Method, device, computer-readable medium, and program for preventing afterimage display.

Abstract

This prevents charge from accumulating on the TFT in the blinking portion of the SDI signal, where the light repeatedly turns on and off for each field. [Solution] The system receives and decodes an SDI signal, generates a decoded signal, extracts a timecode from the decoded signal, stores the fields contained in the decoded signal in a queue, performs a first determination to determine the luminescence brightness of the portion where the timecode corresponding to the field stored in the queue is displayed, sets a first luminescence brightness if a first result is obtained from the first determination, and sets a second luminescence brightness according to the result of the second determination if a second result is obtained from the first determination.

Description

Technical Field

[0001] The present invention relates to an afterimage display prevention method, a device, a computer-readable medium, and a program, and more particularly, to an afterimage display prevention method, a device, a computer-readable medium, and a program for preventing afterimages caused by time code display in a liquid crystal panel.

Background Art

[0002] In liquid crystal panels, afterimages may occur when the display is switched. Several methods for suppressing generated afterimages have been conventionally known. For example, among a plurality of display regions, switching of items to be displayed and a region where item switching is performed are determined, and when switching of items and a region where item switching is performed are determined, the brightness of a portion of a light source corresponding to the region where item switching is performed is lowered to a predetermined first target value, the item to be displayed in the determined region is switched, and when it is determined that an elapsed time after the item is switched reaches a predetermined time, a liquid crystal display device that restores the brightness of the light source to the brightness before the brightness is lowered is known (see, for example, Patent Document 1 (pages 5-8), Figure 4).

[0003] Further, for example, when a user does not use a screen saver for suppressing generated afterimages to continue displaying an image, a color display image displayed on a liquid crystal panel that forms one pixel with three sub-pixels of red, green, and blue is configured such that the difference between the color of a character / pattern pixel and the color of its background pixel is only a difference in brightness of any one of the three colors, the brightness of the sub-pixels is set with N (N is a positive integer) bits of gradation, both of the different brightnesses are set to N / 2 gradation or more, the difference in brightness is set within N / 4 gradation, and a method for generating a color display image that generates an image by making the green brightness of a character / pattern equal to the green brightness of its background pixel is also known (see, for example, Patent Document 2 (pages 3-4, Figure 1)).

Prior Art Documents

Patent Documents

[0004] [Patent Document 1] Japanese Patent Publication No. 2011-128595 [Patent Document 2] Japanese Patent Publication No. 2009-223101 [Overview of the project] [Problems that the invention aims to solve]

[0005] However, in the case of Serial Digital Interface (SDI) signals, there was a problem where charge accumulated in the thin-film transistors (TFTs) in the blinking portion of the time code displayed on the LCD panel, where the light repeatedly turned on and off for each field. This blinking was then stored in the TFTs, causing the user to see an afterimage.

[0006] The present invention has been made in view of these problems, and its objective is to provide a method, device, computer-readable medium, and program for preventing afterimages by determining the luminescence brightness of the portion of a liquid crystal panel in which a time code is displayed, thereby reducing the difference in brightness that occurs in the portion of the liquid crystal panel in which a time code is displayed. [Means for solving the problem]

[0007] The present invention provides a method for preventing afterimage display, comprising the steps of: receiving and decoding an SDI signal and generating a decoded signal; extracting a time code from the decoded signal; storing fields included in the decoded signal in a queue; making a first determination to determine the luminescence brightness of the portion where the time code corresponding to the field stored in the queue is displayed, and setting a first luminescence brightness if a first result is obtained from the first determination; and making a second determination to determine the luminescence brightness of the portion where the time code corresponding to the field stored in the queue is displayed, and setting a second luminescence brightness according to the result of the second determination if a second result is obtained from the first determination.

[0008] This configuration makes it possible to provide a method for preventing charge accumulation in the TFT in the blinking portion of the liquid crystal panel, where light is repeatedly turned on and off for each field of the SDI signal.

[0009] The afterimage prevention device of the present invention is configured to receive and decode an SDI signal, generate a decoded signal, extract a time code from the decoded signal, store the fields contained in the decoded signal in a queue, perform a first determination to determine the luminescence brightness of the portion where the time code corresponding to the field stored in the queue is displayed, set a first luminescence brightness if a first result is obtained from the first determination, and if a second result is obtained from the first determination, perform a second determination to determine the luminescence brightness of the portion where the time code corresponding to the field stored in the queue is displayed, and set a second luminescence brightness according to the result of the second determination.

