JP2003295108A - Image display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image display device capable of giving a three- dimensional view closer to a natural feeling and further correcting fluctuation of aberration due to the individual difference of optical systems by representing a wavefront curvature in an image of a projected object in the image display device for directly projecting an image, etc., on the retina of an observer. <P>SOLUTION: A light beam made incident on a beam splitter 101 of a wavefront curvature modulating means 100 is reflected in the minus X direction, made incident on a movable mirror 103 through a convex lens 102, and reflected in the plus X direction by a reflection surface 104a moved to the position of a distance f-d by a piezoelectric actuator 105 to connect focus at the position where the light beam advances by a distance d, being made incident on the convex lens 102 again. The convex lens 102 deflects the laser beam, the laser beam with a wavefront curvature identical to a beam emitted from an apparent light emitting point 125 transmits the beam splitter 101 to be emitted from the wavefront curvature modulating means 100. A position adjusting means 120 perform fine adjustment of the position of the movable mirror 103. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image display device which scans a light beam and directly projects an image on the retina of an eye.

[0002]

2. Description of the Related Art Conventionally, a so-called head-mounted display is known, in which a small liquid crystal display or the like of about 1 inch square is fixed to a headband or the like and mounted on the head of an observer to provide images and the like. Has been. As a means for providing a stereoscopic image in this device, the left-eye display displays a left-eye viewpoint image, and the right-eye display displays a right-eye viewpoint image. A means for stereoscopic viewing by difference is used.

The small liquid crystal display uses a liquid crystal having a property that the orientation of crystals is changed by application of a voltage, and shields color filters of three primary colors of light, red, green and blue. It functions as a display. The liquid crystal itself does not emit light, and the light such as a backlight that passes through the color filter is a light source, and the liquid crystal display expresses an image by transmitting or blocking the light.

[0004]

However, since the positional relationship between the liquid crystal display and the retina of the observer is constant, the image of the object incident on the observer's eye is visually three-dimensional and has a depth. It was a stereoscopic image without feeling, which caused the observer to feel discomfort.

The present invention has been made to solve the above-mentioned problems, and utilizes an object such as a retinal scanning type display for directly projecting an image or the like on the retina of an observer to enter the observer's eye. By expressing the wavefront curvature in the image, it is possible to realize a stereoscopic view closer to a natural feeling, and by providing the position adjusting means, it is possible to correct variation in aberration due to subtle individual differences in the optical system. An object is to realize an image display device.

[0006]

In order to achieve the above object, the image display device of the invention according to claim 1 modulates at least one light source and a light beam emitted from the light source according to an image signal. The modulation means, the wavefront curvature modulation means for modulating the wavefront curvature of the light flux modulated by the modulation means, the scanning means for scanning the light flux modulated by the wavefront curvature modulation means, and the light flux scanned by the scanning means Optical means for entering the pupil of the observer,
An image display device for displaying an image corresponding to the image signal on the retina of the observer, wherein the wavefront curvature modulating means comprises:
An optical element and a moving means for moving the optical element in the optical axis direction of the light flux are provided.

In the image display device having this structure, the moving means moves the optical element in the optical axis direction of the light beam, whereby the wavefront curvature of the light beam incident on the wavefront curvature modulating means can be modulated.

Further, in the image display device according to a second aspect of the present invention, in addition to the configuration of the first aspect of the invention, the optical element is a reflecting means for reflecting the light flux and is modulated by the modulating means. A polarized beam splitter that transmits linearly polarized light in a predetermined direction and reflects linearly polarized light in a direction orthogonal to the predetermined direction, and a light beam reflected or transmitted by the polarizing beam splitter is condensed. And a quarter wave plate provided between the light collecting means and the polarization beam splitter. The quarter wave plate is arranged in the optical axis direction. It is configured to be rotatable on a plane orthogonal to each other.

In the image display device having this structure, in addition to the operation of the invention according to claim 1, the quarter-wave plate can rotate on a plane orthogonal to the optical axis direction.

Further, in the image display device of the invention according to claim 3, in addition to the configuration of the invention according to claim 1 or 2, the wavefront curvature modulating means separates the position of the optical element from the moving means. The position adjusting means for adjusting is provided.

In the image display device having this structure, in addition to the effect of the invention according to claim 1 or 2, the wavefront curvature modulating means can adjust the position of the optical element separately from the moving means by the position adjusting means.

Further, in the image display device according to a fourth aspect of the present invention, at least one light source, modulation means for modulating the light flux emitted from the light source according to an image signal, and the light flux modulated by the modulation means. A wavefront curvature modulating means for modulating the wavefront curvature, a scanning means for scanning the light flux modulated by the wavefront curvature modulating means, and an optical means for causing the light flux scanned by the scanning means to enter an observer's pupil. And an image display device for displaying an image corresponding to the image signal on the retina of the observer, wherein the wavefront curvature modulating means has a plurality of reflecting surfaces having different positions in the optical axis direction of the light flux. It has an optical element having.

In the image display device having this structure, the wavefront curvature of the light beam incident on the wavefront curvature modulating means can be modulated by the optical element having a plurality of reflecting surfaces having different positions in the optical axis direction of the light beam.

Further, in the image display apparatus according to the invention of claim 5, at least one light source, modulation means for modulating the light flux emitted from the light source according to the image signal, and the light flux modulated by the modulation means. A wavefront curvature modulating means for modulating the wavefront curvature, a scanning means for scanning the light flux modulated by the wavefront curvature modulating means, and an optical means for causing the light flux scanned by the scanning means to enter an observer's pupil. An image display device for displaying an image corresponding to the image signal on the retina of the observer, wherein the wavefront curvature modulating means has a variable focal length optical system in which a focal length varies with a change in shape or physical property value. Equipped with elements.

In the image display device having this structure, the wavefront curvature of the light beam incident on the wavefront curvature modulating means can be modulated by the variable focal length optical element whose focal length varies with changes in shape or physical property value.

Further, in the image display device according to a sixth aspect of the present invention, in addition to the configuration of the fourth or fifth aspect of the invention, the wavefront curvature modulating means includes a position of the optical element or the variable focal length optical element. Is provided with a position adjusting means.

In the image display device having this structure, in addition to the operation of the invention according to claim 4 or 5, the wavefront curvature modulating means changes the position of the optical element or the variable focal length optical element separately from the moving means by the position adjusting means. Can be adjusted.

In addition to the configuration of the invention described in claim 3 or 6, the image display device of the invention according to claim 7 is characterized in that light reflected by the optical element or light transmitted through the variable focal length optical element is used. And a position adjusting means for adjusting the position of the optical element or the focal length variable optical element according to the position of the light detected by the light detecting means. Has become.

In the image display device having this structure, in addition to the operation of the invention according to claim 3 or 6, the position adjusting means has an optical element or a variable focal length optical element according to the position of the light detected by the light detecting means. The position of can be adjusted.

Further, in the image display device of the invention according to claim 8, in addition to the structure of the invention according to any one of claims 1 to 7, the wavefront curvature modulating means is arranged closer to the light source than the scanning means. The position where the light beam is incident on the scanning means and the position of the observer's pupil are optically conjugate with each other.

