Current sensing calibration method and current sensing calibration system

Abstract

The current sensing calibration method comprises the following steps: setting a first calibration current; inputting the first calibration current to a current sensing circuit to detect a first real digital code; obtaining offset calibration data according to the first real digital code and a first ideal digital code corresponding to the first real digital code; inputting the calibration current to a current sensing circuit to detect a third real digital code; and obtaining gain calibration data according to the second real digital code, the third real digital code, the second ideal digital code and the third ideal digital code, and obtaining channel temperature calibration data of at least one pixel of the display panel after calibrating the current sensing circuit according to the offset calibration data and the gain calibration data. The present disclosure also relates to a current sensing calibration system.

Description

Technical Field

[0001] The present invention provides a current sensing calibration method and a current sensing calibration system, and more particularly, provides a current sensing calibration method and a current sensing calibration system capable of correcting temperature data errors. Background Art

[0002] With the rapid development of technology, various micro-light-emitting diode (micro-LED) devices have been widely adopted in our daily lives. Since temperature changes may be introduced in different environments, white point shift effects may occur in Micro-LED devices. The white point shift effect of Micro-LED devices may cause the color temperature and brightness of the light signal emitted by the Micro-LED device to be unstable. At present, detecting the temperature of Micro-LED components to calibrate the light signal is the main technology to solve the white point shift effect.

[0003] However, since the parts for detecting the temperature of the Micro-LED element may not match, erroneous temperature data may be introduced. When the introduced temperature data has errors, the accuracy of the optical signal for calibrating the Micro-LED element will be reduced.

[0004] Therefore, developing a temperature data error correction mechanism to improve the accuracy of the optical signal for calibrating Micro-LED devices is an important issue. Summary of the invention

[0005] An embodiment of the present invention provides a current sensing calibration method. The current sensing calibration method includes setting a first calibration current according to a current range of a display panel; inputting the first calibration current to a current sensing circuit and detecting a first real digital code output by the current sensing circuit; obtaining offset calibration data according to the first real digital code and a first ideal digital code corresponding to the first calibration current; setting a second calibration current and a third calibration current according to the current range of the display panel; inputting the second calibration current to the current sensing circuit and detecting a second real digital code output by the current sensing circuit; inputting the third calibration current to the current sensing circuit and detecting a third real digital code output by the current sensing circuit; obtaining gain calibration data according to the second real digital code, the third real digital code, the second ideal digital code corresponding to the second calibration current, and the third ideal digital code corresponding to the third calibration current; and obtaining channel temperature calibration data of at least one pixel of the display panel after calibrating the current sensing circuit according to the offset calibration data and the gain calibration data.

[0006] Another embodiment of the present invention provides a current sensing calibration system. The current sensing calibration system includes at least one pixel, a multiplexer, a current sensing circuit and a processor. At least one pixel is placed on a display panel. The multiplexer is coupled to at least one pixel and a current calibration terminal. The current sensing circuit is coupled to the multiplexer and is used to generate digital data related to the temperature of at least one pixel. The processor is coupled to the current sensing circuit and is used to calibrate the digital data of the current sensing circuit. The processor sets a first calibration current according to a current range of the display panel. The first calibration current is input to the current calibration terminal and is received by the current sensing circuit through the multiplexer. The processor detects a first real digital code output by the current sensing circuit. The processor obtains offset calibration data according to the first real digital code and a first ideal digital code corresponding to the first calibration current. The processor sets a second calibration current and a third calibration current according to the current range of the display panel. The second calibration current is input to the current calibration terminal and is received by the current sensing circuit through the multiplexer. The processor detects a second real digital code output by the current sensing circuit. The third calibration current is input to the current calibration terminal and is received by the current sensing circuit through the multiplexer. The processor detects a third real digital code output by the current sensing circuit. The processor obtains gain calibration data according to the second real digital code, the third real digital code, the second ideal digital code corresponding to the second calibration current, and the third ideal digital code corresponding to the third calibration current. After calibrating the current sensing circuit according to the offset calibration data and the gain calibration data, the processor obtains channel temperature calibration data of at least one pixel of the display panel. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 FIG. 1 is a block diagram of an embodiment of a current sensing calibration system of the present invention.

