JP2008026288A - Measuring instrument - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a measuring instrument capable of making light from a light source get incident highly efficiently into a pointer plate to enhance a brightness of a light emitting pointer, while thinning a disk pointer to restrain an inertia moment from increasing. <P>SOLUTION: A photoreception face of the pointer plate 1 is divided into two, the first reflecting face 1d and two of the second reflecting faces 1e, 1f are provided to correspond thereto, and the second reflecting faces 1e, 1f are formed in a front face side of a surface 1g that is a surface of the front face side in a disk part 11 of the pointer plate 1. The second photoreception face 1c is set into a shape to bend the light incident into the second photoreception face 1c to a direction of the second reflecting faces 1e, 1f. The light from the light source is thereby made to get incident highly efficiently into the pointer plate to enhance the brightness of the light emitting pointer, while thinning the disk pointer to restrain the inertia moment from increasing, because almost all quantities of the light emitted from a light emitting diode 4 can be introduced into the disk part 11, in the measuring instrument. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an instrument that is installed, for example, in an automobile cab and displays various information.

  One conventional instrument is a disk pointer instrument having a disk-shaped pointer. The disk pointer is formed by providing, for example, a linear reflecting portion that reflects light on a pointer plate formed in a disk shape from a translucent material, and a portion of the pointer plate excluding the reflecting portion is made opaque. . When the pointer plate is irradiated with light from a light source arranged behind the pointer plate, this light travels in the disk and enters the light reflecting portion, and is reflected toward the front side by the light reflecting portion. A linear reflection part is visually recognized as a pointer. (For example, refer to Patent Document 1).

By adopting a configuration in which the reflecting portion formed on the disk functions as a light emission pointer, the shape of the pointer can be freely set, and the design flexibility of the pointer can be increased.
Japanese Patent No. 3013090

  In the above-described conventional instrument, the pointer has a disk shape, so that the moment of inertia of the pointer is larger than that of a normal bar-shaped pointer. Therefore, in order to make the response speed of the pointer, that is, the degree of change of the physical quantity that can be indicated by the pointer equivalent to that of a normal bar-shaped pointer, it is necessary to use a higher torque movement as the movement for rotating the pointer.

  Generally, when the torque generated by the movement is increased, the physique of the movement increases. In order to minimize the increase in the physique of the movement while using the disk pointer, it is necessary to reduce the moment of inertia of the disk pointer.

  One way to reduce the moment of inertia of the disk pointer is to make it thinner. When the thickness is reduced, it becomes difficult to make the light from the light source enter the pointer plate with high efficiency. That is, part of the light from the light source escapes outside the pointer plate. As a result, there is a problem that the luminance of the light emission indicator is lowered.

  The present invention has been made in view of the above-described problems, and makes it possible to increase the brightness of a light emitting pointer by making light from a light source enter the pointer plate with high efficiency while reducing the thickness of a disk pointer and suppressing an increase in moment of inertia. The purpose is to provide an instrument that can

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

  The instrument according to claim 1 of the present invention is a dial provided with a display, and a pointer disposed on the front side or the back side of the dial, formed in a disc shape from a translucent material, and indicating the display A pointer plate provided with a portion, a light source arranged so that light can be incident inside the pointer plate, and a movement that rotationally drives a rotating shaft having one end fixed to the pointer plate, A first light incident surface formed in an annular shape coaxially with the rotation axis so that light from the light source is incident on the back side of the center portion of the pointer plate, and light incident from the first light incident surface On the outer peripheral side of the first reflecting surface, on the outer peripheral side of the first reflecting surface, and on the outer peripheral side of the first reflecting surface. A second reflecting surface provided coaxially with the first reflecting surface and reflecting light incident from the second light incident surface toward the outer periphery of the pointer plate; The second reflecting surface is formed on the front surface side in the axial direction of the rotation axis rather than the front surface on the surface of the pointer plate where the pointer portion is provided, and the second light incident surface receives light incident from the second light incident surface. It is characterized by being formed in a shape that refracts toward the outer peripheral side of the pointer plate.

