JP3373482B2 - Retinal display device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a retinal display device, and more particularly to a retinal display device capable of projecting a visible ray directly onto the retina of an eyeball to focus a desired image.

[0002]

2. Description of the Related Art A general display device requires a display device such as a cathode ray tube and an LCD (Liquid Crystal Display) panel. Since these display devices occupy a large space, the entire image display device becomes large, and a large space is required at the installation location.

Therefore, in order to reduce the weight and size of the image display device and to make it portable, a retina display device that does not require a display device is disclosed in Japanese Patent Laid-Open Nos. 4-22919 and 4-23579.
JP-A-49-45629, JP-A-49-45630, JP-A-49-45632 and the like.

The retinal display device disclosed in Japanese Patent Laid-Open Nos. 4-22919 and 4-23579 has a structure in which an image on a liquid crystal panel is directly projected onto the retina of an eyeball. on the other hand,
The retinal display device disclosed in JP-A-49-45629, JP-A-49-45630, and JP-A-49-45632 two-dimensionally outputs light from a light source whose brightness is modulated by a video signal directly to the retina of an eyeball. The image is formed by scanning and expanding the image.

[0005]

However, the above-mentioned retinal display device using a liquid crystal panel has the following problems. That is, although a flat image is always formed on the liquid crystal panel, there are individual differences in the visual acuity and the curve of the retina. There is a problem in that each user must make optical adjustments such as diopter and aberration correction according to eye characteristics such as myopia, hyperopia, and astigmatism. In particular, adjustment is difficult when the visual acuity of the left and right eyes is different, and there is a problem that a large burden is placed on the eyes if not adjusted properly.

On the other hand, in the above-mentioned structure in which light is two-dimensionally scanned and developed on the retina, focus adjustment of the optical system (objective lens) is not taken into consideration, so that the apparatus is similar to the conventional example using the liquid crystal panel. There is a problem in that each user must make optical adjustments according to the characteristics of the eye. Also,
Since the synchronization signal is detected from the light whose brightness is modulated by the video signal and used, there is a problem that the image quality is likely to be deteriorated due to a malfunction of the optical deflector.

The present invention has been made in view of the above points, and it is not necessary to perform optical adjustment such as diopter correction and aberration correction according to eye characteristics such as myopia, hyperopia, and astigmatism, and a proper image can be obtained. It is an object of the present invention to provide a compact retinal display device that forms an eye.

[0008]

In order to achieve the above object, a retinal display device of the present invention is a retinal display device for recognizing an image by directly irradiating a visible ray on the retina of an eyeball, and A light emitting means for converting into visible light, a converging optical system for converging the visible light so that a minute beam spot is formed, and a visible light condensed by the converging optical system are focused on the retina. In addition, an autofocus adjusting means for detecting a focused state on the retina by the reflected light from the retina and drivingly controlling the converging optical system based on the detection signal, and deflecting the visible light based on the video signal And a light deflecting means.

Further, in addition to performing automatic focus adjustment on the entire surface of the image formed on the retina, the focus is partially removed so that the perception of perspective is performed, and autostereoscopic and perspective effects are provided. The images of the left and right eyeballs may be offset so that they can be recognized.

[0010]

According to this structure, when the visible light converted from the image signal by the light emitting means is condensed by the converging optical system and is deflected by the light deflecting means, the automatic focus adjusting means drives the converging optical system. The visible light is focused on the retina. Therefore, visible light remains in focus on any part of the retina, so that the recognized image is always in focus regardless of the characteristics of the eye.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a schematic configuration of an embodiment of the present invention. FIG. 2 is a perspective view showing the configuration of the main part thereof.

The retinal display device of the present embodiment is a retinal display device for recognizing an image by directly irradiating the retina 25 of the eyeball 20 with visible light, and is mainly configured as follows. That is, as shown in FIG. 1, a light emitting diode (hereinafter, referred to as “LED”) 2 that converts a video signal input from the input terminal 9 into visible light 2
And a converging optical system 8 for condensing the visible light, and an automatic focus adjusting means for driving and controlling the converging optical system 8 so that the visible light condensed by the converging optical system 8 is focused on the retina 25. 10 and a light deflecting device 18 that deflects the visible light (that is, changes the emission angle) based on the video signal.

