JPH07270714A - Eyeball projection type video display device - Google Patents

Abstract

PURPOSE:To miniaturize an eyeball projection type video display device having a see-through function. CONSTITUTION:This eyeball projection type video display device has a clock transmission type LCD31 which displays videos, a concave half mirror 34 and half mirror 35 which make the videos displayed on this transmission type LCD31 and the external light 33 transmitting through the transmission type LCD31 incident on the inside of the eyeball 33 of an observer, a back light 36 for the transmission type LCD31 which is arranged on the outer side of the optical path of this external light 32, a reflection type louver optical system 38 which has plural reflection surfaces, reflects a part of illuminating light 37 from the back light 36 by these reflection surfaces, allows transmission of a part of the external light 32 and makes the reflected illuminating light 37 and the transmitted external light 32 made incident on the transmission type LCD31 and a liquid crystal shutter 39 which switches over the transmission and shielding of the external light 32.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is capable of observing an image displayed on an image display device, which is attached to the face or head of an observer, and an external image can be observed by opening and closing a liquid crystal shutter or the like. The present invention relates to an eyeball projection type image display device having a so-called see-through function.

[0002]

2. Description of the Related Art Conventionally, as an eyeball projection type image display device having a so-called see-through function, for example, Japanese Patent Laid-Open No. 2-1
The one described in No. 32411 is known. Figure 10
FIG. 1 is a schematic configuration diagram of a conventional eyeball projection type image display device. In this eyeball projection type image display device, the display light 2 emitted from the CRT 1 is made incident on the half mirror 4 via the collimator 3. Display light 2 incident on the half mirror 4
Is reflected by the reflecting surface 5, passes through the concave half mirror 6, and enters the half mirror 7. The display light 2 that has entered the half mirror 7 is reflected by the reflecting surface 8, enters the concave half mirror 6 again, is reflected by the reflecting surface 9 and enters the eyeball 10.
On the other hand, when the shutter (not shown) is opened, the external light 11 causes the half mirror 4, the concave half mirror 6 and the half mirror 7 to be exposed.
And is incident on the eyeball 10. In such an eyeball projection type image display device, the external image can be observed together with the image displayed by the CRT.

[0003]

However, in the conventional eyeball projection type image display device, the CRT 1 is arranged outside the optical path of the external light 11, and the display light 2 from the CRT 1 is divided into the half mirror 7 and the concave half mirror 6. Since the half mirror 4 is used so that the magnified image can be observed by reflecting the light between the two devices, the whole apparatus becomes large. A liquid crystal display may be used instead of the CRT 1, but in this case, since a backlight is usually used, the see-through function is lost in such an arrangement.

An object of the present invention is to achieve miniaturization of an eyeball projection type image display device having a see-through function.

[0005]

SUMMARY OF THE INVENTION An eyeball projection type image display device of the present invention includes a transmissive liquid crystal display element for displaying an image, an image displayed on the transmissive liquid crystal display element and the transmissive liquid crystal display element. A projection optical system that allows the transmitted external light flux to enter the observer's eyeball, a light source for the transmissive liquid crystal display element arranged outside the optical path of the external light flux, and a plurality of reflective surfaces. And a split type partial reflection / transmission optical system for reflecting the light flux from the light source by the reflecting surface, transmitting the external light flux, and allowing the reflected and transmitted light flux to enter the transmissive liquid crystal display element. It is a thing.

[0006]

In the eyeball projection type image display apparatus of the present invention, the external light flux passes through the split type partial reflection transmission optical system and the transmission type liquid crystal display element and is incident on the observer's eyeball by the projection optical system. On the other hand, the light flux from the light source is reflected by the split type partial reflection / transmission optical system and is incident on the transmission type liquid crystal display element, and then is incident on the eyeball of the observer by the projection optical system.

Since the split type partial reflection / transmission optical system is used as an optical path synthesizing means for synthesizing the external light flux and the light flux from the light source, the conventional eyeball which synthesizes the external light flux and the light flux from the light source by using a half mirror. As compared with the projection type image display device, the eyeball projection type image display device having the see-through function can be downsized. Further, since the light source is arranged outside the optical path of the external light flux, it does not obstruct the optical path of the external light flux, and the observer can observe a good external image.

