Image display apparatus

Abstract

An image display apparatus includes a light source unit including light emitting elements halving different wavelengths, wherein n (n is an integer higher that 2) light emitting elements have at least one wavelength; and a light-up controller which drives the light emitting elements having different wavelengths in a time-sequential manner within a time period, wherein the light-up controller divides the n light emitting elements having at least one wavelength into m (m is an integer satisfying 2≦m≦n) light-up groups having a same light-up timing, and the m light-up groups are alternately lighted at a frequency of 1/m within the time period, so that any one of the m light-up groups can be lighted within the time period.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings in which:

FIG. 1 is a timing chart illustrating a driving signal of a light source unit, wherein the driving signal is generated by a light-up controller of a related art image display apparatus;

FIG. 2 is a schematic view illustrating a configuration of an image display apparatus according to an exemplary embodiment of the present invention;

FIG. 3 is a block diagram illustrating a configuration of a light source unit and a light controller used in the image display apparatus of FIG. 1, according to an exemplary embodiment of the present invention;

FIG. 4 is a timing chart illustrating a driving signal of a light source unit, wherein the driving signal is generated by a light controller of the image display apparatus of FIG. 1, according to an exemplary embodiment of the present invention;

FIG. 5 is a graph illustrating a light output of an LED according to temperature, wherein the horizontal axis denotes time and the vertical axis denotes a relative value of light output;

FIG. 6 is a timing chart illustrating a driving signal of a light source unit, wherein the driving signal is generated by a light controller of an image display apparatus, according to another exemplary embodiment of the present invention; and

FIG. 7 is a graph illustrating brightness changes during the operation of the image display apparatus described with respect to FIG. 6, according to another exemplary embodiment of the present invention.

Claims

1. An image display apparatus comprising: a light source which comprises a plurality of light emitting elements having substantially different wavelengths, wherein n light emitting elements have at least one wavelength and n is an integer greater than 2; anda light-up controller which drives the light emitting elements having the substantially different wavelengths in a time-sequential manner within a time period,wherein the light-up controller divides the n light emitting elements into m light-up groups having a substantially same light-up timing, the m light-up groups are alternately lighted up at a frequency of 1/m within the time period, so that at least one of the m light-up groups is lighted up within the time period, and m is an integer satisfying 2≦m≦n.

2. The image display apparatus of claim 1, wherein the light-up controller comprises: a temperature detector which detects the temperature of the n light emitting elements;a light-up mode selector which selectively changes a simultaneous light-up mode, in which the n light emitting elements are substantially simultaneously lighted up, and a dispersed light-up mode in which the n light emitting elements are divided into the m light-up groups to be alternately lighted up at different times, whereinthe light-up mode selector transits between the simultaneous light-up mode and the dispersed light-up mode according to the temperature detected by the temperature detector.

3. The image display apparatus of claim 2, wherein the light-up mode selector selects the simultaneous light-up mode if the temperature detected by the temperature detector is below a threshold value, and selects the dispersed light-up mode if the temperature detected by the temperature detector exceeds the threshold value.

4. The image display apparatus of claim 3, wherein the threshold value is a permissible level for brightness degradation of the light source.

5. The image display apparatus of claim 2, wherein: the light source comprises a base member mounted with the light emitting element; andthe temperature detector comprises a temperature sensor disposed on the base member.

6. The image display apparatus of claim 2, wherein: the light source comprises a base member mounted with the light emitting element; andthe temperature detector comprises a plurality of temperature sensors which are respectively adjacent to the light emitting elements and are disposed on the base member.

7. The image display apparatus of claim 1, wherein the light emitting elements are light emitting diodes (LEDs).

8. The image display apparatus of claim 2, wherein the temperature detector comprises one of a temperature sensor disposed at the light source, and a plurality of temperature sensors which are respectively adjacent to the light emitting elements and disposed at the light source.

9. A method of displaying an image, the method comprising: driving a plurality of light emitting elements having substantially different wavelengths in a time-sequential manner within a time period; anddividing the plurality of light emitting elements, wherein n light emitting elements have at least one wavelength, where n is an integer greater than 2, into m light-up groups having a substantially same light-up timing, wherein the m light-up groups are alternately lighted up at a frequency of 1/m within the time period, so that at least one of the m light-up groups is lighted up within the time period, and m is an integer satisfying 2≦m≦n.

10. The method of claim 9, further comprising: detecting the temperature of the n light emitting elements; andselectively changing a simultaneous light-up mode, in which the n light emitting elements are substantially simultaneously lighted up, and a dispersed light-up mode in which the n light emitting elements are divided into the m light-up groups to be alternately lighted up at different times, wherein transition between the simultaneous light-up mode and the dispersed light-up mode occurs according to the detected temperature.

11. The method of claim 10, further comprising: selecting the simultaneous light-up mode if the temperature detected by the temperature detector is below a threshold value, and selecting the dispersed light-up mode if the temperature detected by the temperature detector exceeds the threshold value.

12. The method of claim 11, wherein the threshold value is a permissible level for brightness degradation of the light source.

13. The method of claim 9, wherein the light emitting elements are light emitting diodes (LEDs).

14. The method of claim 9, wherein the driving comprises driving a spatial modulator in the time-sequential manner, so as to spatially modulate the light beams of the color components.

15. A computer readable medium including a set of instructions for displaying an image, the instructions comprising the following operations: driving a plurality of light emitting elements having substantially different wavelengths in a time-sequential manner within a time period; anddividing the plurality of light emitting elements,wherein n light emitting elements have at least one wavelength into m light-up groups having a substantially same light-up timing, the m light-up groups are alternately lighted up at a frequency of 1/m within the time period so that at least one of the m light-up groups is lighted up within the time period, n is an integer greater than 2 and m is an integer satisfying 2≦m≦n.

16. The computer readable medium of claim 15, further comprising: detecting the temperature of the n light emitting elements; andselectively changing a simultaneous light-up mode, in which the n light emitting elements are substantially simultaneously lighted up, and a dispersed light-up mode in which the n light emitting elements are divided into the m light-up groups to be alternately lighted up at different times, wherein transition between the simultaneous light-up mode and the dispersed light-up mode occurs according to the detected temperature.

17. The computer readable medium of claim 16, further comprising: selecting the simultaneous light-up mode if the temperature detected by the temperature detector is below a threshold value, and selecting the dispersed light-up mode if the temperature detected by the temperature detector exceeds the threshold value.

18. The computer readable medium of claim 17, wherein the threshold value is a permissible level for brightness degradation of the light source.

19. The computer readable medium of claim 15, wherein the light emitting elements are light emitting diodes (LEDs).

20. The computer readable medium of claim 15, wherein the driving comprises driving a spatial modulator in the time-sequential manner, so as to spatially modulate the light beams of the color components.