JPWO2020059620A1 - Display device - Google Patents

Abstract

To provide a display device capable of projecting a clear virtual image while having depth. The display device (10) includes a case (20) and a light field display (30) housed in the case (20) and emitting light. The display device (10) projects the light emitted from the light field display (30) onto a display unit (Fr) arranged outside the case (20), and displays a virtual image (I) on the viewer (Mn). Make it visible. The display device (10) has light-shielding portions (21) and (22) that prevent external light reflected inside the case (20) from being projected and leaking to the outside of the case (20).

Description

The present invention relates to a display device capable of projecting light onto a display unit to provide information.

Some vehicles are equipped with a display device (head-up display device) that provides necessary information to the driver (viewer) by projecting light onto a display unit such as a windshield. As such a conventional technique for a display device, there is a technique disclosed in Patent Document 1.

The display device shown in Patent Document 1 includes a projector that emits light, a screen through which the light emitted from the projector passes, and a case that houses these projectors and the screen. ..

The projector is a projector provided with an optical element such as a DMD (Digital Mirror Device).

The screen is a transmissive screen that is located at the imaging position of the light emitted from the projector. The surface through which the light of the screen passes is provided so as to be inclined with respect to the surface from which the light of the projector is emitted. That is, the screen is provided at an angle with respect to the optical axis of the light emitted from the projector.

Since the surface through which the light of the screen passes is provided so as to be inclined with respect to the surface from which the light of the projector is emitted, the driver can recognize a deep virtual image.

Japanese Unexamined Patent Publication No. 2016-212338

In the display device of Patent Document 1, the surface through which the light of the screen passes is inclined with respect to the surface from which the light of the display means is emitted. Therefore, a part of the screen may deviate from the imaging position of the light emitted from the projector. As a result, the virtual image may become unclear.

An object of the present invention is to provide a display device capable of projecting a clear virtual image while having a depth.

According to the invention of claim 1, it has a case and a light field display housed in the case and emitting light.
A display device that projects light emitted from the light field display onto a display unit arranged outside the case to allow a viewer to visually recognize a virtual image.
Provided is a display device having a light-shielding portion that prevents external light incident from the outside of the case and reflected inside the case from being projected and leaking to the outside of the case.

As described in claim 2, preferably, the light field display is arranged at an angle so as to prevent the external light from being reflected toward the display unit.

According to the first aspect of the present invention, the display device is designed to project the light emitted from the light field display onto a display unit arranged outside the case so that the viewer can visually recognize the virtual image. The light field display continuously emits light having different imaging positions from one end to the other end of the light emitting surface of the light field display, so that a viewer can visually recognize a three-dimensional virtual image. That is, the light field display itself can emit light that projects a deep virtual image. Therefore, it is not necessary to use optical components (projector and screen) or the like as shown in Patent Document 1 in order to project a deep virtual image. Therefore, there is no problem that a part of the screen is removed from the position where the light is formed. As a result, it is possible to provide a display device capable of allowing a viewer to visually recognize a clear image while having a depth.

In addition, the display device has a light-shielding portion that prevents external light incident from the outside of the case and reflected inside the case from being projected and leaking to the outside of the case. Since the case has a light-shielding portion, the external light reflected inside the case is incident on the light-shielding portion and blocked by the light-shielding portion. That is, it is suppressed that the external light incident in the case leaks to the outside. As a result, it is possible to suppress the phenomenon that external light is projected onto the display unit and the visibility of the virtual image is lowered.

In the invention according to claim 2, the light field display is arranged at an angle so as to prevent external light incident from the outside of the case from being reflected toward the display unit. That is, the light field display is tilted so that the light incident on the light field display does not leak to the outside of the case. As a result, the external light incident on the light field display is reflected toward the light-shielding portion. That is, a blocking portion for blocking light is provided on the optical path of the external light reflected by the light field display. As a result, it is possible to more reliably suppress that the external light incident in the case leaks to the outside. That is, it is possible to more reliably suppress the phenomenon that external light is projected onto the display unit and the visibility of the virtual image is lowered.

It is sectional drawing of the display device according to the Example of this invention. It is a perspective view of the light field display shown in FIG. It is a figure explaining the virtual image projected by the light emitted from the light field display shown in FIG. It is a figure explaining the operation of this invention.

