WO2006100988A1

WO2006100988A1 - Image display device, image display monitor, and television receiver

Info

Publication number: WO2006100988A1
Application number: PCT/JP2006/305172
Authority: WO
Inventors: Akihiko Inoue; Takeshi Kumakura; Mitsuhiro Shigeta; Tai Shiraishi
Original assignee: Sharp Kabushiki Kaisha
Priority date: 2005-03-18
Filing date: 2006-03-15
Publication date: 2006-09-28
Also published as: JPWO2006100988A1; JP2011028278A; JP5079856B2; JP2011043827A; JP5021062B2; JP4598061B2

Abstract

When in a first display mode, a control LSI (30) time-divides one-frame period of an input image signal into a plurality of sub-frame periods by a first gradation conversion circuit (34) and a second gradation conversion circuit (35) and outputs them to a display panel, thereby performing image display by time-division drive (pseudo impulse drive). Moreover, when in a second display mode, the control LSI (30) outputs the input image signal as it is to the display panel, thereby performing image display by hold drive. Switching between the first and the second display mode is performed by switching the output in an output data selector (37) according to a mode switching signal. Thus, it is possible to realize an image display device capable of effectively suppressing the dynamic image blurring and reducing the problem of flicker accompanying the pseudo impulse drive.

Description

Specification

Image display device, image display monitor, and television receiver

Technical field

[0001] The present invention relates to an image display device using a hold-type display element such as a liquid crystal display element or an EL (Electro Luminescence) display element.

Background art

In recent years, in addition to CRT (cathode ray tube) display devices, various displays such as liquid crystal display devices, plasma display devices, and organic EL display devices have been developed and commercialized.

[0003] Here, in a display device that performs impulse-type display (display in which only a light emission period is displayed) such as a CRT display device, pixels in a non-selection period are displayed in black. In contrast, in a hold-type display (display that keeps the previous frame image until a new image is written) such as a liquid crystal display device or an organic EL display device, the previous writing is performed in the pixels in the non-selection period. The displayed content is maintained (normal display in the hold type display device).

[0004] In the normal display of such a hold-type display device, there is a problem of motion blur when performing moving image display. The above-mentioned motion blur problem is caused by the fact that the display contents are held in the non-selection period in the pixels of the hold-type display device, and can be solved even if the response speed of the pixels is improved. It is not a thing.

[0005] In a hold-type display device, there is a method of performing time-division driving as a method for preventing moving image blur. Time-division driving is a driving method in which one vertical period (one frame) is divided into a plurality of subframes and signal writing is performed a plurality of times for one pixel.

[0006] That is, even in the hold-type display device, if time-division driving is performed and low-luminance display (display close to black display) is performed with at least one of the subframes, pseudo-impulse display is obtained. Display can be performed, which is effective in preventing motion blur.

For example, Patent Document 1 is disclosed as disclosing time-division driving in a liquid crystal display device.

Patent Document 1: Japanese Patent Publication “Japanese Patent Laid-Open No. 2001-296841 (Publication Date; January 26, 2001)” Patent Document 2: Japanese Patent Publication “JP 2001-184034 Publication (Date of Publication; July 6, 2001)”

Patent Document 3: Japanese Patent Publication “Japanese Patent Laid-Open No. 2003-262846 (Publication Date; September 19, 2003)”

Disclosure of the invention

[0008] However, if pseudo-impulse driving as described above is performed in order to improve moving image performance in a display device using a hold-type display element, the display device in recent years also has a high luminance and a large screen. Along with this, there is a problem that it is easy to generate a flick force. This flickering force becomes particularly prominent when the frame frequency is low or when the luminance is high, and makes the user's eyes tired.

[0009] The present invention has been made in view of the above-described problems, and an object of the present invention is to effectively obtain a moving-image blur suppression effect by pseudo impulse driving and to reduce the accompanying flitz force in pseudo impulse driving. An object of the present invention is to realize an image display device capable of reducing the problem.

In order to solve the above-described problem, the image display device according to the present invention divides one frame period into a plurality of subframe periods, and reproduces luminance within one frame period based on an input image signal. A first display mode in which luminance is distributed to each subframe and image display is performed, and an image is displayed with a single luminance in one frame period so as to reproduce the luminance within one frame period based on the input image signal. It has two display modes, and the image display is performed by switching between the first display mode and the second display mode! /

[0011] According to the above configuration, the image display device has a first display mode and a second display mode. In the first display mode, one frame period is divided into a plurality of subframe periods, and the luminance is distributed to each subframe so that the luminance within one frame period based on the input image signal is reproduced. (Slow, time-division drive display). In the second display mode, image display (so-called hold drive display) is performed with a single luminance in one frame period so as to reproduce the luminance in one frame period based on the input image signal. The first display mode and the second display mode can be switched.

[0012] For this reason, when the motion blur is suppressed, in some cases, the motion blur suppression effect is high, and time-division driving is performed. To generate a display image signal (display in the first display mode), and to suppress the flickering force, a display image signal is generated by hold driving that does not easily generate the flickering force (second Display mode). As a result, it is possible to effectively obtain the motion blur suppression effect by the pseudo impulse drive and to reduce the problem of the flicker force caused by the pseudo impulse drive.

[0013] In order to solve the above problem, another image display device according to the present invention divides one frame period into a plurality of subframe periods, and the sum of the time integral values of luminance in each subframe is the input image. A first signal generating means for generating a display image signal in which the luminance is distributed to each sub-frame so as to reproduce the luminance of one frame period based on the signal, and one frame period as a single frame period. The display signal is switched by switching the output of the second signal generating means for generating the display image signal, the first signal generating means, and the second signal generating means so as to reproduce the luminance of the image. It is characterized by being output to the display unit.

[0014] Further, the image display device includes switching means for switching the outputs of the first signal generating means and the second signal generating means and outputting the display image signal to the display unit. It can be configured.

[0015] In the image display apparatus that performs time-division driving as described above, the luminance is applied to each subframe so that the time integral value of the luminance of each subframe reproduces the luminance characteristics within one frame period based on the input image signal. Is allocated. The time-division drive display is a pseudo impulse display by generating a high-luminance sub-frame and a low-luminance sub-frame due to such luminance distribution to each sub-frame, and is effective for moving image blur. On the other hand, when time-division driving is performed, the effect of suppressing motion blur can be obtained, but at the same time, a problem that flicker force is likely to occur is also caused.

[0016] According to the above configuration, the image display device has a first display mode in which image display is performed by time-division driving and a second display mode in which image display is performed by hold drive. Then, the image display device performs first image generation in the second display mode, and first signal generation means for generating a display image signal when performing image display in the first display mode. Can be used by switching to the second signal generator that generates display image signals at times It is a function. That is, the first display mode in which image display is performed by time-division driving and the second display mode in which image display is performed by hold driving are switched.

[0017] For this reason, when moving image blur is suppressed, the effect of suppressing moving image blur is high, and a display image signal is generated by time-division driving (displayed in the first display mode), and flicker force is reduced. When suppression is desired, a display image signal can be generated (display in the second display mode) by hold driving, which is less likely to generate flickering force. As a result, it is possible to effectively obtain the motion blur suppression effect by the pseudo impulse drive and to reduce the problem of the flicker force caused by the pseudo impulse drive.

Brief Description of Drawings

FIG. 1 is a block diagram illustrating a schematic configuration of a control LSI according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a schematic configuration of the image display apparatus according to Embodiment 1.

FIG. 3 is a diagram showing luminance distribution in a first display mode in the image display device.

FIG. 4 is a diagram showing luminance distribution in a second display mode in the image display device.

FIG. 5 is a diagram showing an operation in a first display mode in the image display device.

FIG. 6 is a diagram showing an operation in a second display mode in the image display device.

FIG. 7 is a block diagram showing a schematic configuration of an image display apparatus according to Embodiment 2.

FIG. 8 is a block diagram showing a schematic configuration of a control LSI in a second embodiment.

FIG. 9 is a block diagram showing a schematic configuration of a control LSI in a third embodiment.

FIG. 10 is a block diagram showing a schematic configuration of a control LSI in a fourth embodiment.

FIG. 11 is a block diagram showing a schematic configuration of an image display apparatus according to Embodiment 5.

FIG. 12 is a block diagram showing a schematic configuration of a control LSI in the seventh embodiment.

FIG. 13 is a diagram showing an example in which a display screen is divided into a plurality of block areas.

FIG. 14 is a block diagram showing a schematic configuration of a region-by-region determination circuit in the seventh embodiment.

FIG. 15 (a) is a diagram showing an example of a block area determined as a moving image area.

FIG. 15 (b) is a diagram showing an example of a block area determined as a still image area. 圆 16] It is a diagram showing a modification of the method for determining a moving image area and a still image area.

