DISPLAY DEVICE AND METHOD FOR DRIVING THE SAME

• US 20120229431A1
• Filed: 03/07/2012
• Published: 09/13/2012
• Est. Priority Date: 03/11/2011
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: HIROKI, Masaaki
• Granted Patent: US 9,558,687 B2
• Time in Patent Office: Days
• US Class Current: 345/204
• CPC Class Codes: G09F 19/14 displaying different signs depending upon the view-point of the observer
• CPC Class Codes: G09G 3/003 to produce spatial visual effects
• CPC Class Codes: H04N 13/31 using parallax barriers
• CPC Class Codes: H04N 13/366 using viewer tracking
• CPC Class Codes: H04N 13/398 Synchronisation thereof; Control thereof

Abstract

In order to display 3D images by a parallax barrier method, a display screen and the eyes of a viewer need to have a specific positional relation. An object is to provide a display device with an extended area where the viewer can perceive 3D images with the naked eye. Attention is focused on the position of the viewer with respect to pixels provided in a display device and a mode of a parallax barrier provided between the viewer and the pixels. This leads to a structure in which the position of the viewer with respect to pixels is specified by using an ultrasonic wave to change a mode of a parallax barrier in accordance with the position of the viewer, thereby achieving the above object.

Claims

1. A display device comprising:

a display panel including a first pixel region for a left eye and a second pixel region for a right eye;

a parallax barrier that covers part of the display panel and is variable in a mode;

a parallax barrier control circuit configured to control the mode of the parallax barrier;

an ultrasonic generator, and

a plurality of detectors configured to detect an ultrasonic wave reflected from a viewer,

wherein the parallax barrier control circuit controls the parallax barrier in accordance with position of the viewer specified by the plurality of detectors such that the parallax barrier prevents the right eye of the viewer from seeing the first pixel region and the left eye of the viewer from seeing the second pixel region.

2. The display device according to claim 1,

wherein the parallax barrier includes a liquid crystal layer sandwiched between a pair of substrates, and

wherein at least one of the pair of substrates is provided with a plurality of electrodes for controlling alignment of liquid crystals in the liquid crystal layer, and each of the plurality of electrodes is electrically connected to the parallax barrier control circuit.

3. The display device according to claim 1, wherein the mode of the parallax barrier is a stripe pattern, a checkered pattern, or a crossed pattern.

4. The display device according to claim 1, wherein a display element provided in the display panel is an organic electroluminescent element.

5. The display device according to claim 1, wherein a display element provided in the display panel is a liquid crystal element.

6. A display device comprising:

a display panel;

a shutter panel including a parallax barrier;

a control device;

an ultrasonic generator, and

a plurality of detectors configured to detect an ultrasonic wave reflected from a viewer,

wherein the display panel, the shutter panel, the ultrasonic generator, and the plurality of detectors are connected to the control device, and

wherein the control device controls the shutter panel to change a mode of the parallax barrier in accordance with position of the viewer specified by the plurality of detectors.

7. The display device according to claim 6,

wherein the shutter panel includes a liquid crystal layer sandwiched between a pair of substrates, and

wherein at least one of the pair of substrates is provided with a plurality of electrodes for controlling alignment of liquid crystals in the liquid crystal layer, and each of the plurality of electrodes is electrically connected to the control device.

8. The display device according to claim 7,

wherein a distance between two electrodes adjacent to each other is the smallest at a center of the display panel, and

wherein the distance between two electrodes adjacent to each other is the largest at a right end and a left end of the display panel.

9. The display device according to claim 6, wherein the mode of the parallax barrier is a stripe pattern, a checkered pattern, or a crossed pattern.

10. The display device according to claim 6, wherein the shutter panel is an active matrix shutter panel including a plurality of transistors.

11. The display device according to claim 10, wherein the plurality of transistors include an oxide semiconductor.

12. The display device according to claim 6, wherein a display element provided in the display panel is an organic electroluminescent element.

13. The display device according to claim 6, wherein a display element provided in the display panel is a liquid crystal element.

14. A method for driving a display device, comprising:

transmitting a pulsed ultrasonic wave towards a space in front of a side where a display surface of the display device faces a viewer;

specifying a position of the viewer based on a time it takes for a reflected pulsed ultrasonic wave to be detected by each of a plurality of detectors;

specifying a pair of right-eye and left-eye pixels facing a front of the viewer by calculating coordinates where a straight line passing through the position of the viewer orthogonally crosses the display surface;

specifying a distance from the pair of right-eye and left-eye pixels to the viewer;

controlling size of a parallax barrier corresponding to the pair of right-eye and left-eye pixels with reference to the distance from the pair of right-eye and left-eye pixels to the viewer so that a right eye of the viewer sees a pixel for the right eye and a left eye of the viewer sees a pixel for the left eye; and

forming the parallax barrier so that a trapezoid in which another pair of right-eye and left-eye pixels is treated as a lower base and a light-blocking portion in the parallax barrier therefor as an upper base falls toward the viewer and is further distorted as the trapezoid is more distant from the pixels facing the front of the viewer in a horizontal direction, and so that the parallax barrier prevents the left eye of the viewer from seeing a pixel region for the right eye and the right eye of the viewer from seeing a pixel region for the left eye.

15. A method for driving a display device, comprising:

transmitting a pulsed ultrasonic wave towards a space in front of a side where a display surface of the display device faces a viewer;

specifying a position of the viewer based on a time it takes for a reflected pulsed ultrasonic wave to be detected by each of a plurality of detectors;

specifying a pair of right-eye and left-eye pixels facing a front of the viewer based on the position of the viewer;

specifying a distance from the pair of right-eye and left-eye pixels to the viewer;

controlling size of a parallax barrier corresponding to the pair of right-eye and left-eye pixels with reference to the distance from the pair of right-eye and left-eye pixels to the viewer so that a right eye of the viewer sees a pixel for the right eye and a left eye of the viewer sees a pixel for the left eye; and

forming the parallax barrier so that a trapezoid in which another pair of right-eye and left-eye pixels is treated as a lower base and a light-blocking portion in the parallax barrier therefor as an upper base falls toward the viewer and is further distorted as the trapezoid is more distant from the pixels facing the front of the viewer in a horizontal direction, and so that the parallax barrier prevents the left eye of the viewer from seeing a pixel region for the right eye and the right eye of the viewer from seeing a pixel region for the left eye.

16. A method for driving a display device, comprising:

transmitting a pulsed ultrasonic wave towards a space in front of a side where a display surface of the display device faces a viewer;

specifying a position of the viewer based on a time it takes for a reflected pulsed ultrasonic wave to be detected by each of a plurality of detectors and an amplitude of the reflected pulsed ultrasonic wave to be detected by each of the plurality of detectors; and

forming a parallax barrier in accordance with the position of the viewer.