JP2004144583A - Measuring instrument with light-emitting pointer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent an appearance of a light-emitting pointer measuring instrument from getting worse by a cause that a periphery of a light shielding cap of a dial gets luminous ring-likely with leakage, to the dial, of one portion of irregular reflection light in a base part of a pointer. <P>SOLUTION: The dial 2 is provided with a protruded part 22 of a convex face coaxially to a through hole 21 (that is, a route of light from a light guide body 5 to the base part 41 of the pointer 4) in the periphery of the through hole 21, and the protruded part 22 is formed sloped-face-likely to make a clearance with respect to the pointer 4 narrow from an outer circumferential side thereof toward the through hole 21. An incident angle to the protruded part 22 of the light reflected toward a protruded part 22 direction gets large thereby in the base part 41 of the pointer 4, compared with that of a conventional combination meter. An emitting direction of the reflected light in the protruded part 22 is greatly turned aside thereby from a visual direction of a driver to preclude visibility for the driver. Resultingly, the appearance of a combination meter 1 is prevented from getting worse by the cause that the periphery of the light shielding cap 8 of the dial 2 gets luminous ring-likely. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a light-emitting pointer instrument that emits a pointer with a light source, and is suitable for use in vehicles and the like.
[0002]
[Prior art]
2. Description of the Related Art As a conventional light-emitting indicator instrument, for example, there is a meter such as a speedometer for an automobile that displays with a pointer, in which light from a light source is guided to the pointer to cause the pointer itself to emit light. This is done by disposing a rotating inner machine on the back side of the dial, extending its pointer shaft from the through hole of the dial to the front side, fixing it to the tip of this pointer shaft, and rotating along the surface of the dial The pointer is formed from a translucent material, and the light from the light source guided by the light guide is supplied to the pointer through the through hole of the dial to cause the pointer to emit light.
[0003]
In this type of light-emitting pointer instrument, since the rotation center area of the pointer is covered with a light-shielding cap, light leaks from this part in the axial direction of the pointer shaft, that is, light in the direction directly toward the driver's eyes is blocked. Is done. However, light leakage may occur in the direction along the dial surface from between the light-shielding cap and the dial. In this case, the area around the light-shielding cap is brightly illuminated in the form of a solar corona during a solar eclipse, and the contrast between the dial and the hands is weakened, and the visibility of the hands may be reduced.
[0004]
As a countermeasure, there is a method in which a light-shielding wall is formed so as to protrude at least in the operation area of the hands around the through-hole at the periphery of the through-hole of the dial (for example, see Patent Document 1).
[0005]
This light-shielding wall is intended to suppress light leakage from the gap between the light guide and the pointer to the dial.
[0006]
[Patent Document 1]
Japanese Utility Model Application Laid-Open No. 3-110316
[Problems to be solved by the invention]
It is possible to some extent to suppress light leakage from the gap between the light guide and the pointer to the dial by the light-shielding wall in the luminous pointer instrument described in Japanese Utility Model Laid-Open No. 3-110316.
[0008]
By the way, in the above-mentioned conventional luminous pointer instrument, most of the light emitted from the light guide and incident on the base of the pointer enters the pointer, but a part thereof is diffusely reflected at the base of the pointer, and this reflected light is reflected. Is incident on the dial. This light is diffusely reflected by the dial, and a part of the light is emitted in the direction of the driver's view. For this reason, the dial around the light-shielding cap may be visually recognized by the driver in a ring shape, and the appearance of the light-emitting pointer instrument may be reduced.
[0009]
The present invention has been made in view of the above problems, and an object of the present invention is to provide a light emitting pointer instrument in which part of diffusely reflected light at the base of the hand leaks to the dial, and the periphery of the light-shielding cap of the dial shines brightly in a ring shape. It is an object of the present invention to provide a light-emitting indicator which can prevent the appearance from being deteriorated.
[0010]
[Means for Solving the Problems]
The present invention employs the following technical means to achieve the above object.
