JPH10104549A - Head mounted display device - Google Patents

Abstract

(57) [Summary] [Problem] A head-mounted display device capable of always observing an electronic image without depending on an external image and obtaining a favorable composite observation image with the electronic image as a foreground with the external image as a background. . SOLUTION: An image display means (1) for displaying an image to be observed, and an observation optical system (2) for converting light from a display image of the image display means into light having a diopter appropriate for an observer. ), And reflecting light from the display image through the observation optical system toward the observation eye (5) and transmitting light from the outside toward the observation eye, whereby light from the display image and light from the outside world are transmitted. Optical path combining means for combining with light (11)
And a dimming means (3) for locally dimming light from the outside in order to selectively darken the background of the display image observed based on the light from the display image. .

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 see-through type head mounted display device.

[0002]

2. Description of the Related Art There has been proposed a head-mounted display device capable of displaying an image displayed on image display means fixed to a user's head in the entire visual field. In a head-mounted display device, a so-called so-called “external image” and an image displayed on an image display unit (hereinafter, referred to as an “electronic image”) can be superimposed and observed. There is a see-through type head mounted display device.

[0003]

In a conventional see-through type head mounted display device, a half mirror is used as a means for combining light from the outside world and light from an image display means. As a result, when the external image and the electronic image are superimposed and observed, it may be difficult to observe the electronic image depending on the external image. Further, since the external image is seen through the electronic image, a favorable composite observation image with the external image as the background and the electronic image as the foreground could not be obtained.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problem, and it is easy to always observe an electronic image without depending on an external image. It is an object of the present invention to provide a head mounted display device capable of obtaining an image.

[0005]

According to the present invention, there is provided an image display means for displaying an image to be observed, and light from a display image of the image display means is provided to an observer. An observation optical system for converting light into an appropriate diopter, and reflecting light from the display image through the observation optical system toward the observation eye and transmitting light from the outside toward the observation eye. An optical path combining means for combining light from the display image and light from the outside, and selectively darkening the background of the display image observed based on the light from the display image. And a dimming means for locally dimming the light from the outside world.

According to a preferred embodiment of the present invention, a polarizer disposed on the outside of the optical path combining means, and an analyzer for transmitting light from the outside polarized into a predetermined polarization state through the polarizer. Further comprising a liquid crystal layer disposed between the polarizer and the analyzer, for locally changing a polarization state of light from the outside via the polarizer. . Alternatively, the dimming unit has a liquid crystal layer disposed outside the optical path synthesizing unit and configured to locally scatter light from the outside. In this case, the liquid crystal layer is preferably a polymer dispersed liquid crystal layer.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, the background of an electronic image can be selectively darkened by locally dimming external light by dimming means composed of a liquid crystal layer, for example.
Specifically, for example, the polarization direction of external light that has been linearly polarized via a polarizer is locally changed by the action of a liquid crystal layer, and the external light whose polarization direction has not changed is transmitted through the analyzer as it is. The external light whose polarization direction has changed is reduced (or shielded) via an analyzer.

As a result, a dark background region is selectively formed as necessary on a part of the external image, and the electronic image is superimposed on the dark background region, so that the external image and the electronic image can be properly formed. Can be observed at the same time. In other words,
According to the present invention, it is possible to always easily observe an electronic image without depending on an external image, and to obtain a favorable observation image with the external image as a background and the electronic image as a foreground. Further, for example, external light can be locally scattered by the action of the polymer dispersed liquid crystal layer, and a dark background region can be selectively formed in a part of the external image. Then, by superimposing the electronic image on the dark background area, the external image and the electronic image can be simultaneously observed in a favorable state.

An embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a diagram schematically showing a configuration of a head mounted display device according to a first embodiment of the present invention. FIG. 2 is a sectional view showing the configuration of the assembly member 3 of FIG.

The head mounted display device shown in FIG. 1 is provided with an image display means composed of a CRT 1, for example. Light from the display image formed on the image display surface 1a of the CRT 1 is converted into light having an appropriate diopter via the observation optical system 2, and then enters the assembly member 3. The observation light reflected by the assembly member 3 reaches the observation eye 5 via the analyzer 4.
On the other hand, light from the outside including the object 7, that is, outside light, passes through the polarizer 6, the assembly member 3, and the analyzer 4 to the observation eye 5.
Reach

As shown in FIG. 2, the assembly member 3 includes a transparent substrate 8, a liquid crystal layer 9, and a transparent substrate 10 in order from the outside. In addition, between the transparent substrate 8 and the liquid crystal layer 9 and between the liquid crystal layer 9 and the transparent substrate 10, a transparent electrode layer,
Functional film (not shown) such as photoconductive layer, protective layer, anti-reflection film
Are formed as necessary. Further, the liquid crystal layer 9 has a function of locally changing the polarization state of external light polarized to a predetermined polarization state via the polarizer 6. Referring back to FIG. 1, a semi-transmissive film 11 is formed on the observation eye side of the analyzer 4, and this semi-transmissive film constitutes an optical path combining means for combining observation light and external light. .

Therefore, the external light 12 which has become, for example, linearly polarized light via the polarizer 6 is locally modulated via the liquid crystal layer 9 of the assembly member 3, and then transmits through the semi-transmissive film 11. On the other hand, the observation light incident on the semi-transmissive film 11 via the observation optical system is reflected by the semi-transmissive film 11 and combined with the external light transmitted through the semi-transmissive film 11. By the way, in the conventional head mounted display device, for example, when the external image includes an object as shown in FIG. 3, even if an electronic image composed of characters is superimposed on a background region outside the object, for example, the background of the object is bright. It was difficult to observe the electronic image.

