side in FIG. 1) through a hole 2d of the dial 2 and has a tip 7 that rotates along the surface of the dial 2 at its tip. Is fixed.

The pointer 7 is made of a transparent material such as acrylic resin. As shown in FIG. 3, the pointer 7 has a light emitting diode 8 built therein, and when the light emitting diode 8 is turned on, the pointer 7 is illuminated.

The light emitting diode 5, the movement 6 and the light emitting diode 8 described above are mounted on the back surface (right side in FIG. 3) of the printed circuit board 3 in the controller 1.
It is driven by 3.

The graduation plate 2 and the printed circuit board 3 described above
As shown in FIG. 3, the components and the like are housed and held in a resin case 9. In addition, the front side of the graduation board 2 (left side in FIG. 3)
As shown in FIG. 3, a transparent cover 11 is attached to the sheet through the dial plate 10. The transparent cover 11 is made of a transparent material such as a polycarbonate resin, protects the inside of the combination meter 1 and maintains airtightness.

Next, the electric circuit configuration of the combination meter 1 according to the first embodiment of the present invention will be described. FIG. 4 shows an electric circuit configuration diagram of the combination meter 1 according to the first embodiment of the present invention. As shown in FIG. 4, the controller 13 of the combination meter 1
The battery 20 is constantly supplied with electric power. In addition, the controller 13 uses the ignition switch 30.
Is connected so that its ON / OFF can be detected. As a result, the combination meter 1 is operated when the ignition switch 30 is on, and the combination meter 1 is off when the ignition switch 30 is off.
The operation of can be stopped. A vehicle speed sensor 14 that detects the traveling speed of the automobile is connected to the controller 13. As a result, the controller 13 controls the turning on / off of the light emitting diodes 5 and 8 in response to ON / OFF of the ignition switch 30, and drives the movement 6 based on the detection signal of the vehicle speed sensor 14 to move the pointer 7 to the pointer 7. Rotate to indicate running speed. Further, the controller 13 includes a water temperature sensor 15 for detecting the engine cooling water temperature of the automobile, a liquid level sensor 16 for detecting the fuel level in the fuel tank, a voltage sensor 17 for detecting the voltage of the battery 20, a lubrication in the engine. Oil level sensors 18 for detecting the oil level are respectively connected. As a result, the controller 13 causes the indicators 21 to 21 to follow the predetermined rules based on the output signals of the sensors 15 to 18.
24 is turned on or off.

In the combination meter 1 according to the first embodiment of the present invention described above, the through hole 3a is provided in the printed board 3 and the light guide 4 is arranged between the dial 2 and the printed board 3. Then, the light emitting diode 5, which is a light source, is mounted on the back surface of the printed board 3 so that light can be emitted toward the dial 2 through the through hole 3a. Further, the incident surface 4 which is the end portion of the light guide 4 on the printed circuit board 3 side.
b through which light from the light emitting diode 5 can enter
The light guide 4 is fitted and fixed at the end of the light guide 4 on the scale 2 side, and an emission surface 4a for emitting light from the light emitting diode 5 toward the scale 2 is formed. An area S4 of the emission surface 4a is formed. Is set to be larger than the area S3 of the through hole 3a. As a result, the two reflecting surfaces of the light guide in the conventional instrument can be eliminated and the light path from the light emitting diode 5 to the scale 2 can be minimized. 2 can ensure a sufficient illuminance, and the light incident surface 4b to the light guide 4, that is, the area S3 of the through hole 3a of the printed circuit board 3 can be made as small as necessary to an electric circuit in the printed circuit board 3. Combination meter 1 that can obtain a sufficiently wide forming space
Can be realized.

Further, since each light guide 4 is fixed to the printed circuit board 3 by fitting each incident surface 4b into the through hole 3a, the light emitting surface 5a of the light emitting diode 5 and each incident surface 4b are in a positional relationship. Is always maintained with high accuracy, and each light guide 4
It is possible to easily carry out the assembling work of the above to the printed circuit board 3.

Further, in the light emitting diode 5 which is the light source, the light emitting surface 5a and the electrode 5b are arranged on the same surface. Thereby, the light emitting diode 5 is
The printed circuit board 3 can be easily electrically connected to the printed circuit board 3 in a state where the printed circuit board 3 is arranged so as to emit light toward the scale plate 2.

FIG. 5 shows an enlarged partial sectional view of a modification of the combination meter 1 according to the first embodiment of the present invention. In this modification, the shape of the light guide 4 is changed from that of the combination meter 1 according to the first embodiment of the present invention described above. That is, as shown in FIG. 5, the light guide 4 is provided with a stopper portion 4d, and the stopper 4d
By bringing d into contact with the printed circuit board 3, the light guide 4
The positions of the printed circuit board 3 and the printed circuit board 3 in the direction of the pointer shaft 6a (the horizontal direction in FIG. 6) are regulated. Thereby, when the combination meter 1 is assembled, the workability when fitting and fixing the light guide 4 in the through hole 3a can be improved.

(Second Embodiment) Next, a combination meter 1 according to a second embodiment of the present invention will be described.

