TWI457906B - Saving circuit area of ​​the display panel drive circuit - Google Patents

Description

Driving circuit for display panel saving circuit area

The present invention relates to a driving voltage, and more particularly to a driving circuit for a display panel that saves circuit area.

According to the current development of technology, the variety of information products has been updated to meet the different needs of the public. Most of the early displays were cathode ray tube (CRT) displays, which were bulky and power-hungry, and the radiation generated was a serious concern for users who used the display for a long time. Today's displays on the market will gradually replace the old CRT monitors with liquid crystal displays (LCDs). Liquid crystal displays have the advantages of being thin and light, low in radiation and low in power consumption, and thus have become the mainstream in the current market.

Furthermore, with the rapid leap forward in panel production technology in recent years, the production cost of touch panels has been greatly reduced. Therefore, touch panels have been widely used in general consumer electronic products, such as mobile phone handsets. Small electronic devices such as digital cameras, digital music players (MP3), personal digital assistants (PDAs), and satellite navigation devices (GPS). On these electronic products, the touch panel is configured on the display screen of the electric appliance to allow Users can perform interactive input operations, greatly improving the user-friendliness of the communication interface between people and machines, and improving the efficiency of input operations.

In order to solve a wide range of power supplies in the application of a single power source for mobile phones Supply specifications, such as 2.3V ~ 4.6V, and reduce the area of the driver chip driving the display panel, and propose a driving method that can simultaneously meet the two requirements. The data driver of the general display device drives the display panel by using an operational amplifier (Op-amp) or a resistor divider. Furthermore, the single-chip liquid crystal driver chip module has become an important trend in order to make the mechanism smaller and better, and to improve the assembly yield and reduce the module cost.

Please refer to the first figure, which is a driving circuit of a display panel of the prior art. As shown, the drive circuit 1' includes a complex digital analog conversion circuit 10' and a complex drive unit 20'. The digital analog conversion circuit 10' receives an input pixel data, converts the input pixel data into a pixel signal, and transmits the pixel signal to the driving unit 20' to generate a driving signal, and the driving unit 20' The driving signal is transmitted to the display panel 2' for the display panel 2' to display a picture. Wherein, the driving circuit 1' of the prior art externally connects one boosting circuit 30' in the liquid crystal driving chip module, and in order to maintain the output signal level of the digital analog conversion circuit 10', the boosting circuit 30' needs to be coupled. A storage capacitor 40'. However, the capacitance of the storage capacitor 40' is large (about 0.1 uF), so the storage capacitor 40' needs to use an external liquid crystal to drive the capacitor component in the chip module, thereby causing an increase in manufacturing cost. In the drive circuit 1', the area of the drive circuit 1' is increased.

Therefore, how to solve the above problem and propose a novel driving circuit for saving the circuit area of the display panel, which can reduce the area occupied by the storage capacitor externally connected to the driving circuit, and even eliminate the storage capacitance in the external liquid crystal driving chip module, so that Can solve the above problems.

One of the objects of the present invention is to provide a display panel that saves circuit area. The driving circuit provides a supply voltage to a plurality of driving units of the display panel by the plurality of boosting units to reduce the external storage capacitor area, and even saves the storage capacitor in the external liquid crystal driving chip module, thereby saving The purpose of the circuit area.

The driving circuit of the display panel for saving circuit area of the present invention comprises a complex digital analog conversion circuit, a complex driving unit and a complex boosting unit. The digital analog conversion circuits respectively convert an input pixel data to generate a pixel signal, and the driving units are respectively coupled to the digital analog conversion circuits, generate a driving signal according to the pixel signal, and transmit the driving signal to The display panel, the display screen, and the boosting units are respectively coupled to the driving units, and generates a supply voltage according to a control signal, and respectively supplies the supply voltage to the driving units. Therefore, the present invention provides a plurality of driving units for supplying a voltage to a display panel by the boosting units, so as to reduce the external storage capacitor area, even without the storage capacitors in the external liquid crystal driving chip module. Save the circuit area for the purpose.

