JP2016006385A - Lighting system of vehicular instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lighting system of a vehicular instrument capable of changing a color of a display screen of a liquid crystal display panel despite a simple configuration.SOLUTION: The lighting system of a vehicular instrument includes: a liquid crystal display panel 31 for displaying an image of vehicle information; a plurality of light-emitting diodes 34 for lighting the liquid crystal display panel 31; and a light guide member 33 for guiding illumination light from the light-emitting diodes 34 provided on the back side of the liquid crystal display panel 31 to the liquid crystal display panel 31. Further, the lighting system includes a pair of a first light source group 34a and a second light source group 34b, the first light source group having a first light source 341 for emitting red light, a second light source 342 for emitting green light, and a third light source 343 for emitting blue light, and the second light source group similarly having fourth-sixth light sources 344-346. A first virtual line 34x formed by connecting the first light source 341 to the fourth light source 344, and a second virtual line 34y formed by connecting the third light source 323 to the sixth light source 346 are disposed so as to cross each other.

Description

  The present invention relates to a lighting device for a vehicle instrument, and is suitable for a lighting device that illuminates a predetermined display area such as a display screen of a liquid crystal display panel.

  Some conventional vehicle meters have a light source or a light guide behind the liquid crystal display panel, and include a lighting device that guides light from the light source such as a light emitting diode to the light guide and transmits the liquid crystal display panel through the light. For example, it is disclosed in Patent Document 1.

JP 2012-73057 A

  In these vehicular instrument lighting devices, it is desired that the background color of the liquid crystal display panel be different depending on the running state of the vehicle. Therefore, a light emitting component that can output a plurality of light emission colors as a light source. It is conceivable to change the background of the liquid crystal display panel using (a light source component in which light emitting elements of three colors are packaged). However, when the liquid crystal display panel is large, in order to display the background uniformly using a single chip light emitting component, a large number of light emitting components (light sources) are required, resulting in high power consumption and high cost. There was a problem of becoming.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an illumination device for a vehicle meter that can change the display screen of a liquid crystal display panel even with a simple configuration by paying attention to the above-described problems.

The illumination device for a vehicle instrument of the present invention is
A display panel for displaying vehicle information as an image;
A plurality of backlights for illuminating the display panel;
A light guide provided on the back side of the display panel for guiding illumination light from the backlight to the display panel,
The backlight is
A first light source group having a first light source that emits red illumination, a second light source that emits green illumination, and a third light source that emits blue illumination;
A second light source group having a fourth light source that emits red illumination, a fifth light source that emits green illumination, and a sixth light source that emits blue illumination;
Are provided in a pair via the light guide,
A first imaginary line connecting the first light source and the fourth light source;
The second imaginary line connecting the third light source and the sixth light source is arranged to intersect.

And a control means for controlling the light emission of the backlight,
The control means adjusts the output of the backlight using pulse width modulation control.

  Also, white illumination light is obtained by turning on all the backlights of the first and second light emitting element groups.

  The present invention relates to a lighting device for a vehicle instrument, and can change the color of a display screen of a liquid crystal display panel even with a simple configuration.

The top view which shows the example of a display of the vehicle meter in embodiment of this invention. Sectional drawing of the meter for vehicles in embodiment same as the above. Sectional drawing of the principal part of the meter for vehicles in embodiment same as the above. Sectional drawing of the light guide member in embodiment same as the above. The figure which shows the arrangement | positioning relationship of the light source in embodiment same as the above.

  Embodiments of the present invention will be described with reference to the accompanying drawings.

  FIG. 1 to FIG. 5 show an embodiment of the present invention, and a vehicle instrument A mounted on a two-wheeled vehicle such as a motorcycle will be described as an example. In this case, the vehicle instrument A is provided with an analog instrument according to the instruction of the pointer and a display using a liquid crystal display panel.

  The vehicle meter A according to the present embodiment is composed of, for example, a combination meter provided at the upper part of the front wheel. As shown in FIGS. 1 and 2, the vehicle meter A is provided inside the housing 1 having a window portion 11 as an exterior member. Is equipped with an analog indicating instrument (other display device) 2 comprising a well-known pointer-type instrument which is a speedometer, and a flat display panel is provided next to the indicating instrument 2. A digital display unit 3 is arranged. The housing 1 includes a window portion 11 made of a transparent resin such as acrylic, and a storage portion 12 that stores the circuit board 4 while holding the circuit board 4 and the like.

  In this case, a display board 21 is attached and fixed to the front side of the instrument drive source that constitutes the indicating instrument 2, and the indication of the pointer 22 provided on the indicating instrument 2 and the display of scales and characters provided on the display board 21. It can be read in a comparative manner so that the portion 21a faces the window portion 11. In addition, the display plate 21 is provided with an opening hole 21b at a central location so that the display form (vehicle display information) of the digital display unit 3 can be read through the opening hole 21b. Further, a space S is provided between the display plate 21 and the window portion 11, and a pointer 22 is rotatably provided in the space S.