In the present invention, the image on the liquid crystal display device may be directly observed and observed, in which case a projection optical system is not particularly required. In this case, the eyeball projection type image display device, a transmissive liquid crystal display element for displaying an image, a light source for a transmissive liquid crystal display element arranged outside the optical path of the external light flux transmitted through the transmissive liquid crystal display element, It has a plurality of reflecting surfaces, reflects a part of the light flux from the light source by these reflecting surfaces, and transmits a part of the external light flux,
And a split type partial reflection / transmission optical system for making the reflected and transmitted light flux enter the transmission type liquid crystal display element. In this eyeball projection type image display device, not only the external image but also the image displayed on the transmissive liquid crystal display element can be observed, and the downsizing of the eyeball projection type image display device can be achieved.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an eyeball projection type image display device of the present invention will be described in detail with reference to the drawings. FIG. 1 is an overall view of a head mounted device (HMD) using an eyeball projection type image display device of the present invention. The HMD 21 is a video display device (not shown),
An eyepiece system that forms an exit pupil by the light flux from the image display element, and a face-mounting section 22 in which a semi-transmissive reflection member having a periodic arrangement in which a reflection area and a transmission area are repeated a plurality of times are incorporated, and an observer. And a headband 23 to be held on the head. The HMD 21 is connected to, for example, a television tuner 25 via a connection line 24. In this example, the television tuner 25 includes an ON / OFF switch 26 for performing an ON / OFF operation of the television tuner 25, an adjusting knob 27 for synchronizing with a television channel, and an antenna 28 for receiving a television signal.
And an earphone 29 to which the audio signal of the television signal received by the antenna 28 is transmitted.

FIG. 2 is a diagram showing a mounting state of the HMD.
Hereinafter, a method of using the HMD 21 will be described. While holding the HMD 21 on the observer's head with the headband 23,
The earphone 29 is attached to the observer's ear. Switch 26 to O
N and adjust knob 27 to tune to the desired television channel. Among the tuning television signals of the television channel received by the antenna 28, the audio signal is transmitted to the earphone 29 and the video signal is transmitted to the HMD 21 via the connection line 24. The observer listens to the sound through the earphone 29, and the face mounting unit 2
Observe the image shown in 2. The observer can also observe the external image by opening and closing a shutter or the like.

FIG. 3 is a schematic configuration diagram of a first embodiment of an eyeball projection type image display device of the present invention. The eyeball projection type image display device of this example is a transmissive liquid crystal display element (LC) for displaying an image.
D) 31, a concave half mirror 34 and a half mirror 35 for causing the image displayed on the transmissive LCD 31 and the external light 32 transmitted through the transmissive LCD 31 to enter the eyeball 33 of the observer, and the optical path of the external light 32. Has a backlight 36 for the transmissive LCD 31 arranged on the outer side and a plurality of reflecting surfaces, and these reflecting surfaces reflect a part of the illumination light 37 from the backlight 36 and a part of the external light 32. A louver optical system 38 that allows the transmitted illumination light 37 and the reflected illumination light 37 and the transmitted ambient light 32 to enter the transmission LCD 31, and a liquid crystal shutter 39 that switches between transmission and blocking of the ambient light 32.

The operation of this example will be described. Backlight 36
A part of the illumination light 37 emitted from is reflected by the reflection type louver optical system 38 and is incident on the transmission type LCD 31. When the illumination light 37 enters the transmissive LCD 31, the display light 40 is emitted from the transmissive LCD 31. This display light 40 is reflected by the half mirror 35 after passing through the concave half mirror 34. Reflected display light 40
Is a half mirror 3 after being reflected by the concave half mirror 34.
After passing through 5, the light enters the eyeball 33 of the observer. Since the display light 40 is reflected by the concave surface of the concave half mirror 34, the observer can observe an enlarged image of the image of the transmissive LCD 31.

