Patent Grant
11423817
This application claims priority under 35 USC § 119 to Korean Patent Application No. 10-2020-0172385, filed on Dec. 10, 2020 in the Korean Intellectual Property Office (KIPO), the entire content of which is incorporated by reference herein in its entirety.
The present disclosure relates to a display device, and more particularly to a display device that performs multi-frequency driving (MFD), and a method of operating the same.
Reduction of power consumption is desirable in a display device employed in a portable device, such as a smartphone, a tablet computer, etc. Recently, in order to reduce the power consumption of the display device, a low frequency driving technique which drives or refreshes a display panel at a frequency lower than a normal driving frequency has been developed.
However, in a conventional display device to which the low frequency driving technique is applied, when a still image is not displayed in an entire region of a display panel, or when the still image is displayed only in a partial region of the display panel, the entire region of the display panel is driven at the normal driving frequency. Thus, in this case, the low frequency driving may not be performed, and the power consumption may not be reduced.
To reduce the power consumption even in the case where the still image is displayed only in the partial region of the display panel, a multi-frequency driving (MFD) technique which drives partial regions of the display panel at different driving frequencies. In a display device to which the MFD technique is applied, a first partial region in which a moving image is displayed may be driven at the normal driving frequency, and a second partial region in which a still image is displayed may be driven at a frequency lower than the normal driving frequency. Accordingly, the power consumption may be reduced even in the case where the still image is displayed only in the partial region of the display panel. However, in the display device to which the MFD technique is applied, a boundary between the partial regions driven at the different driving frequencies may be viewed or perceived by a user.
Some embodiments provide a display device capable of preventing a boundary between partial regions driven at different driving frequencies from being viewed or perceived by a user.
Some embodiments provide a method of operating a display device capable of preventing a boundary between partial regions driven at different driving frequencies from being viewed or perceived by a user.
According to embodiments, there is provided a display device including a display panel having a display region, and a panel driver configured to drive the display panel based on input image data. In a case where the input image data represents a moving image with respect to a first partial region of the display region and represents a still image with respect to a second partial region of the display region, the panel driver performs a normal frequency driving operation on the first partial region, and performs a low frequency driving operation on the second partial region. In a standby mode after the normal frequency driving operation and the low frequency driving operation are performed on the first partial region and the second partial region, respectively, the panel driver sets a portion of the second partial region adjacent to the first partial region as an adjacent region, performs the low frequency driving operation on the first partial region and the second partial region except for the adjacent region, and performs a variable frequency driving operation on the adjacent region.
In embodiments, the variable frequency driving operation for the adjacent region may drive the adjacent region at a variable frequency that gradually decreases from a normal driving frequency to a low frequency along a direction from the first partial region to the second partial region.
In embodiments, the variable frequency may decrease per a pixel row of the adjacent region.
In embodiments, the variable frequency may decrease per N pixel rows of the adjacent region, where N is an integer greater than 0.
In embodiments, the normal frequency driving operation for the first partial region may drive the first partial region at a normal driving frequency, the low frequency driving operation for the second partial region may drive the second partial region at a low frequency lower than the normal driving frequency, and the low frequency driving operation for the first partial region and the second partial region except for the adjacent region may drive the first partial region and the second partial region except for the adjacent region at the low frequency.
In embodiments, a size of the adjacent region may be determined based on an adjacent region size parameter.
In embodiments, the standby mode may be an always on display (AOD) mode or a mode in which a black image is displayed.
In embodiments, the panel driver may include a still image detector configured to detect the still image in an image represented by the input image data by analyzing the input image data.
In embodiments, the panel driver may further include a driving frequency decider configured to determine a driving frequency for the first partial region determined by the still image detector to display the moving image as a normal driving frequency, and to determine a driving frequency for the second partial region determined by the still image detector to display the still image as a low frequency lower than the normal driving frequency.
In embodiments, in the standby mode, the driving frequency decider may set the portion of the second partial region adjacent to the first partial region as the adjacent region, may determine a driving frequency for the first partial region and the second partial region except for the adjacent region as the low frequency, and may determine a driving frequency for the adjacent region as a variable frequency that gradually decreases from the normal driving frequency to the low frequency along a direction from the first partial region to the second partial region.
