JP2017021191A - Electronic apparatus and control method for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display that can both display images at an equal interval and control pseudo impulse to provide high quality images.SOLUTION: According to one embodiment, an electronic apparatus comprises: a frame rate conversion part that converts a first video signal of a first frame rate into a second video signal of a second frame rate having a higher frequency than that of the first frame rate; and a liquid crystal display part that includes a backlight. A display control part has a first mode of supplying the second video signal to the liquid crystal display part, and turning on the backlight only in a period within 50% from the terminal toward a direction of the beginning of a time during which one frame of the second video signal is displayed and turning off the backlight in other periods.SELECTED DRAWING: Figure 2

Description

  Embodiments described herein relate generally to an electronic device and a control method thereof.

  Original images such as movies and animations are usually produced at 24 frames per second (24 fps). When this 24 fps content is broadcast, since the broadcast frequency is 60 fps, it is broadcast by a so-called 23 pull-down method in which a plurality of the same frames are arranged.

  The 23 pull-down method is a method of converting two consecutive frames of the original image into five frames by arranging the odd-numbered frames of the original image in two consecutive frames and the even-numbered frames in three consecutive frames.

  Since two frames of the original image are converted into five frames, the display interval of the converted images is non-uniform. That is, the converted image has a non-uniform arrangement in which the odd-numbered frames of the original image are two consecutive frames and the even-numbered frames are three consecutive frames. The display of the non-uniformly arranged image causes a sense of discomfort and a moving image that do not exist in the original image.

  In order to improve this phenomenon, there is a technique for rearranging frames called reverse pull-down. When displaying on a liquid crystal display device with a drive frequency of 120 Hz, the 23 pull-down video sent by broadcasting is further converted into 4 consecutive frames and 6 consecutive frames by the 46 pull down method, and 10 frames are converted into 5 frames each. Further conversion is performed by a method called 55 pull-down.

  By this conversion, the odd-numbered frames are converted into 5 frames, and the even-numbered frames are converted into 5 frames, so that the display interval of the images is the same as the original image. Thereby, the display with the reality as it is as the original image is realized.

  When a 24 fps video is displayed from an external device such as a DVD player or a BD player on a liquid crystal display device having a drive frequency of 120 Hz, the liquid crystal display device similarly performs a realistic video display by 55 pull-down.

  On the other hand, in the liquid crystal display device, a moving image blur called a hold effect occurs due to the display principle. This moving image blur is caused by the occurrence of an afterimage due to the human visual effect, because the display method of the liquid crystal display device displays with a constant luminance during one frame. In order to solve this moving image blur, there is an impulse control for blinking the backlight every frame.

JP 2006-333288 A JP 2012-8515 A

  In order to further improve the quality of the video display by the liquid crystal display device, a combination of the above-described moving image blur improvement by impulse control and the 55 pull-down method is conceivable. However, when the impulse control and the 55 pull-down method are combined, there is a problem that the display interval of the image is the same as that of the 46 pull-down method, resulting in a non-uniform display interval.

  The present embodiment has been made in view of the above problems, and an object thereof is to provide an electronic apparatus and a control method thereof capable of providing a high-quality image by achieving both uniform image display and pseudo impulse control. .

  According to an embodiment, a frame rate conversion unit that converts a first video signal having a first frame rate into a second video signal having a second frame rate that is higher in frequency than the first frame rate; Includes a liquid crystal display with a backlight. The display control unit supplies the second video signal to the liquid crystal display unit, and displays only one period within 50% from the end of the time for displaying one frame of the second video signal to the start end direction. In the first mode, the backlight is turned on and the other periods are turned off.

It is a figure which shows an example regarding the backlight control in a prior art. It is a figure which shows an example of the liquid crystal display device which concerns on embodiment. It is a figure which shows an example of the process which determines the video type which concerns on embodiment. It is a figure which shows an example regarding the frame rate conversion which concerns on embodiment. It is a figure which shows an example regarding the frame rate conversion which concerns on embodiment. It is a figure which shows an example regarding the frame rate conversion which concerns on embodiment. It is a figure which shows an example regarding the backlight control which concerns on embodiment. It is a figure which shows an example regarding the backlight control which concerns on embodiment. It is a figure which shows an example of the selection screen which selects the method of the frame rate conversion which concerns on embodiment. It is a figure which shows an example of the selection screen which selects the method of the frame rate conversion which concerns on embodiment.

