Abstract:
An optical connector socket includes: a body having an insertion section in which a socket-side optical element is arranged and into which an optical connector plug is inserted; a cover, covered on the body, having an opening communicated with the insertion section; a shutter, openably/closably attached to the cover, for closing the opening; and a herical spring for elastically urging the shutter in a constant-closing direction. The opening is larger than an outside dimension of the optical connector plug inserted into the cover and smaller than that of the shutter. Therefore, there is no light leakage and dust intrusion, the socket can be attached to a device or a wall so as to direct an opening toward a front face without a cap, and an inspection in a state where the socket is assembled in an electronic device can be performed without attaching/detaching the cap to/from the socket.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to an optical connector socket.  
           [0003]    2. Prior Art  
           [0004]    This type of an optical connector socket is provided at a device for outputting and/or inputting a digital signal such as a stationary-type DVD, TV, STB (set top box: an adapter device for a satellite broadcast), CD, MD, amplifier or the like. Further, it has recently been used as an input/output terminal for computer communication using an optical fiber.  
           [0005]    Conventional this type of optical connector sockets are those disclosed in, for example, Japanese Unexamined Patent Application No. 2000-131564 and Japanese Unexamined Patent Application No. 2001-201663. These optical connector sockets have a body provided with an insertion section having a socket-side optical device at the backside and a shutter for approximately closing the insertion section of the body. The aforesaid shutter is attached to the body so as to be capable of opening and closing the insertion section. This shutter aims mainly to prevent a dust or the like from getting into the insertion section of the body.  
           [0006]    However, the above-mentioned conventional optical connector socket has the following problems.  
           [0007]    Specifically, the shutter of these optical connector socket is attached on, the front surface of the body so as to be displaced inwardly of the body by pushing the optical connector plug into the insertion section, so that the dimension of the used shutter is slightly smaller than the dimension of the opening section of the insertion section. Therefore, in a so-called two-way optical connector having a light-emitting device and light-receiving device as a socket-side optical device, light from the light-emitting device is likely to leak to the outside. Since a disorder such as a damage in retina or the like is likely to occur when a man looks the light from the light-emitting device in the eye, the optical connector socket is attached such that the opening section is directed diagonally downward because a safety takes priority over the difficulty in inserting the optical connector plug.  
           [0008]    Further, there is an optical connector socket having no shutter. In this case, a cap is fitted to the opening section of the insertion section for preventing a light leakage and intrusion of dust or the like. However, this cap is small, so that it may sometimes be lost. Moreover, infants are likely to mistakenly drink the cap.  
           [0009]    Additionally, during a check of electrical equipment to which this optical connector socket is installed, for example, during a check of a set top box, the configuration in which the cap is fitted to the optical connector socket requires an operation of pulling out the cap for inserting the optical connector plug, and then, inserting the cap into the optical connector socket.  
         SUMMARY OF THE INVENTION  
         [0010]    The present invention is designed in view of the above circumstances, and aims to provide an optical connector socket that prevents a light leakage and intrusion of dust, does not utilize a cap, can be installed to equipment or wall such that an opening section faces forward with respect to the equipment or wall and does not require an operation of pulling out and inserting a cap even during a check with the socket installed in the electrical equipment.  
           [0011]    The optical connector socket according to the present invention comprises a body having a socket-side optical device installed therein and an insertion section to which a connected optical connector plug is inserted, a cover that is covered on this body and has an opening section communicating with the insertion section, a shutter openably and closably attached to the cover for closing the opening section and an elastic member that always elastically urges this shutter in a closing direction, wherein the opening section is set to have an outside dimension greater than the outside dimension of the optical connector plug inserted to the cover and smaller than the outside dimension of the shutter.  
           [0012]    This optical connector socket can perfectly prevent a light leakage or intrusion of dust.  
           [0013]    Further, a guide projection is provided at the inside of the insertion section of the body for guiding the inserted optical connector plug toward the socket-side optical device, wherein the guide projection becomes narrower toward the backside of the insertion section.  
           [0014]    This configuration enables to face the socket-side optical device of the optical connector socket to a plug-side optical device of the optical connector plug.  
           [0015]    Further, provided at the backside from the guide projection is a locking recess section that engages with a locking convex section provided on an outer surface of the optical connector plug.  
