Voltage regulation device for organic light emitting diode

Abstract

A voltage regulation device for an organic light emitting diode. The voltage regulation device comprises an operational amplifier and a voltage output circuit. The operational amplifier generates an output voltage. The voltage output circuit is coupled to the operational amplifier. The voltage output circuit is controlled by the selection signal to selectively utilize the first operation voltage interval or the second operation voltage interval to generate the control voltage. The voltage value of the control voltage is related to the reference voltage of the organic light emitting diode, and the selection signal is correspondingly generated according to the reference voltage of the organic light emitting diode.

Description

TECHNICAL FIELD

[0001] The present application relates to a driving technique of an organic light-emitting diode (OLED) and a voltage regulating device for an organic light-emitting diode. BACKGROUND

[0002] Currently, the main power consumption of consumer electronics is the power consumption of display screens. Therefore, how to make the display screen more power saving is one of the current research directions. Organic light-emitting diode (OLED) technology can self-luminescence and save the power consumption of the light-emitting backplane, so it is often used in the display screen of consumer electronics.

[0003] In order to adjust the overall brightness of the OLED display screen, the reference voltage coupled to one end of all OLED light-emitting units can be adjusted to achieve this. For example, the reference voltage is pulled down to the required negative voltage to make all OLED light-emitting units improve the overall brightness. The control voltage for making the OLED light-emitting unit not to emit light will need to maintain a fixed voltage difference with the aforementioned reference voltage. Therefore, the control voltage will also operate in the negative voltage range. However, when the reference voltage and the control voltage both operate in a higher negative voltage range, the regulator circuit providing the control voltage will correspondingly increase its power consumption due to the increase in the voltage range. SUMMARY

[0004] The present application provides a voltage regulating device for an organic light-emitting diode, which can reduce the power consumption of the voltage regulating device and still operate normally in a higher negative voltage operating range.

[0005] According to an embodiment of the present application, a voltage regulating device for an organic light-emitting diode includes an operational amplifier and a voltage output circuit. The operational amplifier generates an output voltage. The voltage output circuit is coupled to the operational amplifier. The voltage output circuit is controlled by a selection signal to selectively generate a control voltage using a first operating voltage range or a second operating voltage range. The voltage value of the control voltage is related to the reference voltage of the organic light-emitting diode, and the selection signal is correspondingly generated according to the reference voltage of the organic light-emitting diode.

[0006] According to an embodiment of the present application, a voltage regulating device for an organic light-emitting diode includes a first regulator, a second regulator, and a selector. The first regulator generates a first control voltage according to a first operating voltage range. The second regulator generates a second control voltage according to a second operating voltage range. The selector selectively uses the first control voltage or the second control voltage as a control voltage according to a selection signal. The voltage value of the control voltage is related to the reference voltage of the organic light-emitting diode, and the selection signal is correspondingly generated according to the reference voltage of the organic light-emitting diode.

[0007] Based on the above, the voltage regulation device for organic light-emitting diodes (OLEDs) dynamically switches the operating voltage range in the voltage regulation device through circuit structure design. This allows the voltage regulation device to selectively generate a control voltage to prevent the OLED from emitting light based on the reference voltage of the OLED, reducing the power consumption of the voltage regulation device. Furthermore, it can still provide the corresponding operating voltage normally when the reference voltage of the OLED is in a higher negative voltage operating range. Attached Figure Description

[0008] Figure 1 A schematic diagram illustrating an organic light-emitting diode (OLED) light-emitting unit, driving circuit, and voltage regulation device on a display device according to an embodiment of the present invention is shown.

[0009] Figure 2 Draw Figure 1 A schematic diagram of the reference voltage ELVSS and the control voltage VINITN used to prevent the OLED light-emitting unit from emitting light.

[0010] Figure 3 A schematic diagram illustrating the OLED display unit, driving circuit, and voltage regulation device according to a first embodiment of the present invention is shown.

[0011] Figure 4 A schematic diagram illustrating the waveforms of various signals in the voltage regulation device according to the first embodiment of the present invention is shown.

[0012] Figure 5 A schematic diagram illustrating the OLED display unit, driving circuit, and voltage regulation device according to a second embodiment of the present invention is shown.

[0013] Figure 6 A schematic diagram of the waveforms of each signal in the voltage regulation device according to the second embodiment of the present invention is shown.

[0014] Figure 7 A schematic diagram illustrating an OLED display unit, driving circuit, and voltage regulation device according to a third embodiment of the present invention is shown.

[0015] Figure 8 A schematic diagram illustrating the OLED display unit, driving circuit, and voltage regulation device according to a fourth embodiment of the present invention is shown.

[0016] Figure 9 A schematic diagram illustrating the OLED display unit, driving circuit, and voltage regulation device according to the fifth embodiment of the present invention is shown.

[0017] Figure 10 The diagram illustrates a circuit diagram that can be used as an operational amplifier in various embodiments of the present invention. Detailed Implementation

[0018] Reference will now be made in detail to exemplary embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same component reference numerals are used in the drawings and description to denote the same or similar parts.

[0019] Figure 1 This diagram illustrates a schematic representation of an organic light-emitting diode (OLED) light-emitting unit 110, a driving circuit 120, and a voltage regulation device 130 on a display device according to an embodiment of the present invention. The display device can be a display panel used in consumer electronic devices such as home televisions, mobile phones, smartwatches, tablet computers, and laptop computers. The driving circuit 120 drives the OLED light-emitting unit 110. This embodiment uses... Figure 1 The 6T1C structure is used as an example of the driving circuit 120. The driving circuit 120 can be a structure of 6 transistors combined with 1 capacitor (referred to as the 6T1C structure) or a structure of 8 transistors combined with 1 capacitor (referred to as the 8T1C structure). The user of this embodiment does not limit the circuit structure in the driving circuit 120.