  Hereinafter, embodiments will be described with reference to the drawings. First, prior to describing a specific embodiment, the backlight control of the prior art will be described with reference to FIG.

  FIG. 1 is a diagram illustrating a state in which impulse control is combined with the 55 pull-down method. FIG. 1A shows an arrangement of 55 pull-down video frames. FIG. 1B shows a state in which the backlight is turned on at the timing of displaying an odd-numbered frame in the video frame of FIG. The white frame and the gray frame mean the time when the gray frame turns off the backlight and the time when the white frame turns on the backlight.

  Since the backlight is turned off at the display timing of odd-numbered frames, the images displayed on the display 28A are frame A2, frame A3 (light-out period), frame A4, frame A5 (light-out period), frame B1, frame B2 ( Off period), frame B3, frame B4 (off period), and frame B5. During the extinguishing period, the image of the previous frame is held by the hold effect of the liquid crystal display. Therefore, the images actually displayed on the display 28A are the frame A2, the frame A2, the frame A4, the frame A4, the frame B1, the frame B1, the frame B3, the frame B3, the frame B5, and the frame B5. Thus, when the 55 pull-down video and impulse control are used together, the result is 46 pull-down video, resulting in non-uniform display intervals.

  In addition, since the backlight is turned off at frame A5 and the backlight is turned on at frame B1, the image of frame A5 may remain as an afterimage at the timing of displaying frame B1.

  Hereinafter, an apparatus devised to solve the above-described problem will be described. In the following description, a television receiver (hereinafter referred to as “liquid crystal television”) provided with a liquid crystal display is illustrated, but the present invention is not limited to this. In other words, it can be replaced with other devices such as a liquid crystal display device connected to a personal computer, a liquid crystal display device of a DVD player, and a game machine equipped with a liquid crystal display device.

  FIG. 2 shows an example of the configuration of the liquid crystal television according to the embodiment of the present invention. The liquid crystal television 1 includes an input unit (tuner) 11, a signal processing unit (may be referred to as a TS separation unit) 12, a video processing block 21, an audio processing block 31, a main control block 51, and the like.

  In the liquid crystal television 1, the display 28A and the backlight 28B associated therewith may be separate. That is, the display 28A and its associated backlight 28B are non-contact with the liquid crystal television 1, and the display 28A and the associated backlight 28B display a program transmitted by the liquid crystal television 1 by a wireless method at a remote position. There may be. The elements and configurations described below may be realized by software by a processing device, that is, a microcomputer (CPU (Central Processing Unit)), or may be realized by hardware.

  The input unit 11 is connected to an antenna ANT that receives a broadcast provided using a spatial wave (a ground wave or a satellite wave). For example, an STB (Set Top Box) or a video camera device is connected to the input unit 11 as an external video supply source. The video camera device may be a portable terminal device capable of taking an image, such as a tablet PC (Personal Computer) device.

  An external input signal from a broadcast or a video camera device or the like input to the input unit 11 is input to the signal processing unit 12, and the signal processing unit 12 converts a TS (Transport Stream), that is, a video signal (video) and an audio signal from the external input signal. It separates into signal (audio) and control information. The control information includes, for example, SI (Service Information, program arrangement information) describing TS distribution rules and contents, schedule or timing, and the like.

  The video signal (also referred to as video) is decoded by the video decoder 22 of the video processing block 21 and output as a digital video signal (video output).

  A display 28A and a speaker 36 are connected to the video processing block 21 and the audio processing block 31, respectively.

  The video processing block 21 includes a video decoder 22, a video type determination unit 23, a frame rate converter 24, a video processing unit 25, an OSD (On Screen Display) processing unit 26, a display control unit 27, and the like.

  The video type determination unit 23 determines the frame rate of the video signal received from the video decoder 22, determines whether the video signal itself has been pulled down 23, and notifies the frame rate converter 24 of the determination result. In addition, the video type determination unit 23 sends switches (also referred to as selectors) SW1 and SW2 to send the received video signal to the frame rate converter 24 or to the video processing unit 25 according to the determination result. ON / OFF (hereinafter referred to as ON / OFF) control is performed.

  The frame rate converter 24 includes a frame rate converter (without film dejudger processing) 24A that inserts an interpolation frame generated by a frame having the same content and executes frame rate conversion, and an interpolation frame generated by a motion vector. Includes a frame rate converter (with film dejudger process) 24C and a frame buffer 24B. The frame buffer 24B is used as a temporary buffer for the video signal received from the video (video) decoder 22 when executing processing for converting the frame rate.

