Display device

Abstract

To provide an easy-to-assemble display device configured to reduce leakage of light of laminated liquid crystal display panels.SOLUTION: A display device includes: a first display panel 10 for displaying an image on a first display surface 11; a first illumination member 20 which is arranged on the back of the first display panel 10 to illuminate the first display panel 10; a case member 30 arranged on the back of the first illumination member 20 to support the first illumination member 20; a first circuit board 40 arranged on the back of the case member 30 to drive the first display panel 10; and a second display panel 51 displaying an image on a second display surface 51a and having an overlap area Z arranged on the back of the first display panel 10. The first illumination member 20 includes non-light transmissive cover members 23, 24 covering portions other than the surface facing the first display panel 10. The case member 30 includes a guide section 33 which extends from the back of the first illumination member 20 toward the first circuit board 40 and has an end 33c arranged on the back of an overlap area Z.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a display device having a display panel for displaying an image. [Background technology]

[0002] An example of a conventional display device is disclosed in Patent Document 1. In this display device, in order to enlarge the display screen, multiple liquid crystal panels are arranged adjacent to each other, and further, in order to reduce the boundary between the multiple liquid crystal panels, a casing covering the backlight of one liquid crystal panel is cut out and the other liquid crystal display panel is layered on this cutout, thereby reducing the step at the boundary between the liquid crystal display panels. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2010-066706 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the display device described in Patent Document 1, because the casing is cut out and stacked, there is a problem that the light from the backlight of one liquid crystal panel leaks to the other liquid crystal display panel. In addition, there is a problem that one liquid crystal display panel needs to be disposed between one liquid crystal display panel and one circuit board, which makes assembly difficult.

[0005] It is therefore an object of the present invention to provide a display device which reduces light leakage from stacked liquid crystal display panels and is easy to assemble. [Means for solving the problem]

[0006] In order to achieve the above object, the display device of the present invention includes a first display panel 10 that displays an image on a first display surface 11, a first illumination member 20 that is disposed behind the first display panel 10 and illuminates the first display panel 10, a case member 30 that is disposed behind the first illumination member 20 and supports the first illumination member 20, a first circuit board 40 that is disposed behind the case member 30 and drives the first display panel 10, and a second display panel 51 that displays an image on a second display surface 51a and has an overlapping region Z that is disposed behind the first display panel 10, the first illumination member 20 has opaque cover members 23, 24 that cover all surfaces except the surface facing the first display panel 10, and the case member 3 ... of the first illumination member 20. A position not facing the overlapping region Z toward the first circuit board 40, Extending toward the second display panel 51 The end 33c is in the overlapping region Z The second display panel 51 facing Located behind , which serves as a guide surface for the second display panel 51. It is characterized by having a guide portion 33. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a front view of a display device according to an embodiment of the present disclosure. [Diagram 2] 1 is a front view showing an arrangement of an inner case 30 and first and second circuit boards 40, 60 of a display device according to an embodiment of the present disclosure. [Diagram 3] Cross-sectional view taken along line AA in Figure 1. [Figure 4] 4 is a diagram showing a state before ASSY300 is assembled to ASSY200 in FIG. 3. FIG. [Diagram 5] FIG. 3 is a cross-sectional view taken along line BB in FIG. 2 . [Figure 6] FIG. 2 is a diagram showing the configuration of a display device 50. [Figure 7] 3A and 3B are diagrams showing the configuration of a second illumination member 20. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] A display device according to an embodiment of the present disclosure will be described with reference to Figures 1 to 7. The display device is configured as a display device mounted on a vehicle such as an automobile, and displays a predetermined measurement quantity such as the vehicle speed. The present disclosure is not limited to these embodiments, and can be applied to a display device for a vehicle mounted on a moving body such as a motorcycle, or an agricultural machine or a construction machine, for example.

