JP2013003493A - Control device, electric optical device and electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrict occurrence of moving image domain without using an independently adjusted correction voltage.SOLUTION: A control device comprises: detection means that includes gradation values for a plurality of pixels arranged two dimensionally in first and second directions, that is equal to or greater than a threshold value in the gradation value difference between two pixels adjacent to each other in the first direction from a video signal indicating a video sectioned into frames, and that detects a boundary moved in the first direction by one pixel in the successive two frames; conversion means that converts a video signal such that in a case where the boundary detected by the detecting means includes the first and second boundaries successive in the second direction, the first and second boundaries move in the first direction by at least two pixels in successive three frames and the frame the first boundary of which moves is different from the frame the secondary boundary of which moves; and output means that outputs a signal for controlling a voltage applied to a plurality of pixels, according to a video signal obtained through the conversion by the conversion means.

Description

  The present invention relates to a technique for reducing display defects in an electro-optical device.

In an electro-optical device such as a liquid crystal panel, an electro-optical element is sandwiched between a pair of substrates kept at a constant gap. Ideally, the optical state (transmittance or reflectance) of the electro-optic element is controlled by the potential difference (vertical electric field) between the electrode provided on one substrate and the electrode provided on the other substrate. The However, under certain conditions, the optical state may change between two adjacent pixels due to a potential difference (horizontal electric field) between two electrodes provided on one substrate. Such a change in the optical state due to the electric field in the lateral direction may cause, for example, alignment failure (reverse tilt domain) of liquid crystal molecules. The reverse chill domain can cause display problems. In particular, defects that manifest themselves in moving images are called moving image domains. Patent Document 1 discloses correcting the applied voltage to the electro-optic element in order to reduce the potential difference between two adjacent pixels for the purpose of reducing the reverse tilt domain.

JP 2011-53417 A

However, when trying to reduce the reverse tilt domain by correcting the applied voltage for a mass-produced liquid crystal panel, it may be necessary to individually adjust the correction voltage according to variations in characteristics of the liquid crystal panel.
In contrast, the present invention provides a technique for suppressing the occurrence of a moving image domain without using individually adjusted correction voltages.

The present invention includes two adjacent pixels in the first direction from a video signal that includes gradation values of a plurality of pixels that are two-dimensionally arranged in the first direction and the second direction, and that indicates an image divided into frames. A difference between the gradation values of the pixels is equal to or greater than a threshold, and a detection unit that detects a boundary that has moved in the first direction by one pixel in two consecutive frames; and the boundary detected by the detection unit is When including a first boundary and a second boundary continuous in a second direction, the first boundary and the second boundary are:
Conversion means for converting the video signal so that at least two pixels are moved in the first direction in three consecutive frames, and the frame in which the first boundary moves and the frame in which the second boundary moves are different. And a control unit that outputs a signal for controlling a voltage applied to the plurality of pixels in accordance with the video signal converted by the conversion unit.
According to this control apparatus, generation | occurrence | production of the moving image domain in a 1st direction is suppressed.

In a preferred aspect, the converting means includes a frame in which the first boundary moves,
In the frame in which the second boundary moves, the gradation value of the pixel that has passed the moved first boundary is shifted to the intermediate gradation of the gradation values of two adjacent pixels on both sides of the first boundary. The gradation value of the pixel that has passed the second boundary is changed to the intermediate gradation of the gradation values of the two pixels on both sides of the second boundary.
Each may be converted.
According to this control device, it is possible to display an image in which the boundary is visually recognized more smoothly than in the case where no intermediate gradation is used.

In another preferable aspect, the conversion means may switch the frame in which the first boundary moves and the frame in which the second boundary moves every two frames.
According to this control device, it is possible to reduce the deviation of the moving boundary as compared to the case where the frame where the first boundary moves and the frame where the second boundary moves are switched for each frame.

In yet another preferred aspect, the control device includes: a first storage unit that stores (k-1) th frame data when the kth frame data is processed among the video signals; and the video signal. Second storage means for storing data used for specifying the boundary in the (k-2) th frame, and the converting means is adapted to store the first boundary in a frame in which the first boundary moves. A frame in which data of a pixel group including two adjacent pixels and not including two adjacent pixels on the second boundary is replaced with data stored in the first storage unit, and the second boundary moves. In the above, data of a pixel group including two pixels on both sides of the second boundary and not including two pixels on both sides of the first boundary may be replaced with data of the kth frame.
According to this control apparatus, the frame in which the first boundary moves and the frame in which the second boundary moves can be made different.

The present invention also provides an electro-optical device having the above-described control device and the electro-optical element.
According to this electro-optical device, the generation of the moving image domain in the first direction is suppressed.

Furthermore, the present invention provides an electronic apparatus having the above electro-optical device.
According to this electronic device, the occurrence of a moving image domain in the first direction is suppressed.

1 is a block diagram showing a configuration of a liquid crystal display device 1 according to an embodiment. FIG. 6 shows an equivalent circuit of a pixel 111. The figure which illustrates the timing chart of the scanning signal Yi and the data signal Vx. FIG. 11 is a diagram illustrating VT characteristics in the liquid crystal element 120. The figure which illustrates the malfunction on the display resulting from a reverse tilt domain. 2 is a diagram showing a functional configuration of a video processing circuit 30. FIG. 7 is a flowchart showing the operation of the video processing circuit 30. The figure explaining the example of a detection of a risk boundary. The figure which shows the specific example of the process of FIG. 9 is a flowchart showing the operation of a video processing circuit 30 according to Modification 1. The figure which shows the specific example of the process of FIG. 9 is a flowchart showing the operation of a video processing circuit 30 according to Modification 2. The figure which illustrates the pixel which the risk boundary swept. The figure which shows the specific example of the process of FIG. The figure which shows the example of the process which concerns on the modification 3. The figure which shows the structure of the video processing circuit 30 which concerns on the modification 4. FIG. 10 is a diagram showing a configuration of a projector 2100 according to Modification Example 5.

1. Configuration FIG. 1 is a block diagram illustrating a configuration of a liquid crystal display device 1 according to an embodiment. The liquid crystal display device 1 includes a control circuit 10, a liquid crystal panel 100, a scanning line driving circuit 130, and a data line driving circuit 140. The liquid crystal display device 1 is a video signal Vid-i supplied from a host device.
The liquid crystal panel 100 displays an image indicated by n at a timing based on the synchronization signal Sync.
It is a device that displays.