[0020] To adjust the overall brightness of the display device, the reference voltage coupled to one end of all OLED light-emitting units 110 can be adjusted (e.g., Figure 1 The reference voltage ELVSS is used to achieve this. In this embodiment, the reference voltage ELVSS can be the emission light reference voltage signal VSS. For example, the reference voltage ELVSS can be lowered to a negative voltage (here, "negative medium voltage" is used as a substitute for "negative voltage") or even a higher negative voltage (here, "negative high voltage" is used as a substitute for "higher negative voltage") to brighten all OLED light-emitting units 110.

[0021] On the other hand, the driving circuit 120 uses the control voltage VINITN to prevent the OLED light-emitting unit 110 from emitting light. Figure 2 Draw Figure 1 A schematic diagram showing the reference voltage ELVSS and the control voltage VINITN used to prevent the OLED light-emitting unit 110 from emitting light. (Reference) Figure 2 When the reference voltage ELVSS is -6 volts (V), the OLED light-emitting unit 110 emits approximately 100 candela; when the reference voltage ELVSS is -9V, the OLED light-emitting unit 110 emits approximately 2000 candela. The control voltage VINITN, which prevents the OLED light-emitting unit 110 from emitting light, needs to maintain a fixed voltage difference with the reference voltage ELVSS (e.g., ...). Figure 2 (As shown by arrow 210) This is necessary to prevent the OLED light-emitting unit 110 from emitting light when the two ends of the OLED light-emitting unit 110 are respectively coupled to the reference voltage ELVSS and the control voltage VINITN. Figure 2The values ​​shown are for illustrative purposes only, and users of this embodiment may adjust them according to their needs. Figure 2 Any value in the range. For example, although Figure 2 In this embodiment, the voltage value of the control voltage VINITN is greater than the voltage value of the reference voltage ELVSS. However, in other embodiments, the voltage value of the control voltage VINITN may be less than or equal to the voltage value of the reference voltage ELVSS.

[0022] On the other hand, based on the voltage withstand capability, process components can be classified into process components corresponding to the negative low voltage range (e.g., 0V to -1.2V), the negative medium voltage range (0V to -8V), and the negative high voltage range (0V to -20V). Figure 2 Voltage range VR1 is located in the aforementioned negative medium voltage range, while voltage range VR2 is located in the aforementioned negative high voltage range. To ensure that the control voltage VINITN outputs a voltage value located in the aforementioned negative high voltage range, Figure 1 The voltage regulation device 130 needs to be implemented using process components capable of withstanding negative high voltage ranges, but process components capable of withstanding negative high voltage ranges are expensive, thus increasing costs. On the other hand, most use Figure 1 Display devices are not frequently used in bright light environments, in which case higher brightness, such as 2000 candela, is required. In indoor environments, display devices can often be used at low brightness (e.g., 100 to 200 candela), meaning that the reference voltage ELVSS is typically used in the negative medium voltage range.

[0023] Since the voltage regulator 130 providing the control voltage VINITN needs to support the voltage value in the aforementioned negative high-voltage range, it must not only be able to operate normally in the negative high-voltage range, but also operate normally in the negative high-voltage range. In this situation, when charging and discharging the display panel in the display device, based on the power formula (power is the product of current and voltage), the power consumption of the voltage regulator 130 operating in the negative high-voltage range will be much greater than the power consumption of the voltage regulator 130 operating in the negative medium-voltage range.

[0024] To enable the voltage regulating device 130 of the embodiments of the present application to reduce power consumption and still operate normally in a higher negative voltage operating range (i.e., a negative high voltage range), the voltage regulating device 130 is capable of dynamically adjusting its own operating voltage range in accordance with the voltage value of the control voltage VINITN to be output. For example, when the control voltage VINITN to be output is in the negative medium voltage range, the operating voltage range of the voltage regulating device 130 is correspondingly switched to the negative medium voltage range, thereby reducing power consumption. When the control voltage VINITN to be output is in the negative high voltage range, the operating voltage range of the voltage regulating device 130 is correspondingly switched to the negative high voltage range, thereby still operating normally in a higher negative voltage operating range and providing the required control voltage VINITN. The following embodiments in accordance with the spirit of the present application are presented to provide a detailed description.

[0025] Figure 3 A schematic diagram of the OLED display unit 310, the driving circuit 320, and the voltage regulating device 330 of the first embodiment of the present application is shown. Figure 3 The structure of the driving circuit 320 is simplified. One end of the OLED display unit 310 receives a reference voltage ELVSS. The driving circuit 320 mainly presents a parasitic capacitance Cp connected to the other end of the OLED display unit 310 and a switch SWT for receiving the control voltage VINITN. When charging and discharging the display device, the parasitic capacitance Cp at the other end of the OLED display unit 310 is usually charged and discharged, thereby affecting the overall power consumption of the display device.

[0026] The voltage regulating device 330 includes a first regulator 331, a second regulator 332, and a selector 333. The first regulator 331 generates a first control voltage VINITN1 according to a first operating voltage range. In detail, the first regulator 331 includes a first operational amplifier OP1 and an output stage circuit 331-2. The first operational amplifier OP1 generates a first output voltage at its two output terminals according to an input voltage VIN1. The output stage circuit 331-2 is coupled to the first operational amplifier OP1. The output stage circuit 331-2 includes transistors MN1 and MP1. The output stage circuit 331-2 generates the first control voltage VINITN1 according to the first output voltage generated by the first operational amplifier OP1, a first power voltage VPHV, and a first ground voltage VGHV. The first power voltage VPHV and the first ground voltage VGHV are related to the first operating voltage range. The first operating voltage range of the present embodiment can be the aforementioned negative high voltage range, and the first operational amplifier OP1 in the first regulator 331, the transistors MN1 and MP1 in the output stage circuit 331-2 all employ process components capable of withstanding the negative high voltage range. The first power voltage VPHV can be 0 V, and the first ground voltage VGHV can be -20 V. The first operational amplifier OP1 operates between the first power voltage VPHV and the first ground voltage VGHV.

