JP7468285B2 - Display device - Google Patents

Description

This disclosure relates to a display device mounted on a vehicle, etc.

Conventionally, a display device is known that has a light guide member and a sub-case that holds the light guide member. The sub-case holds the light guide member and is then attached to another main case, so that the light guide member is positioned relative to the light source.

JP 2002-244595 A

When assembling the subcase to the main case, there is a risk that the light-guiding member will come into contact with other structures, such as the main case. In particular, if the light-guiding member is held so that it protrudes from the subcase, it is likely to hit other structures and become misaligned. If the light-guiding member is not held in an appropriate position relative to the subcase, it will not be positioned in an appropriate position relative to the light source, and there is a risk that the light from the light source will not be guided properly.

This disclosure has been made in consideration of these circumstances, and aims to provide a display device that can improve assembly accuracy.

To solve the above-mentioned problems, the display device of the present disclosure includes a light source, a light guide member having an entrance surface disposed in front of the light source, an exit surface that emits light guided from the entrance surface in front of the entrance surface, and a light guide portion having an outer peripheral surface and connecting the entrance surface and the exit surface, a subcase that houses the light guide member, and a main case that houses the subcase, the subcase having a protective wall that covers a portion of the outer peripheral surface of the main case, and a hook that presses the light guide portion against the protective wall from another portion of the outer peripheral surface, and the light guide member has a hook receiver that is provided in the other portion of the outer peripheral surface and engages with the hook.

The display device disclosed herein can improve assembly accuracy.

1 is a front view of a display device according to an embodiment of the display device of the present disclosure. FIG. 2 is a cross-sectional view taken along line II-II in FIG. FIG. 2 is a cross-sectional view taken along line III-III in FIG. FIG. 4 is an external perspective view of the rear light guide member as viewed from the front and above. Rear view of the lighting case.

An embodiment of the display device of the present disclosure will be described with reference to the attached drawings. The display device of the present disclosure is mounted on vehicles such as automobiles and motorcycles, ships, agricultural machinery, and construction machinery, for example.

FIG. 1 is a front view of a display device 1 which is an embodiment of a display device according to the present disclosure.
FIG. 2 is a cross-sectional view taken along line II-II in FIG.
FIG. 3 is a cross-sectional view taken along line III-III in FIG.

In the following description, "front," "rear," "upper," "lower," "right," and "left" follow the definitions of "Fr.", "Re.", "To.", "Bo.", "R," and "L" in Figures 1 to 3. Note that the side of the display device 1 that is visible to the user is defined as "front."

The display device 1 mainly includes a display unit 10 (rear member), a circuit board 20, a case 30, a rear light-guiding member 50 (light-guiding member), a front light-guiding member 60, and a diffusion plate 70.

The display unit 10 has a display panel, a backlight unit, and a bezel 11.

The display panel is, for example, a TFT (Thin Film Transistor) type liquid crystal display panel. The display panel has a pair of glass substrates that encapsulate a liquid crystal layer. Transparent electrodes are formed on the pair of glass substrates using ITO (Indium Tin Oxide) or the like. The display panel also has a pair of polarizing plates (polarizing filters) arranged to sandwich the pair of glass substrates. The display panel is connected to the circuit board 20 via a flexible printed circuit board (FPC (Flexible Printed Circuits)) not shown. The display panel is controlled by a control unit of the circuit board 20, and a driving 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, and the transmittance of each pixel of the display panel changes, causing the display panel to display an image.

The backlight unit is provided behind the display panel. The backlight unit is composed of a light source board and a light guide member, and illuminates the display panel from behind. The light source board is mounted with a plurality of LEDs (Light Emitting Diodes), which are an example of a light source. The light source board is connected to the circuit board 20 via a flexible board such as an FPC. When a drive current is supplied, the LEDs emit light toward the light guide member. The light guide member guides the light emitted by the LEDs toward the display panel.

The bezel 11 is a metal frame that houses the display panel and backlight unit. The display panel covers the front surface of the display unit 10, leaving at least the display screen exposed.

The circuit board 20 is supported by the case 30 and disposed behind the display unit 10. The circuit board 20 mainly includes a control unit for controlling the display unit 10 and a number of light sources 21.

The control unit has a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), etc., and executes predetermined calculation processing according to a program written in the ROM, for example. The control unit acquires, for example, vehicle speed, engine RPM, various vehicle information, navigation information, etc. from the vehicle's ECU (Electronic Control Unit) via various sensors, etc. The control unit displays information on the display unit 10 based on the acquired information.

