Computer graphics processing and selective visual display system – Plural physical display element control system – Display elements arranged in matrix
Reexamination Certificate
2000-04-28
2002-01-01
Shalwala, Bipin (Department: 2673)
Computer graphics processing and selective visual display system
Plural physical display element control system
Display elements arranged in matrix
C345S099000, C345S100000, C345S204000, C345S205000
Reexamination Certificate
active
06335720
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a data transfer method used in a display apparatus driving circuit for driving a display apparatus such as a flat display and, more particularly, to an improved data transfer method for a driving integrated circuit, which can reduce the average data transfer amount.
2. Related Background Art
Conventionally, data for one line must be transferred to a driving circuit of a flat display (to be referred to as an FPD hereinafter: Flat Panel Display) since the display operation on the FPD is performed by a line or dot sequential method. More specifically, in a conventional display, all the bits of display data must be transferred in synchronism with the frame frequency. Also, driving data of a driving integrated circuit is updated each time display data is transferred.
FIG. 1
is a physical schematic diagram showing the conventional data transfer method. The system shown in
FIG. 1
includes a display apparatus (panel)
1
, information line side driving integrated circuits (segment drivers)
2
, segment bus boards
5
, data buses
7
, clock signal lines
8
, serial data input signal lines
9
, and a controller
10
.
FIG. 2
is a schematic diagram of the segment drivers
2
in the conventional data transfer method shown in FIG.
1
. The video data buses
7
for supplying video data ID
0
to ID
7
and the clock signal line
8
for supplying clocks (CLK) are connected in parallel with the segment drivers
2
(
2
-
1
,
2
-
2
,
2
-
3
, . . . ), and the serial data input signal (CSDi) line
9
is cascade-connected to these drivers
2
. The first segment driver
2
-
1
receives a serial data input signal CSDi from the controller
10
. A serial data output signal a output from the first segment driver
2
-
1
is connected to the serial data input pin of the second segment driver
2
-
2
, and a serial data output signal b output from the second segment driver
2
-
2
is connected to the serial data input pin of the third segment driver
2
-
3
.
FIG. 3
is a timing chart in the conventional data transfer method shown in FIG.
1
.
FIG. 4
is a block diagram showing the arrangement of the driver in the conventional data transfer method shown in FIG.
1
.
The conventional data transfer method will be explained below with reference to
FIGS. 1
to
4
. As shown in
FIG. 3
, segment image data (video data) for all the drivers are serially transferred in an 8-bit width, and when first data, i.e., D
0
to D
7
, of these image data are supplied, the serial data input signal CSDi simultaneously changes to “1”. Then, the first segment driver
2
-
1
shown in
FIG. 2
begins to latch the input image data and simultaneously begins to count the number of clocks. When the segment driver
2
-
1
has counted
20
clocks CLK, it completes the data input operation, and sets the serial data output signal a to be “1”. Similarly, the second and third segment drivers receive image data in the same procedure as described above. With this operation, data D
0
to D
159
are received as image data of the first segment driver, data D
160
to D
319
are received as image data of the second segment driver, and data D
320
to D
479
are received as image data of the third segment driver, thus completing the transfer operation of image data for one horizontal scanning period.
However, in the above-mentioned prior art, since each driving integrated circuit has neither a latch memory nor a multiplexer circuit, sequentially transferred data are latched by a required amount (corresponding to the data holding performance of the integrated circuit), or data corresponding to a sub-scanning width are sequentially transferred using n driving integrated circuits via a shift register to form 1-line data.
Therefore, in the conventional data transfer method, even when a display apparatus with memory characteristics such as a ferroelectric liquid crystal display (to be referred to as an FLCD hereinafter: Ferroelectric Liquid Crystal Display) is to be driven, data for one line are transferred.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a display apparatus wherein two kinds of informations are transmitted through a common bus in time series.
Another object of the present invention is to provide a display apparatus which can recognize an arrangement position even in case of using the same curcuit structure of IC.
The present invention has been made in consideration of the conventional problems, and has as its object to reduce the average data transfer amount from a controller to drivers in a display apparatus driving circuit. By reducing the data transfer amount, consumption power and radiation noise are expected to be reduced.
In order to achieve the above object, according to the present invention, in a data transfer method for transferring data to information-side drivers for driving a display apparatus, driver circuits each comprising a chip address/video data discrimination circuit and a unit driver are mounted around the display apparatus, each unit driver is set with its own chip address by means of a hardware pattern, and data exchange with the driver circuits is performed, so that chip address information and video data information are time-divisionally transferred to the target unit driver by utilizing a chip address/video data common bus line and a chip address/video data discrimination control signal.
According to a preferred embodiment of the present invention, the display apparatus comprises a flat display. Each driver circuit comprises an integrated circuit having the chip address/video data discrimination circuit and one unit driver. The unit driver comprises a chip address terminal consisting of a plurality of pins, which are used for setting its own address. Each unit driver comprises a latch means for holding previous data until it receives new data, and outputting data in accordance with the held data, and transfers data of only the unit driver whose video data has changed. In this case, the output pins of each unit driver are divided into a plurality of blocks, and data of only blocks whose video data have changed are transferred. Alternatively, only data between output pin blocks designated by start and end block signals of the output pins of each unit driver are transferred.
According to the present invention, when, for example, a segment-side driving integrated circuit comprises a latch circuit, a multiplexer circuit, and a chip address discrimination circuit to realize a data transfer method with control data, only changed data are transferred to the driving integrated circuit, thus reducing the average data transfer amount. More specifically, the driving integrated circuits for the flat display are mounted around the panel, and data exchange with the integrated circuits is performed so that a controller outputs data with address information and control information (driver output block information/start block information/end block information) to a target driving integrated circuit. In this manner, the integrated circuit can receive target data on the basis of the address information and the control information. Therefore, the controller designates only a position where data has changed and outputs the data thereto, thereby realizing the above-mentioned concept.
In the prior art, since chip select signals are required in units of chips, a large-screen, high-resolution display which is expected to be developed in future suffers an increase in the number of scanning lines, and the number of drivers increases accordingly, resulting in an increase in the number of signal lines.
According to an embodiment of the present invention, there is provided a data transfer method which can reduce the number of signal lines between a controller and drivers in a display apparatus driving circuit and has a predetermined number of signal lines independently of the resolution of a display apparatus.
According to another embodiment of the present invention, as scanning-side drivers for driving a display apparatus, u
Ina Kenzo
Mizutome Atsushi
Mori Hideo
Murayama Kazuhiko
Canon Kabushiki Kaisha
Fitzpatrick ,Cella, Harper & Scinto
Lewis David L.
Shalwala Bipin
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