Abstract:
The present invention provides a low-profile operation input device of which assembling work is easily performed and the productivity is high. An operation input device includes a base; a printed board in which a plurality of push-button switches are mounted on a circumference while an MR sensor is mounted, the printed board being integrally provided on the base; a ring operation plate placed on the push-button switches; a ring operation dial in which a ring magnet is integrally provided in a concentric fashion on a lower surface, the ring operation dial being coaxially placed on the operation plate; and a fixture inserted in a fixing hole of the operation dial, the fixture coupling at least two elastic pawls to the base, thereby retaining the operation dial while rotatably supporting the operation dial, the elastic pawls being projected from a lower surface of the fixture.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to an operation input device which is applicable to a mobile telephone and a portable music player. 
         [0003]    2. Description of the Related Art 
         [0004]    Conventionally, for example, an operation input device incorporated in a mobile telephone and the like includes a base; a printed board which is integrally placed on the base with a plurality of push-button switches and a magnetic-field detection element mounted on an upper surface thereof; an operation plate which is supported by the base in a vertically movable manner on the printed board; and a disc-shaped operation dial which is rotatably fitted on an upper surface of the operation plate, a ring magnet in which N-poles and S-poles are alternatively arranged being fitted on a lower surface of the disc-shaped operation dial. In the operation input device, the magnetic-field detection element detects a change in magnetic flux of the ring magnet by rotating the disc-shaped operation dial, and the push-button switches are operated through the operation plate by pressing the disc-shaped operation dial (refer to, for example, Japanese Patent Application Laid-Open No. 2005-106126). 
         [0005]    However, as shown in FIGS. 3 and 4 of Japanese Patent Application Laid-Open No. 2005-106126, in the above-described operation input device, an operation dial 70 is rotatably supported on an operation plate 50 supported by a metal base 10. In order that the operation plate 50 rotatably supports the operation dial 70, it is necessary that a predetermined thickness be ensured for the operation plate 50, which makes it difficult to realize a low-profile operation input device. In the case where the operation dial 70 is fitted on the metal base 10 with the operation plate 50 interposed in between, it is necessary that the operation plate 50 be fitted on the metal base 10 after the operation dial 70 is rigidly caulked to the operation plate 50, which results in troublesome assembling and low productivity. 
       SUMMARY OF THE INVENTION 
       [0006]    In view of the foregoing, the present invention provides a low-profile operation input device of which the assembling work is easily performed and thus the productivity is high. 
         [0007]    In order to solve the above-mentioned problem, an operation input device according to the present invention includes: a base; a printed board in which a plurality of push-button switches are mounted on a circumference while a magnetic-field detection element is mounted, the printed board being integrally provided on the base; a ring operation plate which is placed on the push-button switches; a ring operation dial in which a ring magnet is integrally provided in a concentric fashion on a lower surface, the ring operation dial being coaxially placed on the operation plate; and a fixture which is inserted in a fixing hole of the operation dial, the fixture coupling at least two support legs to the base, thereby retaining the operation dial while rotatably supporting the operation dial, the support legs being projected from a lower surface the fixture, wherein the magnetic-field detection element can detect a change in magnetic flux of the ring magnet by rotating the operation dial, and the push-button switches can be operated through the operation plate by pressing down the operation dial. 
         [0008]    According to the present invention, because the operation dial is rotatably supported with the fixture interposed in between, it is not necessary that the operation plate have a high rotation support function. Therefore, the operation plate and thus the operation input device can be reduced in thickness. Additionally, the fixture is coupled to the base, so that the operation dial can be retained while being rotatably supported. Therefore, the number of man-hours is decreased, and the productivity is enhanced. 
         [0009]    According to an embodiment of the present invention, at least the two support legs projected from the lower surface of the fixture may elastically engage with at least two elastic holders which are cut and raised from the base. Accordingly, the fixture can be attached to the base through one-touch operation, so that the productivity is further enhanced. 
         [0010]    According to another embodiment of the present invention, the fixture may be formed in a ring shape, the fixture may retain a push button in an operation hole thereof and the push-button switches mounted on the printed board can be operated by the push button. Accordingly, a multifunctional operation input device can be obtained. 
         [0011]    In an electronic instrument according to the present invention, the aforementioned operation input device is attached with the operation dial exposed so as to be operable from the outside. 
