JP2018180291A - Display device for vehicles - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display device for vehicles with which it is possible to reduce the distortion of a display image.SOLUTION: A display device 1A for vehicles comprises: an image display device 3 for emitting display light 11 that corresponds to a display image to be visually recognized by a driver 200 of a vehicle 100; a reflection mirror 7 for reflecting the display light 11 and projecting a display image to a reflection unit 102 of a windshield 101 of the vehicle 100; and a light conductor 5 arranged in an optical path between the image display device 3 and the reflection mirror 7 and constituted by being arranged in plurality in a direction that a light guide path 61 for guiding a portion of the display light 11 along the optical path intersects at right angles. The light conductor 5 includes a light conductor emission surface 5b for emitting the guided display light 11, the light conductor emission surface 5b being a curved surface formed in a convex shape toward the reflection mirror 7 side.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a display device for a vehicle.

  Conventionally, in a display device for a vehicle such as a head up display (HUD: Head Up Display) device, distortion may occur in a display image mainly due to an aberration generated by a windshield or an optical system having a free curved surface shape. . As a method of correcting the distortion of the display image, for example, techniques described in Patent Documents 1 to 3 have been proposed.

  Patent Document 1 discloses a head-up display device that reduces a three-dimensional distortion of a virtual image caused by an aberration by a screen having an imaging surface formed in a convex shape.

  Patent Document 2 discloses an image display apparatus in which a plano-convex cylindrical lens is disposed in an optical path between a display and a concave mirror to reduce an aberration caused by the concave mirror.

  Patent Document 3 discloses a projection display apparatus for a vehicle which utilizes a thin plate-shaped flexible display device in a curved state.

Patent No. 5370427 gazette JP, 2010-224016, A JP, 2015-230329, A

  In recent years, with the evolution of in-vehicle systems, information required during driving has increased, and there is a need to simultaneously display more information, which requires a larger display screen for a vehicle display device. However, as the display screen becomes larger, distortion of the display image tends to be large, and there is room for improvement.

  An object of the present invention is to provide a display device for a vehicle capable of reducing distortion of a display image.

  In order to achieve the above object, a display device for a vehicle according to the present invention includes an image display device for emitting display light corresponding to a display image to be visually recognized by a driver of the vehicle, and a window of the vehicle by reflecting the display light. A reflective mirror for projecting the display image on a reflective portion of the shield, and a light guide disposed in an optical path between the image display device and the reflective mirror and guiding a portion of the display light along the optical path And a light guide formed by arranging a plurality of light paths in a direction perpendicular to the light path, the light guide having a light exit surface for emitting the guided display light, and the light exit surface is the light guide. It is characterized in that it is a curved surface formed in a convex shape toward the reflection mirror side.

  In the vehicle display device, it is preferable that the emission surface is a convex curved surface formed such that the display image displayed on the image display device matches the display image.

  In the above-described display device for a vehicle, it is preferable that the light guide be formed by bringing a plurality of transparent columnar members into close contact with each other in a direction orthogonal to the light path.

  In the display device for a vehicle, the reflection mirror preferably includes a spherical mirror having a curved surface formed in a concave shape.

  The display apparatus for a vehicle according to the present invention has an effect that distortion of a display image can be reduced.

FIG. 1 is a view showing an arrangement example of a display device for a vehicle according to the embodiment. FIG. 2 is a perspective view showing a schematic configuration of a display unit according to the embodiment. FIG. 3 is a partial perspective view showing a schematic configuration of the light guide according to the embodiment. FIG. 4 is a perspective view showing a schematic configuration of the image display device according to the embodiment. FIG. 5 is a perspective view showing a schematic configuration of a display unit according to the embodiment. FIG. 6 is a view showing an arrangement example of a display device for a vehicle according to a modification of the embodiment.