Conventional technology:

1'‧‧‧ drive circuit

10'‧‧‧Digital Analog Conversion Circuit

20’‧‧‧Drive unit

30'‧‧‧Boost circuit

40'‧‧‧ Storage Capacitor

this invention:

1‧‧‧Data Drive Circuit

10‧‧‧珈玛电路

2‧‧‧ display panel

20‧‧‧Drive circuit

200‧‧‧Digital analog conversion circuit

202‧‧‧ drive unit

204‧‧‧Boost unit

3‧‧‧ pixel structure

30‧‧‧Boost circuit

32‧‧‧ Storage Capacitor

300‧‧‧resistance

302‧‧‧ Capacitance

40‧‧‧Boost unit

400‧‧‧ flying capacitor

402‧‧‧First transistor

404‧‧‧Second transistor

406‧‧‧ Third transistor

408‧‧‧ fourth transistor

410‧‧‧ Storage Capacitor

50‧‧‧ drive unit

52‧‧‧Drive unit

60‧‧‧Image memory

70‧‧‧Boost unit

700‧‧‧Control transistor

702‧‧‧ diode

704‧‧‧Storage inductance

706‧‧‧ output capacitor

The first figure is a driving circuit of a display panel of the prior art; the second figure is a block diagram of a data driving circuit of a preferred embodiment of the present invention. The third figure is a parasitic RC equivalent circuit of the source line of the display panel of the present invention; the fourth figure is a circuit diagram of the driving circuit of a preferred embodiment of the present invention; and the fifth figure is another The circuit diagram of a driving circuit of a preferred embodiment; the sixth drawing is a circuit diagram of a driving circuit according to another preferred embodiment of the present invention; and the seventh drawing is a circuit diagram of a boosting unit according to a preferred embodiment of the present invention. The eighth drawing is a circuit diagram of a boosting unit according to another preferred embodiment of the present invention; and the ninth drawing is a circuit diagram of a boosting unit according to another preferred embodiment of the present invention.

In order to provide a better understanding and understanding of the structural features and the achievable effects of the present invention, please refer to the preferred embodiments and the detailed descriptions as follows: please refer to the second figure, which is A block diagram of a data driving circuit of a preferred embodiment of the invention. As shown, the data driving circuit 1 includes a gamma circuit 10 and a driving circuit 20. The gamma circuit 10 generates a plurality of input signals according to a gamma curve, the input signals are voltage signals of different levels, and the gamma circuit 10 transmits the input signals to the driving circuit 20, and the driving circuit 20 is respectively based on the complex input. The pixel data and the input signals generate a plurality of driving signals, and the driving signals are transmitted to a display panel 2 to drive the display panel 2 to display a picture.

In addition, please refer to the third figure together, which is a parasitic RC equivalent circuit of the source line of the display panel of the present invention. As shown, a preferred embodiment of the present invention is applied to a display panel 2 which is a thin film transistor liquid crystal display (TFT-LCD). The display panel 2 includes a plurality of pixel structures 3 respectively coupled to the plurality of driving units 202 of the driving circuit 20 (as shown in the fourth figure), and the pixels on each source line in the display panel 2 The structure 3 is a Thin-Flim Transistor (TFT), and the pixel structure 3 can be equivalent to a resistor 300 connected in series to a capacitor 302. This is a technique well known to those skilled in the art, and therefore will not be repeated here.

