Abstract:
A method of driving a display apparatus, includes (a) providing a plurality of processors outputting a plurality of output signals, respectively; (b) providing a plurality of frames, wherein each of the plurality of frames has an averaging pattern for averaging characteristic errors of the plurality of processors and has a plurality of lines; (c) performing a first scanning on a predetermined frame of the plurality of frames such that a predetermined line of the plurality of lines of the predetermined frame is not scanned; and (d) performing a second scanning on a specific frame of the plurality of frames such that a line corresponding to the predetermined line of the specific frame is scanned, the specific frame having a same averaging pattern as the averaging pattern of the predetermined frame.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an active matrix type liquid crystal display apparatus. More particularly, the present invention relates to a liquid crystal display apparatus in which a noise is not displayed as a regular pattern, if an interlaced scanning is performed for jumping over a horizontal display line every other line to write an image data, when an enlarged display is performed on an image display unit, and a display method. 
     2. Description of the Related Art 
     In an active matrix type liquid crystal display apparatus, characteristic errors of signal processors are averaged to improve the quality of display. 
     FIG. 1 is a configuration diagram showing an example of a liquid crystal display apparatus using this averaging operation. 
     An input image signal Sin is provided with analog R, G and B signals, and is inputted to a time base converter  101 . The input image signal Sin may be any of an interlace signal and a progressive signal. The time base converter  101  samples the successively supplied input image signal Sin through a sampling and holding circuit, and then divides the data into n sections in parallel to drop the frequency. 
     As the input image signal Sin becomes high accurate, an operation frequency of a sampling and holding circuit in an image display driver  104  becomes higher associated with the higher accuracy. Thus, it is difficult to attain a function of the image display driver  104 . As shown in FIG. 1, inner operations of the image display driver  104  can be performed in parallel by providing n input terminals for the image display driver  104 , in order to drop the operation frequency. The time base converter  101  performs a 2n-paralleling process on the input image signal Sin. So, the signals obtained by the 2n-paralleling process are processed in parallel to each other by 2n signal processors  1  to 2n to drop the operational frequency. 
     Here, a position at which the time base converter  101  starts sampling the input image signal Sin can be arbitrarily determined in accordance with an SP control signal Ssp 2  inputted to the time base converter  101  from a switching controller  106 . In short, a data processed by the sampling and holding circuit different for each frame is supplied to a particular pixel. This is an averaging principle. 
     In the switching controller  106 , its averaging period is set at a 2n vertical period and a 2n horizontal period. The vertical period corresponds to the 2n of the number of signal processors  1  to 2n. The horizontal period corresponds to the 2n of the number of signal processors  1  to 2n. The 2n vertical period and the 2n horizontal period will be described later. 
     The time base converter  101  performs a parallel time base conversion on the input image signal Sin to generate conversion image signals SC 1  to SC2n. The number of conversion image signals SC 1  to SC2n is equal to two times the division ratio n. The time base converter  101  is connected to 2n signal processors  1  to 2n which are connected parallel to each other. The time base converter  101  outputs the conversion image signals SC 1  to SC2n to the signal processors  1  to 2n, respectively. 
     The signal processors  1  to 2n perform a signal process, such as a γ conversion, a data inversion and the like, on the conversion image signals SC 1  to SC2n, respectively, to thereby generate processed image signals SP 1  to SP2n. 
     The signal processors  1  to 2n are connected to a switching selector  103 . The switching selector  103 , in response to a selector signal Ssel 2  outputted from the switching controller  106 , selects half n signals from the image signals (the processed image signals SP 1  to SP2n) corresponding to 2n dots stored in the signal processors  1  to 2n. This is because the switching selector  103  samples the processed image signals corresponding to the latter n dots while the switching selector  103  outputs the processed image signals corresponding to the former n dots as image signals S 1  to Sn. 
     The switching selector  103  outputs the image signals S 1  to Sn divided into the n sections, from n output sections SO 1  to SOn. The image signal S 1  is outputted from the first output section SO 1  of the switching selector  103 , the image signal S 2  is outputted from the second output section SO 2 , and the image signal Sn is outputted from the n-th output section SOn. 
     The processed image signal processed by which number of signal processor among the signal processors  1  to 2n to be outputted as the image signal S 1  from the first output section SO 1  can be selected as desired. At this time, the processed image signals outputted as the image signals S 2 , S 3  to Sn from the second, third to n-th output sections SO 2 , SO 3  to SOn following the first output section SO 1  are selected such that they are arranged in order with respect to the processed image signal outputted as the image signal S 1  from the first output section SO 1 . 
     For example, the number of signal processors  1  to 2n is defined as 8 (n=4). Here, it is assumed that the processed image signal SP 3  outputted from the third signal processor  3  is outputted as the image signal S 1  from the first output section SO 1  of the switching selector  103 . In this case, the processed image signals SP 3 , SP 4 , SP 5  and SP 6  outputted from the signal processors  3 ,  4 ,  5  and  6  in the former period are outputted as the image signals S 1  to S 4 , from the first to fourth output sections SO 1  to SO 4 . Also in the latter period, the processed image signals SP 7 , SP 8 , SP 1  and SP 2  outputted from the signal processors  7 ,  8 ,  1  and  2  are outputted as the image signals S 1  to S 4 , from the first to fourth output sections SO 1  to SO 4 . 
     The image signals S 1  to Sn outputted from the output sections SO 1  to SOn of the switching selector  103  are supplied to the image display driver  104 . The image display driver  104  is provided with a plurality of blocks arrayed along an image display unit  105  composed of a liquid crystal panel and the like. The image display driver  104  outputs the image signals to the image display unit  105 , each time it samples the image signals S 1  to Sn divided into the n sections by the switching selector  103  by using an n-division clock signal, or after it completes sampling the image signals in one horizontal period. 
     The image signals S 1  to Sn outputted from the switching selector  103  are inputted to one terminal of the plurality of blocks of the image display driver  104 , and sequentially shifted to another block. Then, the image display driver  104  samples a pixel data of each block at a predetermined frequency. 
