JP2004340915A - Measuring instrument for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To uniform on a plane on the optical waveguide by designing a light guide plate, exercising structural ingenuity, namely, the luminous intensity of graduation on a measuring instrument. <P>SOLUTION: An angle θ, formed by a reflecting surface 31 and the rear surface 3b of the optical waveguide 3, is set larger on the reflecting surface 31 the farther away the surface 31 is located from a light-emitting diode 4, namely where the quantity of light entering from the light-emitting diode 4 is smaller. Thus, the quantity of light reflected on the reflecting surfaces 31 in the visual direction of a driver is made nearly equal at eight reflecting surfaces 31, thus uniforming the luminous brightness of graduation in a combination meter 1. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  TECHNICAL FIELD The present invention relates to a vehicle instrument suitable for use in an automobile or the like.

  2. Description of the Related Art In recent years, various methods have been employed in vehicle instruments mounted on automobiles in order to ensure good and novel visibility.

  For example, the present applicant has proposed a vehicle instrument having the following configuration in the invention previously filed.

That is, the light guide includes a light guide provided on the dial and made of a material that transmits light, and a light source that enters light into the light guide. And a reflecting portion that forms a part of the scale of the instrument. This aims to realize a novel-looking vehicle instrument by making the scale of the instrument three-dimensionally visible (for example, see Patent Document 1).
Japanese Patent Application No. 2002-248898

  In general, the scales of the vehicle instrument are arranged, for example, radially and in an arc.

  However, in the above-described vehicle instrument, there is a problem that it is difficult to make the light emission luminance of all the scales arranged radially and circularly uniform. That is, the brightness of the light from the light source that has entered the light guide plate is attenuated as it travels through the light guide plate. For this reason, there is a problem in that the light emission luminance is reduced as the distance from the light source to the reflecting portion, that is, the scale, becomes larger.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to improve the configuration of the light guide plate and to make the emission luminance of the plane provided on the light guide plate, that is, the scale of the meter uniform. It is to provide.

  The present invention employs the following technical means to achieve the above object.

  The vehicle instrument according to claim 1 of the present invention is provided on a dial, a light source, a light guide plate made of a transparent material and disposed on a front surface side of the dial, and provided on the light guide plate, and travels in the light guide plate. A plurality of planes for reflecting light from the light source toward the driver's viewing direction, the planes forming scales of the instrument and moving from the dial toward the driver's viewing direction as the distance from the light source increases. The angle formed between the flat surface and the rear surface, which is the dial-side surface of the light guide plate, is set so as to increase as the distance from the light source increases.

  In the above-described configuration, the magnitude of the angle formed between the plane and the back surface that is the dial-side surface of the light guide plate is 0 when the plane and the back surface of the light guide plate are on the same plane, in other words, when there is no scale. Degrees. On the other hand, when a scale, that is, a plane is formed, the angle formed between the plane and the back surface of the light guide plate becomes larger than 0 degrees.

  In addition, light from the light source travels in the light guide plate in a direction substantially parallel to the back surface of the light guide plate, and when this light is reflected by a plane, a part of the light is directed to the driver's viewing direction, that is, the dial and the light guide plate. On the other hand, the vehicle travels in a substantially vertical direction, so that the driver emits light on the plane and visually recognizes it as a scale.

  Here, the emission luminance of the plane visually recognized by the driver, that is, the component of the driver's viewing direction in the reflected light of the light emitted from the light source on the plane, is such that the angle formed between the plane and the back surface of the light guide plate is 0 degrees. It increases as the size increases, and reaches a maximum at approximately 45 degrees. Therefore, by adjusting the angle formed between the plane and the back surface of the light guide plate, the light emission luminance of the plane can be adjusted.

  By the way, in a plurality of planes, when the angle formed between the plane and the back surface of the light guide plate is set to be the same, due to the attenuation of light in the light guide plate, a plane with a greater distance from the light source is more visually recognized by the driver. The light emission luminance of the plane is reduced. As a result, there arises a problem that the light emission luminance of the scale is not uniform and the appearance of the vehicle instrument is reduced.

