KR980010482A - Apparatus and method for conducting light patterns through an information display to produce an autostereoscopic display - Google Patents

Abstract

Flat screen autostereoscopic displays for luminescent wide angle stereoscopic images use a flat screen that displays a plurality of regularly spaced and light patterns, such as thin vertical light emitting lines. Light rays are formed by using electrically switchable materials such as liquid crystals or electrochromic materials. The liquid crystal display is located at the front of the light beam. The display and light rays are arranged in such a way that the observer sees the light emitting line passing through one set of pixels through the left eye and the light emitting line passing through another set of pixels through the right eye.

Description

Apparatus and method for conducting light patterns through an information display to produce an autostereoscopic display

This application claims the rights of US Provisional Application No. 60 / 020,939, filed July 1, 1996.

Many technical fields are contemplating the use of video transmission to display three-dimensional (3D) images. Non-holographic techniques require projection of different (stereoscopic) images in the left and right eyes. Recently, technology has been developed that does not require the use of special glass. One device developed by Dimension Technologies, Inc. (DTI), based in Rochester, New York, includes the use of parallax illumination. The device is described in detail in Eisland and Morris on "Glass-free 3D" on Information Display 3/92, pages 9-12. This article describes a typical black and white or color liquid crystal display (LCD) viewer. One of the display devices located in front of the is described. LCDs are two-dimensional arrays of controllable elements (pixels) each arranged in new and horizontal rows, typically 640 columns by 480 columns, in an active area of 8x6 inches. It is illustrated later, and the amount of light conducted by the individual pixels can be controlled such that an image with gray shaded areas can be displayed.

To produce 3-D images, the LCD displays half of the left and right sides of the stereo pair on alternating columns of pixels at the rate of NTSC television's standard rate-30 frames / second. The left image appears on odd columns, and the right image appears on even columns. Therefore, each complete stereoscopic image consists of 320 columns x 480 columns.

In this display, both halves of the stereo pair are simultaneously displayed by use of a very thin 320 grating, a special illumination plate located behind the LCD which optically generates a very bright uniformly spaced vertical line. The lines are spaced a predetermined distance to the column of pixels, and because of the parallax, the left eye sees all of these lines passing through the odd column of LCD, while the right eye sees the lines passing through the column of columns. Such structures are clearly described in US Pat. Nos. 5,457,574, 4,829,385, 4,717,949, 5,036,365, 5,040,878, and 5,500,765, and the specification herein incorporated by reference.

In such a display, there is a relationship that is assembled between the viewing distance (displaying on the viewer) (partially) nominating the dimensions of the "viewing zones" and the distance between the illumination plate and the LCD. These viewing zones are areas within the front of the display where the viewer can sense 3D images. As a result, if the position of the viewer head is not appropriate for the screen and the ray, the eye cannot see the different images and the 3D effect will disappear.

Different head tracking devices are used to track head operation and solve this problem. By way of example, U. S. Patent No. 5,457, 574 discloses a smooth stereoscopic image that tracks the viewer's head (as shown by way of example in FIGS. 7A and 7B of this patent) as it moves laterally. Similar designs can be used to give the effect of a "looking" feature that allows the observer to see different perspectives of the target as he moves his head. This is accomplished by turning a suitable stroboscopic lamp.

This implementation of the parallax illumination concept is bulky by multiple ramps or moving elements for head tracking that requires accurate alignment. As a result, the size becomes huge, and the reliability of the display is lowered.

The present invention relates to an apparatus for conducting light emitting sites through an information display to produce an autostereoscopic display. These devices include a light source for emitting light and a light blocking module for selectively blocking the light from the light source to form the light emitting site. Such light blocking module is composed of an electronically switchable material such as liquid crystal or an electrochromic material by supplying power.

By way of example, the switchable material is sandwiched between a pair of substrates having electrodes, with one electrode arranged in parallel spaced electrode lines. By applying power to the electrodes, the switchable material is selectively switched to allow light to pass selectively.

