Pre-charging circuit and control method of passive matrix organic light emitting display

Abstract

The embodiment of the present specification provides a pre-charging circuit for a passive matrix organic light-emitting display, including a processor, an operational amplifier, a current limiting resistor, a protection circuit and a voltage divider circuit; the processor is configured to make the reference voltage terminal output a pre-charging voltage to the positive input terminal of the operational amplifier when receiving an instruction; the voltage divider circuit is configured to sample the voltage of the column driving circuit, determine the sampling voltage, and input the sampling voltage to the negative input terminal of the operational amplifier; the operational amplifier is configured to output a high level to the protection circuit when the sampling voltage is less than the pre-charging voltage, and pre-charge the column driving circuit through the current limiting resistor. Thus, the voltage overshoot phenomenon can be effectively reduced or eliminated, the power consumption can be reduced, and the service life of the organic light-emitting display panel can be extended. At the same time, by pre-charging, the pre-charging process can be more accurately controlled to improve the pre-charging effect.

Description

Technical Field

[0001] The embodiments of the present specification relate to the field of circuit technology, and in particular to a pre-charging circuit for a passive matrix organic light emitting display. Background Art

[0002] Organic light-emitting display technology has attracted widespread attention for its advantages such as excellent color performance, viewing angle and low power consumption. However, with the continuous development of organic light-emitting display technology, its pre-charging technology has become an important research direction. The existing pre-charging technology has problems such as the individual differences of organic light-emitting display units affected by the lines of rows and columns, slow pre-charging speed, poor pre-charging effect, etc., which affect the effect of organic light-emitting display. Therefore, a new pre-charging technology is needed to solve these problems. Summary of the invention

[0003] In view of this, the embodiments of this specification provide a pre-charging circuit for a passive matrix organic light-emitting display. One or more embodiments of this specification also relate to a pre-charging circuit control method, a computing device, a computer-readable storage medium, and a computer program to solve the technical defects existing in the prior art.

[0004] According to a first aspect of an embodiment of this specification, there is provided a pre-charging circuit for a passive matrix organic light emitting display, characterized in that it includes a processor, an operational amplifier, a current limiting resistor, a protection circuit and a voltage divider circuit;

[0005] The reference voltage terminal of the processor is electrically connected to the positive input terminal of the operational amplifier;

[0006] The negative input terminal of the operational amplifier is electrically connected to the voltage divider circuit;

[0007] The output end of the operational amplifier is electrically connected to one end of the protection circuit;

[0008] The other end of the protection circuit is electrically connected to one end of the current limiting resistor;

[0009] The other end of the current limiting resistor is suitable for being electrically connected to the column driving circuit;

[0010] One end of the voltage divider circuit is suitable for being electrically connected to the column driving circuit;

[0011] The other end of the voltage divider circuit is electrically connected to the ground end;

[0012] The processor is configured to, upon receiving an instruction, cause the reference voltage terminal to output a pre-charge voltage to the positive input terminal of the operational amplifier;

[0013] The voltage divider circuit is configured to sample the voltage of the column driving circuit, determine a sampled voltage, and input the sampled voltage to the negative input terminal of the operational amplifier;

[0014] The operational amplifier is configured to output a high level to the protection circuit when the sampling voltage is less than the pre-charge voltage, and to pre-charge the column driving circuit through the current limiting resistor.

[0015] In a possible implementation, the protection circuit is a diode;

[0016] The output terminal of the operational amplifier is electrically connected to the anode of the diode;

[0017] The cathode of the diode is electrically connected to one end of the current limiting resistor.

[0018] In a possible implementation, the device further includes a switching circuit;

[0019] The first end of the switching circuit is electrically connected to the control end of the controller;

[0020] The second terminal of the switching circuit is electrically connected to the output terminal of the operational amplifier;

[0021] The third terminal of the switching circuit is electrically connected to the ground terminal.