[0027] The second regulator 332 generates a second control voltage VINITN2 according to a second operating voltage range. In detail, the second regulator 332 includes a second operational amplifier OP2 and an output stage circuit 332-2. The second operational amplifier OP2 generates a second output voltage at its two output terminals according to an input voltage VIN2. The output stage circuit 332-2 is coupled to the second operational amplifier OP2. The output stage circuit 332-2 generates the second control voltage VINITN2 according to the second output voltage generated by the second operational amplifier OP2, a second power voltage VPMV, and a second ground voltage VGMV. The second power voltage VPMV and the second ground voltage VGMV are related to the second operating voltage range. The second operating voltage range of the present embodiment can be the aforementioned negative medium voltage range and the second operational amplifier OP2 in the first regulator 332, the transistors MN2 and MP2 in the output stage circuit 332-2 can employ process components capable of withstanding the negative medium voltage range, without necessarily having to employ process components capable of withstanding the negative high voltage range. The second power voltage VPMV can be 0 V, and the second ground voltage VGMV can be -8 V. The second operational amplifier OP2 operates between the second power voltage VPMV and the second ground voltage VGMV.

[0028] The selector 333 selects one of the first control voltage VINITN1 and the second control voltage VINITN2 as the control voltage VINITN according to the selection signal SEL. The voltage value of the control voltage VINITN is related to the reference voltage ELVSS coupled to the OLED display unit 310, and the selection signal SEL can be generated accordingly according to the reference voltage ELVSS of the OLED display unit 310. The selector 333 can include switches SW1 and SW2 which are selectively turned on according to the selection signal SEL. Since the selector 333 needs to support the negative high voltage range, the switches SW1 and SW2 need to use process components that can withstand the negative high voltage range.

[0029] The voltage regulating device 330 of the present embodiment can simultaneously enable the first regulator 331 and the second regulator 332, and select one of the first control voltage VINITN1 and the second control voltage VINITN2 as the control voltage VINITN through the selector 333. In the case of simultaneously enabling the regulators 331 and 332, although both the regulators 331 and 332 have power consumption, since the static power consumption of the regulators 331 and 332 (the order of magnitude of power consumption is about 10-6) is much greater than the dynamic power consumption of the overall components of the voltage regulating device 330 (the order of magnitude of power consumption is about 10-3) which are all operating in the negative high voltage range, the simultaneous enablement of the regulators 331 and 332 can still save part of the power consumption.

[0030] The voltage regulating device 330 of the present embodiment can also selectively enable one of the regulators 331 and 332 according to the operating voltage range in which the control voltage VINITN is located, and turn off the other regulator 331 and 332 which is not needed, so as to save more power consumption. In the present embodiment, the voltage value of the control voltage VINITN is determined based on the reference voltage ELVSS and the voltage difference 210, so the voltage regulating device 330 or other circuits can adjust the voltage value of the control voltage VINITN generated by the voltage regulating device 330 by adjusting the reference voltage ELVSS, so as to generate the selection signal SEL accordingly, and selectively enable or turn off the regulators 331 and 332. Figure 2

[0031] Figure 4 The waveform diagram of the signals in the voltage regulating device 330 of the first embodiment of the present application is shown. Figure 4 The label 410 represents the driving timing of the display device, which is the display stage (for example, the display stage 411) for displaying a picture and the vertical blanking area (for example, the vertical blanking area 412) for switching the display picture. The signal Vsync of the present embodiment is the vertical synchronization signal of the display device, and has a pulse in the vertical blanking area 412. Please refer to the following description and the accompanying drawings.​Figure 3 With Figure 4 According to the required operating voltage range, one of the first control voltage VINITN1 and the second control voltage VINITN2 is selectively selected as the control voltage VINITN. For example, at time period 413, the voltage adjusting device 330 selects the second control voltage VINITN2 as the control voltage VINITN according to the selection signal SEL; at time period 414, the voltage adjusting device 330 selects the first control voltage VINITN1 as the control voltage VINITN according to the selection signal SEL.

[0032] To alleviate the possible voltage surge during the switching of the first regulator 331 and the second regulator 332, the first regulator 331 and the second regulator 332 can be enabled simultaneously during the whole time period, and the first control voltage VINITN1 and the second control voltage VINITN2 generated by the first regulator 331 and the second regulator 332 are required to be the same during the switching (e.g. time periods 415 and 416). In another embodiment according to the present application, the first regulator 331 and the second regulator 332 can also be switched in a non-overlapping manner during the time periods 415 and 416 to avoid the short circuit current within the circuit. That is, in one embodiment, the first regulator 331 and the second regulator 332 can be both turned off during the time periods 415 and 416, and the first regulator 331 is enabled after the time period 415, and the second regulator 332 is enabled after the time period 416. In the above case, the voltage value of the control voltage VINITN is maintained by the parasitic capacitance (e.g. the parasitic capacitance Cp of the display device) in the display device. Figure 3

[0033] During the non-consideration time period of the regulators 331 and 332 which are not selected by the selection signal SEL (e.g. the non-consideration time period 421 is the time period when the first regulator 331 is not selected; the non-consideration time period 422 is the time period when the second regulator 332 is not selected), the first regulator 331 in the time period 421 or the second regulator 332 in the time period 422 can be selected to be turned off to save power, or to be kept on to save the start-up time.

[0034] ​When switching the first regulator 331 and the second regulator 332 to provide the corresponding voltage, it is noted that the operating voltage range that the regulators 331 and 332 can provide are not the same, and the first operating voltage range (the negative high voltage range) corresponding to the first regulator 331 can include the second operating voltage range (the negative medium voltage range) corresponding to the second regulator 332. Therefore, it is required to use the first regulator 331 to boost or step down the control voltage VINITN in the first operating voltage range (the negative high voltage range) that exceeds the second operating voltage range (the negative medium voltage range), and when the control voltage VINITN is boosted or stepped down to be within the second operating voltage range (the negative medium voltage range), the switching from the first regulator 331 to the second regulator 332 is performed.