[0011]
A luminous pointer instrument according to claim 1 of the present invention has a dial, a rotating inner machine which is disposed on the back side of the dial, and has a pointer shaft extending rotatably through a through hole of the dial. A pointer made of a translucent material that is supported at the base of the pointer shaft at the tip thereof and rotates along the surface of the dial, and a light-shielding cap attached to the pointer so as to cover at least the surface of the rotation center region of the pointer. A light guide made of a translucent material that is arranged on the back side of the dial and allows light to enter the base through the through hole, and a light source that is arranged on the back side of the dial so that light can enter the light guide. A light-emitting pointer instrument for guiding light from a light source through a light guide to be incident on a base of the pointer to emit a pointer, and the dial has a protruding surface substantially coaxial with the through-hole around the through-hole. The protruding surface has a gap with the pointer from the outer peripheral side toward the through hole. And configured to be formed to be smaller.
[0012]
By the way, most of the light emitted from the light guide and entering the base of the pointer enters the pointer, but a part of the light is diffusely reflected at the base of the pointer. The diffusely reflected light at the base of the pointer is emitted in all directions, but the intensity of normal reflected light, that is, light in the reflected light direction (hereinafter, referred to as main reflected light) in which the incident angle and the outgoing angle have the same relationship, is high. Will be the highest. Therefore, the intensity of light in the direction in which the emission angle at the base of the pointer is small, or in other words, in the direction in which the angle formed with the direction of the pointer axis is small, is highest.
[0013]
In a conventional light-emitting indicator instrument, the light incident surface from the light guide at the base of the pointer and the dial surface are in a substantially parallel relationship. For this reason, the angle of incidence of the main reflection light of the diffuse reflection light at the base of the hands when entering the dial is substantially the same as the emission angle at the base of the hands, and further, the emission angle is equal to this incidence angle. Emitted from the board. In other words, the light is emitted at a small angle with the direction of the pointer axis, in other words, at an angle close to the viewing direction of the driver. Thus, there is a problem that the dial around the light-shielding cap is visually recognized by the driver in a ring shape, and the appearance of the light-emitting pointer instrument is reduced.
[0014]
On the other hand, in the luminous pointer instrument according to claim 1 of the present invention, the dial has a protruding surface substantially coaxial with the through hole around the through hole (ie, the path of light from the light guide to the base of the pointer). The projecting surface is so arranged that the gap with the pointer becomes smaller from the outer peripheral side toward the through hole, in other words, the projecting surface extends from the center of the pointer toward the tip of the pointer. It is formed in the shape of an inclined surface that moves away from the pointer in the direction of the pointer axis. For this reason, the angle of incidence when the main reflection light of the diffuse reflection light at the base of the pointer is incident on the dial, that is, the protruding surface, becomes larger than the angle of incidence in the conventional light emitting pointer instrument, and subsequently, this angle of incidence The light exits at an exit angle equal to. This emission direction deviates greatly from the driver's visual recognition direction as compared with the emission direction in the conventional light emitting pointer instrument. That is, the diffuse reflection light at the base of the pointer is not visually recognized by the driver. As a result, it is possible to prevent a part of the diffusely reflected light at the base of the pointer from leaking to the dial, and to prevent the periphery of the light-shielding cap of the dial from shining brightly in a ring shape and deteriorating the appearance of the light-emitting pointer instrument.
[0015]
In the invention described in claim 2, the projecting surface is configured to be an axisymmetric curved surface with the central axis of the through hole as an axis. Thereby, the protruding surface can be easily formed on the dial.
[0016]
According to the third aspect of the present invention, the projecting surface is formed by a plurality of planes. Thereby, the protruding surface can be easily formed on the dial.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an example in which a light-emitting indicator according to an embodiment of the present invention is applied to a combination meter 1 mounted on an automobile will be described with reference to the drawings.
[0018]
The combination meter 1 is provided in front of a driver's seat in the cabin of the vehicle, and displays the operating state (running speed, engine speed, and the like) of the vehicle so that the driver can visually recognize the operating state by rotating the hands 4. . Further, since the hands 4 are displayed by light emission, good visibility can be obtained.
[0019]
FIG. 1 is a cross-sectional view of a combination meter 1 according to one embodiment of the present invention. In FIG. 1, the right side is the driver's seat side, and the left-right direction is the driver's visual recognition direction.
