JP2002286511A - Indicating instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an indicating instrument made by exercising ingenuity in forming a light guide plate so as to increase the rate of light introduction from a directional light source into the light guide plate for lighting a dial plate from its back side. SOLUTION: An introduction part 50a of the light guide plate 50 has a curved cross section substantially in a V shape and extends toward a light emitting surface of an LED 100. A cutout 52 having a V-shaped cross section is formed in an end part of the introduction part 50a so as to open from its back side toward the emitting surface of the LED 100.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an indicating instrument.

[0002]

2. Description of the Related Art Conventionally, for example, indicating instruments for passenger cars include:
Japanese Unexamined Utility Model Application Publication No. 3-91915 discloses a technique. In this indicator, the light of the light emitting diode is introduced into the light guide plate provided on the back side of the scale plate from the end face, and the introduced light is incident on the scale plate from the surface of the light guide plate to illuminate the scale plate. It has become.

[0003]

By the way, in the indicating instrument described above, the light introducing portion of the light emitting diode of the light guide plate has only a simple end face, and the introducing portion has
No structural innovation has been made to increase the light utilization of the light emitting diode.

[0004] To cope with this, as shown in FIG. 8, a wiring board 2 is provided on the back side of the light guide plate 1, and a light emitting diode 3 is provided on the surface of the wiring board 2, so that the light guide plate 1 The light emitting surface 3a of the light emitting diode 3 is opposed to the light emitting surface 3a.
It is conceivable that the section is curved in a substantially V-shaped section toward a.

However, the light of the light emitting diode 3 has a strong directivity, and even if the light is incident from the light emitting surface 3a of the light emitting diode 3 to the substantially V-shaped cross-section facing portion 1a of the light guide plate 1 from the back side thereof, Most of the incident light is reflected by the back surface of the facing portion 1a in the directions of arrows a and b in FIG. Therefore, the rate of introduction of light from the light emitting diode 3 into the light guide plate 1 is low, and as a result, the rate of light emission from the light guide plate 1 to the scale plate located on the surface side of the light guide plate 1 is also low. Occurs.

Therefore, in order to cope with the above, the present invention devises the structure of the light guide plate so as to increase the light introduction rate from the directional light source to the light guide plate that illuminates the scale plate from the back side. It is an object of the present invention to provide an indicating instrument elaborating the above.

[0007]

In order to solve the above-mentioned problems, in the indicating instrument according to the first aspect of the present invention, there is provided a translucent scale plate (40) and a light guide plate provided along the back surface of the scale plate. (50) a pivot provided with a pointer shaft (72) provided on the back side of the light guide plate and rotatably extending through the light guide plate toward the center hole (41) of the scale plate; An inner machine (70), a pointer (90) supported by the tip of a pointer shaft through a center hole of the scale plate so as to rotate along the surface of the scale plate, and a rear surface side of the light guide plate. And a light source (100) for allowing light to enter the light guide plate from the back side thereof.

In the indicating instrument, the light source is a light source that emits directional light from its light emitting surface, and the light guide plate is
Introducing portion (50a) extending in a substantially V-shaped cross section from a portion of the back surface facing the light emitting surface of the light source toward the light emitting surface.
The introduction portion has a notch (52) having a V-shaped cross section that opens toward the light emitting surface of the light source at the extension end portion.

Thus, when the light source emits the directional light from the light emitting surface toward the introduction portion of the light guide plate, the light enters the notch of the introduction portion. Then, since the notch has a V-shaped cross section, the light thus incident is introduced into the introduction portion without being substantially reflected by both walls of the notch. The light thus introduced is guided inside the light guide plate and illuminates the scale plate from the surface of the light guide plate.

Here, as described above, since the light of the light source is introduced into the light guide plate without being substantially reflected, the utilization ratio of the light guide plate to the light of the light source is very high. Therefore, since the luminance of the scale plate can be extremely high, even if the pointer rotated by the rotating inner machine indicates on the scale plate, the visibility of the instruction is remarkably improved.

