TWI493530B - Display system and drive voltage generating device of the same - Google Patents

Description

Display system and driving voltage generating device thereof

The present invention relates to a driving technique, and more particularly to a display system and a driving voltage generating device therefor.

The display system is the most intuitive output interface in various electronic devices such as desktop computers, notebook computers, smart phones and tablets. By means of the display system, the user can easily know the state of the electronic device or the calculation result generated according to the input.

In a general liquid crystal or its related display system, different modules or components often provide different voltages and currents by a high voltage reference voltage generating module or a low voltage reference voltage generating module due to different voltages required. . However, since the high-voltage reference voltage generating module needs to be driven at a higher voltage, it takes a period of time for the driving voltage to climb to a higher level immediately after the system is started, so that a stable reference voltage can be generated accordingly. Reference current. During this time, the associated circuit will not function properly because the connected module cannot capture this current. Under certain circumstances, the inability to draw current will cause the floating state of the relevant circuit, and it is easy to be affected by noise to generate a large current and thus damage the circuit.

So how to design a new display system and its drive voltage generation The device to solve the above problems is an urgent problem to be solved in the industry.

Accordingly, an aspect of the present invention provides a driving voltage generating apparatus including: a high reference voltage generating circuit, a low reference voltage generating circuit, a current input control circuit, and a driving voltage generating circuit. The high reference voltage generating circuit generates a first reference current and a first reference voltage according to the first supply voltage, wherein the first supply voltage stabilizes the first reference current after the first settling time from the start. The low reference voltage generating circuit generates a second reference current and a second reference voltage according to the second supply voltage that is less than the first supply voltage, wherein the second supply voltage is from the start to the second stable time after the second reference current is stabilized A stable time is short. The current input control circuit is coupled to the high reference voltage generating circuit and the low reference voltage generating circuit to generate an output reference current according to the first reference current and/or the second reference current. The driving voltage generating circuit is configured to generate a driving voltage according to the output reference current. Before the first settling time, the current input control circuit generates the output reference current only according to the second reference current or simultaneously generates the output reference current according to the first reference current and the second reference current. After the first settling time, the current input control circuit generates an output reference current based on at least the first reference current.

According to an embodiment of the invention, the low reference voltage generating circuit further includes a current mirror for outputting the second reference current to the current input control circuit in a proportional relationship.

According to another embodiment of the present invention, the driving voltage generating device further includes: a first switching switch and a second switching switch. The first switch is connected to the high reference voltage generating circuit and the current input control circuit for the first stable time The first reference current is stopped before being output to the current input control circuit, and the first reference current is output to the current input control circuit after the first stabilization time. The second switch is connected to the low reference voltage generating circuit and the current input control circuit to output the second reference current to the current input control circuit before the first settling time, and to stop outputting the second reference current after the first settling time Current input control circuit. The low reference voltage generating circuit further includes a current mirror for outputting the second reference current to the current input control circuit in a proportional relationship.

According to still another embodiment of the present invention, the first reference voltage and the second reference voltage are output to the power control circuit such that the power control circuit operates according to the first reference voltage and the second reference voltage.

According to still another embodiment of the present invention, the current input control circuit generates an output reference current according to the input of the first reference current and the second reference current.

According to another embodiment of the present invention, the driving voltage is output to the channel driving module, and the channel driving module drives the display panel according to the driving voltage.

According to an embodiment of the invention, the driving voltage is output to the gamma voltage driving module, and the gamma voltage driving module drives the source driver according to the driving voltage.

Therefore, another aspect of the present invention provides a display system including: a display panel, a source driver and a gate driver, a driving amplification module, and a driving voltage generating device. The driving amplification module includes a plurality of driving amplifiers for driving the source driver and/or the display panel according to the driving voltage. The driving voltage generating device includes: a high reference voltage generating circuit, a low reference voltage generating circuit, a current input control circuit, and a driving voltage generating electricity road. The high reference voltage generating circuit generates a first reference current and a first reference voltage according to the first supply voltage, wherein the first supply voltage stabilizes the first reference current after the first settling time from the start. The low reference voltage generating circuit generates a second reference current and a second reference voltage according to the second supply voltage that is less than the first supply voltage, wherein the second supply voltage is from the start to the second stable time after the second reference current is stabilized A stable time is short. The current input control circuit is coupled to the high reference voltage generating circuit and the low reference voltage generating circuit to generate an output reference current according to the first reference current and/or the second reference current. The driving voltage generating circuit is configured to generate a driving voltage according to the output reference current. Before the first settling time, the current input control circuit generates the output reference current only according to the second reference current or simultaneously generates the output reference current according to the first reference current and the second reference current. After the first settling time, the current input control circuit generates an output reference current based on at least the first reference current.

