JP2016048344A - Head-up display system and virtual image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a virtual image display device and head-up display system that offer improved visibility.SOLUTION: A virtual image display device includes a display panel having first pixels for displaying a first parallax image and second pixels for displaying a second parallax image, and an optical system for displaying an image within a field of view of a user as an optical virtual image, and satisfies the following condition, where θ represents an angle (minutes) between a direction in which a user's eye looks at the first ( or second) pixels in the virtual image of the first (or second) parallax image and a direction in which the user's eye looks at pixels adjacent to the first (or second) pixels, m represents a magnification of the optical system for displaying the virtual image, P represents an array pitch (mm) of the first and second pixels, and L represents a distance (mm) from the user's eye to the virtual image.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to a head-up display system and a virtual image display device.

  There is known a technique for superimposing and displaying as a virtual image an image in which auxiliary information for supporting driving is drawn on a foreground viewed from a driver riding on a vehicle, such as a head-up display (HUD). Yes. Then, as disclosed in Patent Document 1, the parallax amount of the left-eye virtual image and the right-eye virtual image is changed and visually recognized by both the left and right eyes, and the virtual image viewed from the driver is displayed by fusing. A virtual image display device that changes a distance is known.

Japanese Patent Laying-Open No. 2005-301144

  An object of the present disclosure is to provide a virtual image display device and a head-up display system with improved visibility.

  In order to solve the above problems, a virtual image display device includes a display panel having a first pixel that displays a first parallax image, a second pixel that displays a second parallax image, and an output of the display panel. And an optical system that displays an image as an optical virtual image within the visual field of the user, and satisfies the following conditions.

  Here, θ: an angle (minute) formed by the direction of viewing the first pixel and the direction of viewing the pixel adjacent to the first pixel in the virtual image of the first parallax image by the user's eye, or the above An angle (minute) formed by a user's eye in a virtual image of the second parallax image between a direction of viewing the second pixel and a direction of viewing a pixel adjacent to the second pixel, m: the optical system , P: the arrangement pitch (mm) of the first pixel and the second pixel, and L: the distance (mm) from the user's eye to the virtual image.

  The present disclosure can provide a virtual image display device and a head-up display system with improved visibility.

Sectional drawing which shows the structure of the head-up display system 100 The block diagram which shows the structure of the display device 220 and the parallax barrier 230 The figure which looked at the situation which uses head up display system 100 from the inside of a car Relationship diagram between pitch of display device 220 and pitch of virtual image (IL and IR) Schematic diagram showing the relationship between the Landolt ring 510, the eyes 520, and the viewing angle for visual acuity Schematic showing the positional relationship between the virtual image pixel IL for the left eye and the eyes 620 of the driver

  Hereinafter, embodiments will be described in detail with reference to the drawings as appropriate. However, more detailed description than necessary may be omitted. For example, detailed descriptions of already well-known matters and repeated descriptions for substantially the same configuration may be omitted. This is to avoid the following description from becoming unnecessarily redundant and to facilitate understanding by those skilled in the art.

In addition, the inventor (s) provides the accompanying drawings and the following description in order for those skilled in the art to fully understand the present disclosure, and these are intended to limit the claimed subject matter. It is not a thing.
(Embodiment 1)
[1. Head-up display system configuration]
The head-up display system 100 of the present disclosure is provided, for example, in a driver seat of the automobile 10. Hereinafter, a specific configuration of the head-up display 100 will be described with reference to the drawings.

  FIG. 1 shows a cross section of the configuration of the head-up display system 100 according to the first embodiment. The head-up display system 100 includes a virtual image display device 200 and a combiner 400.

  The virtual image display device 200 includes a display device 220, a parallax barrier 230, and a control unit 250 (not shown in FIG. 1) such as a microcomputer. The virtual image display device 200 is arranged, for example, inside the dashboard of the vehicle, reflects an image displayed by the display device 220 via the combiner 400, and guides the observer D inside the vehicle to display the virtual image I.