On the other hand, when the liquid crystal shutter 39 is switched to be transmitted, the external light 32 is incident on the reflection type louver optical system 38. Part of the external light 32 is transmitted through the reflective louver optical system 38, and is incident on the eyeball 33 of the observer via the transmissive LCD 31, the concave half mirror 34 and the half mirror 35.
Therefore, the observer can directly observe the external image through the transmissive LCD 31, the concave half mirror 34, and the half mirror 35.

When only the image of the transmissive LCD 31 is desired to be observed, the liquid crystal shutter 39 is shielded and switched to the external light 3
By shutting off 2, the observer can observe only the image of the transmissive LCD 31.

FIG. 4 is a diagram showing how the reflective louver optical system used in the first embodiment transmits and reflects. In this example, as shown in FIG. 1, the reflective louver optical system 38 is arranged to be inclined with respect to the liquid crystal shutter 39, the transmissive LCD 31, the concave half mirror 34, and the half mirror 35 of FIG. Further, the reflective louver optical system 38 is provided with a plurality of reflective surfaces 38a having a predetermined angle with respect to this surface.

Transmission and reflection of the reflective louver optical system 38 will be described. Illumination light 37 emitted from the backlight 36 is reflected by the reflecting surface 38a, and then enters the transmissive LCD 31 of FIG. On the other hand, part of the external light 32 is reflected by the reflecting surface 38a or is absorbed when a light absorbing member is attached to the back side of the reflecting surface 38a, but part of the external light 32 passes between the reflecting surfaces 38a, and the outside light 32 of The light enters the observer's eyeball 33 through the transmissive LCD 31, the concave half mirror 34, and the half mirror 35.

FIG. 5 is a diagram showing the manner of transmission and reflection of another reflective louver optical system used in the first embodiment. As shown in FIG. 5, the reflective louver optical system 38 is connected to the liquid crystal shutter 39, the transmissive LCD 31, the concave half mirror 3 shown in FIG.
4 and the half mirror 35, and in this case, the reflecting surface 38a is arranged with respect to the surface of the reflective louver optical system 38 so that the illumination light 37 enters perpendicularly to the transmissive LCD 31. It is necessary to provide it at an angle different from that of the reflecting surface 38a of FIG.

As described above, in the first embodiment of the eyeball projection type image display apparatus of the present invention, the ambient light and the illumination light are superposed by using the reflection type louver optical system, and the superimposition is performed by using the half mirror. The entire device can be made thinner than in the case where it is performed, and therefore, the eye projection type image display device having a see-through function can be downsized.

Next, a second embodiment of the eyeball projection type image display device of the present invention will be described. The configuration and operation of this example are substantially the same as those of the first example except that a split reflection prism is used instead of the reflective louver optical system, and therefore the description of the overall configuration and operation is omitted, and the split reflection is omitted. Only transmission and reflection of the prism will be described. FIG. 6 is a diagram showing how the split reflective prism used in the second embodiment transmits and reflects. In this example, the split reflection prism 41 is
The liquid crystal shutter 39, the transmissive LCD 31, the concave half mirror 34, and the half mirror 35 of FIG. 3 are tilted, and the backlight 36 is arranged above the split reflection prism 41. The split reflection prism 41 has a plurality of partial reflection surfaces 41a, which are provided with a partial reflection coating, on the transmissive LCD 31 side. Further, on the liquid crystal shutter 39 side, a plurality of antireflection surfaces 41b parallel to the partial reflection surface 41a and provided with an antireflection coating are provided.

Transmission and reflection of the split reflection prism 41 will be described. Illumination light 37 emitted from the backlight 36 is reflected by the partial reflection surface 41a, and then enters the transmissive LCD 31 of FIG. On the other hand, the external light 32 passes through the split reflection prism 41, and enters the eyeball 33 of the observer through the transmissive LCD 31, the concave half mirror 34 and the half mirror 35 shown in FIG.

