WO2009066937A1

WO2009066937A1 - 3-d image display device for controlling viewing distance

Info

Publication number: WO2009066937A1
Application number: PCT/KR2008/006835
Authority: WO
Inventors: Byoung Su Lee
Original assignee: Siliconfile Technologies Inc.
Priority date: 2007-11-20
Filing date: 2008-11-20
Publication date: 2009-05-28
Also published as: KR20090051791A; KR100923908B1

Abstract

The present invention relates to a 3-D image display device using a flat panel display unit capable of, even when a distance between a viewer and a display device is varied, adjusting a viewing distance to display a clear 3-D image depending on a varied distance by differently adjusting a field of view on the flat panel display unit for each display region.

Description

3-D IMAGE DISPLAY DEVICE FOR CONTROLLING VIEWING

DISTANCE

Technical Field

[1] The present invention relates to a 3-dimensional (3-D) image display device using a flat panel display unit, and more particularly, a 3-D image display device capable of, even when a distance between a viewer and a display device is varied, controlling a viewing distance to display a clear 3-D image depending on a varied distance by differently adjusting a field of view on the flat panel display unit for each display region. Background Art

[2] Generally, a 3-D image display device on a flat panel display unit is implemented by using a lenticular lens or parallax barrier type and a polarizer type. In such a method, a 3-D image is obtained by dividing horizontal pixels of the flat panel display unit into left-eye image representation and right-eye image representation and allowing each eye of a viewer to see different images while image information to be seen by a left eye and image information to be seen by a right eye are sequentially displayed.

[3] However, in the conventional 3-D methods using a lenticular lens, a barrier, or a polarizer, a single flat panel display unit is separately viewed by left and right eyes. Therefore, image quality and brightness are reduced by half in comparison with a typical 2D image. Accordingly, the flat panel display unit should have high brightness and high density.

[4] In this regards, the inventors have proposed, in Korean Patent Application No.

2005-0038266 (Korean Patent Publication No. 10-0586221), a novel 3-D image display device as shown in FIG. 1 including a reflector or shutter array 20 vertically arranged on a line of pixels of the flat panel display unit 10, and a vibrator 30 which is arranged in one end of the reflector or shutter array and vibrates the reflector or shutter array from left to right or from right to left, wherein the light emitted from the flat panel display unit is directed to a viewer located at a certain angle, so that a 3-D image can be viewed without image quality degradation or brightness reduction.

[5] However, in the aforementioned 3-D image display device proposed by the inventors, a plurality of reflectors or shutters 20 are connected together to a single vibrator 30 and simultaneously driven. Although this 3-D image display device has advantages such as a simple manufacturing process and a clear 3-D image for a distant viewer, it was difficult to provide a clear image to a viewer located in a close location. Therefore, the conventional 3-D image display device failed to adequately respond to a case where a viewer moves from a close location to a distant location or from a distant location to a close location. Disclosure of Invention

Technical Problem

[6] The present invention provides a 3-D image display device capable of, when a distance between a viewer and a flat panel display unit is varied, providing a clear 3-D image to a viewer located in a changed location, so that a view can readily adjust a viewing distance to allow an accurate 3-D image to be seen in a close location as well as a distant location. Technical Solution

[7] According to an aspect of the present invention, there is provided a 3-dimensional image display device using a flat panel display unit, the display device comprising: a plurality regional shutter means disposed in front of the flat panel display unit to individually restrict a field of view of a plurality of display regions consisting of at least one pixel; an independent driving means which is disposed in each of the regional shutter means, independently driven, and used to control a field of view by individually moving each of the regional shutter means; and a control means which adjusts a viewing distance by controlling individual operations of the independent driving means, and controls display of image information in synchronization with the controlled field of view.

[8] The regional shutter means may include a plurality of vertical shutter lines formed in the unit of at least one pixel column. The vertical shutter line may include a projection lens capable of forming an individual line for each display region.

