Image display device

Abstract

To provide an image display device that can be miniaturized. [Solution] The image display device 1 comprises a display unit 2 that emits display light L, an optical unit 3 that reflects the display light L and guides it outwards, and a case 4 that houses the display unit 2 and the optical unit 3. The optical unit 3 includes a first mirror 31 that reflects the display light L emitted from the display unit 2, and a second mirror 32 that reflects the display light L reflected by the first mirror 31. The second mirror 32 is mounted in an installation hole 4A formed in the case 4 and is provided exposed to the outside of the case 4.

Description

Technical Field

[0001] The present invention relates to an image display device.

Background Art

[0002] Conventionally, as an image display device, for example, as described in Patent Document 1, display light emitted from a display is sequentially reflected by a first mirror (plane mirror) and a second mirror (concave mirror), guided toward a windshield, and a display image corresponding to the display light is projected onto the windshield to display a virtual image in front of the driver's eye point.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above-described image display device, there is room for improvement in that it is difficult to miniaturize the device. For example, in the above-described image display device, in order to move the virtual image in the vertical direction, it is conceivable to rotate the second mirror, but it is necessary to install a rotation mechanism on the back side of the second mirror. Further, in the above-described image display device, in order to counter vibration, it is necessary to increase the rigidity of the second mirror by adhering accessory parts to the second mirror, etc., and a space for installing parts for increasing the rigidity is required. Therefore, it is difficult to miniaturize the device.

[0005] Therefore, an object of the present invention is to provide an image display device capable of miniaturizing the device.

Means for Solving the Problems

[0006] In other words, the image display device according to the present invention comprises a display unit that emits display light, an optical unit that reflects the display light and guides it toward the outside, and a case that houses the display unit and the optical unit, wherein the optical unit includes a first mirror that reflects the display light emitted from the unit and a second mirror that reflects the display light reflected by the first mirror, and the second mirror is mounted in an installation hole formed in the case and is provided exposed to the outside of the case. [Effects of the Invention]

[0007] The image display device according to the present invention makes it possible to miniaturize the device. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a diagram showing a schematic configuration of an image display device according to an embodiment. [Figure 2] Figure 2 is an exploded perspective view of an image display device according to this embodiment. [Modes for carrying out the invention]

[0009] Embodiments of the present invention will be described in detail below with reference to the drawings. However, the present invention is not limited by these embodiments. Furthermore, some of the components in the following embodiments may be easily substituted or substantially identical to those that are easily substituted by those skilled in the art.

[0010] [Embodiment] This embodiment relates to an image display device. In the following description, of the three intersecting directions, the first direction is referred to as the "front-to-back direction X," the second direction as the "vehicle width direction Y," and the third direction as the "height direction Z." Here, the front-to-back direction X, the vehicle width direction Y, and the height direction Z are mutually orthogonal. The front-to-back direction X corresponds to the front-to-back direction of the vehicle on which the image display device is mounted. The vehicle width direction Y corresponds to the vehicle width direction of the vehicle on which the image display device is mounted. The vehicle width direction Y and the height direction Z correspond to the intersecting directions that cross the front-to-back direction X. Furthermore, unless otherwise specified, each direction used in the following description represents the direction when each part is mounted on a vehicle. Note that "orthogonal" here includes approximately orthogonal.

[0011] As shown in Figure 1, the image display device 1 is installed in the vehicle 100 and is a device that displays an image. For example, it is a head-up display device that projects display light L onto a display member 103 of the vehicle 100 to display a virtual image S. The image display device 1 projects display light L onto the display member 103 in the vehicle 100, causing the driver of the vehicle 100 to perceive a virtual image S in front of the eye point EP. The display member 103 is, for example, a windshield. Note that the display member 103 may be a member other than a windshield. The image display device 1 is positioned below the display member 103 and is installed, for example, in an instrument panel provided on the dashboard. The eye point EP is predetermined as the driver's viewpoint position.

