KR20220059818A - Display apparatus having 2-pin pixel circuit with improved signal detection capability - Google Patents

Abstract

The present specification provides a pixel circuit with a reduced number of contacts, and discloses how such a pixel circuit can operate. The pixel circuit according to the present specification is a pixel circuit comprising a positive power terminal and a negative power terminal related to power required for driving a pixel driving circuit unit for driving a plurality of light emitting devices, the positive power terminal being connected to the data driving circuit, and the negative power supply terminal being connected to the data driving circuit, The power terminal may be connected to the scan driving circuit. The pixel circuit may be driven by a potential difference between the signal output from the data driving circuit and the signal output from the scan driving circuit.

Description

DISPLAY APPARATUS HAVING 2-PIN PIXEL CIRCUIT WITH IMPROVED SIGNAL DETECTION CAPABILITY

The present invention relates to a pixel included in a display device, and more particularly, to a pixel circuit having two contacts connected to the outside.

1 is a circuit diagram schematically illustrating the structure of a general pixel.

Referring to FIG. 1 , a pixel including three light emitting devices R, G, and B may be identified. A typical pixel needs 4 contacts. Two contacts (Vcc, GND) related to power required to drive a pixel, a contact connected to a scan line that simultaneously turns on pixels arranged in a row direction (Scan), and data to which signals related to video data are input It is a contact point (Data) connected to a line.

Such a pixel driving circuit is generally implemented through a deposition method on a semiconductor wafer, etc., but as the number of contacts increases, the transfer efficiency may be lowered. In addition, as interest in display panels using micro LEDs has recently increased, a pixel driving circuit smaller than a conventional pixel is required. However, this also acts as a limit in reducing the size of the pixel as the number of contacts increases.

Republic of Korea Patent Publication No. 10-2017-0111788

An object of the present specification is to provide a pixel circuit having a reduced number of contacts, and to provide a method in which the pixel circuit can operate.

The present specification is not limited to the above-mentioned problems, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.

A display device according to the present specification for solving the above problems includes: a display panel including a plurality of pixel circuits; a scan driving circuit connected to any one of a plurality of scan lines connected to a negative power terminal of each pixel circuit to drive pixel circuits arranged in a row direction; and a data driving circuit configured to output a signal related to driving of a plurality of light emitting devices included in each pixel circuit through a plurality of data lines connected to both power terminals of each pixel circuit. In this case, the pixel circuit includes: a plurality of light emitting devices; a positive power terminal connected to the data driving circuit; a negative power terminal connected to the scan driving circuit; a pixel-embedded memory unit for storing data related to driving of a plurality of light emitting devices input through the positive power terminals; a light emitting device driving unit for driving the plurality of light emitting devices according to the driving data of each light emitting device stored in the pixel built-in memory unit; and a reference voltage supply unit for outputting a voltage that fluctuates according to a change in the potential of the negative power terminal to the pixel embedded memory unit and the light emitting device driving unit to operate circuits included in the pixel embedded memory unit and the light emitting device driving unit; may include In particular, the pixel embedded memory unit may receive data related to driving of the plurality of light emitting devices through an output terminal of a comparator having a non-inverting input terminal connected to the positive power terminal and an inverting input terminal connected to the negative power terminal.

According to an embodiment of the present specification, the pixel embedded memory unit includes at least one shift register; and at least one flip-flop for switching the operation of the shift register.

According to an exemplary embodiment of the present specification, a signal output from the data driving circuit has a reference potential, a first potential higher than the reference potential, or a second potential higher than the first potential, and a signal related to driving the light emitting devices may be a signal having at least one or more pulses that change from the first potential to the second potential.

According to an embodiment of the present specification, the scan driving circuit may output a signal having a driving data input section of the light emitting device and a driving section of the light emitting device for each scan line.

According to an exemplary embodiment of the present specification, the signal output from the scan driving circuit has a reference potential, a first potential higher than the reference potential, or a second potential higher than the first potential, and the driving data input section includes a first A signal having a potential, and the driving period of the light emitting device may be a signal having at least one or more pulses that change from a reference potential to a first potential.