17] FIG. 17 is a block diagram showing a schematic configuration of a region-by-region determination circuit in the seventh embodiment. Explanation of symbols

1, 2, 3 Image table device

10 Display panel (display section)

20 frame memory (first signal generator)

30, 60, 70, 80, 90

Control LSI (first signal generation means, second signal generation means)

31 Line buffer (first signal generator)

32 Timing controller

33 Frame memory data selector (first signal generator)

34 First gradation conversion circuit (first signal generator)

35 Second gradation conversion circuit (first signal generator)

36 gradation conversion data selector (first signal generator)

37 Output data selector (switching means)

50 Mode switching switch (switching means)

51 Image source switching switch (Image source judging means, switching means)

61 Movie Z still image judgment circuit (judgment means, movie Z still image judgment means, switching means)

71 Luminance measurement circuit (judgment means, luminance measurement means, switching means)

81 Frame frequency measurement circuit (determination means, frame frequency measurement means, switching means)

91 Judgment circuit for each area (Judgment means, movie Z still picture judgment means, switching means)

91 'Judgment circuit for each region (judgment means, luminance measurement means, switching means)

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1

One embodiment of the present invention is described below with reference to FIGS. First, a schematic configuration of the image display apparatus according to the first embodiment will be described with reference to FIG. In FIG. 2, the image display device 1 includes a display panel 10 and a frame memory 2. 0, control LSI 30, and mode switching switch 50 are provided.

The display panel 10 constitutes image display means, and includes a display element array 11, a TFT substrate 12, source drivers 13a to 13d, and gate drivers 14a to 14d. The display element array 11 includes a plurality of display elements 1 la (pixel portions) using a liquid crystal material or an organic EL member arranged in a matrix.

[0022] In the display area of the TFT substrate 12, a pixel electrode 12a for driving the display element 11a and a TFT 12b as a switching element for turning on / off the charge supply (display voltage) to the pixel electrode 12a are provided. They are arranged in a matrix corresponding to the display elements 11a. In the periphery of the display area of the display element array 11 and the TFT substrate 12, a source driver and a gate driver for driving the pixel electrode 12a and the display element 11a are arranged through the TFTs 12b, respectively. Yes. Regarding the source driver, a configuration in which the first to fourth source drivers 13a to 13d are connected in cascade is illustrated, and for the gate driver, a configuration in which the first to fourth gate drivers 14a to 14d are connected in cascade is illustrated. Illustrated.

[0023] In the display area of the TFT substrate 12, a plurality of source voltage lines connected to the source driver and supplied with a source voltage (display voltage) and a gate voltage (scanning signal voltage) connected to the gate driver are supplied. A plurality of gate voltage lines are provided so as to cross each other. A pixel electrode 12a and a TFT 12b are provided in the vicinity of the intersection.

[0024] The gate electrode of TFT12b is connected to the corresponding gate voltage line (the gate voltage line at the intersection), and the source electrode of TFT12b is connected to the corresponding source voltage line (the source voltage line at the intersection) The drain electrode of the TFT 12b is connected to the pixel electrode 12a.

[0025] The frame memory 20 stores an image signal displayed on the display panel 10 for one frame. The control LSI 30 is display control means for controlling each part. The mode switching switch 50 outputs a mode switching signal to the control LSI 30 by a user operation so that the display mode can be switched by a user instruction.

[0026] In the image display device 1 having the above-mentioned configuration, the basic image display method is described. If it is as follows.

[0027] First, from the control LSI 30, a panel image signal (display image signal) displayed on each pixel portion for one horizontal line is sequentially transferred to the first source driver 13a in synchronization with the clock signal. The Since the first to fourth source drivers 13a to 13d are cascade-connected as shown in FIG. 2, 1 is supplied to the first to fourth source drivers 13a to 13d by the pulse of the clock signal for one horizontal pixel. Panel image signals for the number of horizontal pixels are held. In this state, when a latch pulse signal is output from the control LSI 30 to the first to fourth source drivers 13a to 13d, the display voltage level corresponding to the image signal of each pixel unit is 1 from each source driver 13a to 13d. Output to the source voltage lines for the number of horizontal pixels.

[0028] Further, the control LSI 30 outputs an enable signal, a start pulse signal, and a vertical shift clock signal as control signals to the respective gate dryers 14a to 14d. While the enable signal is at a low level, the gate voltage line is turned off. When the enable signal is at a high level and the start pulse signal is input, the first gate voltage line of the corresponding gate driver is turned on at the rising edge timing of the vertical shift clock signal. When the enable signal is high and no start pulse signal is input, the gate voltage line next to the gate voltage line that was previously turned on is the timing of the rising edge of the vertical shift clock signal. Turns on.

[0029] During the period when the display voltage for one horizontal pixel is being output to the source voltage line, one horizontal pixel connected to the gate voltage line by turning on one gate voltage line Each TFT 12b for several minutes is turned on. As a result, charges (display voltages) from the respective source voltage lines are supplied to the respective pixel electrodes 12a corresponding to the number of horizontal pixels, thereby changing the state of the display element 11a and performing image display. By repeating the display control as described above for each horizontal line, an image is displayed on the entire display screen.

[0030] The image display device 1 according to the first embodiment aims to effectively obtain a moving-image blur suppression effect by pseudo impulse driving and to reduce the problem of flickering force associated with pseudo impulse driving. . And according to the contents of the display image to achieve this purpose It is characterized in that the display mode is switched. This feature point will be described in detail below.

[0031] In the image display device 1, a configuration in which the display mode is switched based on a user instruction input by the mode switching switch 50 is illustrated. That is, when the user operates the mode switching switch 50 in order to switch the display mode, a mode switching signal is input from the mode switching switch 50 to the control LSI 30, and display mode switching control is performed in the control LSI 30.

The image display device 1 has a first display mode in which time-division driving is performed in order to perform pseudo impulse display that suppresses motion blur. That is, in the first display mode, the display panel 10 is driven by dividing one frame into a plurality of subframes. Furthermore, the image display device 1 has a second display mode in which normal hold driving is performed.

[0033] First, the first display mode in which time-division driving is performed will be described. In the first display mode in which time-division driving is performed, the luminance is distributed to each subframe so that the time integral value of the luminance of each subframe reproduces the luminance characteristics within one frame period based on the input image signal. . The time-division drive display becomes a pseudo impulse display by generating a high-luminance sub-frame and a low-luminance sub-frame by such luminance distribution to each sub-frame, and is effective for moving image blur.

[0034] Here, an example of the luminance distribution ratio to the sub-frame in the first display mode is shown in Table 1 below. Table 1 below assumes that the subframe is divided into two subframes, the first half and the second half, and that the time ratio of the subframe is 1: 1. Figure 3 shows the luminance distribution based on the distribution ratio in Table 1 above.

[0035] [Table 1] Input image signal Subframe gradation level Subframe luminance Subframe Frame luminance Gradation level S'J Half Second half First half Second half Brightness difference (Integrated luminance)

0.0 0.0 0.0 0.0 0.0 0.0 0.0

53.3 0.0 73.0 0.0 50.0 50.0 25.0

73.0 0.0 100.0 0.0 100.0 1 00.0 50.0

87.7 73.0 100.0 50.0 100.0 49.9 75.0

1 00.0 100.0 100.0 100.0 1 00.0 0.0 100.0

* Unit (%) Figure 3 shows the first display mode that emphasizes video display performance. The gradation level of the input image signal is 0% (frame brightness 0%), 53.3% (frame). The luminance distribution of the subframes is shown as an example for each of the cases of 25% brightness, 73.0% (50% frame brightness), 87.7% (75% frame brightness), and 100% (100% frame brightness). Show. The relationship between the frame brightness and the gradation level of the input image signal satisfies the following equation (1). In addition, it is known that in equation (1), when y (gamma characteristic) = 2.2, characteristics close to the actual display can be obtained.

[0036] [Equation 1] Frame luminance = (input image signal gradation level) ^r

= ((First half sub-frame gradation level) ^r + (second half sub-frame gradation level) ^{2 In} the first display mode shown in Table 1 and Fig. 3, the frame brightness is in the range of 0 to 50%. The luminance of one subframe (in this example, the first half subframe) is fixed to the minimum luminance (0%), and the luminance of the other subframe (in this example, the second half subframe) is changed. In the range of 50 to 100%, the luminance of one subframe (in this example, the second half subframe) is fixed at the maximum luminance (100%), and the luminance of the other subframe (in this example, the first half subframe) is changed. Let

[0037] It should be noted that the luminance distribution ratio in the first display mode shown in Table 1 and FIG. 3 is set so that the luminance difference between subframes is maximized at each gradation level, thereby preventing motion blur. The distribution is the most effective. However, in the present invention, the luminance distribution ratio of the subframes in the first display mode in which time-division driving is performed is the above-described distribution ratio. It is not limited.

