JP3328028B2 - Head mounted video display - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a head mounted image display device.

[0002]

2. Description of the Related Art Conventionally, a head-mounted type which is held on an observer's head for the purpose of enjoying a large-screen image by an individual or to be able to carry the image outdoors and view the image. Video display devices have been devised.

For example, FIG. 5 shows an example of a conventional head-mounted image display device, and is a partial cross-sectional view showing a state where an observer is using the image display device. This head-mounted video display device 101 has a video display element 102 mounted on the observer's head and arranged in front of both eyes, and an audio reproduction element 103 for reproducing audio. These video display elements 102
And the audio reproduction element 103 are provided with a video signal supply code 104.
And a video / audio signal supply unit (not shown) via an audio signal supply cord 105.

[0006] A projection optical system 107 is mounted in the device opening 106 at a position near the face of the image display element 102. The projection optical system 107 is arranged at a predetermined distance from the image display element 102 so that the image displayed on the image display element 102 is enlarged and projected into the eyeball 108 of the observer.

[0005] With such a head-mounted image display device, the power of a large-screen image can be obtained with a small image display element, and the observer can enjoy the image in a comfortable posture without leaking image information to the surroundings. However, since there is an individual difference in the eye width of the observer, the image projected by the projection optical system 107 may not be properly guided into the eyeball 108 in some cases.

For this reason, Japanese Patent Application Laid-Open No. 2-82175, Japanese Patent Application Laid-Open No. Hei 4-26288, and Japanese Patent Application No. Hei 4-267504 disclose the projection optical system for the right eye and the left eye of the projection optical system according to the individual difference in the distance between the eyes. A head mounted image display device in which the distance between the exit pupils can be adjusted has been devised.

On the other hand, the head-mounted video display device is mounted on the observer's head, so that it is necessary to reduce the size and weight of the video display device in order to reduce fatigue and prevent danger. Used.

[0008]

However, an image display device using this liquid crystal has visual dependency. That is, in general, light emitted in a direction within about 5 ° from the normal direction of the liquid crystal display element has a high contrast, so that a good image can be obtained. However, a good image can be obtained in other directions. It will be difficult.

That is, the image display element 102 shown in FIG.
Since the numerical aperture of the light beam emitted from the projection optical system 107 is small, the diameter of the exit pupil of the exit pupil 109 by the projection optical system 107 is limited to a small value. Also, to increase the amount of light guided to the eyeball,
If it is attempted to enhance the light collecting property of the light from the image display device using a lens system or the like, the exit pupil is limited to a small size.

Therefore, in order for the observer 110 to obtain a good image, it is necessary to receive light for obtaining a good image on the entire surface of the left and right pupils 111 and 112 of the observer. The observer's pupil must be placed in the area where good light intersects.

In FIG. 6, since the left eye pupil 111 of the observer 110 overlaps the exit pupil 109, a good image is observed with the left eye, but the right eye pupil 112 deviates from the exit pupil 109. This indicates a state in which good images cannot be observed with the right eye and binocular vision cannot be performed.

In general, the observer does not know whether or not the observer is observing with both eyes, and in order to confirm this, he must close one eye and confirm whether or not he can observe both eyes.
In addition, it is difficult to know in which direction the device should be adjusted when the pupil is shifted. Therefore, the observer must perform complicated pupil alignment when using the head-mounted image display device.

Further, as shown in Japanese Patent Application Laid-Open No. 5-66340, providing a mechanism for photoelectrically detecting the pupil position of the observer and automatically adjusting the interpupillary distance complicates the apparatus. As a result, the weight, which is the most problematic for the head-mounted image display device, becomes heavy, and problems such as a poor feeling of wearing and fatigue due to long-term observation tend to occur.

The present invention has been made in view of the above-mentioned problems of the prior art, and has as its object to provide a head-mounted image display which allows a viewer to easily perform complicated pupil alignment operations. It is to provide a device.

[0015]

In order to achieve the above object, a head-mounted image display device according to the present invention comprises an image display means for displaying an image, and an image displayed on the image display means. In a head-mounted image display device including a projection optical system used to project into the eyeball of the observer,
An image interception unit that intercepts the image display to the image display unit or intercepts the image from the image display unit, and the observer in the optical path that guides the display image of the image display unit to the eyeball of the observer. The projection optical system includes at least one concave reflecting mirror or a translucent concave reflecting mirror arranged so that a pupil can be observed, and illuminating means for illuminating an eyeball of an observer to determine a pupil shift. In adjusting the pupil position of the observer, the image blocking means and the lighting means are operated.

