Electronic equipment and liquid crystal display

• US 6,014,126 A
• Filed: 08/16/1995
• Issued: 01/11/2000
• Est. Priority Date: 09/19/1994
• Status: Expired due to Term

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Nishihara, Yasutomo
• Primary Examiner(s): Lao, Lun-Yi
• Application Number:
  US08/515,974
• Time in Patent Office: 1,609 Days
• Field of Search: 345/1-3, 345/132, 345/10, 345/11, 345/87, 345/185, 345/187, 345/201, 345/501, 345/507, 345/508, 345/511, 348/441, 348/443, 348/444, 348/445
• US Class Current: 345/698
• CPC Class Codes: G09G 2340/0435 Change or adaptation of the frame rate of the video stream
• CPC Class Codes: G09G 3/3666 with the matrix divided into sections
• CPC Class Codes: G09G 5/006 Details of the interface to the display terminal specific for a display terminal using a CRT G09G1/167; using a flat panel G09G3/2096; circuits for interfacing with colour displays G09G5/04
• CPC Class Codes: G09G 5/399 using two or more bit-mapped memories, the operations of which are switched in time, e.g. ping-pong buffers

Abstract

Electronic equipment comprising a display controller for outputting display data of a first frame frequency, and a frequency converting circuit for converting the display data of the first frame frequency to output display data of a second frame frequency which is higher than the first frame frequency and a non-integral multiple of the first frame frequency. Accordingly, the second frequency can be approximated to a frequency such that enables a high-frequency driven display device to render the optimal display characteristics, thereby enabling a display of high-quality image by eliminating the ghost and flicker on the screen.

Claims

1. Electronic equipment comprising:

an interface unit for outputting display data of a first frame frequency; and

frequency converting means, connected to said interface unit, for converting the display data of said first frame frequency to output display data of a second frame frequency, said second frame frequency being higher than said first frame frequency and a non-integral multiple of said first frame frequency;

wherein a first timing signal controlling input timing of the display data of said first frame frequency is asynchronous with a second timing signal controlling input timing of the display data of said second frame frequency, and wherein said second timing signal has a frequency which is a non-integral multiple of the frequency of said first timing signal.

2. The electronic equipment as defined in claim 1, wherein said electronic equipment is connected to a direct matrix type liquid crystal display device which displays the display data of said second frame frequency.

3. The electronic equipment as defined in claim 1 further comprising selecting means for selecting whether one of or both of the display data of said first frame frequency from said interface unit and the display data of said second frame frequency from said frequency converting means are outputted.

4. The electronic equipment as defined in claim 3, wherein said electronic equipment is connected to:

(1) one of an active matrix type liquid crystal display device and a cathode ray tube display device, both of which display the display data of said first frame frequency; and

(2) a direct matrix type liquid crystal display device which displays the display data of said second frame frequency.

5. The electronic equipment as defined in claim 1, wherein said frequency converting means includes:

writing means for writing the display data of said first frame frequency;

a frame memory, connected to said writing means, for storing the display data of said first frame frequency; and

readout means for reading out the display data stored in said frame memory as the display data of said second frame frequency faster than said writing means writes the display data of said first frame frequency.

6. The electronic equipment as defined in claim 5, wherein:

said writing means includes a writing address generating unit for assigning an address of the display data to be written into said frame memory by outputting a writing address signal; and

said readout means includes a readout address generating unit for assigning an address of the display data to be read out from said frame memory by outputting a readout address signal,

said writing address signal and readout address signal being inputted into said frame memory when the display data are written and read out, respectively.

7. The electronic equipment as defined in claim 5, wherein:

said frame memory includes two storage units;

said writing means includes a writing address generating unit for assigning an address of the display data to be written into said frame memory by outputting a writing address signal; and

said readout means includes a readout address generating unit for assigning an address of the display data to be read out from said frame memory by outputting a readout address signal,

said writing address signal and readout address signal being inputted into said two storage units alternately.

8. A direct matrix type liquid crystal display device comprising a connector for receiving input display data of a first frame frequency from electronic equipment on a host side and frequency converting means for converting said input display data into display data of a second frame frequency which is higher than said first frame frequency,

wherein a first timing signal controlling input timing of the display data of said first frame frequency is asynchronous with a second timing signal controlling input timing of the display data of said second frame frequency, and wherein said second timing signal has a frequency which is a non-integral multiple of the frequency of said first timing signal.

9. The liquid crystal display device as defined in claim 8, wherein said frequency converting means includes:

writing means for writing the display data of said first frame frequency;

a frame memory, connected to said writing means, for storing the display data of said first frame frequency; and

readout means for reading out the display data stored in said frame memory as the display data of said second frame frequency faster than said writing means writes the display data.

10. The liquid crystal display device as defined in claim 9, wherein:

said writing means includes a writing address generating unit for assigning an address of the display data to be written into said frame memory by outputting a writing address signal; and

said readout means includes a readout address generating unit for assigning an address of the display data to be read out from said frame memory by outputting a readout address signal,

said writing address signal and readout address signal being inputted into said frame memory when the display data are written and read out, respectively.

11. The liquid crystal display device as defined in claim 9, wherein:

said frame memory includes two storage units;

said writing means includes a writing address generating unit for assigning an address of the display data to be written into said frame memory by outputting a writing address signal; and

said readout means includes a readout address generating unit for assigning an address of the display data to be read out from said frame memory by outputting a readout address signal,

said writing address signal and readout address signal being inputted into said two storage units alternately.

12. A liquid crystal device comprising:

frequency converting means for converting input display data of a first frame frequency from electronic equipment on a host side into display data of a second frame frequency which is higher than said first frame frequency;

skipping method level control means, connected to an output side of said frequency converting means, for performing a multi-level display to increase the number of colors available for color display;

a direct matrix type liquid crystal panel; and

driving means, connected to an output side of said skipping method level control means, for driving said liquid crystal panel,

wherein a first timing signal controlling input timing of the display data of said first frame frequency is asynchronous with a second timing signal controlling input timing of the display data of said second frame frequency, and wherein said second timing signal has a frequency which is a non-integral multiple of the frequency of said first timing signal.