JP7582009B2 - Display device - Google Patents

Description

The present invention relates to a display device for a head-up display.

Head-up display devices that display virtual images by irradiating display light onto a projection member such as a windshield are known in vehicles. A conventional display device technology is disclosed in Patent Document 1, in which a relay board (FPC: flexible printed circuits) is connected to a display element (TFT liquid crystal: thin-film-transistor liquid-crystal display) via a flexible flat cable (FFC: flexible flat cable).

The display device shown in Patent Document 1 is placed in the dashboard of a vehicle and includes a display element that displays information, a flexible flat cable connected to the display element, an intermediate board that is electrically connected to the flexible flat cable, a holder that holds the display element and the intermediate board, and a cover that covers the display element from the opposite side of the holder.

International Publication No. 2020/085160

In the display device shown in Patent Document 1, there was a risk that the position of the relay board would shift due to errors during assembly or vibrations after assembly, resulting in load (stress) being applied to the area near the connection point of the display element. When a load is applied, color unevenness and changes in the polarization characteristics of the display element occur. This was particularly noticeable in in-vehicle display devices, which are in an environment with a lot of vibration.

The objective of the present invention is to provide a display device equipped with a holder that can hold the relay board more accurately.

According to the present invention, a display device is provided that includes a display element that displays information, a flexible flat cable connected to the display element, an intermediate board that is electrically connected to the flexible flat cable, and a holder that holds the display element and the intermediate board. The intermediate board has a notch at a lateral end located within the plane of the intermediate board and perpendicular to the extension direction of the flexible flat cable. The holder further includes an intermediate board mounting surface on which the intermediate board is mounted, a retainer that is provided at a position opposite to the intermediate board mounting surface and spaced apart to hold down the intermediate board, and a hook that is provided on the intermediate board mounting surface and extends toward the retainer. The hook is elastically deformable in the front and back directions of the intermediate board mounting surface, and fits into the notch to restrict movement of the intermediate board toward the display element and to bias the intermediate board toward the retainer.

The present invention provides a display device equipped with a holder that can hold the relay board more accurately.

1 is a schematic diagram of a vehicle equipped with a head-up display device having a display device according to an embodiment of the present invention. 1 is a schematic diagram of a head-up display device having a display device according to an embodiment of the present invention. 1 is an exploded perspective view of a display device according to an embodiment of the present invention; 1 is a perspective view of a display device according to an embodiment of the present invention; 1 is a perspective view of a display element, a flexible flat cable, and a relay substrate according to an embodiment of the present invention. 1 is a cross-sectional perspective view of a main portion of a display device according to an embodiment of the present invention; 1 is a diagram illustrating the operation of a display device according to an embodiment of the present invention; FIG. 4 is an explanatory diagram of a gap in a display device according to one embodiment of the present invention. FIG. 1 is an exploded perspective view of a display device according to a different embodiment. FIG. 1 is a perspective view of a display device according to a different embodiment. 11 is a perspective view of a display element, a flexible flat cable, and a relay substrate according to a different embodiment. FIG. 11A to 11C are diagrams illustrating the operation of a display device according to a different embodiment.

The following describes an embodiment of the present invention with reference to the attached drawings. Note that the embodiment shown in the attached drawings is an example of the present invention, and the present invention is not limited to this embodiment.

Example 1
Referring to Fig. 1, the head-up display device 100 is installed in the dashboard of a vehicle 110. The head-up display device 100 emits display light L representing an image toward a windshield 111, which is an example of a projection target member of the vehicle 110. The display light L is reflected by the windshield 111 and reaches a viewer 120 (mainly the driver of the vehicle 110). As a result, a virtual image V is displayed so as to be visible to the viewer 120.

See also FIG. 2. The head-up display device 100 includes a display device 10 that emits display light L, a plane mirror 52 that reflects the display light L, a concave mirror 53 that reflects the display light L toward the windshield 111, and a housing 60 that forms the outer shape of the entire device.

The display device 10 has an illumination device 20a that emits light, and emits display light L that represents an image from the display element 20 under the control of a control unit mounted on the relay board 22.

The plane mirror 52 reflects the display light L emitted by the display device 10 toward the concave mirror 53. The concave mirror 53 reflects the display light L reflected by the plane mirror 52 toward the windshield 111 while magnifying it.

