JP7111070B2 - head-up display device - Google Patents

Description

The present invention relates to a head-up display device.

2. Description of the Related Art In recent years, a head-up display device is sometimes used as a vehicle display device. A head-up display device projects image display light onto a vehicle windshield or the like, and displays a virtual image based on the image display light superimposed on the scenery outside the vehicle. A device that presents a stereoscopic image by separately generating image display light for the left eye and for the right eye has also been proposed (see, for example, Patent Document 1).

JP 2014-10418 A

In order to increase the display size of the virtual image, it is required to increase the magnification of the projection optical system that projects the image display light. However, if the magnifying power of the projection optical system is increased, the virtual image will appear more distorted due to distortion aberration or the like that occurs in the optical system. In addition, due to the occurrence of distortion aberration that looks different in the left and right eyes, it becomes difficult for the left and right eyes to recognize the same virtual image as the same image, which may cause visual fatigue.

SUMMARY OF THE INVENTION It is an object of the present invention to improve the visibility of a high-magnification virtual image.

A head-up display device according to one aspect of the present invention includes a light source, a fly-eye lens that divides output light from the light source into a plurality of illumination light beams, and a shutter that selectively shields a first region or a second region of the fly-eye lens. and superimpose a plurality of first illumination light beams emitted from the first region of the fly-eye lens to generate the first illumination light, and superimpose a plurality of second illumination light beams emitted from the second region of the fly-eye lens. a condenser for generating second illumination light; a display unit for modulating the first illumination light to generate left-eye display light; modulating the second illumination light to generate right-eye display light; The display light for the right eye is projected toward the virtual image presentation board, the display light for the left eye reflected by the virtual image presentation board is directed to the left side area of the eye box, and the display light for the right eye is directed to the right side area of the eye box. A concave mirror and image processing for generating an image for the left eye by performing a first distortion correction process on the image for display, and generating an image for the right eye by performing a second distortion correction process different from the first distortion correction process on the image for display. a shutter control unit that operates the shutter so that the first illumination light and the second illumination light are alternately generated; and a display unit that displays an image for the left eye when the first illumination light is generated and the second illumination light and a display control unit that causes the display unit to display the image for the right eye when the is generated.

It should be noted that arbitrary combinations of the above-described constituent elements and mutual replacement of the constituent elements and expressions of the present invention in methods, devices, systems, etc. are also effective as aspects of the present invention.

ADVANTAGE OF THE INVENTION According to this invention, the visibility of the virtual image of high magnification can be improved.

It is a figure which shows typically the structure of the head-up display apparatus which concerns on embodiment. FIGS. 2A to 2C are diagrams schematically showing optical paths of display light. FIGS. 3A to 3E are diagrams schematically showing an image displayed on the display unit and a virtual image presented based on the image in a comparative example. FIGS. 4A to 4E are diagrams schematically showing an image displayed on the display section and a virtual image presented based on the image in this embodiment. It is a figure which shows the structure of the head-up display apparatus which concerns on embodiment in detail. It is a figure which shows the structure of the head-up display apparatus which concerns on embodiment in detail. FIGS. 7(a) to 7(c) are front views schematically showing configurations of a fly-eye lens and a shutter. FIGS. 8A to 8C are diagrams showing operational effects of the head-up display device according to the embodiment. FIGS. 9A to 9C are diagrams showing operational effects of the head-up display device according to the embodiment. It is a figure which shows in detail the structure of the head-up display apparatus which concerns on another embodiment.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. Specific numerical values and the like shown in these embodiments are merely examples for facilitating understanding of the invention, and do not limit the invention unless otherwise specified. In the present specification and drawings, elements having substantially the same functions and configurations are denoted by the same reference numerals to omit redundant description, and elements that are not directly related to the present invention are omitted from the drawings. do.

FIG. 1 is a diagram schematically showing the configuration of a head-up display device 10 according to an embodiment. In the present embodiment, head-up display device 10 is installed in the dashboard of vehicle 60, which is an example of a mobile object. The head-up display device 10 projects the display light 52 onto the windshield 62, which is a virtual image presentation board, and presents the virtual image 50 in front of the traveling direction of the vehicle 60 (right direction in FIG. 1). A user 70 such as a driver can visually recognize the virtual image 50 superimposed on the real scenery through the windshield 62 . Therefore, the user 70 can obtain the information shown in the virtual image 50 without moving the line of sight while the vehicle is running. In FIG. 1, the traveling direction (front-rear direction) of the vehicle 60 is the z-direction, the vertical direction (up-down direction) of the vehicle 60 is the y-direction, and the left-right direction of the vehicle 60 is the x direction.

The virtual image 50 is presented, for example, at a position about 2 m to 5 m in front of the user 70 . A field of view (FOV) corresponding to the display size of the virtual image 50 is, for example, about 5 degrees in the horizontal direction and about 2 degrees in the vertical direction.

