Abstract:
In displaying a price label, the price can be displayed at low resolution without any problem, but a bar code requires a high resolution display. In view of this, the invention provides an electrode structure for a display apparatus that can suppress increases in cost and power consumption while preventing image quality degradation, even when a low-resolution display area and a high-resolution display area are mixed on the same display. A liquid crystal panel  10  has a main display section  11  and a sub-display section  12 . In the main display section  11 , pixels are arranged in a matrix pattern. In the sub display section  12 , rectangle-shaped pixels are arranged in a single row, and the pixel pitch in the sub display section  12  is m/n of that in the main display section  11  (n and m are integers).

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
       [0001]     This application claims priority from, and incorporates by reference the entire disclosure of, the following Japanese Patent Applications, 
        (1) No. 2003-325378, filed on Sep. 18, 2003.     No. 2004-069888, filed on Mar. 12, 2004.        
 
       BACKGROUND OF THE INVENTION  
       [0004]     1. Field of the Invention  
         [0005]     The present invention relates to a display apparatus that produces a display by applying a voltage to an electro-optical conversion material and, more particularly, to a display apparatus having display areas of different resolutions, wherein the electro-optical conversion material is a liquid crystal material.  
         [0006]     2. Description of the Related Art  
         [0007]     In the fields of various measuring instruments, electronic shelf labeling systems, etc., it is practiced to produce a display of ordinary characters, graphics, or the like, which does not require a particularly high resolution, and a display of bar code or the like, which requires a high resolution, simultaneously on a single display panel.  
         [0008]     Patent Document 1 (Japanese Examined Patent Publication No. H07-65909) discloses a technique for displaying a character screen, on which numerical values measured by a measuring instrument or various kinds of information are displayed in numbers or letters, and a bar code screen, on which the numerical values measured or the various kinds of information are displayed in bar code, simultaneously on a single display panel. However, with the technique disclosed in Patent Document 1, as the character screen and the bar code screen are displayed at the same resolution, the resolution of the display panel has had to be made to match the resolution required of the bar code display; that is, even when a low resolution suffices for the display of the character screen, the entire display panel has had to be designed to provide the high resolution required of the bar code display, resulting in the problem that the display panel requires the use of higher performance driving circuits, etc. and the cost increases unnecessarily.  
         [0009]     A technique that addresses the above problem is disclosed in Patent Document 2 (Japanese Unexamined Patent Publication No. 2003-222893). The technique disclosed in Patent Document 2 concerns an electronic shelf labeling system that displays a matrix display section, in which ordinary characters are displayed, and a bar code display section, in which bar code is displayed by static driving, simultaneously on a single panel but at different resolutions. This display panel has a dot display section comprising column electrodes and row electrodes arranged in a matrix pattern, and a rectangular-segment display section comprising one common electrode and segment display electrodes disposed opposite the common electrode and electrically connected to the column electrodes in a one-to-one corresponding relationship. As the rectangular-segment display section is driven by the static driving method, the display panel as a whole is constructed using a liquid crystal material having a memory operation mode.  
         [0010]     According to the technique disclosed in Patent Document 2, the dot display section for displaying ordinary character information is driven in time division fashion by using the column electrodes and row electrodes, while the segment display section for displaying bar code is driven by static driving (non-time-division driving) by using the one common electrode and the segment display electrodes disposed opposite to it. In this technique, a signal is input to each segment display electrode via its corresponding column electrode by electrically connecting the segment display electrode to the column electrode. This leaves no choice but to make the segment display electrodes correspond one for one with the column electrodes, leading to the problem that the number of segment display electrodes cannot be made larger than the number of column electrodes. There has also been the problem that, when the resolution of the segment display section is made higher than the resolution of the dot display section, a non-display area having no display pixels occurs in the segment display section and it is not possible to use that area for display. An object of the present invention is to solve these problems associated with Patent Document 2.  
       SUMMARY OF THE INVENTION  
       [0011]     According to a first mode for carrying out the present invention, there is provided a display apparatus which comprises an electro-optical conversion material placed between a plurality of signal electrodes and a plurality of scanning electrodes, and which produces a display by changing optical properties of the electro-optical conversion material by applying a prescribed voltage to each of a plurality of display pixels formed where the signal electrodes overlap the scanning electrodes, wherein the plurality of display pixels are divided on each of the signal electrodes into at least two groups, one consisting of main display pixels and the other consisting of sub-display pixels, and wherein the main display pixels are arranged one spaced apart from another in a direction in which the scanning electrodes are scanned, and at least two of the sub-display pixels are arranged in overlapping fashion in the direction in which the scanning electrodes are scanned, and arranged one spaced apart from the other in a direction orthogonal to the direction in which the scanning electrodes are scanned.  
         [0012]     In the display apparatus according to the first mode, each of the signal electrodes comprises a main signal electrode portion on which the main display pixels are formed, and sub-signal electrode portions connected to the main signal electrode portion and arranged one spaced apart from the other in the direction orthogonal to the scanning direction in corresponding relationship to the sub-display pixels.  
         [0013]     In the display apparatus according to the first mode, the sub-signal electrode portions are connected to the main signal electrode portion by a portion formed in the shape of a narrow path.  
         [0014]     In the display apparatus according to the first mode, the scanning electrodes are divided into two groups, one consisting of main scanning electrodes arranged in a main display section where the main display pixels are formed and the other consisting of sub-scanning electrodes arranged in a sub-display section where the sub-display pixels are formed, and the sub-scanning electrodes include at least an upper sub-scanning electrode and a lower sub-scanning electrodes, the upper and lower sub-scanning electrodes together comprising wiring electrode portions extending parallel to each other in the direction orthogonal to the scanning direction and a plurality of comb-shaped electrode portions protruding from the respective wiring electrode portions of the upper and lower sub scanning electrodes in directions opposing each other, wherein the comb-shaped electrode portions of the upper sub scanning electrode and the comb-shaped electrode portions of the lower sub scanning electrodes are arranged in alternating fashion in the direction orthogonal to the scanning direction.  
         [0015]     In the display apparatus according to the first mode, the scanning electrodes forming the sub display pixels include a middle sub scanning electrode in addition to the upper sub scanning electrode and the lower sub scanning electrode, and the middle sub scanning electrode is disposed between the upper sub scanning electrode and the lower sub scanning electrode, and is formed in a corrugated shape to conform with the shapes of the upper sub scanning electrode and the lower sub scanning electrode.  
         [0016]     In the display apparatus according to the first mode, interconnections for connecting the scanning electrodes and the signal electrodes to an external circuit that applies a prescribed voltage between the electrodes are provided on one side of a display substrate, and the one side of the substrate is located on a sub display pixel side.  
         [0017]     According to a second mode for carrying out the present invention, there is provided a display apparatus comprising: a plurality of signal lines connected to a plurality of pixel electrodes via switching devices; a plurality of scanning lines for controlling the switching of the switching devices; a common electrode disposed opposite the plurality of pixel electrodes; and an electro-optical conversion material sandwiched between the common electrode and the pixel electrodes, wherein the plurality of pixel electrodes are divided on each of the signal lines into at least two groups, one consisting of main pixel electrodes and the other consisting of sub pixel electrodes, and wherein the main pixel electrodes are arranged one spaced apart from another in a direction in which the scanning lines are scanned, and at least two of the sub pixel electrodes are arranged in overlapping fashion in the direction in which the scanning lines are scanned, and arranged one spaced apart from the other in a direction orthogonal to the direction in which the scanning lines are scanned.  