[0012] The image display device 1 comprises a display unit 2, an optical unit 3, and a case 4. The display unit 2 and the optical unit 3 are housed in the case 4 and emit display light L from an opening toward a display member 103. The opening is, for example, a hole formed in the upper part of the case 4. A light-transmitting member 6 is attached to the opening. The light-transmitting member 6 functions as an emission window that emits display light L from the case 4. The display unit 2 is a unit that emits display light L, and for example, emits display light L corresponding to a virtual image S. The display unit 2 operates by receiving a control signal from a control device provided outside the case 4, for example. The display unit 2 is installed in the case 4 at the rear side and lower position in the front-rear direction X, and emits display light L upward.

[0013] The optical unit 3 is an optical system unit that reflects display light L and guides it toward the display member 103, and includes, for example, a first mirror 31 and a second mirror 32. The first mirror 31 reflects the display light L emitted from the display unit 2. For example, the first mirror 31 is configured as a planar mirror and is installed in the case 4 on the rear side in the front-rear direction X, above the display unit 2. The first mirror 31 is rotatably supported by a rotation mechanism 5. The rotation mechanism 5 is a mechanism that rotates the first mirror 31 about an axis intersecting the incident direction of the display light L. For example, the rotation mechanism 5 rotates the first mirror 31 about an axis along the vehicle width direction Y or the horizontal direction, and raises and lowers the first mirror 31. The rotation mechanism 5 operates by receiving a control signal from, for example, a control device provided outside the case 4.

[0014] The first mirror 31 is formed to be smaller than the second mirror 32. For example, the first mirror 31 has a smaller reflective surface than the second mirror 32, or it is made to be lighter than the second mirror 32. As a result, the image display device 1 can have a smaller rotating mechanism 5 compared to the case where the first mirror 31 is formed to be larger than the second mirror 32, thus enabling miniaturization of the rotating mechanism 5.

[0015] The second mirror 32 reflects the display light L reflected by the first mirror 31 and guides the display light L to the outside of the case 4 through the light-transmitting member 6. The second mirror 32 is configured, for example, as a concave mirror and is installed on the front side in the front-to-back direction X compared to the first mirror 31.

[0016] As shown in Figure 2, case 4 has a lower case 41 and an upper case 42. Figure 2 shows case 4 with the upper case 42 removed from the lower case 41 and the second mirror 32 removed from case 4. Case 4 is, for example, a hollow box, and is constructed by attaching the upper case 42 to the top of the lower case 41. The lower case 41 is formed, for example, by raising four side walls from the edge of the rectangular bottom surface, and leaving the top ceiling open. The upper case 42 is attached to close the open top of the lower case 41. A light-transmitting member 6 is assembled to the upper case 42.

[0017] The second mirror 32 is mounted in an installation hole 4A formed in the case 4 and is exposed to the outside of the case 4. The installation hole 4A is formed in the second mirror 32 by cutting out one side wall. The installation hole 4A is a hole that connects the inside and outside of the case 4 and is formed, for example, by cutting out a portion of the side wall of the lower case 41 downwards from the upper end. The installation hole 4A is formed by cutting out a large portion of one side wall. The second mirror 32 is mounted in the case 4 so as to cover the installation hole 4A. For example, the second mirror 32 is positioned to cover the installation hole 4A from the outside of the lower case 41 and is assembled to the lower case 41 by screws or the like and fixed to the case 4. Note that the second mirror 32 may be fixed by a method other than screws, and may be done using adhesive, double-sided tape, etc. The second mirror 32 is provided as part of the case 4 by being assembled at the position of the installation hole 4A.

[0018] Next, the operation of the image display device 1 according to this embodiment and the miniaturization of the image display device 1 will be described.

[0019] As shown in Figure 1, the operation of the image display device 1 begins with the emission of display light L. That is, the display unit 2 operates in response to a control signal from a control device (not shown) and emits display light L toward the first mirror 31. The display light L enters the first mirror 31, is reflected by the first mirror 31, and enters the second mirror 32. The display light L is then reflected by the second mirror 32 and projected onto the display member 103 through the light-transmitting member 6. The driver of the vehicle 100 can recognize the display light L projected onto the display member 103 as a virtual image S.