In one embodiment, at least two switchable patterns of the predetermined spaced electrode lines in parallel are each connected to an independent busbar for each electrode pattern, in one pattern of electrode lines engaged with another pattern of electrode lines. A pattern of electrode lines is provided, and each of the busbars can be independently electroactive to form parallel rays of light in different locations on the light blocking module. By activating different electrodes at different times, this embodiment can be used to track the head. That is, different electrodes can be activated as the viewer is positioned.

The optical site radiation apparatus of the present invention has advantages over the prior art. By way of example, the optical site radiating device of the present invention using electronically switchable materials having various electrode patterns is thinner and much lighter than prior art devices. Moreover, these devices can perform the head tracking function simply by switching the appropriate electrode structure ON / OFF.

As a result, the light pattern emitting device of the present invention can be used to implement a head tracking system similar to that disclosed in US Pat. No. 5,457,574. However, the present invention can further facilitate this result by the multiple electrode pattern by eliminating the inconvenience of the control and bulkiness of the stroboscopic lamp. In a similar manner, multiple electrode patterns can be used to simplify head tracking of multiple observers by rearranging multiple lamps disclosed in the prior art.

The present invention discloses various approaches to fabricating compact backlighting systems that can be used to form 3D images with parallax illumination. In the present invention, the DTI autostereoscopic display concept is utilized except that the present invention utilizes a new concept to form backlighting.

In one approach, an electronically switchable material is provided between the appropriate electrode patterns to fabricate the backlight blocking assembly. By way of example, the electronically switchable material may be an electrochromic or liquid crystalline material (ie, nematic or dispersed polymer). Of course, polymers sprayed on electrochromic or liquid crystal materials utilize or do not utilize polarizer / analyzer combinations as required or necessary. By supplying power between the two electrodes, the electronically switchable material can be made to emit light from the light source of the backlight through the LC material and selectively allow conduction of light continuously through the liquid crystal display (LCD) panel.

1 is an exemplary diagram illustrating a 2D / 3D display according to the present invention.

2 is an exemplary diagram illustrating an electrode configuration for use in the light blocking module of the present invention.

3 illustrates an exemplary electrode design in accordance with the present invention.

4 illustrates an exemplary alternative electrode design in accordance with the present invention.

5 is an exemplary diagram illustrating the use of a light emitting waveguide in accordance with the present invention.

1 illustrates a 2D / 3D display system according to the present invention. The light source 10 includes a scattering surface and a pair of lamps 14 positioned on each side portion of the scattering surface 12. Light radiation is emitted from the lamp 14, passes through the scattering surface 12 and then through the polarizer 16. Light is then charged through the light blocking module 18 and passes through the analyzer 32 (first polarizer) and the LCD 36 in accordance with the present invention.

In this embodiment of the present invention, the optically switchable material is selectively switchable because the light blocking module 18 allows for selective conduction of light that radiates from the light source 10 and passes through the light blocking module 18. And 20. By way of example, the switchable material is a liquid crystal material or an electrochromic material. In FIG. 1, the light blocking module 18 includes two glass plates 22 having a liquid crystal material sandwiched between the modules. An indium tin oxide (ITO) ground electrode 24 is deposited on the inner side of one glass plate, and the selectively deposited tin oxide electrode pattern 26 has two electrodes for the liquid crystal material 20. It is deposited on the inner side of another glass plate 22 to sandwich. In FIG. 1, the selectively deposited tin oxide electrode pattern 26 is an interdigitated electrode pattern consisting of a plurality of parallel electrodes 28 connected to the busbar 30 as illustrated in FIG. It is in form. The electrode 28 illustrated in FIG. 2 has a width W and is divided by the pitch P. Referring again to FIG. 1, between the electrode pattern 26 and the ITO ground electrode 24. By applying power, the liquid crystal material will be aligned with the area corresponding to the electrode. Therefore, the light is selectively blocked by the blocking module 18 so that only a selective portion is emitted. This light then passes through liquid crystal display 36 and then continues through analyzer 32 and shadow mask 34 (if necessary or required). 1 illustrates the use of a "positive mode" liquid crystal material. In positive mode, the polarizer and analyzer are in a crossed relationship (ie, directed at an angle of 90 °). Light is polarized by passing through the flat tube 16. If a voltage is applied to the liquid crystal (via the electrode), the standard nematic liquid crystal material will rotate the direction of the 90 ° polarized light as it is aligned to conduct through the analyzer 32 directed at a 90 ° angle to the polarizer. As a result, if no voltage is applied to the blocking module operating in the positive mode, light is not blocked by the blocking module but rather uniform light is conducted from the light source 10 through the blocking module and into the LCD. Such light may be required for two dimension displays.