         [0018]     In the display apparatus according to the second mode, interconnections for connecting the pixel electrodes and the common electrode to an external circuit that applies a prescribed voltage between the electrodes are provided on one side of a display substrate, and the one side of the substrate is located on a sub display pixel side.  
         [0019]     In the display apparatus according to the first and second modes, the electro-optical conversion material is a liquid crystal material.  
         [0020]     The present invention has the effect of being able to set the number of pixels for a high-resolution display area independently of the number of signal lines in a display apparatus that has a plurality of signal lines (signal electrodes) and a plurality of scanning lines (scanning electrodes) and that produces a plurality of display areas of different resolutions on a single display panel by time division driving.  
         [0021]     Furthermore, since there is no need to make the signal (pixel) electrodes in the main display section correspond one for one with the signal (pixel) electrodes in the sub display section, the present invention has the effect of being able to increase the number of sub-signal (pixel) electrodes beyond the number of main signal (pixel) electrodes, thereby making the pixel density (resolution) of the sub display section higher than that of the main display section; this offers the effect of being able to use the entire area of the sub display section as a display area without leaving any non-display areas having no display pixels in the sub display section. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0022]     The present invention is illustrated by way of example, and not by limitation, in the figures of the accompanying drawings in which like reference numerals indicate similar element, in which:  
         [0023]     The present invention will be more clearly understood from the description as set forth below with reference to the accompanying drawings, wherein:  
         [0024]      FIG. 1A  is a plan view of a liquid crystal panel according to a first embodiment.  
         [0025]      FIG. 1B  is a plan view schematically showing an array of scanning electrodes in the liquid crystal panel according to the first embodiment.  
         [0026]      FIG. 2A  is an enlarged plan view of an essential portion of some electrodes, showing the spatial relationship between signal electrodes and scanning electrodes according to the first embodiment.  
         [0027]      FIG. 2B  is a diagram showing a signal electrode taken from  FIG. 2A .  
         [0028]      FIG. 2C  is a diagram showing scanning electrodes in a sub display section  12  in  FIG. 1A .  
         [0029]      FIG. 3  is a plan view of the liquid crystal panel according to the first embodiment.  
         [0030]      FIG. 4A  is a plan view of a liquid crystal panel according to a second embodiment.  
         [0031]      FIG. 4B  is a plan view schematically showing an array of scanning electrodes in the liquid crystal panel according to the second embodiment.  
         [0032]      FIG. 5A  is an enlarged plan view of an essential portion of some electrodes, showing the spatial relationship between signal electrodes and scanning electrodes according to the third embodiment.  
         [0033]      FIG. 5B  is an enlarged plan view of an essential portion of some electrodes, showing the scanning electrodes in the sub display section according to the third embodiment.  
         [0034]      FIG. 6A  is an enlarged plan view of an essential portion of some electrodes, showing the spatial relationship between signal electrodes and scanning electrodes according to a fourth embodiment.  
         [0035]      FIG. 6B  is an enlarged plan view of an essential portion of some electrodes, showing the scanning electrodes in the sub display section according to the fourth embodiment.  
         [0036]      FIG. 6C  is an enlarged plan view of an essential portion of a signal electrode, showing a modified example of the signal electrode according to the fourth embodiment, in which the signal electrode comprises a main display portion, a first sub display portion, and a second sub display portion.  
         [0037]      FIG. 6D  is a diagram showing another modified example of the signal electrode in which the second sub display portion shown in  FIG. 6C  is disposed at the head of the main display portion.  
         [0038]      FIG. 7A  is an enlarged plan view of an essential portion of some electrodes, showing the spatial relationship between signal electrodes and scanning electrodes according to a fifth embodiment.  
         [0039]      FIG. 7B  is an enlarged plan view of an essential portion of some electrodes, showing the scanning electrodes in the sub display section according to the fifth embodiment.  
         [0040]      FIG. 8  is a plan view showing an essential portion of a liquid crystal panel according to a sixth embodiment.  
         [0041]      FIG. 9  is a plan view showing an essential portion of a liquid crystal panel according to a seventh embodiment.  
         [0042]      FIG. 10A  is a plan view of a liquid crystal panel according to an eighth embodiment.  
         [0043]      FIG. 10B  is a connection diagram for the liquid crystal panel according to the eighth embodiment.  
         [0044]      FIG. 10C  is a cross-sectional view of the liquid crystal panel taken along line  10 C- 10 C in  FIG. 10A .  
         [0045]      FIG. 11A  is an enlarged plan view of an essential portion of some electrodes, showing the spatial relationship between signal electrodes and scanning electrodes according to the eighth embodiment.  
         [0046]      FIG. 11B  is a diagram showing a signal electrode taken from  FIG. 11A .  
         [0047]      FIG. 11C  is an enlarged plan view of an essential portion of some electrodes, showing the scanning electrodes in the sub display section according to the eighth embodiment. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0048]     The best mode for carrying out the invention will be described below with reference to first to eighth embodiments.  
       Embodiment 1  
       [0049]      FIGS. 1, 2 , and  3  are diagrams showing the first embodiment of the present invention.  FIG. 1  shows a liquid crystal panel according to the first embodiment:  FIG. 1A  is a plan view of the liquid crystal panel, and  FIG. 1B  is a plan view schematically showing an array of scanning electrodes.  FIG. 2  presents enlarged plan views showing essential portions of electrodes:  FIG. 2A  shows the spatial relationship between signal electrodes and scanning electrodes (their positional relationship as viewed from the top),  FIG. 2B  shows the plan shape of a signal electrode taken from  FIG. 2A , and  FIG. 2C  shows the plan shape of a portion of the scanning electrodes in a sub display section. In  FIG. 2 , the sub display section is shown by reducing its size, top to bottom, for illustrative purposes.  FIG. 3  is a plan view showing the liquid crystal panel of the first embodiment.  
         [0050]     An outline of the liquid crystal panel  10  will be described with reference to  FIG. 3 . A main display section  11  capable of displaying numbers, letters, and other desired graphics is formed in the upper part of the liquid crystal panel  10 , and the sub display section  12  for displaying bar code or the like in fixed characters is formed in the lower part. The liquid crystal panel  10  comprises two glass substrates overlaid one on top of the other (one on the front side and the other on the rear side of  FIG. 3 ), with a plurality of transparent signal electrodes  20  and a plurality of transparent scanning electrodes  30  formed on the opposing surfaces of the respective substrates; a nematic type liquid crystal is sandwiched between these electrodes, forming display pixels at positions where the signal electrodes  20  overlap the scanning electrodes  30 . The liquid crystal panel  10  of  FIG. 3  is, for example, a liquid crystal panel employing the so-called passive driving scheme in which voltage application to each display pixel  35  (hatched portion) is accomplished, not by means of a switching device, but by applying a voltage in time division fashion to the corresponding signal electrode  20  and scanning electrode  30 . In the embodiments of the present invention, glass substrates are used, but alternatively, film substrates may be used.  
         [0051]     The plurality of signal electrodes  20  (one indicated by hatching), each identical in shape and extending in the longitudinal direction (in the vertical direction in  FIG. 3 ), are arranged at equally spaced intervals in the latitudinal direction (in the horizontal direction in  FIG. 3 ). The scanning electrodes  30  are formed extending in the latitudinal direction of the signal electrodes  20 , and are arranged at equally spaced intervals in the longitudinal direction of the signal electrodes  20 . Each signal electrode  20  comprises a main signal electrode portion  21  disposed in the main display section  11 , and sub-signal electrode portions  22  and  23  disposed in the sub display section  12 . On the other hand, the scanning electrodes  30  are divided into two groups of differently shaped electrodes, one consisting of main scanning electrodes  31  formed in the main display section  11  and the other consisting of sub scanning electrodes  32  formed in the sub display section  12  (though not explicitly shown in  FIG. 3 , the latter electrodes are comb-shaped as will be described later).  
