Projection type display device

Abstract

The present invention provides a projection-type display device that can expand the projection area while suppressing an increase in the size of the aperture. [Solution] The projection-type display device 100 comprises a projector 10 that emits projection light L, a mirror 20 that reflects the projection light L in the projection direction, a projector drive unit 30 and a link mechanism 40 that rotate the mirror 20 to change the projection direction of the projection light L while moving the position of the projector 10 relative to the mirror 20, and a housing 60 that houses the projector 10, the mirror 20, the projector drive unit 30, and the link mechanism 40, and has an opening 61 through which the projection light L traveling in the projection direction passes. The projector drive unit 30 and the link mechanism 40 move the position of the projector 10 as the mirror 20 rotates so that the change in the shape and position of the optical cross-section LC obtained by cutting the projection light L passing through the opening 61 in a direction intersecting the optical axis direction of the projection light L is minimized.

Description

Technical Field

[0001] This disclosure relates to a projection display device.

Background Art

[0002] The reflection projection unit of the projector described in Patent Document 1 includes a first mirror and a second mirror that reflect a projection image, and the projection image is moved by rotating the second mirror around the rotation axis (see FIGS. 5(a) and 5(b) of Patent Document 1, paragraph 0020).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the configuration described in Patent Document 1 above, due to the rotation of the second mirror, the reflection direction of the projection light related to the projection image from the second mirror changes. Therefore, it is necessary to increase the size of the opening of the projector through which the projection light passes.

[0005] This disclosure has been made in view of the above actual situation, and an object thereof is to provide a projection display device that can suppress an increase in the size of the opening while expanding the projection area.

Means for Solving the Problems

[0006] To achieve the above object, the projection display device according to this disclosure includes a projector that emits projection light, a mirror that reflects the projection light in the projection direction, and a drive unit that rotates the mirror to change the projection direction of the projection light while moving the position of the projector with respect to the mirror. The system comprises a housing having an opening through which the projected light traveling in the projection direction passes, and housing the projector, the mirror, and the drive unit, The drive unit moves the position of the projector as the mirror rotates, such that the change in the shape and position of the cross-section obtained by cutting the projected light passing through the opening in a direction intersecting the optical axis direction of the projected light is minimized. [Effects of the Invention]

[0007] According to this disclosure, it is possible to expand the projection area while suppressing an increase in the size of the opening. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic diagram of a vehicle equipped with a projection display device according to one embodiment of the present disclosure. [Figure 2] This is a schematic diagram of a projection display device according to the same embodiment. [Figure 3A] This is a schematic diagram of a projection display device according to the same embodiment. [Figure 3B] This is a schematic diagram of a projection display device according to the same embodiment. [Figure 3C] This is a schematic diagram of a projection display device according to the same embodiment. [Figure 4A] This figure shows the window portion and the projection light cross-section according to the same embodiment. [Figure 4B] This figure shows the window portion and the projection light cross-section related to the comparative example. [Figure 5] This is a perspective view of the guide section according to the same embodiment. [Figure 6] This is a perspective view of the guide section relating to a modified example of this disclosure. [Figure 7A] This is a schematic diagram of a projection-type display device including a link mechanism according to the same embodiment. [Figure 7B] This is a schematic diagram of a projection-type display device including a link mechanism according to the same embodiment. [Figure 7C] This is a schematic diagram of a projection-type display device including a link mechanism according to the same embodiment. [Figure 8A]It is a schematic diagram of a projection display device including a link mechanism according to a modification of the present disclosure. [Figure 8B] It is a schematic diagram of a projection display device including a link mechanism according to a modification of the present disclosure. [Figure 8C] It is a schematic diagram of a projection display device including a link mechanism according to a modification of the present disclosure. [Figure 9] It is a schematic cross-sectional view of a housing near a window portion according to a modification of the present disclosure.

Embodiments for Carrying Out the Invention

[0009] A projection display device according to an embodiment of the present disclosure will be described with reference to the drawings. As shown in FIG. 1, the projection display device 100 is mounted on the vehicle 200. In this example, the projection display device 100 is mounted on the side mirror 201 of the vehicle 200. The projection display device 100 projects a projection image PI onto the projection surface PL by projecting projection light L onto the projection surface PL. The projection image PI is an image including characters, figures, symbols, etc. The projection surface PL is, for example, a road surface or the interior of the vehicle. The projection display device 100 is configured to be able to change the projection direction of the projection light L. The projection display device 100 can switch the display position of the projection image PI between the road surface and the interior of the vehicle by changing the projection direction of the projection light L. Note that the projection display device 100 may be mounted on other parts of the vehicle 200 than the side mirror 201 of the vehicle 200. For example, it may be mounted on the vehicle body of the vehicle 200, the interior of the vehicle (ceiling surface or dashboard), above the rear glass of the vehicle 200, etc. Also, the projection surface PL is not limited to, for example, the road surface and the interior of the vehicle, and may be the vehicle body or the glass surface of the vehicle 200. Furthermore, in the above example, the projection display device 100 changed the location of the projection surface PL between the road surface and the interior of the vehicle by changing the projection direction of the projection light L, but it may also only move the display position of the projection image PI on the same projection surface PL (only the road surface if it is the road surface). Furthermore, the vehicle 200 is not limited to a four-wheel vehicle, and may be a two-wheel vehicle or the like.

