Display device

Abstract

To achieve a high-quality illumination level by devising reflection structure of a case.SOLUTION: A display device 1 includes a middle case 9 that reflects light emitted from a light source 10 to illuminate a display region of a display panel 7. The middle case 9 includes a box part 91 formed along one side of the display panel 7, a primary reflection surface 92 and a secondary reflection surface 93 provided in a top surface part of the box part 91, and a third-order reflection surface 95 opposite to the display region of the display panel 7. The primary reflection surface 92 diffuses the light emitted from the light source 10 in a longitudinal direction of the box part 91, the secondary reflection surface 93 allows the light in the box part 91 to emit toward the third-order surface 95 through a light emission opening 94, and the third-order reflection surface 95 reflects the light emitted from the light emission opening 94 to guide the reflected light to the display region of the display panel 7.SELECTED DRAWING: Figure 11

Description

Technical Field

[0001] The present disclosure relates to a display device.

Background Art

[0002] Conventionally, as an illumination structure (backlight) of a display device having a liquid crystal panel, surface emission illumination is performed only by a reflection structure of a case such as a white resin that holds the liquid crystal panel, without using a dimmable dedicated component such as a light guide or a diffusion plate, from a point light source such as an LED. For example, the reflection structure of the case shown in Patent Document 1 is composed of a primary reflection surface provided directly above the LED and a secondary reflection surface that reflects this light to illuminate the non-display surface of the liquid crystal panel.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the reflection structure of the case shown in Patent Document 1, a luminance difference such that the vicinity of the light source is bright and it becomes dark as the distance from the light source increases is likely to occur, and there is room for improvement.

[0005] Therefore, an object of the present disclosure is to provide a display device that realizes a high-quality illumination level by devising the reflection structure of the case.

Means for Solving the Problems

[0006] On one side, the following solution means is provided. A display panel having a display area, A circuit board on which a light source is mounted, A display device including a case that reflects light emitted from the light source to illuminate the display area. The case includes: a box portion formed along one side of the display panel; a primary reflection surface and a secondary reflection surface provided on the top surface of the box portion; a tertiary reflection surface facing the display area; a light emission opening that emits light from the box portion and guides it to the tertiary reflection surface or the display area. The light source is disposed at the bottom of the box portion and at the central portion in the longitudinal direction of the box portion, and emits light from the bottom of the box portion toward the top surface. The primary reflection surface is provided on the top surface of the box portion and at the central portion in the longitudinal direction of the box portion, and diffuses the light emitted from the light source in the longitudinal direction of the box portion. The secondary reflection surface is provided on the top surface of the box portion along the longitudinal direction of the box portion, and reflects the light in the box portion toward the light emission opening. The light emission opening is formed near the top surface of the box portion along the longitudinal direction of the box portion, emits light from the box portion, and guides it to the tertiary reflection surface or the display area. The tertiary reflection surface guides the light emitted from the light emission opening to the display area, providing a display device.

Advantages of the Invention

[0007] According to the present disclosure, by devising the reflection structure of the case, it is possible to provide a display device that realizes a high-quality illumination level.

Brief Description of the Drawings

[0008]

Figure 1

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Figure 9

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Figure 11

Embodiments for Carrying Out the Invention

[0009] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings.

[0010] FIG. 1 shows a vehicle instrument 2 in which a display device 1 of the present embodiment is incorporated. As shown in FIG. 1, the display device 1 is incorporated into the vehicle instrument 2 together with a meter 3 that displays speed and the like (the illustration of the pointer is omitted), and displays vehicle information and the like.

[0011] As shown in FIGS. 1 to 4, the vehicle instrument 2 includes a lower case 4 that forms the side and rear surfaces, and a glass 5 that forms the front surface. In the space covered by the lower case 4 and the glass 5, a dial plate 6 of the meter 3 and the display device 1 are accommodated. A display window 6a is formed in the dial plate 6, and information displayed in the display range (display area 7a of the display panel 7) of the display device 1 is visually recognized through this display window 6a.

[0012] As shown in FIGS. 2 to 4, the display device 1 includes a display panel 7 having a display area 7a to be described later, a circuit board 8, a middle case 9, a light source 10, a conductive rubber 11, and a cell holder 12.

[0013] The display panel 7 is, for example, a liquid crystal panel, and includes a display surface 7b and a non-display surface (opposite surface) 7c provided at a position opposite to the display surface 7b. The display information displayed on the display surface 7b of the display panel 7 is favorably visually recognized by illuminating the non-display surface 7c with uniform luminance.

[0014] The circuit board 8 mounts the control circuit and the light source 10 of the display panel 7. The light source 10 is, for example, an LED.