According to an embodiment of the invention, the low reference voltage generating circuit further includes a current mirror for outputting the second reference current to the current input control circuit in a proportional relationship.

According to another embodiment of the present invention, the driving voltage generating device further includes: a first switching switch and a second switching switch. The first switch is connected to the high reference voltage generating circuit and the current input control circuit to stop outputting the first reference current to the current input control circuit before the first settling time, and output the first reference current to the first settling time after the first settling time Current input control circuit. The second switch is connected to the low reference voltage generating circuit and the current input control circuit to output the second reference current to the power before the first settling time And inputting the control circuit, and stopping the output of the second reference current to the current input control circuit after the first stabilization time. The low reference voltage generating circuit further includes a current mirror for outputting the second reference current to the current input control circuit in a proportional relationship.

According to still another embodiment of the present invention, the first reference voltage and the second reference voltage are output to the power control circuit such that the power control circuit operates according to the first reference voltage and the second reference voltage.

According to still another embodiment of the present invention, the current input control circuit generates an output reference current according to the input of the first reference current and the second reference current.

According to another embodiment of the present invention, the driving amplification module is a channel driving module to drive the display panel according to the driving voltage.

According to an embodiment of the invention, the driving amplification module is a gamma voltage driving module to drive the source driver according to the driving voltage.

The advantage of the application of the present invention is that by the design of the driving voltage generating device, when the supply voltage received by the high reference voltage generating circuit does not reach a stable state and cannot provide a stable reference current, the circuit can be assisted by a stable low reference voltage generating circuit. A certain amount of current is supplied in advance, so that the driving voltage generating circuit generates the driving voltage according to the driving voltage, and when the driving voltage is not provided, the corresponding circuit easily reaches the above state due to the high current burning caused by the noise interference in the floating state. The purpose.

1‧‧‧Display system

10‧‧‧ display panel

12‧‧‧Source Driver

14‧‧‧ Gate Driver

16‧‧‧Drive Amplifier Module

18‧‧‧Drive voltage generating device

200‧‧‧Drive Amplifier

202‧‧‧High reference voltage generation circuit

204‧‧‧Low reference voltage generation circuit

206‧‧‧ Current input control circuit

208‧‧‧Drive voltage generating circuit

210‧‧‧Power Control Circuit

30, 32‧‧‧current mirror

50‧‧‧First switch

52‧‧‧Second switch

1 is a block diagram of a display system in accordance with an embodiment of the present invention.

FIG. 2 is a block diagram of a driving amplification module and a driving voltage generating device further included in the display system according to an embodiment of the invention.

FIG. 3 is a circuit diagram of a high reference voltage generating circuit, a low reference voltage generating circuit, and a current input control circuit according to an embodiment of the present invention.

4 is a circuit diagram of a high reference voltage generating circuit, a low reference voltage generating circuit, and a current input control circuit in another embodiment of the present invention.

FIG. 5 is a circuit diagram of a high reference voltage generating circuit, a low reference voltage generating circuit, and a current input control circuit according to another embodiment of the present invention.

Figure 6 is a diagram showing the relationship between the output reference current and the first supply voltage in an embodiment of the present invention.

Please refer to Figure 1. 1 is a block diagram of a display system 1 in accordance with an embodiment of the present invention. The display system 1 includes a display panel 10, a source driver 12, and a gate driver 14.