  Note that the method of processing by the frame rate converter (without film dejudger processing) 24A and the method of conversion performed by the frame rate converter (with film dejudger processing) 24C are instructed by the remote control terminal (remote controller) 71 ( It can be switched by operation input). According to an instruction (operation input) from the remote control terminal (remote controller) 71, ON / OFF of the switch SW3 and the switch SW4 is controlled.

  The video processing unit 25 converts the digital video signal decoded by the video decoder 22 into a predetermined resolution and output method that can be displayed on the display 28A.

  The display control unit 27 includes an LCD control unit 27A and a backlight control unit 27B. The LCD control unit 27A converts the video signal converted by the control unit video processing unit 25 into a display drive signal capable of suitable display (video reproduction) on the display 28A. The LCD control unit 27A also synthesizes an OSD (On Screen Display) signal from the OSD processing unit 26 and a display drive signal. Note that the output of the LCD control unit 27A may be output to an output terminal 29 to which an external monitor device or a projection device (projector device) connected to the outside can be connected, for example.

  The backlight control unit 27B controls the timing for turning on the backlight 28B. The timing at which the backlight control unit 27B turns on the backlight 28B is determined based on the frame rate of the video signal determined by the video type determination unit 23 and the determination result as to whether the video is pulled down.

  The sound processing block 31 includes a sound (may be referred to as audio) decoder 32, a sound (may be referred to as audio) processing unit 33, a delay unit 34, a DA (Digital to Analog) converter 35, and the like.

  The audio processing unit 33 converts the audio signal decoded by the audio decoder 32 into a predetermined format that can be suitably reproduced by the speaker 36. The DA converter 35 converts the audio signal converted by the audio processing unit 33 into an analog audio output signal. Thereby, when the speaker 36 is connected to the DA converter 35, the speaker 36 outputs an audible sound (analog voice (audio) output). Note that the output of the DA converter 35 may be branched to an output terminal 37 to which an AV (Audio Visual) amplifier or the like can be connected, for example. The audio signal input to the DA converter 35 is controlled to be delayed by a predetermined amount (time) by the delay unit 34 in accordance with the type of content. For example, when the content is a game, the size (length) of the delay (time) defined by the delay unit 34 is the size (length) of the delay (time) applied when the broadcast signal (program) is reproduced. Smaller (shorter).

  The operation unit 61 inputs a control command corresponding to a direct operation by the user to the main control block 51.

  The receiving unit 62 inputs a command corresponding to an instruction (operation input) from the remote control terminal (remote controller) 71 to the main control block 51.

  The communication interface 63 implements wireless communication with a short-range wireless communication device compliant with, for example, the Wi-Fi (Wireless Fidelity) standard. As the short-range wireless communication standard, for example, Bluetooth (registered trademark) standard, NFC (Near Field Communication), or the like can be used. The communication interface 63 may be either a wired system or a wireless system. For example, a communication unit capable of exchanging signals with a wireless keyboard, a mouse, or the like is connected. The communication interface 63 performs direct communication with, for example, a tablet terminal (smart phone or portable PC (personal computer)).

  The network control unit 64 controls access to the network NTW, acquisition of information from various services (web pages) or servers on the network NTW, transmission of input information for acquiring information, and the like. Thereby, access to a site on the network, content, and the like are possible.

  The USB interface 65 enables use of, for example, a storage device (USB HDD) compatible with the USB standard, for example, an external device compliant with the USB standard, such as a keyboard, for example, a DVD drive.

  The HDMI (registered trademark) interface (control unit) 66 enables wired communication between devices using the HDMI (High-definition Digital Media Interface) standard or the MHL (Mobile High-definition Link) standard. The HDMI interface 66 can be connected to a recorder device that records a program received by the liquid crystal television. By connecting with these devices, it is possible to view the recorded program held by the recorder device.

  A storage device (HDD (Hard Disk Drive)) 67 is used for storing a recorded program by normal recording in which a user designates a channel (or program name) and time and records in units of programs.

  The main control block 51 is connected to the operation unit 61, the receiving unit 62, the communication interface 63, the network control unit 64, the USB interface 65, the HDMI interface 66, the storage device 67, and the like described above, and controls the operations thereof. The main control block 51 includes, for example, a CPU (main processing circuit) 52, a ROM (read only memory) 53, a RAM (random access memory (work memory)) 54, and the like. The CPU (main processing circuit) 52 executes processing corresponding to an input signal and a control signal based on a control program held in the ROM 53 in a work area provided by the RAM 54.

