Patent Publication Number: US-2009225050-A1

Title: Touch panel, liquid crystal display apparatus, and method for manufacturing thereof

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a touch panel to be disposed on a liquid crystal display panel via an air layer, a liquid crystal display apparatus, and a method for manufacturing thereof. 
     2. Description of the Related Art 
     A liquid crystal display apparatus equipped with a touch panel is used in various fields such as POS (Point of Sales) terminals, ATMs (Automatic Teller Machines), ticket machines and car audio equipment. Moreover, a liquid crystal display apparatus equipped with a touch panel is utilized in wide fields such as PDAs (Personal Data assistants) and smartphones which also provide a telephone function. In such a kind of liquid crystal display apparatus, the load imposed by an input plane, which also serves as a display surface, includes load caused by an input operation. Further, in the case of a liquid crystal display apparatus which has an enhanced portability, there is for example a load imposed while it is transported in a bag or carried in the pocket of clothes, and the magnitude of the load as well as the factor to cause the load spans a wide spectrum. Furthermore, due to the characteristics of the application and structure of a liquid crystal display apparatus having a touch panel, a component to be disposed inside the liquid crystal display apparatus is subject to strict dimensional requirements especially when used in a liquid crystal display apparatus that has high percentage of the component occupying the volume of the liquid crystal display, and therefore thickness reduction and weight reduction are necessary conditions for the component. 
       FIG. 1  shows a sectional view of a liquid crystal display apparatus relating to the present invention. As shown in  FIG. 1 , liquid crystal display panel  110  is configured such that TFT substrate  111  disposed with a TFT (Thin Film Transistor) pattern for driving a liquid crystal thereon and color filter substrate  112  formed with an opposing electrode layer thereon are disposed with a liquid crystal layer interposed therebetween. TFT substrate  111  and color filter  112  are attached with polarizing plate  113 ,  114  respectively. Touch panel  120  is of an analog resistive film type in which upper substrate  121  which is formed on one side with a transparent conductive film as a position detection electrode, and lower substrate  122  which is similarly formed with a transparent conductive film are placed such that the transparent conductive films of each substrate  121 ,  122  are opposite each other and the substrates are held by a double-faced adhesive agent provided on the peripheral edge part of each substrate  121 ,  122 . 
     Liquid crystal display panel  110  and touch panel  120  are placed directly on chassis frame  131  or placed in such a way that a double-faced adhesive agent which also has a spacer function to maintain a fixed gap is provided on the peripheral edge part of each panel  110 ,  120 . Further, there is provided air layer  140  having a predetermined thickness between liquid crystal display panel  110  and touch panel  120 . 
     However, in a liquid crystal display apparatus, although it has air layer  140 , due to the effects such as a load to touch panel  120  during input operation, warping of touch panel  120 , warping of liquid crystal display panel  110 , deformation of touch panel  120  and deformation of liquid crystal display panel  110  caused by other loads, and both deformations of those panels  110 ,  120 , there may be a case in which lower substrate  122  of touch panel  120  and polarizing plate  113  disposed on top of liquid crystal display panel  110  come abnormally close to each other. In such a case, in the liquid crystal display apparatus, interference fringes take place and a problem arises in that the display condition is impaired by the interference fringes. Further, there is also a case in which lower substrate  122  of touch panel  120  and polarizing plate  113  of liquid crystal display panel  110  come into contact and stick to each other resulting in a problem in which normal functions such as operation of the liquid crystal display apparatus cannot be performed. 
     As related art for solving such problems, Japanese Utility Model Application Laid-Open No. 03-020832 is disclosed, and a typical configuration example thereof is shown in  FIG. 2 . In this configuration example, it is configured such that dot-form spacer  124  (hereinafter referred as dot spacer  124 ) is disposed within touch panel  120 , and another dot spacer  144  is disposed on lower substrate  122  of touch panel  120  so as to be placed at the same position with dot spacer  124 . Since, with this configuration, the surface of lower substrate  122  of touch panel  120  and the display surface of liquid crystal display panel  110  are kept at a fixed distance, it is possible to achieve the effect of preventing the occurrence of interference fringes. 
