JPH07250292A - Eyeball projection type video display device - Google Patents

Abstract

PURPOSE:To provide an eyeball projection type video display device with which plural images in different image forming states can be simultaneously observed or can be observed while being switched and the projecting position of an image can be changed corresponding to the change of the image. CONSTITUTION:Concerning the eyeball projection type video display device provided with a video display element 13 and a projective optical system for projecting the image displayed on this video display element onto the eyeball 3 of an observer, the projective optical system is provided with an optical path forming means 14 for forming plural optical paths by branching an optical path from the video display device. Optical elements 15 and 16 provided with different types of optical performance are arranged at these plural optical paths, and light flux passed through one of these plural optical paths at least is selectively guided to the eyeball of the observer by optical path selecting means 16 and 21.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an eyeball projection type image display device for projecting an image into the eyeball of an observer.

[0002]

2. Description of the Related Art Conventionally, an image is displayed by using an image display device such as a CRT display or a liquid crystal display device, and the image is directly displayed on the retina in the eyeball of an observer by using an optical system such as a lens system or a concave mirror. 2. Description of the Related Art There is known an eyeball projection type image display device for projecting. In this type of device, a large screen image can be obtained by using a small image display element by increasing the magnification of the optical system. Also recently
Attention has been focused on a head-mounted image display device provided with a support for mounting this type of image display device on the observer's head. This head-mounted image display device is a new type of image display device that allows an observer to see a large screen image in any posture.

FIG. 8 shows a general example of an eyeball projection type image display apparatus that can be mounted on the head, as disclosed in Japanese Patent Laid-Open No. 2-281891. FIG. 8A is a diagram showing a state in which an observer is wearing the head-mounted image display device.
(B) is a front view showing a part of the internal structure of the head-mounted image display device. In the figure, a head-mounted image display device 50 includes a main body 51 including an optical system and the like, and a band-shaped frame 53 for mounting and holding the device on a head 52 of an observer. Inside the main body 51, liquid crystal display elements 55 each having a backlight 54 are arranged corresponding to the left and right eyes of an observer, and an eyeball projection lens 56 is arranged between the liquid crystal display elements 55 and the eyes. ing. The light flux emitted from the backlight 54 passes through the image display portion of the liquid crystal display element 55 and is guided to the eyeball of the observer through the eyeball projection lens 56, and the image displayed on the liquid crystal display element 55 is displayed on the left and right sides of the observer. Each image is formed on the retina in the eyeball. Thereby, the observer can observe the virtual image of the enlarged image.
Also, stereoscopic observation can be performed by displaying images having parallax on the left and right liquid crystal display elements 55. In this case, the convergence angle and the diopter, that is, the sense of discomfort occurs when observing that the position where the optical axes of the left and right eyeballs intersect with the position where the left and right eyeballs are in focus, respectively. The position of 55 is moved slightly inward and the virtual image is formed at a finite distance to improve the convergence angle and the diopter.

Further, in Japanese Patent Application Laid-Open No. 5-48991, FIG.
A head-mounted image display device having a configuration as shown in FIG. This device comprises a main body 60 and a spectacle-shaped frame 61. The liquid crystal image display element 62 provided inside the main body 60 is arranged with the image display surface facing forward, and in front of this image display surface, a reflection plate 63 inclined by approximately 45 ° is arranged, and the lower side thereof. Is provided with a reflector 64 that is substantially orthogonal to the reflector 63, and the reflector 64 and the eyeball 6 of the observer.
A projection optical system 66 is disposed between the optical system 5 and the optical system 5. Reflector 6
The elements 3 and 64 are integrally configured so as to be movable in parallel in the direction of the line of sight of the observer. The light flux from the image displayed on the liquid crystal display element 62 is sequentially reflected by the reflectors 63 and 64,
It is guided into the observer's eyeball 65 via the projection optical system 66. This allows the observer to see the virtual image of the magnified image. Further, the reflectors 63 and 64 are integrally moved in parallel in the direction of the line of sight of the observer, whereby the optical path length between the liquid crystal display element 60 and the projection optical system 66 is changed to enable the diopter adjustment.

