JP3373265B2 - 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 video display device, and more particularly to a head-mounted video display device which can be mounted on a head to view a magnified virtual image.

[0002]

2. Description of the Related Art Conventionally, portable video display devices have been widely used. However, since it is portable, the display portion is small, and an object for holding the device is required, which makes it difficult to view the image while walking or while performing other work. In recent years, a head-mounted image display device has been proposed as a display device that solves these problems, and has been studied and developed, and is proposed in, for example, JP-A-4-131814.

FIG. 5 shows the configuration of a conventional head-mounted image display device. In FIG. 5, 51 is a liquid crystal display, 5
Reference numeral 2 is a reflection mirror, 53 is a convex lens, and 54 is a half mirror. In this conventional head-mounted image display device, the image displayed on the liquid crystal display 51 is reflected by the reflection mirror 52.
Is reflected by the convex lens 53 and enlarged as a virtual image, and the wearer can see the virtual image through the half mirror 54. At this time, the outside scenery can be seen at the same time.

[0004]

However, according to the above-mentioned conventional structure, there is a case where an image is observed in a state where the diopter adjustment is not sufficiently performed because the diopter adjustment is manually performed.
The degree of fatigue of the eyes was increased, and this was a cause of reduced visual acuity.
An object of the present invention is to provide a head-mounted image display device in which diopter adjustment is favorably performed and eye fatigue can be reduced.

[0005]

Head-mounted image display apparatus according to claim 1 Means for Solving the Problems] includes a video display unit, a magnifying optical system for enlarging a virtual image displayed by the video display means, expansion Forming state detecting means for detecting an image forming state on the retina of the image magnified by the image forming optical system ;
Direction and drive the image magnified by the magnifying optical system.
Image forming position changing means for changing the image forming position so as to form an image on the retina, and the image forming state detecting means and the image displaying means.
A line light source that is optically arranged at a conjugate position
These light fluxes are reflected and guided to the magnifying optical system, and at the retina
A half that transmits the light flux that is reflected and returned through the magnifying optical system.
It is placed in a position that is optically conjugate with the reflection means and the linear light source
The cross-sectional area of the light beam that has passed through
The light flux in one of the two areas
Light blocking means and the progress of the light flux not blocked by this light blocking means.
Located on the front side in the row direction, one area is shielded by the shading means.
Of two or more areas that are lined up in the same direction as the two areas
And a light detecting means for detecting the light intensity.

[0006]

[0007] head-mounted image display apparatus according to claim 2, wherein, in the head-mounted image display apparatus according to claim 1,
The wavelength of the light emitted from the linear light source exceeds 830 nm. Head-mounted image display apparatus according to claim 3, wherein, in the head-mounted image display apparatus according to claim 1,
The linear light source is an LED array. The head-mounted image display device according to claim 4 , wherein the image display means and the image display hand are provided.
For enlargement to enlarge the image displayed by the step as a virtual image
Retina of the image magnified by the optical system and the magnifying optical system
Image forming state detecting means for detecting the upper image forming state, and this image forming state
The information from the state detection means is used to drive the magnifying optical system
Image magnified by the magnifying optical system driven in the axial direction
Image formation position that changes the image formation position so that the image is formed on the retina
The image forming state detecting means includes a point light source optically arranged in a conjugate position with the image display means, and a light flux from the point light source is reflected and guided to the magnifying optical system and reflected by the retina. Then, the semi-reflecting means for transmitting the light flux returned through the magnifying optical system, the anamorphic optical system for generating an astigmatic difference in the light flux transmitted through the semi-reflecting means, and the anamorphic optical system are transmitted. The forward direction of the
In a direction not affected by the anamorphic optics
Influenced by the image formation point of the light flux and the anamorphic optical system
Direction of light flux positioned between the image point of the light flux
And a light detecting means for detecting the intensity distribution of the light flux on a plane perpendicular to the direction .

[0008] head-mounted image display apparatus according to claim 5, wherein, in the head-mounted image display apparatus according to claim 4,
The wavelength of the light emitted from the point light source exceeds 830 nm. Head-mounted image display apparatus according to claim 6, wherein, in the head-mounted image display apparatus according to claim 4,
The point light source is an LED.