  On the other hand, in the vehicle instrument according to the first aspect of the present invention, the angle between the flat surface and the rear surface which is the dial-side surface of the light guide plate is set to be larger as the distance from the light source is larger. Configuration.

  Thus, in a plane close to the light source, the amount of light from the light source incident on the plane is large, and the component of the reflected light on the plane in the driver's viewing direction is small. On the other hand, in a plane far from the light source, the amount of light from the light source incident on the plane is small, and the component of the reflected light on the plane in the viewing direction of the driver is large. Therefore, the amount of light reflected on each plane and traveling in the driver's viewing direction can be made uniform, in other words, the light emission luminance of each plane in the driver's viewing direction, that is, the scale of the instrument can be made uniform.

  In this case, if at least one of the planes is textured as in the vehicle instrument according to claim 3 of the present invention, the angle formed between the plane and the back surface of the light guide plate is adjusted. Both, and the effect of adjusting the amount of diffuse reflection by the textured surface, it is possible to make the light emission luminance of a plane more uniform.

  In the vehicle instrument according to claim 2 of the present invention, the dial, the light source, the light guide plate made of a transparent material, which is disposed on the front side of the dial, and provided on the light guide plate, travel in the light guide plate. A plurality of planes that reflect light from the light source toward the driver's viewing direction, the planes forming a scale of the instrument, and from the dial toward the driver's viewing direction as the distance from the light source increases. The flat surface is subjected to a graining process, and the roughness of the graining process is set to be higher as the plane is farther from the light source.

  Here, by performing the graining on the flat surface, the light incident on the grained surface is diffused and reflected, so that the emission luminance in the driver's viewing direction can be increased as compared with the case where the graining is not performed.

  By changing the roughness of the graining process, for example, the pitch of minute irregularities, it is possible to change the light emission luminance when light is diffusely reflected on the grained surface. In other words, when the roughness of the graining is rough, that is, when the pitch of the fine unevenness is large, the emission luminance is low, and when the roughness of the graining is dense, that is, when the pitch of the fine unevenness is small, the emission brightness is high. Become.

  In the vehicle instrument according to the second aspect of the present invention, the surface is set so that the roughness of the graining process becomes higher as the distance from the light source increases.

  As a result, in a plane close to the light source, the amount of light from the light source incident on the plane is large, and the component of the diffuse reflection light on the plane in the viewing direction of the driver is small. On the other hand, in a plane far from the light source, the amount of light from the light source incident on the plane is small, and the component of the diffuse reflection light on the plane in the viewing direction of the driver is large. Therefore, the amount of light reflected on each plane and traveling in the driver's viewing direction can be made uniform, in other words, the light emission luminance of each plane in the driver's viewing direction, that is, the scale of the instrument can be made uniform.

  In the vehicle instrument according to claim 4 of the present invention, the plurality of planes are arranged on an arc, and the light from the light source traveling in the light guide plate is arranged on the outer peripheral side of the plurality of planes in the visual recognition direction of the driver. A configuration in which a belt-like reflecting portion that reflects light toward the light source is provided.

  When the vehicle instrument is a pointer instrument, the scale of the instrument is generally arranged on an arc along the rotation locus of the pointer.

  At this time, if a strip-shaped light emitting portion is provided on the outer peripheral side of the scale arranged on the arc, the contour of the pointer instrument can be made to stand out. In a conventional vehicle instrument, a band-shaped light transmitting portion is provided on the dial, and the light source for illuminating the light transmitting portion is arranged on the back side of the dial. However, in such a configuration, there is a problem that the emission luminance of the belt-shaped light emitting unit is low.

  Therefore, when the light guide plate is provided with a band-shaped reflection portion on the outer peripheral side of a plurality of planes serving as scales, the band-shaped reflection portion is visually recognized with almost the same brightness as the scale of the light guide plate. By highlighting the outline shape of the vehicle instrument more brightly, it is possible to emphasize the existence of the vehicle instrument and to make the appearance of the vehicle instrument novel.

  In this case, as in the vehicle instrument according to the fifth aspect of the present invention, if the belt-shaped reflecting portion is formed as an aggregate of a plurality of minute reflecting surfaces, for example, an aggregate of a diamond cut surface, a grain surface, or the like, the belt-shaped reflecting portion can be formed as a belt. Can be made to emit light with substantially uniform brightness over the entire reflection portion.