For the display device 220, a liquid crystal display, an organic light emitting diode (electroluminescence), a plasma display, or the like is used. The display device 220 can display various information such as a road plan, a distance to a preceding vehicle, a remaining battery capacity of the car, a current vehicle speed, and the like according to control from the control unit 250.
The combiner 400 is an optical member having a positive power, and is composed of a concave mirror. The combiner 400 is a half mirror, and can reflect part of the light projected from the display device 220 in the direction of the observer D. And the observer can recognize a virtual image through the combiner 400 by making the distance of the combiner 400 and the display panel 220 smaller than a focal distance. The present invention can also be applied to an optical member of a convex lens instead of the optical member of a concave mirror such as the combiner 400. The head-up display system 100 may form a virtual image optical system by combining not only the combiner 400 but also a lens, a mirror or the like as appropriate. [2. Configuration of Display Device 220 and Parallax Barrier 230]
FIG. 2 is a configuration diagram of the display device 220 and the parallax barrier 230.

  The display device 220 includes pixels including R (RED), G (Green), and B (Blue) sub-pixels 221 and 222. In Embodiment 1, each pixel of the display device 220 is spatially divided as a left-eye pixel and a right-eye pixel. That is, the pixels of the display device 220 are alternately assigned as the left eye pixel 221 and the right eye pixel 222. A pixel pair in which the left-eye pixel and the right-eye pixel are paired is arranged at a predetermined pixel pitch, as will be described in detail later.

  The parallax barrier 230 is configured by depositing a light shielding material such as chromium on a glass substrate (not shown). The parallax barrier 230 is formed in a one-dimensional stripe shape on the glass substrate. A portion where a light shielding material such as chromium is not deposited is formed as an opening. In the parallax barrier 230, light shielding portions and openings are provided alternately and periodically, and openings 231 are formed at a predetermined pitch. The ratio between the opening width and the light shielding width of the parallax barrier may not be 1: 1 (the opening width and the light shielding width are the same). The light emitted from the display device 220 is controlled by the aperture 231, and after being reflected by the combiner 400, the light emitted from the left-eye pixel 221 passes to the left eye of the observer D and the right-eye pixel. The light emitted from 222 reaches the right eye of the observer D. Thereby, the display device 220 and the parallax barrier 230 can present an image with parallax to the observer D.

  The control unit 250 controls the display image of the display device 220. The display device 220 outputs a display image according to control from the control unit 250.

  The parallax barrier 230 has openings 231 formed at predetermined intervals. The light emitted from the display device 220 is controlled by the aperture 231, the light emitted from the left eye pixel 221 is directed to the left eye of the observer D, and the light emitted from the right eye pixel 222 is observed to the observer D. Reach the right eye. Thereby, the display device 220 and the parallax barrier 230 can present an image with parallax to the observer D. FIG. 3 is a view of the situation in which the driver who is the observer D is using the head-up display system 100 from the inside of the vehicle. By using the head-up display system 100, virtual images of parallax images (left-eye virtual image IL and right-eye virtual image IR) are displayed at the reference virtual image position. By viewing the left-eye virtual image IL and the right-eye virtual image IR, the driver perceives that the image S obtained by stereoscopically viewing them is farther away.

[3. Relationship between pitch of display device 220 and pitch of virtual image (IL and IR)]
FIG. 4A shows the pixel pitch of the display device 220. On the other hand, FIG. 4B shows the pixel pitch of the virtual image images IL and IR.

  As illustrated in FIG. 4A, each pixel of the display device 220 is alternately assigned along the column as the right-eye pixel 421 and the left-eye pixel 422. Let P be the period of each pixel of the right eye pixel 421 and the left eye pixel 422. At this time, the period when the pixel pair in which the right-eye pixel 421 and the left-eye pixel 422 are paired as one unit is 2P. This means that the period of the adjacent right-eye pixels 421 in the display panel 220 is 2P. Similarly, it means that the cycle of the adjacent left-eye pixels 422 in the display panel 220 is 2P.