Further, in the indicating instrument according to the second aspect of the present invention, a translucent scale plate (40), a light guide plate (200) provided along the back surface of the scale plate, and a back surface of the light guide plate. A rotary inner machine (70) having a pointer shaft (72) provided on the side and rotatably extending through the light guide plate toward the center hole (41) of the dial; A pointer (90) supported at the tip of the pointer shaft through a center hole of the dial so as to rotate along the surface; and an outer peripheral surface (20) of the light guide plate.
0a) and a plurality of light sources (210) for emitting light to the light guide plate from the outer peripheral surface thereof.

In the indicating instrument, each of the plurality of light sources is a light source that emits directional light from its light emitting surface, and the light guide plate is a portion of the outer peripheral surface that faces each light emitting surface of each light source. And a guide portion (200b) extending in a V-shape toward each of the light-emitting surfaces. V-shaped notch (52).

Thus, when each light source emits directional light from its light emitting surface toward each corresponding introduction part, the light of each light source enters the cutout of each corresponding introduction part. Light that has entered the notch as described above is introduced into the corresponding introduction portion without being substantially reflected by both walls of the notch because the notch is V-shaped. Each light thus introduced is guided in the light guide plate and illuminates from the surface of the light guide plate. Here, as described above, since the light of each light source is introduced into the light guide plate without being substantially reflected, the utilization rate of the light guide plate for the light of each light source is very high. Therefore, since the brightness of the embossing plate can be very high, even if the pointer rotated by the rotating inner machine indicates on the dial, the visibility of the instruction is remarkably improved.

According to a third aspect of the present invention, in the first or second aspect, the width of the opening surface where the notch opens is D, the width of the light emitting surface of the light source is d, and the notch is A predetermined distance between the opening surface of the light source and the light emitting surface of the light source is L,
When the spread angle α of the light emitted from the light emitting surface of the light source toward the outer peripheral side of the light emitting surface is 30 degrees, D = d + 2Ltan
30 is established.

[0015] Thereby, the function and effect of the invention described in claim 1 or 2 can be further improved.

According to a fourth aspect of the present invention, in the first aspect of the present invention, the light source is a light emitting diode. This allows
Under the directivity of the light emitting diode, the same function and effect as the invention according to any one of claims 1 to 3 can be achieved.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIGS. 1 and 2 show an example in which the present invention is applied to a combination meter for a passenger car, and the combination meter is disposed on an instrument panel in a passenger compartment of the passenger car. As shown in FIGS. 1 and 2, the combination meter includes a vehicle speedometer S, an indicator I, and a tachometer T. The vehicle speedometer S, the indicator I, and the tachometer T are:
It is mounted in a housing comprising a casing 10, an annular dial plate 20 and a front panel 30. Note that the facing plate 20 is formed on the bottom wall 21 of the casing 1.
0 opening 11. Further, the front panel 30 is mounted on the front end side opening 22 of the dial plate 20.

The vehicle speedometer S has a scale plate unit U. The scale plate unit U is attached to an opening 21 a formed in the bottom wall 21 of the dial plate 20 from the back side. The scale plate unit U includes a scale plate 40,
A light guide plate 50 and a holder 60 having a U-shaped cross section are provided.

The scale plate 40 has a substantially arc-shaped vehicle speed scale 41 along the outer periphery thereof, which scales the vehicle speed of the passenger car.
The scales and characters of the vehicle speed scale portion 41 are black. The scale plate 40 is configured to transmit light except for the scales and characters of the scale portion 41.

The light guide plate 50 is provided on the scale plate 40 along the back surface thereof.
Together with the holder 60. Note that the holder 6
Numeral 0 is attached to the opening 21a of the bottom wall 21 of the return plate 20 at the peripheral wall.

The vehicle speedometer S includes a rotating inner unit 70, a wiring board 80, and a pointer 90. The rotating inner unit 70 is connected to the inner unit body 7
1 and a pointer shaft 72, and the inner machine main body 71 is mounted on the bottom wall 12 in the casing 10 at a position corresponding to the scale plate 40. The pointer shaft 72 is turned from the inner machine main body 71 to the center hole 42 of the dial 40 through the through hole 81 of the wiring board 80, the opening 61 of the bottom wall of the holder 60, and the opening 51 of the light guide plate 50. Extends movably.