     However, in this configuration, dot spacer  214  in touch panel  120  and dot-spacer  144  provided on lower substrate  122  are disposed at the same position. As the result of this, the transmittance of a portion in which dot-spacers  124  and  144  are overlapped is given by T=T 1 ×T 2 ×T 3 , when letting the transmittance of a position without the dot-spacer be T 1 , that of dot spacer  124  of touch panel  120  be T 2 , and that of dot-spacer  144  in air layer  140  be T 3  as shown in  FIG. 3 . Therefore, transmittance T of a portion in which dot-spacers  124  and  144  overlap with each other is inevitably smaller than transmittance T 1  in the position where there is no dot-spacer, and smaller than transmittance T 2  in the case in which the dot-spacer is existent in either in touch panel  120  or in air layer  140 , and smaller than transmittance T 3 . 
     For this reason, when the portion in which dot-spacer  124  and dot-spacer  144  overlap with each other increases, there is a risk of degradation of display performance such that the existence of dot-spacer  124 ,  144  is visually recognizable, or dot-spacer  124 ,  144  is misrecognized as a foreign object in the display panel  110 . Therefore, this configuration has a problem in that it is difficult to concurrently prevent the occurrence of interference fringes and to maintain display performance. 
     Further, in recent years, as shown in  FIG. 4 , there is also disclosed a configuration in which instead of providing an air layer between touch panel  120  and liquid crystal display panel  110 , touch panel  120 , on which adhesive material  151  is provided in advance, is directly pasted to the surface of liquid crystal display panel  110 . However, this configuration has a problem in that the manufacturing cost of a touch panel is high, the yield of a liquid crystal display apparatus in the manufacturing process is low, the initial cost for such equipment investment is high, and the load during the input operation is likely to propagate to the surface of the liquid crystal display panel. Therefore, in this configuration, there are many problems such as that since display irregularities occur when the touch panel is pressed, it is necessary, as a countermeasure thereof, to improve the structure of the liquid crystal display panel. 
     Further, there is a liquid crystal display apparatus having a structure in which instead of using the above described adhesive material, a transparent material such as a resin material is coated on the entire display surface of the liquid crystal display panel and thereafter a touch panel is mounted onto the liquid crystal display panel thereafter curing the resin material. However, in this configuration as well, there are many problems such as high manufacturing cost, low reliability and the like. Therefore, in a liquid crystal display apparatus, in which as the result of taking manufacturing cost and reliability into account, a touch panel in which a structure provided with an air layer is adopted and a touch panel of this structure is mounted, as disclosed in Japanese Patent Laid-Open No. 63-26624 and Japanese Patent Laid-Open No. 2001-51262, in order to prevent the sticking or the occurrence of interference fringes when the touch panel and the liquid crystal display panel come into contact, there is an example which adopts a configuration in which surface roughening is applied to mutually opposing surfaces such as when, for example, a microscopic asperity is provided on the display surface of the liquid crystal display panel or a film processed to have an equivalent asperity is pasted thereto so that the surface of the liquid crystal display panel or the surface of the lower substrate of the touch panel is not a smooth surface. 
     In such a configuration, although the sticking between the liquid crystal display panel and the touch panel and the occurrence of interference fringes may be solved, it is thought that the image quality performance and display performance of a liquid crystal display apparatus will be affected since degradations in display visibility and optical characteristics will be caused. When a sample in which anti-glare processing is applied on the surface of the polarizing plate provided on the color filter substrate making up a liquid crystal display panel is actually fabricated and used, a problem occurs in which fine size characters displayed on the liquid crystal display apparatus are blurred and also in which degradation in contrast occurs in the result of an optical measurement, and in which the level at which actual use becomes possible is not been reached. 