[0035] For example, when the control voltage VINITN is to be switched from the negative medium voltage range to a voltage within the negative high voltage range, the first control voltage VINITN1 provided by the first regulator 331 is switched to the second control voltage VINITN2 provided by the second regulator 332 using the selector 333, and at this time, both the first control voltage VINITN1 and the second control voltage VINITN2 are within the second voltage range (the negative medium voltage range). Then, the voltage level of the first control voltage VINITN1 as the control voltage VINITN is lowered to the first voltage range (the negative high voltage range) using the first regulator 331, so that the switching from the regulator 332 to the regulator 331 is completed. Conversely, when the control voltage VINITN is to be switched from the negative high voltage range to a voltage within the negative medium voltage range, since the second regulator 332 cannot provide the voltage level within the negative high voltage range, the voltage level of the first control voltage VINITN1 provided by the first regulator 331 is lowered to the second voltage range (the negative medium voltage range) first, and then the first control voltage VINITN1 provided by the first regulator 331 is switched to the second control voltage VINITN2 provided by the second regulator 332 using the selector 333, so that the switching from the regulator 331 to the regulator 332 is completed.

[0036] Figure 5 A schematic diagram of the OLED display unit 310, the driving circuit 320, and the voltage regulating device 530 of the second embodiment of the present application is shown. Figure 5 The OLED display unit 310 and the driving circuit 320 are as shown in Figure 3The voltage regulating device 530 includes an operational amplifier OP1 and a voltage output circuit 531. The operational amplifier OP1 generates an output voltage according to an input voltage VIN1. The voltage output circuit 531 is coupled to the operational amplifier OP1. The voltage output circuit 531 is controlled by a selection signal SEL to selectively generate a control voltage VINITN using a first operating voltage interval (in this embodiment, a voltage interval corresponding to a first power voltage VPHV and a first ground voltage VGHV, such as a negative high voltage interval) or a second operating voltage interval (in this embodiment, a voltage interval corresponding to a second power voltage VPMV and a second ground voltage VGMV, such as a negative medium voltage interval). The first voltage interval is different from the second voltage interval. The voltage value of the control voltage VINITN is related to a reference voltage ELVSS of the OLED light emitting unit 310, and the selection signal SEL is correspondingly generated according to the reference voltage ELVSS.

[0037] Since the power consumption of the voltage regulating device 530 mainly comes from charging and discharging the parasitic capacitance Cp of the driving circuit 320 in the display device, in consideration of saving hardware resources and static power consumption, the embodiment can be designed as Figure 5 The structure of the voltage regulating device 530 can dynamically switch the first output stage circuit 532 or the second output stage circuit 533 in the voltage output circuit 531 according to the voltage requirement of the control voltage VINITN to correspondingly provide the control voltage VINITN.

[0038] In detail, Figure 5 The voltage output circuit 531 includes a first output stage circuit 532, a second output stage circuit 533, and a selector 534. The first output stage circuit 532 operates in a first voltage interval corresponding to a first power voltage VPHV and a first ground voltage VGHV, such as a negative high voltage interval. In other words, the first power voltage VPHV and the first ground voltage VGHV are related to the first operating voltage interval. The first output stage circuit 532 includes a first upper arm transistor MP1 and a first lower arm transistor MN1. The first end (drain end) of the first upper arm transistor MP1 is coupled to the first power voltage VPMV. The second end (source end) of the first upper arm transistor MP1 is coupled to the output end of the voltage output circuit 530. The control end (gate end) of the first upper arm transistor MP1 is coupled to the selector 534. The first end (source end) of the first lower arm transistor MN1 is coupled to the output end of the voltage output circuit 531. The second end (drain end) of the first lower arm transistor MN1 is coupled to the first ground voltage VGMV. The control end (gate end) of the first lower arm transistor MN1 is coupled to the selector 534.

[0039] The second output stage circuit 533 operates in a second voltage interval corresponding to the second power supply voltage VPMV and the second ground voltage VGMV, for example, a negative middle voltage interval. In other words, the second power supply voltage VPMV and the second ground voltage VGMV are related to the second operation voltage interval. The second output stage circuit 533 includes a second upper arm transistor MP2 and a second lower arm transistor MN2. A first end (a drain end) of the second upper arm transistor MP2 is coupled to the second power supply voltage VPMV. A second end (a source end) of the second upper arm transistor MP2 is coupled to the output end of the voltage output circuit 531. A control end (a gate end) of the second upper arm transistor MP2 is coupled to the selector 534. A first end (a source end) of the second lower arm transistor MN2 is coupled to the output end of the voltage output circuit 531. A second end (a drain end) of the second lower arm transistor MN2 is coupled to the second ground voltage VGMV. A control end (a gate end) of the second lower arm transistor MN2 is coupled to the selector 534.

[0040] The selector 534 selectively provides the output voltage generated by the operational amplifier OP1 to one of the first output stage circuit 532 and the second output stage circuit 533 according to the selection signal SEL. The selector 534 includes a first upper arm switch SWUA, a second upper arm switch SWUB, a first lower arm switch SWLA, and a second lower arm switch SWLB. The first upper arm switch SWUA is coupled between the first output end POUT1 of the operational amplifier OP1 and the control end of the first upper arm transistor MP1. The second upper arm switch SWUB is coupled between the first output end POUT1 of the operational amplifier OP1 and the control end of the second upper arm transistor MP2. The first lower arm switch SWLA is coupled between the second output end POUT2 of the operational amplifier OP1 and the control end of the first lower arm transistor MN1. The second lower arm switch SWLB is coupled between the second output end POUT2 of the operational amplifier OP1 and the control end of the second lower arm transistor MN2.