In the image display device having this structure, in addition to the operation of the invention according to any one of claims 1 to 7, the wavefront curvature modulating means is arranged closer to the light source than the scanning means, and the light beam is incident on the scanning means. And the position of the observer's pupil can be made optically conjugate.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of an image display device according to the present invention will be described below with reference to the drawings. First, the configuration of the retina scanning display 1 according to the present invention will be described with reference to FIG. FIG. 1 is an overall configuration diagram showing the overall configuration of the retinal scanning display 1.

As shown in FIG. 1, the retinal scanning display 1 is provided with a light source unit 2 for processing an image signal supplied from the outside. The light source unit 2 is provided with a video signal supply circuit 3 which receives a video signal from the outside and generates each signal which is an element for synthesizing a video based on the video signal.
Output a video signal 4, a horizontal synchronizing signal 5, a vertical synchronizing signal 6, and a depth signal 7. In addition, the light source unit 2
R lasers 13 and G for emitting red (R), green (G), and blue (B) video signals respectively transmitted from the video signal supply circuit 3 as video signals 4 respectively. An R laser driver 10, a G laser driver 9, and a B laser driver 8 for driving the laser 12 and the B laser 11, respectively are provided. Further, a first collimating optical system 14 provided so as to collimate the laser light emitted from each laser into parallel light, and a dichroic mirror 15 for combining the collimated laser light,
A coupling optical system 16 for guiding the combined laser light to the optical fiber 17 is provided. A semiconductor laser such as a laser diode or a solid-state laser may be used as the R laser 13, the G laser 12, and the B laser 11. Further, the light source unit 2 is the modulating means in the present invention.

In the retina scanning display 1, the second collimating optical system 18 for collimating the laser light propagated from the light source unit 2 into parallel light again, and the wavefront curvature for modulating the collimated laser light. Modulation means 1
00, a horizontal scanning system 19 that horizontally scans the modulated laser light using the polygon mirror 19a, and laser light that is scanned by the horizontal scanning system 19 and is incident through the first relay optical system 20. A vertical scanning system 21 that scans in the vertical direction using the galvano mirror 21a is provided, and a second relay optical system 22 is provided so that the laser light scanned by the vertical scanning system 21 enters the pupil 24 of the observer. Has been.
The first relay optical system 20 includes a laser beam formed on the polygon mirror 19a of the horizontal scanning system 19 and a vertical scanning system 21.
The second relay optical system 22 makes the laser light imaged on the galvanometer mirror 21a conjugate with the laser light imaged on the galvanometer mirror 21a and the position of the pupil 24 of the observer. They are provided so as to be conjugated with the laser light imaged in. The horizontal scanning system 19 and the vertical scanning system 21 are the scanning means in the present invention.
The relay optical system 20 and the second relay optical system 22 are optical means in the present invention.

Further, the drive circuit 23 is provided to drive the wavefront curvature modulating means 100 based on the depth signal 7 output from the video signal supply circuit 3. The horizontal scanning system 19 and the vertical scanning system 21 are respectively connected to the video signal supply circuit 3, and scan the laser light in synchronization with the horizontal synchronizing signal 5 and the vertical synchronizing signal 6 output from the video signal supplying circuit 3, respectively. It is configured.

The wavefront curvature modulating means 100 converges the laser light reflected by the beam splitter 101 and the beam splitter 101 for separating the incident laser light into the transmitted light and the reflected light reflected in the direction perpendicular to the transmitted light. Convex lens 1
02 and a movable mirror 103 that is movable and reflects the laser light focused on the convex lens 102 in the incident direction. The beam splitter 101 has a cube-like shape in which two right-angled prisms each having a dielectric multilayer film on its slope are stuck together, and the slope 101a (see FIG. 2) has about 50% of the amount of incident light. Is reflected at a right angle and about 50% is transmitted.

The movable mirror 103 includes a mirror 104 having a reflecting surface 104a (see FIG. 2) obtained by applying a mirror coating of a metal film on the surface of a transparent plate material such as glass.
For example, the piezoelectric actuator 105 is formed by stacking piezoelectric type piezoelectric elements, and the piezoelectric actuator 105 is
The mirror 104 fixed to the piezoelectric actuator 105 is driven by being applied with a drive voltage from the drive circuit 23.
The positional relationship between the convex lens 102 and the convex lens 102 is changed. The movable mirror 103 is movable in the direction perpendicular to the mirror surface of the mirror 104 (the X-axis direction in FIG. 2), and the optical axes of the laser beams passing through the beam splitter 101 and the convex lens 102 are aligned on a straight line. ing. The piezoelectric actuator 105 is the moving means in the present invention, and the mirror 104 is the reflecting means in the present invention.

Further, the movable mirror 103 is fixed to the movement adjusting section 120a of the position adjusting means 120 for finely adjusting the reference position of the movable mirror 103 in the optical axis direction, and the distance between the convex lens 102 and the movable mirror 103 is set. Fine adjustment can be performed by rotating the screw of the screw feed fine movement table 120b fixed to the movement adjusting unit 120a. The position adjusting means 120 is located at a position where the observer is the movable reference of the movable mirror 103 when the drive voltage is not applied to the piezoelectric actuator 105 or when a predetermined reference voltage for position adjustment is applied. It is provided to make adjustments to move the movable mirror 103.
Since each optical system has a subtle individual difference, in order to make the predetermined wavefront curvature of the laser light the initial value at the position which is the movable reference of the movable mirror 103, that is, the initial position, the movable mirror 103 is set to the initial value. Fine adjustment to move to the initial position is required. With this position adjusting means 120, fine adjustment can be performed so that the same effect of the wavefront curvature modulating means 100 can be obtained even if the focal position of the eye is different due to the individual difference of the observer.

Next, with reference to FIG. 1, the process of the image display apparatus according to the embodiment of the present invention from the reception of the video signal from the outside to the projection of the video on the retina of the observer will be described. explain.

As shown in FIG. 1, in the retina scanning type display 1 of the present embodiment, when the video signal supply circuit 3 provided in the light source unit section 2 receives the supply of the video signal from the outside, the video signal is supplied. The circuit 3 outputs an R video signal, a G video signal, and a B video signal for outputting laser lights of red, green, and blue colors.
A video signal 4, which is a video signal, a horizontal synchronizing signal 5, a vertical synchronizing signal 6, and a depth signal 7 are output. The R laser driver 10, the G laser driver 9, and the B laser driver 8 respectively use the R laser 13, the G laser 12, and the B laser 1 based on the input R video signal, G video signal and B video signal.
Each drive signal is output to 1. Based on this drive signal, the R laser 13, the G laser 12, and the B laser 11 each generate a laser beam and output each to the first collimating optical system 14. The laser light generated from the point light source is collimated into parallel light by the first collimating optical system 14, and is further incident on the dichroic mirror 15 to be combined into one light beam, and then combined with the coupling optical system 16. Is guided to be incident on the optical fiber 17.