The light source 21 is provided on the front surface 20a of the circuit board 20. The light source 21 is, for example, a top-view type (upper surface emitting type) LED. Multiple light sources 21 (8 pieces) are provided to correspond to the number of segments used in the gauge 2, which has eight circular designs arranged in a row.

The case 30 has a lower case 31, a middle case 32 (main case), a lighting case 40 (sub-case), and a facing member 38.

The lower case 31 is a light-shielding resin (e.g., white polypropylene) that forms the outer shell of the display device 1. The lower case 31 mainly houses the lighting case 40, the display unit 10, and the circuit board 20 supported by the middle case 32 in its internal space.

The middle case 32 is a light-blocking resin (e.g., white polypropylene). The middle case 32 mainly supports and fixes the display unit 10 and the circuit board 20. The middle case 32 also houses and supports the lighting case 40. The middle case 32 has a board-side opening end 33. The board-side opening end 33 contacts the circuit board 20, thereby dividing the lighting range of each light source 21 into a number corresponding to the number of segments, which is the number of gauges 2.

The lighting case 40 is made of a light-blocking resin (e.g., white polypropylene). The lighting case 40 houses and fixes the rear light-guiding member 50 and the diffusion plate 70 (details will be described later). In other words, the lighting case 40, the rear light-guiding member 50, and the diffusion plate 70 are treated as a single component when assembled to the middle case 32.

The lighting case 40 houses the rear light guide member 50, thereby reflecting the light emitted from the rear light guide member 50 and making it re-enter the rear light guide member 50. The lighting case 40 extends from the rear to the front, and together with the middle case 32, divides the lighting range of each light source 21 into a number corresponding to the number of gauges 2, which is eight. The lighting case 40 has a front opening end 46 and a rear opening end 47. The front opening end 46 is an opening end located in front of each lighting range, and by contacting the diffusion plate 70, divides the lighting range into a closed space together with the board side opening end 33. The rear opening end 47 is an opening end located behind the front opening end 46 and forward at a certain distance from the circuit board 20.

The configuration for housing and supporting the rear light-guiding member 50 in the lighting case 40 will be described later.

The end cover member 38 is a light-blocking resin (e.g., black ABS resin). The end cover member 38 covers from the front the areas of the display unit 10 other than the display screen and the inside of the case 30 that should be shielded from the user. The end cover member 38 is combined with the lower case 31 in front of the lower case 31, so that it also functions as the outer shell of the front of the display device 1.

The facing member 38 is disposed in front of the forward light-guiding member 60, and exposes each protrusion 61 of the forward light-guiding member 60 from an opening 39. Eight openings 39 are provided, corresponding to the number of segments. The openings 39 are disposed in a position overlapping the bezel 11 of the display unit 10 when viewed from the front, and are illuminated by light from the light source 21 via the forward light-guiding member 60 to form a gauge 2 adjacent to the display screen of the display unit 10. The gauge 2 indicates, for example, the high or low engine speed by the number of lights or the color of the lights.

The rear light-guiding member 50 is made of a transparent resin (e.g., polymethyl methacrylate (PMMA)). The rear light-guiding member 50 guides the light from the light source 21 to the diffusion plate 70. Here, FIG. 4 is an external perspective view of the rear light-guiding member 50 as viewed from the front and above.

The rear light-guiding member 50 has an incident surface 51, an exit surface 52, a light-guiding section 53, an arm section 57, and a hook receiver 58.

The incident surface 51 is a surface that is approximately perpendicular to the front-rear direction and is the rear end surface of the rear light-guiding member 50. The incident surface 51 is disposed in front of the light source 21 so as to face the light source 21, and is the surface into which the light from the light source 21 is incident.

The exit surface 52 is a surface that is approximately perpendicular to the front-rear direction and is the front end surface of the rear light-guiding member 50. The exit surface 52 emits light that is incident from the entrance surface 51 and guided through the light-guiding section 53 in front of the entrance surface 51.

The light guide section 53 is a portion between the incident surface 51 and the exit surface 52, and guides the light incident from the incident surface 51 to the exit surface 52. The light guide section 53 is generally L-shaped and has a curved shape with a bent section 53b. Specifically, the light guide section 53 has a curved shape that bends inward in the front-to-rear direction so that the incident surface 51 is located outside the outer edge 10a of the display unit 10 (rear member) and at least a part of the exit surface 52 is located inside the outer edge 10a.