Similarly, as illustrated in FIG. 4B, each pixel of the virtual image (IL, IR) is alternately displayed along the column as the right-eye pixel 431 and the left-eye pixel 432. When the magnification of the virtual image optical system (including the combiner 400) is m, the period of each pixel of the right-eye pixel 431 and the left-eye pixel 432 is mP. At this time, the period when a pixel pair including the right-eye pixel 431 and the left-eye pixel 432 is taken as a unit is 2 mP. This means that the period of the adjacent right-eye pixels 431 in the virtual image is 2 mP. Similarly, it means that the cycle of the adjacent left-eye pixels 432 in the virtual image is 2 mP.
[4. Relationship between Landolt ring and vision]
FIG. 5 is a schematic diagram showing the relationship between the Landolt ring 510, the eyes 520, and the viewing angle θ with respect to visual acuity.

  The Landolt ring is an index used to determine visual acuity. The shape of the Landolt ring is a ring in which a cut is formed at one of the top, bottom, left and right. In the visual acuity determination, the visual acuity is determined by determining the break of the Landolt ring when the person to be determined is viewed from a certain distance. Here, the angle formed by the width of the cut of the Landolt ring and the center of the eye of the person to be judged is referred to as a viewing angle (unit: minute). Here, the viewing angle is represented as θ. At this time, the relational expression between visual acuity and visual angle is defined as follows.

That is, when the viewing angle θ is 1 minute, the visual acuity becomes 1.0. As the viewing angle θ decreases, it becomes difficult to identify the position of the Landolt ring break. On the other hand, when the viewing angle θ is increased, it becomes easier to distinguish the position of the cut of the Landolt ring. People with good eyesight can distinguish small breaks.
[5. Positional relationship between virtual image pixel IL and eyes]
FIG. 6 is a schematic diagram showing the positional relationship between the virtual image pixel IL for the left eye and the left eye 620 of the driver. Here, only the nth pixel center 610 of the virtual image pixel IL for the left eye and the (n + 1) th pixel center 611 of the virtual image pixel IL are shown as representatives. The interval between the nth pixel center 610 and the (n + 1) th pixel center 611 of the virtual image pixel IL is 2 mP as shown in FIG. Here, the distance from the left eye 620 of the driver to the virtual image pixel IL for the left eye is L. In addition, an angle (viewing angle) formed between the direction in which the left eye 620 of the driver views the nth pixel center 610 of the virtual image pixel IL and the direction in which the (n + 1) th pixel center 611 of the virtual image pixel IL is viewed is θ. To do. At this time, the viewing angle θ, the magnification m of the virtual image optical system, the period P of each pixel of the right eye pixel 421 and the left eye pixel 422, and the distance L from the left eye 620 of the driver to the virtual image pixel IL for the left eye Satisfies the following formula.

  In the headed-up display system 100, an image displayed by the display device 220 is enlarged by a magnification m of the virtual image optical system and displayed as a virtual image. Even if the display device 220 is so high-definition that it exceeds the resolution of the human eye, the image may be enlarged by the virtual image optical system so that the pixel can be decomposed by the human eye. Further, since the pixels of the display device 220 are spatially divided into two for the right eye and for the left eye, the pitch of the left eye (right eye) as a virtual image pixel is further increased. When the pixel becomes large, it becomes possible to distinguish one pixel as one pixel depending on the visual acuity of the driver, and the visibility deteriorates. Therefore, in order to realize the head-up display 100 with good visibility, it is necessary to devise so that even if the image is enlarged by the virtual image optical system, the pixels cannot be decomposed by human eyes.

