JPH0749464A - Head installation type display device - Google Patents

Abstract

PURPOSE:To reduce an adverse effect due to conduction of stereoscopic observation for a long time in a display device having a head part on board. CONSTITUTION:A head installation type display device 1 having two display parts 4 built in a box body 2 and a belt 3 for installing the box body 2 on the head part is provided with a convergence angle regulating means 5 for regulating the convergence angle formed by the visual lines of both eyes in the display part 4; and a focus distance regulating means 6 for regulating the focus distance with the eyes in the display part 4, and the convergence angle and the focus distance are regulated and changed every prescribed time by the convergence angle regulating means 5 and the focus distance regulating means 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a head-mounted display device, and more particularly to a head-mounted display device (hereinafter, HMD: Head Mounted D) for displaying a stereoscopic image of a twin-lens type.
called isplay).

BACKGROUND OF THE INVENTION A typical display device in recent years is a CRT (CathodeRay TRT).
ube) display device and liquid crystal display device (hereinafter, LCD: Liquid
d Crystal Display)).

When a stereoscopic image is displayed using a display device such as a CRT display device or an LCD, first, two images for the left eye and one for the right eye are alternately displayed, and the two images are used exactly. Each eye creates the same line of sight as when looking at the real thing, then using deflection glasses, liquid crystal goggles, etc., the two images are momentarily blinked alternately right and left in a timely manner for viewing. It gives a double image to a person, and also a three-dimensional image. By the way, the position of the stereoscopic image at this time is related to the distance between the two images.

A display device using a CRT display device is, for example, a desktop type EWS (Engi
neering Work Station), personal computer (hereinafter simply referred to as PC), word processor (hereinafter,
It is a general display device in a word processor, etc.), and has the advantage of being able to obtain a large-screen display device at a relatively low cost.
When obtaining a large-screen display device, the size of the CRT display device itself becomes large, and there is a drawback that the installation place is limited.

On the other hand, the LCD has low power consumption and is lightweight.
Because of its thinness, it is often used as a display device for laptop and notebook type personal computers, word processors, etc., but generally it is difficult to increase the screen size, and when the screen size increases, the cost is higher than that size. There is a drawback of this.

Therefore, the HMD has been attracting attention as a display device that can have a large screen regardless of the installation location.

[0007]

2. Description of the Related Art A so-called stereoscopic effect such as depth and perspective when viewing an object can be obtained by seeing different images with the left and right eyes. When you look at a familiar landscape for a test and alternately close one of the eyes, you will notice various differences. In order to artificially create a stereoscopic effect, two images with such a difference can be shown to the left and right eyes, and this technology is called the "binocular parallax method".
Say.

[0008] The HMD is a pair of liquid crystal displays arranged in front of the eyes, and displays two images having the above-mentioned difference, and sets the convergence angle and the focal length to predetermined values, thereby spectacles and binoculars. As shown in FIG. 8, the left and right liquid crystal displays are displayed as if viewing a large screen display device with a small device by giving different images to both eyes. When artificially giving a convergence angle of 3 degrees with a tilt of 1.5 degrees with respect to the plane where the image is formed, a person with a distance between both eyes of 65 mm (this value is the average value of Japanese people) is about 1.24 m. Considering to look ahead, we realized a 30-degree angle of view by combining a 0.7-inch type liquid crystal display and a lens with a focal length of about 27 mm, and the distance between the liquid crystal display and the lens was 26.4 m.
At m, an optical system having a display screen of about 33 inches at 1.24 m can be obtained.

Further, since the HMD has independent display units for the left eye and the right eye, respectively, an image for the left eye and an image for the right eye are displayed by using deflection glasses, liquid crystal goggles or the like like a CRT display device or an LCD. There is no need to separate, and by using both visual differences, it is possible to display stereoscopically in "Virtual Reality" or "Pseudo 3D (three Dimension)" that makes you feel as if you are in the world. .

[0010]

However, it has been reported that such a conventional head-mounted display device is not good for the eyes when viewed for a long time because of the following reasons. .

That is, in normal viewing, the two images viewed by both eyes have a combination of the focusing distance and the line-of-sight angle determined according to the target distance, but an artificial stereoscopic effect is obtained. In this case, as shown in FIG. 9, the focusing distance is always kept at the position of the screen, and the line of sight is taken at various angles.

