Liquid crystal display device, method for controlling liquid crystal display device, and electronic apparatus

Abstract

The invention provides a liquid crystal display device, a control method of the liquid crystal display device, and an electronic apparatus. A display control circuit (20) performs a first correction on the pixel data of a video pixel on the basis of the pixel data of two or more peripheral video pixels, and performs a second correction on the basis of the pixel data of two or more peripheral video pixels. Determining whether or not both a voltage corresponding to a gradation level of pixel data of a video pixel of interest in the pixel data after the first correction and a voltage corresponding to a gradation level of pixel data of a video pixel adjacent to the video pixel of interest are voltages within an intermediate gradation range; when both voltages are within the range of intermediate gradation, a second correction is performed that cancels out the first correction performed on the pixel data of the video pixel of interest, and the pixel data after the first correction is supplied to the panel pixel, or when the second correction is performed, the pixel data after the first correction is supplied to the panel pixel. A data signal based on the pixel data after the second correction is supplied to the panel pixels.

Description

TECHNICAL FIELD

[0001] The present application relates to a liquid crystal display device, a control method of a liquid crystal display device, and an electronic apparatus. BACKGROUND

[0002] As the miniaturization and high definition of liquid crystal panels have progressed in recent years, the gap between pixel electrodes becomes narrow, and the influence of the electric field generated between pixel electrodes adjacent to each other, that is, the electric field in the parallel direction to the substrate surface (lateral electric field) becomes non-negligible. Specifically, due to the lateral electric field, the orientation of liquid crystal molecules, which is called disclination, becomes poor, and this is seen as a display defect.

[0003] Therefore, a technique has been proposed in which, in a case where the lateral electric field is strong and it is expected that a display defect caused by disclination will be seen, image data supplied from a higher-level device is corrected so that the difference in voltage applied to adjacent pixel electrodes is made small. In addition, such correction is sometimes called disclination correction or field correction (for example, see the description of Patent Document 1).

[0004] Patent Document 1: Japanese Patent Application Publication No. 2011-170235

[0005] However, in disclination correction like the above-described technique, the correction of image data supplied from a higher-level device means that the display according to the image data is not performed, and there is a problem that so-called display violation occurs. SUMMARY

[0006] A liquid crystal display device of one embodiment of the present disclosure includes a liquid crystal panel including panel pixels, and a display control circuit that controls the liquid crystal panel. The gray scale of an image pixel included in image data is specified by pixel data. The image pixel includes a first image pixel and a first adjacent image pixel adjacent to the first image pixel. The display control circuit supplies a data signal based on a voltage corresponding to the gray scale specified by the pixel data of the first image pixel to a panel pixel corresponding to the first image pixel, and supplies a data signal based on a voltage corresponding to the gray scale specified by the pixel data of the first adjacent image pixel to a panel pixel corresponding to the first adjacent image pixel. In a case where both the gray scale specified by the pixel data of the first image pixel and the gray scale specified by the pixel data of the first adjacent image pixel are in a range of an intermediate gray scale which is higher than a first threshold gray scale and lower than a second threshold gray scale, the voltage of the data signal supplied to the panel pixel corresponding to the first image pixel is set to be different from the voltage of the data signal supplied to the panel pixel corresponding to the first image pixel in a case where at least one of the gray scale of the first image pixel and the gray scale of the first adjacent image pixel is outside the range of the intermediate gray scale.

[0007] Another type of liquid crystal display device includes: a liquid crystal panel having panel pixels; and a display control circuit that controls the liquid crystal panel, wherein image pixels constituting image data are arranged in a first direction and a second direction, the grayscale level of the image pixels is specified by pixel data, and the display control circuit performs a first correction on the image pixel based on the pixel data of two or more image pixels adjacent to the image pixel in the first direction, the direction opposite to the first direction, the second direction, or the direction opposite to the second direction, and determines the number of pixels of the image pixel of interest in the first-corrected pixel data. If the voltage corresponding to the gray level of the image pixel and the voltage corresponding to the gray level of the pixel data of the image pixel adjacent to the image pixel of interest in either the first or second direction are both within a first range, and if the voltages of both are within an intermediate gray level range above a first threshold voltage and below a second threshold voltage, a second correction is performed to cancel the first correction performed on the pixel data of the image pixel of interest, and the pixel data after the first correction is supplied to the panel pixel, or, if the second correction is performed, a data signal based on the pixel data after the second correction is supplied to the panel pixel.

[0008] In another control method for a liquid crystal display device, the liquid crystal display device includes: a liquid crystal panel having panel pixels; and a display control circuit that controls the liquid crystal panel, wherein the grayscale level of an image pixel constituting image data is specified by pixel data, the image pixel including: a first image pixel; and a first adjacent image pixel adjacent to the first image pixel. In this control method, a data signal based on a voltage of a grayscale level specified by the pixel data of the first image pixel is supplied to the panel pixel corresponding to the first image pixel, and a data signal based on a grayscale level specified by the pixel data of the first image pixel is supplied to the panel pixel corresponding to the first adjacent image pixel. When the gray level specified by the pixel data of the image pixel is within an intermediate gray level range that is above a first threshold gray level and below a second threshold gray level, the voltage of the data signal supplied to the panel pixel corresponding to the first image pixel is set to be different from the voltage of the data signal supplied to the panel pixel corresponding to the first image pixel when at least one of the gray level of the first image pixel and the gray level of the first adjacent image pixel is outside the intermediate gray level range. Attached Figure Description

[0009] Figure 1This diagram shows a projection-type display device that utilizes the liquid crystal display device of the first embodiment.

[0010] Figure 2 This is a block diagram showing the structure of a projection display device.

[0011] Figure 3 This is a three-dimensional diagram showing the structure of a liquid crystal panel in a projection display device.

[0012] Figure 4 This is a cross-sectional view showing the structure of a liquid crystal panel.

[0013] Figure 5 It is a block diagram showing the electrical structure of a liquid crystal panel.

[0014] Figure 6 This is a diagram showing the structure of the pixel circuitry in a liquid crystal panel.

[0015] Figure 7 It is a block diagram showing the structure of the processing circuit in a projection display device.

[0016] Figure 8 This is a diagram illustrating an example of the VT characteristics in a liquid crystal element.

[0017] Figure 9 This is a diagram used to illustrate the orientation of an LCD panel.

[0018] Figure 10 This is a diagram showing an example of the filter coefficients of the smoothing circuit in the processing circuit.

[0019] Figure 11 This is a diagram showing an example of smoothing circuitry applied to image pixels before and after its application.

[0020] Figure 12 This is a diagram of an example of a two-dimensional table representing a recovery circuit in a processing circuit.

[0021] Figure 13 It is a diagram used to illustrate the operation of the processing circuit.

[0022] Figure 14 It is a diagram used to illustrate the operation of the processing circuit.

[0023] Figure 15 It is a diagram used to illustrate the operation of the processing circuit.

[0024] Figure 16 It is a flowchart showing the operation of the processing circuit.

[0025] Figure 17 This is a diagram showing the structure of the processing circuit in the liquid crystal display device according to the first embodiment.

[0026] Figure 18 It is a diagram used to illustrate the operation of the processing circuit.

[0027] Figure 19 It is a diagram used to illustrate the operation of the processing circuit.

[0028] Figure 20 It is a diagram used to illustrate the operation of the processing circuit.

