Abstract:
An electromechanical device including a key top member (i.e., a push button cover device) used in a push button mechanism. The key top member has a main body, a frame surrounding the main body, and a hinge portion supporting the key top main body. The hinge portion is formed integrally to the frame. The electromechanical device can be used in an operation panel of an image forming apparatus. The hinge and the main body are less susceptible to breakage during transport, installation and maintenance because they are surrounded by the frame.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to an electromechanical device for controlling an image forming apparatus. The electromechanical device includes a key top member (i.e., a push button cover device), a push button mechanism/actuator, and an operation panel.  
         [0003]     2. Description of the Related Art  
         [0004]     Conventionally, an image forming apparatus such as a copier or a printer includes an operation panel for inputting instructions. The instructions are input to the image forming apparatus by using a push button which moves a tactile switch that is formed on a board in the operation panel. The push button is set within an aperture, hole or recess formed on a top board of the operation panel. The push button is installed from a bottom side of the top board. In general, these push buttons are integrally formed with a hinge mechanism for tilting and a biasing mechanism for biasing movement in a predetermined direction. The push buttons are generally formed by injection molded plastic.  
         [0005]     However, because the injection molded plastic of the hinge mechanism or the biasing mechanism is delicate, these mechanisms are easily damaged during transportation, assembly, maintenance or repair.  
         [0006]     It is an object of the present invention to solve the above-mentioned problems. It is another object of the present invention to provide a key top member (push button cover device) which is easy to handle, install and remove. It is still another object of the invention to provide a push button mechanism which is easier and less expensive to produce, resulting in an improved yield and reduced production cost.  
       SUMMARY OF THE INVENTION  
       [0007]     One embodiment of the invention includes a key top member (push button cover device) used in a push button mechanism has a key top main body, a frame surrounding the key top main body, and a hinge portion supporting said key top main body. The hinge is formed integrally to the frame. The hinge and the key top main body are not less susceptible to damage because they are surrounded by the frame. Another embodiment includes a push button mechanism including the above mentioned key top member. Another embodiment includes an operation panel that includes the above-mentioned push button mechanism. Another embodiment includes an image forming apparatus operation panel that includes the above-mentioned operation panel. 
     
    
     BRIEF DESCRITION OF THE DRAWINGS  
       [0008]     A more complete application of the invention and many of the attendant advantages thereof will be readily obtained as same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings where in:  
         [0009]      FIG. 1  is an outside drawing showing copier  100  in an embodiment according to the present invention.  
         [0010]      FIG. 2  is a perspective view showing the operation panel of the copier  100  shown in  FIG. 1 .  
         [0011]      FIG. 3  (A) is a plane view showing a cover  22  of the operation panel  20  shown in  FIG. 2 .  
         [0012]      FIG. 3  (B) is a side elevation showing a cover  22  of the operation panel  20  shown in  FIG. 2 .  
         [0013]      FIG. 4  is a perspective view showing a relation of a cover  22 , boards  61 ,  62 , and display unit  50  in the above-mentioned embodiment.  
         [0014]      FIG. 5  is sectional view showing a condition of the board  61  attached to the cover  22 .  
         [0015]      FIG. 6  is a perspective view showing the key top member  30 .  
         [0016]      FIG. 7  is a sectional view showing cross-section view of the key top member  30  in  FIG. 2 .  
         [0017]      FIG. 8  (A) is a sectional view showing the aspect of the key top member  30  in  FIG. 6 .  
         [0018]      FIG. 8  (B) is a plane view showing the aspect of the key top member  30  in  FIG. 6 .  
         [0019]      FIG. 9  is a sectional view showing the action of the key top member  30 .  
         [0020]      FIG. 10  (A) is a plane view showing a base  21  of the operation panel  20  in  FIG. 2 .  
         [0021]      FIG. 10  (B) is a side elevation showing a base  21  of operation panel  20  in  FIG. 2 .  
