This application claims priority under 35 USC § 119 to Korean Patent Application No. 10-2020-0028617, filed on Mar. 6, 2020 in the Korean Intellectual Property Office (KIPO); the Korean Patent Application is incorporated by reference.
The technical field relates to display devices and methods of operating the display devices.
A display device may include pixels, a data driver providing data voltages to the pixels, a gate driver providing gate signals to the pixels, and a controller controlling the data driver and the gate driver.
The controller transfers image data to the data driver, which provides the pixels with the data voltages corresponding to the image data. In order to transfer the image data, a high speed interface, such as one of a unified standard interface for TV (a USI-T interface), a unified standard interface for notebook and monitor (a USI-GF interface), etc., may be used between the controller and the data driver.
In a display device using the USI-T interface or the USI-GF interface, the controller may transmit a clock-embedded data signal, and the data driver may recover a clock signal from the clock-embedded data signal using a clock data recovery (CDR) circuit, and may sample and restore a data signal using the recovered clock signal. To allow the recovered clock signal to have a desired frequency and/or a desired phase, the controller may transfer, as the clock-embedded data signal, a training pattern that periodically toggles, and the data driver may perform a clock training operation (or a locking operation) using the training pattern.
When a frame frequency is drastically changed, for example, when the frame frequency is changed to a half of the frame frequency, a lock sensing error of the data driver that determines the recovered clock signal in an unlock state to be in a lock state may occur, a clock signal corresponding to the changed frame frequency may not be recovered, and thus an operation error of the data driver may occur.
Some embodiments may be related to a display device capable of preventing an operation error of a data driver even if a frame frequency is drastically changed.
Some embodiments may be related to a method of operating a display device capable of preventing an operation error of a data driver even if a frame frequency is drastically changed.
According to embodiments, a display device may include the following elements: a display panel including a plurality of pixels; a controller configured to provide a clock-embedded data signal, the clock-embedded data signal including image data in an active period and including a training pattern in a blank period; and a data driver configured to recover the image data from the clock-embedded data signal based on an internal clock signal in the active period, to provide data voltages corresponding to the image data to the plurality of pixels in the active period, and to perform a training operation for the internal clock signal by using the training pattern included in the clock-embedded data signal in the blank period. The training pattern in the blank period includes a first training clock signal modulated with a first modulation period during a first time, and includes a second training clock signal modulated with a second modulation period different from the first modulation period after the first time.
The display device may include a shared back channel electrically connected between the controller and the data driver. The data driver may include a clock data recovery circuit configured to recover the image data from the clock-embedded data signal in the active period, to perform the training operation that trains the internal clock signal based on the first training clock signal modulated with the first modulation period, and to inform the controller of a lock state of the internal clock signal through the shared back channel in response to the second training clock signal modulated with the second modulation period, and a data converting circuit configured to convert the image data into the data voltages in the active period, and to provide the data voltages to the plurality of pixels in the active period.
The clock data recovery circuit may include the following elements: a data recovery circuit configured to recover the image data from the clock-embedded data signal in response to the internal clock signal in the active period; a clock recovery circuit electrically connected to the data recovery circuit, configured to generate the internal clock signal, and configured to perform the training operation for the internal clock signal in response to a training enable signal; and a lock sensing circuit electrically connected to at least one of the data recovery circuit and the clock recovery circuit, configured to detect whether the internal clock signal is in the lock state or in an unlock state by determining whether the clock-embedded data signal has an edge in each clock period of the internal clock signal, and configured to provide the training enable signal to the clock recovery circuit when the internal clock signal is in the unlock state.
In embodiments, in response to the first training clock signal modulated with the first modulation period, the lock sensing circuit may provide the training enable signal to the clock recovery circuit, and may inform the controller of the unlock state of the internal clock signal through the shared back channel, and, in response to the second training clock signal modulated with the second modulation period, the lock sensing circuit may inform the controller of the lock state of the internal clock signal through the shared back channel.
The first time may be a clock phase locking time defined in a standard of an interface between the controller and the data driver.
The first modulation period may correspond to three times of a clock period of the internal clock signal, and the second modulation period may correspond to two times of the clock period of the internal clock signal.