           [0016]    This configuration can assuredly fix the optical connector plug inserted into the optical connector socket. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0017]    [0017]FIG. 1 is an exploded perspective view schematically showing an optical connector socket according to the embodiment of the present invention;  
         [0018]    [0018]FIG. 2 is a partial cutaway perspective view schematically showing a state wherein a top surface of a shield cover, top wall of the cover and top wall section of a body are removed from the optical connector socket according to the embodiment of the present invention;  
         [0019]    [0019]FIG. 3 is a longitudinal sectional view schematically showing the optical connector socket according to the present invention;  
         [0020]    [0020]FIG. 4 is a cross-sectional side view schematically showing the optical connector socket according to the present invention; and  
         [0021]    [0021]FIG. 5 is a schematic plan view showing an optical connector plug connected to the optical connector socket according to the present invention. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0022]    [0022]FIG. 1 is an exploded perspective view schematically showing the optical connector socket according to the present invention, FIG. 2 is a partial cutaway perspective view schematically showing a state wherein a top surface of a shield cover, top wall of the cover and top wall section of a body are removed from the optical connector socket of the present invention, FIG. 3 is a longitudinal sectional view schematically showing the optical connector socket according to the present invention, FIG. 4 is a cross-sectional view schematically showing the optical connector socket according to the present invention and FIG. 5 is a schematic plan view showing an optical connector plug connected to the optical connector socket according to the present invention.  
         [0023]    The optical connector socket A according to the embodiment of the present invention comprises a body  100  having a socket-side optical device  600  installed therein and an insertion section  110  to which a connected optical connector plug B is inserted, a cover  200  that covers the body  100  and has an opening section  210  communicating with the aforesaid insertion section  110 , a shutter  300  openably and closably attached to the cover  200  so as to close the aforesaid opening section  210  and a helical spring  500  serving as an elastic member for elastically urging this shutter  300  toward its closing direction at all times, wherein the aforesaid opening section  210  is set to be greater than the outside dimension of the optical connector plug inserted into the cover  200  as well as smaller than the outside dimension of the shutter  300 .  
         [0024]    Before explaining the optical connector socket A, the optical connector plug B connected to this optical connector socket A will firstly be explained.  
         [0025]    This optical connector plug B, as shown in FIG. 5, has an optical fiber B 1  and a plug body B 2  made of synthetic resin and obtained by molding the optical fiber B 1 .  
         [0026]    An opening (not shown) that faces to the edge section of the optical fiber B 1  is formed at the leading edge of the above-mentioned plug body B 2 . Further, provided at both of left and right side faces of the plug body B 2  are locking convex sections B 21  that are engaged with locking recess sections  180  of the optical connector socket A. Additionally, formed on the top surface of this plug body B 2  is a locking groove B 22  that is engaged with a locking pawl  160  of the optical connector socket A.  
         [0027]    The above-mentioned body  100  is molded by synthetic resin or the like having insulating property and has formed thereto the insertion section opens from its front side toward its backside. Provided at the backside of this insertion section  110  are two parallel cylindrical light-shielding cylinders  130  each having an opening section facing to the opening section of the insertion section  110 . The socket-side optical device  600  described later is set to the backside of these light-shielding cylinders  130 . Provided at the backsides of both left and right side faces of the body  100  are optical device insertion openings  140  that communicate with the aforesaid light-shielding cylinders  130 . The socket-side optical device  600  inserted from the optical device insertion opening  140  is positioned at the rear of the light-shielding cylinder  130 .  
         [0028]    Provided at the trailing edge sides of the above-mentioned optical device insertion openings  140  are slits for lead  141  to which lead terminals  612  and  622  of the socket-side optical device  600  inserted into the optical device insertion openings  140  are fitted. Because of the existence of these slits for lead  141 , the lead terminals  612  and  622  of the socket-side optical device  600  are positioned at the backside from the surfaces of left and right wall sections of the body  100 . Therefore, the above-mentioned lead terminals  612  and  622  do not become obstacles upon covering the cover  200  over the body  100 .  
         [0029]    Further, the upper sidewall  150  of this body  100  has a notch  120  formed so as to direct from the front side toward the backside as shown in FIG. 1. Accordingly, the aforesaid upper sidewall  150  is formed approximately into a shape of a concave character as seen flatly. The locking pawl  160  for locking the inserted optical connector plug B is provided from the backside toward the front side of the aforesaid notch  120 . This locking pawl  160  has formed at its leading edge a projecting section  161  that slopes downward to project downwardly toward the backside, this projecting section  161  being engaged with the locking groove B 22  of the inserted optical connector plug B. It is to be noted that this locking pawl  160  is set to have a length so as not to hinder the opening and closing of the shutter  300 .  