The laser light propagated by the optical fiber 17 is collimated again by the second collimating optical system 18 when it is emitted from the optical fiber 17, and is incident on the wavefront curvature modulating means 100.

Here, the modulation of the wavefront curvature will be described. The light emitted from the light source propagates as a wave of light traveling at a constant velocity and in phase in all directions centered on the light source, a so-called equipotential spherical wave. The spherical wave depends on the distance between the light source and the observer. Has different radius of curvature. If the light source is near, the image has a small radius of curvature, and if the light source is far, the image has a large radius of curvature. The observer can recognize the deviation of the radius of curvature and feel a perspective. In the present invention, the curvature of the spherical wave of the light, that is, the wavefront curvature is artificially modulated and expressed in an image or the like.
It is possible to provide the observer with a stereoscopic view that is more natural. The wavefront curvature modulating means 100 that realizes the modulation of the wavefront curvature will be described later.

The laser light emitted from the wavefront curvature modulating means 100 is incident on the polarization plane 19b of the polygon mirror 19a of the horizontal scanning system 19. The polygon mirror 19a is a BD (Beam Detecto) output by an optical sensor (not shown).
The rotation speed is calculated based on the r) signal, and the uniform rotation speed is adjusted based on the BD signal so as to synchronize with the horizontal synchronization signal 5 output from the video signal supply circuit 3. The laser light incident on the polarization plane 19b of the polygon mirror 19a is horizontally scanned and emitted through the first relay optical system 20 to the polarization plane 21b of the galvanometer mirror 21a of the vertical scanning system 21. In the first relay optical system 20, the image formed on the polarization plane 19b of the polygon mirror 19a and the image formed on the polarization plane 21b of the galvano mirror 21a are adjusted so as to have a conjugate relationship, and Polygon mirror 1
The trouble of 9a is corrected. Galvano mirror 21a
Like the polygon mirror 19a, in synchronization with the vertical synchronizing signal 6, the polarization plane 21b reciprocally vibrates so as to reflect the incident light in the vertical direction.
The laser light is scanned in the vertical direction by a. The laser beam two-dimensionally scanned in the horizontal direction and the vertical direction by the horizontal scanning system 19 and the vertical scanning system 21 is a galvano mirror 2
The image formed on the polarization plane 21b of 1a and the pupil 2 of the observer.
The second relay optical system 22 provided so as to have a conjugate relationship with the image formed at the position of 4 makes it enter from the pupil 24 of the observer and is projected on the retina. The observer can recognize the image by the laser light thus two-dimensionally scanned and projected on the retina.

Next, a method of modulating the wavefront curvature in the retinal scanning display 1 will be described with reference to FIGS. 2 and 3 are schematic diagrams showing a mode in which the laser light is modulated by the wavefront curvature modulating means 100.

As shown in FIG. 2, the wavefront curvature modulating means 10
The laser beam collimated into parallel light by the second collimating optical system 18 (see FIG. 1) is incident on the beam splitter 101 of 0 in the −Y direction as incident light. About 50% of the amount of the incident laser light is reflected by the slope 101a and enters the convex lens 102 provided in the reflection direction (-X direction). By the way, when the drive voltage applied from the drive circuit 23 to the piezoelectric actuator 105 shown in FIG. 1 is 0 or a predetermined reference value, the movable mirror 10 is moved.
So that the reflecting surface 104a of the mirror 104 of No. 3 is fixed at a position away from the principal point of the convex lens 102 by a distance f,
The screw feed fine movement table 120b of the position adjusting means 120 is operated and adjusted in advance by the observer. Reflective surface 1
When the distance between 04a and the principal point of the convex lens 102 is f, the laser light incident on the convex lens 102 is not reflected by the convex lens 10.
The light is refracted and converged by 2, and is focused on the reflecting surface 104a. In this case, the laser light is reflected by the reflecting surface 104a in the coaxial direction with the incident light (+ X direction), and the mirror 104
The laser light that was a convergent light upon entering the lens becomes a diffused light after being reflected and enters the convex lens 102 again.

The diffused light reflected by the reflecting surface 104a in the + X direction and incident on the convex lens 102 has the same divergence angle as the convergent light converged by the convex lens 102 before being reflected by the reflecting surface 104a, and at the time of further convergence. Since it passes through the same optical path in the same optical system as above, this diffused light is refracted at the same angle as when converged when passing through the convex lens 102, and is collimated into parallel light. The laser light collimated into parallel light is again incident on the beam splitter 101, about 50% of the light amount thereof passes through the slope 101a, and is a direction (+ X direction) perpendicular to the incident light from the second collimating optical system 18. Then, the light is emitted as light emitted from the wavefront curvature modulating means 100.

As shown in FIG. 3, the drive circuit 23
When a predetermined drive voltage from (see FIG. 1) is applied, the piezoelectric actuator 105 is driven, and this drive moves the movable mirror 103 in the + X direction. In this case, the distance between the reflecting surface 104a of the mirror 104 and the principal point of the convex lens 102 is changed to fd. Second collimating optical system 18
The laser light that is incident light that is incident as parallel light in the −Y direction from the beam splitter 10 is similar to the above case.
About 50% of the inclined surface 101a of No. 1 is reflected in the -X direction and is incident on the convex lens 102. The convex lens 102 is + X
The laser light incident from the direction is emitted in the -X direction so as to be refracted and converged.
Since the reflecting surface 104a of 04 is moved to a position closer to the convex lens 102 by the distance d than the focal length f of the convex lens 102, the laser light is not converged on the reflecting surface 104a. The laser light is reflected by the reflecting surface 104a in the + X direction and then travels a distance d, that is, a distance f.
The light is focused at the position of -2d and is incident on the convex lens 102 again.

The convex lens 102 receives the incident laser light,
The convex lens 1 refracts the spread in a converging direction.
Since the refractive index of 02 itself does not change, the convex lens 102 that collimates the light emitted from the position of the focal length f into parallel light cannot collimate the light emitted from the position of the distance f-2d in parallel. Therefore, the distance f
Since the laser light focused at -2d enters the convex lens 102, the spread angle of the laser light becomes smaller, but it is not collimated into parallel light, and the laser light passing through the convex lens 102 spreads after passing through the convex lens 102. The beam enters the beam splitter 101 while maintaining the angle. About 50% of the laser light that has entered the beam splitter 101 passes through the slope 101a, and is emitted in the + X direction while maintaining the spread angle, that is, as diffused light. The wavefront curvature modulating means 100 emits laser light as emitted light, which is laser light having a predetermined spread angle, that is, diffused light having a large wavefront curvature unlike parallel light.