[0020] In the image display device 1, when changing the position of the virtual image S in the height direction Z, the first mirror 31 is rotated. That is, the rotation mechanism 5 is activated, and the first mirror 31 rotates around an axis along the vehicle width direction Y or the horizontal direction. This changes the reflection direction of the display light L at the first mirror 31, making it possible to adjust the position of the virtual image S in the height direction Z. At this time, by rotating the first mirror 31, the image display device 1 can be made smaller compared to when the second mirror 32 is rotated. In other words, even when the second mirror 32 is rotated, it is possible to adjust the position of the virtual image S in the height direction Z, but by rotating the first mirror 31, which is smaller than the second mirror 32, the rotation trajectory range or rotation space of the first mirror 31 can be reduced, and the rotation mechanism 5 can be made smaller. For this reason, the case 4 can be made smaller, and the device can be made smaller.

[0021] In the image display device 1, the second mirror 32, which is a concave mirror, is attached to the position of the installation hole 4A of the case 4 and is provided so as to be exposed outside the case 4. Therefore, the image display device 1 does not need to accommodate the second mirror 32 inside the case 4, and the case 4 can be made small, thereby achieving miniaturization of the device. For example, compared with the case where the second mirror 32 is accommodated inside the case 4, there is no need to provide a clearance between the case 4 on the back side of the second mirror 32. Further, the image display device 1 does not need to rotate the second mirror 32, which is larger than the first mirror 31, for adjusting the position in the height direction Z of the virtual image S, and also does not need a rotation mechanism for rotating the second mirror 32, thereby achieving miniaturization of the device.

[0022] Further, in the image display device 1, since the second mirror 32 is attached to the installation hole 4A of the case 4 and fixed to the case 4, the outer edge of the second mirror 32 is supported by the case 4. Therefore, the rigidity of the second mirror 32 can be ensured, and it is possible to omit the installation of accessory parts for enhancing the rigidity of the second mirror 32. Thereby, miniaturization of the device can be achieved and cost reduction of the device can be achieved.

[0023] As described above, the image display device 1 according to the present embodiment can achieve miniaturization of the image display device 1 by providing the second mirror 32 so as to be exposed outside the case 4.

[0024] Further, the image display device 1 according to the present embodiment can achieve miniaturization of the image display device 1 by rotating the first mirror 31, which is smaller than the second mirror 32, so as to make the rotation mechanism 5 small.

[0025] Although the image display device according to the present embodiment has been described, the image display device according to the present invention is not limited to the above-described embodiment, and various modifications are possible within the scope described in the claims. The image display device according to the present embodiment may be configured by appropriately combining the components of the above-described embodiments and modification examples.

[0026] For example, in the embodiment described above, the case in which the optical unit 3 has two mirrors, a first mirror 31 and a second mirror 32, was described. However, the optical unit 3 may include the first mirror 31 and the second mirror 32 and have three or more mirrors. Even in this case, the device can be miniaturized in the same way as the image display device 1 according to the embodiment described above. [Explanation of Symbols]

[0027] 1: Image display device 2: Display Unit 3:Optical department 4: Case 4A: Installation hole 5: Rotation mechanism 31: First Mirror 32: Second Mirror 41: Light-emitting element L:Display light

Claims

1. A display unit that emits display light, An optical unit that reflects the aforementioned display light and guides it toward the outside, The system comprises a case housing the display unit and the optical unit, The optical unit includes a first mirror that reflects the display light emitted from the display unit, and a second mirror that reflects the display light reflected by the first mirror. The second mirror is mounted in an installation hole formed in the case and is exposed to the outside of the case. Image display device.

2. The aforementioned first mirror is smaller than the aforementioned second mirror. The system further includes a rotation mechanism that rotates the first mirror about an axis intersecting the incident direction of the display light. The image display device according to claim 1.

Images