     On the other hand, to solve the above described problems, conventionally, it is necessary to set the thickness of the air layer to a sufficient amount, for example, from about 0.15 mm to 1.0 mm in order that the touch panel and the liquid crystal display panel will not readily come into contact with each other taking into consideration that the warping of the touch panel may take place for example in an amount of about 0.1 mm, and that the liquid crystal display panel or the touch panel may deform due to a load which is imposed during input operation of the touch panel by a specifically designed input pen or by fingers, and due to an environmental load such as heat. Accordingly, a problem remains in which a liquid crystal display apparatus inevitably has a large outer dimension in the thickness direction of the entire apparatus. Therefore, it has been difficult to realize a liquid crystal display apparatus which maintains the display quality of a liquid crystal display apparatus, is inexpensive, and which can be downsized. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a touch panel, a liquid crystal display apparatus and a method for manufacturing thereof, which enables prevention of interference fringes and sticking between the liquid crystal display panel and the touch panel without impairing the display performance of the liquid crystal display panel, and to reduce the thickness of the entire liquid crystal display apparatus. 
     In order to achieve the above described object, the touch panel relating to the present invention includes a dot spacer disposed on an inner transparent conductive film and is configured to be disposed on a display surface of a liquid crystal display panel via an air layer, wherein 
     an another dot spacer is disposed on a surface opposite to the display surface of the liquid crystal display panel at a position which does not overlap with the dot spacer within a predetermined viewing angle range in the display surface. 
     Further, the liquid crystal display apparatus relating to the present invention is configured such that a touch panel including a dot spacer disposed in an inner transparent conductive film is disposed on a display surface of a liquid crystal display panel via an air layer, wherein 
     an another dot spacer is disposed on the air layer at a position which does not overlap with the dot spacer within a predetermined viewing angle range in the display surface. 
     Further, the method for manufacturing a touch panel relating to the present invention comprises: for manufacturing a touch panel which includes a dot space disposed on an inner transparent conductive film and that is disposed on a display surface of a liquid crystal display panel via an air layer, 
     forming an another dot spacer at a position of a surface opposite to the display surface of the liquid crystal display panel, wherein the position does not overlap with the dot spacer within a predetermined viewing angle range in the display surface. 
     Further, the method for manufacturing the liquid crystal display apparatus relating to the present invention comprises: for manufacturing a liquid crystal display apparatus in which a touch panel having a dot spacer disposed on an inner transparent conductive film that is disposed on a display surface of a liquid crystal display panel via an air layer, 
     forming an another dot spacer at a position of the air layer, wherein the position does not overlap with the dot spacer within a predetermined viewing angle range on the display surface. 
     As so far described, according to the present invention, another dot spacer is disposed such that the liquid crystal display panel and the touch panel will not come into contact in the air layer by as an input operation such as using a touch panel, and is disposed so as not to be visually recognized in which the position of the another dot spacer is same as the position of the dot spacer of the touch panel. This configuration enables preventing interference fringes without impairing the display performance of the liquid crystal display panel and preventing sticking between the liquid crystal display panel and the touch panel. As a result of this, according to the present invention, it becomes possible to decrease the thickness of the air layer as well as to decrease the thickness of the touch panel. Therefore, according to the present invention, it is possible to decrease the outer dimension in the thickness direction of the entire liquid crystal display apparatus and thereby realize a liquid crystal display apparatus mounted with an inexpensive and high-quality touch panel. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a sectional view to show a first example of a liquid crystal display apparatus relating to the present invention; 
         FIG. 2  is a sectional view to show a second example of the liquid crystal display apparatus relating to the present invention; 
         FIG. 3  is a sectional view to illustrate transmittance in the second example of the liquid crystal display apparatus relating to the present invention; 
         FIG. 4  is a sectional view to show a third example of the liquid crystal display apparatus relating to the present invention; 
         FIG. 5  is a sectional view to show a first exemplary embodiment; 
         FIG. 6A  is a plan view to show the liquid crystal display apparatus of the first exemplary embodiment; 
         FIG. 6B  is a plan view to show a reference example; 
         FIG. 7  is a sectional view to show in detail the principal part of the liquid crystal display apparatus of the first exemplary embodiment; 
         FIG. 8  is a sectional view to show the liquid crystal display apparatus of a second exemplary embodiment; and 
         FIG. 9  is a schematic view to show a printing apparatus used in the manufacturing method of the present exemplary embodiments. 