         [0022]      FIG. 11  (A) is a sectional view showing cross-section view of  FIG. 2  along the line A-A.  
         [0023]      FIG. 11  (B) is a sectional view showing cross-section view of  FIG. 2  along the line B-B.  
         [0024]      FIG. 11  (C) is a sectional view showing cross-section view of  FIG. 2  along the line C-C.  
         [0025]      FIG. 12  is a perspective view showing how to use the key top member  30 .  
         [0026]      FIG. 13  is a sectional view showing another embodiment of the key top member  30  in  FIG. 6 . 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0027]     Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views, and more particularly to  FIG. 1  thereof, there is illustrated a copier  100  as example of an image forming apparatus.  
         [0028]     The copier  100  includes an operation panel  20  and a main body  10 . The operation panel  20  is fixed in the upper end of the front (Y-side in  FIG. 1 ) of the main body  10 . The main body  10  has a three-dimensional rectangular shape. The main body includes a component that reads a document, and records on paper or another sheet medium an image based on the document.  
         [0029]     The main body  10  includes a scanner device, a photo sensitive body, a light scanning device, a developing unit, a transfer device, a fixing unit, a communication device, and a control unit. The scanner device reads image information of a manuscript. The image information is transferred to the light scanning device functioning as a light-exposing mechanism. The light scanning device exposes a surface of the photo sensitive body according to the image information for the purpose of making a latent image. The latent image on the photo sensitive body is developed using toner by the developing unit for changing the latent image into a tangible image. The tangible image on the photo sensitive body is transferred to paper by the transfer device. Then tangible image on paper is fixed by the fixing unit. The communication device receives input signals from the operation panel  20 . The control unit controls each of the unit or the device in the main body  10  according to instructions that are included in the input signal from the operation panel  20 . In addition, an automatic document feeder (ADF) is used for automatic feed of manuscripts. In one embodiment, the main body  10  furthermore includes the ADF.  
         [0030]     As shown in  FIG. 2 , the operation panel  20  includes a housing having a cover (or upper cover)  22  and a base (or lower cover)  21 . The cover  22  and the base  21  are configured to be mutually engaged. The housing includes boards  61 ,  62 , a display unit  50 , and other many parts (cf.  FIG. 4 ) in its internal space.  
         [0031]     As shown in  FIG. 3 (A), and  FIG. 3 (B), cover  22  includes a top board  22   a  and a side wall  22   b . The top board  22   a  is substantially rectangle and has a longitudinal direction along an X axis direction. The side wall  22   b  is formed on the edge of the top board  22   a . Cover  22  looks like the U character when viewing the YZ plane. As shown in  FIG. 3 (A), in the center of top board  22   a , there is an aperture (hole for a display window)  22   c  having a longitudinal direction along an X axis direction. On one lateral side of aperture  22   c  is a first interface part  29  having plural rectangular apertures that are used to insert plural push buttons relate to functions of copier  100 . On another lateral side of aperture  22   c  is a second interface part  28  having plural circular apertures that are used to insert plural push buttons and their corresponding push button cover devices (hereinafter described as key top members) related to a numeric keypad or another control device. In one embodiment, the cover  22  is formed by injection molding assuming plastic.  
         [0032]     As shown in  FIG. 4 , the board  61  is accommodated in an internal space of the housing (this housing forming a part of an operation panel) corresponding to the first interface part  28 , and the board  62  is accommodated in an internal space of the housing corresponding to the second interface part  29 .  
         [0033]     The board  61  is an approximately square-shaped epoxy board. Plural electronic parts forming an electric circuit are located on the front-back both sides of the board  61 .  
         [0034]     As shown in  FIG. 5 , which is a sectional view along A-A Line of  FIG. 2 , the board  61  is fixed to plural pipe-shaped portions  22   h  formed on the under surface of the top board  22   a  by bolts  56 . Key top members and corresponding switches are located in an internal space that is formed by the top board  22   a  of the cover  22  and upper surface of the board  61 . The size of the key top member and a corresponding switch may be different within or among embodiments. While potentially differing in size, the key top member and a corresponding switch of various sizes share a substantially similar design.  