In embodiments, a time length of a second time during which the variable frequency driving operation is performed on the adjacent region may be substantially equal to a time length of a first time during which the normal frequency driving operation and the low frequency driving operation are respectively performed on the first partial region and the second partial region.
In embodiments, the panel driver may include a counter configured to increase a count value from an initial value for a first time during which the normal frequency driving operation and the low frequency driving operation are respectively performed on the first partial region and the second partial region.
In embodiments, the counter may decrease the count value increased for the first time to the initial value in the standby mode. In the standby mode, the panel driver may perform the variable frequency driving operation on the adjacent region until the count value reaches the initial value, and may perform the low frequency driving operation on an entire region of the display region after the count value reaches the initial value.
In embodiments, the counter may stop decreasing the count value when the standby mode is exited before the count value increased for the first time reaches the initial value, and may resume decreasing the count value when the standby mode is re-entered.
According to embodiments, there is provided a method of operating a display device including a display panel having a display region. In the method, a normal frequency driving operation is performed on a first partial region of the display region in a case where input image data represents a moving image with respect to the first partial region, a low frequency driving operation is performed on a second partial region of the display region in a case where the input image data represents a still image with respect to the second partial region, a portion of the second partial region adjacent to the first partial region is set as an adjacent region in a standby mode after the normal frequency driving operation and the low frequency driving operation are performed on the first partial region and the second partial region, respectively, the low frequency driving operation is performed on the first partial region and the second partial region except for the adjacent region in the standby mode, and a variable frequency driving operation is performed on the adjacent region in the standby mode.
In embodiments, to perform the variable frequency driving operation on the adjacent region, the adjacent region may be driven at a variable frequency that gradually decreases from a normal driving frequency to a low frequency along a direction from the first partial region to the second partial region.
In embodiments, to perform the normal frequency driving operation on the first partial region, the first partial region may be driven at a normal driving frequency. To perform the low frequency driving operation on the second partial region, the second partial region may be driven at a low frequency lower than the normal driving frequency. To perform the low frequency driving operation on the first partial region and the second partial region except for the adjacent region, the first partial region and the second partial region except for the adjacent region may be driven at the low frequency.
In embodiments, a time length of a second time during which the variable frequency driving operation is performed on the adjacent region may be substantially equal to a time length of a first time during which the normal frequency driving operation and the low frequency driving operation are respectively performed on the first partial region and the second partial region.
In embodiments, a count value may be increased from an initial value for a first time during which the normal frequency driving operation and the low frequency driving operation are respectively performed on the first partial region and the second partial region, and the count value increased for the first time may be decreased to the initial value in the standby mode. The variable frequency driving operation for the adjacent region may be performed until the count value reaches the initial value.
In embodiments, to decrease the count value to the initial value, decreasing the count value may be stopped when the standby mode is exited before the count value increased for the first time reaches the initial value, and decreasing the count value may be resumed when the standby mode is re-entered.
As described above, in a display device and a method of operating the display device according to embodiments, in a standby mode after a normal frequency driving operation and a low frequency driving operation are performed on a first partial region and a second partial region, respectively, a portion of the second partial region adjacent to the first partial region may be set as an adjacent region, the low frequency driving operation may be performed on the first partial region and the second partial region except for the adjacent region, and a variable frequency driving operation may be performed on the adjacent region. Accordingly, even if the first and second partial regions are driven at different driving frequencies, a boundary between the first and second partial regions may be prevented from being viewed or perceived by a user.
Illustrative, non-limiting embodiments will be more clearly understood from the following detailed description in conjunction with the accompanying drawings.
Hereinafter, embodiments of the present disclosure will be explained in detail with reference to the accompanying drawings.
Referring to
The display panel 110 may include the display region DR in which a plurality of pixels PX is formed. The display panel 110 may further include a plurality of data lines connected to the data driver 130, a plurality of scan lines connected to the scan driver 140, and the plurality of pixels PX coupled to the plurality of data lines and the plurality of scan lines. In some embodiments, each pixel PX may include at least one capacitor, at least two transistors and an organic light emitting diode (OLED), and the display panel 110 may be an OLED display panel. In other embodiments, the display panel 110 may be a liquid crystal display (LCD) panel, or any other suitable display panel.
