Abstract:
A switch for an electronic device includes a main printed circuit board having a contact point mode pattern at an upper surface thereof; and a rotor rotatively installed on the main printed circuit board with one or more brushes mounted therein so as to be connected to the contact point mode pattern. The rotor may be engaged to a moving member of the electronic device so that the rotor is rotated to different orientations depending on the operational mode of the electronic device. Because the rotor is directly installed on the main printed circuit board, the number of construction components is reduced, and the product can be more compact.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to a mode switch of a video cassette recorder mechanism, and more particularly, to a mode switch of a video cassette recorder (VCR) which detects operation locations of a loading device. The mode switch converts the operation locations into electric signals, then transmits the signals to a system control unit of the VCR.  
           [0003]    2. Background of the Related Art  
           [0004]    Generally, a video cassette recorder (VCR) includes a tape deck mechanism having a tape loading device, a cassette tape loading device, a tape driving device, a brake operating device, a brake device, a driving force shielding device, and a system control unit for controlling an operation of the tape deck mechanism.  
           [0005]    In response to a user pushing operational mode keys such as play, stop, fast forward, and rewind, the system control unit controls each component of the tape deck mechanism. Also, a mode switch converts the mode of the tape deck mechanism into an electric signal and outputs the signal to the system control unit, thereby controlling operations of the deck mechanism by the system control unit. Typically, a cam gear rotated by a driving motor is installed on the tape deck mechanism of the VCR, and the mode switch is engaged to the cam gear. The mode switch outputs the signal based on a detected rotation angle of the cam gear. By the control signal output from the mode switch, modes such as play, reverse play, fast forwarding, rewinding, cue, and review are performed.  
           [0006]    [0006]FIG. 1 is a disassembled perspective view showing a conventional mode switch, and FIG. 2 is a longitudinal section view of FIG. 1.  
           [0007]    As shown, in the conventional mode switch  10 , a rotor  12  is ratably engaged to a stator  11 , and the stator  11  is fixed to a main printed circuit board  20 .  
           [0008]    An engaging hole  21 , a welding hole  22 , and terminal engaging holes  23  are formed at the main printed circuit board  20  of a single surface type having circuit devices only at a lower portion thereof.  
           [0009]    A fixing hook  11   a  is formed at one side of the stator  11  so as to be inserted to the engaging hole  21 . A welding hole  22  of the main printed circuit board  20 , receives a protrusion  11   b  formed at a bottom surface of the stator  11 . Terminals  11   e  are formed at the other side of the stator  11 .  
           [0010]    Before assembling the stator  11  to the main printed circuit board  20 , the rotor  12  is assembled to the stator  11 . To this end, an engaging hole  11   d  is formed at a center portion of the stator  11  on which a contact point mode pattern  11   c  is formed, and engaging hooks  12   a  is formed at a center portion of a lower surface of the rotor  12 .  
           [0011]    A protrusion  12   c  engaged to the cam gear is formed at an upper surface of the rotor  12 , and one or more brushes  12   b  are mounted in the rotor  12  so as to be connected to the contact point mode pattern  11   c  of the stator  11 .  
           [0012]    Accordingly, first of all, the engaging hooks  12   a  of the rotor  12  are fitted to the engaging hole  11   d  to fix the rotor  12  to the stator  11 . Then the fixing hook  11   a  of the stator  11  is fitted to the engaging hole  21  of the main printed circuit board  20 . The protrusions  11   b  of the stator  11  are fitted to the welding holes  22 , and the terminals  11   e  are fitted to the terminal engaging holes  23 . Subsequently, the stator  11  is fixed to the main printed circuit board  20  by soldering the terminals  11   e  of the stator  11 .  
           [0013]    In this conventional rotation mode switch, the stator  11  is fixed to the main printed circuit board  20  by soldering between the fixing hook  11  a and the terminals  11   e . If the cam gear is rotated by a driving force of a cam driving motor not shown in drawings, the rotor  12  engaged to the cam gear is rotated.  
           [0014]    At this time, if the brushes  12   b  of the rotor  12  are contacted to the contact point mode pattern  11   c  of the stator  11  at a predetermined position, a control unit (not shown) detects a corresponding mode by a combination between the brushes  12   b  and the contact point mode pattern  11   c . The detected signal is fed back to the cam driving motor to operate an operating device into a specific mode.  
           [0015]    However, in the conventional mode switch of a VCR, since the rotor is engaged to the stator and the stator is fixed to the main printed circuit board, an entire thickness of the VCR becomes large.  
           [0016]    As opposed to the conventional trend that a VCR using a tape cassette and a DVD using an optical disc are separately purchased, current consumers prefer to purchase a product which includes both the VCR and the DVD. In case of the unified type device, since mechanisms of the VCR and the DVD have to be installed in the same device, an entire structure becomes complicated.  