         [0035]     The following describes a key top member or switch inserted into key aperture  23 .  
         [0036]      FIG. 6  shows a perspective view of the key top member  30 . In one embodiment, the key top member  30  is formed by injection molding with plastic. The key top member  30  includes a key top main body  32 , a key top frame  31 , a key top hinge  33 , and an extension portion  34 . The key top main body  32  is substantially square. The key top frame  31  is shaped substantially rectangle and surround the key top main body  32 . The key top hinge  33  includes a pair of plates connected both of the key top frame  31  and the key top main body  32  so that the key top main body  32  can swing. The extension portion  34  disposed in upper edge portion of the Y side wall extends toward Y direction.  
         [0037]     As shown in  FIG. 6  and  FIG. 7  that is a sectional view YZ plane of  FIG. 6 , the key top main body  32  has a push portion  32   a  that protrudes up and that is located in a portion of the substantially center circle of the key top main body  32 . The actuation portion  32   c  is circular cylinder that is located in under side of the key top main body along the Z direction. A pair of bar-shaped portions  32   b  are disposed in the under surface on the corners of the key top main body in a direction opposite of the Y direction.  
         [0038]     As shown in  FIG. 6  and  FIG. 7 , the key top frame  31  includes the first leg portion  31   a  and a pair of second leg portions  31   b . The first leg portion  31   a  is located in center of the edge along the Z direction. The first leg portion  31   a  is disposed at the edge of the opposite direction of the Y direction. The second leg portions  31   b  are located in the two corners of the key top frame  31  in the Y direction along the Z direction. Furthermore, the curve portion  31  is disposed at the edge of the key top frame  31  in the Y direction. Furthermore, the curve portion  31   c  is formed in a substantially center portion of the Y direction edge. The curve portion  31   c  bulges toward the opposite direction of the Y direction.  
         [0039]     As shown in  FIGS. 6, 7  and  13 , the two regions/plates  33  of the key top main body  32  are thinner than other portion of the key top main body  32 , thus enabling elastic deformation when pressed. Each of two regions/plates  33  is connected to both of the key top frame  31  and the key top main body  32  so that the key top main body  32  can swing. And each of regions/plates  33  are connected with a rounded corner which avoids stress concentration.  
         [0040]     The extension portion  34  is substantially square board having a circular hole  34   a  in its center portion, as shown in  FIG. 6  and  FIG. 7 . The extension portion  34   a  is located in the upper edge of the Y direction in the key top frame  31 , and is formed in parallel with XY plane.  
         [0041]     As shown in  FIG. 8 (A), the key top member  30  formed as discussed above is assembled with cover  22  by inserting push portion  32   a  into the key aperture  23 .  
         [0042]     Furthermore, as shown in  FIG. 8 (A) and  FIG. 8 (B), the cover  22  has three support feet  22   d  surrounding the key aperture  23  on the under surface of the top board  22 . Cover  22  also has a split pin  24  including a pair of projecting portions  22   e  at a position that is predetermined distance away from the aperture  23  in the Y direction.  
         [0043]     The key top member  30  is attached to the cover  22  so that an inner wall surface of the curve portion  31   c  is enclosed in the pipe shaped portion  22   h  with a minimum clearance between them. In this attached status, the frame  31  is fixed between the board  61  and support feet  22   d . This fixes a position of the key top member  30  in the Z direction. The position of the support feet  22   d  are disposed in the positions correspond to the positions of the first leg portion  31   a  and the second leg portion  31   b . Additionally, the key top member  30  fixed in the XY plane by the insertion of the split pin  24  to the circular hole  34   a.    
         [0044]     As shown in  FIG. 8 (B), the top board  22   a  has guide ribs  22   f  that are along the Y direction and substantially same altitude with the split pin  24 .  