[0008] Figure 2A Is for Figure 1 Schematic diagram of the offset error of the current sensing circuit in the current sensing calibration system.

[0009] Figure 2B Is for Figure 1 Schematic diagram of the gain error of the current sensing circuit in the current sensing calibration system.

[0010] Figure 3A Is for Figure 1 Schematic diagram of calibrating the offset error of the current sensing circuit in the current sensing calibration system.

[0011] Figure 3B Is for Figure 1 FIG. 1 is a diagram illustrating calibration results after an offset error of a current sensing circuit is calibrated in a current sensing calibration system of FIG.

[0012] Figure 4A Is for Figure 1Schematic diagram of calibrating the gain error of the current sensing circuit in the current sensing calibration system.

[0013] Figure 4B Is for Figure 1 FIG. 1 is a diagram showing calibration results after the gain error of the current sensing circuit is calibrated in the current sensing calibration system of FIG.

[0014] Figure 5 Is for Figure 1 Schematic diagram of calibrating channel temperature data of a current sensing circuit in a current sensing calibration system.

[0015] Figure 6 Is for Figure 1 In the current sensing calibration system, the circuit architecture of the current sensing circuit is shown.

[0016] Figure 7 Is for Figure 1 Schematic diagram of the waveforms associated with the current sensing circuit in the current sensing calibration system.

[0017] Figure 8 Is for Figure 1 A flow chart of executing a current sensing calibration method in a current sensing calibration system.

[0018] The reference numerals are described as follows:

[0019] 100: Current sensing calibration system

[0020] 10, 10a, 10b, 10c: Pixels

[0021] 11: Multiplexer

[0022] 12: Current sensing circuit

[0023] 13: Processor

[0024] 20: Display Panel

[0025] Ireal: real pixel current

[0026] Ic: Current calibration terminal

[0027] IV: Current-to-voltage converter

[0028] ADC: Analog-to-Digital Converter

[0029] D1: Digital data

[0030] MEM: Memory

[0031] D2: Calibration code

[0032] C1, C2: Conversion function straight line

[0033] L1: Ideal transfer function straight line

[0034] L2: True transfer function line

[0035] L3, L4: Transfer function straight line

[0036] Ic1: First calibration current

[0037] Ic2: Second calibration current

[0038] Ic3: Third calibration current

[0039] D3: Digital code

[0040] D4: Pixel digital code

[0041] D5: Digital code

[0042] 14: Compensation circuit

[0043] Ics: current

[0044] Iref: reference current

[0045] Vcs: first reference voltage

[0046] Vcm: Second reference voltage

[0047] CKref: reference clock signal

[0048] VIO, VTDC: output voltage

[0049] SW1: First switch

[0050] SW2: Second switch

[0051] SW3: The third switch

[0052] C: Capacitance

[0053] AMP: amplifier

[0054] CMP: Comparator

[0055] TDC: Time to Digital Converter

[0056] V H : Precharge voltage

[0057] DATA[9:0]: digital code

[0058] T1, T2, T3: time length

[0059] DATA1, DATA2, DATA3: digital code

[0060] S801 to S808: Steps DETAILED DESCRIPTION

[0061] Figure 1 1 is a block diagram of an embodiment of a current sensing calibration system 100 of the present invention. The current sensing calibration system 100 includes at least one pixel 10 disposed on a display panel 20, a multiplexer 11 coupled to the at least one pixel 10 and a current calibration terminal Ic, and a current sensing circuit 12 coupled to the multiplexer 11, for generating digital data D1 associated with the temperature of at least one pixel 10. In the current sensing calibration system 100, since the elements (such as the current-voltage converter IV and the analog-to-digital converter ADC) for detecting the temperature of the display panel 20 may not match, the current sensing calibration system circuit 12 may output an erroneous digital code. However, the digital code can be corrected in the current sensing calibration system 100. In the current sensing calibration system 100, the processor 13 can set a first calibration current according to the current range of the display panel 20. In one embodiment, the processor 13 can select an appropriate current range according to the table T1 to set the first calibration current.

