Current supply circuit and display device including the same

Abstract

The current supply circuit according to the present embodiment may include a voltage / current converter that converts a data voltage received from a data driving circuit into a data current, and a first current mirror circuit that mirrors the data current to allow a light-emitting diode current to flow to a light-emitting diode array, and the data current may be adjusted based on the grayscale value of the light-emitting diode array.

Description

Technology Field

[0001] The present embodiment relates to a current supply circuit and a display device including the same. Background Technology

[0002] The display device may include various types of panels, such as organic light-emitting diodes (OLEDs) and liquid crystal displays (LCDs), and includes a data driving circuit, a gate driving circuit, a current supply circuit, etc., for driving pixels arranged on the panel.

[0003] The data driving circuit determines the data voltage or data current according to the image data and controls the brightness of the pixels by supplying the data voltage or data current to the pixels of the panel through the data line.

[0004] Since the light-emitting diode voltage or light-emitting diode current delivered to the pixel's light-emitting diode is determined in correspondence with the magnitude of the data voltage or data current delivered from the data driving circuit, and the brightness of the panel is determined accordingly, it is necessary to appropriately adjust the light-emitting diode voltage or current according to the required brightness of the display device.

[0005] In particular, when a light-emitting diode current with a constant magnitude or rate of change is supplied regardless of the pixel's grayscale value, it fails to provide appropriate resolution for each grayscale area, and a problem arises where unnecessary power is consumed. The problem to be solved

[0006] Against this backdrop, the object of the present invention is to provide a circuit capable of appropriately compensating for data voltage or data current to enable the realization of a desired pixel brightness in a display device, and a display device including the same.

[0007] In addition, the objective of the present invention is to provide a circuit capable of converting data voltage into a data current using a voltage / current converter and controlling the converted data current to adjust the resolution for each grayscale range of pixels, and a display device including the same.

[0008] In addition, the objective of the present invention is to provide a circuit and a display device including the same that can improve resolution by reducing the amount of data current change according to the data voltage input by lowering the current mirror ratio in the low-gradation range, and simultaneously supply additional compensation current in the high-gradation range to match the driving range of the light-emitting diode. means of solving the problem

[0009] To achieve the aforementioned objective, in one aspect, the present embodiment may provide a current supply circuit comprising: a voltage / current converter that converts a data voltage received from a data driving circuit into a data current; and a first current mirror circuit that mirrors the data current to allow a light-emitting diode current to flow to a light-emitting diode array, wherein the data current has a first rate of change in a first grayscale interval and a second rate of change in a second grayscale interval based on the data voltage.

[0010] To achieve the aforementioned objective, in another aspect, the present embodiment may provide a current supply circuit comprising: a first current mirror circuit that mirrors a data current through first and second transistors and outputs it to a light-emitting diode; a voltage / current converter comprising an amplifier that receives and outputs a data voltage through a first input terminal and a third transistor that receives the output voltage of the amplifier at a gate terminal and generates the data current; and a compensation current generation circuit that supplies a compensation current to the first current mirror circuit to change the data current.

[0011] In order to achieve the aforementioned objective, in another aspect, the present embodiment may provide a data processing circuit for controlling a light-emitting diode current transmitted to a light-emitting diode of a display device, wherein the display device comprises: a first current mirror circuit that generates the light-emitting diode current corresponding to the data current; and a compensation current generation circuit that supplies a compensation current to the first current mirror circuit, and the data processing circuit controls the light-emitting diode current by transmitting a current control signal that changes the data current or the compensation current. Effects of the invention

[0012] As described above, according to the present embodiment, the resolution can be improved by reflecting the grayscale characteristics of pixels in the display device, and the power consumption during the operation of the display device can be reduced.

[0013] In addition, according to the present embodiment, the driving of the light-emitting diode and the brightness of the pixel can be finely controlled for each grayscale range.

[0014] In addition, according to the present embodiment, compatibility with existing display device operating conditions can be ensured, and at the same time, the resolution in the low-gradation area can be improved. Brief explanation of the drawing

[0015] FIG. 1 is a drawing showing the configuration of a display device according to one embodiment of the present invention. FIG. 2 is a first exemplary diagram showing the signal flow of a current supply circuit according to one embodiment of the present invention. FIG. 3 is a diagram showing the signal timing of a current supply circuit according to one embodiment of the present invention. FIG. 4 is a first example drawing of a current supply circuit according to one embodiment of the present invention. FIG. 5 is a second exemplary diagram showing the signal flow of a current supply circuit according to one embodiment of the present invention. FIG. 6 is a diagram showing a compensation current generation circuit according to one embodiment of the present invention. FIG. 7 is a second example drawing of a current supply circuit according to one embodiment of the present invention. FIG. 8 is a diagram showing the correlation between data voltage and data current according to one embodiment of the present invention. FIG. 9 is a diagram illustrating a current supply circuit control method of a data processing circuit according to an embodiment of the present invention. Specific details for implementing the invention

[0016] FIG. 1 is a drawing showing the configuration of a display device according to one embodiment of the present invention.