The display panel 10 can include a plurality of pixel units (not shown) to form a pixel array. In one embodiment, the gate driver 14 can provide a signal for turning on the gate of the pixel unit to open the columns of pixels in a progressive scan manner, so that the data signal provided by the source driver 12 can be input to In the pixel unit, a display screen is generated accordingly. The display system 1 may further include other modules, such as but not limited to components such as a timing controller and a backlight module, in order to make the timing of the data input correctly and the display panel 10 to generate a display screen viewable by the user according to the light source. So that the display system 1 can operate accordingly.

Please also refer to Figure 2. FIG. 2 is a diagram showing a driving amplification module 16 and a driving voltage generating device further included in the display system 1 according to an embodiment of the invention. Set the block diagram of 18. The drive amplifier module 16 includes a complex drive amplifier 200 for driving the source driver 12 and/or the display panel 10 shown in FIG. 1 in accordance with the drive voltage Vdr. In one embodiment, the driving amplification module 16 can be a gamma voltage driving module to drive the source driver 12 of FIG. 1 according to the driving voltage Vdr. In one embodiment, the driving amplification module 16 can be a channel driving module disposed in the source driver 12 to drive the display panel 10 of FIG. 1 according to the driving voltage Vdr.

The driving voltage generating device 18 is configured to generate the driving voltage Vdr described above. In the present embodiment, the driving voltage generating device 18 includes a high reference voltage generating circuit 202, a low reference voltage generating circuit 204, a current input control circuit 206, and a driving voltage generating circuit 208.

In one embodiment, the high reference voltage generating circuit 202 and the low reference voltage generating circuit 204 are each a bandgap circuit. The high reference voltage generating circuit 202 generates the first reference current Ir1 and the first reference voltage Vr1 according to the first supply voltage VDDA. Wherein, after the first supply voltage VDDA is self-started, the first reference current Ir1 is stabilized by the first stabilization time.

The low reference voltage generating circuit 204 generates the second reference current Ir2 and the second reference voltage Vr2 according to the second supply voltage VDDD that is smaller than the first supply voltage VDDA. Wherein, after the second supply voltage VDDD is self-started, the second reference current Ir2 is stabilized by the second settling time. Since the second supply voltage VDDD is smaller than the first supply voltage VDDA, the second supply voltage VDDD reaches the target value faster and it brings the reference current to a stable second settling time, which will be shorter than the first settling time.

It should be noted that the term "stable" as used herein may refer to an operating area in which the generated current does not change with the supply voltage under normal operation of the system. For example, the system can generate a first supply voltage VDDA and a second supply voltage VDDD that are respectively greater than 9 volts and 3.3 volts without changing the current according to the system voltage by the power supply related circuit. Depending on the application, the first supply voltage VDDA and the second supply voltage VDDD can be set to a stable stabilization time by a time point at which the newly started 0 volts reaches 9 volts and 3.3 volts, respectively. In other embodiments, it is also possible to set the first supply voltage VDDA and the second supply voltage VDDD to a specific ratio of 9 volts and 3.3 volts, respectively, starting at 0 volts (eg, 90%, ie, 8.1 volts and 2.98 volts, respectively). At the point in time, it is considered to achieve a stable stabilization time. It is to be understood that, in various embodiments, the above-described voltage values, as well as the settings of the specific ratios, may be adjusted as appropriate without being limited by the above values.

The current input control circuit 206 is connected to the high reference voltage generating circuit 202 and the low reference voltage generating circuit 204 to generate an output reference current Iro according to the first reference current Ir1 and the second reference current Ir2. The driving voltage generating circuit 208 generates a driving voltage Vdr based on the output reference current Iro.

Wherein, before the first settling time, since the first supply voltage VDDA received by the high reference voltage generating circuit 202 has not reached a sufficient potential value, the first reference current Ir1 generated thereof will also be unstable, and is not sufficient to supply the driving. The voltage generating circuit 208 generates a stable driving voltage Vdr. Therefore, the current input control circuit 206 can be different before the first settling time. In an embodiment, the output reference current Iro is generated only according to the second reference current Ir2, or the output reference current Iro is generated according to the first reference current Ir1 and the second reference current Ir2, so as to prevent the first supply voltage VDDA from reaching stable state. , causing the first reference current Ir1 to be unstable. After the first settling time, the current input control circuit 206 will generate the output reference current Iro according to the first reference current Ir1 that has reached a stable state. On the other hand, the first reference voltage Vr1 and the second reference voltage Vr2 may be additionally output to a power control circuit 210 for controlling power on, off, and reset, so that the power control circuit 210 is based on the first reference voltage Vr1 and The second reference voltage Vr2 operates.