The liquid crystal panel 100 is a device that displays an image according to a supplied signal. The liquid crystal panel 100 has a display area 101. A plurality of pixels 111 are arranged in the display area 101. In this example, m rows and n columns of pixels 111 are arranged in a matrix. The liquid crystal panel 100 includes an element substrate 100a, a counter substrate 100b, and a liquid crystal layer 105. The element substrate 100a and the counter substrate 100b are bonded to each other with a constant interval. A liquid crystal layer 105 is sandwiched between the element substrate 100a and the counter substrate 100b. The element substrate 100 a is provided with m rows of scanning lines 112 and n data lines 114. The scanning lines 112 and the data lines 114 are provided on the surface facing the counter substrate 100b.
The scanning line 112 and the data line 114 are electrically insulated. A pixel 111 is provided corresponding to the intersection of the scanning line 112 and the data line 114. The liquid crystal panel 100 is m × n
The pixel 111 is included. Corresponding to each of the pixels 111, the element substrate 100a is provided with individual pixel electrodes 118 and TFTs 116. In the following, a plurality of scanning lines 11
In order to distinguish 2, the first, second, third,..., (M−1) th in order from the top in FIG.
The m-th scanning line 112 is called. Similarly, when distinguishing a plurality of data lines 114, the first, second, third,..., (N−1) th, nth column data lines 114 are sequentially arranged from the left in FIG.
That's it. In FIG. 1, since the facing surface of the element substrate 100a is the back side of the paper, the scanning lines 112, data lines 114, TFTs 116, and pixel electrodes 118 provided on the facing surface should be indicated by broken lines, but are difficult to see. Therefore, each is indicated by a solid line.

A common electrode 108 is provided on the counter substrate 100b. The common electrode 108 is provided on the surface facing the element substrate 100a. The common electrode 108 is connected to all the pixels 11.
1 is common. That is, the common electrode 108 is a so-called solid electrode provided over almost the entire surface of the counter substrate 100b.

FIG. 2 is a diagram illustrating an equivalent circuit of the pixel 111. The pixel 111 includes a TFT 116, a liquid crystal element 120, and a capacitor element 125. The TFT 116 is an example of a switching unit that controls application of a voltage to the liquid crystal element 120. In this example, the TFT 116 is an n-channel field effect transistor. The liquid crystal element 120 is an element whose optical state changes according to an applied voltage. In this example, the liquid crystal panel 100 is a transmissive liquid crystal panel, and the optical state that changes is the transmittance. The liquid crystal element 120 includes the pixel electrode 118, the liquid crystal layer 105, and the common electrode 1.
08. In the pixel 111 in the i-th row and the j-th column, the gate and the source of the TFT 116 are connected to the scanning line 112 in the i-th row and the data line 114 in the j-th column, respectively.
The drain of the TFT 116 is connected to the pixel electrode 118. The capacitor element 125 is an element that holds a voltage written in the pixel electrode 118. One end of the capacitor 125 is connected to the pixel electrode 118, and the other end is connected to the capacitor line 115.

When a signal indicating an H level voltage is input to the i-th scanning line 112, the source and drain of the TFT 116 become conductive. When the source and drain of the TFT 116 are conducted, the pixel electrode 118 has the same potential as the data line 114 in the j-th column (ignoring the on-resistance between the source and drain of the TFT 116). A voltage (hereinafter referred to as “data voltage”) corresponding to the gradation value of the pixel 111 in the i-th row and j-th column is applied to the data line 114 in the j-th column in accordance with the video signal Vid-in.
A signal indicating a data voltage is referred to as a “data signal”. The common electrode 108 includes
A common potential LCcom is applied by a circuit (not shown). The capacitor line 115 is supplied with a temporally constant potential Vcom (in this example, Vcom = LCcom) by a circuit (not shown). That is, a voltage corresponding to the difference between the data voltage and the common potential LCcom is applied to the liquid crystal element 120. Hereinafter, description will be made using an example in which the liquid crystal layer 105 is a VA (Vertical Alignment) type and is a normally black mode in which the gradation of the liquid crystal element 120 is in a black state when no voltage is applied. Unless otherwise specified, a ground potential not shown is a voltage reference (0 V).

Refer to FIG. 1 again. The control circuit 10 is a control device that outputs a signal for controlling the scanning line driving circuit 130 and the data line driving circuit 140. The control circuit 10 is a scanning control circuit 2
0 and a video processing circuit 30. The scanning control circuit 20 generates a control signal Xctr, a control signal Yctr, and a control signal Ictr based on the synchronization signal Sync, and outputs the generated signals. The control signal Xctr is a signal for controlling the data line driving circuit 140, and indicates, for example, the timing for supplying the data signal (the start of the horizontal scanning period). The control signal Yctr is a signal for controlling the scanning line driving circuit 130, and indicates, for example, the timing for supplying the scanning signal (the start of the vertical scanning period). The control signal Ictr is sent from the video processing circuit 3
This is a signal for controlling 0, for example, the timing of signal processing. Video processing circuit 3
0 processes the video signal Vid-in, which is a digital signal, at the timing indicated by the control signal Ictr and outputs it as a data signal Vx, which is an analog signal. Video signal Vi
d-in is digital data for designating the gradation value of the pixel 111, respectively. The gradation value indicated by the digital data is supplied by the data signal Vx in the order according to the vertical scanning signal, the horizontal scanning signal, and the dot clock signal included in the synchronization signal Sync.

The scanning line driving circuit 130 is a circuit that outputs the scanning signal Y in accordance with the control signal Yctr. The scanning signal supplied to the i-th scanning line 112 is referred to as a scanning signal Yi. In this example, the scanning signal Yi is a signal for sequentially and exclusively selecting one scanning line 112 from the m scanning lines 112. The scanning signal Yi is a signal that becomes a selection voltage (H level) for the selected scanning line 112 and a non-selection voltage (level) for the other scanning lines 112. Note that a plurality of scanning lines 112 are substituted for the driving in which one scanning line 112 is sequentially selected exclusively.
So-called MLS (Multiple Line Selection) driving may be used.

The data line driving circuit 140 is a circuit that samples the data signal Vx and outputs the data signal X in accordance with the control signal Xctr. A data signal supplied to the data line 114 in the j-th column is referred to as a data signal Xj.

FIG. 3 is a diagram illustrating a timing chart of the scanning signal Yi and the data signal Vx. The scanning signal Yi is a signal that sequentially becomes H level exclusively. In the liquid crystal panel 100, a period during which one frame image is displayed is referred to as a “frame”. That is, a period from when the scanning signal Y1 becomes H level to when the scanning signal Y1 becomes H level again is a frame. For example, if the frequency of the vertical scanning signal included in the synchronization signal Sync is 60 Hz, the frame is 16.7 milliseconds. A period in which one scanning line 112 is selected is referred to as a “horizontal scanning period (H)”. FIG. 3 illustrates the data signal Vx in the first row. In this example,
The polarity of the data voltage is inverted every frame. Frame to which positive data voltage is applied (
In “positive writing”), the data signal Vx indicates a higher voltage than the reference voltage Vcnt by an amount corresponding to the gradation value of each pixel. In a frame to which a negative data voltage is applied (“negative writing”), the data signal Vx indicates a lower voltage than the reference voltage Vcnt according to the gradation value of each pixel. The voltage of the data signal Vx is in the range from the voltage Vw (+) corresponding to white to the voltage Vb (+) corresponding to black in the positive frame, and corresponds to white in the negative frame. A voltage Vb (− corresponding to black from the voltage Vw (−)
). The voltage Vw (+) and the voltage Vw (−) are in a symmetric relationship with respect to the voltage Vcnt. The voltages Vb (+) and Vb (−) are also symmetrical with respect to the voltage Vcnt. Note that the voltage waveform of the data signal Vx is different from the voltage applied to the liquid crystal element 120 (potential difference between the pixel electrode 118 and the common electrode 108). Further, the vertical scale of the voltage of the data signal Vx in FIG. 3 is enlarged as compared with the voltage waveform of the scanning signal or the like in FIG.