[0062] Setting mode Current range unit 1 0～1 uA 2 0～10 uA 3 0～50 uA

[0063] Table T1

[0064] Next, the first calibration current is input to the current calibration terminal Ic and is received by the current sensing circuit 12 through the multiplexer 11. The processor 13 obtains the offset calibration data according to the first real digital code and the first ideal digital code corresponding to the first calibration current. The processor 13 sets the second calibration current and the third calibration current according to the current range of the display panel 20. The second calibration current is input to the current calibration terminal Ic and is received by the current sensing circuit 12 through the multiplexer 11. The processor 13 detects the second real digital code output by the current sensing circuit 12. The third calibration current is input to the current calibration terminal Ic and is received by the current sensing circuit 12 through the multiplexer 11. The processor 13 detects the third real digital code output by the current sensing circuit 12. The processor 13 obtains the gain calibration data according to the second real digital code, the third real digital code, the second ideal digital code corresponding to the second calibration current, and the third ideal digital code corresponding to the third calibration current. After the processor 13 calibrates the current sensing circuit 12 according to the offset calibration data and the gain calibration data, it obtains the channel temperature calibration data of at least one pixel 10 of the display panel 20. The details of the current sensing calibration method will be described later.

[0065] Figure 2A1 is a schematic diagram of the offset error of the current sensing circuit in the current sensing calibration system 100. As mentioned above, since the components for detecting the temperature of the display panel 20 (such as the current-voltage converter IV and the analog-to-digital converter ADC) may not match, offset error and gain error may occur, thereby introducing digital code errors. Therefore, the current sensing circuit 12 may output an erroneous digital code. Figure 2A , the offset error b is illustrated. The X-axis represents the analog voltage input to the analog-to-digital converter ADC of the current sensing circuit 12. The Y-axis represents the digital code output by the current sensing circuit 12. The transfer function line C1 can be regarded as an ideal transfer function line, expressed as: y = (m1) x. In this embodiment, m1 is the slope of the transfer function line C1. By introducing the offset error b, the transfer function line C2 can be regarded as a true transfer function line, expressed as: y = (m1) x + b.

[0066] Figure 2B FIG. 1 is a schematic diagram of the gain error of the current sensing circuit 12 in the current sensing calibration system 100 . Figure 2B In FIG. 1 , the X-axis represents the analog voltage input to the analog-to-digital converter ADC of the current sensing circuit 12. The Y-axis represents the digital code output by the current sensing circuit 12. The transfer function straight line C1 can be regarded as an ideal transfer function straight line, which is expressed as: y = (m1) x, as shown in FIG. Figure 2A as well as Figure 2B . By introducing the gain error, the transfer function line C3 can be regarded as a true transfer function line, expressed as y=(m2)x. In the present embodiment, m2 is the slope of the transfer function line C3. Since the slope m1 of the transfer function line C1 is different from the slope m2 of the transfer function line C3, it indicates that the gain error of the current sensing circuit 12 has been introduced. This will cause the digital code to be introduced into the current sensing circuit 12. In practice, both the offset error and the gain error will be introduced into the current sensing circuit 12. Therefore, when the "ideal" transfer function line C1 is defined as y=(m1)x, the "true" transfer function line can be defined as y=(m2)x+b.

[0067] Figure 3AThis is a schematic diagram of calibrating the offset error of the current sensing circuit 12 in the current sensing calibration system 100. In this embodiment, the processor 13 can select a current range of 0 to 1uA according to Table T1. The first digital code can be a 10-bit code, such as D[0:9]. The value range of the first digital code D[0:9] can be written as D0001 to D1024. Therefore, the current range of 0 to 1uA can be quantized into 1024 quantization levels. The processor 13 can select the first calibration current stored in the memory MEM and the first ideal digital code corresponding to the first calibration current. For example, the first calibration current Ic1 can be selected as 0.5uA. The first ideal digital code can be selected as D[0:9]=D0512. In Figure 3A In FIG. 1 , the X-axis represents the current. The Y-axis represents the digital code. For the ideal transfer function line L1, when the first calibration current Ic1 is 0.5uA, the first ideal digital code output by the current sensing circuit 12 is D[0:9]=D0512. As mentioned above, an offset error may be introduced into the current sensing circuit 12. In other words, when the first calibration current Ic1 is input into the current sensing circuit 12, the first "real" digital code may be output as D0550 according to the "real" transfer function line L2. Therefore, the offset error may be obtained by the difference between the first real digital code D550 and the first ideal digital code D512.

