JP3131631B2 - Image 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 compact, lightweight, low power consumption, high brightness, high definition, high environmental resistance, which generates a high-precision image in a part of the human visual field like eyeglasses. The present invention relates to an image display device.

[0002]

2. Description of the Related Art A typical example of the prior art is a so-called head mounted display equipped with a liquid crystal display device. A liquid crystal display (LCD) is used as a head mounted image display device. In this method, an image is generated by mounting a small LCD directly on the field of view of eyeglasses. However, since the LCD is not self-luminous, it is necessary to mount a white light called a backlight, and there is a limit in miniaturization and weight reduction, and it is too heavy to use as glasses, which is inconvenient. In addition, there is a fundamental problem in performance related to visibility such as definition and contrast.

Further, since the liquid crystal display is mounted on the lens portion of the glasses, a method of suspending from the head is inevitable, and the type of mounting on the human body is extremely limited. In addition, since the display impairs daily vision, the purpose of use and the environment are limited, and in some cases, it is dangerous.

[0004]

SUMMARY OF THE INVENTION According to the present invention, in order to solve the above-mentioned drawbacks of the conventional image generating system, an image display section, a transmission section, and an image generation section are separately provided, and a portion to be mounted on a human head. Is simplified and the size and weight are greatly reduced. In addition, a high-brightness and high-definition image is displayed without disturbing a normal field of view of life, and convenience in daily life is remarkably improved.

[0005]

As means for solving the above-mentioned problems, in the present invention, an image display section, a transmission section and an image generation section are separately provided, and the human head has a very simple configuration. Attach only the display. The electronics unit for generating, adjusting, and processing images is mounted on clothes, such as pockets and belts, and the images obtained therefrom are transmitted to and displayed on the display unit in the above-mentioned eyeglass part.

More specifically, a small and high-definition self-luminous display is used for the image generation / processing section, and the image is transferred to a known optical fiber system by a known optical lens technique. The image is transmitted to the display unit of the eyeglass part. Accordingly, the display unit can be limited to a function of converting a fiber image into a real image by an optical lens system and displaying the actual image.

Further, according to the present invention, in the image generation / processing section, high definition / high resolution realized by the latest LSI technology is realized.
High-brightness field emission display (FE
We propose to use D). FEDs have the feature that they can be made smaller and more precise without sacrificing brightness and image quality.
In addition, the power consumption is 10 times less than that of the current liquid crystal display.
It can be reduced by a factor of one. Further, it has a feature that a computer function, for example, an image processing function can be integrated on the same substrate as the FED.

The present invention proposes the use of a display (EL) utilizing the electroluminescence phenomenon of a semiconductor in addition to the FED. This is because the same function as the FED can be expected. In addition, the present invention proposes not only the above-described image display method at the eyeglass part, but also a method of directly or indirectly projecting the light from the optical fiber onto the eyeball retina. This makes it possible to omit most of the optical system of the display unit, thereby achieving further reduction in size and weight, and can be an effective auxiliary device for people with low visual acuity.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The basic structure of the present invention in FIG. 1 shows an example <br/>. The image from the image generation unit is transmitted to the image projection optical system via an optical fiber bundle. The optical system is mounted directly or indirectly through a part of eyeglasses on a human head including ears, and projects an image on a part of the eyeglass field of view. The image projection surface is subjected to a lens coated with a half mirror, a grainy surface of an aluminum material, or a thin film treatment that reflects only a specific wavelength at a high level.

As shown in FIG. 2, the optical system has functions such as rotation and zoom functions, focus adjustment, and distortion correction.
The optical system in the image generation unit performs image formation for rotation and tilt of the zoom mechanism and image display element itself, and correction by software using the image conversion mechanism.

The image generator has a basic structure of an image display and a circuit for driving the image display, and also includes a control mechanism for controlling an additional mechanism such as a line-of-sight shutter. Further, the image processing / control section is constituted by a converter having a preprocessing mechanism for inputting an image signal generated from a television tuner or a personal computer to the image display driver of the present invention. As an image display, a small image generating device (for example, a liquid crystal system,
EL system, FED system, etc.)
It can be configured with a minimum size on condition that low power consumption is satisfied. Among various display mechanisms, an FED system having characteristics of high luminance, high resolution, and low power consumption can be employed. The image display element has, for example, an outer shape of 12 m.
mx 9 mm, 800 x 600 dots, full color (or 16.7 million colors).