[0020]
Dial 2 is formed of a thin plate such as resin or metal, and has scales and numerals (not shown) on its surface (the right surface in FIG. 1). A substantially central portion of the dial 2 is provided with a through hole 21 through which a shaft 31 serving as a pointer shaft described later is inserted. Further, a raised portion 22 which is a protruding surface substantially coaxial with the through hole 22 is formed around the through hole 21 of the dial 2. As shown in FIG. 1, the raised portion 22 has a spherical shape that is an axisymmetric curved surface about the center axis of the through hole 22, and is closer to the hands 4 than the other part of the dial 2 (right side in FIG. 1). It is formed so as to protrude. The center of the spherical surface as the raised portion 22 is located on the back side (left side in FIG. 1) of the raised portion 22 and on the pointer shaft 31 or an extension thereof. Accordingly, as shown in FIG. 1, the size of the gap between the raised portion 22 and the pointer 4 decreases from the outer peripheral side of the raised portion 22 toward the through hole 21.
[0021]
On the back side of the dial 2, a movement 3, which is a rotation internal machine for rotating the hands 4, is arranged. The movement 3 includes, for example, a cross-coil type driving unit and the like, and rotates the shaft 31 serving as a pointer shaft by an angle corresponding to an external electric signal. The shaft 31 extends to the front surface side of the dial 2 so as to be rotatable through the through hole 21 of the dial 2. The pointer 4 is fixed to the tip of the shaft 31. The movement 3 is mounted and fixed on a printed circuit board 7 arranged on the back side of the dial 2.
[0022]
The pointer 4 is formed of a translucent material, for example, a transparent acrylic resin or a polycarbonate resin. As shown in FIG. 1, the pointer 4 is fixed to the distal end of the shaft 31 at its base 41 and rotates integrally with the shaft 31. In addition, from the base 41, an indicator 43 extends in the radial direction of the shaft 31. The instructing unit 43 rotates along the surface of the dial 2 according to the rotation of the shaft 31, and instructs a predetermined physical quantity together with a scale or the like (not shown) on the dial 2. The pointer 4 has a reflection surface 42. The reflecting surface 42 reflects the light emitted from the light emitting diode 6, which is the light source, which has entered the pointer 4 from the base 41 toward the pointing unit 43. A halftone reflection layer (not shown) is provided on the back surface 44 of the instruction unit 43 by printing in order to diffusely reflect the light incident on the back surface 44 so that the driver can visually recognize the light.
[0023]
A printed circuit board 7 is arranged on the back side of the dial 2 (the left side in FIG. 1). The printed circuit board 7 forms an electric circuit portion of the combination meter 1, and the movement 3 is mounted and fixed, and the light emitting diode 6 as a light source for illuminating the hands 4 is mounted thereon.
[0024]
A light guide 5 for guiding the light emitted by the light emitting diode 6 to the pointer 4 and causing the pointer 4 to emit light is disposed between the pointer 4 and the light emitting diode 6. The light guide 5 is formed of a transparent acrylic resin or a polycarbonate resin which is a translucent material. At a substantially central portion of the light guide 5, a through hole 51 for inserting the shaft 31 of the movement 3 is provided. Further, as shown in FIG. 1, a reflection surface 52 is provided on a peripheral edge of the rear surface of the through hole 51. Further, a reflection surface 53 is provided on an outer peripheral portion of the light guide 51. The light from the light emitting diode 6 that has entered the light guide 5 travels inside the light guide 5 as shown by arrows in FIG. 1 while being reflected by the reflection surfaces 53 and 52, and the pointer of the light guide 5. Light is emitted toward the base 41 of the pointer 4 from the light emitting surface 54 which is the end face on the fourth side. Then, the light is reflected by the reflecting surface 41 of the pointer 4 toward the indicating section 43, and further travels inside the indicating section 43 while repeating reflection. This light is diffusely reflected on the halftone dot reflection layer provided on the back surface 44 of the pointer 4, so that the indicator 43 is illuminated and displayed. Since the light emitting surface 54 emits light in an annular shape, the hands 4 are always displayed with a stable luminance regardless of the rotation angle.
[0025]
Meanwhile, light emitted from a portion of the end surface 5b of the light guide 5 that is not opposed to the pointer 4 may travel rightward in FIG. 1, that is, toward the driver, and dazzle the driver. Therefore, the pointer 4 is provided with a light-shielding cap 8 for covering the surface of the rotation center area, which is a portion corresponding to the light emitting surface 54 of the pointer 4. The light-shielding cap 8 is formed of a metal sheet having a light-shielding property or a resin. When the driver looks at the combination meter 1, the pointer 4 is visually recognized with only the indicator 43 extending from the light shielding cap.