According to an exemplary embodiment of the present specification, the scan driving circuit may output the signal having the second potential after the driving period of the light emitting device until the driving data input period of the next frame.

Other specific details of the invention are included in the detailed description and drawings.

According to one aspect of the present specification, since the number of contacts required for signal transmission is reduced compared to that of a conventional pixel, yield and efficiency can be increased in the process of manufacturing on a wafer.

According to another aspect of the present specification, it is possible to miniaturize the pixel circuit as much as the number of contacts is reduced, so that it is suitable for a small display or a driving circuit of a micro LED.

According to another aspect of the present specification, even when a signal for driving a light emitting device has a small voltage, the signal-to-noise ratio (SNR) is increased, so that accurate signal detection is possible.

Effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the following description.

1 is a circuit diagram schematically illustrating the structure of a general pixel.
2 is a display device including a plurality of pixel circuits according to the present specification.
3 is a block diagram schematically illustrating the configuration of a pixel circuit according to the present specification.
4 is a waveform diagram of a signal output to drive a pixel circuit in the display device according to the present specification.
5 is a timing reference diagram for the operation of one pixel circuit.
6 is a reference diagram of the operation of the pixel embedded memory unit in the driving data input section according to the present specification.
7 is a reference diagram of a comparator for outputting data related to driving of a light emitting device to an embedded pixel memory unit according to the present specification.
8 is a block diagram schematically illustrating a configuration of an embedded pixel memory unit according to an exemplary embodiment of the present specification.

Advantages and features of the invention disclosed herein, and methods of achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present specification is not limited to the embodiments disclosed below, but may be implemented in various different forms, and only the present embodiments allow the disclosure of the present specification to be complete, and those of ordinary skill in the art to which this specification belongs. It is provided to fully inform those skilled in the art (hereinafter, 'those skilled in the art') the scope of the present specification, and the scope of the present specification is only defined by the scope of the claims.

The terminology used herein is for the purpose of describing the embodiments and is not intended to limit the scope of the present specification. In this specification, the singular also includes the plural unless specifically stated otherwise in the phrase. As used herein, “comprises” and/or “comprising” does not exclude the presence or addition of one or more other components in addition to the stated components. Like reference numerals refer to like elements throughout, and "and/or" includes each and every combination of one or more of the recited elements. Although "first", "second", etc. are used to describe various elements, these elements are not limited by these terms, of course. These terms are only used to distinguish one component from another. Accordingly, it goes without saying that the first component mentioned below may be the second component within the spirit of the present invention.

Unless otherwise defined, all terms (including technical and scientific terms) used herein will have the meaning commonly understood by those of ordinary skill in the art to which this specification belongs. In addition, terms defined in a commonly used dictionary are not to be interpreted ideally or excessively unless specifically defined explicitly. Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is a display device including a plurality of pixel circuits according to the present specification.

Referring to FIG. 2 , the display apparatus 100 according to the present specification may include a display panel 110 , a scan driving circuit 120 , a data driving circuit 130 , and a controller 140 .

The display panel 110 may include a plurality of pixels (PX) according to the present specification. The plurality of pixels PX may be arranged in a matrix form m X n (m, n is a natural number). However, the pattern in which the plurality of pixels are arranged may be arranged in various patterns according to embodiments, such as a zigzag type.

The display panel 110 is a liquid crystal display (LCD), a light emitting diode (LED) display, an organic LED (OLED) display, an active-matrix OLED (AMOLED) display, an electrochromic display (ECD), a digital mirror device (DMD), It can be implemented as one of AMD (Actuated Mirror Device), GLV (Grating Light Valve), PDP (Plasma Display Panel), ELD (Electro Luminescent Display), VFD (Vacuum Fluorescent Display), and other types of flat panel display or flexible display It may be implemented as a display. In this specification, the LED display panel will be described as an example.

