JP4118072B2 - Display device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a display device such as a liquid crystal display device, and more particularly to a technique for identifying an insulating substrate constituting the display device.
[0002]
[Prior art]
With recent progress in semiconductor process technology, it has become technically possible to form a pixel array portion and a drive circuit constituting a liquid crystal display device on the same glass substrate. The more complicated the structure of the glass substrate, the worse the production yield, and the higher the possibility that defects such as disconnection and short circuit will occur after production.
[0003]
In order to analyze such defects at the time of manufacture, conventionally, a bar code is attached to a glass substrate for management. For example, information such as a manufacturing date, a manufacturing location, a manufacturing number, and a manufacturing process condition is recorded in the bar code.
[0004]
[Problems to be solved by the invention]
However, because the scanner's barcode reading accuracy is not so high, reading errors may occur, especially when dirt is attached to a part of the barcode. Cheap. Increasing the size of the barcode reduces the possibility of misrecognition, but in the case of liquid crystal display devices for portable devices, the space for attaching the barcode is limited, and the size of the barcode itself is increased. It is difficult.
[0005]
Further, in order to read bar code information, a scanner is always required, and the reading work is costly. Further, in order to read bar code information, a scanner must be placed near the bar code, which makes it difficult to read the bar code after the liquid crystal display device is incorporated into the system. Therefore, the barcode information cannot be read in the process of assembling the liquid crystal display device (module process) or the shipping inspection process.
[0006]
The present invention has been made in view of such a point, and an object thereof is to provide a display device capable of electrically outputting identification information of an insulating substrate constituting the display device.
[0007]
According to one aspect of the present invention, a switching element disposed in the vicinity of the intersection of the lined signal line and the scanning line;
A signal line driving circuit for driving the signal line;
In a display device in which a scanning line driving circuit for driving a scanning line is formed on an insulating substrate,
On the insulating substrate, an identification information output circuit that outputs identification information of the corresponding insulating substrate is formed,
The identification information output circuit outputs identification information of the corresponding insulating substrate in the form of serial data,
On the insulating substrate, switching means for the number of bits of the identification information is provided,
The identification information output circuit includes a shift register that outputs a control signal for controlling on / off of the corresponding switching unit,
The display device characterized in that the shift register starts to operate in response to a signal supplied from the scanning line driver circuit, and outputs the control signal using a signal supplied from the signal line driver circuit as a clock. Provided.
[0008]
In the present invention, since the identification information output circuit for outputting the identification information of the insulating substrate is provided in the insulating substrate, the insulating substrate can be managed easily and accurately without attaching a barcode.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a display device according to the present invention will be specifically described with reference to the drawings. Hereinafter, a liquid crystal display device will be described as an example of the display device.
[0010]
FIG. 1 is a layout diagram of an embodiment of a glass substrate constituting a liquid crystal display device. On the glass substrate of FIG. 1, a pixel array unit 1 in which pixel TFTs (Thin Film Transistors) are formed in the vicinity of intersections of signal lines and scanning lines arranged in a row, and a signal line driving circuit for driving the signal lines ( X driver) 2, a scanning line driving circuit (Y driver) 3 for driving the scanning lines, and an identification information output circuit 4 which is a characteristic part of the present embodiment.
[0011]
The identification information output circuit 4 outputs the identification information of the corresponding glass substrate as a serial code signal from one identification information output line L1.
[0012]
FIG. 2 is a circuit diagram showing a detailed configuration of the identification information output circuit 4. As illustrated, the identification information output circuit 4 includes switches SW1 to SWn corresponding to the number of bits representing the identification information. Each switch SW1 to SWn is associated with each output terminal of the shift register 10, and when a shift pulse is output from a specific output terminal of the shift register 10, the corresponding switch SW1 to SWn is turned on.
[0013]
As shown in FIG. 3, both the power supply pattern 5 and the ground pattern 6 are connected to one end of each of the switches SW1 to SWn, and one of the patterns is cut by a laser or the like in the manufacturing process. Alternatively, instead of cutting with a laser or the like, either the power supply pattern 5 or the ground pattern 6 may be connected to one end of each of the switches SW1 to SWn by patterning in the PEP process. As a result, the voltage at one end of each of the switches SW1 to SWn changes from the power supply voltage VDD to the ground voltage GND. The other ends of the switches SW1 to SWn are all connected to the identification information output line L1.
[0014]
The pixel TFT formed on the glass substrate and the TFTs in the signal line driving circuit 2 and the scanning line driving circuit 3 are all formed of polysilicon. Note that only part of the signal line driver circuit 2 and the scanning line driver circuit 3 may be formed over the glass substrate.
[0015]
Next, the operation of the liquid crystal display device of this embodiment will be described. First, in the process of manufacturing a liquid crystal display device, for each glass substrate, the power supply pattern 5 or the ground pattern 6 connected to each end of the switches SW1 to SWn in FIG. . For example, if “1” is set, the ground pattern 6 is disconnected, and if “0” is set, the power supply pattern 5 is disconnected.
[0016]
The completed liquid crystal display device drives the scanning lines by the scanning line driving circuit 3 and drives the signal lines by the signal line driving circuit 2, similarly to the conventional liquid crystal display device. Shift registers SR1 to SR768 in the scanning line driving circuit 3 supply shift pulses to the individual scanning lines while shifting the time.
[0017]
FIG. 4 is a diagram illustrating an example of data of the identification information output line L1. In the case of an XGA standard liquid crystal display device, since there are 768 scanning lines, identification information of a maximum of 768 bits can be output. However, the number of bits of identification information is not particularly limited as long as it is 768 bits or less.