  Light is emitted radially from a light source, such as a light emitting diode, but the range of high brightness is substantially conical. On the other hand, the light incident surface of the pointer plate is limited in size. Therefore, a light guide member, such as a lens, is used for converting light traveling in a conical shape into a cylindrical parallel light beam so that light emitted from the light source is incident on the light incident surface of the pointer plate with high efficiency. In other words, the light guide member is disposed between the light source and the light incident surface of the pointer plate, and the light emitted from the light source is converted into parallel light beams having a width substantially equal to the width of the light incident surface to be incident on the light incident surface. ing.

  At this time, if the thickness of the pointer plate, that is, the thickness of the disc-shaped portion on which the pointer portion is formed is equal to the width of the light incident surface, the light enters from the light incident surface toward the outer periphery of the pointer plate at the reflecting surface. Most of the reflected light can travel toward the outer periphery of the pointer plate. In other words, the light emitted from the light source can be used for light emission display of the pointer portion with high efficiency to increase the light emission luminance of the pointer.

  However, if the pointer plate is made thinner, the reflecting surface becomes smaller correspondingly, and part of the light incident on the pointer plate from the light incident surface cannot enter the reflecting surface and is emitted outside the pointer plate. That is, the utilization efficiency of the light emitted from the light source for the light emission display of the pointer portion is reduced, and the light emission luminance of the pointer portion is reduced.

  According to the configuration of the meter according to the first aspect of the present invention described above, the light emitted from the light source enters the first light incident surface and the second light incident surface separately. That is, the light incident on the first light incident surface is reflected by the first reflecting surface toward the outer periphery of the pointer plate and travels in the disc-shaped portion of the pointer plate. The light incident on the second light incident surface is refracted in the direction toward the second reflective surface on the second light incident surface and is incident on the second reflective surface, where it is reflected toward the outer periphery of the pointer plate and reflected by the disk of the pointer plate. It progresses in the shape part.

  Thereby, even when the disk pointer is thinned, the light emitted from the light source can be used for the light emission display of the pointer portion with high efficiency, and the emission luminance of the pointer can be increased.

  Here, the position in the axial direction of the rotation axis of the front-side end portion on the first reflecting surface is substantially the same as the front-side surface of the area where the pointer portion is provided on the pointer plate. Therefore, the light traveling from the vicinity of the front-side end portion of the first reflecting surface toward the outer periphery of the pointer plate travels along the front-side surface of the area where the pointer portion is provided in the pointer plate.

  In the configuration of the instrument according to the first aspect of the present invention, the second reflecting surface is formed on the front side in the axial direction of the rotation axis rather than the front side surface of the area where the pointer portion is provided on the pointer plate. For this reason, it can prevent that the light from the front side edge part vicinity of the 1st reflective surface mentioned above is interrupted by the 2nd reflective surface, and cannot contribute to the light emission display of a pointer | guide part.

  As described above, it is possible to provide an instrument capable of increasing the brightness of the light emission pointer by making the light from the light source incident on the pointer plate with high efficiency while reducing the thickness of the disk pointer and suppressing the increase of the moment of inertia.

  In the meter according to claim 2 of the present invention, the shape of the second light incident surface and the shape of the second reflective surface are such that the incident angle of the light incident from the second light incident surface on the second reflective surface is the entire angle of the pointer plate. It is characterized by being set to be larger than the reflection angle.

  According to the above-described configuration, the entire amount of light incident on the second reflecting surface is reflected into the pointer plate and travels again in the direction of the pointer plate in the pointer plate. As a result, light emitted from the second reflecting surface to the outside of the pointer plate, that is, lost light that does not contribute to the light emission display of the pointer is eliminated, and the light emitted from the light source is used for light emission display of the pointer portion with high efficiency. Brightness can be increased.

  The meter according to claim 3 of the present invention is characterized in that a plurality of second reflecting surfaces are provided coaxially with each other.

  The second reflecting surface is formed on the front surface side in the axial direction of the rotation shaft rather than the front surface side surface of the region where the pointer portion is provided on the pointer plate. For this reason, when the second reflection surface is enlarged so as to reliably use the light incident from the second light incident surface for the pointer light emission display in the configuration including one second reflection surface, the pointer portion of the second reflection surface is provided. The protruding length of the formed area from the front surface is increased. That is, the axial length of the pointer plate is increased.