[0005]

In these conventional eyeball projection type image display devices, it is not possible to switch the image to be observed in accordance with the observer's request or the nature of the observation system. It is impossible. Further, in stereoscopic observation, when the projection position of the virtual image changes according to the vergence angle of both eyes, the observation can be performed in the most natural state.
In the one described in Japanese Patent No. 2881891, since the projection distance of the virtual image is fixed, a sense of discomfort is accompanied when observing a stereoscopic image. Further, the one described in JP-A-5-48891 has a diopter adjusting mechanism and therefore the projection position of the virtual image can be changed. However, in a general diopter adjusting mechanism, a change in vergence angle between both eyes, that is, It is impossible to change the virtual image position following the change in the image.

The present invention has been made in view of the above problems, and an object thereof is an eyeball projection capable of simultaneously observing or switching a plurality of images having different image formation states. Type image display device. Another object of the present invention is to provide an eyeball projection type image display device capable of changing the projection position of an image according to the change of an image.

[0007]

An eyeball projection type image display device of the present invention comprises an image display element and a projection optical system for projecting an image displayed on the image display element into an observer's eyeball. The projection optical system includes an optical path forming means for branching an optical path from the image display element to form a plurality of optical paths, and a light path for guiding a light flux passing through at least one of the plurality of optical paths to an eyeball of an observer. An optical path selecting means, wherein the plurality of optical paths have different optical performances.

In order to give different optical performances to a plurality of optical paths, different optical elements are arranged in each optical path. When the plurality of optical paths have different magnifications as different optical performances, optical elements having different magnifications are arranged in the respective optical paths. When the sizes of the visual fields of the plurality of optical paths are different as different optical performances, an optical element that regulates the size of the visual field is arranged in each optical path.

Further, as the optical path forming means, a transflective element for branching an optical path from the image display element into a reflected optical path and a transmitted optical path is used, and an imaging lens having different magnifications in the reflected optical path and the transmitted optical path. It is possible to dispose a field diaphragm having a variable aperture size arranged at an image forming position by the image forming lens. This field stop changes the size of the observable field by changing the size of the aperture. Further, when the aperture stop is used so that the light in the optical path is blocked when the aperture is completely closed, the aperture stop also functions as the optical path selecting means.

Further, a transflective element that transmits the light flux that has passed through the reflected light path and receives and reflects the light flux that has passed through the transmitted light path at a position different from the light flux, and the two transmissive elements behind the transmissive reflective element. By providing an eyepiece lens that is arranged eccentrically with respect to at least one of the light fluxes, images of the light fluxes that have passed through both optical paths are formed without overlapping, so that it is possible to observe two images at the same time. .

If two eyeball projection type image display devices as described above are provided corresponding to the left and right eyes of an observer, binocular observation or stereoscopic observation can be performed. In the case of adjusting the focus position according to the change of the stereoscopic image, the image display element for the left eye and the projection optical system for the left eye, the image display element for the right eye and the projection optical system for the right eye are provided, and the left side is provided. The image displayed on the image display element for the eye is projected onto the left eyeball of the observer by the projection optical system for the left eye, and the image displayed on the image display element for the right eye is observed by the projection optical system for the right eye. In the eyeball projection type image display device adapted to project to the right eyeball of the observer, the left eye image display element and the right eye image display element have a parallax or a convergence angle corresponding to the left and right eyeballs of the observer. Different images are displayed, and the left-eye projection optical system and the right-eye projection optical system form a plurality of optical paths by branching the optical paths from the left-eye image display element and the right-eye image display element, respectively. Equipped with optical path forming means for the left eye and the right eye, A plurality of optical paths formed by the light path forming means are different from each other positions may be configured so as to form a virtual image. Then, by switching the plurality of optical paths by the optical path selecting means, it is possible to switch between the virtual image projected at the far position and the virtual image projected at the near position for observation. This switching can be performed according to the depth of the image or the distance of the main observation target.

A polarization beam splitter can be used as the optical path forming means, and a polarization plane varying means arranged between the polarization beam splitter and the image display element can be used as the optical path selecting means. Further, as the optical path forming means, it is possible to use a transflective element for branching the light flux from the image display element into a transmitted optical path and a reflected optical path, and a reflective mirror having power is arranged in each of the transmitted optical path and the reflected optical path.
Further, shutter means for each of the transmitted light path and the reflected light path can be provided as an optical path selection means.