FIG. 4 is a diagram illustrating the relationship between the applied voltage and transmittance (V-T characteristics) in the liquid crystal element 120. In order for the liquid crystal element 120 to have a transmittance corresponding to the gradation value specified by the video signal Vid-in, a voltage corresponding to the gradation value may be applied to the liquid crystal element 120. However, in the liquid crystal element 120, a display defect due to a so-called reverse tilt domain may occur under certain conditions. This defect is considered to be one of the causes that the liquid crystal molecules are unstable due to the influence of the transverse electric field when the liquid crystal molecules are in an unstable state, so that the alignment state according to the applied voltage becomes difficult. The “lateral electric field” refers to an electric field between the pixel electrode 118 in a certain pixel 111 and the pixel electrode 118 in another (for example, adjacent) pixel 111.

The “unstable state” of the liquid crystal molecules means, for example, when the voltage applied to the liquid crystal element 120 is in the voltage range A of FIG. The voltage range A is a range that is not less than the black level voltage Vbk and lower than the threshold value Vth1. The threshold value Vth1 corresponds to a voltage at which the relative transmittance is 10%. In the voltage range A, the regulation force (the force that determines the alignment of liquid crystal molecules) due to the vertical electric field (the electric field between the pixel electrode 118 and the common electrode 108) is slightly higher than the regulation force due to the alignment film. The alignment state of liquid crystal molecules tends to be disturbed. The transmittance range (gradation range) corresponding to the voltage range A is referred to as “gradation range a”.

The case where the liquid crystal molecules are “affected by the lateral electric field” refers to a case where the potential difference between the adjacent pixel electrodes 118 is larger than a certain threshold value. This is a case where a black pixel and a white pixel are adjacent to each other in an image to be displayed. “Black pixel” refers to a pixel having a black level or a gradation close to the black level. More specifically, the pixel 111 includes the liquid crystal element 120 whose applied voltage is in the voltage range A. “White pixel” refers to a pixel having a white level or a gradation close to the white level. More specifically, the pixel 111 includes the liquid crystal element 120 whose applied voltage is in the voltage range B. The voltage range B is a range not less than the threshold value Vth2 and not more than the white level voltage Vwt. The threshold value Vth2 corresponds to a voltage at which the relative transmittance is 90%, for example. The transmittance range corresponding to the voltage range B is referred to as “tone range b”.

It can be said that the pixel 111 whose gradation value is in the gradation range a is in a situation where a reverse tilt domain is likely to occur due to a lateral electric field when adjacent to the pixel 111 whose gradation value is in the gradation range b. Note that the pixel 111 whose gradation value is in the gradation range b is the pixel 111 whose gradation value is in the gradation range a.
Even when adjacent to, the influence of the vertical electric field is dominant and the state is stable, so that a reverse tilt domain does not occur.

FIG. 5 is a diagram illustrating a display defect caused by the reverse tilt domain. FIG.
Shows images displayed from the kth frame to the (k + 3) th frame with respect to (partial) pixels 111 in a certain row. In this example, the image indicated by the video signal Vid-in is
This is an image in which a black pixel region moves leftward by one pixel per frame with a white pixel as a background. At this time, a kind of tailing phenomenon that a pixel that should change from a black pixel to a white pixel does not become a white pixel due to the occurrence of a reverse tilt domain becomes apparent (occurs to the extent that it is visually recognized). Hereinafter, a region where a tailing phenomenon is observed in a moving image is referred to as a “moving image domain”. The moving image domain is considered to be generated when the following two conditions are satisfied.
(1) There is a boundary between white pixels and black pixels. That is, the white pixel and the black pixel are adjacent to each other.
(2) The boundary between the white pixel and the black pixel moves by one pixel.
That is, it is considered that the reverse tilt domain is likely to occur in the black pixel, and that the pixel in this state is continuously generated as the area of the black pixel moves, so that the tailing phenomenon becomes apparent. Note that when the black pixel region moves by two or more pixels for each frame with the white pixel as the background, this tailing phenomenon does not become apparent (or is hardly visible). this is,
This is because the above condition (2) is not satisfied.

FIG. 6 is a diagram illustrating a functional configuration of the video processing circuit 30. The video processing circuit 30 includes a boundary detection unit 32, a conversion unit 33, and an output unit 34. The boundary detection unit 32 (an example of a detection unit) detects a risk boundary from the video signal Vid-in. As already explained, the video signal V
id-in is a signal indicating video (set of still images) divided into frames. The video of each frame is indicated by gradation values of a plurality of pixels 111 arranged two-dimensionally in the row direction (an example of the first direction) and the column direction (an example of the second direction). “Risk boundary” means that two of the two adjacent pixels 111 in the row direction have a gradation value difference (difference in applied voltage) of two pixels 111 that is equal to or greater than a threshold value, and is continuous 2 A boundary moved in the row direction by one pixel in one frame. When the conversion unit 33 (an example of conversion means) includes a first boundary (for example, an odd row boundary) and a second boundary (for example, an even row boundary) in which the boundary detected by the boundary detection unit 32 is continuous in the column direction. , The first boundary and the second boundary are at least 2 in three consecutive frames
The video indicated by the video signal Vid-in is converted so as to move in the row direction by pixels (two pixels in this example). That is, the conversion unit 33 converts a boundary that moves by one pixel every frame into a boundary that moves by two pixels every two frames. Here, the conversion unit 33
The video signal is converted so that the frame in which the first boundary moves is different from the frame in which the second boundary moves (that is, the boundary between two adjacent rows alternately moves every other frame). The output unit 34 outputs a data signal Vx for controlling a voltage applied to the liquid crystal panel 100 (an example of an electro-optical element) according to the video signal converted by the conversion unit 33.
The output unit 34 includes, for example, a DA converter that converts a video signal Vid-in indicating digital data into an analog data signal Vx.

