WO2014017035A1

WO2014017035A1 - Display device

Info

Publication number: WO2014017035A1
Application number: PCT/JP2013/004183
Authority: WO
Inventors: 盛吾種
Original assignee: 株式会社デンソー
Priority date: 2012-07-25
Filing date: 2013-07-05
Publication date: 2014-01-30
Also published as: JP2014025759A; JP5704134B2

Abstract

A display device is provided with: display parts (41, 42, 53) each having a shape representing desired display contents; a light source unit (30) for emitting illumination beams; and a front cover (20) disposed on the viewer side from the display parts, and is configured such that illumination beams (A1, B1, C1) emitted from the light source unit are reflected by the front cover (20), travel to the display parts (41, 42, 53), thereafter are further reflected by the display parts (41, 42, 53) and transmitted through the front cover (20), and travel to the viewer. Consequently, the optical path lengths from the light source unit (20) to the display parts (41, 42, 53) can be made uniform, thereby making it possible to suppress illumination unevenness.

Description

Display device

Cross-reference of related applications

This disclosure is based on Japanese Application No. 2012-165025 filed on July 25, 2012, the contents of which are incorporated herein by reference.

This disclosure relates to a display device applied to, for example, an in-vehicle meter.

The on-vehicle meters disclosed in Patent Documents 1 and 2 are structured to illuminate by irradiating light from a light source onto a display board (or a decorative member) from the viewer side.

In the case of the illumination structure described above, on the viewer side of the display board, it is necessary to dispose the light source so as to be hidden in a position that does not enter the viewer's field of view. I don't get it. Then, since the optical path length from the light source to the illumination location differs depending on the illumination location, illumination unevenness occurs such that the location near the light source is bright and the location is dark.

JP 2011-13106 A Japanese Patent No. 4835820

The present disclosure has been made in view of the above points, and an object of the present disclosure is to provide a display device in which illumination unevenness is suppressed in a structure in which a display unit is illuminated from a viewer side.

According to one aspect of the present disclosure, the display device includes a display unit formed in a shape that represents desired display content, a light source device that emits illumination light, and a translucent light disposed on the viewer side of the display unit. And the illuminating light emitted from the light source device is reflected toward the display unit by the translucent reflector, and then further reflected by the display unit, whereby the translucent It is comprised so that it may permeate | transmit to a viewer through a reflecting plate.

According to this, the optical path length from the light source device to the display unit is the first optical path length from the light source device to the translucent reflector (see symbols A1, B1, and C1 in FIG. 2), and the translucent reflector. And the second optical path length from the display unit to the display unit (see symbols A2, B2, and C2 in FIG. 2). Therefore, the second optical path length becomes longer for the display portion at the position where the first optical path length becomes shorter (see reference numerals A1 and A2 in FIG. 2), and the display portion at the position where the first optical path length becomes longer. Can easily realize that the second optical path length is shortened (see symbols B1 and B2 in FIG. 2). Therefore, it is possible to suppress the optical path length (first optical path length + second optical path length) from the light source device to the display unit from being different depending on the position of the display unit, and thus it is possible to suppress uneven illumination.

The above and other objects, features and advantages of the present disclosure will become more apparent from the following detailed description with reference to the accompanying drawings. In the drawing
The front view of the display apparatus which concerns on 1st Embodiment of this indication. Sectional drawing of the display apparatus shown in FIG. The elements on larger scale of the display part of the display apparatus shown in FIG. IV arrow view of FIG. The modification of the display part of the display apparatus shown in FIG. Sectional drawing of the light source device of the display apparatus which concerns on 1st Embodiment. Sectional drawing explaining the structure of the control film of the light source device shown in FIG. The modification of the light source device of the display apparatus which concerns on 1st Embodiment. The front view of the display apparatus which concerns on 2nd Embodiment of this indication.

Hereinafter, each embodiment in which the display device according to the present disclosure is applied to a vehicle-mounted meter will be described with reference to the drawings. In each of the following embodiments, configurations of portions denoted by the same reference numerals in the drawings are the same or equivalent to each other, and the description thereof is cited.