The first modulation period may correspond to four times of a clock period of the internal clock signal, and the second modulation period may correspond to two times of the clock period of the internal clock signal.
The display device may include a shared back channel electrically connected between the data driver and the controller. The data driver may detect an unlock state of the internal clock signal, and may inform the controller of the unlock state of the internal clock signal through a shared back channel. In response to the unlock state of the internal clock signal received in the active period, the controller may stop transferring the clock-embedded data signal including the image data, and may transfer the clock-embedded data signal including the training pattern in the active period.
The training pattern in the active period may be substantially a same as the training pattern in the blank period.
The training pattern in the active period may be different from the training pattern in the blank period.
The training pattern in the active period may include only the second training clock signal modulated with the second modulation period.
The second modulation period may correspond to two times of a clock period of the internal clock signal.
The data driver may include a plurality of data driver integrated circuits, and the plurality of data driver integrated circuits may share the shared back channel.
According to embodiments, a display device may include the following elements: a display panel including a plurality of pixels; a controller configured to provide a clock-embedded data signal, the clock-embedded data signal including image data in an active period and including a training pattern in a blank period; and a data driver configured to receive the clock-embedded data signal, to recover the image data from the clock-embedded data signal based on an internal clock signal in the active period, to provide data voltages corresponding to the recovered image data to the plurality of pixels in the active period, and to perform a training operation for the internal clock signal by using the training pattern included in the clock-embedded data signal in the blank period. The controller detects whether a frame frequency is changed, and transfers the training pattern including a first training clock signal modulated with a first modulation period during a first time and including a second training clock signal modulated with a second modulation period different from the first modulation period after the first time in the blank period when or after the frame frequency is changed.
In embodiments, when the frame frequency is not changed, the controller may transfer the training pattern including only the second training clock signal modulated with the second modulation period in the blank period.
The first modulation period may correspond to three times of a clock period of the internal clock signal, and the second modulation period may correspond to two times of the clock period of the internal clock signal.
The first modulation period may correspond to four times of a clock period of the internal clock signal, and the second modulation period may correspond to two times of the clock period of the internal clock signal.
Embodiments may be related to a method of operating a display device. In the method, a controller of the display device transfers a clock-embedded data signal including image data to a data driver of the display device in an active period, the data driver recovers the image data from the clock-embedded data signal based on an internal clock signal to provide data voltages corresponding to the recovered image data to a plurality of pixels of a display panel of the display device in the active period, the controller transfers the clock-embedded data signal including a training pattern to the data driver in a blank period, and the data driver performs a training operation for the internal clock signal by using the training pattern included in the clock-embedded data signal in the blank period. The training pattern in the blank period includes a first training clock signal modulated with a first modulation period during a first time, and includes a second training clock signal modulated with a second modulation period different from the first modulation period after the first time.
The data driver may detect an unlock state of the internal clock signal, and the data driver may inform the controller of the unlock state of the internal clock signal through a shared back channel.
The controller may stop transferring the clock-embedded data signal including the image data in response to the unlock state of the internal clock signal received in the active period, and the controller may transfer the clock-embedded data signal including the training pattern to the data driver in the active period.
According to embodiments, a training pattern transferred from a controller to a data driver in a blank period may include a first training clock signal modulated with a first modulation period during a first time, and a second training clock signal modulated with a second modulation period different from the first modulation period after the first time. Accordingly, even if a frame frequency of the display device is changed, a lock sensing error of the data driver may be prevented, and an operation error of the data driver may be prevented.
Example embodiments are described with reference to the accompanying drawings. Although the terms “first,” “second,” etc. may be used to describe various elements, these elements should not be limited by these terms. These terms may be used to distinguish one element from another element. A first element may be termed a second element without departing from teachings of one or more embodiments. The description of an element as a “first” element may not require or imply the presence of a second element or other elements. The terms “first,” “second,” etc. may be used to differentiate different categories or sets of elements. For conciseness, the terms “first,” “second,” etc. may represent “first-type (or first-set),” “second-type (or second-set),” etc., respectively.
The expression “during the first/second time” may mean “(substantially) throughout the first/second time” and/or “for the period of the first/second time.”