  Furthermore, if the belt-like reflecting portion is formed concentrically with the arc as in the vehicle instrument according to claim 6 of the present invention, the belt-like reflecting portion is arranged on the arc of the pointer instrument. Being concentric with the multiple scales, the presence of the pointer instrument can be made clearer.

  Hereinafter, an example in which the vehicle meter according to the present invention is applied to a combination meter mounted on an automobile will be described with reference to the drawings.

(1st Embodiment)
FIG. 1 is a partial front view of a combination meter 1 which is a vehicle instrument according to a first embodiment of the present invention.

  FIG. 2 is a sectional view of the combination meter 1 according to the first embodiment of the present invention, and is a sectional view taken along line II-II in FIG. 2, the left side is the driver's seat side, and the combination meter 1 is visually recognized by the driver from the left side of FIG.

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

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

  The combination meter 1 is disposed at a position visible to a driver in front of a driver's seat of a vehicle, and displays various information related to the vehicle. FIG. 1 shows a tachometer that indicates the engine speed of the vehicle, which is a part of the tachometer.

  The combination meter 1 includes a dial 2 for displaying various kinds of information and allowing the driver to visually recognize the information.

  The dial 2 is made of a thin plate made of a translucent material, for example, a transparent polycarbonate, and has a numeral 21 as shown in FIG. Numeral 21 is used to indicate the engine rotation speed of the vehicle together with a pointer 8 described later, and is arranged on an arc as shown in FIG. The numeral 21 is formed by printing or hot stamping the front surface 2a (the left surface in FIG. 2) or the rear surface 2b (the right surface in FIG. 2) of the dial 2. That is, a treatment such as providing an opaque coloring layer or a semi-transparent coloring layer in a portion other than the numeral 21 and keeping the numeral 21 transparent or providing a semi-transparent coloring layer is performed. . In the combination meter 1 according to the first embodiment of the present invention, the numeral 21 is colored in semi-transparent yellow, and the portions other than the numeral 21 are colored in semi-transparent dark blue. Therefore, when a light-emitting diode 15 which is a light source disposed on the back surface 2b side of the dial 2, which will be described later, is turned on, the dial 2 is transmitted and illuminated by the light emitted from the light emitting diode 15, and the numeral 21 is displayed in a dark blue background. Is displayed in yellow.

  The dial 2 is provided with a through hole 2c as shown in FIG. The through hole 2c is used to connect a shaft 7a, which is a pointer shaft of a movement 7, which is a rotating inner machine, disposed on the back side of the dial 2 (right side in FIG. 2) to the front side of the dial 2 (left side in FIG. 2). It is intended to extend to. The light guide plate 3 is arranged on the front surface 2 a side of the dial 2.

  The light guide plate 3 is formed in a substantially flat shape from a transparent material, for example, a colorless and transparent polycarbonate resin, and is disposed on the surface 2 a side of the dial 2 so as to be substantially in close contact with the dial 2.

  As shown in FIG. 2, the light guide plate 3 has a through hole 3c. When the combination meter 1 is assembled, the through-hole 3c overlaps the through-hole 2c of the dial 2, and the movement of the rotation inner machine 7, which is disposed on the back surface 3b side (right side in FIG. 2) of the light guide plate 3, is provided. This is for extending the shaft 7a, which is a pointer shaft, to the front side of the dial 2 (the left side in FIG. 2).

  As shown in FIG. 2, the light guide plate 3 reflects light from a light emitting diode 4 which is a light source, which will be described later, traveling in the light guide plate 3 in the driver's viewing direction, that is, toward the left in FIG. A plurality of reflecting surfaces 31 (eight in the combination meter 1 according to the first embodiment of the present invention) are provided. The reflection surface 31 is provided so as to form a concave portion on the back surface 3b of the light guide plate 3, as shown in FIG. The eight reflecting surfaces 31 are arranged radially around the through-hole 3c and at substantially equal angular intervals on an arc. In the combination meter 1 according to the first embodiment of the present invention, these eight reflecting surfaces 31 constitute, together with the numeral 21 of the dial 2 and a pointer 8 described later, a scale of a tachometer for indicating an engine rotation speed of the vehicle. are doing.