[0068] Figure 3B FIG. 1 is a schematic diagram of a calibration result after the offset error of the current sensing circuit 12 is calibrated in the current sensing calibration system 100. As mentioned above, the offset error can be obtained by the difference between the first real digital code D550 and the first ideal digital code D512. The offset error can be regarded as the offset calibration data for calibrating the real transfer function straight line L2. Figure 3B In the example, the true transfer function line L2 can be calibrated by shifting D550-D512=38 codes in the quantization code space to generate the transfer function line L3. In other words, the offset calibration data can be used to compensate for the offset data code (ie, D550) of the true transfer function line L2 of the current sensing circuit 12.

[0069] Figure 4A1 is a schematic diagram of calibrating the gain error of the current sensing circuit in the current sensing calibration system 100. In the quantization code space, after calibrating the true transfer function line L2 by moving D550-D512=38 codes to generate the transfer function line L3, the transfer function line L3 can be further calibrated, and the slope of the transfer function line L3 can be adjusted to generate the transfer function line L4, as shown in the figure below. The processor 13 can select the second calibration current stored in the memory MEM and the second ideal digital code corresponding to the second calibration current. For example, the second calibration current Ic2 can be selected as 0.25uA. The second ideal digital code can be selected as D[0:9]=D0256. Further, the processor 13 can select the third calibration current stored in the memory MEM and the third ideal digital code corresponding to the third calibration current. For example, the third calibration current Ic3 can be selected as 0.75uA. The third ideal digital code can be selected as D[0:9]=D0768. For the ideal transfer function line L1, when the second calibration current Ic2 is 0.25uA, the second ideal digital code output by the current sensing circuit 12 is D[0:9]=D0256. When the third calibration current Ic2 is 0.75uA, the third ideal digital code output by the current sensing circuit 12 is D[0:9]=D0768. As mentioned above, gain error can be introduced into the current sensing circuit 12. In other words, when the second calibration current Ic2 is input to the current sensing circuit 12, the second "real" digital code can be output according to the transfer function line L3, which is D0273. Similarly, when the third calibration current Ic3 is input to the current sensing circuit 12, the third "real" digital code can be output according to the transfer function line L3, which is D0750. In other words, the processor 13 can generate the real slope of the transfer function line L3 according to the second real digital code D0273 and the third real digital code D0768. Furthermore, the processor 13 can generate an ideal slope of the transmission line L1 according to the second ideal digital code D0256 and the third ideal digital code D0768. Therefore, the gain error can be obtained by the difference between the actual slope and the ideal slope.

[0070] Figure 4B FIG. 1 is a schematic diagram of the calibration result after the gain error of the current sensing circuit 12 is calibrated in the current sensing calibration system 100. As mentioned above, the gain error can be obtained by the difference between the actual slope and the ideal slope. The gain error can be regarded as the gain calibration data for calibrating the transfer function line L3. In other words, the gain calibration data can be used to compensate for the slope error of the transfer function line L3 to generate the transfer function line L4. In addition, FIG. 3A to FIG. 3B In the example, after calibrating the offset error and gain error, the transfer function straight line L4 can approach the ideal transfer function straight line L1. Figure 1In the embodiment of the present invention, the error of the digital code D1 can be corrected to generate a calibrated digital code D2. This will result in that the calibrated digital code D2 does not introduce an offset error or a gain error. Therefore, by means of the calibration mechanism, the current sensing calibration system 100 can improve the accuracy of detecting the temperature of the display panel 20. In addition, the first calibration current Ic1, the first ideal digital code, the second calibration current Ic2, the second ideal digital code, the third calibration current Ic3 and the third ideal digital code can be predetermined and stored in the memory MEM of the processor 13.

