JP2011047790A - Display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem wherein, in dial plate illumination of an instrument, light entering a light guide plate from a light source leaks from a side surface other than a surface facing to a display surface, and is not supplied efficiently to the display surface. <P>SOLUTION: A belt-like light guide having a plurality of groove parts having an approximately V-shaped cross section which are formed on the rear surface is arranged between the dial plate composed of a translucent material and the light source, and the belt-like light guide is positioned on an index point of the dial plate and covered with a reflection member. In this case, the end of the belt-like light guide is enclosed from the side together with the light source by an end enclosing part formed on the end of the reflection member, and a part other than the end is opened. Hereby, illumination light leaking from the belt-like light guide is returned to the belt-like light guide and used effectively for dial plate illumination. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a display device suitable for use in vehicles, aircraft instruments, and the like.

  In general, scales, numbers, and the like of a display device used in a vehicle instrument are arranged on an arc on the outer peripheral side of the dial along the rotational movement of the pointer. The scales, numbers, and the like are transmitted and illuminated by a plurality of light sources arranged in an arc shape immediately below the scales, numbers, and the like. However, in such a configuration, a large number of light sources are required to reduce the uneven light emission luminance of the dial, and power consumption and cost increase.

  Therefore, in order to transmit and illuminate with a small number of light sources with uniform brightness, a light guide plate made of a translucent material is arranged on the back side of the dial, and light from the light source is made incident on the light guide plate so that the characters are A technique for transmitting through a board is known. In this case, by adjusting the shape of the light guide plate, unevenness in light emission luminance can be reduced, and further low power consumption and cost can be achieved.

  For example, in Patent Document 1, a plurality of reflection surfaces are formed on the side surface of a strip-shaped light guide plate having an arc shape in plan view, and light from two light sources arranged at both ends of the light guide plate is displayed on the display surface by the plurality of reflection surfaces. A display device that reflects to the side is disclosed.

JP 2004-184221 A

  In the display device of Patent Document 1, light incident on the light guide plate from the light source leaks from the side surface other than facing the display surface, and is not efficiently supplied to the display surface.

The present invention has been made in view of the above, and a reflective surface is provided toward the side surface of the light guide plate that does not face the display surface, and the leaked light is returned into the light guide to increase efficiency. An object is to provide an apparatus.

  In order to achieve the above object, the dial is made of a translucent material and has an indicator portion arranged in an arc shape, and is formed from the translucent material in an arc shape in plan view, and the dial is formed on the back side of the dial. A strip-shaped light guide having a plurality of substantially V-shaped groove portions formed on the back surface opposite to the front surface facing the dial, and disposed on the back surface side of the strip-shaped light guide body. A light source mounted on the wiring board, the illumination light from the light source is incident on the strip light guide from its end surface, and is emitted from the surface of the strip light guide facing the dial, In the display device that illuminates the dial from the back side, an end surrounding portion that surrounds the light source from the side is formed at the end, and an opening that opens toward the index portion at a portion other than the end And a body surrounding portion surrounding the belt-shaped light guide is formed. And a reflecting member having a reflecting surface formed on the inner surface of the end portion surrounding portion and the main body surrounding portion, and the end portion of the strip light guide is housed in the end portion surrounding portion of the reflecting member. It is characterized by that.

ADVANTAGE OF THE INVENTION According to this invention, the display apparatus which can improve the utilization efficiency of illumination light with a simple structure can be provided.

  The best mode for carrying out the present invention will be described below with reference to the drawings. In the following description of the drawings, the same or equivalent parts are denoted by the same or equivalent reference numerals. However, it should be noted that the drawings are schematic and different from the actual ones. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

  Further, the embodiment described below exemplifies an apparatus for embodying the technical idea of the present invention, and the technical idea of the present invention is to arrange the components and the like as follows. Not specific. The technical idea of the present invention can be variously modified within the scope of the claims.