It is not necessary that all of the plurality of optical paths formed by the optical path forming means have different optical performances.
It suffices if at least two of the plurality of optical paths have different optical performances.

[0014]

The concept of the present invention is shown in FIG. Video display element 1
The image displayed on the screen is projected by the projection optical system 2 to the observer's eyeball 3
Projected inside. The optical path from the image displayed on the image display element 1 enters a plurality of optical paths formed behind the optical path forming means 3, that is, at least one of the three optical paths 4, 5, and 6 in this figure. These optical paths have different optical performances, and optical elements 8, 9 and 10 are provided for that purpose.

The optical path selecting means 7 selects any one of the three optical paths 4, 5, 6 formed by the optical path forming means, and only the light beam selected by the optical path selecting means 7 is the eyeball 3 of the observer. Will be led to. Therefore, the observer can see different images depending on the optical path selection. A single optical path or a plurality of optical paths may be selected. By configuring the plurality of optical paths so that the projection magnifications are different, it is possible to switch and observe images of a desired size by selecting the optical paths.

Further, if the plurality of optical paths are constructed so that the image projection positions are different, the images can be seen at different positions by selecting the optical paths. This configuration is effective for stereoscopic observation,
Images with different depths can be switched and observed by selecting the optical path. If the optical path is selected according to the change of the image displayed on the image display element 1, the focus position of the observer's eye can be changed according to the sense of depth of the displayed image. It becomes possible to approximate the diopter, and it is possible to eliminate the discomfort caused by the difference between the convergence angle and the diopter.

Further, the optical elements having different optical performances arranged in the two optical paths of the first optical path and the second optical path contribute to the formation of the image of the field frame having different sizes or shapes. When the optical element is used and the selection of the first optical path or the second optical path can be switched, the observation image of the field frame desired by the observer can be switched and observed.

[0018]

EXAMPLE 2 FIG. 2 is a view showing the schematic arrangement of an optical system according to the first example of the present invention. In the figure, reference numeral 11 denotes an eyeball projection type image display device, and a CRT display 13 for image display is provided inside a housing 12 thereof, and a 45 in front thereof.
A half mirror 14 for forming an inclined optical path is arranged. An imaging lens 15 and a field diaphragm 16 having a variable aperture size are arranged in the optical path on the transmission side of the half mirror 14.
A relay lens 17 is arranged in the vicinity of the field stop 16 so that its front focus substantially coincides with the principal point of the imaging lens 15. A 45 ° oblique mirror 18 is arranged on the front side of the relay lens 17. On the other hand, the half mirror 14
A 45 ° oblique mirror 19, an imaging lens 20, and a field stop 21 having a variable aperture size are arranged in the optical path on the reflection side of
A relay lens 22 is arranged in the vicinity of the field stop 21 so that its front focal point substantially coincides with the principal point of the imaging lens 20. A half mirror 23 and an eyepiece lens 24 are arranged on the front side of the relay lens 22. The front focus of the eyepiece lens 24 substantially coincides with the field stops 16 and 21. The optical axis of the transmission optical path of the half mirror 14 (optical axis of the relay lens 17) is slightly decentered from the optical axis of the eyepiece lens 24, and the optical axis of the reflection optical path (optical axis of the relay lens 22) is slightly downward. Is eccentric to. Further, although the imaging lenses 15 and 20 are the same lens, the CRT display 13
The distance from the image forming lens 20 is farther.
Also, from the CRT display 13 to the field diaphragms 16 and 21.
The optical path lengths up to are almost equal.