[0010] This configuration makes it possible to provide a device that prevents charge from accumulating in the TFT in the blinking portion of the liquid crystal panel where light is repeatedly turned on and off for each field of the SDI signal.

[0011] The computer-readable medium for preventing afterimage display of the present invention, when executed by a computer processing unit, records a program that causes the processing unit to perform the afterimage display prevention method of the present invention.

[0012] This configuration makes it possible to provide a computer-readable medium that prevents charge from accumulating in the TFT in the blinking portion of the liquid crystal panel, where light is repeatedly turned on and off for each field of the SDI signal.

[0013] The program for preventing afterimage display of the present invention, when executed by a computer processing unit, causes the processing unit to perform the afterimage display prevention method of the present invention.

[0014] This configuration makes it possible to provide a program for preventing charge accumulation in the TFT in the blinking portion of the LCD panel, where the light repeatedly turns on and off for each field of the SDI signal. [Effects of the Invention]

[0015] According to the present invention, an SDI signal is received and decoded, a decoded signal is generated, a time code is extracted from the decoded signal, fields included in the decoded signal are stored in a queue, a first determination is made to determine the luminescence brightness of the portion where the time code corresponding to the field stored in the queue is displayed, a first luminescence brightness is set if a first result is obtained from the first determination, a second determination is made to determine the luminescence brightness of the portion where the time code corresponding to the field stored in the queue is displayed, and a second luminescence brightness is set according to the result of the second determination, thereby making it possible to prevent afterimages displayed on the liquid crystal panel. [Brief explanation of the drawing]

[0016] [Figure 1] This is a conceptual diagram showing an example of an environment in which a residual image prevention device according to one aspect of the present invention is used. [Figure 2] This is an illustrative configuration diagram of a liquid crystal monitor on which a residual image prevention device according to one aspect of the present invention is implemented. [Figure 3] This is a functional block diagram of a residual image display prevention device according to one aspect of the present invention. [Figure 4] This is a flowchart showing a method for preventing afterimage display according to one aspect of the present invention. [Figure 5] This is a flowchart showing a method for preventing afterimage display according to one aspect of the present invention. [Figure 6] This figure illustrates an example of a time code display generated by a method for preventing afterimage display according to one aspect of the present invention. [Figure 7] This figure illustrates an example of the luminescence brightness generated by a method for preventing afterimage display according to one aspect of the present invention. [Figure 8]It is a flowchart illustrating an afterimage display prevention method according to another aspect of the present invention. [Figure 9] It is a flowchart illustrating an afterimage display prevention method according to another aspect of the present invention. [Figure 10] It is a diagram explaining an example of emission luminance generated by the afterimage display prevention method according to another aspect of the present invention. MODE FOR CARRYING OUT THE INVENTION

[0017] Hereinafter, aspects of the present invention will be described in detail with reference to the drawings. The afterimage display prevention method, device, computer-readable medium, and program of the present invention can be used, for example, when producing video. For the purpose of description, the present specification describes a case where a video editing company produces video transmitted from a video production company via a communication line. However, the present invention can also be used in applications other than video production.

[0018] Figure 1 is a conceptual diagram showing an example of an environment in which an afterimage display prevention device 101 according to an aspect of the present invention is used. The afterimage display prevention device 101 of the present invention is mounted, for example, on a liquid crystal monitor 102. The liquid crystal monitor 102 is a monitor used in a video editing company 100 when editing video transmitted from a video production company via a communication line.

[0019] In the present specification, it is assumed that an SDI signal conforming to the SDI standard is used for video transmission between the video editing company 100 and the video production company. The SDI standard is a standard defined by the Society of Motion Picture and Television Engineers (SMPTE). In the signal format of the SDI standard, one frame includes two fields. One field includes active video and ancillary data. The ancillary data includes a vertical blanking period, a horizontal blanking period, and time code data.

[0020] The timecode is displayed alternately at regular intervals on a portion of the LCD monitor 102 screen in the form of "hours:minutes.seconds,frame" and "hours:minutes.seconds;frame," for example, "01:15.50,03" or "01:15.50;03." For example, in the NTSC (National Television System Committee) area, the SDI signal image has 30 frames per second, and the display of the frame portion starts from 00 and increases by 1 up to 29, and when it reaches 30, the seconds digit increases by 1, and the display of the frame portion returns to 00. The timecode will be explained in detail with reference to Figure 6.

