Head mounted display and method for controlling the same

• US 10,515,573 B2
• Filed: 12/14/2017
• Issued: 12/24/2019
• Est. Priority Date: 12/26/2016
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: Hwang, Gunwoo, Lee, Sanglyn
• Primary Examiner(s): Yang, Nan-Ying
• Application Number:
  US15/842,681
• Publication Number:
  US 20180182273A1
• Time in Patent Office: 740 Days
• CPC Class Codes: G02B 2027/011 comprising device for correcting geometrical aberrations, distortion
• CPC Class Codes: G02B 2027/014 comprising information/image processing systems
• CPC Class Codes: G02B 2027/0141 characterised by the informative content of the display
• CPC Class Codes: G02B 27/0172 characterised by optical features
• CPC Class Codes: G06F 1/163 Wearable computers, e.g. on a belt
• CPC Class Codes: G06F 3/011 Arrangements for interaction with the human body, e.g. for user immersion in virtual reality blind teaching G09B21/00
• CPC Class Codes: G06F 3/012 Head tracking input arrangements
• CPC Class Codes: G09G 2310/0286 Details of a shift registers arranged for use in a driving circuit
• CPC Class Codes: G09G 2310/0289 Details of voltage level shifters arranged for use in a driving circuit
• CPC Class Codes: G09G 2310/08 Details of timing specific for flat panels, other than clock recovery
• CPC Class Codes: G09G 2320/0261 in the context of movement of objects on the screen or movement of the observer relative to the screen
• CPC Class Codes: G09G 2320/028 by changing the viewing angle properties, e.g. widening the viewing angle, adapting the viewing angle to the view direction
• CPC Class Codes: G09G 2340/14 Solving problems related to the presentation of information to be displayed
• CPC Class Codes: G09G 2354/00 Aspects of interface with display user
• CPC Class Codes: G09G 3/001 using specific devices not provided for in groups G09G3/02 - G09G3/36, e.g. using an intermediate record carrier such as a film slide; Projection systems; Display of non-alphanumerical information, solely or in combination with alphanumerical information, e.g. digital display on projected diapositive as background slide projectors per se G03B23/00 = 42 HP
• CPC Class Codes: G09G 3/002 to project the image of a two-dimensional display, such as an array of light emitting or modulating elements or a CRT
• CPC Class Codes: G09G 3/2096 Details of the interface to the display terminal specific for a flat panel suitable for both CRT and flat panel G09G5/006; specific for a CRT G09G1/167

Abstract

A head mounted display (HMD) may include: a sensor configured to measure a motion of the HMD; a controller configured to generate image data based on first sensing information measured by the sensing unit at a first time point; and a display device configured to frame-shift the generated image data, and output the frame-shifted image data to a display panel. The display device may frame-shift the image data using second sensing information measured by the sensor at a second time point after the first time point, and the second time point may correspond to a time point immediately before the controller outputs the image data to the display panel after generating the image data.

Claims

1. A head mounted display (HMD), comprising:

a sensor configured to sense a motion of the HMD;

a controller configured to generate image data based on first sensing information acquired by the sensor at a first time point; and

a display device configured to receive the generated image data as input image data and to frame-shift the input image data, and output the frame-shifted image data to a display panel, and

wherein the display device frame-shifts the image data based on second sensing information acquired by the sensor at a second time point after the first time point,

wherein the display device comprises a complementary filter configured to convert the first and second sensing information into an Euler angle, and an angle-pixel conversion unit configured to calculate pixel shift information based on the Euler angle.

2. The HMD of claim 1, wherein the second time point corresponds to a point in time that occurs within 1 ms before a time the controller outputs the image data to the display panel after generating the image data.

3. The HMD of claim 1, wherein the display device comprises:

a first image processing unit configured to remove distortion contained in the input image data, based on lens correction information, and to output first processed image data;

a frame shifting unit configured to receive the first processed image data and to generate a signal for frame-shifting the first processed image data outputted from the first image processing unit, based on the pixel shift information, the frame shifting unit configured to output frame-shifted image data; and

a second image processing unit configured to apply distortion to the image data outputted from the frame shifting unit, based on the lens correction information.

4. The HMD of claim 3, wherein the frame shifting unit frame-shifts the first processed image data using a vector value of the pixel shift information which is calculated based on the first and second sensing information.

5. The HMD of claim 1, wherein the display panel comprises data lines and gate lines which cross each other, and

the display device comprises:

a data driver configured to convert the input image data into data voltages and output the data voltages to the data lines;

a gate driver configured to sequentially output gate pulses synchronized with the data voltages to the gate lines; and

a timing controller configured to compensate for the image data inputted to the data driver, and control an output timing,

wherein the timing controller frame-shifts the image data outputted to the display panel by shifting a data application signal that determines the output timing of the image data inputted to the data driver.

6. The HMD of claim 5, wherein when the data application signal is shifted within a unit clock of the image data inputted to the data driver, the image data outputted to the display panel is frame-shifted to the left or right.

7. The HMD of claim 5, wherein when the data application signal is shifted by one or more unit clocks of the image data inputted to the data driver, the image data outputted to the display panel is frame-shifted upward or downward.

8. The HMD of claim 1, wherein a time interval between the second time point and the first time point is equal to a time required for the controller to generate one image frame based on the first sensing information.

9. A method for control an HMD, comprising:

measuring a motion of the HMD at a first time point;

generating image data based on first sensing information measured at the first time point;

measuring a motion of the HMD at a second time point after the first time point;

generating frame-shifted image data by frame-shifting the image data based on second sensing information measured at the second time point; and

outputting the frame-shifted image data to a display panel,

wherein the generating the frame-shifted image data comprises converting the fast and second sensing information into an Euler angle, and calculating pixel shift information based on the Euler angle.

10. The method of claim 9, wherein the second time point corresponds to a point in time that occurs within 1 ms before a time the frame-shifted image data is output to the display panel.

11. The method of claim 9, wherein generating the frame-shifted image data comprises:

removing distortion contained in the image data based on lens correction information;

frame-shifting the image data from which the distortion is removed, based on the pixel shift information; and

applying distortion to the frame-shifted image data based on the lens correction information.

12. The method of claim 11, wherein frame-shifting the image data based on the pixel shift information comprises frame-shifting a position of the image data outputted to the display panel using a vector value of the pixel shift information which is calculated based on the first and second sensing information.

13. The method of claim 11, wherein the display panel comprises data lines and gate lines which cross each other, and

the outputting of the frame-shifted image data to the display panel comprises:

converting the input image data into data voltages and outputting the data voltages to the data lines;

sequentially outputting gate pulses synchronized with the data voltages to the gate lines; and

compensating for the image data, and controlling an output timing,

wherein the controlling of the output timing comprises frame-shifting the image data outputted to the display panel by shifting a data application signal that determines the output timing of the input image data.

14. The method of claim 13, wherein when the data application signal is shifted within a unit clock of the input image data, the image data outputted to the display panel is frame-shifted to the left or right.

15. The method of claim 13, wherein when the data application signal is shifted by one or more unit clocks of the input image data, the image data outputted to the display panel is frame-shifted upward or downward.

16. The method of claim 9, wherein a time interval between the second time point and the first time point is equal to a time required for generating one image frame based on the first sensing information.