Please refer to Figure 3. 3 is a circuit diagram of a high reference voltage generating circuit 202, a low reference voltage generating circuit 204, and a current input control circuit 206 in accordance with an embodiment of the present invention.

In the present embodiment, the high reference voltage generating circuit 202 and the low reference voltage generating circuit 204 include current mirrors 30 and 32, respectively, to output the first and second reference currents Ir1 and Ir2 to the current input control circuit 206. The current mirrors 30 and 32 can be output in a proportional relationship by the channel parameter ratio (such as the aspect ratio: W/L) of the branch components on both sides. In the present embodiment, the current input control circuit 206 itself is also a current mirror for adding according to the input first and second reference currents Ir1 and Ir2, and generating an output reference current Iro.

Therefore, even before the first supply voltage VDDA received by the high reference voltage generating circuit 202 has not reached the stable first settling time, the output reference current Iro may not be too small due to the existence of the second reference current Ir2. Or unstable. In this embodiment, after the first supply voltage VDDA reaches a stable first stabilization time, the current input control circuit 206 can continue to generate the output reference current Iro according to the addition of the first and second reference currents Ir1 and Ir2.

It should be noted that the circuit shown in FIG. 3 is only an example. In other embodiments, other circuits may be used to achieve the same effect, and are not limited to the circuit shown in FIG.

Please refer to FIG. 4A, FIG. 4B and FIG. 4C. 4A is a diagram showing a relationship between a first reference current Ir1 and a first supply voltage VDDA according to an embodiment of the present invention. FIG. 4B is a diagram showing the relationship between the second reference current Ir2 and the second supply voltage VDDD according to an embodiment of the present invention. 4C is a diagram showing the relationship between the output reference current Iro and the first supply voltage VDDA in an embodiment of the present invention. Wherein, the output reference current Iro is generated according to the circuit architecture of FIG.

As can be seen from FIG. 4A, before the first supply voltage VDDA reaches the operation section A, the first supply voltage VDDA cannot stabilize the first reference current Ir1. In FIG. 4B, the second supply voltage VDDD quickly reaches the operation interval B, and a relatively stable second reference current Ir2 can be provided. Therefore, as shown in FIG. 4C, since the output reference current Iro is generated by the first reference current Ir1 and the second reference current Ir2, the output reference current Iro can be mainly driven by the second reference current Ir2 before the operation interval A. The voltage generating circuit 208 is used, and after the operation section A, the output reference current Iro is mainly used by the first reference current Ir1 to be supplied to the driving voltage generating circuit 208.

Please refer to Figure 5. Figure 5 is a high reference in another embodiment of the present invention Circuit diagrams of voltage generation circuit 202, low reference voltage generation circuit 204, and current input control circuit 206.

The driving voltage generating device 18 of the present embodiment further includes a first switching switch 50 and a second switching switch 52, as compared with the embodiment of FIG. The first changeover switch 50 is connected to the high reference voltage generation circuit 202 and the current input control circuit 206, and the second changeover switch 52 is connected to the low reference voltage generation circuit 204 and the current input control circuit 206.

Before the first settling time, the first switch 50 is in an open state, so that the first reference current Ir1 stops outputting to the current input control circuit 206, and the second switch 52 is turned on, so that the second reference current Ir2 The output is output to the current input control circuit 206. After the first stabilization time, the first switch 50 is turned on to output the first reference current Ir1 to the current input control circuit 206, and the second switch 52 is in an open state to stop the second reference current Ir2. The output is output to the current input control circuit 206.

