Abstract:
A protective sheet mount structure for a display is provided which may be employed in electronic cash registers, for example. The structure includes a frame mount formed on a frame of a display around an opening through which a display screen is exposed, a protective sheet covering the display screen, and a sheet mount frame fitted in the frame mount detachably to retain the protective sheet on the frame of the display.

Description:
This application is a continuation of application Ser. No. 09/233,981 filed Jan. 20, 1999, now U.S. Pat. No. 6,152,550. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Technical Field of the Invention 
     The present invention relates generally to a easy-to-replace protective sheet mount structure for a display which may be used in electronic terminal devices such as electronic cash registers. 
     2. Background Art 
     FIG. 22 shows a conventional electronic cash register which includes a display  60  and a key board  61 . Data is inputted using the key board  61  and then indicated on the display  60 . 
     The display  60  has a protective sheet  72  directly attached to a display screen thereof. It is, thus, difficult to replace the protective sheet  72 . Such a structure also cannot keep free from mist of water to the display screen of the display perfectly. 
     SUMMARY OF THE INVENTION 
     It is therefore an object of the invention to provide an easy-to-replace protective sheet mount structure for a display which may be used in electronic terminal devices such as electronic cash registers. 
     It is another aspect of the invention to provide an improved protective sheet mount structure for a display designed to keep free from mist of water to a display screen. 
     According to one aspect of the invention, there is provided a display apparatus which comprises: (a) a casing having an opening formed therein; (b) a tough sensitive display installed in the casing with a touch screen exposed through the opening; (c) a frame mount provided on the casing around the opening; (d) a protective sheet covering the touch screen; and (e) a sheet mount frame fitted in the frame mount detachably to retain the protective sheet on the casing. 
     In the preferred mode of the invention, a sealing member is further provided which is disposed between the casing and the sheet mount frame around the opening. 
     The opening is of a rectangular shape. The frame mount is provided around right and left side portions and a lower portion of the opening and has recesses formed in right and left portions and a lower portion of the frame mount. The sheet mount frame is of a rectangular shape and has a slip-on rib formed on an upper edge thereof and protrusions formed on right and left side portions and a lower portion. The slip-on rib is fit on an upper edge of the opening of the casing. The protrusions engage the recesses of the frame mount to install the sheet mount frame on the frame mount. 
     A drain groove is formed in the frame mount around the opening outside the sealing member. A drain hole is formed in the drain groove for draining water entering the drain groove. 
     Right and left drain grooves may be formed which extend along right and left sides of the opening. A lower drain groove may be formed which extends along a lower portion of the opening and which leads to the right and left drain grooves. Right and left drain holes may be formed in the right and left drain grooves, respectively. 
     The frame mount is of a rectangular shape and has recesses formed on upper right and left side portions thereof. The protective sheet is of a rectangular shape and has lugs formed on upper right and left side portions thereof and a step portion formed on a lower end portion thereof. The lugs are fitted in the recesses of the frame mount. The step portion is fitted on a lower edge of the opening of the casing. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will be understood more fully from the detailed description given hereinbelow and from the accompanying drawings of the preferred embodiment of the invention, which, however, should not be taken to limit the invention to the specific embodiments but are for the purpose of explanation and understanding only. 