FIG. 6 shows an enlarged partial sectional view of the combination meter 1 according to the second embodiment of the present invention. Second
In the combination meter 1 according to the above embodiment, the shape of the light guide 4 and the emission direction of light from the light emitting diode 5 are changed with respect to the combination meter 1 according to the above first embodiment. That is, as shown in FIG. 6, the light guide 4 is projected to the back surface side of the printed circuit board 3,
A reflecting surface 4c for reflecting the light from the light emitting diode 5 toward the dial 2 is provided, and the light emitting diode 5 emits light in a direction parallel to the printed circuit board 3 and is reflected by the reflecting surface 4c of the light guide 4. Is mounted on the back surface of the printed circuit board 3 so that the incident light enters. In the combination meter 1 according to the first embodiment described above, the light emitting diode 5 is
It was necessary to mount the light emitting surface 5a on the printed circuit board 3 with the through hole 3a aligned. In other words, the mounting position of the light emitting diode 5 was uniquely determined by the position of the through hole 3a. However, in the combination meter 1 according to the second embodiment, the position of the light emitting diode 5 with respect to the through hole 3a, that is, the light guide 4 can be freely selected within a certain range. Therefore, the degree of freedom in the mounting position of the light emitting diode 5 is improved as compared with the case of the combination meter 1 according to the first embodiment, so that the degree of freedom in designing the electric circuit pattern on the printed circuit board 3 can be improved. . Further, in this case, the number of reflections in the light path from the light emitting diode 5 to the graduation plate 2 (arrow in FIG. 5) is set to once (twice in the conventional instrument) to minimize the attenuation of the light quantity. A scale plate 2 equivalent to the case of the combination meter 1 according to the first embodiment described above.
The illuminance can be secured.

In the combination meter 1 according to the first and second embodiments of the present invention described above, the light emitting diode 5 is used as a light source for illuminating the dial 2, but another light source, for example, is used. A light bulb or the like may be used. Further, in the combination meter 1 according to the first embodiment of the present invention, its modified example and other modified examples, the light emitting diode 8 is used as a light source for displaying the pointer 7 by light emission, but other light sources, for example, A light bulb or the like may be used. Further, the pointer 7 itself may be formed by a light source such as a cold cathode tube.

[Brief description of drawings]

FIG. 1 is a partially enlarged sectional view of a combination meter 1 according to a first embodiment of the present invention, which is an enlarged view of a portion I in FIG.

FIG. 2 is a front view of the combination meter 1 according to the first embodiment of the present invention.

3 is a sectional view of the combination meter 1 according to the first embodiment of the present invention, which is a sectional view taken along line III-III in FIG.

FIG. 4 is an electric circuit configuration diagram of the combination meter 1 according to the first embodiment of the present invention.

5 is a partial enlarged cross-sectional view of a modification of the combination meter 1 according to the first embodiment of the present invention, which corresponds to an enlarged view of a portion I in FIG.

FIG. 6 is a partially enlarged sectional view of the combination meter 1 according to the second embodiment of the present invention.

[Explanation of symbols]

1 Combination meter (display device) 2 scale plate 2a Scale part 2b number part 2c character part 2d hole 21 Water temperature indicator 22 Fuel indicator 23 Voltage indicator 24 Oil indicator 3 Printed circuit board (electrical wiring board) 4 Light guide 4a exit surface 4b Incident surface 4c reflective surface 4d stopper part 5 Light emitting diode (light source) 5a light emitting surface 5b electrode 6 movements 6a Pointer shaft 7 guidelines 8 light emitting diodes 9 cases 10 Back plate 11 transparent cover 12 Solder 13 Controller 14 vehicle speed sensor 15 Water temperature sensor 16 Liquid level sensor 17 Voltage sensor 18 Oil level sensor 20 battery 30 ignition switch

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 2F074 AA02 BB06 CC02 DD03 EE03                       FF01                 3D044 BA04 BA22 BA26 BA27 BA28                       BB01 BD02 BD13                 5C096 AA27 BA01 BB48 CC06 FA11                       FA17

Claims (3)

[Claims] 1. A display device comprising: a scale board; a light source for illuminating the scale board; and an electric wiring board arranged substantially parallel to the back surface side of the scale board, wherein the electric wiring board is provided. A through hole, and a light guide disposed between the scale board and the electric wiring board, wherein the light source faces the scale board through the through hole on the back surface of the electric wiring board. The light guide is mounted so as to be able to emit light, and the light guide body is fitted and fixed in the through hole such that an end portion on the electric wiring board side can enter light from the light source,
An emission surface for emitting light from the light source toward the scale is formed at an end portion on the scale side, and the area of the emission surface is set to be larger than the area of the through hole. Display device. 2. The display device according to claim 1, wherein the light source is a light emitting diode, and the light emitting surface and the electrode are arranged on the same surface. 3. A display device comprising: a graduation plate; a light source for illuminating the graduation plate; and an electric wiring board arranged substantially parallel to a back surface side of the graduation board, wherein the electric wiring board is provided. And a light guide disposed between the scale board and the electric wiring board, wherein the light source emits light on a back surface of the electric wiring board in a direction substantially parallel to the electric wiring board. The end portion of the light guide on the electric wiring board side is fitted and fixed in the through hole so that light from the light source can enter,
An emission that has a reflecting surface that reflects the light from the light source toward the scale plate, and that emits the light from the light source toward the scale plate at the end portion of the light guide body on the scale plate side. A surface is formed, and the area of the emission surface is set to be larger than the area of the through hole.