  Hereinafter, an embodiment of a display device for a vehicle according to the present invention will be described in detail with reference to the drawings. The present invention is not limited by this embodiment. In addition, constituent elements in the following embodiments include those that can be easily conceived by those skilled in the art or those that are substantially the same. Moreover, various omissions, replacements, and changes can be made to the components in the following embodiments without departing from the scope of the invention.

[Embodiment]
FIG. 1 is a view showing an arrangement example of a display device for a vehicle according to the embodiment. FIG. 2 is a perspective view showing a schematic configuration of a display unit according to the embodiment. FIG. 3 is a partial perspective view showing a schematic configuration of the light guide according to the embodiment. FIG. 4 is a perspective view showing a schematic configuration of the image display device according to the embodiment. FIG. 5 is a perspective view showing a schematic configuration of a display unit according to the embodiment. FIG. 6 is a view showing an arrangement example of a display device for a vehicle according to a modification of the embodiment. FIGS. 1 and 6 are diagrams showing the positional relationship between elements when a vehicle equipped with a display device for a vehicle is viewed from the side. FIG. 3 is an enlarged view of a portion A in FIG. 2 and is a partially transparent view showing the configuration of the light guide. FIG. 4 is a view showing the image display device in the display state of the display image. FIG. 5 is a diagram showing the display unit in the display state of the display image.

  The display apparatus 1A for vehicles which concerns on embodiment is a head-up display (HUD) apparatus mounted in vehicles 100, such as a motor vehicle, as shown in FIG. 1, for example. The vehicle display device 1A is disposed inside a dashboard (not shown) of the vehicle 100, and projects a display image on the windshield 101 of the vehicle 100. The display apparatus 1A for a vehicle projects a display image on the reflection part 102 of the windshield 101, and displays the virtual image 110 in front of the eye point 201 of the vehicle 100. The reflector 102 is located on the windshield 101 in front of the eye point 201. The reflecting portion 102 is semi-transmissive, and reflects display light incident from the vehicle display device 1A toward the eye point 201. The eye point 201 is a position predetermined as a viewpoint position of the driver (driver) 200 seated on the driver's seat (not shown). The driver 200 recognizes the image reflected by the windshield 101 as a virtual image 110. The virtual image 110 is recognized to the driver 200 in front of the windshield 101. The display apparatus 1 </ b> A for vehicle includes a display unit 2, a reflection mirror 7, and a housing 9.

  The display unit 2 displays various information on the vehicle. The various information on the vehicle includes information for assisting the driving of the driver 200. The display unit 2 is accommodated in the housing 9 so as to touch the outside air of the vehicle display device 1A. The display unit 2 emits display light 11 corresponding to a display image to be visually recognized by the driver 200 of the vehicle 100. The display unit 2 includes an image display device 3 and a light guide 5.

  The image display device 3 emits display light 11 corresponding to a display image to be visually recognized by the driver 200 of the vehicle 100. The image display device 3 includes, for example, a display, a diffusion sheet, a lens array, an LED, a backlight, a substrate, and a heat sink. The display is made of, for example, a transmissive or semi-transmissive TFT liquid crystal display (Thin Film Transistor Liquid Crystal Display) or the like. The display displays a display image including numbers, characters, figures, and the like in accordance with a control instruction from a control unit (not shown) mounted on the vehicle 100. The diffusion sheet is formed in a thin plate shape, and is disposed between the display and the lens array. The diffusion sheet diffuses and emits light incident from the lens array toward the display. The lens array is, for example, a microlens array, and is an optical element in which a plurality of substantially hemispherical lenses are arranged in a plane. The lens array is arranged such that the convex portion of each lens protrudes toward the display, and the opposite plane faces the LED. Each lens of the lens array emits light incident from the LED toward the display. An LED (Light Emitting Diode) is a light source. The plurality of LEDs are mounted on the front side (display side) of the substrate. The backlight is configured by the above-described LEDs, a lens array, and a diffusion sheet, and illuminates the display from the back side. The heat sink is a heat dissipating member, is integrally formed with the substrate, and is disposed in contact with the outside air outside the vehicle display device 1A. The heat sink is stacked on the back surface side of the substrate, and releases the heat stored in the substrate to the outside of the vehicle display device 1A.