The luminous flux emitted from the CRT display 13 is divided into two by the half mirror 14 to form two optical paths, a transmitted optical path and a reflected optical path. In the transmitted light path, the image displayed on the CRT display 13 is magnified and imaged at a predetermined magnification β at the position of the field stop 16 by the imaging lens 15. This light flux is reflected by the mirror 18 via the relay lens 17, guided to the half mirror 23,
The light flux reflected here reaches the eyepiece lens 24. on the other hand,
In the reflection optical path of the half mirror 14, the image displayed on the CRT display 13 is reduced and imaged at the position of the field stop 21 by the imaging lens 20 via the mirror 19. From the CRT display 13 to the field stop 16 and 21
Since the distance to is almost equal, the reduction ratio is almost 1 /
Beta. This light flux is guided to the half mirror 23 via the relay lens 22, but enters a little lower side of the light flux reflected from the mirror 18, and the transmitted light flux reaches the eyepiece lens 24. These two light fluxes emerge from the eyepiece lens 24 as substantially parallel light fluxes, enter the observer's eyeball 3 and form an image on the retina 25, but the positions of the two light fluxes are displaced. On the retina 25, an image with small magnification is formed on the upper side and an image with large magnification is formed on the lower side. These images appear to the observer at infinity.

The appearance of the observed image is shown in FIG. On the upper side, an image with a large magnification near the center of the display element 13 passing through the transmitted light path can be seen, and on the lower side, an image with a small magnification in a relatively wide range of the display element 13 passing through the reflected light path can be seen. The sizes of the fields of view 26 and 27 can be adjusted by changing the size of the openings of the field stops 16 and 21 of FIG. In this state, the observer can observe a fine portion in an image with a large magnification and can see the relationship between the enlarged portion and the entire image in an image with a small magnification.
When only the image with the higher magnification is to be observed, the field stop 16 is opened wide and the field stop 21 is completely closed. On the contrary, when only the image with the lower magnification is to be observed,
The field stop 21 may be opened wide and the field stop 16 may be closed completely. In this way, by selecting the optical path with the field diaphragms 16 and 21, it is possible to select the magnification of the image to be observed, and it is also possible to select the size of the field of view to be observed.

As described above, in the present embodiment, the same lens with different arrangement is used as the optical element for giving different magnifications to the two optical paths, but of course different lenses may be used. In the present application, even when the same optical element is arranged differently, it is considered to be included in the concept that different optical elements are arranged in each optical path. If each of the image forming lenses is a variable power lens, the magnification can be changed not only by switching between the two images but also by the image alone in each optical path.

In this embodiment, a variable aperture stop is used as an optical element that gives different field sizes, and it also serves as an optical path selecting means. Since only the opening and closing of the diaphragm is performed, the optical path can be selected quickly. When the optical path selecting means is separately provided, the aperture does not necessarily have to be variable, but since the size of the field of view can be changed for each image alone, a variable diaphragm is preferable.

Although the magnification and the size of the visual field can be selected in this embodiment, various selections can be made in addition to this. For example, if a reticle plate is arranged as a measuring means near the field stop of one optical path, the image due to the light flux that has passed through this optical path will appear to have overlapping scales, which is useful for measuring the size and unevenness of the image-displayed object. It is convenient.
Further, if a filter is provided in one optical path, only a specific portion in the image displayed on the CRT display 12 can be emphasized and observed. In particular, a TV that can obtain this image display device through a medical device such as an endoscope or a microscope.
When used as an image display means, it may be necessary to appropriately switch and observe a normal image and a special image for diagnosis or treatment, which is particularly suitable for such an application.

Although not particularly shown in FIG. 2, the eyeball projection type image display apparatus of this embodiment may be mounted on the head of an observer by the same supporting mechanism as in the prior art. At this time, it is preferable to use a reflecting surface or the like so that the image display element and each optical element can be arranged on the temporal region of the observer because the balance at the time of mounting can be easily taken. Further, in the present embodiment, only the configuration corresponding to one eyeball is shown, but if two identical eyeballs are provided for the left and right eyeballs of the observer, binocular observation or stereoscopic observation can be performed.

