JP2001027740A - Retina display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compact retina display device forming a proper image wherein the need of optical adjustment such as diopter and aberration correction in accordance with the characteristics of the eyes of short-sightedness, long-sightedness and astigmatism or the like is eliminated. SOLUTION: A video signal inputted from an input terminal 9 is converted into a visible light beam by an LED(light emitting diode) 2. The visible light beam is condensed by a converging optical system 8, and the converging optical system 8 is moved and controlled along a Z-axis by an autofocusing means 10 so as to execute focusing on a retina 25. The visible light beam is deflected by a light deflector 18 consisting of prisms 14 and 15 or the like which are respectively independent with respect to X and Y-axes regulating a video based on the video signal, so that the video is recognized.

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 for projecting a visible light beam directly on a retina of an eyeball to focus a target image.

[0002]

2. Description of the Related Art A general display device requires a display device such as a cathode ray tube or 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 for an installation place.

To reduce the weight, size, and portability of a video display device, a retinal display device that does not require a display device is disclosed in Japanese Patent Application Laid-Open Nos. 4-22919 and 4-23579.
And JP-A-49-45629, JP-A-49-45630, and JP-A-49-45632.

A retinal display device disclosed in Japanese Patent Application Laid-Open Nos. 4-22919 and 4-23579 has a configuration in which an image on a liquid crystal panel is directly projected on a retina of an eyeball. on the other hand,
A retinal display device disclosed in JP-A-49-45629, JP-A-49-45630, and JP-A-49-45632 discloses a two-dimensional retinal display device in which light from a light source whose luminance is modulated by a video signal is directly applied to the retina of an eyeball. It is configured to form an image by performing scanning and development.

[0005]

However, the retinal display device using a liquid crystal panel has the following problems. In other words, despite the fact that 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. For each user, there is a problem that it is necessary to make optical adjustments such as diopter and aberration correction in accordance with eye characteristics such as myopia, hyperopia, and astigmatism. In particular, when the visual acuity of the right and left eyes is different, adjustment is difficult, and if not properly adjusted, there is a problem that a heavy load is imposed on the eyes.

On the other hand, in the above-described configuration in which light is scanned and developed two-dimensionally on the retina, since the focus adjustment of the optical system (objective lens) is not taken into consideration, the device is arranged in the same manner as in the conventional example using the liquid crystal panel. There is a problem that optical adjustment according to the characteristics of the eye must be performed for each user. Also,
Since the synchronizing signal is detected and used from the light whose luminance is modulated by the video signal, there is also a problem that the image quality is apt to be deteriorated due to malfunction of the optical deflector.

The present invention has been made in view of the above points, and does not require optical adjustment such as diopter and aberration correction according to eye characteristics such as myopia, hyperopia, and astigmatism. It is an object of the present invention to provide a compact retinal display device for forming a retinal display.

[0008]

According to the present invention, there is provided a retinal display device for recognizing an image by irradiating a visible light directly on a retina of an eyeball. A light emitting means for converting the light into visible light, a converging optical system for condensing the visible light so that a minute beam spot is formed, and a convergent optical system for focusing the visible light on the retina. Automatically focusing means for detecting a focus state on the retina by reflected light from the retina and driving and controlling the converging optical system based on the detection signal; and deflecting the visible light based on the video signal. Light deflecting means.

Furthermore, in addition to performing automatic focus adjustment on the entire surface of the image formed on the retina, automatic focus adjustment is performed by partially defocusing so as to recognize perspective, The image of the left and right eyeballs can be shifted so as to be recognized.

[0010]

According to this structure, when the visible light converted from the video signal by the light emitting means is condensed by the converging optical system and deflected by the light deflecting means, the automatic focus adjusting means drives the converging optical system. To focus visible light on the retina. Therefore, the visible light is kept in focus at any part on the retina, and 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.

The retinal display device of this embodiment is a retinal display device for recognizing an image by irradiating a visible ray directly onto the retina 25 of the eyeball 20, and has the following configuration. That is, as shown in FIG. 1, a light emitting diode (hereinafter, referred to as “LED”) 2 that converts a video signal input from an input terminal 9 into visible light.
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 for deflecting the visible light based on the video signal (that is, changing the light emission angle).

The LED 2 is a light emitting unit that emits monochromatic visible light whose luminance is modulated by the video signal amplified by the amplifier 1. By providing the LED 2 with a fixed light-collecting optical system, the light emitted from the LED 2 can be effectively used.

In place of the LED 2, other light emitting means such as a semiconductor laser may be used. In this case, if the spread of the beam due to diffraction can be neglected, the retina 25 may be scanned using only the sharp directivity of the laser beam itself without using the converging optical system 8 or the automatic focusing unit 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 high-precision image, the converging optical system 8 is used to form a finer beam spot on the retina 25. Is preferred.

