KR101072469B1 - Active shutter glasses - Google Patents

Abstract

The present invention provides a particle flow space including the charged black particles capable of absorbing visible light in a sealed state; A predetermined front substrate and a back substrate; And a partition wall partitioning between the front substrate and the rear substrate so as to form a particle flow space and having a dielectric film coated on both sides of the metal electrode, wherein a transparent electrode is formed on the front substrate and / or the rear substrate. The electrophoretic shutter glasses of claim 1, wherein the black particles in the particle flow space move in the direction of the substrate or the partition wall to change visible light transmission through the substrate according to the electric field directions applied to the metal electrode and the transparent electrode. Provided is a stereoscopic image display system in which an electrophoretic shutter glasses and an information display device for sequentially displaying left and right eye images by using a time division technique are linked to each other to realize a stereoscopic image.

Description

Active Shutter Glasses {ACTIVE SHUTTER GLASSES}

The present invention relates to a pair of glasses for alternating the left and right eye glasses to pass through the visible light to feel a stereoscopic image, and more particularly, a particle flow space in which charged black particles capable of absorbing visible light are contained in a sealed state. part; A predetermined front substrate and a back substrate; And a partition wall partitioning between the front substrate and the rear substrate so as to form a particle flow space and having a dielectric film coated on both sides of the metal electrode, wherein a transparent electrode is formed on the front substrate and / or the rear substrate. The present invention relates to an electrophoretic shutter eyeglass, characterized in that the black particles in the particle flow space move in the direction of the substrate or the partition wall and change the visible light transmission through the substrate according to the electric field directions applied to the metal electrode and the transparent electrode. .

The method of realizing a stereoscopic image by alternately displaying left and right eye images by time division can maintain the resolution of the information display device as it is, there is no limitation on the viewing angle, and the image quality is relatively low. It has been developed and used using LCD and PDP flat panel display elements. As shown schematically in FIG. 1, the stereoscopic image forming apparatus includes a flat panel display device capable of alternating left and right eye images by a time division technique, and a left eye image showing visible light transmittance through the left and right eye glasses. It is composed of a device that makes the viewer feel three-dimensional by adjusting in synchronization with the right eye image. Here, in order for the viewer to feel a three-dimensional effect, the left eye image and the right eye image must be clearly separated from each other. If the left eye sees a part or most of the right eye image at the same time, or the right eye sees a part or most of the left eye image, the image becomes double or stereoscopic.

Currently, active liquid crystal shutter glasses are mainly used as a method for alternately supplying left and right eye images to a viewer's left and right eyes. The cell cross section of the active liquid crystal shutter glasses normally used is shown typically in FIG. Such shutter glasses consist of the front glass substrate 10 and the back glass substrate 11. Each glass substrate is coated with an electrode material (eg ITO) that is transparent to visible light, and the electrode surface is coated with a polyimide-based liquid crystal alignment layer. The liquid crystal alignment layer is determined using a rubbing process, and most of the liquid crystal alignment layer is configured such that the rubbing direction of the front substrate alignment layer and the rubbing direction of the rear substrate alignment layer are 90 degrees.

The liquid crystal material 13 is filled between the two substrates, and the distance between the substrates is kept constant using the spacer 17, and then the front glass substrate and the back glass substrate are encapsulated using a photocurable adhesive or the like. As the liquid crystal material, various liquid crystal materials used in liquid crystal displays can be used, including twisted nematic liquid crystal materials. When the linear polarizers 14 and 15 are attached to the front and back glass substrates, respectively, by the lamination method, and the transparent electrodes are connected to terminals capable of applying voltage, the liquid crystal shutter glasses are completed. At this time, the linear polarizing plates 14 and 15 are arranged such that their polarization directions are 90 degrees or the same as each other.

3 schematically illustrates an operation process of the liquid crystal shutter glasses as one example. First, the visible light passing through the linear polarizing plate 14 of the front glass substrate is rotated by 90 degrees while passing through the twisted nematic liquid crystal material layer, and the polarizing plate on the back glass arranged to match the polarizing direction of the visible light ( While the image is transmitted to the corresponding viewer's eye through 15P2), the image is blocked by the polarizing plate 15P1 on the rear glass substrate disposed at 90 degrees to the polarization direction of the visible light. Accordingly, the image is transmitted only to one of the left eye and the right eye. Next, when voltage is applied to the liquid crystal layer, the change in the polarization direction does not occur while the visible light passes through the liquid crystal, so that the visible light is blocked in the rear glass polarizing plate 15P2 and passed through the polarizing plate 15P1. Therefore, before and after the application of voltage, the left eye image and the right eye image can be alternately transferred to the left eye and the right eye in order.