The head-up display device 10 includes an illumination section 12 , a display section 14 , a concave mirror 16 and a control device 18 . The head-up display device 10 is connected with an external device 64 .

The illumination unit 12 generates illumination light for illuminating the display unit 14 . The illumination unit 12 has a light source such as an LED (Light Emitting Diode) and an optical element for adjusting the intensity distribution and angle distribution of light output from the light source to generate illumination light.

The display unit 14 modulates the illumination light to generate display light. The display unit 14 includes a display element such as a liquid crystal panel. Based on the image signal transmitted from the control device 18, the display unit 14 generates the display light 52 of the display content corresponding to the image signal.

The concave mirror 16 reflects the display light 52 generated by the display unit 14 and projects it toward the windshield 62 . The concave mirror 16 projects the display light 52 so that the display light 52 reflected by the windshield 62 is directed toward the eyebox 76 where the eyes 72 of the user 70 are located. Thereby, the user 70 can visually recognize the virtual image 50 based on the display light 52 . The concave mirror 16 is configured to magnify an image based on the display light 52 and present it to the user 70. For example, the concave mirror 16 is configured to magnify the image displayed on the display unit 14 by a factor of 0.6 or more. The reflecting surface of the concave mirror 16 is composed of a free curved surface such as an aspherical surface.

The control device 18 generates a display image and controls the operations of the lighting unit 12 and the display unit 14 so that a virtual image 50 corresponding to the display image is presented. The control device 18 is connected to an external device 64 and generates display images based on information from the external device 64, for example.

The external device 64 is a device that generates the original data of the display image displayed as the virtual image 50 . The external device 64 is, for example, an electronic control unit (ECU) of the vehicle 60, a navigation device, a mobile device such as a mobile phone, a smart phone, or a tablet. The external device 64 transmits image data necessary for displaying the virtual image 50 , information indicating the content and type of the image data, and information about the vehicle 60 such as the speed and current position of the vehicle 60 to the control device 18 .

FIGS. 2A to 2C are diagrams schematically showing the optical paths of the display lights 52C, 52L and 52R. FIGS. 2(a) to 2(c) show the configuration of the head-up display device 10 viewed from above the vehicle 60, omitting the lighting unit 12 and the windshield 62 for clarity. Display lights 52C, 52L, and 52R shown in FIGS. 2A to 2C, respectively, exit the display unit 14, are reflected by the concave mirror 16 and the windshield 62 (not shown), and then enter the eyebox 76. head to

The eyebox 76 is a range within which the virtual image 50 presented by the head-up display device 10 is visible. The eyebox 76 is set long in the horizontal direction (x direction) so as to encompass the left eye 72L and the right eye 72R of the user 70 . The length of the eyebox 76 in the horizontal direction is set, for example, to about twice the distance between the pupils of the user's 70 eyes 72L and 72R. The interpupillary distance of both eyes 72L and 72R varies from person to person, but is generally about 60 mm to 70 mm. The length of the eyebox 76 in the left-right direction is set to, for example, approximately 120 mm to 130 mm. 2A to 2C, the right eye 72R of the user 70 is located in the right area 76R of the eyebox 76, and the left eye 72L of the user is located in the left area 76L of the eyebox 76. To position.

FIG. 2(a) schematically shows the optical path of the center display light 52C toward the center 76C of the eyebox 76. FIG. The central display light 52C is display light emitted along the optical axis 54 of the optical system of the head-up display device 10 as indicated by the arrow C. As shown in FIG. Optical axis 54 is defined as an optical path that emerges from center 14C of display portion 14 toward center 76C of eyebox 76 . The concave mirror 16 is configured to have a symmetrical shape in the horizontal direction (x direction) with respect to the optical axis 54, and the central display light 52C is reflected at the center 16C of the concave mirror 16 or its vicinity. Since the center display light 52C is projected toward the center 76C of the eyebox 76, in the normal usage mode shown in FIG. 52C does not enter. As a result, the virtual image 50C based on the central display light 52C is not visually recognized by the user 70 .

FIG. 2(b) schematically shows the optical path of the left-eye display light 52L toward the left region 76L of the eyebox 76. As shown in FIG. The left-eye display light 52L is display light that is emitted obliquely to the optical axis 54 as indicated by an arrow L, and is emitted leftward from the center 14C of the display section 14 . Therefore, the left-eye display light 52L is reflected at or near a position 16L shifted leftward from the center 16C of the concave mirror 16 . The left-eye display light 52L is incident on the left eye 72L of the user 70, so that the user 70 visually recognizes the left-eye virtual image 50L based on the left-eye display light 52L.