The data driver 130 may generate the data signals DS based on output image data ODAT and a data control signal DCTRL received from the controller 150, and may provide the data signals DS to the plurality of pixels PX through the plurality of data lines. In some embodiments, the data control signal DCTRL may include, but not be limited to, an output data enable signal, a horizontal start signal and a load signal. In some embodiments, the data driver 130 and the controller 150 may be implemented with a single integrated circuit, and the single integrated circuit may be referred to as a timing controller embedded data driver (TED). In other embodiments, the data driver 130 and the controller 150 may be implemented with separate integrated circuits.
The scan driver 140 may generate the scan signals SS based on a scan control signal SCTRL received from the controller 150, and may sequentially provide the scan signals SS to the plurality of pixels PX on a row-by-row basis through the plurality of scan lines. In some embodiments, the scan control signal SCTRL may include, but not be limited to, a scan start signal, a scan clock signal, etc. In some embodiments, the scan driver 140 may be integrated or formed in a peripheral portion adjacent to the display region DR of the display panel 110. In other embodiments, the scan driver 140 may be implemented with one or more integrated circuits.
The controller (e.g., a timing controller (TCON)) 150 may receive the input image data IDAT and a control signal CTRL from an external host processor (e.g., a graphic processing unit (GPU), an application processor (AP) or a graphic card). In some embodiments, the control signal CTRL may include an adjacent region size parameter ARSP representing a size of an adjacent region (e.g., the number of pixel rows (or scan lines) in the adjacent region) on which a variable frequency driving operation is to be performed, and/or a mode signal SMODE representing whether an operation mode of the display device 100 is one of a normal mode, a standby mode or any other mode. In some embodiments, the control signal CTRL may further include, but not be limited to, a vertical synchronization signal, a horizontal synchronization signal, an input data enable signal, a master clock signal, etc. The controller 150 may generate the data control signal DCTRL, the scan control signal SCTRL and the output image data ODAT based on the control signal CTRL and the input image data IDAT. The controller 150 may control an operation of the data driver 130 by providing the output image data ODAT and the data control signal DCTRL to the data driver 130, and may control an operation of the scan driver 140 by providing the scan control signal SCTRL to the scan driver 140.
The panel driver 120 of the display device 100 according to embodiments may drive the entire display region DR of the display panel 110 at a low frequency lower than a normal driving frequency (e.g., about 60 Hz, about 120 Hz, about 144 Hz, etc.) when a still image is displayed in the entire display region DR of the display panel 110. Further, when a still image is displayed only in a portion of the display region DR of the display panel 110, the panel driver 120 may drive the portion of the display region DR at the low frequency, and may drive the remaining portion of the display region DR at the normal driving frequency. Thus, the panel driver 120 of the display device 100 according to embodiments may perform multi-frequency driving (MFD) that drives partial regions of the display region DR at different driving frequencies. To perform this operation, in some embodiments, the controller 150 of the panel driver 120 may include a still image detector 160 that detects the still image in an image represented by the input image data IDAT by analyzing the input image data IDAT, and a driving frequency decider 170 that determines a driving frequency for a first partial region of the display region DR determined by the still image detector 160 to display a moving image as the normal driving frequency, and determines a driving frequency for a second partial region of the display region DR determined by the still image detector 160 to display the still image as the low frequency lower than the normal driving frequency.
In an example where a moving image is displayed in the entire display region DR of a display panel 110a as illustrated in
In another example where a still image is displayed in the entire display region DR of a display panel 110b as illustrated in
In still another example where a moving image is displayed in a first partial region PR1 of a display region DR of a display panel 110c and a still image is displayed in a second partial region PR2 of the display region DR of the display panel 110c as illustrated in
For example, as illustrated in
In a case where the normal frequency driving operation and the low frequency driving operation are respectively performed on the first partial region PR1 and the second partial region PR2, or in a case where the first partial region PR1 and the second partial region PR2 are driven at the different driving frequencies NDF and LF, a driving transistor of each pixel PX in the first partial region PR1 and a driving transistor of each pixel PX in the second partial region PR2 may receive different stresses. Thus, by the different stresses, a hysteresis deviation or a driving characteristic deviation between the driving transistors of the pixels PX in the first and second partial regions PR1 and PR2 may increase as a time during which the first and second partial regions PR1 and PR2 are driven at the different driving frequencies NDF and LF increases. Thereafter, even if the entire display region DR of the display panel 110 is driven at the same driving frequency to display an image having the same gray level, a boundary between the first and second partial regions PR1 and PR2 may be viewed or perceived by a user.
