JPH05323903A - Liquid crystal display device - Google Patents

Abstract

PURPOSE:To obtain the display device which is simple in manufacture process and can invert an image upside down and horizontally by equipping a scanning line driving circuit with a circuit which selects scanning lines in specific order and its reverse order and applies a scanning voltage. CONSTITUTION:When a switch circuit 203 of each scanning line is ON and a switch circuit 205 is OFF, shift pulses ire transferred in order from an upper shift register 201(a) to lower shift registers 201(b), 201(c).... Then an output of each shift register 201 is connected to each scanning line 101 through a buffer gate 209, so the respective scanning lines are selected in order in a normal direction from the top to the bottom and applied with the voltage. When the switch circuit 203 of each scanning line is OFF and the switch circuit 205 is ON, the shift pulses are transferred in the reverse order from the lower shift registers to the upper shift register. The respective scanning lines are therefore selected in the reverse direction from the bottom to the top and applied with the voltage.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly to a projection type liquid crystal display device.

[0002]

2. Description of the Related Art A projection type liquid crystal display device such as a projection type television or a projection type display device using a liquid crystal display element converts white light into three primary color lights such as red, blue and green by using a dichroic mirror or a color filter. The color image is displayed by once splitting the light into individual liquid crystal display elements and making each light into an image for each color, and then optically combining them again and projecting them on a screen, for example. ..

In designing the optical system of such a projection type liquid crystal display device, usually, the distance between the light source and the projection lens and each liquid crystal display element, the optical path length for each color, the number of reflections in the optical path, etc. are considered. It is difficult to make all three colors the same, and the display image must be inverted for any one of the three liquid crystal display elements for each color light as described above.

In order to further reduce the size and cost of such a projection type liquid crystal display device, it is necessary to reduce the size of the liquid crystal display element and the optical system, particularly the lens and dichroic mirror. For this purpose, a method of combining the liquid crystal display elements into a single plate can be considered, but in order not to reduce the definition of the image, the pixel density must be three times that of the three-plate type, and it is necessary to miniaturize the pixels. , Realization is not easy. Therefore, each liquid crystal display element must be made small, but if it is made too small, a problem arises in that the connection terminals to the external liquid crystal drive circuit become too small and connection becomes difficult.

Therefore, a method has been devised in which the liquid crystal drive circuit arranged outside the liquid crystal display element as described above is integrated on the same substrate as the liquid crystal display element.

The liquid crystal drive circuit comprises a scanning line drive circuit and a signal line drive circuit. The scanning line drive circuit sequentially selects the scanning lines arranged in a row and applies a voltage thereto. For example, in the case of an active matrix type liquid crystal display element, a voltage is applied to the gate of the connected TFT to turn it on. To do. The signal line driver circuit sequentially applies a serial image signal to the signal lines arranged in a row in a time-division manner, and when the drain-source of the thin film transistor connected to this is turned on, a liquid crystal display is displayed. An image signal is written in each pixel of the device.

The above operation is sequentially performed for each scanning line, and the image signal sent as a serial signal is written so that a predetermined display state is obtained over all pixels, and the whole liquid crystal display element is displayed. A predetermined image is represented. Further, since the television signal of the NTSC system or the like is an interlaced signal, the odd-numbered scan lines are first selected in sequence, and then the even-numbered scan lines are selected in sequence.

In the conventional liquid crystal display device, since the scanning is performed as described above, the vertical or horizontal direction of the display image is determined by the structure of the drive circuit. That is,
Since the scanning line drive circuit sequentially selects the scanning lines from the top to the bottom (or from the bottom to the top) of the display screen, the vertical direction of the display image is determined by the order in which the scanning line drive circuit selects the scanning lines. To be done. Further, since the signal line driver circuit sequentially supplies and writes image signals from left to right or from right to left of the display screen, the order in which the signal line driver circuit selects signal lines is in the left-right direction of the display image. Determined by

Therefore, in the projection type liquid crystal display device using the liquid crystal display element integrated with the driving circuit as described above,
It is necessary to design and manufacture two types of liquid crystal display elements, one that displays an image in the normal direction and the other that displays an image that is vertically or horizontally reversed. There is a problem in that two types of liquid crystal display device processes are required from the design to the liquid crystal display device manufacturing, the manufacturing process is complicated, the manufacturing cost is high, and it is uneconomical.