[0071] Figure 5 1 is a schematic diagram of the channel temperature data of the calibrated current sensing circuit 12 in the current sensing calibration system 100. In order to further improve the accuracy of detecting pixel temperature, the current sensing calibration system 100 also considers the current change of the pixel at a fixed temperature. For example, the real pixel current Ireal of at least one pixel 10a, 10b and / or 10c of the display panel 20 can be input to the current sensing circuit 12 at a fixed temperature (e.g., 65 degrees Celsius). Subsequently, the processor 13 can detect the real pixel digital code D3 output by the current sensing circuit 12 after calibrating the current sensing circuit 12 according to the offset calibration data and the gain calibration data. Next, the processor 13 can obtain the ideal pixel digital code corresponding to the fixed temperature for generating channel temperature calibration data, as shown in Table T2.

[0072]

[0073] Table T2

[0074] Here, for a fixed temperature, due to the different working states and circuit lifespans of pixels 10a, 10b, and 10c, the real pixel digital codes received by the current sensing circuit 12 will also be different. For example, for a fixed temperature, the real pixel digital code of channel 1 corresponding to pixel 10a is D_CH1[9:0]. The real pixel digital code of channel 2 corresponding to pixel 10b is D_CH2[9:0]. The real pixel digital code of channel 3 corresponding to pixel 10c is D_CH3[9:0]. The ideal pixel digital code of pixels 10a, 10b, and 10c at a fixed temperature is D[9:0]. Therefore, the current sensing calibration system 100 can generate channel temperature calibration data based on the difference between the real pixel digital code and the ideal pixel digital code in each channel. For example, the channel temperature calibration data δCH1 of channel 1 corresponding to pixel 10a can be generated by the difference between D[9:0] and D_CH1[9:0]. Similarly, the channel temperature calibration data δCH2 corresponding to channel 2 of pixel 10b can be generated by the difference between D[9:0] and D_CH2[9:0]. Similarly, the channel temperature calibration data δCH3 corresponding to channel 3 of pixel 10c can be generated by the difference between D[9:0] and D_CH3[9:0]. In other words, Figure 5 In the embodiment of the present invention, the real pixel digital code D3 can be calibrated by removing the offset error and the gain error to generate the pixel digital code D4. Then, the pixel digital code D4 can be further calibrated by the temperature compensation circuit 14 to eliminate the code deviation caused by the temperature. Finally, since the offset error, the gain error and the code deviation caused by the temperature are removed, the digital code D5 will be very close to the real digital code. In addition, the temperature compensation circuit 14 can be integrated into the processor 13. The temperature compensation circuit 14 can also be coupled to the processor 13. Any reasonable technical or hardware modification falls within the scope disclosed by the present invention.

[0075] Figure 61 is a circuit architecture of a current sensing circuit 12 in a current sensing calibration system 100. The current sensing circuit 12 may include: a current-voltage converter IV for converting a current signal into a voltage signal, and an analog-to-digital converter ADC coupled to the current-voltage converter IV for digitizing the voltage signal to generate a digitized voltage signal. The circuit details of the current sensing circuit 12 are as follows. The current sensing circuit 12 includes a first switch SW1, a second switch SW2, an amplifier AMP, a capacitor C, a third switch SW3, a comparator CMP, and a time-to-digital converter TDC. The first switch SW1 includes an input terminal coupled to the multiplexer 11 to receive the current Ics, and an output terminal. The second switch SW2 includes an input terminal for receiving a reference current Iref, and an output terminal coupled to the output terminal of the first switch SW1. The amplifier AMP includes a first input terminal coupled to the output terminal of the first switch SW1, a second input terminal for receiving a first reference voltage Vcs, and an output terminal. The capacitor C includes a first terminal coupled to the first input terminal of the amplifier AMP, and a second terminal coupled to the output terminal of the amplifier AMP. The third switch SW3 includes an input terminal coupled to the first input terminal of the capacitor C, and an output terminal coupled to the second terminal of the capacitor C. The comparator CMP includes a first input terminal coupled to the output terminal of the amplifier AMP, a second input terminal for receiving a second reference voltage Vcm, and an output terminal. The time-to-digital converter TDC includes a first input terminal coupled to the output terminal of the comparator CMP, a second input terminal for receiving a reference clock signal CKref, and an output terminal for outputting a digital code D1.