Each pixel PX may include a plurality of light emitting devices. The light emitting device may be a light emitting diode (LED). The light emitting diode may be a micro LED having a size of 80 μm or less. One pixel PX may output various colors through a plurality of light emitting devices having different colors. For example, one pixel PX may include a light emitting device composed of red, green, and blue colors. As another example, if a white light emitting device may be further included, the white light emitting device may replace any one of the red, green, and blue light emitting devices. Each light emitting element included in one pixel PX is called a 'sub pixel'.

Each pixel PX may include a pixel driving circuit for driving a plurality of sub-pixels. The pixel driving circuit may drive a turn-on or turn-off operation of a sub-pixel according to a control signal output from the scan driving circuit 120 and/or the data driving circuit 130 . The pixel driving circuit may include at least one thin film transistor and at least one capacitor. The pixel driving circuit may be implemented by a stacked structure on a semiconductor wafer.

The display panel 110 may include scan lines SL ₁ to SL _m arranged in a row direction and data lines DL ₁ to DL _n arranged in a column direction. Pixels PX may be positioned at intersections of the scan lines SL ₁ to SL _m and the data lines DL ₁ to DL _n . Each pixel PX may be connected to any one scan line SL _k and any one data line DL _k . The scan lines SL ₁ to SL _m may be connected to the scan driving circuit 120 , and the data lines DL ₁ to DL _n may be connected to the data driving circuit 130 .

The scan driving circuit 120 may drive pixels connected to any one of the scan lines SL ₁ to SL _m . Preferably, in the scan driving circuit 120 , the scan lines SL ₁ to SL _m may be sequentially selected. For example, pixels connected to the first scan line SL ₁ may be driven during the first scan driving period, and pixels connected to the second scan line SL ₂ may be driven during the second scan driving period. The operation of the scan driving circuit 120 according to the present specification will be described in more detail later.

The data driving circuit 130 may output a signal related to gradation to each pixel through the data lines DL ₁ to DL _n . Although one data line is connected to a plurality of pixels in the longitudinal direction, a signal related to grayscale may be input only to pixels connected to the scan line selected by the scan driving circuit 120 . The operation of the data driving circuit 130 according to the present specification will be described in more detail later.

The control unit 140 may output a control signal to execute the operations of the scan driving circuit 120 and the data driving circuit 130 . The controller 140 may output a control signal corresponding to image data corresponding to one image frame to the scan driving circuit 120 and the data driving circuit 130 , respectively.

3 is a block diagram schematically illustrating the configuration of a pixel circuit according to the present specification.

Referring to FIG. 3 , the pixel circuit 1000 according to the present specification may include a plurality of light emitting devices R/G/B and a pixel driving circuit unit 1100 . According to an embodiment, the plurality of light emitting devices may be micro LEDs. The pixel driving circuit unit 1100 serves to drive a plurality of light emitting devices. That is, the pixel driving circuit unit 1100 may play a role of controlling the plurality of light emitting devices to operate according to the color and brightness of light to be output by the pixel for each frame.

The positive power terminal Vcc and the negative power terminal GND are contacts related to power required for driving the plurality of light emitting devices R/G/B and the pixel driving circuit unit 1100 . Accordingly, all of the electrical energy required for the operation of the pixel circuit 1000 according to the present specification may be supplied by the potential difference between the positive power terminal Vcc and the negative power terminal GND. The positive power terminal Vcc may be connected to the data driving circuit 130 , and the negative power terminal GND may be connected to the scan driving circuit 120 .

In the pixel circuit 1000 according to the present specification, it can be confirmed that a contacting point electrically connected to the outside is composed of a positive power terminal Vcc and a negative power terminal GND. Compared with the pixel shown in FIG. 1 , it can be seen that the pixel circuit 1000 according to the present specification has two fewer contacts. Accordingly, in order to operate as a pixel of the display panel despite relatively few contacts, the positive power terminal Vcc of the pixel circuit 1000 according to the present specification is connected to the data driving circuit 130 , and the negative power terminal (GND) is characterized in that it is connected to the scan driving circuit (120). That is, the pixel circuit 1000 operates due to a potential difference between the signal output from the data driving circuit 130 and the signal output from the scan driving circuit 120 .