         [0052]     Referring to  FIG. 2 , the plan shapes of the signal electrodes  20  and the scanning electrodes  30  will be described in further detail. First, the plan shape of the signal electrodes  20  will be described with reference to  FIG. 2B . The signal electrodes  20  each comprise the main signal electrode portion  21  disposed in the main display section  11  and the sub-signal electrode portions  22  and  23  disposed in the sub display section  12 ; the main signal electrode portion  21  is formed in the shape of a long strip extending vertically in the main display section  11 . The two sub-signal electrode portions  22  and  23  in the sub display section  12  are identical in shape, each being formed in the shape of a rectangle. The main signal electrode potion  21  is connected to the sub-signal electrode portions  22  and  23  by narrow thin wiring lines (narrow path portions)  24 . The narrow path portions  24  are each formed with a width of 10 μm.  
         [0053]     The plan shapes of the sub scanning electrodes  32  formed in the sub display section will be described in detail with reference to  FIG. 2C . The sub scanning electrodes  32  include an upper sub scanning electrode  33  and a lower sub scanning electrode  34 . The upper sub scanning electrode  33  comprises a comb-shaped electrode  33   b  formed with a plurality of rectangular protrusions protruding like the teeth of a comb downwardly from a wiring electrode portion  33   a  which extends along the latitudinal direction (the horizontal direction in the figure) of the signal electrodes  20 . Likewise, the lower sub scanning electrode  34  comprises a comb-shaped electrode  34   b  formed with a plurality of rectangular protrusions protruding like the teeth of a comb upwardly from a wiring electrode portion  34   a . The comb-shaped electrode portion  33   b  of the upper sub scanning electrode  33  and the comb-shaped electrode portion  34   b  of the lower sub scanning electrode  34  are arranged to alternate with each other in interleaving fashion in the horizontal direction.  
         [0054]     Next, referring to  FIG. 2A , a description will be given of the display pixels  35  formed where the signal electrodes  20  overlap the scanning electrodes  30  in the two-dimensional plane shown in  FIG. 3 . In  FIG. 3 , the signal electrodes  20  are indicated by solid lines, and the scanning electrodes  30  by dashed lines. First, the display pixels formed in the main display section  11  will be described. The main signal electrode portion  21  of each signal electrode  20  intersects at right angles with the main scanning electrodes  31 , and a square-shaped main display pixel  36  (indicated by hatching) is formed at each of their intersections. The main display pixels  36  are arranged in a matrix pattern in the main display section  11 .  
         [0055]     Next, display pixels  37  and  38  in the sub display section  12  will be described. As earlier described, each signal electrode  20  includes the pair of sub-signal electrode portions  22  and  23  formed in the sub-display section  12  and connected via the narrow path portions  24  to the main signal electrode portion  21  formed in the main display section  11 . The sub-signal electrodes  22  and  23  are arranged to be spaced a prescribed distance apart from each other in the horizontal direction. Of the pair of sub-signal electrodes  22  and  23  provided on each signal electrode  22 , the left-hand sub-signal electrode  22  overlaps the comb-shaped electrode portion  33   b  of the upper sub scanning electrode  33 , to form the sub display pixel  37 . Likewise, of the pair of sub-signal electrodes  22  and  23  provided on each signal electrode  22 , the right-hand sub-signal electrode  23  overlaps the comb-shaped electrode portion  34   b  of the lower sub scanning electrode  34 , to form the sub display pixel  38 . Bar code is displayed using these sub display pixels  37  and  38 .  
         [0056]     The sub display pixels  37  and  38  can be controlled on and off independently of each other, since they are driven by different scanning electrodes in time division fashion; as shown in  FIG. 2A , the number of pixels in the horizontal direction in the sub display section  12  is twice the number of pixels in the main display section  11 . The main signal electrodes  21  are arranged at a pitch of 0.254 mm (100 dpi) in the main display section  11 , while the sub-signal electrodes  22  and  23  are arranged at a pitch of 0.127 mm (200 dpi) in the sub display section  12 .  
         [0057]     The driving method of the liquid crystal panel  10  according to the present embodiment will be described with reference to  FIG. 1 .  FIG. 1B  is a diagram schematically showing, in order to explain the concept of the driving method, the main scanning electrodes  31  arranged in the main display section  11  and the upper scanning electrode  33  and lower scanning electrode  34  arranged in the sub display section  12 . It is assumed here that a voltage averaging method is employed and the main scanning electrodes  31  are selected for scanning in sequence from the top of the main display section  11 .  
         [0058]     After the main scanning electrodes  31  have been selected in sequence, the upper sub scanning electrode  33  is selected. If only a particular one of the plurality of sub display pixels  37  needs to be set ON and the remaining pixels OFF in the sub display section  12 ; then, during the period that the upper sub scanning electrode  33  is selected, an ON waveform is applied to the main signal electrode  21  connected to the sub-signal electrode  22  forming the sub display pixel  37  to be set ON. If this particular pixel is to be set OFF, an OFF waveform is applied to this signal electrode  21 .  
         [0059]     Likewise, when the lower sub scanning electrode  34  is selected, if only a particular one of the sub display pixels  38  needs to be set ON and the remaining pixels OFF, then during the period that the lower sub scanning electrode  34  is selected, an ON waveform is applied to the main signal electrode  21  connected to the sub-signal electrode  23  forming the sub display pixel  38  to be set ON. If this particular pixel is to be set OFF, an OFF waveform is applied to this signal electrode  21 .  
         [0060]     In this way, letters and other desired graphics can be displayed at 100 dpi in the main display section  11 , while displaying bar code at 200 dpi in the sub display section  12 . Here, the wiring electrode portion  33   a  of the upper sub scanning electrode  33  is formed as a long, narrow strip so as to cross the narrow path portions  24  of the signal electrodes  20 ; as a result, unwanted light emission that occurs at the positions where the wiring electrode portion  33   a  crosses the narrow path portions  24  (the positions where light emission should not occur) is not noticeable because the width of each narrow path portion  24  is small.  
       Embodiment 2  
       [0061]     The second embodiment will be described with reference to  FIG. 4 . In the second embodiment, the sub display section  42  is located in one corner of the liquid crystal panel  40 .  FIG. 4A  is a plan view of the liquid crystal panel, and  FIG. 4B  is a plan view schematically showing an array of scanning electrodes.  
         [0062]     The arrangement of the main display section  41  and the sub display section  42  will be described with reference to  FIG. 4A . The sub display section  42  is disposed in the lower right corner of the liquid crystal panel  40 , and the area other than the sub display section  42  is allocated as the main display section  41 . The liquid crystal panel  40  is a passive liquid crystal panel, as in the first embodiment.  
         [0063]     The electrode configuration and the driving method will be described with reference to  FIG. 4B . The scanning electrodes  41  are divided into two groups, one consisting of main scanning electrodes  43  and  44  formed in the main display section  41  and the other consisting of sub scanning electrodes  45  and  46  formed in both the main display section  41  and the sub display section  42 .  