         [0030]    Moreover, guide projections  190  that become narrower in width toward the backside of the insertion section are provided at the insides of both left and right sidewalls of this body  100 . These guide projections  190  are for guiding the optical connector plug B inserted to the insertion section  110  to a predetermined position, i.e., for guiding the optical fiber B 1  of the optical connector plug B to a position facing to the light-shielding cylinder  130  and consequently, to the socket-side optical device  600 . Accordingly, a size of the narrowest section between a pair of guide projections  190  provided at both left and right sidewalls is set slightly smaller than the outer shape of the optical connector plug B.  
         [0031]    Locking recess sections  180  that are engaged with the locking convex sections B 21  formed at the outer surface of the optical connector plug B are formed at the insides of both left and right sidewalls of the body  100  and at the backsides from the above-mentioned guide projections  190 . These locking recess sections  180  are holes penetrating the aforesaid left and right sidewalls. Therefore, the locking convex sections B 21  of the optical connector plug B climbing over the guide projections  190  are fitted to the locking recess sections  180 , to thereby be locked with respect to the body  100 .  
         [0032]    The notches  112  for the shutter where shaft fitting sections  231  of the cover  200  enter upon attaching the cover  200  are formed at the frontward lower sides of the left and right sidewalls of this body  100 , i.e., at the left and right frontward lower sides of the insertion section  110 . These notches for the shutter  112  are open to the front side of the body  100 .  
         [0033]    Additionally, mounting bosses  170  with four steps are projected from the trailing edge of this body  100 . These mounting bosses  170  are inserted into holes  710  at a printed circuit board  700 . The diameter of the aforesaid hole  710  is set such that a small diameter section  171  at the leading edge side of the mounting boss  170  can be inserted thereto but a large diameter section  172  of the base side cannot be inserted thereto. Therefore, the small diameter section  171  of the mounting boss  170  is inserted into the aforesaid hole  710  and the small diameter section  171  is melted, whereby the optical connector socket A can be installed at a position apart from the printed circuit board  700  by a height of the large diameter section  172 .  
         [0034]    Further, approximately wedge-shaped projecting sections  111  are formed at both left and right side faces of the aforesaid notch  120  on the top surface of the front edge section of this body  100 . These projecting sections  111  are provided for fixing the cover  200  described later to the body  100 .  
         [0035]    The above-mentioned shutter  300  is molded by synthetic resin or the like having insulating property and formed into an approximately rectangular shape as a whole. A size W3 of a lateral width of this shutter  300  is set smaller than a lateral width W1 of the insertion section  110 . Similarly, a height H3 of the shutter  300  is set smaller than a height H1 of the insertion section  110 . Accordingly, the shutter  300  can fall inwardly of the insertion section  110  of the body  100 . It is to be noted that this shutter  300  can be made not only of the synthetic resin or the like having insulating property but also of a metallic material or synthetic resin having conductivity.  
         [0036]    Further, a single support shaft  800  is fittingly engaged with the shaft engaging sections  231  formed at both lower sides at the back surface side of this shutter  300 . This support shaft  800  serves as a center of the pivotal movement of this shutter  300 .  
         [0037]    When the cover  200  is attached to the body  100  with the support shaft  800  of the shutter  300  fittingly engaged with the shaft engaging sections  231 , the shaft engaging sections  231  are fitted into the notch section  112  for the shutter by the body  100  for closing the shaft engaging sections  231  with the body  100 , so that the shutter  300  can securely be shaft-supported to the cover  200 .  
         [0038]    Externally fitted at nearly the center of the above-mentioned support shaft  800 , as shown in FIG. 3, is the helical spring  500  serving as an elastic member for always elastically urging the shutter  300  shaft-supported by the body  100  toward the closing direction. This helical spring  500  is composed of a helical section  510  having the aforesaid support shaft  800  internally fitted thereto and one end  520  and the other end  530  of the helical section  510 . The above-mentioned one end  520  and the other end  530  are extended to a tangential direction of a coil of the helical spring  500 .  
         [0039]    With the aforesaid support shaft  800  internally fitted to the helical spring  500 , the one end  520  of this helical spring  500  comes in contact with the rear surface of the shutter  300  while the other end  530  thereof comes in contact with the bottom surface of the insertion section  110  of the body  100  respectively. Accordingly, the displacement from the opening direction to the closing direction of the shutter  300  is performed against the elastic force of the helical spring  500 . Therefore, the shutter  300  is always elastically urged toward the closing direction by the helical spring  500 .  