  As shown in FIG. 4, the image display device 3 includes a housing 3a having a rectangular parallelepiped shape, and a display screen 3b provided on one surface of the housing 3a. The housing 3a is a case in which various parts constituting the image display device 3 such as a display are assembled, and the housing 3a is accommodated. The housing 3a is made of an insulating resin material or the like. The housing 3a in the present embodiment has a rectangular parallelepiped shape. The display screen 3 b is a display screen of a display in the image display device 3. For example, a display image 35 is displayed on the display screen 3 b by the image display device 3. In addition, although the display image 35 is represented by the square frame in the example of illustration, it is not limited to this.

  The light guide 5 is disposed in an optical path between the image display device 3 and the reflection mirror 7 and guides the display light 11 emitted from the image display device 3 toward the reflection mirror 7. As shown in FIGS. 2 and 3, the light guide 5 has a light guide incident surface 5 a for receiving the display light 11 emitted from the image display device 3 and a light guide for emitting the guided display light 11. And a body exit surface 5b. The light guide incident surface 5 a is a flat surface formed at a position facing the display screen 3 b of the image display device 3. On the other hand, the light guide emission surface 5b is a curved surface formed in a convex shape toward the reflection mirror 7 side. The light guide emission surface 5b in the present embodiment includes a display image 35 displayed on the image display device 3 and a display image of the virtual image 110 formed by being reflected by the reflection portion 102 of the windshield 101 via the reflection mirror 7. Are convex curved surfaces formed to coincide with each other. The convex curved surface includes, for example, a semicylindrical curved surface, a spherical surface, an aspherical surface including a free curved surface, and the like.

  The light guide 5 is formed by bringing a plurality of transparent columnar members 51 in close contact with each other in the direction orthogonal to the light path. Each columnar member 51 is made of, for example, glass fiber, fibrous synthetic resin, or the like. Each columnar member 51 has a columnar member incident surface 51 a and a columnar member emission surface 51 b. The columnar member incident surface 51a and the columnar member emission surface 51b each have a substantially circular shape approximating a hexagon. The plurality of columnar member incident surfaces 51a constitute the light guide incident surface 5a. Since the light guide incident surface 5 a is a flat surface, each columnar member incident surface 51 a is orthogonal to the side surface of each columnar member 51. On the other hand, the plurality of columnar member emission surfaces 51 b constitute the light guide emission surface 5 b. Since the light guide emission surface 5 b is a convexly formed curved surface, each columnar member emission surface 51 b is not necessarily orthogonal to the side surface of each columnar member 51. That is, most of the plurality of columnar member emission surfaces 51b are inclined with respect to each columnar member incident surface 51a. Of the plurality of columnar member emission surfaces 51 b, the vertex portion of the light guide emission surface 5 b forming the convex curved surface is substantially orthogonal to the side surface of the columnar member 51. The inclination angle of the columnar member emission surface 51b differs depending on the position on the light guide emission surface 5b. A part of the display light 11 incident from each columnar member incident surface 51a passes through the inside of each columnar member 51 without reducing energy by total reflection, and exits from each columnar member emission surface 51b. That is, the light guide 5 is configured by arranging a plurality of light guide paths 61 for guiding a part of the display light 11 along the light path in the direction orthogonal to the light path.

  The reflection mirror 7 is disposed at a position substantially facing the display unit 2 in the housing 9. The reflection mirror 7 is, for example, a spherical mirror having a concave curved surface, and a reflective film is formed on the surface of a concave and spherical synthetic resin member by vapor deposition or the like. The reflection mirror 7 reflects the display light 11 and projects a display image on the reflection portion 102 of the windshield 101 of the vehicle 100. The reflection mirror 7 has a function as a magnifying glass, and enlarges the display image displayed on the display unit 2 and projects the image on the reflection portion 102 of the windshield 101. That is, the virtual image 110 visually recognized by the driver 200 includes an enlarged image of the display image 55 displayed on the display unit 2.