Referring to
The display panel 110 may include a plurality of data lines, a plurality of gate lines, and the plurality of pixels PX coupled to the plurality of data lines and the plurality of gate lines. Each pixel PX may include a switching transistor, and a liquid crystal capacitor coupled to the switching transistor, and the display panel 110 may be a liquid crystal display (LCD) panel. Each pixel PX may include at least two transistors, at least one capacitor, and an organic light emitting diode (OLED); the display panel 110 may be an OLED display panel. Each pixel PX may include an inorganic light emitting diode or a quantum dot light emitting diode, and the display panel 110 may be an inorganic light emitting diode display panel or a quantum dot light emitting diode display panel.
The gate driver 120 may generate the gate signals GS based on a gate control signal GCTRL received from the controller 160, and may provide the gate signals GS to the plurality of pixels PX through the plurality of gate lines. The gate control signal GCTRL may include a gate start signal and a gate clock signal. The gate driver 120 may be an amorphous silicon gate (ASG) driver integrated in a peripheral portion of the display panel 110. The gate driver 120 may be implemented with one or more gate integrated circuits (ICs). The gate driver 120 may be mounted directly on the display panel 110, or may be coupled to the display panel 110 in a form of a chip on film (COF).
The data driver 130 may receive a clock-embedded data signal CEDS including image data IDAT from the controller 160, may generate the data voltages DV based on the clock-embedded data signal CEDS, and may provide the data voltages DV to the plurality of pixels PX through the plurality of data lines. As illustrated in
The controller 160, e.g., a timing controller (TCON), may receive the image data IDAT and a control signal CTRL from an external host processor, e.g., a graphic processing unit (GPU) or a graphic card. The image data IDAT may be RGB image data including red image data, green image data, and blue image data. The control signal CTRL may include a vertical synchronization signal, a horizontal synchronization signal, an input data enable signal, a master clock signal, and/or the like. The controller 160 may generate the clock-embedded data signal CEDS and the gate control signal GCCTL based on the image data IDAT and the control signal CTRL. The controller 160 may control an operation of the gate driver 120 by providing the gate control signal GCTRL to the gate driver 120, and may control an operation of the data driver 130 by providing the clock-embedded data signal CEDS to the data driver 130.
In the display device 100, a high speed interface for transferring the image data IDAT, such as at least one of a unified standard interface for TV (a USI-T interface), a unified standard interface for notebook and monitor (a USI-GF interface), etc., may be used between the controller 160 and the data driver 130, and the image data IDAT may be transferred from the controller 160 to the data driver 130 in the form of the clock-embedded data signal CEDS defined in a standard of the high speed interface. For example, as illustrated in
In the display device 100, the controller 160 may transfer the clock-embedded data signal CEDS including the image data IDAT to the data driver 130 in an active period of a frame period of the display device 100, and may transfer the clock-embedded data signal CEDS including a training pattern to the data driver 130 in a blank period of the frame period. The data driver 130 may recover the image data IDAT from the clock-embedded data signal CEDS based on the internal clock signal in the active period, and may provide the data voltages DV corresponding to the recovered image data RDAT to the plurality of pixels PX in the active period. In the blank period, the data driver 130 may perform a training operation for the internal clock signal using the training pattern included in the clock-embedded data signal CEDS. The training operation (or a locking operation) for the internal clock signal may be an operation that adjusts a frequency and/or a phase of the internal clock signal to allow the internal clock signal to have a desired frequency and/or a desired phase corresponding to the training pattern.
The display device 100 may further include, between the controller 160 and the data driver 130, a shared forward channel SFC for the controller 160 to inform the data driver 130 of transferring the training pattern as the clock-embedded data signal CEDS, and a shared back channel SBC for data driver 130 to inform the controller 160 of a lock state or an unlock state of the internal clock signal. The controller 160 may inform the data driver 130 of transferring the training pattern by changing the shared forward channel SFC to a low level. The data driver 130 may inform the controller 160 of the unlock state of the internal clock signal by changing the shared back channel SBC to a low level, and may inform the controller 160 of the lock state of the internal clock signal by changing the shared back channel SBC to a high level. As illustrated in
To provide the data voltages DV to the plurality of pixels PX in the active period and to perform the training operation for the internal clock signal in the blank period, the data driver 130 may include a clock data recovery (CDR) circuit 140 and a data converting circuit 150. The clock data recovery circuit 140 may generate the recovered image data RDAT using the clock-embedded data signal CEDS in the active period, and may perform the training operation for the internal clock signal using the training pattern in the blank period. The data converting circuit 150 may convert the recovered image data RDAT into data voltages DV in the active period, and may provide the data voltages DV to pixels PX in the active period. When the data driver 130 includes the plurality of data driver ICs 132, . . . , 134, each data driver IC 132, . . . , 134 may include a clock data recovery circuit 140 and a data converting circuit 150.
