Display apparatus and display apparatus drive method

• US 20040141094A1
• Filed: 10/09/2003
• Published: 07/22/2004
• Est. Priority Date: 01/21/2002
• Status: Active Grant

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Funamoto, Taro, Kumamoto, Yasuhiro
• Granted Patent: US 7,265,741 B2
• Time in Patent Office: Days
• US Class Current: 348/554
• CPC Class Codes: G09G 2310/02 Addressing, scanning or driving the display screen or processing steps related thereto
• CPC Class Codes: G09G 2310/0251 Precharge or discharge of pixel before applying new pixel voltage
• CPC Class Codes: G09G 2310/061 for resetting or blanking
• 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 2320/06 Adjustment of display parameters
• CPC Class Codes: G09G 2320/0606 Manual adjustment
• CPC Class Codes: G09G 2320/0613 The adjustment depending on the type of the information to be displayed
• CPC Class Codes: G09G 2320/062 Adjustment of illumination source parameters
• CPC Class Codes: G09G 2320/0633 by amplitude modulation of the brightness of the illumination source
• CPC Class Codes: G09G 2320/064 by time modulation of the brightness of the illumination source
• CPC Class Codes: G09G 2320/10 Special adaptations of display systems for operation with variable images
• CPC Class Codes: G09G 2330/021 Power management, e.g. power saving
• CPC Class Codes: G09G 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence
• CPC Class Codes: H04N 21/482 End-user interface for program selection broadcast systems using EPGs H04H60/72
• CPC Class Codes: H04N 5/66 Transforming electric information into light information scanning details H04N3/00
• CPC Class Codes: H04N 7/08 Systems for the simultaneous or sequential transmission of more than one television signal, e.g. additional information signals, the signals occupying wholly or partially the same frequency band , e.g. by time division H04N7/007 takes precedence
• CPC Class Codes: H04N 7/0887 for the transmission of programme or channel identifying signals

Abstract

An EPG extraction portion extracts EPG information; a program type decision portion decides the type of broadcast program using the extracted EPG information, and outputs a ratio modification signal to change the ratio of the image display interval to the black display interval according to the program type; a driving pulse generation portion generates a gate driver control signal which changes the write timing of a frequency-doubled image signal and frequency-doubled black display signal in one field interval, according to the ratio modification signal; and, a gate driver changes the write timing of the frequency-doubled image signal and frequency-doubled black display signal according to the gate driver control signal, to change the ratio of the image display interval to the black display interval.

Claims

1. A hold-type display device, which continues display of an image for a prescribed display interval, comprising:

conversion means for converting an input image signal into a high-frequency signal including a high-frequency image signal obtained by increasing the frequency of the image signal and a black display signal for the display of black;

generation means for generating a timing signal to change the write timing in a prescribed interval of said high-frequency image signal and said black display signal, in order to modify the ratio within said prescribed interval of the interval for image display by said high-frequency image signal and the interval for black display by said black display signal; and

display means for modifying the write timing of the high-frequency image signals and black display signals of the high-frequency signals converted by said conversion means according to the timing signal generated by said generation means and for displaying the image.

2. The display device according to claim 1, further comprising:

reception means for receiving television broadcast signals including electronic program guide information,

extraction means for extracting electronic program guide information from the television broadcast signal received by said reception means, and

decision means for deciding the type of broadcast program based on the electronic program guide information extracted by said extraction means and for outputting a ratio modification signal to change the ratio of the image display interval by said high-frequency image signal to the black display interval by said black display signal according to the broadcast program type decision; and

wherein

said generation means includes generation means for programs which generates said timing signal according to the ratio modification signal output from said decision means.

3. The display device according to claim 2, wherein said decision means, on deciding that the type of said broadcast program is a first type, outputs to said generation means for programs a first ratio modification signal to set said black display interval to a first black display interval, and on deciding that the type of said broadcast program is a second type in which images are mainly displayed with motion amounts smaller than for said first type, outputs to said generation means for programs a second ratio modification signal to set said black display interval to a second black display interval shorter than said first black display interval;

and,

when said first ratio modification signal is input, said generation means for programs generates a first timing signal which sets said black display interval to said first black display interval according to said first ratio modification signal, and when said second ratio modification signal is input, said generation means for programs generates a second timing signal which sets said black display interval to said second black display interval according to said second ratio modification signal.

4. The display device according to claim 1, further comprising operation means for accepting operations by a user and outputting a ratio modification signal to change the ratio of the image display interval by said high-frequency image signal to the black display interval by said black display signal according to the user operations;

and

wherein said generation means comprises generation means for the user, which generates said timing signal according to the ratio modification signal output from said operation means.

5. The display device according to claim 1, further comprising power supply means for supplying electrical power supplied from outside to the device unit,

an internal battery detachably attached to the device unit for supplying power to the device unit when power is not being supplied to the device unit by said power supply means, and

judgment means for judging the state of supply of power by said power supply means and outputting a ratio modification signal to change the ratio of the image display interval by said high-frequency image signal to the black display interval by said black display signal;

and

wherein said generation means includes generation means for power which generates said timing signal according to the ratio modification signal output from said judgment means.

6. The display device according to claim 5, wherein:

said display means further includes light-emitting means which emits light for display, and brightness control means which controls the brightness of said light-emitting means;

said judgment means, upon judging that power is being supplied from said power supply means, outputs to said generation means for power a first ratio modification signal to set said black display interval to a first black display interval, and outputs to said brightness control means a first brightness control signal to set the brightness of said light-emitting means to a first brightness level, and, upon judging that power is being supplied from said internal battery, outputs to said generation means for power a second ratio modification signal to set said black display interval to a second black display interval shorter than said first black display interval, and outputs to said brightness control means a second brightness control signal to set the brightness of said light-emitting means to a second brightness level lower than said first brightness level;

said generation means for power, when said first ratio modification signal is input, generates a first timing signal which sets said black display interval to said first black display interval in response to said first ratio modification signal, and when said second ratio modification signal is input, generates a second timing signal which sets said black display interval to said second black display interval in response to said second ratio modification signal; and

,

said brightness control means, when said first brightness control signal is input, sets the brightness of said light-emitting means to said first brightness level in response to said first brightness control signal, and when said second brightness control signal is input, sets the brightness of said light-emitting means to said second brightness level in response to said second brightness control signal.

7. The display device according to any of claims 1 through 6, wherein said conversion means converts said image signal into a frequency-doubled signal, including a frequency-doubled image signal with doubled frequency and a frequency-doubled black display signal for black display.

8. The display device according to any of claims 1 through 7, wherein said display means includes a liquid crystal panel having a plurality of source lines to which are supplied pixel signals, a plurality of gate lines to which are supplied scan signals, and a plurality of pixel cells positioned in matrix form at the intersections of said source lines and said gate lines.

9. The display device according to claim 8, wherein said pixel cells are OCB cells.

10. A display device driving method, which is a driving method for a hold-type display device which continues display of an image during a prescribed display interval, comprising the steps of:

a conversion step of converting an input image signal into a high-frequency signal comprising a high-frequency image signal obtained by increasing the frequency of the image signal and a black display signal for the display of black;

a generation step of generating a timing signal to change the write timing in a prescribed interval of said high-frequency image signal and said black display signal, in order to modify the ratio within said prescribed interval of the image display interval by said high-frequency image signal and the black display interval by said black display signal; and

a display step of modifying the write timing of high-frequency image signals and black display signals of the high-frequency signals converted in said conversion step according to the timing signal generated in said generation step, and displaying the image.