The wavefront curvature of the laser light emitted from the wavefront curvature modulating means 100 as diffused light and entering the polarization plane 19b of the polygon mirror 19a of the horizontal scanning system 19 shown in FIG. , Apparent emission point 12
The wavefront curvature is equivalent to that of the light emitted from No. 5. Further, the wavefront curvature of the parallel light emitted when the distance between the reflecting surface 104a and the principal point of the convex lens 102 is f on the polarization surface 19b of the polygon mirror 19a is equivalent to that of the light emitted from infinity. It becomes a curvature. Here, the first relay optical system 20
The image formed on the polarization plane 19b of the polygon mirror 19a and the image formed on the polarization plane 21b of the galvano mirror 21a by the second relay optical system 22 are also formed by the second relay optical system 22 on the polarization plane 21b of the galvano mirror 21a. Since each relay optical system is provided so that the image formed at (1) and the image formed at the position of the pupil 24 of the observer have a conjugate relationship with each other, on the polarization plane 19b of the polygon mirror 19a. The image formed and the image formed at the position of the pupil 24 of the observer have a conjugate relationship. Therefore, the wavefront curvature of the laser light on the polarization plane 19b of the polygon mirror 19a becomes the same as the wavefront curvature at the position of the pupil 24 of the observer.

When the observer focuses the apparent light emitting point 125 of the laser light incident on the eye from the pupil 24, the laser light is imaged on the retina of the observer. by the way,
Since the observer can identify the difference in the wavefront curvature of the laser light by the focusing operation (so-called adjusting action), the observer can recognize the perspective based on the difference in the wavefront curvature of the laser light. That is, it is felt that the laser light having a large wavefront curvature is emitted from a near position, and the laser light having a small wavefront curvature is emitted from a distant position.
Therefore, in this case, the observer has an apparent emission point 125.
Then, it is recognized that the light emitting point of the laser light exists at a position corresponding to the distance to the polarization plane 19b that is conjugate to the position of the pupil 24.

Convex lens 102 of wavefront curvature modulating means 100
Assuming that the focal length of 4 is 4 mm, the wavefront curvature modulation means 100 can express a perspective of about 30 cm to infinity only by moving the movable mirror 103 by about 30 μm. In addition, the focal length of the convex lens 102 is 2
In the case of mm, the movable mirror 103 only moves about 10 μm, and the wavefront curvature modulating means 100 has about 30 c.
It is possible to express a sense of perspective from m to infinity. For example,
When a substantially parallel laser beam with a small wavefront curvature is scanned and enters the eye, an observer can recognize it as a screen presented on a screen several tens of meters away, and a laser beam with a large wavefront curvature. Is scanned and is incident on the eye,
An observer can recognize it as a screen presented on the screen several tens of cm away.

As described above, in the retinal scanning display 1 of this embodiment, R, G, and B generated based on the R, G, and B video signals output from the video signal supply circuit 3 are generated.
The G and B laser lights are combined to form the wavefront curvature modulating means 100.
Is incident on. The wavefront curvature modulating means 100 modulates the wavefront curvature of the incident laser light and emits it to the horizontal scanning system 19. The horizontal scanning system 19 scans the incident laser beam in the horizontal direction and emits it to the vertical scanning system 21.
Reference numeral 1 scans the incident laser beam in the vertical direction and makes it enter the pupil 24 of the observer. The observer can recognize the perspective by identifying the difference in the wavefront curvature of the incident laser light.

The present invention is not limited to the above embodiment, but various modifications can be made. A modified example of the present invention will be described with reference to FIGS. 4 and 5
Is a line CCD (Charge Coupled) on the optical path on the incident light side.
FIG. 9 is a diagram showing a modification in which a device) sensor 401 is provided, and the reference position of the movable mirror 103 is automatically adjusted by the position adjusting means 120 based on the output value thereof. FIG. 6 is a flow chart showing the control of the movement of the position adjusting means 120 based on the output value of the line CCD sensor 401. FIG. 7 is a diagram showing a modified example of the wavefront curvature modulating means 100 when the polarization beam splitter 106 is used instead of the beam splitter 101. FIG. 8 is a schematic diagram for explaining the polarization direction of laser light passing through the quarter-wave plate 107. Figure 9
FIG. 4 is a schematic diagram for explaining a polarization direction of laser light passing through a rotated quarter-wave plate 107. Figure 1
0 and FIG. 11 are diagrams showing modified examples of the wavefront curvature modulating means 100 when the movable multistage mirror 111 is used instead of the movable mirror 103. FIG. 12 is an overall configuration diagram showing the overall configuration of the retinal scanning display 1 when the variable focus lens 301 is used instead of the movable mirror 103.
13 and 14 are diagrams showing a modification example in which the variable focus lens 301 is used instead of the movable mirror 103.

In the modified examples shown in FIGS. 4 and 5, a line CCD sensor 401 is provided on the optical path of the laser beam on the incident light side,
This is a modified example in which the position adjusting means 120 is controlled based on the output value of the line CCD sensor 401.
As shown in FIGS. 4 and 5, in this modification, the drive circuit 2
3 (see FIG. 1), when the driving voltage applied to the piezoelectric actuator 105 is 0 or a predetermined reference value, the distance between the reflecting surface 104a and the principal point of the convex lens 102 is f so that the movable mirror 103 has a distance f. The position is adjusted automatically. This adjustment is performed by the position adjusting means 120 fixed to the movable mirror 103. The position adjusting means 120 is formed by a movement adjusting section 120a and a pulse motor fine movement table 120c, and the pulse motor fine movement table 120 is provided.
The movable mirror 10 is attached to the movement adjustment unit 120a fixed to c.
The piezoelectric actuator 105 of No. 3 is fixed. still,
The line CCD sensor 401 is the light detecting means in the present invention.

On the incident light side of the beam splitter 101, a line CCD sensor 401 is provided at a position at a distance L2 from the beam splitter 101 with reference to the passing position of the optical axis of the laser light. Pulse motor fine movement table 120
The line CCD sensor 401 includes a pulse motor fine movement drive unit 404, a mirror position control unit 403, and a CC.
It is connected via the D output reading unit 402.

The incident light is incident on the wavefront curvature modulating means 100--
The laser light incident in the Y direction is reflected by the beam splitter 101.
Is reflected in the -X direction on the slope 101a of the
The laser light of a is incident on the convex lens 102 provided at a position separated from the optical axis passing position by the distance L1. Convex lens 102
The laser beam that has passed through is reflected in the + X direction by the reflecting surface 104a of the mirror 104 located at the distance f in the example shown in FIG. 4 and the distance f-d in the example shown in FIG. Pass through the beam splitter 10
Re-enter 1. The laser light is about 5 times on the slope 101a.
0% is transmitted in the + X direction, but about 50% thereof is reflected to the incident light side (+ Y direction). Line CCD sensor 40
1 is provided so that the reflected laser light can be read.

The laser light emitted from the wavefront curvature modulating means 100, that is, the emitted light advances in the + X direction in the figure,
An image is formed on the polarization plane 19b of the polygon mirror 19a of the horizontal scanning system 19 shown in FIG. In this case, the inclined surface 101a and the polarization plane 1 are based on the position where the laser beam passes through the optical axis.
The distance from 9b is L3. Since the polarization plane 19b and the pupil 24 of the observer are adjusted by the first relay optical system 20 and the second relay optical system 22 so as to be in an optically conjugate relationship, the position of the pupil 24 of the observer is adjusted. The wavefront radius of curvature of the laser light is regarded as the wavefront radius of curvature at the position of the polarization plane 19b.