[0017] Referring to FIG. 1, the display device (100) may include a panel (110), a data driving circuit (120), a gate driving circuit (130), a data processing circuit (150), etc.

[0018] A plurality of data lines (DL), gate lines (GL), etc. are arranged on the panel (110), and a plurality of pixels (P: Pixel) can be arranged.

[0019] The panel (110) may be formed by separating or integrally forming one or more of a display panel (not shown) and a touch panel (not shown), and the panel (110) may be a variety of panels such as an LCD (Liquid Crystal Display), OLED (Organic Light Emitting Diode), LED (Light Emitting Diode), and mini-LED, but is not limited thereto.

[0020] Pixels (P) placed on the panel (110) may include one or more light-emitting diodes (LEDs) and one or more transistors. The brightness or resolution of the pixel (P) may be determined by the voltage or current delivered to the pixel (P).

[0021] If the panel (110) is a liquid crystal display, the light-emitting diode (LED) can be defined as a backlight, and the brightness of the panel (110) can be determined according to the light-emitting power of the light-emitting diode.

[0022] The data driving circuit (120) can supply data voltage to the pixel (P) through the data line (DL). The data voltage supplied through the data line (DL) can be transmitted to the pixel (P) connected to the data line (DL) according to the scan signal of the gate driving circuit (130). If necessary, the data driving circuit (120) can be defined as a source driver.

[0023] The data driving circuit (120) can transmit an analog signal to the pixel (P) in the form of voltage or current, and can further include a voltage / current converter (not shown) to change the state of the data voltage or data current and supply it to the light-emitting diode (LED), etc. of the pixel (P).

[0024] The data driving circuit (120) can receive an analog signal (e.g., voltage, current, etc.) formed at each pixel (P) through a sensing line (SL) (not shown) and can determine the characteristics of the pixel (P). In addition, the data driving circuit (120) can sense changes in the characteristics of each pixel (P) over time and transmit them to the data processing circuit (150).

[0025] Each pixel (P) can be defined as a pixel electrode, a common electrode, etc., and the brightness of the pixel (P) can be quantified as a grayscale value (Greyscale) and can serve as a reference point for brightness control of the panel (110). For example, a data voltage (V_data) corresponding to the grayscale value (Greyscale) can be obtained, and the brightness of the panel (110) can be adjusted according to the correlation between the data voltage (V_data) and the data current (I_data).

[0026] The data driving circuit (120) is in the form of supplying voltage to a light-emitting diode (LED) and may have the form of a driving chip in the form of a plurality of integrated circuits. For example, the plurality of driving chips can transmit an analog signal to the light-emitting diode (LED) in the form of a data voltage.

[0027] The pixel sensing circuit (not shown) may include an analog front end (AFE), a sample and hold (S / H), an amplifier (AMP), an analog-to-digital converter (ADC), etc.

[0028] The analog front section (not shown) can sense the pixel (P) and process the current transmitted from the pixel (P) to form a sensing voltage (Vi).

[0029] The sample-and-hold section (not shown) signal-separates the analog front-end and the amplifier, temporarily stores the sensing voltage (Vi) output from the analog front-end, and then uses the sensing voltage (Vi) or the difference between the sensing voltage and the reference voltage ( Vi) can be input into the amplifier section.

[0030] The amplifier (not shown) receives the sensing voltage (Vi) transmitted to the input terminal or the difference between the sensing voltage and the reference voltage ( After amplifying Vi), it can be transmitted to the analog-to-digital converter.

[0031] The analog-to-digital converter (not shown) can convert the output voltage of the amplifier into a digital signal (Ao).

[0032] The gate driving circuit (130) can supply a scan signal of a turn-on voltage or a turn-off voltage to the gate line (GL). When the scan signal of the turn-on voltage is supplied to the pixel (P), the pixel (P) is connected to the data line (DL), and when the scan signal of the turn-off voltage is supplied to the pixel (P), the connection between the pixel (P) and the data line (DL) is disconnected. If necessary, the gate driving circuit (130) can be defined as a gate driver. The scan signal of the gate driving circuit (130) can define the turn-on timing or turn-off timing of the transistor of the pixel (P).

[0033] The data processing circuit (150) can supply various control signals to the data driving circuit (120) and the gate driving circuit (130). The data processing circuit (150) can transmit a data control signal (DCS) that controls the data driving circuit (120) to supply data voltage to each pixel (P) according to each timing, or transmit a gate control signal (GCS) to the gate driving circuit (130). If necessary, the data processing circuit (150) can be defined as a timing controller (T-Con).

[0034] The data processing circuit (150) can output image data (RGB) converted from externally input image data to match the data signal format used by the data driving circuit (120) and transmit it to the data driving circuit (120).

