Abstract:
A Manufacturing method for reflecting panel of reflective liquid crystal display. The developing/etching time for the photoresistor layer is such controlled as to achieve rough bottom faces under insufficient development and incomplete etching. Multiple polishedmicro-mirror face protuberances remain to achieve better optical properties. By means of the manufacturing method, the strength of the reflected light is controlled to produce uniform light and reduce glare.

Description:
BACKGROUND OF THE INVENTION 
     The present invention is related to a manufacturing method for reflecting panel of reflective liquid crystal display, in which the exposure time or developing/etching time is controlled to achieve insufficient exposure or incomplete development for creating small etching depth. 
     FIGS. 5A to  7  show the manufacturing method for a reflecting panel of a conventional liquid crystal display. The reflecting panel  8  of the such liquid crystal display includes a substrate board  81  which is sprayed with photoresistor  82  and preheated. Then the reflecting panel  8  is covered by a photomask  9  and exposed. Then a developer is used to develop the exposed section or not exposed section so as to form multiple protuberance  83  on the photoresistor  82 . Then the semiproduct of reflecting panel  8  is placed upright and heat-treated to soften the protuberances  83  and round the surface thereof. Finally, a metal film  84  is precipitated onto the reflecting panel  8  to naturally form multiple deformed sections  841  and multiple bottom faces  842 . The deformed section  841  has an asymmetrical section. Light beam is reflected by the deformed section  841  at a predetermined angle. 
     The photoresistor  82  of the reflecting panel  8  of the liquid crystal display is etched by an etchant. However, the etching depth is very small. Therefore, in heat-treatment, it is hardly apparent to make the protuberances  83  flow downward due to gravity and it is difficult to achieve a desired deformation amount of the deformed section  841 . In FIG. 5, the substrate board  81  is tilted to help in making the asymmetrical section. However, the shape of the deformed section  841  is hard to control. Moreover, the photoresistor is thoroughly etched downward to the substrate board  81 . After the metal film  84  is precipitated, the bottom faces  842  are polished faces which totally reflect the light. As a result, the reflected light is very strong and glare. A human eye can hardly stare the panel for a long time and clearly see the picture shown by the display. 
     SUMMARY OF THE INVENTION 
     It is therefore a primary object of the present invention to provide a manufacturing method for reflecting panel of reflective liquid crystal display. The exposure time or developing/etching time for the photoresistor of the reflecting panel is controlled to achieve insufficient exposure or incomplete development/etching. The etched bottom faces have irregular roughness for scattering light beam and controlling strength of the reflected light as well as reduce glare. Therefore, the display can display clearer pictures. 
     The present invention can be best understood through the following description and accompanying drawings wherein: 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a flow chart of the present invention; 
     FIG. 2A shows a first step of the manufacturing procedure of the present invention; 
     FIG. 2B shows a second step of the manufacturing procedure of the present invention; 
     FIG. 2C shows a third step of the manufacturing procedure of the present invention; 
     FIG. 2D shows a fourth step of the manufacturing procedure of the present invention; 
     FIG. 2E shows a fifth step of the manufacturing procedure of the present invention; 
     FIG. 3 is a top view of the present invention; 
     FIG. 4 shows that the reflecting panel of the present invention scatters light beam; 
     FIG. 5A shows a first step of the manufacturing procedure of a conventional reflecting panel of reflective liquid crystal display; 
     FIG. 5B shows a second step of the manufacturing procedure of a conventional reflecting panel of reflective liquid crystal display; 
     FIG. 5C shows a third step of the manufacturing procedure of a conventional reflecting panel of reflective liquid crystal display; 
     FIG. 5D shows a fourth step of the manufacturing procedure of a conventional reflecting panel of reflective liquid crystal display; 
     FIG. 5E shows a fifth step of the manufacturing procedure of a conventional reflecting panel of reflective liquid crystal display; 
     FIG. 5F shows a sixth step of the manufacturing procedure of a conventional reflecting panel of reflective liquid crystal display; 
     FIG. 6 is a side sectional view of the conventional reflecting panel of reflective liquid crystal display, showing that the light beam is reflected by the reflecting panel; and 