The line CCD sensor 401 has a plurality of CCs.
D elements (not shown) are arranged in a row, and each CCD element can detect the laser beam and its light amount. The amount of laser light reflected by the beam splitter 101 toward the incident light side (+ Y direction) is read by the line CCD sensor 401, and the detected value is output to the CCD output reading unit 402. By the way, the laser light is a light flux whose amount of light gradually decreases at the beam end. CC
The D output reading unit 402 reads the center of the light beam, that is, a position where a predetermined reference value of the light amount on the optical axis is, for example, 1 / e ² based on the output from each CCD element, and outputs it to the mirror position control unit 403. Then, the mirror position control unit 403 determines the beam diameter of the laser light with that position as the end of the beam. The mirror position control unit 403 performs a calculation for driving the pulse motor fine movement table 120c based on the determined beam diameter, and outputs a signal based on the result to the pulse motor fine movement table driving unit 404. The pulse motor fine movement drive unit 404 generates a drive voltage for driving the pulse motor fine movement base 120c based on the input signal to move the pulse motor fine movement base 120c in the X-axis direction, thereby performing movement adjustment. The movable mirror 103 fixed to the pulse motor fine movement table 120c is also moved via the section 120a, and its position is controlled. Each process of this control will be described in detail with reference to the flowchart of FIG. Hereinafter, each step of the flowchart is abbreviated as "S".

As shown in FIG. 6, in the retinal scanning display 1, "input of set value R of virtual image presentation position" is made by an input means (not shown) (S1). The set value R of the virtual image presentation position is a predetermined initial value of the radius of curvature of the wavefront, and normally, a value at which the radius of curvature of the wavefront is infinite is used as an initial value. The threshold to be considered is entered. Next, the mirror position control unit 403 "determines the mirror position Z from the set value R based on a preset calculation formula or table."
(S2). Each optical system has individual differences, and some errors occur. However, using the reference optical system, the reflecting surface 104 of the mirror 104 in the initial state is preset.
The relationship between the position Z of the mirror 104 based on the positional relationship between a and the principal point of the convex lens 102 and the set value R is defined.
Based on this, a relational expression between R and Z or a table based on the relation between R and Z is set, and in order to reduce the loop operation for error correction in each step after S4, the mirror position control is performed. In the part 403, the position Z of the mirror 104 in the initial state is obtained in S2. Furthermore, the mirror position control unit 403 determines, based on the result of S2,
A control signal is output to the pulse motor fine motion drive unit 404. The pulse motor fine movement drive unit 404 generates a drive voltage for driving the pulse motor fine movement base 120c based on the control signal, and applies it to the pulse motor fine movement base 120c. Then, the pulse motor fine movement table 120c "moves the mirror to the position Z by the pulse motor" (S3).
That is, the mirror 104 is moved to the initial position Z.

Next, the CCD output reading unit 402
"Read the output value of each CCD element" (S4). The line CCD sensor 401 reads the amount of the received laser beam in the + Y direction by each CCD element and outputs it to the CCD output reading unit 402. CCD output reading unit 40
2 outputs the read value to the mirror position control unit 403. Since the mirror position control unit 403 “determines the beam radius r1 of the light flux from the output value of each CCD element”, it determines which CCD element has obtained the light amount regarded as the end of the beam.
The beam radius r1 is determined based on the output value of the D output reading unit 402 (S5).
In the mirror position control unit 403, assuming that the beam radius of the laser light before the modulation of the wavefront curvature, that is, the incident light is r0, the wavefront curvature R1 of the laser light reflected in the + Y direction.
And the wavefront curvature R at the polarization plane 19b of the polygon mirror 19a which is optically conjugate with the position of the pupil 24 of the observer.
2 and are calculated. That is, "from the following formula, the radius of curvature R1 of the wavefront on the CCD and the radius of curvature R of the wavefront on the pupil
An operation for "calculating 2" is performed (S6). R1 = r1 (L1 + L2-f) / (r1-r0) ... (1) R2 = R1 + (L3-L2) ... (2) A line from the apparent light emitting point 125 obtained by the mathematical expression (1). The optical path length to the CCD sensor 401, that is, the wavefront radius of curvature R1 is substituted into the equation (2), and in the equation (2),
The wavefront curvature R2 at the position of the pupil 24 of the observer is derived.

Next, the mirror position control section 403 performs "comparison between the set value R and the measured value R2" (S7), and if R2 <R + δR (3) is not satisfied (S7: NO). , "Move the mirror to the lens side by one step by the pulse motor" (S9).
Here, δR represents an allowable value of the deviation of the wavefront radius of curvature from the set value R, and this allowable value determines the error or accuracy of the wavefront radius of curvature of the laser light at the position of the pupil 24. That is, the measured value R2 of the radius of curvature of the wavefront of the laser light
Is larger than the set value R, it means that the beam spread of the laser light is smaller than the initial value, and the distance between the convex lens 102 and the movable mirror 103 is long,
The mirror position control unit 403 is the pulse motor fine movement drive unit 4
A signal is output to 04, and a drive voltage is applied to the pulse motor fine movement table 120c to operate the pulse motor fine movement table 120c for one step so that the distance between the movable mirror 103 and the convex lens 102 becomes shorter. Then, the process returns to S4.

If the equation (3) is satisfied in S7, that is, the measured value R2 of the wavefront curvature radius of the laser light is smaller than the set value R (S7: YES), the mirror position control section 403 determines that "the set value is set". Compare R with measured value R2 "
(S8). If R2> R−δR (4) is not satisfied (S8: NO), “the mirror is moved by one step to the side opposite to the lens by the pulse motor” (S).
10). That is, the measured value R of the wavefront curvature radius of the laser light
If 2 is smaller than the set value R, it means that the beam spread of the laser beam is larger than the initial value, and as shown in FIG. 5, the distance between the convex lens 102 and the movable mirror 103 is short, and The mirror position control unit 403 outputs a signal to the pulse motor fine movement base drive unit 404 to apply a drive voltage to the pulse motor fine movement base 120c to move the movable mirror 103.
The pulse motor fine movement base 120c is operated by one step so that the distance between the convex lens 102 and the convex lens 102 is increased. Then, the process returns to S4.

When the equation (4) is satisfied in S8, that is, the measured value R2 of the wavefront curvature radius of the laser light is larger than the set value R (S8: YES), R2 = R ± δR (5) ), Indicating that the radius of curvature of the wavefront of the laser light is within the allowable range of the initial value, the mirror position control unit 403 displays
It is determined that the position Z of the movable mirror 103 has reached the initial position, and the process ends. In this state, as shown in FIG.
In the wavefront curvature modulating means 100 in the present embodiment, the same effect as that when the observer adjusts the screw feed fine movement table 120b can be obtained.