  Therefore, as in the configuration described above, if a plurality of second reflecting surfaces are provided coaxially with each other, an increase in the protruding length from the front surface of the area where the pointer portion of each second reflecting surface is provided is suppressed. However, the sum of the areas of the plurality of second reflecting surfaces can be increased, and the light incident from the second light incident surface can be used for light emission display of the pointer portion with high efficiency.

  The meter according to claim 4 of the present invention is a meter having a disk-shaped pointer plate, wherein the pointer plate has a first light incident surface and a second light incident surface on which light from a light source disposed on the back surface of the pointer plate is incident. And a first reflection that reflects light from a light source incident on the first light incident surface and the second light incident surface corresponding to the first light incident surface and the second light incident surface toward the radially outer side of the pointer plate. And a second reflective surface, the second reflective surface being positioned relatively above the first reflective surface in the axial direction of the pointer plate.

  Even with such a configuration, it is possible to achieve the same operational effects as the instrument according to the first aspect.

  Hereinafter, a case where the meter according to the present invention is applied to a speedometer S incorporated in a combination meter 100 mounted on an automobile will be described with reference to the drawings.

  FIG. 1 is a partial front view of a combination meter 100 including a speedometer S according to an embodiment of the present invention.

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

  FIG. 3 is an enlarged view of part III in FIG.

  FIG. 4 is an enlarged view of a portion IV in FIG.

  FIG. 5 is a schematic diagram for explaining an electric circuit configuration of the speedometer S according to the embodiment of the present invention.

  The combination meter 100 is disposed at a position visible from the driver in front of the driver's seat of the automobile, and includes a speedometer S for displaying the traveling speed of the automobile as shown in FIG. And various indicators. The driver's seat is on the left side of the combination meter 100 in FIG. 2, and the combination meter 100 is visually recognized from the left side in FIG.

  In the speedometer S, as shown in FIG. 2, a pointer plate 1 and a dial plate 6 are arranged from the front side, that is, the viewer side. Below, the structure of the speedometer S is demonstrated.

  The pointer plate 1 is formed of a translucent material such as a colorless and transparent polycarbonate resin or acrylic resin into a disk shape having a cross-sectional shape as shown in FIG. As shown in FIG. 2, the pointer plate 1 receives light from a substantially annular disk portion 11 having a groove portion 1 a that is a pointer portion, and a light emitting diode 4 that is formed on the inner peripheral side of the disk portion 11 and is a light source. It comprises a light guide part 12 that receives light and guides it into the disk part 11.

  The disk portion 11 has an annular disk shape such as a CD (Compact Disc). As shown in FIG. 2, the thickness of the disk portion 11 is formed so as to gradually decrease from the center portion toward the tip side. In the central part adjacent to the light guide part 12, while ensuring a plate thickness that can guide light to the disk part 11 with high efficiency, the moment of inertia is reduced by gradually reducing the thickness toward the tip side. I am aiming. The disk part 11 is provided with a groove part 1a as a pointer part. The groove portion 1a opens to the front surface side of the disk portion 11, that is, the back surface 1j that is the surface opposite to the front surface 1g in the viewer direction, and its cross-sectional shape is formed in a V shape as shown in FIG. Yes. As shown in FIG. 1, the groove 1 a is formed in a straight line extending along the radius of the disk part 11 to the outer periphery of the disk part 11. In the speedometer S according to the embodiment of the present invention, the slopes 1a1 and 1a2 forming the groove 1a are as shown in FIG. 3 with respect to the plate thickness direction of the disk portion 11, that is, the axial direction of the pointer plate 1. , And an angle of 45 °. This is because the incident angle when the light from the light emitting diode 4 traveling in the disk portion 11 is incident on the inclined surfaces 1a1 and 1a2 is larger than 42 degrees, which is the total reflection angle of the resin material forming the pointer plate 1. In order to make the traveling direction of the reflected light on the inclined surfaces 1a1 and 1a2 as much as possible to the driver, in other words, to be in the axial direction of the pointer plate 1, it is set to 45 °. As a result, the light traveling in the disk portion 11 and entering the inclined surfaces 1a1 and 1a2 can be totally reflected. That is, as shown in FIG. 3, the total amount of light incident on the inclined surfaces 1a1 and 1a2 can be reflected in the viewer direction to increase the light emission luminance of the pointer portion 1a.