  FIG. 1 is a plan view according to a first example of the embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along the line AA in FIG. 1 and is a partial explanatory view showing a configuration for illuminating the indicator portions 21 and 22. . 3 is a plan view of the light guide 3 of the display device 1 shown in FIG. 1, FIG. 4 is an external perspective view of the light guide 3, FIG. 5 is a partial external perspective view of the light guide 3, and FIG. FIG. 7 is a plan view of the first reflecting member 13, and FIG. 8 is a perspective view of the first reflecting member 13 when the strip-shaped light guide 3 is removed from the display device 1 shown. 9 is a partial plan view of a meter including the display device 1 according to the second embodiment, FIG. 10 is a cross-sectional view taken along line AA in FIG. 9, and FIG. 11 is an external perspective view of the first reflecting member of the display device shown in FIG. 12 is an explanatory cross-sectional view of the display device 1, and FIG. 13 is an explanatory view for explaining a concentric boss structure for attaching the first reflecting member 13 and the strip-shaped light guide 3 to the printed circuit board 6.

  The display device 1 according to the present embodiment is incorporated in the meter 100. The meter 100 is disposed at a position visible from the driver in front of the driver's seat of the automobile, and includes a plurality of meters and the like, and displays various information related to the automobile so that the driver can visually recognize the information. In FIG. 1, the example which applied the display apparatus 1 which concerns on this Embodiment to the speedometer is shown.

  As shown in FIGS. 1 and 2, the display device 1 according to the present embodiment includes a dial 2, a light guide 3, light sources 4 and 5, a printed circuit board 6, a movement 7, a pointer 8, A controller 9, a case 10, a facing plate 11, and a front cover 12 are provided.

  The dial 2 is made of a thin plate made of a light-transmitting material such as acrylic resin or polycarbonate resin, and has an indicator portion arranged in an arc shape. Specifically, as shown in FIG. 1, the dial 2 includes a scale portion 21 in which a plurality of scales 21 a are arranged in an arc shape, and a plurality of scale portions 21 are formed on the inner peripheral side of the scale portion 21. A number portion 22 is formed by arranging numbers 22 a in an arc shape and concentrically with the scale portion 21, and the scale portion 21 and the number portion 22 constitute a main indicator portion.

  The scale portion 21 and the number portion 22 are formed by printing or hot stamping on the front surface or back surface of the dial 2. That is, a colored layer having a light-impermeable property is provided in a part other than the scale part 21 and the number part 22, and the scale part 21 and the number part 22 are kept transparent, or a process such as providing a translucent colored layer is performed. It has been given.

  Further, white and smoke color diffusion printing for diffusing light emitted from the surface of the light guide 3 is performed at positions corresponding to the scale portion 21 and the number portion 22 on the back surface of the dial 2.

  The light guide 3 is made of a light-transmitting plastic material such as transparent acrylic resin, polycarbonate resin, silicone resin, and cyclopolyolefin resin, and is formed in a thin plate shape. As shown in FIGS. 1 and 2, the light guide 3 is formed so that its plan view shape is an arc shape (horse-shoe shape) and covers the scale portion 21 and the number portion 22 on the back side of the dial 2. Has been.

  As shown in FIGS. 3 to 5, the light guide 3 includes guide portions 31 and 32 formed by bending both end portions corresponding to both ends of the arc shape of the light guide 3 in the back surface direction. Incident surfaces 31a and 32a, which are entrances of light emitted from the light sources 4 and 5, are provided at the tips of the guide portions 31 and 32, respectively, so as to be a plane substantially perpendicular to the main optical axis direction of the light sources 4 and 5. It has been.

  The upper surfaces 31b and 32b of the guide portions 31 and 32 are continuously formed with surfaces having an angle greater than the critical angle from the inside of the guide portions 31 and 32 to the air outside the guide portions 31 and 32. Thereby, the guide parts 31 and 32 guide the light received by the incident surfaces 31a and 32a (light emitted from the light sources 4 and 5 and traveling in a direction substantially perpendicular to the front surface 3a and the back surface 3b of the light guide 3). The light is reflected by the upper surfaces 31 b and 32 b of the light guides 31 and 32 and can be guided to light traveling in the direction along the front surface 3 a and the back surface 3 b of the light guide 3.

