JP2020008869A - On-vehicle display device - Google Patents

Abstract

To provide an on-vehicle display device that can clearly display a far virtual image and a near virtual image forward a vehicle.SOLUTION: A first intermediate image screen 15 and second intermediate image screen 16 are arranged forward an image projector 11. The two intermediate image screens 15 and 16 are arranged at a different position, and a near virtual image 25b is projected from the first intermediate image screen 15, and a far virtual image 25a is projected from the second intermediate image screen 16. The second intermediate image screen 16 is arranged at a focus position and, between the image projector 11 and the first intermediate image screen 15, a correction optical element 17 is arranged that corrects an optical path length.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an in-vehicle display device configured so that a viewer in a vehicle can see a virtual image formed in front of the half mirror portion through the half mirror portion.

  Patent Literatures 1 and 2 disclose inventions relating to an in-vehicle display device used as a head-up display device.

  The on-vehicle display device described in Patent Literature 1 is provided with a first screen and a second screen which are transmission screens in front of an image projector, and the first screen and the second screen are provided from the image projector. The distance is different. An optical part of a concave mirror is provided in front of the first screen and the second screen. An image projected from the video projector is formed on each of the first screen and the second screen, and the images are reflected by the optical unit and projected on a windshield or a combiner of the vehicle.

  The image formed on the first screen and the image formed on the second screen form a virtual image in front of the windshield and the combiner, and the occupant of the vehicle sees this virtual image. However, since the arrangement positions of the first screen and the second screen are different, this virtual image appears to exist at different positions in front of the vehicle.

  The image projector is provided with a red light source, a green light source, a blue light source, and a liquid crystal display to which light from each light source is applied. Further, the video projector is provided with a variable focus lens. The image is projected from the image projector to the first screen and the second screen in a time-division manner.However, since the first screen and the second screen are different in distance from the image projector, the varifocal lens is It is always running so that it can focus on both the first and second screens.

  The on-vehicle display device described in Patent Literature 2 includes a first projection lens and a second projection lens provided in front of a projector, and a first screen and a second screen provided further in front of the projector. The image projected on the first screen via the first projection lens is reflected by the reflection mirror to become a first virtual image in front of the vehicle, and the image projected on the second screen via the second projection lens is reflected by the reflection mirror. Thus, a second virtual image ahead of the vehicle is formed.

  Since the positions of the first projection lens and the first screen are fixed, the display position of the first virtual image is fixed. On the other hand, the second screen is moved in the optical axis direction by the motor, and the second projection lens is also moved in the optical axis direction following the motor, so that the display position of the second virtual image is shifted to the second position in front of the vehicle. Moves back and forth in conjunction with screen movement.

  The on-vehicle display device described in Patent Literature 1 displays the current vehicle speed of the vehicle using a first virtual image at a fixed position during traveling of the vehicle, and displays a warning for an interrupted vehicle using a second virtual image. In this warning display, a frame surrounding the interrupted vehicle is displayed, the second screen moves back and forth according to the distance between the own vehicle and the interrupted vehicle, and the display position of the warning display frame (second virtual image) is determined by the own vehicle. And move back and forth according to the distance between the vehicle and the interrupt.

JP 2015-34919 A JP-A-2005-11211

  Both of the on-vehicle display devices described in Patent Literature 1 and Patent Literature 2 can visually observe virtual images formed at different positions in front of the vehicle.

  However, in the in-vehicle display device described in Patent Literature 1, it is necessary to project an image from the image projector to the first screen and the second screen in a time-division manner, and to always operate the variable focus lens. Therefore, the video projector has a complicated structure, and the control of the video projector is also complicated.

  The on-vehicle display device described in Patent Literature 2 has a first projection lens and a second projection lens in which a circular lens is divided into two, but a projection lens in which a circular lens is divided into two. Is not easy to manufacture, and expensive lenses must be used. Further, since the first projection lens and the second projection lens are in close contact with each other and projection light is given to the two projection lenses from the projector, the positions of the first projection lens and the second projection lens are made different in the optical axis direction. Sometimes, a ghost may be formed by any of the lenses.