As illustrated in
The clock recovery circuit 142 may generate the internal clock signal ICLK, and may perform the training operation for the internal clock signal ICLK in response to a training enable signal TES. The clock recovery circuit 142 may include a phase detector 143, a charge pump 144, a low pass filter 145, and a voltage control oscillator 146. The phase detector 143 may generate a signal (e.g., an up signal and/or a down signal) corresponding to a phase difference between the internal clock signal ICLK and the clock-embedded data signal CEDS. In response to the signal of the phase detector 143, the charge pump 144 may provide a current to the low pass filter 145, or may draw a current from the low pass filter 145. In response to a positive current or a negative current from the charge pump 144, the low pass filter 145 may increase or decrease a control voltage. The charge pump 144 may remove or reduce a high frequency noise component of the internal clock signal ICLK. The voltage control oscillator 146 may adjust a frequency and/or a phase of the internal clock signal ICLK in response to the control voltage from the low pass filter 145. The clock recovery circuit 142 may be implemented as a phase locked loop (PLL) circuit as illustrated in
The lock sensing circuit 147 may detect whether the internal clock signal ICLK is in the lock state or in the unlock state (or a lock fail) by determining whether the clock-embedded data signal CEDS has an edge in each clock period of the internal clock signal ICLK (for example, not only in the blank period, but also in the active period). For example, as illustrated in
The data converting circuit 150 may include a shift register array that sequentially stores the recovered image data RDAT, a data latch array that loads the recovered image data RDAT stored in the shift register array in response to a load signal, a digital-to-analog converter array that converts the recovered image data RDAT output from the data latch array into the data voltages DV using gamma voltages, and an output buffer array that outputs the data voltages DV to the plurality of data lines.
As illustrated in
Referring to
Referring to
Thus, in the display device 100, the training pattern transferred as the clock-embedded data signal CEDS from the controller 160 to the data driver 130 in the blank period may include a first training clock signal modulated with a first modulation period during a first time, and may include a second training clock signal modulated with a second modulation period different from the first modulation period after the first time. The first time may be a (minimum) clock phase locking time, for example about 4,500 clock periods (4500T), defined in a standard of an interface, for example the USI-T interface or the USI-GF interface, between the controller 160 and the data driver 130.
The first modulation period of the first training clock signal may correspond to 3T (i.e., three times of the clock period T of the internal clock signal ICLK), and the second modulation period of second training clock signal may correspond to 2T (i.e., two times of the clock period T of the internal clock signal ICLK). Thus, as the training pattern in the blank period, the controller 160 may transfer the training clock signal 3T_TCLK modulated with the modulation period corresponding to the three clock periods 3T during the first time, and may transfer the training clock signal 2T_TCLK modulated with the modulation period corresponding to the two clock periods 2T after the first time. In response to the training clock signal 3T_TCLK modulated with the modulation period corresponding to the three clock periods 3T, the lock sensing circuit 147 may determine that the internal clock signal ICLK is in the unlock state, may provide the training enable signal TES to the clock recovery circuit 142, and may inform the controller 160 of the unlock state of the internal clock signal ICLK through the shared back channel SBC. When the training clock signal 3T_TCLK modulated with the modulation period corresponding to the three clock periods 3T is transferred, the clock recovery circuit 142 may perform the training operation for the internal clock signal ICLK in response to the training enable signal TES. Since the training clock signal 3T_TCLK modulated with the modulation period corresponding to the three clock periods 3T is transferred during the first time (for example, during the clock phase locking time defined in the USI-T interface standard or the USI-GF interface standard), and the training operation for the internal clock signal ICLK is performed during the first time, the lock sensing circuit 147 may determine that the internal clock signal ICLK is in the unlock state during the first time, but the internal clock signal ICLK generated by the clock recovery circuit 142 may be actually in the lock state at a time point after the first time. If the training clock signal 2T_TCLK modulated with the modulation period corresponding to the two clock periods 2T is transferred after the first time, in response to the training clock signal 2T_TCLK modulated with the modulation period corresponding to the two clock periods 2T, the lock sensing circuit 147 may determine that internal clock signal ICLK is in the lock state, and may inform the controller 160 of the lock state of the internal clock signal ICLK through the shared back channel SBC. The controller 160 may stop transferring the training pattern in response to the lock state of the internal clock signal ICLK received through the shared back channel SBC.