The above-described shutter glasses for stereoscopic images using liquid crystals have some problems to be improved.

First, the transmittance of visible light of liquid crystal shutter glasses is relatively low. As shown schematically in FIG. 2, the use of a polarizing plate is essential for shutter glasses using a liquid crystal as a light valve. Accordingly, the visible light transmittance does not exceed 50% at maximum. In view of the visible light transmittance of the glass substrate and the transparent electrode, the visible light transmittance of the liquid crystal shutter glasses is about 30%. Therefore, when viewing a stereoscopic image using liquid crystal shutter glasses having low visible light transmittance, the luminance of the information display element representing the time-division left eye image and the right eye image should be relatively increased, which causes an increase in power consumption of the information display element.

Second, the operating speed of a conventional liquid crystal shutter is generally about 4 to 8 msec. In this regard, the operation behavior of the liquid crystal shutter when the voltage pulse is applied is schematically shown in FIG. That is, there is a certain delay time for the left eye image to reach the maximum transmittance in a state where a voltage is applied, and there is a constant delay time for the right eye image to be blocked. That is, the time when the left eye image is opened and the time when the right eye image is closed or the time when the right eye image is opened and the time when the left eye image is closed overlap each other, resulting in a double overlap between the left eye image and the right eye image recognized by the viewer. It will cause crosstalk. Therefore, it is essential to minimize the reaction time with respect to the applied voltage of the liquid crystal shutter as much as possible. In order to solve the above problem, an overdrive driving method and a ferroelectric liquid crystal material are employed, but the crosstalk generation of the image is not reduced to a level that the viewer cannot perceive.

Finally, the production cost of the shutter glasses for stereoscopic image viewing should be low. The liquid crystal shutter glasses discussed in the above examples are manufactured through complex manufacturing processes such as transparent electrode coating and patterning, alignment layer coating and rubbing, spacer insertion, liquid crystal filling, bonding, polarizing plate lamination, and flat plate protective layer coating. This leads to an increase in yield and a decrease in yield, thereby increasing manufacturing costs. Therefore, the shutter glasses which employ the raw material with simple manufacturing process and low manufacturing cost will be needed.

Therefore, there is a high need for a technology that can solve the above problems.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-described problems of the prior art and the technical problems required from the past.

Specifically, the inventors of the present invention, after examining various and in-depth studies, have developed an electrophoretic shutter glasses including a particle flow space portion, a front substrate, a back substrate, and a partition wall having a specific structure as described later. As compared with the conventional liquid crystal shutter glasses, it was confirmed that these electrophoretic shutter glasses exhibited high transmittance and fast reaction speed and were manufactured at low cost, and completed the present invention.

Electrophoretic shutter glasses according to the present invention,

A particle flow space portion including charged black particles capable of absorbing visible light in a sealed state;

A front substrate coated with a dielectric film on a transparent substrate, the dielectric film being arranged to face the particle flow space;

A back substrate coated with a dielectric film on a transparent substrate and arranged such that the dielectric film faces a particle flow space portion at a position opposite the front substrate; And

A partition wall partitioning between the front substrate and the rear substrate so as to form the particle flow space and having a dielectric film coated on both surfaces of the first electrode, which is a metal electrode;

It contains,

Between the transparent substrate and the dielectric film of the front substrate and / or between the transparent substrate and the dielectric film of the back substrate, a second electrode which is a transparent electrode exhibiting the opposite pole to the first electrode when a voltage is applied is formed,

According to the electric field applied to the first electrode and the second electrode, the black particles in the particle flow space move in the direction of the substrate or the partition wall and change the visible light transmittance that passes through the substrate.

Accordingly, in the electrophoretic shutter glasses according to the present invention, a voltage in the form of a pulse is formed between the first electrode (transparent electrode) positioned on the front substrate and / or the rear substrate and the second electrode (metal electrode) positioned on the partition wall. The applied black particles are applied by electrostatic attraction or repulsion to change their position, which is driven in a shutter manner that blocks or passes visible light to the substrate as a result.