This is an unnatural state that is impossible in daily life, and if this unnatural state is continued for a long time, the time required to switch the focus is more than double that of a healthy person and the eyes are in focus. In cases where the "adjustment" of changing action is diagnosed as "abnormal", or when the eye movement is measured, both eyes should normally move symmetrically, but sometimes one eye stops moving. A symptom called "motion collapse" may appear. Whenever this "collaborative movement collapse" occurs, it is diagnosed as a strabismus.

As described above, continuing unreasonable stereoscopic vision without taking any measures may adversely affect the focus adjustment of the eyes.

[Purpose] In view of the above problems, it is an object of the present invention to reduce the adverse effects of long-term stereoscopic vision.

[0015]

According to the invention described in claim 1, as shown in FIG. 1, two display parts 4 built in a housing 2 and the housing 2 are mounted on a head. In the head-mounted display device 1 including the belt portion 3, the convergence angle adjusting means 5 for adjusting the convergence angle formed by the lines of sight of the eyes on the display portion 4 and the focal length between the eyes on the display portion 4 are adjusted. Focal length adjusting means 6, and by adjusting and changing the convergence angle and the focal length at predetermined intervals by the convergence angle adjusting means 5 and the focal length adjusting means 6,
It has achieved the above objectives.

In this case, in addition to the invention described in claim 1, as described in claim 2, when the convergence angle is adjusted by the convergence angle adjusting means in the direction of decreasing the convergence angle, the focal length adjusting means 6 It is effective to adjust the focal length so that the focal length becomes longer.

[0017]

According to the invention described in claim 1, since the convergence angle and the focal length are adjusted and changed by the convergence angle adjusting means and the focal length adjusting means at predetermined time intervals, one of the convergence angle and the focal length is determined. The combination is determined without being fixed.

As a result, the adverse effect of long-term stereoscopic vision is reduced.

In this case, according to the invention of claim 2,
When the convergence angle is adjusted by the convergence angle adjusting means to be smaller, the focal length adjusting means adjusts the focal length to be longer, so that the focal length with respect to the convergence angle is adjusted to a natural state. To be done.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to FIGS.
Will be described with reference to.

First, the configuration of this embodiment will be described.

FIG. 2 is an external view of the HMD 1 in this embodiment. In FIG. 2, the HMD 1 is composed of a housing 2 having a built-in display unit 4 and a stretchable belt unit 3 for mounting the housing 2 on the user's head.

FIG. 3 is a cross sectional view of the HMD 1 in this embodiment.

As shown in FIG. 3, the display section in the housing 2 is
A backlight 11 including a cold cathode tube (fluorescent lamp),
A reflector 12 that efficiently irradiates the light from the backlight 11 forward, an active matrix type color LCD 13L (13R) of about 1 inch size, and a color LCD 13L
Reflecting mirror 14 for reflecting the image displayed on (13R)
L (14R) and a convex lens 15L (15R) consisting of an optical lens made of glass, which is illuminated by the backlight 11 to produce a color LCD 13L (13R).
The image (light) transmitted through is reflected by the reflection mirror 14L (14R).
Is reflected by the convex lens 15L (15R) and reaches the eye EL (ER) of the operator.

In FIG. 3, 16 is a color LCD 13.
It is a guide rail that serves as a guide when the support member 13a that supports L (13R) is moved up and down by the drive unit 6 (focal length adjusting means).

FIG. 4 is a diagram for explaining the operation of the convergence angle adjusting means.

Here, the reflection mirror 14L (14R) is
It is rotatably provided around the shaft 17, and as shown in FIG. 4, by being driven by a drive motor 5 (convergence angle adjusting means) having a gear 5a that meshes with a gear 18 provided on the shaft 17, , Operator's eyes EL (ER)
The position can be adjusted in a horizontal position, that is, in the range from 0 ° to 3 ° outward.

FIG. 5 is a diagram for explaining the operation of the focus position adjusting means.