[0016]

[0017]

According to the present invention, there is provided an image interception means for intercepting the image display on the image display means or intercepting the image from the image display means, and observing the image displayed on the image display means in an optical path for guiding the image to the observer's eyeball. A projection optical system having at least one concave reflecting mirror or a translucent concave reflecting mirror arranged so that the observer can observe the observer's pupil, and illumination for illuminating the observer's eyeball to determine pupil shift Means, when adjusting the position of the pupil of the observer, the image blocking means and the illuminating means are operated, so when the observer's own pupil is illuminated with the image display blocked, When an image is formed at a distance by a concave reflecting mirror or a translucent concave reflecting mirror, and the pupil of the observer does not match the exit pupil of the display device and there is a pupil shift, the observer views the distant image. Pupil shift because it cannot be seen in the axial direction Easily see that there, eye width and pupil shift adjustment can be performed in a simple operation based thereon.

[0018]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a head mounted image display apparatus according to the present invention.
FIG. 1 is a diagram showing the configuration of the first embodiment of the present invention, and this figure shows only an optical system for one of the right and left eyes. The image display device of the present embodiment has a visual axis A of the observer's eyeball E.
A beam splitter prism 2 having a semi-transmissive surface 3 coated on the joining surface so as to form an angle of about 45 ° with respect to the visual axis A; It comprises a concave reflecting mirror 4 arranged opposite to the image display element 1 with the beam splitter prism 2 interposed therebetween, and a backlight 5 arranged behind the liquid crystal image display element 1. The projection optical system that projects the light into the eyeball E includes a concave reflecting mirror 4 and a semi-transmissive surface 3. The focal point reflected by the semi-transmissive surface 3 of the concave reflecting mirror 4 is arranged so as to be located near the pupil of the observer's eyeball E.

In this embodiment, at the time of normal image observation, the light beam that has exited the image display device 1 is transmitted through the semi-transmissive surface 3 and is reflected by the concave reflecting mirror 4 to become substantially parallel light. Then, the light returns to the semi-transmissive surface 3 and is reflected this time, enters the eyeball E of the observer, and is displayed as a distant image in front of the observer.

In order to adjust the pupil shift and the interpupillary distance based on the present invention, the following interpupillary and pupil shift adjustments are performed. First,
Since the light from the image display element 1 is directly incident on the eyeball E of the observer, it becomes an obstacle when adjusting the pupil shift. In view of this, the display circuit of the image display element 1 is provided with an electric image cut-off means so that the image signal is stopped so that the screen becomes dark when the pupil shift is adjusted.

In addition to the above-described method of electrically stopping the video signal, when a liquid crystal video display device is used, the liquid crystal video display element itself is not a light-emitting display element. Since the backlight 5 is always required, the backlight 5 may be turned off. Further, it is of course possible to block the display light with a mechanical shutter or the like.

When the pupil shift is adjusted, the above-mentioned eyepiece optical system reflects light from the pupil of the observer placed near the focal point of the concave reflecting mirror 4 toward the concave reflecting mirror 4 via the semi-transmissive surface 3. Then, the light is reflected by the concave reflecting mirror 4 in the opposite direction to become substantially parallel light, which is again reflected by the semi-transmissive surface 3 in the direction of the pupil of the observer, and is guided to the eyeball E of the observer as a substantially parallel light flux. Is observed as a distant virtual image. If the observer's pupil does not match the exit pupil of the display device and there is a pupil shift, it is not possible to see the image of his own pupil in the visual axis direction. By adjusting the interpupillary adjustment mechanism of the video display device (not shown), the image of the pupil of the user can be viewed in the visual axis direction.

In the case of the present embodiment, the observer is informed that the pupil position is deviated by using the eyeball E of the observer itself. In this case, when the focal length of the concave reflecting mirror 4 is f and the distance between the concave reflecting mirror 4 and the iris of the observer's eye E is d, it is important that f is substantially equal to d. If the condition is remarkably deviated, the virtual image of the iris reflected by the concave reflecting mirror 4 cannot be distant, so that the observer cannot clearly observe the image of the iris.

In order to observe the image of the pupil of the observer, illumination means for illuminating the pupil is required. As described above, if the image from the video display element 1 is blocked when the video display device is mounted, the inside of the device becomes dark and the observer's pupil cannot be observed. Therefore, illumination means for illuminating the observer's pupil is required. In the case of the present embodiment, the light source 6 such as an LED, a miniature light bulb or the like is arranged outside the field of view, and is turned on only when the pupil shift is adjusted. An interlocking means (not shown) is provided for interlocking the lighting of the illuminating means 6 and the operation of the above-mentioned image intercepting means. It is designed to block light.

