Abstract:
A rotating apparatus for a liquid crystal display comprises: a main body provided with a mounting recess having a predetermined radius of curvature; a liquid crystal display provided, at its bottom surface, with a curved portion corresponding to the mounting recess so that the curved portion rotates in surface contact with the surface of the mounting recess; and an angle regulator for guiding the rotation, in a predetermined direction, of the LCD and setting a position of the LCD when rotated to a predetermined position. The angle regulator includes: a plurality of bosses protruding from the bottom surface of the LCD; guide holes formed along a curvature of the mounting recess so as to form passageways through which the bosses are rotated; guide rails protruding from both sides of the guide holes toward the bottom surface of the mounting recess; and sliders which slide along the guide rails and engage the bosses.

Description:
CLAIM OF PRIORITY 
     This application makes reference to, incorporates the same herein, and claims all benefits accruing under 35 U.S.C. §119 from an application entitled ROTATING APPARATUS FOR LIQUID CRYSTAL DISPLAY earlier filed in the Korean Intellectual Property Office on 28 Jan. 2004 and thereby duly assigned Serial No. 2004-5519. 
     BACKGROUND OF THE INVENTION 
     1. Technical Field 
     The present invention relates to a rotating apparatus for a liquid crystal display and, more particularly, to a rotating apparatus for a liquid crystal display capable of enabling a fine angle adjustment and simplifying its rotation structure by rotating the entire liquid crystal display in such a manner that angle adjustment of the liquid crystal display is made by a surface contact of its lower surface rather than by a hinge shaft. 
     2. Related Art 
     Generally, an electronic device such as a telephone (e.g., key-phone terminal), a printer, etc. employs a liquid crystal display (hereinafter refer to as ‘LCD’) to display a set operation mode and an operational state of the device as a user manipulates a button of the device. 
     The LCD is constituted so as to enable angle adjustment of the LCD from a main body of the electronic device (such as the telephone or the printer), thereby providing convenience of use. 
     An example of an angle adjusting device of an LCD has been disclosed in Korean Patent Publication No. 1997-0031647, entitled ANGLE ADJUSTING DEVICE FOR LCD OF A TELEPHONE filed by the assignee of the present invention. 
     In the angle adjusting device for the LCD of the telephone, a wired or wireless telephone comprises: an upper cover provided with an LCD mounted thereon and fixed thereto by a screw; a lower cover engaged with the upper cover and fixed to an upper housing of the telephone; a hinge enabling the upper cover and the lower cover to be rotated within a predetermined angle; a first groove, a second groove, a third groove and a fourth groove for indicating an angle of the LCD, respectively; a lock for locking the LCD after the completion of the angle adjustment of the LCD; a resilient member which pushes the lock into inner parts of the grooves by a resilient force when the lock protrudes into inlets of the first to fourth grooves; and a handle for moving the upper cover and the lower cover upward and downward. The angle adjustment step of the LCD is composed of four steps. 
     However, the conventional LCD angle adjusting device, as described above, has a problem in that fine angle adjustment is impossible since the angle adjustment is accomplished by the predetermined four steps. 
     In addition, prior art arrangements have other problems, such as increase in the number of parts, excessive assembly time, and an unacceptable failure rate, since the lock is supported by the resilient means so as to require a large number of parts for adjusting the angle of the LCD. 
     In order to solve the problems described above, the present inventor has disclosed a new configuration in Korean Patent No. 10-0299130, entitled ANGLE ADJUSTING STRUCTURE FOR AN LCD. 
     A vertical angle adjusting device of an LCD can be vertically rotated about a coupling axis by hinging both side walls of a mounting recess of a main body housing with both sides of one end of the LCD. The vertical angle adjustment device is installed at a lower case of the LCD, is provided with a sawtooth thread formed like a part of a circular gear about the coupling axis, and a resilient rib integrally formed with the housing at the mounting recess of the main body housing so as to correspond with the sawtooth thread. A sharply protruding shape is coupled with the sawtooth thread, and when the LCD is rotated about the coupling axis, the end part of the resilient rib is inserted and fixed into recesses of the sawtooth thread by stages. 
     However, the latter configuration has a problem in that the above composition still cannot accomplish a very fine and smooth angle adjustment, although its angle adjustment width is somewhat decreased in comparison to the former configuration. 
     Further, the latter configuration is also burdened by an inferior design due to external protrusion of the angle adjusting device. 