     The operation of the liquid crystal display apparatus shown in FIG. 1 will be described below with reference to FIGS. 2A to  6 . 
     FIGS. 2A to  2 H show averaging patterns generated by the switching controller  106  if the number of signal processors  1  to 2n is 8 (n=4), namely, formats  1  to  8 . One table described in each of FIGS. 2A to  2 H shows an averaging pattern in one frame. A horizontal axis indicates an order in a horizontal direction, and a vertical axis indicates an order in a vertical direction. 
     Numerals in the respective tables denote the numbers corresponding to the processed image signals SP 1  to SP 8  outputted from the selected signal processors  1  to  8 . A slant line portion indicates that the processed image signal SP 1  outputted from the first signal processor  1  is selected. 
     FIGS. 3A to  3 H show display images when the averaging patterns of FIGS. 2A to  2 H are used, respectively. Numerals in respective tables indicate that the image data (processed image signals) SP 1  to SP 8  processed by the signal processors  1  to  8  corresponding to its number are displayed. A slant line portion indicates a position on the display screen of the image display unit  105  of the processed image signal SP 1  processed by the first signal processor  1 . A horizontal axis indicates a pixel which is a set of respective dots of R, G and B of the image display unit  105 , and a vertical axis indicates a horizontal line. 
     A first frame (a format  1 ) of FIG. 3A is exemplified and described. In the first pixel on the first horizontal line, the processed image signal SP 1  processed by the first signal processor  1  is indicated as a number [1]. Hereafter, in order from the second pixel to the eighth pixel, the processed image signals SP 2  to SP 8  processed by the second to eighth signal processors  2  to  8  are indicated as respective numbers [2, 3, 4, 5, 6, 7 and 8]. 
     Similarly, in the first pixel on the second horizontal line, the processed image signal SP 3  processed by the third signal processor  3  is indicated as a number [3]. After the first pixel on the second horizontal line, the processed image signals SP 4 , SP 5 , SP 6 , SP 7 , SP 8 , SP 1  and SP 2  are sequentially indicated as numbers [4, 5, 6, 7, 8, 1 and 2]. This case implies that the processed image signal SP 1  processed by the first signal processor  1  is indicated in the seventh pixel on the second horizontal line. The procedure after that is same. Thus, its description is omitted. 
     Here, in the successive eight horizontal lines, it is selected such that the same image data (for example, the processed image signal SP 1 ) is not displayed in a particular pixel (for example, the first pixel). This selecting method is performed on one frame (the successive eight horizontal lines). Thus, in order to uniformly locate the image signals (the processed image signals SP 1  to SP 8 ) processed by the 8 signal processors  1  to  8  in all eight pixels on all the eight horizontal lines, 8 frames are needed as shown in FIGS. 3A to  3 H. 
     FIGS. 4A to  4 H show a display images when a 1.6-times enlarged displaying is performed on each of the averaging patterns of FIGS. 2A to  2 H. The 1.6-times enlarged displaying is attained by using the following method. From image data of five lines, each of image data of three lines is displayed as two lines. In each of FIGS. 4A to  4 H, from five lines A to E in each of FIGS. 3A to  3 H, each of the lines A, B and D is displayed with two lines to thereby carry out the enlarged displaying. 
     If such enlarged displaying is done, data of one line is enlarged as the two lines. Thus, in the enlarged portion, the averaging pattern is similarly enlarged. Also, in this case, the data is written to the image display unit  105 , two times in one horizontal period. Thus, a write time is equal to half the normal time. So, in order to reserve the write time corresponding to the one horizontal period similarly to the normal case, an interlaced scanning is performed on the enlarged result of each of FIGS. 4A to  4 H, as shown in each of FIGS. 5A to  5 H. A half-tone dot meshing portion indicates a line jumped over in each frame. Even-numbered lines are jumped over in each of the odd-numbered frames, and odd-numbered lines are jumped over in each of even-numbered frames. 
     As mentioned above, when the 1.6-times enlarged displaying is done in the image display unit  105 , the interlaced scanning is carried out for making the write time equal to the normal case that the 1.6-times enlarged displaying is not done. 
     Next, FIG. 6 is explained. The processed image signal SP 1  ([1]) processed by the first signal processor S 1  is extracted from the remaining portion that is not jumped over in each of 8 formats in FIGS. 5A to  5 H. FIG. 6 shows the state that in this case, the portions [1] included in the 8 formats are overwritten. As shown in FIG. 6, blank portions BK are generated. As a result, the noise in the form of lattice is displayed. 
     As mentioned above, when the number of signal processors is 2n, the averaging period is as follows. That is, if a certain pixel in the image display unit  105  is noted, the averaging is attained in a vertically temporal time axis at the 2n vertical periods. Similarly, the averaging is attained in the horizontally time base axis at the 2n horizontal periods. That is, the perfectly averaging operation are possible in the vertical period and the horizontal period corresponding to the number of signal processors. 
     However, when the enlarged displaying is done, if the interlaced scanning is carried out, the jumped over one horizontal (line) data is not drawn on the image display unit  105 . This causes the averaging operation to be imperfect. The image signal finally outputted from the certain particular signal processor is displayed on the image display unit  105 , as shown in FIG.  6 . Its certain determined pattern is displayed on the image display unit  105  as the noise in the form of lattice. 
     In addition, in order to improve the quality of the display after the averaging operation, Japanese Laid Open Patent Application (JP-A-Heisei, 4-355788) discloses a technique that a switching circuit can switch between one of terminals of a driving circuit and one of signal processors at a vertical period or a horizontal period freely. However, although the switching circuit can be arbitrarily switched between them at the vertical or horizontal period, its period is always predetermined to be fixed. Therefore, when the interlaced scanning is done based on the fixed period, averaging patterns obtained by the fixed period are inadequate. Thus, it is difficult to surely guard against the noise in the form of lattice, as mentioned above. 