[0035] Additionally, the data processing circuit (150) can generate a signal to control various circuits, such as transistors included in the current supply circuit (not shown) of the panel (110), and transmit it to the panel (110).

[0036] Since the brightness of the light-emitting diode (LED) of the panel (110) is controlled by a current supply circuit (not shown), the data processing circuit (150) can determine the brightness of the pixel (P) by controlling the current supply circuit.

[0037] The data processing circuit (150) defines some of the total light-emitting diodes (LEDs) as blocks and can finely control the grayscale value for each target position of the panel (110) by selectively controlling the light-emitting diodes (LEDs) of each block.

[0038] The transistor (not shown) in this specification may be a field effect transistor (FET), and various types such as a bipolar junction transistor (BJT) may be applied.

[0039] FIG. 2 is a first exemplary drawing showing the signal flow of a current supply circuit according to one embodiment of the present invention.

[0040] FIG. 3 is a diagram showing the signal timing of a current supply circuit according to one embodiment of the present invention.

[0041] Referring to FIG. 2, the current supply circuit (200) may include a voltage / current converter (210), a current mirror circuit (220), etc.

[0042] The signal flow of the current supply circuit (200) can be defined by the data voltage transmitted through the data line (DL) and the scan signal transmitted through the gate line (GL).

[0043] The current supply circuit (200) may receive a data voltage (V_data) from the data driving circuit (120) or receive a data current (I_data) converted by the voltage-current converter (123). Here, the data voltage (V_data) and the data current (I_data) may be signals used for the operation of the current supply circuit (200) after the voltage or current transmitted from the data driving circuit (120) is converted.

[0044] The voltage / current converter (210) may be omitted depending on the type of analog signal transmitted from the data driving circuit (120). For example, if the signal transmitted from the data driving circuit (210) is a data current (I_data), the voltage-current converter (210) is omitted, and the data current (I_data) can be transmitted directly to the current mirror circuit (220).

[0045] The current mirror circuit (220) can receive a scan signal from the gate driving circuit (130) and transmit an output voltage or output current corresponding to the timing to the light-emitting diode (290).

[0046] The output voltage or output current of the current mirror circuit (220) can correspond to the magnitude of the data voltage (V_data) or data current (I_data).

[0047] The magnitude of the current delivered to the light-emitting diode (290) can be defined according to the voltage at the output terminal (OUT) of the current mirror circuit (220) and the light-emitting diode voltage (V_LED) at one end of the light-emitting diode (290). Additionally, the magnitude of the light-emitting diode current (I_LED), which is the current delivered to the light-emitting diode (290), can be defined according to the state of the transistor connected to the output terminal of the current mirror circuit (220).

[0048] FIG. 2 is a diagram showing the signal flow for controlling the brightness of a light-emitting diode (290) by an analog signal of a current supply circuit (200), wherein the voltage / current converter (210) or the current mirror circuit (220) may be omitted or replaced with another circuit.

[0049] Referring to Fig. 3, the timing of the input signal and output signal of the current supply circuit can be compared.

[0050] In the current mirror circuit (220), a data voltage or data current can be supplied through the data line (DL), and a scan signal can be supplied through the gate line (GL).

[0051] The output voltage of the signal at the output terminal (OUT) of the current mirror circuit (220) can be generated in response to the pulse timing (t1, t2, t3) of the scan signal of the gate line (GL).

[0052] The signal at the output terminal (OUT) of the current mirror circuit (220) may be a signal that mirrors and outputs a data voltage or data current transmitted to the data line (DL). In this case, the current mirror circuit (220) may be a current mirror circuit in which a plurality of transistors are combined, but is not limited thereto.

[0053] The magnitude of the signal (H4, H5, H6) at the output terminal (OUT) of the current mirror circuit (220) may be the same as the magnitude of the data voltage or data current (H1, H2, H3), and may be defined to have a corresponding relationship with a constant correlation or a signal magnitude ratio of a constant multiple.

[0054] The input and output signals of the current mirror circuit (220) are examples of the magnitude and waveform of each signal, and are not limited to the form of FIG. 3.

[0055] The current mirror circuit (220) may further include a voltage compensation circuit (not shown) to maintain the ratio of the desired input signal and output signal, and may change or compensate the magnitude and state of the input signal and output signal by a control signal of the data processing device (150).

[0056] FIG. 4 is a first example drawing of a current supply circuit according to one embodiment of the present invention.

[0057] Referring to FIG. 4, the current supply circuit (200) may include a voltage / current converter (210), a first current mirror circuit (220), a light-emitting diode (290), etc.

[0058] The first current mirror circuit (220) may include a first transistor (221) connected to a first node (Node 1) and a second transistor (222) connected to a second node (Node 2) to mirror the data current (I_data) and allow current to flow through the light-emitting diode array.

[0059] The first transistor (221) can directly receive a data voltage (V_data) or a data current (I_data) transmitted from a data driving circuit (not shown), and can receive a signal that converts or compensates each voltage or current.