[0010] As shown in FIG. 2, the projection display device 100 includes a projector 10, a mirror 20, a projector drive unit 30, a link mechanism 40, a control unit 50, and a housing 60. In the following description, the traveling direction of the projection light L emitted by the projector 10 is defined as the X direction, the traveling direction of the projection light L reflected by the mirror 20 is defined as the Y direction, and the direction orthogonal to the X direction and the Y direction is defined as the Z direction.

[0011] The housing 60 is made of a light-shielding resin or metal and houses the projector 10, the mirror 20, the projector drive unit 30, the link mechanism 40, and the control unit 50. The housing 60 has an opening 61 that is a through hole communicating the inside and outside of the housing 60. The projection light L passes through the opening 61. The housing 60 includes a window portion 62 that closes the opening 61. The window portion 62 is formed in a plate shape from a light-transmissive resin or glass, and the projection light L passes therethrough. The window portion 62 is provided at a position of the housing 60 facing the projection surface PL (see FIG. 1).

[0012] The projector 10 emits the projection light L in the X direction under the control of the control unit 50. The projector 10 may be any of a liquid crystal method, a DLP (Digital Light Processing) method, and an LCOS (Liquid crystal on silicon) method.

[0013] The mirror 20 reflects the projection light L from the projector 10 toward the window portion 62 in the Y direction. The mirror 20 is a convex mirror convex in the Y direction and reflects the reflected projection light L so as to spread it. The mirror 20 is formed to extend in the Z direction. Note that the mirror 20 is not limited to this, and the mirror 20 may be convex in the Z direction.

[0014] The projector drive unit 30 linearly moves the projector 10 in the X direction under the control of the control unit 50. The projector drive unit 30 includes a motor (not shown) and a conversion mechanism that converts the rotational motion of the motor into a linear motion. The projector drive unit 30 may also be a solenoid.

[0015] The control unit 50 controls the projector drive unit 30 and the projector 10. The control unit 50 consists of a CPU (Central Processing Unit), a GDC (Graphics Display Controller), ROM (Read Only Memory), RAM (Random Access Memory), and the like.

[0016] As shown in Figures 2, 3A, 3B, and 3C, the projector 10 is moved in the X direction between different positions P1, P2, and P3 by the projector drive unit 30. Position P1 is located between positions P2 and P3 in the X direction. Position P3 is located further back from the mirror 20 than position P1, and position P2 is located further forward from the mirror 20 than position P1. For example, the distance from position P1 to position P3 is set to be longer than the distance from position P1 to position P2.

[0017] As shown in Figures 5, 7A, 7B, and 7C, the link mechanism 40 rotates the mirror 20 around the rotation axis AX as the projector 10 moves. The rotation axis AX extends in the Z direction. The rotation axis AX is located at the lower end of the mirror 20 (the end closer to the window portion 62). The link mechanism 40 is provided on both sides of the projector 10 in the Z direction. The link mechanism 40 may also be provided on one side of the projector 10.

[0018] The link mechanism 40 comprises a guide section 41, a link rod section 42, and a shaft section 43. As shown in Figure 5, the guide portion 41 has a guide hole 41A that is elongated in the X direction. The shaft portion 43 is inserted into the guide hole 41A so as to be movable in the X direction. The shaft portion 43 is cylindrical and fixed to the projector 10.

[0019] As shown in Figures 7A, 7B, and 7C, the link rod portion 42 includes ends 42A and 42B. The end portion 42A of the link rod 42 is connected to a position away from the rotation axis AX of the mirror 20, in this example, to the end furthest from the rotation axis AX of the mirror 20, so as to be rotatable relative to it. The end portion 42B of the link rod portion 42 is slidably and rotatably inserted into the cylindrical shaft portion 43.

[0020] As the projector 10 moves between positions P1, P2, and P3, the shaft portion 43 moves in the X direction along the guide hole of the guide portion 41. This changes the angle between the link rod portion 42 and the mirror 20, thereby changing the mirror angle.