     SUMMARY OF THE INVENTION 
     The present invention has been made to solve the above-described problems of the conventional method of driving a display apparatus. An object of the present invention is to provide a method of driving a display apparatus which can obtain a high quality display without any noise in a form of lattice, in which an averaging operation can be perfectly done even if a interlaced scanning is done. In this case, the display apparatus can be an active matrix type liquid crystal display apparatus. 
     In order to achieve an aspect of the present invention, a method of driving a display apparatus, includes: (a) providing a plurality of processors outputting a plurality of output signals, respectively; (b) providing a plurality of frames, wherein each of the plurality of frames has an averaging pattern for averaging characteristic errors of the plurality of processors and has a plurality of lines; (c) performing a first scanning on a predetermined frame of the plurality of frames such that a predetermined line of the plurality of lines of the predetermined frame is not scanned; and (d) performing a second scanning on a specific frame of the plurality of frames such that a line corresponding to the predetermined line of the specific frame is scanned, the specific frame having a same averaging pattern as the averaging pattern of the predetermined frame. 
     In order to achieve another aspect of the present invention, a method of driving a display apparatus, further includes: (e) performing a third scanning on the predetermined frame such that all lines of the predetermined frame are scanned; and (f) performing a forth scanning on the specific frame such that all lines of the specific frame are scanned, and wherein one of first and second groups is performed selectively, the first group including the (c) and (d) steps and the second group including the (e) and (f) steps 
     In this case, the first group is performed when each of the plurality of frames is displayed to be enlarged such that a single line of the plurality of lines is displayed as the lines of two, and the second group is performed when each of the plurality of frames is displayed not to be enlarged. 
     In order to achieve still another aspect of the present invention, a method of driving a display apparatus, includes: (aa) providing a plurality of processors of M (M is a positive integer) outputting a plurality of output signals of the M, respectively; (ab) providing a plurality of frames, wherein each of the plurality of frames is formed to be a matrix with a plurality of lines of the M rows and a plurality of pixels of the M columns, and wherein the plurality of output signals of the M are inputted to the plurality of pixels of the M columns on a specific line of the plurality of lines of the M rows, respectively, and are inputted to the plurality of pixels of the M of a specific column of the M columns on the plurality of lines of the M rows, respectively, to generate an averaging pattern in the each frame; and (ac) performing a scanning on a predetermined frame of the plurality of frames such that a predetermined line of the plurality of lines of the predetermined frame is not scanned, and (ad) performing a scanning on a specific frame of the plurality of frames such that a line corresponding to the predetermined line of the specific frame is scanned, the specific frame having a same averaging pattern as the averaging pattern of the predetermined frame. 
     In this case, the plurality of output signals of the M are obtained by a result that an image signal is time-base converted to generate a plurality of converted signals of the M and the plurality of converted signals of the M are inputted to the plurality of processors of the M, respectively. 
     Also in this case, each of the plurality of frames is displayed to be enlarged such that a single line of the plurality of lines of the M rows is displayed as the lines of two. 
     Further in this case, the (ab) step includes providing the plurality of frames of double the M which have a plurality of the averaging patterns of the M type. 
     In this case, when the (c) step is performed, an even-numbered line as the predetermined line of the predetermined frame is not scanned and an odd-numbered line of the predetermined frame is scanned, and when the (d) step is performed, an odd-numbered line of the specific frame is not scanned and an even-numbered line as the line of the specific frame is scanned. 
     Also in this case, when the pixel of P-th (P is a positive integer) of the plurality of the pixels of the M columns on a predetermined line of the plurality of lines of the M rows inputs the output signal outputted from the processor of Q-th (Q is a positive integer) of the plurality of processors of the M, the pixel of (the P+1)-th of the plurality of the pixels of the M columns on the predetermined line inputs the output signal outputted from the processor of (the Q+1)-th of the plurality of processors of the M. 
     Further in this case, a single cycle of averaging characteristic errors of the plurality of processors of the M consists of the plurality of frames of double the M which have a plurality of the averaging patterns of the M. 
     In order to achieve yet still another aspect of the present invention, a display apparatus, includes: a display unit displaying an image based on a plurality of frames; a time base converter dividing an image signal on a time base in response to a first control signal to generate a plurality of converted signals of M (M is a positive integer); a plurality of processors of the M outputting a plurality of output signals of the M based on the plurality of converted signals of the M, respectively; a frame generating unit generating the plurality of frames based on the plurality of output signals in response to a second control signal such that each of the plurality of frames has an averaging pattern for averaging characteristic errors of the plurality of processors of the M; and a control circuit generating the first and second control signals such that the time base converter generates the plurality of converted signals of double the M in a single period of the averaging in response to the first control signal, and the frame generating unit generates the plurality of frames of double the M in the single period in response to the second control signal. 
     In this case, the display unit is a liquid crystal display of active matrix type. 
     Also in this case, the control circuit generates the first control signal such that the time base converter generates the plurality of converted signals of double the M in a vertical period corresponding to (the M×2) and a horizontal period corresponding to the M in response to the first control signal. 
     Further in this case, the control circuit generates the second control signal such that the frame generating unit generates the plurality of frames of double the M in a vertical period corresponding to (the M×2) and a horizontal period corresponding to the M in response to the second control signal. 
     In this case, a division ratio when the time base converter divides the image signal corresponds to (the M divided by 2). 
     In order to achieve another aspect of the present invention, a display apparatus, includes: a plurality of processors outputting a plurality of output signals, respectively; a plurality of frames, wherein each of the plurality of frames has an averaging pattern for averaging characteristic errors of the plurality of processors and has a plurality of lines; a scanning unit performing a first scanning on a predetermined frame of the plurality of frames such that a predetermined line of the plurality of lines of the predetermined frame is not scanned, and performing a second scanning on a specific frame of the plurality of frames such that a line corresponding to the predetermined line of the specific frame is scanned, the specific frame having a same averaging pattern as the averaging pattern of the predetermined frame. 
     In this case, the scanning unit performs a third scanning on the predetermined frame such that all lines of the predetermined frame are scanned, and performs a forth scanning on the specific frame such that all lines of the specific frame are scanned, and performs one of first and second groups selectively, the first group including the first and second scannings and the second group including the third and fourth scannings. 