           [0017]    Accordingly, in case of the unified type product, a cassette tape is thicker than an optical disc, and a carrier for mounting the cassette tape to the deck mechanism has to be large. Therefore, the VCR becomes thick, which causes an entire thickness of the unified type to be large.  
         SUMMARY OF THE INVENTION  
         [0018]    An object of the invention is to solve at least the above problems and/or disadvantages and to provide at least the advantages described hereinafter.  
           [0019]    Therefore, an object of the present invention is to provide a mode switch of a VCR which can greatly slim a unified type product which includes both a VCR and a DVD by simplifying a structure of the mode switch.  
           [0020]    To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, there is provided a mode switch of a VCR comprising: a main printed circuit board having a contact point mode pattern at an upper surface thereof; and a rotor rotative installed on the main printed circuit board with brushes mounted therein so as to be connected to the contact point mode pattern. The rotor is engaged to a cam gear of the VCR.  
           [0021]    An engaging hole is formed on the main printed circuit board so that the rotor can be rotative installed on the main printed circuit board, and one or more engaging hooks are fitted to the engaging hole at the center of the rotor.  
           [0022]    The main printed circuit board may include devices and electrical patterns on both surfaces.  
           [0023]    Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objects and advantages of the invention may be realized and attained as particularly pointed out in the appended claims. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0024]    The invention will be described in detail with reference to the following drawings, in which like reference numerals refer to like elements, and wherein:  
         [0025]    [0025]FIG. 1 is a disassembled perspective view showing a mode switch in accordance with a conventional art;  
         [0026]    [0026]FIG. 2 is a longitudinal section view of FIG. 1;  
         [0027]    [0027]FIG. 3 is a disassembled perspective view showing a mode switch in accordance with the present invention;  
         [0028]    [0028]FIG. 4 is an assembled perspective view showing a mode switch in accordance with the present invention;  
         [0029]    [0029]FIG. 5A is a longitudinal section view of the mode switch of FIG. 4;  
         [0030]    [0030]FIG. 5B is an enlarged view of the central portion of the mode switch shown in  5 A; and  
         [0031]    [0031]FIG. 6 is a sectional view of a mode switch according to another embodiment of the invention.  
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0032]    Reference will now be made in detail to preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.  
         [0033]    As shown, a mode switch  100  of the present invention comprises: a main printed circuit board  110  having a contact point mode pattern  112  at an upper surface thereof; and a rotor  120  rotative installed on the main printed circuit board  110 . Brushes  121  are mounted therein so as to be connected to the contact point mode pattern  112 . A protrusion  123  on the rotor  112  is engaged to a cam gear of the VCR (not shown).  
         [0034]    In case of a unified type product which includes both a VCR and a DVD player, slimming the product is very important to obtain competitiveness. As a result, any technique to make the mode switch slimmer is very desirable. To this end, in the mode switch  100  of the present invention, the rotor  120  is directly installed on the main printed circuit board  110  without the need for a separate stator.  
         [0035]    An engaging hole  111  is formed on the main printed circuit board  110  so that the rotor  120  can be rotative installed on the main printed circuit board  110 . One or more engaging hooks  121  are formed at a center portion of the rotor  120  and the engaging hooks are configured to engage the engaging hole  111  of the printed circuit board  110 .  
         [0036]    The main printed circuit board  110  used in the present invention is configured such that circuit devices can be mounted on a lower surface thereof, and the contact point mode pattern  112  is formed at an upper surface thereof.  
         [0037]    That is, the circuit devices for driving each construction component are located on the lower surface of the main printed circuit board  110 . At the upper surface of the main printed circuit board  110 , the contact point mode pattern  112  of copper foil is exposed to outside so as to be contacted to one or more brushes  122  on the rotor. Although copper foil is preferred for the contact point mode pattern  112 , any electrically conductive material could be used. The position of the brushes on the contact point mode pattern indicate an operating mode of the VCR.  
         [0038]    A tape deck (not shown) is generally located on an upper portion of the main printed circuit board  110 . A cam gear is mounted on a lower surface of the tape deck so as to be rotated by the driving motor.  
         [0039]    The rotor  120  is installed on the main printed circuit board  110  by the engaging hooks  121 . An engaging protrusion  123  engaged to the cam gear is formed at an upper surface thereof, so that the engaging protrusion  123  is engaged to the cam gear when the tape deck mechanism is located above the main printed circuit board  110 .  