         [0064]     The main scanning electrodes  43  are formed extending in the horizontal direction across the entire surface of the liquid crystal panel  40 , as in the first embodiment. The main scanning electrodes  44  are disposed to one side of the sub display section  42 , the electrodes  44  extending halfway along the width of the liquid crystal panel  40  and stopping so that their wiring lines do not enter the sub display section  42 . The pitch of the main scanning lines  43  in the vertical direction is the same as that of the main scanning lines  44 . The sub scanning electrodes  45  and  46  each comprise a straight portion formed in the main display section  41  and a comb-shaped portion formed in the sub display section  42 .  
         [0065]     In the main display section  41  shown in  FIG. 4A , the signal electrodes (not shown) are arranged at right angles to the scanning electrodes  43 ,  44 ,  45 , and  46 . Of these signal electrodes, those that do not enter the sub display section  42  comprise only main signal electrodes. On the other hand, the signal electrodes that enter the sub display section  42  are each made up of a main signal electrode in the main display section  41  and two rectangular sub-signal electrodes in the sub display section, as in the first embodiment. Main display pixels in the main display section  41  are formed at the intersections between the main signal electrodes and the scanning electrodes  43  and  44 . Sub display pixels in the sub display section are formed at the intersections between the sub-signal electrodes and the scanning electrodes  45  and  46 .  
         [0066]     Next, the driving method will be described with reference to  FIG. 4B . Here also, the voltage averaging method is employed, and the scanning electrodes  43 ,  44 ,  45 , and  46  are selected in sequence from the top of the main display section  41 .  
         [0067]     During the period when any one of the main scanning electrodes  43  and  44  in the main display section  41  in  FIG. 4A  is selected, a driving waveform for displaying a graphic in the main display section  41  is applied to the signal electrodes. When the “scanning electrode  45 ” is selected, a driving waveform for displaying a graphic in the main display section  41  is applied to those signal electrodes that do not enter the sub display section  42  in  FIG. 4A . At the same time, a driving waveform for displaying a graphic, for example, bar code, in the sub display section  42  is applied to those signal electrodes that enter the sub display section  42 . Likewise, when the scanning electrode  46  is finally selected, a driving waveform for displaying a graphic in the main display section  41  is applied to those signal electrodes that do not enter the sub display section  42  in  FIG. 4A . At the same time, a driving waveform for displaying a graphic, for example, bar code, in the sub display section  42  is applied to those signal electrodes that enter the sub display section  42 . The waveform applied to each signal electrode here is either an ON waveform or an OFF waveform.  
         [0068]     In the second embodiment, the main display section  41  is enlarged by forming the scanning electrodes  45  and  46  so as to be shared between the main display section  41  and the sub display section  42 , as shown in  FIG. 4B . As in the first embodiment, the main signal electrodes are arranged at 100 dpi as viewed in the direction of arrangement of the signal electrodes, while the sub-signal electrodes are arranged at 200 dpi as viewed in the direction of arrangement of the signal electrodes. This means that the pixel pitch in the sub display section  42  is one half of the pixel pitch in the main display section. Further, as in the first embodiment, each main signal electrode and its corresponding sub-signal electrodes are connected by thin wiring lines.  
       Embodiment 3  
       [0069]     The third embodiment will be described with reference to  FIG. 5 .  FIG. 5A  shows how the signal electrodes overlap the scanning electrodes in a two-dimensional plane, and  FIG. 5B  shows the sub scanning electrodes in the sub display section. In  FIG. 5A , the signal electrode configuration differs from the first and second embodiments in that each signal electrode comprises one main signal electrode  51  and three sub-signal electrode portions  53 ,  54 , and  55  connected to it by thin wiring lines (narrow path portions: line width is about 10 μm); otherwise, the configuration is the same. Here, the sub-signal electrode portion  53  indicates the leftmost one of the three horizontally arranged sub-signal electrodes of the signal electrode  50 . Likewise,  54  indicates the middle one, and  55  indicates the signal electrode portion located at the rightmost end.  
         [0070]     In  FIG. 5B , the upper sub scanning electrode  56  is formed in the shape of a comb whose teeth are pointed downward, and the pitch of the teeth in the horizontal direction is twice as large as that of the main signal electrodes  51 . The middle sub scanning electrode  57  is formed in the shape of a periodically repeating rectangle; the period of the rectangle is also twice as large as the pitch of the main signal electrodes  51 . The lower sub scanning electrode  58  is formed in the shape of a comb whose teeth are pointed upward, and the pitch of the teeth is twice as large as that of the main signal electrodes  51 . The sub scanning electrodes  56 ,  57 , and  58  are formed in an interleaving fashion, and electrically insulated from each other.  
         [0071]     Turning back to  FIG. 5A , the pixel arrangement will be described. In the figure, the signal electrodes are indicated by solid lines, and the scanning electrodes by dashed lines. The main signal electrodes  51  in the main display section are arranged at a pitch of 0.381 mm (67 dpi) in the horizontal direction in the figure. Since the main scanning electrodes  52  are also arranged at the same pitch in the vertical direction in the figure, the main display section is a dot matrix with a pixel pitch of 0.381 mm. In the sub display section, the portions where the sub-signal electrodes  53 ,  54 , and  55  overlap the sub scanning electrodes  56 ,  57 , and  58  form the sub display pixels for displaying bar code or the like. The upper sub scanning electrode  56  overlaps only with adjacent sub-signal electrodes  55  and  53  (for example,  53 ′) between two adjacent signal electrodes  50 ; in this case, the upper sub scanning electrode  56  overlaps the two sub-signal electrodes, the sub-signal electrode  55  on the left and the sub-signal electrode  53  (for example,  53 ′) on the right. On the other hand, the middle sub-signal electrode  57  overlaps only the middle sub-signal electrode  54  of each signal electrode  50 . The lower sub scanning electrode  58  overlaps only adjacent sub-signal electrodes  53  and  55  (for example,  55 ′) between two adjacent signal electrodes  50 ; in this case, the lower sub scanning electrode  58  overlaps the two sub-signal electrodes, the sub-signal electrode  55  (for example,  55 ′) on the left and the sub-signal electrode  53  on the right. The pitch of the thus formed sub display pixels is 0.127 mm (200 dpi), which is one-third of the pixel pitch in the main display section.  
         [0072]     The driving method is substantially the same as that employed in the first and second embodiments. After the main scanning electrodes  52  in the main display section have been selected in sequence, the sub scanning electrodes  56 ,  57 , and  58  in the sub display section are selected in sequence for scanning. When the upper sub scanning electrode  56  is selected, driving waveforms corresponding to the display data, such as a bar code, to be displayed by the sub display pixels formed by the overlapping of the upper sub scanning electrode  56  and the sub-signal electrode portions  55  and  53  (for example,  53 ′) are applied to the signal electrode  50  having the sub-signal electrode  55  and the signal electrode  50  having the sub-signal electrode  53  (for example,  53 ′), respectively. Next, when the middle sub scanning electrode  57  is selected, driving waveforms corresponding to the display data, such as a bar code, to be displayed by the sub display pixels formed by the overlapping with the respective sub-signal electrodes  54 , are applied to the signal electrodes  50  having the respective sub-signal electrodes  54 . Finally, when the lower sub scanning electrode  58  is selected, driving waveforms corresponding to the display data, such as a bar code, to be displayed by the sub display pixels formed by the overlapping of the lower sub scanning electrode  58  and the sub-signal electrodes  53  and  55  (for example,  55 ′) are applied to the signal electrode  50  having the sub-signal electrode  53  and the signal electrode  50  having the sub-signal electrode  55  (for example,  55 ′), respectively.  
