Shift register and image display apparatus containing the same
A shift register has an output stage formed by a first transistor connected between an output terminal and a first clock terminal and a second transistor connected between the output terminal and a ground. Third and fourth transistors are connected in series between the gate of the first transistor (first node) and the ground. A second node between the third and fourth transistors is connected to a power source via a fifth transistor. The fifth transistor has its gate connected to the first node. Accordingly, when the third and fourth transistors are turned off to raise the first node in level, the fifth transistor is turned on, whereby a predetermined voltage is applied to the second node.
1. A shift register comprising:
an input terminal and an output terminal;
first and second clock terminals to which first and second clock signals are input, respectively, said first and second clock signals being shifted in phase from each other;
first, second and third voltage terminals to which first, second and third voltages are applied, respectively;
a first transistor connected between said output terminal and said first clock terminal;
a second transistor connected between said output terminal and said first voltage terminal;
a first node to which a control electrode of said first transistor is connected;
a second node to which a control electrode of said second transistor is connected; and
a driving section for applying said first voltage to said first node and a voltage corresponding to said third voltage to said second node in synchronization with said second clock signal, while applying a voltage corresponding to said second voltage to said first node and said first voltage to said second node in response to an input signal input to said input terminal, wherein
said driving section includes a compensation circuit for charging said second node to a level at which a conducting state of said second transistor is kept in synchronization with said first clock signal during a period in which said second transistor is in the conducting state.
2. The shift register according to claim 1 , wherein
said compensation circuit includes:
fourth and fifth voltage terminals to which predetermined fourth and fifth voltages are applied, respectively;
a third transistor connected between said second node and said fourth voltage terminal;
a fourth transistor connected between a control electrode of said third transistor and said second node, having a control electrode connected to said fifth voltage terminal; and
a capacitive element connected between said control electrode of said third transistor and said first clock terminal.
3. The shift register according to claim 2 , wherein
said capacitive element is a metal oxide semiconductor capacitive element.
4. A shift register comprising a plurality of shift registers connected in cascade, each being defined in claim 1 .
5. An image display apparatus using said shift register defined in claim 1 as a scanning-line driving circuit.