FIG. 2C schematically shows the optical path of the right-eye display light 52R heading for the right-side region 76R of the eyebox 76. As shown in FIG. The right-eye display light 52R is display light that is emitted obliquely with respect to the optical axis 54 as indicated by an arrow R, and is emitted from the center 14C of the display section 14 toward the right. Therefore, the right-eye display light 52R is reflected at a position 16R deviated to the right from the center 16C of the concave mirror 16 or in the vicinity thereof. The right-eye display light 52R is incident on the right eye 72R of the user 70, so that the user 70 visually recognizes the right-eye virtual image 50R based on the right-eye display light 52R.

The virtual images 50C, 50L, 50R shown in FIGS. 2A to 2C have distortion (for example, distortion or distortion aberration) caused by the reflection of the display lights 52C, 52L, 52R by the concave mirror 16. can occur. The amount of distortion produced by the concave mirror 16 can be increased by reflecting the display light at positions further away from the center 16C of the concave mirror 16 . Therefore, the distortion of the left-eye virtual image 50L and the right-eye virtual image 50R becomes larger than the distortion of the center virtual image 50C displayed by the center display light 52C.

Further, asymmetrical distortion in the left-right direction may occur in the left-eye virtual image 50L and the right-eye virtual image 50R. For example, in the case of the left-eye virtual image 50L shown in FIG. Since the light is reflected at the far position 16LL depending on the direction, the distortion amount at the left end of the left eye virtual image 50L increases. Conversely, in the case of the right-eye virtual image 50R shown in FIG. Since the light is reflected at the farther position 16RR in the right direction, the amount of distortion at the right end of the right-eye virtual image 50R increases.

3A to 3E schematically show a display image 140 displayed on the display unit 14 and virtual images 150L, 150C, 150R, and 150 presented based on the display image 140 in the comparative example. FIG. 4 is a diagram showing; FIG. 3A shows an example of a display image 140 displayed on the display unit 14, showing a grid-like test pattern in which straight lines in the vertical direction and straight lines in the horizontal direction are arranged at regular intervals. FIGS. 3B to 3D show a left-eye virtual image 150L, a center virtual image 150C, and a right-eye virtual image 150R presented when the display image 140 of FIG. 3A is displayed on the display unit 14. . FIG. 3(e) shows the virtual image 150 as viewed with both eyes.

A central virtual image 150C shown in FIG. 3C corresponds to the central virtual image 50C based on the central display light 52C in FIG. A left-eye virtual image 150L shown in FIG. 3B corresponds to the left-eye virtual image 50L based on the left-eye display light 52L in FIG. In left-eye virtual image 150L, the distortion on the left side of the virtual image is relatively large. A right-eye virtual image 150R shown in FIG. 3D corresponds to the right-eye virtual image 50R based on the right-eye display light 52R in FIG. Contrary to the left eye virtual image 150L, the right eye virtual image 150R has a relatively large distortion on the right side of the virtual image. Therefore, it can be said that left-eye virtual image 150L and right-eye virtual image 150R have distortion aberrations opposite to each other in the horizontal direction.

FIG. 3E schematically shows a virtual image 150 visually recognized by the user 70 with both eyes when the display image 140 is displayed on the display unit 14 . FIG. 3(e) is obtained by superimposing the left-eye virtual image 150L shown in FIG. 3(b) and the right-eye virtual image 150R shown in FIG. 3(d). As shown in the figure, the left-eye virtual image 150L and the right-eye virtual image 150R have distortion aberration that makes them look different on the left and right, so it is difficult to fuse them and see them as the same image. Forcing the left-eye virtual image 150L and the right-eye virtual image 150R to look the same may cause visual fatigue and dizziness, which is not preferable.

In general, when the difference in the amount of distortion between the image for the left eye and the image for the right eye is 5% or more in binocular vision, it becomes difficult to fuse the two images and view them as the same image. In order to suppress the distortion aberration, countermeasures such as making the reflecting surface of the concave mirror 16 a free-form surface such as an aspherical surface or performing a predetermined distortion correction process on the display image 140 are conceivable. However, when trying to increase the curvature of the concave mirror 16 in order to increase the magnification of the virtual image by the concave mirror 16, it becomes difficult to make the difference in the amount of distortion between the left-eye virtual image 150L and the right-eye virtual image 150R less than 5%.

Therefore, in the present embodiment, a left-eye image and a right-eye image are separately prepared as display images to be displayed on the display unit 14, and different distortion correction processing is performed on the left-eye image and the right-eye image. . Specifically, the image for the left eye is subjected to a first distortion correction process for reducing or canceling the distortion occurring in the virtual image for the left eye 150L. Also, the image for the right eye is subjected to a second distortion correction process for reducing or canceling the distortion occurring in the virtual image for the right eye 150R. The second distortion correction process is a correction process in a different mode from the first distortion correction process. For example, the second distortion correction process is a correction process in which the amount of correction is opposite to that of the first distortion correction process in the horizontal direction.