[0060] One terminal of the first transistor (221) can be connected in common with the gate terminal of the first transistor (221) and the gate terminal of the second transistor (222) to form a current mirror circuit (220). In this case, the signal received by the first transistor (221) can be stably transmitted to the second transistor (222).

[0061] The second transistor (222) can receive a signal transmitted from the first transistor (221) and supply current to the light-emitting diode (290). The second transistor (222) is connected to the gate terminal of the first transistor (221) and can output a light-emitting diode current (I_LED) corresponding to a data current (I_data).

[0062] The second transistor (222) can mirror the data current (I_data) transmitted to the first transistor (221) and transmit it to the light-emitting diode (290). Here, mirroring may be defined as outputting a current of the same magnitude as the received current, but may also be defined as outputting a signal having a corresponding relationship with a certain correlation or a signal magnitude ratio of a certain multiple.

[0063] The first and second transistors (221, 222) may be field effect transistors (FETs) and bipolar junction transistors (BJTs).

[0064] A voltage / current converter (210) is disposed between the data driving circuit (not shown) and the first transistor (221) to convert the data voltage (V_data) into a data current (I_data), but the voltage / current converter (210) may be omitted if the type of signal transmitted from the data driving circuit (not shown) is a data current (I_data).

[0065] The voltage / current converter (210) may include an amplifier (211), a third transistor (212), a second current mirror circuit (213), a reference resistor (214), etc., to convert a data voltage (V_data) received from a data driving circuit into a data current (I_data).

[0066] The amplifier (211) can receive a data voltage (V_data) through a first input terminal—e.g., a positive input terminal—and generate an output voltage. The output terminal of the amplifier (211) can be connected to a third transistor (212) to provide an output voltage, and the second input terminal of the amplifier (211)—e.g., a negative input terminal) can be connected to one terminal of the third transistor.

[0067] One end of the reference resistor (R_ref) (214) can be connected to the common node of the second input terminal of the amplifier (211) and one terminal of the third transistor (212), and the other end can have a ground voltage (GND).

[0068] The second current mirror circuit (213) may be a current mirror circuit formed by the fourth transistor (216) and the fifth transistor (217), and may have various current mirroring ratios depending on the size and parameter conditions of the fourth transistor (216) and the fifth transistor (217).

[0069] The second current mirror circuit (213) receives the power supply voltage (VCC) at one end of the fourth and fifth transistors (216, 217), and at the other end receives the voltage from one terminal of the third transistor (212) and transmits it to the gate terminal of the fourth transistor (216). Here, the power supply voltage (VCC) can be any voltage transmitted from the power supply and can be a separate signal distinct from the data voltage (V_data).

[0070] The second current mirror circuit (213) can generate a data current (I_data) by mirroring the current flowing through one terminal of the third transistor (212) and can transmit it to the first current mirror circuit (220).

[0071] The second current mirror circuit (213) can change the slope of the change of the data current (I_data) relative to the data voltage (V_data) by adjusting the mirroring ratio. For example, the amount of change of the data current (I_data) according to the data voltage (V_data) in the low-gradation region can be reduced, and the amount of change of the data current (I_data) according to the data voltage (V_data) in the high-gradation region can be increased. By doing so, a higher resolution than that of conventional circuits can be achieved.

[0072] The light-emitting diode (290) may be an individual device, but may be defined as an array of multiple light-emitting diodes composed of one channel (CH1). Additionally, the light-emitting diode (290) may include multiple channels to form a panel.

[0073] The light-emitting diode (290) or pixel may have various brightness values, and may represent brightness by being defined as a numeric value such as 0 to 255 as a grayscale value. The grayscale value of the light-emitting diode (290) or pixel is defined as a grayscale section divided into a first grayscale section and a second grayscale section, and the data current (I_data) and light-emitting diode current (I_LED) of the first grayscale section and the second grayscale section may be defined.

[0074] Any one end of the voltage / current converter (210), the first transistor (221), and the second transistor (222) may be supplied with the same voltage—e.g., ground voltage—but is not limited thereto. In this case, one end of each circuit (210, 221, 222) may be supplied with the same voltage to set a reference point for signal transmission.

[0075] FIG. 5 is a second exemplary diagram showing the signal flow of a current supply circuit according to one embodiment of the present invention.

[0076] Referring to FIG. 5, the signal flow of the current supply circuit (300) can be determined by the voltage / current converter (310), the current mirror circuit (320), the compensation current generation circuit (330), etc.

[0077] The voltage / current converter (310) can receive a data voltage (V_data) from a data driving circuit (not shown) and convert it into a first data current (I_data1) to output it.

[0078] The voltage / current converter (310) forms a common node—e.g., a first node—with the current mirror circuit (320) and can transmit to the first data current (I_data1) through this. If the current compensation circuit (330) is not present or the compensation current generation circuit (330) does not transmit the compensation current (I_com), the first data current (I_data1) may be the same as the second data current (I_data2).