     Also in this case, the scanning unit performs the first group when each of the plurality of frames is displayed to be enlarged such that a single line of the plurality of lines is displayed as the lines of two, and performs the second group when each of the plurality of frames is displayed not to be enlarged. 
     Further in this case, when the scanning unit performs the first scanning, the scanning unit scans an odd-numbered line of the predetermined frame without scanning an even-numbered line as the predetermined line of the predetermined frame and when the scanning unit performs the second scanning, the scanning unit scans an even-numbered line as the line of the specific frame without scanning an odd-numbered line of the specific frame. 
     In order to achieve still another aspect of the present invention, a display apparatus, includes: a plurality of processors of M (M is a positive integer) outputting a plurality of output signals of the M, respectively; a frame generating unit generating a plurality of frames, wherein each of the plurality of frames is formed to be a matrix with a plurality of lines of the M rows and a plurality of pixels of the M columns, and wherein the plurality of output signals of the M are inputted to the plurality of pixels of the M columns on a specific line of the plurality of lines of the M rows, respectively, and are inputted to the plurality of pixels of the M of a specific column of the M columns on the plurality of lines of the M rows, respectively, to generate an averaging pattern in the each frame; and a scanning unit performing a scanning on a predetermined frame of the plurality of frames such that a predetermined line of the plurality of lines of the predetermined frame is not scanned, and performing a scanning on a specific frame of the plurality of frames such that a line corresponding to the predetermined line of the specific frame is scanned, the specific frame having a same averaging pattern as the averaging pattern of the predetermined frame. 
     In this case, a display apparatus further includes: a time base converter time-converting an image signal to generate a plurality of converted signals of the M, and wherein the plurality of processors of the M input the plurality of converted signals of the M to output the plurality of output signals of the M, respectively. 
     Also in this case, each of the plurality of frames is displayed to be enlarged such that a single line of the plurality of lines of the M rows is displayed as the lines of two. 
     Further in this case, the frame generating unit generates the plurality of frames of double the M which have a plurality of the averaging patterns of the M type. 
     In this case, when the pixel of P-th (P is a positive integer) of the plurality of the pixels of the M columns on a predetermined line of the plurality of lines of the M rows inputs the output signal outputted from the processor of Q-th (Q is a positive integer) of the plurality of processors of the M, the pixel of (the P+1)-th of the plurality of the pixels of the M columns on the predetermined line inputs the output signal outputted from the processor of (the Q+1)-th of the plurality of processors of the M. 
     Also in this case, a single cycle of averaging characteristic errors of the plurality of processors of the M consists of the plurality of frames of double the M which have a plurality of the averaging patterns of the M. 
     In order to achieve yet still another aspect of the present invention, a computer readable recording medium for recording a program for a process, includes: (g) providing a plurality of processors outputting a plurality of output signals, respectively; (h) providing a plurality of frames, wherein each of the plurality of frames has an averaging pattern for averaging characteristic errors of the plurality of processors and has a plurality of lines; (i) performing a first scanning on a predetermined frame of the plurality of frames such that a predetermined line of the plurality of lines of the predetermined frame is not scanned; and (j) performing a second scanning on a specific frame of the plurality of frames such that a line corresponding to the predetermined line of the specific frame is scanned, the specific frame having a same averaging pattern as the averaging pattern of the predetermined frame. 
     In a liquid crystal display apparatus of the present invention, an input image signal is divided on a time base and then an active matrix type displaying is performed on an image display unit while rearranging the divided image signals in accordance with an averaging format. In the liquid crystal display apparatus, the same averaging format is used in a frame interlaced (jumped over) of an even-numbered line and another frame interlaced (jumped over) of an odd-numbered line, when an interlaced scanning is performed on the image display unit. 
     That is, as one embodiment to attain the present invention, a liquid crystal display includes: a time base converter for dividing an input image signal on a time base; a plurality of signal processors for respectively performing a signal process on the divided image signal; a switching selector for selecting outputs of the respective signal processors; an image display unit for sequentially receiving the outputs selected by the switching selector and carrying out a display of an active matrix type; and a first switching controller for outputting a control signal to control a selection order of the outputs of the respective signal processors in the switching selector in accordance with a set averaging format, wherein the first switching controller is designed so as to use the same averaging format in a frame jumping over an even-numbered line and a frame jumping over an odd-numbered line, at a time of a interlaced scanning in the image display unit. 
     Also, the present invention may be designed so as to include: a second switching controller for using he averaging formats which are respectively different between the frame jumping over the even-numbered line and the frame jumping over the odd-numbered line, as the averaging format; and a selecting circuit for selecting the respective control signals from the first switching controller and the second switching controller, wherein it may be designed so as to select the control signal from the second switching controller if the interlaced scanning is not done in the image display unit. 
     Moreover, in the present invention, a displaying method is provided that in a liquid crystal display, which divides an input image signal on a time base and then carries out a display of an active matrix type on an image display unit while rearranging the divided image signals in accordance with an averaging format, uses the same averaging format in a frame jumping over an even-numbered line and a frame jumping over an odd-numbered line, at a time of a interlaced scanning in the image display unit. 
     According to the present invention, in an active matrix type liquid crystal display, when a interlaced scanning is done to display an image signal by jumping over a horizontal display line every other line, such as an enlarged display and the like, the same averaging format is used in a frame jumping over an even-numbered line and a frame jumping over an odd-numbered line. 