  Further, as shown in FIG. 3, the light guide plate 3 is provided with an incident surface 32 for introducing light from a light emitting diode 4 described later into the light guide plate 3.

  A printed circuit board 5 is arranged on the back side (right side in FIG. 2) of the dial 2. The printed board 5 is made of, for example, a glass epoxy board or the like, and forms an electric circuit portion of the combination meter 1.

  As shown in FIG. 3, a light emitting diode 4 as a light source is mounted on the printed board 5 so that light can be incident on an incident surface 32 of the light guide plate 3. In addition, in the combination meter 1 according to the first embodiment of the present invention, a white light emitting diode is used as the light emitting diode 4.

  A movement 7 is mounted on the printed board 5. The movement 7 is formed of an electric actuator such as a cross-coil motor or a stepping motor, and the pointer shaft has an angle corresponding to an external electric signal (in the combination meter 1 according to the first embodiment of the present invention, an engine rotation signal). The shaft 7a is rotated. The shaft 7a of the movement 7 extends outward through the through-hole 2c of the dial 2 and the through-hole 3c of the light guide plate 3, and a pointer 8 is fixed to the end thereof. The pointer 8 is formed of a translucent material, for example, an acrylic resin, and is illuminated and displayed by light emitted from a light emitting diode (not shown) mounted on the printed circuit board 5.

  A light emitting diode 15 as a light source for transmitting and illuminating the dial 2 is mounted on the printed circuit board 5.

  Further, on the printed circuit board 5, a controller 6 for controlling turning on / off of the light emitting diodes 4 and 15 and controlling driving of the movement 7 is mounted. The controller 6 includes, for example, a microcomputer or the like.

  As described above, the dial 2, the light guide plate 3, and the printed board 5 are housed and held in a case 9 formed of a resin material, as shown in FIG.

  As shown in FIG. 2, a transparent cover 11 is mounted on the surface of the light guide plate 3 through a substantially frame-shaped facing plate 10. The transparent cover 11 is formed of a transparent resin thin plate, glass, or the like, and prevents entry of dust, moisture, and the like into the inside of the combination meter 1.

  Next, the configuration of the light guide plate 3, which is a feature of the combination meter 1 according to the first embodiment of the present invention, particularly the shape of the reflection surface 31 as a scale of the tachometer and its function and effect will be described.

  As shown in FIG. 3, the light emitted from the light emitting diode 4 that has entered the light guide plate 3 from the incident surface 32 travels in the light guide plate 3 in the direction indicated by the arrow in FIG.

  The reflecting surface 31 moves away from the light-emitting diode 4 as the light source, that is, as it goes from left to right in FIG. 3, it moves away from the dial 2 in the driver's visual recognition direction, that is, away from bottom to top in FIG. 3. So inclined.

  Further, the angle θ formed between the reflection surface 31 and the back surface 3b of the light guide plate 3 is set so that the distance from the light emitting diode 4 is large, that is, the reflection surface 31 located on the right side in FIG. .

  The width B of the reflection surface 31 in the driver's viewing direction, that is, the width of the scale is the same for each reflection surface 31.

  When light from the light emitting diode 4 traveling in the light guide plate 3 is reflected by the reflection surface 31, a part of the reflected light travels in the driver's viewing direction (upward in FIG. 3) and is visually recognized by the driver. The reflection surface 31 is displayed by light emission and visually recognized as a scale.

  At this time, most of the light reflected by the reflecting surface 31 travels in an angle direction equal to the exit angle from the reflecting surface 31, that is, the incident angle, but is also reflected in directions other than the exit angle. Among them, the ratio of the amount of light reflected toward the driver in the viewing direction, that is, the direction substantially perpendicular to the back surface 3b of the light guide plate 3 is such that the angle θ between the reflection surface 31 and the back surface 3b of the light guide plate 3 is 0. The angle θ increases as the angle increases, and reaches a maximum when the angle θ is approximately 45 degrees.