The pixel driving circuit unit 1100 may include a pixel embedded memory unit 1140 . The pixel built-in memory unit 1140 may store data related to driving of a plurality of light emitting devices input through the positive power terminal Vcc. The signal related to driving of the plurality of light emitting devices may be a signal input in a digital format. That is, the display panel 110 according to the present specification may be a device having pixels of a digital driving method.

The pixel driving circuit unit 1100 may further include a reference voltage supply unit 1120 that outputs a voltage for operating a circuit included in the pixel embedded memory unit 1140 .

In addition, the pixel driving circuit unit 1100 may further include a bias current supply unit 1110 , a reset unit 1130 , and a light emitting device driving unit 1150 . The light emitting device driver 1150 is configured to drive the plurality of light emitting devices according to the driving data of each light emitting device stored in the pixel embedded memory unit. The light emitting device driver 1150 may be a circuit that drives the light emitting device in a pulse width modulation (PWM) method. Since the PWM driving method is a technique known to those skilled in the art, a detailed description thereof will be omitted. The bias current supply unit 1110 , the reference voltage supply unit 1120 , and the reset unit 1130 will be described in more detail later.

2 and 3 together, the operating principle of the pixel circuit 1000 and the display apparatus 100 according to the present specification will be described.

4 is a waveform diagram of a signal output to drive a pixel circuit in the display device according to the present specification.

Referring to FIG. 4 , a signal Sync for matching the operations of the scan driving circuit 120 and the data driving circuit 130 for each frame can be identified. The sync signal Sync may be output from the control unit 140 that controls the scan driving circuit 120 and the data driving circuit 130 .

The signal output from the data driving circuit 130 is a reference potential (V ₀ ), a first potential (V ₁ ) higher than the reference potential (V ₀ ), or a second potential (V ₁ ) higher than the first potential (V 1 ) V ₂ ) may have. For example, the reference potential (V ₀ ) may be a reference ground voltage of the display device, the first potential (V ₁ ) may have a potential difference of 0.7V or more from the reference potential (V ₀ ), and the second potential (V 0 ) The potential V ₂ may have a potential difference of 0.7V or more from the first potential V ₁ . And the signal output from the data driving circuit 130, that is, a signal related to driving of the light emitting devices, may be a signal having at least one pulse that changes from a first potential (V ₁ ) to a second potential (V ₂ ). . Data of '0' or '1' may be expressed according to the length of the pulse.

The scan driving circuit 120 may output a signal capable of driving the pixel circuit 1000 for each scan line according to the timing of the sync signal Sync. A signal for driving the pixel circuit 1000 may have a driving data input period (RGB Program) and a light emitting element driving period (PWM Driving) of the light emitting device.

The signal output from the scan driving circuit 120 is also a reference potential (V ₀ ), a first potential (V ₁ ) higher than the reference potential (V ₀ ), or a second potential (V ₁ ) higher than the first potential (V 1 ) It may have a potential (V ₂ ). For example, the reference potential (V ₀ ) may be a reference ground voltage of the display device, the first potential (V ₁ ) may have a potential difference of 0.7V or more from the reference potential (V ₀ ), and the second potential (V 0 ) The potential V ₂ may have a potential difference of 0.7V or more from the first potential V ₁ . That is, the reference potential V ₀ , the first potential V ₁ , and the second potential V ₂ of the signal output from the data driving circuit 130 may be the same.

In the signal output from the scan driving circuit 120 , the driving data input section RGB Program may be a signal having a first potential V ₁ . The driving data input section (RGB Program) may consist of one pulse. The light emitting device driving period (PWM Driving) may be a signal having at least one pulse that changes from the reference potential (V ₀ ) to the first potential (V ₁ ). The light emitting device driving section (PWM Driving) is a region for PWM driving of the light emitting device, and the number of pulses in the light emitting device driving section (PWM Driving) may correspond to the bit size of data related to driving of the light emitting device. can