The LED 2 is a light emitting means for emitting a monochromatic visible light whose brightness is modulated by the video signal amplified by the amplifier 1. By providing a fixed condensing optical system on the LED 2, it is possible to effectively use the light emitted from the LED 2.

Instead of the LED 2, other light emitting means such as a semiconductor laser may be used. In that case, if the spread of the beam due to diffraction can be ignored, the retina 25 may be scanned using only the sharp directivity of the laser beam itself without using the converging optical system 8 and the automatic focusing means 10. . However, in consideration of the size of the laser beam spot with respect to the size of the retina 25, in order to form a highly accurate image, the focusing optical system 8 is used to form a finer beam spot on the retina 25. Preferably.

The LED 2 used in this embodiment emits monochromatic light, and as shown in FIG. 4, it is respectively supplied with the video signals R, G and B from the input terminal 9 (FIG. 1). LEDs 2R, 2 that emit three primary colors of R, G, B
G and 2B may be used to perform a color display.

The video signal input from the input terminal 9 is sent from a video signal source such as a television camera, a television tuner, a VTR or the like. The structure of the input terminal 9 is preferably a connector structure so that it can be detachably connected to the output terminal of the video signal source. By adopting a connector structure, handling becomes easy and the entire device can be made compact and portable. Further, since the video signal source can be selected as appropriate, the applications can be diversified.

The converging optical system 8 condenses the visible light emitted from the LED 2 to form a minute beam spot on the retina 25. At the same time, an optical system driving means 7 described later
It also functions as a focusing lens that moves in the optical axis direction.

In this embodiment, the automatic focus adjustment device 10 constantly adjusts the focus during scanning of the image forming area 30 on the retina 25. Therefore, the focusing optical system can be located at any position in the optical path from the LED 2 to the retina 25. 8 may be arranged.
Therefore, there is an advantage that the degree of freedom in designing the device is high.

The automatic focusing means 10 is an optical system for moving the converging optical system 8 along the direction of its optical axis (here, it coincides with the optical axis of the eyeball 20 and is parallel to the Z axis). System drive means 7, a photosensor 4 that receives the reflected light from the retina 25, a detector 5 that outputs a signal corresponding to the light receiving area of the photosensor 4, and the optical system based on the signal from the detector 5. And a focus control circuit (Z-axis controller) 6 for controlling the operation of the driving means 7.

The reflected light from the retina 25 guides visible light from the LED 2 toward the retina 25, as shown in FIG.
(Solid line arrow) Since the light travels backward in the elements such as the prisms 16 and 17 (broken line arrow), the prism 3 arranged downstream of the LED 2 separates the optical path from the LED 2 toward the retina 25. That is, the prism 3 functions as a beam splitter. The separated reflected light is used for focus detection as follows.

FIG. 3 shows the positional relationship between the retina 25 and the photosensor 4. In the figure, the prisms 3, 16 and 17 are omitted. The photosensor 4 is used as a unit in which a plurality of photodiode elements 4a are arranged in an array as shown in FIG. The visible light rays B1, B2, B3 that converge toward the surface of the retina 25 are reflected by the prism 3 and the like, and then irradiate the photosensor 4. Here, in the case of the front focus, the incident light B1 on the retina 25 becomes the reflected light B3 and illuminates the range A1 of the photosensor 4. In the case of focusing, the incident light B2 on the retina 25 returns to the optical path of the reflected light B2 and illuminates the range A2 of the photosensor 4. In the case of the rear focus, the incident light B3 on the retina 25 is the reflected light B
It becomes 1 and the range A3 of the photo sensor 4 is irradiated.

As described above, the focus state can be known by the difference in the irradiation area with respect to the photosensor 4 (A1>A2> A3). That is, among the plurality of photodiode elements 4a arranged in an array, a signal indicating light receiving area information such as which one has received light or how many have received light is detected as shown in FIG. It is sent from the device 5 to the focus control circuit 6, and the focus control circuit 6 operates the optical system driving means 7 based on the signal. By thus feeding back the focus shift of the eye, the focus adjustment is performed on the entire surface of the image formed on the retina 25, and the focused state of the beam spot is maintained.

As shown in FIG. 2, after the image forming area 30 defined by the XY axes on the retina 25 has been scanned once, based on the data learned by memory during the scanning,
The focus may be adjusted during the second and subsequent scans. For example, fuzzy control may be adopted. Also,
The focus detection and focus adjustment may be performed every predetermined time or every predetermined number of scans. According to these configurations, the operation of the optical system driving means 7 can be performed at high speed and smoothly.