[9] The 3-dimensional image display device according the present invention may further comprise a focusing lens interposed between the regional shutter means and a flat panel display unit to collect light emitted from the flat panel display unit.

[10] Also, the independent driving means may include a rotatable unit for independently rotating the regional shutter means. The rotatable unit may include: a first piezoelectric ceramic pillar which has a stack of piezoelectric ceramics and interposed between one side of a rear surface of the regional shutter means and a front surface of the flat panel display unit; a second piezoelectric ceramic pillar which also has a stack of piezoelectric ceramics and is spaced from the first piezoelectric ceramic pillar and interposed between the other side of the rear surface of the regional shutter means and the front surface of the flat panel display unit; a first electrode disposed beneath each layer of the first piezoelectric ceramic pillar; a second electrode disposed on each layer of the first piezoelectric ceramic pillar and beneath each layer of the second piezoelectric ceramic pillar; a third electrode disposed on each layer of the second piezoelectric ceramic pillar; an insulator interposed between the first and second electrodes or the second and third electrodes for insulation of each of the electrodes; and a power supply unit which supplies a different level of power to the first to third electrodes to differently generate a mechanical deformation between the first piezoelectric ceramic pillar and the second piezoelectric ceramic pillar and rotate back and forth the regional shutter means on the flat panel display unit. [11] According to the present invention, the independent driving means may include a parallel shift unit which shifts each of the regional shutter means on a plane of the flat panel display unit to adjust a viewing distance. The parallel shift unit may includes: a movable electrode disposed in a rear surface of the regional shutter means; a fixed electrode which is disposed near the movable electrode and fixed in a substrate; and a power supply unit which applies voltages to the movable electrode and the fixed electrode to horizontally move the regional shutter means on a plane and move the movable electrode using an electrostatic force generated by the applied voltages.

Advantageous Effects

[12] According to the present invention, a field of view of the flat panel display unit is independently restricted by a plurality of regional shutter means attached in the unit of one or more pixels or columns, and is controlled by individually setting up a movement degree using an independent driving means included in the regional shutter means, so that an accurate 3-D image can be obtained by easy manipulation in response to the varied distance without limiting a viewing distance even when a distance between a viewer and a display device is varied. Therefore, it is possible to improve distance adaptivity of a 3-D image in a flat panel display unit. Brief Description of the Drawings

[13] The above and other features and advantages of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings in which:

[14] FIG. 1 illustrates a 3-D image display device using a conventional flat panel display unit;

[15] FIG. 2 illustrates optical distribution on a pixel in a conventional flat panel display unit;

[16] FIG. 3 illustrates a 3-D image display device capable of adjusting a viewing distance according to the present invention;

[17] FIG. 4 illustrates a rotatable unit according to the present invention;

[18] FIG. 5 illustrates a detailed construction of an area A of FIG. 4;

[19] FIG. 6 illustrates a different mechanical deformation of the rotatable unit according to the present invention;

[20] FIG. 7 illustrates a condition of the rotatable unit rotating back and forth according to the present invention;

[21] FIG. 8 illustrates an example of light beams propagating to a viewer's right eye according to the present invention;

[22] FIG. 9 illustrates an example of light beams propagating to a viewer's left eye according to the present invention;

[23] FIG. 10 is a plan view illustrating a parallel shift unit according to the present invention;

[24] FIG. 11 is a side view illustrating a parallel shift unit according to the present invention;

[25] FIG. 12 illustrates horizontal movement of the parallel shift unit according to the present invention; and

[26] FIG. 13 illustrates a 3-D image display device further comprising a focusing lens according to another embodiment of the present invention. Best Mode for Carrying Out the Invention

[27] Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[28] Referring to FIG. 3, a 3-dimensional (3-D) image display device capable of controlling a viewing distance according to an embodiment of the present invention comprises: a plurality of regional shutter means which restrict a field of view of each display region obtained by dividing an area where an image is displayed on a flat panel display unit into a plurality of regions; an independent driving means which controls a field of view by independently moving the regional shutter means; and a control means which controls a viewing distance by differently adjusting an individual movement degree of each regional shutter means and controls display of image information in synchronization with the controlled field of view.