[0076] Figure 7 FIG. 1 is a schematic diagram of waveforms related to the current sensing circuit 12 in the current sensing calibration system 100 . Figure 7 , a waveform for controlling the first switch SW1, a waveform for controlling the second switch SW2, a waveform for controlling the third switch SW3, a waveform of the output voltage VIO at the output end of the amplifier AMP, a waveform of the output voltage VTDC at the output end of the comparator CMP, and a digital code D1 represented as DATA[9:0] are shown. In the current sensing circuit 12, the capacitor C can be adjusted according to the standard design. Subsequently, the reference current Iref can also be adjusted according to the capacitor C. The second switch SW2 can be used to pre-charge the capacitor C according to a pre-charge clock with a fixed pulse width. Here, when the second switch SW2 is enabled, the capacitor C can be charged to the pre-charge voltage V H Then, when the second switch SW2 is disabled and the first switch SW1 is enabled, the capacitor C can be discharged to the first reference voltage Vcs. In addition, the third switch SW3 can be used to reset the charging state of the capacitor C in each clock cycle. Here, the pre-charge voltage V His greater than the first reference voltage Vcs. In the current sensing circuit 12, the first reference voltage Vcs can be adjusted. When the first reference voltage Vcs changes, the pre-charge voltage V H In addition, when the output voltage VTDC of the comparator CMP is designed to be independent of the change of the reference voltage Vcs, the second reference voltage Vcm will also be adjusted. In other words, when the first reference voltage Vcs changes, the second reference voltage Vcm can also be adjusted to stabilize the output voltage VTDC of the comparator CMP.

[0077] In the current sensing circuit 12, when the capacitor C is charged to the pre-charge voltage V H When the output of the comparator AMP is at a high voltage (i.e. VIO = V H ). When the capacitor C is discharged to the first reference voltage Vcs, the output terminal of the comparator AMP is at a low voltage (i.e., VIO=Vcs). In addition, the time-to-digital converter TDC can use a fixed reference clock CKref to count the transition time length of the output voltage VTDC of the comparator CMP. For example, the capacitor C can be charged from the pre-charge voltage V H The time length of the discharge to the first reference voltage Vcs is digitized to generate a digital code. For example, the time length T1 of the capacitor C discharge can be digitized to generate a digital code DATA1. Similarly, the time length T2 of the capacitor C discharge can be digitized to generate a digital code DATA2. The time length T3 of the capacitor C discharge can be digitized to generate a digital code DATA3.

[0078] Figure 8 1 is a flow chart of executing a current sensing calibration method in a current sensing calibration system 100. The process of executing the current sensing calibration method includes steps S801 to S808. Any reasonable technical changes fall within the scope disclosed by the present invention. Steps S801 to S808 are described as follows:

[0079] Step S801: setting a first calibration current Ic1 according to a current range of the display panel 20;

[0080] Step S802: inputting a first calibration current Ic1 to the current sensing circuit 12, and detecting a first real digital code output by the current sensing circuit 12;

[0081] Step S803: Obtaining offset calibration data according to the first real digital code and the first ideal digital code corresponding to the first calibration current Ic1;

[0082] Step S804: setting the second calibration current Ic2 and the third calibration current Ic3 according to the current range of the display panel 20;

[0083] Step S805: input the second calibration current Ic2 to the current sensing circuit 12, and detect the second real digital code output by the current sensing circuit 12;

[0084] Step S806: input the third calibration current Ic3 to the current sensing circuit 12, and detect the third real digital code output by the current sensing circuit 12;

[0085] Step S807: Obtain gain calibration data according to the second real digital code, the third real digital code, the second ideal digital code corresponding to the second calibration current Ic2, and the third ideal digital code corresponding to the third calibration current Ic3;

[0086] Step S808 : After calibrating the current sensing circuit 12 according to the offset calibration data and the gain calibration data, obtain the channel temperature calibration data of at least one pixel of the display panel 20 .