The visible light transmittance of the electrophoretic shutter glasses is very good, such as 50% to 70%, the time to respond to the applied voltage is fast in the range of 0.01 msec to 1 msec, and has a number of advantages that the manufacturing process is simple.

In order for such electrophoretic shutter glasses to operate effectively, no aggregation should occur between the particles in the particle flow space. When agglomeration of particles occurs, the mobility of particles in the electric field is drastically reduced, which may cause a problem that the nonuniformity of the shutter performance is increased and the operating time is long. Agglomeration between particles may be caused by the van der Waals attraction of the particles, or may occur due to condensation of moisture or fluid between the particles.

In order to prevent such agglomeration between particles, charged particles are used in the present invention. That is, when the particles are electrically charged with (+) or (-) and the electrostatic repulsive force due to these charges is greater than the Van der Waals attraction, it becomes possible to prevent aggregation between the particles. Therefore, it is preferable that the black particles having excellent visible light absorption provided by the present invention are charged with a (+) or (-) charge so that the electrostatic repulsion force is greater than the Van der Waals attraction.

In the electrophoretic shutter glasses according to the present invention, the inside of the particle flow space is preferably filled with air or gas of low viscosity, or in a vacuum state. The gas of low viscosity is preferably hydrogen or helium, but of course it is not limited to these.

The reaction time of electrophoretic shutter glasses depends on the speed of particle movement in the electric field. The velocity of particle movement is proportional to the electric field formed between the electrodes, proportional to the amount of charge charged to the particles, and inversely proportional to the viscosity of such fluid when fluid is contained within the particle flow space. Therefore, in order to reduce the reaction time of the electrophoretic shutter glasses, it is necessary to increase the electric field, increase the amount of charge accumulated in the particles, or lower the fluid viscosity inside the particle flow space.

However, in order to increase the electric field strength between the electrodes, it is necessary to increase the voltage applied between the spectacle electrodes. This causes a problem of increasing reactive power loss due to charging / discharging during driving of the shutter glasses. Since the reactive power loss is proportional to the square of the applied voltage magnitude, an increase in the applied voltage causes a problem of increasing power consumption of the glasses. Therefore, since there is a limit to increasing the pulse voltage to improve the reaction rate, the preferred pulse voltage may be in the range of 5 V to 50 V, more preferably in the range of 5 V to 25 V.

In addition, increasing the amount of charge charged to the particles lowers the charge retention stability of the particles and increases the rate at which the charge amount decreases with time. Therefore, since there is a limit in increasing the amount of charge charged to the particles to improve the reaction rate, the preferred amount of surface charges charged to the particles may be in the range of 10 μC / m ² to 100 μC / m ² .

In order to lower the fluid viscosity inside the particle flow space, it is preferable to fill a gas having a lower viscosity than the atmosphere (for example, hydrogen or helium) or maintain a vacuum. When the inside of the particle flow space is kept in vacuum, the resistance to particle flow due to buoyancy and gas drag force is eliminated, and thus it is more preferable to extremely improve the reaction speed of the shutter glasses. The vacuum state is preferably in the range of 10 ¹ torr to 10 ^-4 torr, more preferably in the range of 10 ¹ torr to 10 ^-3 torr.

In the present invention, the charged black particles may be spherical, although the shape thereof is not particularly limited.

The charged black particles may preferably be made of a substrate of a polymer material, and the polymer material may be, for example, a low density material such as acrylic, methacrylate, urethane, epoxy, styrene, and the like.

Any color can be used as long as it can color black to realize the black color of the particles, but preferred examples include adding black dyes, graphite, amorphous carbon, and the like.

In the electrophoretic shutter glasses according to the present invention, for example, when the black particles are separated from the positive electrode and fly to the negative electrode, it is necessary to accurately control the flight schedule. As the voltage pulse is applied, electrostatic repulsive force and attractive force act on the particles separated from the electrode, and gravity and buoyancy caused by the gas inside the particle flow space are acted on, thereby affecting the target. However, in order to uniformly and reproducibly control the distribution of the black particles accumulated on the glass substrate or the partition wall surface, it is necessary to minimize the change in gravity due to gravity.