FIG. 3 shows an example of the configuration of such an image generator, and is a block diagram for driving a display element such as an FED. In the figure, an image display element and a certain portion are portions that actually emit light and display an image. The scan driver is a circuit for controlling a scanning line of a CRT, and operates the entire image element at a predetermined time. The data driver is a circuit for turning ON / OFF the scanned signal at a frequency corresponding to a pixel according to image data.
The control circuit is a circuit that controls a scan driver circuit and a data driver circuit, and converts transmitted image data into scan data and ON / OFF data. In order to perform data conversion in batches, in order to display images continuously, the memory is temporarily stored in the memory, converted, and allocated to a plurality of memories to maintain continuity.

The details of the FED will be described later with reference to FIG. The EL display is a system using light emission obtained by an electroluminescence phenomenon. In the 1970's, an orange glowing display using a zinc sulfide (ZnS) polycrystalline thin film to which manganese (Mn) was added as an emission center was developed. As shown in FIG. 5, a voltage 21 is applied between the lower electrode 14 and the upper transparent electrode 18 to excite the light emitting layer 16. The excited luminescent substance 22 (in this case, ZnS) emits light when returning to the ground state. At that time, luminescence centers such as Mn are mixed to promote luminous efficiency. The excitation method includes a voltage method and a current method. Although it has advantages such as response speed, resolution, and low power consumption, it does not have sufficient luminance (brightness) compared to FED, and can be used in the present invention.
When a small size, high brightness, and high resolution are required, the FED can be made smaller, practical, and excellent in portability. (For example, FED is several hundred to 1000 cd
/ M2, EL is about tens of cd / m2, LCD
Is said to be even lower)

The optical fiber is made of a material such as glass or plastic, and has characteristics. In the case of glass, since quartz is used, there is almost no absorption of not only visible light but also ultraviolet light, and light of a wide range of wavelengths can be transmitted over a long distance. On the other hand, plastics generally use an acrylic resin (PMMA) due to its transparency, but in the short wavelength region, extreme absorption occurs and is limited to only the visible light region. In addition, a plastic material has some absorption even in the visible light region, and has a longer distance (1 K) than a quartz material.
m) cannot be expected. However, due to its specific gravity, a light-weight object can be made. In the case of a short distance (about 2 m) and only visible light as in the present invention, a plastic object is sufficient. In both cases, there is enough flexibility,
Compatible with body shapes and movements.

In the embodiment, a quartz fiber bundle having a diameter of 4 mm is used. However, if the purpose is to prevent loss of brightness, an object having a larger diameter can be used. In addition to the optical fiber, the main cause of the decrease in transmitted light of lenses, glass, etc. is largely due to reflection at the boundary with the air. By applying antireflection films on both the input and output surfaces, the transmittance can reach 98%. It is possible to raise. (Approximately 92% when there is no anti-reflection film) It is appropriately selected depending on the transmission efficiency of all optical systems including the brightness (brightness) fiber of the image display element and the portability (flexibility and weight). For example, a general LCD or the like cannot provide sufficient brightness, so that an image display element is enlarged and an aperture ratio of an optical system including a fiber is increased. ), Portability can be realized without deteriorating image quality.

As for the size of the projection plane, the size of a general 17-inch display on a desk may be displayed. For example, in the drawings of the embodiments, the distance of the glasses is assumed, If the angle is set to about 40 degrees, a good result can be obtained which is easy to see and has no feeling of oppression. For example, 20m from the eyeball
If it is placed m m ahead, it becomes a rectangle inscribed in about 15 mm in diameter.

FIG. 6 shows another basic configuration of the present invention .
You. A gaze tracking sensor is further attached to the configuration shown in FIG . Thereby, a function of displaying an image only when the eyeball comes to a certain position is added. Since this can be used as a kind of eyeball switch, coexistence with a daily visual field is facilitated, and it is convenient when performing a plurality of activities at the same time.

The eye tracking sensor has a function of attaching an image pickup device such as a small CCD camera, taking in a pupil shape image, and judging the direction in which the pupil is facing through image processing. As for the mounting position, an imaging device such as a CCD can be installed in front of the eyes. Further, as in a fifth embodiment to be described later, it is possible to make the image sensor and the following elements adjacent to the image generating unit by taking advantage of the two-way, which is an advantage of the optical fiber bundle.