[0022] In a possible implementation, the operational amplifier is configured to output a high level to the switching circuit when the sampling voltage is less than the pre-charge voltage.

[0023] In a possible implementation, the switching circuit is a triode;

[0024] The collector of the transistor is electrically connected to the control terminal of the controller;

[0025] The base of the transistor is electrically connected to the output terminal of the operational amplifier;

[0026] The emitter of the transistor is electrically connected to the ground terminal.

[0027] In a possible implementation, the voltage divider circuit includes a first resistor and a second resistor;

[0028] One end of the first resistor is adapted to be electrically connected to the column driving circuit;

[0029] The other end of the first resistor is electrically connected to one end of the second resistor;

[0030] The other end of the second resistor is electrically connected to the ground end.

[0031] In a possible implementation, a constant current source is further included, and the constant current source includes a first pin, a second pin, and a third pin;

[0032] The first pin of the constant current source is suitable for being electrically connected to a power supply;

[0033] The second pin of the constant current source is electrically connected to the collector of the transistor;

[0034] The third pin of the constant current source is suitable for being electrically connected to the column driving circuit.

[0035] According to a second aspect of an embodiment of this specification, a pre-charging circuit control method is provided, which is applicable to the pre-charging circuit of the above-mentioned passive matrix organic light-emitting display, comprising:

[0036] When receiving the instruction, the processor causes the reference voltage terminal to output the pre-charge voltage to the positive input terminal of the operational amplifier;

[0037] The voltage divider circuit samples the voltage of the column driving circuit, determines the sampling voltage, and inputs the sampling voltage to the negative input terminal of the operational amplifier;

[0038] When the sampling voltage is less than the pre-charge voltage, the operational amplifier outputs a high level to the protection circuit and pre-charges the column driving circuit through the current limiting resistor.

[0039] According to a third aspect of an embodiment of this specification, a computing device is provided, including:

[0040] Memory and processor;

[0041] The memory is used to store computer executable instructions, and the processor is used to execute the computer executable instructions. When the computer executable instructions are executed by the processor, the steps of the above-mentioned pre-charging circuit control method are implemented.

[0042] According to a fourth aspect of the embodiments of this specification, a computer-readable storage medium is provided, which stores computer-executable instructions, and when the instructions are executed by a processor, the steps of the above-mentioned pre-charging circuit control method are implemented.

[0043] According to a fifth aspect of the embodiments of this specification, a computer program is provided, wherein when the computer program is executed in a computer, the computer is caused to execute the steps of the above-mentioned pre-charging circuit control method.

[0044] The embodiment of the present specification provides a pre-charging circuit for a passive matrix organic light-emitting display, including a processor, an operational amplifier, a current limiting resistor, a protection circuit and a voltage divider circuit; the processor is configured to make the reference voltage terminal output a pre-charging voltage to the positive input terminal of the operational amplifier when receiving an instruction; the voltage divider circuit is configured to sample the voltage of the column driving circuit, determine the sampling voltage, and input the sampling voltage to the negative input terminal of the operational amplifier; the operational amplifier is configured to output a high level to the protection circuit when the sampling voltage is less than the pre-charging voltage, and pre-charge the column driving circuit through the current limiting resistor. Thus, the voltage overshoot phenomenon can be effectively reduced or eliminated, the power consumption can be reduced, and the service life of the organic light-emitting display panel can be extended. At the same time, by pre-charging, the pre-charging process can be more accurately controlled to improve the pre-charging effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 is a circuit diagram of a pre-charging circuit for a passive matrix organic light emitting display provided by an embodiment of the present specification;

[0046] Figure 2 is a schematic diagram of an equivalent circuit of an organic light emitting display unit provided in one embodiment of the present specification;

[0047] Figure 3 is a schematic diagram of the photoelectric characteristics of an organic light emitting display unit provided by an embodiment of the present specification;