  Next, determination processing of the video type determination unit 23 of the liquid crystal television 1 will be described. The video signal sent from the video decoder 22 is sent to the video type determination unit 23. The video type determination unit 23 analyzes the received video signal, determines the frame rate and determines whether the video signal is pulled down.

  FIG. 3 is a flowchart showing an operation when the video type determination unit 23 determines the frame rate and determines whether the video signal is a pull-down process.

  When receiving the video signal from the video decoder 22, the video type determination unit 23 starts a video type determination process (S301). The video type determination unit 23 extracts information on the frame rate included in the received frame-by-frame video signal (S302), and determines the frame rate of the video signal (S303). If the frame rate of the received video signal is 24 fps as a result of the determination, the video type determination unit 23 notifies the backlight control unit 27B of the determined frame rate (S304), and the received video signal is converted into the frame rate converter 24. The switch SW1 is turned off and the switch SW2 is turned on (S305), and the video signal is sent to the frame rate converter 24 (S306).

  If the frame rate of the received video signal is not 24 fps as a result of determining the frame rate (S303), the video type determination unit 23 proceeds to a determination process to determine whether the received video signal is a 23 pull-down video (S307).

  The pull-down video determination method determines whether or not the contents of a frame in a certain section are arranged according to a certain rule. For example, the image data of the previous and next frames are compared, and if the amount of matching is greater than a predetermined threshold, it is determined that the same frame has been repeated, and if the amount of matching falls below the predetermined threshold, It is determined that it has been switched.

  FIG. 4 illustrates the 23 pull-down conversion. In the 23 pull-down method, in order to convert the original image of 24 fps shown in FIG. 4A to 60 fps shown in FIG. 4B, the frame A of the original image is arranged twice in succession. This is a method of converting the frame rate by arranging the frame B, which is the next frame of A, three times in succession.

  Therefore, the video type determination unit 23, in 5 consecutive frames, 2 frames in the first half of the 5 frames have the same content, 3 frames in the second half are content frames different from the frames in the first half, and 3 frames have the same content. If it is determined that the received video signal is 23 pull-down video, it is determined (S308). As a result of the determination, if the received video signal is a 23 pull-down video, the video type determination unit 23 notifies the backlight control unit 27B of the found frame rate and pull-down type (S309), and the received video signal is framed. In order to send it to the rate converter 24, the switch SW1 is set to OFF / the switch SW2 is set to ON (S305), and the video signal is sent to the frame rate converter 24 (S306).

  As described above, the frame rate conversion is performed by the frame rate converter (without film dejudger processing) 24A and the frame rate converter (with film dejudger processing) 24C included in the frame rate converter 24. is there. Of these two converters, the converter that actually executes the frame rate conversion process can be determined by an instruction (operation input) from the remote control terminal (remote controller) 71. This decision can be selected by the user according to preference.

  For example, it is assumed that the frame rate converter (without film judger processing) 24A is selected to actually execute frame rate conversion according to an instruction (operation input) from the remote control terminal (remote controller) 71. In response to an instruction (operation input) from the remote control terminal (remote controller) 71, the switch SW3 is set to ON and the switch SW4 is set to OFF. With this switch setting, the video signal transmitted from the video type determination unit 23 is input to the frame rate converter (without film dejudge processing) 24A. The input video signal is subjected to frame rate conversion by a frame rate converter (without film dejudger processing) 24A.

  When it is determined that the frame rate is neither 24 fps nor 23 pull-down video, the video type determination unit 23 sets the switch SW1 to ON / switch SW2 to OFF (S310), and converts the video signal to the video processing unit 25 (S311). To send.

  In the flowchart of FIG. 3, the determination is that the frame rate condition is 24 fps and the pull-down video condition is 23 pull-down video. However, other frame rate conditions and pull-down video conditions are used. May be used as the determination content. Moreover, these conditions may be set in the video type determination unit 23 as conditions that can be rewritten from the network via the network control unit 64, for example, even if they are fixedly set in the video type determination unit 23. For example, the method for converting the frame rate from 24 fps to 60 fps includes not only the 23 pull-down method but also the 2224 pull-down method and the 2332 pull-down method. The present invention can obtain the same effect in these other pull-down methods.