A second embodiment of the present invention is shown in FIGS.
FIG. 4 is a perspective view of the optical system of this embodiment, FIG. 5 (a) is an optical path diagram at long distance display, and FIG. 5 (b) is an optical path diagram at short distance display.
Although one optical system is shown in FIG. 4, in this embodiment, the illustrated optical system is provided for each of the left and right eyeballs of the observer so that stereoscopic observation can be performed. Figure 4
, A liquid crystal display element 28 is arranged as an image display element outside the visual axis of the eyeball 3 of the observer, and a TN liquid crystal (twisted nematic liquid crystal) plate 29 is arranged in front of it as a polarization plane rotating element.
To place. The liquid crystal plate 29 is provided with a control signal line 30, and in accordance with the control signal, the incident surface of the incident light is left as it is (the ON state) and the deflected surface is rotated by 90 ° to emit the light (the OFF state). ) And can be switched. Reference numeral 31 is a polarization beam splitter (PBS) that is disposed in front of the eyeball 3 in the optical path from the liquid crystal display element 28 and is tilted about 45 ° with respect to the optical axis. Here, it is assumed that the PBS 31 reflects S polarized light and transmits P polarized light. A quarter wavelength plate (λ / 4 plate) 32 and a long-distance display concave mirror 33 are arranged in this order on the reflection side of the PBS 31, that is, in the visual axis direction of the eyeball 3, and a liquid crystal display is provided on the transmission side of the PBS 31. Another λ / 4 plate 34 and a short-distance display concave mirror 35 are arranged in this order so as to face the element 28. The optical path length from the liquid crystal display element 28 to the concave mirror 33 (air conversion) is almost equal to the focal length of the concave mirror 33, and the optical path length from the liquid crystal display element 28 to the concave mirror 35 is slightly shorter than the focal length of the concave mirror 35. Specifically, the focal lengths of the concave mirrors 33 and 35 are both 60 mm, and the concave mirror 3 and
The optical path length up to 3 is 60 mm, and the optical path length from the liquid crystal display element 28 to the concave mirror 35 is 58 mm. Reference numeral 36 is a signal line for supplying a video signal to the liquid crystal display element. Here, the PBS 31 forms two optical paths, a transmitted optical path and a reflected optical path.

An image is displayed on the liquid crystal display element 28 by the image signal supplied through the signal line 36. The liquid crystal display element 28 includes a polarizing plate or a polarizing film, and the light flux from the displayed image is linearly polarized light. Here, a case where the light flux from the liquid crystal display element 28 is S-polarized will be described. When the TN liquid crystal plate 29 is turned on by the control signal from the control signal line 30, the luminous flux from the liquid crystal display element 28 is S
The polarized light passes through the TN liquid crystal plate 29, is reflected by the PBS 31 as shown in FIG. 5A, is incident on the λ / 4 plate 32, is converted into circularly polarized light, is reflected by the concave mirror 33, becomes a parallel light beam, and is again reflected. It is converted into P polarized light through the λ / 4 plate 32, and PB
The light passes through S31, enters the eyeball 3, and forms an image on the fundus. A magnified image at infinity can be seen by the observer, and the display becomes a long distance. On the other hand, when the TN liquid crystal plate 29 is turned off, FIG.
As shown in (b), the S-polarized light incident on the TN liquid crystal plate 29 is converted into P-polarized light by rotating the polarization plane by 90 °, transmitted through the PBS 31 and incident on the λ / 4 plate 34, and converted into circularly polarized light. It is reflected by the concave mirror 35 and becomes a divergent light beam, and λ
It is converted into S-polarized light through the / 4 plate 34, reflected by the PBS 31 and incident on the eyeball 3 to form an image on the fundus. An observer can see a magnified image at a position about 170 cm in front, which is a short-distance display.

As described above, in this embodiment, the TN liquid crystal plate 29 is used.
Since it is possible to switch the long-distance / near-distance of the position where the image can be seen by switching ON / OFF of, the image position is changed according to the sense of depth of the image displayed on the liquid crystal display element 28. Can be very easy to see. That is, in this embodiment, images having parallax are displayed on the left and right liquid crystal display elements 28 for stereoscopic observation. However, when a deep image including a landscape such as a distant mountain is displayed, It is more natural for the image to be seen at infinity, and conversely, when an image with less depth is displayed, it is more natural for the image to be seen closer. Therefore, the TN liquid crystal plate 2 can be adjusted according to the content (sense of depth) of the displayed image.
If a control signal for switching perspective is supplied to 9 to select an optical path, the observer focuses the eye at a distance in the case of an image with depth and a near focus in the case of an image without depth. Since the images are aligned, the image can be observed in the same natural state as when observing the actual object itself.