  Further, on the back surface 3b, which is the surface opposite to the surface 3a facing the dial 2 of the light guide 3, a plurality of groove portions 14 are provided at predetermined angular intervals over almost the entire area in the circumferential direction. 3 are formed radially from the center position of the arc in plan view. The groove 14 has a substantially V-shaped cross section and is formed so as to cross the light guide 3 in the width direction.

A reflection surface 14 a that crosses the light guide 3 in the width direction is formed on one surface of the groove portion 14.
The reflection surface 14a is for reflecting the light traveling in the light guide 3 toward the front surface 3a, and is configured to be inclined at a predetermined inclination angle with respect to the back surface 3b.

  Each reflecting surface 14 a is formed so as to reflect light from one of the light sources 4 and 5 toward the surface 3 a side of the light guide 3. For example, each groove portion 14 arranged on the light source 4 side (right side in FIG. 3) with respect to the center line C shown in FIG. 3 has a reflecting surface 14a facing the light source 4 side, and the distance through the light guide 3 is Each groove 14 formed so as to reflect light from the light source 4, which is a light source closer to the groove 14, to the surface 3 a side and disposed on the light source 5 side (left side in FIG. 3) with respect to the center line C, The reflection surface 13a faces the light source 5 side, and is formed so as to reflect light from the light source 5 which is a light source closer to the groove portion 14 through the light guide 3 to the surface 3a side.

  The light sources 4 and 5 are mounted on the printed circuit board 6 and include one or a plurality of LEDs. The light sources 4 and 5 emit light in a direction opposite to the printed circuit board 6 side, and are incident surfaces 31a of the guide portions 31 and 32, respectively. , 32a so that light can enter. In the present embodiment, a vertical light emitting LED that emits light in a direction substantially perpendicular to the mounting surface of the printed circuit board 6 can be used. For example, the light sources 4 and 5 can be configured by two vertically emitting LEDs arranged in the direction along the incident surfaces 31a and 32a, respectively.

  The printed circuit board 6 constitutes an electric circuit section of the combination meter 100 and is disposed on the back side (right side in FIG. 2) of the light guide 3. Light sources 4 and 5, a movement 7 and a controller 9 are mounted on the printed circuit board 6.

  The movement 7 is a rotating internal unit that rotates the shaft 71 by an angle corresponding to an electrical signal from the outside. The shaft 71 of the movement 7 extends to the front side (left side in FIG. 2) of the dial 2 through the through hole 23 of the dial 2, and the pointer 8 is fixed to the tip thereof.

  The pointer 8 is made of a transparent or translucent material such as an acrylic resin, and light is displayed by introducing light from an external light source (not shown).

  The controller 9 is composed of a hybrid IC or the like, and controls turning on and off of the light sources 4 and 5. Further, when an electric signal from the outside is input, the controller 9 drives the movement 7 based on the input electric signal to rotate the shaft 71 to a predetermined angular position.

  The case 10 houses and holds the components such as the dial 2, the light guide 3, the light sources 4 and 5, and the printed board 6 described above.

  A front cover 12 is attached to the front side of the dial 2 (left side in FIG. 2) via a facing plate 11. The front cover 12 is formed of a transparent thin plate-like polycarbonate resin or the like, and maintains the airtightness in the meter 100 well.

As shown in FIG. 7, the first reflecting member 13 has an open upper surface (the dial 2 side), a lower wall 13a formed on the lower surface side, and side walls 13b and 13b formed on both side surfaces. Thus, a main body surrounding portion B is formed. Further, the inner surface of each of the lower wall 13a and the side walls 13b, 13b, that is, the surface on the side of the strip-shaped light guide plate 3 is formed as a reflective surface. Has a function to return.

Further, both end portions of the first reflecting member 13 have a cylindrical shape with openings at both ends to form an end surrounding portion A, and both end surfaces thereof are attached to the printed circuit board 6 by fixing means (not shown). When the strip-shaped light guide 3 is housed in the reflecting member 13, the light sources 4, 5 and both ends of the strip-shaped light guide 3 are surrounded from the periphery, and illumination light emitted from the light sources 4, 5 enters the strip-shaped light guide 3. It is formed so as to be incident.