[0029] Figure 21 It is a flowchart showing the operation of the processing circuit.

[0030] Label Explanation

[0031] 1: Projection type display device; 100R, 100G, 100B: Liquid crystal panel; 110: Pixel circuit; 118: Pixel electrode; 120: Liquid crystal element; 20: Display control circuit; 22R, 22G, 22B: Processing circuit; 221, 221R, 221G, 221B: Smoothing circuit; 223, 223R, 223G, 223B: Recovery circuit; 225, 225R, 225G, 225B: Correction circuit. Detailed Implementation

[0032] Hereinafter, a liquid crystal display device according to an embodiment will be described with reference to the accompanying drawings. In addition, the sizes and scales of the various parts in each drawing are appropriately different from the actual figures. Furthermore, the embodiments described below are preferred examples, and therefore various technically preferred limitations have been added. However, unless otherwise specified in the following description, the scope of this disclosure is not limited to these embodiments.

[0033] Figure 1 This diagram illustrates the optical structure of the projection display device 1 according to the embodiment. As shown, the projection display device 1 includes liquid crystal panels 100R, 100G, and 100B. Inside the projection display device 1 is a lamp unit 2102 composed of a white light source such as a halogen lamp or an LED. The white light emitted from this lamp unit 2102 is separated into three primary colors—red (R), green (G), and blue (B)—by three internal reflectors 2106 and two dichroic mirrors 2108. Specifically, R light is incident on the liquid crystal panel 100R, G light on the liquid crystal panel 100G, and B light on the liquid crystal panel 100B.

[0034] Furthermore, the optical path of B is longer than that of R and G, so it is necessary to prevent losses in the optical path of B. Therefore, a relay lens system 2121, which includes an incident lens 2122, a relay lens 2123, and an exit lens 2124, is provided in the optical path B.

[0035] The liquid crystal panel 100R has pixel circuits arranged in a matrix as described later. In these pixel circuits, the transmittance of light emitted from the liquid crystal element is controlled based on a data signal corresponding to R. That is, in the liquid crystal panel 100R, the emitted light from the liquid crystal element functions as the smallest unit of the image. Through such control, the liquid crystal panel 100R generates a transmissive image of R based on the data signal corresponding to R. Similarly, the liquid crystal panel 100G generates a transmissive image of G based on the data signal corresponding to G, and the liquid crystal panel 100B generates a transmissive image of B based on the data signal corresponding to B.

[0036] Transmitted images of various colors generated by liquid crystal panels 100R, 100G, and 100B are incident on dichroic prism 2112 from three directions. In dichroic prism 2112, the light from R and B is refracted at 90 degrees, while the light from G travels in straight line. Therefore, dichroic prism 2112 synthesizes the images of each color. The synthesized image from dichroic prism 2112 is incident on projection lens 2114. Projection lens 2114 magnifies the synthesized image from dichroic prism 2112 and projects it onto screen Scr.

[0037] Furthermore, the transmitted images of liquid crystal panels 100R and 100B are projected after being reflected by the dichroic prism 2112, while the transmitted image of liquid crystal panel 100G is projected in a straight line. Therefore, each transmitted image of liquid crystal panels 100R and 100B is in a left-right inverse relationship with the transmitted image of liquid crystal panel 100G.

[0038] Figure 2 This is a block diagram showing the electrical structure of the projection display device 1. As shown, the projection display device 1 includes a display control circuit 20 and the aforementioned liquid crystal panels 100R, 100G, and 100B.

[0039] Image data Vid_in is supplied to the display control circuit 20 synchronously with the synchronization signal Sync from a host device or other upper-level device (not shown in the figure). Image data Vid_in represents the image displayed by the projection display device 1. Specifically, in this embodiment, the gray levels in the pixels of the image are specified in 8 bits according to RGB.

[0040] Furthermore, the pixels of the image data Vid_in, or the pixels of the image specified by the correction data of the image data, are described as image pixels, and the data specifying the grayscale level of the image pixels are described as pixel data. However, sometimes image pixels and pixel data are not specifically distinguished in the description. In addition, the pixels of the liquid crystal panel 100R, 100G, or 100B before or after compositing are described as panel pixels. As in this embodiment, when there is a one-to-one correspondence between image pixels and panel pixels, it is not necessary to specifically distinguish between image pixels and panel pixels.

[0041] The synchronization signal Sync includes a vertical synchronization signal indicating the start of vertical scanning in the image data Vid_in, a horizontal synchronization signal indicating the start of horizontal scanning, and a clock signal indicating the timing of one pixel of the image data.

[0042] In this embodiment, the color image projected onto the screen Scr is represented by overlapping the transmissive images of the liquid crystal panels 100R, 100G, and 100B. Therefore, the pixel, which is the smallest unit of the color image, can be divided into red panel pixels based on the liquid crystal panel 100R, green panel pixels based on the liquid crystal panel 100G, and blue panel pixels based on the liquid crystal panel 100B.

[0043] In addition, the red panel pixels, green panel pixels and blue panel pixels should strictly be described as sub-pixels, but in this specification, as mentioned above, they are referred to as panel pixels.

[0044] The display control circuit 20 includes a control circuit 21, processing circuits 22R, 22G, and 22B.

[0045] The control circuit 21 generates control signals Ctr for controlling the LCD panels 100R, 100G and 100B.

[0046] Details of the processing circuits 22R, 22G and 22B will be described later. The processing circuit 22R processes the image data Va_R, which is the R component in the image data Vid_in, and converts it into an analog data signal Vid_R, which is then supplied to the liquid crystal panel 100R.

[0047] Similarly, processing circuit 22G processes the image data Va_G of the G component in the image data Vid_in, converts it into an analog data signal Vid_G, and supplies it to the liquid crystal panel 100G. Processing circuit 22B processes the image data Va_B of the B component in the image data Vid_in, converts it into an analog data signal Vid_B, and supplies it to the liquid crystal panel 100B.

[0048] In addition, the liquid crystal display device consists of a liquid crystal panel 100R, 100G or 100B and a display control circuit 20 that supplies data signals to the liquid crystal panel.

[0049] Next, LCD panels 100R, 100G, and 100B will be described. LCD panels 100R, 100G, and 100B differ only in the color of the incident light, i.e., the wavelength; they are structurally identical. Therefore, for LCD panels 100R, 100G, and 100B, in a general description without specifying the color, the designation will be 100.

[0050] Figure 3This diagram shows the main parts of the LCD panel 100. Figure 4 Is Figure 3 The sectional view is obtained by cutting along the Hh line.

[0051] As shown in these figures, in the liquid crystal panel 100, the element substrate 100a with pixel electrode 118 and the opposing substrate 100b with common electrode 108 maintain a certain gap and are bonded together by sealing material 90 with the electrode forming surfaces facing each other, and liquid crystal 105 is sealed in the gap.

[0052] As the component substrate 100a and the opposing substrate 100b, transparent substrates such as glass and quartz are used respectively. Figure 3 As shown, one side of the component substrate 100a extends from the opposing substrate 100b. In this extended area, a plurality of terminals 106 are arranged laterally in the figure. One end of an FPC (Flexible Printed Circuits) substrate (not shown) is connected to the plurality of terminals 106. Furthermore, the other end of this FPC substrate is connected to the display control circuit 20 and is supplied with the various signals described above.