  The housing 9 is a case in which various components constituting the vehicle display device 1A such as the display unit 2 and the reflection mirror 7 are assembled and a case for accommodating these components is configured. The housing 9 is made of an insulating resin material or the like. The housing 9 has a transparent cover 9 a on the surface facing the windshield 101. The display light 11 reflected by the reflection mirror 7 is irradiated to the reflection portion 102 of the windshield 101 through the transparent cover 9 a.

  The vehicle display device 1A having the above configuration includes the light guide 5 in which a plurality of light guide paths 61 for guiding a part of the display light 11 along the light path is arranged in the direction orthogonal to the light path. Since the body 5 is disposed in the optical path between the image display device 3 and the reflection mirror 7, the display image 35 formed on the display screen 3 b of the image display device 3 is used as the display image 55 for the light guide 5. Is imaged on the light guide exit surface 5b. When a plano-convex lens is used for the light guide 5, the display light 11 is diffused, but a part of the display light 11 emitted from the image display device 3 is incident on the columnar member incident surface 51 a and enters the light guide 61. The light is emitted from the columnar member emission surface 51b while repeating total reflection along the same. Since the light guide emission surface 5b configured by the plurality of columnar member emission surfaces 51b is a curved surface formed in a convex shape, a field curvature generated in the optical system of the vehicle display device 1A is generated by the light guide emission surface 5b. It becomes possible to correct.

  As described above, the vehicle display device 1A according to the present embodiment is disposed in the light path between the image display device 3 and the reflection mirror 7, and guides part of the display light 11 along the light path. A light guide 5 is provided in which a plurality of light guide paths 61 are arranged in the direction orthogonal to the light path. The light guide 5 has a light guide emission surface 5 b for emitting the guided display light 11, and the light guide emission surface 5 b is a curved surface formed in a convex shape toward the reflection mirror 7 side. . Thereby, since it becomes possible to correct the curvature of field generated due to the windshield 101 having the free curved surface shape and the optical system by the light guide 5, distortion of the display image can be reduced, and the display quality can be reduced. Improve. Further, since the light guide exit surface 5b is a curved surface formed in a convex shape, distortion correction sharing of the display image by the reflection mirror 7 can be reduced. Further, since the display image 35 displayed on the image display device 3 can be enlarged, the enlargement ratio of the display image can be increased, and it is possible to cope with the enlargement of the display screen.

  In the vehicle display device 1A according to the present embodiment, the light guide emission surface 5b displays the display image 35 displayed on the image display device 3 and the display image of the virtual image 110 formed by being reflected by the reflection unit 102. Are convex curved surfaces formed to coincide with each other. For example, it is preferable that optical path lengths (for example, L1 and L2) of a plurality of optical paths between the plurality of columnar member emission surfaces 51b and the reflection mirror 7 be substantially equal (L1 ≒ L2).

  Further, in the vehicle display device 1A according to the present embodiment, since the light guide 5 is formed by bringing the plurality of transparent columnar members 51 into close contact with each other in the direction orthogonal to the light path, the light guide 5 is inexpensive. It can be made of glass fiber, fibrous synthetic resin, etc., and it becomes possible to secure superiority in cost.

  In addition, since the vehicle display device 1A according to the present embodiment includes a spherical mirror having a curved surface in which the reflection mirror 7 is formed in a concave shape, cost reduction can be achieved compared to the case of using an aspheric mirror.

  A modification of the above embodiment will be described with reference to FIG. In addition, in the modification of this embodiment, about what is common in the said embodiment, the same code | symbol is attached | subjected and those description is abbreviate | omitted.