(First embodiment)
A display device M1 shown in FIG. 1 is mounted on an instrument panel of a vehicle and is assumed to be visually recognized by a vehicle driver. The display device M1 includes a case 10 and a front cover 20 (translucent reflector) assembled at a predetermined position of the instrument panel, a light source device 30, a display plate 40, and a pointer 50 shown in FIG.

The front cover 20 exhibits a function of preventing dust from entering foreign matter such as dust inside the case 10. Further, the front cover 20 is made of resin, and a light-transmitting material is used. However, the front cover 20 is subjected to a smoke process so that only a portion of the front cover 20 that is illuminated by the light source device 30 and emits light (

various display units

41, 42, and 53 described in detail later) is visually recognized. The transmittance is adjusted.

The case 10 holds the front cover 20, the light source device 30, and the display board 40. The display board 40 is disposed on the non-viewer side (left side in FIG. 2) of the front cover 20 and is disposed perpendicular to the viewing direction (left-right direction in FIG. 2). In the following description, the viewer side is referred to as “front side” and the counter-viewer side is referred to as “back side”. In the example of FIG. 2, the right side of the drawing corresponds to the front side, and the left side of the drawing corresponds to the back side.

The front cover 20 is formed in a flat plate shape, and is disposed obliquely with respect to the display plate 40. In the example of FIG. 2, the front cover 20 is inclined 45 degrees with respect to the display panel 40 so that the upper part of the front cover 20 is located on the near side and the lower part is located on the far side.

The light source device 30 has a light emitting surface 34a (surface light emitting portion) that emits light in a planar shape, and in the example of FIG. 2, the light emitting surface 34a is formed in a flat shape. The light source device 30 is arranged so that the light emitting surface 34 a is perpendicular to the display panel 40. Therefore, the cross-sectional shape combining the display panel 40, the light emitting surface 34a, and the front cover 20 is a right-angled isosceles triangle (a regular triangle in the example of FIG. 2).

The front surface of the display board 40 is provided with

substrate display portions

41 and 42 formed in a shape representing a desired display content such as a plurality of scales, numbers, characters, symbols, and the like. A pointer 50 is disposed on the front side of the display board 40. The rotating shaft 51 attached to the boss part 50 a of the pointer 50 is driven by a motor 52 attached to the back side of the display board 40. A microcomputer (not shown) for controlling the driving of the motor 52 and the light source device 30 is disposed on the back side of the display board 40.

A pointer display unit 53 is provided on the front surface of the pointer 50. The

board display units

41 and 42 and the pointer display unit 53 are illuminated by the light source device 30, and the

display units

41, 42, and 53 appear to emit light to a viewer on the front side of the front cover 20. Will be visible. On the other hand, since the display board 40 and the boss | hub part 50a are formed with the hue which does not reflect illumination light, they cannot be seen from a viewer. Therefore, as shown in FIG. 1, a plurality of scales, numbers, characters, and symbols related to the

substrate display portions

41 and 42, and a pointer display portion 53 formed in the same shape as the shape of the pointer 50 excluding the boss portion 50a. Can be seen floating on the smoked front cover 20.

Next, the illumination of the

display units

41, 42, 53 by the light source device 30 will be described in detail.

Since the light source device 30 is disposed on the anti-viewer side with respect to the front cover 20, the illumination light emitted from the light source device 30 enters from the anti-viewer side of the front cover 20 (arrow A1 in FIG. 2). , B1, C1). The incident light (incident light A1, B1, C1) travels in parallel with the display panel 40 in the example of FIG. In other words, the incident light A1, B1, C1 travels perpendicular to the viewing direction.

Some of the incident lights A1, B1, and C1 pass through the front cover 20 and go straight, but most of the incident lights A1, B1, and C1 are reflected by the surface of the front cover 20 on the side opposite to the viewer and displayed. Proceed toward the plate 40 (see arrows A2, B2, and C2 in FIG. 2). The light thus reflected (first reflected light A2, B2, C2) travels perpendicular to the display panel 40. In other words, the first reflected lights A2, B2, and C2 travel in parallel to the viewing direction.

Thereafter, the first reflected lights A2, B2, and C2 are reflected by the

various display units

41, 42, and 53 and travel toward the front cover 20 (see arrows A3, B3, and C3 in FIG. 2). The light reflected in this way (second reflected light A3, B3, C3) travels perpendicular to the display panel 40. In other words, the second reflected lights A3, B3, C3 travel in parallel to the viewing direction. In addition, since the display board 40 and the boss | hub part 50a are dark colors which do not have reflectivity, most of the 1st reflected lights A2, B2, and C2 which injected into these parts are not reflected.