[0009]

According to the structure of the present invention, by detecting the image forming state on the retina by the image forming state detecting means, the amount of deviation of the image forming position of the image is obtained, and from the information, the image forming position changing means is used. An optical system can be driven to form an image on the retina. Therefore, the image on the retina is always good, and the degree of eye fatigue can be reduced.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of the head-mounted image display apparatus of the first embodiment, and here, the configuration of only one eye is shown. In FIG. 1, 1 is an LED array, 2 is a half mirror, 3 is a wavelength selective mirror, 4 is a total reflection mirror, 5 is a magnifying lens (magnifying optical system), and 6 is a lens driving unit (imaging position changing means). , 7 is a half mirror, 8 is a light blocking member, 9 is a detection lens, 10 is a detector, 11 is a drive control unit (imaging position changing means), 12 is an EL backlight (image display means), and 13 is a liquid crystal display ( Image display means), 14 is a crystalline lens, and 15 is a retina. The image forming state detecting means includes an LED array 1 (line light source), a half mirror (semi-reflecting means) 2, a light blocking member (light blocking means) 8,
And a detector (light detecting means) 10. FIG. 4 is an external view of the head-mounted image display apparatus according to this embodiment when it is mounted.

The image displayed on the liquid crystal display 13 illuminated by the EL backlight 12 is imaged on the retina 15 by the magnifying lens 5 and the crystalline lens 14. That is, the wearer observes the enlarged virtual image. At this time, an LED that emits a light beam with a wavelength of 860 nm, which is optically arranged at a conjugate position with the liquid crystal display 13.
The light flux from the array 1 is reflected by the half mirror 2, the wavelength selective mirror 3 and the total reflection mirror 4 that reflect only the light flux of 830 nm or more, passes through the magnifying lens 5, and is reflected by the half mirror 7, and is reflected by the crystalline lens 14. It is guided up to the retina 15. The light beam reflected by the retina 15 passes through the lens 14, the half mirror 7, the magnifying lens 5, the total reflection mirror 4, the wavelength selective mirror 3, and the half mirror 2. The transmitted light flux has its half area blocked by the light blocking member 8 arranged at a position conjugate with the LED array 1, and is guided to the detector 10 by the detection lens 9. The detection lens 9 serves to conjugate the pupil of the eyeball and the detector 10.

When the image of the LED array 1 is formed on the retina 15 without defocusing, the light beam reflected by the retina 15 forms an image again at the position of the light shielding member 8 so that a half area is formed. After being blocked, the intensity distribution of the light flux reaching the detector 10 by the detection lens 9 becomes uniform. In this case, the image on the liquid crystal display 13 is also focused on the retina 15 without defocusing. Further, when the image of the LED array 1 is formed not on the retina 15 but on the side closer to the crystalline lens 14, the light flux reflected by the retina 15 is displaced not in the position of the light shielding member 8 but in the direction closer to the half mirror 2. The image is re-established in the correct position. In this case, after half the area is blocked by the light blocking member 8, the intensity distribution of the light flux reaching the detector 10 is not uniform, and the intensity on the blocked side becomes small. Also,
When the image of the LED array 1 is formed on the side away from the crystalline lens 14, the light flux reflected by the retina 15 is shielded by the light shielding member 8.
The image is formed again at a position deviated in the direction away from the half mirror 2 instead of at the position. In this case, after half the area is blocked by the light blocking member 8, the intensity distribution of the light flux reaching the detector 10 is not uniform, and the intensity on the blocked side becomes large.

The detector 10 outputs the intensity values in the two regions on the side where the light shielding member 8 is placed and the other side to the drive control unit 11. The drive control unit 11 determines from the output of each area,
It is determined whether the image is formed on the retina 15 or is deviated to either side, and if it is deviated, a signal is output to the lens driving unit 6 so as to move the magnifying lens 5 in the direction to be corrected.

As described above, according to this embodiment, the image formation state detecting means for detecting the image formation state on the retina 15 of the image enlarged by the magnifying lens 5 and the information from the image formation state detecting means are used. By providing the image forming position changing means for driving the magnifying lens 5 to change the image forming position, the image on the retina 15 is always good, and the eye fatigue can be reduced.

