JP2000111827A - Image display device/method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make an image display device thinner while keeping a sufficient viewing angle. SOLUTION: An LED array 1 emits and displays the light of one column pixels of an image. The one column pixel light from the LED array 1 is enlarged by a lens 2 in the vertical direction, and reflected to a viewing point C of a user by a reflecting mirror 3. While moving with a rotary moving belt 8, the reflecting mirror 3 is varied in the direction (direction of reflection) based on the a shape of a mirror angle control guide face 21. A position sensor 10 detects a timing at which a shaft holder 5A fixed on the belt 8A comes nearest, and outputs the information to a control circuit 34 as a mirror position detection signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image display apparatus and method, and more particularly, to an image display apparatus and method that allow a user to view a video image in a free posture when worn on the head.

[0002]

2. Description of the Related Art Recently, a display device called a so-called head mounted display is commercially available. In these head-mounted displays, small cathode ray tubes (CR
T), an image displayed on a display unit such as a liquid crystal display (LCD) or an electroluminescence panel (EL) is generally provided to a user via a magnifying optical system such as a lens and a concave mirror. .

[0003]

However, in the conventional head mounted display, the depth of the magnifying optical system is required, so that there is a problem that the entire device becomes thick.

[0004] When priority is given to reducing the weight and thickness of the device,
There is a problem that the angle of view is limited to about 30 degrees.

The present invention has been made in view of such a situation, and it is an object of the present invention to secure a sufficient angle of view and make the apparatus thinner.

[0006]

According to a first aspect of the present invention, there is provided an image display apparatus, comprising: a display means for displaying a plurality of pixels which are linearly continuous; a reflection means for reflecting light of the pixels displayed by the display means; Moving means for moving the position where the light of the pixel is reflected by the reflecting means; setting means for setting the angle of the light reflected by the reflecting means in accordance with the position moved by the moving means; Control means for linking and controlling the timing and the movement cycle of the movement means.

According to another aspect of the present invention, there is provided an image display method comprising: a display step of displaying a plurality of pixels that are linearly continuous; a reflection step of reflecting light of the pixels displayed in the display step; A moving step of moving a position where light is reflected, a setting step of setting an angle of light reflected by the reflecting step in accordance with the position moved by the moving step, a display timing of the display step, and movement of the moving step And a control step of linking and controlling the cycles.

In the image display device according to the first aspect and the image display method according to the sixteenth aspect, a plurality of pixels that are linearly continuous are displayed, and the light of the displayed pixels is reflected and reflected. The position is moved, and a light reflection angle is set according to the moved position.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below. In order to clarify the correspondence between each means of the invention described in the claims and the following embodiments, each means is described. When the features of the present invention are described by adding the corresponding embodiment (however, an example) in parentheses after the parentheses, the result is as follows. However, of course, this description does not mean that each means is limited to those described.

The image display device according to the first aspect of the present invention has a display means (for example, an LED array 1 in FIG. 1) for displaying a plurality of pixels which are linearly continuous, and reflects the light of the pixels displayed by the display means. Reflection means (for example, reflection mirror 3 in FIG. 1);
A moving unit (for example, the belt 8 in FIG. 1) that moves the position where the light of the pixel is reflected by the reflecting unit, and the angle of the light reflected by the reflecting unit is set according to the position moved by the moving unit. (For example, the mirror angle control guide surface 21 in FIG. 2), and control means (for example, the control circuit 34 in FIG. 4) for linking and controlling the display timing of the display means and the moving cycle of the moving means. It is characterized by the following.

The image display device according to a fourth aspect of the present invention is further characterized by further comprising detecting means (for example, the position detecting sensor 10 in FIG. 1) for detecting the position of the reflecting means.

A configuration example of a magnifying optical system of a head mounted display to which the present invention is applied will be described with reference to the drawings. FIG. 1 is a front view of an enlarged optical system of the head mounted display, and FIG. 2 is a top view.

The LED array 1 of the magnifying optical system disposed inside the housing 20 emits and displays pixels in one vertical column of an image based on image data supplied from an image control system described later. It has been done. The light of the pixels for one column in the vertical direction from the LED array 1 is expanded in the vertical direction by the lens 2 to be parallel light. This parallel light is reflected by the reflection mirror 3 in the direction of the viewpoint C of the user.

A mirror support shaft 4A is fixed to the left end of the upper side of the reflection mirror 3, and the mirror support shaft 4A is rotatably held by a shaft holder 5A fixed to a belt 8A. Similarly, a mirror support shaft 4B is fixed to the left end of the lower side of the reflection mirror 3, and the mirror support shaft 4B is
It is rotatably held by a shaft holder 5B fixed to the belt 8B. The left end 3A (FIG. 2) of the reflection mirror 3 contacts the mirror angle control guide surface 21 (FIG. 2), and the right end 3B.
Are arranged to be in contact with the mirror support guide surface 22.