FIG. 7 is a diagram for explaining the operation of the eye tracking sensor. The line-of-sight tracking sensor photographs the pupil (pupil) deviation and sends the image to the image processing device in order to recognize the direction in which the eyeball is facing. The image processing apparatus obtains, for example, the center of gravity of the received pupil deviation, and determines which side is relatively inclined. Thereafter, it is determined whether the pupil is facing the optical axis (the screen in the case of the first to fourth embodiments, the optical axis in the case of the fifth embodiment), and the shutter (valve) is opened or closed or the screen saver function is turned ON / OF.
F.

FIG. 8 illustrates still another basic configuration of the present invention . It is characterized in that a field emission display (FED) is used for the image generation unit. FED
Comprises an electron source consisting of a group of field emitters switched for each pixel, a gate electrode for controlling the emission of electrons from the electron source, and an anode electrode for emitting fluorescence by irradiation of the electrons emitted from the electron source. It has a feature that it can be reduced in size and definition without sacrificing luminance and image quality, and power consumption can be reduced to one tenth as compared with current liquid crystal displays. Further, it has a feature that a computer function, for example, an image processing function can be integrated on the same substrate as the FED.

As shown in FIG. 4, the general basic structure of the FED is a cathode substrate 1, a cathode electrode 3, an emitter electrode 2 surrounded by an insulating layer 5, and a gate electrode 6 for extracting electrons from the emitter electrode 2. , A phosphor 7, and an anode electrode 9 for accelerating the extracted electrons, each of which is set in a vacuum. In operation, a gate voltage 12 (for example, 30 to 90 volts) is applied between the cathode electrode 3 and the emitter 2 and the gate electrode 6, and free electrons are emitted from the emitter 2 into a vacuum. At the same time, the anode voltage 11 (for example, in the range of several hundred to several tens of kilovolts) applied between the cathode electrode 3 and the anode electrode 8 causes free electrons to be emitted to the phosphor 7 in front of the anode electrode 8. Collision (transition of energy) occurs and emits light.

The wavelength of the emitted light 10 is determined by the phosphor 7, and when a sufficiently high voltage can be obtained, a commonly used phosphor of a CRT can be used as it is.
A transparent anode electrode 8 (ITO) is formed on the end face of a fiber bundle having an opening surface of a size equal to or larger than the image display element, and a phosphor 7 is formed thereon. Thus, when an image is transmitted through several transparent substrates (including a cover glass, for example), a loss due to reflection occurs at each end face, and the problem that the image cannot be efficiently transmitted is solved.

That is, the present invention is characterized in that the phosphor 7 is formed directly on the fiber bundle. On the cathode side, an emitter array from the cathode electrode 3 to the gate electrode 6 is formed on the cathode substrate 1 (silicon wafer or glass substrate), and a predetermined spacer is attached. Crimping or heat bonding. Adhesives that cause deterioration of vacuum degree and contamination are not used, and sufficient cleanliness and flatness of the joint surface can sufficiently maintain and fix the vacuum degree in the FED.

FIG. 9 illustrates a first embodiment of the present invention . It is characterized in that the end face of each optical fiber itself is used as the anode electrode of the FED. After applying a conductive transparent electrode such as an ITO film to the end face,
A phosphor is applied, and a voltage of, for example, about 100 volts is applied thereto to form an anode electrode. This eliminates the need for an image input optical system from the image generator to the optical fiber bundle, eliminates a decrease in luminance, and allows a bright image to be transmitted to the image projection optical system.

FIG. 10 illustrates a second embodiment of the present invention . The image projection optical system is characterized in that an image is directly projected on an eyeball retina. This makes it possible to sense an image even when the visual acuity is extremely reduced. The illustrated device captures pupil information that has traveled in the optical fiber bundle in the opposite direction, detects the direction in which the optical axis of the eyeball faces by detecting the direction of the optical axis of the eyeball, and uses a shutter (valve) when the image is not automatically viewed. ) Has a closing mechanism.
Although various methods are conceivable, the following mechanism is given as an example.

From the probe light source in the image generating section, a pulse which is harmless to the human body and has a wavelength outside the visible light region and which is sufficiently short, such as infrared rays, is generated at regular intervals. An image reflected by the retina through the crystalline lens and probe light returned through the same fiber bundle are acquired by the imaging device. When a person is looking at an image, the pupil and the optical axis coincide with each other, so that the probe light is detected at a constant intensity. Otherwise,
That is, when a person is not looking at the image, only very low reflected light is detected. Through such a procedure, it is recognized whether or not a person is looking at the image, and the opening and closing of the valve is controlled.