  As shown in FIG. 2, the light guide portion 12 is formed in an annular shape from the inner periphery of the disc portion 11 to the center side of the pointer plate 1. As shown in FIG. 2, the light guide portion 12 is provided with a through hole 1 h that fits into a boss portion 2 a of a light shielding cap 2 described later. As shown in FIG. 2, the light guide section 12 is formed so that light from the light emitting diode 4 which is a light source disposed on the back side of the pointer plate 1 is incident adjacent to the through hole 1h. One light incident surface 1b is formed. The first light incident surface 1b is formed in a planar shape substantially orthogonal to the axial direction of the pointer plate 1, that is, the left-right direction in FIG. On the outer peripheral side of the first light incident surface 1b, as shown in FIG. 2, a second light incident surface 1c is formed which is also formed so that light from the light emitting diode 4 enters. As shown in FIG. 2, the second light incident surface 1c is formed coaxially with the first light incident surface 1b and substantially conical. As shown in FIG. 2, the light guide portion 12 is formed with a first reflection surface 1 d that reflects light incident from the first light incident surface 1 b toward the outer peripheral direction of the pointer portion 1, that is, toward the disk portion 11. Yes. The first reflecting surface 1d is formed concentrically with the first light incident surface 1b. On the outer peripheral side of the first reflecting surface 1d, as shown in FIG. 2, two second reflections that reflect the light incident from the second light incident surface 1c toward the outer peripheral direction of the pointer portion 1, that is, toward the disc portion 11. Surfaces 1e and 1f are formed. The two second reflecting surfaces 1e and 1f are formed coaxially with the first reflecting surface 1d and substantially conical. As shown in FIG. 2, the two second reflecting surfaces 1e and 1f are arranged in the order of the second reflecting surface 1e and the second reflecting surface 1f from the first reflecting surface 1d side. Each of the second reflecting surfaces 1e and 1f is located on the front side of the front surface 1g which is the front side surface of the disk portion 11 which is a region provided with the groove portion 1a which is a pointer portion, that is, on the left side of the front surface 1g in FIG. Is formed.

  As shown in FIG. 2, a substantially disc-shaped light shielding cap 2 is attached to the pointer plate 1. As shown in FIG. 2, the light shielding cap 2 is provided with a boss 2a at the center thereof. The light shielding cap 2 is fixed to the pointer plate 1 by fitting the boss portion 2 a into the through hole 1 h of the pointer plate 1. Furthermore, a shaft 3a, which is a rotating shaft of the movement 3 described later, is fitted into the boss portion 2a, whereby the pointer plate 1 is fixed to the shaft 3a. The light shielding cap 2 is formed of a light shielding material, for example, metal or colored resin. The light-shielding cap 2 prevents light from the light-emitting diode 4 from leaking to the center portion of the pointer plate 1 and the front surface side from the light guide portion 12 and directly entering the eyes of the viewer.

  As shown in FIG. 2, a light emitting diode 4 as a light source is disposed behind the pointer plate 1 so as to face the first light incident surface 1 b and the second light incident surface 1 c of the pointer plate 1. It arrange | positions so that the 1 light-incidence surface 1b and the 2nd light-incidence surface 1c can be irradiated. As shown in FIG. 1, eight light emitting diodes 4 are arranged along a rotation axis of the pointer plate 1, that is, an arc concentric with the shaft 3 a of the movement 3. Thereby, irrespective of the rotation angle of the pointer plate 1, that is, the rotation angle of the groove portion 1a which is the pointer portion, the light emission luminance of the groove portion 1a can be stably maintained high.