  The present invention solves the above-mentioned conventional problems, and provides an in-vehicle display device capable of stably forming a virtual image at different positions in front of a vehicle without complicating an optical device. It is an object.

The present invention is directed to a vehicle-mounted display device having a transmission type intermediate image screen and an image projection unit that projects an intermediate image onto the intermediate image screen and projects the intermediate image onto a half mirror unit.
A plurality of the intermediate image screens are provided, and each of the intermediate image screens has a different distance from the image projection unit,
A correction optical element for correcting an optical path length is disposed between at least one of the intermediate image screen and the image projection unit.

  In the in-vehicle display device according to the present invention, one intermediate image screen is disposed at a focus position of the image projection unit, and the correction optical element is provided between the other intermediate image screen and the image projection unit. Can be configured.

  For example, the other intermediate image screen is located at a position farther from the image projection unit than the in-focus position, and the correction optical element is a translucent member having a predetermined thickness.

  Alternatively, the other intermediate image screen is located at a position farther from the image projection unit than the in-focus position, and the correction optical element is a negative lens.

  Alternatively, the other intermediate image screen is located closer to the image projection unit than the in-focus position, and the correction optical element is a positive lens.

  In the vehicle-mounted display device according to the present invention, the first intermediate image screen and the second intermediate image screen are arranged within a range of one screen of an image that can be projected by the image projection unit.

The display device for vehicle according to the present invention forms an intermediate image on the plurality of intermediate image screens from the image projection unit. Here, a plurality of intermediate image screens exist in a displayable area of an intermediate image (a range of one screen: one frame area) which can be formed by the image projection unit, and different images are projected on each intermediate image screen. You.

  Further, since the positions of the respective intermediate image screens are different, virtual images can be formed at different positions in front of the vehicle with images transmitted through the intermediate image screen, and a viewer in the vehicle can view each virtual image. It can be recognized as existing at a different position in front of the vehicle.

  In addition, by disposing a correction optical element for correcting the optical path length between the image projection unit and the intermediate image screen, it becomes possible to form an intermediate image clearly on each of the plurality of intermediate image screens.

Explanatory diagram showing a state where the in-vehicle display device of the embodiment of the present invention is mounted on a vehicle, FIG. 2 is an explanatory diagram showing a component configuration of the vehicle-mounted display device according to the first embodiment of the present invention; Explanatory diagram showing a component configuration of a vehicle-mounted display device according to a second embodiment of the present invention, Explanatory diagram showing a component configuration of a vehicle-mounted display device according to a third embodiment of the present invention, Explanatory diagram showing a component configuration of an in-vehicle display device according to a fourth embodiment of the present invention, Explanatory diagram showing a display example by the in-vehicle display device of the embodiment of the present invention,

  FIG. 1 shows a state in which an in-vehicle display device 10 according to an embodiment of the present invention is mounted on an automobile 1 which is an example of a vehicle.

  In the automobile 1, a windshield glass 4 is mounted between the hood 2 and the ceiling 3, and the windshield glass 4 separates a cabin space 5 from an external space 6 in front of the vehicle. . The windshield glass 4 is curved, and the inner surface 4 a of the windshield glass 4 is directed to the vehicle interior space 5, and the outer surface 4 b of the windshield glass 4 is directed to the front outer space 6. In the first embodiment shown in FIG. 2 and the second embodiment shown in FIG. 3, the windshield glass 4 functions as a half mirror section having a concave curved surface.

  In the third embodiment shown in FIG. 4 and the fourth embodiment shown in FIG. 5, the combiner functions as a half mirror unit. The combiner is disposed closer to the vehicle interior than the windshield glass 4.

