Liquid crystal display apparatus

• US 20040125062A1
• Filed: 12/16/2003
• Published: 07/01/2004
• Est. Priority Date: 10/25/1999
• Status: Active Grant

• Current Assignee: Panasonic Liquid Crystal Display Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Liquid Crystal Display Company Limited (Panasonic Holdings Corporation)
• Inventors: Aratani, Sukekazu, Yamamoto, Tsunenori, Yoneya, Makoto
• Granted Patent: US 8,552,930 B2
• Time in Patent Office: Days
• US Class Current: 345/87
• CPC Class Codes: G09G 2310/024 Scrolling of light from the illumination source over the display in combination with the scanning of the display screen
• CPC Class Codes: G09G 2310/08 Details of timing specific for flat panels, other than clock recovery
• CPC Class Codes: G09G 2320/0252 Improving the response speed
• 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 2340/16 Determination of a pixel data signal depending on the signal applied in the previous frame
• CPC Class Codes: G09G 3/342 using several illumination sources separately controlled corresponding to different display panel areas, e.g. along one dimension such as lines
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence

Abstract

A liquid crystal display apparatus is able to display high quality motion pictures with less after-image when displaying motion pictures and with less fuzzy images without making the response speed of the liquid crystal too fast. The display data emphasized excessively more than a changed value is written into the pixel having any change detected by comparison with the previous display data and its value is made to change excessively more than the value corresponding to its original display data, and then, according to the optical response of the liquid crystal, the lighting time and the lighting period of the light source are controlled for the individual areas of the illumination unit having plural areas.

Claims

1. :

A liquid crystal display apparatus comprising;

a pair of substrates, at least one of which is transparent;

a liquid crystal layer disposed between the pair of substrates;

a plurality of groups of electrodes disposed on at least one of the pair of substrates for applying an electric field to the liquid crystal layer;

a liquid crystal display part having a plurality of active elements connected to the electrodes;

drive means, supplied with display data from means for supplying data to be displayed, for driving individual pixels of the liquid crystal display part by applying a voltage corresponding to the display data to the individual pixels, the drive means including data emphasis means for comparing new display data supplied from the means for supplying data to be displayed with previous display data supplied from the means for supplying data to be displayed, and for emphasizing and converting the new display data to designated display data in response to a result of the comparison and the supplied data;

an illumination unit including a plurality of illumination areas for illuminating the liquid crystal display part; and

illumination control means for controlling an illumination start time and an illumination “

on”

time of each of the illumination areas of the illumination unit in response to a result of the comparison and the supplied data, which is correlated with data emphasis.

2. :

A liquid crystal display apparatus according to claim 1,

wherein in case that any change is detected in the display data by the comparison, the data emphasis means emphasizes and converts the new display data so as to increase the change, and modifies a response of a corresponding pixel of the liquid crystal display part so as to be larger than a value corresponding to an original value of the new display data; and

wherein the illumination control means controls the illumination start time and the illumination “

on”

time of a corresponding one of the illumination areas of the illumination unit so that a time integral value of an amount of light passing through the corresponding pixel while a display characteristic is changing is substantially identical to a time integral value of an amount of light passing through the corresponding pixel while the display characteristic is stable.

3. :

A liquid crystal display apparatus according to claim 1,

wherein in case that any change is detected in the display data by the comparison, the data emphasis means emphasizes and converts the new display data so as to increase the change, and modifies a response of a corresponding pixel of the liquid crystal display part so as to be larger than a value corresponding to an original value of the new display data; and

wherein the illumination control means controls the illumination start time and the illumination “

on”

time of a corresponding one of the illumination areas of the illumination unit so that visual sensation values with respect to light passing through the corresponding pixel in the course of response and after response are substantially identical to each other.

4. :

A liquid crystal display apparatus according to claim 1, wherein the illumination start time and the illumination “

on”

time of the illumination areas of the illumination unit are predefined so as to be equal to average values of values for all the display data dependent on the individual display data according to the response of the liquid crystal display part after data conversion.

5. :

A liquid crystal display apparatus according to claim 2, wherein the illumination start time and the illumination “

on”

time of the illumination areas of the illumination unit are predefined so as to be equal to average values of values for all the display data dependent on the individual display data according to the response of the liquid crystal display part after data conversion.

6. :

A liquid crystal display apparatus according to claim 3, wherein the illumination start time and the illumination “

on”

time of the illumination areas of the illumination unit are predefined so as to be equal to average values of values for all the display data dependent on the individual display data according to the response of the liquid crystal display part after data conversion.