The light guide section 53 has a generally rectangular prism shape. The light guide section 53 has an outer peripheral surface 55 that connects the incident surface 51 (the outer edge) and the exit surface 52 (the outer edge). The outer peripheral surface 55 is made up of four surfaces including two pairs of opposing surfaces: a left surface 55a, a right surface 55b, an upper surface 55c, and a lower surface 55d.

The arms 57 are a pair of linear portions that extend in one direction (the opposite direction to the bending direction of the light guide 53) from the outer edge of the light exit surface 52 and parallel to the light exit surface 52. The arms 57 are disposed on the lighting case 40 to position the rear light guide member 50 in the front-rear direction.

The hook receiver 58 is located near the entrance surface 51 of the outer peripheral surface 55 and is formed at a position corresponding to the hook 42 (described later) of the lighting case 40, and engages with the hook 42. The hook receiver 58 is provided on the upper surface 55c, which is an area of the outer peripheral surface 55 that is not covered by the protective wall 44 (the other area of the outer peripheral surface 55).

The forward light-guiding member 60, like the rearward light-guiding member 50, is made of a transparent resin (e.g., PMMA). The forward light-guiding member 60 guides the light emitted from the rearward light-guiding member 50 further forward. The forward light-guiding member 60 has a protrusion 61 whose tip is exposed from the opening 39. The gauge 2 lights up when light is emitted from the protrusion 61.

The diffusion plate 70 is a thin plate-like member disposed between the rear light-guiding member 50 and the front light-guiding member 60. The diffusion plate 70 is made of transparent resin (e.g., polycarbonate) with opaque diffusion printing and black printing. The diffusion printing is applied to the area corresponding to the protrusion 61, and diffuses and transmits light. The black printing is applied to the area other than the protrusion 61, and blocks light. The diffusion plate 70 is fixed to the front surface of the lighting case 40, for example, by providing an adhesive layer on the back surface.

Next, the lighting case 40 will be described in detail. Figure 5 shows the lighting case 40 as seen from the rear.

The lighting case 40 has a base material 41, a protective wall 44, and a hook 42.

The base material 41 is a plate-shaped member that extends in the left-right direction. The lighting case 40 is supported by the middle case 32 via this base material 41.

The protective wall 44 is a portion that protrudes substantially rearward from the rear surface 41b of the base material 41 with a substantially U-shaped cross section. The protective wall 44 covers a portion of the outer peripheral surface 55 of the light guide portion 53 with respect to other structures, including the area facing the middle case 32. In other words, the protective wall 44 is provided to protect the rear light guide member 50 from contacting the middle case 32 or other structures when the lighting case 40, the rear light guide member 50, and the diffusion plate 70, which are integrated into one component, are attached to the middle case 32.

The protective wall 44 has a shape that corresponds to (follows) the shape of the outer peripheral surface 55, including the bent shape. Specifically, the protective wall 44 is made up of three continuous surfaces, a left wall 44a covering the left surface 55a of the outer peripheral surface 55, a right wall 44b covering the right surface 55b, and a bottom wall 44d covering the bottom surface 55d, and has a cross section that is approximately U-shaped. The left wall 44a and the right wall 44b cover the area from the rear end 53a of the light guiding section 53 (on the same plane as the entrance surface 51) to the rear end of the arm 57. The bottom wall 44d covers the area from the rear end 53a of the light guiding section 53 through the bent section 53b to the tip 53c of the light guiding section 53 (the back side of the exit surface 52).

The left wall 44a and the right wall 44b of the protective wall 44 have left and right ribs 48 that protrude toward the left surface 55a and the right surface 55b (a pair of opposing surfaces) of the outer peripheral surface 55 and push the left surface 55a and the right surface 55b in the opposing direction. The distance between the left and right ribs 48 of the left wall 44a and the right wall 44b may be smaller than the distance between the left surface 55a and the right surface 55b. In this case, the rear light guide member 50 is lightly pressed into the lighting case 40, so that the rear light guide member 50 and the protective wall 44 are in close contact with each other, and positioning accuracy in the left and right direction of the rear light guide member 50 is obtained. This also provides positioning accuracy with the light source 21, and prevents false lighting of the gauge 2. "Pseudo-illumination" refers to a state in which a gauge 2 that is illuminated by the light source 21 is adjacent to a gauge 2 that is not illuminated by the light source 21, and the light of the illuminated light source 21 leaks through the gap between the middle case 32 and the lighting case 40 to the unlit gauge 2 side and enters the light guide portion 53 of the rear light guide member 50 on the unlit gauge 2 side, making the unlit gauge 2 appear to be illuminated. In addition, the bottom wall 44d has a lower rib 49 that presses against the bottom surface 55d.