[0018]
As shown in FIG. 4, the identification information is sequentially transmitted to the identification information output line L1 bit by bit in synchronization with the clock signal. Data on the identification information output line L1 is transmitted to a host device (not shown) via an FPC (flexible printed circuit board) or the like, and identification information is detected.
[0019]
The serial-out signal L2 output from the shift register in the signal line driving circuit 2 and the serial-out signal L3 output from the shift register in the scanning line driving circuit 3 are input to the identification information output circuit 4 in FIG. The The serial out signals of both the drive circuits 2 and 3 are signals output from the last stage register of each shift register. More specifically, the start pulses L4 and L5 inputted to the first stage register of each shift register are sequentially shifted, and the one outputted from the last stage register becomes a serial-out signal.
[0020]
Since the start pulse L4 is input to the signal line driving circuit 2 every time the scanning line driving circuit 3 scans the scanning line once, the scanning line driving circuit 3 scans the scanning line once by the serial-out signal L2. A pulse is output each time.
[0021]
A start pulse L5 is input to the shift register in the scanning line driving circuit 3 at a rate of once per frame, and a shift pulse obtained by sequentially shifting the start pulse by the shift register is supplied to the scanning line.
[0022]
The identification information output circuit 4 according to the present embodiment starts the operation in response to the serial out signal L3, and serially outputs the identification information using the serial out signal L2 output from the shift register in the signal line driving circuit 2 as a clock.
[0023]
Thus, in this embodiment, since the timing signal used by the identification information output circuit 4 is received from the signal line driving circuit 2 and the scanning line driving circuit 3, it is not necessary to generate the timing signal separately, and the circuit configuration is simplified. Can be
[0024]
Further, since the switches SW1 to SWn and the wiring pattern are used for storing the identification information, it can be configured with a simpler circuit than using a memory, a flip-flop, or the like, and hardly affects the overall size of the glass substrate.
[0025]
Further, since the identification information output circuit 4 is driven by the serial-out signals L2 and L3 from the signal line driving circuit 2 and the scanning line driving circuit 3, the identification information output line L1 is monitored to scan with the signal line driving circuit 2. It can be detected whether or not the line drive circuit 3 is operating normally.
[0026]
Furthermore, since the identification signal is continuously output while the liquid crystal display device is driven, the identification signal can be detected at any time by monitoring the identification information output line L1 when necessary.
[0027]
In each of the embodiments described above, it may be possible to arbitrarily select whether or not to output identification information from the identification information output line L1. In this case, it can be realized simply by connecting the switches SW1 to SWn to the identification information output line L1.
[0028]
In the embodiment described above, the signals input to the identification signal input circuit may be L4 and L5, respectively, instead of L2 and L3.
[0029]
【The invention's effect】
As described above in detail, according to the present invention, identification information of an insulating substrate on which a signal line, a scanning line or the like is formed can be output from the insulating substrate to the outside. Is eliminated, and the management of the insulating substrate can be performed easily and accurately.
[0030]
Further, since the identification information is continuously output as long as the display device is in operation, the identification information can be detected whenever necessary, and maintenance is facilitated. In particular, even after the display device is incorporated into various systems, the identification information of the insulating substrate can be detected without being disassembled.
[0031]
Furthermore, since identification information unique to the display panel can be detected, it is possible to construct a mobile system such as a mobile phone with higher safety by using it as various security information.
[Brief description of the drawings]
FIG. 1 is a layout diagram of an embodiment of a glass substrate constituting a liquid crystal display device.
FIG. 2 is a circuit diagram showing a detailed configuration of an identification information output circuit.
FIG. 3 is a diagram showing a state of cutting a power supply pattern or a ground pattern.
FIG. 4 is a diagram illustrating an example of data of an identification information output line.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Pixel array part 2 Signal line drive circuit 3 Scan line drive circuit 4 Identification information output circuit 5 Power supply pattern 6 Ground pattern L1 Identification information output line L2, L3 Serial out signal L4, L5 Start pulse

Claims (2)

Switching elements arranged in the vicinity of intersections of the lined signal lines and scanning lines;
A signal line driving circuit for driving the signal line;
In a display device in which a scanning line driving circuit for driving a scanning line is formed on an insulating substrate,
On the insulating substrate, an identification information output circuit that outputs identification information of the corresponding insulating substrate is formed,
The identification information output circuit outputs identification information of the corresponding insulating substrate in the form of serial data,
On the insulating substrate, switching means for the number of bits of the identification information is provided,
The identification information output circuit includes a shift register that outputs a control signal for controlling on / off of the corresponding switching unit,
The display device , wherein the shift register starts operation by a signal supplied from the scanning line driver circuit and outputs the control signal using a signal supplied from the signal line driver circuit as a clock . The identification information output circuit has a bit fraction said switching means of said identification information,
On the insulating substrate, a power pattern and a ground pattern connected to each end of the switching means are provided,
For each of the switching means, the connection between one end of the switching means and the power supply pattern is cut off, or the connection between one end of the switching means and the ground pattern is cut off,
2. The display device according to claim 1, wherein each of the other ends of the switching means is connected to an identification information output line for outputting the serial data.

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