[0053] On the surface of the component substrate 100a facing the opposing substrate 100b, the pixel electrode 118 is formed, for example, by patterning a transparent conductive layer such as ITO (Indium Tin Oxide).

[0054] Figure 5 This is a block diagram showing the electrical structure of the liquid crystal panel 100. In the liquid crystal panel 100, a scan line driving circuit 130 and a data line driving circuit 140 are provided at the periphery of the display area 10.

[0055] In the display area 10 of the liquid crystal panel 100, pixel circuits 110 are arranged in a matrix. Specifically, in the display area 10, multiple scan lines 12 extend in the horizontal X direction, and multiple data lines 14 extend in the vertical Y direction, and are electrically insulated from the scan lines 12. Furthermore, the pixel circuits 110 are arranged in a matrix corresponding to the intersections of the multiple scan lines 12 and the multiple data lines 14.

[0056] With scan lines 12 having number m and data lines 14 having number n, the pixel circuit 110 is arranged in a matrix with m rows and n columns. Both m and n are integers greater than 2. In the scan lines 12 and pixel circuit 110, to distinguish the rows of the matrix, they are sometimes sequentially labeled 1, 2, 3, ..., (m-1), m rows from top to bottom in the diagram. Similarly, in the data lines 14 and pixel circuit 110, to distinguish the columns of the matrix, they are sometimes sequentially labeled 1, 2, 3, ..., (n-1), n ​​columns from left to right in the diagram.

[0057] The scan line driving circuit 130, under the control of the display control circuit 20, selects scan lines 12 one by one in the order of rows 1, 2, 3, ..., m, and sets the scan signal to the selected scan line 12 to a high level (H). Additionally, the scan line driving circuit 130 sets the scan signal to scan lines 12 other than the selected scan line 12 to a low level (L).

[0058] The data line driving circuit 140 latches one line of data signals supplied from the corresponding color circuits in the processing circuits 22R, 22G or 22B, and outputs the data signals of one line to the pixel circuit 110 located on the scan line 12 via the data line 14 while the scan signal to the scan line 12 is at level H.

[0059] Figure 6 This is a diagram showing the equivalent circuit of four pixel circuits 110, consisting of two rows and two columns, corresponding to the intersections of two adjacent scan lines 12 and two adjacent data lines 14.

[0060] As shown in the figure, the pixel circuit 110 includes a transistor 116 and a liquid crystal element 120. The transistor 116 is, for example, an n-channel thin-film transistor. In the pixel circuit 110, the gate node of the transistor 116 is connected to the scan line 12, while its source node is connected to the data line 14, and its drain node is connected to the pixel electrode 118, which is approximately square when viewed from above.

[0061] A common electrode 108 is provided for all pixels in a manner opposite to the pixel electrode 118. A voltage LCcom is applied to the common electrode 108. Furthermore, liquid crystal 105 is sandwiched between the pixel electrode 118 and the common electrode 108 as described above. Therefore, according to each pixel circuit 110, a liquid crystal element 120 is configured in which the liquid crystal 105 is sandwiched between the pixel electrode 118 and the common electrode 108.

[0062] Furthermore, the storage capacitor 109 is connected in parallel with the liquid crystal element 120. One end of the storage capacitor 109 is connected to the pixel electrode 118, and the other end is connected to the capacitor line 107. The capacitor line 107 is subjected to a time-constant voltage, for example, the same voltage LCcom applied to the common electrode 108. The pixel circuit 110 is arranged in a matrix along the extension direction of the scan line 12 (X-direction) and the extension direction of the data line 14 (Y-direction), therefore the pixel electrodes 118 included in the pixel circuit 110 are also arranged along the X and Y directions.

[0063] In scan line 12 where the scan signal is at level H, the transistor 116 of the pixel circuit 110 corresponding to scan line 12 is turned on. With the transistor 116 on, data line 14 and pixel electrode 118 are electrically connected, so the data signal supplied to data line 14 reaches pixel electrode 118 via the turned-on transistor 116. If scan line 12 is at level L, transistor 116 is turned off, and the voltage of the data signal that has reached pixel electrode 118 is maintained by the capacitance of liquid crystal element 120 and storage capacitor 109.

[0064] As is well known, in the liquid crystal element 120, the orientation of the liquid crystal molecules varies according to the electric field generated by the pixel electrode 118 and the common electrode 108. Therefore, the liquid crystal element 120 has a transmittance corresponding to the effective value of the applied voltage.

[0065] Furthermore, the area in the liquid crystal element 120 that functions as a panel pixel, i.e., the area corresponding to the effective value of transmittance and voltage, is the area where the pixel electrode 118 and the common electrode 108 overlap when viewed from above the element substrate 100a and the opposing substrate 100b. The pixel electrode 118 is approximately square when viewed from above, therefore the shape of the pixels in the liquid crystal panel 100 is also approximately square.

[0066] In addition, in this embodiment, the liquid crystal 105 is in VA (Vertical Alignment) mode, which is a normally black mode where the transmittance is lowest when the applied voltage to the liquid crystal element 120 is zero and the transmittance increases as the applied voltage increases.

[0067] The operation of supplying data signals to the pixel electrodes 118 of the liquid crystal element 120 is performed in the order of rows 1, 2, 3, ..., m during each horizontal scan. As a result, voltages corresponding to the data signals are maintained in the liquid crystal elements 120 of the pixel circuit 110 arranged in m rows and n columns, and each liquid crystal element 120 becomes the target transmittance. Through the liquid crystal elements 120 arranged in m rows and n columns, a transmissive image of the corresponding color is generated.

[0068] In this way, the transmission image is generated according to each RGB, and the composite RGB color image is projected onto the screen Scr.

[0069] Next, for Figure 2 The processing circuits 22R, 22G, and 22B in the circuit will be described.

[0070] Figure 7 This is a block diagram showing the structure of processing circuits 22R, 22G, and 22B.

[0071] As shown in the figure, the processing circuit 22R includes a smoothing circuit 221R and a recovery circuit 223R.

[0072] The smoothing circuit 221R uses the filtering coefficients described later to smooth the image data Va_R of the R component in order to reduce the gray level of adjacent image pixels.

[0073] The recovery circuit 223R analyzes the image data after the gray level has been smoothed by the smoothing circuit 221R. If the gray level of two adjacent image pixels is within the range of intermediate gray levels, the smoothing of the gray level by the smoothing circuit 221R is canceled, and the original gray level is restored.

[0074] Furthermore, regarding the smoothing circuit 221G and the restoration circuit 223G, as well as the smoothing circuit 221B and the restoration circuit 223B, the only difference is the color component of the image data being processed; their circuit structures are the same as those of the smoothing circuit 221R and the restoration circuit 223R, respectively.

[0075] That is, the smoothing circuit 221G and the restoration circuit 223G process the image data Va_G of the G component, and the smoothing circuit 221G and the restoration circuit 223B process the image data Va_B of the B component.

[0076] In the following description, without knowing the color composition, the processing circuits 22R, 22G and 22B will be referred to as 22, the smoothing circuit as 221 and the recovery circuit as 223.

[0077] The reason for smoothing the gray levels using the smoothing circuit 221 will be explained.

[0078] Figure 8 This is a diagram illustrating an example of the voltage-transmittance characteristics (VT characteristics) of the liquid crystal element 120 in normal black mode.