[0021] In NTSC regions, there are 30 frames per second, but the frame rate is more precisely approximately 29.97 fps (frames per second). In PAL (Phase Alternating Line) and SECAM (Sequentiel Couleur a Memoire) regions, there are 25 frames per second, and the frame rate is 25 fps. In this specification, the present invention is described assuming there are 30 frames per second, but is not limited to the number of frames per second.

[0022] Furthermore, as used herein, the term "image" refers to digital video, digital audio, or a combination of digital video and digital audio. As used herein, the term "field" refers to the first or second field contained within a single frame.

[0023] Furthermore, the term "afterimage" as used herein refers to the afterimage that occurs in a liquid crystal panel when flashing occurs, with each field repeatedly switching between illumination and extinguishing, causing charge to accumulate in the TFT and the flashing to be stored in the TFT. In this specification, the term "afterimage" is used to distinguish it from burn-in, a discoloration phenomenon that can occur in, for example, CRT (Cathode Ray Tube) monitors or OLED (Organic Light Emitting Diode) displays.

[0024] Figure 2 is an illustrative configuration diagram of a liquid crystal monitor 102 on which a residual image prevention device 101 according to one aspect of the present invention is implemented. The liquid crystal monitor 102 includes, as an example, a logic circuit 201 on which the residual image prevention method of the present invention is implemented, an SDI connection unit 202 connected to the logic circuit 201 and directly or indirectly connected to a communication line that carries SDI signals to a video production company, a panel 203 connected to the logic circuit 201 that outputs video signals generated by the logic circuit, a central processing unit 204 connected to the logic circuit 201 that performs processing on the network interface, human-machine interface, ventilation fan, etc. in the liquid crystal monitor 102, a switch 205 connected to the central processing unit 204 that includes an ON / OFF switch for time code display, and a memory device 206 connected to the central processing unit 204 that records programs and data necessary for processing by the central processing unit 204.

[0025] The logic circuit 201 may specifically be a PLD (Programmable Logic Device) such as an FPGA (Field Programmable Gate Array). However, the logic circuit 201 is not limited to FPGAs and may be other integrated circuits capable of implementing the afterimage prevention method of the present invention, such as an ASIC (Application Specific Integrated Circuit) or an ASSP (Application Specific Standard Product). The afterimage prevention method of the present invention will be described in detail with reference to Figures 4-5 and 7-8.

[0026] The SDI connection unit 202 may include, for example, a cable adapter for transmitting SDI signals, an equalizer for adjusting the data transmission signal, a cable driver for conforming to the SDI standard, and a reclocker equipped with a reclocking function. However, the SDI connection unit 202 is not limited to the configuration described above and may be other units capable of performing the SDI signal reception processing necessary to implement the afterimage prevention method of the present invention.

[0027] Panel 203 could be, for example, a TFT LCD panel. However, panel 203 is not limited to a TFT LCD panel, and could be other LCD panels suitable for editing images, such as lyotropic LCDs or thermotropic LCDs. Furthermore, there can be various types of TFT LCDs, such as TN (Twisted Nematic) LCDs, which change the brightness from the backlight by changing how voltage is applied to liquid crystal molecules twisted and arranged between two polarizing plates; IPS (In-Plane-Switching) LCDs, which change the brightness from the backlight by changing how voltage is applied to liquid crystal molecules arranged between two polarizing plates to change the rotation of the liquid crystal molecules horizontal to the LCD panel; and VA (Vertical Alignment) LCDs, which change the brightness from the backlight by changing how voltage is applied to liquid crystal molecules arranged vertically between two polarizing plates to change the rotation of the liquid crystal molecules from a direction perpendicular to the LCD panel to a direction horizontal to the LCD panel.

[0028] The central processing unit 204 is the central processing unit of the liquid crystal monitor 102, and specifically, it may be an integrated circuit such as an MPU (Micro-Processing Unit). However, the central processing unit 204 is not limited to an MPU and may be any other integrated circuit that provides the functions of the liquid crystal monitor 102 and is capable of performing the processing required for the logic circuit 201 to execute the afterimage display prevention method of the present invention.

[0029] Switch 205 could be, for example, a DIP switch. However, switch 205 is not limited to a DIP switch and may include other switches that allow the user to choose whether or not to display a timecode.

[0030] The memory device 206 may include, for example, an EEPROM (Electrically Erasable and Programmable Read Only Memory) and flash memory. However, the memory device 206 is not limited to the configuration described above and may include other devices that include non-volatile memory capable of recording programs and data necessary for processing by the central processing unit 204.