[0026]
The dial 2, the light guide 5, the movement 3, the printed board 7, and the like are housed and fixed in a resin case 10. A transparent cover 10 is attached to the case 9 to prevent dust from entering the combination meter 1 and keep the dial 2 and the hands 4 clean.
[0027]
Next, the effect of the raised portion 22 of the dial 2 on the visibility of the combination meter 1 according to one embodiment of the present invention will be described.
[0028]
FIG. 2 is a partially enlarged view of the vicinity of the raised portion 22 and the hands 4 of the dial 2 in the combination meter 1 according to one embodiment of the present invention. In FIG. 2, the dashed line indicates the shape of the dial 200 and the path of light in the conventional combination meter.
[0029]
Most of the light emitted from the light emitting surface 54 of the light guide 5 enters the hands 4 from the base 42 and contributes to the light emission display of the hands 4. However, some light is reflected at the base 42 toward the dial 2 as shown in FIG.
[0030]
Here, in the conventional combination meter, the dial 200 has a shape as shown by a dashed line in FIG. 2, that is, a planar shape substantially parallel to the base 42 of the hands 4. The reflected light reflected toward the dial 200 at the base 42 enters the dial 200 at an incident angle θ2, and subsequently exits the dial 200 at an emission angle θ2. Becomes smaller, that is, it is reflected toward the raised portion 22. In this case, the incident angle to the dial 200 = the outgoing angle = θ2 is a small angle, and the traveling direction of the light C emitted from the dial 200 is substantially parallel to the shaft 31, in other words, the direction close to the viewing direction by the driver. It becomes. Therefore, in the conventional combination meter, the light reflected by the base 42 of the hands 4 and the dial 200 enters the eyes E of the driver as shown in FIG. As a result, the periphery of the light-shielding cap 8 on the dial 200 is visually recognized by the driver in a bright ring shape, and the appearance of the combination meter is reduced.
[0031]
On the other hand, in the combination meter 1 according to one embodiment of the present invention, the reflected light reflected toward the dial 2, that is, the raised portion 22 at the base 42, is transmitted to the dial 200 at an incident angle θ1 as shown in FIG. The light enters and then exits from the raised portion 22 at an emission angle θ1. As described above, the raised portion 22 is formed such that the size of the gap between the raised portion 22 and the pointer 4 decreases from the outer peripheral side of the raised portion 22 toward the through hole 21, that is, the conventional dial It is formed inclined with respect to 200. For this reason, the incident angle θ1 of the reflected light on the raised portion 22 at the base portion 42 is larger than the incident angle θ2 of the conventional combination meter. Accordingly, as shown in FIG. 2, the traveling direction of the light A emitted from the raised portion 22 is substantially parallel to the dial 2 or the pointing portion 43 of the hands 4, in other words, a direction largely deviated from the viewing direction by the driver. Therefore, it is not visually recognized by the driver. This makes it possible to reliably prevent the driver from visually recognizing a portion around the light-shielding cap 8 in the conventional dial 200 in a ring-like shape, thereby reducing the appearance of the combination meter.
[0032]
FIG. 3 is a partial cross-sectional view of a combination meter 1 according to a modification of the embodiment of the present invention.
[0033]
In this modification, the shape of the raised portion 22 of the dial 2 is changed with respect to the combination meter 1 according to the above-described embodiment of the present invention. That is, as shown in FIG. 3, the raised portion 22 is changed from a spherical shape to a conical shape. Also according to this configuration, the traveling direction of the light emitted from the light emitting surface 54 of the light guide 5, reflected by the base 42, and incident on the raised portion 22, and emitted again from the raised portion 22 is greatly increased from the viewing direction of the driver. The direction can be deviated. Therefore, it is possible to reliably prevent the driver from visually recognizing a portion around the light-shielding cap 8 in the conventional dial 200 in a ring-like shape, thereby deteriorating the appearance of the combination meter.
[0034]
FIG. 4 shows a partial cross-sectional view of a combination meter 1 according to another modification of the embodiment of the present invention.