[0079] The current mirror circuit (320) receives a second data current (Idata) and can transmit a corresponding output voltage or output current to the light-emitting diode (290). The output voltage or output current of the current mirror circuit (220) may be equal to the magnitude of the data voltage (V_data) or data current (I_data) or have a constant correlation.

[0080] The magnitude of the light-emitting diode current (I_LED) delivered to the light-emitting diode (290) can be defined according to the voltage at the output terminal (OUT) of the current mirror circuit (220) and the light-emitting diode voltage (V_LED) at one end of the light-emitting diode (390).

[0081] The compensation current generation circuit (330) can compensate for the first data current (I_data1) by transmitting a compensation current (I_com) to the first node and adjust the second data current (I_data2) transmitted to the current mirror circuit (320). Here, the first node may be a common node to which the voltage / current converter (310), the current mirror circuit (320), and the compensation current generation circuit (330) are connected in common.

[0082] The limited characteristics of the first data current (I_data1) are compensated by the compensation current generation circuit (330), thereby enabling more precise brightness control of the pixel (P).

[0083] When the data voltage (V_data) and the first data current (I_data1) increase with a linear correlation in the voltage / current converter (310), the compensation current generation circuit (330) can adjust the rate of change or magnitude of the compensation current (I_com) to independently and individually adjust the slope or current strength of the second data current (I_data2).

[0084] For example, the compensation current generation circuit (330) can supply a compensation current in the form of an amount of current that is insufficient in the high-gradation region to compensate for the reduced light-emitting diode current (I_LED) in the low-gradation region. In this case, the combination of the voltage / current converter (310) and the compensation current generation circuit (330) can produce improved technical effects within the existing light-emitting diode driving region by improving the current resolution in the low-gradation region and compensating for the insufficient current value in the high-gradation region.

[0085] FIG. 6 is a diagram showing a compensation current generation circuit according to one embodiment of the present invention.

[0086] Referring to FIG. 6, the compensation current generation circuit (330) may include a sixth transistor (331), a DC current source (332), a third current mirror circuit (333), a fourth current mirror circuit (336), etc.

[0087] The sixth transistor (331) can receive a bypass voltage (VBP) at its gate terminal and output a base current (I_base) at its terminal. For example, the gate terminal of the sixth transistor (331) can be connected to the gate terminal of the fourth transistor (216) or the fifth transistor (217) of FIG. 4 described above, and in this case, the magnitude and transmission timing of the analog signal can be maintained identically.

[0088] The bypass voltage (VBP) of the sixth transistor (331) may be related to the data voltage (V_data) and may be defined as a current source that outputs the base current (I_base).

[0089] The DC current source (332) is a current source that transmits a DC current (I_dc) and can be connected to one terminal of the sixth transistor (331) and the fifth node. If necessary, the direction of the DC current (I_dc) can be changed.

[0090] The base current (I_base) delivered from the 6th transistor (331) and the DC current (I_dc) delivered from the DC current source (332) can be combined at node 5 to form a compensation current (I_base).

[0091] The base current (I_base) supplied by the sixth transistor (331) can change linearly according to the change in data voltage (V_data), and the DC current (I_dc) supplied by the DC current source (332) can have a constant magnitude. In this case, a compensation current (I_base) of a desired magnitude can be generated by a combination of the base current (I_base) and the DC current (I_dc).

[0092] The third current mirror circuit (333) receives the compensation current (I_base) and can mirror and transmit the compensation current (I_base) to the fourth current mirror circuit (336) through the seventh transistor (334) and the eighth transistor (335). In this case, the third current mirror circuit (333) can transmit a current to the fourth current mirror circuit (336) that has the same magnitude or a different magnitude as the compensation current (I_base) and has a constant correlation.

[0093] The fourth current mirror circuit (336) can transmit the current received from the third current mirror circuit (333) to the current mirror circuit (320) by mirroring it again through the ninth transistor (337) and the tenth transistor (338). The fourth current mirror circuit (336) can transmit a current to the current mirror circuit (320) that has the same magnitude or a different magnitude as the compensation current (I_base) and has a constant correlation.

[0094] The third and fourth current mirror circuits (333, 336) obtain a compensation current (I_com) as the sum of the output currents of the first current source—e.g., the sixth transistor (331) and the second current source—e.g., the DC current source (332)—and can overcome structural limitations of the circuit by mirroring the compensation current (I_com) at a constant ratio through a plurality of transistors. If necessary, the third and fourth current mirror circuits (333, 336) may be omitted so that the compensation current (I_com) can be directly transmitted to the current mirror circuit (320).

[0095] The third current mirror circuit (333) or the fourth current mirror circuit (334) can adjust the mirroring ratio of the compensation current (I_com) at a desired ratio to obtain the slope of the data current (I_data) required for each grayscale.

[0096] FIG. 7 is a second example drawing of a current supply circuit according to one embodiment of the present invention.