In this embodiment, the observer observes the image of his own eye E when adjusting the pupil shift, and his own eye E
By adjusting the position of the image display device so that the image of the eyeball is at the center of the screen, the exit pupil position of the eyepiece optical system and the iris position of the eyeball E can be matched. Instead of looking at the image of the iris of the eye E, the eyeball E and the prism 2
A liquid crystal image display element for displaying an index such as a crosshair for pupil alignment is separately arranged, and the index is reflected by the concave reflecting mirror 4 to form a virtual image thereof at a distance, thereby causing a pupil shift. Can be similarly determined.

[0026]

Next, a second embodiment will be described with reference to FIG. In this embodiment, a semi-transparent concave reflecting mirror 4 'is used as a concave reflecting mirror, and the semi-transmitting surface 3 is constituted by a pellicle beam splitter. In the case of the first embodiment, the concave reflecting mirror 4 is a beam splitter prism 2
Was placed facing the video display element 1 with the
In this embodiment, the translucent concave reflecting mirror 4 'is disposed in front of the translucent surface 3 in front of the visual axis A.

In this embodiment, at the time of normal image observation, the light beam that has exited the image display device 1 is reflected by the semi-transmissive surface 3, and is reflected by the semi-transparent concave reflecting mirror 4 ', and then becomes substantially parallel light. It returns to the semi-transmissive surface 3 as a distant image, and is transmitted this time, enters the eyeball E of the observer, and is displayed as a distant image in front of the observer. When the translucent concave reflecting mirror 4 'is used in such an arrangement, it is possible to perform a so-called superimposition in which an image of the image display element 1 is displayed while being superimposed on an external image.

In this embodiment, a backlight 5 such as a fluorescent tube used in the case of the liquid crystal display 1 is used as an illuminating means for illuminating the eyeball E of the observer, which is a pupil shift indicator.
The illumination light is guided to the illumination position using a light guide 7 or the like, and the illumination is performed. Alternatively,
An external light may be introduced by providing an opening.

The third embodiment will be described with reference to FIG. This embodiment is basically the same as the first embodiment, except that an eyepiece 8 composed of a positive lens is used for the projection optical system. In the case of this example, the liquid crystal image display element 1 is disposed in front of the visual axis A, and the eyeball E and the image display element 1 are arranged.
An eyepiece 8 composed of a positive lens is arranged between the eyepieces 8 and, during normal image observation, the light beam that has exited the image display element 1 becomes substantially parallel light by the eyepiece 8 and becomes a distant image. And is displayed as a distant image in front of the observer.

Then, a translucent concave reflecting mirror 9 is arranged between the eyeball E and the eyepiece 8, and the concave reflecting mirror 9 allows the iris of the observer eyeball E, which is a pupil shift indicator, to be observed as a distant virtual image. I have. In the first and second embodiments, the concave reflecting mirrors 4 and 4 'of the projection optical system are used to image the iris of the eyeball E in order to adjust the pupil shift. Translucent concave reflecting mirror 9 for imaging only E iris
Is arranged separately from the eyepiece 8 of the projection optical system.

The semi-transparent concave reflecting mirror 9 may be provided with, for example, a liquid crystal shutter to include the above-mentioned image blocking means, or may be configured so that the concave reflecting mirror is inserted into the optical path only when the pupil shift is adjusted. You may. Further, if the translucent concave reflecting mirror 9 is kept inserted in the optical path, the illumination light for illuminating the pupil shift indicator is blocked during image observation,
It does not hinder video observation in practical use.

[0033]

[0034]

Next, a fourth embodiment will be described with reference to FIG. In this embodiment, head mounting is achieved by integrally providing two identical display devices having the pupil shift adjusting means according to any of the first to third embodiments so as to correspond to the left and right eyes of the wearer. This is an embodiment in which a type visual display device is configured, and the interpupillary distance between both display devices is adjustable.
FIG. 4A is a plan view showing a state in which the head-mounted visual display device is worn by a wearer, and FIG. 4B is a perspective view at that time. In FIG. It is a display device for the left eye and the right eye, and has a pupil shift adjusting unit as shown in FIGS. In the head-arriving visual display device, a clear observation image cannot be observed unless the exit pupil on the device side and the pupil on the observer side coincide with each other depending on the wearing state of the observer. Because of this pupil alignment, the wearer operates the head-mounted visual display device while observing an image, so that pupil alignment becomes extremely difficult. However, by incorporating the above-described pupil shift adjusting means and providing a well-known interpupillary adjusting mechanism between the two display devices 12 and 13, it is more preferable that the display screens of the display devices 12 and 13 have a video display screen and By allowing the explanation screen for the pupil adjustment method to be displayed alternately, pupil alignment can be easily performed.