However, as illustrated in
In some embodiments, the driving frequency decider 170 may determine the variable frequency VF for the adjacent region AR such that the variable frequency VF decreases per a pixel row of the adjacent region AR. For example, as illustrated in
In other embodiments, the driving frequency decider 170 may determine the variable frequency VF for the adjacent region AR such that the variable frequency VF decreases per N pixel rows of the adjacent region AR, where N is an integer greater than 0. For example, as illustrated in
Further, although
In some embodiments, the driving frequency decider 170 of the panel driver 120 may determine the size of the adjacent region AR based on the adjacent region size parameter ARSP representing the number of pixel rows or scan lines of the adjacent region AR. Further, in some embodiments, the controller 150 of the panel driver 120 may store the adjacent region size parameter ARSP, and the adjacent region size parameter ARSP stored in the controller 150 may be updated to a new adjacent region size parameter ARSP received from the external host processor.
For example, as illustrated in
As described above, in the display device 100 according to embodiments, in the standby mode after the normal frequency driving operation and the low frequency driving operation are performed on the first partial region PR1 and the second partial region PR2, respectively, the portion of the second partial region PR2 adjacent to the first partial region PR1 may be set the adjacent region AR, and the variable frequency driving operation may be performed on the adjacent region AR. That is, the adjacent region AR may be driven at the variable frequency VF that gradually decreases from the normal driving frequency NDF to the low frequency LF along the direction from the first partial region PR1 that has previously displayed the moving image to the second partial region PR2 that has previously displayed the still image. Accordingly, driving characteristics of driving transistors of the pixels PX in the adjacent region AR may be gradually changed along the direction from the first partial region PR1 to the second partial region PR2, the driving transistors of the pixels PX in the adjacent region AR close to the first partial region PR1 may have the driving characteristics similar to driving characteristics of driving transistors of the pixels PX in the first partial region PR1, and the driving transistors of the pixels PX in the adjacent region AR farthest from the first partial region PR1 may have the driving characteristics similar to driving characteristics of driving transistors of the pixels PX in the second partial region PR2′ except for the adjacent region AR. Accordingly, the boundary between the first partial region PR1 and the second partial region PR2 may be prevented from being viewed or perceived by the user.
In some embodiments, a time length of a second time T2 during which the variable frequency driving operation is performed on the adjacent region AR may be substantially the same as a time length of a first time T1 during which the normal frequency driving operation and the low frequency driving operation are respectively performed on the first partial region PR1 and the second partial region PR2. To perform the variable frequency driving operation on the adjacent region AR during the second time T2 having substantially the same time length as the first time T1, the panel driver 120 may further include a counter 180 that increases a count value CV from an initial value (e.g., zero) for the first time T1 during which the normal frequency driving operation and the low frequency driving operation are respectively performed on the first partial region PR1 and the second partial region PR2. Further, the counter 180 may decrease the count value CV increased for the first time T1 to the initial value in the standby mode. In the standby mode, the panel driver 120 may perform the variable frequency driving operation on the adjacent region AR until the count value CV reaches the initial value, and may perform the low frequency driving operation on the entire display region DR of a display panel 110e as illustrated in
Further, in some embodiments, the counter 180 may stop decreasing the count value CV when the standby mode is exited before the count value CV increased for the first time T1 reaches the initial value, and may resume decreasing the count value CV when the standby mode is re-entered. Accordingly, even if the standby mode continues for a time shorter than the first time T1, the variable frequency driving operation for the adjacent region AR may be performed in the next standby mode, and thus the time length of the second time T2 during which the variable frequency driving operation is performed on the adjacent region AR may be substantially the same as the time length of the first time T1 during which the first and second partial regions PR1 and PR2 are driven at the different driving frequencies NDF and LF.
Referring to
In a case where the input image data IDAT represent a moving image with respect to the entire display region DR of a display panel 110 (S210: NO and S215: YES), the panel driver 120 may perform a normal frequency driving operation on the entire display region DR of the display panel 110 (S220). Thus, the panel driver 120 may drive the entire display region DR of the display panel 110 at a normal driving frequency.
Further, in a case where the input image data IDAT represent a still image with respect to the entire display region DR of the display panel 110 (S210: NO and S215: NO), the panel driver 120 may perform a low frequency driving operation on the entire display region DR of the display panel 110 (S225). Thus, the panel driver 120 may drive the entire display region DR of the display panel 110 at a low frequency lower than the normal driving frequency.