FIG. 11 exemplifies such a configuration, and is largely divided into an image processing and control section and an image generating section. The image processing and control unit converts various image data generated from an existing TV tuner or computer into data that matches the drive system of the display element of the present invention. In addition, power is supplied as a power supply. The image generating unit includes the shutter (valve) described in FIG.
And a generating unit. In addition, in order to control the ON / OFF of the shutter, first, a retinal information in which light generated from the probe light source is reflected on the retina of the eyeball, or a CCD or the like for acquiring a reflected light intensity according to a pupil direction. Of image sensors.

The image projection optical system includes a mirror, a projection lens (eyepiece), and a visual acuity adjusting lens. FIG.
As shown in FIG. 2, an image formed by the image display device is transmitted by a fiber bundle, an image is emitted from the other end of the transmission fire bar, collected by an eyepiece, and is totally reflected by a mirror. Transfer the image to the eye via the diopter adjustment lens.

[0029]

The present invention provides: By dividing the image generating unit and the image projecting unit and using an optical fiber bundle for the image transmitting unit, the burden of mounting on the human head can be reduced to the level of ordinary glasses. Or
It is also possible to project on ordinary glasses. 2. By using a sufficiently thin optical fiber, it is possible to secure a field of view that is close to the normal field without blocking the field of view. 3. By using the optical fiber, the eyeball information can be fed back, and by appropriately adding an appropriate sensor, an appropriate image can be arbitrarily viewed at an appropriate time. Example 1) An automatic shutter mechanism is added by equipping a gaze tracking system. Example 2) Automatic diopter adjustment mechanism. Example 3) Enlargement / reduction mechanism, rotation, stereoscopic video, etc. 4. By miniaturizing the image display unit, power consumption can be significantly reduced, and the specification time of a battery-powered television or computer can be extended. Alternatively, the weight of the battery can be reduced. In addition, by installing an auxiliary power supply such as a solar cell in the space of the conventional display,
It is possible to make the battery drive longer or lighter.
Low energy can be realized. 5. In combination with a micro camera, it is possible to form a clear image directly on the retina of a person with visual impairment. 6. Helps protect privacy while working on a computer.

[Brief description of the drawings]

FIG. 1 shows a basic configuration of the present invention.

FIG. 2 is a diagram illustrating an optical system used in the present invention.

FIG. 3 shows an example of a configuration of an image generation unit used in the present invention.

FIG. 4 illustrates a general basic configuration of an FED.

FIG. 5 is a diagram illustrating an EL display.

FIG. 6 shows another basic configuration of the present invention.

FIG. 7 is a diagram for explaining the operation of a gaze tracking sensor.

FIG. 8 shows still another basic configuration of the present invention.

FIG. 9 shows a first embodiment of the present invention.

FIG. 10 illustrates a second embodiment of the present invention.

FIG. 11 illustrates a circuit configuration that can be used in the device shown in FIG.

FIG. 12 is a diagram illustrating an example of an image projection optical system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cathode substrate 2 Emitter electrode 3 Cathode electrode 5 Insulating layer 6 Gate electrode 7 Phosphor 8 Anode electrode 9 Anode electrode 14 Lower electrode 16 Light emitting layer 18 Upper transparent electrode 22 Light emitting material

────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Noriyuki Takamatsu 1-1-4 Umezono, Tsukuba, Ibaraki Pref. Within the Research Institute of Electronics and Technology, (56) References JP-A-10-123453 (JP, A) JP-A-8-50256 (JP, A) JP-A-10-334836 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G02B 27/02 G09F 9/00

Claims (2)

(57) [Claims] An electron source comprising a group of field emitters,
A gate electrode for controlling electron emission from the electron source;
An electron source that fluoresces when irradiated with electrons emitted from a source
It is composed of a node electrode and conductive as the anode electrode.
The end face of the optical fiber coated with the phosphor through the transparent film
An image generation unit to be used and an image transmission unit configured by bundling the optical fibers by the number of pixels.
And directly to the human head including the ears or through a part of eyeglasses, etc.
The image from the image generator is
An image display device comprising: an image projection optical system transmitted by the image transmission unit; and an image projection surface on which the image is projected on a part of a spectacle field of view . 2. The image display device according to claim 1, further comprising a line-of-sight tracking sensor used to add a function of displaying an image only when the eyeball reaches a certain position.