CN1230707C - Circuit structure of liquid crystal display with transmissive area and reflective area - Google Patents

Abstract

According to the structure of the invention, a scanning circuit is used for controlling the opening of the two thin film transistors, and an image data circuit is used for transmitting image data to the pixel capacitor and the holding capacitor. When the thin film transistor of the scanning line is selected by the scanning signal, the image signal on the thin film transistor can charge the pixel capacitor and the holding capacitor, when the scanning signal is removed, the charge in the pixel capacitor is still stored until the scanning line is selected again by the scanning signal and a new voltage value is stored, so that a picture can be formed on the matrix display by the charge stored in the pixel capacitor.

Description

Circuit structure of liquid crystal display with transmissive area and reflective area

technical field

The invention relates to a circuit structure of a display component of a liquid crystal display, in particular to a circuit structure of a display component of a semi-transmissive and semi-reflective liquid crystal display.

Background technique

For a long time, liquid crystal displays have been widely used in digital electronic products such as electronic watches and calculators. And with the continuous development and progress of thin film transistor liquid crystal display technology, due to its advantages of small size, light weight, low driving voltage, and low power consumption, it has been widely used in notebook computers, personal digital processing systems, And color TV, and gradually replace the picture tube of the traditional monitor. At present, the design of thin-film crystal liquid crystal display (TFT-LCD) tends to develop towards a large size.

Generally speaking, for a liquid crystal display having a transmissive area and a reflective area at the same time, its circuit structure is shown in FIG. The display assembly 50 arranged in matrix rows and columns, its enlarged figure is as shown in Figure 1B, a switching device coupled to this display assembly 50 is used to control the transmission of image signals, this display assembly 50 includes a transistor 104 as a switching device, and is composed of The transistor 104 drives a pixel capacitor (pixel capacitor) 106 and a holding capacitor 108 . In general, the transistors 104 used in the liquid crystal display array 200 are usually thin-film transistors (thin-film transistors; TFTs) deposited on a transparent substrate (such as glass). The source or drain electrode of the switching transistor 104 is respectively connected to the electrode of the pixel capacitor 106 and the electrode of the holding capacitor 108 for switching function. And the electrode of this pixel capacitor 106 is formed on the glass substrate on the same side as the display array 200. For a selected image data line 100, the sources or drains of all switching transistors 104 located on the image data line 100 All electrodes receive data signals through the image data line 100 .

When the switching transistor 104 of the scanning line 102 is selected by the scanning signal, the image signal on the switching transistor 104 will cause the pixel capacitor 106 and the holding capacitor 108 to charge to the voltage value relative to the image signal line, thus making each pixel And the electrodes on the opposite sides of the display form a capacitor. When the scan signal is removed, until the scan signal selects the scan line again and stores a new voltage value, the charge in the pixel capacitor 106 is still stored, so through The charge stored in the pixel capacitor 106 can form a frame on the matrix display.

However, for a liquid crystal display having a transmissive area and a reflective area at the same time, the pixel capacitor 106 in the above-mentioned circuit straddles the transmissive area and the reflective area at the same time. Once one of the switching transistor 104 or the pixel capacitor 106 is damaged, It will cause damage to the display unit 50 .

On the other hand, the main function of the holding capacitor 108 is to maintain the voltage across the pixel capacitor 106 at a certain value, that is, before data refresh (Refresh), the voltage across the pixel capacitor 106 is maintained by the holding capacitor 108 of. In a traditional liquid crystal display with a transmissive region and a reflective region, since the holding capacitor 108 must maintain the voltage across the reflective region and the transmissive region at the same time, its capacitance value should be increased to avoid the leakage of a small number of charges causing voltage drop rapidly. In this way, when the data refresh operation is performed, if the refresh is to be completed within the same time, a relatively large driving current is required to charge the holding capacitor 108 , which will increase the difficulty of circuit design.

Contents of the invention

In view of the above-mentioned background of the invention, in a conventional liquid crystal display with both reflective and transmissive functions, since it uses a separate pixel capacitor 106, holding capacitor 108 and switching transistor 104 to form the display component 50, once the Any damage will cause the entire display assembly 50 to be scrapped. On the other hand, since only a single holding capacitor 108 is used to maintain the voltage across the reflective region and the transmissive region at the same time, its capacitance value is usually very large, so when performing a data update (Refresh) action, if the To complete the updating within the same time period, a relatively large driving current is required to charge the holding capacitor 108 , which will increase the difficulty of circuit design. Therefore, the present invention provides a new circuit structure to overcome the above problems.

The main object of the present invention is to provide a liquid crystal display-a display component circuit which can reduce power consumption.

Another object of the present invention is to provide a display element circuit of a liquid crystal display device with a lower operating current.