         [0045]     As shown in  FIG. 8 (A), the switch  64  is fixed on the board  61  under the key top member  30 . This switch  64  substantially shapes a rectangular parallelepiped, and it has an internal electrical contact. The switch  64  has a slider  64   a  shaped as a cylinder. In the shown embodiment, slider  64   a  is always biased to the upper direction (Z direction in  FIG. 8  (A)) by the biasing mechanism. Other configurations are possible. When an external force acts on the slider  64   a , the slider  64   a  moves downward and closes the electrical contact (the switch is then in an ON status). The switch  64  is located in the upper surface of the board  61  so that a vicinity of the center in the slider  64   a  is located immediately below the actuation portion  32   c.    
         [0046]     Furthermore, as shown in  FIG. 9 , when the push portion  32   a  is pushed by external force, the slider  64   a  is moved according to the action of the actuation portion  32   c , and then the slider  64   a  closes the electrical contact. The key top main body  32  pushed by external force is stopped tilting by contacting the bar-shaped portion  32   b  and the board  61 . Thus, the superfluous pressing force does not act on slider  64   a  of the switch  64 .  
         [0047]     Referring again to  FIG. 4 , the board  62  is an approximately oblong-shaped epoxy board. Plural oblong-shaped push button switches or indicating lamps (not shown) are located on the board  62 . The board  62  is fixed to the under surface of the top board  22   a  so that the push button switches and the indicating lamps are exposed from apertures formed on second interface part  29  of the cover  22 .  
         [0048]     As shown in  FIG. 4  and  FIG. 5 , display unit  50  includes a holder  51  and a display main body  60  (for example, liquid crystal display is used) held to the holder  51 . In one embodiment, the holder  51  is formed by sheet metal processing. The display main body  60  is fixed to the holder  51  by four screws (not shown) or other means. Then the display unit  50 , as shown in  FIG. 4 , is attached to the under surface of the top board  22   a  of the cover  22  by using four screws  55  inserted to four bores.  
         [0049]     As shown in  FIG. 10  (A) and  FIG. 10  (B), the base  21  has a bottom board  21   a  and side wall  21   d . The bottom board  21   a  is substantially rectangle and has a longitudinal direction along an X axis direction. The side wall  21   d  is formed at circumference of the bottom board  21   a  having a step. In one embodiment, the base  21  is formed by injection molding assuming plastic.  
         [0050]     The bottom board  21   a  has an underside  21   b  which may be rectangular or another shape. As shown in  FIG. 10  (B), underside  21   b  has a convex shape. The underside  21   b  has the groove  21   c  that is U shaped.  
         [0051]     Along the longitudinal direction of the groove  21   c , there are two metal plates  30 A,  30 B fixed by plural bolts. And the bottom board  21   a  has plural depressions  21   h  that are located along the edge of bottom board  21   a . Each of the depressions  21   h  includes a circular hole.  
         [0052]     In a neighborhood of central part of the Y-direction end of this base  21 , rectangular notch  21   f  is formed by being cut out a part from the underside  21   b  to the side wall  21   d.    
         [0053]     As shown in  FIG. 11 (A) (sectional view along A-A line of  FIG. 2 ),  FIG. 11 (B) (sectional view along B-B line of  FIG. 2 ), and  FIG. 11  (C) (sectional view along C-C line of  FIG. 2 ), screws  55  are inserted into circular bores that are formed at the depressions  21   h . Also, the screws  55  arrive to the tube portions formed in the under surface of the top board  16   a  of the cover  22  through the board  61 , and the holder  51  or the board  62 . In this way, the cover  22  and base  21  are combined. Then the cover  22  and base  21  are mounted on main body  10  by bolt (not shown) by the intermediary of metal plates  30   a ,  30   b . The electronic circuit in the operation panel  20  and the copier main body  10  are electrically engaged through the notch  21   f.    