  A driver's seat 7 is provided in the vehicle interior space 5, and a steering wheel 8 is provided in front of the driver's seat 7. A dashboard 9 is provided in front of the cabin space 5, and the in-vehicle display device 10 according to the embodiment of the present invention is embedded and provided inside the dashboard 9. The in-vehicle display device 10 is a so-called head-up display (HUD) device.

Hereinafter, the arrangement of the optical components of the in-vehicle display device 10 will be described for each embodiment.
FIG. 2 shows a schematic structure of a vehicle-mounted display device 10A according to the first embodiment of the present invention.
An image projection unit (projector) 11 is provided on the in-vehicle display device 10A. The image projection unit 11 has an image generation member 12 and a projection lens 13. The image generating member 12 is a DLP (Digital Light Processing) element (DLP is a registered trademark). The DLP element includes a light source and a digital mirror device (DMD) that controls light from the light source for each pixel. In addition, a multi-color display image can be generated by providing a light source of three primary colors or a color filter.

  The projection lens 13 is formed of an aspherical convex lens or a combination of a plurality of lenses.

  A plurality of intermediate image screens are provided in front of the image projection unit 11. In the following embodiment, two intermediate image screens, a first intermediate image screen 15 and a second intermediate image screen 16, are provided. The first intermediate image screen 15 and the second intermediate image screen 16 are transmission screens. The intermediate image screens 15 and 16 are configured by a microlens array or a diffuser.

  As shown in FIG. 2, the distance along the projection optical axis O from the image projection unit 11 to the first intermediate image screen 15 is along the projection optical axis O from the image projection unit 11 to the second intermediate image screen 16. It is longer than the distance.

  The first intermediate image screen 15 and the second intermediate image screen 16 have different distances from the image projection unit 11, but the two intermediate image screens 15 and 16 are generated by the image generating member 12. It is arranged so as to enter the displayable area of the image of the intermediate image projected by the projection lens 13, that is, the area of one screen of the intermediate image (the one frame area of the intermediate image).

  The first intermediate image screen 15 and the second intermediate image screen 16 may be displaced in the vertical direction (Y direction) in FIG. 2 or may be arranged in a direction orthogonal to the plane of FIG. 2 (X direction). May be displaced. When viewed from the image projection unit 11 side, the lower end of the first intermediate image screen 15 and the upper end of the second intermediate image screen 16 may be in contact with each other. Alternatively, when viewed from the image projection unit 11 side, the first intermediate image screen 15 and the second intermediate image screen 16 may be separated from each other. Further, the first intermediate image screen 15 and the second intermediate image screen 16 may have the same area or may have different areas.

  FIG. 6 shows a display example of two virtual images 25 a and 25 b formed in front of the windshield glass 4. In this display example, the area of the first intermediate image screen 15 for forming the near virtual image 25b is different from the area of the second intermediate image screen 16 for generating the far virtual image 25a. The image screen 15 and the second intermediate image screen 16 are arranged apart in both the X and Y directions.

  In the image projection unit 11, the projection lens 13 and the like are designed so as to focus on the second intermediate image screen 16 located at a position close to the image projection unit 11. Therefore, a correction optical element 17 for correcting an optical path difference is arranged between the image projection unit 11 and the first intermediate image screen 15 located at a position away from the image projection unit 11.

  The correction optical element 17 shown in FIG. 2 is a translucent member such as glass or transparent synthetic resin having a predetermined thickness t in the direction along the projection optical axis O. The difference between the distance from the image projection unit 11 to the first intermediate image screen 15 and the distance from the image projection unit 11 to the second intermediate image screen 16 is ΔL, the refractive index of the correction optical element 17 is n, and the correction is The thickness of the optical element 17 in the direction along the projection optical axis O is represented by t. By setting the thickness t to t = ΔL · n / (n−1), the optical path difference ΔL can be corrected, and the first intermediate image screen 15 and the second intermediate image An intermediate image can be clearly formed on both of the image screens 16.