     The following patents are considered to be generally pertinent to the present invention, but are burdened by the disadvantages set forth above: U.S. Pat. No. 5,808,860 to Ohgami et al., entitled PORTABLE ELECTRONIC APPARATUS WITH DETACHABLY MOUNTED KEYBOARD, issued on Sep. 15, 1998; U.S. Pat. No. 5,764,476 to Ohgami et al., entitled PORTABLE ELECTRONIC APPARATUS HAVING A BASE A DISPLAY AND A MICROPHONE, issued on Jun. 9, 1998; U.S. Pat. No. 5,497,296 to Satou et al., entitled ELECTRONIC APPARATUS WITH HINGED DISPLAY AND LATCH MECHANISM FOR RELEASABLY LATCHING DISPLAY IN CLOSED POSITION, issued on Mar. 5, 1996; U.S. Pat. No. 5,691,880 to Sato et al., entitled PORTABLE ELECTRONIC APPARATUS HAVING A HINGE MECHANISM WHICH ROTATABLY CONNECTS A FLAT DISPLAY UNIT TO A HOUSING INCORPORATING A FRAME FOR SUPPORTING A CIRCUIT BOARD, issued on Nov. 25, 1997; U.S. Pat. No. 4,571,456 to Paulsen et al., entitled PORTABLE COMPUTER, issued on Feb. 18, 1986; U.S. Pat. No. 5,796,579 to Nakajima et al., entitled PORTABLE ELECTRONIC APPARATUS HAVING EXPANSION CONNECTOR COVERED BY PIVOTALLY MOUNTED UPPER AND LOWER COVERS HAVING LATERALLY EXTENDING GUIDE PORTIONS, issued on Aug. 18, 1998; and U.S. Pat. No. 5,689,400 to Ohgami et al., entitled PORTABLE ELECTRONIC APPARATUS INCLUDING SPACE-SAVING COMPONENT MOUNTING FEATURES, issued on Nov. 18, 1997. 
     SUMMARY OF THE INVENTION 
     It is, therefore, an object of the present invention to provide a rotating apparatus for an LCD capable of finely adjusting an angle of the LCD and smoothly adjusting the same. 
     It is another object of the present invention to provide a rotating apparatus for an LCD capable of decreasing shaking of the LCD by decreasing the tolerance of parts through a simplified composition of the angle adjusting device. 
     It is a further object of the present invention to provide a rotating apparatus for an LCD capable of decreasing noise on adjusting the angle by constituting the angle adjusting device in a sliding type arrangement or configuration. 
     It is still another object of the present invention to provide a rotating apparatus for an LCD capable of smoothly accomplishing angle adjustment of the LCD by rotating the LCD through a line contact. 
     According to an aspect of the present invention, there is provided a rotating apparatus for an LCD comprising: a main body provided with a mounting recess having a predetermined radius of curvature; an LCD provided with a curved portion, corresponding to the mounting recess, at its bottom surface so as to allow the curved portion to be rotated in line contact with the surface of the mounting recess; and an angle regulator for guiding rotation, in a predetermined direction, of the LCD, and setting a rotational position of the LCD to a predetermined position. 
     At least one first rib protrudes at an inner surface of the mounting recess, and a second rib protrudes at an alternate position of the first rib at a bottom surface of the curved portion. 
     The angle regulator includes: a plurality of bosses protruding from the bottom surface of the LCD; guide holes formed along a curvature of the mounting recess to form passageways through which the bosses are rotated; guide rails protruding from both sides of the guide holes toward the bottom surface of the mounting recess; and sliders which slide along the guide rails and engage the bosses. 
     Each slider includes a pressing surface contacting an upper surface of the guide rail, and side surfaces bent perpendicular to both sides of the pressing surface so as to be inserted between both side surfaces of the guide rail. A gap between the side surfaces is smaller than that between exterior side surfaces of the guide rail so as to be tightly fitted therein. 
     A first contact protrusion in line contact with the upper surface of the guide rail is formed at an inner portion of the pressing surface of the slider; a second contact protrusion in surface contact with the exterior surface of the guide rail is additionally formed at an inner portion of both side surfaces of the slider; and a boss groove, in which an upper end of the boss is inserted, is additionally formed at the inner portion of the pressing surface of the slider. 
     A rounded portion, having a curvature corresponding to the curvature of the guide rail, is formed at lower ends of both side surfaces of the slider using POM (polyoxymethylene) as a self-lubricant material. 