     Thus, an averaging pattern when a data on a horizontal line is jumped over is used when a different horizontal line is jumped over in another frame, which enables the perfectly averaging operation. Hence, even if the interlaced scanning is done, the noise in the form of lattice can be surely protected. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A more complete understanding of the teachings of the present invention may be acquired by referring to the accompanying figures, in which like reference numbers indicate like features and wherein: 
     FIG. 1 is a block diagram showing an example of conventional liquid crystal display apparatus; 
     FIG. 2A is a view showing an averaging pattern obtained by a conventional switching controller; 
     FIG. 2B is a view showing another averaging pattern obtained by the conventional switching controller; 
     FIG. 2C is a view showing still another averaging pattern obtained by the conventional switching controller; 
     FIG. 2D is a view showing still another averaging pattern obtained by the conventional switching controller; 
     FIG. 2E is a view showing still another averaging pattern obtained by the conventional switching controller; 
     FIG. 2F is a view showing still another averaging pattern obtained by the conventional switching controller; 
     FIG. 2G is a view showing still another averaging pattern obtained by the conventional switching controller; 
     FIG. 2H is a view showing still another averaging pattern obtained by the conventional switching controller; 
     FIG. 3A is a view showing a display image using the averaging pattern of FIG. 2A; 
     FIG. 3B is a view showing a display image using the averaging pattern of FIG. 2B; 
     FIG. 3C is a view showing a display image using the averaging pattern of FIG. 2C; 
     FIG. 3D is a view showing a display image using the averaging pattern of FIG. 2D; 
     FIG. 3E is a view showing a display image using the averaging pattern of FIG. 2E; 
     FIG. 3F is a view showing a display image using the averaging pattern of FIG. 2F; 
     FIG. 3G is a view showing a display image using the averaging pattern of FIG. 2G; 
     FIG. 3H is a view showing a display image using the averaging pattern of FIG. 2H; 
     FIG. 4A is a view showing a display image when a 1.6-times enlarged displaying is performed on FIG. 3A; 
     FIG. 4B is a view showing a display image when a 1.6-times enlarged displaying is performed on FIG. 3B; 
     FIG. 4C is a view showing a display image when a 1.6-times enlarged displaying is performed on FIG. 3C; 
     FIG. 4D is a view showing a display image when a 1.6-times enlarged displaying is performed on FIG. 3D; 
     FIG. 4E is a view showing a display image when a 1.6-times enlarged displaying is performed on FIG. 3E; 
     FIG. 4F is a view showing a display image when a 1.6-times enlarged displaying is performed on FIG. 3F; 
     FIG. 4G is a view showing a display image when a 1.6-times enlarged displaying is performed on FIG. 3G; 
     FIG. 4H is a view showing a display image when a 1.6-times enlarged displaying is performed on FIG. 3H; 
     FIG. 5A is a view showing display image when a interlaced scanning is performed on FIG. 4A; 
     FIG. 5B is a view showing display image when a interlaced scanning is performed on FIG. 4B; 
     FIG. 5C is a view showing display image when a interlaced scanning is performed on FIG. 4C; 
     FIG. 5D is a view showing display image when a interlaced scanning is performed on FIG. 4D; 
     FIG. 5E is a view showing display image when a interlaced scanning is performed on FIG. 4E; 
     FIG. 5F is a view showing display image when a interlaced scanning is performed on FIG. 4F; 
     FIG. 5G is a view showing display image when a interlaced scanning is performed on FIG. 4G; 
     FIG. 5H is a view showing display image when a interlaced scanning is performed on FIG. 4H; 
     FIG. 6 is a view showing a state that a particular image signal is displayed on an image display unit, in the conventional technique; 
     FIG. 7 is a block diagram showing a first embodiment of the present invention; 
     FIG. 8A is a view showing an averaging pattern obtained by the switching controller of the present invention; 
     FIG. 8B is a view showing another averaging pattern obtained by the switching controller of the present invention; 
     FIG. 8C is a view showing still another averaging pattern obtained by the switching controller of the present invention; 
     FIG. 8D is a view showing still another averaging pattern obtained by the switching controller of the present invention; 
     FIG. 8E is a view showing still another averaging pattern obtained by the switching controller of the present invention; 
     FIG. 8F is a view showing still another averaging pattern obtained by the switching controller of the present invention; 
     FIG. 8G is a view showing still another averaging pattern obtained by the switching controller of the present invention; 
     FIG. 8H is a view showing still another averaging pattern obtained by the switching controller of the present invention; 
     FIG. 8I is a view showing still another averaging pattern obtained by the switching controller of the present invention; 
     FIG. 8J is a view showing still another averaging pattern obtained by the switching controller of the present invention; 
     FIG. 8K is a view showing still another averaging pattern obtained by the switching controller of the present invention; 
     FIG. 8L is a view showing still another averaging pattern obtained by the switching controller of the present invention; 
     FIG. 8M is a view showing still another averaging pattern obtained by the switching controller of the present invention; 
     FIG. 8N is a view showing still another averaging pattern obtained by the switching controller of the present invention; 
     FIG. 8O is a view showing still another averaging pattern obtained by the switching controller of the present invention; 
     FIG. 8P is a view showing still another averaging pattern obtained by the switching controller of the present invention; 
     FIG. 9A is a view showing a display image using the averaging pattern of FIG. 8A; 
     FIG. 9B is a view showing a display image using the averaging pattern of FIG. 8B; 
     FIG. 9C is a view showing a display image using the averaging pattern of FIG. 8C; 
     FIG. 9D is a view showing a display image using the averaging pattern of FIG. 8D; 
     FIG. 9E is a view showing a display image using the averaging pattern of FIG. 8E; 
     FIG. 9F is a view showing a display image using the averaging pattern of FIG. 8F; 
     FIG. 9G is a view showing a display image using the averaging pattern of FIG. 8G; 
     FIG. 9H is a view showing a display image using the averaging pattern of FIG. 8H; 
     FIG. 9I is a view showing a display image using the averaging pattern of FIG. 8I; 
     FIG. 9J is a view showing a display image using the averaging pattern of FIG. 8J; 
     FIG. 9K is a view showing a display image using the averaging pattern of FIG. 8K; 
     FIG. 9L is a view showing a display image using the averaging pattern of FIG. 8L; 