[0041] The first upper arm switch SWUA and the second upper arm switch SWUB selectively provide the first output signal on the first output terminal POUT1 to one of the control terminal of the first upper arm transistor MP1 and the control terminal of the second upper arm transistor MP2 according to the selection signal SEL. The first lower arm switch SWLA and the second lower arm switch SWLB selectively provide the second output signal on the second output terminal POUT2 to one of the control terminal of the first lower arm transistor MN1 and the control terminal of the second upper arm transistor MN2 according to the selection signal SEL. In detail, when the voltage value of the control voltage VINITN is set in the negative high voltage interval, the first output stage circuit 532 is used to charge and discharge the OLED display unit 310 and the driving circuit 320. At this time, the selection signal SEL is used to select the first output stage circuit 532 to provide the control voltage VINITN to the output terminal of the voltage adjusting device 530 through the first output stage circuit 532, and the first upper arm switch SWUA and the first lower arm switch SWLA are turned on to provide the output signals (the first output signal and the second output signal) corresponding to the two output terminals (the first output terminal POUT1 and the second output terminal POUT2) of the operational amplifier OP1 to the control terminal of the first upper arm transistor MP1 and the control terminal of the first lower arm transistor MN1, respectively. The second upper arm switch SWUB and the second lower arm switch SWLB are turned off.

[0042] On the contrary, when the voltage value of the control voltage VINITN is set in the negative middle voltage interval, the second output stage circuit 533 is used to charge and discharge the OLED display unit 310 and the driving circuit 320. At this time, the selection signal SEL is used to select the second output stage circuit 533 to provide the control voltage VINITN to the output terminal of the voltage adjusting device 530 through the second output stage circuit 533, and the second upper arm switch SWUB and the second lower arm switch SWLB are turned on to provide the output signals corresponding to the two output terminals of the operational amplifier OP1 to the control terminal of the second upper arm transistor MP2 and the control terminal of the second lower arm transistor MN2, respectively. The first upper arm switch SWUA and the first lower arm switch SWLA are turned off.

[0043] The embodiment Figure 5 The operational amplifier OP1, the switches SWUA, SWUB, SWLA and SWLB in the selector 534, and the transistors MP1 and MN1 in the first output stage circuit 532 need to support the negative high voltage interval, so the aforementioned components need to use process components that can withstand the negative high voltage interval. The transistors MP2 and MN2 in the second output stage circuit 533 can selectively use process components that can withstand the negative middle voltage interval or the negative high voltage interval.

[0044] Figure 6 The waveform diagram of the signals in the voltage adjusting device 330 of the second embodiment of the present application is shown.Figure 4 Reference numeral 610 indicates the driving timing of the display device, specifically the display phase (e.g., display phase 611) for displaying the image and the vertical anti-aliasing zone (e.g., vertical anti-aliasing zone 612) for switching the displayed image. See also... Figure 5 and Figure 6 The control voltage VINITN will be selectively provided through the first output stage circuit 532 or the second output stage circuit 533 according to the required operating voltage range. For example, during time period 621, the voltage regulator 530 selects to provide the control voltage VINITN through the second output stage circuit 533 according to the selection signal SEL; during time period 622, the voltage regulator 530 selects to provide the control voltage VINITN through the first output stage circuit 532 according to the selection signal SEL.

[0045] To mitigate potential surges during the switching of the first output stage circuit 532 and the second output stage circuit 533, the switching periods (e.g., switching periods 615 and 616) can be set within the vertical cancellation region. Alternatively, users of this embodiment can perform the switching of the first output stage circuit 532 and the second output stage circuit 533 in a non-vertical cancellation region as needed.

[0046] Furthermore, to mitigate the aforementioned surges, the first output stage circuit 532 and the second output stage circuit 533 can be simultaneously activated throughout the entire time period, and during switching (e.g., switching periods 415 and 416), the control voltage VINITN generated by the first output stage circuit 532 and the second output stage circuit 533 must have the same value. In another embodiment conforming to the present invention, the first output stage circuit 532 and the second output stage circuit 533 can also perform non-overlapping switching during switching periods 615 and 616 to avoid generating short-circuit current inside the circuit. That is, in one embodiment, the first output stage circuit 532 and the second output stage circuit 533 can both be turned off during switching periods 615 and 616, with the first output stage circuit 532 activated only after period 615, and the second output stage circuit 533 activated only after period 616. In the aforementioned cases, the voltage value of the control voltage VINITN relies on the parasitic capacitance in the display device (e.g., Figure 5 It is maintained by the parasitic capacitance Cp.

[0047] When switching the first output stage circuit 532 and the second output stage circuit 533 to provide the corresponding voltage, it is noted that the operation voltage range that the output stage circuit 532 and 533 can provide is not the same, and the first operation voltage range (negative high voltage range) corresponding to the first output stage circuit 532 can include the second operation voltage range (negative medium voltage range) corresponding to the second output stage circuit 533. Therefore, it is necessary to use the first output stage circuit 532 to boost or step down the control voltage VINITN in the first operation voltage range (negative high voltage range) that exceeds the second operation voltage range (negative medium voltage range), and when the control voltage VINITN is boosted or stepped down to be within the second operation voltage range (negative medium voltage range), the first output stage circuit 532 is switched to the second output stage circuit 533.

[0048] For example, when the control voltage VINITN is to be switched from the negative medium voltage range to a voltage within the negative high voltage range, the control voltage VINITN is switched from the second output stage circuit 533 to the first output stage circuit 532 by using the selector 532, at which time the control voltage VINITN is within the second voltage range (negative medium voltage range). Then, the voltage level of the control voltage VINITN is lowered to the first voltage range (negative high voltage range) by using the first output stage circuit 532, thereby completing the switching of the output stage circuit 533 to 532. Conversely, when the control voltage VINITN is to be switched from the negative high voltage range to a voltage within the negative medium voltage range, since the second output stage circuit 533 cannot provide the voltage level within the negative high voltage range, the voltage level of the control voltage VINITN provided by the first output stage circuit 532 is first lowered to the second voltage range (negative medium voltage range), and then the first output stage circuit 532 is switched to the second output stage circuit 533 by using the selector 333, thereby completing the switching of the output stage circuit 532 to 533.