[0009] In the following, in order to facilitate understanding of the configuration of the display device, the direction in which the driver seated in the driver's seat is viewed from the display device (the first display panel 10 side in FIG. 3) is referred to as the "front" and the opposite side (the first circuit board 40 side) is referred to as the "rear." "Top," "bottom," "right," and "left" follow the definitions of "Fr.", "Re.", "To.", "Bo.", "R," and "L" in FIG. 1 to FIG. 3.

[0010] As shown in Figures 1 to 3, the display device at least includes a first display panel 10, a first lighting member 20, an inner case (case member) 30, a first circuit board 40, a display 50, a second circuit board 60, a cushioning member 70, a cover member 80, and an outer case 90.

[0011] 1, the display device has a display 50 disposed below a first display panel 10 when viewed from the front, and the display 50 (and a second display panel 51 described below) has an overlapping region Z disposed behind the first display panel 10. The display device has a plurality of indicator units 100 disposed on the left and right of the display 50.

[0012] As shown in Figs. 1 and 7, the first display panel 10 is disposed at the front and displays segment-shaped pixels on a substantially rectangular first display surface 11. The first display panel 10 is a TN (Twisted Nematic) type negative liquid crystal panel having segment-shaped pixels in which a liquid crystal material is sandwiched and sealed between two rectangular glass substrates, one above the other, with transparent electrodes formed on both glass substrates using ITO (Indium Tin Oxide) or the like and polarizing plates attached to the front and back of the electrodes. The segment-shaped pixels are formed in a substantially square shape.

[0013] One side of the first display panel 10 is connected to a flexible printed circuit (FPC) 12. The end face of the FPC 12 opposite to the end face connected to the first display panel 10 is connected to a connector mounted on the rear of the first circuit board 40. The FPC 12 electrically connects (conducts) the first display panel 10 and the first circuit board 40, and guides an electrical signal from the first circuit board 40 to the first display panel 10, causing the first display panel 10 to display information.

[0014] The first display panel 10 is controlled by a control means 44 (described later) of the first circuit board 40, and a drive voltage is applied to the liquid crystal layer via the transparent electrodes. This controls the orientation of the liquid crystal molecules in the liquid crystal layer of the first display panel 10, and changes the transmittance of each pixel of the first display panel 10, thereby displaying an image.

[0015] The first illumination member 20 is disposed behind the first display panel 10. As shown in Fig. 7, the first illumination member 20 is composed of a first light guide (light guide member) 21, a first light source member (light source) 22, a back surface reflection sheet (sheet member) 23, a side surface reflection sheet (sheet member) 24, and a diffusion sheet (sheet member) 25. The first illumination member 20 illuminates the first display panel 10 from behind.

[0016] The first light guide 21 is made of a transparent, thin, flat synthetic resin. The first light guide 21 is disposed behind and facing the first display panel 10. When the first light guide 21 receives light emitted from the first light source member 22 when it is turned on, the first light guide 21 introduces the light into the inside, and then emits the illumination light toward the first display panel 10. The first light guide 21 is covered on all sides except the surface facing the first display panel 10 with an opaque covering member made up of the first light source member 22, a back reflecting sheet 23, and a side reflecting sheet 24.

[0017] The first light source member 22 includes an FPC 22a and first light sources 22b, each of which is made up of a plurality of vertical light-emitting LEDs (chip-type light-emitting diodes: Light Emitting Diodes), arranged in a row on the FPC 22a. The FPC 22a is attached to one end 21a of the side surface of the first light guide 21. The first light source 22b is arranged in a recess 21b of the one end 21a of the first light guide 21. The first light source member 22 introduces irradiation light into the first light guide 21.

[0018] The rear reflection sheet 23 is made of an opaque white thin resin sheet. The rear reflection sheet 23 is attached to the rear surface 21c of the first light guide 21, which is the side opposite to the first display panel 10. The rear reflection sheet 23 improves the light guide efficiency of the light guided through the first light guide 21, and reflects the illumination light toward the first display panel 10.