The first modulation period of the first training clock signal may correspond to 4T (i.e., four times of the clock period T of the internal clock signal ICLK), and the second modulation period of second training clock signal may correspond to 2T (i.e., two times of the clock period T of the internal clock signal ICLK). Thus, as the training pattern in the blank period, the controller 160 may transfer the training clock signal 4T_TCLK modulated with the modulation period corresponding to the four clock periods 4T during the first time, and may transfer the training clock signal 2T_TCLK modulated with the modulation period corresponding to the two clock periods 2T after the first time. The clock data recovery circuit 140 may perform the training operation for the internal clock signal ICLK based on the training clock signal 4T_TCLK modulated with the modulation period corresponding to the four clock periods 4T during the first time, and may inform the controller 160 of the lock state of the internal clock signal ICLK through the shared back channel SBC in response to the training clock signal 2T_TCLK modulated with the modulation period corresponding to the two clock periods 2T after the first time.
Even if the frame frequency of the display device 100 is drastically changed (for example, from about 120 Hz to about 60 Hz, or from about 60 Hz to about 120 Hz), because the training clock signal 3T_TCLK modulated with the modulation period corresponding to the three clock periods 3T or the training clock signal 4T_TCLK modulated with the modulation period corresponding to the four clock periods 4T is transferred during the first time, the lock sensing circuit 147 may determine that the internal clock signal ICLK is in the unlock state in response to the training clock signal 3T_TCLK modulated with the modulation period corresponding to the three clock periods 3T or the training clock signal 4T_TCLK modulated with the modulation period corresponding to the four clock periods 4T, and thus a potential lock sensing error (where the training clock signal 2T_TCLK in the unlock state is erroneously determined to be in the lock state) may be prevented. Thus, when the frame frequency of the display device 100 is drastically changed from about 120 Hz to about 60 Hz, the lock sensing circuit 147 may determine that the internal clock signal ICLK is in the unlock state, the clock data recovery circuit 140 may train the internal clock signal ICLK corresponding to the changed frame frequency of about 60 Hz based on the training clock signal 3T_TCLK or 4T_TCLK corresponding to the changed frame frequency of about 60 Hz during the first time. That is, in the display device 100, even if the frame frequency of the display device 100 is drastically changed, the internal clock signal ICLK may be trained corresponding to the changed frame frequency, and thus a problem potentially caused by erroneously determining that the internal clock signal ICLK is in the lock state (given that only the training clock signal 2T_TCLK modulated with the modulation period corresponding to the two clock periods 2T is used as the training pattern) may be prevented. Further, since the training clock signal 2T_TCLK modulated with the modulation period corresponding to the two clock periods 2T is transferred after the first time, a potential problem where the shared back channel SBC cannot be changed to the high level for informing the lock state (given that only the training clock signal 3T_TCLK or 4T_TCLK modulated with the modulation period corresponding to the three clock periods 3T or the four clock periods 4T is used as the training pattern) may be prevented.