  By using the component having the predetermined thickness t as the correction optical element 17, it is not necessary to use an expensive lens. For example, a cover member of the unitized image projection unit 11 is used as the correction optical element 17. It is also possible.

However, in the embodiment of FIG. 2, a negative lens constituted by a concave lens or a compound lens including a concave lens is used as the correction optical element 17 for correcting the optical path difference of the first intermediate image screen 15 at a remote position. Thus, both the first intermediate image screen 15 and the second intermediate layer screen 16 may be made in focus.

  As shown in FIG. 2, a reflection member 18 is provided in front of the first intermediate image screen 15 and the second intermediate image screen 16. The reflecting member 18 is a concave mirror, and has a reflecting function, a condensing function, and an image enlarging function.

  The on-vehicle display device 10 provided in the dash board 9 has an image projection unit 11, a correction optical element 17, a first intermediate image screen 15, a second intermediate image screen 16, and a reflecting member shown in FIG. 18 are stored. The reflecting member 18 faces the windshield glass 4 of the vehicle from below.

The display operation of the in-vehicle display device 10A mounted on the vehicle 1 is as follows.
In the image projection unit 11, an intermediate image is generated by an image generation member 12 which is a DLP element, and the projection lens 13 projects the intermediate image on a first intermediate image screen 15 and a second intermediate image screen 16. The intermediate image is projected on both the first intermediate image screen 15 and the second intermediate image screen 16 within the displayable area of the image projected by the image projection unit 11. That is, an intermediate image is projected on the first intermediate image screen 15 and the second intermediate image screen 16 within the area of one screen (the range of one frame).

  The first intermediate image screen 15 is located at the in-focus position of the image projection unit 11, and the optical path length is adjusted by the correction optical element 17 on the second intermediate image screen 16 so that the image is projected. An intermediate image is clearly formed on both the first intermediate image screen 15 and the second intermediate image screen 16.

  The display light transmitted through the first intermediate image screen 15 and the second intermediate image screen 16 is totally reflected while the image is enlarged by the reflection member 18, and is directed to the windshield glass 4.

  The windshield glass 4 functions as a slightly curved half mirror portion. The light totally reflected by the reflection member 18 is irradiated on the inner surface 4 a of the windshield glass, and a part of the light is focused toward the eyes 21 of a viewer (driver) 20 seated in the driver's seat 7. Is done. As a result, it becomes possible for the eye 21 to visually recognize the virtual image 25 in the external space 6 in front of the windshield glass 4. The imaging position of the virtual image 25 is determined by the focal length of the projection lens 13, the curvature of the reflection member 18, and the like.

  The projection path L1 from the first intermediate image screen 15 via the reflection member 18 to the windshield glass 4 is shorter than the projection path L2 from the second intermediate image screen 16 via the reflection member 18 to the windshield glass 4. ing. Therefore, the near virtual image 25b is formed at a position close to the front of the external space 6 from the windshield glass 4 by the display light transmitted through the first intermediate image screen 15 and directed to the windshield glass 4 via the projection path L1. Image. Further, the display light transmitted through the second intermediate image screen 16 and directed to the windshield glass 4 via the projection path L2 forms a distant virtual image 25a at a position away from the windshield glass 4 in the front external space 6. Image.

  The image generating member 12 used in the in-vehicle display device 10 uses a spatial optical modulation element such as an LCOS instead of the DLP element, and includes a first intermediate image screen 15 and a second intermediate image screen. A hologram image may be generated on the image screen 16. Further, a fine galvanometer mirror composed of a MEMS element can be used as the image generating member 12. The galvanometer mirror generates an image for one screen (one frame) by scanning the visible light laser vertically and horizontally.

FIG. 6 shows a display example of images of the far virtual image 25a and the near virtual image 25b.
In FIG. 6, the X direction is a horizontal direction as viewed from the viewer 20, and the Y direction is a vertical direction as viewed from the viewer 20.