Another object of the present invention is to provide a display component circuit, which is composed of a plurality of pixel capacitors 106, holding capacitors 108, and switching transistors 104, and is independent of each other, so that one of them can be prevented from being damaged, causing damage to the entire display component. scrapped.

A circuit structure of a liquid crystal display component with a transmissive area and a reflective area, the structure at least includes: a first data line; a second data line, the second data line crosses the first data line; a first transistor, The gate of the first transistor is connected to the second data line and the source/drain of the first transistor is connected to the first data line; a first pixel capacitor is connected to the first transistor through the channel of the first transistor The first data line; a first holding capacitor connected to the first transistor, connected to the first data line through the channel of the first transistor; a second transistor, the gate of the second transistor connected to the second data line and The source/drain of the second transistor is connected to the first data line through the channel of the first transistor; a second pixel capacitor is connected to the second transistor, and connected to the channel of the second transistor through the first transistor the first data line; and a second holding capacitor connected to the first transistor, and the first data line is connected to the channel of the first transistor and the second transistor.

A circuit structure of a liquid crystal display component with a transmissive area and a reflective area, the structure at least includes: a first data line; a second data line, the second data line crosses the first data line; a first transistor, The gate of the first transistor is connected to the second data line and the source/drain of the first transistor is connected to the first data line; a first pixel capacitor is connected to the first transistor through the channel of the first transistor The first data line; a first holding capacitor connected to the first transistor, connected to the first data line through the channel of the first transistor; a second transistor, the gate of the second transistor connected to the second data line and The source/drain of the second transistor is connected to the first data line; a second pixel capacitor is connected to the second transistor, and the channel of the two transistors is connected to the first data line; and a second holding capacitor is connected to the first data line. The second transistor is connected to the first data line through the channel of the second transistor.

The invention provides a circuit structure of a semi-transmissive and semi-reflective liquid crystal display component. According to the transflective structure of the present invention, a display component is composed of a plurality of pixel capacitors, storage capacitors and thin film transistors, wherein the transmissive area and the reflective area of the liquid crystal display are composed of different pixel capacitors, holding capacitors Composed of capacitors and thin film transistors, the two regions can be independent of each other, that is, damage to the reflective region will not affect the work of the transmissive region, and vice versa. At the same time, according to the circuit structure of the present invention, since each holding capacitor is only used to maintain a constant voltage across the pixel capacitance in the reflective area or the penetrating area, the holding capacitor value does not need to be too large, so the charging time can be reduced. .

According to the structure of the present invention, a scan line is used to control the opening of two thin film transistors, and an image data line is used to transmit image data to the pixel capacitor and the holding capacitor. When the thin film transistor of the scanning line is selected by the scanning signal, the image signal on the thin film transistor will charge the pixel capacitor and the storage capacitor. When the scanning signal is removed, the scanning signal will select the scanning line again and store a new When the voltage is high, the charge in the pixel capacitor is still stored, so a picture can be formed on the matrix display through the charge stored in the pixel capacitor.

Description of drawings

From the following detailed description of preferred embodiments of the present invention, the purpose, viewpoint and advantages of the present invention can be better understood. Simultaneously be described with reference to the following accompanying drawings of the present invention, wherein:

FIG. 1A and FIG. 1B are schematic diagrams showing the circuit structure of a thin film transistor display component in the prior art;

FIG. 2 is a circuit structure of a display component according to a first preferred embodiment of the present invention; and

FIG. 3 is a circuit structure of a display component according to a second preferred embodiment of the present invention.

Detailed ways

Without limiting the spirit and scope of application of the present invention, the implementation of the present invention is described below with an embodiment; those skilled in the art, after understanding the spirit of the present invention, can apply the structure of the present invention to each In different liquid crystal displays, a display component circuit structure is formed. Utilizing the circuit structure of the present invention can avoid traditionally using only individual pixel capacitors, holding capacitors and switching transistors to form display components, and once one of them is damaged, the entire display component will be damaged. The structure provided by the invention has the advantage that when one of the groups is damaged, the other group can still continue to work. On the other hand, the circuit structure of the present invention can also solve the traditional problem of using only a single holding capacitor to simultaneously maintain the voltage at both ends of the reflective region and the transmissive region. If the data update (Refresh ), the disadvantage of consuming a large driving current. The application of the present invention should not be limited to the preferred embodiment described below.

The invention provides a circuit structure with a plurality of pixel capacitors, holding capacitors and switching transistors to form a display component. In this way, in addition to avoiding the possibility of damage to the display component caused by traditionally forming a display component with only a single pixel capacitor, a holding capacitor and a switching transistor, it can also effectively reduce the size of the required holding capacitor. A detailed description of the present invention is as follows.