In this embodiment, the detector 10 has two
Uses a split photodiode array, but one-dimensional C
The same effect can be obtained with a CD. The same effect can be obtained even if the EL backlight 12 is replaced with a light emitting body such as a fluorescent lamp. Next, a second embodiment of the present invention will be described with reference to the drawings. Figure 2 is the second
It is a block diagram of the head-mounted image display apparatus of the embodiment of the above, and here, the configuration of only one eye is shown. In FIG. 2, 21 is an LED, 22 is a half mirror, 23 is a wavelength selective mirror, 24 is a total reflection mirror, 25 is a magnifying lens (magnifying optical system), 26 is a lens driving unit (imaging position changing means), Two
7 is a half mirror, 28 is a cylindrical lens, 29
Is a first image forming position, 30 is a second image forming position, 31 is a detector, 32 is a drive controller (image forming position changing means), and 33 is E.
L backlight (image display means), 34 is a liquid crystal display (image display means), 35 is a crystalline lens, and 36 is a retina. The image forming state detecting means is an LED (point light source) 21.
And a half mirror (semi-reflecting means) 22, a cylindrical lens (anamorphic optical system) 28, and a detector (light detecting means) 31. FIG. 3 is a diagram for explaining the detector 31. The external view of this embodiment at the time of mounting is the same as FIG. 4 shown in the first embodiment.

The image displayed on the liquid crystal display 34 illuminated by the EL backlight 32 is imaged on the retina 36 by the magnifying lens 25 and the crystalline lens 35. That is, the wearer observes the enlarged virtual image. At this time, an LED that emits a light beam having a wavelength of 860 nm, which is optically arranged at a conjugate position with the liquid crystal display 34.
The light flux from 21 is reflected by the half mirror 22, the wavelength selective mirror 23 and the total reflection mirror 24 that reflect only the light flux of 830 nm or more, passes through the magnifying lens 25, is reflected by the half mirror 27, and is retina by the crystalline lens 35. Guided up to 36. The luminous flux reflected by the retina 36 is the crystalline lens 35.
Then, the light is reflected by the half mirror 27, passes through the magnifying lens 25, is reflected by the total reflection mirror 24 and the wavelength selective mirror 23, and is transmitted through the half mirror 22. The transmitted light flux is refracted by the cylindrical lens 28 in only one direction, the light flux in the non-refractive direction gathers at the first image forming point 29, and the light flux in the refracted direction is in the second direction. It becomes a light beam that converges on the image point 30.

When the image of the LED 21 is formed on the retina 36 without defocusing, the first image forming position 2
9 is at a position conjugate with the LED 21, at which time the detector 3
No. 1 is arranged so that the signals of the four divided regions shown in FIG. 3A are (a + c) = (b + d). In this case, the image on the liquid crystal display 34 is also focused on the retina 36 without defocusing. Also, LE
When the image of D21 is formed not on the retina 36 but on the side close to the crystalline lens 35, the intensity distribution of the light flux reaching the detector 31 is as shown in FIG. 3B, and the output is (a + c)> (B
+ D). When the image of the LED 21 is formed on the side away from the lens 35, the intensity distribution of the light flux reaching the detector 31 is as shown in FIG. 3C, and the output is (a
+ C) <(b + d).

The detector 31 outputs (a + c)-(b + d) as a signal to the drive controller 32. The drive control unit 32 determines whether the image is formed on the retina 36 or is deviated from the positive or negative of the signal, and when it is deviated, the magnifying lens 25 is moved in a correcting direction. Thus, the signal is output to the lens driving unit 26. As described above, according to this embodiment, the image forming state detecting means for detecting the image forming state on the retina 36 of the image enlarged by the magnifying lens 25 and the magnifying lens 25 based on the information from the image forming state detecting means. By providing the image forming position changing means for driving the image forming device to change the image forming position, the image on the retina 36 is always improved and the degree of eye fatigue can be reduced.

In this embodiment, the detector 31 has four
Two-dimensional C
The same effect can be obtained with a CD. Further, the same effect can be obtained by replacing the EL backlight 33 with a light emitting body such as a fluorescent lamp.

[0020]

As described above, in the head-mounted image display device of the present invention, the amount of deviation of the image forming position of the image is obtained by detecting the image forming state on the retina by the image forming state detecting means. From that information, the optical system can be driven by the imaging position changing means to form an image on the retina. Therefore, the image on the retina is always improved automatically, and the degree of eye fatigue can be reduced.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a head-mounted image device according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a head-mounted image device according to a second embodiment of the present invention.