       Embodiment 4  
       [0073]      FIG. 6  presents enlarged plan views showing essential portions of electrodes according to the fourth embodiment:  FIG. 6A  is a diagram showing the spatial relationship between signal electrodes and scanning electrodes according to the fourth embodiment,  FIG. 6B  is a diagram showing the scanning electrodes in the sub display section,  FIG. 6C  is a diagram showing a modified example of a signal electrode in which the signal electrode comprises a main display portion, a first sub display portion, and a second sub display portion, and  FIG. 6D  is a diagram showing another modified example of a signal electrode in which the second sub display portion shown in  FIG. 6C  is disposed at the head of the main display portion.  
         [0074]     The fourth embodiment will be described with reference to  FIG. 6 .  FIG. 6A  shows how the signal electrodes overlap the scanning electrodes in a two-dimensional plane, and  FIG. 6B  shows the sub scanning electrodes in the sub display section. In  FIG. 6A , the signal electrode configuration differs from the first, second, and third embodiments in that each signal electrode comprises one main signal electrode  61  and one sub-signal electrode portion  63  connected to it by a thin wiring line (narrow path portion: line width is about 10 μm); otherwise, the configuration is the same.  
         [0075]     The only difference between the third and fourth embodiments is whether or not the signal electrode portion (area) for forming the sub display pixels is divided into separate portions one for each individual sub display pixel; therefore, the sub scanning electrode shape and the driving method are the same between the third and fourth embodiments.  
         [0076]     In  FIG. 6B , the upper sub scanning electrode  66  is formed in the shape of a comb whose teeth are pointed downward, and the pitch of the teeth in the horizontal direction is twice as large as that of the main signal electrodes  61 . The middle sub scanning electrode  67  is formed in the shape of a periodically repeating rectangle; the period of the rectangle is also twice as large as the pitch of the main signal electrodes  61 . The lower sub scanning electrode  68  is formed in the shape of a comb whose teeth are pointed upward, and the pitch of the teeth is twice as large as that of the main signal electrodes  61 . The sub scanning electrodes  66 ,  67 , and  68  are formed in an interleaving fashion, and are electrically insulated from each other.  
         [0077]     Turning back to  FIG. 6A , the pixel arrangement will be described. In the figure, the signal electrodes are indicated by solid lines, and the scanning electrodes by dashed lines. The main signal electrodes  61  in the main display section are arranged at a pitch of 0.381 mm (67 dpi) in the horizontal direction in the figure. As the main scanning electrodes  62  are also arranged at the same pitch in the vertical direction in the figure, the main display section is a dot matrix with a pixel pitch of 0.381 mm. In the sub display section, the portions where the sub-signal electrode portions  63 R,  63 C, and  63 L overlap the sub scanning electrodes  66 ,  67 , and  68  form the sub display pixels for displaying bar code or the like (here,  63 R indicates the one-third portion in the right of the electrode  63 ,  63 C the one-third portion in the center of the electrode  63 , and the  63 L the one-third portion in the left of the electrode  63 ). The upper sub scanning electrode  66  overlaps only the adjacent sub-signal electrode portions  63 R and  63 L (for example,  63 L′) between two adjacent signal electrodes  60 ; in this case, the upper sub scanning electrode  66  overlaps the two sub-signal electrode portions, the sub-signal electrode portion  63 R on the left and the sub-signal electrode  63 L on the right. On the other hand, the middle sub-signal electrode  67  overlaps only the middle sub-signal electrode portion  63 C of each signal electrode  60 . The lower sub scanning electrode  68  overlaps the adjacent sub-signal electrode portions  63 L and  63 R (for example,  63 R′) between two adjacent signal electrodes  60 ; in this case, the lower sub scanning electrode  68  overlaps the two sub-signal electrode portions, the sub-signal electrode portion  63 R on the left and the sub-signal electrode portion  63 L on the right. The pitch of the thus formed sub display pixels is 0.127 mm (200 dpi), which is one-third of the pixel pitch in the main display section.  
         [0078]     The driving method is substantially the same as that employed in the first and second embodiments. After the main scanning electrodes  62  in the main display section have been selected in sequence, the sub scanning electrodes  66 ,  67 , and  68  in the sub display section are selected in sequence for scanning. When the upper sub scanning electrode  66  is selected, driving waveforms corresponding to the display data, such as bar code, to be displayed by the sub display pixels formed by the overlapping of the upper sub scanning electrode  66  and the sub-signal electrode portions  63 R and  63 L (for example,  63 L′) are applied to the signal electrode  60  having the sub-signal electrode portion  63 R and the signal electrode  60  having the sub-signal electrode portion  63 L (for example,  63 L′), respectively. Next, when the middle sub scanning electrode  67  is selected, driving waveforms corresponding to the display data, such as bar code, to be displayed by the sub display pixels formed by overlapping the respective sub-signal electrode portions  63 C, are applied to the signal electrodes  60  having the respective sub-signal electrode portions  63 C. Finally, when the lower sub scanning electrode  68  is selected, driving waveforms corresponding to the display data, such as bar code, to be displayed by the sub display pixels formed by overlapping the lower sub scanning electrode  68  and the sub-signal electrode portions  63 L and  63 R (for example,  63 R′) are applied to the signal electrode  60  having the sub-signal electrode portion  63 L and the signal electrode  60  having the sub-signal electrode portion  63 R (for example,  63 R′), respectively.  
         [0079]     Here, examples will be shown in which the plurality of display pixels formed on each of the plurality of signal electrodes are divided into three kinds: the main display pixel, the first sub-display pixel, and the second sub-display pixel.  FIG. 6C  is a diagram showing a modified example of the signal electrode in which the signal electrode  60 A comprises a main display portion  62 A, a first sub-display portion  63 A for displaying, for example, bar code, and a second sub-display portion  64 A for displaying, for example, an icon.  FIG. 6D  is a diagram showing another modified example of the signal electrode in which the second sub-display portion  64 A shown in  FIG. 6C  is disposed at the head of the main display portion  62 A, that is, the signal electrode  60 B comprises a main display portion  62 B, a first sub display portion  63 B, and a second sub display portion  64 B. In these modified examples, the signal electrode wiring line extends upward in the figure for connection to a signal electrode driving circuit.  
       Embodiment 5  
       [0080]     The fifth embodiment will be described with reference to  FIG. 7 . As shown in  FIG. 7A , the fifth embodiment differs from the third embodiment in that the signal electrodes  70  alternate between electrodes ( 71 ,  73 ,  75 ), each having three sub-signal electrode portions, and electrodes ( 72 ,  74 ,  76 ), each having two sub-signal electrode portions; otherwise, the configuration is the same as that of the third embodiment. As shown in  FIG. 7B , there are three sub-scanning electrodes: the upper scanning electrode  77 , the middle sub scanning electrode  78 , and the lower scanning electrode  78 . The upper scanning electrode  77  has two kinds of comb-shaped portions differing in width, one being a wide portion which overlaps both the sub-signal electrodes  71   c  and  72   a  or both the sub-signal electrodes  75   c  and  76   a , and the other being a narrow portion which overlaps the sub-signal electrode  73   c . The middle sub-scanning electrode  78  has comb-shaped portions equal in width, the width being just sufficient to cover each of the sub-signal electrode portions  71   b ,  72   b ,  73   b ,  74   a ,  75   b . The lower sub scanning electrode  79  comprises two kinds of portions, one being a wide portion which overlaps both the sub-signal electrode portions  74   b  and  75   a  and the other being a narrow portion which overlaps the sub-signal electrode  73   a . This overlapping arrangement of the sub-signal electrode portions and the sub scanning electrodes repeats every 10 sub-signal electrodes, that is, the same arrangement pattern appears after every 10th sub-signal electrode.  