In order to suppress the vibration of the reflecting mirror 3, the left end 3A and the right end 3B of the reflecting mirror 3 are set.
However, a repulsive force may be generated by a magnetic force and pressed by a spring so as not to directly contact the mirror angle control guide surface 21 or the mirror support guide surface 22.

The motor 6 has a mirror driving circuit 35 (FIG. 4).
Is generated, and the generated rotational torque is transmitted from the gear 7-1 fixed to the motor 6 to the gear 7-3 via the gear 7-2. Gear 7-3
Is provided with gears 7-4A and 7-4B coaxially.
Gears 7-4A and 7-4B have gears 7-5A and 7-5B.
Are engaged with each other. Further, the gears 7-5A, 7
-5B, shafts 9-2A and 9-2B, pulleys 11A,
11B is provided. Therefore, the rotation of the gear 7-3 is controlled by the gears 7-4A and 7-4B and the gears 7-5A and 7-5A.
It is transmitted to pulleys 11A and 11B via -5B.

A pulley 11A that rotates about a shaft 9-2A
And between the pulley 12A that rotates about the shaft 9-1A,
The belt 8A is hung. When the pulley 11A rotates about the shaft 9-2A by the transmitted rotation torque, the shaft holder 5A together with the belt 8A moves the pulley 11A.
And between the pulley 12A. Similarly, the shaft holder 5B moves together with the belt 8B between the pulley 11B and the pulley 12B at the same speed as the shaft holder 5A.

When the reflecting mirror 3 moves together with the belt 8, its left side end 3A and right side end 3B are respectively provided with a mirror angle control guide surface 21 and a mirror support guide surface 22.
The direction (reflection direction) is always determined based on the shape of the mirror angle control guide surface 21 so that the light of the pixel array light-emitting and displayed by the LED array 1 is reflected to the viewpoint C. The angle is changed. The range indicated by the broken line in FIG. 1 is the display area 25 of the image.

Further, in the figure, a plurality of reflecting mirrors 3 are shown to show the movement of the reflecting mirror 3, but actually only one reflecting mirror 3 exists.

The position detecting sensor 10 detects the timing at which the shaft holder 5A fixed to the belt 8A comes closest (the details will be described later with reference to FIG. 7), and uses the information as a mirror position detecting signal as a control circuit. 34 (FIG. 4).

FIG. 3 shows the position and angle of the reflecting mirror 3 at a certain time, and the coordinates of the left side end 3 A of the reflecting mirror 3 which is in contact with the mirror angle control guide surface 21. The intersection point of the mirror supporting guide surface 22 with the perpendicular to the mirror supporting guide surface 22 from the viewpoint C is defined as the origin O (0,
0), the point at the center of the reflecting mirror 3 at a certain point
When (x ₀ , y ₀ ) and the angle of the line of sight (angle OCA) are θ, the angle between the reflection mirror 3 and the mirror supporting guide surface 22 is ((π / 4) − (θ / 2)). The mirror angle control guide surface 21 and the mirror support guide surface 22 are formed such that the following relationship (1) is established.

(Equation 1) Here, L is the distance between the viewpoint C and the origin O (0, 0).
d is the width of the reflection mirror 3.

Further, when the left end portion 3A of the reflecting mirror 3 which is in contact with the mirror control guide surface 21 and (x _1, y _1), the coordinates (x _1, y ₁₎ is the following formula (2) Can be expressed as

(Equation 2)

Further, by substituting equation (1) into equation (2), the following equation (3) is obtained.

(Equation 3)

Therefore, the mirror angle control guide surface 21
Is formed into a shape that satisfies the expression (3).

The reflecting mirror 3 has a length X perpendicular to the center line of the reflecting mirror 3 with respect to the center line of the angle of view, and the center point of the plane reflecting mirror 3 on the center line of the angle of view and the viewpoint. When the distance is L ′, the angle between the center line of the angle of view and the reflecting mirror 3 is φ, and the angle between the center line of the angle of view and the line connecting the LED array 1 and the reflecting mirror 3 is α, It is positioned to satisfy (4). X = L'tan (2φ−α) (4)

Normally, an eye box of a predetermined size (for example, 10 mm × 10 mm × 10 mm) is assumed at the position of the viewpoint C, and when the eye box C is positioned therein, design is performed so that observation can be performed correctly. Will be

Next, an example of the electrical configuration of the image control system of the head mounted display will be described with reference to FIG. The frame memory 31 stores a VCR (Video Cass
etteRecorder) is stored in frame units, and specified by address signals (values P _{1 to} P _n indicating the columns in FIG. 5) input from the control circuit 34.
Pixel data corresponding to one vertical column of the frame (pixels 1 to m in FIG. 5) is output to the register 32.