In this example, the video processing circuit 30 further includes a frame memory 35, a frame memory 36, a frame memory 37, and a VRAM (Video Random Access Memory) 38. The frame memory 35 stores video data of the current frame (kth frame). The frame memory 36 stores the data of the previous ((k−1) th frame) video. The frame memory 37 stores risk boundary data detected in the previous frame (an example of data used to identify a risk boundary). The VRAM 38 stores an image displayed on the liquid crystal panel 100 (data written to the liquid crystal panel 100). In this example, in the frame in which the first boundary moves, the conversion unit 33 uses the first of the data stored in the VRAM 38.
Data of a pixel group (for example, odd rows) including two pixels on both sides of the boundary and not including the two pixels on both sides of the second boundary is replaced with data stored in the frame memory 36. In addition, in the frame in which the second boundary moves, the conversion unit 33 includes, in the data of the VRAM 38, pixels that include two pixels on both sides of the second boundary and do not include two pixels on both sides of the first boundary. The data of the group (for example, even rows) is replaced with the data stored in the frame memory 35.

The video processing circuit 30 further includes a register for storing a flag (not shown). This flag is information for specifying a pixel group (for example, whether an odd row is an even row) whose data is to be rewritten among the data in the VRAM 38. In this example, the value of the flag takes one of two values “0” and “1”. For example, when the value of the flag is “0”, the odd-numbered data is rewritten. When the value of the flag is “1”, the data in even-numbered rows is rewritten.

2. Operation FIG. 7 is a flowchart showing the operation of the video processing circuit 30. Consider a case where an image of the kth frame is a processing target. The flow in FIG. 7 is started when, for example, a signal indicating the start of a new frame (kth frame) is input from the scanning control circuit 20.

In step S100, the video processing circuit 30 updates the data stored in the frame memory. Immediately before the flow of FIG. 7 is started, the frame memory 35 stores the (k−1) th frame data, and the frame memory 36 stores the (k−2) th data.
) Frame data is stored. The frame memory 37 has the (k-1) th
The position of the risk boundary in the frame is stored. In the frame memory 37,
The position of the risk boundary is stored, for example, as the position of the black pixel among white pixels and black pixels adjacent to the risk boundary. In this state, the boundary detection unit 32 reads data stored in the frame memory 35 and writes the read data to the frame memory 36. Further, the boundary detection unit 32 converts the k-th frame data indicated by the video signal Vid-in,
Write to the frame memory 35. When the process of step S100 is completed, the frame memory 35 stores the kth frame data, and the frame memory 36 stores the ((
k-1) Frame data is stored. Further, the frame memory 3 has the (k−) th.
1) The position of the risk boundary in the frame is stored.

In step S101, the boundary detection unit 32 detects a risk boundary from the current frame image and the previous frame image. For example, the risk boundary is detected as follows.
The boundary detection unit 32 detects a boundary between white pixels and black pixels adjacent in the horizontal direction from the image of the current frame. The boundary detection unit 32 has a boundary adjacent to the detected boundary on the white pixel side,
In the frame memory 37, it is determined whether or not the boundary is between a white pixel and a black pixel.

FIG. 8 is a diagram illustrating an example of risk boundary detection. In this example, for the sake of simplicity, only the gradations of four consecutive pixels in a certain row are shown. In the example of FIG. 8A, in the current frame, the first to third pixels counted from the left are white pixels, and the fourth pixel is a black pixel. The boundary between the white pixel and the black pixel is between the third pixel and the fourth pixel (FIG. 8B). In contrast, in the previous frame, the first pixel and the second pixel are white pixels, and the third pixel and the fourth pixel are black pixels. The boundary between the white pixel and the black pixel is between the second pixel and the third pixel (FIG. 8: A). That is, the boundary of the previous frame is a boundary adjacent to the white pixel (third pixel) side of the boundary of the current frame. Therefore, the current frame boundary in FIG. 8A is determined to be a risk boundary. In another example, in the example of FIG. 8B, in the current frame, the first pixel counted from the left is a white pixel, and the second to fourth pixels are black pixels. The boundary between the white pixel and the black pixel is between the first pixel and the second pixel (FIG. 8: D). In contrast, in the previous frame, the first pixel and the second pixel are white pixels, and the third pixel and the fourth pixel are black pixels. The boundary between white and black pixels is
Between the second pixel and the third pixel (FIG. 8C). That is, the boundary of the previous frame is a boundary adjacent to the black pixel (second pixel) side of the boundary of the current frame. Therefore, it is determined that the boundary of the current frame in FIG. 8B is not a risk boundary (a non-risk boundary). FIG.
As can be seen from the above, when the pixel sandwiched by the boundary before and after the movement of one pixel changes from a black pixel to a white pixel, the moved boundary is a risk boundary. When a pixel sandwiched between boundaries before and after movement for one pixel changes from a white pixel to a black pixel, the moved boundary is a non-risk boundary.

Refer to FIG. 7 again. In step S102, the conversion unit 33 determines whether the detected risk boundary satisfies a predetermined condition. This condition is, for example, a condition that a row having a risk boundary continues for a threshold value (for example, 2) or more. When this condition is satisfied (S102: YES), the conversion unit 33 moves the process to step S103. When this condition is not satisfied (S102: NO), the conversion unit 33 performs the process in step S106.
Migrate to

In step S103, the conversion unit 33 determines whether the current frame (kth frame) is an even frame (determines whether the current frame is even or odd). Whether the current frame is even or odd is determined by, for example, the polarity of the data voltage applied in the current frame. For example, when the polarity of the data voltage is positive, it is determined that the frame is an odd frame, and when the polarity of the data voltage is negative, it is determined that the frame is an even frame. The polarity of the data voltage depends on the scan control circuit 20
Is indicated by a control signal Ictr supplied from. When the k-th frame is an even frame (S103: YES), the converting unit 33 proceeds to step S104. When the k-th frame is an odd frame (S103: NO), the conversion unit 33 performs the process in step S1.
Move to 05.

In step S104, first, the conversion unit 33 rewrites the flag value. That is, the flag value is rewritten every two frames. The flag is rewritten from one of the two values to the other value. For example, when the value of the flag is “0”, the value is rewritten to “1”. “If the value of the flag is“ 1 ”, the value is rewritten to“ 0 ”. Next, the conversion unit 33
Reads out the pixel data of the row designated by the flag from the data stored in the frame memory 36 and writes the read data into the VRAM 38. The flag value is "
In the case of “0”, the conversion unit 33 reads out the pixel data of the odd-numbered rows among the data stored in the frame memory 36 and writes the read data into the VRAM 38. in this case,
In the VRAM 38, the pixel data of even-numbered rows cannot be rewritten. The flag value is "1"
In this case, the conversion unit 33 reads out the data of the pixels in the even-numbered rows among the data stored in the frame memory 36 and writes the read-out data into the VRAM 38. In this case, VR
In AM38, the pixel data of the odd-numbered rows cannot be rewritten.

In step S <b> 105, the conversion unit 33 reads out the pixel data of the row specified by the flag from the data stored in the frame memory 35 and writes the read data into the VRAM 38. When the value of the flag is “0”, the conversion unit 33 reads out the data of the odd-numbered pixels among the data stored in the frame memory 35 and writes the read-out data into the VRAM 38. In this case, in the VRAM 38, the pixel data of the even-numbered rows cannot be rewritten. When the value of the flag is “1”, the conversion unit 33 displays the frame memory 35.
Among the data stored in the data, the pixel data of even-numbered rows is read, and the read data is written into the VRAM 38. In this case, in the VRAM 38, the pixel data of the odd-numbered rows cannot be rewritten.