The lock sensing circuit 147 may detect the unlock state of the internal clock signal ICLK in each clock period of the internal clock signal ICLK not only in the blank period, but also in the active period, and may inform the controller 160 of the unlock state of the internal clock signal ICLK through the shared back channel SBC. When/if an electrostatic discharge occurs in the data driver 130, the internal clock signal ICLK may become in the unlock state, and the lock sensing circuit 147 may inform the controller 160 of the unlock state of the internal clock signal ICLK by changing the shared back channel SBC to the low level. Once the controller 160 is informed of the unlock state of the internal clock signal ICLK through the shared back channel SBC, the controller 160 may stop transferring the clock-embedded data signal CEDS including the image data IDAT, and may transfer the clock-embedded data signal CEDS including the training pattern in the active period. If transferring the training pattern is completed in the active period, the controller 160 may resume transferring the clock-embedded data signal CEDS including the image data IDAT.
The training pattern in the active period may be substantially the same as the training pattern in the blank period. For example, as the training pattern in the active period, the controller 160 may transfer the training clock signal 3T_TCLK modulated with the modulation period corresponding to the three clock periods 3T during the first time, and may transfer the training clock signal 2T_TCLK modulated with the modulation period corresponding to the two clock periods 2T after the first time. In another example, as the training pattern in the active period, the controller 160 may transfer the training clock signal 4T_TCLK modulated with the modulation period corresponding to the four clock periods 4T during the first time, and may transfer the training clock signal 2T_TCLK modulated with the modulation period corresponding to the two clock periods 2T after the first time.
The training pattern in the active period may be different from the training pattern in the blank period. The training pattern in the active period may include only the second training clock signal modulated with the second modulation period. Thus, as the training pattern in the active period, the controller 160 may transfer only the training clock signal 2T_TCLK modulated with the modulation period corresponding to the two clock periods 2T. In an example, the controller 160 may transfer the training clock signal 2T_TCLK modulated with the modulation period corresponding to the two clock periods 2T during about 2,000 clock periods (2000T).
In the display device 100, the controller 160 may detect whether the frame frequency of the display device 100 is changed. The controller 160 may detect the change of the frame frequency by detecting a change of an input frame frequency IFF of the image data IDAT. When the frame frequency is not changed, the controller 160 may transfer the training pattern including only the second training clock signal modulated with the second modulation period (e.g., the training clock signal 2T_TCLK modulated with the modulation period corresponding to the two clock periods 2T). When the frame frequency is changed, as the training pattern, the controller 160 may transfer the first training clock signal modulated with the first modulation period (e.g., the training clock signal 3T_TCLK modulated with the modulation period corresponding to the three clock periods 3T or the training clock signal 4T_TCLK modulated with the modulation period corresponding to the four clock periods 4T) during the first time, and may transfer the second training clock signal modulated with the second modulation period (e.g., the training clock signal 2T_TCLK modulated with the modulation period corresponding to the two clock periods 2T) after the first time.
In the display device 100, as the training pattern, the controller 160 may transfer the first training clock signal modulated with the first modulation period (e.g., the training clock signal 3T_TCLK or the training clock signal 4T_TCLK) during the first time, and may transfer the second training clock signal modulated with the second modulation period different from the first modulation period (e.g., the training clock signal 2T_TCLK) after the first time. Accordingly, even if the frame frequency of the display device 100 is changed, the lock sensing error of the data driver 130 may be prevented, and the operation error of the data driver 130 may be prevented.
Referring to
In a blank period BP, the controller 160 may transfer the clock-embedded data signal CEDS including a training pattern to the data driver 130, and the data driver 130 may perform a training operation for the internal clock signal ICLK using the training pattern included in the clock-embedded data signal CEDS (S340, 5345, 5350, and S355). The training pattern in the blank period BP may include a first training clock signal modulated with a first modulation period during a first time, and may include a second training clock signal modulated with a second modulation period different from the first modulation period after the first time.
referring to
Referring to
The data driver 130 may detect the unlock state of the internal clock signal ICLK in each clock period T of the internal clock signal ICLK not only in the blank period BP but also in the active period AP. When/if the internal clock signal ICLK is determined to be in the unlock state in the active period AP (S320: YES), the data driver 130 may inform the controller 160 of the unlock state of the internal clock signal ICLK through the shared back channel SBC (S360). In response to the unlock state of the internal clock signal ICLK received in the active period AP, the controller 160 may stop transferring the clock-embedded data signal CEDS including the image data IDAT (S365), and may transfer the clock-embedded data signal CEDS including the training pattern to the data driver 130 in the active period AP (S340 through S355).