[0021] As shown in Figure 3A, when the projector 10 is at position P1, the mirror angle θ of the mirror 20 is set to 0° as the reference angle. The mirror angle θ is set to be positive when the reflective surface of the mirror 20 moves away from the window 62 or the projector 10 from 0° (clockwise in Figure 3A, etc.), and negative when the reflective surface of the mirror 20 moves towards the window 62 or the projector 10 from 0° (counterclockwise in Figure 3A, etc.). When the mirror angle θ is 0°, the folding angle α of the projected light L at mirror 20 is 90° (see Figure 3A). As the mirror angle θ increases, the folding angle α decreases (see Figure 3C), and as the mirror angle θ decreases, the folding angle α increases (see Figure 3B). By changing the folding angle α, the projection direction of the projected light L can be changed, and consequently, the projection area onto which the projected light L can be projected can be expanded.

[0022] As shown in Figure 3B, when the projector 10 is at position P3, the mirror angle θ of the mirror 20 becomes a negative angle. As shown in Figure 3C, the mirror 20 has a positive angle θ when the projector 10 is at position P2.

[0023] As shown in Figures 3A to 3C, the link mechanism 40 moves the projector 10 relative to the mirror 20 so that, regardless of the change in the mirror angle θ, the change in the shape and position of the optical cross-section LC of the projected light L within the opening 61 is minimized, as shown in Figure 4A. The optical cross-section LC is the shape obtained when the projected light L is cut by the XZ plane within the window 62. The optical cross-section LC is positioned within the window 62 with a margin A. The change in the shape of the optical cross-section LC includes the change in the size of the optical cross-section LC. In other words, the positions P1, P2, and P3 of the projector 10 are set according to the mirror angle θ so that the change in the shape and position of the optical cross-section LC is minimized. As the mirror angle θ changes to move closer to the projector 10 and the window section 62, the projector 10 moves away from the mirror 20. This suppresses large changes in the distance between the projector 10 and the mirror 20 even when the mirror angle θ changes.

[0024] In the comparative example where the projector 10 does not move, when the mirror angle θ changes, as shown in Figure 4B, the size of the optical cross-section LC in the window 62 increases, or the optical cross-section LC extends beyond the window 62. In this embodiment, however, because the projector 10 and the mirror 20 are linked, the optical cross-section LC always remains within the window 62 even when the projection direction of the projected light L changes.

[0025] (effect) According to the embodiment described above, the following effects are achieved. (1) The projection display device 100 includes a projector 10 that emits projection light L, a mirror 20 that reflects the projection light L in the projection direction, a projector drive unit 30 and a link mechanism 40 which are examples of drive units that rotate the mirror 20 around a rotation axis AX in order to change the projection direction of the projection light L while moving the position of the projector 10 relative to the mirror 20, and a housing 60 which houses the projector 10, the mirror 20, the projector drive unit 30 and the link mechanism 40 and has an opening 61 through which the projection light L traveling in the projection direction passes. The projector drive unit 30 and the link mechanism 40 move the position of the projector 10 as the mirror 20 rotates so that the change in the shape and position of the optical cross section LC obtained by cutting the projection light L passing through the opening 61 in a direction intersecting the optical axis direction of the projection light L is small. With this configuration, while the projection area of ​​the projected light L is widened by rotating the mirror 20, the change in the shape of the optical cross-section LC at the aperture 61 is reduced by moving the mirror 20 and the projector 10 in conjunction, thereby suppressing an increase in the size of the aperture 61. Furthermore, even when the mirror 20 rotates, the changes in the shape (including size) and position of the optical cross-section LC are minimized, thus suppressing a decrease in the display quality of the projected image PI. Furthermore, by reducing the size of the opening 61, the inside of the housing 60 becomes less visible from the outside, thereby enhancing the design of the projection display device 100. In addition, the area that appears dazzling from outside the housing 60 can be narrowed.

[0026] (2) The drive unit includes a link mechanism 40 that transmits force between the mirror 20 and the projector 10. The link mechanism 40 transmits the force of the projector 10's movement to the mirror 20, causing the mirror 20 to rotate. This configuration eliminates the need for separate actuators to drive the mirror 20 and the projector 10, thus simplifying the configuration and control. Because projector 10 is larger than mirror 20, the force used to move projector 10 can stably rotate mirror 20.

[0027] This disclosure is not limited to the embodiments and drawings described above. Modifications (including the deletion of components) can be made as appropriate, provided they do not alter the essence of this disclosure. An example of such a modification is described below.