[0079] In normal black mode, the voltage applied to the liquid crystal element 120 is increased in panel pixels with high grayscale levels and high transmittance. On the other hand, the voltage applied to the liquid crystal element 120 is decreased in panel pixels with low grayscale levels and low transmittance.

[0080] For ease of explanation, panel pixels with an applied voltage of VH or higher to the liquid crystal element 120 and a transmittance of TRH are designated as bright panel pixels. Conversely, panel pixels with an applied voltage of VL or lower to the liquid crystal element 120 and a transmittance of TRL are designated as dark panel pixels.

[0081] Regarding VH and VL, the relationship is VH > VL.

[0082] like Figure 9As shown, in the liquid crystal panel 100, when a bright panel pixel L with high transmittance (i.e., a high applied voltage to the liquid crystal element 120) is adjacent to a dark panel pixel D with low transmittance (i.e., a low applied voltage to the liquid crystal element 120), the voltage difference between the pixel electrodes 118 increases. When the voltage difference between the pixel electrodes 118 increases, the lateral electric field generated along the substrate surface increases, and in the region Dis containing the boundary between the two panel pixels, a phenomenon called misalignment of liquid crystal molecules easily occurs. The region Dis, where misalignment occurs, does not have transmittance corresponding to the grayscale level, thus becoming a major cause of reduced display quality.

[0083] To suppress display defects caused by misalignment, a structure is considered to reduce the voltage difference between pixel electrodes in adjacent panel pixels by correcting the difference in gray levels between adjacent image pixels.

[0084] The structure used here is a smoothing circuit 221. The smoothing circuit 221 stores one frame of image data corresponding to the color components in the internal memory, for example, by smoothing the gray levels of adjacent image pixels using filtering coefficients.

[0085] Figure 10 This is a diagram showing an example of a matrix representing the filter coefficients (kernels) used in the convolution operation of the smoothing circuit 221.

[0086] If the filtering coefficients shown in the figure are used, the image data is processed as follows. Specifically, in the arrangement of image pixels constituting the image data, when focusing on a particular image pixel, if the gray level of the pixel of interest is higher than the gray level of its surrounding pixels, the gray level of the pixel of interest is multiplied by the coefficient indicated by the thick box to decrease it, while the gray level of the surrounding pixels is increased by multiplying by the coefficient corresponding to the position. Conversely, if the gray level of the pixel of interest is lower than the gray level of its surrounding pixels, the gray level of the pixel of interest is multiplied by the coefficient indicated by the thick box to increase it, while the gray level of the surrounding pixels is decreased by multiplying by the coefficient corresponding to the position.

[0087] Figure 11 This diagram shows examples of image pixels before and after smoothing, represented by image data. Additionally, the gray levels of the image pixels are represented by shades in the diagram.

[0088] In the smoothing circuit 221, when the grayscale level of the image pixel of interest is black and the image pixels surrounding the image pixel of interest are white (displaying black characters on a white background), a correction is performed that significantly increases the grayscale level of the black image pixel of interest and slightly decreases the grayscale level of the white image pixels surrounding it. That is, when black and white image pixels are adjacent, if there are fewer black image pixels than white image pixels, a relatively weak correction is applied to the white image pixels, and a relatively strong correction is applied to the black image pixels.

[0089] In addition, black image pixels refer to the case where the gray level specified by 8 bits is the lowest decimal value "0", and white image pixels refer to the case where the gray level is the highest decimal value "255".

[0090] Here, the situation of displaying black characters on a white background is referred to as: relative to the image pixel of interest with a grayscale level of black, including adjacent image pixels, there are more image pixels with a grayscale level of white surrounding the image pixel of interest. However, the situation of displaying black characters on a white background also includes: relative to the image pixel of interest with a small (dark) grayscale level, including adjacent image pixels, there are more image pixels with a large (bright) grayscale level surrounding the image pixel of interest.

[0091] Therefore, white background with black characters specifically refers to the display of lines, symbols, characters, etc., with relatively bright image pixels as the background and relatively dark image pixels as the background.

[0092] On the other hand, when the grayscale level of the image pixel of interest is white, and the image pixels surrounding the image pixel of interest are black (black background with white characters), a correction is performed that significantly reduces the grayscale level of the white image pixel of interest and slightly increases the grayscale level of the black image pixels surrounding it. That is, when black image pixels are adjacent to white image pixels, if there are more black image pixels than white image pixels, a relatively strong correction is applied to the white image pixels, and a relatively weak correction is applied to the black image pixels.

[0093] Here, the situation described as displaying white characters on a black background is defined as follows: relative to the image pixel of interest with a white grayscale level, including adjacent image pixels, a significant number of image pixels with a black grayscale level are located around the image pixel of interest. However, this is not limited to the case of displaying white characters on a black background; the situation also includes the following: relative to the image pixel of interest with a large (bright) grayscale level, including adjacent image pixels, a significant number of image pixels with a small (dark) grayscale level are located around the image pixel of interest.

[0094] Therefore, black background with white characters specifically refers to the display of characters with a darker background and brighter pixels.

[0095] In the smoothing of gray levels by the smoothing circuit 221, display inconsistencies can easily become a problem when the gray levels of image pixels are within the intermediate gray level range. Within the intermediate gray level range, the original difference between gray levels is small, but through smoothing, this difference becomes even smaller, resulting in what is perceived as blurriness. Therefore, a recovery circuit 223 is provided to perform a recovery process to prevent display inconsistencies within the intermediate gray level range.

[0096] Furthermore, the range of intermediate gray levels mentioned here refers to the range of gray levels above L_th1 and below L_th2. L_th1 and L_th2 are both threshold gray levels, and when converted to decimal values, they have the relationship 0 < L_th1 < L_th2 < 255.

[0097] When the range of intermediate gray levels is converted into the voltage applied to the liquid crystal element 120, the threshold gray level L_th1 is equivalent to the voltage V_th1, and the threshold gray level L_th2 is equivalent to the voltage V_th2.

[0098] That is, when converting grayscale levels into applied voltages to the liquid crystal element 120, for example, if the applied voltage corresponding to a black image pixel is 0V and the applied voltage corresponding to a white image pixel is 5V, then in the voltage, there is a relationship of 0 < V_th1 < V_th2 < 5.

[0099] The recovery circuit 223 performs the following recovery processes, from the first to the fourth.

[0100] In detail, recovery circuit 223 executes:

[0101] First, the image data smoothed by the grayscale level smoothing circuit 221 is stored in the internal input memory.

[0102] Second, focus on a single image pixel in the accumulated image data and identify the image pixels adjacent to that pixel in a specific direction (e.g., to the right).

[0103] Third, refer to the two-dimensional table to read the recovery amount corresponding to the grayscale data of the pixel of interest and the grayscale data of the adjacent pixels in the image.

[0104] Fourth, the recovered amount is added to the grayscale data of the pixels of interest and stored in the internal output memory.

[0105] The recovery circuit 223 sequentially shifts the pixels of interest in the image data stored in the internal input memory, thereby performing the first to fourth processes on all frames. After performing the first to fourth processes on the image data of one frame, the recovery circuit 223 performs the first to fourth processes on the image data of the next frame in the same way.

[0106] Figure 12 This is a diagram showing an example of a two-dimensional table referenced by the recovery circuit 223.