  FIG. 6 shows the displayable area 31 as an area surrounded by a chain line. The displayable area 31 corresponds to one screen (one frame) of the image projected by the image projection unit 11. By including the far virtual image 25a and the near virtual image 25b in the displayable area 31 for one screen, both the virtual images 25a and 25b can be made clear images.

  In the display example shown in FIG. 6, the distant virtual image 25a is displayed on a forward extension of a center line F extending in the front-rear direction of the vehicle through the center of the steering wheel 8. This coincides with the center of the visual field range when the viewer 20 looks at the front. The near virtual image 25b is located at a position deviated from the center line F, that is, a position deviated from the center of the visual field range when the viewer 20 looks at the front.

  Further, the area of the display area of the near virtual image 25b visually recognized by the viewer 20 is smaller than the area of the display area of the far virtual image 25a.

  Examples of the information displayed as the distant virtual image 25a are a display 41 of the vehicle traveling speed and an arrow display 42 indicating a vehicle traveling instruction. An example of the information displayed as the near virtual image 25b is the car navigation display 43 or the like. Alternatively, in the near virtual image 25b, an energy display indicating a gasoline remaining amount and a power remaining amount, a cumulative mileage display, an engine speed display (tachometer display), a clock display, a temperature display inside and outside a vehicle, a warning display for wearing a seat belt are displayed. May be displayed.

FIG. 3 shows a schematic structure of an in-vehicle display device 10B according to a second embodiment of the present invention.
In the following embodiments, the same components as those of the in-vehicle display device 10A of the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

  In the in-vehicle display device 10B shown in FIG. 3, the first intermediate image screen 15 is disposed at an image forming position of light projected by the image projecting unit 11, that is, at a focusing position. A positive lens composed of a convex lens or a compound lens including a convex lens is used as the correction optical element 27 for correcting the optical path length between the second intermediate image screen 16 and the image projection unit 11.

  Also in the in-vehicle display device 10B, a clear intermediate image in a focused state is formed on both the first intermediate image screen 15 and the second intermediate image screen 16 having different distances from the image projection unit 11. be able to.

FIG. 4 shows a schematic structure of a vehicle-mounted display device 10C according to a third embodiment of the present invention.
In the in-vehicle display device 10C, a combiner 28 is disposed as a half mirror portion inside the windshield glass 4 in the vehicle interior space 5 of the vehicle. The combiner 28 has a structure such as a combination of a Fresnel lens and a half mirror. The combiner 28 has a condensing point on the reflection side, and as a result, the far virtual image 25a and the near virtual image 25b of the external space 6 can be seen by the eyes 21 of the viewer 20.

  The projection optical axis O of the image projection unit 11 is directed obliquely upward and directed to the combiner 28. The second intermediate image screen 16 is arranged at the in-focus position of the image projection unit 11, and the first intermediate image screen 15 is more distant from the image projection unit 11 than the second intermediate image screen 16. In position. A translucent member, which is the same correction optical element 17 as shown in FIG. 2, is disposed between the image projection unit 11 and the first intermediate image screen 15. Thereby, the intermediate image projected from the image projection unit 11 can be focused and formed on both the first intermediate image screen 15 and the second intermediate image screen 16.

In FIG. 4, a negative lens serving as the correction optical element 17 may be used.
In the in-vehicle display device 10C shown in FIG. 4 as well, a near virtual image 25b is formed by the intermediate image formed on the first intermediate image screen 15, and a far virtual image is formed by the intermediate image formed on the second intermediate image screen 16. 25a are formed.

FIG. 5 shows a schematic structure of an in-vehicle display device 10D according to a fourth embodiment of the present invention.
In the in-vehicle display device 10D, the first intermediate image screen 15 is located at the in-focus position of the image projection unit 11, and a correction optical element 27 is provided between the image projection unit 11 and the second intermediate image screen 16. The same positive lens as in the third embodiment is provided.