[0038] In the first display mode in which time-division driving is performed, a moving-image blurring suppression effect can be obtained, but at the same time, a problem that flickering force easily occurs. For this reason, the image display device 1 has a second display mode in which normal hold driving is performed in consideration of suppression of flickering force, in addition to the first display mode having the motion blur effect. In the second display mode, sub-frame luminance distribution, that is, time-division driving is not performed, so as shown in Table 2 and FIG. 4 below, it is constant for each gradation level of the input image signal. Frame luminance is given. In the second display mode, the relationship between the frame luminance and the gradation level of the input image signal satisfies the following expression (2). Also in Eq. (2), when γ (gamma characteristic) = 2.2, the actual display and characteristics are obtained.

[0039] [Table 2]

* Unit (%)

[0040] [Expression 2] Frame luminance = (input image signal gradation level

Next, the configuration of the control LSI 30 for performing the switching control between the first and second display modes will be described with reference to FIG.

As shown in FIG. 1, the control LSI 30 includes a line buffer 31, a timing controller 32, a frame memory data selector 33, a first gradation conversion circuit 34, a second gradation conversion circuit 35, and a gradation conversion data selector. 36, and an output data selector 37.

[0043] In the line buffer 31, the inputted input image signal is received one horizontal line at a time. And retained. The line buffer 31 has a reception port and a transmission port independently, and can receive and transmit an input image signal simultaneously.

The timing controller 32 controls the frame memory data selector 33 by alternately switching the timing of data transfer to the frame memory 20 and data reading from the frame memory 20. The timing controller 32 alternately selects and controls the output timings from the first gradation conversion circuit 34 and the second gradation conversion circuit 35 with respect to the gradation conversion data selector 36. That is, the timing controller 32 switches the gradation conversion data selector 36 between the first half subframe period and the second half subframe period. Further, the timing controller 32 outputs a clock signal, a latch pulse signal, an enable signal, a start pulse signal, and a vertical shift clock signal generated based on the input synchronization signal at a predetermined timing.

[0045] The frame memory data selector 33 is controlled by the timing controller 32, and transfers the input image signal held in the line buffer 31 to the frame memory 20 by one horizontal line at a time. Then, the image signal stored in the frame memory 20 is alternately selected to read out the image signal for each horizontal line. The frame memory data selector 33 transfers the image data read from the frame memory 20 to the second gradation conversion circuit 35.

[0046] The first gradation conversion circuit 34 receives the input image signal from the line buffer 31, and sets the gradation level of the input image signal to the gradation level of the first half subframe for performing time-division driving. Convert and output. When the first gradation conversion circuit 34 performs such gradation level conversion, the LUT (Look-Up Table) stores the gradation level of the input image signal and the gradation level of the first subframe in association with each other. ) Is referenced. In FIG. 1, it is assumed that this LUT is stored in the first gradation conversion circuit 34.

[0047] The second gradation conversion circuit 35 receives the input image signal from the frame memory 20 via the frame memory data selector 33, and converts the gradation level of the input image signal into the latter half for time-division driving. It converts to the gradation level of the subframe and outputs it. When the second gradation conversion circuit 35 performs the gradation level conversion, a LUT (Look-Up Table) that stores the gradation level of the input image signal and the gradation level of the second subframe in association with each other is stored. See Is done. In FIG. 1, it is assumed that this LUT is stored in the second gradation conversion circuit 35.

Note that the first gradation conversion circuit 34 and the second gradation conversion circuit 35 read the gradation level of each subframe corresponding to the gradation level of the input image signal from the LUT, thereby adjusting the gradation level. It is not limited to what performs conversion. For example, the first gradation conversion circuit 34 and the second gradation conversion circuit 35 may be obtained by calculating the gradation level of each subframe corresponding to the gradation level of the input image signal. good.

[0049] The gradation conversion data selector 36 is controlled by the timing controller 32 and switches between an image signal output from the first gradation conversion circuit 34 and an image signal output from the second gradation conversion circuit 35, Output to output data selector 37. That is, the gradation conversion data selector 36 outputs the image signal output from the first gradation conversion circuit 34 to the output data selector 37 during the first half subframe period, and the second gradation conversion circuit during the second half subframe period. The image signal output from the path 35 is output to the output data selector 37.

In addition, the output data selector 37 is directly input with the input image signal and the mode switching signal input to the control LSI 30 and the output signal of the gradation conversion data selector 36. In response to the mode switching signal, the output data selector 37 outputs one of the input image signal and the input signal from the gradation conversion data selector 36 as a panel image signal. That is, when the mode switching signal indicates the first display mode (time division drive), the output data selector 37 outputs the input signal from the gradation conversion data selector 36 as a panel image signal. When the mode switching signal indicates the second display mode (hold drive), the output data selector 37 outputs the input image signal as it is as the panel image signal.

[0051] Here, the operation of the image display device 1 using the control LSI 30 having the above-described configuration will be described with reference to FIG. 5 and FIG. FIG. 5 is a diagram showing a flow of image signals for each horizontal period in the first display mode of the image display device, that is, in time-division driving. FIG. 6 is a diagram showing a flow of image signals for each horizontal period in the second display mode of the image display device, that is, in hold driving.

In FIG. 5 and FIG. 6, the brackets [] indicate image signal transfer periods for one horizontal line. For example, [N, 1] is input to the first horizontal line of the Nth frame. It shows that the input image signal is being transferred. The M-th line indicates an intermediate line of the screen, and in the first embodiment, it is a horizontal line driven by the first gate voltage line of the third gate driver 14c.

[0053] In FIG. 5, C1 is an image signal converted by the first gradation conversion circuit 34 using the input image signal of the frame and horizontal line shown in [] as a source. Is shown. C2 indicates that the image signal converted by the second gradation conversion circuit 35 is transferred by using the input image signal of the frame and horizontal line shown in [] thereafter as a source.

First, the operation of the image display device 1 in the first display mode will be described with reference to FIG. FIG. 5 shows a period during which the image input signal for the first line and the third line of the Nth frame is input.

As shown by an arrow D 1 in FIG. 5, the input input image signal is received by the line buffer 31. Next, as shown by an arrow D2, while the image signal for one line is being received, the line buffer 31 writes to the frame memory 20 via the frame memory data selector 33, and the line buffer 31 Transfer to one gradation conversion circuit 34 is performed. The first gradation conversion circuit 34 outputs the converted image signal as a panel image signal.

[0056] Further, as indicated by an arrow D3, alternately from writing to the frame memory 20, the image signal power of the past horizontal line by one half frame from the line of the image signal to be written is line by line from the frame memory 20. Read out. The image signal read from the frame memory 20 is transferred to the second gradation conversion circuit 35 via the frame memory data selector 33, and the converted image signal is output from the second gradation conversion circuit 35 to the gradation conversion data. A panel image signal is output via the selector 36 and the output data selector 37.

[0057] Further, after the panel image signal for one horizontal line output from the control LSI 30 is transferred to the first to fourth source drivers by the clock signal, the latch voltage signal is applied to each source voltage. A display voltage is output corresponding to the luminance of each pixel unit, such as the line force. At this time, a vertical shift clock signal or a gate start pulse signal is supplied to the gate driver corresponding to the ヽ line on which an image is displayed by supplying charges (display voltage) on the source voltage line, as necessary. The scanning signal of the corresponding gate voltage line is turned on. On the other hand, in a gate driver that does not display an image, the enable signal is set to a low level and the scanning signal of the gate voltage line is turned off.

In the example of FIG. 5, as indicated by an arrow D4, the image signal power for one horizontal line of the Mth line of the Nth frame is transferred to the S source driver, and from the control LSI 30 to the arrow D5. As shown, the enable signal to the third gate driver 14c is set to the high level, and the start pulse signal and the vertical shift clock signal to the third gate driver 14c are supplied as shown by arrows D6 and D7. . As a result, as indicated by an arrow D8, the TFT 12b connected to the first gate voltage line of the third gate driver 14c whose display position corresponds to the Mth line on the screen is turned on, and an image is displayed. At this time, enable signals to the first, second, and fourth gate drivers 14a, 14b, 14c that do not correspond to the display position are set to a low level, and the TFT 12b connected to the gate voltage lines of these gate drivers. Is off.

[0059] Next, as shown by an arrow D9, after being transferred to an image signal force S source driver for one horizontal line of the first line of the Nth frame, from the control LSI 30, as shown by an arrow D10, The enable signal to the one gate driver 14a is set to the high level, and the start pulse signal and the vertical shift clock signal to the first gate driver 14a are supplied as shown by arrows D11 and D12. As a result, as indicated by an arrow D13, the TFT 12b connected to the first gate voltage line of the first gate driver 14a whose display position corresponds to the first line of the screen is turned on, and an image is displayed. At this time, enable signals to the second to fourth gate drivers 14b to 14c that do not correspond to the display position are set to the low level, and the TFTs 12b connected to the gate voltage lines of these gate drivers are turned off. .