[0019] The side reflection sheet 24 is made of an opaque white thin resin sheet. The side reflection sheet 24 is attached to an end face 21d other than the one end 21a of the side face of the first light guide 21. The side reflection sheet 24 reflects illumination light, and improves the light guide efficiency of the light guided through the first light guide 21.

[0020] The diffusion sheet 25 is made of a diffusive and light-transmitting white thin resin sheet. The diffusion sheet 25 is attached to the front surface 21e of the first light guide 21, which is opposite to the back surface 21c of the first light guide 21 and faces the first display panel 10. The diffusion sheet 25 diffuses the illumination light emitted from the first light guide 21 and transmits the light toward the first display panel 10.

[0021] The first circuit board 40 is made of a rigid wiring board in which a wiring pattern is applied to a flat glass epoxy-based base material such as FR-4 (Flame Retardant-4). The first circuit board 40 is disposed behind the first display panel 10 and the middle case 30. The first circuit board 40 is disposed in a position where a part of the first circuit board 40 faces the overlapping region Z. As shown in FIG. 2, the first circuit board 40 has a notch 41 cut into a substantially rectangular shape at the substantially lower center, an upper surface 42 on the upper side, a lower left surface 43 on the lower side, and a lower right surface (not shown) that is symmetrical to the lower left surface 43 with respect to the notch 41.

[0022] The first circuit board 40 mounts various circuit components (not shown) such as a control means 44 that outputs command signals (drive signals) for driving and controlling the first display panel 10 and the first light source member 22, as well as resistors, capacitors, etc.

[0023] The control means 44 has a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), a power supply circuit that controls the power supply of the display device, and executes predetermined arithmetic processing according to a program written in the ROM, for example. The control means 44 acquires vehicle speed information and the like from the vehicle's ECU (Electronic Control Unit), and causes the first display panel 10 to display information based on the acquired information.

[0024] As shown in FIG. 6, the display device 50 is composed of a second display panel 51 disposed in front and provided with a substantially rectangular second display surface 51a, a second lighting member 52 disposed behind the second display panel 51 to illuminate the second display panel 51, a pair of upper and lower frames 53 made of metal that hold and house the second display panel 51 and the second lighting member 52, and an FPC 54 that is connected to the second display panel 51 and the second lighting member 52 (second light source member 56) and leads out from behind the frames 53 to the outside.

[0025] The second display panel 51 is, for example, a dot-matrix type TFT (Thin Film Transistor) type normally black type (black display when no voltage is applied) liquid crystal display panel (LCD: Liquid Crystal Display) having a plurality of pixels, and is rectangular when viewed from the front.

[0026] This liquid crystal display panel has, for example, a pair of front and rear glass substrates in which a TFT liquid crystal layer is enclosed, transparent electrodes are formed on both glass substrates using ITO or the like, and a pair of front and rear polarizing plates (polarizing filters) are arranged to sandwich both glass substrates. The second display panel 51 is electrically connected to the second circuit board 60 via the FPC 54, and displays predetermined information related to the vehicle, such as engine speed, average fuel efficiency, fuel consumption, and outside air temperature, as images on the second display surface 51a based on various information acquired from the vehicle's ECU.

[0027] In the second display panel 51, a drive voltage is applied to the liquid crystal layer via the transparent electrodes under the control of a control means 61 (described later) of the second circuit board 60. This controls the orientation of the liquid crystal molecules in the liquid crystal layer of the second display panel 51, and changes the transmittance of each pixel of the second display panel 51 to display an image.

[0028] The second illumination member 52 includes a second light guide 55 , a second light source member 56 , a reflective sheet 57 , and an optical sheet 58 .

[0029] The second light guide 55 is made of a transparent, flat-plate-like synthetic resin. The second light guide 55 is disposed behind the second display panel 51. When the second light source member 56 is turned on and irradiated with light, the second light guide 55 guides the light thereinto, and then emits the illumination light toward the second display panel 51.

[0030] The second light source member 56 includes an FPC 56a and second light sources 56b, each of which is made up of a plurality of vertical light-emitting LEDs, arranged in a row on the FPC 56a. The FPC 56a is disposed on one end surface of the second light guide 55. The second light source member 56 introduces illumination light into the second light guide 55.