Some of the second reflected lights A3, B3, and C3 are reflected by the surface of the front cover 20 opposite to the viewer, but most of the second reflected lights A3, B3, and C3 pass through the front cover 20 and go straight. Then proceed toward the viewer. As a result, the

various display units

41, 42, and 53 appear to float on the smoked front cover 20.

When the front cover 20 is not smoked, the display board 40 and the boss part 50a are also visible, but the

display parts

41, 42, and 53 are brightly illuminated with the display board 40 as a background. Looks great.

Next, the structure of the

display units

41, 42, and 53 will be described in detail with reference to FIGS. 3 is an enlarged view of a portion (display unit 41) indicated by a one-dot chain line in FIG. 2, and the

display units

42 and 53 have the same structure as the display unit 41, and thus description thereof is omitted.

As shown in FIG. 3, the inner surface of the display unit 41 is formed in a shape having a plurality of pairs of

reflective surfaces

41a and 41b facing each other. The first reflected light A2 incident on the display unit 41 is reflected by one reflecting surface 41a of the pair of reflecting surfaces, and then reflected by the other reflecting surface 41b so as to be directed toward the viewer. Is done. More specifically, as shown in FIG. 4, a plurality of projecting portions having a symbol P as the apex are formed and arranged in a line. The protruding portion has a quadrangular pyramid shape with the symbol P as a vertex. Therefore, the side surfaces of adjacent quadrangular pyramids constitute a pair of reflecting

surfaces

41a and 41b. By adopting the display unit 41 having such a shape in which a quadrangular pyramid is laid, the amount of the second reflected light A3 can be increased.

FIG. 5 shows an example in which a display unit 410 in which a plurality of conical protrusions are arranged is used instead of the quadrangular pyramid display unit 41 shown in FIG. In this case, the side surfaces of adjacent cones constitute a pair of reflecting

surfaces

410a and 410b. In the case of a quadrangular pyramid, the display unit 41 can be spread with the reflection surfaces 41a and 41b, whereas in the case of a cone, the display unit 410 cannot be spread with the reflection surfaces 410a and 410b. As shown in Q, a flat portion is generated. Then, in the flat portion Q, the first reflected light A2 is diffused and reflected, and the amount of the second reflected light A3 traveling in the viewing direction is reduced compared to the example of FIG. 4, but the display portion shown in FIG. It is also possible to adopt 410.

Next, the structure of the light source device 30 will be described in detail with reference to FIGS.

As shown in FIG. 6, the light source device 30 includes a plurality of light sources 32 mounted on a circuit board 31, a diffusion plate 33, and a regulation film 34. The plurality of light sources 32 are arranged such that the optical axis of the light source 32 is parallel to the incident light A1, B1, and C1. Specifically, the entrance surface 33a and the exit surface 33b of the diffusing plate 33 are formed in parallel to the light emitting surface 34a, and a plurality of light sources 32 are arranged facing the entrance surface 33a. Specific examples of the light source 32 include a light emitting diode and a bulb.

The light emitted from the light source 32 and incident from the incident surface 33a is diffused inside the diffusing plate 33 and uniformly emitted from the emitting surface 33b. However, the light emitted from the emission surface 33b is not only the light traveling in the direction perpendicular to the light emission surface 34a (the direction perpendicular to the viewing direction), but also to the light emission surface 34a as shown by the one-dot chain line L1 in FIG. There is also light that travels diagonally. The restriction film 34 functions so that the light L1 traveling obliquely in this way is not emitted from the light emitting surface 34a.

Describing in more detail with reference to FIG. 7, the regulation film 34 (outgoing direction regulation means) is configured by sandwiching the louver layer 341 with the cover material 342. The louver layer 341 is configured by arranging a plurality of light shielding plates 341a. And the light radiate | emitted from the output surface 33b of the diffusion plate 33 advances the optical path 341b formed between the adjacent light-shielding plates 341a. At this time, since the light L1 traveling obliquely is blocked by the light shielding plate 341a, the traveling direction of the light passing through the louver layer 341 is restricted to a direction perpendicular to the light emitting surface 34a.