Note that the operation described above based on FIG. 5 is merely an example for performing time-division driving in the image display device 1, and does not limit the present invention.

[0061] For example, in the above description, the case where the number of divisions into subframes is two is illustrated. The number of divisions of the power frame is not limited to this, and the frame may be divided into three or more subframes. Good. In addition, the subframe division ratio does not need to be an equal division such as 1: 1, and the frame division can be performed at an arbitrary division ratio (for example, 2: 1 or 3: 2). The same applies to Embodiments 2 and 6 described later. Next, the operation of the image display device 1 in the second display mode will be described with reference to FIG. FIG. 6 shows a period during which the image input signal of the first line and the sixth line of the Nth frame is input.

[0063] As shown by an arrow D21 in FIG. 6, when operating in the second display mode, the input image signal input to the control LSI 30 is directly transmitted to the control LSI 30 as a panel image signal only through the output data selector 37. Is output from.

[0064] The panel image signal for one horizontal line output from the control LSI 30 is transferred to the first to fourth source drivers by the clock signal and then given a latch pulse signal. Thus, a display voltage is output corresponding to the luminance of each pixel portion.

[0065] In the example of FIG. 6, as shown by an arrow D22, after the image signal for one horizontal line of the first line of the Nth frame is transferred to the source driver, the control LSI 30 sends the image signal as shown by an arrow D23. The enable signal to the first gate driver 14a is set to a high level. Then, as indicated by arrows D24 and D25, a start pulse signal and a vertical shift clock signal are supplied to the first gate dryer 14a. As a result, as shown by an arrow D26, the TFT 12b connected to the first gate voltage line of the first gate driver 14a is turned on, and an image is displayed. At this time, enable signals to the second to fourth gate drivers 14b to 14d that do not correspond to the display position are set to a low level, and the TFT 12b connected to the gate voltage lines of these gate drivers is turned off. ing.

[0066] Thereafter, data transfer to each gate line after the second line of the Nth frame is performed after the image signal for one horizontal line is transferred to the source driver, as indicated by arrows D27 to D30. When a pulse signal is given, each source voltage line force outputs a display voltage corresponding to the luminance of each pixel portion.

[0067] When writing to the pixel connected to the final gate voltage line of the first gate driver 14a is completed, the enable signal to the second gate driver 14b is subsequently set to the high level, and the second gate driver 14b A start pulse signal and a vertical shift clock signal are supplied. As a result, an image is displayed in the region of the gate voltage line driven by the second gate driver 14b. An image is displayed in the same operation also in the area of the gate voltage line driven by the third gate driver 14c and the fourth gate driver 14d. Note that, in the image display device 1 according to the first embodiment, the display mode is switched according to a user instruction input from the mode switching switch 50. However, the image display device according to the present invention may be configured such that the device itself determines the content of the display image and an appropriate display mode is automatically selected according to the determination result. The image display device having such a configuration will be described in the following second to fourth embodiments.

[Embodiment 2]

The image display apparatus according to the second embodiment is as shown in FIG. The image display device 2 shown in FIG. 7 is different from the image display device 1 shown in FIG. 2 in that it includes a mode switching switch 50 and a control LSI 60 instead of the control LSI 30! / ヽThis is the point. Since other configurations are the same as those of the image display device 1, members having the same configurations and functions as those of the image display device 1 are denoted by the same member numbers as those in FIG. 2, and detailed description thereof is omitted.

In the image display device 2, the control LSI 60 determines whether the display image is a moving image or a still image based on the input image signal, and selects an appropriate display mode according to the determination result. In other words, the time-division driving in the image display device of the present invention is effective in suppressing moving image blur, so when displaying a still image (or a moving image that is close to a still image and has little movement). No effect (or small). Therefore, when the displayed image is a moving image, display is performed in the first display mode by time-division driving with priority given to the moving image blur effect, and when the displayed image is a still image, the flicker force is suppressed. In consideration, it is preferable to perform display in the second display mode by hold driving.

The configuration of the control LSI 60 that performs such a display mode switching operation will be described with reference to FIG. The control LSI 60 includes a control LSI 30 shown in FIG. 1 and a moving image / still image determination circuit 61. In addition, members having the same configuration and operation as those of the control LSI 30 are assigned the same member numbers as in FIG. 1, and detailed descriptions thereof are omitted.

[0072] The moving image Z still image determination circuit 61 receives the input image signal and the input synchronization signal, determines whether the display image is a moving image or a still image based on these signals, and determines the determination. A mode switching signal is output based on the fixed result. The mode switching signal output from the moving image Z still image determination circuit 61 is input to the timing controller 32 and the output data selector 37. That is, in the image display device 2 shown in FIG. 7, the mode switching signal is not generated by a user input, but is generated by the moving image Z still image determination circuit 61 based on the content of the display image.

[0073] Here, with regard to the moving image Z still image determination method in the moving image Z still image determination circuit 61, for example, the data for each corresponding pixel is compared between a plurality of consecutive frames, and changes between these frames. It is possible to use a method for checking whether or not there is a motion vector, a method for extracting a motion vector in a display image from a plurality of continuous frames, and determining a moving image and a still image based on the magnitude of the motion vector. Note that the moving image Z still image determination method is a technique that has already been applied to processing for image compression, and any such known method can be used for the moving image Z still image determination method. For this reason, in the present invention, the specific method for determining the moving image Z still image is not particularly limited.

[0074] The moving image Z still image determination circuit 61 determines whether the display image is a moving image or a still image. The still image here does not have any movement. It does not mean a complete still image only. In other words, the still image here is described as including a picture with relatively little movement relative to the moving picture here.

[0075] For example, the moving image Z still image determination circuit 61 compares the data for each corresponding pixel between consecutive frames, counts the number of pixels whose display has changed between frames, and sets the number of images to a predetermined value. By comparing with the threshold value, it is possible to determine whether there is a large amount of motion (considered as a moving image) and an image and a small amount of motion (considered as a still image).

[Embodiment 3]

The image display apparatus according to the third embodiment has a configuration including a control LSI 70 shown in FIG. 9 instead of the force control LSI 60 having the same configuration as that of the image display apparatus 2 shown in FIG. The control LSI 70 has a configuration in which a luminance measurement circuit 71 is provided in place of the moving image / still image determination circuit 61 for the control LSI 60 shown in FIG.

In the image display device according to the third embodiment, the control LSI 70 measures (calculates) the average luminance of the input image signal, and selects an appropriate display mode according to the result. Snow That is, in the time-division drive in the image display device of the present invention, it is generally difficult to determine the flicker force when the luminance of the display image is high, or when the luminance of the display image is low. Therefore, when the brightness of the display image is low, display is performed in the first display mode by time-division driving with priority given to the motion blur effect, and when the display image brightness is high, suppression of flickering force is considered. Thus, it is preferable to perform display in the second display mode by hold driving.

As shown in FIG. 9, the luminance measurement circuit 71 receives the input image signal and the input synchronization signal, measures (calculates) the average luminance of the display image based on these signals, and based on the result To output a mode switching signal. The mode switching signal output from the luminance measurement circuit 71 is input to the timing controller 32 and the output data selector 37. In calculating the average luminance, the gradation value data in the input image signal is actually used.

Here, as a luminance measuring method in the luminance measuring circuit 71, for example, a method of calculating an average luminance data value (that is, average luminance) of a plurality of pixels in a frame can be considered. The average luminance may be calculated for a single frame or for a plurality of consecutive frames. The average luminance may be calculated by using all the pixels in the frame, or may be calculated by using some pixels from which the frame intermediate force is extracted. Note that the luminance measurement method is a technique that has already been applied to, for example, processing in the case where the backlight of a liquid crystal display device is controlled in accordance with the luminance of a display image. Can also be used. For this reason, in the present invention, the specific method for measuring luminance is not particularly limited.

[Embodiment 4]

The image display device according to the fourth embodiment has a configuration provided with a control LSI 80 shown in FIG. 10 instead of the force control LSI 60 having a configuration substantially similar to that of the image display device 2 shown in FIG. The control LSI 80 is different from the control LSI 60 shown in FIG. 8 in that a frame frequency measurement circuit 81 is provided instead of the moving picture Z still image determination circuit 61.

[0081] In the image display device according to the fourth embodiment, the control LSI 80 transmits the input image signal. The frame frequency is measured, and an appropriate display mode is selected according to the result. That is, in the time-division driving in the image display apparatus of the present invention, it is generally easy to determine the flicker force when the frame frequency is low, which is difficult to determine when the frame frequency is high. Therefore, when the frame frequency of the display image is high, display is performed in the first display mode by time-division driving with priority on the moving image blur effect, and when the frame frequency of the display image is low, the flicker force is reduced. It is preferable to display in the second display mode with hold drive in consideration of suppression.