[0015] The middle case 9 holds the display panel 7 and the circuit board 8. The middle case 9 is formed of a resin with a high reflectance such as white, and has a reflection structure that reflects the light emitted from the light source 10 to illuminate the non-display surface 7c (display area 7a) of the display panel 7. The reflection structure of the middle case 9 will be described later.

[0016] The conductive rubber 11 is a member for energizing the display panel 7 and the circuit board 8.

[0017] The cell retainer 12 is a metal case that presses and fixes the display panel 7, the middle case 9, and the conductive rubber 11 to the circuit board 8.

[0018] Next, the reflection structure of the middle case 9 will be described with reference to FIGS. 5 to 10.

[0019] As shown in FIGS. 5 to 10, the middle case 9 includes a box portion 91, a primary reflection surface 92, a secondary reflection surface 93, a light emission opening portion 94, and a tertiary reflection surface 95.

[0020] The box portion 91 is formed along one side of the display panel 7. For example, when the display panel 7 is a rectangle having a long side and a short side in a front view, the box portion 91 is provided along the long side of the display panel 7. The box portion 91 has a space surrounded by four side wall reflection surfaces 91a, and the bottom is open. The light source 10 mounted on the circuit board 8 is disposed at the bottom of the box portion 91 and at the longitudinal center portion of the box portion 91, and emits light from the bottom surface to the top surface of the box portion 91.

[0021] The first reflecting surface 92 is provided on the top surface of the box portion 91 and at the central portion in the longitudinal direction of the box portion 91. The first reflecting surface 92 is located directly above the light source 10 and has a plurality of inclined surface shapes that diffusely reflect the light emitted from the light source 10 in the longitudinal direction of the box portion 91.

[0022] The second reflecting surface 93 is provided on the top surface of the box portion 91 along the longitudinal direction of the box portion 91. The second reflecting surface 93 has an inclined surface shape that reflects the light in the box portion 91 toward the light emission opening 94. Here, the light in the box portion 91 reflected by the second reflecting surface 93 includes the light directly reaching from the light source 10, the light reflected by the first reflecting surface 92, and the light reflected by the side wall reflecting surface 91a.

[0023] The light emission opening 94 is formed in the vicinity of the top surface of the box portion 91 along the longitudinal direction of the box portion 91. The light emission opening 94 emits the light reflected by the second reflecting surface 93 toward the third reflecting surface 95. Further, the light emission opening 94 emits the light reflected by the side wall reflecting surface 91a toward the non-display surface 7c (display region 7a) of the display panel 7.

[0024] The third reflecting surface 95 is provided so as to face the non-display surface 7c of the display panel 7 with a space therebetween. The third reflecting surface 95 has a curved surface shape that reflects the light emitted from the light emission opening 94 and guides it to the non-display surface 7c (display region 7a) of the display panel 7.

[0025] According to such a reflection structure of the middle case 9, the light from the light source 10 is diffused in the longitudinal direction of the box portion 91 by the first reflecting surface 92, and these lights are guided to the non-display surface 7c (display region 7a) of the display panel 7 by the second reflecting surface 93, the third reflecting surface 95, and the side wall reflecting surface 91a. Therefore, compared with the conventional reflection structure, the light can be diffused over a wider range, and the illumination luminance of the display panel 7 can be smoothed.

[0026] In addition, the display panel 7 is a rectangle having a long side and a short side when viewed from the front. The box portion 91, the secondary reflection surface 93, and the light emission opening 94 are provided along the long side of the display panel 7. The primary reflection surface 92 diffuses the light emitted from the light source 10 in the long side direction of the display panel 7. Therefore, the light from the light source 10 can be diffused over a wider range, and the illumination luminance of the display panel 7 can be made smoother.

[0027] Also, in the middle case 9 of the present embodiment, as shown in FIGS. 7 and 9, in the longitudinal direction of the box portion 91, the opening amount (vertical opening width) of the light emission opening 94 is not uniform and is set to increase as it moves away from the light source 10.

[0028] According to the reflection structure of the middle case 9 like this, the light amount that decreases as it moves away from the light source 10 can be corrected by the opening amount of the light emission opening 94, so that the illumination luminance of the display panel 7 can be made smoother.

[0029] Also, as shown in FIGS. 9 and 10, the middle case 9 of the present embodiment further includes a light emission amount adjustment rib 96 that shields a part of the light emission opening 94 and adjusts the amount of light emitted from the light emission opening 94. For example, in the present embodiment, two light emission amount adjustment ribs 96 are installed at a location close to the light source 10 of the light emission opening 94, and the amount of light emitted at the installation location is reduced.