  The acceptance criteria for visual acuity in the first-class license aptitude test is 0.7 or more for both eyes and 0.3 or more for one eye, or one eye is less than 0.3, or one eye is visible For those who do not, the visual field of the other eye is 150 degrees or more on the left and right, and the visual acuity is 0.7 or more. Therefore, in this embodiment, the visual acuity 0.7 is set as the reference visual acuity. By setting the pixel pitch so that a driver with a visual acuity of 0.7 cannot recognize one pixel, the head-up display 100 with good visibility can be realized. That is, the head-up display 100 with good visibility can be realized by satisfying the following relational expression.

  By setting the magnification m of the virtual image system, the pitch P, and the distance L from the virtual image pixel to the driver's eye so as to satisfy Equation 4, one pixel is recognized as the virtual image pixel displayed on the right and left eyes of the driver. Therefore, a display device with high visibility can be realized.

(Other embodiments)
As described above, the first embodiment has been described as an example of the technique disclosed in the present application. However, the technology in the present disclosure is not limited to this, and can also be applied to an embodiment in which changes, replacements, additions, omissions, and the like are appropriately performed. Moreover, it is also possible to combine each component demonstrated in the said Embodiment 1, and it can also be set as a new embodiment.

  For example, although the parallax barrier 230 is used in the above, the present invention is not limited to this. That is, any other configuration may be used as long as it can control the light distribution of the light projected from the display device 220, such as a lenticular lens or a liquid crystal lens.

  In the above, the combiner system head-up display system 100 is exemplified, but the present invention is not limited to this. For virtual image display, the present invention can be applied to a head-up display system in which a mirror having a positive power or a convex lens is provided in the optical path.

  In the above description, the virtual image display device 200 includes the display device 220, the parallax barrier 230, and the control unit 250 such as a microcomputer, but is not limited thereto. The virtual image display device 200 may include a virtual image optical system.

  In the above description, the visual acuity 0.7 is set as the reference visual acuity, but the present invention is not limited to this. For example, visual acuity 0.8 may be used as the reference visual acuity.

  In the above description, θ is the angle formed between the direction in which the left eye 620 of the driver views the nth pixel center 610 of the virtual image pixel IL and the direction in which the (n + 1) th pixel center 611 of the virtual image pixel IL is viewed. However, the present invention is not limited to this. That is, the angle formed by the direction in which the right eye of the driver views the nth pixel center of the virtual image pixel IR and the direction in which the (n + 1) th pixel center of the virtual image pixel IR is viewed may be θ.

  Note that, among the components described in the attached drawings and detailed description, not only the components essential for solving the problem, but also the components not essential for solving the problem in order to exemplify the above technique. May also be included. Therefore, it should not be immediately recognized that these non-essential components are essential as those non-essential components are described in the accompanying drawings and detailed description.

  Moreover, since the above-mentioned embodiment is for demonstrating the technique in this indication, a various change, substitution, addition, abbreviation, etc. can be performed in a claim or its equivalent range.

  The present invention is not limited to being mounted on a vehicle, but can also be mounted on a simulation system or the like that allows a user to experience the operation with a cockpit of an airplane or a ship or a game machine.

DESCRIPTION OF SYMBOLS 100 Head-up display system 200 Virtual image display apparatus 220 Display device 230 Parallax barrier 250 Control part 400 Combiner

Claims (2)

A display panel having a first pixel for displaying a first parallax image and a second pixel for displaying a second parallax image;
An optical system that displays an image as an optical virtual image in the visual field of the user based on the output of the display panel,
A virtual image display device that satisfies the following conditions:

here,
θ: an angle (minutes) formed by a direction in which the user's eyes view the first pixel and a direction in which a pixel adjacent to the first pixel is viewed in the virtual image of the first parallax image, or An angle (min) formed by the user's eye in the virtual image of the second parallax image between a direction of viewing the second pixel and a direction of viewing a pixel adjacent to the second pixel;
m: magnification at which the virtual image is displayed by the optical system,
P: arrangement pitch (mm) of the first pixel and the second pixel,
L: Distance (mm) from the user's eye to the virtual image.     A vehicle carrying the virtual image display device according to claim 1.