         [0040]    On the other hand, the cover  200  covered over the aforesaid body  100  is molded by synthetic resin or the like having insulating property. This cover  200  is integrally formed by a cover main section  220  having a square pole shape and provided with top, bottom, left and right walls and an approximately frame-like shaped front frame section  230  provided at the front side of the cover main section  220 .  
         [0041]    Formed at the aforesaid front frame section  230  is an opening  210  that communicates with the above-mentioned insertion section  110  when the cover  200  is covered over the body  100 . This opening  210  has an approximately rectangular shape and is set to have a lateral width W2 smaller than the lateral width W3 of the shutter  300  and a height H2 lower than the height H3 of the shutter  300 . Therefore, the above-mentioned opening  210  is set greater than the outer dimension of the optical connector plug B inserted into the cover  200  as well as smaller than the outer dimension of the shutter  300 .  
         [0042]    Accordingly, the relationships of H1&gt;H3&gt;H2, W1&gt;W3&gt;W2 are established among the lateral width W2 and the height H2 of the opening  210 , the lateral width W3 and the height H3 of the shutter  300  and the lateral width W1 and the height H1 of the insertion section  110 . Therefore, the opening  210  can surely be closed when the shutter  300  is in the closing state, thereby preventing light from the light-emitting device  610  of the socket-side optical device  600  from leaking to the outside and preventing unnecessary light from the light-receiving device  620  of the socket-side optical device  600  from being received as a signal.  
         [0043]    Moreover, the shaft engaging sections  231  to which the both ends of the aforesaid support shaft  800  are fitted are provided at both left and right lower sides at the back surface of the aforesaid front frame section  230 . When the support shaft  800  attached to the shutter  300  is fittingly engaged with the shaft engaging sections  231 , the shutter  300  is pivoted inwardly about the support shaft  800 .  
         [0044]    One rectangular-shaped projection  222  for being engaged with a shield cover  400  described later is projectingly provided at each of the left and right sidewalls of the cover main section  220  of the cover  200 . Further, the aforesaid front frame section  230  and the trailing edge section are formed to be slightly higher than the top, bottom, left and right wall sections of the cover main section  220 , whereby they are flatly attached to the surface of the shield cover  400 .  
         [0045]    Moreover, formed at the front edge section of the top wall of this cover  200  are fitting holes  221  to which the projecting sections  111  of the aforesaid body  100  are fitted. The cover  200  is fixed to the body  100  by fitting the projecting sections  111  to the fitting holes  221 .  
         [0046]    The above-mentioned socket-side optical device  600  comprises the light-emitting device  610  that converts an inputted electrical signal into an optical signal and outputs the resultant and the light-receiving device  620  that converts an inputted optical signal into an electrical signal and outputs the resultant. This light-emitting device  610  is fabricated such that a light-emitting chip is molded at nearly the center of a thin-sized rectangular-shaped mold resin  611  and lead terminals  612  connected to the light-emitting chip are externally projected from the mold resin  611 . The aforesaid light-receiving device  620  is fabricated such that a light-receiving chip is molded at nearly the center of a thin-sized rectangular-shaped mold resin  621  and lead terminals  622  connected to the light-receiving chip are externally projected from the mold resin  611 .  
         [0047]    When these light-emitting device  610  and the light-receiving device  620  are inserted into the body  100  from the optical device insertion opening  140 , the respective light-emitting chip and the light-receiving chip are positioned at the backside of the light-shielding cylinders  130 .  
         [0048]    It is to be noted that the lead terminals  612  and  622  of the light-emitting device  610  and the light-receiving device  620  are formed so as to be bent at an approximately right angle for directing toward the rear of the optical connector socket A.  
         [0049]    Additionally, covered over this optical connector socket A is the shield cover  400  formed by bending a conductive metal plate. This shield cover  400  is formed into an approximately a concave character in a downward direction and covers the top, left and right walls of the cover  200  covered over the body  100 . Tongue-piece sections  410  projecting downwardly are formed at left and right lower sides of the shield cover  400 . These tongue-piece sections  410  are inserted into openings formed on a printed circuit board not shown for fixing the optical connector socket A to the aforesaid printed circuit board.  
         [0050]    Rectangular-shaped openings  420  are formed at the left and right walls of this shield cover  400 . These openings  420  are engaged with the projections  222  projectingly formed at the left and right sidewalls of the above-mentioned cover  200 .  