The video signal input to the frame memory 31 is, for example, a video signal of the NTSC system or the like.
The pixel data is sequentially input from the upper left to the lower right in the row direction (horizontal direction) of the image. Therefore, after storing the pixel data for one frame, the frame memory 31
Since it is necessary to extract pixels in one vertical column, the frame memory 31 is used to prevent delay due to the extraction processing.
It is desirable to provide a storage capacity for two frames so that when one is in a write state, it is read from the other.

The register 32 holds one column of pixel data input from the frame memory 31 and controls the control circuit 3.
Under the control of 4, the data is output to the latch circuit 33. The latch circuit 33 outputs one column of pixel data to the LED array 1 under the control of the control circuit 34. LED array 1
The pixel emits light at a brightness corresponding to the pixel data input from the latch circuit 33.

The control circuit 34 controls the operation of each section so that the pixel array displayed one-dimensionally by the LED array 1 is reflected by the reflecting mirror 3 which is moved at a high speed so that a two-dimensional image can be seen. I do. For example, the control circuit 34
The mirror driving circuit 35 is controlled in synchronization with a mirror position detection signal that is input from the position detection sensor 10 and indicates the timing at which the reflection mirror 3 approaches the position detection sensor 10 most. As a result, the mirror drive circuit 35 controls the motor 6 so that the reflection mirror 3 rotates at 60 Hz (rotates 60 times per second). The control circuit 34
Generates a clock used for synchronization and supplies it to each unit.

FIG. 6 shows that the LED array 1
2 shows the relationship between the horizontal position of the pixel to be displayed by light emission and the angle between the viewpoint C and the center of the reflection mirror 3. That is, the pixel row P _i (i =
1, 2,..., N) are reflected by the reflecting mirror 3 located at a point where the angle between the viewpoint C and the center of the reflecting mirror 3 is θ _i that satisfies the following equation (5). The control circuit 34
The mirror driving circuit 35 and the LED array 1 are controlled. θ _i = arctan [((n−2i) / n) tan (FOV / 2)] (5) where FOV is the angle of view from the viewpoint.

[0032] When the position detected by the position detection sensor 10 of the reflection mirror 3 and P _0, the reflecting mirror 3 from the position P _0, it takes only the time t _i to reach the display position of the pixel column P _i. Therefore, at the timing when the time t _i has elapsed from the time when the signal P ₀ is detected by the position detection sensor 10, the pixel row P _i is displayed. The time t _i varies due to dimensional tolerances of parts and the like.
It is preferable that the timing information is stored in the control circuit 34 as a timing table.

FIG. 7 shows a detailed configuration example of the position detection sensor 10. The position detection sensor 10 is configured by a so-called reflection type photoelectric sensor, and includes a light emitting unit 41 and a light receiving unit 4.
2 The light emitting section 41 emits light. The light receiving unit 42 is an object (belt 8A or shaft holder 5A)
Receives the reflected light reflected by the. The intensity of the reflected light received by the light receiving section 42 is greater when the reflection target is the shaft holder 5A than when the reflection target is the belt 8A. Light receiving section 4
2 outputs a detection signal of the shaft holder 5A when the reflected light intensity becomes larger than a predetermined threshold value set in advance. Therefore, the control circuit 34
The mirror position detection signal output to the mirror indicates the moving cycle of the reflecting mirror 3 that rotates and moves together with the belt 8A.

Next, the operation of the head mounted display will be described. The frame memory 31 stores the input image data in frame units, and outputs one column of pixel data of the stored frame image to the register 32 in accordance with the address signal input from the control circuit 34, Hold. The retained pixel data is
The data is supplied from the register 32 to the LED array 1 via the latch circuit 33 in response to the control from the control circuit 34. The LED array 1 responds to the LED lighting control signal from the control circuit 34 at the timing when the time t _i has elapsed since the position detection sensor 10 outputs the detection signal, and corresponds to one vertical column of the input frame image. The pixel data is displayed by light emission.

At this time, the control circuit 34 synchronizes with the mirror position detection signal input from the position detection sensor 10 to
Reflection mirror 3, so as to be positioned on the display position of the pixel column P _i, and controls the motor 6 via the mirror drive circuit 35.
At this time, the angle of the reflection mirror 3 is controlled by the mirror angle control guide surface 21 and the mirror support guide surface 22 so that the light from the LED array 1 is reflected toward the viewpoint C.