Please refer to FIG. 2 , which is a circuit structure of a display unit 300 according to a first preferred embodiment of the present invention, which is used in a thin film transistor liquid crystal display (TFT-LCD) having both a reflective region and a transmissive region. In this circuit structure, a display component circuit is composed of two thin film transistors 202 and 204 , two pixel capacitors 206 and 208 , and two holding capacitors 210 and 212 . The thin film transistor 202, the pixel capacitor 206 and the holding capacitor 210 are used to control the reflective area of the thin film transistor liquid crystal display. The thin film transistor 204, the pixel capacitor 208 and the holding capacitor 212 are used to control the transmissive area of the thin film transistor liquid crystal display.

Gate electronics of the thin film transistors 202 and 204 are coupled to a scan line 302, and the scan line 302 is used to control the thin film transistors 202 and 204 to be turned on or off. The source or drain electrode of the thin film switching transistor 202 is connected to an image data line 304 that transmits image data. out) to select the desired display component. The other source or drain of the thin film transistor 202 is respectively connected to the electrodes of the pixel capacitor 206 and the storage capacitor 210 , and is also connected to the source or drain of another thin film transistor 204 . The other source or drain of the TFT 204 is coupled to the pixel capacitor 208 and the hold capacitor 212 respectively.

During operation, when the scan line 302 is charged or in a high level state, the thin film transistors 202 and 204 are turned on, and an image data is transmitted from the image data line 304 to the electrode of the thin film transistor 202 . At this time, the image signal transmitted from the image data line 304 is input into the pixel capacitor 206 and the storage capacitor 210 , and is also input into the pixel capacitor 208 and the storage capacitor 212 through the thin film transistor 204 . The pixel capacitors 206 and 208 and the holding capacitors 210 and 212 are respectively charged to the voltage value relative to the image signal line 304 , that is, the liquid crystal in the reflective area and the transmissive area of the liquid crystal display is activated. When the scanning signal is removed, until the scanning signal selects the scanning line 302 again and stores a new voltage value, the charge in the pixel capacitors 206 and 208 and the holding capacitors 210 and 212 is still stored, so through this storage in The charges in the pixel capacitors 206 and 208 can form a frame on the display.

Through the above-mentioned circuit structure of the display component, the reflective area and the transmissive area of the thin film transistor liquid crystal display are controlled by different circuit components, so even if one of the components is damaged, such as the pixel capacitor 206, it will only affect the reflective area of the display component 300 at most. , the transmissive area of the display component can still operate independently. And the voltages at both ends of the pixel capacitors 206 and 208 are maintained by the holding capacitors 210 and 212 respectively. Due to the circuit structure of the present invention, the traditional pixel capacitor and the holding capacitor are separated into two parts, so each part is divided into two parts in a unit time. The charge leakage rate under will be lower than the traditional circuit structure, that is, the capacity of the holding capacitor of the present invention does not need to be as large as the capacity of the holding capacitor in the traditional circuit, so when updating data, the driving current of the present invention Can be lower than the traditional circuit structure requirements.

Referring to FIG. 3 , it is a circuit structure of a display unit 400 according to a second preferred embodiment of the present invention, which is also used in a thin film transistor liquid crystal display (TFT-LCD) having both reflective and transmissive regions. In this circuit structure, a display component circuit is composed of two thin film transistors 402 and 404 , two pixel capacitors 406 and 408 , and two holding capacitors 410 and 412 . The thin film transistor 402, the pixel capacitor 406 and the holding capacitor 410 are used to control the reflective area of the thin film transistor liquid crystal display. The thin film transistor 404, the pixel capacitor 408 and the holding capacitor 412 are used to control the transmissive area of the thin film transistor liquid crystal display.

The gates of the TFTs 402 and 404 are coupled to a scan line 302 , and the scan line 302 is used to control the TFTs 402 and 404 to be turned on or off. The source or drain electrode of the thin film switching transistor 402 is connected to an image data line 304 that transmits image data. out) to select the desired display component. The other source or drain of the TFT 402 is respectively connected to the electrodes of the pixel capacitor 406 and the storage capacitor 410 . The source or drain electrode of the TFT 404 is connected to an image data line 304 for transmitting image data, and the other source or drain of the TFT 404 is also coupled to the pixel capacitor 408 and the storage capacitor 412 respectively.

During operation, when the scan line 302 is charged or in a high level state, the thin film transistors 402 and 404 are turned on, and an image data is transmitted from the image data line 304 to electrodes of the thin film transistors 402 and 404 . At this time, the image signal transmitted from the image data line 304 is input into the pixel capacitors 406 and 408 and the holding capacitors 410 and 412 through the thin film transistors 402 and 404 respectively. The pixel capacitors 406 and 408 and the holding capacitors 410 and 412 are respectively charged to the voltage value relative to the image signal line 304 , that is, the liquid crystal in the reflective area and the transmissive area of the liquid crystal display is activated. When the scanning signal is removed, until the scanning signal selects the scanning line 302 again and stores a new voltage value, the charge in the pixel capacitors 406 and 408 and the holding capacitors 410 and 412 is still stored, so through this storage in The charges in the pixel capacitors 406 and 408 can form a frame on the display.