[0107] The two-dimensional table takes as input the gray level of the image pixel of interest and the gray level of the image pixels adjacent to the image pixel of interest, and outputs the recovery amount corresponding to the two gray levels.

[0108] In the two-dimensional table, the horizontal axis represents the gray level of the image pixel of interest, and the vertical axis represents the gray level of the image pixels adjacent to the image pixel of interest. Then, when both the gray level of the image pixel of interest and the gray level of the image pixels adjacent to the image pixel of interest are above the threshold gray level L_th1 and below the threshold gray level Lth2, the recovery amount used to cancel the smoothing of the gray level by the smoothing circuit 221 is read from the two-dimensional table.

[0109] Furthermore, in the two-dimensional table, the areas where the gray level of the image pixel of interest and the gray level of the adjacent image pixels of interest are both above the threshold gray level L_th1 and below the threshold gray level Lth2 are the shaded areas marked in the figure.

[0110] Furthermore, if at least one of the gray level of the image pixel in question and the gray level of an adjacent image pixel is lower than the threshold gray level L_th1 or higher than the threshold gray level Lth2, the readout amount of recovery is zero. If the zero amount of recovery is added to the gray level data of the image pixel in question, the gray level data does not change, thus maintaining the smoothing effect of the smoothing circuit 221.

[0111] In addition, image data including zero recovery is stored in the internal output memory. The image data stored in the internal output memory is read out at a timing consistent with the scanning of the liquid crystal panel 100, converted into an analog data signal, and output.

[0112] Figure 13 , Figure 14 as well as Figure 15 These are diagrams illustrating the specific operation of the processing circuit 22 in the first embodiment. In these diagrams, Figure 13 This diagram illustrates the smoothing and restoration of grayscale levels for adjacent black and white image pixels when displaying black characters on a white background.

[0113] Figure 14This diagram illustrates the smoothing and restoration of grayscale levels for adjacent black and white image pixels when displaying white characters on a black background.

[0114] Figure 15 This diagram illustrates the smoothing and restoration of grayscale levels for adjacent, relatively dark image pixels and relatively bright image pixels in the context of displaying natural images.

[0115] exist Figure 13 In the process, before smoothing, the voltage applied to the liquid crystal element 120 for the image data of black image pixels is set to 0V. Similarly, before smoothing, the voltage applied to the liquid crystal element 120 for the image data of white image pixels is set to 5V.

[0116] When the grayscale level is smoothed by the smoothing circuit 221, the voltage applied to the liquid crystal element 120 corresponding to the black image pixel is corrected to become higher, for example, to become 2.0V, and the voltage applied to the liquid crystal element 120 corresponding to the white image pixel is corrected to become lower, for example, to become 4.6V.

[0117] in addition, Figure 13 This refers to the case of displaying black characters on a white background, where more black image pixels are arranged around black image pixels. Therefore, the amount of grayscale correction in the black image pixels, calculated by applying voltage, is larger in absolute value compared to the amount of grayscale correction in the white image pixels.

[0118] In addition, before smoothing, the gray levels in black image pixels and the gray levels in white image pixels are outside the range of intermediate gray levels after smoothing, so the recovery amount is zero.

[0119] Therefore, after the recovery process of the recovery circuit 223, the voltage applied to the liquid crystal element 120 corresponding to the black image pixel is 2.0V, and the voltage applied to the liquid crystal element 120 corresponding to the white image pixel is 4.6V, which remains unchanged after smoothing.

[0120] exist Figure 14 In the process, the image data of black image pixels will have the applied voltage to the liquid crystal element 120 specified as 0V before correction, and the image data of white image pixels will have the applied voltage to the liquid crystal element 120 specified as 5V before correction.

[0121] When the grayscale level is smoothed by the smoothing circuit 221, the voltage applied to the liquid crystal element 120 corresponding to the black image pixel is corrected to become higher, for example, 1.2V, and the voltage applied to the liquid crystal element 120 corresponding to the white image pixel is corrected to become lower, for example, 3.6V.

[0122] in addition, Figure 14 This refers to the case of displaying white characters on a black background, where more black image pixels are arranged around white image pixels. Therefore, the amount of grayscale correction in the black image pixels, calculated by the applied voltage, is smaller in absolute value compared to the amount of grayscale correction in the white image pixels.

[0123] In addition, before smoothing, the gray levels in black image pixels and the gray levels in white image pixels are outside the range of intermediate gray levels after smoothing, so the recovery amount is zero.

[0124] Therefore, after the recovery process of the recovery circuit 223, the voltage applied to the liquid crystal element 120 corresponding to the black image pixel is 1.2V, and the voltage applied to the liquid crystal element 120 corresponding to the white image pixel is 3.6V, which remains unchanged after smoothing.

[0125] exist Figure 15 In the process, before smoothing, the darker image pixel among adjacent intermediate grayscale image pixels has its applied voltage to the liquid crystal element 120 specified as, for example, 2.0V. Additionally, before smoothing, the brighter image pixel among adjacent intermediate grayscale image pixels has its applied voltage to the liquid crystal element 120 specified as, for example, 3.0V.

[0126] When the grayscale level is smoothed by the smoothing circuit 221, the voltage applied to the liquid crystal element 120 corresponding to the image pixel with the darker grayscale is corrected to become higher, for example, 2.2V, and the voltage applied to the liquid crystal element 120 corresponding to the image pixel with the brighter grayscale is corrected to become lower, for example, 2.8V.

[0127] After smoothing, the gray levels in the darker and brighter image pixels are both within the intermediate gray level range. Therefore, the smoothing effect of the smoothing circuit 221 on the gray levels is canceled out by the recovery circuit 223, returning the gray levels to their original state.

[0128] The voltage applied to the liquid crystal element 120 corresponding to the image pixel with the darker grayscale in the middle returns to the original 2.0V, and the voltage applied to the liquid crystal element 120 corresponding to the image pixel with the brighter grayscale in the middle returns to the original 3.0V.

[0129] According to this first embodiment, when dark image pixels that are expected to cause misalignment are adjacent to bright image pixels, smoothing relative to the surrounding image pixels of the image pixel of interest is maintained, thus suppressing the degradation of display quality caused by misalignment. Furthermore, when they are adjacent at intermediate gray levels, the smoothing of the smoothing circuit 221 is canceled out by the recovery circuit 223, preventing display discrepancies and thus suppressing display blur.

[0130] The processing content of the processing circuits 22R, 22G, and 22B in the first embodiment can be conceptualized as a display control method. Furthermore, as described above, in processing circuits 22R, 22G, and 22B, only the color components of the image data being processed differ; the processing content itself is the same. Therefore, regarding the display control method in processing circuits 22R, 22G, and 22B, the color components are not specified, and the method will be described as the display control method in processing circuit 22.

[0131] Figure 16 This is a flowchart illustrating the display control method.

[0132] First, in the processing circuit 22, the smoothing circuit 221 smooths the gray level of the pixel specified by the image pixels of one frame (step S10).

[0133] Next, in the processing circuit 22, the recovery circuit 223 focuses on a specific image pixel in the image data smoothed by the smoothing circuit 221 (step S11). Then, the recovery circuit 223 determines the image pixel that is adjacent to the image pixel of interest in a specific direction (step S12), and the recovery circuit 223 reads the recovery amount corresponding to the gray level of the image pixel of interest and the determined image pixel gray level with reference to a two-dimensional table (step S13), and adds the read recovery amount to the gray level of the image pixel of interest (step S14).