The modification shown in FIG. 7 is a modification in which the polarization beam splitter 106 is used instead of the beam splitter 101 of the wavefront curvature modulating means 100. As shown in FIG. 7, the laser beam collimated into parallel light by the second collimating optical system 18 (see FIG. 1) is incident on the polarization beam splitter 106 of the wavefront curvature modulating means 100 from the + Y direction as incident light. It

By the way, light is a kind of electromagnetic wave, and electromagnetic wave is a phenomenon in which vibrations of an electric field and a magnetic field propagate. An electromagnetic wave propagating in a vacuum is a plane wave that propagates at the speed of light, the electric field and the magnetic field of which vibrate in directions perpendicular to each other, and is in a plane perpendicular to the traveling direction. Further, for example, the vibration direction of light emitted from an incandescent lamp or the like is uniformly distributed in an arbitrary direction, whereas the vibration direction of laser light (hereinafter, referred to as “polarization direction”) is a single direction. .

The polarization beam splitter 106 has a slope 106.
A is coated with a derivative multilayer film, and the inclined surface 106a reflects light having a polarization direction perpendicular to the XY plane and transmits light having a polarization direction parallel to the XY plane. In the polarization beam splitter 106, XY
When the laser light having the polarization direction perpendicular to the plane is incident from the + Y direction, it is reflected in the −X direction by the inclined surface 106 a and is incident on the ¼ wavelength plate 107.

By the way, the quarter-wave plate 107 is an optical element that changes the phase difference between the incident electric fields of the linearly polarized light and the orthogonal electric fields by a quarter wavelength. Change to circularly polarized light. Further, the incident circularly polarized light is changed to linearly polarized light.

The laser light incident on the quarter-wave plate 107 is changed from linearly polarized light to circularly polarized light by the quarter-wave plate 107, emitted in the −X direction, and entered to the convex lens 10.
2, the light is focused on the reflecting surface 104a of the movable mirror 103 at a position f away from the focal length of the convex lens 102. Further, the laser light is reflected in the + X direction by the reflecting surface 104 a, collimated by the incident convex lens 102 into parallel light, and is incident on the ¼ wavelength plate 107. The laser light incident on the quarter-wave plate 107 as circularly polarized light is 1
It is converted into linearly polarized light in a direction parallel to the XY plane by the / 4 wavelength plate 107 and is emitted to the polarization beam splitter 106. Slope 106a of polarization beam splitter 106
Since the incident laser light is linearly polarized light parallel to the XY plane, the laser light is transmitted. Then, the laser light that has passed through the polarization beam splitter 106 is emitted from the wavefront curvature modulating means 100 in the + X direction as emitted light.

Although not shown in the figure, the movable mirror 103 is moved in the + X direction by a distance d, and the distance between the reflecting surface 104a of the mirror 104 and the principal point of the convex lens 102 is f−.
The process of modulating the wavefront curvature when it is changed to d is the same as in this embodiment. In this variation,
The polarization beam splitter 106 transmits or reflects based on the polarization direction of the laser light, but the loss of the light amount in that case is less than 10%, so that it is much smaller than the loss of the light amount of about 50% by the beam splitter 101. There is an effect that the total loss of light amount in the wavefront curvature modulating means 100 is significantly reduced.

Further, the rotating mechanism 1 is attached to the quarter-wave plate 107.
A case in which 30 is provided and the quarter-wave plate 107 can be arbitrarily rotated will be described with reference to FIGS. 7 to 9. The quarter-wave plate 107 shown in FIGS. 8 and 9 is a view seen from the direction of the arrow along the alternate long and two short dashes line AA ′ shown in FIG. 7, and the direction perpendicular to the XY plane will be described as the Z-axis direction.
The laser light is incident on the quarter-wave plate 107 from the + X direction to the −X direction shown in FIG. The polarization direction 107a of the laser light (incident light) before entering the quarter-wave plate is XY.
The direction perpendicular to the plane is the Z-axis direction in FIGS. 8 and 9. The laser light (incident light) that has entered the quarter-wave plate 107 from the surface of the paper is converted into circularly polarized light in the same manner as described above, reflected by the reflecting surface 104a, and then again quarter-wavelength.
The reflected light enters the wave plate 107 from the back surface of the paper.

As shown in FIG. 8, the quarter-wave plate 107
7 is not rotated by the rotating mechanism 130 shown in FIG. 7, the first optical axis 107b and the second optical axis 107c have an inclination of 45 ° with respect to the Y-axis direction and the Z-axis direction. In this case, the laser light (reflected light) that is re-incident as circularly polarized light on the quarter-wave plate 107 from the back side of the paper is its polarization direction 10
7e is changed in the Y-axis direction, and from the quarter-wave plate 107,
The light is emitted in the + X direction shown in FIG.

Further, as shown in FIG. 9, the rotating mechanism 130
(See FIG. 7) rotates the quarter-wave plate 107,
When the first optical axis 107b and the second optical axis 107c are rotated counterclockwise about the optical axis 107d by an angle θ, the first optical axis 107b and the second optical axis 107c are the Y-axis direction and the Z-axis. It has an inclination of 45 ° -θ with respect to the direction.
In this case, the laser light (reflected light) re-incident as circularly polarized light on the quarter-wave plate 107 from the back side of the paper changes its polarization direction 107e counterclockwise by an angle 2θ from the Y-axis direction. Then, the light is emitted from the quarter-wave plate 107 in the + X direction shown in FIG.

The laser light emitted from the quarter-wave plate 107 enters the polarization beam splitter 106. In this case, by adjusting the rotation angle θ of the quarter-wave plate 107, it is possible to change the amount of laser light passing through the inclined surface 106 a of the polarization beam splitter 106. Slope 1
Since the laser light that has not passed through 06a is reflected in the + Y direction and the amount of light can be detected by the line CCD sensor 401, the radius of curvature of the wavefront can be obtained as in the case described above, and the position adjusting means 120 can be obtained. The position of the movable mirror 103 can be adjusted by.

The modified examples shown in FIGS. 10 and 11 are
This is a modified example in which a movable multistage mirror 111 is used instead of the movable mirror 103 of the wavefront curvature modulating means 100. As shown in FIG. 10, the beam splitter 101 of the wavefront curvature modulating means 100 includes a second collimating optical system 18 (see FIG. 1).
Laser light collimated into parallel light by the reference) is incident in the −Y direction as incident light. In the beam splitter 101, about 50% of the amount of incident laser light is reflected in the −X direction by the slope 101a. The laser light emitted from the beam splitter 101 in the −X direction passes through the convex lens 102 and is focused at a position of a distance f from the principal point of the convex lens 102. The movable multi-stage mirror 111 can be moved in the Y-axis direction by a piezoelectric actuator 113, and the reflection surfaces 112a and 112c of the multi-stage mirror 112 of the movable multi-stage mirror 111 have the optical axis of the speed of light passing through the convex lens 102 as the reflection surface 112a or. 1
When the movable multistage mirror 111 is moved so as to be orthogonal to 12c, the distances between the reflecting surfaces 112a and 112c and the principal point of the convex lens 102 are f and fd, respectively. That is, the reflecting surface 112c is the reflecting surface 1
It is provided at a position closer to the convex lens 102 by a distance d than 12a.