     
    
    
     DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS 
       FIG. 5  shows a sectional view of the liquid crystal display apparatus of an exemplary embodiment;  FIG. 6A  shows a plan view of the liquid crystal display apparatus of an exemplary embodiment; and  FIG. 6B  shows a plan view of a reference example.  FIG. 7  shows a detailed sectional view of the principal part of the liquid crystal display apparatus. 
     As shown in  FIG. 5 , liquid crystal display apparatus  1  of a first exemplary embodiment is configured to have liquid crystal display panel  10 , and touch panel  20  which is disposed on the display surface of liquid crystal display panel  10  via air layer  40 . 
     Liquid crystal display panel  10  is configured such that TFT substrate  11 , which is disposed with a TFT pattern for driving a liquid crystal, and color filter substrate  12 , which is formed such that an electrode layer and a color layer are mutually opposite each other, are disposed interposing a liquid crystal layer between substrates  11  and  12 . TFT substrate  11  and color filter substrate  12  are attached with polarizing plate  13 ,  14  respectively. 
     Touch panel  20  is disposed such that upper substrate  21  which is formed on one side with transparent conductive film  23  as a position detection electrode, and lower substrate  22  which is similarly formed on one side with transparent conductive film  23 , are disposed in such a way that transparent conductive films  23  are opposed to each other. Upper substrate  21  and lower substrate  22  are held with double-faced adhesive agent  25  disposed on the outer peripheral edge part of each substrate  21 ,  22 . Liquid crystal display panel  10  has its outer peripheral part being placed directly on chassis frame  31 . Touch panel  20  is placed on chassis frame  31  with double-faced adhesive agent  32  being interposed therebetween, where double-faced adhesive agent  32 , which also performs a spacer function, is disposed on the outer peripheral edge part of touch panel  20  such that a fixed gap is maintained between touch panel  20  and chassis frame  31 . Moreover, there is provided air layer  40  of a predetermined thickness between liquid crystal display panel  10  and touch panel  20 . Further, backlight component  30  is disposed on the back face side of liquid crystal display panel  10  and backlight component  30  is fixed to chassis frame  31 . 
     Further, in the present exemplary embodiment, other dot spacers  41  are disposed on the surface, which faces air layer  40 , of lower substrate  22  of touch panel  20 , that is, the surface opposite to the display surface of liquid crystal display panel  10 . As shown in  FIGS. 6A and 7 , such dot spacers  41  are disposed at positions which do not coincide with those of dot spacers  24  disposed inside touch panel  20  within a normally used viewing angle range in liquid crystal display panel  10 . 
     As to liquid crystal display apparatus  1  configured as described above, actions relating to the disposition of another dot spacer  41  will be described. 
     Now, as shown in  FIG. 7 , let a maximum angle in a viewing angle range, in which the visibility of liquid crystal display panel  10  is not impaired, be θmax centering on dot spacer  24  disposed inside touch panel  20 . In this case, the range in which positional interference with dot spacer  24  inevitably takes place is given as within a circular region defined by a diameter L and is obtained by projecting a region surrounding dot spacer  24  which is determined depending on a predetermined viewing angle range onto a surface opposite to the display surface. Dot spacer  41  is disposed in the rear face of lower substrate  22  of touch panel  20  in such a way that there is a portion which does not overlap the circular region. 
       FIG. 6A  shows a configuration in which the circular region of dot spacer  24  does not overlap with dot spacer  41  at all in the present exemplary embodiment, with dot spacer  41  being disposed outside the circular region.  FIG. 7  is a sectional view to show the position of dot spacer  41  with respect to dot spacer  24 . As a reference example,  FIG. 6B  shows a configuration example of a state in which the circular region of dot spacer  24  interferes with the position of part of dot spacer  41 . 