[0010]

As described above, in the conventional projection type liquid crystal display device, a liquid crystal display element for displaying an image in a normal direction and an image in which the vertical or horizontal direction is inverted are displayed. Two types of liquid crystal display elements, one with the liquid crystal display element, must be designed and manufactured, and two types of liquid crystal display element processes are required, from the expensive photomask design to the liquid crystal display element manufacturing, which complicates the manufacturing process. However, there is a problem that the manufacturing cost is high and it is uneconomical. The present invention has been made to solve such a problem.

[0011]

A liquid crystal display device of a first invention is a liquid crystal display device, wherein a plurality of scanning lines and a plurality of signal lines are arranged so as to intersect each other in a matrix, and an intersection of the scanning lines and the signal lines. A liquid crystal display device comprising: a pixel arranged for each of the pixels; a scanning line driving circuit that applies a scanning voltage to the scanning line; and a signal line driving circuit that applies a signal voltage to the signal line. However, it is characterized by comprising a circuit for applying the scanning voltage by selecting the scanning lines in a predetermined order and in an order opposite to the predetermined order.

In the liquid crystal display device of the second invention, a plurality of scanning lines and a plurality of signal lines which are arranged so as to intersect each other in a matrix form are provided at each intersection of the scanning lines and the signal lines. A pixel, a scanning line driving circuit for applying a scanning voltage to the scanning line, and a signal line driving circuit for applying a signal voltage to the signal line, wherein the signal line driving circuit is It is characterized by comprising a circuit for selecting a line in a predetermined order and in an order opposite to the predetermined order and applying a signal voltage.

Further, the selection order in the normal direction and the selection order in the opposite direction may be set so that they can be switched at any time by inputting a switching signal to the liquid crystal drive circuit, or as if they were OTPROM (One). Time
As in the case of PROM), once the liquid crystal drive circuit is completed, once the normal order or the reverse direction is selected, the setting may be semipermanently set.

[0014]

Since the scanning line driving circuit has means for sequentially selecting scanning lines in the reverse order from the normal order and applying the scanning voltage, the same one liquid crystal display element can display in the same direction. The image can be displayed upside down by switching. Alternatively, the signal line driving circuit includes means for sequentially selecting signal lines in the order opposite to the normal order and applying a signal voltage, so that the same one liquid crystal display element can change the display direction. By switching, the left and right of the image can be displayed in reverse. As a result, conventionally, two types of liquid crystal display elements having different specifications were required so that the top and bottom or the left and right of the displayed image were reversed. It is possible to solve the problem that the manufacturing process is complicated and the problem that the manufacturing cost is high and uneconomical.

[0015]

Embodiments of the present invention will now be described in detail with reference to the drawings.

(Embodiment 1) FIG. 1 is a diagram schematically showing the structure of a liquid crystal display device according to an embodiment of the present invention centering on a TFT substrate.

This liquid crystal display device includes a liquid crystal display element 100.
The scanning line drive circuit 200 and the signal line drive circuit 300 are formed.

The liquid crystal display device 100 includes a plurality of scanning lines 101 and a plurality of signal lines 103 arranged to intersect in a matrix, the scanning lines 101 and the signal lines 103.
TFT1 arranged at each intersection with and connected to each
05 and the pixel electrode 107 connected to the TFT 105
And a counter substrate (not shown) having a common counter electrode 109 arranged so as to face the pixel electrode 107, and the periphery between the TFT substrate 1 and the counter substrate. The liquid crystal composition, which is clamped by being stopped, is used as a conventional one, and its main part is composed of the liquid crystal composition. The plurality of scanning lines 101 and the plurality of signal lines 103 of the liquid crystal display element 100 are connected to the scanning line drive circuit 200 and the signal line drive circuit 300, respectively, and are driven by these liquid crystal drive circuits.

FIG. 2 is a diagram showing the configuration of the scanning line driving circuit of the liquid crystal display device of the first embodiment. As shown in the figure, the scanning line drive circuit 200 includes a shift register 201.
, Switch circuits 203 and 205, and clock line 207
And a buffer gate 209.

In the shift register 201, the clock input is connected to the clock line 207 and the output is the buffer gate 2
09, and is connected to the scanning line 101 via the switch circuit 203 or the switch circuit 205 and the input of the shift register 201 of the next stage.

Switch circuit 203 and switch circuit 2
Reference numeral 05 is controlled by control signals applied to the control line 211 and the control line 213, respectively, so that one is turned on and the other is turned off. That is, when the switch circuit 203 is on, the switch circuit 205 is off, and when the switch circuit 203 is off, the switch circuit 2 is off.
05 is turned on. Such a switch circuit can be composed of, for example, a TFT switch, a clocked inverter, or a transfer gate. Or O
Like a TPROM, it may be arranged so that once set to either state, the state is held semipermanently. A circuit having such a configuration is provided for each scanning line.