When voltage is applied to the panel, the liquid crystal material aligns with the area corresponding to the electrode line position, as a result of which the light is not rotated to conduct through the analyzer. As a result, light does not conduct from the blocking module to the area corresponding to the electrode line pattern. In this manner, the light rays are formed in an area that allows light to pass through the liquid crystal material 20. These rays are used to illuminate the color filter in the liquid crystal display and form the rays necessary for the operation of the autostereoscopic display described above. The proper design of the width and pitch of these electrode lines conducts a series of light rays of the required width and pitch suitable for the 3D display. The selection of the correct width and pitch to enable 3D display is described, for example, in US Pat. No. 4,717,949.

The present invention is not limited to this change because the display system is designed to operate in a "positive" mode while simultaneously describing the utilized quadrature polarizer. Instead, the panel can be designed to operate in a "negative" mode, that is, a mode with polarizers in parallel. In this case, if no voltage is applied, light is not conducted because no voltage is applied, and light rays (3D illumination) are generated in an area corresponding to the position of the electrode line. In this case all liquid crystal materials will have to be activated to obtain 2D illumination.

By arranging a "shadow mask" glass plate 34 having opaque and transparent spaces of suitable dimensions as shown in FIG. 1, and controlling the thickness of the plate, the emission of light can be controlled. If head tracking and 2D / 3D lighting changes are not required, simple 3D lighting uses a shadow mask or other simple device capable of selective light blocking, and selectively picks up the light emitted from the backlight source forming the beam. It can be obtained simply by positioning this device to shut off.

The electrode pattern shown in FIG. 3 has two sets of electrode patterns 26a and 26b respectively engaged with each other. By applying a voltage to the set of electrode line patterns 26a, a set of light rays are generated. By applying a voltage to another set of electrode line patterns 26b, one set of rays is generated laterally positioned from the first set. By providing each of the two sets of interdigitated electrodes with the same width and pitch electrode lines 28, one or the other electrode is each beam moved laterally from one other spacing S that can be head tracked. It can be utilized to form. By way of example, operation of a head given a particular head position in which a particular electrode pattern is used to form a light beam may occur when the head moves relative to the liquid crystal display, a given set of light beams is turned off, and the next set of light beams needed for the 3D display is needed. It can be detected by attaching a sensor target to the observer head to turn on, and by sensing the position of the target by the sensor tracking means. Therefore, by having various parallel sets of line electrode patterns, schematic head tracking is possible without using mechanical means to move the light generating apparatus. 3 illustrates only two sets of interlocked electrodes, but more than two sets of interlocked electrodes may be used. If desired, the electrodes can be covered on each other electrode by utilizing an insulating layer between the electrode line patterns.