  The digital display unit 3 includes a liquid crystal display panel 31 having a substantially rectangular plate shape that can be visually recognized through the opening 21b, a holding member 32 that houses the liquid crystal display panel (display panel) 31, a circuit board 4, and the like. A wiring (not shown) for connecting the connector and an outer peripheral wall of the holding member 32 that faces the one side of the liquid crystal display panel 31 and holds the light guide member 33 together, that is, a position corresponding to the outside of the display area of the liquid crystal display panel 31, A light-emitting diode (backlight) 34, and a light-guiding member 33 disposed between the liquid crystal display panel 31 and the holding member 32 and having a light-receiving surface 33 a facing the light-emitting diode 34 mounted on the circuit board 4. ing. Note that an optical film such as a diffusion sheet or a prism sheet (not shown) may be provided on one side surface of the light guide member 33 in order to improve the uniformity of the illumination light.

  The liquid crystal display panel 31 is a dot matrix type having pixels (dots) arranged in a matrix. Although the detailed configuration is omitted (not shown), the front glass substrate on which the transparent electrode made of ITO is formed and the rear glass substrate are overlapped and the periphery is fixed with a sealant, and then between each glass substrate The liquid crystal molecules are sealed in and a polarizing film is attached to each glass substrate. In addition, wiring is fixed to one end portion (one end of the quadrangle) on the surface side of the rear glass substrate. Then, when a signal (voltage) is applied to the transparent electrode through the wiring, the liquid crystal display panel 31 displays a vehicle state such as a fuel gauge and a water temperature gauge, and displays the travel distance (ODO, TRIP) and time of the vehicle, Various information such as the outside air temperature can be displayed as a display image, and the light-emitting diode 34 is lit to transmit light.

  In addition, the liquid crystal display panel 31 can change the color of the transmissive part (for example, the image background) by changing the illumination color of the backlight 34 described later, and the vehicle driving mode, gear position, driving state, An expression including a color change according to the alarm state can be performed. Note that the liquid crystal display panel 31 can also be configured using segmented TN liquid crystal elements.

  The light guide member 33 is made of a synthetic resin such as colorless and transparent acrylic or polycarbonate. As shown in FIGS. 3 and 4, the light guide member 33 has a reflective surface 31 b for irradiating illumination light to the liquid crystal display panel 31 side. A uniform flat plate portion 331 and a light adjusting portion 332 for introducing illumination light into the flat plate portion 331 are continuously formed.

  The flat plate portion 331 has a smooth surface facing the liquid crystal display panel 31, and a reflective surface 33 b in which an embossed shape composed of fine concave portions (or convex portions) is formed on the opposite side of this surface. In this case, the embossed shape is provided with a uniform density, but in order to make the illumination to the liquid crystal display panel 31 uniform, light and shade can be provided.

  The light adjusting unit 332 includes a light receiving surface 33 a that refracts illumination light from the light emitting diode 34 and a reflection curved surface 33 c that reflects the illumination light from the light receiving surface 33 a to the flat plate portion 331. In this case, the light receiving surface 33a has a convex shape in the plate thickness direction, and is formed in a concave shape with respect to the plate surface direction as shown in FIG. The light receiving surface 33a having the convex curved surface acts to collect the illumination light and efficiently irradiate the reflective curved surface 33c. Accordingly, the convex curvature of the light receiving surface 33a is set by the directivity of the light emitting diode 34, the distance between the light emitting diode 32 and the light receiving surface 33a, and the position and range of the reflection curved surface 33c.

  The reflection curved surface 33c includes a portion other than the display region (a visual recognition region determined by the opening 21b) on the surface of the flat plate portion 33c on the liquid crystal display panel 31 side, and a reflection surface 33b far from the light adjustment portion 332 of the flat plate portion 331. Curvature is set so that the main illumination light is emitted toward. Therefore, the curvature and inclination angle of the reflection curved surface 33c are set by the display area (transmission illumination range) of the liquid crystal display panel 31 in the flat plate portion 331. For example, the reflective curved surface 33c has a larger curvature when the display area is narrow and irradiation at a shorter distance is sufficient.

  The light adjusting unit 332 is mainly configured by a light receiving surface 33a whose curvature is set corresponding to the light emitting diode, and a reflection curved surface 33c set corresponding to the display region of the liquid crystal display panel 31 via the flat plate portion 33c. Even if the shape of the flat plate portion 331 is a simple flat plate shape, a predetermined display area can be efficiently illuminated. Further, uniform illumination can be measured by the light adjusting unit 332.

  The holding member 32 is made of a synthetic resin material, and is formed with a mounting portion (holding portion) 32 a that houses and holds the flat plate portion 331 of the light guide member 33, and the light guide member 33 is formed by the light emitting diode 34 or the liquid crystal display panel 31. Are held at predetermined intervals. In this case, the holding member 32 is formed of a white light-shielding material in order to efficiently irradiate the liquid crystal display panel 31 without exposing the illumination light from the light-emitting diode 34 to an extra portion. The holding member 32 is formed with a flat surface parallel to the reflecting surface 33b. Even on this surface, the illumination light is reflected toward the liquid crystal display panel 31 side, so that an efficient lighting device is obtained.