     FIG. 7 is a top view of the conventional reflecting panel of reflective liquid crystal display. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Please refer to FIGS. 1 to  4 . The present invention includes steps of: 
     First step  11  of spraying photoresistor: spraying a photoresistor layer  3  onto a top face of a rotated glass substrate material  2 , the photoresistor layer  3  being positive or negative photoresistor, such as Clariant Azp 4620; 
     Second step  12  of exposure: preheating the glass substrate material  2  sprayed with the photoresistor layer  3  in first step  11  at 93° C. for 3 minutes, then the top face of the glass substrate material  2  being covered by a photomask  4  and exposed to UV light (12 mj) for about 25 seconds, the photomask  4  having multiple perforations  41  with predetermined shapes, whereby the photoresistor layer  3  is exposed to form multiple exposed sections  31  and multiple not exposed sections  32  with predetermined shapes; 
     Third step  13  of incomplete development/etching: immerging the semiproduct of reflecting panel exposed in second step  12  into an etchant (not shown) such as a developer, whereby the multiple exposed sections  31  or multiple not exposed sections  32  of the photoresistor layer  3  are incompletely developed/etched, with the multiple exposed sections  31  exemplified, the exposed sections  31  being etched by the etchant and thinned downward to form multiple rough etched bottom faces  33  without touching the substrate board  2 , while the multiple not exposed sections  32  being not developed/etched by the developer, in the third step  13 , the developing/etching time being controlled to be 80 seconds about one half to one third of the conventional time so as to achieve insufficient development and incomplete etching and provide a rough spreading etching effect, the roughness of the surface of the etched bottom faces  33  being within a range of 0.1 μm to 10 μm, the multiple not etched and not exposed sections  32  protruding beyond the etched bottom faces  33  and having a cross-sectional shape complementary to the shape of the photomask  4 , the cross-section being circular, arched, strip-shaped or polygonal or having various shapes which are mixedly arranged, the dimension of length, width and height of the not exposed sections  32  being within a range of about 0.5 μm to 100 μm; 
     Fourth step  14  of heat-treatment: heat-treating the reflecting panel incompletely developed/etched in the third step  13 , that is, heating the reflecting panel to 180° C. for 30 minutes so as to soften the top sections of the not exposed sections  32  into dome-like face, whereby each of the not exposed sections  32  is formed as a micro-mirror face protuberance  34 ; and 
     Fifth step  15  of precipitating metal layer  5 : precipitating a metal film  5  with very thin thickness (such as Al, Ag, Ni, Cr, etc.) onto the top face of the photoresistor layer  3  heat-treated in the fourth step  14  for reflecting light beam, the metal film  5  being one single laminate or multiple laminates, the metal film  5  having multiple spreading faces  51  on the etched bottom faces  33 , the multiple spreading faces  51  having the same roughness as the etched bottom faces  33 , the metal film  5  also having multiple micro-mirror faces  52  on the micro-mirror face protuberances  34 . 
     In third step  13 , the development is performed in shorter time so that the exposed sections  31  of the photoresistor layer  3  are etched to a shallower depth and thus the etched bottom faces  33  have shallower depth. When etched, the etched bottom faces  33  are naturally formed with fine roughness which leads to the same roughness of the spreading faces  51  of the metal film  5  precipitated thereon. The spreading faces  51  have multiple irregular protrusions with different sizes and angles so that the light beam will be reflected in different angles and scattered so as to uniform the light reflected by the micro-mirror faces  52 . Therefore, the pictures displayed by the display will not have glare and the screen of the display will be clearer. 
     In second step  12 , the photoresistor layer  3  can be also exposed in shorter time so as to have the exposed sections  31  with shallower depth. This can also achieve the incomplete development as in third step  13 . In addition, in fourth step  14  of precipitating metal film, the etched bottom faces  33  of the reflecting panel can be naturally formed with spreading faces  51  for scattering light and controlling strength of the reflected light and reduce glare. Therefore, the screen of the display will be clearer. 
     The above embodiments are only used to illustrate the present invention, not intended to limit the scope thereof. Many modifications of the above embodiments can be made without departing from the spirit of the present invention.