Alternatively, in a case where the input image data IDAT represent the moving image with respect to a first partial region of the display panel 110 and represent the still image with respect to a second partial region of the display panel 110 (S210: YES), the panel driver 120 may perform the normal frequency driving operation on the first partial region displaying the moving image (S230), and may perform the low frequency driving operation on the second partial region displaying the still image (S235). Thus, the panel driver 120 may drive the first partial region of the display panel 110 at the normal driving frequency, and may drive the second partial region of the display panel 110 at the low frequency lower than the normal driving frequency. If the first and second partial regions are driven at different driving frequencies, driving transistors of pixels PX in the first and second partial regions may have a hysteresis deviation or a driving characteristic deviation. Further, in a normal mode (S250: NO), the normal frequency driving operation and/or the low frequency driving operation may be repeated (S200 through S235).
In a standby mode after the normal frequency driving operation and the low frequency driving operation are performed on the first partial region and the second partial region, respectively (S250: YES), the panel driver 120 may set a portion of the second partial region adjacent to the first partial region as an adjacent region (S270), may perform the low frequency driving operation on the first partial region and the second partial region except for the adjacent region (S272), and may perform a variable frequency driving operation on the adjacent region (S274). Thus, the panel driver 120 may drive the first partial region and the second partial region except for the adjacent region at the low frequency lower than the normal driving frequency, and may drive the adjacent region at a variable frequency that gradually decreases from the normal driving frequency to the low frequency along a direction from the first partial region to the second partial region. Accordingly, driving characteristics of driving transistors of the pixels PX in the adjacent region may be gradually changed along the direction from the first partial region to the second partial region, and a boundary between the first partial region and the second partial region may be prevented from being viewed or perceived by a user.
In some embodiments, in a case where the standby mode is not exited (S280: NO), the low frequency driving operation for the first partial region and the second partial region except for the adjacent region, and the variable frequency driving operation for the adjacent region may be repeated (e.g., for a predetermined time or for a time substantially the same as a time during which the first and second partial regions are driven at the different driving frequencies) (S270 through S274). Thereafter, if the standby mode is exited (S280: YES), the normal frequency driving operation and/or the low frequency driving operation may be performed (S200 through S235).
As described above, in the method of operating the display device 100 according to embodiments, in the standby mode after the normal frequency driving operation and the low frequency driving operation are performed on the first partial region and the second partial region, respectively, the portion of the second partial region adjacent to the first partial region may be set as the adjacent region, the low frequency driving operation may be performed on the first partial region and the second partial region except for the adjacent region, and the variable frequency driving operation may be performed on the adjacent region. Accordingly, even if the first and second partial regions are driven at the different driving frequencies, the boundary between the first and second partial regions may be prevented from being viewed or perceived by the user.
Referring to
Alternatively, in a case where the input image data IDAT represent the moving image with respect to a first partial region of the display panel 110 and represent the still image with respect to a second partial region of the display panel 110 (S310: YES), the panel driver 120 may perform the normal frequency driving operation on the first partial region displaying the moving image (S330), and may perform the low frequency driving operation on the second partial region displaying the still image (S335). Further, a counter 180 of the panel driver 120 may increase a count value CV from an initial value for a first time during which the normal frequency driving operation and the low frequency driving operation are respectively performed on the first partial region and the second partial region (S340). In a normal mode (S350: NO), the normal frequency driving operation and/or the low frequency driving operation may be repeated (S300 through S340).
In a standby mode after the normal frequency driving operation and the low frequency driving operation are performed on the first partial region and the second partial region, respectively (S350: YES), while the count value CV is greater than the initial value (S360: NO), the panel driver 120 may decrease the count value CV increased for the first time (S365), may set a portion of the second partial region adjacent to the first partial region as an adjacent region (S370), may perform the low frequency driving operation on the first partial region and the second partial region except for the adjacent region (S372), and may perform a variable frequency driving operation on the adjacent region (S374). In a case where the standby mode is not exited (S380: NO), decreasing the count value CV, the low frequency driving operation for the first partial region and the second partial region except for the adjacent region, and the variable frequency driving operation for the adjacent region may be repeated (S360 through S374).