As described in detail above, in the present embodiment, the illumination light incident on the front cover 20 is reflected by the front cover 20 and travels toward the

display units

41, 42, 53, and then the

display units

41, 42, 53. Further, the light is reflected and transmitted through the front cover 20 toward the viewer.

With this configuration, the optical path length from the light source device 30 to the

display units

41, 42, 53 is displayed from the first optical path length from the light source device 30 to the front cover 20 (see arrows A1, B1, C1) and from the front cover 20. This is the total length of the second optical path lengths (see arrows A2, B2, and C2) up to the

portions

41, 42, and 53. For this reason, the optical path length (first optical path length + second optical path length) from the light source device 30 to the

display units

41, 42, 53 is the same regardless of the positions of the

display units

41, 42, 53 on the display board 40. Can be. Therefore, illumination unevenness on the display board 40 can be suppressed.

Furthermore, according to this embodiment, the following effects are exhibited.

<Operation effect 1>
Here, when a part of the illumination light emitted from the light source device 30 (see symbol L1) goes directly to the

display units

41, 42, and 53 without passing through the front cover 20 (translucent reflector), the illumination light is emitted. Since the display part illuminated by L1 has a shorter optical path length than other display parts, it appears bright. That is, the effect of suppressing illumination unevenness is reduced. In this embodiment in view of this point, the light source device 20 causes the illumination light emitted from the light source device 20 to go directly to the

display units

41, 42, and 53 without passing through the front cover 20 (translucent reflector). There is a restriction film 34 (outgoing direction restriction means) for restriction. Therefore, direct illumination of the

display units

41, 42, and 53 can be suppressed as described above, and the effect of suppressing illumination unevenness can be improved.

<Operation effect 2>
The front side surface of the display unit 41 is formed in a flat shape, and the back side surface of the display unit 41 is formed in a shape having a plurality of pairs of

reflective surfaces

41a and 41b facing each other. The light incident on the display unit 41 from the reflective reflector is reflected by one reflective surface 41a of the pair of reflective surfaces, and then reflected by the other reflective surface 41b so as to travel toward the viewer. Reflected. According to this, when reflecting the 1st reflected light with the display part 41, it can accelerate | stimulate that it concentrates and reflects in a visual recognition direction, without diffusing. Therefore, the luminance of the display unit 41 can be improved, and as a result, the amount of emitted light required for the light source device 20 can be reduced.

<Operation effect 3>
The back side surface of the display unit 41 is formed in a shape in which a plurality of protrusions are arranged, and the pair of

reflection surfaces

41a and 41b are configured by side surfaces of adjacent protrusions. According to this, the arrangement of the pair of reflecting

surfaces

41a and 41b so as to reflect the first reflected light incident in the viewing direction as it is in the viewing direction is merely by forming a plurality of protrusions on the display unit 41. It can be easily realized.

<Operation effect 4>
The protrusion formed on the display unit 41 has a quadrangular pyramid shape. According to this, as described above with reference to FIG. 5, since the display unit 41 can be spread with the reflection surfaces 41a and 41b, the flat portion Q where the reflection surfaces 41a and 41b are not formed can be eliminated. . Alternatively, the flat portion Q can be reduced. Here, since such a flat portion Q appears dark to the viewer with low luminance, a portion that appears dark and a portion that appears bright in the display unit 41 are generated. That is, when the flat portion Q exists, luminance unevenness occurs in the display unit 41. In contrast, in the present embodiment, the flat portion Q can be eliminated or reduced as described above, so that the luminance unevenness can be suppressed.

<Operation effect 5>
A display board 40 disposed on the back side of the front cover 20 (translucent reflector) and provided with a plurality of scales; a pointer 50 disposed on the front side of the display board 40 and rotated to point to the scales; The display unit 53 is attached to the pointer 50. Here, in the case of the display device M1 provided with the pointer 50, the shadow of the pointer 50 by illumination light is reflected on the display board 40. However, in this embodiment, the 1st reflected light which goes to the pointer | guide 50 is irradiated in parallel with a visual recognition direction. Therefore, the shadow of the pointer 50 is reflected at a position hidden by the pointer 50 when viewed from the viewer. Therefore, since the shadow of the pointer 50 is not visible to the driver, the appearance of the display device M1 can be improved.