[0097] Referring to FIG. 7, the current supply circuit (300) may include a voltage / current converter (310), a first current mirror circuit (320), a compensation current generation circuit (330), etc.

[0098] The first current mirror circuit (320) can mirror the data current (I_data) through the first and second transistors (T1, T2) and output it to the light-emitting diode.

[0099] The first current mirror circuit (320) may include a first transistor (T1) that receives a data current (I_data) and a second transistor (T2) that generates a light-emitting diode current (I_LED). One terminal of the first current mirror circuit (320) may be supplied with a common voltage—e.g., a ground voltage (GND)—with the first transistor (T1).

[0100] The first current mirror circuit (320) is connected to the gate terminal of the first transistor (T1) and the gate terminal of the second transistor (T2) to supply a light-emitting diode current (I_LED) proportional to the data current (I_LED) to the light-emitting diode (390).

[0101] The voltage / current converter (310) may include an amplifier (311), a third transistor (312), a second current mirror circuit (313), a reference resistor (314), etc.

[0102] The amplifier (311) can receive and output a data voltage (V_data) through the first input terminal, and the second input terminal can be connected to another terminal of the third transistor (312)—for example, a drain terminal or a source terminal—to receive a feedback signal.

[0103] The third transistor (312) can receive the output voltage of the amplifier at its gate terminal and generate a basic signal that generates a data current.

[0104] The second current mirror circuit (313) can be connected to one terminal of the third transistor (312)—e.g., the source terminal or the drain terminal—to receive voltage or current. Additionally, the second current mirror circuit (313) can generate a data current (I_data) based on the difference between the voltage formed at one terminal of the third transistor (312) and the supply voltage (VCC).

[0105] The second current mirror circuit (313) can mirror the current flowing to one terminal of the third transistor (312) by the fourth and fifth transistors (T4, T5) and can adjust the current amplification ratio.

[0106] The compensation current generation circuit (330) may include a sixth transistor (331), a DC current source (332), a third current mirror circuit (333), a fourth current mirror circuit (336), etc.

[0107] The gate terminal of the sixth transistor (331) can be connected to a common node—e.g., node 4—formed by the gate terminal of the fourth transistor (T4) and the gate terminal of the fifth transistor (T5). Through this, the sixth transistor (331) can receive a voltage identical to the bypass voltage (VBP) formed at node 4 and can perform operations linked to the signal strength and timing of the second current mirror circuit (313). When the bypass voltage (VBP) of node 4 changes, the voltage of the gate terminal of the sixth transistor (331) can also change in the same way.

[0108] The sixth transistor (331) can be separated from the bypass voltage (VBP) of node 4 and perform separate driving as needed.

[0109] The DC current source (332) can supply DC current to one terminal of the sixth transistor (331)—e.g., node 5—and a compensation current (I_com) can be generated by the base current (I_base) supplied by the sixth transistor (331) and the DC current (I_dc) of the DC current source.

[0110] The third and fourth current mirror circuits (333, 336) can generate a compensated data current (I_data) by outputting a current to node 1 that has the same magnitude or constant correlation as the compensation current (I_com).

[0111] Here, one terminal of the third transistor (333) and the DC current source (332) can be supplied with a common voltage—e.g., ground voltage (GND)—and one terminal of the fourth transistor (336) and the sixth transistor (331) can be supplied with a common voltage—e.g., power supply voltage (VCC).

[0112] FIG. 8 is a diagram showing the correlation between data voltage and data current according to one embodiment of the present invention.

[0113] Referring to FIG. 8, the correlation between the data voltage (V_data) and the data current (I_data) can be compared, and the graph may reflect the operation of the current supply circuit or data processing circuit of FIG. 1 to 7 described above.

[0114] In a current supply circuit with a voltage / current converter as shown in Fig. 4, the data voltage (V_data) and data current (I_data) can be represented as a graph having a linear correlation (400A).

[0115] In this case, since the data current (I_data) is determined by the data voltage (V_data) and the reference resistor (R_ref), there are limitations in changing the correlation between the data voltage (V_data) and the data current (I_data) without a separate operation. In particular, the same resolution characteristics—for example, the rate of change of the data current (I_data) with respect to changes in the data voltage (V_data)—are maintained in both low and high grayscale ranges.

[0116] As shown in Fig. 7, in a current supply circuit with a voltage / current converter and a compensation current generation circuit, the data voltage (V_data) and data current (I_data) can have a linear correlation in each section, and the slope and position of the graph can be changed in each section (400B).

[0117] For example, a reference voltage (V_ref) and a reference current (I_ref) can be defined, and the graph of the light-emitting diode current (I_LED) can be adjusted accordingly.

[0118] In the low-gradation section—for example, the first gradation section (Section 1)—the ratio of current mirroring is lowered to have high current resolution, thereby reducing the change in the light-emitting diode current (I_LED) relative to the data voltage (V_data) and thereby improving the current resolution.

