Radiant energy – Photocells; circuits and apparatus – Photocell controlled circuit
Reexamination Certificate
2001-04-24
2003-12-09
Sugarman, Scott J. (Department: 2873)
Radiant energy
Photocells; circuits and apparatus
Photocell controlled circuit
C073S862046, C382S124000
Reexamination Certificate
active
06661019
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an active matrix circuit, a method of driving an active matrix circuit, and a surface pressure distribution detecting apparatus.
2. Description of the Related Art
An active matrix circuit basically includes selection lines extending along rows, signal lines extending along columns, active devices disposed at respective locations where the selection lines and the signal lines cross each other, a vertical scanning circuit for outputting selection pulses to sequentially scan the selection lines thereby selecting active devices, and a horizontal scanning circuit for outputting control pulses to open or close the respective signal lines thereby inputting or outputting a signal to selected active devices. The active matrix circuit having above structure may be used, for example, in a liquid crystal display, a surface pressure distribution detecting apparatus, etc. When the active matrix circuit is used in a display device such as a liquid crystal display, the horizontal scanning circuit outputs an image signal to pixel electrodes connected to corresponding active devices. When the active matrix circuit is used in a surface pressure distribution detecting apparatus such as a fingerprint detector, the horizontal scanning circuit inputs a pressure signal applied to electrodes connected to corresponding active devices.
The horizontal scanning circuit described above includes a transfer circuit including a shift register which transfers a horizontal start pulse from a first stage to a final stage in a stage-by-stage fashion in response to a horizontal clock signal thereby outputting control pulses. The vertical scanning circuit includes a vertical transfer circuit which transfers, in response to a vertical clock signal, a vertical start pulse from a first stage to a final stage in a stage-by-stage fashion. Conventionally, the start pulses and the clock signals are supplied to the transfer circuits from an external timing generator. However, use of an external timing generator results in complexity of the overall structure of a system using an active matrix circuit. Furthermore, the horizontal or vertical scanning circuit according to the conventional technique includes a voltage multiplying circuit for internally stepping up a low-voltage start pulse or clock pulse input from the outside and supplying resultant high-voltage pulses to the transfer circuit. However, in this voltage multiplying circuit, the clock signals supplied to the respective stages of the transfer circuit are stepped up using a single level shifter, and thus a very large load is imposed upon the level shifter. As a result, a large signal delay occurs and large power is consumed.
SUMMARY OF THE INVENTION
The above-described problems in the conventional technique can be solved according to aspects of the present invention as described below. According to a first aspect of the present invention, there is provided an active matrix circuit comprising selection lines extending along rows, signal lines extending along columns, active devices disposed at respective locations where the selection lines and the signal lines cross each other, a vertical scanning circuit for outputting selection pulses to sequentially scan the selection lines thereby selecting active devices, and a horizontal scanning circuit for outputting control pulses to open or close the respective signal lines thereby inputting or outputting a signal to selected active devices, the active matrix circuit being characterized in that: the vertical scanning circuit includes a transfer circuit for transferring an input start pulse from a first stage to a final stage in a stage-by-stage fashion in response to a clock signal thereby generating a selection pulse, and also includes a start pulse generating circuit which internally generates a start pulse by processing a selection pulse output from the final stage of the transfer circuit and applies the resultant start pulse to the first stage of the transfer circuit.
According to a second aspect of the present invention, there is provided an active matrix circuit comprising selection lines extending along rows, signal lines extending along columns, active devices disposed at respective locations where the selection lines and the signal lines cross each other, a vertical scanning circuit for outputting selection pulses to sequentially scan the selection lines thereby selecting active devices, and a horizontal scanning circuit for outputting control pulses to open or close the respective signal lines thereby inputting or outputting a signal to selected active devices, the active matrix circuit being characterized in that: the horizontal scanning circuit includes a horizontal transfer circuit for transferring a horizontal start pulse from a first stage to a final stage in a stage-by-stage fashion in response to a horizontal clock signal thereby outputting a control pulse; and the vertical scanning circuit includes a vertical transfer circuit for transferring a vertical start pulse from a first stage to a final stage in a stage-by-stage fashion in response to a vertical clock signal and also includes a vertical clock signal generator which generates a vertical clock signal by processing a control pulse output from the final stage of the horizontal transfer circuit and supplies the resultant vertical clock signal to the vertical transfer circuit.
According to a third aspect of the present invention, there is provided an active matrix circuit comprising selection lines extending along rows, signal lines extending along columns, active devices disposed at respective locations where the selection lines and the signal lines cross each other, a vertical scanning circuit for outputting selection pulses to sequentially scan the selection lines thereby selecting active devices, and a horizontal scanning circuit for outputting control pulses to open or close the respective signal lines thereby inputting or outputting a signal to selected active devices, the active matrix circuit being characterized in that: the horizontal scanning circuit includes a transfer circuit for transferring an input start pulse from a first stage to a final stage in a stage-by-stage fashion in response to a clock signal thereby generating a control pulse, and also includes a start pulse generating circuit which internally generates a start pulse by processing a control pulse output from the final stage of the transfer circuit and applies the resultant start pulse to the first stage of the transfer circuit.
According to a fourth aspect of the present invention, there is provided an active matrix circuit comprising selection lines extending along rows, signal lines extending along columns, active devices disposed at respective locations where the selection lines and the signal lines cross each other, a vertical scanning circuit for outputting selection pulses to sequentially scan the selection lines thereby selecting active devices, and a horizontal scanning circuit for outputting control pulses to open or close the respective signal lines thereby inputting or outputting a signal to selected active devices, the active matrix circuit being characterized in that: the horizontal scanning circuit includes a horizontal transfer circuit for transferring a horizontal start pulse from a first stage to a final stage in a stage-by-stage fashion in response to a horizontal clock signal thereby outputting a control pulse; the vertical scanning circuit includes a vertical transfer circuit for transferring a vertical start pulse from a first stage to a final stage in a stage-by-stage fashion in response to a vertical clock signal; and the active matrix circuit further comprises a reset circuit for, in response to a reset pulse supplied from the outside, forcedly resetting the horizontal transfer circuit and the vertical transfer circuit into their initial states.
According to a fifth aspect of the present invention, there is provided an active matrix circuit comprising selection lines
Furusato Takao
Ichikawa Hiroaki
Hanig Richard
Kananen Ronald P.
Rader & Fishman & Grauer, PLLC
Sony Corporation
Sugarman Scott J.
LandOfFree
Active matrix circuit, method of driving the same, and... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Active matrix circuit, method of driving the same, and..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Active matrix circuit, method of driving the same, and... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3103073