4A to 4E schematically show images 40L and 40R displayed on the display unit 14 and virtual images 50L, 50R and 50 presented based on the images 40L and 40R in this embodiment. FIG. 4 is a diagram showing; FIG. 4(a) schematically shows a left-eye image 40L to be displayed on the display unit 14, which is an image obtained by performing the first distortion correction process on the display image 140 of FIG. 3(a). The left-eye image 40L is subjected to, for example, an asymmetrical distortion correction process in the left-right direction so that the amount of correction at the left end of the image is maximized. FIG. 4(b) schematically shows a right-eye image 40R to be displayed on the display unit 14, which is an image obtained by subjecting the display image 140 of FIG. 3(a) to the second distortion correction process. The image for the right eye 40R is subjected to distortion correction processing that is asymmetric in the horizontal direction, for example, so that the amount of correction at the right end of the image is maximized.

FIG. 4C schematically shows the left-eye virtual image 50L presented by the left-eye display light 52L when the display unit 14 displays the left-eye image 40L. As illustrated, by performing the first distortion correction processing on the left-eye image 40L, the distortion aberration caused by the concave mirror 16 is reduced or canceled, and the left-eye image looks the same as the display image 140 shown in FIG. A virtual image 50L can be presented. FIG. 4D schematically shows the right-eye virtual image 50R presented by the right-eye display light 52R when the display unit 14 displays the right-eye image 40R. As shown in the figure, by performing the second distortion correction process on the right eye image 40R, the distortion aberration caused by the concave mirror 16 is reduced or canceled, and the right eye image that looks the same as the display image 140 shown in FIG. A virtual image 50R for use can be presented.

FIG. 4(e) schematically shows the virtual image 50 visually recognized by the user 70 with both eyes when the left-eye virtual image 50L of FIG. 4(c) and the right-eye virtual image 50R of FIG. 4(d) are presented. FIG. 4(e) is obtained by superimposing the left-eye virtual image 50L shown in FIG. 4(c) and the right-eye virtual image 50R shown in FIG. 4(d). As shown in the figure, the left-eye virtual image 50L and the right-eye virtual image 50R look substantially the same, so it is easy to fuse them and view them as the same image. In the present embodiment, by presenting such a virtual image 50, visual fatigue and dizziness can be prevented, and the visibility of the virtual image 50 can be improved.

Next, the configuration of the optical system of the illumination section 12 and the display section 14 for presenting the virtual image 50 as shown in FIG. 4(e) will be described. Usually, when displaying different images for the left eye and the right eye, it is necessary to separately prepare a left-eye display section and a right-eye display section, but providing a plurality of display sections leads to an increase in cost. In this embodiment, the left-eye image 40L and the right-eye image 40R are alternately displayed in a time-division manner on one display unit 14, and the left-eye display light 52L and the right-eye display light 52R are alternately generated in a time-division manner. make it In addition, the display unit 14 is alternately irradiated with the first illumination light for generating the left-eye display light 52L and the second illumination light for generating the right-eye display light 52R in a time division manner. do. As a result, the left eye display light 52L is projected toward the left region 76L of the eyebox 76, and the right eye display light 52R is projected toward the right region 76R of the eyebox 76. FIG.

5 and 6 are diagrams showing in detail the configuration of the head-up display device 10 according to the embodiment. FIG. 5 corresponds to the configuration of FIG. 2(b) and shows an operation state in which the left-eye image 40L is displayed on the display unit 14 and the left-eye display light 52L is generated. FIG. 6 corresponds to the configuration of FIG. 2(c) and shows an operation state in which the right-eye image 40R is displayed on the display unit 14 and the right-eye display light 52R is generated.

Illumination section 12 includes light source 20 , collimator 22 , fly-eye lens 24 , shutter 28 , condenser 30 and field lens 32 . The display section 14 includes a light diffusion plate 34 and a display element 36 . Each optical element constituting the illumination unit 12 and the display unit 14 and the concave mirror 16 are arranged on the optical axis 54 . In the drawings, the direction of the optical axis 54 is the z-direction, and the two directions perpendicular to the z-direction are the x-direction and the y-direction. The x direction is defined by the horizontal direction of the image displayed on the display unit 14 , and the y direction is defined by the vertical direction of the image displayed on the display unit 14 .

The light source 20 is composed of a semiconductor light emitting device such as an LED. The light source 20 outputs white light for illuminating the display section 14 . Collimator 22 collimates the output light of light source 20 to produce a parallel beam along optical axis 54 . The collimator 22 is composed of a parabolic mirror or an ellipsoidal mirror, and the light source 20 is arranged at the focal position of the collimator 22 . The collimator 22 may be composed of a lens instead of a mirror, and may be, for example, a TIR (Total Internal Reflection) lens that utilizes total internal reflection.