As the optical system driving means 7 (FIG. 1), for example, a structure in which a lens frame to which the converging optical system 8 is fixed is moved back and forth along the optical axis by a motor-driven cam is adopted. be able to. As an automatic focus adjustment device,
An automatic focus adjustment device used in a CD (Compact Disk) player or the like can be used.

When the retina 25 is irradiated with visible light, information is transmitted from the photoreceptor cells (not shown) at the back of the retina 25 to the optic nerve 22. The focus depth can be set in advance from the relationship between the beam spot diameter of visible light formed on the retina 25 and the size of photoreceptor cells, and the focus control circuit 6 can perform focus adjustment based on the focus depth. Focus adjustment may be performed on the entire surface of the image formed on the retina 25 (all points of the image forming area 30 in FIG. 2), but for example, by partially defocusing according to the image, It is also possible to generate a depth of field to recognize a sense of perspective.

The optical deflector 18 comprises an XY axis controller 11, an X axis driver 12, a Y axis driver 13, direct motors 14, 15, an X axis prism 16 and a Y axis prism 17.

The light deflecting device 18 deflects the visible light converted from the image signal so that the retina 25 is directly irradiated and two-dimensionally scanned in the X and Y axis directions. It is a device. An X-axis prism 16 and a Y-axis prism 17 having three reflecting surfaces in each of the X- and Y-axis directions, and an X-axis prism 16 and a Y-axis prism so that the visible light is deflected by the reflecting surface. 1
7 and X-axis driver 1 for driving the motors 14 and 15 respectively.
2 and the Y-axis driver 13 are independently provided. Furthermore,
An X-Y axis controller 11 for synchronously controlling the operations of the X-axis driver 12 and the Y-axis driver 13 based on the video signal is provided. As described above, since the deflection is controlled by an independent system for each of the X and Y axes, a clear image can be directly formed on the retina 25.

The visible light converted from the video signal is reflected by the prisms 16 and 17 and irradiates the retina 25, but the motors 14 and 15 for scanning the visible light by driving the prisms 16 and 17. And the like are synchronously controlled by the X-Y axis controller 11 based on the video signal, so that the synchronous signal is not affected by, for example, light that becomes noise.

In FIG. 2, the mechanical portion of the light deflecting device 18 is shown, but the converging optical system 8 and the like are omitted. As shown in the figure, direct motor 1
Reference numerals 4 and 15 respectively include fixed coils 14a and 15a, movable coils 14b and 15b, and shafts 14c and 15c. The axes 14c and 15c have prisms 16 for the X and Y axes,
17 are fixed, and the motors 14 and 15 are O
When N, the shafts 14c and 15c rotate in one direction. still,
As the direct motors 14 and 15, thin motors used in CD players and the like can be used.

The X and Y axis prisms 16 and 17 are optical deflectors each having a regular triangular prism shape as shown in FIG. Therefore,
Each of the rotation angle of 120 °, X of the image forming area 30,
The scanning of one side in the Y-axis direction is completed. Not limited to optical deflectors such as the X and Y axis prisms 16 and 17, a regular triangular prism having three reflecting surfaces or a rotating polygon mirror,
An optical deflector conventionally used in laser printers, facsimiles, electronic copying machines and the like such as a galvano scanner may be used. The configuration in which the plane mirror is rotated within a predetermined angle range, like the galvano scanner, is more compact than the configuration in which the X and Y axis prisms 16 and 17 scan by rotating in one direction. It is possible to save space.

A synchronizing signal is separated from the video signal by the XY-axis controller 11 (FIG. 1), and the synchronizing signal causes the X-axis driver 12 and the Y-axis driver 13 to drive the X-axis and Y-axis motors 14 and 15, respectively. To drive. The visible light from the LED 2 is deflected by the prisms 14 and 15 rotated by the X and Y axis motors 14 and 15. As shown in FIG. 2, the deflected visible light scans the image forming area 30 to form a raster, which is visually perceived by an observer as an image two-dimensionally developed in space.
The scanning with visible light is performed in a fixed order with a deflection frequency of about 30 Hz.