     Diameter L of the circular region, when another dot spacer  41  is not disposed, is calculated by the following equation. 
         L= 2×(thickness (mm) of lower substrate 22 of touch panel 20)×tan(θmax)   (Equation) 
     As the result of another dot spacer  41  being disposed so as not overlap with the circular region of diameter L which satisfies the above equation, it becomes possible to prevent that dot spacers  24  and  41  from being viewed as overlapping each other within a viewing, angle range which is normally used, when the display area on the display surface of the liquid crystal display apparatus is viewed. Therefore, according to the present exemplary embodiment, compared with a configuration relating to the present invention in which dot spacer  41  is not provided in air layer  40 , it becomes possible to prevent impairment of visibility, and also to prevent sticking between lower substrate  22  of touch panel  20  and the surface of liquid crystal display panel  10  as well as the occurrence of interference fringes. 
     As a specific exemplary embodiment, assuming that the viewing angle within which the display performance of a liquid crystal display panel will not be impaired corresponds to a case in which the contrast ratio of white and black intensities is not less than 10:1, when maximum angle θmax is supposed to be 45 degrees and when the thickness of lower substrate  22  of touch panel  20  is supposed to be 0.5 mm, diameter L of the circular region will be 1.0 mm. As shown in  FIG. 6A , as the result of another dot spacer  41  being disposed such that there is a portion which does not overlap with the circular region, it is prevented that another dot spacer  41  and dot spacer  24  are prevented from being visually recognized as overlapping each other. 
     However, it is not necessary to have a configuration in which absolutely no overlapping takes place in the entire display area of the liquid crystal display apparatus. For example, a circular region of diameter L and dot spacer  41  may be overlapped in a portion of the region where demand for the magnitude of viewing angle range is relative low, such as upper and lower side edges and left and right side edges of a display area. When the use of a liquid crystal display apparatus is clearly defined such as when the above mentioned portion or the liquid crystal display apparatus is used in a fixed state in which the viewing angle characteristic in a fixed direction is always important, since a state in which dot spacers  24  and  41  are visually recognized as overlapped with each other as shown in  FIG. 6B  is relatively not likely to take place even when dot spacers  24  and  41  interfere with each other in the circular region of diameter L, there is low risk of visibility being impaired. 
     Moreover, the height of dot spacer  41  in the thickness direction of touch panel  20  is set to be smaller than the thickness of air layer  40  taking into consideration that an excessive load will not be applied such that display irregularities of liquid crystal display panel  10  will be reduced, which takes place when a pressing load is applied to the surface of upper substrate  21  of touch panel  20  by pressing the surface with a pen or a finger tip and thereby dot spacer  41  that is placed on lower substrate  22  of touch panel  20  locally presses the surface of liquid crystal display panel  10 . Moreover, dot spacer  41  is formed like a cone having a circular base whose diameter is about 50 μm. Further, since dot spacer  41  is formed into a size equal to that of dot spacer  24  in touch panel  20  and since transmittance in the vertical direction (thickness direction of touch panel  20 ) is set to be equal to or not more than that of dot spacer  24  so that the base area of dot spacer  41  is smaller than the minimum pixel unit of liquid crystal display panel  10 , the display quality will not be impaired. 
     As the result of providing dot spacer  41 , when an input operation is performed onto the surface of upper substrate  21  of touch panel  20  with a pen or a finger tip, although touch panel  20  is deflected and lower substrate  22  of touch panel  20  and the surface of polarizing plate  13  of liquid crystal display panel  10  come closer to each other, the range where the surface of liquid crystal display panel  10  and the surface of lower substrate  22  of touch panel  20  come closer to each other in a plane is limited since dot spacer  41  is disposed on lower substrate  22  of touch panel  20 . As the result of this, it becomes unlikely that the surface of liquid crystal display panel  10  and the surface of lower substrate  22  of touch panel  20  are always in close proximity or stick to each other, and thus it also becomes possible to suppress the occurrence of interference fringes. 