Please refer to the fourth figure, which is a circuit diagram of a driving circuit according to a preferred embodiment of the present invention. As shown, the drive circuit 20 of the display panel for saving circuit area of the present invention includes a complex digital analog conversion circuit 200, a complex drive unit 202, and a complex boost unit 204. The digital analog conversion circuit 200 converts the input pixel data into a single pixel signal, that is, each of the digital analog conversion circuits 200. The digital analog conversion circuit 200 receives the input pixel data and converts the input pixel data into a pixel signal. The driving units 202 are respectively coupled to the digital analog conversion circuits 200. The driving units 202 generate a driving signal according to the pixel signals, and the driving units 202 transmit driving signals to the display panel 2 for display. The panel 1 displays a screen. In this embodiment, the driving units 202 amplify the pixel signals output by the digital analog conversion circuits 200 to generate a driving signal. The boosting units 204 are respectively coupled to the driving units 202, and the boosting units 204 generate a supply voltage according to a control signal, and the boosting units 204 respectively provide the supply voltages to the The driving unit 202 is configured to generate a driving signal to drive the display panel 2 to display a picture, wherein the driving units 202 are an operational amplifier (OPA). Thus, the present invention provides the supply voltage to the driving units 202 of the display panel 2 by the boosting units 204, respectively, to reduce the external storage capacitor area, and even does not require the storage capacitors in the external liquid crystal driving chip module. And to achieve the purpose of saving circuit area. The control signals received by the driving units 202 can generate control signals from any of the internal control circuits of the display panel 2, and transmit control signals to the boosting units 204, which are generally known in the art. Well-known techniques, so I won't go into details here.

In addition, the driving circuit 20 of the display panel 2 of the present invention is further coupled to a boosting circuit 30. The boosting circuit 30 is coupled to the digital analog converting circuit 200, and the boosting circuit 30 generates the supply voltage. The supply voltage is supplied to the digital analog conversion circuits. Further, the boost circuit 30 is further coupled to a storage capacitor 32 to stabilize the supply voltage output by the boost circuit 30. However, due to the power required by the drive units 202, The power supply that accounts for most of the drive circuit 20 can also be used to boost the power The capacitance of the storage capacitor 32 required by the path 30 is much smaller, so that the area of the storage capacitor can be much reduced, thereby enabling the drive circuit 20 to save circuit area. Moreover, the present invention can save the area of the overall driving circuit 20 by more than 50%.

In addition, since the boosting unit 204 provides the supply voltage to the driving units 202 of the display panel 2, the area of the storage capacitor 32 can be saved much, and the storage capacitor in the liquid crystal driving chip module is not needed. In this way, the booster circuit 30 can be disposed in the drive circuit 20 (not shown).

Please refer to FIG. 5, which is a circuit diagram of a driving circuit according to another preferred embodiment of the present invention. As shown in the figure, the embodiment is different from the above embodiment in that the boosting unit 40 of the present embodiment not only supplies voltage to a single driving unit, but also provides voltage to two or three driving units. As shown in FIG. 5, the boosting unit 40 of the present embodiment is coupled to a first driving unit 50 and a second driving unit 52, and the boosting unit 40 generates a supply voltage to the first driving unit 50 and the second. The driving unit 52 is configured to provide the power required by the first driving unit 50 and the second driving unit 52. Thus, the present invention can reduce the external storage capacitor area, even without the storage capacitor in the external liquid crystal driving chip module. Save the circuit area for the purpose. At the same time, the number of driving units can be reduced, thereby achieving the purpose of saving circuit area and saving cost. In addition, the boosting unit 40 of the embodiment may be disposed on the upper boundary of the side of the driving units 50, 52 and located above the image memory 60.

Please refer to the sixth drawing, which is a circuit diagram of a driving circuit according to another preferred embodiment of the present invention. As shown in the figure, the embodiment is different from the embodiment of the fifth embodiment in that the boosting unit 40 of the present embodiment can provide multiple sets of driving unit power supplies by a group of boosting units, and the dispersion is increased to at least one group of boosting units. Power is supplied to a group of driving units (such as the boosting unit 204 shown in FIG. 4), and therefore, the circuit of the boosting unit 40 can be driven The circuits of the moving units 50, 52 are commonly disposed between the source driving circuit 20 side wafer (IC) boundary and the image memory 60.