[0031] Although the integrated circuit described herein is divided into a logic circuit 201 and a central processing unit 204, the afterimage prevention method of the present invention can be implemented by a single processing unit. Furthermore, the integrated circuit described herein is not limited to an integrated circuit, and may be other devices capable of processing the afterimage prevention method of the present invention.

[0032] Figure 3 is a functional block diagram of a residual image prevention device according to one aspect of the present invention. For example, the residual image prevention method of the present invention is implemented in a logic circuit 201, and the logic circuit 201 can be provided as the residual image prevention device of the present invention. For explanatory purposes, the residual image prevention device will be treated as identical to the logic circuit 201, and the functional blocks of the residual image prevention device will be described.

[0033] The logic circuit 201 includes an SDI signal receiving unit 301 that receives an SDI signal from an external SDI connection unit 202 and decodes the received signal; a time code extraction unit 302 that receives a signal from the SDI signal receiving unit 301 and extracts a time code from the received signal; a time code determination unit 303 that receives a signal from the time code extraction unit 302 and uses the received signal to determine the luminescence brightness of the part to be prevented from displaying afterimages; a time code character generation unit 304 that receives a signal from the time code determination unit 303 and uses the received signal to generate time code character data; a time code character superposition unit 305 that receives a valid video from the SDI signal receiving unit 301, receives time code character data from the time code character generation unit 304, and superimposes the received valid video and the time code character; and a video output unit 306 that receives a signal from the time code character superposition unit 305 and outputs the received signal to the external panel 203.

[0034] With this configuration, the afterimage display prevention device of the present invention can be provided.

[0035] Figures 4 and 5 are flowcharts showing a method for preventing afterimage display according to one aspect of the present invention. The process of the method for preventing afterimage display according to one aspect of the present invention is initiated when the SDI connection unit 202 of the liquid crystal monitor 102 receives an SDI signal from outside the liquid crystal monitor 102.

[0036] In step S401, the logic circuit 201 (SDI signal receiving unit 301) receives the SDI signal from the SDI connection unit 202. The logic circuit 201 (SDI signal receiving unit 301) decodes the received SDI signal and obtains the fields. The process then proceeds to step S402.

[0037] In step S402, the logic circuit 201 (timecode extraction unit 302) extracts the timecode from the field ancillary data acquired in step S401, and the process proceeds to step S403.

[0038] In step S403, the logic circuit 201 (timecode determination unit 303) stores the fields acquired in step S401 into a queue, and processing proceeds to step S404. The queue is a data structure that stores fields in the order in which the SDI signal is decoded. For the purpose of explanation, let N be a natural number for the number of fields stored in the queue (i.e., the number of elements in the queue).

[0039] In step S404, the logic circuit 201 (timecode determination unit 303) counts the number of field changes stored in the queue, and the process proceeds to step S405. For explanatory purposes, let the number of field changes stored in the queue be an integer y (0 ≤ y ≤ N). The counting of the number of field changes y begins when an SDI signal frame is received from the SDI connection unit 202, and the initial value of y may be 0. The elements in the queue are compared, and if the previous element (i.e., the old element) is the second field and the next element (i.e., the new element) is the first field, the value of y is increased by 1; if the previous element is the second field and the next element is the second field, the value of y is not changed; if the previous element is the first field and the next element is the first field, the value of y is not changed; and if the previous element is the first field and the next element is the second field, the value of y is increased by 1.

[0040] In step S405, the logic circuit 201 (timecode determination unit 303) determines whether the number of changes y in the fields stored in the queue is greater than or equal to a threshold x. The threshold x is a predetermined integer (0 ≤ x ≤ N), is changeable, and may be a value stored in the logic circuit 201. If the number of changes y in the fields stored in the queue is greater than or equal to the threshold x, the process proceeds to step S406; otherwise, it proceeds to step S407.

[0041] In step S406, the logic circuit 201 (timecode character generation unit 304) sets the luminescence brightness of the blinking portion of the timecode displayed on panel 203 to 50%. The process then proceeds to step S410. The luminescence brightness is the degree of brightness of the pixels in the blinking portion of the timecode displayed on panel 203.

[0042] In step S407, the logic circuit 201 (timecode determination unit 303) determines whether the most recent element in the queue is the first field. If the most recent element in the queue is the first field, the process proceeds to step S408; otherwise, it proceeds to step S409.

[0043] In step S408, the logic circuit 201 (timecode character generation unit 304) sets the luminescence brightness of the blinking portion of the timecode displayed on panel 203 to 0%. The process then proceeds to step S410.