     Further, dot spacer  41  is formed of an acryl-based resin and the hardness of dot spacer  41  is adapted to be lower than the surface hardness of polarizing plate  13  of liquid crystal display panel  10 . As the result, a press mark is prevented from being formed on the surface of polarizing plate  13  even when dot spacer  41  comes into contact with and presses the surface of polarizing plate  13 . These effects enable decreasing the thickness of air layer  40  to a size at which interference fringes cannot take place even when the surface of liquid crystal display panel  10  and lower substrate  22  of touch panel  20  get closer to each other, thus enabling a reduction in the thickness dimension of entire liquid crystal display apparatus  100  thereby achieving thickness reduction. 
     Next, the method for manufacturing the liquid crystal display apparatus of exemplary embodiments will be described. Description will be made on a method of forming dot spacer  41  on the surface of lower substrate  22  of touch panel  20  in liquid crystal display apparatus  1  in the assembly process of liquid crystal display apparatus  100 . As shown in  FIG. 5 , touch panel  20 , which has been prepared as a component of liquid crystal display apparatus  1 , is of an analog resistive film type in which upper substrate  21 , which is formed on one side with transparent conductive film  23  as a position detection electrode, and in which lower substrate  22 , which is similarly formed with transparent conductive film  23 , are disposed such that transparent conductive films  23  are opposite each other and are held by double-faced adhesive agent  25  provided on the peripheral edge part of each substrate  21 ,  22 . There are disposed at a pitch of 3 mm on transparent conductive film  23  of lower substrate  22 , dot spacers  24  which is formed into sizes in which the diameter of the base is 50 μm and in which the height is 50 μm, using, for example, an acryl-based resin. Lower substrate  22  of touch panel  20  is formed of, for example, silica glass to have a thickness of 0.5 mm. Dot spacer  41  is provided by being printed on the surface of lower substrate  22  of touch panel  20 . 
     Dot spacer  41  is formed by printing by use of, for example, an inkjet-type printing apparatus. For example, as shown in  FIG. 9 , printing apparatus  61  is configured to include nozzle part  62  for ejecting a resin material to form dot spacer  41 , nozzle driving part  63  for driving nozzle part  62 , driving stage  64  on which touch panel  20  is placed, stage driving part  65  for driving driving stage  64 , UV (ultraviolet ray) irradiation part  66  for irradiating touch panel  20  on which dot spacer  41  has been printed with an ultraviolet ray, and control part  67  for controlling nozzle driving part  63 , stage driving part  65 , and UV irradiation part  66  respectively. 
     First, touch panel  20  is placed at a fixed position of driving stage  64  of printing apparatus  61  with the printing surface facing upward. Driving stage  64  and nozzle part  62  are moved to a preprogrammed position based on a command to start the print operation which starts the printing of dot spacer  41  on the surface of lower substrate  22  of touch panel  20 . A colorless and transparent acryl-based resin having ultraviolet curability is used as the resin material that is to be ejected from nozzle part  62 . Because only dot spacer  41  is being printed, it takes time until dot spacer  41  hardens, and because the printed shape will change before dot spacer  41  dries, dot spacer  41  is irradiated with an ultraviolet ray and is thereby caused to adhere to the glass substrate. 
     Driving stage  64 , on which touch panel  20  printed with dot spacer  41  is placed, is moved to a position opposite to UV irradiation part  66  so that the print surface of touch panel  20  is irradiated with an ultraviolet ray. UV irradiation part  66  is of a type which can irradiate light having a wavelength of  185  nm to  405  nm with ultraviolet ray irradiation, and there is concern that the temperature of touch panel  20  may rise due to the irradiation of light. For that reason, an LED (light emitting diode) which is comparatively able to suppress the temperature rise of the object to be irradiated is used as the light source. By irradiating the resin material ejected onto the print surface with an ultraviolet ray which is set to have an irradiation intensity of 300 mW/cm 2 , the resin material is hardened within about 10 seconds thereby completing the printing process. Then, touch panel  20 , which has been formed with dot spacer  41 , is removed from driving stage  64 . By mounting touch panel  20  printed with dot spacer  41  onto a liquid crystal display apparatus which is halfway through assembling and which is in a state prior to the start of the process of mounting touch panel  20 , touch-panel equipped liquid crystal display apparatus  100  is completed. 