Embodiments of the present invention will be described below with reference to the accompanying drawings. In the explanation, the left and right refer to the left and right with respect to the occupant of the vehicle, and the front and rear refer to the front and rear with reference to the traveling direction of the vehicle. In the figure, Fr is the front, Rr is the rear, Le is the left when viewed from the occupant, Ri is the right when viewed from the occupant, Up is the top, and Dn is the bottom.
<Example>

See FIG. The display device 10 is mounted on the vehicle Ve, for example, and projects light onto the windshield Fr (display unit Fr) at the front of the vehicle body. By projecting light onto the windshield Fr, the driver Mn (viewer Mn) recognizes that the image I (virtual image I) is projected in front of the windshield Fr.

The upper part of the image I projected by the display device 10 is tilted toward the front side of the vehicle Ve. By including information such as vehicle speed and navigation information in the image I whose upper portion is tilted, the driver Mn can obtain necessary information during traveling.

The display device 10 emits light from a box-shaped case 20, a light field display 30 fixed in the case 20 and emitting light, a heat sink 11 in contact with the light field display 30, and a light field display 30. It has a plane mirror 40 that reflects the light, a concave mirror 50 that reflects the light reflected by the plane mirror 40 toward the front glass Fr, and a control unit 12 that controls the light emitted by the light field display 30. There is.

The case 20 has a lower case 21 having an open upper portion, an upper case 22 covered with the lower case 21, and a cover 23 fitted in the upper case 22 and made of a transparent resin. .. The case 20 houses a light field display 30, a plane mirror 40, and a concave mirror 50.

The lower case 21 and the upper case 22 are made of a synthetic resin having a light-shielding property. Therefore, it can be said that the lower case 21 and the upper case 22 are light-shielding portions 21 and 22 that prevent the light incident on the light field display 30 from the outside from being reflected in the vehicle interior. Further, the inner wall 20a of the case 20 can be referred to as light-shielding portions 21 and 22. Details of the light-shielding portions 21 and 22 will be described later.

See FIGS. 2 and 3. The light field display 30 includes a display 31 provided on the heat sink 11 and emitting light, a lens array 32 in which a plurality of lenses 32b through which the light emitted from the display 31 passes are arranged, and these lens arrays. 32 and an outer edge wall portion 33 surrounding the outer edge of the display 31 are included.

For the display 31, for example, a flat display can be used. The display 31 has a plurality of pixels 31a that emit light toward the lens array 32. The light emitted by the display 31 is a bundle of light emitted by each pixel 31a.

Each pixel 31a is composed of red, green, and blue sub-pixels. When the sub-pixels emit light, light is emitted toward each lens 32b. By combining the light emission of each sub-pixel, the brightness, hue, and saturation of the light emitted from the pixel 31a can be made different.

The lens array 32 has a flat plate-shaped base plate portion 32a and a lens 32b which is arranged in a plurality of plates on the base plate portion 32a and through which light emitted from the pixels 31a passes.

See FIG. The lens array 32 refracts the light emitted from each pixel 31a in a predetermined direction. The lens array 32 is tilted toward the light-shielding portions 21 and 22 so as to reflect the external light incident on the lens array 32 from the outside of the case 20 (see FIG. 1) toward the light-shielding portions 21 and 22. The lens array 32 is made of, for example, fused silica, optical glass, plastic, or the like.

The base plate portion 32a is provided parallel to the surface of the display 31 that emits light.

See FIG. The shape of the lens 32b includes, for example, a convex shape, a concave shape, a spherical shape, an aspherical shape, and the like. Each lens 32b is provided corresponding to each pixel 31a and refracts the light emitted from each pixel 31a.

The outer edge wall portion 33 is formed of a synthetic resin having a light-shielding property, and prevents external light from entering between the display 31 and the lens array 32.

Here, the light emitted by the light field display 30 refers to the light emitted from each pixel 31a (display 31) and passed through the lens array 32. That is, it can be said that the light emitted from each pixel 31a is emitted from the light field display 30 by passing through the lens array 32.

See FIGS. 1 and 3. The heat sink 11 is formed of, for example, an aluminum alloy or a copper alloy having a high thermal conductivity, and abuts on the display 31 and releases heat transferred from the display 31 to the outside (outside of the case 20). The heat sink 11 is fixed to the lower case 21 so that a part of the heat sink 11 is exposed to the outside.

See FIG. The plane mirror 40 is formed on the surface of the resin plane mirror support portion 41 fixed to the upper case 22, the plane mirror base portion 42 rotatably supported by the plane mirror support portion 41, and the plane mirror base portion 42. It is a full mirror including a plane mirror reflecting unit 43 that reflects the incident light toward the concave mirror 50.