[0031] The reflection sheet 57 is made of an opaque white resin sheet. The reflection sheet 57 is disposed on the back surface of the second light guide 55 and on the end surfaces other than the one end surface. The reflection sheet 57 improves the light guide efficiency of the light guided through the second light guide 55, and reflects the illumination light toward the second display panel 51.

[0032] The optical sheet 58 is made of an optical film such as a BEF (Brightness Enhancement Film) having an uneven surface. The optical sheet 58 is disposed between the second display panel 51 and the second light guide 55. The optical sheet 58 amplifies and diffuses the illumination light emitted from the second light guide 55 and transmits the light toward the second display panel 51.

[0033] Frame 53 is made of a conductive metal material such as aluminum or stainless steel, and has a generally rectangular opening 53a at the front corresponding to second display surface 51a. Frame 53 has bosses 53b at the four rear corners, each of which has a circular cross section and extends toward second circuit board 60. Display 50 is fixed to second circuit board 60 by fasteners such as screws that are inserted into second circuit board 60 from the rear surface of second circuit board 60 and screwed into bosses 53b.

[0034] The second circuit board 60 is made of a rigid wiring board having a wiring pattern formed on a flat glass epoxy base material such as FR-4. The second circuit board 60 is disposed behind the display 50. As shown in FIG. 2, the second circuit board 60 is formed in a substantially rectangular shape and disposed in the cutout portion 41 of the first circuit board 40.

[0035] The second circuit board 60 is equipped with a control means 61 that outputs a command signal (drive signal) for driving and controlling the display 50, and various circuit components (not shown) such as resistors and capacitors. The control means 61 has a graphic controller and executes a predetermined arithmetic processing according to a program written in a ROM, for example. The control means 61 acquires various vehicle information, navigation information, and the like from the vehicle's ECU via the first circuit board 40, and causes the display 50 to display information based on the acquired information. The second circuit board 60 has a sensor 62 for wireless communication and can also acquire various information wirelessly from a mobile phone or the like.

[0036] The cushioning member 70 is made of a material such as rubber or sponge that is light-shielding and elastic, such as black, and is formed into a thick, approximately rectangular shape. As shown in FIG. 3, the cushioning member 70 is attached to the rear reflection sheet 23 behind the first illumination member 20. A part of the cushioning member 70 is disposed in a position facing the overlapping region Z. The cushioning member 70 is disposed on the display 50 side of the first illumination member 20 so as to protrude from the first illumination member 20, and is disposed between the first illumination member 20 and the display 50. The cushioning member 70 has a repulsive force by being held in a compressed state between the first illumination member 20 and the display 50, and functions as a vibration damper for the display 50.

[0037] The end cover member 80 is made of a non-transparent synthetic resin (e.g., polypropylene) of a black color or the like, and is arranged so as to cover the front of the first display panel 10, the display 50, and the indicator unit 100. As shown in Fig. 1, the end cover member 80 has a rectangular first opening 81 that allows the first display panel 10 to be viewed, a rectangular second opening 82 that allows the display 50 to be viewed, and a plurality of third openings 83 that allow the indicator unit 100 to be viewed.

[0038] The inside cover member 80 has a pin (not shown) with a round cross section that protrudes toward the first circuit board 40 and fits into a hole formed in the first circuit board 40, thereby fixing the first circuit board 40. Similarly, the inside cover member 80 has a pin (not shown) that protrudes toward the second circuit board 60 and fits into a hole formed in the second circuit board 60, thereby fixing the second circuit board 60. In this way, the ASSY 300 consisting of the display 50 and the second circuit board 60 is completed.