[0044] In step S409, the logic circuit 201 (timecode character generation unit 304) sets the luminescence brightness of the blinking portion of the timecode displayed on panel 203 to 100%. The process then proceeds to step S410.

[0045] In step S410, the logic circuit 201 (timecode character generation unit 304) generates a timecode character to be displayed on the panel 203 based on the set luminescence brightness, which was extracted in step S402. The logic circuit 201 (timecode character superposition unit 305) superimposes the generated timecode character and the active image of the field decoded in step S401 to generate a video signal. The process then proceeds to step S411.

[0046] In step S411, the logic circuit 201 (video output unit 306) displays the video signal generated in step S410 on the panel 203.

[0047] The process for preventing afterimage display according to one aspect of the present invention involves repeating the process from step S401 to step S411 while the logic circuit 201 receives an SDI signal from the SDI connection unit 202, and terminating when the logic circuit 201 does not receive an SDI signal from the SDI connection unit 202.

[0048] With this configuration, a method for preventing afterimage display according to one aspect of the present invention can be provided.

[0049] Figure 6 illustrates an example of a time code display generated by a method for preventing afterimage display according to one aspect of the present invention.

[0050] In conventional technology, for example, if the timecode of an SDI signal is 1 hour, 15 minutes, 50 seconds, and 3 frames, then the panel 203 displays "01:15.50,03" for the first field of the corresponding frame and "01:15.50;03" for the second field of the corresponding frame. The afterimage that appears to the user as flickering is the "·" above the semicolon ";" between the seconds and frame in the timecode displayed on the panel 203.

[0051] The afterimage prevention method of the present invention sets the luminescence brightness of the upper "·" portion to 0%, 50%, or 100% based on the combination of fields stored in the queue, that is, the combination of whether the fields before and after an element in the queue are first fields or second fields.

[0052] In conventional technology, the luminescence brightness of the upper "·" portion is fixed at 0% for the first field and 100% for the second field. However, the afterimage prevention method of the present invention makes it possible to set the luminescence brightness of the first field to 0% or 50%, and the luminescence brightness of the second field to 50% or 100%, depending on the combination of fields stored in the queue. By having two types of luminescence brightness for each field in the upper "·" portion, it is possible to suppress the occurrence of afterimages for the user in the upper "·" portion.

[0053] Figure 7 illustrates an example of the luminescence brightness generated by a method for preventing afterimage display according to one aspect of the present invention. In the input columns of Figure 7(a) and (b), "Second Field #1" represents the second field of the first frame, and "First Field #2" represents the first field of the second frame. Similarly, #3 to #6 represent the third to sixth frames, respectively. Figure 7(b) shows the case where the video playback speed is faster than in Figure 7(a).

[0054] In conventional technology, regardless of the video playback speed, whether in Figure 7(a) or Figure 7(b), the luminescence of the first field from first field #2 to first field #6 is 0%, and the luminescence of the second field from second field #1 to second field #5 is 100%.

[0055] Next, referring to Figures 4 and 5, the luminescence brightness of the afterimage display prevention method according to one aspect of the present invention will be explained using the number of fields N stored in the queue, the threshold x, and the change in the number of fields stored in the queue y.

[0056] In the case of Figure 7(a), when N=2 and x=1, there are two elements in the queue, and y is either 0 or 1. The second field #1 is determined to be "no" in step S405 and "no" in step S407, so the luminescence is set to 100%. The next first field #2 is determined to be "yes" in step S405, so the luminescence is set to 50%. The next second field #2 is also determined to be "yes" in step S405, so the luminescence is set to 50%. For subsequent fields as well, the determination is made to be "yes" in step S405, so the luminescence is set to 50%.

[0057] In the case of Figure 7(a), when N=5 and x=3, the queue has 5 elements, and y is 0, 1, ..., 4. Since y from 0 to 2 is determined to be "no" in step S405, the luminance of the first field is set to 0% and the luminance of the second field is set to 100%. Since y from 3 to 4 is determined to be "no" in step S405, the luminance of both the first and second fields is set to 50%. For subsequent fields as well, since "yes" is determined in step S405, the luminance is set to 50%.

[0058] In the case of Figure 7(a), when N=10 and x=5, there are 10 elements in the queue, and y is 0, 1, ..., 9. Since y from 0 to 4 is determined to be "no" in step S405, the luminance of the first field is set to 0% and the luminance of the second field is set to 100%. Since y from 5 to 9 is determined to be "no" in step S405, both the luminance of the first field and the luminance of the second field are set to 50%.