         [0081]     In this embodiment, there are five signal electrodes  72  for any two adjacent sub-signal electrodes  70 . In this way, the pixel pitch in the sub display section can be reduced by a factor of 2.5, compared with the pixel pitch in the main display section.  
         [0082]     For the passive liquid crystal panel, not only a nematic type liquid crystal but also a liquid crystal having a memory property, such as a cholesteric type liquid crystal, can be used. With the memory property, since there is no need to perform periodic vertical scanning, the power consumption can be reduced.  
       Embodiment 6  
       [0083]     The sixth embodiment will be described with reference to  FIG. 8 . The sixth embodiment concerns an example in which the present invention is applied to an active liquid crystal panel which contains switching devices formed from thin-film transistors (hereinafter referred to as the TFTs) within the liquid crystal panel.  FIG. 8  is a circuit diagram schematically showing the interconnections between the TFT devices and pixels in the liquid crystal panel.  
         [0084]     A plurality of square-shaped main pixel electrodes  81  form the main display section, and a plurality of rectangle-shaped sub pixel electrodes  82 ,  83  form the sub display section. Signal lines  85 A,  85 B and scanning lines  86  intersect at right angles with each other. A TFT device  801  and a main pixel electrode  81  forming part of the main display section are located at each intersection between the signal lines  85 A,  85 B and the scanning lines  86 . The signal line  85  is connected to the source of the TFT device  801 , and the scanning line  86  is connected to the gate of the TFT device  801 . The drain of the TFT device  801  is connected to the main pixel electrode  81  in the main display section.  
         [0085]     In the sub display section, a TFT device  802  and a rectangle-shaped sub pixel electrode  82  for bar code display are located where the signal line  85 A,  85 B intersects with a scanning line  87 . The signal line  85 A,  85 B is connected to the source of the TFT device  802 , and the scanning line  87  is connected to the gate of the TFT device  802 . The drain of the TFT device  802  is connected to the bar code display sub pixel electrode  82 . Further, the signal line  85  is connected to the source of a TFT device  803 , whose gate is connected to a scanning line  88 . The drain of the TFT device  803  is connected to a bar code display sub pixel electrode  83 . The bar code display sub pixel electrodes  82  and  83  are identical in shape and are arranged alternately.  
         [0086]     The pitch of the sub display electrodes  83  in the horizontal direction in the figure is one half of the pitch of the main display electrodes  81  in the horizontal direction. One common electrode (not shown) is formed on the surface of a substrate that faces the substrate surface on which the main pixel electrodes  81  in the main display section and the sub pixel electrodes  82 ,  83  in the sub display section are formed. The main pixel electrodes  81  in the main display section and the sub pixel electrodes  82 ,  83  in the sub display section are separated from the common electrode by a liquid crystal sandwiched therebetween.  
         [0087]     The driving method of the sixth embodiment will be described below with reference to  FIG. 8 . In the main display section, a selection pulse is applied to the scanning lines  86  ( 881 ,  882 ) in sequence from the top. When the selection pulse is applied, conduction occurs in the TFT device  801  connected to the scanning line  86  to which the selection pulse is applied, and a voltage corresponding to the graphic to be displayed in the main display section is applied to the main pixel electrode  81  via the signal line  85 A,  85 B (hereinafter referred to as the writing). When the selection pulse is applied to another scanning line  86 , the TFT device  801  becomes non-conducting, and the main pixel electrode  81  in the main display section retains the applied voltage. When the selection pulse has been applied to all the scanning lines  86 , and the writing to all the main pixel electrodes  81  in the main display section is completed, the selection pulse is applied to the scanning lines  87  and  88  in sequence, and a voltage corresponding to bar code data is written to the bar code display sub pixel electrodes  82  and  83  in the same manner as described above.  
         [0088]     As a desired driving voltage can be applied to each individual pixel in the active liquid crystal panel, the liquid crystal panel can make use of a polymer dispersed liquid crystal (for example, a polymer network liquid crystal) which has two states, opaque and transparent, and which does not need the provision of polarizers. The present invention is not limited to liquid crystal panels, but is applicable to any display apparatuses whose optical properties are controlled by electrical means using voltage or current. For example, the invention is equally applicable to display apparatuses that use electrophoretic materials or organic light-emitting devices rather than liquid crystal materials.  
       Embodiment 7  
       [0089]      FIG. 9  is a plan view showing an essential portion of a liquid crystal panel according to the seventh embodiment. The seventh embodiment will be described with reference to  FIG. 9 . The seventh embodiment concerns an example in which the present invention is applied to an active liquid crystal panel which contains switching devices formed from thin-film transistors (hereinafter referred to as the TFTs) within the liquid crystal panel.  FIG. 9  is a circuit diagram schematically showing the interconnections between the TFT devices and pixels in the liquid crystal panel.  
         [0090]     A plurality of square-shaped main pixel electrodes  91  form the main display section, and a plurality of rectangle-shaped sub pixel electrodes  92 ,  93 ,  94  form the sub display section. Signal lines  95 A,  95 B,  95 C and scanning lines  96  intersect at right angles with each other. A TFT device  901  and a main pixel electrode  91  forming part of the main display section are located at each intersection between the signal lines  95 A,  95 B,  95 C and the scanning lines  96 . The signal line  95 A,  95 B,  95 C is connected to the source of the TFT device  901 , and the scanning line  96  is connected to the gate of the TFT device  901 . The drain of the TFT device  901  is connected to the main pixel electrode  91  in the main display section.  
         [0091]     In the sub display section, TFT devices  902 ,  903 , and  904  and rectangle-shaped sub pixel electrodes  92 A,  92 B, and  92 C for bar code display are respectively located where the signal line  95 A,  95 B,  95 C intersects with scanning line  97 ,  98 , and  99 . The signal line  95 A,  95 B,  95 C is connected to the sources of the TFT devices  902 ,  903 , and  904 , and the scanning lines  97 ,  98 , and  99  are connected to the gates of the TFT device  902 ,  903 , and  904 , respectively. The drains of the TFT device  902 ,  903 , and  904  are connected to the bar code display sub pixel electrodes  92 A,  92 B, and  92 C, respectively. The bar code display sub pixel electrodes  92 ,  93 , and  94  are identical in shape and are arranged in this order in a repetitive manner. In the figure, the scanning line  98  being formed in a rectangular shape indicates that the scanning line  98  does not intersect with the other scanning lines  97  and  99 . That is, as the scanning lines  97 ,  98 , and  99  are formed on the same layer, they must be formed so as not to intersect with each other, and this can be accomplished by forming the scanning line  98  in a rectangular shape. Likewise, the wiring line between the source of the TFT  903  and the signal line  95 A is routed so as to circumvent the TFT  902  in order to avoid an electrical short between the source and drain formed on the same layer.  
         [0092]     The pitch of the sub display electrodes  92 ,  93 ,  94  in the horizontal direction in the figure is one thirds of the pitch of the main display electrodes  91  in the horizontal direction. One common electrode (not shown) is formed on the surface of a substrate that faces the substrate surface on which the main pixel electrodes  91  in the main display section and the sub pixel electrodes  92 ,  93 ,  94  in the sub display section are formed. The main pixel electrodes  91  in the main display section and the sub pixel electrodes  92 ,  93 ,  94  in the sub display section are separated from the common electrode by a liquid crystal sandwiched therebetween.  