[0048] Figure 4 It is a periodic waveform diagram provided by an embodiment of this specification;

[0049] Figure 5 is a schematic diagram of an organic light emitting display passive matrix provided by an embodiment of the present specification;

[0050] Figure 6 This is a row driving timing diagram of a pre-charging circuit of a passive matrix organic light emitting display provided by an embodiment of the present specification;

[0051] Figure 7 is a flow chart of a control method for a pre-charging circuit provided by an embodiment of this specification;

[0052] Figure 8 It is a structural block diagram of a computing device provided by an embodiment of this specification. DETAILED DESCRIPTION

[0053] Many specific details are described in the following description to facilitate a full understanding of this specification. However, this specification can be implemented in many other ways than those described herein, and those skilled in the art can make similar generalizations without violating the connotation of this specification, so this specification is not limited to the specific implementation disclosed below.

[0054] The terms used in one or more embodiments of this specification are only for the purpose of describing specific embodiments, and are not intended to limit one or more embodiments of this specification. The singular forms of "a" and "the" used in one or more embodiments of this specification and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings. It should also be understood that the term "and / or" used in one or more embodiments of this specification refers to and includes any or all possible combinations of one or more associated listed items.

[0055] It should be understood that although the terms first, second, etc. may be used to describe various information in one or more embodiments of this specification, this information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of one or more embodiments of this specification, the first may also be referred to as the second, and similarly, the second may also be referred to as the first. Depending on the context, the word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining".

[0056] First, the terms involved in one or more embodiments of this specification are explained.

[0057] Microcontroller Unit (MCU), also known as single-chip microcomputer (Single Chip Microcomputer) or single-chip microcomputer.

[0058] The Central Processing Unit (CPU) is the computing and control core of the computer system and the final execution unit for information processing and program running.

[0059] In this specification, a pre-charging circuit for a passive matrix organic light-emitting display is provided. This specification also relates to a pre-charging circuit control method, a computing device, and a computer-readable storage medium, which are described in detail one by one in the following embodiments.

[0060] See also Figure 1 , Figure 1 A circuit diagram of a pre-charging circuit for a passive matrix organic light emitting display provided according to an embodiment of the present specification is shown.

[0061] According to the first aspect of the embodiments of the present specification, a pre-charging circuit for a passive matrix organic light-emitting display is provided, characterized in that it includes a processor, an operational amplifier, a current limiting resistor, a protection circuit and a voltage divider circuit; the reference voltage terminal of the processor is electrically connected to the positive input terminal of the operational amplifier; the negative input terminal of the operational amplifier is electrically connected to the voltage divider circuit; the output terminal of the operational amplifier is electrically connected to one end of the protection circuit; the other end of the protection circuit is electrically connected to one end of the current limiting resistor; the other end of the current limiting resistor is suitable for being electrically connected to a column driving circuit; one end of the voltage divider circuit is suitable for being electrically connected to the column driving circuit; the other end of the voltage divider circuit is electrically connected to the ground terminal; the processor is configured to, upon receiving an instruction, cause the reference voltage terminal to output a pre-charging voltage to the positive input terminal of the operational amplifier; the voltage divider circuit is configured to sample the voltage of the column driving circuit, determine the sampling voltage, and input the sampling voltage to the negative input terminal of the operational amplifier; the operational amplifier is configured to output a high level to the protection circuit when the sampling voltage is less than the pre-charging voltage, and pre-charge the column driving circuit through the current limiting resistor.

[0062] In practical applications, organic light-emitting display is a current-controlled device. Its brightness is proportional to the average time of current passing through. When the current does not reach the light-emitting threshold of the organic light-emitting display, the brightness of the device is very small. When the current reaches its light-emitting threshold, the light intensity of the organic light-emitting display will increase as the current increases. An organic light-emitting display unit can be simplified into an LED and a 20~30 PF parasitic capacitor in parallel, such as Figure 2 shown.