While the head mounted image display device of the present invention has been described based on several embodiments, the present invention is not limited to these embodiments, and various modifications are possible.

[0037]

As is apparent from the above description, according to the head mounted image display apparatus of the present invention, the image display means for interrupting the image display on the image display means or the image from the image display means. And projection optics having at least one concave reflecting mirror or translucent concave reflecting mirror arranged in the optical path for guiding the display image of the image display means to the eyeball of the observer so that the observer can observe the observer's pupil. System, having illumination means for illuminating the observer's eyeball to determine pupil shift,
When adjusting the observer's pupil position, the image blocking means and the illuminating means are operated, so that when the observer's own pupil is illuminated in a state where the image display is interrupted, those images become concave reflectors or When an image is formed in the distance by the translucent concave reflecting mirror and the pupil of the observer does not match the exit pupil of the present display device and there is a pupil shift, the observer can view the distant image in the visual axis direction. Because it is not possible, it is easy to see that there is a pupil shift,
Based on this, the interpupillary distance and pupil shift can be adjusted by a simple operation.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a first embodiment of a head mounted video display device of the present invention.

FIG. 2 is a diagram showing a configuration of a second embodiment.

FIG. 3 is a diagram illustrating a configuration of a third embodiment.

FIG. 4 is a plan view and a perspective view showing a state in which a head-mounted visual display device according to a fourth embodiment is mounted.

FIG. 5 is a partial cross-sectional view illustrating an example of a conventional head-mounted image display device.

FIG. 6 is a plan view showing a state in which the exit pupil of the head-mounted image display device and the pupil of the observer are shifted.

[Explanation of symbols]

 E: observer's eyeball A: visual axis 1 ... liquid crystal image display element 2 ... beam splitter prism 3 ... semi-transmissive surface 4 ... concave reflecting mirror 4 '... translucent concave reflecting mirror 5 ... backlight 6 ... light source 7 ... light guide 8 ... eyepiece lens 9 ... translucent concave reflecting mirror 12, 13 ... display device

Claims (7)

(57) [Claims] 1. A head mounted image display device comprising: image display means for displaying an image; and a projection optical system used to project the image displayed on the image display means into an eyeball of an observer. in the image blocking means for blocking an image from the image display unit or block the video display to the video display unit, watching the viewer in the optical path for guiding to the eye the display image of said image display means
Before having at least one concave or semi-transparent concave reflector arranged so that the observer can observe the observer's pupil
Operation and Kito projection optical system, and a lighting means for illuminating the observer's eye to determine the pupil displacement, when adjusting the pupil position of the observer, said illuminating means and said image blocking means A head-mounted image display device, characterized in that the head-mounted image display device is adapted to be operated. 2. The image forming apparatus according to claim 1, wherein the projection optical system includes the at least one concave reflecting mirror or translucent concave reflecting mirror, and a reflective / transmissive surface having both a function of transmitting light and a function of reflecting light. The image light beam emitted from the display means is folded between the concave reflecting mirror or the translucent concave reflecting mirror and the reflective / transmissive surface to form a folded optical path, whereby the optical path is folded to reduce the size of the projection optical system. The head-mounted image display device according to claim 1 , wherein the head-mounted image display device is configured to be realized. 3. When the lighting means is turned on, the image cutoff means is operated in conjunction with the lighting of the lighting means, so that the image is darkened without displaying an image on the screen of the image display means, and pupil shift adjustment is performed. 3. The apparatus according to claim 2, wherein
The head-mounted image display device according to claim 1. 4. The image display means has a display circuit for receiving and displaying an image signal electrically, the image cutoff means includes an electric image cutoff means in a display circuit of the image display means, The image is darkened without displaying an image on the screen of the image display means by stopping the image signal by the electric image cutoff means.
4. The head mounted image display device according to 2 or 3 . 5. The image display means includes an image display element having a screen for displaying an image, and a backlight disposed at a position opposite to the projection optical system with respect to the image display element. 4. The image display device according to claim 2 , wherein the image blocking unit turns off the backlight of the image display unit to darken the image without displaying the image on the screen of the image display unit.
The head-mounted image display device according to claim 1. 6. The head mounted image display device according to claim 2, wherein said image cutoff means is constituted by a mechanical shutter. 7. A head-mounted image display device for a right eye, wherein the head-mounted image display device guides an image to a right eye of an observer,
A head-mounted image display device for the left eye that guides an image to the left eye of the observer, and an interval between the head-mounted image display device for the right eye and the head-mounted image display device for the left eye The head-mounted image display device according to any one of claims 1 to 6 , wherein a viewer's eye width can be adjusted by changing.