[0119] The first grayscale section (Section 1) may be a voltage range below the reference voltage (V_ref), and in this case, a first compensation current having a first slope may be generated.

[0120] In the high-gradation section—for example, in the second gradation section (Section 2), the light-emitting diode current (I_LED) that was reduced in the low-gradation section can be additionally supplied through a compensation current generation circuit (not shown) to realize the light-emitting diode driving area of ​​the high-gradation section.

[0121] In the high-gradation section, the change in the light-emitting diode current (I_LED) relative to the data voltage (V_data) is increased, and an additional current can be supplied equal to the DC power supply (I_dc).

[0122] The second grayscale section (Section 2) may be a voltage range that exceeds the reference voltage (V_ref), and in this case, a second compensation current having a second slope may be generated. In this case, the second slope may be greater than the first slope.

[0123] The first grayscale section and the second grayscale section can form a single continuous grayscale section, and the data current (I_Data) according to the change in data voltage (V_data) can represent a continuous graph.

[0124] As shown in FIG. 8, by adjusting the intensity of the light-emitting diode current (I_LED) for each grayscale interval, it is possible to continuously implement light-emitting diode currents (I_LED) having different current gradients for each grayscale interval in response to changes in data voltage (V_data). Additionally, the current gradients for each grayscale interval may have the same current gradient as needed, and this can be determined by the current mirroring ratio.

[0125] The light-emitting diode driving region may have a driving region specified by the maximum data voltage (V_data) and the maximum light-emitting diode current (I_LED), and can be implemented by optimizing the operating range within the light-emitting diode driving region using the method described above.

[0126] Here, the grayscale interval may be an interval specified by the grayscale value of a light-emitting diode array or pixel, and the data current (I_data) or light-emitting diode current (I_LED) may be specified by a reference voltage (V_ref) and a reference current (I_ref) that implement a reference grayscale value.

[0127] In FIG. 8, since the data current (I_data) or the light-emitting diode current (I_LED) is a current that has the same or constant correlation, each term may be confused or used interchangeably.

[0128] FIG. 9 is a diagram illustrating a current supply circuit control method of a data processing circuit according to an embodiment of the present invention.

[0129] Referring to FIG. 9, the data processing circuit (540) can control the operation of each circuit by transmitting control signals (CS1, CS2) of the voltage / current converter (510) and the compensation current generation circuit (530).

[0130] The current supply circuit (500) of the display device may include a first current mirror circuit (520), a voltage / current converter (510), a compensation current generation circuit (530), etc.

[0131] The voltage / current converter (510) can convert the data voltage transmitted through the data line in the data driving circuit into a first data current (I_data1) and may further include a current mirror circuit (not shown) that can adjust the ratio of the second data current (I_data2) as needed.

[0132] The first current mirror circuit (520) can generate a light-emitting diode current corresponding to the second data current (I_data2).

[0133] The compensation current generation circuit (530) can supply a compensation current (I_com) to the first current mirror circuit (520). If necessary, the compensation current generation circuit (530) may further include a DC current source (not shown) that supplies a DC current and a third current mirror circuit (not shown) that generates a compensation current (I_com) corresponding to the DC current.

[0134] The data processing circuit (540) can change the brightness of the light-emitting diode (LED) by directly controlling the data driving circuit (not shown) or by controlling the current supply control circuit (500).

[0135] The data processing circuit (540) can control the light-emitting diode current (I_LED) by transmitting current control signals (CS1, CS2) that change the first and second data currents (I_data1, I_data2) or the compensation current (I_com) to the current supply circuit (500).

[0136] The data processing circuit (540) can control the compensation current (I_com) by transmitting a control signal that adjusts the magnitude of the DC current supplied from the DC current source of the compensation current generation circuit (530).

[0137] The data current (I_data1, I_data2) can be determined according to the grayscale value of the light-emitting diode or pixel, and the data processing circuit (540) can determine the data current (I_data1, I_data2) such that the slope of the data voltage-data current in the low grayscale section below the reference grayscale value is smaller than the slope of the data voltage-data current in the high grayscale section exceeding the reference grayscale value.

[0138] Additionally, the data processing circuit (540) can determine and control the magnitude, slope, etc. of the data current (I_data1, I_data2) and compensation current (I_com) based on data regarding the preset reference data voltage and reference data current.