[0063] Furthermore, to make the organic light-emitting display emit light, the current source must first charge the capacitor to the light-emitting voltage of the organic light-emitting display, which will take a long time to charge and the response time will be slow. Therefore, a pre-charging circuit can be added to the current source driving circuit to pre-charge its capacitor to a pre-calculated voltage that is slightly lower than its threshold voltage VTH, and then drive it with an accurate constant current source, thereby improving its electro-optical response speed. Figure 3 (a) It is known that when the applied voltage is less than the threshold voltage of the organic light-emitting display, the current flowing through the device is close to zero. When the applied voltage exceeds the threshold voltage, it is found that the current density increases with the increase of the applied voltage. Figure 3 As shown in (b), the relationship between voltage and brightness of organic light-emitting display is nonlinear. If voltage driving is used to achieve brightness level differentiation, the driving voltage must have high precision, which places high demands on the design of the driving power supply and is not easy to achieve. Figure 3 As shown in (c), the current and the luminous brightness have a good linear relationship, so as long as the current flowing through the organic light-emitting display unit is well controlled, the brightness level can be simply and effectively distinguished.

[0064] In summary, the brightness of an organic light-emitting display unit is proportional to the current flowing through the display unit, and needs to be driven by a current source. Since the inflow current of an organic light-emitting display is in a power series relationship with the applied voltage, it is known that a small voltage change will inevitably lead to a large range of current changes. Therefore, the magnitude of the current must be precisely controlled. Figure 4 As can be seen from the waveform shown, in a scanning cycle, when Anode is high and Cathode is low, Anode goes through three stages: dprecharge, display, and discharge. Theoretically, in a cycle, the first is precharge, followed by display, and then discharge. Figure 4 It can be seen from the Anode (anode) and Cathode (cathode) display waveforms that in a cycle of actual application, the first action is discharge, then precharge, and then display.

[0065] Existing organic light emitting display passive matrix display such as Figure 5 . Segment (column driven) and Commmon (row driven). Figure 4 It can be seen from the displayed waveform that in a scanning cycle of actual application, the first action is discharge, followed by precharge, and then display. The reason is that due to the manufacturing process of the matrix and the leakage between adjacent row and column electrodes, there is a partial charge on the distributed capacitor of the adjacent display unit. When the next scanning cycle starts, direct charging will cause the voltage across the parasitic capacitor of the organic light-emitting display unit to exceed the threshold voltage of the organic light-emitting display unit, resulting in the current source being unable to accurately control its luminous brightness. Therefore, in a scanning cycle, the voltage across the parasitic capacitor of the organic light-emitting display unit is first discharged.

[0066] Since the brightness of the organic light-emitting display unit is proportional to the current flowing through the display unit, a current source is required to drive it. Since the inflow current of the organic light-emitting display and the applied voltage are in a power series relationship, it is known that a small voltage change will inevitably lead to a large range of current changes. Therefore, the magnitude of the current must be precisely controlled. Therefore, the current and voltage of the organic light-emitting display must be monitored and controlled.

[0067] Therefore, in a possible implementation of the embodiment of the present application, the protection circuit is a diode; the output end of the operational amplifier is electrically connected to the positive electrode of the diode; the negative electrode of the diode is electrically connected to one end of the current limiting resistor. In a possible implementation, it also includes a switching circuit; the first end of the switching circuit is electrically connected to the control end of the controller; the second end of the switching circuit is electrically connected to the output end of the operational amplifier; and the third end of the switching circuit is electrically connected to the ground end.

[0068] In a possible implementation, the operational amplifier is configured to output a high level to the switching circuit when the sampling voltage is less than the pre-charge voltage.

[0069] In a possible implementation, the switching circuit is a transistor; the collector of the transistor is electrically connected to the control end of the controller; the base of the transistor is electrically connected to the output end of the operational amplifier; and the emitter of the transistor is electrically connected to the ground end.