         [0012]    Accordingly, the low-profile electronic instrument is obtained with high productivity. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]      FIGS. 1A and 1B  show perspective views of an operation input device according to a first embodiment of the present invention when viewed from different angles; 
           [0014]      FIG. 2  shows an exploded perspective view of the operation input device of  FIG. 1A ; 
           [0015]      FIG. 3  shows a partially exploded perspective view of the operation input device of  FIG. 2  when viewed from above; 
           [0016]      FIGS. 4A and 4B  show partially exploded perspective views of the operation input device of  FIG. 2  when viewed from different angles; 
           [0017]      FIG. 5  shows an exploded perspective view of the operation input device of  FIG. 1B ; 
           [0018]      FIG. 6  shows a partially exploded perspective view of the operation input device of  FIG. 5  when viewed from below; 
           [0019]      FIG. 7A  shows a bottom view of the operation input device of  FIG. 1A , and  FIG. 7B  shows a longitudinal cross-sectional view taken along the line B-B of  FIG. 7A ; 
           [0020]      FIGS. 8A and 8B  show longitudinal cross-sectional views taken along the lines VIIIA-VIIIA and VIIIB-VIIIB of  FIG. 7A ; 
           [0021]      FIG. 9A  shows a bottom view of the operation input device of  FIG. 1 , and  FIG. 9B  shows a longitudinal cross-sectional view taken along the line B-B of  FIG. 9A ; 
           [0022]      FIGS. 10A and 10B  show perspective views of an operation input device according to a second embodiment of the present invention when viewed from different angles; 
           [0023]      FIG. 11  shows an exploded perspective view of the operation input device of  FIG. 10A  when viewed from above; 
           [0024]      FIG. 12  shows a partially exploded perspective view of the operation input device of  FIG. 11  when viewed from a different angle; 
           [0025]      FIG. 13  shows an exploded perspective view of the operation input device of  FIG. 10A  when viewed from below; 
           [0026]      FIG. 14  shows a partially exploded perspective view of the operation input device of  FIG. 11  when viewed from below; 
           [0027]      FIGS. 15A and 15B  show longitudinal cross-sectional views of the operation input device of  FIG. 10A ; and 
           [0028]      FIG. 16A  shows a bottom view of the operation input device of  FIG. 10A , and  FIG. 16B  shows a longitudinal cross-sectional view taken along the line B-B of  FIG. 16A . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0029]    Preferred embodiments according to the present invention will be described below with reference to the accompanying drawings of  FIGS. 1A to 16B . An operation input device  1  according to a first embodiment is incorporated in, e.g., a mobile telephone (not shown), so that a scroll bar in a monitor can be scrolled to provide a selection instruction through a later-described push button  40 . 
         [0030]    As shown in  FIGS. 2 and 3 , the operation input device  1  includes a metal base  10 , a resin film cover  30 , a push button  40 , an operation plate  45 , an operation dial  50 , and a ring fixture  60 . A flexible printed board  20  adheres integrally to the metal base  10 . A central push-button switch  31   a  formed by a dome-shaped movable contact and four push-button switches  31   b  to  31   e  adhere to a lower surface of the resin film cover  30 . The push button  40  is used to operate the central push-button switch  31   a.  The operation plate  45  is placed on the push-button switches  31   b  to  31   e.  A ring magnet  53  is fixed to a lower surface of the operation dial  50 . The ring fixture  60  retains the operation dial  50  in the metal base  10 . 
         [0031]    As shown in  FIGS. 3 and 6 , the metal base  10  is formed in a substantially circular shape, and four elastic holders  12  are cut and raised at equal pitches on a circumference with respect to the center of the base  10 . In the elastic holders  12 , jig holes  13  and  14  are provided outside a pair of opposing elastic holders  12  and  12 , and clearance portions  15  and  15  in which MR sensors  26  and  26  are fitted are formed outside the remaining pair of elastic holders. 
         [0032]    The printed board  20  formed of a flexible resin film includes a substantially circular board main body  20   a  and a lead portion  20   b.  An adhesive agent is applied onto a back side of the substantially circular board main body  20   a,  and the lead portion  20   b  is extended from the board main body  20   a.  A conductive portion  21   a  is provided at the center of the board main body  20   a,  and conductive portions  21   b  to  21   e  are arranged around the conductive portion  21   a  at equal pitches on a circumference. Each of the conductive portions  21   a  to  21   e  includes a ring fixed contact portion and a pair of fixed contact portions disposed in the ring fixed contact portion. In the printed board  20 , engagement holes  22  and jig holes  23  and  24  are made at positions corresponding to the elastic holders  12  and the jig holes  13  and  14  of the metal base  10 . In the board main body  20   a,  notches  25  in which the MR sensors  26  to be described later are fitted are formed in the outer peripheral edge. The MR sensors  26  have a characteristic of reacting to a laterally-passing magnetic flux to output a detection signal. The MR sensors  26  placed in an inverted manner are inserted in the notches  25  of the printed board  20  and connected to the printed board  20 . In the conductive portions  21   a  to  21   e,  the fixed contact portions may concentrically be formed, and one of the fixed contact portions may be disposed at the center of the other fixed contact portion having a substantially C-shape when viewed from above. 