  A display device 1B for a vehicle according to a modification of the present embodiment differs from the display device 1A for a vehicle in that a folding mirror 13 is provided. The folding mirror 13 is disposed on the optical path of the display light 11 emitted from the display unit 2. The folding mirror 13 is configured of, for example, a flat mirror or a spherical mirror that reflects the display light 11. The folding mirror 13 reflects the display light 11 emitted from the display unit 2 toward the reflection mirror 7.

  The display apparatus 1B for vehicles which concerns on the modification of this embodiment is arrange | positioned on the optical path of the image display device 3, the reflective mirror 7, and the display light 11, and the display light 11 radiate | emitted from the image display device 3 Since the folding mirror 13 for reflecting toward the reflection mirror 7 and the light guide 5 disposed in the light path between the image display device 3 and the folding mirror 13 are provided, the same effect as the above embodiment can be obtained. it can.

  In the above embodiment and its modification, the light guide 5 is described as being made of glass fiber, fibrous synthetic resin or the like. However, the present invention is not limited to this, and the light guide 5 may be made of ulexite. Ulexite is an ore generally referred to as TVite, and is an assembly in which transparent fibrous crystals are completely aligned in parallel. Thereby, the same effect as glass fiber etc. can be acquired.

  Further, although the image display device 3 is described as including the display, the lens array, the LED, the heat sink, and the like in the above embodiment and the modification thereof, the image display device 3 includes the laser unit, the MEMS mirror, the screen, and the like. It may be configured.

  Moreover, although the said embodiment and its modification demonstrated as what contains the reflective mirror 7 and / or the folding mirror 13, it does not restrict to this, for example, the reflective light 7 or the reflective mirror 7 from the image display device 3 is folded. It may be projected onto the windshield 101 via the light guide 5 without passing through the mirror 13.

  Moreover, in the said embodiment and its modification, although the reflection part 102 was a part of windshield 101, it may be not only this but a combiner etc., for example.

  Further, in the above embodiment and its modification, the reflection mirror 7 is a spherical mirror having a concavely formed curved surface, but is not limited to this and may be a parabolic mirror having a paraboloid. It may be a plane mirror. The reflection mirror 7 may be an aspheric mirror.

  Further, in the embodiment and the modification thereof, the columnar member incident surface 51a and the columnar member emission surface 51b have a substantially circular shape approximating to a hexagonal shape, but the present invention is not limited to this. It may be square or square. That is, the light guide 5 may have a honeycomb structure or may have a lattice structure.

1A, 1B Vehicle display device 2 Display unit 3 Image display device 3a Case 3b Display screen 5 Light guide 5a Light guide incident surface 5b Light guide output surface 7 Reflection mirror 9 Case 9a Transparent cover 11 Display light 13 Folded Mirror 35, 55 Display image 51 Columnar member 51a Columnar member incident surface 51b Columnar member emission surface 61 Light guide path 100 Vehicle 101 Windshield 102 Reflector 110 Virtual image 200 Driver 201 Eye point

Claims (4)

An image display device for emitting display light corresponding to a display image to be visually recognized by a driver of the vehicle;
A reflective mirror that reflects the display light and projects the display image on a reflective portion of a windshield of the vehicle;
A light guide, which is disposed in a light path between the image display device and the reflection mirror, and in which a plurality of light guide paths for guiding a part of the display light along the light path are arranged in a direction orthogonal to the light path. Equipped with a light,
The light guide has an emission surface for emitting the guided light.
The display device for a vehicle, wherein the emission surface is a curved surface formed in a convex shape toward the reflection mirror side. The display device for a vehicle according to claim 1, wherein the emission surface is a convex curved surface formed such that a display image displayed on the image display device matches the display image. The display device for a vehicle according to claim 1, wherein the light guide is formed by bringing a plurality of transparent columnar members into close contact with each other in a direction orthogonal to the light path. The display device for a vehicle according to any one of claims 1 to 3, wherein the reflection mirror includes a spherical mirror having a curved surface formed in a concave shape.

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