The optical column of pixels P _i emitted displayed in the LED array 1 is enlarged in the vertical direction by the lens 2, it is reflected by the reflection mirror 3, and is incident on the viewpoint C. The above operations are
1A and 12A are rotated clockwise in FIG. 2, and the belt 8A, and thus the reflection mirror 3, is rotated clockwise, and this is repeated. The reflection mirror 3 is a pulley 11A.
, The LED array 1 is turned off.

As described above, according to the present embodiment, the LED
By reflecting the pixel rows displayed one-dimensionally by the array 1 on the reflecting mirror 3 rotating and moving at 60 Hz, it is possible to display a two-dimensional image utilizing the effect of afterimages from the viewpoint of the user. Become.

Next, another configuration example of the magnifying optical system of the head mounted display will be described with reference to FIGS. FIG. 8 shows a front view of the magnifying optical system, and FIG. 11 shows a side view. In this example, the gear 52 fixed to the motor 51 includes a gear 53-
1, 53-2. The mirror support rod 54
Two rotatable shafts 53-1A and 53-2A are supported on the plane of the gears 53-1 and 53-2. As shown in FIG. 10, the reflection mirror 3 is supported on the mirror support rod 54 via a leaf spring material 55. Note that the reflection mirror 3 may be supported via another elastic body instead of the leaf spring member 55.

Therefore, when the gear 52 rotates clockwise in FIG. 8 by the rotation torque generated by the motor 51, the gears 53-1 and 53-2 rotate counterclockwise. With the rotation of the gears 53-1 and 53-2, the mirror support rod 54 and the reflection mirror 3 move as shown in FIG.
It rotates while maintaining a state parallel to the D array 1. At this time, as shown in FIG.
The angle of the movement is constantly controlled so that the light of the pixel array light-emitted and displayed by the LED array 1 is reflected to the viewpoint C by virtue of the action of the spring coefficient of the eating and sleeping goods 55. .

In this example, the gears 53-1 and 53-1,
The rotation cycle of 53-2 is controlled to be 60 Hz, and the mirror support rod 54 and the reflection mirror 3 also move in parallel with the same cycle. However, since the angle of the reflection mirror 3 depends on the spring coefficient of the leaf spring material 55, it is necessary to select a leaf spring material 55 having an appropriate spring coefficient.

Also in this example, the rotation speed of the motor 51, that is, the position of the reflection mirror 3, and the LED array 1
Are controlled by linking.

In this embodiment, the pixels of one vertical column of the image are displayed on the LED array 1 (at this time, the upward direction of the display screen is rightward (or leftward) in FIG. However, an image of one horizontal row may be displayed on the LED array 1 (at this time, the upward direction of the display screen is the upward direction (or downward direction) in FIG. 8). However, images are generally landscape, so LE
Displaying one row of pixels on the D array 1 can reduce the number of LEDs in the LED array 1.

Further, a linear motor may be used as a power source for moving the reflecting mirror 3 in parallel.

In the present embodiment, when the user's pupil diameter is D and the angle of view is FOV, it can be mounted within a depth of about D / sin (FOV / 2) (thickness in the user's line of sight). It is possible. For example, assuming that the user's pupil diameter D is 6 mm, a head mounted display having an angle of view FOV of 60 degrees has a depth of about 12 (= 6 / sin (60/2)) mm.

Therefore, it is possible to realize a lightweight and thin head-mounted display having a high degree of freedom in its shape and mounting method, for example, a spectacle type, a hat type, and a hachimaki type.

According to this embodiment, a head-mounted display having a wide angle of view can be realized.
Images requiring high resolution, such as maps, newspapers, and photographs, can be displayed.

Further, if the present embodiment is applied to a display device for displaying a virtual reality space using a so-called virtual reality application, it is possible to give a user a high degree of realism.

[0048]

As described above, according to the image display device of the first aspect and the image display method of the sixteenth aspect, a plurality of pixels that are linearly continuous are displayed, and the displayed pixels are displayed. Since the position where light is reflected is moved and the display timing of the pixel and the movement period are linked and controlled, it is possible to secure a sufficient angle of view and make the device thinner.

[Brief description of the drawings]

FIG. 1 is a front view showing a configuration example of a magnifying optical system of a head mounted display to which the present invention is applied.

FIG. 2 is a top view illustrating a configuration example of a magnifying optical system of a head mounted display to which the present invention is applied.

FIG. 3 is a diagram illustrating the shape of a mirror angle control guide surface 21;

FIG. 4 is a block diagram showing an example of an electrical configuration of an image control system of a head mounted display to which the present invention is applied.