To minimize the gravitational effect on the particles, it is necessary to reduce the density of the black particles or to reduce the size of the particles. Reducing the size of the particles increases the surface area per unit volume, resulting in too large a drag force caused by the gas acting on the particle surface, reducing the mobility of the particles and ultimately slowing the response of the shutter glasses. This will occur. Therefore, in order to reduce the gravitational effect acting on a particle | grain, the black particle provided by this invention uses the low density material or the hollow sphere which empty the center part of a particle.

The hollow spheres which have empty the inside of the particle and lower the apparent density may be used in various methods of manufacturing conventional hollow spheres such as internal gas generation, solvent encapsulation followed by solvent evaporation.

In the hollow sphere, the apparent density decreases as the ratio of the outer diameter (R1) to the inner diameter (R2) is close to 1, but the thinner the shell thickness (R1-R2) of the hollow sphere has a problem of lowering the blocking effect against visible light. Therefore, it is preferable that the ratio of inner diameter R2 / outer diameter R1 is 0.1-0.9 range, and it is more preferable that it is 0.3-0.7 range.

The diameter of the charged black particles is preferably in the range of 0.5 μm to 20 μm, more preferably in the range of 1 μm to 10 μm. In addition, when these particles are filled on the electrode surface, it is preferable that the packing density is high. For this purpose, particles having different sizes may be used rather than particles of a single size. It is preferable that the diameter ratio of the small diameter particles to the large diameter particles is in the ratio range of 0.2 to 0.4: 1.

In addition, the ratio of the mixing amount of the small particles and the large particles is preferably in the range of 2: 8 to 4: 6, and more preferably 3: 7 for the mixing ratio of small diameter particles to large diameter particles.

In the electrophoretic shutter glasses according to the present invention, the planar shape of the particle flow space portion is preferably a symmetrical structure of square or hexagonal shape. The planar shape of the particle flow space may be a variety of shapes, but in the electrophoretic shutter glasses, the reaction time of particles with respect to the application of an electric field is shortened and uniformly stacked. It is preferable to use a part.

This particle flow space may be one in the electrophoretic shutter glasses or may be formed in a combination of two or more.

In one preferred example, the structure may further include an electrode pillar including a third electrode which is a metal electrode coated with a dielectric in the center of the particle flow space in a plane.

This structure provides an additional electrode structure inside the particle flow space to more uniformly control the intensity of the electric field applied to the transparent electrode on the substrate, allowing the particles to be uniformly stacked on the dielectric of the transparent electrode.

In the electrophoretic shutter glasses according to the present invention, the second electrode may be selectively included between the transparent substrate and the dielectric film of the front substrate and the transparent substrate and the dielectric film of the back substrate, as defined above, or may be included respectively. . Preferably, the second electrode is included in each of these sites, so that the operation reliability can be improved and a fast reaction speed can be provided.

The transparent substrate is not particularly limited as long as it is a material exhibiting high transmittance to visible light, and examples thereof include materials such as glass and transparent plastics, and glass having high visible light transmittance and scratch resistance may be used. It may be desirable.

The present invention also provides electrophoretic shutter glasses in which the visible light transmittance of the left and right eye glasses is sequentially changed as described above; And an information display device for sequentially displaying left and right eye images by a time division technique, wherein the electrophoretic shutter glasses and the information display device are linked to each other to provide a stereoscopic image display system.

The information display device is not particularly limited but is preferably a flat panel display device, and non-limiting examples of the flat panel display device include LCD, PDP, OLED, and the like.

As described above, the electrophoretic shutter glasses according to the present invention can significantly reduce the crosstalk between the left and right eye images by dramatically improving the operating speed of the shutter, and lowering visible light transmission such as a polarizing plate. It is possible to improve the visible light transmittance without using the, the manufacturing process is simple, there is an effect that can reduce the manufacturing cost.