  The holding member 32 is provided with a display holding portion 32 b that positions and holds the liquid crystal display panel 31, and acts as a spacer between the circuit board 4 and the liquid crystal display panel 31. Further, the liquid crystal display panel 31 and the light guide member 33 can be held so as to be sandwiched between the metallic restraining members 35.

  The light emitting diode 34 can be a chip LED and is mounted on the circuit board 4 so as to face the light receiving surface 33 a of the light guide member 33. In this case, as shown in FIG. 5, the light-emitting diodes 34 are arranged in a row in the vicinity of two opposing sides of the liquid crystal display panel 31, and a first light source 341 that emits red illumination and green illumination are provided. A first light source group 34a having a second light source 342 that emits light, a third light source 343 that emits blue illumination, a fourth light source 344 that emits red illumination, and a fifth light source 345 that emits green illumination. And a second light source group 34 b having a sixth light source 346 that emits blue illumination are provided so that their irradiation directions face each other through the light guide member 33.

  In addition, a first virtual line 34x that connects the first light source 341 and the fourth light source 344 that emit the same red color, and a second virtual line that connects the third light source 323 and the sixth light source 346 that emit the same blue color. The line 34y is arranged to intersect. Therefore, even when the light receiving surface 33a of the light guide member 33 and the light emitting diode 34 are provided separately for each color, the first light source 341 and the sixth light source 346 are opposed to each other in the main illumination path. Therefore, it is easy to mix colors. Similarly, illumination lights from the third light source 343 and the fourth light source 344 are also likely to be mixed. Further, these light sources 341, 343, 345, and 346 are adjacent to the second light source 342 or the fifth light source 345 disposed therebetween, so that they are easily mixed with each other.

  In addition, the liquid crystal display panel 31 can be illuminated in white by lighting all the light emitting diodes 34 (341 to 346). Further, in this case, since a wide range can be illuminated without waste with two light emitting diodes 34 of three colors, an efficient illumination structure is obtained.

  As the circuit board 4, for example, a hard printed board in which a copper foil wiring pattern is applied to a board made of an epoxy resin material can be applied. In addition to the connector 41, although not shown, a liquid crystal display panel 31, a light emitting diode 34, Alternatively, electronic components such as a motor 23 for driving the indicator 2 and a control means 42 including a microcomputer for controlling the motor 23 are mounted. The circuit board 4 is provided with a light emitting diode 24 for illuminating the pointer 22 and a light emitting diode 25 for illuminating the display portion 21 a of the display panel 21.

  Further, the control means 42 can change the color mixture ratio by adjusting the output luminance of each of the light emitting diodes 34 of the first and second light source groups 34a and 34b using pulse width modulation control, so that the desired illumination can be changed. The liquid crystal display panel 31 can be illuminated with colors.

  In addition, although the illumination device for a vehicle instrument of the present invention has been described as an example in the configuration of the above-described embodiment, the present invention is not limited to this, and the configuration of the present invention is not limited thereto. It goes without saying that various improvements and design changes can be made without departing from the scope of the invention.

  For example, the vehicular instrument A having the indicating instrument 2 using the pointer 22 has been described. However, the indicating instrument 2 is omitted, and the liquid crystal display panel 31 of the digital display unit 3 is configured to display information such as the vehicle speed. The same effects as those of the above-described embodiment may be obtained.

  The present invention can be applied, for example, as an illumination device for a vehicle instrument mounted on a moving body including an automobile, a motorcycle, an agricultural machine, or a construction machine.

DESCRIPTION OF SYMBOLS 1 Case 11 Window part 12 Storage part 2 Indicator instrument 21 Display board 21a Display part 21b Opening hole part 22 Pointer 23 Motor 24, 25 Light emitting diode 3 Digital display part 31 Liquid crystal display panel (display panel)
32 holding member 32a mounting part (holding part)
32b Display holder 33 Light guide member 33a Light receiving surface 33b Reflecting surface 33c Reflecting curved surface 331 Flat plate portion 332 Light adjusting unit 34 Light emitting diode (backlight)
341 to 346 First to sixth light sources 34a First light source group 34b Second light source group 34x First virtual line 34y Second virtual line 35 Holding member 4 Circuit board 41 Connector 42 Control means A Vehicle instrument S space

Claims (3)

A display panel for displaying vehicle information as an image;
A plurality of backlights for illuminating the display panel;
A light guide provided on the back side of the display panel for guiding illumination light from the backlight to the display panel,
The backlight is
A first light source group having a first light source that emits red illumination, a second light source that emits green illumination, and a third light source that emits blue illumination;
A second light source group having a fourth light source that emits red illumination, a fifth light source that emits green illumination, and a sixth light source that emits blue illumination;
Are provided in a pair via the light guide,
A first imaginary line connecting the first light source and the fourth light source;
An illumination device for a vehicle meter, wherein a second imaginary line connecting the third light source and the sixth light source intersects with each other. Control means for controlling the emission of the backlight;
The lighting device for a vehicle meter according to claim 1, wherein the control means adjusts the output of the backlight using pulse width modulation control.   3. The illumination device for a vehicle meter according to claim 1, wherein white illumination light is obtained by turning on all the backlights of the first and second light emitting element groups.

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