Referring to
Referring to
In a method of operating the display device 100, as the training pattern, the controller 160 may transfer the first training clock signal modulated with the first modulation period (e.g., the training clock signal 3T_TCLK or the training clock signal 4T_TCLK) during the first time, and may transfer the second training clock signal modulated with the second modulation period different from the first modulation period (e.g., the training clock signal 2T_TCLK) after the first time. Accordingly, even if a frame frequency of the display device 100 is changed, a lock sensing error of the data driver 130 may be prevented, and an operation error of the data driver 130 may be prevented.
A method of operating a display device 100 illustrated in
Referring to
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A method of operating a display device 100 illustrated in
Referring to
When/if the frame frequency is changed (S570: YES), the controller 160 may transfer a first training clock signal modulated with a first modulation period during a first time (S340), and a data driver 130 may perform a training operation for an internal clock signal ICLK based on the first training clock signal modulated with the first modulation period (S345). The controller 160 may transfer a second training clock signal modulated with a second modulation period after the first time (S350), and the data driver 130 may inform the controller 160 of a lock state of the internal clock signal ICLK through a shared back channel SBC in response to the second training clock signal modulated with the second modulation period (S355).
When/if the frame frequency is not changed (S570: NO), the controller 160 may transfer the second training clock signal modulated with the second modulation period to the data driver 130 during a second time (S580). The data driver 130 may perform the training operation for the internal clock signal ICLK based on the second training clock signal modulated with the second modulation period (S585), and may inform the controller 160 of the lock state of the internal clock signal ICLK through the shared back channel SBC if the internal clock signal ICLK is locked by the training operation (S590).
Referring to
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The processor 1110 may perform various computing functions or tasks. The processor 1110 may be/include at least one of an application processor (AP), a microprocessor, a central processing unit (CPU), etc. The processor 1110 may be coupled to other components via an address bus, a control bus, a data bus, etc. The processor 1110 may be further coupled to an extended bus such as a peripheral component interconnection (PCI) bus.
The memory device 1120 may store data for operations of the electronic device 1100. The memory device 1120 may include at least one non-volatile memory device such as at least one of an erasable programmable read-only memory (EPROM) device, an electrically erasable programmable read-only memory (EEPROM) device, a flash memory device, a phase change random access memory (PRAM) device, a resistance random access memory (RRAM) device, a nano floating gate memory (NFGM) device, a polymer random access memory (PoRAM) device, a magnetic random access memory (MRAM) device, a ferroelectric random access memory (FRAM) device, etc., and/or at least one volatile memory device such as a dynamic random access memory (DRAM) device, a static random access memory (SRAM) device, a mobile dynamic random access memory (mobile DRAM) device, etc.
The storage device 1130 may be/include at least one of a solid state drive (SSD) device, a hard disk drive (HDD) device, a CD-ROM device, etc. The I/O device 1140 may be/include an input device such as at least one of a keyboard, a keypad, a mouse, a touch screen, etc., and/or an output device such as at least one of a printer, a speaker, etc. The power supply 1150 may supply power for operations of the electronic device 1100. The display device 1160 may be coupled to other components through the buses and/or other communication links.
In the display device 1160, a training pattern transferred from a controller to a data driver may include a first training clock signal modulated with a first modulation period during a first time, and a second training clock signal modulated with a second modulation period different from the first modulation period after the first time. Accordingly, even if a frame frequency of the display device 1160 is changed, a lock sensing error of the data driver may be prevented, and an operation error of the data driver may be prevented.
Embodiments may be applied an electronic device 1100 including the display device 1160. Embodiments may be applied to at least one of a television (TV), a digital TV, a 3D TV, a mobile phone, a smart phone, a tablet computer, a virtual reality (VR) device, a wearable electronic device, a personal computer (PC), a home appliance, a laptop computer, a personal digital assistant (PDA), a portable multimedia player (PMP), a digital camera, a music player, a portable game console, a navigation device, etc.
Although example embodiments have been described, many modifications are possible in the example embodiments. Accordingly, all such modifications are intended to be included within the scope of the claims.
Number | Date | Country | Kind |
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10-2020-0028617 | Mar 2020 | KR | national |