The plane mirror reflecting unit 43 is arranged on the optical path of the light that has passed through the lens array 32. The plane mirror reflecting portion 43 is formed of, for example, a metal such as aluminum or silver formed in a thin film shape.

The concave mirror 50 was formed and incident on the surface of the concave mirror support portion 51 made of resin fixed to the lower case 21, the concave mirror base portion 52 rotatably supported by the concave mirror support portion 51, and the concave mirror base portion 52. It includes a concave mirror reflecting portion 53 that reflects light toward the front glass Fr.

The concave mirror reflecting unit 53 is arranged on the optical path of the light reflected by the plane mirror reflecting unit 43, and reflects the light reflected by the plane mirror reflecting unit 43 toward the front glass Fr. By projecting light onto the windshield Fr via the concave mirror reflecting portion 53, the image I visually recognized by the driver Mn is magnified. The plane mirror reflecting portion 43 is formed of, for example, a metal such as aluminum or silver formed in a thin film shape.

See FIGS. 1 and 3. The control unit 12 controls the direction of the light emitted by the light field display 30 so that the light passing through the lens array 32 is incident on the plane mirror 40. That is, the control unit 12 controls the light emitted by each pixel 31a so that the light that has passed through the lens array 32 goes in a predetermined direction.

The driver Mn recognizes that the light emitted from the light field display 30 is projected onto the windshield Fr to project an image I whose angle is tilted forward by θ. Such an image I is projected by forming light from the windshield Fr at different imaging positions. That is, in order for the driver Mn to visually recognize the deep image I, the light field display 30 needs to emit light having a different imaging position (light forming the image I).

The control unit 12 continuously emits light having a different imaging position from one end 32c (left end 32c in the drawing) to the other end 32d (right end 32d in the drawing) of the light field display 30. The light emitted by each pixel 31a is controlled so that the image I whose upper portion is tilted forward can be visually recognized. Further, the control unit 12 can control the light emitted from each pixel 31a to freely change the imaging position of the light emitted from the lens array 32. As a result, the tilt angle of the image I can be freely changed. By controlling the light emitted from each pixel 31a by the control unit 12, an arbitrary image I visually recognized by the driver Mn is projected.

Next, the operation of the present invention will be described.

See FIG. The display device 10 is mounted on the vehicle Ve, for example, and emits light toward the windshield Fr. When the light is projected onto the windshield Fr, the driver Mn visually recognizes an arbitrary image I projected in front of the windshield Fr. Here, the display device 10 includes a light field display 30.

See FIG. 4 (a). FIG. 4A shows a diagram in which a light field display 130 is provided with a surface that emits light directed upward. The control unit controls the light emitted by each pixel 131a so that the light field display 130 continuously emits light having a different imaging position from one end 132c to the other end 132d of the lens array 132. The light emitted from one end 132c of the lens array 132 is imaged at a position separated from the windshield Fr by a distance L1, and the light emitted from the other end 132d of the lens array 132 is separated from the windshield Fr by a distance L2. The image will be formed at the correct position. These relationships are L1 <L2. As a result, the image I tilted by an angle θ toward the traveling direction of the vehicle Ve is visually recognized.

See FIG. 4 (b). FIG. 4B shows a diagram in which external light is incident on the light field display 130 in FIG. 4A. In such a display device 110, since the light field display 130 faces the plane mirror, the external light incident on the lens array 32 may be reflected by the windshield Fr via the plane mirror. Therefore, the visibility of the image visually recognized by the driver Mn may decrease.

See FIG. 4 (c). FIG. 4C shows a diagram in which a light field display 30 is provided whose surface that emits light is inclined toward the inner wall 20a of the case 20. The control unit 12 (see FIG. 1) continuously emits light having a different imaging position from one end 32c to the other end 32d of the lens array 32, and the light emitted from the lens array 32. Controls the light emitted by each pixel 31a so that is directed in a predetermined direction. Further, the control unit 12 controls the light emitted by each pixel 31a so that the inclination of the image I is the same as in the case of FIG. 4A even when the light field display 30 is provided at an inclination. As a result, the image I tilted by an angle θ toward the traveling direction of the vehicle Ve can be visually recognized.