[0059] In the case of Figure 7(b), when N=2 and x=1, there are two elements in the queue and y is either 0 or 1. The first field #1 is determined to be "no" in step S405 and "yes" in step S407, so the luminescence is set to 0%. The next first field #1 is determined to be "no" in step S405 and "yes" in step S407, so the luminescence is set to 0%. The next second field #1 is determined to be "yes" in step S405, so the luminescence is set to 50%. The next second field #1 is determined to be "no" in step S405 and "yes" in step S407, so the luminescence is set to 100%. The next first field #2 is determined to be "yes" in step S405, so the luminescence is set to 50%. The next field, #2, is determined to be "No" in step S405 and "Yes" in step S407, so the luminescence is set to 0%. The same explanation can be applied to subsequent fields.

[0060] In the case of Figure 7(b), when N=5 and x=3, the queue has 5 elements, and y is 0, 1, and 2. Since y is determined to be "no" in step S405 from 0 to 2, the luminescence of the first field is set to 0%, and the luminescence of the second field is set to 100%. The same explanation can be given for subsequent fields.

[0061] In the case of Figure 7(b), when N=10 and x=5, there are 10 elements in the queue, and y is 0, 1, ..., 4. Since y from 0 to 4 is determined to be "no" in step S405, the luminance of the first field is set to 0% and the luminance of the second field is set to 100%.

[0062] Figures 8 and 9 are flowcharts showing a method for preventing afterimage display according to another aspect of the present invention. The process of the method for preventing afterimage display according to another aspect of the present invention is initiated when the SDI connection unit 202 of the liquid crystal monitor 102 receives an SDI signal from outside the liquid crystal monitor 102.

[0063] The processing in step S801 is the same as the processing in step S401, the processing in step S802 is the same as the processing in step S402, the processing in step S803 is the same as the processing in step S403, the processing in step S804 is the same as the processing in step S404, the processing in step S805 is the same as the processing in step S407, the processing in step S806 is the same as the processing in step S408, the processing in step S807 is the same as the processing in step S405, the processing in step S808 is the same as the processing in step S406, the processing in step S809 is the same as the processing in step S409, the processing in step S810 is the same as the processing in step S410, and the processing in step S811 is the same as the processing in step S411. Since these are the same processes, their explanations will be omitted.

[0064] The process for preventing afterimage display according to another aspect of the present invention involves repeating the process from step S801 to step S811 while the logic circuit 201 receives an SDI signal from the SDI connection unit 202, and terminating when the logic circuit 201 does not receive an SDI signal from the SDI connection unit 202.

[0065] With this configuration, a method for preventing afterimage display according to another aspect of the present invention can be provided.

[0066] Figure 10 illustrates an example of the luminescence brightness generated by a method for preventing afterimage display according to another aspect of the present invention. In the input columns of Figures 10(a) and (b), "Second Field #1," etc., as in Figures 7(a) and (b), #1 means the first frame, #2 means the second frame, and similarly, #3 to #6 mean the third to sixth frames, respectively. Figure 10(b) shows the case where the video playback speed is faster than in Figure 10(a).

[0067] In conventional technology, regardless of the video playback speed, whether it is Figure 10(a) or Figure 10(b), the luminescence of the first field from first field #2 to first field #6 is 0%, and the luminescence of the second field from second field #1 to second field #5 is 100%.

[0068] Next, referring to Figures 4 and 5, the luminescence brightness of the afterimage display prevention method according to another aspect of the present invention will be explained using the number of fields N stored in the queue, the threshold x, and the change in the number of fields stored in the queue y.

[0069] In the case of Figure 10(a), when N=2 and x=1, there are two elements in the queue, and y is either 0 or 1. The second field #1 is determined to be "no" in step S805 and "no" in step S807, so the luminescence is set to 100%. The next first field #2 is determined to be "yes" in step S805, so the luminescence is set to 0%. The next second field #2 is determined to be "no" in step S805 and "yes" in step S807, so the luminescence is set to 50%. The next first field #3 is determined to be "yes" in step S805, so the luminescence is set to 0%. The next second field #3 is determined to be "no" in step S805 and "yes" in step S807, so the luminescence is set to 50%. The same explanation can be applied to subsequent fields.