The LED 2 used in the present embodiment emits monochromatic light. As shown in FIG. 4, each of the LEDs 2 receives a video signal R, G, B input from an input terminal 9 (FIG. 1). LEDs 2R and 2 that emit light of three primary colors of R, G and B
The color display may be performed using G and 2B.

The video signal input from the input terminal 9 is transmitted from a video signal source such as a television camera, a television tuner, and a VTR. 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 the connector structure, the handling becomes easy and the whole apparatus can be made compact and portable. In addition, since the video signal source can be appropriately selected, diversification of uses becomes possible.

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, the optical system driving means 7 described later
Also functions as a focusing lens that moves in the optical axis direction.

In this embodiment, the focus is always adjusted by the automatic focusing device 10 during the scanning of the image forming area 30 on the retina 25. Therefore, the focusing optical system is 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 moves the focusing optical system 8 along the direction of its optical axis (here, coincides with the optical axis of the eyeball 20 and is parallel to the Z axis). System driving means 7, a photosensor 4 for receiving light reflected from the retina 25, a detector 5 for outputting a signal corresponding to a light receiving area of the photosensor 4, and the optical system based on a signal from the detector 5. 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 arrow) Since the light travels backward through the elements such as the prisms 16 and 17 (dashed arrow), the light is separated from the light path from the LED 2 to the retina 25 by the prism 3 arranged downstream of the LED 2. That is, the prism 3 functions as a beam splitter. The separated reflected light is used for focus detection as follows.

FIG. 3 shows a positional relationship between the retina 25 and the photosensor 4. In the figure, prisms 3, 16, 17 and the like are omitted. The photo sensor 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, and B3 converging toward the surface of the retina 25 irradiate the photosensor 4 after being reflected by the prism 3 and the like. Here, in the case of the front focus, the incident light B1 to the retina 25 becomes the reflected light B3, and irradiates the range A1 of the photosensor 4. In the case of focusing, the incident light B2 with respect to the retina 25 returns along the optical path of the reflected light B2, and irradiates the range A2 of the photosensor 4. In the case of the back focus, the incident light B3 to the retina 25 is the reflected light B
It becomes 1 to irradiate the area A3 of the photosensor 4.

As described above, the focus state can be known from the difference in the irradiation area on the photosensor 4 (A1>A2> A3). In other words, of the plurality of photodiode elements 4a arranged in an array, a signal indicating information on the light receiving area such as which one of the plurality of photodiode elements 4a is received or the number of received light is detected as shown in FIG. The focus control circuit 6 operates the optical system driving means 7 based on the signal sent from the device 5 to the focus control circuit 6. As described above, the focus of the entire image formed on the retina 25 is adjusted by feeding back the defocus of the eyes, and the focused state of the beam spot is maintained.

As shown in FIG. 2, after the image forming area 30 defined by the X and Y axes on the retina 25 has been scanned once, based on the data stored and learned at the time of scanning,
The focus adjustment at the time of the second and subsequent scans may be performed. For example, fuzzy control may be adopted. Also,
The focus detection and the 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 configuration is employed 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. be able to. In addition, as an automatic focusing device,
An automatic focusing device used for a CD (Compact Disk) player or the like can be used.

When the retina 25 is irradiated with visible light, information is transmitted to the optic nerve 22 from photoreceptors (not shown) at the back of the retina 25. The depth of focus 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 the photoreceptor cells, and the focus can be adjusted by the focus control circuit 6 based on the depth of focus. Focus adjustment may be performed on the entire surface of the image formed on the retina 25 (all points of the image forming region 30 in FIG. 2), but, for example, by partially defocusing according to the image, a predetermined It is also possible to cause the depth of field to be generated and to recognize the perspective.

The light 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 video signal so that the retina 25 is directly irradiated and two-dimensionally scanned in the X and Y directions. 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
Motors 14 and 15 for driving the motor 7 and the X-axis driver 1 for driving the motors 14 and 15 respectively
2 and the Y-axis driver 13 independently. Furthermore,
An X-Y-axis controller 11 is provided for synchronously controlling the operations of the X-axis driver 12 and the Y-axis driver 13 based on the video signal. Thus, since the deflection is controlled by an independent system for each of the X and Y axes, a clear image can be formed directly 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. The motors 14 and 15 which scan the visible light by driving the prisms 16 and 17 are provided. Are controlled synchronously by the XY-axis controller 11 based on the video signal, so that the synchronization signal is not affected by, for example, noise light.