The color LCD 13L (13R) is
As shown in FIG. 5, a drive unit 6 having a wire 19 provided on the support member 13 a, pulleys 20 and 21 for holding the wire 19, and a gear meshing with a gear provided on the pulley 21.
Is guided by the guide rail 16 to move up and down, and the focal length with the eyes is adjusted.

FIG. 6 is a block diagram showing the arrangement of the main parts of the HMD 1 of this embodiment.

In FIG. 6, the HMD 1 is a reflection mirror 1.
Drive motor 5 for rotating 4L (14R) and collar L
The drive unit 6 that moves the CD 13L (13R) up and down, the driver 30 that outputs the display data to the color LCD 13L (13R), and the timer 31 that measures the time based on the display data output start time by the driver 30 are provided. .

FIG. 7 is a block diagram of the driver 30 shown in FIG.

The driver 30, as shown in FIG.
The R separation circuit 32, the L display driver 33L, the R display driver 33R, the L memory 34L, and the R memory 34R are included.

The L / R separation circuit 32 separates the display image data for the left eye and the display image data for the right eye based on a control signal from the outside so as to perform stereoscopic display from the input image data. The display image data for the left eye and the display image data for the right eye are image data created in advance with a predetermined parallax.

The L display driver 33L and the R display driver 33R drive the color LCDs 13L and 13R, respectively, based on the left eye display image data and the right eye display image data separated by the L / R separation circuit 32. The memory 34L for L and the memory 34R for R
Is an L display driver 33L and an R display driver 33
It is a buffer memory for temporarily storing the display image data for the left eye and the display image data for the right eye to be displayed by R.

Next, the operation (action) of this embodiment will be described.

In this embodiment, as in a normal movie, an image of 24 frames per second (a stereoscopic image in this embodiment) is displayed, so that a signal of one frame is output every 1/24 seconds as input data. Given, this 1-frame signal is 1/48
It is composed of display image data for the right eye and display image data for the left eye as one field signal per second.

Here, as the input data of the L / R separation circuit 32, the display image data for the right eye and the display image data for the left eye are alternately input, and 1 is input by the L / R separation circuit 32.
The display image data for the right eye and the display image data for the left eye are separated every / 48 seconds and are output to the L display driver 33L and the R display driver 33R, respectively.

Since each L display driver 33L and R display driver 33R receives only 1/48 second of input data, the 1/48 second of data is respectively transferred to L
By temporarily storing the memory 34L for R and the memory 34R for R as a field memory, it is possible to display the display image data for the right eye and the display image data for the left eye during one frame display period.

Here, for example, the left and right color LCDs 13
If the screen size of L and 13R is about 2 inches, and if the color LCDs 13L and 13R are placed 100 mm away from the positions of the eyes EL and ER, the left and right eyes EL looking at these display surfaces are displayed. , ER are completely combined, that is, the images displayed on the two screens are combined 1000 mm from the eyes EL and ER.
It's a distance. In this case, the combined screen has a size of about 20 inches.

As described above, in order to obtain a screen to be combined 1 m ahead of the eyes, the convex lenses 15L and 15R with a magnification of 2 are arranged in front of the left and right eyes EL and ER, 15 mm from the eyes EL and ER. The focal length f1 at a position 1 m ahead of the eyes EL and ER at the positions of the eyes EL and ER is 19.6.
If it is mm, the focal length f2 may be set to 197 mm. In this way, the left and right color LCDs 13L,
13R and the positions of the convex lenses 15L and 15R and the convex lens 1
When the focal lengths f2 of 5L and 15R are set, the images peeped in from the left and right finder parts are naturally combined, as if they were 1
The optical system is such that a 20-inch image exists at a distance of m, so that the displayed image can be viewed easily.

The focal length is calculated by [Equation 1].

[0043]

[Equation 1] In the case of such a configuration, the left and right color LCDs 13
The distance between L and 13R can be adjusted freely according to the distance between the eyes of the viewer.

In the optical system described above, the color LC
When stereoscopic display is performed by the D13L and 13R, as described above, the focus distance is the color LCD 13.
The line of sight is taken at various angles while being kept at the L and 13R positions at all times, and the operator sees the display image in an unnatural state that is not possible in daily life.