The wiring board 80 is supported on the upper surface of the inner machine main body 71 in parallel with the scale plate 40, and the light emitting diode 100 is disposed on the surface of the wiring board 80 near the axis of the pointer shaft 72. Has been established. Here, the light emitting diode 100 is located immediately above the pointer shaft 72 as can be seen from FIG.

The pointer 90 is provided on a boss 91 of the pivot base 91.
At a, the pointer 90 is supported by the tip of the pointer shaft 72, and the pointer 90 is rotatable along the surface of the scale plate 40.

Next, a detailed configuration of the light guide plate 50 will be described in relation to the configuration of the light emitting diode 100 with reference to FIGS. As shown in FIGS. 4 and 5, the light emitting diode 100 (hereinafter, referred to as LED 100) includes a rectangular parallelepiped casing 110 made of a white electric insulating resin. The part 112 is formed in a concave shape.
The housing portion 112 is opened outward from the upper wall 111 of the casing 110 at the opening 112a, and the bottom surface 112b of the housing portion 112 is parallel to the upper wall 111. Further, the inner peripheral surface 112c of the housing portion 112 extends from the opening 112a to the bottom surface 112c in order to increase the light reflection efficiency.
It inclines toward the end toward b.

The LED 100 includes both lead frames 120 and 130.
Reference numerals 20 and 130 extend from the peripheral wall of the casing 110 in a substantially U-shape in opposite directions, and are soldered to the surface of the wiring board 80. Note that each of the lead frames 120 and 130 is
These constitute the cathode and anode of the LED 100, respectively.

The LED 100 is an LED chip 14
0, and this LED chip 140
12 and adhered to the inner end of the lead frame 120 with silver paste. The LED chip 140 emits light toward the opening side of the housing 112.

In the housing 112, a covering member 150 is provided.
The covering member 150 is formed by filling a transparent potting resin such as an epoxy resin. The LED chip 140, the gold wire 141, and both the lead frames 120, 1
Cover each of the 30 inner ends. Note that the covering member 150 emits light from the LED chip 140 from its surface (corresponding to the opening surface of the housing portion 112). Also, the LED chip 140
Is connected to the lead frame 1 by the gold wire 141 at its positive electrode.
30 is electrically connected to the inner end of the lead frame 120 at its negative electrode.

Here, the light distribution and intensity of the LED 100 will be described. The surface of the covering member 150, that is, the housing part 1
The opening surfaces of the twelve openings 112a correspond to the light emitting surfaces of the LEDs 100. Therefore, the LED 100 emits light from the light emitting surface. The light emitted from the light emitting surface of the LED 100 has a spread. Therefore, if the diameter of the light emitting surface is d, and both normals to the light emitting surface that define the diameter d are a and b, the light from the light emitting surface spreads outward, but the strong range of this light Figure 6
Is specified at a predetermined angle α as shown by. In the present embodiment, the LED 100 such as the cross-sectional shape of the housing 112 and the position of the LED chip 140 is set so that the predetermined angle α is 30 degrees.
Are set. Therefore, the strong angle range of the light emitted from the light emitting surface of the LED 100 is specified by the predetermined angle β including the predetermined angle α as shown in FIG.

Further, as shown in FIG. 2, the light guide plate 50 has an introduction portion 50a.
The LED is located just above the pointer shaft 72 in FIG.
It is formed so as to be curved in a substantially V-shaped cross section toward the 100 side and to extend from the opening 61 of the holder 60. As shown in FIG. 3, the introduction portion 50a is curved in a substantially V-shaped cross-section so as to have a convex cross-section toward the scale plate 40.
A notch 52 having a V-shaped cross section is formed at the tip of the introduction portion 50a from the back side. Here, the top 52 a of the notch 52 is the LED chip 14 of the LED 100.
It is on the axis of 0 (the axis of the light emitting surface), and the opening angle γ of the notch 52 is about 90 degrees. The introduction unit 50
The extension a may be provided only on the back surface side of the light guide plate 50.

In this embodiment, the diameter of the opening of the notch 52 facing the light emitting surface of the LED 100 is D as shown in FIG.
Assuming that a predetermined distance between the light emitting surface and the light emitting surface is L, both diameters d and D
And the predetermined interval L, a relationship expressed by the following equation 1 is established. Note that the light emitting surface of the LED 100 and the opening surface of the notch 52 are parallel to each other.