A fly-eye lens 24 splits the output light from the light source 20 into a plurality of illumination light beams. The fly-eye lens 24 has a first lens surface 25 and a second lens surface 26. A plurality of lens elements are arrayed in the x direction and the y direction on each of the first lens surface 25 and the second lens surface 26. are arranged in Each lens element forming the fly-eye lens 24 has a rectangular shape and is configured to have a similar shape to the rectangular display section 14 . For example, if the vertical and horizontal aspect ratio of the display unit 14 is 1:2, the vertical and horizontal aspect ratio of each lens element constituting the fly-eye lens 24 is also 1:2.

Each lens element of the first lens surface 25 converges parallel light beams incident on the first lens surface 25 . The focal point of each lens element of first lens surface 25 is located at the corresponding lens element of second lens surface 26 . That is, the distance in the z direction between the first lens surface 25 and the second lens surface 26 corresponds to the focal length of each lens element of the first lens surface 25 . As a result, the parallel light flux incident on the first lens surface 25 is converged on each lens element of the second lens surface 26 . Each lens element of the second lens surface 26 can be regarded as a virtual point light source, and a split illumination light beam is emitted from each lens element of the second lens surface 26 .

The shutter 28 blocks part of the plurality of illumination light fluxes emitted from the fly-eye lens 24 . The shutter 28 selectively shields the first area 24a or the second area 24b of the fly-eye lens 24. As shown in FIG. Here, the first region 24a of the fly's eye lens 24 refers to a region on the right side of the optical axis 54 in the x direction. Also, the second region 24b of the fly-eye lens 24 is a region on the left side of the optical axis 54 in the x direction.

7A to 7C are front views schematically showing configurations of the fly-eye lens 24 and the shutter 28. FIG. FIG. 7(a) shows the fly-eye lens 24 viewed from the first lens surface 25. FIG. As shown, the first lens surface 25 has a plurality of lens elements 25a and 25b arranged in the x and y directions. A first region 24a of the fly-eye lens 24 is provided with a plurality of first lens elements 25a, and a second region 24b of the fly-eye lens 24 is provided with a plurality of second lens elements 25b. The fly-eye lens 24 has a symmetrical shape, and the first lens element 25a and the second lens element 25b have the same shape or optical characteristics.

FIG. 7(b) shows the fly-eye lens 24 viewed from the second lens surface 26. FIG. In FIG. 7B, the horizontal direction is opposite to that in FIG. 7A. The second lens surface 26 is configured in the same manner as the first lens surface 25. A plurality of lens elements 26a and 26b are arranged on the second lens surface 26 in the x direction and the y direction. A first region 24a of the fly-eye lens 24 is provided with a plurality of third lens elements 26a, and a second region 24b of the fly-eye lens 24 is provided with a plurality of fourth lens elements 26b. The third lens element 26a and the fourth lens element 26b have the same shape or optical properties.

A plurality of illumination light beams are emitted from the second lens surface 26 . Specifically, a plurality of first illumination light beams are emitted from the first region 24a of the second lens surface 26, and each third lens element 26a emits one first illumination light beam. Similarly, a plurality of second illumination light beams are emitted from the second region 24b of the second lens surface 26, and each fourth lens element 26b emits one second illumination light beam.

FIG. 7(c) shows the shutter 28 viewed from the fly-eye lens 24. FIG. The shutter 28 is composed of, for example, a liquid crystal shutter with variable transmittance. The shutter 28 has a first area 28a and a second area 28b. The first region 28a of the shutter 28 overlaps the first region 24a of the fly-eye lens 24 in the z-direction, and the second region 28b of the shutter 28 overlaps the second region 24b of the fly-eye lens 24 in the z-direction. area.

By changing the transmittance of the first region 28a, the shutter 28 switches between a transmitting state and a blocking state of the plurality of first illumination light beams emitted from the first region 24a. The shutter 28 changes the transmittance of the second region 28b overlapping the second region 24b of the fly-eye lens 24 in the z-direction, thereby changing the transmission state and shielding of the plurality of second illumination light beams emitted from the second region 24b. switch state.

The shutter 28 operates in a first state in which the first region 28a is in a transmitting state and the second region 28b is in a blocking state, thereby transmitting only the plurality of first illumination light beams and blocking the plurality of second illumination light beams. (see Figure 5). The shutter 28 operates in a second state in which the first region 28a is in the blocking state and the second region 28b is in the transmitting state, thereby blocking the plurality of first illumination light beams and transmitting only the plurality of second illumination light beams. (See FIG. 6).