  Next, the frame rate conversion process performed by the frame rate converter 24 based on the content of the determination result of the video type determination unit 23 will be described.

  As described above, the frame rate converter 24 includes a frame rate converter (without film de-judder processing) 24A and a frame rate converter (with film de-judder processing) 24C. The frame rate is converted by the converter. The converter used when converting the frame rate is determined by an instruction (operation input) of the remote control terminal (remote controller) 71 by the user.

  FIG. 5 is a diagram showing how the frame rate is converted by the frame rate converter (without film de-judder processing) 24A. The manner of conversion of the frame rate when the user selects the frame rate conversion by the frame rate converter (without film de-judder processing) 24A will be described with reference to FIGS. 5A and 5B. The example of FIG. 5A is a video signal before frame rate conversion sent from the video type determination unit 23, and is a 24 fps video signal. The example of FIG. 5B is a video signal after frame rate conversion, and is a video signal of 72 fps (= 24 fps × 3). The frame rate converter (without film de-judder processing) 24A executes a process of continuously arranging frames having the same contents on the video signal of FIG. 5A in order to convert the frame rate. Specifically, the content of the interpolated frame to be generated uses the content of the frame of FIG. 5A that is the original video signal.

  As a result, the converted video has an arrangement in which three frames having the same contents are continuously arranged as shown in FIG.

  FIG. 6 shows how the frame rate is converted by the frame rate converter (with film dejudger processing) 24C. The manner of frame rate conversion when the user selects frame rate conversion by the frame rate converter (with film dejudger processing) 24C will be described with reference to FIGS. 6A and 6B. The example in FIG. 6A is a video signal before frame rate conversion, as in FIG. 5A, and is a 24 fps video signal. The example in FIG. 6B is a video signal after frame rate conversion, and is a 72 fps (= 24 fps × 3) video signal. The frame rate converter (with film dejudger processing) 24C creates an interpolated frame based on the motion vector of an adjacent frame for the video signal in FIG. 6A in order to convert the frame rate. Specifically, the content of the interpolation frame to be generated is determined by determining the content of the interpolation frame based on the motion vector of the content of the frame A and the content of the frame B in FIG. Is to go. As shown in FIG. 6B, the frame rate converter (with film dejudger processing) 24C performs the contents of frame A as the next frame of frame A based on the motion vectors of the contents of frames A and B. Frame A2B1, which is a frame that is close to, and that takes into account the contents of frame B, is created. In addition, a frame A1B2 that is close to the content of the frame B and takes the content of the frame A into consideration is created as the next frame.

  As a result, in the converted video, all the frames are arranged differently as shown in FIG.

  5 and 6, the frame rate of the converted video signal is 72 fps, but the frame rate of the converted video signal may be other than this. In the frame rate converter (without film de-judder processing) and 24A and the frame rate converter (with film de-judder processing) 24C, the converted frame rates may be different values. Even if the frame rate after conversion is fixedly set in the frame rate converter (without film dejudger processing) 24A and the frame rate converter (with film dejudger processing) 24C, for example, from the network to the network control unit The frame rate converter (without film dejudger processing) 24A and the frame rate converter (with film dejudger process) 24C may be set as values rewritable via H.64.

  Next, processing of the backlight control unit 27B that controls turning on / off of the backlight 28B when the video signal whose frame rate has been converted by the frame rate converter 24 is displayed on the display 28A will be described.

  FIGS. 7A to 7F show the state of backlight control in the case where the video signal whose frame rate has been converted by the frame rate converter (without film dejudge processing) 24A is displayed on the display 28A. .

  The example of FIG. 7A is a video signal before frame rate conversion sent from the video type determination unit 23, and the frame rate is set to 24 fps. The example of FIG. 7B is a video signal obtained by converting the video signal of the example of FIG. 7A by the frame rate converter (without film dejudge processing) 24A, and has a frame rate of 72 fps. The video signal is (= 24 fps × 3). The example of FIG. 7C represents the lighting timing of the backlight when the video signal of the example of FIG. 7B is displayed on the display 28A having the same drive frequency as the video signal. The white part and the gray part of the frame mean the time when the gray part of the first half of each frame is turned off, and the time when the white part of the second half of each frame is turned on.