Similarly, through the above-mentioned circuit structure of the display component, the reflective area and the transmissive area of the thin film transistor liquid crystal display are controlled by different circuit components, so even if one of the components is damaged, such as the pixel capacitor 406, it will only affect this display component at most. The reflective area of 400 can still operate independently for the transmissive area of the display component. In addition, the thin film transistors 402 and 404 of this circuit structure are independent of each other, so the pixel capacitor 408 and the holding capacitor 412 are not affected by the thin film transistor 402, that is, even if the thin film transistor 402 is damaged, its transmissive region can still work. Moreover, the voltages at both ends of the pixel capacitors 406 and 408 in this structure are maintained by the holding capacitors 410 and 412 respectively, so the holding capacitors of the present invention do not need to be as large as the conventional ones. Therefore, when updating data, the present invention The driving current can be lower than the requirements of the traditional circuit structure.

The present invention has been described above with preferred embodiments, which are only used to help understand the implementation of the present invention, and are not intended to limit the spirit of the present invention. After those skilled in the art understand the spirit of the present invention, they will not depart from the spirit of the present invention. Within the scope, when some modifications and equivalent changes can be made, the scope of patent protection shall depend on the scope of the attached patent application and its equivalent field.

Claims (10)

1. the circuit structure of tool penetrating region and echo area liquid crystal display displays assembly, this structure comprises at least:

First data line;

Second data line, this second data line is across this first data line;

One the first transistor, the source/drain that this first transistor grid connects this second data line and this first transistor connects this first data line;

One first pixel capacitor connects this first transistor, and the raceway groove by this first transistor connects this first data line;

One first keeps capacitor to connect this first transistor, and the raceway groove by this first transistor connects this first data line;

The raceway groove that the source/drain that one transistor seconds, this transistor seconds grid connect this second data line and this transistor seconds sees through this first transistor connects this first data line;

One second pixel capacitor connects this transistor seconds, is connected this first data line with the raceway groove of transistor seconds by this first transistor; And

One second keeps capacitor to connect this first transistor, is connected this first data line with the raceway groove of transistor seconds by this first transistor.

2. circuit structure as claimed in claim 1, wherein this second data line is in order to the unlatching of controlling this first transistor and transistor seconds or closes.

3. circuit structure as claimed in claim 1, wherein when this first and second transistor was unlocked, this first and second pixel capacitance kept capacitor to be recharged with this first and second.

4. circuit structure as claimed in claim 1, wherein to keep capacitor be in order to controlling this LCD penetrating region for this first transistor and this first pixel and first, and this transistor seconds and this second pixel and the second maintenance capacitor are in order to control the echo area of this LCD.

5. circuit structure as claimed in claim 1, wherein to keep capacitor be in order to controlling this LCD echo area for this first transistor and this first pixel and first, and this transistor seconds and this second pixel and the second maintenance capacitor are in order to control the penetrating region of this LCD.

6. the circuit structure of tool penetrating region and echo area liquid crystal display displays assembly, this structure comprises at least:

First data line;

Second data line, this second data line is across this first data line;

One the first transistor, the source/drain that this first transistor grid connects this second data line and this first transistor connects this first data line;

One first pixel capacitor connects this first transistor, and the raceway groove by this first transistor connects this first data line;

One first keeps capacitor to connect this first transistor, and the raceway groove by this first transistor connects this first data line;

One transistor seconds, the source/drain that this transistor seconds grid connects this second data line and this transistor seconds connects this first data line;

One second pixel capacitor connects this transistor seconds, and the raceway groove by this transistor seconds connects this first data line; And

One second keeps capacitor to connect this transistor seconds, and the raceway groove by this transistor seconds connects this first data line.

7. circuit structure as claimed in claim 6, wherein this second data line is in order to the unlatching of controlling this first transistor and transistor seconds or closes.

8. circuit structure as claimed in claim 6, wherein when this first and second transistor was unlocked, this first and second pixel capacitance kept capacitor to be recharged with this first and second.

9. circuit structure as claimed in claim 6, wherein to keep capacitor be in order to controlling this LCD penetrating region for this first transistor and this first pixel and first, and this transistor seconds and this second pixel and the second maintenance capacitor are in order to control the echo area of this LCD.

10. circuit structure as claimed in claim 6, wherein to keep capacitor be in order to controlling this LCD echo area for this first transistor and this first pixel and first, and this transistor seconds and this second pixel and the second maintenance capacitor are in order to control the penetrating region of this LCD.

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