As described above, it may be driven when a constant potential difference exists between the positive power terminal Vcc and the negative power terminal GND of the pixel circuit 1000 according to the present specification. During the driving data input period (RGB Program) and the light emitting device driving period (PWM Driving), the data driving circuit 130 applies a voltage between the first potential V ₁ and the second potential V ₂ to the positive power terminal. (Vcc), the scan driving circuit 120 may apply a voltage between the reference potential (V ₀ ) and the first potential (V ₁ ) to the negative power terminal (GND). Accordingly, during the driving data input period (RGB Program) and the light emitting device driving period (PWM Driving), the pixel circuit 1000 according to the present specification is generated by the potential difference between the positive power terminal Vcc and the negative power supply terminal GND. drive is possible Meanwhile, the scan driving circuit 120 may output a signal having the second potential V ₂ before the driving data input period (RGB Program) of the next frame after the light emitting device driving period (PWM driving). At this time, since there is little potential difference between the positive power terminal Vcc and the negative power terminal GND, the pixel circuit 1000 according to the present specification may not be driven.

The scan driving circuit 120 may output a signal capable of sequentially driving the pixel circuit 1000 to the plurality of scan lines SL ₁ to SL _m . In this case, the scan driving circuit 120 may output a signal delayed by a preset time interval (1H) between the scan line and the scan line. In this case, the preset time interval 1H may be the same as the driving data input period RGB Program.

The data driving circuit 130 may output a signal related to driving of the plurality of pixel circuits 1000 . The signal related to the driving of the pixel circuit 1000 is a signal including data related to the brightness of light to be output by the plurality of light emitting devices included in the pixel circuit 1000 within one frame. A signal output from the data driving circuit 130 to each data line DL ₁ to DL _n includes data corresponding to the number m of pixels arranged in the vertical direction in the display panel 110 . In one data line, an interval between data signals associated with driving of each pixel circuit 1000 by the data driving circuit 130 may be the same as the driving data input period RGB Program.

Meanwhile, in FIG. 4 , the data driving circuit 130 shows that the data signal RGB related to driving the pixel circuit 1000 has the same shape, but the shape of the signal may vary depending on the color to be expressed. It should be understood that there is

Hereinafter, how the signal shown in FIG. 4 is input to one pixel circuit 1000 to drive the pixel circuit 1000 will be described. For convenience of understanding, the 1-1 pixel circuit 1000 where the first scan line SL ₁ and the first data line DL ₁ meet will be described as an example.

5 is a timing reference diagram for the operation of one pixel circuit.

Referring to FIG. 5 , a sync signal Sync output to the controller 140 may be checked to distinguish a frame from a frame. According to the sync signal Sync, a signal input through the first data line DL ₁ and the first scan line SL ₁ may be checked. A signal through the No. 1 data line DL ₁ is input to a positive power terminal Vcc, and a signal through the No. 1 scan line SL ₁ is input to a negative power terminal GND. The pixel driving circuit unit 1100 may start to operate due to a potential difference between the positive power terminal Vcc and the negative power terminal GND.

First, the bias current supply unit 1110 may output a bias current to the reference voltage supply unit 1120 . The reference voltage supply unit 1120 may output a voltage having a preset size to the reset unit 1130 , the pixel embedded memory unit 1140 , and the light emitting device driver 1150 . Among the voltages shown in FIG. 3 , “VDD_int” is a voltage for operating circuits included in the reset unit 1130 and the pixel embedded memory unit 1140 , and “V-bias” is the light emitting device driver 1150 . ) to drive the voltage. However, it is obvious that the type and magnitude of the voltage output from the reference voltage supply unit 1120 is not limited to the examples shown in the drawings, and may be set in various ways.

The reset unit 1130 may initialize the pixel embedded memory unit 1140 . The pixel embedded memory unit 1140 may store a signal output from the reference voltage supply unit 1120 during a driving data input period (RGB Program) after being initialized, that is, a signal related to driving of light emitting devices (video data). Thereafter, the pixel embedded memory unit 1140 is respectively transmitted to the light emitting device driving unit 1150 by the PWM control signal PWM CLK input through the negative power terminal GND during the light emitting device driving period (PWM Driving). It is possible to output a signal for PWM driving the light emitting device of Each of the light emitting devices R/G/B outputs various brightnesses according to the PWM driving signal of the light emitting device driver 1150 (refer to 'Output' in FIG. 5 ).