<Operation effect 6>
The light source device 30 has a light emitting surface 34a (surface light emitting unit) that emits illumination light in a planar shape. In the example of FIG. 6, the light emitted from the light source 32 is diffused by the diffusion plate 33, thereby realizing surface emission on the light emitting surface 34 a. Here, when the light source device 30 has a structure in which the light emitted from the light source 32 is emitted as it is to the front cover 20, that is, when the point light emission is performed contrary to the present embodiment, the front of the incident light A1, B1, C1. The incident angle to the cover 20 varies depending on the part of the front cover 20. Then, it becomes difficult to set the first reflected lights A2, B2, and C2 in the viewing direction. In addition, the optical path length from the light source device 30 to the

display units

41, 42, and 53 (first optical path length + second optical path length) is prevented from being the same regardless of the position of the display unit. In the present embodiment in view of this point, since surface emission is performed as described above, it is possible to easily realize the first reflected light A2, B2, and C2 to be in the viewing direction and the same optical path length.

(Second Embodiment)
The light source device 30 according to the first embodiment is configured such that a plurality of light sources 32 are arranged on a surface parallel to the light emitting surface 34a, and light from the light sources 32 is emitted perpendicularly to the light emitting surface 34a. It is a direct type. On the other hand, in this embodiment shown in FIG. 8, an edge type light source device 300 described below is employed.

That is, the circuit board 31 on which the light source 32 is mounted is arranged perpendicular to the light source light emitting surface 34a, and the light from the light source 32 is emitted in parallel to the light emitting surface 34a. Then, the light from the light source 32 is incident from the edge portion 330 a of the diffusion plate 330, and then reflected by the reflecting surface 330 b formed in a tapered shape and incident on the regulation film 34. In other words, the diffusing plate 330 has a tapered shape in which the reflecting surface 330b is inclined with respect to the issuing surface 34a, and the light of the light source 32 incident from the edge portion 330a is reflected by the reflecting surface 330b and is incident on the regulation film. . According to this, the dimension of the light source device 30 in the thickness direction (vertical direction in FIG. 8) can be reduced.

(Third embodiment)
As shown in FIG. 9, the display device M <b> 2 according to this embodiment includes a liquid crystal display 60. The liquid crystal display 60 includes a frame 61 and a display panel 62 supported by the frame 61. In the example of FIG. 9, a plurality of liquid crystal displays 60 are arranged side by side. The liquid crystal display 60 may be disposed on the front side of the display panel 40, may be inserted into the opening of the display panel 40, or may be disposed on the back side of the display panel 40 and the opening of the display panel 40. Alternatively, the display panel 62 may be positioned.

On the display board 40,

display units

43 and 44 for decoration purposes are provided. These

display units

43 and 44 have the same structure as that of the first embodiment, and are illuminated with the first reflected light irradiated in the viewing direction.

By the way, in the case where a light source is disposed behind the

display units

43 and 44 and the

display units

43 and 44 are transmissively illuminated contrary to the configuration of the present embodiment, the light from the light source is contained in the

display units

43 and 44. Therefore, the shape of the

display units

43 and 44 is limited to a shape that can sufficiently secure the light guide property. For example, the line widths of the

display units

43 and 44 are required to be greater than or equal to a predetermined value. In addition, when the

display units

43 and 44 are configured by a plurality of parts, a light source is required for each part, and thus the shape is limited to a shape that reduces the number of parts.

On the other hand, according to this embodiment which illuminates from the front side of the

display units

43 and 44, it is easy to realize a design with a narrow line width or a design composed of a plurality of parts without being restricted by the above. it can.

Also, when the mounting space of the display device M2 is flat, a display surface having a shape that is flatter than the display panel 62 manufactured for general purposes may be required. In some cases, it may be desired to respond to this request by arranging two general-purpose display panels 62 as shown in FIG. However, since the frame 61 exists around the display panel 62, there is a space that cannot be displayed between the two display panels 62 arranged side by side. Then, there is a need to decorate this space with the display unit 44 and make the gap between the display panels 62 inconspicuous. However, when the transmission illumination structure described above is employed, a light source must be disposed between the two liquid crystal displays 60 arranged side by side, making it difficult to mount the light source.

display parts

43 and 44, since the

display parts

43 and 44 can be arrange | positioned, without receiving restrictions of light source mounting, between the two display panels 62 arranged side by side. Decorating with the display unit 44 can be easily realized.