[0087] The details of step S801 to step S808 have been described in detail above, so they will not be repeated here. In the flow sensing calibration system 100, since the offset error, gain error and temperature deviation can be compensated or removed, the digital code of the detected temperature will be close to the real digital code. Therefore, the accuracy of the digital code used for various temperature compensation processes can be improved.

[0088] In summary, the present invention discloses a current sensing calibration method and a current sensing calibration system. The current sensing calibration system can use a calibration current to detect and correct offset error and gain error. In addition, the current sensing calibration system can generate channel temperature calibration data of at least one pixel of the display panel to correct the deviation of the temperature code. Therefore, the current sensing calibration system can be applied to various temperature compensation procedures to provide a reliable digital code.

[0089] The above description is only a preferred embodiment of the present invention. All equivalent changes and modifications made according to the claims of the present invention should fall within the scope of the present invention.

Claims

1. A current sensing calibration method, comprising: Setting a first calibration current according to a current range of a display panel; Inputting the first calibration current to a current sensing circuit, and detecting a first real digital code output by the current sensing circuit; Obtaining offset calibration data according to the first real digital code and a first ideal digital code corresponding to the first calibration current; Setting a second calibration current and a third calibration current according to the current range of the display panel; Inputting the second calibration current to the current sensing circuit, and detecting a second real digital code output by the current sensing circuit; Inputting the third calibration current to the current sensing circuit, and detecting a third real digital code output by the current sensing circuit; Obtaining gain calibration data according to the second real digital code, the third real digital code, a second ideal digital code corresponding to the second calibration current, and a third ideal digital code corresponding to the third calibration current; and After the current sensing circuit is calibrated according to the offset calibration data and the gain calibration data, channel temperature calibration data of at least one pixel of the display panel is obtained. 2 . The current sensing calibration method as claimed in claim 1 , wherein the offset calibration data is generated according to a difference between the first real digital code and the first ideal digital code.

3. The current sensing calibration method as claimed in claim 1, further comprising: Generating a real slope according to the second real digital code and the third real digital code; and Generating an ideal slope according to the second ideal digital code and the third ideal digital code; The gain calibration data is generated by a difference between the actual slope and the ideal slope.

4. The current sensing calibration method as claimed in claim 1, further comprising: Inputting a real pixel current of the at least one pixel of the display panel at a fixed temperature into the current sensing circuit; After calibrating the current sensing circuit according to the offset calibration data and the gain calibration data, detecting a real pixel digital code output by the current sensing circuit; Obtaining an ideal pixel digital code corresponding to the fixed temperature to generate the channel temperature calibration data; The channel temperature calibration data is generated according to a difference between the real pixel digital code and the ideal pixel digital code. 5 . The current sensing calibration method as claimed in claim 1 , wherein the current sensing circuit comprises a current-to-voltage converter and an analog-to-digital converter. 6 . The current sensing calibration method as claimed in claim 5 , wherein the offset calibration data is used to compensate for an offset data code of the current sensing circuit. 7 . The current sensing calibration method as claimed in claim 5 , wherein the gain calibration data is used to compensate a slope of a transfer function line of the current sensing circuit. 8 . The current sensing calibration method as claimed in claim 1 , wherein the first calibration current, the first ideal digital code, the second calibration current, the second ideal digital code, the third calibration current and the third ideal digital code are predetermined and stored in a memory.

9. A current sensing calibration system, comprising: At least one pixel is disposed on a display panel; a multiplexer coupled to the at least one pixel and a current calibration terminal; a current sensing circuit coupled to the multiplexer and configured to generate digital data related to a temperature of the at least one pixel; and; a processor coupled to the current sensing circuit and used to calibrate the digital data of the current sensing circuit; The processor sets a first calibration current according to a current range of the display panel, the first calibration current is input to the current calibration end and is received by the current sensing circuit through the multiplexer, the processor detects a first real digital code output by the current sensing circuit, the processor obtains offset calibration data according to the first real digital code and a first ideal digital code corresponding to the first calibration current, the processor sets a second calibration current and a third calibration current according to the current range of the display panel, the second calibration current is input to the current calibration end and is received by the current sensing circuit through the multiplexer, the processor detects the A second real digital code is output by the current sensing circuit, the third calibration current is input to the current calibration end and is received by the current sensing circuit through the multiplexer, the processor detects a third real digital code output by the current sensing circuit, the processor obtains gain calibration data according to the second real digital code, the third real digital code, a second ideal digital code corresponding to the second calibration current, and a third ideal digital code corresponding to the third calibration current, and the processor obtains channel temperature calibration data of at least one pixel of the display panel after calibrating the current sensing circuit according to the offset calibration data and the gain calibration data. 10 . The current sensing calibration system of claim 9 , wherein the offset calibration data is generated according to a difference between the first real digital code and the first ideal digital code.