     In the drawings: 
     FIG. 1 is a perspective view which shows an electronic cash register with an easy-to-replace protective sheet replace structure according to the invention; 
     FIG. 2 is a partially cross sectional view which shows a display tilt adjusting mechanism; 
     FIG.  3 ( a ) is a partial view which shows a stay holder when a stay is moved upward; 
     FIG.  3 ( b ) is a partial view which shows a stay holder when a stay is moved downward; 
     FIG. 4 is a top view of the electronic cash register in FIG. 1; 
     FIG. 5 is a side view which shows an upper casing of a housing of an electronic cash register; 
     FIG. 6 is a longitudinal cross sectional view of the upper casing in FIG. 5; 
     FIG. 7 is a partial plan view which shows a bill holder; 
     FIGS.  8 ( a ) and  8 ( b ) are partial cross sectional views taken along the line A—A in FIG. 7; 
     FIG. 9 is a plan view which shows a frame of a casing of a display; 
     FIG. 10 is a vertical cross sectional view taken along the line B—B in FIG. 9; 
     FIG. 11 is a partially cross sectional view which shows a sheet mount frame holder formed on the frame in FIG. 9; 
     FIG. 12 is a plan view which shows a sheet mount frame for mounting a protective sheet on a casing of a display; 
     FIG.  13 ( a ) is a side view as viewed from D in FIG. 12; 
     FIG.  13 ( b ) is a side view as viewed from E in FIG. 12; 
     FIG.  13 ( c ) is a side view as viewed from F in FIG. 12; 
     FIG. 14 is a plan view which shows a protective sheet; 
     FIG. 15 is a partially cross sectional view taken along the line G—G in FIG. 14; 
     FIG. 16 is a side view which shows a stay supporting tilting motion of a display; 
     FIG. 17 is a top view as viewed from the direction H in FIG. 16; 
     FIG. 18 is an illustration which shows a support shaft installed in a stay holder; 
     FIG. 19 is a plan view which shows a stay holder; 
     FIG. 20 is a side view as viewed from the direction I in FIG. 19; 
     FIG. 21 is a front view as viewed from the direction J in FIG. 19; and 
     FIG. 22 is a perspective view which shows a conventional electronic cash register. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to the drawings, particularly to FIG. 1, there is shown an electronic cash register with an easy-to-replace protective sheet mount structure for a display according to the present invention. 
     The electronic cash register has a housing  1 . The housing  1  consists of a lower casing  2  and an upper casing  3 . The lower casing  2  has disposed therein a chassis mount (not shown) having the bottom in which an opening is formed. The lower casing  2  has an engaging portion  5  formed on an upper edge. 
     The upper casing  3 , as shown in FIGS. 4 to  6 , includes an upper wall  6  and a side wall  7  surrounding the periphery of the upper wall  6 . The side wall  7  has an engaging portion  7 A formed on a lower edge thereof. The upper wall  6  has formed thereon a bill holder  8 , a pen holder  4 , a bearing assembly  9 , and a display mount  10 . The lower casing  2  and the upper casing  3  are joined in tight engagement of the engaging portions  5  with the engagement portion  7 A. 
     The bill holder  8 , as clearly shown in FIGS. 7,  8 ( a ), and  8 ( b ), has a bill tray  11  formed with a flat recess. A bill holding mechanism  12  is disposed on the center of a rear end of the bill tray  11 . The bill holding mechanism  12  includes a holder latch  13  formed on a rear wall of the bill tray  11 , a gripper  14  secured detachably by the holder latch  13 , a cushion plate  15  retained by the gripper  14 , and a steel ball  16 . The gripper  14  has formed therein a cushion chamber  17  in which the cushion plate  15  and the steel ball  16  are disposed. The cushion plate  17  produces elastic pressure urging the steel ball  16  into constant engagement with the bill tray  11 , thereby allowing, as indicated by P in FIG.  8 ( b ), a bill to be held between the bill tray  11  and the steel ball  16  tightly. 
     The upper wall  6  has the pen holder  4  formed behind the bill holder  8 . The pen holder  4  is defined by a protrusion  18  extending in a width-wise direction of the upper wall  6  in parallel to the rear wall of the bill holder  8 . 
     The bearing assembly  9  includes, as clearly shown in FIGS. 4 to  6 , a front display mount protrusion  20 , a rear display mount protrusion  21 , and right and left bearings  24 . The display mount protrusions  20  and  21  extend in the width-wise direction of the upper casing  3 . The bearings  24  are installed between the display mount protrusions  20  and  21 . 
     The display mount  10  includes a font slant wall  25  and a rear slant wall  26 . Rectangular walls  27 , as clearly shown in FIGS. 4 and 6, are formed on both sides of the front slant wall  25 . The rectangular walls  27  have formed therein stay guide slots  28 . 
     The display  30  is, as shown in FIGS. 1 and 2, pivotably supported by the bearing assembly  9 . The display  30  includes a casing  33  consisting of rear and front covers  31  and  32 , a touch sensitive panel  34 , and a protective sheet  35 . 