[0070] In a possible implementation, the voltage divider circuit includes a first resistor and a second resistor; one end of the first resistor is electrically connected to the column driving circuit; the other end of the first resistor is electrically connected to one end of the second resistor; and the other end of the second resistor is electrically connected to the ground terminal.

[0071] In a possible implementation, a constant current source is also included, which includes a first pin, a second pin and a third pin; the first pin of the constant current source is suitable for being electrically connected to a power supply; the second pin of the constant current source is electrically connected to the collector of the transistor; and the third pin of the constant current source is suitable for being electrically connected to a column driving circuit.

[0072] The controller may be an MCU or a CPU, the reference voltage terminal may be VREF, the diode may be D1, the transistor may be Q1, the operational amplifier may be U1, the voltage divider circuit may be composed of R2 and R3, and the first resistor and the second resistor are R2 and R3. R1 is a current limiting resistor.

[0073] For details, see Figure 1 In the embodiments of this specification, the pre-charging circuit of the passive matrix organic light-emitting display is composed of VREF, U1, Q1, D1, R1, R2, and R3. VREF is the reference value of the pre-charging voltage provided by the MCU, U1 is an operational amplifier, and R1 is a pre-charging current-limiting resistor. R2 and R3 form a voltage divider circuit to actually monitor the voltage drop of the Segment (column drive). Q1 and D1 form a Segment (column drive) switching circuit and a protection circuit to prevent the display circuit from emitting light in the pre-charging state. VCC is the power supply, I1 is a constant current source, and CONTROL is a signal from the MCU to control the constant current source to work and shut down VREF.

[0074] By setting pre-charging in the embodiments of this specification, each display unit can be more fully pre-charged, so that when the display driving circuit lights up the display unit, the luminous performance and stability of the display unit are improved, thereby improving the overall display effect. At the same time, due to the improved pre-charging effect, the service life and stability of the display panel are also indirectly improved.

[0075] Furthermore, the pre-charging process of the pre-charging circuit of the above passive matrix organic light emitting display is described in detail, as shown below.

[0076] After the MCU receives the instruction, VREF outputs the reference value of the pre-charge voltage and transmits it to the non-inverting input of the U1 operational amplifier. The reference value needs to be set to be less than the Segment (column drive) threshold voltage after conversion by the U1 operational amplifier. The Segment (column drive) voltage is sampled through a voltage divider circuit composed of R2 and R3, and the sampled voltage signal is transmitted to the inverting input of the U1 operational amplifier. In the pre-charge state, because the voltage on the Segment (column drive) is less than the VREF reference value voltage after the voltage divider of R2 and R3, the output of the U1 operational amplifier outputs a high level. The output of the U1 operational amplifier is controlled in two ways. One way is that Q1 controls the CONTROL signal to prevent I1 from being a constant current source output to the Segment (column drive). The other way is that D1 pre-charges the current limiting resistor of R1 through the isolation diode, and the Segment (column drive) is pre-charged through the current limiting resistor of R1. When selecting the current limiting resistor for R1 pre-charge, refer to Figure 2 Since the inflow current of an organic light-emitting display is in a power series relationship with the applied voltage, a small voltage change will inevitably lead to a large change in the current. Therefore, the magnitude of the current must be precisely controlled.

[0077] Furthermore, when the rising voltage of the Segment (column drive) is equal to the voltage of the VREF reference value after being divided by R2 and R3, that is, the inverting input terminal of the U1 operational amplifier is consistent with the VREF voltage of the inverting input. The output of the U1 operational amplifier is low level, the R1 pre-charged current limiting resistor has no current output, Q1 is cut off, the CONTROL signal is high level, and the VREF output pre-charge voltage reference value is turned off. The I1 constant current source works and outputs a voltage greater than the Segment (column drive) threshold voltage, and the organic light emitting display is displayed. A pre-charging process ends and enters the next cycle.