(Other embodiments)
The present disclosure is not limited to the description of the above-described embodiment, and may be modified as follows. Moreover, you may make it combine the characteristic structure of each embodiment arbitrarily, respectively.

-You may comprise so that the luminescent color of the light emission surface 34a can be changed by providing the light source 32 of a different luminescent color. In this case, the color of the

display units

41, 42, and 53 can be changed by changing the emission color of the light emitting surface 34a according to various environments such as the driving state of the vehicle. For example, the display unit 41 includes a case where the vehicle is driven in a mode in which priority is given to improving exhaust emission and energy consumption, and a case in which the vehicle is driven in a mode in which drivability such as acceleration is prioritized. , 42, 53 are preferably changed.

In the example of FIG. 3, the display unit 41 is formed in a structure having a pair of

reflective surfaces

41 a and 41 b facing each other. However, these

reflective surfaces

41 a and 41 b are eliminated, The display unit may be formed by printing on the display board 40 or the pointer 50.

In the example of FIG. 2, the light source device 30 is disposed on the upper side of the front cover 20, but is disposed on the lower side of the front cover 20, and the inclination angle of the front cover 20 is changed to a direction rotated 90 degrees. May be.

In the example of FIG. 4, the protruding portion of the display unit 41 has a quadrangular pyramid shape, but other shapes such as a conical shape shown in FIG.

In the example of FIG. 2, the front cover 20 has a flat plate shape, but the front cover 20 may be a curved surface. However, a flat shape is preferable because it can easily realize a difference in optical path length.

In the example of FIG. 2, the cross-sectional shape combining the display panel 40, the light emitting surface 34a, and the front cover 20 is configured to be an equilateral triangle, but may be a right isosceles triangle or a right triangle. It may be a non-right triangle or a non-isosceles triangle.

Although the present disclosure has been described based on the embodiments, it is understood that the present disclosure is not limited to the embodiments and structures. The present disclosure includes various modifications and modifications within the equivalent range. In addition, various combinations and forms, as well as other combinations and forms including only one element, more or less, are within the scope and spirit of the present disclosure.

Claims

A display unit (41, 42, 43, 44, 53) having a shape representing a desired display content;
A light source device (30) for emitting illumination light;
A translucent reflector (20) disposed on the viewer side of the display unit;
With
In the display unit, the light source device, and the light transmissive reflector, illumination light (A1, B1, C1) emitted from the light source device is reflected by the light transmissive reflector and proceeds toward the display unit. Then, the display device is configured to be further reflected by the display unit and pass through the translucent reflecting plate toward the viewer.
The said light source device has an emission direction control means (34) which controls that the illumination light radiate | emitted from the said light source device goes directly to the said display part not via the said translucent reflector. Item 4. The display device according to Item 1.
The viewer side surface of the display unit has a flat shape,
The surface on the anti-viewer side of the display unit is a shape having a plurality of pairs of reflective surfaces (41a, 41b) facing each other,
The light incident on the display unit from the translucent reflecting plate is reflected by one reflecting surface (41a) of the pair of reflecting surfaces, and then reflected by the other reflecting surface (41b). The display device according to claim 1, wherein the display device reflects light toward a viewer.
The surface on the anti-viewer side of the display unit has a shape in which a plurality of protrusions are arranged,
The display device according to claim 3, wherein the pair of reflecting surfaces are configured by side surfaces of the adjacent protruding portions.
5. The display device according to claim 4, wherein the protruding portion has a quadrangular pyramid shape.
A display plate (40) disposed on the non-viewer side of the translucent reflector and provided with a plurality of scales;
A pointer (50) disposed on the viewer side of the display board and pointing to the scale by turning;
With
The display device according to any one of claims 1 to 5, wherein the display unit (53) is attached to the pointer.
The display device according to any one of claims 1 to 6, wherein the light source device includes a surface light emitting unit (34a) that irradiates illumination light in a planar shape.