If the number of electrode patterns 26 is two or more, a more complex design is needed to insulate and utilize "crossover". One approach for a three-electrode set without crossover is a first pair of electrode patterns 26 on the glass sheet 22A and a second pair of opposing grass sheets 22B as shown in FIG. This can be accomplished by having the electrode pattern 26. Each electrode pattern 26A, 26B on the sheet 22A includes a plurality of electrode lines having a uniform pitch, and each pattern 26A, 26B is mutually relatively evenly interlocked with each other. The third and fourth electrode patterns 26C and 26D are positioned on the glass sheet 22B. The electrode pattern 26C has a width wider than the other electrode patterns so that in effect the wide electrode lines of the pattern 26C are aligned with two adjacent electrode lines 41 and 42 from the electrode patterns 26A and 26B, respectively. It includes an electrode line having. As a result, when a voltage is applied between the electrode patterns 26A and 26C, the electric field is applied only within the area corresponding to the electrode line 14. When a voltage is applied between the electrode patterns 26B and 26D, the electric field is applied only within the area corresponding to the electrode 43.

Another approach to obtaining 2D / 3D illumination is to use waveguide winries to generate light rays.

FIG. 5 illustrates a side view of an embodiment where the backlight 50 is provided with a parallel column pattern 52 of material having a high index of refraction. The pattern of parallel rows would be a function to provide light rays similar to the parallel electrodes described above. The thickness of the deposition material 52 depends on the aspect ratio of the line used. Typically, the waveguide line will have the same width and pitch as the electrode line described above. By way of example, in one embodiment, the width of the high index material line is 38-50 microns for an aspect ratio of approximately 1. The high index material is deposited on the substrate 54 with the smooth side. Substrate glass 54 is customary float grass. By "high index" material, it means that the material 52 has a higher bending index than the bending index of the material deposited on the material 54. By using the light source 56 along the lower side of the substrate 54 and the high index material 52, light emitted from the light source 56 will be refracted into the pattern through the pattern of the high index material 52. As a result, by depositing the high index material 52 in a separate parallel line similar to the electrode line described above, the light beam is formed by the light redirected through the high index material 52.

If necessary, further layers can be added to improve the performance of the guided light. By way of example, scattering layer 58 may be deposited on high index material 52 if desired to widen the viewing angle. Scattering layer 58 may be comprised of a material suitable for scattering light, such as, for example, a porous glass layer or an epoxy filled with SiO 2 or TiO 2. Additionally or alternatively, a lensing layer 54 may be provided on the top of the scattering layer 52 to focus the emitted light. The radius of the lens 54 will be limited to the divergence angle required for the display. By way of example, a radius of approximately three to four times the width of the high index line 50 will provide a diverging angle of approximately 20-30 (generally considered to be a required viewing angle), thus providing a viewing angle of 20-30. to provide.

The high index material should be higher than the substrate glass utilized in the backlight. By way of example, since a typical substrate glass has an index of about 1.5, an index of 1.8 or more would be sufficient for the high index material 50 in this case. The high index material may be organic or inorganic (ie silicon nitride or oxynitride). Since this film is a high index, light in the substrate plate will be refracted wherever there is a high index line. The angle of refraction can be controlled by the index line and the index of the substrate. Additionally, scattering centers can be created on the top of the high index line to scatter light over wide angles, if necessary. In addition, a cylindrical lens may be formed on the high index light for further control on the divergence angle.

Moreover, one embodiment of the invention is illustrated by the following examples without being limited in any way to the claimed invention.

A 7 "x 7" backlight panel for 2D / 3D illumination is assembled according to the design illustrated in FIG. To test the head tracking concept, the two electrode sets illustrated in FIG. 3 are utilized, with the two electrode patterns being moved laterally by 76 microns. Using lithographic deposition techniques, 191.3 micron pitch and 38 micron wide indium tin oxide (ITO) electrode lines are formed on the substrate to form two electrode patterns. ITO ground electrodes are formed on opposing substrates. LC panels are tested with nematic LCs under negative mode.

Light rays are generated with good contrast and width and pitch control and good uniformity of light intensity presented in this standard.

Although the invention has been described in detail for purposes of illustration, such details are to be made by those skilled in the art only without departing from the spirit and scope of the invention as defined by the following claims. This sufficiency would have been understood.