     The slider and the boss are fastened by a fastening screw, and the tightening force of the fastening screw is greater than a rotational force by weight of the LCD. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A more complete appreciation of the invention, and many of the attendant advantages thereof, will be readily apparent as the same becomes better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings in which like reference symbols indicate the same or similar components, wherein: 
         FIGS. 1 and 2  illustrate a configuration of an angle adjusting device for a liquid crystal display; 
         FIG. 3  illustrates another configuration of an angle adjusting device for a liquid crystal display; 
         FIG. 4  illustrates an angle adjusting device for a liquid crystal display in accordance with an embodiment of the present invention; 
         FIG. 5  is a disassembled view of an angle adjusting device for a liquid crystal display in accordance with an embodiment of the present invention; 
         FIG. 6  illustrates a bottom surface of the arrangement of  FIG. 5 ; 
         FIG. 7  illustrates a bottom surface of an angle adjusting device for a liquid crystal display in accordance with an embodiment of the present invention; 
         FIG. 8  illustrates a rotated state of the bottom surface of the angle adjusting device for a liquid crystal display in accordance with an embodiment of the present invention; 
         FIG. 9  is a cross-sectional view taken along the line  7 A- 7 A′ of  FIG. 7 ; 
         FIG. 10  is a perspective view illustrating a configuration of a slider of the present invention; and 
         FIG. 11  illustrates a bottom surface of the LCD in accordance with an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention will now be described more fully with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in different forms, and the invention should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, the thickness of layers and regions are exaggerated for clarity, and like numbers refer to like elements throughout the specification. 
     Referring to  FIGS. 1 and 2 , in the angle adjusting device for the LCD of a telephone, a wired or wireless telephone comprises: an upper cover  14  provided with an LCD  20  mounted thereon and fixed thereto by a screw; a lower cover  16  engaged with the upper cover  14  and fixed to an upper housing  12  of the telephone; a hinge  22  enabling the upper cover  14  and the lower cover  16  to be rotated within a predetermined angle; a first groove  26 , a second groove  28 , a third groove  30  and a fourth groove  32  for indicating an angle of the LCD  20 , respectively; a lock  24  for locking the LCD  20  after the completion of the angle adjustment of the LCD  20 ; a resilient member  25  which pushes the lock  24  into inner parts of the grooves by a resilient force when the lock  24  protrudes into inlets of the first to fourth grooves  26 ,  28 ,  30  and  32 ; and a handle  18  for moving the upper cover  14  and the lower cover  16  upward and downward. The angle adjustment step of the LCD  20  is composed of four steps. 
     However, the LCD angle adjusting device as described above has a problem in that fine angle adjustment is impossible since the angle adjustment is accomplished by the predetermined four steps. 
     In addition, the LCD angle adjusting device as described above has other problems, specifically, an increased number of parts, an excessive assembly time, and an unacceptable failure rate, since the lock  24  is supported by the resilient member  25  so as to require a large number of parts for adjusting the angle of the LCD. 
     Referring to  FIG. 3 , a vertical angle adjusting device of an LCD  40  can be vertically rotated about a coupling axis by hinging both side walls of a mounting recess  18  of a main body housing  10  with both sides of one end of the LCD  40 . The vertical angle adjustment device is installed at a lower case of the LCD  40 , and is provided with a sawtooth thread  33  formed like a part of a circular gear about the coupling axis, and a resilient rib  52  integrally formed with the housing at the mounting recess  18  of the main body housing  10  so as to correspond with the sawtooth thread. A sharply protruded shape is coupled with the sawtooth thread, and when the LCD  40  is rotated about the coupling axis, the end part of the resilient rib  52  is inserted and fixed into recesses of the sawtooth thread by stages. 
     However, the latter configuration has a problem that the above composition still cannot accomplish a very fine and smooth angle adjustment, although its angle adjustment width is somewhat decreased in comparison to the former configuration. 
     Furthermore, the latter configuration also is burdened by an inferior design due to external protrusion of the angle adjusting device. 
     As shown in  FIG. 4 , a main body  100  (shown as a key phone terminal) is provided with a mounting recess  110  having a predetermined radius of curvature so that the LCD  200  is rotatably mounted in a vertical direction. 
     The LCD  200  is provided with an upper case  210 , a lower case  230 , and an LCD plate  250  installed between the cases  210  and  230 . A curved portion  231 , having a predetermined radius of curvature corresponding to the mounting recess  110 , is formed at a lower side of a bottom surface of the lower case  230 . 
     As shown  FIGS. 5 and 11 , a first rib  111  in line contact with a bottom surface of the curved portion  231  protrudes from the inner surface of the mounting recess  110 , and a second rib  231   a  in line contact with the inner surface of the mounting recess  110  protrudes in an alternate position with the first rib  111  at a bottom surface of the curved portion  231 . 
     In this connection, the height of the first rib  111  is made greater than that of the second rib  231   a , and the bottom surface of the curved portion  231  initially contacts the upper surface of the first rib  111 . The second rib  231   a  is additionally manufactured in consideration of the distribution of force or a difference between heights of each part, and the like. 
     As described above, the LCD  200  is constructed so that the curved portion  231  can be smoothly and vertically rotated by line contact with the mounting recess  110 , and thereby rotated by an angle regulator  270  (see  FIG. 6 ) at a predetermined angle, and then stopped. 