5 and 6, the shutter 28 is arranged on the light exit side of the fly-eye lens 24, that is, between the fly-eye lens 24 and the condenser 30. In the arrangement shown in FIGS. The shutter 28 may be arranged on the light incident side of the fly-eye lens 24 , or may be arranged between the collimator 22 and the fly-eye lens 24 , that is, between the light source 20 and the fly-eye lens 24 . Moreover, although the fly-eye lens 24 has the first lens surface 25 and the second lens surface 26 integrally formed, the first lens surface 25 and the second lens surface 26 may be separated. That is, instead of the fly-eye lens 24, a combination of a first fly-eye lens corresponding to the first lens surface 25 and a second fly-eye lens corresponding to the second lens surface 26 may be used. In this case, the shutter 28 may be arranged between the first fly-eye lens and the second fly-eye lens.

A condenser 30 superimposes a plurality of illumination light beams emitted from the fly-eye lens 24 to generate illumination light. Condenser 30 is composed of a convex lens. The condenser 30 causes the illumination light flux emitted from each lens element of the fly-eye lens 24 to illuminate the entire display area of the display section 14 . Therefore, a plurality of illumination light beams emitted from the fly-eye lens 24 overlap each other in the display area of the display section 14 .

In the present embodiment, a plurality of first illumination light fluxes emitted from the first region 24a of the fly-eye lens 24 and a plurality of second illumination light fluxes emitted from the second region 24b of the fly-eye lens 24 are selectively selected. is incident on the capacitor 30 at . The condenser 30 generates the first illumination light 56a by superimposing the plurality of first illumination light beams, so that the display section 14 is illuminated with the first illumination light 56a. The first illumination light 56 a enters the display section 14 from the right side of the optical axis 54 . Also, the condenser 30 generates the second illumination light 56b by superimposing the plurality of second illumination light beams. The second illumination light 56b enters the display section 14 from the left side of the optical axis 54, contrary to the first illumination light 56a.

The field lens 32 is provided after the condenser 30 and adjusts the light distribution of the first illumination light 56a and the second illumination light 56b. The field lens 32 distributes the light of the first illumination light 56a and the second illumination light 56b so that the range in which the reflecting surface of the concave mirror 16 exists and the range in which the display lights 52L and 52R are incident on the concave mirror 16 correspond to each other. to adjust.

The light diffusion plate 34 is provided on the light incident side of the display element 36 and configured to diffuse the first illumination light 56 a and the second illumination light 56 b incident on the display element 36 . The light diffusing plate 34 is composed of, for example, a transmissive screen such as a microbead film. The light diffusing plate 34 functions like a backlight for the display element 36 so that the display element 36 looks like a self-luminous display.

The display element 36 modulates the illumination light to generate display light 52 . The display element 36 is a transmissive display element such as a liquid crystal panel, and modulates the illumination light incident on each pixel in the display area to generate display light 52 corresponding to the display content of the image displayed in the display area. do. The display element 36 may be a DMD (Digital Mirror Device) or a reflective display element such as an LCOS (Liquid Crystal on Silicon).

As shown in FIG. 5, the display element 36 modulates the first illumination light 56a to generate left-eye display light 52L. Since the first illumination light 56a is incident on the display unit 14 from the right side of the optical axis 54, the left-eye display light 52L generated based on the first illumination light 56a is displayed as indicated by an arrow L. The light is emitted from the portion 14 toward the left. Left-eye display light 52L emitted from the center 14C of the display section 14 enters a position 16L shifted leftward from the center 16C of the concave mirror 16 .

As shown in FIG. 6, the display element 36 modulates the second illumination light 56b to generate right-eye display light 52R. Since the second illumination light 56b is incident on the display unit 14 from the left side of the optical axis 54, the right-eye display light 52R generated based on the second illumination light 56b is displayed as indicated by an arrow R. The light is emitted from the portion 14 toward the right side. The right-eye display light 52R emitted from the center 14C of the display section 14 is incident on the concave mirror 16 at a position 16R shifted to the right from the center 16C.

The control device 18 includes an image processing section 42 , a shutter control section 44 and a display control section 46 .

The image processing unit 42 generates display images to be displayed on the display unit 14 . The image processing unit 42 applies a first distortion correction process to the display image to generate a left eye image 40L, and applies a second distortion correction process to the display image to generate a right eye image 40R. The processing modes of the first distortion correction process and the second distortion correction process are appropriately set according to the distortion of the left-eye virtual image 50L and the right-eye virtual image 50R generated in the optical system of the head-up display device 10. FIG.

The shutter control section 44 controls the operation of the shutter 28 . The shutter control unit 44 switches the operation of the shutter 28 between the first state and the second state so that the first illumination light 56a and the second illumination light 56b are alternately generated. The shutter control unit 44 switches the operating state of the shutter 28 at such a speed that the switching between the left-eye virtual image 50L and the right-eye virtual image 50R cannot be perceived by the human eye. The switching speed between the first state and the second state is, for example, 60 times or more (60 Hz or more) per second.

