This application claims the benefit of priority to Chinese Patent Application No. 201310754285.3, filed with the Chinese Patent Office on Dec. 31, 2013 and entitled “DRIVING CIRCUIT AND DRIVING METHOD FOR A DISPLAY DEVICE” the content of which is incorporated herein by reference in its entirety.
With the rapid development of display devices, the quality requirement of images shown by the display devices is increasing gradually. Electromagnetic Interference (EMI) existing in the display devices is a critical factor affecting the quality of the images shown by the display devices. However, the value of electromagnetic interference is closely associated with driving methods for the display devices. In this way, the driving methods for the display devices are believed to be a critical factor affecting the quality of images.
In this way, as shown in
The present disclosure is described in detail in conjunction with the embodiments and the accompanying drawings. It should be understood that the embodiments described herein are only used to explain the present disclosure, and not to limit the present disclosure. Moreover, it is also noted that only relevant portions associated with the present disclosure and not all portions of the present disclosure are shown in the drawings for purposes of clarity.
The first source driving circuit 17 includes a first transistor unit 13 including a plurality of transistors, wherein a drain of each transistor of the first transistor unit 13 is connected to a source of a transistor of a corresponding pixel unit, a source of each transistor of the first transistor unit 13 is configured to receive a source driving signal for the transistor of the pixel unit, and a gate of each transistor of the first transistor unit 13 is configured to receive a clock signal for driving pixel unit of a single color from an output end of a corresponding control subunit. The second source driving circuit 19 includes a second transistor unit 15 including a plurality of transistors, wherein a drain of each transistor of the second transistor unit 15 is connected to a source of a transistor of a corresponding pixel unit, a source of each transistor of the second transistor unit 15 is configured to receive a source driving signal for the transistor of the pixel unit and a gate of each transistor of the second transistor unit 15 is configured to receive a clock signal for driving pixel unit of a single color from an output end of a corresponding control subunit. The number of the transistors in the first transistor unit 13 or the second transistor unit 15 is the same as the number of the columns of sub-pixel units in the display device. For example, in the case that the display device has 720 columns and each pixel is formed by a red sub-pixel, a green sub-pixel and a blue sub-pixel, then there will be 2160 transistors in each of the first transistor unit 13 and the second transistor unit 15.
Alternatively, the first control unit 12 has three control subunits for controlling the transmission of the clock signal of a first pixel, the clock signal of a second pixel and the clock signal of a third pixel respectively, for example, for controlling the transmission of the clock signal of a red pixel, the clock signal of a green pixel and the clock signal of a blue pixel. That is, the control subunit corresponding to the red pixel in the first control unit 12 controls all columns of red pixels in the display device, the control subunit corresponding to the green pixel in the first control unit 12 controls all columns of green pixel in the display device and the control subunit corresponding to the blue pixel in the first control unit 12 controls all columns of blue pixel in the display device. Accordingly, the second control unit 14 also has three control subunits for controlling the transmission of the clock signal of the first pixel, the clock signal of the second pixel and the clock signal of the third pixel respectively. Alternatively, each of the first control unit 12 and the second control unit 14 can have four control subunits for controlling the transmission of the clock signal of the first pixel, the clock signal of the second pixel, the clock signal of the third pixel and the clock signal of the fourth pixel respectively, for example, for controlling the transmission of the clock signal of the red pixel, the clock signal of the green pixel, the clock signal of the blue pixel and the clock signal of the yellow pixel respectively. The number of the control subunits is not limited in the embodiment as long as the pixels in the display device can be driven.