[0049] In other embodiments consistent with the present application, the voltage regulating device mainly discharges the positive terminal voltage point of the OLED display unit 310, because it is generally desired to lower the positive terminal voltage value of the OLED display unit 310. Therefore, in consideration of further saving hardware resources, it is possible to only switch the discharge path (for example, the path corresponding to the lower arm transistor) of the output stage circuit in the voltage regulating device to provide the control voltage VINITN within different operation voltage ranges, as shown in Figure 7 . Figure 7 A schematic diagram of the OLED display unit 310, the driving circuit 320, and the voltage regulating device 730 of the third embodiment of the present application is shown. Figure 7 The OLED display unit 310 and the driving circuit 320 are described as Figure 3 corresponding components.

[0050] The voltage adjusting device 730 includes an operational amplifier OP1 and a voltage output circuit 731. The operational amplifier OP1 generates an output voltage according to an input voltage VIN1. The voltage output circuit 731 is coupled to the operational amplifier OP1. The voltage output circuit 731 is controlled by a selection signal SEL to selectively generate a control voltage VINITN using a first operation voltage interval (a voltage interval corresponding to a first power voltage VPHV and a first ground voltage VGHV, such as a negative high voltage interval) or a second operation voltage interval (a voltage interval corresponding to a second power voltage VPMV and a second ground voltage VGMV, such as a negative medium voltage interval). The first power voltage VPHV and the second power voltage VPMV of the present embodiment have the same voltage value, for example, 0V.

[0051] In detail, Figure 7 The voltage output circuit 731 includes a first output stage circuit 732, a second output stage circuit 733, and a selector 734. The first output stage circuit 732 operates in a first voltage interval corresponding to the first power voltage VPHV and the first ground voltage VGHV, such as a negative high voltage interval. The circuit structure of the first output stage circuit 732 is similar to that of the first output stage circuit 532. Figure 5 The first output stage circuit 532.

[0052] Figure 7 With Figure 5 The main difference is that the second output stage circuit 733 only includes a second lower arm transistor MN2, and the selector 734 only includes a first lower arm switch SWLA and a second lower arm switch SWLB. In detail, the first end (source end) of the second lower arm transistor MN2 is coupled to the output end of the voltage output circuit 731. The second end (drain end) of the second lower arm transistor MN2 is coupled to the second ground voltage VGMV. The control end (gate end) of the second lower arm transistor MN2 is coupled to the selector 734. The selector 734 selectively provides the second output voltage generated by the second end of the operational amplifier OP1 to one of the control end of the first lower arm transistor MN1 of the first output stage circuit 732 and the control end of the second lower arm transistor MN2 of the second output stage circuit 733 according to the selection signal SEL. In other words, the present embodiment switches the lower arm discharge paths of the output stage circuits 731 and 732 to dynamically switch the operation voltage interval in the voltage adjusting device 730, thereby providing the corresponding control voltage VINITN.

[0053] The present embodiment Figure 7The operational amplifier OP1, the switches SWLA and SWLB in the selector 733, and the transistors MP1 and MN1 in the first output stage circuit 732 need to support the negative high voltage range, and therefore the aforementioned components need to use process components that can withstand the negative high voltage range. The transistors MP2 and MN2 in the second output stage circuit 733 can selectively use process components that can withstand the negative medium voltage range or the negative high voltage range.

[0054] In other embodiments consistent with the present application, it is also possible to design the voltage adjustment device to mainly charge the positive terminal voltage point of the OLED display unit 310. Therefore, in consideration of further saving hardware resources, the control voltage VINITN at different operating voltage ranges can be provided by only switching the charging path (e.g., the path corresponding to the upper arm transistor) of the output stage circuit in the voltage adjustment device, as shown in Figure 8 . Figure 8 A schematic diagram of an OLED display unit 310, a driving circuit 320, and a voltage adjustment device 830 of a fourth embodiment of the present application is shown. Figure 8 The OLED display unit 310 and the driving circuit 320 are as described above with respect to Figure 3 the corresponding components.

[0055] The voltage adjustment device 830 includes an operational amplifier OP1 and a voltage output circuit 831. The voltage output circuit 831 is coupled to the operational amplifier OP1. The voltage output circuit 831 is controlled by a selection signal SEL to selectively generate the control voltage VINITN using a first operating voltage range (a voltage range corresponding to the first power voltage VPHV and the first ground voltage VGHV, such as the negative high voltage range) or a second operating voltage range (a voltage range corresponding to the second power voltage VPMV and the second ground voltage VGMV, such as the negative medium voltage range) in the present embodiment. The first ground voltage VGHV and the second ground voltage VGMV in the present embodiment have the same voltage value.

[0056] In detail, Figure 8 The voltage output circuit 831 includes a first output stage circuit 832, a second output stage circuit 833, and a selector 834. The first output stage circuit 832 operates in a first voltage range corresponding to the first power voltage VPHV and the first ground voltage VGHV, such as the negative high voltage range. The circuit structure of the first output stage circuit 832 is similar to Figure 5 the first output stage circuit 532.

[0057] Figure 8 and Figure 5The main difference is that the second output stage circuit 833 only includes the second upper arm transistor MP2, and the selector 834 only includes the first upper arm switch SWUA and the second upper arm switch SWUB. In detail, the first end (drain end) of the second upper arm transistor MP2 is coupled to the second power supply voltage VPMV.

[0058] The second end (source end) of the second upper arm transistor MP2 is coupled to the output end of the voltage output circuit 831.

[0059] The control end (gate end) of the second lower arm transistor MN2 is coupled to the selector 834.