         [0033]    The resin film cover  30  has a planar shape with which the board main body  20   a  can be covered. In the back side to which the adhesive agent is applied, push-button switches  31   a  to  31   e  formed of flat dome-shaped inversion springs adhere to positions corresponding to the conductive portions  21   a  to  21   e  respectively. In the resin film cover  30 , engagement holes  32  and jig holes  33  and  34  are provided at positions corresponding to the elastic holders  12  and the jig holes  13  and  14  of the metal base  10  respectively. In the resin film cover  30 , clearance portions  35  in which the MR sensors  26  are fitted are formed at the outer peripheral edge. 
         [0034]    As shown in  FIGS. 2 and 5 , the push button  40  has an outer peripheral shape which can be fitted in a fixing hole  51  of an operation dial  50  to be described later, and a pair of rotation stopping pawls  41  and  41  is projected coaxially at lower edge portions of the outer periphery. Chamfers  42  are formed to prevent fluttering in base portions on both sides of the rotation stopping pawls  41 . 
         [0035]    The operation plate  45  is concentrically formed in a ring shape having a diameter which can be placed on the push-button switches  21   b  to  21   e.  A pair of rotation stopping projections  46  is projected at the inner peripheral edge of the operation plate  45 , and the rotation stopping projections  46  are latched in the rotation stopping pawls  41  of the push button  40 . Notches  47  are provided at positions corresponding to the clearance portions  15  of the metal base  10 . Operating projections  48  are provided in a protruding manner on a lower surface of the operation plate  45  to press the push-button switches  21   b  to  21   e.  A sliding sheet may adhere integrally to an upper surface of the operation plate  45  to smoothly rotate the operation dial  50  which will be described later, a resin material having small frictional resistance may be applied to the operation plate  45 , or satin finishing may be performed to the operation plate  45  to decrease the frictional resistance. 
         [0036]    As shown in  FIGS. 4A and 4B , the operation dial  50  is concentrically formed in a ring shape with which the metal base  10  can be covered, and a fixing hole  51  in which the push button  40  can be fitted is provided at the center of the operation dial  50 . A ring magnet  53  is positioned and fixed to the operation dial  50  with a ring rib  52  interposed therebetween. The ring rib  52  is projected from the peripheral edge of the lower surface of the operation dial  50 . N-poles and S-poles are alternately arranged in the ring magnet  53 . Particularly, in the first embodiment, the ring magnet  53  does not directly contact the operation plate  45 . Therefore, advantageously, the low-profile operation input device having small frictional resistance acting on the operation dial  50  and is capable of being smoothly operated is obtained. The operation dial  50  is not limited to the circular shape, but the operation dial  50  may be formed in, e.g., a regular octagonal shape as long as the operation dial  50  can be rotated. 
         [0037]    As shown in  FIGS. 2 and 5 , the ring fixture  60  has an outer diameter with which the ring fixture  60  can be fitted in the fixing hole  51  of the operation dial  50  to retain the operation dial  50 . The ring fixture  60  has an operation hole  61  having an inner diameter with which the push button  40  can be fitted in the ring fixture  60  to retain the push button  40 . Support legs  62  are projected from the lower surface of the ring fixture  60 , and the support leg  62  can elastically engage with the elastic holder  12  of the metal base  10 . Position regulating projections  63  are provided on the ring fixture  60 , and each position regulating projection  63  is located on one side of the base portion of the support leg  62 . 