See FIG. 4 (d). FIG. 4D shows a diagram in which external light is incident on the light field display 30 in FIG. 4C. The lower case 21 and the upper case 22 are formed of a synthetic resin that blocks light. Therefore, it can be said that the inner wall 20a of the case 20 (lower case 21 and upper case 22) is light-shielding portions 21 and 22 that block light. Here, since the surface of the light field display 30 that emits light is tilted toward the light-shielding portions 21 and 22, the external light incident on the lens array 32 is reflected toward the light-shielding portions 21 and 22 and is reflected toward the light-shielding portions 21 and 22. It is blocked by 21 and 22. As a result, the reflection of external light toward the windshield Fr is suppressed. That is, it is possible to prevent the visibility of the image visually recognized by the driver Mn from being lowered.

Next, the effect of the present invention will be described.

See FIG. The display device 10 is designed so that the light emitted from the light field display 30 is projected onto the display unit Fr arranged outside the case 20 so that the viewer Mn can visually recognize the virtual image I. The light field display 30 continuously emits light having different imaging positions from one end 32c to the other end 32d of the surface of the light field display 30 that emits light, and makes the viewer visually recognize the three-dimensional virtual image I. be able to. That is, light that projects a deep virtual image I can be emitted from the light field display 30 itself. Therefore, it is not necessary to use optical components (projector and screen) or the like as shown in Patent Document 1 in order to project a deep virtual image I. Therefore, there is no problem that a part of the screen is removed from the position where the light is formed. As a result, it is possible to provide a display device 10 capable of allowing the viewer Mn to visually recognize a clear image I while having a depth.

In addition, the display device 10 has light-shielding portions 21 and 22 that prevent external light incident from the outside of the case 20 and reflected inside the case 20 from being projected and leaking to the outside of the case 20. Since the case 20 has the light-shielding portions 21 and 22, the external light reflected inside the case 20 is incident on the light-shielding portions 21 and 22 and blocked by the light-shielding portions 21 and 22. That is, it is suppressed that the external light incident on the case 20 leaks to the outside. As a result, it is possible to suppress the phenomenon that the external light is projected onto the display unit Fr and the visibility of the virtual image I is lowered.

Further, the light field display 30 is arranged at an angle so as to prevent external light incident from the outside of the case 20 from being reflected toward the display unit Fr. That is, the light field display 30 is tilted so that the light incident on the light field display 30 does not leak to the outside of the case 20. As a result, the external light incident on the light field display 30 is reflected toward the light-shielding portions 21 and 22. That is, the light-shielding portions 21 and 22 that block the light are provided on the light path of the external light reflected by the light field display 30. As a result, it is possible to more reliably suppress that the external light incident on the case 20 leaks to the outside. That is, it is possible to more reliably suppress the phenomenon that the external light is projected onto the display unit Fr and the visibility of the virtual image I is lowered.

The vehicle equipped with the display device according to the present invention may be a two-wheeled vehicle or a three-wheeled vehicle in addition to a four-wheeled vehicle. Furthermore, it can be applied to vehicles other than vehicles, construction machinery, and the like.

Also, the reflectors and concave mirrors shown in the examples are not essential components. That is, the reflector and / or the concave mirror can be eliminated if necessary. On the contrary, in order to increase the optical path length from the display means to the display unit, the number of reflectors and / or concave mirrors can be increased as needed.

Further, in the embodiment, the display unit is described as a windshield. However, the display device according to the present invention can also project light onto a display unit including a so-called combiner.

That is, the present invention is not limited to the examples as long as the actions and effects of the present invention are exhibited.

The display device of the present invention is suitable for mounting on a vehicle.

10 ... Display device 11 ... Heat sink 12 ... Control unit 20 ... Case 21 ... Light-shielding unit (lower case)
22 ... Shading part (upper case)
30 ... Light field display 31 ... Display 31a ... Pixel 32 ... Lens array 32b ... Lens 33 ... Outer edge wall Fr ... Display (windshield)
I ... Virtual image (image)
Mn ... Visualizer (driver)
Ve ... Vehicle

Claims (2)

It has a case and a light field display that is housed in this case and emits light.
A display device that projects light emitted from the light field display onto a display unit arranged outside the case to allow a viewer to visually recognize a virtual image.
A display device having a light-shielding portion that prevents external light incident from the outside of the case and reflected inside the case from being projected and leaking to the outside of the case. The display device according to claim 1, wherein the light field display is arranged at an angle so as to prevent the external light from being reflected toward the display unit.

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