Claims (22)

A light source for emitting light; A light blocking module comprising an electronically switchable material by applying a potential, said light blocking module for selectively blocking said light from said light source to form said light pattern. Device for conducting light patterns. 2. The apparatus of claim 1, wherein the light blocking module selectively blocks the light to form a pattern of light rays. The light blocking module of claim 1, wherein the light blocking module selectively switches the switchable material by applying the potential to the electrode and the pair of substrates having a switchable material sandwiched between the substrates. And at least one electrode on each of said substrates for selective passage therethrough. Apparatus for conducting light patterns through an information display to produce an autostereoscopic display. The light blocking module of claim 1, wherein the light blocking module includes at least one electrode arranged in a pattern of the elongated predetermined spaced electrode lines, wherein the electrode lines are formed on a bus bar to form a series of light rays emitted from a light source. And conducting the light pattern through the information display to produce an autostereoscopic display characterized in that it is connected by. 5. The apparatus of claim 4, wherein the light beam corresponds to a position of the electrode line. The apparatus of claim 4, wherein the light pattern is conducted through an information display to produce the light. 2. The apparatus of claim 1, wherein the switchable material is comprised of a liquid crystal material. 10. The apparatus of claim 1, wherein the switchable material is made of an electrochromic material. The light blocking module of claim 1, wherein the light blocking module comprises at least two electrode patterns of an elongated predetermined spaced electrode line, an electrode line of one pattern interlocking with an electrode line of another pattern, and independent for each electrode pattern. An auto-stereoscopic display comprising an electrode line of each pattern connected to an in-bus bar, each bus bar being capable of independent electrode activation to form parallel rays in different positions on the light blocking module, respectively. Apparatus for conducting the light pattern through the information display to produce a. 2. The apparatus of claim 1, comprising a liquid crystal information display device, wherein the light pattern is emitted into the display device. A light source for emitting light; And a light blocking module comprising an electronically switchable material for selectively blocking the light. The light source of claim 10, wherein the blocking module comprises a pair of substrates sandwiching the electronically switchable material, each of the substrates having an electrode, the electrode selectively activating the electronically switchable material to provide the light source. And is designed to selectively block light from the device. 12. The device of claim 11, wherein the electrodes in the light blocking module include at least one electrode arranged in a pattern of parallel predetermined spaced electrode lines, the electrode lines forming a series of light rays radiating from the light source. Device for emitting a light pattern on a surface, wherein the light pattern is connected by a busbar. 13. The apparatus of claim 12, wherein the light beam corresponds to the position of the electrode line. 12. The apparatus of claim 10, wherein said switchable material is comprised of a liquid crystal material. Emitting light from a light source; Selectively blocking the steel from the light source to form the light emitting site using an electronically switchable material by applying a potential, the light pattern through the information display to create an autostereoscopic display. How to evangelize. 16. The method of claim 15, wherein said selectively blocking comprises at least one electrode arranged in a pattern of parallel, evenly spaced electrode lines, said electrode lines being capable of forming a series of rays radiating from said light source. A method of conducting light patterns through an information display to produce an autostereoscopic display characterized by being connected by a busbar. 17. The method of claim 16, wherein the switchable material consists of a liquid crystal material. 17. The method of claim 16, wherein said switchable material is comprised of an electrochromic material. A light source for emitting light; A light blocking module for selectively blocking the light from the light source to form the light pattern; The light blocking module comprises a substrate and a material having a higher index of refraction than the substrate, wherein the high index material is deposited in the pattern on the substrate to collect light to form a light pattern for conducting through the display. An apparatus for conducting light patterns through an information display to produce an autostereoscopic display. 20. The apparatus of claim 19, comprising a light scattering layer covering the high index material. 20. The apparatus of claim 19, wherein the pattern of high index material is arranged in a plurality of parallel rows to form a series of light emitting lines. 22. The apparatus of claim 21, comprising a lenzing layer in each of said rows to produce an autostereoscopic display. ※ Note: The disclosure is based on the initial application.