The housing 60 defines the exterior of the entire device and includes a fan 51 inside. The relay board 22 is made of a printed circuit board on which various electronic components such as a CPU (Central Processing Unit) are mounted, and controls the emission of the display light L from the display device 10.

Refer to Figures 3, 4, and 5. The display device 10 includes a display element 20 that displays information, a flexible flat cable 21 connected to the display element 20, a relay board 22 electrically connected to the flexible flat cable 21, a holder 30 that holds the display element 20 and the relay board 22, and a cover 40 that covers the display element 20 from the opposite side of the holder 30. The cover 40 is formed with a cover portion 41 that folds back to cover the flexible flat cable 21.

The relay board 22 is formed in a substantially rectangular shape, and has rectangular notches 23, 23 at the lateral ends located within the plane of the relay board 22 and perpendicular to the extension direction of the flexible flat cable 21. In other words, one side of the substantially rectangular relay board 22 is connected to the flexible flat cable 21. Also, notches 23, 23 are formed on the side adjacent to the side connected to the flexible flat cable 21. The lateral width of the relay board 22 is greater than the lateral width of the flexible flat cable 21.

Please also refer to FIG. 6. FIG. 6 shows the display device 10 in a state in which it is upside down with respect to the state shown in FIG. 3. The holder 30 has a relay board mounting surface 31 on which the relay board 22 is mounted. A rib 32 is provided at the end of the relay board mounting surface 31 in the width direction, which rises in the vertical direction of the relay board mounting surface 31. The rib 32 is provided with a retainer 33 that holds the relay board 22 so as to prevent the relay board 22 from floating up at a position opposite the relay board mounting surface 31 and spaced apart. In addition, an end retainer 33a that holds down the end of the relay board 22 is provided at the tip of the relay board mounting surface 31. The end retainer 33a prevents the relay board 22 from floating up and also prevents the relay board 22 from displacing in a direction away from the flexible flat cable 21. In other words, the edge of the tip of the relay board 22 abuts against the end retainer 33a, and the surface is held down by the end retainer 33a. The tip of the relay board 22 can also be said to be the side opposite the side connected to the flexible flat cable 21.

The relay board mounting surface 31 is provided with a hook 34 that extends toward the retainer 33. The hook 34 is provided so that it can elastically deform in the front-to-back direction of the relay board mounting surface 31. By fitting into the notch 23, the hook 34 restricts the movement of the relay board 22 in the direction of the display element 20 (towards the flexible flat cable 21) and also urges the relay board 22 towards the retainer 33.

The hook 36 also has a base end 36 that extends along the relay board mounting surface 31 from an opening 35 formed at the lateral end of the relay board mounting surface 31, and an inclined portion 37 that extends from the base end 36 at an angle toward the retainer 33.

See also FIG. 7. The holder 30 is formed so that the angle α between the display element mounting surface 39 on which the display element 20 is placed and the relay board mounting surface 31 is 90 degrees or less. The direction in which the inclined portion 37 of the hook 34 extends is within the range of the angle α. For example, the angle β from the relay board mounting surface 31 to the extension direction of the inclined portion 37 of the hook 34 may be set to be smaller than the angle α, but it is preferable to set the angle β to be 1/2 of the angle α.

In general, when making the holder 30 of the present invention by injection molding in a mold, the mold can be removed in the normal direction to the display element mounting surface (TFT surface) 39 and the normal direction to the relay substrate mounting surface (FPC surface) 31 to achieve good shaping. However, in this configuration, each surface forms an acute angle, and the normals are positioned so that they face each other. Therefore, in this invention, the extension direction of the hook 34 is oriented at the acute angle α, making it possible to mold even with this positional relationship of the TFT surface and the FPC surface.

See also Figure 8. A gap 38 is formed on the relay board mounting surface 31 of the holder 30, surrounding the periphery of the hook 34. The retainer 33 is formed so as to fit within the range of the gap 38 when viewed in the direction in which the hook 34 extends.