[29] In this case, the flat panel display unit 100 is a typical 2-dimensional (2D) image display device such as a cathode-ray tube (CRT) or a liquid crystal display (LCD). The display region 150 is any region including one or more pixels 110 emitting light to display an image on the flat panel display unit, and its size and shape can be variously selected depending on a regional shutter means which restricts the field of view. In other words, the display region 150 is defined as a plurality of virtual regions where a field of view of the light emitted from the pixels is restricted by the regional shutter means rather than actual regions obtained by partitioning the flat panel display unit by one or more pixels. Accordingly, the display region 150 can be defined in the unit of a pixel or column depending on the size and shape of the regional shutter means. Also, the display region 150 can be defined in a larger unit, e.g., in the unit of several pixels or columns. [30] The regional shutter means is provided on front surface of the flat panel display unit

100 in order to restrict a field of view of the light emitted from a plurality of display regions 150. It should be noted that the regional shutter means can be formed in the unit of a pixel or column, or several pixels or columns.

[31] Although, in the aforementioned embodiment, a plurality of regional shutter means for blocking a single flat panel display unit 100 are formed by a plurality of vertical shutter lines 200 formed in the unit of a pixel column, the configuration of the regional shutter means is not limited thereto, and may be variously selected.

[32] In this case, the regional shutter means controls a field of view such that an image for a left eye is directed to a viewer's left eye and an image for a right eye is directed to a viewer's right eye by controlling the traveling direction of the light radiated from each pixel 110 to a predetermined direction as shown in FIG. 2. The regional shutter means consists of a material capable of forming an individual line such that a field of view can be restricted by dividing the single flat panel display unit into the unit of a pixel or column and individually blocking each display region.

[33] That is, when a field of view is controlled based on a property of refracting the traveling direction of light to a predetermined direction, the regional shutter means preferably consists of a projection lens capable of readily forming an individual line. In addition, when a field of view is controlled by controlling a reflection angle of light to propagate to a predetermined direction, the regional shutter means may consist of a reflecting plate capable of forming an individual line. When a field of view is controlled by absorbing the light for displaying an undesired image and allowing only the light directed to a predetermined direction to be displayed, the regional shutter means may consist of an absorbing plate capable of an individual line. When a field of view is controlled by directly guiding the traveling direction of light, the regional shutter means may consist of an optical fiber array.

[34] The independent driving means is provided behind each regional shutter means such that a field of view of the light emitted from each display region can be controlled in the unit of a pixel or pixel column by individually moving the regional shutter means. Also, the independent driving means is independently driven by a control signal of the control means.

[35] The independent driving means may consist of a rotatable unit 300 which spaces out the regional shutter means from the flat panel display unit 100 in a predetermined distance and controls a field of view by rotating the regional shutter means back and forth in response to an applied voltage to control a viewing distance where a clear image can be displayed. Otherwise, the independent driving means may consist of a parallel shift unit 400 which controls a field of view by horizontally moving the regional shutter means on a plane of the flat panel display unit 100 so as to control a viewing distance.

[36] As shown in FIGS. 4 and 5, the rotatable unit 300 preferably consists of a piezoelectric actuator using a piezoelectric material which generates a mechanical force from a mechanical deformation caused by an applied electric voltage.