The shift register 201 receives the shift pulse output from the preceding shift register and receives the clock pulse input from the clock line 207,
The shift pulse is delayed according to the cycle of this clock pulse and output to the shift register of the next stage.

Therefore, when the switch circuit 203 of each scanning line is on and the switch circuit 205 is off, the shift pulse shifts from the upper shift register 201 (a) to the lower shift registers 201 (b), 201 (c), 201. (D) ...
Are sequentially transferred to. Since the output of each shift register 201 is connected to each scanning line 101 via the buffer gate 209, each scanning line is sequentially selected in the normal direction from top to bottom and a voltage is applied.

When the switch circuit 203 of each scanning line is off and the switch circuit 205 is on, the shift pulse is directed from the lower shift register to the upper shift register, for example, the shift register 201 in FIG.
(D), 201 (c), 201 (b), 201 (a) are sequentially transferred in the order opposite to the normal direction. The output of each shift register 201 is the buffer gate 2
Since each scanning line is connected to each scanning line 101 through 09, each scanning line is sequentially selected from the bottom to the top in the direction opposite to the normal direction and a voltage is applied.

As a result, the liquid crystal display element 100 is driven in the normal scanning direction from top to bottom when the switch circuit 203 of each scanning line is on and the switch circuit 205 is off, so that a normal image is displayed. Further, when the switch circuit 203 of each scanning line is off and the switch circuit 205 is on, the scan circuit is driven from the lower side to the upper side in the scanning direction opposite to the normal direction, and thus an image which is upside down from the normal image is displayed. ..

As described above, the liquid crystal display device according to the first embodiment of the present invention includes a circuit, the main part of which is composed of the switch circuits 203 and 205 and the control lines 211 and 213 for controlling them. By doing so, the liquid crystal display element 1
The scan line 00 can be scanned from the top to the bottom and from the bottom to the top in both the forward and reverse directions, whereby the top and bottom of the image can be easily reversed.

(Embodiment 2) FIG. 3 is a diagram showing a configuration of a scanning line driving circuit of a liquid crystal display device according to a second embodiment. In the figure, in order to facilitate understanding of the explanation, the first
The same numbering as that of the first embodiment is used for the numbering of the same components as in the first embodiment.

As shown in the figure, the scanning line drive circuit 400
Is a shift register 401 and switch circuits 403, 4
05, a clock line 407, and a buffer gate 409.

The clock input of the shift register 401 is connected to the clock line 407. The output of the shift register 401 is connected to the scan line 101 via the switch circuit 405 and the buffer gate 409 and to the input of the shift register of the next stage, while it is connected to the input of the shift register of the next stage via the switch circuit 403. Connected to input.

Switch circuit 403 and switch circuit 4
Reference numeral 05 is controlled by control signals applied to the control line 411 and the control line 413, respectively, so that one is turned on and the other is turned off. That is, when the switch circuit 403 is on, the switch circuit 405 is off, and when the switch circuit 403 is off, the switch circuit 405 is on. A circuit having such a configuration is provided for each scanning line.

In the shift register 401, when the switch circuit 403 is off as shown in FIG.
When 5 is on, the shift pulse output from the shift register of the previous stage is received at the input while the clock line 40
7 receives a clock pulse input to the clock input 7 and delays the shift pulse received at the input corresponding to the cycle of the clock pulse and outputs the delayed shift pulse to the shift register of the next stage. Output to the scanning line 101 through the gate 409. Therefore, the shift pulse of each scanning line is applied to the upper shift register 40.
Shift registers 401 (b), 401 below 1 (a)
(C), 401 (d), ... Since the output of each shift register 401 is connected to each scanning line 101 via the switch circuit 405 and the buffer gate 409, each scanning line is sequentially selected from top to bottom in the normal direction and a voltage is applied. To be done.

When the switch circuit 403 of each scanning line is on and the switch circuit 405 is off, the shift register 401 moves in the opposite direction to the above.
3, while receiving the shift pulse output from the lower shift register via 3 and receiving the clock pulse input from the clock line 407 at the clock input, delaying the shift pulse according to the cycle of this clock pulse. It outputs to the upper shift register via the switch circuit 403 and scan line 1 via the buffer gate 409.
Output to 01. Therefore, the shift pulse is directed from the lower shift register to the upper shift register, for example, in FIG. 3, shift registers 401 (d), 401
(C), 401 (b), and 401 (a) are sequentially transferred in the order opposite to the normal direction. Since the output of each shift register 401 is connected to each scanning line 101 via the switch circuit 403 and the buffer gate 409, each scanning line is sequentially selected from the bottom to the top in the direction opposite to the normal direction. Voltage is applied.