[0134] If the gray levels of two image pixels are both above the threshold gray level L_th1 and below the threshold gray level L_th2, then the read-out recovery amount is the value of the gray level of the image pixel of interest restored to the smoothed gray level by canceling the smoothing circuit 221.

[0135] On the other hand, if at least one of the gray levels of the two image pixels is less than the threshold gray level L_th1 or higher than the threshold gray level L_th2, the readout recovery amount is zero, and the gray level of the image pixel of interest is maintained in a smoothed state based on the smoothing circuit 221.

[0136] The recovery circuit 223 determines whether all image pixels of a frame have been focused on (step S15). If the determination result is "no", the recovery circuit 223 shifts the image pixels of interest to another image pixel (step S16), and returns the processing steps to step S12. Therefore, steps S12 to S16 are repeatedly executed until all image pixels of a frame have been focused on.

[0137] If the determination result of step S15 is "yes", it means that all the image pixels of one frame have been focused on. Therefore, the processing circuit 22 transfers the processing object of the image pixels to the next frame (step S17) and returns the processing step to step S10.

[0138] As long as image data Vid_in is supplied from the host device (until the power is turned off), the processing steps S11 to S17 are repeated.

[0139] In the first embodiment, when displaying black characters on a white background, a stronger correction is applied to darker image pixels than to brighter image pixels during grayscale smoothing. Specifically, from the perspective of the voltage applied to the liquid crystal element 120, as... Figure 13 As shown, the applied voltage corresponding to the image pixel with a gray level of white is corrected from 5.0V to 4.6V, thus applying a correction of 0.4V. In contrast, the applied voltage corresponding to the image pixel with a gray level of black is corrected from 0V to 2.0V, thus applying a correction of 2.0V stronger than that of the black image pixel.

[0140] Conversely, in the first embodiment, when displaying black characters on a white background, the correction of bright image pixels is weak, and misalignment is easily seen in the panel pixels that represent the bright image pixels.

[0141] Therefore, a second embodiment that suppresses such misalignment will be described. The projection display device 1 of the second embodiment differs from the first embodiment only in the structure of the processing circuits 22R, 22G, and 22B. Therefore, regarding the second embodiment, the processing circuits 22R, 22G, and 22B, which differ from the first embodiment, will be described.

[0142] Figure 17 This is a block diagram showing the structure of processing circuits 22R, 22G, and 22B in the second embodiment. In the second embodiment, a correction circuit 225R is provided after the recovery circuit 223R in the processing circuit 22R. Similarly, a correction circuit 225G is provided after the recovery circuit 223G in the processing circuit 22G, and a correction circuit 225B is provided after the recovery circuit 223B in the processing circuit 22B.

[0143] The correction circuits 225R, 225G, and 225B differ only in the color composition of the object they process; the processing content is the same. Therefore, when describing correction circuits 225R, 225G, and 225B without knowing the color composition, the correction circuit will be labeled as 225 for explanation.

[0144] The correction circuit 225 adds a recovery amount to the smoothed grayscale level, focusing on a specific image pixel in the image data of one frame stored in the internal output memory of the recovery circuit 223.

[0145] Then, if the threshold gray level is between the gray level of the image pixel of interest and the gray level of an image pixel adjacent to the image pixel of interest in a specific direction (e.g., to the right), the correction circuit 225 reduces the gray level of the image pixel of interest by a predetermined amount. Furthermore, the predetermined amount can be, for example, a predetermined constant, or an amount set to increase as the gray level of the image pixel of interest exceeds the threshold gray level.

[0146] Additionally, although not specifically illustrated, for convenience, the threshold grayscale is set to L_th3.

[0147] On the other hand, if the threshold gray level L_th3 is not located between the gray level of the image pixel of interest and the gray level of the image pixel adjacent to the image pixel of interest, the correction circuit 225 does not perform any processing on the gray level of the image pixel of interest.

[0148] Furthermore, the threshold grayscale L_th3 in the correction circuit 225, when converted in terms of the voltage applied to the liquid crystal element 120, becomes a threshold voltage V_th3 that satisfies the following first and second conditions. Specifically, as the first condition, in the display of black characters on a white background, when white and black image pixels are adjacent, the threshold voltage V_th3 is a voltage lower than the voltage after correcting the voltage applied to the liquid crystal element 120 corresponding to the white image pixel through grayscale smoothing. Furthermore, as the second condition, in the display of white characters on a black background, when white and black image pixels are adjacent, the threshold voltage V_th3 is a voltage higher than the voltage after correcting the voltage applied to the liquid crystal element 120 corresponding to the white image pixel through grayscale smoothing.

[0149] refer to Figure 13 and Figure 14 For example, the threshold voltage V_th3 in the correction circuit 225 is less than 4.6V and higher than 3.6V.

[0150] If the threshold voltage V_th3 is between the applied voltage corresponding to the dark image pixel and the applied voltage corresponding to the bright image pixel, the correction circuit 225 reduces the gray level of the bright image pixel by a predetermined amount.

[0151] Additionally, this is an example of a threshold voltage V_th3, which is actually set to a voltage that makes the observed skewness less noticeable.

[0152] The correction circuit 225 stores image data with reduced grayscale levels or unprocessed image data in the internal output memory. The image data stored in the internal output memory is read out at a timing consistent with the scanning of the liquid crystal panel 100, converted into analog data signals, and output.

[0153] Figure 18 , Figure 19 as well as Figure 20 These are diagrams illustrating the specific operation of the processing circuit 22 in the second embodiment. In these diagrams, Figure 18 and Figure 13 Similarly, this image represents the case where black characters are displayed on a white background. Figure 19 and Figure 14 Similarly, this image represents the case where white characters are displayed on a black background. Figure 20 and Figure 15 Similarly, this is a diagram representing the display of natural images.

[0154] exist Figure 18 In the case of displaying black characters on a white background, the voltage applied to the liquid crystal element 120 before smoothing, the voltage applied to the liquid crystal element 120 after smoothing, and the voltage applied to the liquid crystal element 120 after restoration processing are compared with the black and white image pixels. Figure 13 same.

[0155] Here, when displaying black characters on a white background, the voltage applied to the liquid crystal element 120 after restoration processing is 2.0V for black image pixels. Conversely, the voltage applied to the liquid crystal element 120 after restoration processing is 4.6V for white image pixels.

[0156] The threshold voltage V_th3 is between 2.0V and 4.6V, so the gray level of white image pixels is reduced due to smoothing. It does not change during restoration processing, but is reduced due to the correction circuit 225.

[0157] exist Figure 18 The example shown illustrates that, when displaying black characters against a white background, the voltage applied to the liquid crystal element 120 decreases from 4.6V after the recovery process to 4.1V for the white image pixels.

[0158] Furthermore, in the correction circuit 225, the darker image pixel, which is black in this case, is not the object of correction. Therefore, in the black image pixel, the voltage applied to the liquid crystal element 120 will not change from the 2.0V after the recovery process due to the correction.