[0028] (modified version) In the above embodiment, the mirror 20 was a convex mirror, but it is not limited to a convex mirror; it may be a flat mirror, a concave mirror, or a free-form mirror. For example, as shown in Figures 8A, 8B, and 8C, the mirror 120 is a concave mirror, which is a free-form surface. The mirror 120 reflects the projected light L from the projector 10, and the reflected projected light L intersects at the cross point CP near the window 62. The cross point CP is the cross point of the outermost light beam in the optical cross section LC, which is perpendicular to the optical axis of the projected light L. As shown in Figure 9, the cross point CP is located inside the opening 61 or inside the window section 62. By locating the cross point CP near the opening 61 in this way, the size of the window section 62 can be reduced. Furthermore, the crossing point CP is distributed within the distribution range AR across the entire optical cross-section LC perpendicular to the optical axis of the projected light L. The distribution range AR of the crossing point CP overlaps with at least a portion of the window portion 62. In this way, by positioning the crossing point CP near the opening 61, the size of the window portion 62 can be reduced. In this example, the projected light L was crossed when viewed from the Z direction, but instead of this, or in addition to this, the projected light L may be crossed when viewed from the X direction or the Y direction. The modifications described above produce the following effects. The mirror 20 is a free-form surface that is concave in at least one direction, the Y direction, and causes the reflected projected light L to propagate while crossing near the aperture 61. This configuration allows for a reduction in the size of the opening 61.

[0029] In the above embodiment, the projector 10 moved linearly in the X direction, but it may also move in a curved direction in the X direction. When the projector 10 moves in a curved direction in the X direction, the guide portion 141 may be curved in the X direction, as shown in Figure 6. The guide portion 141 may include two straight portions 47A and 47B located at both ends in the X direction, and a curved portion 47C between the two straight portions 47A and 47B. In this case, the shaft portion 43 moves together with the projector along the curved guide hole 141A of the guide portion 141. By making the shape of the guide hole 141A of the guide section 141 conform to the movement trajectory of the end portion 42A (see Figures 7A to 7C), the relative position of the projector 10 and the mirror 20 does not change significantly, thereby maintaining the imaging conditions and enabling the projection of a stable projected image PI.

[0030] In the above embodiment, the rotation axis AX of the mirror 20 was located at the lower end of the mirror 20 (the end on the window portion 62 side), but it may be located at other locations, for example, at the center or upper end of the mirror 20 in the Y direction. Furthermore, although the end 42A of the link rod portion 42 was connected to the upper end of the mirror 20 (the end on the window portion 62 side), it may be connected to any position on the mirror 20 as long as it is away from the rotation axis AX. For example, in the modified examples shown in Figures 8A, 8B, and 8C, the end 42A of the link rod portion 42 is connected to approximately the center of the mirror 20 in the Y direction.

[0031] In the above embodiment, the projection display device 100 was equipped with a projector drive unit 30 for moving the projector 10, but the projector drive unit 30 may be replaced with a mirror drive unit for rotating the mirror 20. In this case, the link mechanism 40 may transmit the rotational force of the mirror 20 as the moving force of the projector 10. In the above embodiment, the projection display device 100 was equipped with one mirror 20, but it may be equipped with multiple mirrors that guide the projected light L to the window portion 62. In the above embodiment, the window portion 62 may be omitted, and the projected light L may pass through the opening 61 of the housing 60. In the above embodiment, the link mechanism 40 may be omitted. In this case, the mirror 20 and the projector 10 may be moved by separate actuators. [Explanation of Symbols]

[0032] 10…Projector 20,120…Mirror 30…Projector drive unit 40...Link mechanism, 41,141...Guide section, 41A,141A...Guide hole, 42...Link rod section, 42A,42B...End section, 43...Shaft section, 47A,47B...Straight section, 47C...Curved section 50…Control Unit 60...Housing, 61...Opening, 62...Window section 100...Projection display device 200...vehicle, 201...side mirror θ…Mirror angle, α…Folding angle, A…Margin, L…Projected light, P1, P2, P3…Position, LC…Light cross section, CP…Crossing point, AR…Distribution range, PI…Projected image, AX…Rotation axis, PL…Projected surface

Claims

1. A projector that emits projected light, A mirror that reflects the projected light in the projection direction, A drive unit that rotates the mirror to change the projection direction of the projected light while moving the position of the projector relative to the mirror, The system comprises a housing having an opening through which the projected light traveling in the projection direction passes, and housing the projector, the mirror, and the drive unit, The drive unit moves the position of the projector as the mirror rotates, such that the change in the shape and position of the cross-section obtained by cutting the projected light passing through the opening in a direction intersecting the optical axis of the projected light is minimized. Projection type display device.

2. The aforementioned mirror is a planar mirror, a concave mirror, a convex mirror, or a free-form mirror. The projection display device according to claim 1.

3. The mirror is a free-form surface that is concave in at least one direction, and causes the reflected projected light to travel while crossing near the opening. The projection display device according to claim 1.

4. The drive unit includes a link mechanism that transmits force between the mirror and the projector. The link mechanism transmits the force of the projector's movement to the mirror, causing the mirror to rotate, or transmits the force of the mirror's rotation to the projector, causing the projector to move. A projection display device according to any one of claims 1 to 3.

Images