FIG. 3 is an explanatory diagram of a detector according to a second embodiment.

FIG. 4 is an external view of the first and second embodiments when mounted.

FIG. 5 is a configuration diagram of a conventional head-mounted image display device.

[Explanation of symbols]

1 LED Array (Linear Light Source) 2 Half Mirror (Semi-Reflecting Means) 5 Magnifying Lens (Magnifying Optical System) 6 Lens Driving Unit (Image Forming Position Changing Means) 8 Light Shielding Member (Light Shielding Means) 10 Detector (Light Detecting Means) 11 Drive Control Section (Image Forming Position Changing Means) 12 EL Backlight (Image Displaying Means) 13 Liquid Crystal Display (Image Displaying Means) 21 LED (Point Light Source) 22 Half Mirror (Semi-Reflecting Means) 25 Magnifying Lens (Magnifying Optical System) ) 26 lens drive section (imaging position changing means) 28 cylindrical lens (anamorphic optical system) 31 detector (light detecting means) 32 drive control section (imaging position changing means) 33 EL backlight (image display means) 34 Liquid crystal display (video display means)

─────────────────────────────────────────────────── --- Continuation of the front page (56) References JP-A-6-125515 (JP, A) JP-A-3-37039 (JP, A) JP-A-3-168623 (JP, A) JP-A-2- 252432 (JP, A) JP 61-172552 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G02B 27/02 H04N 5/64 511

Claims (6)

(57) [Claims] 1. A video display means and the video display means.
Magnification optical system that magnifies the image displayed as a virtual image
And on the retina of the image magnified by the magnifying optical system
Image forming state detecting means for detecting the image forming state of the
The magnifying optical system is controlled by the information from the state detecting means.
It is driven in the direction of the optical axis and magnified by the magnifying optical system.
Change the image formation position so that the captured image is formed on the retina.
And a image position changing means, the imaging condition detection means comprises a linear light source that is disposed on the image display unit is optically conjugate position to the magnifying optical system reflects the light beam from the line source A semi-reflecting unit that guides and transmits the light flux that is reflected by the retina and returned through the magnifying optical system, and is disposed at an optically conjugate position with the linear light source.
Of the light flux cross-sectional area of the light beam transmitted through the semi-reflecting means
Of one of the two areas that divide it in half across the center
Light blocking means for blocking the light beam , and one region located in front of the light beam traveling direction not blocked by the light blocking means by the light blocking means
Are aligned in the same direction as the direction in which the two areas are shielded
It is composed of a light detecting means for detecting the light intensity of two or more areas.
That the head part-mounted image display device. 2. The wavelength of the light emitted from the linear light source is 830.
The head-mounted image display device according to claim 1, wherein the image display device has a thickness of more than 1 nm. 3. A line light source is an LED array according to claim 1
The head-mounted image display device described. 4. A video display means and the video display means.
Magnification optical system that magnifies the image displayed as a virtual image
And on the retina of the image magnified by the magnifying optical system
Image forming state detecting means for detecting the image forming state of the
The magnifying optical system is controlled by the information from the state detecting means.
It is driven in the direction of the optical axis and magnified by the magnifying optical system.
Change the image formation position so that the captured image is formed on the retina.
And a image position changing means, the imaging condition detection means, said image display means and the point light source is located in an optically conjugate position to the magnifying optical system reflects the light beam from the point light source A semi-reflecting means for guiding the light beam reflected by the retina and returning through the magnifying optical system, and an anamorphic optical system for generating an astigmatic difference in the light beam passing through the semi-reflecting means. In front of the traveling direction of the light flux that has passed through the morphic optical system,
Direction not affected by the anamorphic optics
Image point of the light flux of and the anamorphic optical system
The light located between the image forming point of the light flux in the direction of receiving the sound
Detected by the light detection means from Na Ru head unit mounted image display device the intensity distribution <br/> of the light beam on a surface perpendicular to the traveling direction of the bundle. 5. The wavelength of light emitted from a point light source is 830.
The head-mounted image display device according to claim 4, wherein the image display device has a thickness exceeding nm. 6. The head-mounted image display device according to claim 4, wherein the point light source is an LED.