[0060] The selector 834 selectively provides the first output voltage generated by the first end of the operational amplifier OP1 to one of the control end of the first lower arm transistor MN1 of the first output stage circuit 832 and the control end of the second lower arm transistor MN2 of the second output stage circuit 833 according to the selection signal SEL. In other words, the present embodiment switches the upper arm discharge path of the output stage circuits 831 and 832 to dynamically switch the operating voltage interval in the voltage regulating device 830, thereby providing the corresponding control voltage VINITN.

[0061] The present embodiment Figure 8 The operational amplifier OP1, the switches SWUA and SWUB in the selector 833, and the transistors MP1 and MN1 in the first output stage circuit 832 need to support the negative high voltage interval, so the aforementioned components need to use process components that can withstand the negative high voltage interval. The transistors MP2 and MN2 in the second output stage circuit 833 can selectively use process components that can withstand the negative medium voltage interval or the negative high voltage interval.

[0062] In other embodiments consistent with the present application, it is also possible to design to switch the voltage interval of the output stage circuit in the voltage regulating device to be the first voltage interval or the second voltage interval, thereby dynamically switching the operating voltage interval in the voltage regulating device, thereby providing the corresponding control voltage VINITN, as shown in Figure 9 . Figure 9 A schematic diagram of the OLED display unit 310, the driving circuit 320, and the voltage regulating device 830 of the fifth embodiment of the present application is shown. Figure 9 The OLED display unit 310 and the driving circuit 320 are as described above with regard to Figure 3 the corresponding components.

[0063] The voltage adjusting device 830 includes an operational amplifier OP1 and a voltage output circuit 931. The voltage output circuit 931 is coupled to the operational amplifier OP1. The voltage output circuit 931 is controlled by a selection signal SEL to selectively use a first operation voltage range (a voltage range corresponding to the first power voltage VPHV and the first ground voltage VGHV, such as a negative high voltage range) or a second operation voltage range (a voltage range corresponding to the second power voltage VPMV and the second ground voltage VGMV, such as a negative medium voltage range) to generate the control voltage VINITN.

[0064] In detail, Figure 8 The voltage output circuit 931 includes an upper arm transistor MP1, a lower arm transistor MN1, a first selector 932 and a second selector 933. A second terminal of the upper arm transistor MP1 is coupled to an output terminal of the voltage output circuit 930. The output terminal is used to provide the control voltage VINITN to the driving circuit 320. The first selector 932 selectively couples one of the first power voltage VPMV and the second power voltage VPHV to a first terminal of the upper arm transistor MP1 according to the selection signal SEL. A first terminal of the lower arm transistor MN1 is coupled to the output terminal of the voltage output circuit 930. The second selector 933 selectively couples one of the first ground voltage VGHV and the second ground voltage VGMV to a second terminal of the lower arm transistor MN1 according to the selection signal SEL. The first power voltage VPHV and the first ground voltage VGHV are related to the first operation voltage range. The second power voltage VPMV and the second ground voltage VGMV are related to the second operation voltage range.

[0065] When the voltage adjusting device 830 is desired to provide the control voltage VINITN to the driving circuit 320 in the first operation voltage range, the first selector 932 couples the first power voltage VPMV to the first terminal of the upper arm transistor MP1, and the second selector 933 couples the first ground voltage VGHV to the second terminal of the lower arm transistor MN1. In this way, an output stage circuit 934 composed of the upper arm transistor MP1 and the lower arm transistor MN1 can provide the control voltage VINITN through the first operation voltage range. Conversely, when the voltage adjusting device 830 is desired to provide the control voltage VINITN to the driving circuit 320 in the second operation voltage range, the first selector 932 couples the second power voltage VPMV to the first terminal of the upper arm transistor MP1, and the second selector 933 couples the second ground voltage VGMV to the second terminal of the lower arm transistor MN1. In this way, the output stage circuit 934 composed of the upper arm transistor MP1 and the lower arm transistor MN1 can provide the control voltage VINITN through the second operation voltage range. Figure 9The first selector 932 and the second selector 933 can need to reduce the on-resistance to avoid the circuit structure from consuming each voltage level, and thus can be implemented by using process components with a larger size.

[0066] The present embodiment Figure 9 Each component in the operational amplifier OP1, the first selector 932, the second selector 933, and the output stage circuit 934 needs to support the negative high voltage range, and thus the aforementioned components need to use process components that can withstand the negative high voltage range.

[0067] Figure 10 A circuit diagram of an operational amplifier OPN that can be used in each embodiment of the present application is shown. Figure 10 The operational amplifier OPN is a circuit structure of the operational amplifiers OP1 and OP2 in Embodiments 1-9, and can be used as a reference for the present embodiment. The present embodiment can also be implemented by using an operational amplifier with other circuit structures. Figure 3 , 5 , 7-9, and can be used as a reference for the present embodiment. The present embodiment can also be implemented by using an operational amplifier with other circuit structures. Figure 3 , 5 , 7-9, and can be used as a reference for the present embodiment. The present embodiment can also be implemented by using an operational amplifier with other circuit structures. Figure 10 This is only one example. Figure 10 The operational amplifier OPN can receive a voltage VIN1 and provide corresponding output voltages at a first output terminal POUT1 and a second output terminal POUT2, respectively.

[0068] In summary, the voltage adjustment device for an organic light emitting diode according to the embodiments of the present application can dynamically switch the operating voltage range in the voltage adjustment device by the design of the circuit structure, so that the voltage adjustment device can selectively generate a control voltage for making the organic light emitting diode not emit light based on the reference voltage of the organic light emitting diode, reduce the power consumption of the voltage adjustment device, and still normally provide the corresponding operating voltage when the reference voltage of the organic light emitting diode is in a higher negative voltage operating range.

[0069] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than limiting them; although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or make equivalent replacements for some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A voltage regulating device for an organic light emitting diode, characterized by, Comprising: an operational amplifier generating an output voltage; and a voltage output circuit coupled to the operational amplifier, wherein the voltage output circuit is controlled by a selection signal to selectively utilize a first operating voltage range or a second operating voltage range to generate a control voltage, the first operating voltage range being different from the second operating voltage range, wherein a voltage value of the control voltage is related to the reference voltage of the organic light emitting diode, and the selection signal is correspondingly generated according to the reference voltage of the organic light emitting diode.