  In the display device 1 configured as described above, when the light sources 4 and 5 emit light under the control of the controller 9, the light incident on the guide portions 31 and 32 from the incident surfaces 31 a and 32 a is transmitted to the guide portions 31 and 32. The light is reflected by the upper surfaces 31 b and 32 b, guided to light traveling in the direction along the front surface 3 a and the back surface 3 b of the light guide 3, and travels in the light guide 3. As shown in FIG. 6, most of the light that travels in the light guide 3 reaches the reflecting surface 14a of the groove 14 and is reflected by the reflecting surface 14a to be emitted from the surface 3a side to the outside. Is done.

  The light reflected by the reflecting surface 14a of each groove 14 and emitted from the front surface 3a of the light guide 3 is diffused by diffusion printing applied to positions corresponding to the scale portion 21 and the number portion 22 on the back surface of the dial 2. The The diffused light has a uniform brightness at the location, and is transmitted and illuminated to the scale portion 21 and the number portion 22 of the dial 2 so as to emit light.

  According to the present embodiment, the light from the light sources 4 and 5 is reflected toward the dial 2 side by the reflecting surfaces 14a of the plurality of grooves 14 formed radially from the center position on the light guide 3. By diffusing the reflected light by diffusive printing, the brightness becomes uniform at the location, and the scale portion 21 and the number portion 22 of the dial 2 can be transmitted and illuminated with uniform brightness. The visibility of the display device 1 can be improved by suppressing the occurrence of light emission luminance spots on the scale portion 21 and the numerical portion 22.

  Further, since the light incident from the light sources 4 and 5 is guided by the guide portions 31 and 32 to the light traveling in the direction along the front surface 3a and the back surface 3b of the light guide 3, a vertical light emitting type LED is used as the light source. 6 is used by mounting.

  Further, since the back surface of the dial 2 is subjected to diffusion printing, it is not necessary to install a component such as a diffusion sheet for diffusing the light emitted from the front surface 3a of the light guide 3, and the increase in the number of components is suppressed. be able to.

In addition, the leaked portion of the illumination light emitted from the light sources 4 and 5 is reflected in the strip-shaped light guide 3 by the reflection surfaces formed on the inner wall surfaces of the end surrounding portions A at both ends of the first reflection member 13. Returned and travels forward along the strip-shaped light guide 3.

Further, the light leaked from the lower surface and both side surfaces of the strip-shaped light guide 3 is returned again into the strip-shaped light guide plate 3 by the reflecting surfaces formed inside the lower wall 13a and the both side walls 13b, 13b of the first reflecting member 13. Then, it travels forward along the inside of the strip-shaped light guide 3.
As a result, since the amount of light emitted from the surface of the strip-shaped light guide plate 3 toward the indicator portion 40 can be used without omission, the indicator portion 40 can be displayed brightly, and the efficiency can be improved.

The display device 1 according to the present embodiment is configured such that, in addition to the main indicator portions (indicator portions) 21 and 22, the sub indicator portion 41 (see FIG. 9) is an illumination target with respect to the configuration shown in the first embodiment. For this reason, a part of the illumination light emitted from the light sources 4 and 5 is leaked toward the back surface of the dial 2 and reflected by a reflective surface (not shown) on the back surface of the dial 2, which is further reflected by the second. It is the point which made it the structure which illuminates the sub display part 41 with the reflective surface of the reflective member 42 of this. This will be described below with reference to FIGS.

  That is, the sub indicator unit 41 is a display of a pictograph provided on the dial 2 in addition to the main indicator units 21 and 22, an odd trip display device, and the like, and any device that requires transmission illumination by a backlight may be used. For example, in the case of the pictogram shown in FIG. 9, it has the same structure as the main indicator parts 21 and 22 and is backlit.

Further, as shown in FIG. 10, the first reflecting member 13 ′ is a side surface facing the sub display portion 41 among the side surfaces of the end portion A with respect to the structure of the first reflecting member 13 shown in the first embodiment. Is provided with an opening 13'd, and most of the light emitted from the corresponding light source 4 or 5 is supplied to the incident surface of the strip-shaped light guide 3, while a part of the opening 13'd is provided. The light is leaked from d toward the back surface of the dial 2, reflected on the back surface toward the reflecting surface of the second reflecting member 42, and the reflected light is further reflected on the reflecting surface of the second reflecting member 42 on the sub display unit. The light is reflected in the 41 direction, and the sub display unit 41 is backlit.