As a result, in the liquid crystal display element 100, when the switch circuit 403 of each scanning line is off and the switch circuit 405 is on, the liquid crystal display element 100 is driven in the normal scanning direction from the upper side to the lower side. When the image is displayed and the switch circuit 403 of each scanning line is on and the switch circuit 405 is off, the scan circuit is driven from the bottom to the top in the scanning direction opposite to the normal direction, and thus the vertical direction is reversed contrary to the normal image. Display the image.

As described above, the liquid crystal display device according to the second embodiment of the present invention includes a circuit, the main part of which is composed of the switch circuits 403 and 405 and the control lines 411 and 413 for controlling them. By doing so, the liquid crystal display element 1
The scan line 00 can be scanned from the top to the bottom and from the bottom to the top in both the forward and reverse directions, whereby the top and bottom of the image can be easily reversed.

(Embodiment 3) FIG. 4 is a diagram showing the configuration of a liquid crystal display device according to the third invention, focusing on its signal line drive circuit. In the same figure, in order to facilitate understanding of the explanation, the same numbers as in the first embodiment are used as the numbering of the same components as in the first embodiment.

As in the case of the first embodiment, the liquid crystal display device 100 has a plurality of scanning lines 101 and a plurality of signal lines 103 arranged to intersect in a matrix, the scanning lines 101 and the signals. The TFT 105 arranged at each intersection with the line 103 and connected to each of the intersections, and the TFT 10
5, a TFT substrate 1 having a pixel electrode 107 connected thereto, a counter substrate (not shown) having a common counter electrode 109 arranged so as to face the pixel electrode 107, and the TFT substrate 1 described above. It is a general one as has been conventionally used, the main part of which is composed of a liquid crystal composition which is sandwiched and sandwiched between a liquid crystal composition and a substrate. A plurality of scanning lines 101 and a plurality of signal lines 103 of the liquid crystal display element 100 are respectively provided with a scanning line driving circuit 200,
It is connected to the signal line drive circuit 300 and driven by these liquid crystal drive circuits. (Scan line driving circuit 200
Is a general method in which scanning lines are sequentially selected in a normal direction and a voltage is applied. The signal line driving circuit 300 of this liquid crystal display device includes a shift register 301, switch circuits 303 and 305, a clock line 307, and a TFT 3.
09 and a signal input line 310.

The clock input of the shift register 301 is connected to the clock line 307. Further, the output of the shift register 301 is passed through the switch circuit 305 to the TFT 3
09 is connected to the input of the shift register of the next stage and is connected to the input of the shift register of the previous stage via the switch circuit 303. The signal input line 310 is connected to the signal line 103 via the drain and source of the TFT 309.

Switch circuit 303 and switch circuit 3
05 is controlled by control signals applied to the control line 311 and the control line 313, respectively, and one is turned on and the other is turned off. That is, when the switch circuit 303 is on, the switch circuit 305 is off, and when the switch circuit 303 is off, the switch circuit 305 is on. The circuit having such a configuration is provided for each signal line.

In the shift register 301, the switch circuit 303 is off and the switch circuit 30 is in the state shown in FIG.
When 5 is on, the shift pulse output from the previous stage, that is, the left shift register is received at the input, while the clock pulse input from the clock line 307 is received at the clock input, and the clock pulse is input in accordance with the cycle of the clock pulse. The shift pulse received at the input of is delayed and output to the next stage, that is, the right shift register, and is also output to the gate of the TFT 309 via the switch circuit 305.
Therefore, the shift pulse of each signal line is the left shift register 3
01 (a) to the right shift registers 301 (b), 30
1 (c) ... are sequentially transferred. The output of each shift register 301 is passed through the switch circuit 305 to the TFT 3
Since it is connected to the gate of 09, the drain-source of the TFT 309 is turned on, each signal line is sequentially selected from the right to the left in the normal direction, and the signal voltage is output from the signal input line 310 at each timing. Applied and written.

When the switch circuit 303 of each signal line is on and the switch circuit 305 is off, the shift register 301 moves in the opposite direction to the above.
3 receives the shift pulse output from the right shift register via 3 while receiving the clock pulse input from the clock line 307 at the clock input and delaying the shift pulse corresponding to the cycle of the clock pulse. It outputs to the left shift register via the switch circuit 303 and also to the gate of the TFT 309. Therefore, the shift pulse is directed from the right shift register to the left shift register, for example, shift registers 301 (c), 301 (b), 301 (a) in FIG.
In this order, the data is sequentially transferred in the reverse order of the normal direction.
Since the output of each shift register 301 is connected to the gate of the TFT 309, the drain-source of the TFT 309 is turned on, and each signal line is sequentially selected from right to left in the direction opposite to the normal direction. Signal input line 310
Voltage is applied from.