The laser light passing through the convex lens 102 in the -X direction is focused on the reflecting surface 112a at a distance d,
It is reflected in the + X direction by the reflecting surface 112a. The reflected laser light enters the convex lens 102 along the same optical path as when passing through the convex lens 102. The convex lens 102 collimates the passing laser light into parallel light and emits it to the beam splitter 101. Beam splitter 10
The inclined surface 101a of No. 1 transmits about 50% of the amount of incident laser light, and the wavefront curvature modulator 100 emits the transmitted laser light in the + X direction as emitted light of parallel light.

Further, as shown in FIG. 11, the reflecting surface 112
When the movable multistage mirror 111 changes so that c overlaps with the optical axis of the laser light passing through the convex lens 102, the laser light passing through the convex lens 102 does not focus on the reflecting surface 112c, and is reflected by the reflecting surface 112c in the + X direction. And is focused at a position at a distance d from the reflecting surface 112c. The laser light that re-enters the convex lens 102 from this position is
The light emitted from a position at a distance f−2d in the −X direction from the principal point of the convex lens 102 enters the convex lens 102 with the same divergence angle. Since the focal length of the convex lens 102 is f, the convex lens 102 cannot collimate the laser light into parallel light, and as diffused light having the same spread angle as the light emitted from the apparent light emitting point 125 in the X-axis direction,
The light is emitted to the beam splitter 101. The slope 101a of the beam splitter 101 transmits about 50% of the incident laser light amount, and the wavefront curvature modulating means 100
Emits this laser light in the + X direction as emitted light.

The eye can recognize the difference in the wavefront curvature, but it is not so sensitive, so that the modulation of the wavefront curvature does not necessarily have to be continuously performed from infinity to the close range. For example,
Even if the radius of the wavefront curvature is 50 cm, 1 m, 3 m, 5 m, and infinity and the discontinuous wavefront curvature is modulated in about five steps, a substantially sufficient effect can be obtained. In this modification, the drive circuit 23 (see FIG. 1) has a movable multistage mirror 1
In order to move 11 in the Y-axis direction, it suffices to perform voltage control in four steps, which has the effect of simplifying the circuit.

The modified examples shown in FIGS. 12 to 14 are
The movable mirror 10 of the wavefront curvature modulating means 100 in FIG.
This is a modified example in which a variable focus lens 301 is used instead of No. 3. As shown in FIG. 12, the wavefront curvature modulating means 300 of the retinal scanning display 1 includes a variable focus lens 30.
1 and the convex lens 302. Also,
The varifocal lens 301 is provided with position adjusting means 120 including a movement adjusting unit 120a and a screw feed fine movement table 120b, as in the present embodiment, and an observer operates the screw feed fine movement table 120b. By moving the position of the varifocal lens 301, it is possible to correct variation in aberration due to a subtle individual difference between the varifocal lens 301 and the convex lens 302. The other configurations of the retinal scanning display 1 are the same as those in the above-described present embodiment. The variable focus lens 301
Is the variable focal length optical element in the present invention.

Next, as shown in FIG. 13, the varifocal lens 301 of the wavefront curvature modulating means 300 has a transparent fluid 30.
4 is held between the two diaphragms 303, the piezoelectric bimorph 305 to which the driving voltage from the driving circuit 23 (see FIG. 12) is applied drives the deformable diaphragm 303, and thus the variable focus lens 301 Fluctuate the focal position of. Laser light collimated into parallel light by the second collimating optical system 18 (see FIG. 12) is incident on the varifocal lens 301 from the −X direction as incident light. Principal point of variable focus lens 301 and convex lens 3
The distance to the principal point of 02 is fixed to the distance 2f0 by the position adjusting means 120.

When the focal length f1 of the varifocal lens 301 is adjusted to be the same distance f0 as that of the convex lens 302, the laser light passing through the varifocal lens 301 has the principal point of the varifocal lens 301 and the principal point of the convex lens 302. The laser beam passing through the convex lens 302 is collimated because it is focused in the middle of the point and enters the convex lens 302 as light emitted in the + X direction from the distance f0 in the -X direction. The wavefront curvature modulating means 300 emits the laser light collimated into the parallel light as emitted light in the + X direction.

Further, as shown in FIG. 14, when the diaphragm 303 is changed by driving the piezoelectric bimorph 305 and the focal length f1 of the varifocal lens 301 is adjusted to be larger than f0, the varifocal is changed from the -X direction. The laser light incident on the lens 301 is varifocal lens 3
After passing 01, it converges at a position of a distance f1 longer than the focal length f0 of the convex lens 302. Further, the laser light is + from the distance 2f0-f1 in the −X direction with respect to the convex lens 302.
It is incident as light emitted in the X direction, that is, light emitted from a position closer than the focal length f0 of the convex lens 302. In this case, the laser light passing through the convex lens 302 having the focal length f0 is not collimated into parallel light, and the wavefront curvature modulating means 300 emits this laser light in the + X direction as outgoing light of diffused light having a spread angle. The diffused light having this divergence angle has the same wavefront curvature as the laser light emitted from the apparent light emitting point 125. In this modification, since the beam splitter 101 is not used, it is possible to suppress the loss of the light amount of the laser light, and since a lens having a large mass is not operated, it is difficult to cause a delay in the focal length variation timing, etc. There is an effect that modulation can be performed at a relatively high speed.

Further, the piezoelectric actuators 105 and 113
The piezoelectric bimorph 305 is not limited to the piezoelectric type, and an actuator of an electrostatic type, a magnetic type or the like can be used. Further, the polarization beam splitter 106 and the quarter-wave plate 107 may be combined with the movable multistage mirror 111 to form the wavefront curvature modulating means 100.

[0073]

As described above, in the image display device according to the first aspect of the present invention, the moving means moves the optical element in the optical axis direction of the light flux, so that the wavefront of the light flux incident on the wavefront curvature modulating means. The curvature can be modulated. Therefore, the movement of the optical element in the optical axis direction allows the observer to recognize an image with perspective, and when the movement of the optical element is repeated at high speed, the observer can recognize a more natural image. be able to.

In the image display device according to the second aspect of the invention, in addition to the effect of the first aspect of the invention, the quarter-wave plate can rotate on a plane orthogonal to the optical axis direction.
Therefore, the amount of light incident on the pupil of the observer can be easily set by the rotation angle of the quarter-wave plate.

Further, in the image display device of the invention according to claim 3, in addition to the effect of the invention according to claim 1 or 2, the wavefront curvature modulating means controls the position of the optical element separately from the moving means by the position adjusting means. Can be adjusted. Therefore, the observer can easily set a suitable focus position by using the position adjusting means.

In the image display device according to the fourth aspect of the present invention, the wavefront curvature of the light beam incident on the wavefront curvature modulating means is changed by the optical element having a plurality of reflecting surfaces having different positions in the optical axis direction of the light beam. Can be modulated. Therefore,
It is possible to make the observer recognize an image with a perspective by the reflecting surfaces at different positions, and it is possible to make the observer recognize a more natural image by repeating the switching of the reflecting surfaces at high speed.