[0070] In the case of Figure 10(a), when N=5 and x=3, the number of elements in the queue is 5, and y is 0, 1, ..., 4. The second field #1 is determined to be "no" in step S805 and "no" in step S807, so the luminescence is set to 100%. The next first field #2 is determined to be "yes" in step S805, so the luminescence is set to 0%. The next second field #2 is determined to be "no" in step S805 and "no" in step S807, so the luminescence is set to 100%. The next first field #3 is determined to be "yes" in step S805, so the luminescence is set to 0%. The next second field #3 is determined to be "no" in step S805 and "yes" in step S807, so the luminescence is set to 50%. The same explanation can be given for subsequent fields.

[0071] In the case of Figure 10(a), when N=10 and x=5, the number of elements in the queue is 10, and y is 0, 1, ..., 9. Second field #1 is determined to be "no" in step S805 and "no" in step S807, so the luminescence is set to 100%. Next first field #2 is determined to be "yes" in step S805, so the luminescence is set to 0%. Next second field #2 is determined to be "no" in step S805 and "no" in step S807, so the luminescence is set to 100%. Next first field #3 is determined to be "yes" in step S805, so the luminescence is set to 0%. Next second field #3 is determined to be "no" in step S805 and "no" in step S807, so the luminescence is set to 100%. The next first field #4 is determined to be "yes" in step S805, so the luminescence is set to 0%. The next second field #4 is determined to be "no" in step S805 and "yes" in step S807, so the luminescence is set to 50%. Subsequent fields can be explained in a similar manner.

[0072] In the case of Figure 10(b), when N=2 and x=1, there are two elements in the queue, and y is either 0 or 1. The first field #1 is determined to be "yes" in step S805, so the luminescence is set to 0%. The next first field #1 is also determined to be "yes" in step S805, so the luminescence is set to 0%. The next second field #1 is determined to be "no" in step S805 and "yes" in step S807, so the luminescence is set to 50%. The next second field #1 is determined to be "no" in step S805 and "yes" in step S807, so the luminescence is set to 100%. The next first field #2 is determined to be "yes" in step S805, so the luminescence is set to 0%. The next first field #2 is also determined to be "yes" in step S805, so the luminescence is set to 0%. The same explanation can be given for subsequent fields.

[0073] In the case of Figure 10(b), when N=5 and x=3, the number of elements in the queue is 5, and y is 0, 1, 2. The first field #1 is determined to be "yes" in step S805, so the luminescence is set to 0%. The next first field #1 is also determined to be "yes" in step S805, so the luminescence is set to 0%. The next second field #1 is determined to be "no" in step S805 and "no" in step S807, so the luminescence is set to 100%. The next second field #1 is also determined to be "no" in step S805 and "no" in step S807, so the luminescence is set to 100%. The next first field #2 is determined to be "yes" in step S805, so the luminescence is set to 0%. The next first field #2 is also determined to be "yes" in step S805, so the luminescence is set to 0%. The same explanation can be given for subsequent fields.

[0074] In the case of Figure 10(b), when N=10 and x=5, the number of elements in the queue is 10, and y is 0, 1, ..., 4. The first field #1 is determined to be "yes" in step S805, so the luminescence is set to 0%. The next first field #1 is also determined to be "yes" in step S805, so the luminescence is set to 0%. The next second field #1 is determined to be "no" in step S805 and "no" in step S807, so the luminescence is set to 100%. The next second field #1 is determined to be "no" in step S805 and "no" in step S807, so the luminescence is set to 100%. The next first field #2 is determined to be "yes" in step S805, so the luminescence is set to 0%. The next first field #2 is also determined to be "yes" in step S805, so the luminescence is set to 0%. The same explanation can be given for subsequent fields.

[0075] The computer-readable medium for preventing afterimage display in the present invention, although not shown in the figures, may be recording media such as magnetic tape, magnetic disks (e.g., hard disks), optical disks (e.g., CD (Compact Disc), CD-R (Compact Disc Recordable), CD-RW (Compact Disc ReWritable), DVD (Digital Versatile Disc), DVD-ROM (DVD Read Only Memory), DVD-R (DVD Recordable), DVD-RW (DVD ReWritable), DVD-RAM (DVD RAM (Random Access Memory)), Blu-ray Disc®), flash memory (e.g., SSD (Solid State Drive), USB (Universal Serial Bus) memory, memory card), etc.).

[0076] The program for preventing afterimage display of the present invention, although not shown in the figures, can be part of software that sequentially describes computer processing. The program for preventing afterimage display of the present invention is stored in a storage device (main memory), and when executed, the CPU (Central Processing Unit) can sequentially read, interpret, and execute the instructions written in the program.