The display control section 46 controls the operation of the display section 14 . The display control unit 46 generates an image signal for driving the display element 36 so that the left-eye image 40L and the right-eye image 40R are alternately displayed on the display element 36 . The display control unit 46 switches the image displayed on the display element 36 in synchronization with the operation of the shutter 28 . The display control unit 46 causes the display element 36 to display the left-eye image 40L when the shutter 28 operates in the first state and the first illumination light 56a is generated. The display control unit 46 causes the display element 36 to display the right-eye image 40R when the shutter 28 operates in the second state and the second illumination light 56b is generated. Thereby, the left-eye display light 52L and the right-eye display light 52R are alternately generated.

FIGS. 8A to 8C are diagrams showing operational effects of the head-up display device 10 according to the embodiment. FIG. 8(a) schematically shows the positions of the eyes 72L and 72R in the eyebox 76, with the left eye 72L and the right eye 72R positioned near the centers of the left region 76L and the right region 76R of the eyebox 76, respectively. . FIG. 8B shows how virtual images 150L and 150R appear according to the comparative example. In the comparative example, since the display image 140 displayed on the display unit 14 is not subjected to distortion correction processing, virtual images 150L and 150R that look different on the left and right sides are presented. FIG. 8(c) shows how virtual images 50L and 50R appear according to the embodiment, and shows a case where images 40L and 40R subjected to different distortion correction processes are displayed on the display unit 14. FIG. According to the present embodiment, by separately preparing the left-eye image 40L and the right-eye image 40R, it is possible to reduce the difference in appearance between the left-eye virtual image 50L and the right-eye virtual image 50R. and the right-eye virtual image 50R can be easily fused. Thereby, the visibility of the virtual image 50 visually recognized by binocular vision can be improved, and the occurrence of visual fatigue and dizziness can be suitably prevented.

FIGS. 9A to 9C are diagrams showing the effects of the head-up display device 10 according to the embodiment, and the positions of both eyes 72L and 72R in the eyebox 76 are shown in FIGS. 8A to 8C. ) indicates a different case. As shown in FIG. 9A, the positions of both eyes 72L and 72R are shifted to the right compared to FIG. is shifted near the right edge of the

FIG. 9B shows how the virtual images 150L and 150R appear according to the comparative example, and how the virtual images 150L and 150R appear when the display image 140 displayed on the display unit 14 is not subjected to distortion correction processing. indicates Since the left eye 72L is positioned near the center of the eyebox 76, the virtual image 150L viewed with the left eye is less affected by distortion. This is similar to how the central virtual image 50C appears based on the central display light 52C shown in FIG. 2(a). On the other hand, since the right eye 72R is located near the right end of the eyebox 76, the amount of distortion is greater than that of the right eye virtual image 150R shown in FIG. 8(b). Therefore, the difference in appearance between the left-eye virtual image 150L and the right-eye virtual image 150R shown in FIG. 9B is large, and it is difficult to equate the two as fusion.

FIG. 9(c) shows how virtual images 50L and 50R appear according to the embodiment, and shows a case where images 40L and 40R subjected to different distortion correction processes are displayed on the display unit 14. FIG. Since the left eye 72L is positioned near the center of the eye box 76, the correction amount of the first distortion correction processing for the left eye virtual image 50L is excessive. On the other hand, since the right eye 72R is positioned near the right end of the eyebox 76, the correction amount of the second distortion correction processing for the right eye virtual image 50R is insufficient. As a result, the left-eye virtual image 50L and the right-eye virtual image 50R shown in FIG. 9(c) remain distorted, but the images are similarly distorted in the horizontal direction. Therefore, according to the present embodiment, even if the positions of the eyes 72L and 72R in the eyebox 76 are shifted in the horizontal direction, the difference in appearance between the left-eye virtual image 50L and the right-eye virtual image 50R can be reduced. Fusion of the left-eye virtual image 50L and the right-eye virtual image 50R can be facilitated. Thereby, the visibility of the virtual image 50 visually recognized by binocular vision can be improved, and the occurrence of visual fatigue and dizziness can be suitably prevented.

If the positions of the eyes 72L and 72R in the left-right direction are further shifted from the eyebox 76, and only one of the left eye 72L and the right eye 72R is positioned in the eyebox 76, the virtual image can be viewed with only one eye. There is no problem of difficulty in fusion in binocular vision.

FIG. 10 is a diagram showing in detail the configuration of a head-up display device 210 according to another embodiment. The head-up display device 210 differs from the above embodiment in that it includes a condenser 230 made up of a concave mirror instead of the condenser 30 made up of a convex lens. The head-up display device 210 will be described with a focus on the differences from the above-described embodiment.