In step S <b> 106, the conversion unit 33 reads the data stored in the frame memory 36 and writes the data of all the pixels in the VRAM 38. Step S104 ~
When any process of S106 ends, the conversion unit 33 shifts the process to step S107.

In step S107, the boundary detection unit 32 writes data indicating the position of the risk boundary detected in the current frame in the frame memory 37.
In step S108, the output unit 34 outputs a signal indicating a voltage corresponding to the gradation value indicated by the data stored in the VRAM 38 as the data signal Vx.
The video processing circuit 30 repeatedly executes the processes of steps S100 to S107 each time a signal indicating the start of a new frame is input.

FIG. 9 is a diagram showing a specific example of the processing of FIG. Here, only the pixel portion of 6 rows and 9 columns in the image indicated by the video signal Vid-in is shown as an example. Shown on the left is data stored in the frame memory 35, that is, data indicating an image of the current frame. Shown second from the left is data stored in the frame memory 36, that is, data indicating an image of the previous frame. Shown third from the left is data stored in the frame memory 37, that is, data indicating the position of the risk boundary in the previous frame. In this example, the position of the risk boundary is stored as the position of the black pixel adjacent to the risk boundary. The rightmost one is VR
Data stored in the AM 38, that is, an image (display image) displayed on the liquid crystal panel 100 is shown. A plurality of images arranged in the vertical direction indicate changes in the image as the frame progresses. For example, as an example of the frame memory 35, the data shown at the top is the data of the kth frame, and the data shown at the bottom is the data of the (k + 3) th frame. The video signal Vid-in shows an image in which the black area moves to the right by one pixel per frame with the white area as the background.

Now, consider the process for the image of the kth frame. In this example, the value of the flag is “0” at the time when the processing of the k-th frame is started. A risk boundary is detected in the k-th frame image (step S101). These risk boundaries satisfy the determined conditions (S102: YES). In this example, k is an even number (S103: YES).
Therefore, the value of the flag is rewritten to “1”. Since the value of the flag is “1”, the even-numbered row data of the previous frame is written as the even-numbered row data of the display image (S104).
). A symbol * shown beside the display image indicates that the data in the row has been rewritten.

Next, processing for the (k + 1) th frame image will be considered. A risk boundary is detected in the image of the (k + 1) th frame (step S101). These risk boundaries satisfy the determined conditions (S102: YES). Since k is an even number, (k + 1)
Is an odd number (S103: NO). Since the value of the flag is “1”, the even-numbered row data of the current frame is written as even-numbered row data of the display image (S105).

Next, processing for the image of the (k + 2) th frame will be considered. A risk boundary is detected in the image of the (k + 2) th frame (step S101). These risk boundaries satisfy the determined conditions (S102: YES). (K + 2) is an even number (S103
: YES) Therefore, the value of the flag is rewritten to “0”. Since the value of the flag is “0”, the odd-numbered row data of the previous frame is written as the odd-numbered row data of the display image (S104).

Next, processing for the image of the (k + 3) th frame will be considered. A risk boundary is detected in the image of the (k + 3) th frame (step S101). These risk boundaries satisfy the determined conditions (S102: YES). (K + 3) is an odd number (S103
: NO). Since the value of the flag is “0”, the odd-numbered row data of the current frame is written as the odd-numbered row data of the display image (S104).

Thereafter, the same processing is performed for the (k + 4) th frame and the (k + 5) th frame. An image (that is, the liquid crystal panel 100) written in the VRAM 38 by these processes.
The image displayed in (2) shows an image in which a black region moves to the right by two pixels every two frames alternately with an odd row and an even row, with a white region as a background. That is, the video processing circuit 3
0 is an image in which the boundary moves by one pixel every frame, and an image in which the boundary moves by two pixels every two frames (however, a frame in which an odd line moves and a frame in which an even line moves) It can be said that it has been converted. Since the converted image does not satisfy the moving image domain generation condition (2), the moving image domain does not occur (or is hardly visible). That is, the generation of the moving image domain is suppressed by the processing of the video processing circuit 30.

3. Other Embodiments The present invention is not limited to the above-described embodiments, and various modifications can be made. Hereinafter, some modifications will be described. Two or more of the following modifications may be used in combination.

3-1. Modification 1
FIG. 10 is a flowchart showing the operation of the video processing circuit 30 according to the first modification. Details of the image conversion processing in the video processing circuit 30 are not limited to those described in the embodiment.
In Modification 1, an image whose boundary moves by one pixel per frame is not distinguished from odd-numbered rows and even-numbered rows, and is converted into an image whose boundary moves by two pixels every two frames for all rows. The In the first modification, the flag for specifying the line to be rewritten is not used. In the first modification, the frame memory 36 is not used.

In step S200, the boundary detection unit 32 updates the data stored in the frame memory. In step S201, the detection unit 32 detects a risk boundary from the image of the kth frame and the image of the (k−1) th frame. In step S202,
The conversion unit 33 determines whether the detected risk boundary satisfies a predetermined condition. If this condition is satisfied (S202: YES), the conversion unit 33 moves the process to step S203. When this condition is not satisfied (S202: NO), the conversion unit 33 shifts the processing to step S204. The process of steps S200 to S202 is the same as that of step S100.
To S102.

In step S203, the conversion unit 33 determines whether the current frame (kth frame) is an even frame (even / odd of the current frame). When the kth frame is an even frame (
(S203: YES), the conversion unit 33 moves the process to step S204. When the k-th frame is an odd frame (S203: NO), the conversion unit 33 performs the process in step S205.
Migrate to

In step S <b> 204, the conversion unit 33 reads data stored in the frame memory 35 and writes the read data to the VRAM 38. In the VRAM 38,
All rows of data are rewritten.
In step S <b> 205, the conversion unit 33 does not rewrite the VRAM 38.
When the process of step S204 or S205 ends, the video processing circuit 30 proceeds to step S206.

In step S <b> 206, the boundary detection unit 32 writes data indicating the position of the risk boundary detected in the current frame in the frame memory 37. In step S207, the output unit 34 outputs a signal indicating a voltage corresponding to the gradation value indicated by the data stored in the VRAM 38 as the data signal Vx. The video processing circuit 30 repeatedly executes the processes of steps S200 to S206 every time a new frame is started.

FIG. 11 is a diagram illustrating a specific example of the processing of FIG. Here, as in the example of FIG. 9, only the pixel portion of 6 rows and 10 columns in the image indicated by the video signal Vid-in is shown as an example. The image indicated by the video signal Vid-in is the same as the example of FIG. Modification 1
In FIG. 2, the frame memory 36 is not used, but the image of the previous frame is shown for reference.