[0082] As a more specific example, when the frame frequency is determined to be approximately 60 Hz, display is performed in the first display mode, and when the frame frequency is determined to be approximately 50 Hz, the second display is performed. It is preferable to display in the mode. In such a case, the threshold of the frame frequency used as a reference for switching the display mode may be set between 50 Hz and 60 Hz. Note that it is generally preferable to set the frame frequency threshold between 50 Hz and 60 Hz for television image signals of 50 Hz (PAL system) and 60 Hz (NTSC system). It is because it is used.

As shown in FIG. 10, the frame frequency measurement circuit 81 receives the input synchronization signal, measures the frame frequency of the display image based on the input synchronization signal, and based on the result, determines the mode. A switching signal is output. The mode switching signal output from the frame frequency measurement circuit 81 is input to the timing controller 32 and the output data selector 37.

Here, as a frame frequency method in the frame frequency measuring circuit 81, for example, a synchronous counter that operates with a clock (for example, an output of a crystal oscillator) having a fixed frequency in the frame frequency measuring circuit 81 is used. And a method of extracting the input synchronization signal force frame frequency by counting the vertical period of the input synchronization signal is considered, but in the present invention, a specific method for measuring the frame frequency is particularly limited. It is not something.

[0085] It should be noted that each of the configurations described in Embodiments 2 and 4 can be used in any two configurations or a combination of all three configurations in the image display device according to the present invention. is there. Further, it is possible to use a combination of the configuration of the mode switching switch 50 described in the first embodiment. [0086] Furthermore, the moving image Z still image determination process in the second embodiment, the luminance measurement process in the third embodiment, or the frame frequency measurement process in the fourth embodiment is continuously performed during the input period of the image signal. It is also possible. However, in order to reduce the burden on the processing in the moving image Z still image determination circuit 61, the luminance measurement circuit 71, or the frame frequency measurement circuit 81, for example, a configuration in which determination or measurement is performed intermittently every certain period of time. It may be completed.

[Embodiment 5]

The image display device according to the fifth embodiment is characterized in that an appropriate display mode is selected in accordance with a supply source (image source) of an image displayed on the display panel 10. That is, many image display apparatuses in recent years are configured to be able to supply image signals with various image source powers such as a computer, a television tuner, a video, or a game. Depending on the image source, the characteristics of the supplied image signal (particularly the moving image characteristics) are characterized to some extent. For example, an image signal supplied from a personal computer is usually an image having a low moving image characteristic (an image close to a still image with little movement) as compared with an image signal of other video sources.

Therefore, in the image display device according to the fifth embodiment, the image source is determined. For example, when the image source is something other than a personal computer, time-division driving is performed with priority on the moving image blur effect. If the image is displayed in the first display mode and the image source is a personal computer, the display may be performed in the second display mode in which the hold drive is performed in consideration of suppression of the flick force. .

An image display apparatus that performs such control is configured as shown in FIG. 11, for example. The image display device 3 shown in FIG. 11 is different from the image display device 1 shown in FIG. 1 in that an image source switching switch 51 is provided instead of the mode switching switch 50. Since the other configuration is the same as that of the image display device 1, members having the same configuration and operation as those of the image display device 1 are denoted by the same member numbers as those in FIG. 1, and detailed description thereof is omitted.

In the image display device 3, the image source is switched based on a user instruction input by the image source switching switch 51, and a mode switching signal is output based on the selected image source. This mode switching signal is input to the control LSI 30 and Subsequent operations are the same as those of the image display apparatus 1 shown in the first embodiment. The image source switching control is general in an image display apparatus capable of displaying image signals of a plurality of image source forces, and thus detailed description thereof is omitted.

[0091] The configuration described in the fifth embodiment can be used in any combination with the configurations described in the fourth embodiment.

[Embodiment 6]

In the image display device according to the sixth embodiment, as in the image display devices according to the second and third embodiments described above, the device itself determines the content of the display image, and an appropriate display is performed according to the determination result. In this configuration, the mode is automatically selected. However, in the image display devices according to the second and third embodiments, the display mode is switched for the entire frame image, whereas the image according to the sixth embodiment is used. The display device is characterized in that each pixel of the frame image is determined and the display mode is switched for each determined pixel.

[0093] For example, in the image display device according to the sixth embodiment, in the input image, a pixel on which a moving image is displayed and a pixel on which a still image is displayed are determined. For pixels that display in the first display mode with time-division drive giving priority to the motion blur effect, and display still images, the second display mode with hold drive is used in consideration of suppression of flickering force. Display control such as display can be performed.

An image display device that performs such display control can be basically realized with the same configuration as the image display device in the second embodiment. That is, in the second embodiment, the moving image Z still image determination circuit 61 in the control LSI 60 performs the determination of the moving image Z still image for the entire frame image. In the sixth embodiment, the moving image Z still image determination circuit 61 The circuit 61 may determine a moving image Z still image for each pixel, and switch and output a mode switching signal for each pixel that has been determined to be a moving image Z still image.

In the image display device having the same configuration as that of the image display device in the third embodiment, the luminance measurement circuit 71 measures the luminance for each pixel, and switches the mode for each pixel that has received the luminance measurement. The signal may be switched and output. In this case, in the input image, the brightness of the display image is determined to be low and the brightness of the display image is high. Display control in which pixels are displayed in the first display mode giving priority to the motion blur effect, and in high brightness pixels, display is performed in the second display mode in consideration of suppression of flickering force. It can be performed.

[Embodiment 7]

In the image display device according to the seventh embodiment, similarly to the image display devices according to the second and third embodiments described above, the device itself determines the content of the display image, and an appropriate display is performed according to the determination result. In this configuration, the mode is automatically selected. However, in the image display devices according to the second and third embodiments, the display mode is switched for the entire frame image, whereas the image according to the seventh embodiment is used. The display device is characterized in that a region is determined for a frame image, and a display mode is switched for each determined region.

[0097] For example, in the image display device according to the seventh embodiment, in the input image, a region where a moving image is displayed (moving region) and a region where a still image is displayed (still image region) are determined. In the video area, priority is given to the video blur effect to display in the first display mode with time-division drive! Display control such as display in the display mode can be performed.

[0098] Alternatively, an area where the display image has a low brightness (low brightness area) and a display image having a high brightness (high brightness area) are determined in the input image. It is also possible to perform display control such that display is performed in the first display mode with priority on the effect, and display is performed in the second display mode in consideration of suppression of the flickering force in the high luminance region.

The image display device according to the seventh embodiment has a configuration including a control LSI 90 shown in FIG. 12 instead of the force control LSI 60 having a configuration substantially similar to that of the image display device 2 shown in FIG. The control LSI 90 has a configuration in which a determination circuit 91 for each region and a delay buffer 92 are further provided in addition to the control LSI 30 shown in FIG.

[0100] The input image signal and the input synchronization signal are input to the determination circuit 91 for each region, and the determination circuit 91 for each region determines the content of the input image signal for each predetermined block region based on these input signals. Then, a mode switching signal based on the determination result is output. For example, the area determination circuit 91 divides the display screen into a plurality of block areas as shown in FIG. The input image contents are determined and the mode switching signal is switched for each block area. In Fig. 13, the display screen is divided into block areas of Y rows and X columns in units of 8 X 8 pixels. Illustrated.

[0101] In addition, since the area determination circuit 91 collects all the information of all the pixels in the block area and then derives the content determination result of the block area, the delay time until the mode switching signal is output. appear. The delay buffer 92 takes this delay time into account, and in order to synchronize the time timing of the mode switching signal output from the area-by-area determination circuit 91 and the video signal output as the panel image signal, It has been introduced in the previous stage.

[0102] Here, an example of the configuration of each region determination circuit 91 will be described with reference to FIG. The area-by-area determination circuit 91 shown in FIG. 14 exemplifies a configuration for determining an area where a moving image is displayed (moving area) and an area where a still image is displayed (still image area) in the input image. .

The area-by-area determination circuit 91 includes a moving image Z still image determination circuit 911, a pixel position calculation circuit 912, a determination information recording circuit 913, and an in-area mode determination circuit 914.

[0104] The moving image Z still image determination circuit 911 has basically the same function as the moving image Z still image determination circuit 61 shown in the second embodiment, and is based on the input image signal. Can be determined for each pixel. For example, the moving image Z still image determination circuit 911 outputs 1 to the determination information recording circuit 913 when it is determined to be a moving image and 0 when it is determined to be a still image.

The pixel position calculation circuit 912 calculates the screen position of the input pixel and the screen position of the output pixel based on the input synchronization signal.