  On the other hand, the brightness of the light from the light emitting diode 4 traveling in the light guide plate 3 is inversely proportional to the square of the distance from the light emitting diode 4 as the light source. That is, the luminance decreases as the distance from the light emitting diode 4 increases. Therefore, the amount of light incident on each reflecting surface 31 decreases as the distance from the light emitting diode 4 increases.

  For this reason, when the angle θ formed between the reflecting surface 31 and the back surface 3b of the light guide plate 3 is the same for all eight reflecting surfaces 31, that is, the operation is performed among the reflected light reflected by the reflecting surface 31. When the ratio of the amount of light traveling in the viewing direction of the driver is the same for all eight reflecting surfaces 31, the amount of light traveling in the viewing direction of the driver from each of the reflecting surfaces 31, that is, the light emission of the reflecting surface 31 viewed from the driver. The luminance decreases as the distance from the light emitting diode 4 increases, in conjunction with the decrease in the amount of light incident on each reflection surface 31. Therefore, there is a problem that the light emission luminance of the scale becomes uneven in the combination meter.

  On the other hand, in the combination meter 1 according to the first embodiment of the present invention, the angle θ formed between the reflection surface 31 and the back surface 3b of the light guide plate 3 is set to the reflection surface 31 having a large distance from the light emitting diode 4, that is, the incident light. The larger the reflection surface 31 having a smaller amount of light from the light emitting diode 4, the larger the setting.

  In other words, the reflection surface 31 having a greater distance from the light emitting diode 4, that is, the reflection surface 31 having a smaller amount of incident light from the light emitting diode 4, travels in the driver's viewing direction among the reflected light reflected by the reflection surface 31. It is configured so that the ratio of the amount of light to be emitted becomes large.

  Thus, the amount of light reflected on each of the reflecting surfaces 31 in the driver's viewing direction can be made substantially equal on the eight reflecting surfaces 31, and the light emission luminance of the scale in the combination meter 1 can be made uniform.

  In this case, the angle θ formed between the reflecting surface 31 of each reflecting surface 31 and the back surface 3b of the light guide plate 3 is, specifically, [the amount of light incident on the reflecting surface 31] × [the reflected light Ratio of the amount of light traveling in the driver's viewing direction] is determined to be the same value. In other words, the magnitude of the angle θ corresponds to the amount of light incident on the reflecting surface 31 which is inversely proportional to the square of the distance from the light emitting diode 4, and the proportion of the amount of reflected light that travels in the driver's viewing direction among the reflected light is emitted. What is necessary is just to determine in proportion to the square of the distance from the diode 4.

  Next, the electric circuit configuration of the combination meter 1 according to the first embodiment of the present invention described above will be described.

  As shown in the electric circuit configuration diagram of FIG. 4, the controller 6 is constantly supplied with power from the battery 13. The controller 6 is connected to the ignition switch 12 so as to detect its operation state (ON or OFF), and controls the lighting of the light emitting diodes 4 and 15 based on the detection result. A rotation sensor 14 is connected to the controller 6, and the controller 6 drives the movement 7 based on the detection signal to rotate the shaft 7a to a predetermined angle.

  Next, the operation of the combination meter 1 according to the first embodiment of the present invention, which is configured as described above, will be described, in particular, how the dial 2 is visually recognized.

  (1) When the ignition switch 40 is turned on.

  When the ignition switch 12 is turned on by the driver, the controller 6 detects that the ignition switch 12 is turned on, and the controller 6 turns on the light emitting diodes 4 and 15. At the same time, a light emitting diode (not shown), which is a light source for causing the hands 8 to emit light, is turned on. As a result, the reflective surface 31, the numeral 21, and the pointer 8 serving as the scale are displayed by light emission. In addition, the controller 6 drives the movement 7 based on the detection signal from the rotation sensor 14 to rotate the shaft 7a to a predetermined angle, that is, an angle corresponding to the engine rotation speed of the vehicle.

  (2) When the ignition switch 40 is turned off.

  When the ignition switch 12 is turned off by the driver, the controller 6 detects that the ignition switch 12 is turned off, and stops energizing the light emitting diode 4 and a light emitting diode (not shown) for illuminating the pointer 8 to turn off the light. . Thereby, the reflecting surface 31, the numeral 21, and the pointer 8 which are the scales are turned off.