     The rear cover  31  has a pair of cover bearings (not shown) mounted on right and left lower portions of an inner wall thereof. The cover bearings are arranged in alignment with the bearings  24  of the bearing assembly  9 . A supporting shaft (not shown) is inserted through the cover bearings of the rear cover  31  and the bearings  24  of the bearing assembly  9  to support the rear cover  31  pivotably so that the display  30  may tilt back and forth (i.e., a lengthwise direction of the cash register) within a given angular range. 
     The front cover  32  of the display  30 , as shown in FIGS. 9 to  11 , includes a rectangular frame  32 A which has claws  51 , as clearly shown in FIG. 10, formed on an upper, left, and right edges for attachment to the rear cover  31 . The frame  32 A has a frame mount  52  formed on right and left side surface and a lower surface thereof. The frame mount  52  has vertical drain grooves  153  formed in side portions thereof and also has a horizontal drain groove  154  formed in a lower portion thereof. The horizontal drain groove  154  leads to lower ends of the vertical drain grooves  153  and has drain holes  55  formed in ends thereof. 
     The vertical drain grooves  153  have recesses  56  formed in central portions thereof for attachment of a sheet mount frame  60 , as will be described later in detail, to it. U-shaped holders  58 , as clearly shown in FIGS. 9 and 10, are formed in ends and center of the lower portion of the frame mount  52 . Each of the holders  58 , as shown in FIG. 11, consists of a pair of claws  57 . Sheet lug insertion recesses  59  are formed in upper ends of the side portions of the frame mount  52 . 
     The rear cover  31  of the casing  33  has formed therein recesses for engagement with the claws  51  of the front cover  32 . The casing  33  has disposed therein, as shown in FIG. 1, the touch sensitive panel  34  which has a touch screen on which a touch switch section and a display section are arranged adjacent to each other. The rear and front covers  31  and  32  have lower portions  31   d  and  32   d  curved to form a round bottom  33 A of the casing  33 . The round bottom  33 A is placed between the front and rear display mount protrusions  20  and  21  in contact therewith. 
     A transparent protective sheet  35 , as shown in FIG. 1, covers the touch screen of the touch sensitive panel  34  exposed through an opening  32   a , as shown in FIG. 9, of the front cover  32  of the casing  33 . 
     The sheet mount frame  60  is attached to the frame mount  52  to hold the protective sheet  35  tightly between the sheet mount frame  60  and the frame mount  52 . 
     The sheet mount frame  60 , as clearly shown in FIGS.  12  and  13 ( a ), has vertical ribs  61  and claw-like protrusions  62  formed on sides of a rear wall thereof and also has a horizontal rib  63  formed on a lower end of the rear wall. The horizontal rib  63 , as shown in FIGS. 12,  13 ( b ), and  13 ( c ), has barb-like protrusions  64  formed on ends and center thereof. The sheet mount frame  60  has a seal  65  attached to the rear wall around an opening thereof and also has a slip-on rib  66  formed on the upper portion thereof. 
     The protective sheet  35  has, as shown in FIG. 14, lugs  67  projecting from upper ends horizontally and also has, as shown in FIG. 15, a lower end bent to form a step  68 . The lugs  67  are inserted into the sheet lug insertion recesses  59  of the frame  32 A of the front cover  32 . The step  68  is fit on an inner lower edge of the frame  32 A. The sheet mount frame  60  is installed on the frame mount  52  by bringing the slip-on rib  66  of the sheet mount frame  60  into engagement with an inner upper edge of the frame mount  52  and forcing the claw-like protrusions  62  and the protrusions  64  into the recesses  56  and the holders  58 , respectively, thereby attaching the protective sheet  35  to the frame  32 A to cover the opening  32   a  of the frame  32 A. The removing of the protective sheet  35  is achieved easily by reversing the above described operations. 
     The frame  32 A has, as described above, the drain grooves  153  and  154  and the drain holes  55 . Additionally, the sheet mount frame  60  has the seal  65  attached to the rear surface thereof which is held tightly between the sheet mount frame  60  and the protective sheet  35  on the frame  32 A. If, therefore, drops of water are adhered on the front cover  32  around the opening  32   a , most of them enter the drain grooves  153  or  154  and are drained from the drain holes  55 . Even if drops of water are adhered inside the drain grooves  153  and  154 , the seal  65  avoids intrusion of them into the casing  33 . 