FIG. 5 is a diagram for explaining processing of a control circuit 34;

FIG. 6 is a diagram for explaining processing of a control circuit 34;

FIG. 7 is a block diagram showing a detailed configuration example of the position detection sensor 10.

FIG. 8 is a front block diagram showing another configuration example of the magnifying optical system of the head mounted display to which the present invention is applied.

FIG. 9 is a view for explaining parallel movement of the reflection mirror 3 of FIG. 8;

FIG. 10 is a diagram illustrating the operation of the reflection mirror 3 of FIG.

FIG. 11 is a side block diagram showing another configuration example of the magnifying optical system of the head mounted display to which the present invention is applied.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 LED array 2 Lens 3 Reflection mirror 3A Reflection mirror left edge 3B Reflection mirror right edge 4 Mirror support shaft 5 Axis holder 6 Motor 7 Gear 8 Belt 9 Axis 10 Position detection sensor 11 Pulley 12 Pulley 21 Mirror angle control guide surface 22 Mirror support guide surface 31 Frame memory 32 Register 33 Latch circuit 34 Control circuit 35 Mirror drive circuit 51 Motor 52 Gear 53 Gear 54 Mirror support rod 55 Leaf spring material

Claims (16)

[Claims] 1. An image display device mounted on a user's head for displaying an image, comprising: display means for displaying a plurality of pixels which are linearly continuous; and reflection means for reflecting light of the pixels displayed by the display means. Means for moving the position where the light of the pixel is reflected by the reflecting means; and setting for setting the angle of the light reflected by the reflecting means in accordance with the position moved by the moving means. An image display apparatus comprising: a control unit that controls the display timing of the display unit and the moving cycle of the moving unit in a linked manner. 2. The image display device according to claim 1, wherein the moving unit moves the reflecting unit in a direction orthogonal to a straight line formed by pixels displayed by the display unit. 3. The image display device according to claim 1, wherein the control unit turns off the display of the display unit when the reflection unit moves in a predetermined direction. 4. The image display device according to claim 1, further comprising a detection unit configured to detect a position of the reflection unit. 5. The image display device according to claim 1, wherein said moving means includes a linear motor. 6. The image display device according to claim 1, wherein said moving means includes a belt. 7. The image display device according to claim 1, wherein said moving means includes a gear. 8. The image display device according to claim 7, wherein the reflection unit is connected to a support rod connected to the gear via an elastic body. 9. The image display device according to claim 7, wherein said reflection means vibrates in a forced synchronous manner with movement of said support rod. 10. The display means is an LED array,
10. The image display device according to claim 1, wherein pixels of one vertical column or one horizontal row of the image are simultaneously displayed. 11. The image display device according to claim 1, wherein said reflection means is a plane reflection mirror. 12. The depth of the plane reflecting mirror in the line of sight is D / s, where D is the pupil diameter of the user and FOV is the angle of view.
12. The method according to claim 11, wherein the value is about in (FOV / 2).
An image display device according to claim 1. 13. A length X perpendicular to a center line of the plane reflecting mirror with respect to the center line of the angle of view is defined by: L is a distance between the center point of the plane reflecting mirror and the viewpoint on the center line of the angle of view. When the angle between the center line of the angle of view and the plane reflecting mirror is θ, and the angle between the center line of the angle of view and the line connecting the display unit and the plane reflecting mirror is α, The image display device according to claim 11, wherein X = Ltan (2θ−α) is satisfied. 14. The image display apparatus according to claim 11, wherein said setting means is a guide for controlling an angle of said plane reflecting mirror. 15. The shape (x ₁ , y ₁ ) of the guide is such that a distance between a center point of the plane reflecting mirror and a viewpoint on a center line of an angle of view is L, a width of the plane reflecting mirror is 2d, Assuming that the angle between the center line of the angle of view and the plane reflecting mirror is θ, x ₁ = {L + dsin ((π / 4) − (θ / 2))} tan θ
+ Dcos ((π / 4) - (θ / 2)) y 1 = dsin ((π / 4) - (θ / 2)) The image display apparatus according to claim 14, characterized in that meet. 16. An image display method of an image display device mounted on a user's head and displaying an image, comprising: a display step of displaying a plurality of pixels that are linearly continuous; and a light of the pixels displayed in the display step. A reflecting step of reflecting light, a moving step of moving a position where the light of the pixel is reflected in the reflecting step, and an angle of light reflected in the reflecting step corresponding to the position moved in the moving step. And a control step of linking and controlling the display timing of the display step and the movement cycle of the movement step.