Hereinafter, how the pixel embedded memory unit 1140 operates in the driving data input section (RGB Program) and the light emitting device driving section (PWM Driving) will be described in more detail.

6 is a reference diagram of the operation of the pixel embedded memory unit in the driving data input section according to the present specification.

Referring to FIG. 6 , the embedded pixel memory unit 1140 including the shift register 1141 can be identified. The pixel embedded memory unit 1140 may receive a voltage VDD_int for operating the shift register 1141 from the reference voltage supply unit 1120 . In addition, the shift register 1141 may be connected to the negative power terminal GND. Accordingly, the shift register 1141 may be operated by a potential difference between the voltage VDD_int output from the reference voltage supply unit 1120 and the negative power terminal GND.

Meanwhile, the reference voltage supply unit 1120 may output to the pixel embedded memory unit 1140 a voltage that changes together according to a change in the potential of the negative power terminal GND. As described above, the signal output from the scan driving circuit 120 and input through the negative power terminal GND during the driving data input period RGB Program is a reference potential V ₀ to a first potential V ₁ . ) can be increased. At this time, when the reference voltage supply unit 1120 also stores data related to driving of the light emitting device in the pixel driving circuit unit 1100 , that is, during the driving data input period (RGB Program), the potential of the negative power terminal GND is As much as it rises (from V ₀ to V1), it is possible to output the increased voltage. During the driving data input period (RGB Program), the voltage output from the data driving circuit 130 is increased due to the simultaneous rise of the potential output from the power supply VDD_int and the negative power terminal GND supplied from the reference voltage supply unit 1120. It is possible to select a specific section from the signal to be input to the shift register 1141 .

Meanwhile, video data related to driving of the light emitting device input through the positive power supply terminal Vcc is branched and one is directly input to the shift register 1141, and the other is a low pass filter (LPF). may be input to the shift register 1141 through A signal that has passed through the low-pass filter (LPF) may be input to 'CLK' of the shift register 1141 , and a signal that has not passed through the low-pass filter (LPF) is transferred to 'DATA' of the shift register 1141 . can be entered. "0" or "1" may be input through the input potential difference between the two signals.

In addition, the pixel circuit 1000 according to the present specification according to the present specification further includes a comparator to improve robustness from noise of data signals related to driving of a plurality of light emitting devices input through the positive power terminals. may include

7 is a reference diagram of a comparator for outputting data related to driving of a light emitting device to an embedded pixel memory unit according to the present specification.

Referring to FIG. 7 , the non-inverting input terminal (Col_shift, '+') of the comparator is connected to the positive power supply terminal (Vcc), and the inverting input terminal (Row_shift, '-') of the comparator is the negative power supply terminal GND ) and the output terminal Vout of the comparator may be connected to the pixel embedded memory unit 1140. Referring to Fig. 6 above, the power supply VDD_int supplied from the reference voltage supply unit 1120 and The potential output from the negative power terminal GND should rise simultaneously, and the voltage difference should be maintained at a specific value (eg, 0.7V or 1V) or more, but the signal output from the data driving circuit 130 is shifted In this case, when the voltage difference falls below a specific value due to an external influence, data related to driving of the light emitting device cannot be accurately input to the shift register 1141 . However, as shown in FIG. 7 , the voltage level difference between the positive power supply terminal Vcc and the negative power supply terminal GND is amplified through a comparator, and the shift register 1141 is used as data related to driving of a plurality of light emitting devices. ), accurate data input is possible despite external influences, that is, signal-to-noise characteristics can be robust.

8 is a block diagram schematically illustrating the configuration of the pixel embedded memory unit 1140 according to an embodiment of the present specification.