[0159] exist Figure 19 In the case of displaying white characters on a black background, regarding the black and white image pixels, the voltage applied to the liquid crystal element 120 before smoothing, the voltage applied to the liquid crystal element 120 after smoothing, and the voltage applied to the liquid crystal element 120 after restoration processing are compared with... Figure 14 same.

[0160] Here, when displaying white characters on a black background, the voltage applied to the liquid crystal element 120 after restoration processing is 1.2V for black image pixels. Conversely, the voltage applied to the liquid crystal element 120 after restoration processing is 3.6V for white image pixels.

[0161] Since the threshold voltage V_th3 is not between 1.2V and 3.6V, the grayscale level of the white image pixels is not corrected by the correction circuit 225. Therefore, when displaying white characters on a black background, the voltage applied to the liquid crystal element 120 for the white image pixels does not change from the 3.6V after the recovery process.

[0162] exist Figure 20 In displaying natural images, for bright and dark image pixels, the applied voltage to the liquid crystal element 120 before smoothing, the applied voltage to the liquid crystal element 120 after smoothing, and the applied voltage to the liquid crystal element 120 after restoration processing are compared with... Figure 15 same.

[0163] Here, when displaying a natural image, the voltage applied to the liquid crystal element 120 after restoration processing is 2.0V for dark image data. Conversely, for bright image data, the voltage applied to the liquid crystal element 120 after restoration processing is 3.0V.

[0164] Since the threshold voltage V_th3 is not between 2.0V and 3.0V, the grayscale level of bright image data is not corrected by the correction circuit 225. Therefore, when displaying a natural image, the voltage applied to the liquid crystal element 120 for bright image data will not change from the 3.0V after the recovery process.

[0165] According to this second embodiment, similarly to the first embodiment, when dark image pixels are adjacent to bright image pixels, smoothing of the image pixels surrounding the image pixel of interest is maintained, thus suppressing the degradation of display quality caused by misalignment. Furthermore, when the pixels are adjacent at intermediate gray levels, the smoothing of the smoothing circuit 221 is canceled out by the recovery circuit 223, preventing display discrepancies and thus suppressing display blur.

[0166] Furthermore, in the second embodiment, in a display where bright image pixels become the background relative to dark image pixels, the bright image pixels adjacent to the dark image pixels are corrected after smoothing, so that the error can be suppressed compared to the first embodiment.

[0167] The processing circuits 22R, 22G, and 22B in the second embodiment have the same processing content as in the first embodiment, and can be conceptualized as a display control method.

[0168] Figure 21 This is a flowchart illustrating the display control method. Figure 21 In the process of restoring a single frame, the following steps are performed: Figure 16 A correction process was added to the correction circuit 225. This added correction process will be explained.

[0169] In processing circuit 22, correction circuit 225 focuses on a specific image pixel in one frame of image data that has been restored by restoration circuit 223 with a restoration amount (including zero) (step S21). Then, correction circuit 225 determines the image pixel that is adjacent to the image pixel of interest in a specific direction (step S22).

[0170] The correction circuit 225 determines whether the threshold gray level L_th3 is located between the gray level of the image pixel of interest and the gray level of the determined image pixel (step S23).

[0171] If the result is determined to be "yes", the correction circuit 225 will reduce the gray level of the image pixel by a predetermined amount (step S24).

[0172] On the other hand, if the determination result is "no", the correction circuit 225 does not perform any processing on the gray level of the image pixel of interest, and the processing sequence jumps to step S25.

[0173] After step S24, or if the determination result in step S23 is "no", the correction circuit 225 determines whether all image pixels of a frame are of interest (step S25). If the determination result is "no", the correction circuit 225 shifts the image pixels of interest to another image pixel (step S26), and the processing returns to step S22.

[0174] Therefore, in the correction circuit 225, steps S21 to S26 are also repeatedly executed until all the image pixels of the one frame are of interest.

[0175] If the determination result of step S25 is "yes", it means that all the image pixels of one frame have been focused on. Therefore, the processing circuit 22 transfers the image pixel processing step to the next frame (step S27) and returns the processing step to step S10.

[0176] As long as image data Vid_in is supplied from the host device (until the power is turned off), the processing steps S10 to S17 and S21 to S27 are repeatedly executed.

[0177] In addition, liquid crystal display devices can also be applied to electronic devices other than projection display devices 1. For example, they can also be applied to electronic viewfinders in head-mounted displays, cameras or interchangeable-lens digital cameras, portable information terminals, and watch displays.

[0178] Based on the examples above, for instance, master the following methods.

[0179] A liquid crystal display device of method 1 includes: a liquid crystal panel having panel pixels; and a display control circuit that controls the liquid crystal panel such that the grayscale level of an image pixel constituting image data is specified by pixel data, the image pixel including: a first image pixel; and a first adjacent image pixel adjacent to the first image pixel, the display control circuit supplying a data signal to the panel pixel corresponding to the first image pixel, the data signal being based on a voltage of a grayscale level specified by the pixel data of the first image pixel, and supplying a data signal to the panel pixel corresponding to the first adjacent image pixel, the data signal being based on a voltage of a grayscale level specified by the pixel data of the first adjacent image pixel. When the gray level of the data signal corresponding to the first image pixel is within the intermediate gray level range (above a first threshold gray level and below a second threshold gray level), the voltage of the data signal supplied to the panel pixel corresponding to the first image pixel is set to be different from the voltage of the data signal supplied to the panel pixel corresponding to the first image pixel when at least one of the gray level of the first image pixel and the gray level of the first adjacent image pixel is outside the intermediate gray level range.

[0180] According to the liquid crystal display device of method 1, it is possible to suppress the blurring of the display caused by intermediate grayscale.

[0181] Furthermore, when focusing on a specific image pixel, this image pixel is an example of "the first image pixel," and the image pixel adjacent to this image pixel on the right is an example of "the first adjacent image pixel." Threshold gray level Lth_1 is an example of "the first threshold gray level," and threshold gray level Lth_2 is an example of "the second threshold gray level."

[0182] In addition, "adjacent" also includes situations where the two are adjacent but not touching.

[0183] In the liquid crystal display device of Method 2 of Method 1, the image pixel includes a second adjacent image pixel, which is an image pixel other than the first adjacent image pixel and is adjacent to the first image pixel. After smoothing the gray level specified by the pixel data of the first image pixel based on the gray level specified by the pixel data of the first adjacent image pixel and the gray level specified by the pixel data of the second adjacent image pixel, the display control circuit determines whether the gray level specified by the pixel data of the first image pixel and the gray level specified by the pixel data of the first adjacent image pixel are within the range of the intermediate gray level or outside the range.

[0184] According to the liquid crystal display device of method 2, it is possible to suppress the degradation of display quality caused by misalignment, thereby suppressing the blurring of the display generated in the intermediate grayscale.

[0185] Additionally, an image pixel that is adjacent to the image pixel of interest on the left, right, top, or bottom is an example of a "second adjacent image pixel".

[0186] In the liquid crystal display device of the specific method 3 of method 2, the display control circuit reduces the gray level of the smoothed first image pixel when the gray level of the smoothed first image pixel is higher than the gray level of the smoothed first adjacent image pixel, and at least one of the gray level of the smoothed first image pixel and the gray level of the smoothed first adjacent image pixel is outside the range of the intermediate gray level.

[0187] According to the liquid crystal display device of method 3, it is possible to suppress the misalignment that is easily seen in relation to bright image pixels.