[37] The piezoelectric actuator includes: a first piezoelectric ceramic pillar 310 which has a stack of piezoelectric ceramics (PZTs) and interposed between one side of a rear surface of the regional shutter means and a front surface of the flat panel display unit 100; a second piezoelectric ceramic pillar 320 which also has a stack of piezoelectric ceramics (PZTs) and is spaced from the first piezoelectric ceramic pillar 310 and interposed between the other side of the rear surface of the regional shutter means and the front surface of the flat panel display unit 100; a first electrode 330 disposed beneath each layer of the first piezoelectric ceramic pillar 310; a second electrode 340 disposed on each layer of the first piezoelectric ceramic pillar 310 and beneath each layer of the second piezoelectric ceramic pillar 320; a third electrode 350 disposed on each layer of the second piezoelectric ceramic pillar 320; an insulator 360 interposed between the first and second electrodes or the second and third electrodes for insulation of each of the electrodes; and a power supply unit which supplies a different level of power to the first to third electrodes 330, 340, and 350 to differently generate a mechanical deformation in the first piezoelectric ceramic pillar 310 and the second piezoelectric ceramic pillar 320 and rotate back and forth the regional shutter means on the flat panel display unit 100.

[38] Accordingly, as shown in FIG. 6, the mechanical deformation is differently generated such that the first piezoelectric ceramic pillar 310 has a height hi, and the second piezoelectric ceramic pillar 320 has a height h2. Each regional shutter means is rotated back and forth as much as the difference of the heights. Similarly, the rotation angle of each regional shutter means can be differently controlled by differently applying voltages to other regional shutter means.

[39] In addition, as shown in FIGS. 10 and 11, the parallel shift unit 400 preferably consists of a linaer actuator which generates a electrostatic force caused by an applied electric voltage.

[40] The parallel shift unit 400 includes: a movable electrode 410 disposed in a rear surface of the regional shutter means; a fixed electrode 420 which is disposed near the movable electrode and fixed in a substrate; and a power supply unit which applies voltages to the movable electrode 410 and the fixed electrode 420 to generate a electrostatic force for shifting the movable electrode 410 and horizontally move the regional shutter means on a plane. In this case, the movable electrode 410 and the fixed electrode 420 are preferably obtained by alternately arranging a plurality of bar-shaped electrodes. [41] Accordingly, when an electrostatic attractive or repulsive force is generated between the movable electrode and the fixed electrode depending on the voltage applied from the power supply unit of the parallel shift unit 400, the movable electrode 410 is shifted on the fixed electrode 420 by the generated force. Together with the shift of the movable electrode, the regional shutter means is also horizontally moved. As a result, a field of view is controlled by controlling the traveling direction of the light emitted from the flat panel display unit.

[42] The control means includes a region adjustment controller which transmit, to the power supply unit of each independent driving means, a control signal having various voltage values based on how differently each regional shutter means is shifted, so that a viewing distance can be accurately adjusted by differently controlling a field of view for each display region on a single flat panel display unit in response to the variation of the distance of a viewer.

[43] In this case, the control means preferably further includes a symmetry adjustment controller programmed to collectively recognize addresses of the regional shutter means symmetrically disposed and control their movement degrees in combination, such that the regional shutter means symmetrically arranged in the left and right sides with respect to the regional shutter means located in the center of the flat panel display unit which is typically a center of a viewing area of a viewer can be simultaneously adjusted toward the viewer located in the center to improve convenience of controlling a viewing distance.

[44] In addition, the control means preferably further includes a displacement setup unit which differently sets up movement degrees of the regional shutter means for each region to prevent the regional shutter means from being moved within an unnecessarily excessive range when the independent driving means is driven for adjusting the viewing distance, such that a larger movement degree is set for the regional shutter means located near edges of the flat panel display unit, and a smaller movement degree is set for the regional shutter means located in the center of the flat panel display unit.

[45] According to another embodiment of the present invention, a focusing lens 210 is further included between the regional shutter means such as a projection lens or a reflector and the display region to collect light beams emitted from the flat panel display unit and transmit them to the regional shutter means as shown in FIG. 13.