         [0051]    Subsequently explained is a connection between the optical connector socket A and the optical connector plug B having the above-mentioned configuration.  
         [0052]    Firstly, the plug body B 2  of the optical connector plug B is inserted into the opening  210  of the cover  200  from the insertion section  110 . Then, the shutter  300  is pressed by the plug body B to thereby fall downwardly against the elastic force of the helical spring  500 . Further, when the plug body B 2  is inserted into the insertion section  110 , the leading edge of the plug body B 2  comes in contact with the guide projections  190  of the body  100 . When the plug body B 2  is further inserted into the insertion section  110  with this state, the optical fiber B 1  of the optical connector plug B surely faces to the socket-side optical device  600  since the plug body B 2  is guided by the guide projections  190 .  
         [0053]    When the plug body B 2  is inserted into the insertion section  110  to the end, the locking convex sections B 21  of the optical connector plug B climbing over the guide projections  190  are engaged with the locking recess sections  180  of the body  100 . Simultaneously, the projecting section  161  of the locking pawl  160  of the body  100  is engaged with the locking groove B 22  of the plug body B 2 .  
         [0054]    With this state, the optical fiber B 1  at the light-receiving side of the optical connector plug B surely faces to the light-emitting device  610  of the socket-side optical device  600  of the optical connector socket A, while the optical fiber B 1  at the light-emitting side of the optical connector plug B surely faces to the light-receiving device  620  of the socket-side optical device  600  of the optical connector socket A. As a result, the optical connector plug B is completely connected to the optical connector socket A.  
         [0055]    In the case of pulling out the optical connector plug B inserted into the optical connector socket A, the plug body B 2  is pulled outwardly. Then, the locking convex sections B 21  of the optical connector plug B climb over the guide projections  190  adjacent to the locking recess sections  180  of the body  100 , thereby providing a disengagement. Simultaneously, the locking projection  161  of the locking pawl  160  comes out of the locking groove B 22  of the plug body B 2 , thereby providing disengagement.  
         [0056]    When the plug body B 2  is completely pulled out from the insertion section  110 , there is no external force to the shutter  300 , whereby the shutter  300  rises up to return to the original position, i.e., the position for closing the insertion section  110 , due to the elastic force of the helical spring  500 .  
         [0057]    Although the optical connector socket A is a so-called two-way optical connector socket in which the socket-side optical device  600  has the light-emitting device  610  and the light-receiving device  620  in the above-mentioned embodiment, it is needless to say that the present invention can be applied to a so-called one-way optical connector socket having only one of the light-emitting device and light-receiving device.  
         [0058]    The optical connector socket according to the present invention comprises a body having a socket-side optical device installed therein and an insertion section to which a connected optical connector plug is inserted, a cover that is covered on this body and has an opening section communicating with the insertion section, a shutter openably and closably attached to the cover for closing the opening section and an elastic member that always elastically urges this shutter in a closing direction, wherein the opening section is set to have an outside dimension greater than the outside dimension of the optical connector plug inserted to the cover and smaller than the outside dimension of the shutter.  
         [0059]    Therefore, the opening section is surely closed by the shutter in case where the optical connector plug is not connected to the optical connector socket, whereby there is no need to use a cap as conventionally, and a light leakage or intrusion of dust can be eliminated. Accordingly, there is no concern about the occurrence of a disorder such as a damage in retina or the like when a man looks the light from the light-emitting device in the eye. Therefore, it is unnecessary to perform an attachment such that the opening section is directed diagonally downward as conventionally, so that it is possible to give priority to the easiness upon inserting the optical connector plug. Further, operation of pulling out and inserting a cap is not required even during a check with the socket installed in the electrical equipment.  
         [0060]    Further, a guide projection is provided at the inside of the insertion section of the body for guiding the inserted optical connector plug toward the socket-side optical device, wherein the guide projection becomes narrower toward the backside of the insertion section.  
         [0061]    Therefore, the socket-side optical device of the optical connector socket can surely be faced to a plug-side optical device of the optical connector plug.  
         [0062]    Further, provided at the backside from the guide projection is a locking recess section that engages with a locking convex section provided on an outer surface of the optical connector plug.  
         [0063]    Therefore, the optical connector plug inserted into the optical connector socket can surely be fixed.  
         [0064]    The above-mentioned socket-side optical device comprises a light-emitting device and a light-receiving device. Accordingly, the optical connector socket can be provided that is safety and has reduced checking process even with being installed to electrical equipment.