The hook 42 is an elastic protruding piece that extends rearward from the back surface 41b of the base material 41. The tip 42a of the hook 42 engages with the hook receiver 58 on the upper surface 55c (the other of the pair of opposing surfaces), which is the other area of the outer circumferential surface 55, and the hook 42 sandwiches the light guide section 53 with the lower wall 44d. At this time, the lower wall 44d covers the lower surface 55d (one of the pair of opposing surfaces), and since the lower wall 44d has a lower rib 49, the lower surface 55d is pressed against the lower wall 44d and comes into close contact.

In such a display device 1, a part of the rear light guide member 50 is covered with the protective wall 44, and the other part of the rear light guide member 50 is attached to the protective wall 44 by the hook 42, so that the rear light guide member 50 is reliably fixed to the lighting case 40. Therefore, as described above, when the lighting case 40 and the rear light guide member 50 are assembled to the middle case 32 as an integral part, the rear light guide member 50 can be reduced from contacting other structures such as the middle case 32. Even if the lighting case 40 comes into contact with other structures, there is no risk of the rear light guide member 50 being displaced from the lighting case 40, and the rear light guide member 50 is suitably positioned with respect to the light source 21 that is indirectly positioned via the middle case 32 and the circuit board 20.

As a result, the display device 1 can be assembled with improved precision. Furthermore, as a result of the display device 1 being assembled with improved precision, false lighting of the gauge 2 can be prevented, and the appearance of the display device 1 when in use can be improved.

Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are included in the scope of the invention and its equivalents described in the claims.

For example, in the above embodiment, the protective wall 44 covers the light guide section 53 from the rear end 53a (and the incident surface 51) forward, but it may protrude further than the rear end 53a and extend to the rear (circuit board 20 side).

Although an example has been described in which the light-guiding member is the rear light-guiding member 50, it may also be a light-guiding member that is arranged facing the dial arranged in front and illuminates the dial. Although an example has been described in which the rear member is the display unit 10, various members such as a dial, a pointer, or another light-guiding member may be used as the rear member.

In the above description, the light guide section 53 is generally rectangular prism shaped, but it may be a cylinder, a triangular prism, or a polygonal prism with more than a square prism.

1 Display device 2 Gauge 10 Display unit 10a Outer edge 11 Bezel 20 Circuit board 20a Front surface 21 Light source 30 Case 31 Lower case 32 Middle case 33 Board side opening edge 38 Back cover member 39 Opening 40 Illumination case 41 Base material 41b Rear surface 42 Hook 42a Tip 44 Protective wall 44a Left wall 44b Right wall 44d Bottom wall 46 Front opening edge 47 Rear opening edge 48 Left and right ribs 49 Bottom rib 50 Rear light guide member 51 Incident surface 52 Emitting surface 53 Light guide portion 53a Rear end 53b Bent portion 53c Tip 55 Outer peripheral surface 55a Left surface 55b Right surface 55c Top surface 55d Bottom surface 57 Arm portion 58 Hook receiver 60 Front light guide member 61 Protrusion 70 Diffuser plate

Claims (5)

A light source;
a light guiding member including an incident surface disposed in front of the light source, an exit surface that emits light guided from the incident surface in front of the incident surface, and a light guiding portion having an outer peripheral surface and connecting the incident surface and the exit surface;
a sub-case that houses the light guide member;
A main case that houses the sub-case,
the sub-case has a protective wall that covers a portion of an area of the outer circumferential surface of the main case, and a hook that presses the outer circumferential surface against the protective wall from another area of the outer circumferential surface,
The light guide member has a hook receiver that is provided in another region of the outer circumferential surface and engages with the hook. The display device according to claim 1, wherein the protective wall covers at least the area where the outer circumferential surface faces the main case. The outer circumferential surface is made up of a plurality of surfaces including at least one pair of opposing surfaces,
The protective wall covers at least one of the pair of opposing surfaces,
The display device according to claim 1 , wherein the hook sandwiches the light guide section and the protective wall from the other of the pair of opposing surfaces. The outer circumferential surface is made up of a plurality of surfaces including at least one pair of opposing surfaces,
The display device according to claim 1 , wherein the protective wall has ribs protruding toward the at least one pair of opposing surfaces. Further comprising a rear member disposed rearward of the light exit surface,
the main case is a case that supports the rear member,
The display device according to claim 1 , wherein the light guide portion has a curved shape in the front-rear direction such that the entrance surface is located outside an outer edge of the rear member and at least a portion of the exit surface is located inside the outer edge of the rear member.

Images