1 is a schematic diagram of an apparatus for implementing a stereoscopic image by displaying a left eye image and a right eye image by a time division technique;
2 is a schematic cross-sectional view of a liquid crystal shutter eyeglass according to the prior art that sequentially transfers the left eye image and the right eye image alternately to the left eye and the right eye;
3 is a schematic diagram showing the operating principle of the liquid crystal shutter glasses according to the prior art;
4 is a schematic diagram showing the switching behavior of the liquid shutter glasses according to the prior art;
5 is a schematic diagram showing the operating principle of the electrophoretic shutter glasses according to an embodiment of the present invention;
6 is a schematic diagram showing the shape of a hollow sphere according to one embodiment of the present invention;
7 is a schematic diagram showing planar shapes of a particle flow space according to one embodiment of the present invention;
8 is a schematic view showing the planar shapes of the particle flow space according to another embodiment of the present invention.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings, but the scope of the present invention is not limited thereto.

5 is a schematic vertical cross-sectional view showing the structure of the electrophoretic shutter glasses according to an embodiment of the present invention.

Referring to FIG. 5, the transparent electrode 12 formed on the glass substrates 10 and 11 and the metal electrode 19 formed in the partition wall are coated with a dielectric 18. The dielectric 18 is not particularly limited but is preferably various polymer materials including polyimide, Teflon, polyethylene, polyurethane, and the like; Materials having excellent insulation resistance and relatively low dielectric constant, such as SiO ₂ , Al ₂ O ₃ , Si ₃ N ₄ , MgO, ZrO, and the like; And the like can be used. In addition, as the metal electrode 19, any metal that can be used as an electrode may be used, but various materials including Cu, Al, Ag, Au, or an alloy thereof having excellent electrical conductivity are preferably used. It is possible.

Since the black particles 20 filled in the particle flow space 21 formed between the front substrate 10 and the rear substrate 11 preferably have a low density, a low density polymer may be used to implement black color. To this end, black dyes, graphite, amorphous carbon, and the like are added. The polymer material may be any one capable of making low-density spheres such as acrylic, methacrylate, urethane, epoxy, and styrene. As a method of charging the spheres, a charge control agent (BontroN07, Orient Chemical Industries Ltd.) may be added, an electron beam may be irradiated to the prepared sphere, or an ion beam may be irradiated to the prepared sphere. And the like can be used.

In FIG. 5, (a) shows a form in which black particles 20 are arranged on the front and rear substrates 10 and 11 to block visible light, and (b) black particles 20 are arranged on the partition wall. It shows the form through which visible light is transmitted. The shape (a) and the shape (b) may be changed depending on the direction of the applied electric field to change the transmittance of visible light of the glass substrate. The direction of the electric field can be changed to a voltage in the form of a pulse. For example, in the case of black particles charged with (+), if the front and rear electrodes 12 are negative (-) and the partition electrode 19 is (+), the black particles 20 as shown in FIG. Are arranged on the front and rear electrodes 12 by electrostatic attraction to block visible light, and the front and rear electrodes 12 are positive and the partition electrode 19 is negative. As the black particles 20 are arranged in the partition wall by the electrostatic attraction, visible light may be transmitted. That is, the black particles 20 serve as a shutter by electrophoresis in the particle flow space 21 in the same manner as described above.

The structure of FIG. 5 implements the shutter glasses by stacking the black spheres 20 on the surfaces of the front glass substrate 10 and the rear glass substrate 11 by electrophoresis. In this case, the black spheres 20 Depending on the visible light absorption performance, a method of stacking only on the surface of the front substrate 10 or the rear substrate 11 may be used.

6, the schematic diagram which shows the shape of the hollow sphere used as black particle 20 is shown.

Referring to FIG. 6, the apparent density and the visible light absorbency vary according to the ratio R2 / R1 of the inner diameter R2 to the outer diameter R1 of the hollow sphere. That is, as the ratio R2 / R1 increases, the apparent density decreases but the visible light absorbance decreases. When the ratio R2 / R1 decreases, the visible light absorbance increases but the apparent density increases.

FIG. 7 is a schematic diagram showing the planar shapes of the particle flow space 21 according to one embodiment of the present invention.

Referring to FIG. 7, the planar structure of the particle flow space part 21 may have various shapes. As shown in FIG. 7, the particle flow space part 21 having a planar shape having a square shape or a hexagonal shape may be formed. It is possible to use. In the electrophoretic shutter glasses, it is preferable to use the particle flow space 21 in the form of a square or hexagonal column as a structure to shorten the reaction time of particles according to the application of an electric field and to uniformly stack the particles.