         [0038]    A process for assembling the above-described components will be described below. A pair of positioning pins which are jigs (not shown) is inserted and positioned in the jig holes  13  and  14  in the metal base  10 . Then, the pair of jig pins is inserted in the jig holes  23  and  24  of the printed board  20  on which the MR sensors  26  and  26  are mounted at predetermined positions, whereby the elastic holders  12  of the metal base  10  are fitted in the engagement holes  22  of the printed board  20  such that the elastic holders  12  are adhesively bonded integrally to the printed board  20 . Then, the jig pins are inserted in the jig holes  33  and  34  of the resin film cover  30  to adhesively bond the resin film cover  30  integrally to the board main body  20   a  of the printed board  20 , whereby the push-button switches  31   a  to  31   e  formed of the dome-shaped inversion springs are positioned in the conductive portions  21   a  to  21   e  respectively. 
         [0039]    Then, the operation plate  45  is placed and positioned on the push-button switches  31   b  to  31   e  while the push button  40  is placed and positioned on the push-button switch  31   a,  whereby the rotation stopping projections  46  of the operation plate  45  are latched to the rotation stopping pawls  41  of the push button  40 . After the push button  40  is fitted in the fixing hole  51  of the operation dial  50 , the ring fixture  60  is inserted in a gap between the push button  40  and the operation dial  50 , and the support legs  62  of the ring fixture  60  elastically engage with the elastic holders  12  of the metal base  10 . Therefore, the ring fixture  60  retains the operation dial  50 , and the ring fixture  60  also retains the push button  40  and the operation plate  45  in the metal base  10 . Furthermore, the position regulating projections  63  of the ring fixture  60  meet the chamfers  42  of the push button  40  to prevent the rotation of the push button  40 . Therefore, the rotation of the operation plate  45  engaging with the push button  40  is also prevented. The method for fixing the ring fixture  60  to the metal base  10  is not limited to the elastic engagement, and caulking or welding may also be adopted. 
         [0040]    In the first embodiment, the push button  40  and the operation plate  45  placed on the push-button switches  31   a  to  31   e  are biased upward by spring force of the dome-shaped inversion springs. Therefore, the vertical fluttering is not generated, and excessive rotation caused by inertia force can be prevented in the operation dial  50 , so that erroneous operation is hardly generated. The push button  40 , the operation plate  45 , and the operation dial  50  can be assembled on the metal base  10  through one-touch operation by fixing the ring fixture  60  to the metal base  10 , so that an operation input device having excellent productivity can advantageously be obtained. 
         [0041]    An operation method in the case of applying the operation input device  3  having the above-described configuration to a mobile telephone will be described below. When the operation dial  50  is rotated about the axis of the ring fixture  60 , the operation dial  50  is rotated in a sliding manner on the operation plate  45  and the ring fixture  60 . The ring magnet  53  integral with the operation dial  50  is also rotated, the pair of MR sensors  26  detects a change in magnetic field, and a rotating direction and a rotating amount are detected based on the detected change in magnetic field. The detection result is reflected as a movement of a scroll bar displayed on a monitor screen through a control circuit (not shown). When the scroll bar reaches a desired position, the push button  40  is pressed to invert the inversion spring of the central push-button switch  31   a,  and an electric current is passed through the corresponding conductive portion  21   a  to output a selection instruction. Alternatively, the peripheral portion of the operation dial  50  is pressed down, and the inversion springs of the push-button switches  31   b  to  31   e  are appropriately inverted by the pressing projections  48  of the operation plate  45 , whereby current may be passed through the corresponding conductive portions  21   b  to  21   e.    
         [0042]    Accordingly, in the first embodiment, because the MR sensors  26  are used, it is not necessary that the ring magnet  53  be placed above the MR sensors  26 , and advantageously, a low-profile operation input device can be obtained. 
         [0043]    In a second embodiment, as shown in  FIGS. 10A to 16B , a basic structure is substantially the same as that of the first embodiment. The second embodiment differs from the first embodiment in that a Hall element  27  is used. The Hall element  27  has a characteristic of detecting a vertically-passing magnetic flux to output an output signal. In the second embodiment, the same components as the first embodiment are designated by the same reference numerals, and only a different component is described. 
         [0044]    That is, in the second embodiment, because the Hall elements  27  are used, it is necessary that the Hall elements  27  be disposed immediately below the ring magnet  53 . Therefore, notches  25  are provided in protrusions  20   c  extended from the outer peripheral edge of the printed board  20 , and the inverted Hall elements  27  are disposed in the notches  25  ( FIGS. 11 and 12 ), whereby the ring magnet  53  is disposed immediately above the Hall elements  27  ( FIG. 16 ). Because other structures are identical to those of the first embodiment, the description is not repeated. 
         [0045]    The operation input device according to the present invention can be applied not only to mobile telephones but also to other mobile instruments and other electronic instruments obviously.