  As shown in FIG. 2, a light guide 5 is arranged between the first light incident surface 1 b and the second light incident surface 1 c of the pointer plate 1 and the light emitting diode 4. The light guide 5 is formed in a cylindrical shape from a translucent material, for example, a colorless and transparent acrylic resin or polycarbonate resin, and is arranged concentrically with the shaft 3 a of the movement 3 that is the rotating shaft of the pointer plate 1. The light guide 5 refracts the light emitted radially from the light emitting diode 4 that is a point light source and refracts it by a lens action and a prism action, and converges the light into a substantially parallel light beam. 2 fulfills the function of emitting light toward the light incident surface 1c.

  As shown in FIG. 2, a dial 6 is disposed behind the pointer plate 1. The dial 6 is formed of a light-transmitting material, for example, a thin plate such as a colorless and transparent polycarbonate resin or acrylic resin. As shown in FIG. 1, the dial 6 includes characters 6 a and scales 6 b as display units. The characters 6a and scales 6b are formed by printing or hot stamping the front surface or the back surface of the dial plate 6. That is, a translucent colored layer is applied to the characters 6a and the scale 6, and a light-shielding black colored layer is applied to the background portion around the characters 6a and the scale 6b. In the speedometer S according to the embodiment of the present invention, the characters 6a and the scale 6b are formed as a translucent white colored layer.

  A light emitting diode 7 is arranged behind the dial 6 as shown in FIG. The dial 6 is illuminated by light emitted from the light emitting diode 7. As the light emitting diode 7, for example, a white light emitting diode is used. When the light emitting diode 7 is turned on, the character 6a and the scale 6b are lit and displayed in white on a black background on the dial 6.

  As shown in FIG. 2, a printed circuit board 8 is disposed behind the dial 6. The printed circuit board 8 is made of, for example, a glass epoxy substrate, and constitutes not only the speedometer S but also an electric circuit portion of the combination meter 100. A light emitting diode 4 for illuminating the pointer plate 1, a movement 3 to be described later for rotating the pointer plate 1, and a light emitting diode 7 for transmissively illuminating the dial 6 are mounted on the printed circuit board 8. Furthermore, a controller 9 is mounted on the printed circuit board 8 to control turning on / off the light emitting diodes 4, 7 and drive control of the movement 3. The controller 9 is composed of, for example, a microcomputer.

  The movement 3 for rotating the pointer plate 1 is composed of an electric actuator such as a stepping motor or a cross coil type rotating machine. The movement 3 is driven by the controller 9 described above so as to rotate the shaft 3a that is the rotation axis by an angle corresponding to the traveling speed calculated based on the detection signal from the speed sensor 16. Thereby, the groove part 1a of the pointer plate 1 indicates the traveling speed in cooperation with the dial plate 6.

  As shown in FIG. 2, a light shielding cylinder 10 is disposed between the dial 6 and the printed board 8. The light shielding tube 10 is formed in a cylindrical shape from, for example, a resin material, and is disposed so as to surround the light emitting diode 4 and the light guide 5. The light shielding tube 10 prevents light emitted from the light emitting diode 4 from being transmitted through the dial 6 and prevents light emitted from the light emitting diode 7 from entering the pointer plate 1. In the speedometer S according to the embodiment of the present invention, the light shielding cylinder 10 is formed integrally with a casing 11 described later.

  The pointer plate 1, the movement 3, the dial plate 6, the printed circuit board 8, and the like described above are accommodated and fixed in the casing 11. The casing 11 is made of, for example, a resin material.

  On the front side of the dial 6 (left side in FIG. 2), a substantially frame-shaped facing plate 12 is mounted. The facing plate 12 is made of, for example, a resin material. As shown in FIG. 2, a transparent cover 13 is attached to the viewer side end of the facing plate 12. The transparent cover 13 is formed from a thin plate such as a transparent resin or glass. The facing plate 12 and the transparent cover 13 improve the appearance of the speedometer S and prevent dust and moisture from entering the speedometer S.

  On the other hand, as shown in FIG. 2, a lower cover 14 that covers the back surface of the printed circuit board 8 and the movement 3 is mounted behind the casing 11 by fastening means such as screws. The lower cover 14 is made of, for example, a resin material.