11. The current sensing calibration system of claim 9, wherein the processor generates a real slope according to the second real digital code and the third real digital code, the processor generates an ideal slope according to the second ideal digital code and the third ideal digital code, and the gain calibration data is generated by a difference between the real slope and the ideal slope.

12. A current sensing calibration system as described in claim 9, wherein at a fixed temperature, a real pixel current of the at least one pixel of the display panel is input into the current sensing circuit, and after the processor calibrates the current sensing circuit according to the offset calibration data and the gain calibration data, a real pixel digital code output by the current sensing circuit is detected, and the processor obtains an ideal pixel digital code corresponding to the fixed temperature for generating the channel temperature calibration data, and the channel temperature calibration data is generated based on a difference between the real pixel digital code and the ideal pixel digital code.

13. The current sensing calibration system of claim 9, wherein the current sensing circuit comprises: a current-to-voltage converter for converting a current signal into a voltage signal; and An analog-to-digital converter is coupled to the current-to-voltage converter and is used for converting the voltage signal into a digital code. 14 . The current sensing calibration system of claim 13 , wherein the offset calibration data is used to compensate for an offset data code of the current sensing circuit. 15 . The current sensing calibration system as claimed in claim 13 , wherein the gain calibration data is used to compensate a slope of a transfer function line of the current sensing circuit. 16 . The current sensing calibration system of claim 9 , wherein the first calibration current, the first ideal digital code, the second calibration current, the second ideal digital code, the third calibration current and the third ideal digital code are predetermined and stored in a memory of the processor.

17. The current sensing calibration system of claim 9, wherein the current sensing circuit comprises: A first switch, comprising: an input terminal coupled to the multiplexer; and an output terminal; A second switch, comprising: an input terminal for receiving a reference current; and an output terminal coupled to the output terminal of the first switch; An amplifier comprising: a first input terminal coupled to the output terminal of the first switch; a second input terminal, for receiving a first reference voltage; and an output terminal; A capacitor, comprising: a first terminal coupled to the first input terminal of the amplifier; and a second terminal coupled to the output terminal of the amplifier; A third switch, comprising: an input terminal coupled to the first terminal of the capacitor; and an output terminal coupled to the second terminal of the capacitor; A comparator comprising: a first input terminal coupled to the output terminal of the amplifier; a second input terminal, for receiving a second reference voltage; and an output terminal; and A time-to-digital converter comprising: a first input terminal coupled to the output terminal of the comparator; a second input terminal for receiving a reference clock signal; and An output terminal is used to output a digital code.

18. A current sensing calibration system as described in claim 17, wherein when the second switch is enabled, the capacitor is charged to reach a pre-charge voltage, when the second switch is disabled and the first switch is enabled, the capacitor is discharged to the first reference voltage, and the third switch is used to reset a charging state of the capacitor at each clock cycle, and the pre-charge voltage is greater than the first reference voltage.

19. The current sensing calibration system of claim 18, wherein the output of the comparator is at a high voltage when the capacitor is charged to reach the pre-charge voltage, and the output of the comparator is at a low voltage when the capacitor is discharged to the first reference voltage.

20. The current sensing calibration system of claim 18, wherein the time-to-digital converter digitizes a length of time for the capacitor to discharge from the pre-charge voltage to the first reference voltage to generate the digital code, and when the first reference voltage changes, the second reference voltage is adjusted to stabilize an output of the comparator.

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