In the first embodiment, the polarization direction of the external light, which has become, for example, linearly polarized light via the polarizer 6, is locally changed by the action of the liquid crystal layer 9. Therefore, the external light whose polarization direction has not changed passes through the analyzer 4 as it is,
The external light whose polarization direction has changed is reduced (or shielded) via the analyzer 4. As a result, as shown in FIG. 4, a dark background region is selectively formed outside the object as necessary,
By superimposing the electronic image on the dark background region, the external image and the electronic image can be simultaneously observed in a favorable state.

As described above, the liquid crystal layer 9 constitutes dimming means for locally dimming the external light.
Can selectively darken the background of the electronic image as required. As a result, in the first embodiment, it is possible to always easily observe the electronic image without depending on the external image, and to obtain a favorable composite observation image with the external image as the background and the electronic image as the foreground.

FIG. 5 is a diagram schematically showing a configuration of a head mounted display device according to a second embodiment of the present invention. The second embodiment has a configuration similar to that of the first embodiment. However, in the second embodiment, the liquid crystal layer 9 of the assembly member 3 has a function of locally scattering external light, and the polarizer 6 and the analyzer The fourth embodiment differs from the first embodiment only in that the fourth embodiment is not provided and that a semi-permeable membrane 11 is formed on the assembly member 3 on the observation eye side. Therefore, in FIG. 5, elements having the same functions as those of the components of the first embodiment are denoted by the same reference numerals as in FIG. Hereinafter, the second embodiment will be described focusing on the differences from the first embodiment.

In the second embodiment, the liquid crystal layer 9 of the assembly member 3 is
Is formed of, for example, a polymer dispersed liquid crystal layer.
Therefore, the external light passing through the liquid crystal layer 9 of the assembly member 3 is locally scattered, and a part of the external image is darkened in accordance with the local scattering of the external light. That is, also in the second embodiment, as in the first embodiment, a dark background region is selectively formed as necessary on a part of the external image, and an electronic image is superimposed on the dark background region, thereby obtaining The external image and the electronic image can be simultaneously observed in a favorable state.

In each of the above embodiments, since the position of the liquid crystal layer 9 of the assembly member 3 is not conjugate to the position of the outside world, the dark background area formed in a part of the outside world image by the action of the liquid crystal layer 9 is not formed. The observer sees it as a blurred image. This blurred image becomes large when the liquid crystal layer 9 of the assembly member 3 is too close to the pupil of the observation eye 5. Therefore, it is desirable that the liquid crystal layer 9 of the assembly member 3 be arranged at a distance of at least about 2 cm from the pupil of the observation eye 5.

In the first embodiment, the semi-permeable membrane 1
1 and the liquid crystal layer 9 are configured as separate members. However, as shown in the second embodiment, the semi-transmissive film 11 as the optical path synthesizing means and the liquid crystal layer 9 as the light reducing means can be integrally formed in the common assembly member 3. Further, in each of the above-described embodiments, the semi-transmissive film 11 is used as the optical path synthesizing means, but the optical path synthesizing means may be constituted by a polarization splitting film.

[0019]

As described above, according to the present invention, it is possible to easily observe an electronic image without depending on an external image, and obtain a good composite observation image with the external image as a background and the electronic image as a foreground. And a head-mounted display device that can be realized.

[Brief description of the drawings]

FIG. 1 is a view schematically showing a configuration of a head mounted display device according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing a configuration of an assembly member 3 of FIG.

FIG. 3 is a diagram showing an object observed in a conventional head mounted display device and an electronic image which is difficult to observe.

FIG. 4 is a diagram showing an object observed in the head mounted display device of the present invention and an electronic image which is easy to observe.

FIG. 5 is a diagram schematically showing a configuration of a head mounted display device according to a second embodiment of the present invention.

[Description of Signs] 1 CRT (image display means) 1a image display surface 2 observation optical system 3 assembly member 4 analyzer 5 observation eye 6 polarizer 7 object 8 substrate 9 liquid crystal layer 10 substrate 11 semi-transmissive film

Claims (5)

[Claims] 1. An image display unit for displaying an image to be observed, an observation optical system for converting light from a display image of the image display unit into light having a diopter appropriate for an observer, By reflecting light from the display image toward the observation eye via the observation optical system and transmitting light from the outside toward the observation eye, light from the display image and light from the outside world An optical path combining means for combining light from the outside image to selectively darken the background of the display image observed based on the light from the display image. A head-mounted display device comprising: an optical unit. 2. The optical system according to claim 1, further comprising: a polarizer disposed on an external side of the optical path combining unit; and an analyzer that transmits light from the external world polarized to a predetermined polarization state through the polarizer. The light means comprises a liquid crystal layer disposed between the polarizer and the analyzer, for locally changing a polarization state of light from the outside via the polarizer. 2. The head-mounted display device according to 1. 3. The device according to claim 1, wherein the dimming unit includes a liquid crystal layer disposed outside the optical path combining unit and configured to locally scatter light from the external environment. Head mounted display device. 4. The head mounted display device according to claim 3, wherein the liquid crystal layer is a polymer dispersed liquid crystal layer. 5. The head-mounted display device according to claim 1, wherein the dimming unit is arranged at a distance of at least 2 cm from a pupil of the observation eye. .