[0039] The outer case 90 is made of a black or other opaque synthetic resin (e.g., polypropylene) and is formed into a pair of roughly box shapes, front and rear, and houses the first display panel 10, the first illumination member 20, the middle case 30, the first circuit board 40, the display 50, the second circuit board 60, the cushioning member 70, and the back cover member 80 inside. The outer case 90 is disposed in front of the first display panel 10, the display 50, and the back cover member 80, and has a translucent panel 91 formed by insert molding to make these visible. The translucent panel 91 is made of, for example, a transparent material (e.g., a synthetic resin such as acrylic, inorganic glass, etc.).

[0040] The inner case 30 is made of a light-shielding white synthetic resin (e.g., polypropylene) and is disposed in front of the first circuit board 40. As shown in Fig. 2, the inner case 30 has a first housing section 31 that holds the first display panel 10 and the first illumination member 20, a second housing section 32 that disposes the indicator section 100, a guide section 33, a first support piece 34, and a second support piece 35.

[0041] The first accommodating section 31 is disposed on the upper surface 42 of the first circuit board 40. The first accommodating section 31 holds the first display panel 10 on its front surface. The first accommodating section 31 has hook-shaped locking pieces 31a, 31b at the top and bottom edges when viewed from the front, which locking pieces 31a, 31b have an eave-like shape (hook-like shape) that protrude toward the first display panel 10. The upper locking piece 31a is formed inelastically and fits into the upper glass substrate of the first display panel 10. The lower locking piece 31b is formed in a cantilever shape and has elasticity, which locks into a partially extended portion of the lower glass substrate of the first display panel 10.

[0042] In this manner, the first display panel 10 is engaged with the locking pieces 31a and 31b and held in the first housing portion 31. The first housing portion 31 supports the first lighting member 20 on a mounting surface 31c disposed on the back surface of the first lighting member 20, as shown in FIG.

[0043] The placement surface 31c is not formed in a position facing the overlapping region Z. The placement surface 31c has a step portion 31d that is recessed toward the first circuit board 40 so as to avoid the buffer member 70. The step portion 31d has a gap with the buffer member 70.

[0044] The guide portion 33 has a vertical portion 33a, where a part of the step portion 31d on the display 50 side extends from the rear side of the first illumination member 20 toward the first circuit board 40, and a horizontal portion 33b, which extends from the vertical portion 33a toward the display 50 and has an end portion 33c disposed behind the display 50 facing the overlapping region Z. The guide portion 33 has an inclined slope portion 33d between the vertical portion 33a and the horizontal portion 33b.

[0045] The second accommodating section 32 is disposed on the lower left surface section 43 of the first circuit board 40. As shown in Fig. 5, the indicator section 100 can adopt a well-known configuration including a dial 101 on which an indicator design is printed, a cylindrical lighting chamber 32a formed in the second accommodating section 32 of the inner case 30 in accordance with the indicator design, and a light source 45 consisting of an LED disposed in the lighting chamber.

[0046] As shown in Figures 2 and 3, the first support piece 34 extends from the first circuit board 40 side of the first accommodating portion 31 toward the cutout portion 41 in a rectangular cross section, then extends from between the first circuit board 40 and the second circuit board 60 toward the rear of the second circuit board 60, and further extends toward the second circuit board 60, and is ultimately formed so as to support the rear of the second circuit board 60.

[0047] As shown in Figures 2 and 3, the second support piece 35 extends from the first circuit board 40 side of the second accommodating section 32 toward the cutout portion 41 in a rectangular cross section, then extends from between the first circuit board 40 and the second circuit board 60 toward the rear of the second circuit board 60, and further extends toward the second circuit board 60, and is finally formed so as to support the rear of the second circuit board 60.

[0048] The inner case 30 is fixed to the first circuit board 40 by fasteners such as screws that are inserted into the first circuit board 40 from the rear surface of the first circuit board 40 and screwed into the inner case 30. In this way, an ASSY 200 consisting of the first display panel 10, the first illumination member 20, the inner case 30, the first circuit board 40, and the cushioning member 70 is completed.