2. The voltage conversion device according to claim 1, characterized by The voltage output circuit comprises: a first output stage circuit operating in the first operating voltage range; a second output stage circuit operating in the second operating voltage range; and a selector selectively providing the output voltage to one of the first output stage circuit and the second output stage circuit according to the selection signal.

3. The voltage conversion device of claim 2, wherein The first output stage circuit comprises: a first upper arm transistor having a first end coupled to a first power voltage, a second end coupled to an output of the voltage output circuit, and a control end coupled to the selector; and a first lower arm transistor having a first end coupled to the output of the voltage output circuit, a second end coupled to a first ground voltage, and a control end coupled to the selector, wherein the first power voltage and the first ground voltage are related to the first operating voltage range.

4. The voltage conversion device according to claim 3, characterized by The second output stage circuit comprises: a second upper arm transistor having a first end coupled to a second power voltage, a second end coupled to the output of the voltage output circuit, and a control end coupled to the selector; and a second lower arm transistor having a first end coupled to the output of the voltage output circuit, a second end coupled to a second ground voltage, and a control end coupled to the selector, wherein the second power voltage and the second ground voltage are related to the second operating voltage range.

5. The voltage conversion device of claim 4, wherein, The selector comprises: a first upper arm switch coupled between a first output of the operational amplifier and the control end of the first upper arm transistor; a second upper arm switch coupled between the first output of the operational amplifier and the control end of the second upper arm transistor, wherein the first upper arm switch and the second upper arm switch selectively provide a first output signal on the first output to one of the control end of the first upper arm transistor and the control end of the second upper arm transistor according to the selection signal; a first lower arm switch coupled between a second output of the operational amplifier and the control end of the first lower arm transistor; and a second lower arm switch coupled between the second output of the operational amplifier and the control end of the second lower arm transistor, wherein the first lower arm switch and the second lower arm switch selectively provide a second output signal on the second output to one of the control end of the first lower arm transistor and the control end of the second lower arm transistor according to the selection signal.

6. The voltage conversion device of claim 3, wherein The second output stage circuit includes: a second lower arm transistor, a first end of which is coupled to the output end of the voltage output circuit, a second end of which is coupled to a second ground voltage, and a control end of which is coupled to the selector, wherein a second supply voltage and the second ground voltage are related to the second operating voltage interval.

7. The voltage conversion device of claim 6, wherein, The selector includes: a first lower arm switch coupled between a second output end of the operational amplifier and the control end of the first lower arm transistor; and a second lower arm switch coupled between the second output end of the operational amplifier and the control end of the second lower arm transistor, wherein the first lower arm switch and the second lower arm switch selectively provide a second output signal on the second output end to one of the control end of the first lower arm transistor and the control end of the second lower arm transistor according to the selection signal.

8. The voltage conversion device of claim 3, wherein, The second output stage circuit includes: a second upper arm transistor, a first end of which is coupled to the output end of the voltage output circuit, a second end of which is coupled to a second supply voltage, and a control end of which is coupled to the selector, wherein the second supply voltage and a second ground voltage are related to the second operating voltage interval.

9. The voltage conversion device of claim 8, wherein, The selector includes: a first upper arm switch coupled between a first output end of the operational amplifier and the control end of the first upper arm transistor; and a second upper arm switch coupled between the first output end of the operational amplifier and the control end of the second upper arm transistor, wherein the first upper arm switch and the second upper arm switch selectively provide a first output signal on the first output end to one of the control end of the first upper arm transistor and the control end of the second upper arm transistor according to the selection signal.

10. The voltage conversion device of claim 1, wherein, The voltage output circuit includes: an upper arm transistor, a second end of which is coupled to an output end of the voltage output circuit; a first selector which selectively couples one of a first supply voltage and a second supply voltage to a first end of the upper arm transistor according to the selection signal; a lower arm transistor, a first end of which is coupled to the output end of the voltage output circuit; and a second selector which selectively couples one of a first ground voltage and a second ground voltage to a second end of the lower arm transistor according to the selection signal, wherein the first supply voltage and the first ground voltage are related to the first operating voltage interval, and the second supply voltage and the second ground voltage are related to the second operating voltage interval.

11. The voltage conversion device of claim 1, wherein, The voltage regulating device is coupled to a driving circuit of the organic light emitting diode, wherein the driving circuit utilizes the control voltage to make the organic light emitting diode not emit light.

12. The voltage conversion device of claim 1, wherein, The switching point of the selection signal is located in a vertical blanking interval of a driving timing of the display panel.

13. A voltage regulating device for an organic light emitting diode, characterized in that including: a first regulator which generates a first control voltage according to a first operating voltage interval; a second regulator which generates a second control voltage according to a second operating voltage interval; and and a selector to selectively apply one of the first control voltage and the second control voltage as a control voltage in accordance with a selection signal, wherein a voltage value of the control voltage is related to the reference voltage of the organic light emitting diode, and the selection signal is correspondingly generated in accordance with the reference voltage of the organic light emitting diode.

14. The voltage conversion device of claim 13, wherein, The first regulator comprises: a first operational amplifier to generate a first output voltage; and a first output stage circuit coupled to the first operational amplifier to generate the first control voltage in accordance with the first output voltage, a first supply voltage and a first ground voltage, wherein the first supply voltage and the first ground voltage are related to the first operating voltage range.

15. The voltage conversion device of claim 13, wherein, The first regulator comprises: a second operational amplifier to generate a second output voltage; and a second output stage circuit coupled to the second operational amplifier to generate the second control voltage in accordance with the second output voltage, a second supply voltage and a second ground voltage, wherein the second supply voltage and the second ground voltage are related to the second operating voltage range.

Images