Please refer to the seventh figure, which is a circuit diagram of a boosting unit according to a preferred embodiment of the present invention. As shown in the figure, the boosting unit 40 of the present invention can be a capacitive boosting circuit, and the boosting unit 40 includes a flying capacitor 400, a first transistor 402, a second transistor 404, and a third battery. The crystal 406, a fourth transistor 408 and a storage capacitor 410. The first capacitor 410 is coupled to one end of the flying capacitor 400, and the other end of the first transistor 402 receives an input voltage V _IN and is controlled by a first control signal XA. The second transistor 404 is coupled to the first capacitor 402 and controlled by a second control signal XB to output a supply voltage. One end of the third transistor 406 is coupled to the other end of the flying capacitor 400. The other end of the third transistor 406 receives the input voltage V _IN and is controlled by the second control signal XB. One end of the fourth transistor 408 is coupled to the flying capacitor 400 and the third transistor 406, and the fourth transistor 408 is another. One end is coupled to a ground and controlled by the first control signal XA, and one end of the storage capacitor 410 is coupled to the second transistor 404, and the other end of the storage capacitor 410 is coupled to the ground to store and output the supply voltage. In this way, after receiving the input voltage V _IN , the boosting unit 40 of the embodiment controls the first to fourth transistors 402 to 408 by using the first control signal XA and the second control signal XB to generate a supply voltage and output to Drive unit 50, 52.

Please refer to the eighth figure, which is a circuit diagram of a boosting unit according to another preferred embodiment of the present invention. As shown in the figure, the difference between the embodiment and the embodiment of the seventh embodiment is that the boosting unit 40 of the present embodiment does not need to use the storage capacitor 410. Since the boosting unit 40 of the present invention is used to provide the driving unit 50, The supply voltage of 52, while the drive units 50, 52 only need to drive the panel (such as the display panel 2 shown in the fourth figure), which is not The digital analog conversion circuit (such as the digital analog conversion circuit 200 shown in FIG. 4) maintains the function of the accurate reference voltage, so that the power supply can be greatly oscillated without the storage capacitor. Therefore, the boosting unit of this embodiment 40 can only use the flying capacitor 400 to generate the supply voltage, without the need to store the capacitor, can be used to supply the power required by the driving units 50, 52, and can reduce the circuit area to achieve cost reduction.

Please refer to the ninth figure, which is a circuit diagram of a boosting unit according to another preferred embodiment of the present invention. As shown in the figure, the boosting unit 70 of the present embodiment is different from the boosting unit 40 of the seventh and eighth embodiments in that the boosting unit 70 of the present embodiment is an inductive boosting unit. The boosting unit 70 of the embodiment includes a control transistor 700, a diode 702, a storage inductor 704 and an output capacitor 706. One end of the control transistor 700 receives the input voltage V _IN and is controlled by a control signal VC. One end of the diode 702 is coupled to the control transistor 700, and the other end of the diode 702 is coupled to the ground, and the storage inductor 704 is coupled. The control transistor 700 and the diode 702 are connected to store the input voltage V _IN , and one end of the output capacitor 706 is coupled to the storage inductor 704 , and the other end of the output capacitor 706 is coupled to the ground to store the input voltage V _IN . The energy is generated and supplied to the drive units 50, 52.

In summary, the driving circuit of the display panel for saving circuit area of the present invention converts an input pixel data by a complex digital analog conversion circuit to generate a pixel signal, and the plurality of driving units are respectively coupled to the digital analog conversion circuits. Amplifying the pixel signal to generate a driving signal, and transmitting the driving signal to the display panel to display a picture, and the plurality of boosting units are respectively coupled to the driving units, and generating a signal according to a control signal The voltage is supplied and the supply voltage is separately supplied to the drive units. Thus, the present invention provides a supply by the boosting units respectively. The voltage is applied to the plurality of driving units of the display panel to reduce the area of the external storage capacitor, and even the storage capacitor in the external liquid crystal driving chip module is not needed, thereby achieving the purpose of saving the circuit area.