  The on-vehicle display element 10 according to each of the above-described embodiments includes a first intermediate image screen 15 and a second intermediate image Since the image screens 16 face each other, an intermediate image can be projected onto the intermediate image screens 15 and 16 almost simultaneously. Therefore, complicated control such as alternately projecting an image onto a plurality of intermediate image screens is not required. Further, even when the distance between the image projection unit 11 and the intermediate image screens 15 and 16 is changed to form the distant virtual image 25a and the near virtual image 25b, all the intermediate images can be obtained by using the correction optical elements 17 and 27. A clear intermediate image can be generated on the screen.

  In the above embodiment, two intermediate image screens are used, but three or more intermediate image screens may be used.

Reference Signs List 1 automobile 4 windshield glass 5 cabin space 6 external space 10, 10A, 10B, 10C, 10D in-vehicle display device 11 image projection unit 12 image generation member 13 projection lens 15 first intermediate image screen 16 second intermediate image Screens 17 and 27 Correcting optical element 18 Reflecting member 20 Viewer 25 Virtual image 25a Far image 25b Near image 31 Displayable area

The present invention is directed to a vehicle-mounted display device having a transmission type intermediate image screen and an image projection unit that projects an intermediate image onto the intermediate image screen and projects the intermediate image onto a half mirror unit.
Said intermediate image screen is provided with a plurality, each of the intermediate image screen is the distance differences from the image projection unit, between at least one of said intermediate image screen wherein the image projection unit, to correct the optical path length Correction optics are arranged,
A plurality of the intermediate image screens are displaced in at least one of a vertical direction and a horizontal direction within a range of one screen of an image that can be projected by the image projection unit .
In addition, the present invention is a transmission type intermediate image screen, and an image projection unit that projects an intermediate image onto the intermediate image screen and projects the intermediate image onto a half mirror unit,
A plurality of the intermediate image screens are provided, each of the intermediate image screens has a different distance from the image projection unit, and an optical path length is corrected between at least one of the intermediate image screens and the image projection unit. Correction optical elements are arranged, and distances from the half mirror portion of a plurality of virtual images displayed in front of the half mirror by the respective intermediate image screens are different from each other,
The plurality of virtual images are displaced in at least one of the vertical direction and the horizontal direction within a range of one screen of an image that can be projected by the image projection unit.

The second intermediate image screen 16 is located at the in-focus position of the image projecting unit 11, and the optical path length is adjusted by the correction optical element 17 on the first intermediate image screen 15 so that the image is projected. An intermediate image is clearly formed on both the first intermediate image screen 15 and the second intermediate image screen 16.

Claims (6)

A transmission type intermediate image screen, and an image projection unit that projects the intermediate image onto the intermediate image screen and projects the intermediate image onto a half mirror unit,
A plurality of the intermediate image screens are provided, and each of the intermediate image screens has a different distance from the image projection unit,
A vehicle-mounted display device, wherein a correction optical element for correcting an optical path length is disposed between at least one of the intermediate image screen and the image projection unit.   2. The on-vehicle vehicle according to claim 1, wherein one intermediate image screen is disposed at a focus position of the image projection unit, and the correction optical element is provided between another intermediate image screen and the image projection unit. Display device.   3. The in-vehicle display device according to claim 2, wherein the other intermediate image screen is located at a position farther from the image projection unit than a focus position, and the correction optical element is a translucent member having a predetermined thickness.   The in-vehicle display device according to claim 2, wherein the other intermediate image screen is located at a position farther from the image projection unit than a focus position, and the correction optical element is a negative lens.   3. The in-vehicle display device according to claim 2, wherein the other intermediate image screen is located at a position closer to the image projection unit than a focus position, and the correction optical element is a positive lens.   The in-vehicle display according to any one of claims 1 to 5, wherein the first intermediate image screen and the second intermediate image screen are arranged within a range of one screen of an image that can be projected by the image projection unit. apparatus.

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