  FIG. 5 is a partial front view of a modified example of the combination meter 1 which is a vehicle instrument according to the first embodiment of the present invention.

  In the combination meter 1 as the vehicle instrument according to the first embodiment of the present invention described above, the reflection surface 31 of the light guide plate 3 forms one instrument, that is, a tachometer indicating the engine speed. In this modified example, the scales of two instruments are formed on one light guide plate 3.

  That is, as shown in FIG. 5, the light guide plate 3 is provided with reflecting surfaces 31a and 31b corresponding to two kinds of instruments, and the reflecting surface 31a, the numeral 21a of the dial 2 and the hands 81 are used for the vehicle. A water temperature gauge for indicating the engine cooling water temperature is constituted, and a fuel gauge for indicating the remaining fuel amount of the vehicle is constituted by the reflection surface 31b, the numeral 21b of the dial 2, and the hands 82.

  Also in this case, the angle θ formed between the reflection surfaces 31a and 31b and the back surface 3b of the light guide plate 3 is set to be larger for the reflection surface 31a or 31b having a larger distance from the light emitting diode 4, so that the above-described first embodiment of the present invention is achieved. The same effect as in the case of the combination meter 1 which is a vehicle instrument according to the embodiment, that is, the light emission luminance of each of the reflecting surfaces 31a and 31b which are the scales of the instrument can be made uniform.

(2nd Embodiment)
FIG. 6 is a sectional view of the combination meter 1 according to the second embodiment of the present invention, and corresponds to a sectional view taken along line III-III of FIG.

  The combination meter 1 according to the second embodiment of the present invention differs from the combination meter 1 according to the first embodiment of the present invention in that the configuration of the reflection surface 31 of the light guide plate 3 is changed. Except for the configuration of the reflection surface 31 of the light guide plate 3, the configuration is substantially the same as that of the first embodiment. Therefore, the description of the same parts as the combination meter 1 according to the first embodiment of the present invention will be omitted, and the parts unique to the second embodiment, that is, the configuration of the reflection surface 31 of the light guide plate 3 will be described.

  In the light guide plate 3 of the combination meter 1 according to the second embodiment of the present invention, the magnitude of the angle θ between the reflection surface 31 and the back surface 3b of the light guide plate 3 is set to be the same for all eight reflection surfaces 31. ing. The reflecting surface 31 is subjected to a graining process, and a grained surface 33 formed by uniformly distributing a large number of fine irregularities over the entire area is formed.

  Further, the textured surface 33 formed on each reflection surface 31 is formed such that the larger the distance from the issue, the closer the textured surface 31 is to the roughness of the textured processing, that is, the finer the pitch of the fine irregularities constituting the textured surface 33 is. Have been.

  The proportion of the amount of light that travels in the driver's viewing direction among the reflected light that is diffusely reflected by the grain surface 33 increases as the pitch of the fine irregularities forming the grain surface 33 increases.

  In the combination meter 1 according to the second embodiment of the present invention, the grained surface 33 having a larger distance from the light emitting diode 4, that is, the smaller the light amount from the light emitting diode 4 that is incident, the smaller the grained surface 33 constituting the grained surface 33 is. The pitch of the irregularities is made dense so that the ratio of the amount of light traveling in the driver's viewing direction among the diffuse reflected light reflected on the grained surface 33 is increased.

  As a result, the amount of light reflected toward the driver's viewing direction on the embossed surface 33 of each reflecting surface 31 is made substantially equal on the eight reflecting surfaces 31, and the light emission luminance of the scale in the combination meter 1 is made uniform. Can be.

  When the light from the light emitting diode 4 is diffusely reflected by the textured surface 33 of the reflection surface 31, the amount of light reflected by the reflection surface 31 and traveling in the driver's visual recognition direction is a plane light in the first embodiment of the present invention. When the angle θ formed between the reflection surface 31 and the back surface 3b of the light guide plate 3 is the same as compared with the reflection surface 31 in the shape of a circle, the angle θ increases, that is, the scale luminance increases. Therefore, by providing the textured surface 33 on the reflection surface 31, it is possible to increase the scale luminance without increasing the angle θ between the reflection surface 31 and the back surface 3b of the light guide plate 3. .