If the count value CV reaches the initial value (S360: YES), the panel driver 120 may finish the variable frequency driving operation for the adjacent region, and may perform the low frequency driving operation on the entire display region DR of the display panel 110 (S390). As described above, since the count value CV is increased from the initial value for the first time, and the variable frequency driving operation is performed for a second time during which the count value CV is decreased to the initial value, a time length of the second time during which the variable frequency driving operation is performed on the adjacent region may be substantially the same as a time length of the first time during which the normal frequency driving operation and the low frequency driving operation are respectively performed on the first partial region and the second partial region.
In some embodiments, when the standby mode is exited before the count value CV increased for the first time reaches the initial value (S380: YES), the panel driver 120 may stop decreasing the count value CV (S385). Further, when the standby mode is re-entered after decreasing the count value CV is stopped, the panel driver 120 may resume decreasing the count value CV. Accordingly, even if the standby mode continues for a time shorter than the first time, the variable frequency driving operation for the adjacent region may be performed in the next standby mode, and thus the time length of the second time during which the variable frequency driving operation is performed on the adjacent region may be substantially the same as the time length of the first time during which the first and second partial regions are driven at the different driving frequencies.
As described above, in the method of operating the display device 100 according to embodiments, in the standby mode after the normal frequency driving operation and the low frequency driving operation are performed on the first partial region and the second partial region, respectively, the portion of the second partial region adjacent to the first partial region may be set as the adjacent region, the low frequency driving operation may be performed on the first partial region and the second partial region except for the adjacent region, and the variable frequency driving operation may be performed on the adjacent region. Accordingly, even if the first and second partial regions are driven at the different driving frequencies, a boundary between the first and second partial regions may be prevented from being viewed or perceived by a user.
Referring to
The processor 1110 may perform various computing functions or tasks. The processor 1110 may be an application processor (AP), a micro processor, 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. Further, in some embodiments, 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. For example, the memory device 1120 may include at least one non-volatile memory device such as 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 a solid state drive (SSD) device, a hard disk drive (HDD) device, a CD-ROM device, etc. The I/O device 1140 may be an input device such as a keyboard, a keypad, a mouse, a touch screen, etc, and an output device such as 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 or other communication links.
In the display device, in a standby mode after a normal frequency driving operation and a low frequency driving operation are performed on a first partial region and a second partial region, respectively, a portion of the second partial region adjacent to the first partial region may be set as an adjacent region, the low frequency driving operation may be performed on the first partial region and the second partial region except for the adjacent region, and a variable frequency driving operation may be performed on the adjacent region. Accordingly, even if the first and second partial regions are driven at different driving frequencies, a boundary between the first and second partial regions may be prevented from being viewed or perceived by a user.
The present disclosure may be applied to any display device 1160, and any electronic device 1100 including the display device 1160. For example, the present disclosure may be applied to a mobile phone, a smart phone, a wearable electronic device, a tablet computer, a television (TV), a digital TV, a 3D TV, 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.
The foregoing is illustrative of embodiments and is not to be construed as limiting thereof. Although a few embodiments have been described, those skilled in the art will readily appreciate that many modifications are possible in the embodiments without materially departing from the novel teachings and advantages of the present disclosure. Accordingly, all such modifications are intended to be included within the scope of the present disclosure as defined in the claims. Therefore, it is to be understood that the foregoing is illustrative of various embodiments and is not to be construed as limited to the specific embodiments disclosed, and that modifications to the disclosed embodiments, as well as other embodiments, are intended to be included within the scope of the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2020-0172385 | Dec 2020 | KR | national |
| Number | Name | Date | Kind |
|---|---|---|---|
| 6831617 | Miyauchi | Dec 2004 | B1 |
| 9196222 | Moon et al. | Nov 2015 | B2 |
| 10665168 | Park | May 2020 | B2 |
| 20070229664 | Nagaoka | Oct 2007 | A1 |
| 20150146097 | Izumi | May 2015 | A1 |
| 20150170607 | Shin | Jun 2015 | A1 |
| Number | Date | Country |
|---|---|---|
| 10-2015-0069850 | Jun 2015 | KR |
| 10-2016-0124360 | Oct 2016 | KR |
| 10-2017-0109135 | Sep 2017 | KR |
| Number | Date | Country | |
|---|---|---|---|
| 20220189363 A1 | Jun 2022 | US |
