Display device

A display device has first row select lines for selecting rows of picture elements, picture element signal lines for supplying picture element signals to picture elements which are selected, a drive unit having drive circuits arrayed at respective picture elements each for driving the corresponding actuator in response to a picture element signal, and a selector unit for selecting the actuators corresponding to selected picture elements. Each of the drive circuits has a drives potential generating circuit for applying a drive potential based on a signal from a picture element signal line to upper electrodes of actuators. The selector unit has selector circuits for applying a select potential to lower electrodes of the actuators corresponding to selected picture elements.

What is claimed is:

1. A display device comprising:

a display unit having capacitive elements arrayed so as to correspond respective picture elements and displaceable for turning on and off the corresponding picture elements;

each of said capacitive elements having a capacitor structure having a pair of electrodes;

a plurality of select lines for supplying the picture elements with instructions of selection and unselection;

a plurality of signal lines for supplying respective picture element signals to each of the picture elements which have been selected;

a drive unit having drive circuits arrayed so as to correspond respective picture elements and driving an capacitive element selected from said capacitive elements in response to an instruction from one of the select lines and a signal from one of the signal lines; and

a selector unit for selecting said capacitive element which corresponds to the selected respective picture elements;

each of said drive circuits having a drive potential generating circuit for applying a drive potential based on the signal from said signal line to one of electrodes having said capacitive element;

said selector unit having selector circuits for applying select potentials to the other of the electrodes having said capacitive element corresponding to the selected picture elements.

2. A display device according to claim 1, wherein each of said drive circuits controls said drive potential generating circuit to translate an output thereof into three states based on the signal from said signal line.

3. A display device according to claim 2, wherein each said drive circuits comprises:

a first logic gate for inhibiting a first signal from being inputted from a first control line included in said signal line when not selected and allowing said first signal to be inputted from said first control line when selected based on a select signal from one of said select lines; and

a second logic gate for inhibiting a second signal from being inputted from a second control line included in said signal line when not selected and allowing said second signal to be inputted from said second control line when selected based on the select signal from said select line;

wherein each of said drive circuits controls said drive potential generating circuit to translate the output thereof into three states based on first and second signals from said signal line.

4. A display device according to claim 2, wherein one of said three states comprises a state in which said drive potential generating circuit has a high output impedance.

5. A display device according to claim 3, wherein said drive potential generating circuit has a series circuit of a first thin-film transistor and a second thin-film transistor which are connected between a high-level power supply and a low-level power supply, the arrangement being such that said first signal is applied to a gate of said first thin-film transistor and said second signal is applied to a gate of said second thin-film transistor.

6. A display device according to claim 5, wherein a potential difference between said high-level power supply and said low-level power supply is lower than a maximum voltage which is applied between the electrodes of said capacitive element.

7. A display device according to claim 5, wherein said first thin-film transistor has a channel of a first conductivity type and said second thin-film transistor has a channel of a second conductivity type.

8. A display device according to claim 5, wherein said first thin-film transistor and said second thin-film transistor have respective channels of the same conductivity type.

9. A display device according to claim 1, wherein said selector circuit has a series circuit of a third thin-film transistor and a fourth thin-film transistor which are connected between a high-level power supply and a low-level power supply, said series circuit having a common drain connected to the other of the electrodes of said capacitive element.

10. A display device according to claim 9, wherein a potential difference between said high-level power supply and said low-level power supply is lower than a maximum voltage which is applied between the electrodes of said capacitive element.

11. A display device according to claim 9, wherein said third thin-film transistor has a channel of a first conductivity type and said fourth thin-film transistor has a channel of a second conductivity type.

12. A display device according to claim 9, wherein said third thin-film transistor and said fourth thin-film transistor have respective channels of the same conductivity type.

13. A display device according to claim 1, wherein each of said selector circuits is assigned commonly to a row of said picture elements.

14. A display device according to claim 1, further including a first board and a second board, at least said capacitive elements being disposed on said first board, at least said driver unit being disposed on said second board, said first board and said second board being bonded to each other.

15. A display device according to claim 14, wherein said second board has a plurality of interconnection circuit forming areas associated respectively with said drive circuits, each of said interconnection circuit forming areas having:

a select line extending in a row direction in a region near another one of the interconnection circuit forming areas which is assigned upwardly or downwardly of said each interconnection circuit forming area;

a signal line extending in a column direction in a region near another one of the interconnection circuit forming areas which is assigned leftwardly or rightwardly of said each interconnection circuit forming area; and

an electrode pad connected to said one of the electrodes of the corresponding capacitive element, said electrode pad and said drive circuit being disposed in a circuit forming region defined by said select line and said signal line.

16. A display device according to claim 15, wherein said drive potential generating circuit has a series circuit of a first thin-film transistor and a second thin-film transistor which are connected between a high-level power supply and a low-level power supply, each of said interconnection circuit forming areas further having:

a high-level power supply line extending in the row direction in a region thereof shared by another one of the interconnection circuit forming areas which is assigned upwardly or downwardly of said each interconnection circuit forming area; and

a low-level power supply line extending in the row direction in a region thereof shared by another one of the interconnection circuit forming areas, other than said other of the interconnection circuit forming areas, which is assigned upwardly or downwardly of said each interconnection circuit forming area.

17. A display device according to claim 14, wherein each of said selector circuits is assigned commonly to a row of said picture elements, said second board having electrode pads disposed in peripheral regions thereof and connected to said selector circuits, respectively, said electrode pads being connected to interconnections extending to ends of said second board.

18. A display device according to claim 14, wherein each of said drive circuits comprises:

a first logic gate for inhibiting a first signal from being inputted from a first control line included in said signal line when not selected and allowing said first signal to be inputted from said first control line when selected based on a select signal from one of said select lines; and

a second logic gate for inhibiting a second signal from being inputted from a second control line included in said signal line when not selected and allowing said second signal to be inputted from said second control line when selected based on the select signal from said select line;

wherein for controlling said drive potential generating circuit to translate the output thereof into three states based on first and second signals from said signal line,

said first control line is extended across one end of said second board in the column direction;

said second control line is extended across another end, opposite to said one end, of said second board; and

said select line is extended across an end of said second board in said row direction.

19. A display device according to claim 18, wherein said first control line, said second control line, and said select line are extended across the corresponding ends of said second board to a reverse surface of said second board by end face printing.

20. A display device according to claim 18, wherein said drive potential generating circuit has a series circuit of a first thin-film transistor and a second thin-film transistor which are connected between a high-level power supply and a low-level power supply;

said high-level power supply having at least one first lead-in line extending in the column direction from one of the ends of said second board, and a plurality of branch lines branched from said first lead-in line along odd-numbered rows or even-numbered rows;

said low-level power supply having at least one second lead-in line extending in the column direction from one of the ends of said second board, and a plurality of branch lines branched from said second lead-in line along rows which are different from the rows along which said first branch lines are branched.

21. A display device according to claim 20, wherein at least said first lead-in line and said second lead-in line are extended across the corresponding ends of said second board to a reverse surface of said second board by end face printing.

22. A display device according to claim 17, wherein the interconnections extending from said electrode pads are extended across the ends of said second board to a reverse surface of said second board by end face printing.

23. A display device according to claim 1, wherein said capacitive element is an actuator.