     As shown in  FIGS. 5 to 8 , the angle regulator  270  includes: a plurality of bosses  271  protruding from the bottom surface of the LCD  200 ; a guide hole  272  formed along a curvature of the mounting recess  110  to form a passageway through which the boss  271  is rotated; a guide rail  273  protruding at both sides of the guide hole  272  toward the bottom surface of the mounting recess  110 ; and a slider  290  for sliding along the guide rail  273  and engaging with the boss  271 . 
     As shown in  FIG. 10 , the slider  290  includes a pressing surface  291  contacting an upper surface of the guide rail  273 , and side surfaces  293  and  295  bent at a right angle relative to both sides of the pressing surface  291  for insertion between both side surfaces of the guide rail  273 . 
     A gap d between both side surfaces  293  and  295  is, as shown in  FIG. 6 , smaller than a gap D between exterior surfaces of the guide rail  273  so as to achieve a tight fit therein. Therefore, when the LCD  200  is angularly adjusted, lateral movement (in a direction perpendicular to the side surface of the guide rail  273 ) is prevented. 
     A first contact protrusion  297  (see  FIG. 10 ) in line contact with the upper surface of the guide rail  291  is formed at an inner portion of the pressing surface  291  of the slider  290 , and a second contact protrusion  298  in surface contact with the exterior surface of the guide rail  273  is additionally formed at an inner portion of both side surfaces  293  and  295  of the slider  290 . 
     The first and second contact protrusions  297  and  298  serve to decrease contact area between the slider  290  and the guide rail  273 . 
     A boss groove  299 , in which an upper end of the boss  271  is inserted, is additionally formed at the inner portion of the pressing surface  291  of the slider  290 . In this connection, a through-hole  299   a  is formed at a center portion of the boss groove  299  so as to connect the slider  290  and the boss  271  by passing through a fastening screw  301  (see  FIG. 6 ). 
     The fastening screw  301  provides a force for supporting the LCD  200  rotated to a predetermined position by adjusting its tightening force. 
     A rounded portion R (see  FIG. 10 ) having a curvature corresponding to the curvature of the guide rail  273  is formed at lower ends of both side surfaces  293  and  295  of the slider  290 . As a result, the slider  290  precisely engages the guide rail  273  so as to provide for smooth rotation of the LCD  200 . In addition, the slider  290  uses POM (polyoxymethylene) as an abrasion resisting and self-lubricant material. 
     Hereinafter, the angle adjusting operation of the LCD  200  in accordance with an embodiment of the present invention will be described. 
     First, when a user pushes an upper or lower center portion of the LCD  200  (see  FIG. 4 ) to adjust the angle of the LCD  200 , the curved portion  231  protruding from the lower case  230  of the LCD  200  is slid along the mounting recess  110  of the main body  100 . At this point, the curved portion  231  is rotated in line contact with the first rib  111  formed at the bottom surface of the mounting recess  110  and the second rib  231   a  (see  FIG. 11 ) formed at the bottom surface of the curved portion  231  so as to be smoothly rotated. 
     On the other hand, the slider  290  (see  FIG. 6 ) connected to the boss  271  is slid along the guide rail  273  during the rotation as described above, and the slider  290  is formed of a self-lubricant material to smoothly accomplish the sliding operation. 
     Referring to  FIGS. 6 ,  9  and  10 , both side surfaces  293  and  295  of the slider  290  are tightly fitted to the both side surfaces of the guide rail  273  so as to prevent the LCD  200  from moving laterally in a direction perpendicular to both surfaces of the guide rail  273  (see arrows A in  FIG. 9 ) so as to provide for stable rotation of the LCD  200 . 
     When the user releases the force from the LCD  200 , the LCD  200  maintains the rotated angle. At this point, since the tightening force of the fastening screw  301  is greater than the rotational force by weight of the LCD  200 , the LCD  200  can be maintained in position. 
     When the LCD  200  is rotated as described above, the upper-limit angle and the lower-limit angle are determined since the boss  271  is stopped by both ends of the guide hole  272 . 
     As described above, the present invention has the advantage of smoother rotation of the LCD  200  due to formation of the curved portion  231  at the bottom surface of the LCD  200 , provision of the mounting recess  110  corresponding to the curved portion  231  at the main body, and formation of the first rib  111  and second rib  231   a  at the mounting recess  110  and the curved portion  231 , respectively, so that the LCD  200  is rotated by line contact. 
     In addition, the present invention has another advantage of decreased noise when adjusting the angle due to use of the guide rail  273  and the slider  290  during rotation of the LCD  200 . 
     The present invention has a further advantage in that shaking of the LCD  200  is reduced by decreasing tolerance of parts through simplification of the composition of the angle adjusting device resulting, in part, from use of guide rail  273  and the slider  290  during rotation of the LCD  200 . 
     While this invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiment, but on the contrary, it is intended to cover various modification within the spirit and the scope of the appended claims.