     FIG. 9M is a view showing a display image using the averaging pattern of FIG. 8M; 
     FIG. 9N is a view showing a display image using the averaging pattern of FIG. 8N; 
     FIG. 9O is a view showing a display image using the averaging pattern of FIG. 8O; 
     FIG. 9P is a view showing a display image using the averaging pattern of FIG. 8P; 
     FIG. 10A is a view showing display image when the 1.6-times enlarged displaying is performed on FIG. 9A; 
     FIG. 10B is a view showing display image when the 1.6-times enlarged displaying is performed on FIG. 9B; 
     FIG. 10C is a view showing display image when the 1.6-times enlarged displaying is performed on FIG. 9C; 
     FIG. 10D is a view showing display image when the 1.6-times enlarged displaying is performed on FIG. 9D; 
     FIG. 10E is a view showing display image when the 1.6-times enlarged displaying is performed on FIG. 9E; 
     FIG. 10F is a view showing display image when the 1.6-times enlarged displaying is performed on FIG. 9F; 
     FIG. 10G is a view showing display image when the 1.6-times enlarged displaying is performed on FIG. 9G; 
     FIG. 10H is a view showing display image when the 1.6-times enlarged displaying is performed on FIG. 9H; 
     FIG. 10I is a view showing display image when the 1.6-times enlarged displaying is performed on FIG. 9I; 
     FIG. 10J is a view showing display image when the 1.6-times enlarged displaying is performed on FIG. 9J; 
     FIG. 10K is a view showing display image when the 1.6-times enlarged displaying is performed on FIG. 9K; 
     FIG. 10L is a view showing display image when the 1.6-times enlarged displaying is performed on FIG. 9L; 
     FIG. 10M is a view showing display image when the 1.6-times enlarged displaying is performed on FIG. 9M; 
     FIG. 10N is a view showing display image when the 1.6-times enlarged displaying is performed on FIG. 9N; 
     FIG. 10O is a view showing display image when the 1.6-times enlarged displaying is performed on FIG. 9O; 
     FIG. 10P is a view showing display image when the 1.6-times enlarged displaying is performed on FIG. 9P; 
     FIG. 11A is a view showing display image when the interlaced scanning is performed on FIG. 10A; 
     FIG. 11B is a view showing display image when the interlaced scanning is performed on FIG. 10B; 
     FIG. 11C is a view showing display image when the interlaced scanning is performed on FIG. 10C; 
     FIG. 11D is a view showing display image when the interlaced scanning is performed on FIG. 10D; 
     FIG. 11E is a view showing display image when the interlaced scanning is performed on FIG. 10E; 
     FIG. 11F is a view showing display image when the interlaced scanning is performed on FIG. 10F; 
     FIG. 11G is a view showing display image when the interlaced scanning is performed on FIG. 10G; 
     FIG. 11H is a view showing display image when the interlaced scanning is performed on FIG. 10H; 
     FIG. 11I is a view showing display image when the interlaced scanning is performed on FIG. 10I; 
     FIG. 11J is a view showing display image when the interlaced scanning is performed on FIG. 10J; 
     FIG. 11K is a view showing display image when the interlaced scanning is performed on FIG. 10K; 
     FIG. 11L is a view showing display image when the interlaced scanning is performed on FIG. 10L; 
     FIG. 11M is a view showing display image when the interlaced scanning is performed on FIG. 10M; 
     FIG. 11N is a view showing display image when the interlaced scanning is performed on FIG. 10N; 
     FIG. 11O is a view showing display image when the interlaced scanning is performed on FIG. 10O; 
     FIG. 11P is a view showing display image when the interlaced scanning is performed on FIG. 10P; 
     FIG. 12 is a view showing a state that a particular image signal is displayed on an image display unit in the present invention; and 
     FIG. 13 is a block diagram showing a second embodiment of the present invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Embodiments of the present invention will be described below with reference to the attached drawings. 
     FIG. 7 is a block diagram showing a first embodiment of an active matrix type liquid crystal display apparatus of the present invention. Here, it is shown as a liquid crystal display apparatus used as an image display unit of a personal computer and the like. In addition, the same symbols are given to those equivalent to the conventional configuration shown in FIG.  1 . 
     An input image signal Sin is provided with analog R, G and B signals, and is inputted to a time base converter  101 . The input image signal Sin may be any of an interlace signal and a progressive signal. The time base converter  101  samples the successively supplied input image signal Sin through a sampling and holding circuit, and then divides the data into n sections in parallel to drop the frequency. 
     As the input image signal Sin becomes high accurate, an operation frequency of a sampling and holding circuit in an image display driver  104  becomes higher associated with the higher accuracy. Thus, it is difficult to attain a function of the image display driver  104 . As shown in FIG. 7, inner operations of the image display driver  104  can be performed in parallel by providing n input terminals for the image display driver  104 , in order to drop the operation frequency. The time base converter  101  performs a 2n paralleling process on the input image signal Sin. So, the signals obtained by the 2n-paralleling process are processed in parallel to each other by 2n signal processors  1  to 2n to drop the operational frequency. 
     Here, a position at which the time base converter  101  starts sampling the input image signal Sin can be arbitrarily determined in accordance with an SP control signal Ssp 2  inputted to the time base converter  101  from a switching controller  102 . In short, a data processed by the sampling and holding circuit different for each frame is supplied to a particular pixel. This is an averaging principle. 
     Here, in the switching controller  102 , its averaging period is not different from the 2n vertical period and the 2n horizontal period of the conventional switching controller  106 . Then, its vertical period is set at a 2n×2 vertical period equal to two times the conventional vertical period, and its horizontal period is set at the 2n horizontal period. The vertical period corresponds to two times the 2n of the number of signal processors  1  to 2n. The horizontal period corresponds to the 2n of the number of signal processors  1  to 2n. 
     The time base converter  101  performs a parallel time base conversion on the input image signal Sin to generate conversion image signals SC 1  to SC2n. The number of conversion image signals SC 1  to SC2n is equal to two times the division ratio n. The time base converter  101  is connected to 2n signal processors  1  to 2n which are connected parallel to each other. The time base converter  101  outputs the conversion image signals SC 1  to SC2n to the signal processors  1  to 2n, respectively. 