7. :

A liquid crystal display apparatus according to claim 1, wherein the illumination start time and the illumination “

on”

time of the illumination areas of the illumination unit are changed adaptively and determined so as to be average values weighted with a number of display data to be displayed at an area among values dependent on the individual display data according to the response of the liquid crystal display part after data emphasis and conversion.

8. :

A liquid crystal display apparatus according to claim 2, wherein the illumination start time and the illumination “

on”

time of the illumination areas of the illumination unit are changed adaptively and determined so as to be average values weighted with a number of display data to be displayed at an area among values dependent on the individual display data according to the response of the liquid crystal display part after data emphasis and conversion.

9. :

A liquid crystal display apparatus according to claim 3, wherein the illumination start time and the illumination “

on”

time of the illumination areas of the illumination unit are changed adaptively and determined so as to be average values weighted with a number of display data to be displayed at an area among values dependent on the individual display data according to the response of the liquid crystal display part after data emphasis and conversion.

10. :

A liquid crystal display apparatus according to claim 1, wherein the light source includes a sheet-type light emitting element.

11. :

A liquid crystal display apparatus comprising;

a liquid crystal display part for displaying a picture signal;

drive means for driving the liquid crystal display part, the drive means including picture signal emphasis means for comparing a new picture signal supplied from means for supplying a picture signal with a previous picture signal supplied from means for supplying a picture signal, and emphasizing and converting the new picture signal in response to a result of the comparison and the supplied picture signal;

at least one light source; and

an illumination unit including a light amount adjusting part for adjusting an amount of light from the light source for a plurality of illumination areas of the illumination unit; and

illumination control means for controlling the light amount adjusting part of the illumination unit in response to a result of the comparison and the supplied picture signal, which is correlated with picture signal emphasis, to control a lighting timing and a lighting period of time of the light source.

12. :

A liquid crystal display apparatus according to claim 11, wherein the light amount adjusting part of the illumination unit is transparent to light when a voltage is not applied to the light amount adjusting part.

13. :

A liquid crystal display apparatus according to claim 11, wherein the light source includes a sheet-type light emitting element.

14. :

A liquid crystal display apparatus according to claim 11,

wherein in case that any change is detected in the picture signal by the comparison, the picture signal emphasis means emphasizes and converts the new picture signal so that a display of a corresponding pixel in the liquid crystal display part is changed with a value more than a value corresponding to an original picture signal by arrival of a next picture signal; and

wherein the illumination control means controls the light amount adjusting part of the illumination unit so that a time integral value of an amount of light passing through the corresponding pixel while the display of the corresponding pixel is changing is substantially identical to a time integral value of an amount of light passing through the corresponding pixel while the display of he corresponding pixel is stable.

15. :

A liquid crystal display apparatus according to claim 11,

wherein in case that any change is detected in the picture signal by the comparison, the picture signal emphasis means emphasizes and converts the new picture signal so that the change increases, and changes a display of a corresponding pixel in the liquid crystal display part with a value more than a value corresponding to an original picture signal by an arrival of next picture signal; and

wherein the illumination control means controls the light amount adjusting part of the illumination unit so that visual sensation values with respect to the light passing through the corresponding pixel in the course of response and after response are substantially identical to each other.

16. :

A liquid crystal display apparatus according to claim 11, wherein the lighting timing and the lighting period of time of the light source are predefined so as to be average values of values for all the display data dependent on the individual display data according to the response of the liquid crystal display part after data conversion.

17. :

A liquid crystal display apparatus according to claim 14, wherein the lighting timing and the lighting period of time of the light source are predefined so as to be average values of values for all the display data dependent on the individual display data according to the response of the liquid crystal display part after data conversion.

18. :

A liquid crystal display apparatus according to claim 11, wherein the lighting timing and the lighting period of time of the light source are changed adaptively and determined so as to be average values weighted with the number of display data to be displayed at an area illuminated by the illumination unit among values dependent on the individual display data according to the response of the liquid display part after data emphasis and conversion.

19. :

A liquid crystal display apparatus according to claim 12, wherein the lighting timing and the lighting period of time of the light source are changed adaptively and determined so as to be average values weighted with the number of display data to be displayed at an area illuminated by the illumination unit among values dependent on the individual display data according to the response of the liquid display part after data emphasis and conversion.

20. :

A liquid crystal display apparatus according to claim 14, wherein the lighting timing and the lighting period of time of the light source are changed adaptively and determined so as to be average values weighted with the number of display data to be displayed at an area illuminated by the illumination unit among values dependent on the individual display data according to the response of the liquid display part after data emphasis and conversion.