[46] Accordingly, the light beams corresponding to RGB signals emitted from one or more pixels included in the display device are collected in a single point by the focusing lens 210. The collected light beams propagate to a predetermined direction by the regional shutter means such as a projection lens for restricting a field of view. Therefore, it is possible to prevent image signals emitted at an undesired angle from being directed to a viewer located at a predetermined angle. This allows a clearer 3-D image to be displayed.

[47] Now, operations of the aforementioned 3-D image display device capable of adjusting a viewing distance according to the present invention will be described.

[48] First, a case where the independent driving means for moving a plurality of regional shutter means such as projection lenses forming a vertical blocking line are implemented by a rotatable unit using a piezoelectric actuator will be described.

[49] The light beams generated by image information displayed in the flat panel display unit are radiated from the pixels 110. The propagating directions of these light beams are restricted by a vertical shutter line 200 disposed on a front surface of the flat panel display unit 100, so that a field of view to a viewer can be restricted.

[50] When a viewer changes a view location and moves close to the flat panel display unit, the viewer may be not able to view a clear 3-D image. Accordingly, the field of view is controlled by differently adjusting the movement degree of the vertical shutter line 200 such that the viewer can view a clear 3-D image in a changed location.

[51] Specifically, when different voltages are applied to the first to third electrodes 330,

340, and 350 forming a piezoelectric actuator as a signal for making a clear right-eye image directed to a right eye of a viewer, the amount of mechanical deformation is differently generated for the first and second piezoelectric ceramic pillars 310 and 320 depending on the applied voltage. That is, as shown in FIG. 7, the first piezoelectric ceramic pillar 310 is contracted to have a height of hi, and the second piezoelectric ceramic pillar 320 is expanded to have a height of h2, so that the projection lens of the vertical shutter line 200 is rotated while it is slanted at a predetermined angle.

[52] In this case, after a single vertical shutter line 200 is rotated at a predetermined angle, the slopes of other adjacent vertical shutter lines 200 are also individually adjusted. Since a plurality of vertical shutter lines are located in front of the same flat panel display unit, the rotation angles are adjusted to be different slightly but not significantly between just adjacent vertical shutter lines. That is, in order to provide a clear 3-D image even in a close distance, since the focal distance is changed as a viewer moves close to the flat panel display unit, a field of view should be also differently adjusted between the vertical shutter line located in the center which is closest to the viewer and the vertical shutter line located in the edge which is farthest.

[53] As described above, in order to allow a viewer to obtain a clear 3-D image in a changed location, the rotatable units 300 are sequentially adjusted and their rotation angles are also differently adjusted for each display region 150 to direct the light beams of an image for a right-eye to a viewer's right eye. That is, when the rotatable units 300 are individually adjusted such that a field of view of the vertical shutter line 200 can be independently controlled, the light beams emitted from the flat panel display unit to display the right-eye image are directed to the viewer's right eye by the controlled field of view as shown in FIG. 8.

[54] In this case, if the control means is provided with a symmetric adjustment controller, the control means may control left and right symmetric vertical shutter lines in combination with respect to the vertical shutter line located in the center of the flat panel display unit to more readily adjust the viewing distance.

[55] Then, as shown in FIG. 9, similar processes to those described for the right-eye control are repeated by independently rotating the vertical shutter line 200 while different voltages are applied to the first to third electrodes 330, 340, and 350 of the rotatable unit in order to control a field of view of each vertical shutter line for the left- eye image. Accordingly, the light beams emitted from the flat panel display unit for displaying the left-eye image are directed to the viewer's left eye by the controlled field of view.

[56] As described above, in the vertical shutter line 200 in which a field of view is individually controlled for each display region 150, left-eye and right-eye images arrive at viewer's left and right eyes, respectively, while the rotation angles of the rotatable units 300 are changed by individually driving them. Accordingly, a viewer can recognize a virtual 3-D image (i.e., a projected surface) by a simple manipulation even in a changed distance.