  The backlight control unit 27B determines the conversion ratio based on the frame rate information before the frame rate conversion notified from the video type determination unit 23 and the frame rate of the video signal after the frame rate conversion received from the frame rate converter 24. Recognize

  In the example of FIG. 7C, the conversion ratio by frame rate conversion is three times. In this way, when the conversion ratio is an odd multiple, the backlight control unit 27B determines that the backlight lighting time is within 50% of the second half of the display time of each frame, and the end of the lighting time is the end of the display time of each frame. Control is performed so that the backlight is repeatedly turned on and off so as to match.

  By controlling in this way, it is possible to achieve both uniform image display and pseudo impulse control.

  In addition, by setting the backlight lighting time within 50% of the second half of the display time of each frame, it is assumed that the user feels that the luminance is lowered when viewing the display 28A. Therefore, the backlight control unit 27 performs control so as to change the luminance of the backlight when it is lit according to the lighting time of the backlight, in order to eliminate discomfort when the user looks at the display 28A.

  (D) of FIG. 7 represents the state of the backlight lighting time of (C) of FIG. 7 separately for each of a plurality of backlight columns arranged immediately below the display 28A. The lighting time in each column of backlights is the lighting time within 50% of the second half of the display time of one frame of the video signal, and the end of the lighting time matches the end of the display time of each frame. Represents.

  The example of (E) of FIG. 7 is another example of the video signal after the video signal of (A) of FIG. 7 is subjected to frame rate conversion by a frame rate converter (without film dejudge processing). 144 fps (= 24 fps × 6). The example of FIG. 7F represents the lighting timing of the backlight when the video signal of the example of FIG. 7E is displayed on the display 28A having the same drive frequency as the video signal. The white frame and the gray frame mean the time when the gray frame turns off the backlight and the time when the white frame turns on the backlight.

  In the example of FIG. 7F, the conversion ratio by frame rate conversion is 6 times. Thus, when the conversion ratio is an even multiple, the backlight control unit 27B turns on so that the backlight lighting time is the display time of each frame, and the start of the lighting time coincides with the start of display of each frame. It is also possible to control to turn off and off every other frame. Further, as in the example of FIG. 7C, the backlight lighting time is within 50% of the latter half of the display time of each frame, and the backlight is set so that the end of the lighting time coincides with the end of the display time of each frame. You may control to repeat lighting on and off.

  By controlling in this way, it is possible to achieve both uniform image display and pseudo impulse control.

  Note that, as shown in FIG. 7C, the backlight control unit 27B in the present embodiment has a backlight lighting time within 50% of the latter half of the display time of each frame, and the lighting time ends at each frame. Control that repeats lighting and extinguishing of the backlight so as to coincide with the end of the display time of, and as shown in FIG. 7F, the lighting time of the backlight is the display time of each frame. It has a function capable of two controls, that is, control to repeat lighting and extinction every other frame so that the start of time coincides with the start of display of each frame. However, at least as shown in FIG. 7C, the backlight control unit 27B has the lighting time of the backlight within 50% of the latter half of the display time of each frame, and the end of the lighting time is the display of each frame. It is only necessary to have a function capable of controlling to repeatedly turn on and off the backlight so as to coincide with the end of time.

  8A to 8C show the state of backlight control when the video signal whose frame rate has been converted by the frame rate converter (with film dejudge processing) 24C is displayed on the display 28A. .

  The example of FIG. 8A is a video signal before frame rate conversion sent from the video type determination unit 23, and the frame rate is 24 fps. The example of FIG. 8B is a video signal after the video signal of the example of FIG. 8A is frame rate converted by the frame rate converter (with film dejudge processing) 24C, and has a frame rate of 72 fps. The video signal is (= 24 fps × 3). The example in FIG. 8C represents the lighting timing of the backlight when the video signal in the example in FIG. 8B is displayed on the display 28A having the same drive frequency as the video signal. The white part and the gray part of the frame mean the time when the gray part of the first half of each frame is turned off, and the time when the white part of the second half of each frame is turned on.

  In the example of FIG. 8C, the conversion ratio by frame rate conversion is three times. In this way, when the conversion ratio is an odd multiple, the backlight control unit 27B determines that the backlight lighting time is within 50% of the second half of the display time of each frame, and the end of the lighting time is the end of the display time of each frame. Control is performed so that the backlight is repeatedly turned on and off so as to match.