     It is noted that although a configuration in which dot spacer  41  is formed by an inkjet-type printing method is adopted, it may of course be formed by for example, screen printing, photolithography, and the like. 
     As so far described, liquid crystal display apparatus  1  is configured such that another dot spacer  41 , whose size is minute, is disposed in air layer  40 , which is provided between liquid crystal display panel  10  and touch panel  20 , at a position which is different from that of dot spacer  24  of touch panel  20  within a predetermined viewing angle range normally used for the display of liquid crystal display panel  10 . Since, with another dot spacer  41  being disposed in this way, positional interference between dot spacers  24  and  41  does not take place, it becomes possible to prevent a direct contact between the surface of liquid crystal display panel  10  and the rear face of touch panel  20  without highlighting the existence of the dot spacers, thereby constantly keeping a fixed spacing even when liquid crystal display panel  10  and touch panel  20  come close to each other. In this respect, liquid crystal display apparatus  1  has an advantage in that it can maintain display performance and inhibit the occurrence of interference fringes thus further preventing a decline in optical performance. Therefore, according to liquid crystal display apparatus  1 , it becomes possible to decrease the thickness of air layer  40  and thereby reduce the outer dimension in the thickness direction of entire liquid crystal display apparatus  1  thereby, achieving thickness reduction and weight reduction. 
     Second Exemplary Embodiment 
       FIG. 8  shows the liquid crystal display apparatus of a second exemplary embodiment. The present exemplary embodiment is different from the first exemplary embodiment in that dot spacer  43  is formed on the surface of polarizing plate  13  included in color filter substrate  12  which makes up the liquid crystal display panel. 
     As shown in  FIG. 8 , projection-like dot spacers  43  of a predetermined size are formed in a regular arrangement on polarizing plate  13  on color filter substrate  12  by use of a printing and coating method onto the surface of polarizing plate  13  which is generally practiced in the manufacturing process of polarizing plate  13 . Subsequently, polarizing plate  13  on which dot spacers  43  have been made is pasted onto color filter substrate  12  of liquid crystal display panel  10  to make up liquid crystal display panel  10 . At this moment, dot spacer  43  that is to be formed on polarizing plate  13  is defined and processed so as to be disposed at a position where interference with dot spacer  24  in touch panel  20  can be avoided. 
     Further, the design must be such that when the positional accuracy in pasting polarizing plate  13  with respect to liquid crystal display panel  10  is set to be plus and minus 0.3 mm for both the up-and-down and left-and-right directions, the mounting position of touch panel  20  with respect to the liquid crystal display apparatus can be adjusted by plus and minus 0.3 mm in both the up-and-down and left-and-right directions. In practice, since dot spacer  43  formed on the surface of polarizing plate  13  and dot spacer  24  of touch panel  20  are defined to be in such a position that they do not overlap with each other in position, transmittance decline is suppressed to a minimum and therefore display performance will not be affected by the level of incidence in which interference occurs by partial overlapping of dot spacer  43  and dot spacer  24 . 
     It is noted that electronic equipment to which the present invention is preferably applied includes: for example, liquid crystal display apparatuses equipped with a touch panel, for example, a liquid crystal display apparatus which is equipped with a touch panel and which has a telephone function as well; portable liquid crystal display apparatuses such as PDAs and mobile computers; car navigation systems as well as liquid crystal display apparatuses which involve relatively frequent input operations such as POS terminals at convenience stores, ATMs and ticket machines. 
     While the invention has been shown and described with particular reference to exemplary embodiments thereof, the invention is not limited to these embodiments. It will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the claims. 
     This application is based upon and claims the benefit of priority from Japanese patent application No. 2008-53330, filed on Mar. 4, 2008, the disclosure of which is incorporated herein in its entirety by reference.