         [0040]    Brushes  122  are fixed in the rotor  120 , and the brushes  122  are selectively connected to the contact point mode pattern  112  of the main printed circuit board  110 . Accordingly, the rotor  120  engaged to the cam gear is rotated around the engaging hooks  121  as the cam gear is rotated, and at this time, a control unit (not shown) can detect a specific mode of the VCR based on a position of the brushes on the contact point mode pattern  112 .  
         [0041]    The engaging hooks  121  of the rotor  120  have an elastic force, and an inclined plane  121   a  is formed at an end part of the engaging hooks  121  to allow the engaging hooks  121  to be smoothly engaged to the engaging hole  111 . A stopping portion  121   b  is formed just above the inclined plane  121   a . The engaging hooks  121  can be formed integrally with the rotor  120 , and the rotor  120  can be inserted to the main printed circuit board  110  by forming an additional member.  
         [0042]    Processes for assembling the rotor  120  to the main printed circuit board  110  in the mode switch  100  of the VCR of the present invention will be explained as follows.  
         [0043]    First, the engaging hooks  121  of the rotor  120  are fitted to the engaging hole  111  of the main printed circuit board  110  and slightly pressed, so that the inclined plane  121   a  formed at the end part of the engaging hooks  121  is pressed against an inner circumferential surface of the engaging hole  111 , and such that the engaging hooks  121  are elastically deformed. If the rotor  120  is pressed downwardly, the engaging hooks  121  elastically come back to an initial position. At this time, the stopping portion  121   b  of the engaging hooks  121  abut the lower surface of the main printed circuit board  110 , thereby engaging the rotor  120  to the main printed circuit board  110 . The rotor  120  can be rotated by being connected to the cam gear. Also, a predetermined interval has to be maintained between the rotor  120  and the main printed circuit board  110 .  
         [0044]    If the engaging hooks  121  are engaged to the engaging hole  111 , the brushes  122  of the rotor  120  are connected to the contact point mode pattern  112  of the main printed circuit board  110 . The rotor  120  is rotative engaged on the main printed circuit board  110  and at the same time, is engaged with the cam gear.  
         [0045]    Hereinafter, operations for detecting a mode in the mode switch of the present invention will be explained.  
         [0046]    If the cam gear is rotated by the driving force of the cam gear driving motor, the rotor  120  engaged to the cam gear is rotated. At this time, if the brushes  122  of the rotor  120  are contacted to the contact point mode pattern  112  of the main printed circuit board  110 , the control unit detects a corresponding mode by a combination between the brushes  122  and the contact point mode pattern  112 . Then, the detected signal is fed back to the cam gear driving motor to operate the operating device into a specific mode.  
         [0047]    [0047]FIG. 6 is a sectional view of another mode switch embodying the invention. In this embodiment, a hole  131  is formed in a printed circuit board  130 . A plurality of contact point mode patterns  132  are formed on an upper surface of the printed circuit board  130 . The contact point mode patterns  132  are arranged in a ring around the hole  131 .  
         [0048]    A generally cylindrical contactor  150 , is arranged within the hole  131 . The contactor  150  includes a hole  151  passing therethrough. A flange  152  is configured to abut with the upper surface of the circuit board. The flange ensures that the contactor is maintained at the proper distance about the top surface of the circuit board.  
         [0049]    The contactor  150  also includes one or more brushes  153 , which project from sides of the contactor  150 . All of the brushes  153  are electrically conductive, and they are all electrically coupled to each other.  
         [0050]    A rotor  140  is mounted on the circuit board  130 . An engaging hook  141  passes through the holes in the contactor and the printed circuit board so that the rotor  140  is mounted on the circuit board. The rotor also includes a plurality of contact protrusions  142  are formed on a lower surface of the rotor  140 . The height of the protrusions  142  is sufficient to push the brushes  153  into contact with the contact point mode patterns  132  formed on the upper surface of the circuit board.  
         [0051]    An engaging protrusion  143  is formed on an upper surface of the rotor  140 . A cam gear of a VCR mechanism engages the engaging protrusion  143  to rotate the rotor  140 . The rotation of the rotor causes certain contact protrusions  142  to press brushes  153  into contact with the contact point mode patterns  132 . The pattern of electrically coupled contact point mode patterns  132  is then sensed to determine the specific operation mode of the device.  
         [0052]    As aforementioned, in the mode switch of the present invention, no separate stator is required. Instead, the rotor is installed directly on the main printed circuit board, thereby reducing the number of components and slimming the product.  
         [0053]    The foregoing embodiments and advantages are merely exemplary and are not to be construed as limiting the present invention. The present teaching can be readily applied to other types of apparatuses. The description of the present invention is intended to be illustrative, and not to limit the scope of the claims. Many alternatives, modifications, and variations will be apparent to those skilled in the art. In the claims, means-plus-function clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents but also equivalent structures.