[0078] See also Figure 6 , Figure 6The timing characteristics diagram of the organic light-emitting display Segment (column drive). When the monitoring MCU issues the organic light-emitting display Segment (column drive) instruction, the reference value of the pre-charge voltage output by VREF is established, the high level of the CONTROL signal is pulled to a low level, and the Segment (column drive) is charged; when the Segment (column drive) is charged to the threshold voltage, the CONTROL signal is high, and the MCU turns off the reference value of the pre-charge voltage output by VREF, and the precharge ends. Because the CONTROL signal is high, I1 is a constant current source working output to the Segment (column drive) organic light-emitting display to emit light, and enter the display state.

[0079] Furthermore, when the MCU receives the shutdown command, the CONTROL signal and VREF are both low level, Commmon (row driver) is still low level, that is, low resistance state, and the Segment (column driver) discharges through Commmon (row driver) and enters the discharge state. When one cycle is completed, the next cycle begins.

[0080] Since the organic light-emitting display is a current-type device, if it is driven by a constant voltage source, the electrode resistance on the row and column electrodes is inconsistent due to the problems of the organic light-emitting display passive matrix manufacturing process, and the distributed capacitance between the wiring and the adjacent organic light-emitting display units, leakage, etc., will make the current flowing through the organic light-emitting display units at various positions on the screen inconsistent, thereby affecting the uniformity of the display brightness. From the volt-ampere characteristic curve of the organic light-emitting display, it can be concluded that even a small change in voltage will cause a large fluctuation in current, and the current source and the luminous brightness show a good linear relationship. Therefore, the embodiment of this specification adopts a current source drive. And in order to improve its electro-optical response speed and achieve a better display effect, a pre-charging technology is proposed. This technology can effectively reduce or eliminate the voltage overshoot phenomenon, reduce power consumption and extend the service life of the organic light-emitting display panel. At the same time, by pre-charging, the pre-charging process can be controlled more accurately and the pre-charging effect can be improved.

[0081] See also Figure 7 , Figure 7 A flow chart of a pre-charging circuit control method provided according to an embodiment of the present specification is shown, which is applicable to the pre-charging circuit of the above-mentioned passive matrix organic light-emitting display, and specifically includes the following steps.

[0082] Step 701: upon receiving the instruction, the processor causes the reference voltage terminal to output a pre-charge voltage to the positive input terminal of the operational amplifier;

[0083] Step 702: the voltage divider circuit samples the voltage of the column driving circuit, determines the sampled voltage, and inputs the sampled voltage to the negative input terminal of the operational amplifier;

[0084] Step 703: When the sampling voltage is less than the pre-charge voltage, the operational amplifier outputs a high level to the protection circuit and pre-charges the column driving circuit through the current limiting resistor.

[0085] The embodiment of the present specification provides a pre-charging circuit for a passive matrix organic light-emitting display, including a processor, an operational amplifier, a current limiting resistor, a protection circuit and a voltage divider circuit; the processor is configured to make the reference voltage terminal output a pre-charging voltage to the positive input terminal of the operational amplifier when receiving an instruction; the voltage divider circuit is configured to sample the voltage of the column driving circuit, determine the sampling voltage, and input the sampling voltage to the negative input terminal of the operational amplifier; the operational amplifier is configured to output a high level to the protection circuit when the sampling voltage is less than the pre-charging voltage, and pre-charge the column driving circuit through the current limiting resistor. Thus, the voltage overshoot phenomenon can be effectively reduced or eliminated, the power consumption can be reduced, and the service life of the organic light-emitting display panel can be extended. At the same time, by pre-charging, the pre-charging process can be more accurately controlled to improve the pre-charging effect.

[0086] The above is a schematic scheme of a pre-charging circuit control method of this embodiment. It should be noted that the technical scheme of the pre-charging circuit control method and the technical scheme of the pre-charging circuit control method described above belong to the same concept, and the details not described in detail in the technical scheme of the pre-charging circuit control method can be referred to the description of the technical scheme of the pre-charging circuit of the passive matrix organic light-emitting display described above.