The determination information recording circuit 913 records the determination result in the moving image Z still image determination circuit 911 based on the screen position of the input pixel input from the pixel position calculation circuit 912. In other words, the determination information recording circuit 913 uses the input pixel position output from the pixel position calculation circuit 912 (the position of the currently input pixel on the screen) as an address, and the determination by the video Z still image determination circuit 911 is performed. Record the results (1 or 0) sequentially. For example, if the display resolution is 480 x 640 pixels and the current input pixel position is 50 and 100 pixels, Record 1-bit (1 or o) judgment result of movie Z still image as address (50, 100).

The intra-region mode determination circuit 914 reads out the determination result in the block region to which the output pixel belongs from the determination information recording circuit 913 based on the screen position of the output pixel input from the pixel position calculation circuit 912 and outputs them. Calculates the mode in the block area and outputs a mode switching signal

When the pixel position calculation circuit 913 receives the output pixel position (the position on the screen of the pixel from which the mode switching signal is to be output) from the pixel position calculation circuit 913, the intra-region mode determination circuit 914 divides the pixel. Which block area is included is calculated. Taking the case of the pixel P in FIG. 13 as an example, the pixel P is required to be included in the block area Area (j, i). This calculation formula depends on the size of the block area. In other words, if the display screen is divided into blocks of MXN pixels (M and N are integers), the Y coordinate (ordinate) on the screen of pixel P is Py and the X coordinate (abscissa) is Px. For example, the block area Area (j, i) including the pixel P is derived by the following equation.

[0108] j = int (Py ÷ M)

i = int (Px ÷ N)

Where int () is a function that rounds down the decimal point of the number in 0 and converts it to an integer.

[0109] For example, when an area is divided into 8 x 8 pixel blocks, if the output pixel position is 50 (Py) vertical and 100 (Px) horizontal,

i = int (50 ÷ 8) = int (6. 25) = 6

j = int (100 ÷ 8) = int (12.5) = 12

Pixel P can be calculated to be included in the block area of Area (6, 12) in FIG.

[0110] Next, the intra-region mode determination circuit 914 simultaneously reads out the determination results for all the pixels in the block for which the output pixel position force is also calculated from the determination information recording circuit 913, and there are more moving images and still pixels. (Ie, determine which number is greater, 1 or 0).

[0111] For example, Fig. 15 (a) shows the result that the count number of still pixels (0) is 20 pixels and the count number power of moving pixels (1) is 4 pixels in a block area of 8 x 8 pixel size. Is shown. In this case, since the count number of moving pixels (1) is larger in this block area, the intra-area mode determination circuit 914 determines that this block area is a moving image area, and the moving image performance is improved. Output a mode switching signal to display the first display mode

Further, in the example of FIG. 15B, since the number of still pixels is larger, the intra-region mode determination circuit 914 determines that this block region is a still image region, and flits. A mode switching signal is output to display the second display mode so as to suppress the force.

[0113] Further, the method for determining the contents of the block area is not limited to the method for determining whether there are more moving pixels or still pixels as described above. Other methods such as simplifying the circuit and reducing the capacity for recording judgment results are also conceivable.

[0114] Another example of the content determination method of the block area will be described with reference to FIG.

[0115] The procedure of FIG. 16 (In 0, the decision information recording circuit 913 adds all judgment results (1 or 0) of moving pixels or still pixels in units of one row in the block area. The added value for each row is recorded as shown in Fig. 16. In Fig. 16, the added value of the moving image prime number in the example shown in Fig. 15 (a) is recorded. In the above method (determination based on whether there are more moving pixels or stationary pixels), the recorded information is the result of the force determination that required 64 bits for 8 bits X columns 8 bits in one block area. By adding in advance in units of one line, one line of one block becomes 4 bits, and the record information of one block area can be half of 32 bits.

[0116] Further, when the in-region mode determination circuit 914 reads the recorded information from the determination information recording circuit 913, the steps (ii) to (iii) are performed without counting the number of 1s and 0s in the block. In this way, the number of moving pixels in the block area can be determined by reading out and adding 4 bits of data for 8 rows. By comparing the obtained number of moving pixels in the block area with 32, which is 50% of all the pixels in the block area, it is possible to determine whether the block area is a moving image area or a still image area.

[0117] A method of switching the signal generation means to the panel image signal based on the mode switching signal is: Since it is the same as that of each said embodiment, detailed description is abbreviate | omitted here.

In addition, in the control LSI 90 having the configuration shown in FIG. 12, if the per-region determination circuit 91 ′ shown in FIG. 17 is used instead of the per-region determination circuit 91, the luminance of the display image in the input image is low (low (Brightness area) and display image brightness can be determined as a high brightness area (high brightness area), and display control can be performed based on the determination result.

This area-by-area determination circuit 91 ′ has a luminance measurement circuit 915 instead of the moving picture Z still image determination circuit 911, and the other configurations are the same as those of the area-by-area determination circuit 91 shown in FIG. You can. The luminance measurement circuit 915 has basically the same function as the luminance measurement circuit 71 shown in the third embodiment, and determines whether the luminance is high or low for each pixel based on the input image signal. be able to. For example, the moving image Z still image determination circuit 911 outputs 1 to the determination information recording circuit 913 when it is determined as high luminance and 0 when it is determined as low luminance. Since the subsequent operation can be the same operation as that of the above-described region-by-region determination circuit 91, detailed description thereof is omitted.

[0120] In the above description, an example in which a display image is divided into block areas for each 8 X 8 pixel block has been described. However, the size of the divided block area is limited to an 8 X 8 pixel size. You can also divide by any NXM pixel size (N and M are natural numbers).

[0121] Further, the area into which the display image is divided may not be every rectangular block as in the above example, but can be divided in an arbitrary shape. Furthermore, the areas into which the display image is divided may not be all the same size area, and the size of the divided area may be changed according to the input image signal. For example, if the pattern of the input image is fine, the divided area is reduced where the pattern is small, and the divided area is increased where the image is smooth.

[0122] Also, in the above example, the mode determination in the divided area is the force determined by the majority decision of the number of pixels occupying that area, even if this determination line is reduced to 30% instead of 50% alone. It can be as large as 70%. If this judgment line is made variable by an external operation, the video quality can be adjusted to the user's preference.

[0123] The image display devices in the above-described first to seventh embodiments can function as an image display monitor such as a liquid crystal monitor, and can also function as a television receiver. [0124] When the image display device functions as an image display monitor, it can be realized by providing a signal input unit (for example, an input port) for inputting an image signal input from the outside to the control LSI. On the other hand, when the image display device functions as a television receiver, the image display device can be realized by including a tuner unit. This tuner unit selects a channel of the television broadcast signal and inputs the television image signal of the selected channel to the control LSI as an input image signal.

In order to solve the above problems, the image display device according to the present invention divides one frame period into a plurality of subframe periods, and reproduces luminance within one frame period based on an input image signal. A first display mode in which luminance is distributed to each subframe and image display is performed, and an image is displayed with a single luminance in one frame period so as to reproduce the luminance within one frame period based on the input image signal. It has two display modes, and the image display is performed by switching between the first display mode and the second display mode! /

[0126] According to the above configuration, the image display device has a first display mode and a second display mode. In the first display mode, one frame period is divided into a plurality of subframe periods, and the luminance is distributed to each subframe so that the luminance within one frame period based on the input image signal is reproduced. (Slow, time-division drive display). In the second display mode, image display (so-called hold drive display) is performed with a single luminance in one frame period so as to reproduce the luminance in one frame period based on the input image signal. The first display mode and the second display mode can be switched.

[0127] For this reason, if the motion blur is suppressed, the motion blur suppression effect is high. In this case, the display image signal is generated by time-division driving (displayed in the first display mode), and the flicker force is reduced. When suppression is desired, a display image signal can be generated (display in the second display mode) by hold driving, which is less likely to generate flickering force. As a result, it is possible to effectively obtain the motion blur suppression effect by the pseudo impulse drive and to reduce the problem of the flicker force caused by the pseudo impulse drive.

[0128] In the image display device, the second display mode may be configured to reproduce a predetermined luminance with one frame period as a single frame period. [0129] In the image display device, the second display mode can be configured such that one frame period is divided into a plurality of subframe periods, and the luminance input to each subframe is equal. .

[0130] In addition, the image display device may include a switching unit that switches between the first display mode and the second display mode.

[0131] Further, the image display device can be configured to switch between the first display mode and the second display mode by an input operation from the outside.

[0132] Further, the image display device can be configured to switch between the first display mode and the second display mode based on the content of the input image.

[0133] Further, the image display device is configured to switch between the first display mode and the second display mode by determining whether the content of the input image is a moving image or a still image. can do.

[0134] Further, in the above image display device, when it is determined that the input image is a moving image,

When the first display mode is selected and it is determined that the input image is a still image, the second display mode can be selected.

[0135] Further, the image display device can be configured to switch between the first display mode and the second display mode based on the average luminance of the input image.