In order to reduce the harmful effects of continuing such a state for a long time, in this embodiment, the color LCD 13 is used.
When display data is input to L and 13R, the timer 31 is initialized and time measurement is started.

The timer 31 outputs a control signal to the drive motor 5 and the drive unit 6 every predetermined time (for example, 15 minutes), and drives based on this control signal. The reflection mirror 14L by the motor 5,
The angle of convergence is adjusted by adjusting the inclination of 14R, and the driving unit 6 causes the color LCDs 13L, 13
The focal length is adjusted by adjusting the position of R.

In this case, the relationship between the angle of convergence and the focal length is
When the convergence angle is reduced by the drive motor 5, the focal length is adjusted by the drive unit 6 so that the convergence angle and the focal length are adjusted in a natural state.

As a result, it is possible to view the stereoscopic display while maintaining the balance between the vergence angle and the focal length in the stereoscopic view that may adversely affect the focus adjustment of the eyes.

As described above, in the present embodiment, the convergence angle and the focal length are adjusted and changed by the drive motor 5 and the drive unit 6 at predetermined intervals, so that the convergence angle and the focal length become either. The combination is determined without being fixed.

As a result, adverse effects due to long-term stereoscopic vision are reduced.

Although the invention made by the present inventor has been specifically described based on the preferred embodiments, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the invention. Needless to say.

For example, in the above embodiment, the convergence angle and the focal length are adjusted every 15 minutes.
The time for adjusting the vergence angle and the focal length can be set arbitrarily.

In this case, since the vergence angle changes based on the displayed stereoscopic image, the focal length may be adjusted according to the change in the vergence angle.

In the above description, the invention mainly made by the inventor is applied to the head mounted display device which is the background field of use, but the invention is not limited thereto.

For example, it can be applied to all display devices for stereoscopic display.

[0056]

According to the first aspect of the present invention, both the convergence angle and the focal length are adjusted by adjusting and changing the convergence angle and the focal length at predetermined intervals by the convergence angle adjusting means and the focal length adjusting means. The combination can be determined without being fixed, and this can reduce the adverse effects of long-term stereoscopic viewing.

In this case, according to the second aspect of the invention, when the convergence angle adjusting means adjusts the convergence angle in the direction of decreasing, the focal length adjusting means adjusts the focal length in the direction of increasing the convergence angle. The focal length for can be adjusted in a natural direction.

[Brief description of drawings]

FIG. 1 is a principle diagram of a head-mounted display device according to the present invention.

FIG. 2 is an external view of the HMD in this embodiment.

FIG. 3 is a cross-sectional view of the HMD in this embodiment.

FIG. 4 is a diagram for explaining the operation of the convergence angle adjusting means.

FIG. 5 is a diagram for explaining the operation of the focus position adjusting means.

FIG. 6 is a block diagram showing a main configuration of an HMD of this embodiment.

FIG. 7 is a block diagram of the driver shown in FIG.

FIG. 8 is a diagram for explaining the operation principle of the HMD.

FIG. 9 is a diagram for explaining a problem of stereoscopic vision.

[Explanation of symbols]

 1 HMD (head mounted display device) 2 case 3 belt part 4 display part 5 drive motor (convergence angle adjusting means) 6 drive part (focal length adjusting means) 11 backlight 12 reflector 13L, 13R color LCD 13a support Member 14L, 14R Reflecting mirror 15L, 15R Convex lens 16 Guide rail 17 Shaft 18 Gear 19 Wire 20, 21 Pulley 30 Driver 31 Timer 32 L / R separation circuit 33L L display driver 33R R display driver 34L L memory 34R For R memory

Claims (2)

[Claims] 1. A head mounted display device comprising two display parts built in a housing and a belt part for mounting the housing on a head, wherein a convergence angle formed by the lines of sight of both eyes of the display part. And a focal length adjusting unit for adjusting the focal length with the eyes on the display unit, wherein the convergence angle adjusting unit and the focal length adjusting unit adjust the convergence angle at predetermined intervals. A head-mounted display device characterized by adjusting and changing the focal length. 2. The head according to claim 1, wherein when the vergence angle adjusting means adjusts the vergence angle in the direction of decreasing, the focal length adjusting means adjusts the focal length in the direction of increasing the focal length. On-board display device.