Each of control ends 121 of the first control subunits 120 receives the first control signal to turn on or off the first control unit 12 and each input end 122 of the first control subunits 120 is connected to a timing driving circuit 11 to receive the clock signal. Each of control ends 141 of the second control units 140 receives the second control signal to turn on or off the second control unit 14 and each input end 142 of the second control units 140 is connected to the timing driving circuit 11 to receive the clock signal. Each of the output ends 123 of the first control subunit 120 and the output ends 143 of the second control subunit 140 is connected with a respective gate of the transistor of the corresponding pixel unit, and control ends 121 of the plurality of first control subunit 120 are electrically connected with each other, the control ends 141 of plurality of the second control subunit 140 are also electrically connected with each other. That is, each of the control ends 121 of the first control subunits 120 of the first control unit 12 receives a first control signal and each of the control ends 141 of the second control subunits 140 of the second control unit 14 receives a second control signal. Alternatively, the clock signal is a high-level clock signal CKH which is provided by the timing driving circuit 11.
In the driving circuit of the embodiment of the present disclosure, the first control unit 12 receives the first control signal through the control end 121 to turn on or off the first control unit 12 and the second control unit 14 receives the second control signal through the control end 141 to turn on or off the second control unit 14. When each control subunit of the first control unit 12 and the second control unit 14 is turned on, the display device is driven by the clock signal in a bilateral driving method in the driving circuit of the embodiment of the present disclosure. When one control subunit of the first control unit 12 and the second control unit 14 is turned on and the other control subunit is turned off, the display device is driven by the clock signal in an unilateral driving method. In this way, the driving circuit according to the embodiments of the present disclosure enables switching between a unilateral driving method and a bilateral driving method of the clock signal for the display device by the first control signal and the second control signal.
As each of the control subunits of the two control units in the driving circuit in the embodiment is configured to turn on or off the driving circuit, each of the control subunits can be a diode, a transistor, and a transfer gate, etc. The specific form of the control subunit is not defined in the embodiment as long as the control subunit can be used to turn on or off the driving circuit. Alternatively, the control subunit includes a transfer gate and an inverter.
Alternatively, the display device also includes an external flexible circuit board. The control ends 121 of the plurality of control subunits 120 of the first control unit 12 are connected with a first control signal line disposed on the external flexible circuit board and the control ends 141 of the plurality of control subunits of the second control unit 14 are connected with a second control signal line disposed on the external flexible circuit board. The first control signal line and the second control signal line individually receive the control signal respectively. As the first control signal line connected with each of control ends 121 of the plurality of control subunits 120 of the control unit 12 is provided on the external flexible circuit board, the first control unit 12 can be turned on or off easily and conveniently by the external flexible circuit board, such that the first source driving circuit 17 is turned on or off. Correspondingly, as the second control signal line connected with each of control ends 141 of the plurality of control subunits 140 of the control unit 14 is also provided on the external flexible circuit board, the second source driving circuit 19 can also be turned on or off by the external flexible circuit board. As such, the driving of each of the pixels in the display device by the clock signal in the unilateral driving method or in the bilateral driving method can be controlled easily and conveniently through the external flexible circuit board. After the masking design of the display device has been contracted to be manufactured, if the driving method of the CKH for the display device needs to be switched to reduce the value of electromagnetic interference, it can be realized by providing the first control signal line and the second control signal line on the external flexible circuit board, thereby reducing the cost of switching between unilateral driving and bilateral driving for the CHK and improving the working efficiency.
The two control units and the two transistor units are used to connect with the timing driving circuit and the two source driving circuits in present embodiment, such that the display device is driven by the CKH signal in the unilateral driving method or in the bilateral driving method. The control units and the transistor units are both disposed in non-display region of the display device.
As can be seen in
In this way, the transition time value of the clock signal at nodes in a unilateral driving circuit and in a bilateral driving circuit sufficiently illustrates that the value of electromagnetic interference in the unilateral driving circuit is relatively smaller than that in the bilateral driving circuit. Furthermore, the value of electromagnetic interference of the circuit can also be changed by adjusting the clock signal of the control unit.
According to the driving circuit of the display device provided in the embodiment of the present disclosure, by adding two control units between the timing driving circuit and each of two source driving circuits and disposing the control signal lines of the control unit on the external flexible circuit board, the driving method of the CHK signal is easily and conveniently switched by the external flexible circuit board to be either a unilateral driving method or a bilateral driving method.