In addition to the change in the contents of the image, for example, in the case of an image in which an object of interest (person, automobile, etc.) is approaching (or moving away from), the long distance is determined according to the object distance. If the display and the short-distance display are switched, the change of the vergence angle of both eyes of the observer and the change of the focus are interlocked, so that the image can be observed in a very realistic state.

In these cases, if the signal for controlling the TN liquid crystal plate 29 is supplied in synchronization with the image displayed by the image signal, the automatic switching can be performed, which is preferable. Such a control signal can be generated from, for example, an autofocus signal of a television camera that shoots a video signal. When a video signal is created by computer graphics or the like, a control signal for the TN liquid crystal plate 29 may also be created when the video is created.

In this embodiment, since the focal lengths of the two concave mirrors 33 and 35 are made equal, the change of the viewing angle when switching between the long-distance display and the short-distance display is small.
Further, in this embodiment, a distance of 2 mm is provided between the image display surface of the liquid crystal display element 28 and the concave mirrors for long distance and short distance display (the distance to the principal point position of the projection optical system).
When the focal lengths of the two concave mirrors are substantially equal to each other, it is preferable that the difference be 1 mm or more because the difference between the long-distance image and the short-distance image can be clearly recognized.

If the PBS 31 reflects S-polarized light and transmits P-polarized light, the relationship between transmission and reflection is reversed. FIG. 6 shows a perspective view of the main part of the optical system of the third embodiment of the invention, FIG. 7 (a) shows a long-distance display, and FIG. 7 (b) shows a short-distance display optical path diagram. Similar to the second embodiment, only one of the left and right eye optical systems is shown here. Further, the constituent elements having the same functions as those in the second embodiment are designated by the same reference numerals, and the description thereof will be omitted.

A plasma display 37 is arranged as an image display element outside the visual axis of the eyeball 3 of the observer. Also, eyeball 3
The half mirror 38 is arranged as a transflective element for transmitting or reflecting with respect to the optical axis in the optical path from the plasma display 37 on the front surface of the half mirror 38 at an angle of about 45 °, and its reflection side, that is, the visual axis direction of the eyeball 3. Further, a liquid crystal shutter 39 and a concave mirror 33 are arranged in this order as light transmission blocking control means, and another liquid crystal shutter 40 and a concave mirror 35 face the plasma display 37 on the transmission side of the half mirror 38.
Are arranged in this order. The focal lengths of the concave mirrors 33 and 35 and the optical path lengths between them and the plasma display 37 are the same as in the second embodiment. 41 is a liquid crystal shutter control circuit,
42 and 43 are signal lines for supplying control signals to the liquid crystal shutters 39 and 40, respectively.

The plasma display 37 displays an image by the image signal supplied through the image signal line 36.
The perspective switching signal supplied by the signal line 30 corresponds to the depth of the image displayed by the image signal. The shutter control circuit 41 receives a perspective switching signal, and supplies a signal to one of the liquid crystal shutters through the signal lines 42 and 43 to set one of the liquid crystal shutters in a transmissive state and the other in a closed state according to the perspective. That is, when the distance switching signal is a long distance display signal, the liquid crystal shutter 39 is in a transparent state, and the liquid crystal shutter 40 is in a closed state.
Reverse the shielding relationship.

The light flux from the image displayed on the plasma display 37 is split by a half mirror 38 into two optical paths, a reflection side and a transmission side, and enters the liquid crystal shutters 39 and 40, respectively. When the distance switching signal is the long distance display signal, the transmitted light flux is blocked by the liquid crystal shutter 40 as shown in FIG.
After passing through 9, the image is magnified and reflected by the concave mirror 33, again passes through the liquid crystal shutter 39, passes through the half mirror 38, and is guided to the eyeball 3 as a magnified image at infinity. When the distance switching signal is a short distance display signal, the reflected light beam is blocked by the liquid crystal shutter 39, but the transmitted light beam is transmitted through the liquid crystal shutter 40 and enlarged and reflected by the concave mirror 35, as shown in FIG. 7B. ,
It again passes through the liquid crystal shutter 40, is reflected by the half mirror 38, and is guided to the eyeball 3 as a magnified image of a short distance forward.