  Next, the electric circuit configuration and operation of the speedometer S according to one embodiment of the present invention will be described with reference to FIG.

  As shown in FIG. 5, power is constantly supplied from the battery 16 to the controller 9. Moreover, the controller 9 is connected so that the ignition switch 15 can detect the operation state (ON or OFF).

  As shown in FIG. 4, the light emitting diodes 4 and 7 and the movement 3 are connected to the controller 9.

  As shown in FIG. 4, the controller 9 is connected to a speed sensor 17 for detecting the traveling speed of the automobile so that a detection signal can be input. For example, an electromagnetic pickup type or the like is used as the speed sensor 17 and detects the number of revolutions of a propeller shaft that is an output shaft of an automobile transmission, for example.

  When the ignition switch 15 is switched to the ON state by the driver's operation, the controller 9 detects it and starts the operation of the speedometer S. That is, the light emitting diodes 4 and 7 are turned on. At the same time, the travel speed of the automobile is calculated based on the detection signal from the speed sensor 17, and the movement 9 is driven so that the calculated travel speed is at the angular position indicated by the groove 1a of the pointer plate 1.

  As a result, the characters 6a and scales 6b of the dial 6 are lit and displayed in white. At the same time, the groove 1a of the pointer plate 1 is also lit and displayed in white.

  Here, since the pointer plate 1 is colorless and transparent, the characters 6 a and the scale 6 b of the dial plate 6 are clearly visible through the pointer plate 1.

  Next, the configuration of the pointer plate 1, which is a feature of the speedometer S according to the embodiment of the present invention, particularly the configuration of the light guide unit 12, and the function and effect thereof will be described.

  The light path from the light emitted from the light emitting diode 4 to the pointer plate 1 until reaching the disk portion 11 in which the groove portion 1a as the pointer portion is formed will be described.

  First, in the conventional instrument Y, the light emitted radially from the light emitting diode 104 is refracted by the light guide 105 to become a substantially parallel light beam as shown in FIG. Is incident on.

  Of the light incident on the light receiving surface 102, the light incident on the reflecting surface 103, that is, the light that follows the optical paths P, Q, and R in FIG. 6 is reflected toward the outer peripheral side of the pointer plate 101 by the reflecting surface 103. The light enters the disk portion 106. On the other hand, of the light incident on the light receiving surface 102, the light not incident on the reflecting surface 103, that is, the light that follows the optical paths U and V in FIG. 6, is emitted to the outside of the pointer plate 101 as shown in FIG. However, the light does not enter the disk portion 106. That is, in the conventional meter Y, only a part of the light emitted from the light emitting diode 104 is introduced into the disk portion 106 and contributes to the light emission display of the pointer (not shown). Therefore, there is a problem that the light emission luminance of the pointer is not sufficient.

  On the other hand, in the speedometer S according to the embodiment of the present invention, in the light guide portion 12 of the pointer plate 1, the light receiving surfaces are two light receiving surfaces arranged coaxially with each other, that is, the first light receiving surface. 1b and the second light receiving surface 1c. Further, in addition to the first reflecting surface 1d corresponding to the reflecting surface 103 of the conventional speedometer Y, two second reflecting surfaces 1e and 1f are added as reflecting surfaces. These 2nd reflective surfaces 1e and 1f are formed in the front side rather than the surface 1g which is the front side in the disc part 11 of the pointer | guide plate 1, ie, the driver | operator side, as shown in FIG. As shown in FIG. 4, the second light receiving surface 1c can refract the light incident on the second light receiving surface 1c in a direction incident on either the second reflecting surface 1e or the second reflecting surface 1f. The shape is set.