As a result, the liquid crystal display element 100 is driven in the normal direction from left to right when the switch circuit 303 of each signal line is off and the switch circuit 305 is on, so that an image in the normal direction is displayed. Further, when the switch circuit 303 of each signal line is on and the switch circuit 305 is off, the image is driven from right to left in the direction opposite to the normal direction. indicate.

As described above, the liquid crystal display device according to the third embodiment of the present invention is provided with a circuit whose main part is composed of the switch circuits 303 and 305 and the control lines 311 and 313 for controlling them. By doing so, the liquid crystal display element 1
The 00 signal line can be driven from left to right and from right to left in both the forward and reverse directions, so that the left and right of the image can be easily reversed.

The liquid crystal drive circuit according to the present invention is particularly suitable for a projection type liquid crystal display device, but the application is not limited to this. For example, it can be used for a display device such as a viewfinder of some video cameras, which displays an image through a complicated optical system and in which the image is inverted by the optical system with a regular image signal.

Further, the liquid crystal drive circuit according to the present invention is not limited to the configuration as in the above embodiment. It suffices that the image displayed by at least one of the scanning line driving circuit and the signal line driving circuit is arranged so that the image can be reversed vertically or horizontally. Regarding the scanning method,
For example, it can be applied to a liquid crystal display device with an image display scanning method consisting of two fields in which every other line is grouped and scanned, or the image signal writing method to the signal line can be applied, for example, to the upper half and lower half of the screen. It can also be applied to a liquid crystal display device in which data is divided and written with.

Further, the switch circuits 203, 205, 30
3, 305 and the like are not limited to those described in detail in the above embodiment. Besides, for example, a circuit using a transfer gate or a clocked inverter can be applied.

Further, the selection order in the normal direction and the selection order in the reverse direction may be set so that they can be switched at any time by inputting a switching signal to the liquid crystal drive circuit, or as if the OTPROM ( One
For example, a time PROM), once the liquid crystal drive circuit is completed, it is possible to semipermanently set the normal order or the reverse order.

[0047]

As described above in detail, the liquid crystal display device of the present invention can easily reverse the left and right or the top and bottom of the image while the manufacturing process is simple and the manufacturing cost is kept low. This is the liquid crystal display device.

[Brief description of drawings]

FIG. 1 is a diagram schematically showing a configuration of a liquid crystal display device according to a first embodiment of the present invention, focusing on a TFT substrate.

FIG. 2 is a diagram showing a configuration of a scanning line driving circuit of the liquid crystal display device of the first embodiment.

FIG. 3 is a diagram showing a configuration of a scanning line driving circuit of a liquid crystal display device of a second embodiment.

FIG. 4 is a diagram showing a configuration of a liquid crystal display device according to a third invention, centering on a signal line drive circuit thereof.

[Explanation of symbols]

1 ... TFT substrate, 101 ... Scanning line, 103 ... Signal line, 1
05 ... TFT, 107 ... Pixel electrode, 109 ... Common counter electrode, 200 ... Scan line drive circuit, 201 ... Shift register, 203, 205 ... Switch circuit, 207 ... Clock line, 209 ... Buffer gate, 300 ... Signal line drive circuit

Claims (2)

[Claims] 1. A plurality of scanning lines and a plurality of signal lines arranged to intersect in a matrix, pixels arranged at each intersection of the scanning lines and the signal lines, and scanning on the scanning lines. In a liquid crystal display device having a scanning line drive circuit for applying a voltage and a signal line drive circuit for applying a signal voltage to the signal line, the scanning line drive circuit arranges the scanning lines in a predetermined order and in a predetermined order. Is equipped with a circuit for applying a scanning voltage by selecting in the reverse order. 2. A plurality of scanning lines and a plurality of signal lines which are arranged so as to intersect in a matrix form, a pixel which is arranged at each intersection of the scanning lines and the signal lines, and a scanning line which scans the scanning lines. In a liquid crystal display device having a scanning line drive circuit for applying a voltage and a signal line drive circuit for applying a signal voltage to the signal line, the signal line drive circuit arranges the signal lines in a predetermined order and in a predetermined order. Is equipped with a circuit for selecting in the reverse order and applying a signal voltage.