The same image forming areas 30 of the left and right eyes 20
Although visible light may be scanned with respect to the left and right eyes, parallax is generated by causing the left and right eyeballs 20 to have a predetermined amount of deviation in the image forming regions 30, and as a result, a stereoscopic image and perspective are obtained. It is possible to recognize images with

Further, by fixing the device of this embodiment to the head so as not to obstruct the field of view of the eyeball 20, it is possible to perform superimposing display for what is actually being viewed. For example, even when the image is overlapped with the entire field of view or the edge of the field of view, the eye is focused on both the object actually viewed and the two-dimensionally scanned and expanded image. , You can always see both objects and images without straining your eyes.

As described above, in the present embodiment, since the method of directly drawing on the retina 25 with visible light is adopted, it is possible to always see a clear image regardless of the direction of the face.
Moreover, since it can be made into an ultra-compact structure, it is not necessary to install it if it is fixed to the head and used. In addition, characteristics such as visual acuity and retina shape depend on the person (that is, for each eyeball).
Although different, in the present embodiment, since the focus is adjusted by the reflected light from the retina 25, anyone can view a proper image without depending on such characteristics.

The retina display device of the present invention is a video display device used for virtual reality or the like; TV, VT.
Video display device used for R, personal computer, movie, security system, presentation tool, etc .; 3D TV
It can be suitably used for a display device for a control panel of an automobile, an airplane, a spacecraft, a ship, a railway, etc. In particular, it is suitable for applications that require constant display in the field of view.

[0036]

As described above, according to the present invention, in the retinal display device for recognizing an image by directly irradiating the retina of the eyeball with the visible light, the light emitting means for converting the image signal into the visible light is provided. A converging optical system for condensing the visible light, an automatic focus adjusting means for driving and controlling the converging optical system so that the visible light condensed by the converging optical system is focused on the retina, and the image. Since it is configured to include a light deflecting unit that deflects the visible light based on a signal, it is unnecessary to perform optical adjustment such as diopter and aberration correction according to eye characteristics such as myopia, hyperopia, and astigmatism. It is possible to realize a compact retinal display device that forms an appropriate image.

Further, the focus of the image formed on the retina is partially defocused to perform automatic focus adjustment so that the sense of perspective is recognized, or the images of the left and right eyes are displaced to give a stereoscopic effect. It can also be made to recognize perspective.

[Brief description of drawings]

FIG. 1 is a block diagram schematically showing the configuration of an embodiment of the present invention.

FIG. 2 is a perspective view showing a main configuration of an embodiment of the present invention.

FIG. 3 is a diagram showing a relationship between a photo sensor used in an embodiment of the present invention and a front focus, a focus, and a rear focus.

FIG. 4 is a schematic diagram showing a configuration of a light emitting device for color display which can be used in an example of the present invention.

[Explanation of symbols]

1 ... Amplifier 2 ... LED 2R, 2G, 2B ... LED 3 ... Prism 4 ... Photo sensor 5 ... Detector 6 ... Focus control circuit 7 ... Optical system driving means 8 ... Converging optical system 9… Input terminal 18 ... Optical deflector 11 ... XY controller 12 ... X-axis driver 13 ... Y-axis driver 14 ... Direct motor for X-axis 14a ... Fixed coil 14b ... Moving coil 14c ... Axis 15… Direct motor for Y-axis 15a ... Fixed coil 15b ... Moving coil 15c… Axis 16 ... X-axis prism 17 ... Y-axis prism 20 ... Eyeball 22 ... Optic nerve 25 ... Retina 30 ... Image forming area

Claims (4)

(57) [Claims] 1. A light emitting means for converting a video signal into the visible light in a retinal display device for recognizing an image by directly irradiating the visible light on the retina of an eyeball,
A converging optical system that condenses the visible light so that a minute beam spot is formed, and a visible light condensed by the converging optical system is focused on the retina by reflected light from the retina. An auto focus adjusting means for detecting a focused state on the retina and drivingly controlling the converging optical system based on the detection signal; and a light deflecting means for deflecting the visible light based on the video signal Retina display device characterized by. 2. The retina display apparatus according to claim 1, wherein automatic focus adjustment is performed on the entire surface of the image formed on the retina. 3. The retina display apparatus according to claim 1, wherein the focus of the image formed on the retina is partially defocused to perform automatic focus adjustment. 4. The retina display device according to claim 1, wherein the images of the left and right eyes are misaligned.