  The light emitted radially from the light emitting diodes 4 and converted into parallel rays by the light guide 5 is incident on the first light receiving surface 1b or the second light receiving surface 1c as shown in FIG. The light incident on the first light receiving surface 1b travels as shown by optical paths P, Q, and R in FIG. 4, and is reflected by the first reflecting surface 1d toward the outer peripheral side of the pointer plate 1, that is, the disk portion 11. It progresses while repeating reflection in the disk part 11. Here, since both the 2nd reflective surfaces 1e and 1f are formed in the front side rather than the surface 1g which is the surface of the front side in the disc part 11 of the pointer plate 1, the light reflected by the 1st reflective surface 1d is It is surely incident on the disk portion 11 without being blocked by the second reflecting surfaces 1e and 1f. On the other hand, the light incident on the second light receiving surface 1c travels as indicated by the optical paths U and V in FIG. 4, and when entering the second light receiving surface 1c, the outer side of the pointer plate 1, that is, upward in FIG. The light is refracted toward the second incident surface 1e or the second incident surface 1f. These lights are reflected by the second reflecting surface 1e or the second reflecting surface 1f toward the outer peripheral side of the pointer plate 1, that is, toward the disc portion 11, and travel while being repeatedly reflected in the disc portion 11. Here, the shapes of the second light receiving surface 1c and the second reflecting surfaces 1e and 1f are such that the incident angle of the incident light on the second reflecting surfaces 1e and 1f is larger than the total reflection angle of the material of the pointer plate 1. Is set. For this reason, since the light that has passed through the second light receiving surface 1c and entered the second reflecting surfaces 1e and 1f is always totally reflected by the second reflecting surfaces 1e and 1f, the light incident from the second light receiving surface 1c is second reflected. By preventing leakage from the surfaces 1e and 1f to the outside, the light emitted from the light emitting diode 4 can be used for illumination of the groove 1a with high efficiency.

  As described above, in the speedometer S according to the embodiment of the present invention, both the light incident on the first light receiving surface 1 b and the light incident on the second light receiving surface 1 c are introduced into the disk portion 11. That is, in the speedometer S according to the embodiment of the present invention, the entire amount of light emitted from the light emitting diode 4 can be guided into the disk portion 11 and used for the light emission display of the groove portion 1a.

  The light that has entered the disk portion 11 travels as indicated by the broken-line arrows in FIG. 1, enters the slopes 1a1, 1a2 of the groove 1a, and further enters the slopes 1a1, 1a2 as shown in FIG. Reflected toward the front side, the groove 1a is visually recognized as a light emission indicator.

  As described above, in the speedometer S according to the embodiment of the present invention, the pointer plate 1 is thinned to suppress an increase in the moment of inertia, and the light from the light emitting diode 4 is incident on the pointer plate 1 with high efficiency. The speedometer S that can increase the brightness of the groove 1a can be realized.

  Note that the slopes 1a1 and 1a2 of the groove portion 1a, which is a pointer portion provided in the pointer plate 1 of the speedometer S according to the embodiment of the present invention described above, may be a smooth plane, or may be infinitely fine by sandblasting, a mold, or the like. It is also possible to provide a diffuse reflection surface by providing unevenness. In the case of a diffuse reflection surface, the inclination angles of the inclined surfaces 1a1 and 1a2 are not necessarily 45 °.

  In addition, in the speedometer S according to the embodiment of the present invention described above, two second reflecting surfaces are provided, but it is not necessary to limit to two, and one or three or more may be used. Good.

  Further, the boss 2 a of the light shielding cap 2 may be integrated with the pointer plate 1. Further, the boss 2a may be divided from the cap 2 and formed as a separate part.

  In the speedometer S according to the embodiment of the present invention described above, the number of the light emitting diodes 4 for illuminating the pointer plate 1 is eight. However, the number of the light emitting diodes 4 is not limited to eight. Any number may be used as long as the light emission luminance of the groove 1a can be stably maintained high regardless of the rotation angle, that is, the rotation angle of the groove 1a as the pointer.

  Moreover, you may give an anti-glare film process to the surface 1g of the indicator plate 1 of the speedometer S by one Embodiment of this invention demonstrated above. In this case, it is possible to prevent the external light incident on the surface 1g from being reflected by the surface 1g and reducing the visibility of the speedometer S.

  In the speedometer S according to the embodiment of the present invention described above, the pointer plate 1 remains colorless and transparent. However, the light-shielding colored layer except the portion corresponding to the groove portion 1a on the surface 1g of the pointer plate 1 is used. May be formed. In that case, what is necessary is just to form the character 6a and scale 6b formed in the dial 6 in the outer peripheral side rather than the pointer plate 1. FIG.