Next, the operation of the display device 10 described above will be described.
6, when assembling the relay board 22 to the holder 30, the relay board 22 is inserted between the relay board mounting surface 31 and the retainer 33 as shown by the arrow (1), and then moved as shown by the arrow (2). At this time, the relay board 22 is moved with the hook 34 retracted in the opposite direction to the retainer 33, and when the notch 23 of the relay board 22 is positioned at the position of the hook 34, the hook 34 fits into the notch 23.

As a result, the relay board 22 is biased in the pressing direction as shown by the arrow (3), restricting the relay board 22 from moving toward the flexible flat cable 21 (the display element 20). Even if the relay board 22 attempts to move in the width direction as shown by the arrow (4), the hook 34 restricts the relay board 22 from moving in the width direction.

If the hook 34 were not present, the relay board 22 would be free in the planar direction of the relay board mounting surface 31, and if the relay board 22 were to move toward the flexible flat cable 21 for some reason, the elasticity of the flexible flat cable 21 would put pressure on the connection part of the display element 20, which could impair the display quality. In this regard, in the present invention, the hook 34 acts as a stopper for the relay board 22, preventing the elasticity of the flexible flat cable 21 from putting pressure on the connection part of the display element 20.

Please refer to Figures 7 and 8. Figure 8 shows the display device 10 upside down compared to Figure 7. The retainer 33 is located within the gap 38 when viewed in the direction in which the hook 34 extends, as indicated by the arrow (5). If the retainer 33 were located directly below the relay board mounting surface 31, a slide piece would be required to remove it from the mold in the vertical direction in the drawing. However, in the present invention, the retainer 33 is located in a position where it can be seen from the gap 38 created by the hook 34, making injection molding in the mold easier.

Example 2
Next, a display device 10 according to a different embodiment will be described. Note that the same components as those in the display device 10 shown in Figures 3 to 8 will be assigned the same reference numerals and description thereof will be omitted.
9, 10 and 11, the display device 10 includes a display element 20, a flexible flat cable 21, a relay board 22, a holder 30, and a cover 40.

See also FIG. 12. The holder 30 further has a relay board mounting surface 31 on which the relay board 22 is placed, a retainer 33 that is provided at a distance from the relay board mounting surface 31 and that holds down the relay board 22, and a hook 34 that extends toward the retainer 33. The hook is provided so as to be elastically deformable in the front-rear direction of the relay board mounting surface 31, and has an abutment portion 34a that abuts against the end of the base end side of the relay board 22 to limit the movement of the relay board 22 in the direction of the display element 20, and a step portion 34b that urges the relay board 22 toward the retainer 33.

Next, the operation of the display device 10 according to the above-described different embodiment will be described.
Refer to Fig. 12. When assembling the relay board 22 to the holder 30, the relay board 22 is inserted between the relay board mounting surface 31 and the retainer 33 as shown by the arrow (6), and then moved as shown by the arrow (7). At this time, the relay board 22 is moved with the hook 34 retracted in the opposite direction to the retainer 33, but when the base end of the relay board 22 reaches the position of the hook 34, the hook 34 returns to its original position and hooks onto the base end of the relay board 22.

As a result, the abutment portion 34a of the hook 34 restricts the relay board 22 from moving toward the flexible flat cable 21. In addition, the step portion 34b of the hook 34 biases the relay board 22 against the retainer 33. In this way, the hook 34 acts as a stopper for the relay board 22, preventing the flexible flat cable 21 from pressing against the connection portion of the display element 20.

Next, we will explain the functions and effects of the display device 10 described above.

As described above, in the display device 10 including the display element 20 for displaying information, the flexible flat cable 21 connected to the display element 20, the relay board 22 electrically connected to the flexible flat cable 21, and the holder 30 for holding the display element 20 and the relay board 22, the relay board 22 has a notch 23 at a lateral end located in the plane of the relay board 22 and perpendicular to the extension direction of the flexible flat cable 21, and the holder 30 further has a relay board mounting surface 31 on which the relay board 22 is mounted, a retainer 33 that is provided at a distance from the relay board mounting surface 31 and holds down the relay board 22, and a hook 34 that is provided on the relay board mounting surface 31 and extends toward the retainer 33, and the hook 34 is elastically deformable in the front-rear direction of the relay board mounting surface 31, and by fitting into the notch 23, it restricts the movement of the relay board 22 toward the display element 20 and urges the relay board 22 toward the retainer 33.