FIG. 2 shows the mechanical parts of the light deflecting device 18, but does not show the converging optical system 8 and the like. As shown in FIG.
Reference numerals 4 and 15 respectively comprise fixed coils 14a and 15a, movable coils 14b and 15b, and shafts 14c and 15c. The axes 14c and 15c have prisms 16 for X and Y axes,
17 are fixed, and the motors 14 and 15 are
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 having a regular triangular prism shape as shown in FIG. Therefore,
With a rotation angle of 120 °, X,
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 mirror having three reflecting surfaces, a rotating polygon mirror (polygon mirror),
An optical deflector conventionally used in a laser printer, a facsimile, an electronic copier, or the like may be used, such as a galvano scanner. A configuration in which the plane mirror is rotated within a predetermined angle range, such as a galvano scanner, is more compact than a configuration in which scanning is performed by rotating in one direction, such as the X and Y-axis prisms 16 and 17, so that the apparatus is internally mounted. Space can be saved.

The XY-axis controller 11 (FIG. 1) separates a synchronizing signal from the video signal, and the X-axis driver 12 and the Y-axis driver 13 control the X- and Y-axis motors 14 and 15 according to the synchronizing signal. 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 recognized by a viewer as a two-dimensionally developed image in space.
The scanning with visible light is performed in a fixed order at a deflection frequency of about 30 Hz.

The same image forming area 30 of the left and right eyeballs 20
May be scanned with visible light, but a parallax is generated by providing a predetermined amount of deviation between the left and right eyeballs 20 in the image forming area 30, and as a result, a three-dimensional image or perspective Can be recognized.

Further, by fixing the apparatus of the present embodiment to the head so as not to obstruct the field of view of the eyeball 20, it is also possible to perform superimposed display of what is actually seen. For example, even when the image overlaps the entire field of view or the edge of the field of view, the eye is in focus on both the object actually viewed and the two-dimensionally scanned and developed image. You can always see both objects and images without straining your eyes.

As described above, in the present embodiment, a method of drawing directly on the retina 25 with visible light is adopted, so that a clear image can always be seen regardless of the face direction.
Moreover, since it can be formed into a microminiature structure, if it is used fixed on the head, no installation place is required. In addition, characteristics such as eyesight and retinal shape are different depending 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, anybody can view a proper image without depending on such characteristics.

The retinal display device of the present invention is a video display device used for virtual reality or the like; TV, VT
R, PC, movie, security system, video display device used for presentation tools, etc .; 3D TV
Video display device used for the like; it can be suitably used for a display device for a control panel of a car, an airplane, a spacecraft, a ship, a railway, or the like. In particular, it is suitable for applications in which display must always be performed in the field of view.

[0036]

As described above, according to the present invention, in a retinal display device for recognizing an image by irradiating a visible light directly onto a retina of an eyeball, a light emitting means for converting an image signal into the visible light is provided. A focusing optical system for focusing the visible light, an automatic focus adjusting means for driving and controlling the focusing optical system so that the visible light focused by the focusing optical system is focused on a retina, Optical deflection means for deflecting the visible light based on a signal is provided, so that optical adjustment such as diopter and aberration correction according to eye characteristics such as myopia, hyperopia, and astigmatism is unnecessary, A compact retinal display device that forms an appropriate image can be realized.

Further, the image formed on the retina is partially out of focus and automatic focus adjustment is performed so that the sense of perspective is recognized. Or you can make them recognize the perspective.

[Brief description of the drawings]

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

FIG. 2 is a perspective view showing a configuration of a main part of the 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 front, in-focus, and rear focus.

FIG. 4 is a schematic view illustrating a configuration of a light emitting element for color display that can be used in an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Amplifier 2 ... LED2R, 2G, 2B ... LED3 ... Prism 4 ... Photosensor 5 ... Detector 6 ... Focus control circuit 7 ... Optical system driving means 8 ... Convergent optical system 9 ... Input terminal 18 ... Optical deflector 11 ... XY-axis controller 12 ... X-axis driver 13 ... Y-axis driver 14 ... X-axis direct motor 14a ... fixed coil 14b ... movable coil 14c ... axis 15 ... Y-axis direct motor 15a ... fixed coil 15b ... movable coil 15c … Axis 16… X-axis prism 17… Y-axis prism 20… Eyeball 22… Optical nerve 25… Retina 30… Image formation area

Claims (4)

[Claims] 1. A retinal display device for recognizing an image by irradiating a visible light directly onto a retina of an eyeball, a light emitting means for converting an image signal into the visible light,
A converging optical system for condensing the visible light so that a fine beam spot is formed, and a reflected light from the retina so that the visible light condensed by the converging optical system is focused on the retina. Automatic focusing means for detecting a focus state on the retina and driving and controlling the converging optical system based on the detection signal; and light deflecting means for deflecting the visible light based on the video signal. A retinal display device. 2. The retinal display device according to claim 1, wherein automatic focusing is performed on the entire surface of the image formed on the retina. 3. The retinal display device according to claim 1, wherein an automatic focus adjustment is performed by partially defocusing an image formed on the retina. 4. The retinal display device according to claim 1, wherein the left and right eyeball images are shifted.