[0136] Further, in the image display device, when the average luminance of the input image is determined to be low, the first display mode is selected, and when the average luminance of the input image is determined to be high, The second display mode can be selected.

[0137] Further, the image display device can be configured to switch between the first display mode and the second display mode based on the frame frequency of the input image.

[0138] Also, in the above image display device, when the frame frequency of the input image is determined to be high !, the first display mode is selected, and the frame frequency of the input image is determined to be low. In addition, the second display mode can be selected.

[0139] Further, in the image display device, the threshold of the frame frequency serving as a reference for switching between the first display mode and the second display mode is set between 50 Hz and 60 Hz. It can be set as a structure. [0140] Further, the image display device may be configured to switch between the first display mode and the second display mode based on the result of the image source determination for determining the input source of the input image. I'll do it.

[0141] Also, the image display device is configured to determine the content of the input image for each pixel based on the input image signal, and to switch between the first display mode and the second display mode based on the determination result. It can be.

[0142] Also, in the image display device, the content of the input image is determined for each of the divided regions based on the input image signal, and the first display mode and the second display are determined based on the determination result. The display mode can be switched.

[0143] In order to solve the above problem, another image display device according to the present invention divides one frame period into a plurality of subframe periods, and the sum of the time integral values of the luminance values of the respective subframes represents the input image. A first signal generating means for generating a display image signal in which the luminance is distributed to each sub-frame so as to reproduce the luminance of one frame period based on the signal, and one frame period as a single frame period. The display signal is switched by switching the output of the second signal generating means for generating the display image signal, the first signal generating means, and the second signal generating means so as to reproduce the luminance of the image. It is characterized by being output to the display unit.

[0144] Further, the image display device includes switching means for switching the outputs of the first signal generating means and the second signal generating means and outputting the display image signal to the display unit. It can be configured.

[0145] In the image display device that performs time-division driving as described above, the luminance is applied to each subframe so that the time integral value of the luminance of each subframe reproduces the luminance characteristics within one frame period based on the input image signal. Is allocated. The time-division drive display is a pseudo impulse display by generating a high-luminance sub-frame and a low-luminance sub-frame due to such luminance distribution to each sub-frame, and is effective for moving image blur. On the other hand, when time-division driving is performed, the effect of suppressing motion blur can be obtained, but at the same time, a problem that flicker force is likely to occur is also caused.

[0146] According to the above configuration, the image display device performs the image display by time-division driving. 1 display mode and a second display mode for displaying an image by hold drive. Then, the image display device performs first image generation in the second display mode, and first signal generation means for generating a display image signal when performing image display in the first display mode. Sometimes it can be used by switching to the second signal generating means for generating the display image signal. That is, the first display mode in which image display is performed by time-division driving and the second display mode in which image display is performed by hold driving are switched.

[0147] For this reason, if the motion blur is suppressed, the motion blur suppression effect is high. In this case, the display image signal is generated by time-division driving (displayed in the first display mode), and the flicker force is reduced. When suppression is desired, a display image signal can be generated (display in the second display mode) by hold driving, which is less likely to generate flickering force. As a result, it is possible to effectively obtain the motion blur suppression effect by the pseudo impulse drive and to reduce the problem of the flicker force caused by the pseudo impulse drive.

[0148] Further, the image display device can be configured such that the output of the first signal generation means and the second signal generation means can be switched by an external input operation.

[0149] According to the above configuration, the user can perform the display mode switching operation, and a display image in which the moving image blur and the flicker force are adjusted according to the user's preference can be obtained. .

[0150] Further, the image display device includes a determination unit that determines the content of the input image based on the input image signal, and based on the determination result of the determination unit, the first signal generation unit and The output of the second signal generating means can be switched.

[0151] According to the above configuration, since the switching of the display mode is performed based on the content determination result of the input image by the determination unit, the display mode can be appropriately selected without requiring a complicated effort from the user. Is switched.

[0152] Further, in the image display device, the determination unit may be a moving image Z still image determination unit that determines whether the input image is a moving image or a still image. At this time, when it is determined that the input image is a moving image, the output of the first signal generation means is output as a display image signal to the display unit, and when it is determined that the input image is a still image. The output of the second signal generating means is preferably output to the display unit as a display image signal.

[0153] According to the above configuration, the moving image Z still image determining unit determines whether the input image is a moving image or a still image, and selects an appropriate display mode according to the determination result. In other words, the time-sharing drive in the above image display device is effective in suppressing moving image blur, so that it is effective when displaying still images (or moving images that are close to still images and have little movement). There is no (or small). Therefore, when the display image is a moving image, display is performed in the first display mode with priority on the moving image blur effect, and when the display image is a still image, the suppression of flickering force is considered. Can be displayed in 2 display modes

[0154] In the image display device, the determination unit may be a luminance measurement unit that measures the average luminance of the input image. At this time, when it is determined that the average luminance of the input image is low, the output of the first signal generation means is output as a display image signal to the display unit, and the average luminance of the input image is determined to be high In addition, it is preferable to output the output of the second signal generating means to the display unit as a display image signal.

[0155] According to the above configuration, the luminance measuring unit measures the average luminance of the input image and selects an appropriate display mode according to the result. That is, in the time-division drive in the image display device, generally, the flicker force is determined when the luminance of the display image is high, and the flicker force is not easily determined when the luminance of the display image is low. Therefore, when the brightness of the display image is low, display is performed in the first display mode with priority given to the motion blur effect, and when the brightness of the display image is high, the second is considered in consideration of suppression of the flicker force. The display mode can be used.

[0156] In the image display device, the determination unit may be a frame frequency measurement unit that measures a frame frequency of an input image. At this time, when it is determined that the frame frequency of the input image is high, the output of the first signal generation means is output as a display image signal to the display unit, and the frame frequency of the input image is determined to be low. In addition, it is preferable to output the output of the second signal generating means to the display unit as a display image signal. [0157] According to the above configuration, the frame frequency measurement unit measures the frame frequency of the input image and selects an appropriate display mode according to the result. That is, in the time-division drive in the image display device, generally, when the frame frequency is high, it is easy to determine the flicker force when the frame frequency is low, which is difficult to determine. Therefore, when the frame frequency of the display image is high, display is performed in the first display mode giving priority to the moving image blur effect, and when the frame frequency of the display image is low, suppression of flickering force is considered. Thus, display can be performed in the second display mode.

[0158] In addition, the image display device preferably has a threshold value set between 50 Hz and 60 Hz as a threshold value of a frame frequency serving as a reference for switching the display mode.

[0159] According to the above configuration, the display mode is changed between a frame frequency of 50 Hz (PAL system) and a frame frequency of 60 Hz (NTSC system), which are generally used as TV image signals. Switching can be performed.

[0160] Further, the image display device includes an image source determination unit that determines an input source of an input image, and the first signal generation unit and the second signal generation unit based on a determination result of the image source determination unit. The output of the signal generating means can be switched.

[0161] According to the above configuration, the image source determination unit determines the input source of the input image, and selects an appropriate display mode according to the result. That is, many image display apparatuses in recent years are configured to be able to supply image signals from various image sources such as a computer, a television tuner, a video, or a game. Depending on the image source, the characteristics of the supplied image signal (especially animation characteristics) are characterized to some extent.

[0162] For this reason, the image display apparatus determines the image source. For example, when the image source supplies an image with low moving image characteristics (for example, a personal computer), the flicker force is suppressed. In consideration, display in the second display mode.If the image source has high video characteristics and supplies images, display in the first display mode giving priority to the motion blur effect. It can be performed.

[0163] Also, in the image display device, the determination means determines the content of the input image for each pixel based on the input image signal, and based on the determination result of the determination means, the first The output of the signal generating means and the second signal generating means can be switched for each pixel.

[0164] In the image display device, the determination unit is a moving image Z still image determination unit that determines, for each pixel, whether the input image is a still image or a moving image, and the input image is a moving image. For the determined pixel, the output of the first signal generating means is output as a display image signal to the display unit, and for the pixel for which the input image is determined to be a still image, The output of the second signal generation means can be output to the display unit as a display image signal.

[0165] Alternatively, the determining means is a luminance measuring means for measuring the luminance of the input image for each pixel, and for the pixel determined to have a low luminance of the input image, the first signal generating means. The output is output to the display unit as a display image signal, and the output of the second signal generation unit is output to the display unit as a display image signal for a pixel determined to have a high luminance of the input image. It can be configured.

[0166] According to the above configuration, for example, the moving image Z still image determination unit determines the region (moving image region) where the moving image is displayed in the input image and the region (still image region) where the still image is displayed. In the moving image area, the display is performed in the first display mode giving priority to the moving image blur effect, and in the still image area, the display is performed in the second display mode in consideration of suppression of the flickering force. Control can be performed.