         [0093]     The driving method of the seventh embodiment will be described below with reference to  FIG. 9 . In the main display section, a selection pulse is applied to the scanning lines  96  ( 991 ,  992 ) in sequence from the top. When the selection pulse is applied, conduction occurs in the TFT device  901  connected to the scanning line  96  to which the selection pulse is applied, and a voltage corresponding to the graphic to be displayed in the main display section is applied to the main pixel electrode  91  via the signal line  95 A,  95 B,  95 C (hereinafter referred to as writing). When the selection pulse is applied to another scanning line  96 , the TFT device  901  becomes non-conducting, and the main pixel electrode  91  in the main display section retains the applied voltage. When the selection pulse has been applied to all the scanning lines  96 , and writing to all the main pixel electrodes  91  in the main display section is completed, the selection pulse is applied to the scanning lines  97 ,  98 , and  99  in sequence, and a voltage corresponding to bar code data is written to the bar code display sub pixel electrodes  92 ,  93 , and  94  in the same manner as described above.  
       Embodiment 8  
       [0094]      FIGS. 10 and 11  are diagrams showing the eighth embodiment of the present invention.  FIG. 10A  is a plan view of a liquid crystal panel,  FIG. 10B  is a connection diagram for explaining the connections of integrated circuits and electrodes, and  FIG. 10C  is a cross-sectional view of the liquid crystal panel taken along line  10 C- 10 C in  FIG. 10A .  FIG. 11A  is a diagram showing the positional relationship between signal electrodes and scanning electrodes in a two-dimensional plane,  FIG. 11B  is a diagram showing the plan shape of a signal electrode taken from  FIG. 11A , and  FIG. 11C  shows the plan shape of a portion of the scanning electrodes in the sub display section. In  FIG. 11 , the sub display section is shown by reducing its size, top to bottom, for illustrative purposes.  
         [0095]     An external view of the liquid crystal panel will be described with reference to  FIG. 10A . A bottom glass substrate  101  (hereinafter referred to as the bottom glass) and a top glass substrate  102  (hereinafter referred to as the top glass) are overlaid one on top of the other by aligning the upper sides and the right and left sides between them. The bottom glass  101  is larger than the top glass  102 , and thus has an area  100  extending beyond the lower side. Two integrated circuits  106  for display are mounted on this area  100 . Inside an area  105  where the bottom glass  101  and the top glass  102  overlap, there are formed a main display section  104  (indicated by dashed lines) in the upper part and a sub display section  103  (indicated by dashed lines) in the lower part as viewed in the plane of  FIG. 10A . The main point of the plan structure of the present embodiment is that the integrated circuits  106  for display are mounted in close proximity to the sub display section  103 .  
         [0096]     The arrangement of the wiring lines and the electrodes and the connections between the integrated circuits  106  and the electrodes will be described by referring to  FIG. 10A  in conjunction with  FIG. 10B . The liquid crystal panel shown is a passive driving liquid crystal panel. Main scanning electrodes  108 , an upper sub scanning electrode  1009 , and a lower sub scanning electrode  1010  are formed (as indicated by dashed lines) on the back surface of the top glass  102  serving as the top substrate, while a plurality of signal electrodes  107 , a plurality of interconnecting wiring lines  1011 ,  1012 , and a plurality of input/output electrodes are formed on the upper surface of the bottom glass  101  serving as the bottom substrate. The interconnecting wiring lines  1011  and  1012  on the left and right sides are brought out from the left and right sides of the left- and right-hand integrated circuits  106 , respectively, and are routed along the peripheral areas of the bottom glass  101  into the areas of the bottom glass  101  that are adjacent to the left and right sides of the main display section  104  and sub-display section  103 . Here, the interconnecting wiring lines  1011  and  1012  are connected by means of anisotropic conductive particles (not shown) to the main scanning electrodes  108  and the upper and lower sub scanning electrodes  1009  and  1010  formed on the top glass  102 . Of the interconnection wiring lines  1011  on the left side, the uppermost wiring line is connected to the lower sub-scanning electrode  1010 , the second uppermost wiring line is connected to the upper sub-scanning electrode  1009  on the top glass  102 , and the remaining wiring lines are connected to the main scanning electrodes  108  formed on the area of the top glass  102  that substantially corresponds to the lower half of the main display section  104 . The interconnection wiring lines  1012  on the right side are connected to the main scanning electrodes  108  formed on the area of the top glass  102  that substantially corresponds to the upper half of the main display section  104 . The comb-shaped electrode portions of the upper and lower sub scanning electrodes  1009  and  1010  are not shown in  FIG. 10 . Further, in the figure, oblique dotted lines indicate that the main scanning electrodes  108  and the signal lines  107  are formed in a repetitive manner.  
         [0097]     The integrated circuits  106  each contain a scanning electrode driving circuit, a signal electrode driving circuit, a liquid crystal panel driving power supply circuit, an interface circuit, and their control circuits integrated on a single chip; in the embodiment of the present invention, NJU6821 manufactured by New Japan Radio Co., Ltd. is used. This integrated circuit  106  has a plurality of input terminals, a plurality of scanning electrode driving terminals, and a plurality of signal electrode driving terminals. These terminals are connected to the connecting portions of the signal electrodes  107 , the interconnecting wiring lines  1011  and  1012 , and the input/output electrodes  1013  via an anisotropic conductive film (ACF, not shown) formed by mixing conductive particles (and insulating particles in some cases) into an insulating adhesive material. NJU6821 used as the integrated circuit here has 80 scanning electrode driving terminals; 40 terminals are arranged on each of the two shorter sides of the rectangular chip. In the present embodiment, of the scanning electrode driving terminals on the left-hand integrated circuit  106 , terminals 0 to 39 (designated COM0 to COM39 in the device specification) are used and, of the scanning electrode driving terminals on the right-hand integrated circuit  106 , terminals 40 to 79 (designated COM40 to COM79) are used. Further, one of the integrated circuits  106  is used in the master mode in which the power supply and other control functions are enabled, and the other integrated circuit  106  is used in the slave mode in which these control functions are disabled. The main display section  104  comprises a dot matrix having 78 lines and a resolution of 100 dpi, while the sub display section  103  has a resolution of 200 dpi.  
         [0098]     As shown in  FIG. 10C , the liquid crystal panel  150  according to the eighth embodiment of the present invention comprises the first glass substrate  101  and the second glass substrate  102 , and the plurality of signal electrodes  200  extending in the vertical direction (as viewed in the plane of  FIG. 10C ) are formed in orderly fashion on one surface of the first glass substrate  101 , while the scanning electrodes  300  are formed on one surface of the second glass substrate  102 ; these electrode arrays are each covered with an alignment film  400 . The first and second glass substrates with the plurality of signal electrodes  200  and the plurality of scanning electrodes  300  formed on their opposing surfaces are sealed with a seal material  500  by providing a gap therebetween, and an electro-optical conversion material, for example, a liquid crystal  600 , is filled into the gap; in this structure, a display image is produced by varying the optical characteristics of the electro-optical conversion material by applying a prescribed voltage to each of the plurality of display pixels formed at positions where the signal electrodes  200  overlap the scanning electrodes  300 . The integrated circuits  106  are mounted between the signal electrodes  200  and external terminals  700 , and signal lines in the integrated circuits are connected between them.  