Further, in the image display device according to the fifth aspect of the invention, the wavefront curvature of the light beam incident on the wavefront curvature modulating means is modulated by the focal length variable optical element whose focal length varies with changes in shape or physical property value. can do. Therefore, it is possible to make the observer recognize an image with perspective by the change of the focal length by the variable focal length optical element, and to make the observer recognize a more natural image by repeating the change of the focal length at high speed. be able to.

Further, in the image display device according to the invention of claim 6, in addition to the effect of the invention according to claim 4 or 5, the wavefront curvature modulating means includes an optical element or a focal length separately from the moving means by the position adjusting means. The position of the variable optical element can be adjusted. Therefore, the observer can easily adjust the suitable focus position by using the position adjusting means.

In addition, in the image display device of the invention according to claim 7, in addition to the effect of the invention according to claim 3 or 6, the position adjusting means is an optical element according to the position of the light detected by the light detecting means. Alternatively, the position of the variable focal length optical element can be adjusted. Therefore, the focus position suitable for the observer can be automatically adjusted.

Further, in the image display device of the invention according to claim 8, in addition to the effect of the invention according to any one of claims 1 to 7, the wavefront curvature modulating means is arranged closer to the light source than the scanning means,
The position where the light beam is incident on the scanning means and the position of the observer's pupil can be made optically conjugate. Therefore, it is possible to reduce the influence on the wavefront curvature based on the distance on the optical path until the light flux emitted from the wavefront curvature modulating means enters the observer's pupil.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram showing an overall configuration of a retina scanning display 1.

FIG. 2 is a schematic diagram showing a mode in which laser light is modulated by wavefront curvature modulating means 100.

FIG. 3 is a schematic diagram showing a mode in which laser light is modulated by the wavefront curvature modulating means 100.

FIG. 4 shows a line CCD sensor 401 provided on an optical path on the incident light side, and the position adjusting means 1 is based on the output value thereof.
FIG. 11 is a diagram showing a modified example in which the reference position of the movable mirror 103 is automatically adjusted by 20.

FIG. 5 is a view showing a line CCD sensor 401 provided on an optical path on the incident light side, and position adjusting means 1 based on an output value thereof.
FIG. 11 is a diagram showing a modified example in which the reference position of the movable mirror 103 is automatically adjusted by 20.

FIG. 6 is a flowchart showing control of movement of the position adjusting means 120 performed based on the output value of the line CCD sensor 401.

FIG. 7 is a diagram showing a modified example of the wavefront curvature modulating means 100 when a polarization beam splitter 106 is used instead of the beam splitter 101.

FIG. 8 is a schematic diagram for explaining a polarization direction of laser light passing through the quarter-wave plate 107.

FIG. 9 is a schematic diagram for explaining a polarization direction of laser light passing through a rotated quarter-wave plate 107.

10 is a wavefront curvature modulating means 10 when a movable multistage mirror 111 is used instead of the movable mirror 103. FIG.
It is a figure which shows the modification of 0.

11 is a wavefront curvature modulating means 10 when a movable multistage mirror 111 is used instead of the movable mirror 103. FIG.
It is a figure which shows the modification of 0.

FIG. 12 is an overall configuration diagram showing an overall configuration of a retinal scanning display 1 when a variable focus lens 301 is used instead of a movable mirror 103.

FIG. 13 is a diagram showing a modified example in which a variable focus lens 301 is used instead of the movable mirror 103.

FIG. 14 is a diagram showing a modified example in which a variable focus lens 301 is used instead of the movable mirror 103.

[Explanation of symbols]

1 Retina scanning display 19 Horizontal scanning system 20 1st relay optical system 21 Vertical scanning system 22 Second relay optical system 24 pupil 100 Wavefront curvature modulating means 101 beam splitter 102 convex lens 103 movable mirror 104 mirror 105 Piezoelectric actuator 106 Polarizing beam splitter 107 1/4 wave plate 111 Movable multi-stage mirror 120 Position adjustment means 130 rotation mechanism 301 Variable focus lens 401 line CCD sensor

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 2H041 AA23 AB14 AC01 AZ02 AZ05                 2H045 AA01 AB01 BA20 BA24 BA32                       CB01 DA02 DA12 DA15

Claims (8)

[Claims] 1. At least one light source, modulating means for modulating a light beam emitted from the light source according to an image signal, and wavefront curvature modulating means for modulating a wavefront curvature of the light beam modulated by the modulating means, The scanning means for scanning the light beam modulated by the wavefront curvature modulating means, and the optical means for making the light beam scanned by the scanning means enter the pupil of the observer, the image signal on the retina of the observer. An image display device displaying an image corresponding to, wherein the wavefront curvature modulating means includes an optical element and a moving means for moving the optical element in the optical axis direction of the light flux. Display device. 2. The optical element is a reflection means for reflecting the light flux, and transmits linearly polarized light in a predetermined direction of the light flux modulated by the modulation means, and a direction orthogonal to the predetermined direction. Between the polarizing beam splitter that reflects the linearly polarized light of (1), a condensing unit that condenses the light beam reflected or transmitted by the polarizing beam splitter and enters the optical element, and between the condensing unit and the polarizing beam splitter. The image according to claim 1, further comprising: a quarter-wave plate provided on the image plane, the quarter-wave plate being configured to be rotatable on a plane orthogonal to the optical axis direction. Display device. 3. The image display device according to claim 1, wherein the wavefront curvature modulating means includes position adjusting means for adjusting the position of the optical element, separately from the moving means. . 4. At least one light source, modulation means for modulating a light beam emitted from the light source according to an image signal, and wavefront curvature modulation means for modulating the wavefront curvature of the light beam modulated by the modulation means, The scanning means for scanning the light beam modulated by the wavefront curvature modulating means, and the optical means for making the light beam scanned by the scanning means enter the pupil of the observer, the image signal on the retina of the observer. An image display device for displaying an image corresponding to, wherein the wavefront curvature modulating means includes an optical element having a plurality of reflecting surfaces at different positions with respect to the optical axis direction of the light flux. Display device. 5. At least one light source, a modulation means for modulating a light flux emitted from the light source according to an image signal, and a wavefront curvature modulation means for modulating the wavefront curvature of the light flux modulated by the modulation means. The scanning means for scanning the light beam modulated by the wavefront curvature modulating means, and the optical means for making the light beam scanned by the scanning means enter the pupil of the observer, the image signal on the retina of the observer. An image display device for displaying an image corresponding to, wherein the wavefront curvature modulating means includes a variable focal length optical element whose focal length varies with changes in shape or physical property values. . 6. The wavefront curvature modulating means comprises position adjusting means for adjusting the position of the optical element or the variable focal length optical element.
The image display device according to. 7. A light detecting means for detecting light reflected by the optical element or light passing through the variable focal length optical element, wherein the position adjusting means is arranged at a position of the light detected by the light detecting means. The image display device according to claim 3, wherein the position of the optical element or the variable focal length optical element is adjusted in accordance with the adjustment. 8. The wavefront curvature modulating means is disposed closer to the light source than the scanning means, and the position where a light beam is incident on the scanning means and the pupil position of an observer are in an optically conjugate relationship. The image display device according to any one of claims 1 to 7.