The embodiment of the present disclosure also provides a display device including the driving circuit according to any embodiment of the present disclosure,
An embodiment of the present disclosure also provides a method for driving a display device in order to facilitate unilateral-bilateral driving switching of a clock signal in driving circuit in the embodiment of the present disclosure.
Step 201, providing a clock signal to a first control unit and a second control unit, respectively.
A timing driving circuit provides the clock signal to the first control unit and the second control unit, respectively. When the driving method in the embodiment is used to reduce the problem of degraded quality of the image caused by electromagnetic interference in the display device, the clock signal is a CKH signal.
Step 202, turning off the first control unit or the second control unit by a control signal when the value of electromagnetic interference in the display device exceeds a predetermined electromagnetic interference threshold value.
After the display device is sealed, the value of electromagnetic interference inside the display device will be measured so as to select a proper driving method for the display device based thereon. When the display device is operated under different working conditions, the value of electromagnetic interference varies. If the display device is operating in a specific condition and the value of electromagnetic interference inside the display device exceeds the predetermined electromagnetic interference threshold value, the driving method of the clock signal is switched to a unilateral driving method.
Particularly, when the value of electromagnetic interference caused by the clock signal of the first control unit to the display device is larger than the value of electromagnetic interference caused by the clock signal of the second control unit to the display device, the first control unit is turned off. When the value of electromagnetic interference caused by the clock signal of the second control unit to the display device is larger than the value of electromagnetic interference caused by the clock signal of the first control unit to the display device, the second control unit is turned off. For example, where there is a speaker or an electrical line adjacent to the first source driving circuit, the value of electromagnetic interference in the display device caused by the first source driving circuit is larger than the value of electromagnetic interference value in the display device caused by the second source driving circuit, the first control unit should be turned off at this time. Or, when the first control unit and the second control unit are in the same environment and it is difficult to determine which one should be turned off, the first control unit and the second control unit are separately turned off, and the value of electromagnetic interference in the display device is measured each time. The driving method with a relatively small value of electromagnetic interference will be selected, i.e., the control unit corresponding to a relatively small value of electromagnetic interference is turned on and the control unit corresponding to a relatively large value of electromagnetic interference is turned off.
In an exemplary embodiment, when the control subunit includes a transfer gate and an inverter, if a gate of P-type thin film field effect transistor directly receives a control signal, the control unit corresponding to the control signal is turned on when the control signal is in high level and the control unit corresponding to the control signal is turned off when the control signal is in low level. If a gate of N-type thin film field effect transistor directly receives the control signal, the control unit corresponding to the control signal is turned off when the control signal is in high level and the control unit corresponding to the control signal is turned on when the control signal is low-level.
According to the driving switching method provided by the embodiment of the present disclosure, it is capable of utilizing the driving circuit according to any embodiment of the present disclosure to switch the driving method of the clock signal to a unilateral driving method or to a bilateral driving method. According to the driving switching method of the embodiment of the present disclosure, as turning on or off of the first control unit and the second control unit can be achieved only by the control signal received by the first control signal line and the second control signal line provided on the external flexible circuit board, the driving method for the clock signal can be controlled by altering the external flexible circuit board.
As can be appreciated, the embodiments described above are not exhaustive descriptions of all embodiments of the present disclosure. Although specific embodiments of the present disclosure are described, the disclosure is not limited to these embodiments. Various modifications and variations may be made on the technical solutions of the present disclosure by those skilled in the art in light of the methods and circuits, and other technical contents described above without departing from the scope of the disclosure, or equivalent embodiments with equivalent modifications may be obtained. In this way, any simple modifications, equivalent variations and modifications made to the embodiments based on the essence of the technical solution without departing the scope of the technical solutions of the present disclosure are intended to fall within the scope of this disclosure.
Number | Date | Country | Kind |
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201310754285.3 | Dec 2013 | CN | national |