FIG. 7 is a diagram showing the state of transmission and reflection of another split reflection prism used in the second embodiment. Figure 7
3, the split reflection prism 41 may be arranged in parallel to the liquid crystal shutter 39, the transmissive LCD 31, the concave half mirror 34 and the half mirror 35 of FIG.
In this case, it is necessary to provide the partial reflection surface 41a and the antireflection surface 41b so that the illumination light 37 enters perpendicularly to the transmissive LCD 31.

As described above, in the second embodiment of the eyeball projection type image display apparatus of the present invention, it is possible to achieve downsizing of the eyeball projection type image display apparatus having the see-through function as in the case of the first embodiment. Moreover, since the vignetting of the external light is small, it becomes easier to observe the external image.

Next, a third embodiment of the eyeball projection type image display device of the present invention will be described. In this example, as the split type partial reflection / transmission optical system, a split reflection prism 41 having a shape obtained by combining two split reflection prisms shown in FIG. 7 is used, and illumination light is emitted using two backlights. Since the configuration and the operation are almost the same as those of the first and second embodiments, the description of the entire configuration and the operation is omitted, and only the transmission and reflection of the split reflection prism will be described. FIG. 8A shows the second
It is a figure which shows the mode of transmission and reflection of the division reflection prism used in an Example, (b) is a front view of this division reflection prism. In this example, the split reflection prism 41 is
The liquid crystal shutter 39, the transmissive LCD 31, the concave half mirror 34, and the half mirror 35 of FIG. 3 are parallel to the backlight 36, and the illumination light 36 is the transmissive L of FIG.
The split reflection prism 41 is arranged above and below the split reflection prism 41 so as to be incident perpendicularly to the CD 31.
Similar to the second embodiment, the split reflection prism 41 is a transmission type L
The CD 31 side has a plurality of partially reflective surfaces 41a having a partially reflective coating, and the liquid crystal shutter 39 side has a plurality of antireflective surfaces 41b parallel to the partially reflective surface 41a and having an antireflective coating.

Transmission and reflection of the split reflection prism 41 will be described. The illumination light 37 emitted from the upper backlight 36 is the partial reflection surface 41a of the upper half of the split reflection prism 41, and the illumination light 37 emitted from the lower backlight 36 is the partial reflection of the lower half of the split reflection prism 41. Surface 4
1a, respectively, and then the transmissive LCD 3 of FIG.
It is incident on 1. On the other hand, the external light 32 reflects the split reflection prism 4
1 through the transmissive LCD 31, the concave half mirror 34, and the half mirror 35 shown in FIG.
Is incident on.

As described above, in the third embodiment of the eyeball projection type image display apparatus of the present invention, the eyeball projection type image display apparatus having the see-through function can be miniaturized as in the case of the first and second embodiments. In addition, since the vignetting of the external light is small, the external image can be more easily observed, and since the illumination light is emitted by using two backlights, the entire device can be made thinner.

Next, a fourth embodiment of the eyeball projection type image display device of the present invention will be described. In this example, a disk-shaped split reflection prism 41 is used as the split type partial reflection / transmission optical system, and a ring-shaped backlight is used as the light source. The configuration and the operation are almost the same as those of the above-mentioned embodiment. FIG. 9A is a diagram showing how the split reflective prism used in the third embodiment transmits and reflects, and FIG. 9B is a front view of the split reflective prism. In this example, the split reflection prism 41 and the backlight 36 are arranged parallel to the liquid crystal shutter 39, the transmissive LCD 31, the concave half mirror 34, and the half mirror 35 of FIG. Similar to the second and third embodiments, the split reflection prism 41 has a plurality of partial reflection surfaces 4 provided with a partial reflection coating on the transmissive LCD 31 side.
1a has a plurality of antireflection surfaces 41b parallel to the partial reflection surface 41a and provided with an antireflection coating on the liquid crystal shutter 39 side. The transmission and reflection of the split reflection prism 41 are almost the same as in the third embodiment.