As a result, the light sources of the main indicator parts 21 and 22 and the sub indicator part 41 can be shared and the cost can be reduced without providing separate light sources.
In addition, the ratio of the light quantity used for the illumination of the main index parts 21 and 22 and the light quantity used for the illumination of the sub index part 41 can be easily changed by changing the size of the opening 13'd. Can do.

A method for fixing the first reflecting member 13 (13 ′) and the strip-shaped light guide 3 to the printed circuit board 6 will be described below with reference to FIG.
That is, a pair of mounting holes 6a, 6a are formed in the printed circuit board 6, and a pair of bosses 13e (13) fitted into the pair of mounting holes 6a, 6a on the end surface of the first reflecting member 13 (13 '). ′ E) is erected, and a pair of mounting holes 13f and 13f (13 ′) are formed on the other end surface of the first reflecting member 13 (13 ′) opposite to the end surface provided with the pair of bosses 13e and 13′e. f, 13'f) and a pair of bosses 3e, 3e, 3e which are fitted into the pair of mounting holes 13f, 13f (13'f, 13'f) on the end face of the strip-shaped light guide 3, respectively. (3'e, 3'e) is erected.

Further, the pair of mounting holes 6a, 6a, the boss 13e (13'e), the mounting holes 13f, 13f (13'f, 13'f) and the boss 3e (3'e) are concentric. Is set.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the components without departing from the scope of the invention in the implementation stage. Various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiments. For example, some components may be deleted from all the components shown in the embodiment.

1 is a partial plan view of a meter including a display device according to a first embodiment of the present invention. It is AA sectional drawing in FIG. It is a top view of the light guide of the display apparatus shown in FIG. It is an external appearance perspective view of a light guide. It is a partial external appearance perspective view of a light guide. It is sectional explanatory drawing when a strip | belt-shaped light guide is remove | excluded among the display apparatuses shown in FIG. It is a top view of the 1st reflective member. It is a perspective view of the 1st reflective member. It is a fragmentary top view of the meter containing the display apparatus which concerns on 2nd Example. It is AA sectional drawing in FIG. It is an external appearance perspective view of the 1st reflection member of the display apparatus shown in FIG. It is a cross-sectional explanatory view of a display device. It is explanatory drawing for demonstrating the concentric boss structure for attaching a 1st reflective member and a strip | belt-shaped light guide with respect to a printed circuit board.

DESCRIPTION OF SYMBOLS 1 Display apparatus 2 Dial 3 Light guide 4,5 Light source 6 Printed circuit board 7 Movement 8 Pointer 9 Controller 10 Case 11 Turn-back plate 12 Front cover 13, 13 '1st reflection member 14 Groove part 14a Reflective surface 21 Scale part 21a Scale 22 Number part 22a Number 31, 32 Guide part 40 2nd reflection member A End part surrounding part B Main body surrounding part

Claims (1)

Dial made of a translucent material and having an indicator portion arranged in an arc shape;
A groove portion that is formed of a light-transmitting material in an arc shape in plan view, is disposed on the back surface side of the dial so as to overlap the indicator portion, and has a substantially V-shaped cross section on the back surface opposite to the front surface facing the dial A plurality of strip-shaped light guides,
A light source mounted on a wiring board disposed on the back side of the strip light guide,
Illumination light from the light source is incident on the strip-shaped light guide from its end face, emitted from the surface of the strip-shaped light guide facing the dial, and illuminates the dial from the back surface.
An end surrounding portion that surrounds the light source from the side is formed at the end, and has an opening that opens toward the indicator portion at a portion other than the end, and the belt-shaped light guide is A body enclosing portion is formed, and a reflection member is formed on the inner surface of the end portion enclosing portion and the body enclosing portion;
The display device is characterized in that the end portion of the strip-shaped light guide is housed in the end portion surrounding portion of the reflecting member.

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