         [0054]     The key top member  30  in the above-mentioned embodiment is surrounded by the frame  31 , as shown in  FIG. 6 . This construction provides protection to key top member  30  during transport and assembly so that portions of key top member (e.g., key top hinge  33 ) are not subject to breakage. Also, as shown in  FIG. 12 , the key top member  30  can be attached to the cover  22  by gripping the frame. In the situation in which key top member  30  is assembled, the frame  31  is fixed by the cover  22  and board  61 . Therefore, the key top main body  32  is engaged to the frame  31  by a pair of the hinges  33  maintains the clearance between the key top main body  32  and the key aperture  23  of the cover  22  free from being shifted.  
         [0055]     The frame  31  of the key top member  30  in the above-mentioned embodiment has a curve portion  31   c  as shown in  FIG. 8 . If the position for the curve portion  31  is changed according to a position of the each of key top member should be attached to, the each key top member is not attached to wrong position. For instance, regarding the key top member  30  shown in  FIG. 8 , if the curve portion  31   c  is formed to a different position or is not formed, the frame  31  and the pipe-shaped portion may hit each other so that the key top member  30  can not be attached to the key aperture  23 . This previously described construction prevents a wrong mounting of the key top member  30 . This is particularly useful in the case where only a color of the key top member is different. In general, the above-described construction prevents the occurrence of the defective goods and make for an improved production yield ratio.  
         [0056]     As shown in  FIG. 8 , because the guide ribs (not shown) are formed around an insertion position of the key top member  30 , the positioning of the key top member  30  is easy. In addition, even if the mounting of the key top member is incomplete, the key top member  30  is guided to a desired position and the circular hole  34   a  of the extension position  34  engage to the split pin  24 . Therefore, the above-mentioned construction prevents the occurrence of the defective mounting and reduces a time for the mounting.  
         [0057]     The present invention is not limited to the above-mentioned embodiments. Although the actuation portion  32   c  of the key top member  30  shown in the previously described figures is disposed in the vicinity of the center of the push portion  32   a , the actuation portion  32   c  can alternatively be located below the push portion  32   a . For instance, as shown in  FIG. 13 , the actuation portion  32   c  can be located in the edge of the key top main body  32 . The operation feeling of the key top member  30  is changed according to changing the position of the actuation portion  32   c . For example, the operation feeling of the key top member  30  can be become similar to one of the other key top members by changing the portion of the actuation portion  32   c . As shown in  FIG. 13 , light source can be disposed in the position of the under the push portion  32   a . The Light emitting device (LED) can be used as light source. In this instance, it is preferable that the push portion  32   a  has a light transmission portion. Furthermore, it is preferable that the midpoint of a pair of the hinges  33  and the center of the push portion  32   a , and the position in the XY plane of the actuation portion  32   c  should be on a line so that the key top hinge  33  has no distortion.  
         [0058]     Furthermore, the operation panel  20  in the embodiments discussed above, can make for the improvement of the yield ratio and reduce a time for the mounting because the operation panel  20  has a above mentioned push button mechanism  30  including the key top member  30 . And this reduces the production cost of the operation panel  20 .  
         [0059]     In addition, the copier  100  as an image forming apparatus can reduce the produce cost of the image forming apparatus.  
         [0060]     Furthermore, although the key top member  30  has one key top main body  32  in the embodiments discussed above, the key top member  30  can have plural key top main body  32  and a common frame  31 .  
         [0061]     Furthermore, although the key top member  30  and operation panel  20  are used for the copier  100  in the embodiments discussed above, the key top member  30  and operation panel  20  can be used for another type of image forming apparatus, for example, a printer, a facsimile and a multifunction peripheral. The multifunction peripheral has plural functions selected from a copier function, a facsimile function, a printer function, and a scanner function.  
         [0062]     Numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein.  
         [0063]     That application is based on Japanese patent application 2005-198304 filed in the Japanese Patent Office on Jul. 7, 2005, the entire contents of which are hereby incorporated by reference.