[0077] In this specification, the configuration of the present invention has been described using a luminescence brightness of 50% for preventing afterimage display. However, the luminescence brightness for preventing afterimage display is not limited to 50%.

[0078] In this specification, steps S407 and S805 involve the logic circuit 201 (timecode determination unit 303) determining whether the most recent element in the queue is the first field. However, it will be readily apparent to those skilled in the art that a similar afterimage prevention method can be constructed even if, instead of determining whether the most recent element in the queue is the second field, the logic circuit 201 (timecode determination unit 303) determines whether the most recent element in the queue is the second field.

[0079] The method for preventing afterimage display described herein was independent of the video playback speed. However, it will be easily understood by those skilled in the art that, for example, a method for preventing afterimage display can be constructed in which the video playback speed is determined, and steps S401 to S411 are used if the video playback speed is fast, and steps S801 to S811 are used if the video playback speed is slow.

[0080] According to the present invention, the occurrence of afterimages for the user can be suppressed. [Industrial applicability]

[0081] This invention can be widely used in industries where the display of time codes in video footage acquired by camera equipment, etc., is required. [Explanation of Symbols]

[0082] 100 Video Editing Companies 101 Afterimage Prevention Device 102 LCD monitors 201 Logic Circuits 202 SDI Connection Unit 203 Panel 204 Central Processing Unit 205 Switch 206 Memory device 301 SDI signal receiving unit 302 Timecode Extraction Unit 303 Timecode determination unit 304 Timecode Character Generation Unit 305 Timecode Character Overlay Section 306 Video Output Section

Claims

1. The steps include receiving and decoding an SDI signal, and generating a decoded signal, The steps include extracting a timecode from the decoded signal, The steps include storing the fields included in the decoded signal in a queue, A first determination is made to determine the luminescence brightness of the portion where the time code corresponding to the field stored in the queue is displayed, and if a first result is obtained from the first determination, a first luminescence brightness is set. If a second result is obtained by the first determination, a second determination is made to determine the luminous intensity of the portion where the time code corresponding to the field stored in the queue is displayed, and a second luminous intensity is set according to the result of the second determination. A method for preventing afterimage display, characterized by comprising the following features.

2. The method for preventing afterimage display according to claim 1, characterized in that the first determination is based on counting the number of changes in the fields stored in the queue, and the second determination is based on whether the field stored in the queue is the first field.

3. The method for preventing afterimage display according to claim 1, characterized in that the first determination is based on whether the field stored in the queue is the first field, and the second determination is based on counting the number of changes in the field stored in the queue.

4. The method for preventing afterimage display according to claim 1, further comprising the step of generating a time code character using the luminescence brightness.

5. The method for preventing afterimage display according to claim 4, further comprising the step of superimposing the timecode character onto the effective image of the field.

6. The method for preventing afterimage display according to claim 5, further comprising the step of outputting a video signal including the effective image on which the timecode character is superimposed.

7. It receives and decodes the SDI signal, and generates the decoded signal. The timecode is extracted from the decoded signal, The fields included in the decoded signal are stored in a queue. A first determination is made to determine the luminescence brightness of the portion where the timecode corresponding to the field stored in the queue is displayed, and if a first result is obtained from the first determination, a first luminescence brightness is set. When the second result is obtained by the first determination, a second determination is made to determine the luminous intensity of the portion where the timecode corresponding to the field stored in the queue is displayed, and the second luminous intensity is set according to the result of the second determination. A device for preventing afterimage display, characterized by being configured in such a way.

8. The afterimage prevention device according to claim 7, characterized in that the first determination is based on counting the number of changes in the fields stored in the queue, and the second determination is based on whether the field stored in the queue is the first field.

9. The afterimage prevention device according to claim 7, characterized in that the first determination is based on whether the field stored in the queue is the first field, and the second determination is based on counting the number of changes in the field stored in the queue.

10. The afterimage display prevention device according to claim 7, further configured to generate a time code character using the luminous intensity.

11. The afterimage prevention device according to claim 10, further configured to superimpose the timecode character onto the effective image of the field.

12. The afterimage prevention device according to claim 11, further configured to output a video signal including the effective image superimposed with the timecode character.

13. A computer-readable medium characterized by recording a program that, when executed by a computer processing unit, causes the processing unit to perform the afterimage display prevention method described in any one of claims 1 to 6.

14. A program characterized by causing a computer processing unit to perform the afterimage display prevention method described in any one of claims 1 to 6 when executed by the computer processing unit.

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