Claims

Claim 1 A voltage / current converter that converts a data voltage received from a data driving circuit into a data current; a first current mirror circuit that mirrors the data current to cause a light-emitting diode current to flow in a light-emitting diode array; and a compensation current generation circuit connected to the voltage / current converter and controlling the data current transmitted to the first current mirror circuit, wherein the data current has a first rate of change in a first grayscale section and a second rate of change in a second grayscale section based on the data voltage, and the compensation current generation circuit includes a first current source that outputs a base current defined by the data voltage; and a second current source connected to the first current source and outputting a direct current. Claim 2 A current supply circuit according to claim 1, wherein the rate of change of the data current in the first grayscale section and the second grayscale section is determined according to a reference data current and a reference data voltage, and the rates of change of the data current in the first grayscale section and the second grayscale section are different. Claim 3 delete Claim 4 delete Claim 5 In claim 1, the compensation current generating circuit obtains the compensation current as the sum of the output currents of the first current source and the second current source, and outputs the compensation current by mirroring it through a plurality of transistors, a current supply circuit. Claim 6 In claim 1, the first current mirror circuit comprises: a first transistor receiving the data current; and a second transistor connected to the gate terminal of the first transistor and outputting the light-emitting diode current corresponding to the data current, wherein one terminal of the first transistor is connected in common to the gate terminal of the first transistor and the gate terminal of the second transistor, a current supply circuit. Claim 7 In claim 1, the voltage / current converter comprises: an amplifier receiving the data voltage at a first input terminal; a third transistor receiving the output voltage of the amplifier at a gate terminal; and a reference resistor connected in common with the second input terminal of the amplifier and one terminal of the third transistor, a current supply circuit. Claim 8 In claim 7, the voltage / current converter further comprises a second current mirror circuit that generates the data current by mirroring the current flowing to the other terminal of the third transistor, a current supply circuit. Claim 9 In claim 1, the voltage / current converter and the first current mirror circuit are a current supply circuit that receives a voltage of the same magnitude through one terminal of a reference resistor included in the voltage / current converter, one terminal of a first transistor included in the first current mirror circuit, and one terminal of a second transistor. Claim 10 A voltage / current converter comprising: a first current mirror circuit that mirrors a data current through first and second transistors and outputs it to a light-emitting diode; an amplifier that receives and outputs a data voltage through a first input terminal; and a third transistor that receives the output voltage of the amplifier at a gate terminal and generates the data current; and a compensation current generation circuit that supplies a compensation current to the first current mirror circuit to change the data current, wherein the compensation current generation circuit comprises: a first current source that outputs a base current defined by the data voltage; and a second current source connected to the first current source and outputting a direct current. Claim 11 In claim 10, the first current mirror circuit comprises: a first transistor receiving the data current; and a second transistor having one terminal supplied with a common voltage with the first transistor and a gate terminal connected to the gate terminal of the first transistor to supply a light-emitting diode current proportional to the data current to the light-emitting diode. Claim 12 In claim 10, the voltage / current converter further comprises a second current mirror circuit that generates the data current with a deviation between the voltage formed at one terminal of the third transistor and an external supply voltage (VCC), and the other terminal of the third transistor is connected to the second input terminal of the amplifier, a current supply circuit. Claim 13 In claim 10, the compensation current generating circuit generates a first compensation current having a first slope in a voltage range below a reference voltage and generates a second compensation current having a second slope in a voltage range above the reference voltage, wherein the second slope is greater than the first slope, a current supply circuit. Claim 14 In claim 12, the second current mirror circuit determines the rate of change of the data current according to the change of the data voltage, and the compensation current generation circuit determines the magnitude of the compensation current, a current supply circuit. Claim 15 In claim 12, the second current mirror circuit comprises a fourth transistor and a fifth transistor, and the compensation current generation circuit comprises: a sixth transistor connected to a common node formed by the gate terminal of the fourth transistor and the gate terminal of the fifth transistor, and changing the output voltage according to a bypass voltage formed at the common node; a DC current source supplying a DC current to one terminal of the sixth transistor; and a third current mirror circuit that receives the output current of the sixth transistor and the DC current of the current source to generate the compensation current and supply it to the first current mirror circuit. Claim 16 A data processing circuit for controlling a light-emitting diode current transmitted to a light-emitting diode of a display device, wherein the display device comprises: a first current mirror circuit for generating the light-emitting diode current corresponding to the data current; and a compensation current generating circuit for supplying a compensation current to the first current mirror circuit, wherein the data processing circuit controls the light-emitting diode current by transmitting a current control signal that changes the data current or the compensation current, and wherein the compensation current generating circuit comprises: a DC current source for supplying a DC current; and a third current mirror circuit for generating the compensation current corresponding to the DC current, and wherein the data processing circuit controls the compensation current by adjusting the magnitude of the DC current. Claim 17 In claim 16, the display device further includes a voltage / current converter that converts a data voltage transmitted through a data line in a data driving circuit into a data current, the voltage / current converter includes a second current mirror circuit that generates the data current, and the data processing circuit controls the data current by adjusting the mirroring ratio of the second current mirror circuit. Claim 18 delete Claim 19 In claim 16, the data current is determined according to the grayscale value of the light-emitting diode, and the data processing circuit determines the data current such that the slope of the data voltage-data current in a low grayscale section below the reference grayscale value is smaller than the slope of the data voltage-data current in a high grayscale section exceeding the reference grayscale value. Claim 20 In claim 16, the data processing circuit determines the magnitude of the data current and the compensation current based on data regarding a preset reference data voltage and reference data current.

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