The invention is a novelty, progressive and available for industrial use, and should meet the requirements of the patent application stipulated in the Patent Law of China, and the invention patent application is filed according to law, and the prayer bureau will grant the patent as soon as possible. prayer.

However, the above description is only a preferred embodiment of the present invention, and is not intended to be used. Limiting the scope of the practice of the invention, the shape described in the scope of the patent application of the present invention Equivalent changes and modifications of the structure, features, and spirits are all included in the scope of the present invention.

2‧‧‧ display panel

20‧‧‧Drive circuit

200‧‧‧Digital analog conversion circuit

202‧‧‧ drive unit

204‧‧‧Boost unit

3‧‧‧ pixel structure

30‧‧‧Boost circuit

32‧‧‧ Storage Capacitor

300‧‧‧resistance

302‧‧‧ Capacitance

Claims (14)

A driving circuit for saving a circuit area of a display panel, comprising: a complex digital analog conversion circuit, which respectively converts an input pixel data to generate a pixel signal; and a plurality of driving units respectively coupled to the digital analog conversion circuits, The pixel signal generates a driving signal, and transmits the driving signal to the display panel to display a picture; and a plurality of boosting units respectively coupled to the driving units, and generates a supply voltage, and respectively provides the supply Voltage to the drive units. The driving circuit of claim 1, wherein the boosting units generate the supply voltage according to a control signal. The driving circuit of claim 2, wherein any control circuit inside the display panel generates the control signal and transmits the control signal to the boosting units. The driving circuit of claim 1, further comprising: a boosting circuit coupled to the digital analog conversion circuits, the boosting circuit generating and supplying the supply voltage to the digital analog conversion circuits. The driving circuit of claim 1, further coupled to a boosting circuit coupled to the digital analog conversion circuit, the boosting circuit generating and providing the supply voltage to the digital analog conversion circuits. The driving circuit of claim 1, wherein the display panel comprises a plurality of pixel structures, and the pixel structures are respectively coupled to the driving units. The driving circuit of claim 1, wherein the driving units are an operational amplifier (OPA). A driving circuit as described in claim 1, which is applied to a data driving circuit of the display panel. The driving circuit of claim 1, wherein the display panel is a thin film transistor liquid crystal display (TFT-LCD). A driving circuit for saving a circuit area of a display panel, comprising: a complex digital analog conversion circuit, which respectively converts an input pixel data to generate a pixel signal; and a plurality of driving units respectively coupled to the digital analog conversion circuits, The pixel signal generates a driving signal, and transmits the driving signal to the display panel to display a picture; and at least one boosting unit coupled to the driving units, generates a supply voltage, and supplies the supply voltage To some of the drive units of the drive units. The driving circuit of claim 10, wherein the boosting unit generates the supply voltage according to a control signal. The driving circuit of claim 10, wherein the boosting unit comprises: a flying capacitor for generating the supply voltage; and a first transistor having one end coupled to one end of the flying capacitor and the other end receiving An input voltage is controlled by a first control signal; a second transistor coupled to the flying capacitor and the first transistor, and controlled by a second control signal to output the supply voltage; a third transistor having one end coupled to the other end of the flying capacitor, the other end receiving the input voltage and controlled by the second control signal; and a fourth transistor coupled to the flying capacitor and the first end Three transistors, the other end The ground is coupled to the ground and controlled by the first control signal. The driving circuit of claim 12, wherein the boosting unit further comprises: a storage capacitor, one end of which is coupled to the second transistor, and the other end of which is coupled to the ground to store and output the supply voltage . The driving circuit of claim 10, wherein the boosting unit comprises: a transistor, one end of which receives an input voltage and is controlled by a control signal; and a diode having one end coupled to the electric The other end of the crystal is coupled to a ground end; a storage inductor coupled to the transistor and the diode to store energy of the input voltage; and an output capacitor coupled to the storage inductor at one end and coupled to the other end The ground terminal outputs the energy of the input voltage and generates the supply voltage.