Now, consider the process for the image of the kth frame. A risk boundary is detected in the k-th frame image (step S201). These risk boundaries satisfy the determined conditions (S202: YES). In this example, k is an even number (S203: YES). Therefore, the data of all the rows in the current frame are written in the display image (S204).
A symbol * shown beside the display image indicates that the data in the row has been rewritten.

Next, processing for the (k + 1) th frame image will be considered. A risk boundary is detected in the image of the (k + 1) th frame (step S201). These risk boundaries satisfy the determined conditions (S202: YES). Since k is an even number, (k + 1)
Is an odd number (S203: NO). Therefore, the display image data cannot be rewritten (
S205).

Thereafter, the same processing is performed for frames after the (k + 2) th frame. An image written in the VRAM 38 by these processes (that is, an image displayed on the liquid crystal panel 100) shows an image in which the black region moves to the right by two pixels every two frames with the white region as the background. . That is, it can be said that the video processing circuit 30 converts an image whose boundary moves by one pixel every frame into an image whose boundary moves by two pixels every two frames. Since the converted image does not satisfy the moving image domain generation condition (2), the moving image domain does not occur (or is hardly visible). That is, the generation of the moving image domain is suppressed by the processing of the video processing circuit 30.

3-2. Modification 2
FIG. 12 is a flowchart showing the operation of the video processing circuit 30 according to the second modification. In the second modification, in addition to the conversion process described in the embodiment, the gradation of a pixel sandwiched between the boundary before movement and the boundary after movement is converted into an intermediate gradation.

In step S300, the boundary detection unit 32 updates the data stored in the frame memory. In step S301, the boundary detection unit 32 detects a risk boundary from the kth frame image and the (k−1) th frame image. In step S302, the conversion unit 33 determines whether the detected risk boundary satisfies a predetermined condition. When this condition is satisfied (S302: YES), the conversion unit 33 performs the process in step S30.
3 When this condition is not satisfied (S302: NO), the conversion unit 33 proceeds to step S306. The processing of steps S300 to S302 is the same as step S1.
This is performed in the same manner as the process from 00 to S102.

In step S303, the conversion unit 33 determines whether the current frame (kth frame) is an even frame (even / odd of the current frame). When the kth frame is an even frame (
(S303: YES), the conversion unit 33 moves the process to step S304. When the k-th frame is an odd frame (S303: NO), the conversion unit 33 performs the process in step S305.
Migrate to

In step S304, the conversion unit 33 first rewrites the flag value. Next, the conversion unit 33 reads out the pixel data of the row specified by the flag from the data stored in the frame memory 36 and writes the read data into the VRAM 38. When the value of the flag is “0”, the conversion unit 33 reads out the data of the odd-numbered pixels among the data stored in the frame memory 36 and writes the read-out data into the VRAM 38. In this case, in the VRAM 38, the pixel data of the even-numbered rows cannot be rewritten. When the value of the flag is “1”, the conversion unit 33 includes the data stored in the frame memory 36.
Data of pixels in even rows is read and the read data is written into the VRAM 38. In this case, in the VRAM 38, the pixel data of the odd-numbered rows cannot be rewritten.

In step S <b> 305, the conversion unit 33 reads out the pixel data of the row specified by the flag from the data stored in the frame memory 35 and writes the read data into the VRAM 38. When the value of the flag is “0”, the conversion unit 33 reads out the data of the odd-numbered pixels among the data stored in the frame memory 35 and writes the read-out data into the VRAM 38. In this case, in the VRAM 38, the pixel data of the even-numbered rows cannot be rewritten. When the value of the flag is “1”, the conversion unit 33 displays the frame memory 35.
Among the data stored in the data, the pixel data of even-numbered rows is read, and the read data is written into the VRAM 38. In this case, in the VRAM 38, the pixel data of the odd-numbered rows cannot be rewritten. When the process of step S304 or S305 ends, the conversion unit 33
The process proceeds to step S307.

In step S307, the conversion unit 33 rewrites the gradation value of the pixel whose risk boundary has been swept into the intermediate gradation in the rewritten row. The intermediate gradation means a gradation between the gradation value of the white pixel and the gradation value of the black pixel. The gradation value of the intermediate gradation is determined in advance. Alternatively, a gradation value determined according to the gradation value of the white pixel and the black pixel, such as an average value of the gradation value of the white pixel and the gradation value of the black pixel, may be used as the intermediate gradation.

FIG. 13 is a diagram illustrating a pixel whose risk boundary has been swept away. Here, for the sake of explanation, five consecutive pixels in a certain row of the display image are shown. In the previous frame, the first pixel and the second pixel counted from the left are white pixels, and the third to fifth pixels are black pixels. The boundary between the white pixel and the black pixel is between the second pixel and the third pixel (FIG. 13E). In the current frame, the first to fourth pixels are white pixels, and the fifth pixel is a black pixel. The boundary between the white pixel and the black pixel is between the fourth pixel and the fifth pixel (FIG. 13: F). “Pixels with swept risk boundaries”
A pixel sandwiched between the boundary of the previous frame and the boundary of the current frame in the display image. FIG.
In the example, the two pixels sandwiched between the boundary E and the boundary F are “pixels whose risk boundary has been swept”.

Refer to FIG. 12 again. In step S <b> 306, the conversion unit 33 reads the data stored in the frame memory 36 and writes the data of all the pixels in the VRAM 38. When the process of step S306 ends, the conversion unit 33 moves the process to step S308.

In step S307, the boundary detection unit 32 writes data indicating the position of the risk boundary detected in the current frame in the frame memory 37. In step S309, the output unit 34 outputs a signal indicating a voltage corresponding to the gradation value indicated by the data stored in the VRAM 38 as the data signal Vx. The video processing circuit 30 repeatedly executes the processes of steps S300 to S309 every time a new frame is started.

FIG. 14 is a diagram illustrating a specific example of the processing of FIG. Here, as in the example of FIG. 9, only the pixel portion of 6 rows and 9 columns of the image indicated by the video signal Vid-in is shown as an example. The image indicated by the video signal Vid-in is the same as the example of FIG.

Now, consider the process for the image of the kth frame. In this example, the value of the flag is “0” at the time when the processing of the k-th frame is started. A risk boundary is detected in the k-th frame image (step S301). These risk boundaries satisfy the determined conditions (S302: YES). In this example, k is an even number (S303: YES).
Therefore, the value of the flag is rewritten to “1”. Since the value of the flag is “1”, the even-numbered row data of the previous frame is written as the even-numbered row data of the display image (S304).
). In the rewritten row, the pixel whose risk boundary has been swept is rewritten to an intermediate gradation (S306). A symbol * shown beside the display image indicates that the data in the row has been rewritten.