         [0099]     The plan shapes of the signal electrodes  107  and the upper and lower sub scanning electrodes  1009  and  1010  will be described in further detail with reference to  FIG. 11 . The reference numerals the same as those in  FIG. 10  indicate the same members or areas.  
         [0100]     The plan shape of the signal electrode  107  will be described with reference to  FIG. 11B . The signal electrode  107  comprises, from the top of  FIG. 11B , a strip portion  107  for forming pixels in the main display section  104  shown in  FIG. 10A , a rectangular portion  113  for forming pixels in the sub display section  103  shown in  FIG. 10A , and a strip portion  114  for connection with a signal electrode driving terminal on the integrated circuit  106 , and the respective portions are interconnected by narrow paths. Each portion has the same width, but the width may be made different for each portion. The width of each narrow path is 10 μm.  
         [0101]     The plan shapes of the upper and lower sub scanning electrodes  1009  and  1010  will be described in detail with reference to  FIG. 1C . The upper sub-scanning electrode  1009  comprises a comb-shaped electrode formed with a plurality of rectangular protrusions, protruding downwardly like the teeth of a comb, from a wiring electrode portion of the upper sub-scanning electrode  1009  which extends along the latitudinal direction of the signal electrodes  107 . Likewise, the lower sub scanning electrode  1010  comprises a comb-shaped electrode formed with a plurality of rectangular protrusions, protruding upwardly like the teeth of a comb, from a wiring electrode portion of the lower sub-scanning electrode  1010 . The comb-shaped electrode of the upper sub-scanning electrode  1009  and the comb-shaped electrode of the lower sub-scanning electrode  1010  are arranged alternating with each other in interleaving fashion in the horizontal direction. The width of each comb-shaped electrode tooth is approximately equal to the width of the signal electrode  107 , and the length is also approximately equal to the length of the rectangular portion  113  of the signal electrode  107  in the sub-display section  103 .  
         [0102]     Next, referring to  FIG. 11A , a description will be given of the display pixels formed where the signal electrodes  107  overlap the main scanning electrodes  108  and the upper and lower sub scanning electrodes  1009  and  1010  in the two-dimensional plane. In the figure, the signal electrodes  107  are indicated by solid lines, and the main scanning electrodes  108  and the upper and lower sub scanning electrodes  1009  and  1010  by dashed lines. The pixels in the main display section  104  are square-shaped regions formed at the intersections between the main scanning electrodes  108  and the signal electrodes  107 , and are arranged in a matrix pattern. As the signal electrodes  107  are displaced from the comb-shaped electrodes by a half pitch in the latitudinal direction, a rectangular region  111  overlapping the comb-shaped electrode of the upper sub display electrode  109  and a rectangular region  112  overlapping the lower sub scanning electrode  1010  are formed on the rectangular portion of each signal electrode  107  in the sub display section  103 . The respective regions  111  and  112  are pixels in the sub display section  103 .  
         [0103]     First, a liquid crystal panel was experimentally produced with the electrode structure of the first embodiment employed for the display section, and with the integrated circuits of the eighth embodiment mounted adjacent to the main display section. Generally, in the liquid crystal panel according to the present invention, as the area of each sub scanning electrode is significantly larger than the area of each main scanning electrode, the capacitive load of each sub scanning electrode significantly increases (by a factor of 20 to 40) compared with the capacitive load of each scanning electrode. Further, in the first experimental product, as the integrated circuits had to be connected to the upper and lower sub scanning electrodes by long thin wiring lines, the resistance of the wiring to the sub-scanning electrodes increased. As a result, because of the large wiring resistance and the large capacitive load, the driving voltage to the sub display section was attenuated by about 0.2 V compared with the driving voltage to the main display section, and a situation occurred where the sub display section could not be driven to produce a display while the main display section could be driven properly to produce a display. This problem has been solved by properly setting the conditions, such as reducing the resistance of the interconnecting wiring, lowering the driving frequency (reducing the response speed of the liquid crystal material), and selecting a liquid crystal material having a steep T-V characteristic (the relationship between the transmittance and the root mean square value of the applied voltage).  
         [0104]     The eighth embodiment has been devised by conducting a series of studies aimed at eliminating the above constraints. In the eighth embodiment, the resistance of the wiring to the upper and lower sub-scanning electrodes  1009  and  1010  can be reduced because the driving integrated circuits  106  are mounted adjacent to the sub display section  103 . This serves to reduce the amount of attenuation of the driving voltage and, thereby, to eliminate the above constraints that require reducing the wiring resistance, lowering the driving frequency, and selecting a liquid crystal material having a steep T-V characteristic.  
         [0105]     Generally, the reduction of the wiring resistance is accomplished by increasing the thickness of the transparent electrodes but, in the case of a display apparatus having a reflective function, this method entails a reduction in reflectance. In contrast, since the eighth embodiment allows the use of a wiring material having a relatively high resistance, the reflectance can be increased. Further, in the eighth embodiment, the signal electrodes  107  and the interconnecting wiring lines  1011  and  1012  are arranged as shown in  FIG. 10B . In the area  100 , the signal electrodes  107  have oblique wiring portions. On the other hand, the interconnecting wiring lines  1011  and  1012  are bent at approximately 90°. As a result, the area  100  has regions at its left and right edges where neither the signal electrodes  1087  nor the interconnecting wiring lines  1011  and  1012  are formed. Here, the interconnecting wiring lines for the sub scanning electrodes  1009  and  1010  are increased in width to reduce the wiring resistance. In this way, in the eighth embodiment, the extended area  100  of the bottom glass  101  has a region (space) where no wiring patterns are formed between the signal electrodes  107  and the interconnecting wiring lines  1011 ; therefore, of the interconnecting wiring lines  1011 , the wiring lines connecting to the upper and lower sub-scanning electrodes  1009  and  1010  are made wider than the other wiring lines by using this region, to further reduce the wiring resistance.  
         [0106]     In the present embodiment, the integrated circuits, each capable of driving both the scanning electrodes and the signal electrodes by a single chip, have been mounted on the glass; here, it should be noted that the point of the invention to be achieved by this embodiment is to minimize the wiring resistance between the driving signal supply source and the sub scanning electrodes in the liquid crystal panel. Therefore, if the terminal electrodes, at which the driving signals to the scanning electrodes and the signal electrodes are received, are to be provided only on one side of the liquid crystal panel, the terminal electrodes should be provided on the sub-display section side, as in the sixth embodiment. This method serves to reduce the resistance of the wiring to the sub-scanning electrodes, thus reducing the amount of attenuation of the driving signals. The above description has been given by dealing with the method that mounts the integrated circuits on the glass substrate (the method known as chip-on-glass or COG), but other mounting methods may be used, in which case also, similar effects to those achieved by the present invention can be obtained. These other methods include: a method that mounts an integrated circuit on a flexible film-like substrate (called the flexible printed circuit or FPC), and connects the wiring lines on this substrate to the terminal electrodes on the liquid crystal panel (the method known as chip-on-film or COF); a method that mounts an integrated circuit on a rigid circuit board, and connects between the liquid crystal panel and the circuit board by using a flexible film-like substrate (the method known as chip-on-board or COF); and a method that mounts an integrated circuit on a tape-like substrate (the method known as tape automated bonding or TAB).  
         [0107]     Other than the reduction of the wiring resistance, the eighth embodiment has the feature of facilitating the etching for forming the electrode patterns and the alignment of the top and bottom glasses  101  and  102 , because the shapes of the sub scanning electrodes  1009  and  1010  are simplified compared with the first embodiment.