In addition, although the glasses corresponding to the left eye or the right eye may be manufactured with one of the particle flow spaces 21, it is also possible to manufacture a combination of a plurality of particle flow spaces 21.

8 is a schematic diagram showing the planar shape of the particle flow space 21 according to another embodiment of the present invention.

Referring to FIG. 8, in the structure of the particle flow space 21 shown in FIG. 7, a structure in which an electrode 19 structure such as a partition wall is provided in the particle flow space 21 is illustrated. Such a structure allows the intensity of the electric field applied to the transparent electrode on the substrate to be uniformly adjusted so that the particles are more uniformly stacked on the dielectric of the transparent electrode.

Those skilled in the art to which the present invention pertains will be able to perform various applications and modifications within the scope of the present invention based on the above contents. Therefore, the above contents are for illustrating the present invention, and the scope of the present invention is not limited to these.

Claims (17)

A particle flow space portion including charged black particles capable of absorbing visible light in a sealed state;
A front substrate coated with a dielectric film on a transparent substrate, the dielectric film being arranged to face the particle flow space;
A back substrate coated with a dielectric film on a transparent substrate and arranged such that the dielectric film faces a particle flow space portion at a position opposite the front substrate; And
A partition wall partitioning between the front substrate and the rear substrate so as to form the particle flow space and having a dielectric film coated on both surfaces of the first electrode, which is a metal electrode;
It contains,
Between the transparent substrate and the dielectric film of the front substrate and / or between the transparent substrate and the dielectric film of the back substrate, a second electrode which is a transparent electrode exhibiting the opposite pole to the first electrode when a voltage is applied is formed,
Electrophoretic shutter glasses, characterized in that the black particles in the particle flow space portion is moved in the direction of the substrate or the partition wall to change the visible light transmission through the substrate in accordance with the electric field direction applied to the first electrode and the second electrode. 2. The electrophoretic shutter glasses according to claim 1, wherein the interior of the particle flow space is filled with air or gas of low viscosity or kept in a vacuum state. 3. The electrophoretic shutter glasses according to claim 2, wherein the low viscosity gas is hydrogen or helium. 3. The electrophoretic shutter glasses according to claim 2, wherein the vacuum is in the range of 10 ¹ torr to 10 ^-4 torr. 2. The electrophoretic shutter eyeglasses according to claim 1, wherein the charged black particles are spherical. The electrophoretic shutter glasses of claim 1, wherein the charged black particles are made of a polymer substrate. 7. The electrophoretic shutter glasses of claim 6, wherein the charged black particles are dyed by one or more polymer bases selected from the group consisting of black dyes, graphite, and amorphous carbons, thereby displaying black color. 2. The electrophoretic shutter glasses of claim 1, wherein the charged black particles are hollow spheres. 9. The electrophoretic shutter glasses of claim 8, wherein the hollow spheres have an inner diameter / outer diameter ratio of 0.1 to 0.9. The electrophoretic shutter glasses of claim 1, wherein the electrified black particles have a diameter of 0.5 μm to 20 μm. 2. The electrophoretic shutter glasses according to claim 1, wherein the charged black particles have a ratio of small diameter diameter particles to large diameter particles in a range of 0.2 to 0.4: 1. The electrophoretic shutter glasses according to claim 11, wherein the charged black particles are mixed in a ratio of small diameter particles to large diameter particles in a range of 2: 8 to 4: 6. 2. The electrophoretic shutter glasses according to claim 1, wherein the planar shape of the particle flow space portion is a symmetrical structure of square or hexagonal shape. The electrophoretic shutter glasses according to claim 13, further comprising an electrode pillar including a third electrode which is a metal electrode coated with a dielectric in the center of the particle flow space in plan view. The electrophoretic shutter glasses according to claim 1, wherein the second electrode is formed between the transparent substrate and the dielectric film of the front substrate and between the transparent substrate and the dielectric film of the back substrate. An electrophoretic shutter glasses according to any one of claims 1 to 15, wherein the visible light transmittance of the left eye and right eye glasses is sequentially changed alternately; And
An information display device for sequentially displaying left eye and right eye images by a time division technique;
3. The stereoscopic image display system of claim 1, wherein the electrophoretic shutter glasses and the information display element are linked to each other to implement a stereoscopic image. The stereoscopic image display system according to claim 16, wherein the information display element is a flat panel display element.

Images