  In the above-described embodiment, the case where the instrument is applied to the speedometer S has been described as an example. However, the present invention is not limited to the speedometer S, and other types of instruments, for example, the engine rotational speed of the automobile are indicated. It may be applied to a tachometer, a fuel meter that indicates the amount of remaining fuel in the fuel tank, a water temperature meter that indicates the engine cooling water temperature, and the like. A single combination meter 100 may include a plurality of instruments according to the present invention.

It is a partial front view of the combination meter 100 provided with the speedometer S by one Embodiment of this invention. It is the II-II sectional view taken on the line in FIG. It is the III-III sectional view taken on the line in FIG. It is the IV section enlarged view in FIG. It is a schematic diagram explaining the electric circuit structure of the speedometer S by one Embodiment of this invention. FIG. 6 is a partially enlarged cross-sectional view of a conventional speedometer Y and corresponds to FIG. 4.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pointer plate 11 Disc part 12 Light guide part 1a Groove part (pointer part)
1a1, 1a2 Slope 1b 1st light incident surface 1c 2nd light incident surface 1d 1st reflective surface 1e 2nd reflective surface 1f 2nd reflective surface 1g Surface 1h Through-hole 2 Light-shielding cap 2a Boss part 3 Movement 3a Shaft (rotating shaft)
4 Light emitting diode (light source)
5 Light guide 6 Dial 6a Character (display part)
6b Scale (display section)
7 Light Emitting Diode 8 Printed Circuit Board 9 Controller 10 Shading Cylinder 11 Casing 12 Turn Plate 13 Transparent Cover 14 Lower Cover 15 Ignition Switch 16 Battery 17 Speed Sensor 100 Combination Meter 101 Pointer Plate 102 Incident Surface 103 Reflecting Surface 104 Light Emitting Diode 105 Light Guide 106 Disk part P, Q, R, U, V Optical path S Speedometer (instrument)

Claims (4)

A dial with a display,
A pointer plate that is disposed on the front side or the back side of the dial, is formed in a disc shape from a translucent material, and includes a pointer unit that indicates the display unit;
A light source arranged so that light can be incident inside the pointer plate;
An instrument having a movement whose one end is rotationally driven by a rotation shaft fixed to the pointer plate,
The pointer plate includes a first light incident surface formed in an annular shape coaxially with the rotation axis so that light from the light source is incident on a back surface side of a central portion of the pointer plate, and the first light incident surface A first reflecting surface that reflects light incident from the surface toward the outer peripheral direction of the pointer plate, and a second incident light provided coaxially with the first incident surface on the outer peripheral side of the first incident surface. And a second reflecting surface provided coaxially with the first reflecting surface on the outer peripheral side of the first reflecting surface and reflecting light incident from the second light incident surface toward the outer periphery of the pointer plate. Prepared,
The second reflecting surface is formed on the front side in the axial direction of the rotation shaft from the front side surface of the area where the pointer portion is provided in the pointer plate,
The instrument is characterized in that the second reflection surface is formed in a shape that refracts light incident from the second light incident surface toward an outer peripheral side of the pointer plate.   The shape of the second light incident surface and the shape of the second reflective surface are such that the incident angle of the light incident from the second light incident surface on the second reflective surface is larger than the total reflection angle of the pointer plate. The instrument according to claim 1, wherein   The instrument according to claim 1, wherein a plurality of the second reflecting surfaces are provided coaxially with each other. In an instrument having a disk-shaped pointer plate,
The pointer plate corresponds to a first light incident surface and a second light incident surface on which light from a light source disposed on the back surface of the pointer plate is incident, and the first light incident surface and the second light incident surface. A first reflecting surface and a second reflecting surface for reflecting light from the light source incident on the first light incident surface and the second light incident surface toward a radially outer side of the pointer plate;
The instrument according to claim 1, wherein the second reflecting surface is positioned relatively above the first reflecting surface in the axial direction of the pointer plate.

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