The head-up display device 210 includes an illumination section 212 , a display section 14 , a concave mirror 16 and a control device 18 . The display unit 14, concave mirror 16 and control device 18 are configured in the same manner as in the above-described embodiment. Illumination section 212 includes light source 20 , collimator 22 , fly-eye lens 224 , shutter 228 , condenser 230 and field lens 32 . The light source 20, collimator 22, and field lens 32 are the same as in the above embodiments.

The fly-eye lens 224 is configured similarly to the fly-eye lens 24 according to the above-described embodiment, and has a first lens surface 25 and a second lens surface 26 . In the fly-eye lens 224, the horizontal directions of the first region 224a and the second region 224b are opposite to those of the above embodiment. Specifically, the first area 224 a is provided on the left side of the optical axis 254 and the second area 224 b is provided on the right side of the optical axis 254 . This is because the left and right directions are reversed because the illumination light flux is folded back by 90 degrees by the condenser 230 composed of a concave mirror.

The shutter 228 is configured in the same manner as the shutter 28 according to the above-described embodiment, but the horizontal directions of the first area 224a and the second area 224b are opposite to those of the above-described embodiment. Specifically, the first area 228 a is provided on the left side of the optical axis 254 and the second area 228 b is provided on the right side of the optical axis 254 .

The condenser 230 superimposes a plurality of illumination light fluxes emitted from the fly-eye lens 224 to generate illumination light. Condenser 230 superimposes a plurality of first illumination light beams emitted from first region 224a of fly-eye lens 224 to generate first illumination light 256a. The condenser 230 superimposes a plurality of second illumination light beams emitted from the second region 224b of the fly-eye lens 224 to generate second illumination light (not shown).

Also in this embodiment, the same effects as those of the above-described embodiments can be obtained. Further, according to the present embodiment, by using a concave mirror as the capacitor 230, the width of the lighting section 212 in the z direction can be reduced, and a more compact head-up display device 210 can be realized.

Although the present invention has been described with reference to the above-described embodiments, the present invention is not limited to the above-described embodiments. is also included in the present invention.

DESCRIPTION OF SYMBOLS 10... Head-up display apparatus 12... Illumination part 14... Display part 16... Concave mirror 18... Control device 20... Light source 24... Fly-eye lens 24a... 1st area|region 24b... 2nd area|region 28... Shutter 30 Capacitor 40 Display image 40L Left eye image 40R Right eye image 42 Image processing unit 44 Shutter control unit 46 Display control unit 50 Virtual image 52 Display light , 52L... Display light for left eye, 52R... Display light for right eye, 56a... First illumination light, 56b... Second illumination light, 72L... Left eye, 72R... Right eye, 76... Eye box, 76L... Left area, 76R... Right side region.

Claims (5)

a light source;
a fly-eye lens that divides the light output from the light source into a plurality of illumination light beams;
a shutter that selectively shields the first region or the second region of the fly-eye lens;
A plurality of first illumination light fluxes emitted from the first area of the fly-eye lens are superimposed to generate first illumination light, and a plurality of second illumination light fluxes emitted from the second area of the fly-eye lens are superimposed. a condenser for generating the second illumination light by
a display unit that modulates the first illumination light to generate left-eye display light and modulates the second illumination light to generate right-eye display light;
The display light for the left eye and the display light for the right eye are projected toward a virtual image presentation plate, the display light for the left eye reflected by the virtual image presentation plate is directed toward the left region of the eyebox, and the display light for the right eye is directed toward the left region of the eyebox. a concave mirror directed toward the right region of the eyebox;
An image processing unit that performs a first distortion correction process on a display image to generate a left eye image, and performs a second distortion correction process different from the first distortion correction process on the display image to generate a right eye image. When,
a shutter control unit that operates the shutter so that the first illumination light and the second illumination light are alternately generated;
a display control unit that causes the display unit to display the image for the left eye when the first illumination light is generated, and displays the image for the right eye on the display unit when the second illumination light is generated. head-up display device. The image processing unit performs the first distortion correction processing so as to reduce left-right asymmetric distortion caused by the left-eye display light being reflected at a position shifted to the left with respect to the center of the concave mirror. and performing the second distortion correction process so as to reduce left-right asymmetrical distortion caused by the display light for the right eye being reflected at a position shifted to the right with respect to the center of the concave mirror. The head-up display device according to claim 1. 3. The head-up display device according to claim 1, wherein said shutter is provided between said fly-eye lens and said condenser. The head-up display device according to any one of claims 1 to 3, wherein the condenser is a convex lens. The head-up display device according to any one of claims 1 to 3, wherein the condenser is a concave mirror.

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