[0035]
In another modification, the shape of the light guide 5 and the mounting position of the light emitting diode 6 on the printed circuit board 7 are changed from the combination meter 1 according to the embodiment of the present invention described above. That is, as shown in FIG. 4, the light guide 5 is formed in a substantially cylindrical shape having an outer diameter corresponding to the base 41 of the pointer 4, and is disposed substantially coaxially with the shaft 31. Above, the light emitting diode 6 was moved to a position where light could enter the light guide 5. In this case, the same effects as those of the embodiment of the present invention can be obtained. Further, since the light guide 5 and the light emitting diode 6, which are the illuminating means for emitting the hands 4, are arranged near the shaft 31, the dial 2 can be used for display effects (for example, scales, character lighting, etc.). Space for the device can be secured.
[0036]
FIG. 5 is a perspective external view of a dial 2 in another modification of the combination meter 1 according to one embodiment of the present invention. In FIG. 5, the pointer 4, the light shielding cap 8, and the like are omitted for easy understanding. The right side in FIG. 5 is the driver's seat side.
[0037]
In the combination meter 1 according to the embodiment of the present invention and the modification example described above, the shape of the raised portion 22 is spherical or conical, that is, curved. On the other hand, in another modified example, as shown in FIG. 5, it is configured as an aggregate of a plurality of planes 23. Also in this case, similarly to the above-described embodiment of the present invention, the portion around the light-shielding cap 8 in the conventional dial 200 is visually recognized by the driver as a ring, and the appearance of the combination meter is reduced. Failures can be reliably prevented.
[0038]
In the combination meter 1 according to the embodiment of the present invention and the modified example described above, the pointer 4 reflects the light from the light-emitting diode 6 and causes the indicating section 43 to emit light to display the dot. Although a layer is used, other means, such as applying a light color (white, silver, etc.) to the back surface 44, providing a textured surface on the back surface 44, or a light diffusing substance May be mixed.
[0039]
Further, in the combination meter 1 according to the embodiment of the present invention and the modified example described above, the light emitting diode 6 is used as a light source, but another light source, for example, a light bulb or a discharge tube may be used.
[Brief description of the drawings]
FIG. 1 is a sectional view of a combination meter 1 according to an embodiment of the present invention.
FIG. 2 is a partially enlarged view of the periphery of the raised portion 22 and the pointer 4 of the dial 2 in the combination meter 1 according to one embodiment of the present invention.
FIG. 3 is a partial cross-sectional view of a modification of the combination meter 1 according to one embodiment of the present invention.
FIG. 4 is a sectional view of a modification of the combination meter 1 according to one embodiment of the present invention.
FIG. 5 is a perspective external view of a dial 2 in another modification of the combination meter 1 according to one embodiment of the present invention.
[Explanation of symbols]
1 Combination meter (luminous pointer meter)
2 Dial 21 Through hole 22 Raised part (projecting surface)
3 movement (rotating inner machine)
31 Shaft (pointer shaft)
4 pointer 41 base 42 reflecting surface 43 indicator 44 back 5 light guide 51 through hole 52, 53 reflecting surface 54 light emitting surface 6 light emitting diode (light source)
7 Printed circuit board 8 Light shielding cap 9 Case 10 Transparent cover 200 Dial A Light C Light E Eye θ1, θ2 Incident angle

Claims (3)

Dial and
A rotating inner machine that is arranged on the back side of the dial and extends a pointer shaft so as to be rotatable through a through hole of the dial,
A pointer made of a translucent material that is supported at the base of the pointer shaft at the tip thereof and rotates along the surface of the dial,
A light-shielding cap attached to the pointer so as to cover at least the surface of the rotation center region of the pointer,
A light guide made of a translucent material that is arranged on the back side of the dial and allows light to enter the base through the through hole;
A light source arranged on the back side of the dial so that light can enter the light guide,
A light emitting pointer instrument that guides the light from the light source through the light guide, enters the base of the pointer, and emits the pointer,
The dial has a protruding surface substantially coaxial with the through hole around the through hole,
The light emitting pointer instrument, wherein the projecting surface is formed such that a gap between the projecting surface and the pointer decreases from the outer peripheral side toward the through hole. The light-emitting pointer instrument according to claim 1, wherein the protruding surface is an axisymmetric curved surface about a central axis of the through hole. The luminous indicator of claim 1, wherein the protruding surface is formed by a plurality of planes.

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