[0031]

D = d + 2Ltan α = d + 2Ltan30 If the relationship of the expression 1 is satisfied, the light from the light emitting surface of the LED 100 is introduced without being substantially reflected by the V-shaped walls 52b of both cross sections of the notch 52. It is introduced into the section 50a. This means that the introduction from the LED 100 into the introduction portion 50a of the light guide plate 50 through the notch 52 is performed efficiently and effectively.

In the present embodiment configured as described above, when the LED chip 140 emits light, the LED 100 emits directional light from its light emitting surface toward the introduction portion 50 a of the light guide plate 50. Along with this, the light of the LED 100 enters the notch 52 of the introduction part 50a. Then, since the expression of Equation 1 is established as described above, the light thus incident is applied to both V-shaped walls 52 of the notch 52.
The light is introduced into the introduction part 50a without being substantially reflected by the light-receiving element a.

The light introduced as described above is guided inside the light guide plate 50 and the scale plate 40 is moved from the surface of the light guide plate 50.
To illuminate the scale plate 40 through the portion of the scale plate 40 except for the scales and characters.
Here, as described above, since the light of the LED 100 is introduced into the light guide plate 50 without being substantially reflected, the LE 100
The utilization rate of the light guide plate 50 for the light of D100 is very high. Therefore, since the luminance of the scale plate 40 can be extremely high, even if the pointer 90 rotated by the rotating inner unit 70 indicates the vehicle speed on the scale plate 40, the visibility to the instruction is significantly improved.

FIG. 7 shows a modification of the above embodiment. In this modification, the light guide plate 200 and the plurality of L
The ED 210 is employed in place of the light guide plate 50 and the LED 100 described in the above embodiment. Light guide plate 200
Is accommodated in the holder 60 along the back surface of the scale plate 40, and a plurality of introduction portions 200b are formed on the outer peripheral surface 200a of the light guide plate 200 at predetermined angular intervals. Since each of the introduction units 200b has the same configuration, only an example configuration will be described. The introduction portion 200b is formed to protrude radially outward from the outer peripheral surface 200a of the light guide plate 200 in a substantially V-shape, and the two V-shaped surface portions 201 of the introduction portion 200b are moved toward each other. It is curved so as to be concave. In addition, a V-shaped notch 202 is formed at the tip of the introduction portion 200b.

The plurality of LEDs 210 are arranged in the holder 60 along the outer peripheral surface 200a of the light guide plate 200 at positions corresponding to the respective introduction portions 200b. Each of the LEDs 210 has the same configuration and function as the above-described LED 100, and each of the LEDs 210 faces the notch 202 of each of the corresponding introduction portions 200b on its light emitting surface. Here, the opening angle of the notch 202 is the same as the opening angle of the notch 52 described in the above embodiment,
The geometric relationship between the light emitting surface of the LED 210 and the opening of the corresponding notch 202 is such that the equation of Equation 1 is substantially satisfied. Is set corresponding to the geometric relationship of. Other configurations are the same as those of the above embodiment.

In the present modified example having such a configuration, the introduction of light from each LED 210 to the light guide plate 200 will be described with reference to an example of the corresponding introduction unit 200b and LED 210. When the LED 210 emits directional light from the light emitting surface toward the corresponding introduction unit 200b, LE
The light of D210 corresponds to the notch 202 of the corresponding introduction unit 200b.
Incident inside.

Then, since the equation (1) is satisfied in the present modification as described above, the light incident on the notch 202 is almost reflected by both V-shaped walls of the notch 202. Without being introduced into the introduction unit 200b. The light thus introduced is guided inside the light guide plate 200 and the scale plate 40
To illuminate the scale plate 40 through the portion of the scale plate 40 except for the scales and characters.
Here, as described above, since the light of the LED 210 is introduced into the light guide plate 200 without being reflected, L
The utilization rate of the light guide plate 200 for the light of the ED 210 is very high. The same applies to the relationship between the remaining LEDs 210 and the corresponding introduction unit 200b. Therefore, even in this modification, the luminance of the scale plate 40 can be made extremely high. Therefore, even if the pointer 90 rotated by the rotating inner device 70 indicates the vehicle speed on the scale plate 40, the user can visually recognize the instruction. The properties are significantly improved.