Therefore, even before the first supply voltage VDDA received by the high reference voltage generating circuit 202 has not reached the stable first settling time, the output reference current Iro may not be too small or unstable due to the input of the second reference current Ir2. In this embodiment, after the first supply voltage VDDA reaches a stable first stabilization time, the current input control circuit 206 generates an output reference current Iro according to the first reference current Ir1. However, in another embodiment, after the first switching switch 50 and the second switching switch 52 are controlled, the current input control circuit 206 can also simultaneously according to the first reference current Ir1 and the second reference after the first stabilization time. The current Ir2 produces an output reference current Iro.

It should be noted that the circuit shown in FIG. 5 is only an example. In other embodiments, other circuits may be used to achieve the same effect, and are not limited to the circuit shown in FIG.

Please refer to Figure 6. Figure 6 is a diagram showing the relationship between the output reference current Iro and the first supply voltage VDDA in an embodiment of the present invention. Wherein, the output reference current Iro is generated according to the circuit architecture of FIG.

In this embodiment, before the first supply voltage VDDA reaches the operation interval A, due to the setting of the switching switch, the output reference current Iro may be provided only by the second reference current Ir2 outputted by the current mirror multiple (Ir2×N), The amount of current supplied by the second reference current Ir2 is made more sufficient, and after the first supply voltage VDDA reaches the operation section A, the output reference current Iro is supplied to the driving voltage generating circuit 208 by the first reference current Ir1.

The present disclosure has been disclosed in the above embodiments, but it is not intended to limit the disclosure, and any person skilled in the art can make various changes and refinements without departing from the spirit and scope of the disclosure. The scope of protection of the disclosure is subject to the definition of the scope of the patent application.

16‧‧‧Drive Amplifier Module

18‧‧‧Drive voltage generating device

200‧‧‧Drive Amplifier

202‧‧‧High reference voltage generation circuit

204‧‧‧Low reference voltage generation circuit

206‧‧‧ Current input control circuit

208‧‧‧Drive voltage generating circuit

210‧‧‧Power Control Circuit

Claims (8)

A driving voltage generating device includes: a high reference voltage generating circuit for generating a first reference current and a first reference voltage according to a first supply voltage, wherein the first supply voltage is first stabilized after being activated Time for stabilizing the first reference current; a low reference voltage generating circuit for generating a second reference current and a second reference voltage according to the second supply voltage less than the first supply voltage, wherein the second supply After the voltage is self-started until the second reference current reaches a stable state, the second settling time is shorter than the first settling time; a current input control circuit is configured to be connected to the high reference voltage generating circuit and the low reference voltage generating circuit And generating an output reference current according to the first reference current and/or the second reference current; and a driving voltage generating circuit for generating a driving voltage according to the output reference current; wherein before the first settling time, The current input control circuit generates the output reference current only according to the second reference current or simultaneously according to the first reference power The current and the second reference current generate the output reference current; after the first settling time, the current input control circuit generates the output reference current according to at least the first reference current. The driving voltage generating device of claim 1, wherein the low reference voltage generating circuit further comprises a current mirror for adjusting the ratio of the second reference current to the current input control circuit. The driving voltage generating device of claim 1, further comprising: a first switching switch for connecting the high reference voltage generating circuit and the current input control circuit to enable the first reference before the first settling time a current stop outputting to the current input control circuit, and outputting the first reference current to the current input control circuit after the first settling time; and a second switch for connecting the low reference voltage generating circuit and the The current input control circuit outputs the second reference current to the current input control circuit before the first settling time, and stops outputting the second reference current to the current input control circuit after the first settling time. The driving voltage generating device of claim 3, wherein the low reference voltage generating circuit further comprises a current mirror for adjusting the ratio of the second reference current to the current input control circuit. The driving voltage generating device of claim 1, wherein the first reference voltage and the second reference voltage are output to a power control circuit, so that the power control circuit is configured according to the first reference voltage and the second reference voltage Operate to control the opening, closing and resetting of a power source. The driving voltage generating device of claim 1, wherein the current input control circuit generates the output reference current according to the input of the first reference current and the second reference current. The driving voltage generating device of claim 1, wherein the driving voltage is output to a channel driving module, and the channel driving module drives a display panel according to the driving voltage. The driving voltage generating device of claim 1, wherein the driving voltage is output to a gamma voltage driving module, and the gamma voltage driving module drives a source driver according to the driving voltage.