Next, processing for the (k + 1) th frame image will be considered. A risk boundary is detected in the image of the (k + 1) th frame (step S301). These risk boundaries satisfy the determined conditions (S302: YES). Since k is an even number, (k + 1)
Is an odd number (S303: NO). Since the value of the flag is “1”, the even-numbered row data of the current frame is written as even-numbered row data of the display image (S305). In the rewritten row, the pixel whose risk boundary has been swept is rewritten to an intermediate gradation (S306).

Next, processing for the image of the (k + 2) th frame will be considered. A risk boundary is detected in the image of the (k + 2) th frame (step S301). These risk boundaries satisfy the determined conditions (S302: YES). (K + 2) is an even number (S303
: YES) Therefore, the value of the flag is rewritten to “0”. Since the value of the flag is “0”, the odd-numbered row data of the previous frame is written as the odd-numbered row data of the display image (S304). In the rewritten row, the pixel whose risk boundary has been swept is rewritten to an intermediate gradation (S306).

Next, processing for the image of the (k + 3) th frame will be considered. A risk boundary is detected in the image of the (k + 3) th frame (step S301). These risk boundaries satisfy the determined conditions (S302: YES). (K + 3) is an odd number (S303
: NO). Since the flag value is “0”, the odd-numbered row data of the current frame is written as the odd-numbered row data of the display image (S304). In the rewritten row, the pixel whose risk boundary has been swept is rewritten to an intermediate gradation (S306).

Thereafter, the same processing is performed for the frames after the (k + 4) th frame. An image written in the VRAM 38 by these processes (that is, an image displayed on the liquid crystal panel 100) is a black region with 2 pixels every 2 frames, with black regions alternately with odd rows and even rows. Images that move to the right are shown. That is, the video processing circuit 30 converts an image whose boundary moves by one pixel every frame, an image whose boundary moves by two pixels every two frames (however, a frame where odd rows move and a frame where even rows move) It can be said that it was converted to Since the converted image does not meet the video domain generation condition (2),
The video domain does not occur (or is difficult to see). That is, the generation of the moving image domain is suppressed by the processing of the video processing circuit 30. In addition, since the intermediate gradation is displayed on the pixels sandwiched between the boundary before and after the movement, the boundary portion of the black region is easily visually recognized as having a smooth shape.

3-3. Modification 3
The order of frames in which odd lines are rewritten and frames in which even lines are rewritten in the display image is not limited to that described in the embodiment. In the embodiment, an example has been described in which a frame in which odd-numbered rows are rewritten and a frame in which even-numbered rows are rewritten are switched every two frames (FIG. 9 and the like). However, the timing for switching between a frame in which odd lines are rewritten and a frame in which even lines are rewritten is not limited to every two frames.

FIG. 15 is a diagram illustrating an example of processing according to the third modification. In this example, a frame in which odd lines are rewritten and a frame in which even lines are rewritten are switched every frame.
In the process according to the third modification, for example, in the flow of FIG. 7, step S104 is replaced with a process of “rewriting even-line data of the display image with data of the previous frame”, and step S10.
5 is replaced by a process of “rewriting data in odd-numbered rows of the display image with data of the current frame”. In this case, a flag for designating a line to be rewritten is unnecessary, and the processing can be simplified as compared with the embodiment. On the other hand, an example in which a frame in which odd lines are rewritten and a frame in which even lines are rewritten switches every two frames is 1
Compared to the case of switching for each frame, the deviation of the moving boundary can be reduced (
In FIG. 15, the boundary of odd lines always moves to the right ahead of the boundary of even lines, but in the example of FIG. 9, the pattern preceded by odd lines and the pattern preceded by even lines are alternately repeated. ).

3-4. Modification 4
FIG. 16 is a diagram illustrating a configuration of the video processing circuit 30 according to the fourth modification. Video processing circuit 30
The configuration is not limited to that described in the embodiment. In this example, the video processing circuit 30 includes a delay circuit 31, a boundary detection unit 32, a conversion unit 33, an output unit 34, and a frame memory 37.
And have. The delay circuit 31 is a circuit that accumulates the video signal Vid-in, reads the video signal Vid-in after a predetermined time (for example, one frame), and outputs it as the video signal Vid-d. Delay circuit 3
1 has a FIFO (First In First Out) memory or a multi-stage latch circuit. Accumulation and readout in the delay circuit 31 are controlled by a control signal Ictr from the scanning control circuit 20. The boundary detection unit 32 detects a risk boundary in the current frame. The frame memory 37 is storage means for storing information for specifying the risk boundary in the previous frame. The boundary detection unit 32 refers to the frame memory 37 based on the video signal Vid-in (indicating the image of the current frame) and the video signal Vid-d (indicating the image of the previous frame). Detect boundaries. For example, the risk boundary is detected as follows. The boundary detection unit 32 identifies two pixels in which the difference in gradation value between adjacent pixels is equal to or greater than a threshold value for the pixels in the target row in the video signal Vid-in. The boundary between the two pixels specified here is the first candidate for the risk boundary. Further, the boundary detection unit 32
Calculates the difference between the gradation value indicated by the video signal Vid-in and the gradation value indicated by the video signal Vid-d. From this difference, the boundary detection unit 32 identifies a pixel that has changed from a black pixel to a white pixel. Among the first risk boundary candidates, the boundary adjacent to the pixel changed from the black pixel to the white pixel is the second risk boundary candidate. Of the second risk boundary candidates, the boundary indicated by the frame memory 37 that the boundary adjacent on the white pixel side is the risk boundary in the previous frame is the risk boundary.

Based on the detection result in the boundary detector 32, the converter 33 converts the video signal Vid-out.
Is generated. In this example, when the risk boundary detected by the boundary detection unit 32 satisfies a predetermined condition, the conversion unit 33 converts the risk boundary into a boundary that moves by two pixels in two frames. This conversion is performed, for example, by selecting one of the video signal Vid-in and the video signal Vid-d as the video signal Vid-out in accordance with the even / odd frame number, as in the processing described in the embodiment. This is done by outputting.

The specific method for detecting the risk boundary in the boundary detection unit 32 is not limited to that described in the embodiment and the fourth modification. Any algorithm or signal processing may be used to detect the risk boundary as long as the risk boundary can be detected. The configuration of the video processing circuit 30 for detecting the risk boundary (in particular, the number of frame memories and the data stored in the frame memories) is not limited to that described in the embodiment and the fourth modification.
For example, the data stored in the frame memory 37 may be any type of data as long as it is used for specifying the position of the risk boundary in the previous frame. For example, the data stored in the frame memory 37 may be image data of the previous frame. In this case, the risk boundary of the previous frame can be specified by comparison with the image of the previous frame. Further, the division of functions between the functional components of the video processing circuit 30 is not limited to that described in the embodiment and the fourth modification. The video processing circuit 30 only needs to have the functions described in the embodiment and the modification as a whole.