Further, when the conversion rate by the frame rate conversion is an even multiple, as in the example of FIG. 7F, the backlight control unit 27B is the display time of each frame, and the lighting time of the backlight. It may be controlled to repeat lighting and extinguishing every other frame so that the start of the display coincides with the start of display of each frame.
Next, when converting the frame rate by the frame rate converter 24, whether to use the frame rate converter (without film dejudge processing) 24A or the frame rate converter (with film dejudge processing) 24C. Processing in the case of selection by the remote control terminal (remote controller) 71 will be described.

  As a display mode for displaying an image on the display 28A of the liquid crystal television 1, a case where the frame rate is converted using a frame rate converter (without film dejudger processing) 24A is used. The case of converting the frame rate using the converter (with film dejudger processing) 24C is set as a “smooth video” display mode.

  FIG. 9 shows the mode switching when changing to the “clear video” display mode, and FIG. 10 shows the mode switching when changing to the “smooth video” display mode.

  For example, when the “display mode switching” button 71a of the remote control terminal (remote controller) 71 is turned on, the display 28A of the liquid crystal television 1 “displays a clear image” 81 as shown in FIG. “Mode switching confirmation screen” is displayed. This “display mode switching confirmation screen” is, for example, a display mode in which the current display mode displayed on the display 28A of the liquid crystal television 1 is “smooth video”, and the user has pressed the “display mode switching” button 71a. Displayed. If the user selects “Yes” 82 using the remote control terminal (remote controller) 71 among “Yes” and “No” displayed on the display 28A of the liquid crystal television 1, an instruction from the remote control terminal (remote controller) 71 is given. (Operation input) sets the switch SW3 to ON and the switch SW4 to OFF. Thereby, the video signal transmitted from the video type determination unit 23 is input to the frame rate converter (without film dejudge processing) 24A.

  Similarly, when the “display mode switching” button 71a of the remote control terminal (remote controller) 71 is turned on, the display 28A of the liquid crystal television 1 has a screen such as “Do you want to make a clear image?” 83 shown in FIG. Is displayed, when the user selects “Yes” 84 using the remote control terminal (remote controller) 71, the switch SW3 is turned OFF / switch SW4 is turned ON by an instruction (operation input) from the remote control terminal (remote controller) 71. Set to Thereby, the video signal transmitted from the video type determination unit 23 is input to the frame rate converter (with film judger processing) 24C.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 1 ... Television receiver, 21 ... Video processing block, 22 ... Video decoder, 23 ... Video type determination device, 24 ... Frame rate converter, 25 ... Video processing part, 26 ... OSD processing unit, 27 ... display control unit, 28A ... display, 28B ... backlight, 51 ... main control block, 71 ... remote control terminal (remote controller).

Claims (5)

A frame rate conversion unit that converts a first video signal having a first frame rate into a second video signal having a second frame rate having a frequency higher than the first frame rate;
A liquid crystal display with a backlight;
The second video signal is supplied to the liquid crystal display unit, and the backlight is turned on only within a period of 50% from the end of the time for displaying one frame of the second video signal to the start end direction. A display control unit having a first mode for turning off other periods;
An electronic device. The frame rate conversion unit repeats different frames of the first video signal the same number of times and generates an intermediate video signal to convert the frame rate;
A function unit that generates a plurality of intermediate images between the adjacent frames by image interpolation based on a motion vector using adjacent frames of the first video signal, and converts a frame rate;
The electronic device according to claim 1, comprising at least one of the following. The display control unit turns on the backlight only during a period of 50% or less from the end of the time for displaying one frame of the second video signal toward the start end, and turns off the backlight during the other period. The first mode for controlling the light;
The backlight is turned on from the start to the end of the time for displaying one frame of the second video signal, and the backlight from the start to the end of the time for displaying one frame of the second video signal. A second mode for controlling the backlight so as to alternately exist every other frame;
The electronic apparatus according to claim 1, further comprising: one of the modes that can be selected. When the backlight is turned on only within a period of 50% from the end of the time for displaying one frame to the start end, the display control unit changes the lighting brightness according to the ratio of the turn-on period. The electronic device according to claim 1, wherein A frame rate conversion control unit, a liquid crystal display unit with a backlight, a display control unit,
In a method for controlling an electronic device having
Converting a first video signal having a first frame rate into a second video signal having a second frame rate having a frequency higher than that of the first frame rate;
The second video signal is supplied to the liquid crystal display unit, and the backlight is turned on only within a period of 50% from the end of the time for displaying one frame of the second video signal to the start end direction. , Display control to turn off the other period,
An electronic device control method comprising:

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