  By the way, the light guide plate 3 is generally formed by molding a transparent resin. In order to improve the appearance of the combination meter 1, the flatness of the surface 3a shown in FIG. There is a need. For this reason, in the combination meter 1 according to the first embodiment of the present invention, in the portion of the front surface 3a of the light guide plate 3 corresponding to the reflection surface 31 where the angle θ formed between the reflection surface 31 and the back surface 3b of the light guide plate 3 is large. Molding defects such as so-called sink marks are likely to occur. To prevent this, it is necessary to increase the thickness t of the light guide plate 3 shown in FIG. 3 to some extent.

  On the other hand, in the combination meter 1 according to the second embodiment of the present invention, as described above, the scale luminance can be increased without increasing the angle θ between the reflection surface 31 and the back surface 3b of the light guide plate 3. Thus, the thickness of the light guide plate 3 can be reduced, and the depth dimension (the left-right dimension in FIG. 2) of the combination meter 1 can be reduced.

  In the combination meter 1 according to the second embodiment of the present invention described above, the angle θ between the reflection surface 31 and the back surface 3b of the light guide plate 3 is the same for all eight reflection surfaces 31. Although set, a different angle may be used for at least one of the eight reflecting surfaces 31.

(Third embodiment)
FIG. 7 is a partial front view of the combination meter 1 according to the third embodiment of the present invention.

  FIG. 8 is an enlarged view of a portion VIII in FIG.

  FIG. 9 is a sectional view taken along line IX-IX in FIG.

  The combination meter 1 according to the third embodiment of the present invention is obtained by changing the configuration of the light guide plate 3 in the combination meter 1 according to the first embodiment of the present invention.

  That is, as shown in FIG. 7, a ring-shaped light emitting portion 34 which is a band-shaped reflecting portion is provided on the outer peripheral side of eight reflecting surfaces 31 arranged at substantially equal angular intervals on a circular arc in the light guide plate 3. is there.

  As shown in FIG. 8, the ring light-emitting portion 34 is formed on the dial 2 side of the light guide plate 3 as an aggregate of diamond cut surfaces 34a, which are minute reflection surfaces. That is, as shown in FIG. 9, the ring light emitting portion 34 is formed by providing a large number of small quadrangular pyramid-shaped concave portions adjacent to each other on the surface of the light guide plate 3 on the dial 2 side. Four triangles forming the quadrangular pyramid are the diamond cut surfaces 34a.

  The ring light-emitting unit 34 is visually recognized as an aggregate of minute brilliant spots by reflecting light from the light-emitting diodes 4 traveling in the light guide plate 3 on the diamond-cut surface 34a in the viewing direction of the driver.

  That is, the provision of the ring light emitting portion 34 on the light guide plate 3 increases the number of components in addition to the effect of the combination meter 1 according to the first embodiment of the present invention, that is, the uniformity of the light emission luminance of the scale that is the reflection surface 31. Without making the combination meter 1, the appearance of the combination meter 1 can be made novel by emphasizing the existence of the tachometer which is a pointer instrument in the combination meter 1.

  Note that, in the combination meter 1 according to the third embodiment of the present invention described above, the diamond cut surfaces 34a forming the ring light emitting unit 34 form a large number of small quadrangular pyramid-shaped recesses adjacent to each other. Instead of a quadrangular pyramid, a triangular pyramid may be used. Further, a textured surface may be provided instead of the diamond cut surface 34a as the minute reflection surface forming the ring light emitting unit 34.

  Further, in the combination meter 1 according to the first to third embodiments of the present invention described above, the reflecting surface 31 is a smooth plane, but at least one of the eight reflecting surfaces 31 is provided with a textured surface 33. Is also good.

  Further, in the combination meter 1 according to the first to third embodiments of the present invention described above, the number of the reflecting surfaces 31 of the light guide plate 3 is eight, but it is not necessary to limit the number to eight. May increase or decrease.

  Further, in the combination meter 1 according to the first to third embodiments of the present invention described above, the width dimension B of the reflection surface 31 of the light guide plate 3 is one type, that is, the same in the total reflection surface 31. B may be a plurality of types.