Referring to FIG. 8 , it can be seen that the pixel embedded memory unit 1140 includes three shift registers and one flip-flop. Each of the shift registers may include a plurality of flip-flops. In general, one pixel circuit includes three light emitting elements. For example, data related to driving of each light emitting device in the one frame may be 8 bits. In this case, the pixel embedded memory unit 1140 may include three shift registers capable of storing 8 bits. As another example, data related to driving of each light emitting device in the one frame may be 11 bits extended from 8 bits for gamma correction or mismatch correction. In this case, the pixel embedded memory unit 1140 may include three shift registers capable of storing 11 bits. The three shift resists are connected in series, so that data related to driving of the light emitting device may be sequentially input.

Meanwhile, the pixel embedded memory unit 1140 may include at least one flip-flop for switching the operation of the shift register. The operation switching of the shift register means data writing and output switching in a driving data input section (RGB Program) and a light emitting device driving section (PWM Driving). A flip-flop for switching the operation of the shift register may be located at the end (last) of the input terminal of the shift register. Accordingly, the data output from the data driving circuit 130 may further include an additional 1 bit in addition to the data related to driving of the light emitting device. For example, the signal output from the data driving circuit 130 during one frame may be 25 bits (= 8 bits x 3 + 1 bit) or 33 bits (= 11 bits x 3 + 1 bit).

The additional 1 bit is included in the first part of the signal, but finally arrives at the flip-flop for switching the operation of the shift register. When the additional 1 bit is input to the flip-flop, the shift register may output a signal to a switching circuit to output the stored data to the light emitting device driver 1150 .

As mentioned above, although the embodiments of the present specification have been described with reference to the accompanying drawings, those of ordinary skill in the art to which this specification belongs can realize that the present invention may be embodied in other specific forms without changing the technical spirit or essential features thereof. you will be able to understand Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive.

100: display device
110: display panel
120: scan driving circuit
130: data driving circuit
140: control unit
1000: pixel circuit
1100: pixel driving circuit unit
1110: bias current supply unit
1120: reference voltage supply unit
1130: reset unit
1140: Pixel built-in memory unit
1141: shift register
1150: light emitting element driving unit

Claims (6)

a display panel including a plurality of pixel circuits;
a scan driving circuit connected to any one of a plurality of scan lines connected to a negative power terminal of each pixel circuit to drive pixel circuits arranged in a row direction; and
A display device comprising: a data driving circuit for outputting signals related to driving of a plurality of light emitting devices included in each pixel circuit through a plurality of data lines connected to both power terminals of each pixel circuit;
The pixel circuit is
a plurality of light emitting devices;
a positive power terminal connected to the data driving circuit;
a negative power terminal connected to the scan driving circuit;
a pixel-embedded memory unit for storing data related to driving of a plurality of light emitting devices input through the positive power terminals;
a light emitting device driving unit for driving the plurality of light emitting devices according to the driving data of each light emitting device stored in the pixel embedded memory unit; and
A reference voltage supply unit for outputting a voltage that varies according to a change in the potential of the negative power terminal to the pixel built-in memory unit and the light emitting device driving unit to operate the circuits included in the pixel embedded memory unit and the light emitting device driving unit; including,
The pixel built-in memory unit receives data related to driving of a plurality of light emitting devices through an output terminal of a comparator having a non-inverting input terminal connected to the positive power terminal and an inverting input terminal connected to the negative power terminal Device. The method according to claim 1,
The pixel embedded memory unit may include at least one shift register; and at least one flip-flop for switching the operation of the shift register. The method according to claim 1,
The signal output from the data driving circuit has a reference potential, a first potential higher than the reference potential, or a second potential higher than the first potential;
The signal related to the driving of the light emitting devices is a signal having at least one pulse that changes from a first potential to a second potential. The method according to claim 1,
The scan driving circuit is a display device for outputting a signal having a driving data input section of a light emitting device and a driving section of the light emitting device for each scan line. 5. The method according to claim 4,
The signal output from the scan driving circuit has a reference potential, a first potential higher than the reference potential, or a second potential higher than the first potential,
The driving data input section is a signal having a first potential,
The light emitting device driving period is a signal having at least one or more pulses that change from a reference potential to a first potential. 6. The method of claim 5,
The scan driving circuit is configured to output a signal having the second potential after the driving period of the light emitting device until the driving data input period of a next frame.

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