[0087] Figure 8 The block diagram of a computing device 800 according to an embodiment of the present specification is shown. The components of the computing device 800 include but are not limited to a memory 810 and a processor 820. The processor 820 is connected to the memory 810 via a bus 830, and a database 850 is used to store data.

[0088] The computing device 800 also includes an access device 840 that enables the computing device 800 to communicate via one or more networks 860. Examples of these networks include a public switched telephone network (PSTN), a local area network (LAN), a wide area network (WAN), a personal area network (PAN), or a combination of communication networks such as the Internet. The access device 840 may include one or more of any type of network interface (e.g., a network interface card (NIC)) of wired or wireless, such as an IEEE 802.11 wireless local area network (WLAN) wireless interface, a world-wide interoperability for microwave access (Wi-MAX) interface, an Ethernet interface, a universal serial bus (USB) interface, a cellular network interface, a Bluetooth interface, and a near field communication (NFC).

[0089] In one embodiment of the present specification, the above components of the computing device 800 and Figure 8 Other components not shown in the figure may also be connected to each other, for example, via a bus. It should be understood that Figure 8 The computing device structure block diagram shown is only for the purpose of illustration, and is not intended to limit the scope of this specification. Those skilled in the art can add or replace other components as needed.

[0090] The computing device 800 may be any type of stationary or mobile computing device, including a mobile computer or mobile computing device (e.g., a tablet computer, a personal digital assistant, a laptop computer, a notebook computer, a netbook, etc.), a mobile phone (e.g., a smart phone), a wearable computing device (e.g., a smart watch, smart glasses, etc.), or other types of mobile devices, or a stationary computing device such as a desktop computer or a personal computer (PC). The computing device 800 may also be a mobile or stationary server.

[0091] Among them, the processor 820 is used to execute the following computer executable instructions, which implement the steps of the above-mentioned pre-charging circuit control method when executed by the processor. The above is a schematic scheme of a computing device of this embodiment. It should be noted that the technical scheme of the computing device and the technical scheme of the above-mentioned pre-charging circuit control method belong to the same concept, and the details of the technical scheme of the computing device that are not described in detail can all be referred to the description of the technical scheme of the above-mentioned pre-charging circuit control method.

[0092] An embodiment of the present specification further provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, implement the steps of the above-mentioned pre-charging circuit control method.

[0093] The above is a schematic scheme of a computer-readable storage medium of this embodiment. It should be noted that the technical scheme of the storage medium and the technical scheme of the pre-charging circuit control method described above are of the same concept, and the details not described in detail in the technical scheme of the storage medium can be found in the description of the technical scheme of the pre-charging circuit control method described above.

[0094] An embodiment of the present specification further provides a computer program, wherein when the computer program is executed in a computer, the computer is caused to execute the steps of the above-mentioned pre-charging circuit control method.

[0095] The above is a schematic scheme of a computer program of this embodiment. It should be noted that the technical scheme of the computer program and the technical scheme of the pre-charging circuit control method described above are of the same concept, and the details not described in detail in the technical scheme of the computer program can be found in the description of the technical scheme of the pre-charging circuit control method described above.

[0096] The above is a description of a specific embodiment of the specification. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in an order different from that in the embodiments and still achieve the desired results. In addition, the processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0097] The computer instructions include computer program codes, which may be in source code form, object code form, executable files or some intermediate forms, etc. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signal, telecommunication signal and software distribution medium, etc. It should be noted that the content contained in the computer-readable medium may be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media do not include electric carrier signals and telecommunication signals.

[0098] It should be noted that, for the above-mentioned method embodiments, for the sake of simplicity of description, they are all expressed as a series of action combinations, but those skilled in the art should be aware that the embodiments of this specification are not limited by the order of the actions described, because according to the embodiments of this specification, some steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the embodiments of this specification.