[0049] The flow of assembling ASSY300 to ASSY200 will be described. As shown in Fig. 4, first, the display 50 of ASSY300 is placed against the guide portion 33 of ASSY200. Then, the display 50 is rotated along the guide portion 33. Then, the second circuit board 60 of ASSY300 is placed on the first support piece 34 and the second support piece 35. Then, the overlapping region Z of the display 50 is disposed behind the first illumination member 20 and the buffer member 70. The combined ASSY200 and ASSY300 are positioned on the end cover member 80 as described above.

[0050] By forming it in this manner, the guide portion 33 serves as a guide surface for the display unit 50, and the display unit 50 can be easily assembled between the first display panel 10 and the first circuit board 40.

[0051] The first illumination member 20 is formed by bonding a diffusion sheet 25 and a back reflector sheet 23, which are thin sheet materials, to the front and rear surfaces of a first light guide 21 having a thin plate thickness. Moreover, the inner case 30 (the mounting surface 31c) is not formed in the overlapping region Z. By forming it in this manner, the distance between the first display surface 11 of the first display panel 10 and the second display surface 51a of the display 50 can be reduced.

[0052] A buffer member 70 is disposed between the first lighting member 20 and the display 50. By forming it in this manner, it is possible to prevent light leakage from the second lighting member 52 and to prevent abnormal noise caused by interference between the first lighting member 20 and the display 50.

[0053] The present disclosure is not limited to the above-described embodiment, and various modifications are possible within the scope of the gist of the present disclosure. [Explanation of symbols]

[0054] 10 First display panel 11 First display surface 20 First lighting member 21 First light guide (light guide member) 21a one end 21b Recess 21c back 21d End face 21e front 22 First light source member (light source) 23 Back reflective sheet (sheet material) 24 Side reflective sheet (sheet material) 25 Diffusion sheet (sheet material) 30 Inner case (case material) 31 First storage section 31c Placement part 31d Stepped section 32 Second storage section 33 Guide section 33a Vertical section 33c end 33b Horizontal part 33d Slope 34 First support piece 35 Second support piece 40 First circuit board 41 Cutout 42 Top part 43 Lower left side 50 Display 51 Second display panel 51a Second display surface 52 Second lighting member 53 Frames 55 Second light guide 56 Second light source member 57 Reflective sheet 58 Optical Sheet 60 Second Circuit Board 70 Cushioning material 80 End cover material 90 Outer case 91 Translucent Panel 100 Indicator part 200 ASSY 300 ASSY Z overlap area

Claims

1. a first display panel that displays an image on a first display surface; a first illumination member disposed behind the first display panel and configured to illuminate the first display panel; a case member disposed behind the first lighting member and supporting the first lighting member; a first circuit board disposed behind the case member and configured to drive the first display panel; a second display panel that displays an image on a second display surface and has an overlap region that is disposed behind the first display panel; the first illumination member has a light-opaque covering member that covers a surface other than a surface facing the first display panel, The case member extends toward the first circuit board from a position behind the first lighting member that does not face the overlapping region, and the end portion extending toward the second display panel is positioned behind the second display panel facing the overlapping region, and has a guide portion that serves as a guide surface for the second display panel.

2. The display device according to claim 1 , wherein a portion of the first circuit board is disposed in a position facing the overlapping region.

3. 2. The display device according to claim 1, further comprising a buffer member between the first illumination member and the second display panel in the overlapping region.

4. 2. The display device according to claim 1, further comprising a second illumination member disposed behind the second display panel for illuminating the second display panel.

5. a second circuit board disposed behind the second display panel and configured to drive the second display panel; 2. The display device according to claim 1, wherein the second circuit board is supported at its rear by the case member.

6. the first illumination member has a plate-shaped light guide member facing the first display panel and a light source disposed at one end of the light guide member, 2 . The display device according to claim 1 , wherein the cover member is made of a non-transparent sheet member attached to a surface of the light guide member other than the surface facing the first display panel.

7. 7. The display device according to claim 6, wherein the first illumination member has a light-transmitting sheet member attached to a surface of the light guide member facing the first display panel.

Images