The present invention is not limited to the above-mentioned embodiments, but various modifications and changes can be made. For example, between the concave half mirror 34 and the half mirror 35, λ / 4
A plate may be placed to reduce direct light from the transmissive LCD 31. A mechanical shutter or the like may be used instead of the liquid crystal shutter 39. Further, a lens may be provided on the shutter side of the reflective louver optical system 38 or the split reflective prism 41 to form an external image once on the transmissive LCD 31. In addition, the split reflection prism 4
In the case of using No. 1, it is not necessary to apply the partial reflection coating to the partial reflection surface 41a and the antireflection coating to the antireflection surface 41b.

Preferred examples of the present invention are shown below. (1) The eyeball projection type image display device according to claim 1, further comprising a shutter for blocking and passing the external light flux.

(2) The eyeball projection type image display device according to any one of (1), (2), (3) or (1) above, characterized in that the shutter is provided outside the split type partial reflection / transmission optical system.

(3) The division type partial reflection / transmission optical system is a reflection type louver optical system.
2. The eyeball projection type image display device described in 2, 3, (1) or (2).

(4) The division type partial reflection / transmission optical system is a division reflection prism.
3. The eyeball projection type image display device according to 3, (1) or (2).

(5) The eyeball projection type image display device according to claim 1, wherein a plurality of the light sources are provided and a split type partial reflection / transmission optical system corresponding to each light source is further provided.

[0033]

As described above, according to the eyeball projection type image display apparatus of the present invention, since the split type partial reflection / transmission optical system is used as the optical path synthesizing means for synthesizing the external light flux and the light flux from the light source, It is possible to reduce the size of the eyeball projection type image display device having the see-through function as compared with the conventional eyeball type projection image display device which combines the external light flux and the light flux from the light source using the half mirror.

[Brief description of drawings]

FIG. 1 is an HM using an eyeball projection type image display device of the present invention.
It is a general view of D.

FIG. 2 is a diagram showing a mounting state of an HMD.

FIG. 3 is a schematic configuration diagram of a first embodiment of an eyeball projection type image display device of the present invention.

FIG. 4 is a diagram showing how the reflective louver optical system used in the first example transmits and reflects.

FIG. 5 is a diagram showing how a reflective louver optical system used in the first example transmits and reflects.

FIG. 6 is a diagram showing how a split reflecting prism used in a second embodiment transmits and reflects.

7A and 7B are diagrams showing the states of transmission and reflection of another split reflection prism used in the second embodiment.

FIG. 8A is a diagram showing a state of transmission and reflection of a split reflection prism used in a third embodiment, and FIG. 8B is a front view of the split reflection prism.

FIG. 9A is a diagram showing a state of transmission and reflection of a divided reflection prism used in a fourth embodiment, and FIG. 9B is a front view of this divided reflection prism.

FIG. 10 is a schematic configuration diagram of a conventional eyeball projection type image display device.

[Explanation of symbols]

 31 Transmissive LCD 32 External Light 33 Eyeball 34 Concave Half Mirror 35 Half Mirror 36 Backlight 37 Illumination Light 38 Reflective Louver Optical System 38a Reflective Surface 39 Liquid Crystal Shutter 40 Display Light 41 Divided Reflective Prism 41a Partially Reflective Surface 41b Antireflection Surface

Claims (3)

[Claims] 1. A transmissive liquid crystal display element for displaying an image, and projection optics for allowing an image displayed on the transmissive liquid crystal display element and an external light flux transmitted through the transmissive liquid crystal display element to enter an eyeball of an observer. A system, a light source for the transmissive liquid crystal display element arranged outside the optical path of the external light flux, and a plurality of reflecting surfaces, which reflect the light flux from the light source and the external light flux. Through the
An eyeball projection type image display device, comprising: a split type partial reflection / transmission optical system that allows reflected and transmitted light beams to enter the transmission type liquid crystal display element. 2. The eyeball projection type image display device according to claim 1, wherein the projection optical system has a concave half mirror and is provided with a shutter for blocking or passing external light from the external world. 3. A face mounting portion having an image display element and an eyepiece lens system for forming an exit pupil by a light flux from the image display element, and a support member for holding the face mounting portion on an observer's head. In the eyeball projection type image display device, the face mounting part includes a semi-transmissive reflection member having a periodic arrangement in which a reflection area and a transmission area are repeated a plurality of times, respectively.