  Further, in the combination meter 1 according to the first to third embodiments of the present invention described above, the shape of the reflection surface 31 of the light guide plate 3 is rectangular, but need not be limited to a rectangle, and a shape other than a rectangle, for example, It may be circular or oval.

  Further, in the combination meter 1 according to the first to third embodiments of the present invention described above, a white light emitting diode is used as the light emitting diode 4, but a light emitting diode of another emission color may be used.

  Further, in the combination meter 1 according to the first and second embodiments of the present invention described above, the light emitting diodes 4 and 15 are used as light sources, but at least one of them is connected to another light source such as a light bulb or a discharge lamp. It may be replaced with an electric light or the like.

  Also, the combination meter 1 according to the embodiment of the present invention has been described by taking a tachometer, a water temperature gauge, and a fuel gauge as examples, but it is not necessary to limit the invention to these meters. You may.

1 is a partial front view of a combination meter 1 which is a vehicle instrument according to a first embodiment of the present invention. FIG. 2 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 II-II in FIG. 1. It is sectional drawing of the combination meter 1 by 1st Embodiment of this invention, Comprising: It is sectional drawing in the III-III line in FIG. FIG. 2 is a configuration diagram illustrating an electric circuit in the combination meter 1 according to the first embodiment of the present invention. It is a partial front view of a modification of the combination meter 1 which is a vehicle instrument according to the first embodiment of the present invention. It is sectional drawing of the combination meter 1 by 2nd Embodiment of this invention, Comprising: It corresponds to the III-III line sectional view in FIG. It is a partial front view of combination meter 1 by a 3rd embodiment of the present invention. FIG. 8 is an enlarged view of a portion VIII in FIG. 7. FIG. 9 is a sectional view taken along line IX-IX in FIG. 8.

Explanation of reference numerals

1 Combination meter (vehicle instrument)
2 Dial 2a Front surface 2b Back surface 2c Through hole 21 Numeral 3 Light guide plate 3a Surface 3b Back surface 3c Through hole 31 Reflecting surface (flat surface, scale)
32 entrance surface 33 embossed surface 34 ring light-emitting part (band-shaped light-emitting part)
34a Diamond cut surface (micro reflection surface)
4 Light emitting diode (light source)
Reference Signs List 5 printed board 6 controller 7 movement 7a shaft 8 pointer 9 case 10 dial plate 11 transparent cover 12 ignition switch 13 battery 14 rotation sensor 15 light emitting diode

Claims (6)

Dial and
A light source,
A light guide plate made of a transparent material, which is disposed on the front side of the dial,
A plurality of planes provided on the light guide plate and reflecting light from the light source traveling in the light guide plate toward a driver's viewing direction;
The plane forms a scale of an instrument and is provided to be inclined so as to move away from the dial in the direction of a driver's view as the distance from the light source increases,
An instrument for a vehicle, wherein an angle formed between the flat surface and a rear surface, which is the dial-side surface of the light guide plate, is set to be greater as the distance from the light source is larger. Dial and
A light source,
A light guide plate made of a transparent material, which is disposed on the front side of the dial,
A plurality of planes provided on the light guide plate and reflecting light from the light source traveling in the light guide plate toward a driver's viewing direction;
The plane forms a scale of an instrument, and is provided so as to be inclined so as to move away from the dial in the direction of the driver's view as the distance from the light source increases,
An instrument for a vehicle, wherein the flat surface is subjected to a graining process, and the roughness of the graining process is set to be denser as the distance from the light source is larger.   The vehicle instrument according to claim 1, wherein at least one of the flat surfaces is subjected to a graining process. The plurality of planes are arranged on an arc,
A belt-like reflecting portion that reflects light from the light source traveling in the light guide plate toward a driver's viewing direction is provided on an outer peripheral side of the plurality of planes. 4. The instrument for a vehicle according to 3.   The vehicle instrument according to claim 4, wherein the strip-shaped reflecting portion is an aggregate of a plurality of minute reflecting surfaces.   The vehicular instrument according to claim 4 or 5, wherein the strip-shaped reflector is formed concentrically with the arc.

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