     The signal processors  1  to 2n perform a signal process, such as a γ conversion, a data inversion and the like, on the conversion image signals SC 1  to SC2n, respectively, to thereby generate processed image signals SP 1  to SP2n. The signal processors  1  to 2n are connected to a switching selector  103 . 
     The switching selector  103 , in response to a selector signal Ssell outputted from the switching controller  102 , selects half n signals from the image signals (the processed image signals SP 1  to SP2n ) corresponding to 2n dots stored in the signal processors  1  to 2n. This is because the switching selector  103  samples the processed image signals corresponding to the latter n dots while the switching selector  103  outputs the processed image signals corresponding to the former n dots as image signals S 1  to Sn. 
     The switching selector  103  outputs the image signals S 1  to Sn divided into the n sections, from n output sections SO 1  to SOn. The image signal S 1  is outputted from the first output section SO 1  of the switching selector  103 , the image signal S 2  is outputted from the second output section SO 2 , and the image signal Sn is outputted from the n-th output section SOn. 
     The processed image signal processed by which number of signal processor among the signal processors  1  to 2n to be outputted as the image signal S 1  from the first output section SO 1  can be selected as desired. At this time, the processed image signals outputted as the image signals S 2 , S 3  to Sn from the second, third to n-th output sections SO 2 , SO 3  to SOn following the first output section SO 1  are selected such that they are arranged in order with respect to the processed image signal outputted as the image signal S 1  from the first output section SO 1 . 
     For example, the number of signal processors  1  to 2n is defined as 8 (n=4). Here, it is assumed that the processed image signal SP 3  outputted from the third signal processor  3  is outputted as the image signal S 1  from the first output section SO 1  of the switching selector  103 . In this case, the processed image signals SP 3 , SP 4 , SP 5  and SP 6  outputted from the signal processors  3 ,  4 ,  5  and  6  in the former period are outputted as the image signals S 1  to S 4 , from the first to fourth output sections SO 1  to SO 4 . Also in the latter period, the processed image signals SP 7 , SP 8 , SP 1  and SP 2  outputted from the signal processors  7 ,  8 ,  1  and  2  are outputted as the image signals S 1  to S 4 , from the first to fourth output sections SO 1  to SO 4 . 
     The image signals S 1  to Sn outputted from the output sections SO 1  to SOn of the switching selector  103  are supplied to the image display driver  104 . The image display driver  104  is provided with a plurality of blocks arrayed along an image display unit  105  composed of a liquid crystal panel and the like. The image display driver  104  outputs the image signals to the image display unit  105 , each time it samples the image signals S 1  to Sn divided into the n sections by the switching selector  103  by using an n-division clock signal, or after it completes sampling the image signals in one horizontal period. 
     The image signals S 1  to Sn outputted from the switching selector  103  are inputted to one terminal of the plurality of blocks of the image display driver  104 , and sequentially shifted to another block. Then, the image display driver  104  samples a pixel data of each block at a predetermined frequency. 
     The operation of the liquid crystal display apparatus shown in FIG. 7 will be described below with reference to FIGS. 8A to  12 . 
     FIGS. 8A to  8 P show averaging patterns generated by the switching controller  102  if the number of signal processors  1  to 2n is 8 (n=4), namely, formats  1  to  8 . One table described in each of FIGS. 8A to  8 P shows an averaging pattern in one frame. The each of formats  1  to  8  in FIGS. 8A to  8 P corresponds to the formats  1  to  8  in FIGS. 2A to  2 H, respectively. A horizontal axis indicates an order in a horizontal direction, and a vertical axis indicates an order in a vertical direction. Numerals in the respective tables denote the numbers corresponding to the processed image signals SP 1  to SP 8  outputted from the selected signal processors  1  to  8 . A slant line portion indicates that the processed image signal SP 1  outputted from the first signal processor  1  is selected. 
     Each of FIGS. 9A to  9 P shows a display image when the averaging pattern of each of FIGS. 8A to  8 P is used. Numerals in respective tables indicate that the image data (processed image signals) SP 1  to SP 8  processed by the signal processors  1  to  8  corresponding to its number are displayed. A slant line portion indicates a position on the display screen of the image display unit  105  of the processed image signal SP 1  processed by the first signal processor  1 . A horizontal axis indicates a pixel which is a set of respective dots of R, G and B of the image display unit  105 , and a vertical axis indicates a horizontal line. 
     A first frame (a format  1 ) of FIG. 9A is exemplified and described. In the first pixel on the first horizontal line, the processed image signal SP 1  processed by the first signal processor  1  is indicated as a number [1]. Hereafter, in order from the second pixel to the eighth pixel, the processed image signals SP 2  to SP 8  processed by the second to eighth signal processors  2  to  8  are indicated as respective numbers [2, 3, 4, 5, 6, 7 and 8]. 
     Similarly, in the first pixel on the second horizontal line, the processed image signal SP 3  processed by the third signal processor  3  is indicated as a number [3]. After the first pixel on the second horizontal line, the processed image signals SP 4 , SP 5 , SP 6 , SP 7 , SP 8 , SP 1  and SP 2  are sequentially indicated as numbers [4, 5, 6, 7, 8, 1 and 2]. This case implies that the processed image signal SP 1  processed by the first signal processor  1  is indicated in the seventh pixel on the second horizontal line. The procedure after that is same. Thus, its description is omitted. 
     Here, in the successive eight horizontal lines, it is selected such that the same image data (for example, the processed image signal SP 1 ) is not displayed in a particular pixel (for example, the first pixel). This selecting method is performed on one frame (the successive eight horizontal lines). Thus, in order to uniformly locate the image signals (the processed image signals SP 1  to SP 8 ) processed by the 8 signal processors  1  to  8  in all eight pixels on all the eight horizontal lines, 8 frames are needed. 
     In this embodiment, the switching controller  102  is set at the 2n×2 vertical period and the 2n horizontal period. Thus, as shown in FIGS. 8A to  9 P, it is designed such that the same averaging pattern is used in an odd-numbered frame and an even-numbered frame which are adjacent to each other. As shown in FIGS. 8 and 9, one round or cycle of the averaging operation is completed in 16 frames. 