[0167] Alternatively, in the input image, the luminance measurement means determines the region where the luminance of the display image is low (low luminance region) and the region where the luminance of the display image is high (high luminance region). Therefore, display control can be performed such that display is performed in the first display mode giving priority to the motion blur effect, and display is performed in the second display mode in consideration of suppression of flickering force in a high luminance region. it can.

[0168] In the image display device, the determination means determines the content of the input image for each of the divided areas based on the input image signal, and based on the determination result of the determination means. Thus, the output of the first signal generating means and the second signal generating means can be switched for each region.

[0169] Also, in the image display device, the determination means determines whether the input image is a still image or a moving image. A video that determines whether or not the image is divided into a plurality of areas. Z Still image determination means, and displays the output of the first signal generation means for areas where the input image is determined to be a video. Output to the display unit as a display image signal, and for an area where the input image is determined to be a still image, the output of the second signal generation means is output to the display unit as a display image signal. can do.

[0170] In the image display device, the determination unit is a luminance measurement unit that measures the luminance of the input image for each of the divided areas, and it is determined that the average luminance of the input image is low. For the area, the output of the first signal generation means is output as a display image signal to the display unit, and for the area where the average luminance of the input image is determined to be high, the second signal generation is performed. The output of the means can be output to the display unit as a display image signal.

[0171] Further, a liquid crystal monitor used for a personal computer or the like is configured by combining the image display device and a signal input unit for transmitting an image signal input from the outside to the image display device. Is possible.

[0172] In addition, a liquid crystal television receiver can be configured by combining the image display device and a tuner unit.

Industrial applicability

[0173] In an image display device that performs time-division driving to suppress moving image blur, the flicker force can be reduced, and the image display device uses a hold-type display element such as a liquid crystal display element or an EL display element. Applicable to.

Claims

The scope of the claims

[1] Divide one frame period into multiple subframe periods, and distribute the luminance to each subframe to reproduce the luminance within one frame period based on the input image signal. Display mode,

A second display mode for displaying an image with a single luminance in one frame period so as to reproduce the luminance within one frame period based on an input image signal;

An image display device characterized by performing image display by switching between the first display mode and the second display mode.

[2] The image display device according to [1], wherein the second display mode reproduces a predetermined luminance with one frame period as a single frame period.

[3] The image display device according to [1], wherein in the second display mode, one frame period is divided into a plurality of subframe periods, and the luminance input to each subframe is equal.

[4] The image display device according to any one of [1] to [3], further comprising switching means for switching between the first display mode and the second display mode.

5. The image display device according to claim 1, wherein the first display mode and the second display mode are switched by an input operation with an external force.

6. The image display device according to any one of claims 1 to 4, wherein the first display mode and the second display mode are switched based on the content of the input image.

[7] The method according to claim 6, wherein the content of the input image is a moving image or a still image, and the first display mode and the second display mode are switched. Image display device.

[8] If the input image is determined to be a video, select the first display mode above,

8. The image display device according to claim 7, wherein when the input image is determined to be a still image, the second display mode is selected.

9. The image display device according to claim 6, wherein the first display mode and the second display mode are switched based on an average luminance of the input image.

[10] When the average luminance of the input image is determined to be low, select the first display mode above. 10. The image display device according to claim 9, wherein when the average luminance of the input image is determined to be high !, the second display mode is selected.

11. The image display device according to claim 6, wherein the first display mode and the second display mode are switched based on a frame frequency of the input image.

[12] When the frame frequency of the input image is determined to be high, select the first display mode above,

12. The image display device according to claim 11, wherein when the frame frequency of the input image is determined to be low, the second display mode is selected.

[13] The request, wherein a threshold of a frame frequency that is a reference for switching between the first display mode and the second display mode is set between 50 Hz and 60 Hz. Item 13. The image display device according to Item 12.

[14] The method according to claim 1, wherein the first display mode and the second display mode are switched based on a result of image source determination for determining an input source of the input image.

5. The image display device according to any one of 4 and 4.

[15] The content of the input image is determined for each pixel based on the input image signal, and the first display mode and the second display mode are switched based on the determination result. The image display device according to any one of!

[16] The content of the input image is determined for each of the divided areas based on the input image signal, and the first display mode and the second display mode are switched based on the determination result The image display device according to claim 1.

[17] Divide one frame period into multiple subframe periods, and add luminance to each subframe so that the sum of the time integral values of each subframe reproduces the luminance of one frame period based on the input image signal. First signal generating means for generating a display image signal to which

Second signal generating means for generating a display image signal so as to reproduce a predetermined luminance with one frame period as a single frame period;

By switching the outputs of the first signal generating means and the second signal generating means, An image display device that outputs a display image signal to a display unit.

18. The apparatus according to claim 1, further comprising switching means for switching the outputs of the first signal generating means and the second signal generating means to output a display image signal to the display unit.

8. The image display device according to 7.

19. The image display device according to claim 17 or 18, wherein the output of the first signal generating means and the second signal generating means can be switched by an input operation of an external force.

[20] having determination means for determining the content of the input image based on the input image signal;

19. The image display device according to claim 17, wherein outputs of the first signal generation unit and the second signal generation unit are switched based on a determination result of the determination unit.

21. The image display device according to claim 20, wherein the determination unit is a moving image Z still image determination unit that determines whether the input image is a moving image or a still image.

[22] When it is determined that the input image is a moving image, the output of the first signal generation means is output to the display unit as a display image signal.

22. The image display device according to claim 21, wherein when the input image is determined to be a still image, the output of the second signal generation unit is output to the display unit as a display image signal.

23. The image display device according to claim 20, wherein the determination unit is a luminance measurement unit that measures an average luminance of the input image.

[24] When it is determined that the average luminance of the input image is low, the output of the first signal generation means is output to the display unit as a display image signal.

24. The image display device according to claim 23, wherein when it is determined that the average luminance of the input image is high, the output of the second signal generation unit is output to the display unit as a display image signal.

25. The image display device according to claim 20, wherein the determination means is a frame frequency measurement unit that measures a frame frequency of an input image.

[26] The first signal generating means when it is determined that the frame frequency of the input image is high Is output to the display unit as an image signal for display,

26. The image display device according to claim 25, wherein when the frame frequency of the input image is determined to be low, the output of the second signal generation means is output to the display unit as a display image signal. .

[27] The switching means is set between 50 Hz and 60 Hz as a frame frequency threshold value used as a reference for switching the outputs of the first signal generating means and the second signal generating means. 27. The image display device according to claim 26, further comprising a threshold value.

[28] having an image source determination means for determining an input source of the input image;

The switching means switches the outputs of the first signal generation means and the second signal generation means based on the determination result of the image source determination means! Item 17. The image display device according to Item 17 or 18.

[29] The determination means determines the content of the input image for each pixel based on the input image signal, and based on the determination result of the determination means, the first signal generation means and the second signal generation means 21. The image display device according to claim 20, wherein the output is switched for each pixel.

[30] The determination unit is a moving image Z still image determination unit that determines, for each pixel, whether the input image is a still image or a moving image.

For a pixel for which the input image is determined to be a moving image, the output of the first signal generation means is output to the display unit as a display image signal, and the pixel for which the input image is determined to be a still image is output. 30. The image display device according to claim 29, wherein the output of the second signal generation means is output to the display unit as a display image signal.

[31] The determination means is a luminance measurement means for measuring the luminance of the input image for each pixel, and outputs the output of the first signal generation means to a pixel determined to have a low luminance of the input image. A display image signal is output to the display unit, and the output of the second signal generation unit is output to the display unit as a display image signal for a pixel that is determined to have a high luminance of the input image. 30. The image display device according to claim 29.

[32] The determining means determines the content of the input image for each of the divided areas based on the input image signal, 18. The image display device according to claim 17, wherein outputs of the first signal generation unit and the second signal generation unit are switched for each region based on a determination result of the determination unit.

[33] The determination unit is a moving image Z still image determination unit that determines whether the input image is a still image or a moving image for each of the divided areas.

For an area where the input image is determined to be a moving image, the output of the first signal generation means is output to the display unit as a display image signal, and the area where the input image is determined to be a still image 35. The image display device according to claim 32, wherein the output of the second signal generating means is output to the display unit as a display image signal.

[34] The determination unit is a luminance measurement unit that measures the luminance of the input image for each of the divided areas.

For the area where the average luminance of the input image is determined to be low, the output of the first signal generation means is output as a display image signal to the display unit, and the average luminance of the input image is determined to be high. 33. The image display device according to claim 32, wherein an output of the second signal generation means is output to the display unit as a display image signal for the area.

[35] The image display device according to any one of claims 1 and 34,

An image display monitor, comprising: a signal input unit for transmitting an image signal input from an external cover to the image display device.

[36] A television receiver comprising the image display device according to any one of claims 1 and 34.