This configuration makes it possible to provide a display device 10 equipped with a holder 30 that can hold the relay board 22 more accurately.

The angle α between the display element mounting surface 39 on which the display element 20 is placed and the relay substrate mounting surface 31 is 90 degrees or less, and the direction in which the hooks 34 extend is within the range of the angle α. With this configuration, by orienting the extension direction of the hooks 34 to the acute angle α, molding is possible even with the acute angle positional relationship between the display element mounting surface 39 and the relay substrate mounting surface 31 (positional relationship between the TFT surface and the FPC surface).

In addition, a gap 38 is formed on the relay board mounting surface 31 of the holder 30 surrounding the periphery of the hook 34, and the retainer 33 is formed so as to fit within the gap 38 when viewed in the direction in which the hook 34 extends. If the retainer 33 were provided directly below the relay board mounting surface 31, a slide piece would be required to remove it from the mold in the vertical direction in the drawing, but in the above configuration of the present invention, the retainer 33 is provided in a position where it can be seen from the gap 38 created by the hook 34, making injection molding in the mold easier.

In addition, in a display device 10 including a display element 20 for displaying information, a flexible flat cable 21 connected to the display element 20, a relay board 22 electrically connected to the flexible flat cable 21, and a holder 30 for holding the display element 20 and the relay board 22, the holder 30 further includes a relay board mounting surface 31 on which the relay board 22 is mounted, a retainer 33 that is provided at a distance from the relay board mounting surface 31 and holds down the relay board 22, and a hook 34 extending toward the retainer 34. The hook 34 is provided so as to be elastically deformable in the front-rear direction of the relay board mounting surface 31, and includes an abutment portion 34a that abuts against the end of the base end side of the relay board 22 to limit the movement of the relay board 22 toward the display element 20, and a step portion 34b that urges the relay board 22 toward the retainer 34.

This configuration makes it possible to provide a display device 10 equipped with a holder 30 that can hold the relay board 22 more accurately.

As long as the functions and effects of the present invention are achieved, the present invention is not limited to the examples.

The display device 10 of the present invention is suitable for use as a head-up display device 100 for a vehicle.

10: Display device 20: Display element 21: Flexible flat cable (FFC)
22: Intermediate substrate 23: Notch 30: Holder 31: Intermediate substrate mounting surface 33: Holder 34: Hook 38: Gap 39: Display element mounting surface α: Angle between display element mounting surface and intermediate substrate mounting surface

Claims (4)

A display device including a display element for displaying information, a flexible flat cable connected to the display element, a relay board electrically connected to the flexible flat cable, and a holder for holding the display element and the relay board,
the intermediate substrate has a notch at a lateral end portion located in a plane of the intermediate substrate and perpendicular to an extending direction of the flexible flat cable,
the holder further includes a relay board mounting surface on which the relay board is mounted, a presser that is disposed at a position opposite to and spaced from the relay board mounting surface and presses down the relay board, and a hook that is disposed on the relay board mounting surface and extends toward the presser,
The hook is arranged to be elastically deformable in the front and back directions of the relay substrate mounting surface, and by fitting into the notch, restricts the movement of the relay substrate toward the display element and urges the relay substrate toward the retainer. an angle between a display element mounting surface on which the display element is mounted and the intermediate substrate mounting surface is 90 degrees or less;
2. The display device according to claim 1, wherein the direction in which the hook extends is within the range of the angle. a gap is formed on the relay board mounting surface of the holder so as to surround the hook;
3. The display device according to claim 1, wherein the retainer is formed so as to be contained within the range of the gap when viewed in the extending direction of the hook. A display device including a display element for displaying information, a flexible flat cable connected to the display element, a relay board electrically connected to the flexible flat cable, and a holder for holding the display element and the relay board,
the holder further includes a relay board mounting surface on which the relay board is mounted, a presser that is disposed at a position opposite to and spaced from the relay board mounting surface and presses down the relay board, and a hook that extends toward the presser,
The hook is elastically deformable in the front-to-back directions of the relay substrate mounting surface, and is characterized in that it has an abutment portion that abuts against the end of the base end of the relay substrate to limit movement of the relay substrate toward the display element, and a step portion that urges the relay substrate toward the retainer.

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