In implementing the present invention, in the above-described embodiment, an example in which the present invention is applied to the vehicle speedometer S has been described. However, the present invention is not limited to this. With the same configuration, the same operation and effect as the above embodiment can be achieved.

In implementing the present invention, the light guide plate 50
In this case, the introduction portion 50a is not limited to the vicinity of the axis of the pointer shaft 72, and may be provided anywhere on the back surface of the light guide plate 50 as long as light can be effectively guided into the light guide plate 50.
The LED 100 is provided on the surface of the wiring board 80 at a position facing the introduction portion 50a. This can also achieve substantially the same operation and effect as the above embodiment.

In implementing the present invention, the LED 10
Instead of being limited to 0, a light source having high directivity substantially similar to the LED may be used instead of the LED 100.

In practicing the present invention, the present invention may be applied not only to passenger cars, but also to various types of indicator instruments for vehicles, and may be applied to indicator instruments for general industrial equipment. Good.

[Brief description of the drawings]

FIG. 1 is a partially broken front view showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along line 2-2 in FIG.

FIG. 3 is an enlarged partial sectional view showing a configuration of an introduction portion of the light guide plate of FIG. 1 in relation to an LED.

FIG. 4 is an enlarged sectional view of the LED of FIG. 3;

FIG. 5 is a front view of the LED of FIG. 4;

FIG. 6 is a side view of the LED of FIG. 3;

FIG. 7 is a plan view showing a modification of the embodiment.

FIG. 8 is a partial sectional side view of a light guide plate, a light emitting diode, and a wiring board in a conventional indicating instrument.

[Explanation of symbols]

Reference numeral 40: scale plate, 41: central hole, 50, 200: light guide plate, 50a, 200b: introduction part, 52, 202: notch, 70: rotary inner machine, 72: pointer shaft, 90: pointer, 10
0, 210 ... LED.

Claims (4)

[Claims] 1. A translucent scale plate (40), and a light guide plate (50) provided along the back surface of the scale plate.
And a pointer shaft (72) provided on the back side of the light guide plate and rotatably extending through the light guide plate toward the center hole (41) of the scale plate. (70) a pointer (90) supported at the tip of the pointer shaft through a center hole of the scale plate so as to rotate along the surface of the scale plate; A light source (100) provided to input light to the light guide plate from the back side thereof, wherein the light source is a light source that emits directional light from its light emitting surface; Has an introduction portion (50a) extending in a substantially V-shaped cross section from a portion of the back surface facing the light emission surface of the light source toward the light emission surface, and the introduction portion is provided at the extension tip portion. And a finger having a notch (52) having a V-shaped cross section that opens toward the light emitting surface of the light source. Instrument. 2. A translucent scale plate (40), and a light guide plate (200) provided along a back surface of the scale plate.
And a pointer shaft (72) provided on the back side of the light guide plate and rotatably extending through the light guide plate toward the center hole (41) of the scale plate. (70) a pointer (90) supported by a tip end of the pointer shaft through a center hole of the dial so as to rotate along the surface of the dial, and an outer peripheral surface (200a) of the light guide plate. ), And a plurality of light sources (21) for entering light into the light guide plate from the outer peripheral surface thereof.
0), wherein each of the plurality of light sources is a light source that emits directional light from its light emitting surface, and wherein the light guide plate emits light from each of the light sources on its outer peripheral surface. An introduction portion (200b) extending in a V-shape from each portion facing the surface toward each of the light-emitting surfaces, wherein each of the introduction portions has a corresponding one of the corresponding light sources at its extending end. An indicating instrument having a V-shaped notch (52) opening toward the light emitting surface of (1). 3. The width of an opening surface where the notch opens is D.
The width of the light emitting surface of the light source is d, the predetermined distance between the opening surface of the notch and the light emitting surface of the light source is L,
When the spread angle α of the light emitted from the light emitting surface of the light source toward the outer peripheral side of the light emitting surface is 30 degrees, D = d + 2Lt
The indicating instrument according to claim 1, wherein an30 is satisfied. 4. The indicating instrument according to claim 1, wherein the light source is a light emitting diode.