     Each of FIGS. 10A to  10 P shows a display image when a 1.6-times enlarged displaying is performed in the averaging pattern of each of FIGS. 9A to  9 P. The 1.6-times enlarged displaying is attained by using the following method. From image data of five lines, each of image data of three lines is displayed as two lines. In each of FIGS. 10A to  10 P, from five lines A to E in each of FIGS. 8A to  8 P, each of the lines A, B and D is displayed with two lines to thereby carry out the enlarged displaying. 
     If such enlarged displaying is done, data of one line is enlarged as the two lines. Thus, in the enlarged portion, the averaging pattern is similarly enlarged. Also, in this case, the data is written to the image display unit  105 , two times in one horizontal period. Thus, a write time is equal to half the normal time. So, in order to reserve the write time corresponding to the one horizontal period similarly to the normal case, an interlaced scanning is performed on the enlarged result of each of FIGS. 10A to  10 P, as shown in each of FIGS. 11A to  11 P. A half-tone dot meshing portion indicates a line jumped over in each frame. Even-numbered lines are jumped over in each of the odd-numbered frames, and odd-numbered lines are jumped over in each of even-numbered frames. 
     As mentioned above, when the 1.6-times enlarged displaying is done in the image display unit  105 , the interlaced scanning is carried out for making the write time equal to the normal case that the 1.6-times enlarged displaying is not done. 
     Next, FIG. 12 is explained. The processed image signal SP 1  ([1]) processed by the first signal processor S 1  is extracted from the remaining portion that is not jumped over in each of 8 formats in FIGS.  11 A to  11 P. The FIG. 12 shows the state that in this case, the portions [1] included in the 8 formats are overwritten. As shown in FIG. 12, it is understood that the processed image signal Sp 1  processed by the first signal processor  1  is embedded in all pixels in the image display unit  105 . This is similar even in a case of taking notice of the other signal processors  2  to  8 . 
     In this way, when the interlaced scanning is performed, a certain line jumped over in a frame having an averaging pattern is not jumped over in another frame having the same averaging pattern. Accordingly, it is possible to perfectly average the characteristic errors of the signal processors in all pixels on one screen. Also, it is possible to obtain the display quality in which a mark pattern having a particular regularity is not displayed. 
     It will be described below with reference to the first frame in FIG.  11 A and the second frame in FIG.  11 B. In the first frame in FIG.  11 A and the second frame in FIG. 11B, the same averaging pattern described as format  1  is used. The image signal SP 1  processed by the first signal processor  1  and inputted to the portions of the first pixel on the second line, the seventh pixel on the fourth line, the sixth pixel on the sixth line, the second pixel on the eighth line, the eighth pixel on the tenth line, and the third pixel on the twelfth line, of the first frame is jumped over not to be displayed on the screen as the result of the interlaced scanning. The above-mentioned portions jumped over in the first frame are displayed by using the second frame having the same averaging pattern as the first frame. The portions jumped over in the second frame are already displayed in the first frame. This is also similar in the third and fourth frames, the fifth and sixth frames, . . . , and the fifteenth and sixteenth frames. 
     FIG. 13 is a block diagram showing a second embodiment of the present invention. In this embodiment, its basic configuration is similar to that of the first embodiment. However, its switching control system is further thought out. 
     As shown in FIG. 13, the second embodiment includes a first switching controller  102 , a second switching controller  106 , a display mode judging circuit  107  and a switching control signal selecting circuit  108 . 
     In the first switching controller  102 , it is set at the 2n horizontal period in the 2n×2 vertical period. The first switching controller  102  is used when the interlaced scanning is done. The second switching controller  106  generates a control signal when the interlaced scanning is not carried out. It is set at the 2n horizontal period in the 2n vertical period. 
     The display mode judging circuit  107  outputs a judgment output signal Sm indicative of a display mode to the switching control signal selecting circuit  108 . The switching control signal selecting circuit  108  selects one of selector signals Ssel 1 , Ssel 2  and one of SP control signals Ssp 1 , Ssp 2  respectively outputted from the first and second switching controllers  102 ,  106 , in accordance with the judgment output signal Sm. The selected SP control signal is inputted to the time base converter  101  as the SP control signal Ssp. The selected selector signal is inputted to the switching selector  103  as the selector signal Ssel to select the its switching period. Since the configurations and the operations of the other sections are similar, their explanations are omitted here. 
     In the second embodiment, the control signal Ssp 1  and the selector signal Ssel 1  of the 2n horizontal period in the 2n×2 vertical period of the first switching controller  102  are selected by the display mode judging circuit  107  and the switching control signal selecting circuit  108 , if the interlaced scanning is done, for example, when the enlarged displaying is performed. This selection can attain the display quality similar to that of the first embodiment. 
     If the interlaced scanning is not done, the control signal Ssp 2  and the selector signal Ssel 2  of the 2n horizontal period in the 2n vertical period of the second switching controller  106  are selected by the display mode judging circuit  107  and the switching control signal selecting circuit  108 , if the interlaced scanning is not done. This selection can maintain the display quality similar to that of FIG.  1 . 
     In the explanation of the operation in this embodiment, the case of the eight signal processors is described, namely, the case of n=4 is described. However, of course, n is not limited to this value. Also, of course, the enlargement magnification is not limited to the 1.6-times. Moreover, the input image signal in the present invention may be any of the interlace signal and the progressive signal. So, it may be applied to any signal. 
     As mentioned above, according to the present invention, in the active matrix type liquid crystal display apparatus, when the interlaced scanning is done to display the image signal by jumping over the horizontal display line every other line, for the enlarged displaying and the like, the same averaging format is used as each of the frame in which the even-numbered lines are jumped over and the frame in which the odd-numbered lines are jumped over. In short, the averaging pattern in which the horizontal lines are jumped over is used for another frame when the different horizontal lines are jumped over, which enables the perfectly averaging operation. Hence, even if the interlaced scanning is done, it is possible to obtain the display quality in which the pattern having the particular regularity, such as the noise in the form of lattice is not displayed.