[57] Then, whenever the location of a viewer is changed, the aforementioned processes are repeated. That is, in order to obtain a 3-D image at each location, a field of view of each vertical shutter line 200 is separately controlled for each display region by adjusting the rotatable unit 300. As a result, a clear 3-D image can be viewed in a close location as well as a distant location.

[58] Now, another embodiment of the present invention will be described. In this embodiment, the independent driving means for moving a plurality of regional shutter means consisting of projection lenses forming a vertical shutter line is a parallel shift unit.

[59] When a viewer changes a viewing location and moves close to the flat panel display unit, a field of view is controlled by differently adjusting a movement degree of the vertical shutter line 200 in order to allow a viewer to view a clear 3-D image in the changed location.

[60] First, when a voltage as a control signal for making a clear left-eye image directed to the left eye is applied to the movable electrode 410 and the fixed electrode 420 of the parallel shift unit, an electrostatic attractive or repulsive force is generated between the movable electrode and the fixed electrode in response to the applied voltage.

[61] Accordingly, as the movable electrode 410 horizontally moves by a displacement s, and the vertical shutter line 200 connected to the movable electrode 410 also horizontally moves by a displacement s, to control the field of view. In addition, a movement degree for allowing the left-eye image to arrive at the left eye of a viewer in the changed location is set up by horizontally moving a single vertical shutter line and then individually horizontally moving other adjacent vertical shutter lines.

[62] In this way, in order to obtain a clear 3-D image in the changed location, the light beams of the left-eye image is directed to the left eye by sequentially adjusting the parallel shift unit for each display region 150 and individually adjusting the movement degree of the vertical shutter line 200. Then, a viewer controls a field of view by setting up a movement degree of each vertical shutter line for allowing the right-eye image to be directed to the right eye while repeating control of the parallel shift unit.

[63] Through the aforementioned processes, the vertical shutter line is used to individually adjust a field of view in the changed close location for each certain display region. The left-eye and right-eye images arrive at viewer's left and right eyes, respectively, while the movement degree is changed by individually driving the parallel shift unit, so that it is possible to view a clear virtual 3-D image (i.e., a projected surface) in the changed location.

[64] While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the appended claims.

Claims

[1] A 3-dimensional image display device using a flat panel display unit, the display device comprising: a plurality regional shutter means disposed in front of the flat panel display unit to individually restrict a field of view of a plurality of display regions consisting of at least one pixel; an independent driving means which is disposed in each of the regional shutter means, independently driven, and used to control a field of view by individually moving each of the regional shutter means; and a control means which adjusts a viewing distance by controlling individual operations of the independent driving means, and controls display of image information in synchronization with the controlled field of view.

[2] The 3-dimensional image display device according to claim 1, wherein the regional shutter means includes a plurality of vertical shutter lines formed in the unit of at least one pixel column.

[3] The 3-dimensional image display device according to claim 2, wherein the vertical shutter line guides light emitted from pixels into a predetermined direction, and is made of a material capable of being independently movable and forming an individual line.

[4] The 3-dimensional image display device according to claim 3, wherein the vertical shutter line includes a projection lens capable of forming an individual line for each display region.

[5] The 3-dimensional image display device according to claim 1, further comprising a focusing lens interposed between the regional shutter means and a flat panel display unit to collect light emitted from the flat panel display unit.

[6] The 3-dimensional image display device according to any one of claims 1 to 5, wherein the independent driving means includes a rotatable unit for adjusting a viewing distance by rotating back and forth each of the regional shutter means on the flat panel display unit.

[7] The 3-dimensional image display device according to claim 6, wherein the rotatable unit includes a piezoelectric actuator.

[8] The 3-dimensional image display device according to any one of claims 1 to 5, wherein the independent driving means is a parallel shift unit including a linear actuator for adjusting a viewing distance by shifting each of the regional shutter means on a plane of the flat panel display unit.

[9] The 3-dimensional image display device according to claim 1, wherein the control means includes a region adjustment controller for individually moving the regional shutter means for each display region.