[0030] According to the reflection structure of the middle case 9 like this, by identifying a location where locally strong light is emitted at the light emission opening 94 and providing the light emission amount adjustment rib 96 formed to block the strong light at the identified location, the illumination luminance of the display panel 7 can be made smoother.

[0031] Next, the operation of the reflection structure provided in the middle case 9 will be described with reference to FIG. 11.

[0032] As shown in Fig. 11(a), the light source 10 emits light from the bottom to the top surface of the box portion 91. The light emitted by the light source 10 has a high luminance at the center of the emission angle range and a low luminance as it moves away from the center. The light at the high-luminance center hits the primary reflection surface 92 provided at the central position of the top surface of the box portion 91 and is diffused in the longitudinal direction of the box portion 91. Also, the other light reaches the top surface of the box portion 91 directly or after being reflected by the side wall reflection surface 91a and reaching the top surface of the box portion 91.

[0033] As shown in Fig. 11(b), among the light that reaches the top surface of the box portion 91, the light that hits the secondary reflection surface 93 provided on the top surface of the box portion 91 is guided to the tertiary reflection surface 95 through the light emission opening 94. Also, the light that does not hit the secondary reflection surface 93 and is directly emitted from the light emission opening 94 is guided to the non-display surface 7c (display area 7a) of the display panel 7.

[0034] When the light in the box portion 91 is emitted from the light emission opening 94, the amount of emitted light is corrected based on the opening amount of the light emission opening 94. That is, since the opening amount of the light emission opening 94 is set to increase as it moves away from the light source 10, it is possible to correct the decreasing light amount as it moves away from the light source 10 and smooth the amount of light emitted from the light emission opening 94 in the longitudinal direction of the box portion 91.

[0035] Also, since two light emission amount adjustment ribs 96 are installed at a location near the light source 10 of the light emission opening 94, the light emission amount adjustment ribs 96 shield the locations where locally strong light is emitted, and it is possible to further smooth the amount of light emitted from the light emission opening 94 in the longitudinal direction of the box portion 91.

[0036] The tertiary reflection surface 95 guides the light emitted from the light emission opening 94 to the non-display surface 7c of the display panel 7. At this time, since the light emitted from the light emission opening 94 has a smoothed light amount in the longitudinal direction of the box portion 91, it is possible to uniformly illuminate the non-display surface 7c (display area 7a) of the display panel 7.

[0037] Although the above-described embodiments have been described in detail, the present invention is not limited to specific embodiments, and various modifications and changes are possible within the scope described in the claims. Also, it is possible to combine all or a plurality of the constituent elements of the above-described embodiments.

Explanation of Reference Numerals

[0038] 1 Display device 2 Vehicle instrument 3 Meter 4 Lower case 5 Glass 6 Dial 6a Display window 7 Display panel 7a Display area 7b Display surface 7c Non-display surface 8 Circuit board 9 Middle case 91 Box part 91a Side wall reflecting surface 92 Primary reflecting surface 93 Secondary reflecting surface 94 Light emission opening 95 Tertiary reflecting surface 96 Light emission amount adjustment rib 10 Light source 11 Conductive rubber 12 Cell retainer

Claims

1. A display panel having a display area, A circuit board on which a light source is mounted, A display device comprising: a case that reflects light emitted from the light source to illuminate the display area, The case includes: A box portion formed along one side of the display panel, A primary reflection surface and a secondary reflection surface provided on the top surface of the box portion, A tertiary reflection surface facing the display area, A light emission opening that emits light from the box portion and guides it to the tertiary reflection surface or the display area, The light source is disposed at the bottom of the box portion and at the central portion in the longitudinal direction of the box portion, and emits light from the bottom of the box portion toward the top surface, The primary reflection surface is provided on the top surface of the box portion and at the central portion in the longitudinal direction of the box portion, and diffuses the light emitted from the light source in the longitudinal direction of the box portion, The secondary reflection surface is provided on the top surface of the box portion along the longitudinal direction of the box portion, and reflects the light in the box portion toward the light emission opening, The light emission opening is formed near the top surface of the box portion along the longitudinal direction of the box portion, emits light from the box portion, and guides it to the tertiary reflection surface or the display area, The tertiary reflection surface guides the light emitted from the light emission opening to the display area, a display device.

2. The display device according to claim 1, wherein an opening amount of the light emission opening is set to increase as it moves away from the light source in the longitudinal direction of the box portion.

3. The display device according to claim 1, wherein the case further includes a light emission amount adjustment rib that shields a part of the light emission opening and adjusts an amount of light emitted from the light emission opening.

4. The display panel is a rectangle having a long side and a short side in a front view, The box portion, the secondary reflection surface, and the light emission opening are provided along the long side, The display device according to claim 1, wherein the primary reflection surface diffuses the light emitted from the light source in the long side direction.

Images