[0188] Another type 4 liquid crystal display device includes: a liquid crystal panel having panel pixels; and a display control circuit that controls the liquid crystal panel, wherein image pixels constituting image data are arranged in a first direction and a second direction, the grayscale level of the image pixels is specified by pixel data, and the display control circuit performs a first correction on the image pixel based on the pixel data of two or more image pixels adjacent to the image pixel in the first direction, the direction opposite to the first direction, the second direction, or the direction opposite to the second direction, and determines the image of the image pixel of interest in the first corrected pixel data. Whether the voltage corresponding to the gray level of the pixel data and the voltage corresponding to the gray level of the pixel data of the image pixel adjacent to the image pixel of interest in either the first direction or the second direction are both intermediate gray levels above a first threshold voltage and below a second threshold voltage, if the voltages of both are within the range of the intermediate gray level, a second correction is performed to cancel the first correction performed on the pixel data of the image pixel of interest, and the pixel data after the first correction is supplied to the panel pixel, or, if the second correction is performed, a data signal based on the pixel data after the second correction is supplied to the panel pixel.

[0189] According to the liquid crystal display device of method 4, it is possible to suppress the degradation of display quality caused by misalignment, thereby suppressing the blurring of the display generated in the intermediate grayscale.

[0190] Additionally, the right side is an example of "direction 1", the left side is an example of "direction 1 opposite", the bottom side is an example of "direction 2", and the top side is an example of "direction 2 opposite".

[0191] Voltage V_th1 is an example of the "first threshold voltage", and voltage V_th2 is an example of the "second threshold voltage". Smoothing is an example of the "first correction", and restoration is an example of the "second correction".

[0192] In the control method of the liquid crystal display device of method 5, the liquid crystal display device includes: a liquid crystal panel having panel pixels; and a display control circuit that controls the liquid crystal panel, wherein the gray level of the image pixels constituting image data is specified by pixel data, the image pixels including: a first image pixel; and a first adjacent image pixel adjacent to the first image pixel. In the control method of the liquid crystal display device, a data signal based on a voltage of a gray level specified by the pixel data of the first image pixel is supplied to the panel pixel corresponding to the first image pixel, and a data signal based on a gray level specified by the pixel data of the first image pixel is supplied to the panel pixel corresponding to the first adjacent image pixel. If the gray level data signal corresponding to the pixel data of a pixel is within an intermediate gray level range that is above a first threshold gray level and below a second threshold gray level, the voltage of the data signal supplied to the panel pixel corresponding to the first image pixel is set to be different from the voltage of the data signal supplied to the panel pixel corresponding to the first image pixel when at least one of the gray level of the first image pixel and the gray level of the first adjacent image pixel is outside the intermediate gray level range.

[0193] According to the control method of the liquid crystal display device of method 5, it is possible to suppress the blurring of the display caused by intermediate grayscale.

[0194] The electronic device of method 6 has a liquid crystal display device of any one of methods 1 to 4.

Claims

1. A liquid crystal display device, wherein, The liquid crystal display device includes: a liquid crystal panel having panel pixels; and a display control circuit that controls the liquid crystal panel, a gray scale level of an image pixel constituting image data is specified by pixel data, the image pixel includes: a first image pixel; and a first adjacent image pixel adjacent to the first image pixel, the display control circuit supplies a data signal of a voltage based on a gray scale level specified by pixel data of the first image pixel to a panel pixel corresponding to the first image pixel, the display control circuit supplies a data signal of a voltage based on a gray scale level specified by pixel data of the first adjacent image pixel to a panel pixel corresponding to the first adjacent image pixel, the display control circuit sets the voltage of the data signal supplied to the panel pixel corresponding to the first image pixel to be different from the voltage of the data signal supplied to the panel pixel corresponding to the first image pixel in a case where at least one of the gray scale level specified by the pixel data of the first image pixel and the gray scale level specified by the pixel data of the first adjacent image pixel is outside a range of an intermediate gray scale where both the gray scale level specified by the pixel data of the first image pixel and the gray scale level specified by the pixel data of the first adjacent image pixel are above a first threshold gray scale and below a second threshold gray scale.

2. The liquid crystal display device according to claim 1, wherein the image pixel includes a second adjacent image pixel that is an image pixel other than the first adjacent image pixel and is adjacent to the first image pixel, the display control circuit smoothes the gray scale level specified by the pixel data of the first image pixel based on the gray scale level specified by the pixel data of the first adjacent image pixel and the gray scale level specified by the pixel data of the second adjacent image pixel, determines whether the gray scale level specified by the pixel data of the first image pixel and the gray scale level specified by the pixel data of the first adjacent image pixel are within the range of the intermediate gray scale or outside the range.

3. The liquid crystal display device according to claim 2, wherein the display control circuit lowers the smoothed gray scale level of the first image pixel in a case where the smoothed gray scale level of the first image pixel is higher than the smoothed gray scale level of the first adjacent image pixel and at least one of the smoothed gray scale level of the first image pixel and the smoothed gray scale level of the first adjacent image pixel is outside the range of the intermediate gray scale.

4. A liquid crystal display device including: a liquid crystal panel having panel pixels; and a display control circuit that controls the liquid crystal panel, image pixels constituting image data are arranged in a first direction and a second direction, a gray scale level of the image pixel is specified by pixel data, The display control circuit implements first correction on pixel data of one image pixel based on pixel data of two or more image pixels adjacent to the one image pixel in the first direction, a direction opposite to the first direction, the second direction, or a direction opposite to the second direction, The display control circuit determines whether or not both of a voltage corresponding to a gray scale of pixel data of a concerned image pixel in the first corrected pixel data and a voltage corresponding to a gray scale of pixel data of an image pixel adjacent to the concerned image pixel in either of the first direction and the second direction are intermediate grays of a first threshold voltage or more and a second threshold voltage or less, The display control circuit implements second correction that cancels the first correction on the pixel data of the concerned image pixel when both of the voltages are in the range of the intermediate grays, and supplies the first corrected pixel data to the panel pixel, or, when the second correction is implemented, supplies a data signal based on the second corrected pixel data to the panel pixel.

5. A control method of a liquid crystal display device including: a liquid crystal panel having panel pixels; and a display control circuit that controls the liquid crystal panel, a gray scale of an image pixel constituting image data is specified by pixel data, the image pixel includes: a first image pixel; and a first adjacent image pixel adjacent to the first image pixel, in the control method of the liquid crystal display device, a data signal based on a voltage corresponding to a gray scale specified by pixel data of the first image pixel is supplied to a panel pixel corresponding to the first image pixel, a data signal based on a voltage corresponding to a gray scale specified by pixel data of the first adjacent image pixel is supplied to a panel pixel corresponding to the first adjacent image pixel, when both of the gray scale specified by the pixel data of the first image pixel and the gray scale specified by the pixel data of the first adjacent image pixel are in a range of intermediate grays of a first threshold gray or more and a second threshold gray or less, a voltage of a data signal supplied to the panel pixel corresponding to the first image pixel is set to be different from a voltage of a data signal supplied to the panel pixel corresponding to the first image pixel when at least one of the gray scale of the first image pixel and the gray scale of the first adjacent image pixel is out of the range of the intermediate grays.

6. An electronic device, comprising: The electronic device has the liquid crystal display device according to any one of claims 1 to 4.

Images