     A pair of stays  36  are installed at flanges  36 A, as shown in FIG. 17, on right and left portions of an outer wall of the rear cover  31  using screws and inserted into the stay guide slots  28  formed in the display mount  10 . 
     A display tilt adjusting mechanism  40 , as clearly shown in FIG. 2, which adjusts an angular position of the display  30 , is disposed on an inner surface of the front slant wall  25  of the display mount  10 . The display tilt adjusting mechanism  40  includes stay holders  41  each of which, as shown in FIGS. 19 to  23 , has a plate  43  bent at right angles to a mount flange  42  having a mount hole  42   a  formed therein and a pair of shaft retainers  44  bent at right angles to both sides of the plate  43 . The shaft retainers  44  each have, as shown in FIG. 20, formed therein an elongated hole  45  which extends with an inclination of α (e.g., 15°) to the surface  43   a  of the plate  43 . The shaft retainers  44  each have a mount plate  46  bent at right angles which has formed thereon a spring hook  47 . 
     A resinous sliding plate  148  is, as shown in FIGS.  3 ( a ) and  3 ( b ), attached to the surface  43   a  of the plate  43  for facilitating ease of movement of the stay  36 . A support shaft  48 , as shown in FIGS. 2,  3 ( a ),  3 ( b ), and  18  is inserted through the elongated holes  45  of the shaft retainers  44  so as to be movable in a lengthwise direction of the elongated holes  45 . The support shaft  48  has a roller  49  wound therearound. The support shaft  48 , as shown in FIG. 18, has formed in ends thereof grooves  50 . Coil springs  51  are hung at one end on the grooves  50  of the support shaft  48  and at the other end on the spring hooks  47  of the mount plates  46 , respectively, to elastically urge the support shaft  48  to lower ends  45   b  of the elongated holes  45  to bring the roller  49  into engagement with the sliding plate  48 . 
     The display tilt adjusting mechanism  40  thus constructed is disposed in the upper casing  3  with the mount flanges  42  of the stay holders  41  secured using screws on a mount block  53 , as shown in FIG. 2, formed on the inner wall of the upper casing  3 . Each of the stays  36  extending through one of the stay guide slots  28  inward of the upper casing  3  passes through a nip formed by the roller  49  and the sliding plate  48  of one of the stay holders  41 . Each of the stays  36  has disposed on an end a stopper  54 , as shown in FIG. 2, which is made of a protrusion for avoiding dislodgement of the stay  36  from the stay holder  41 . 
     In operation, when it is required to tilt the display  30  frontward, an operator pulls the display  30  manually. This causes, as shown in FIG.  3 ( a ), each of the stays  36  to be moved upward, thereby lifting up the roller  49  slightly which is pressed against the stay  36 , so that the support shaft  48  is moved upward against the spring pressure of the coil spring  51  along the elongated hole  45 . The elongated hole  45  is, as described above, oriented at the angle a to the surface  43   a  of the plate  43 . The upward movement of the support shaft  48 , thus, causes the roller  49  to move into disengagement from the surface of the stay  36 , thereby releasing the stay  36  from the nip formed by the roller  49  and the sliding plate  148 , which allows the display  30  to be tilted frontward smoothly. 
     When the tilting motion of the display  30  is stopped by the operator, it will cause the support shaft  48  of each of the stay holders  41  to be urged downward by the spring pressure of the coil spring  51  to press the stay  36  against the sliding plate  48  to lock the stay  36 , so that the display  30  is held at a desired angle. 
     When it is required to tilt the display  30  backward, the operator pushes the display  30  manually. This causes the stays  36  to be moved downward. The downward movement of each of the stays  36  increases the nip provided by the roller  49  and the sliding plate  148 . When the operator pushes the display  30  with pressure greater than the nips of the stays  36 , each of the stay  36 , as clearly shown in FIG.  3 ( b ), slides downward along the sliding plate  148 . When the operator stops pushing the display  30 , the display  30  is held at a desired angle. 
     While the present invention has been disclosed in terms of the preferred embodiments in order to facilitate better understanding thereof, it should be appreciated that the invention can be embodied in various ways without departing from the principle of the invention. Therefore, the invention should be understood to include all possible embodiments and modifications to the shown embodiments which can be embodied without departing from the principle of the invention as set forth in the appended claims.