[0099] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0100] The preferred embodiments of this specification disclosed above are only used to help explain this specification. The optional embodiments do not describe all the details in detail, nor do they limit the invention to only the specific implementation methods described. Obviously, many modifications and changes can be made according to the content of the embodiments of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the embodiments of this specification, so that technicians in the relevant technical field can well understand and use this specification. This specification is only limited by the claims and their full scope and equivalents.

Claims

1. A pre-charging circuit for a passive matrix organic light emitting display, characterized in that: It includes a processor, an operational amplifier, a current limiting resistor, a protection circuit and a voltage divider circuit; The reference voltage terminal of the processor is electrically connected to the positive input terminal of the operational amplifier; The negative input terminal of the operational amplifier is electrically connected to the voltage divider circuit; The output end of the operational amplifier is electrically connected to one end of the protection circuit; The other end of the protection circuit is electrically connected to one end of the current limiting resistor; The other end of the current limiting resistor is suitable for being electrically connected to the column driving circuit; One end of the voltage divider circuit is suitable for being electrically connected to the column driving circuit; The other end of the voltage divider circuit is electrically connected to the ground end; The processor is configured to, upon receiving an instruction, cause the reference voltage terminal to output a pre-charge voltage to the positive input terminal of the operational amplifier; The voltage divider circuit is configured to sample the voltage of the column driving circuit, determine a sampled voltage, and input the sampled voltage to the negative input terminal of the operational amplifier; The operational amplifier is configured to output a high level to the protection circuit and precharge the column driving circuit through the current limiting resistor when the sampling voltage is less than the pre-charge voltage; The protection circuit is a diode; The output end of the operational amplifier is electrically connected to the anode of the diode; The cathode of the diode is electrically connected to one end of the current limiting resistor; Also included is a switching circuit; The first end of the switching circuit is electrically connected to the control end of the controller; The second end of the switching circuit is electrically connected to the output end of the operational amplifier; The third terminal of the switching circuit is electrically connected to the ground terminal; The operational amplifier is configured to output a high level to the switching circuit when the sampling voltage is less than the pre-charge voltage; The switching circuit is a triode; The collector of the triode is electrically connected to the control end of the controller; The base of the triode is electrically connected to the output end of the operational amplifier; The emitter of the triode is electrically connected to the ground terminal; The voltage divider circuit includes a first resistor and a second resistor; One end of the first resistor is adapted to be electrically connected to a column driving circuit; The other end of the first resistor is electrically connected to one end of the second resistor; The other end of the second resistor is electrically connected to the ground terminal; Also includes a constant current source, the constant current source includes a first pin, a second pin and a third pin; The first pin of the constant current source is suitable for being electrically connected to a power supply; The second pin of the constant current source is electrically connected to the collector of the transistor; The third pin of the constant current source is suitable for being electrically connected to the column driving circuit.

2. A pre-charging circuit control method, applicable to the pre-charging circuit of the passive matrix organic light emitting display according to claim 1, characterized in that: include: When receiving the instruction, the processor causes the reference voltage terminal to output the pre-charge voltage to the positive input terminal of the operational amplifier; The voltage divider circuit samples the voltage of the column driving circuit, determines a sampled voltage, and inputs the sampled voltage to the negative input terminal of the operational amplifier; When the sampling voltage is less than the pre-charge voltage, the operational amplifier outputs a high level to the protection circuit and pre-charges the column driving circuit through the current limiting resistor.

3. A computing device, characterized in that: include: Memory and processor; The memory is used to store computer executable instructions, and the processor is used to execute the computer executable instructions. When the computer executable instructions are executed by the processor, the steps of the pre-charging circuit control method according to claim 2 are implemented.

4. A computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, implement the steps of the pre-charging circuit control method of claim 2.

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