JPH067239B2 - Electro-optical device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electro-optical device such as a display device and a printer shutter, and more particularly to an electro-optical device having a shift register circuit built in on the same substrate.

[Outline of Invention]

In a matrix electro-optical device including a shift register circuit, an inspection switching transistor is provided at the end of at least one of a line and a control line, and at the same time as an operation test of a pixel selection transistor driving circuit, a signal line,
The control line is checked for disconnection and mutual short circuits.

[Prior Art and its Problems] In an integrated circuit device using a semiconductor thin film, particularly in a matrix-arranged liquid crystal display device, a pixel selection transistor driving circuit (hereinafter referred to as a driving circuit) currently represented by a shift register circuit is a pixel. Many attempts have been made to make it on the same substrate as the part in the same process, and it is in the direction of practical application. However, it is difficult to perform an operation test of the drive circuit by directly connecting the drive circuit to each signal line and control line and forming them on the same substrate, and check for disconnection of the signal line and control line and mutual short circuit check. Must be performed in another inspection process, which causes an increase in inspection cost.

FIG. 1 is a circuit diagram of a liquid crystal display device with a built-in drive circuit, in which the drive circuit is directly connected to the signal lines and control lines of the pixel section and is formed on the same substrate. A pixel portion having lines 2 and control lines 3 and a driving circuit (driving circuit for pixel signal 4 and control signal shift register circuit 5) for driving the pixel selection transistor 1 are formed on the same substrate. It is embedded.

[Means for solving problems]

In order to eliminate these drawbacks, the present invention can perform an operation test of a drive circuit, especially a shift register circuit and a disconnection check of signal lines and control lines and a mutual short-circuit check in a shorter inspection process on the same substrate. It is an object to provide an electro-optical device having such a structure.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 2 is a circuit diagram showing an embodiment of the present invention. As in the case shown in FIG. 1, the pixel portion and the driving circuit portion are formed on the same substrate and directly connected to each other. A switching transistor 6 is provided at the end of each of the signal line 2 connected to 4 and the control line 3 connected to the control signal shift register circuit 5, and the gate electrode of each switching transistor 6 is It is connected to the next signal line or control line. The source electrode of each switching transistor 6 is taken out as a common electrode on the signal line side and the control line side. The switching transistor 6 is sequentially operated by using the clock signal and the data signal input to the common electrode and pixel signal shift register circuit 4, and the clock signal and the data signal input to the control signal shift register 5. Can be switched for each signal line or control line, and disconnection check and mutual short-circuit check of each of the signal line 2 and control line 3 can be performed in the operation test and the inspection process of the drive circuit.

Further, when actually used as a liquid crystal display device, if the common electrode is connected to the ground potential, it does not affect the operation.

Further, FIG. 3 is a circuit diagram showing another embodiment of the present invention, which is similar in configuration to the one embodiment of the present invention, but the signal line 2
Alternatively, the switching transistor 6 provided at the end of the control line 3 is arranged above and below and to the left and right of the pixel portion, and the shift register circuits 4 and 5 are arranged above and below and to the left and right of the pixel portion accordingly. This reduces the operating speed of each shift register circuit 4 and 5 to half,
In addition, since the switching transistor 6 is divided and arranged, there is no problem in layout. Further, in this case, the common electrode, which is a collection of the source electrodes of the switching transistors 6, is collected for each side of the pixel portion and used as a signal reading terminal in the operation test of the corresponding shift register circuit.

〔The invention's effect〕

As described above, according to the present invention, it is possible to perform the operation test of the drive circuit represented by the shift register circuit, the disconnection check of each of the signal line and the control line, and the mutual short circuit check in the same inspection process.

[Brief description of drawings]

FIG. 1 is a circuit diagram of a liquid crystal display device in which a pixel portion and a drive circuit portion are formed on the same substrate and directly connected, and FIG. 2 is a circuit diagram of an electro-optical device according to an embodiment of the present invention. The drawing is a circuit diagram of an electro-optical device according to another embodiment of the present invention. DESCRIPTION OF SYMBOLS 1 ... Pixel selection transistor 2 ... Signal line 3 ... Control line 4 ... Pixel signal shift register circuit 5 ... Control signal shift register circuit 6 ... Switching transistor

Claims (4)

[Claims] 1. A matrix electro-optical device having a built-in shift register circuit, wherein an inspection switching transistor is provided at the end of at least one of a signal line and a control line. 2. The electro-optical device according to claim 1, wherein the gate of the inspection switching transistor is connected to the signal line or control line of the next stage. 3. The electro-optical device according to claim 1, wherein the source of the inspection switching transistor is taken out as a common electrode independently of at least a signal line and a control line. 4. The shift register is arranged above and below a pixel portion, and at least every other one of the switching transistors for inspection is arranged alternately in a signal line or a control line. The electro-optical device described.