3-5. Modification 5
FIG. 17 is a diagram illustrating a configuration of a projector 2100 according to the fifth modification. The projector 2100 is an example of an electronic device that uses the liquid crystal panel 100 as a light valve.
As shown in this figure, a lamp unit 2102 having a white light source such as a halogen lamp is provided inside the projector 2100. The projection light emitted from the lamp unit 2102 is converted into three primary colors of R (red), G (green), and B (blue) by three mirrors 2106 and two dichroic mirrors 2108 arranged inside. To be separated. The separated projection light is guided to the light valves 100R, 100G, and 100B corresponding to the respective primary colors. The light of B color has a long optical path as compared with other R colors and G colors. Therefore, in order to prevent the loss, the incident lens 2122, the relay lens 2123, and the emission lens 21 are used.
24 through a relay lens system 2121.

In the projector 2100, the liquid crystal display device including the liquid crystal panel 100 has R color, G
Three sets are provided corresponding to each of color and B color. The configuration of the light valves 100R, 100G, and 100B is the same as that of the liquid crystal panel 10 described above. Video signals are respectively supplied from the external upper circuits to specify the gradation levels of the primary color components of R, G, and B, and the light valves 100R, 100G, and 100 are driven. The lights modulated by the light valves 100R, 100G, and 100B are incident on the dichroic prism 2112 from three directions. In the dichroic prism 2112,
The light of R color and B color is refracted at 90 degrees, and the light of G color goes straight. Accordingly, after the primary color images are combined, a color image is projected onto the screen 2120 by the projection lens group 2114.

The light valves 100R, 100G, and 100B include a dichroic mirror 2
Since light corresponding to each of R color, G color, and B color is incident by 108, there is no need to provide a color filter. In addition, the transmission images of the light valves 100R and 100B are projected after being reflected by the dichroic prism 2112, whereas the light valve 100G
The transmitted image is projected as it is. Accordingly, the horizontal scanning direction by the light valves 100R and 100B is opposite to the horizontal scanning direction by the light valve 100G, and an image in which left and right are reversed is displayed. FIG. 17 shows an example in which the liquid crystal display device 1 is used for a transmissive projector, but the liquid crystal display device 1 may be used for a reflective projector. In this case, the liquid crystal panel 100 is a reflective liquid crystal panel.

In addition to the projector 2100, the electronic apparatus using the liquid crystal display device 1 is a television, a viewfinder type / monitor direct view type video tape recorder, a car navigation device, a pager, an electronic notebook, a calculator, a word processor, a workstation. Video phones, POS terminals, digital still cameras, mobile phones, devices equipped with touch panels, and the like.

3-6. Other Modifications A specific example of the processing flow by the video processing circuit 30 is not limited to that described in the embodiment. For example, in the embodiment, the data rewriting process is branched depending on whether or not the detected risk boundary satisfies a predetermined condition. However, conditional branching due to risk boundaries may not be performed. For example, steps S102 and S106 may be omitted in the flow of FIG.

The configuration of the liquid crystal panel 100 is not limited to that described in the embodiment. Any configuration may be used as long as it has pixels arranged two-dimensionally. For example, the electro-optical element is not limited to the liquid crystal element 120. Electro-optical elements other than liquid crystal elements such as organic EL (Electro Luminescence) elements may be used. Further, the equivalent circuit of the pixel 111 is not limited to that described with reference to FIG. A pixel circuit having any configuration may be used as long as the gradation can be controlled by an external signal. For example, the switching means is an n-channel type T
It is not limited to FT. A p-channel TFT may be used, or a transmission gate circuit may be used.

In the embodiment, the example in which the liquid crystal panel 100 operates in the normally black mode has been described, but the liquid crystal panel 100 may operate in the normally white mode. In the normally white mode, the white pixel and the black pixel in the embodiment may be read in reverse. For example, a moving image domain is likely to occur in a normally white mode for a pixel that changes from a white pixel to a black pixel.

DESCRIPTION OF SYMBOLS 1 ... Liquid crystal display device, 10 ... Control circuit, 20 ... Scanning control circuit, 30 ... Image processing circuit, 31 ...
Delay circuit 32 ... Boundary detection unit 33 ... Conversion unit 34 ... Output unit 35 ... Frame memory
36 ... Frame memory, 37 ... Frame memory, 38 ... VRAM, 100 ... Liquid crystal panel, 101 ... Display area, 105 ... Liquid crystal layer, 108 ... Common electrode, 111 ... Pixel, 112 ...
Scanning line 114... Data line 115. Capacity line 116 116 TFT 118 pixel electrode 12
DESCRIPTION OF SYMBOLS 0 ... Liquid crystal element, 125 ... Capacitance element, 130 ... Scan line drive circuit, 140 ... Data line drive circuit, 2100 ... Projector, 2102 ... Lamp unit, 2106 ... Mirror, 2108
... Dichroic mirror, 2112 ... Dichroic prism, 2114 ... Projection lens group, 2120 ... Screen, 2121 ... Relay lens system, 2122 ... Incident lens, 2123
... Relay lens, 2124 ... Exit lens

Claims (6)

The gradation of two pixels adjacent to each other in the first direction from a video signal including a gradation value of a plurality of pixels arranged two-dimensionally in the first direction and the second direction and indicating an image divided into frames. Detecting means for detecting a boundary whose value difference is equal to or greater than a threshold and moved in the first direction by one pixel in two consecutive frames;
When the boundary detected by the detection means includes a first boundary and a second boundary that are continuous in the second direction, the first boundary and the second boundary are equivalent to at least two pixels in three consecutive frames, Conversion means for moving in the first direction and converting the video signal so that a frame in which the first boundary moves and a frame in which the second boundary moves are different;
A control device comprising: an output unit that outputs a signal for controlling a voltage applied to the plurality of pixels in accordance with the video signal converted by the conversion unit. In the frame in which the first boundary moves, the conversion unit converts a gradation value of a pixel that has passed the moved first boundary into an intermediate gradation of gradation values of two pixels adjacent to the first boundary. Further, in the frame in which the second boundary moves, the gradation value of the pixel that has passed the second boundary is changed to the intermediate gradation of the gradation values of the two pixels adjacent to the second boundary, respectively. The control device according to claim 1, wherein conversion is performed. The control device according to claim 1, wherein the conversion unit switches a frame in which the first boundary moves and a frame in which the second boundary moves every two frames. First storage means for storing (k−1) th frame data when the kth frame data is processed among the video signals;
Second storage means for storing data used for specifying the boundary in the (k-2) th frame of the video signal;
In the frame in which the first boundary moves, the conversion unit includes data of a pixel group including two pixels on both sides of the first boundary and not including two pixels on both sides of the second boundary. Replacing the data stored in the first storage means,
In the frame in which the second boundary moves, the data of the pixel group including the two pixels on both sides of the second boundary and not including the two pixels on both sides of the first boundary is used as the data of the kth frame. The control device according to claim 1, wherein the control device is replaced. A control device according to any one of claims 1 to 4,
An electro-optical device having the electro-optical element.   An electronic apparatus comprising the electro-optical device according to claim 5.

Images