In this way, the image can be observed in a natural state as in the second embodiment. In each of the embodiments described above, only two optical paths that can be selected are shown, but 3
If one or more optical paths can be selected, the range of selection can be further increased. Further, the configuration of each optical system can be variously changed. As is clear from the above examples, the fact that the optical performance is different in the present invention means the magnification, the size of the visual field,
It means that an image obtained through each optical path is different in some sense, such as color, additional display other than image, convergence of emitted light flux, divergence state (position of virtual image).

[0036]

As can be seen from the above description, according to the present invention, it is possible to provide an eyeball projection type image display apparatus capable of appropriately switching the images to be observed or simultaneously observing a plurality of images. Further, it is possible to provide an eyeball projection type image display device capable of changing an image position in accordance with a change in convergence angle or parallax during stereoscopic observation.

[Brief description of drawings]

FIG. 1 is a conceptual diagram of the present invention.

FIG. 2 is a schematic configuration diagram of the first embodiment.

FIG. 3 is a diagram showing an image displayed according to the first embodiment.

FIG. 4 is a perspective view of an optical system according to a second embodiment.

FIG. 5 is an optical path diagram of the second embodiment.

FIG. 6 is a perspective view of an optical system according to a third embodiment.

FIG. 7 is an optical path diagram of the third embodiment.

FIG. 8 is an explanatory diagram of a conventional eyeball projection type image display device.

FIG. 9 is an explanatory diagram of a conventional eyeball projection type image display device.

Claims (7)

[Claims] 1. An eyeball projection type image display device comprising an image display element and a projection optical system for projecting an image displayed on the image display element into an eyeball of an observer, wherein the projection optical system comprises the image An optical path forming means for branching an optical path from the display element to form a plurality of optical paths; and an optical path selecting means for guiding a light flux passing through at least one of the plurality of optical paths to an eyeball of an observer. An eyeball projection type image display device, wherein the plurality of optical paths have different optical performances. 2. The eyeball projection type image display device according to claim 1, wherein magnifications of the plurality of optical paths are different from each other. 3. The optical path forming means is a transflective element for branching the optical path from the image display element into a reflected optical path and a transmitted optical path, and the reflected optical path and the transmitted optical path are imaging lenses having different magnifications, respectively. 3. The eyeball projection type image display device according to claim 2, further comprising: a field stop having a variable size of an aperture arranged at an image forming position by the image forming lens. 4. A transflective element that transmits a light flux that has passed through the reflected light path and receives and reflects the light flux that has passed through the transmitted light path at a position different from the light flux, and the two transmissive elements behind the transmissive reflective element. The eyeball projection type image display device according to claim 3, further comprising an eyepiece lens that is arranged eccentrically with respect to at least one of the light fluxes. 5. An image displayed on the left-eye image display element, comprising a left-eye image display element and a left-eye projection optical system, a right-eye image display element and a right-eye projection optical system. An eyeball that is projected onto the left eyeball of the observer by the projection optical system for the left eye, and an image displayed on the image display element for the right eye is projected on the right eyeball of the observer by the projection optical system for the right eye. In the projection-type image display device, the left-eye image display element and the right-eye image display element,
Different images having parallax or vergence corresponding to the left and right eyeballs of the observer are displayed, and the left-eye projection optical system and the right-eye projection optical system are the left-eye image display element and the right-eye image, respectively. The optical path forming means is provided for the left eye and the right eye for forming a plurality of optical paths by branching the optical path from the display element,
An eyeball projection type image display device, wherein a plurality of optical paths formed by the optical path forming means form virtual images at different positions. 6. The optical path forming means is a polarization beam splitter, and the optical path selecting means is a polarization plane varying means arranged between the polarization beam splitter and the image display element. An eyeball projection type image display device according to item 1. 7. The optical path forming means is a transmissive / reflecting element, and a reflecting mirror having optical power is arranged in each of the transmissive optical path and the reflective optical path of the transmissive reflective element, and the optical path selecting means is arranged in the transmissive optical path and the reflective optical path. The eyeball projection type image display apparatus according to claim 5, wherein the shutter means is provided in each of the optical paths.