Sapien Semiconductors Inc.

Jae Hoon Lee

Jin Woong Jang

Jun Young Jung

Ji Han Kim

Sung Qwan Oh

Provided is a pixel driving circuit operatable in a low-definition mode and a high-definition mode using the same pixel memory, and a display device including the same. The pixel driving circuit may include a driving line configured to connect between an emitter and a positive power source or between the emitter and a negative power source, a first transistor connected in series on the driving line and turned on in response to a pulse width modulation (PWM) signal, a first driving unit and a second driving unit that are connected in series on the driving line and electrically connected in parallel to each other, and a second transistor connected between a reference voltage source, which is connected to apply a reference voltage to the first driving unit and the second driving unit, and the second driving unit and turned on or off in response to a display mode selection signal.

Pixel driving circuit capable of operating in low-definition mode and high-definition mode using same pixel memory, and display device comprising same

The present specification discloses a pixel driving circuit having a reduced number of external contacts. A conventional digital driving pixel requires two contacts (Vcc, GND) related to power, a contact (row signal, column signal) for inputting two signals for digital driving, a contact (mode selection) for inputting a set value required for driving the pixel, and a contact (reset) for maintaining video data for one frame to implement a cycle function during PWM driving and for inputting a reset signal to clear previous video data before inputting new video data. However, the higher the number of contacts, the lower the efficiency of pick & place in the manufacturing process. Thus, in the present specification, a pixel driving circuit is proposed, which can be digitally driven even when the number of contacts is reduced through combination of a row signal and a column signal.

Pixel driving circuit having reduced number of contacts

The present invention is related to pixels and a display apparatus including: a display unit including a plurality of pixels; a signal control unit for generating a first voltage signal and a second voltage signal; a column driver connected to each of the pixels to transmit the first voltage signal to the pixel through a column line; and a row driver connected to each of the pixels to transmit the second voltage signal to the pixel through a row line, wherein the signal control unit generates the second voltage signal so that a voltage level of the second voltage signal rises to be higher than or equal to a predetermined level value during a non-emission period of the pixel.

Pixels and display apparatus comprising same

Provided is a device for controlling luminance of a display, having a simplified ACL circuit compared to the prior art. The device for controlling luminance of a display calculates the average luminance (Y_avg) when video data is input, and determines the luminance variation (ΔY) according to the average luminance. The device for controlling luminance of a display may adjust the luminance of a display by controlling a current (driving current) that is used to drive a light-emitting diode included in a pixel, instead of modifying video data for the adjustment of luminance. That is, unlike the prior art, the device for controlling luminance of a display does not modify video data, for the control of luminance.

Display brightness control device

The present embodiments disclose a display device. A display device according to an embodiment of the present disclosure comprises a pixel unit including a plurality of pixels, each including a luminous element and a pixel circuit connected to the luminous element, a clock generator configured to generate a plurality of clock signals each corresponding to each of a plurality of subframes constituting a frame, and a parallel to serial converter configured to convert the plurality of clock signals to a serial clock signal and transfer the serial clock signal to the pixel unit, and wherein the pixel circuit of each pixel includes a first pixel circuit configured to control light-emission and non-emission of the luminous element in response to a control signal applied to each of the plurality of subframes and a second pixel circuit configured to store bit values of image data in the frame and generate the control signal based on the stored bit values and the serial clock signal such that each subframe included in the frame is controlled according to each bit value.

Display device

Provided are a pixel having two contacting points and an operating method of the pixel. The pixel includes a positive power terminal and a negative power terminal which are related to power required for driving of a pixel driving circuit unit driving a plurality of light-emitting elements, wherein the positive power terminal is connected to a data driving circuit, and the negative power terminal is connected to a scan driving circuit. The pixel may be driven according to a potential difference between a signal output from the data driving circuit and a signal output from the scan driving circuit.

Pixel having reduced number of contact points, and digital driving method

The present embodiments disclose a pixel driving circuit and a display device including the same. A pixel driving circuit according to an embodiment of the present disclosure includes a first pixel circuit configured to control light-emission and non-emission of the luminous element in response to a control signal applied to each of a plurality of subframes constituting a frame during a light-emitting period and a second pixel circuit storing a bit value of image data in a data writing period and generating the control signal based on the bit value and a clock signal in the light-emitting period.

Pixel driving circuit

The present specification provides a display apparatus allowing brightness of a display panel to be more finely controlled as compared with the related art. The display apparatus according to the present specification includes a display panel in which a plurality of pixels are arranged in m&#xd7;n, and K shift register units configured to sequentially output pulse signals having a width adjusted to adjust brightness of the display panel to m horizontal pixel lines, wherein each of the shift register units includes m main flip-flops and m&#x2212;1 sub-flip-flops connected between the in main flip-flops.

Brightness controllable display apparatus

An LED driving apparatus includes a driving circuit and multiple pixel circuits, each including: a pixel line connecting pixel power sources; an LED in series to the pixel line; two pixel MOSFETs connected in series to the pixel line, wherein the first MOSFET is turned on by the driving circuit and the second MOSFET is connected to the first MOSFET source; and a capacitor connected between the two MOSFET gates. The driving circuit includes: a driving line connecting driving power sources; a current source in series to the driving line; two driving MOSFETs connected in series to the driving line, wherein the first driving MOSFET is connected to the first pixel MOSFET gate and the second driving MOSFET is connected to the second pixel MOSFET gate and the first driving MOSFET source; and a switch connected between the gates of the first pixel and the first driving MOSFETs.

LED driving apparatus having mitigated common impedance effect

Provided are a display device and a method of controlling a brightness of the display device. The method of controlling a brightness of the display device according to an embodiment includes: applying first input image data to a display unit including a plurality of pixels to display a first image; detecting a brightness for each pixel from output image data of the first image displayed on the display unit, and extracting compensation pixels each having a brightness difference exceeding a reference value, the brightness difference being a difference between a detected brightness and a reference brightness; and generating compensation data of the compensation pixels based on the brightness differences of the compensation pixels.

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Ulsan, South Korea

Jae Hoon Lee