Abstract:
A pair of three-dimensional glasses include two lenses, a frame holding the two lenses, a circuit board controlling the two lenses, and a power unit powering the circuit board. The power unit includes a control switch. The control switch extends from an inner surface of the frame. The circuit board is powered on when the control switch is contacted, and powered off when the control switch is not contacted.

Description:
BACKGROUND 
     1. Technical Field 
     The present disclosure generally relates to imaging technology, and particularly to three-dimensional (3D) imaging glasses. 
     2. Description of Related Art 
     The illusion of three dimensions on a two dimensional surface can be created by providing each eye with different visual information. 3D glasses create the illusion of three dimensions when viewing specially prepared images. Passive 3D glasses can have one red color filter lens in front of one eye and one blue or cyan color filter lens in front of the other, or use polarized filters, with one lens polarized vertically and the other horizontally, with the two images required for stereo vision polarized the same way. Polarized 3D glasses allow for a more colorful 3D image, compared to the red-blue lenses which produce only a dull black-and-white picture with red and blue fringes. 
     Active 3D glasses can achieve the 3D image through active function, including dual display 3D glasses and liquid crystal shutter glasses. The dual display 3D glasses have separate video screens for each eye. The liquid crystal shutter glasses cooperate with a 3D display screen, and include two liquid crystal units to shutter right-eye image and left-eye image by turns. The liquid crystal shutter glasses have been distributed to audiences at 3D movies. 
     The active 3D glasses require electric power to perform the shuttering operation, but should also be portable, making power supply a challenge. Continued power supply consumes too much electric power, and electric wires are inconvenient for the portable 3D glasses. Related active 3D glasses may have a switch to turn on or turn off the active 3D glasses. However, users can often forget to turn off the active 3D glasses during standby and idle periods. Some active 3D glasses cooperate with additional devices detecting the usage state of the glasses and control the power supply accordingly. If the active 3D glasses are left unused for a period, the sensor sends signals to stop the power supply. However, such devices are usually expensive. 
     Therefore, it is desirable to provide 3D glasses which can overcome the described limitations. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Many aspects of the 3D glasses can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, emphasis instead being placed upon clearly illustrating the principles of the present disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views. 
         FIG. 1  is an exploded, isometric view of 3D glasses according to one embodiment. 
         FIG. 2  is a partial, isometric view of the 3D glasses of  FIG. 1  when idle. 
         FIG. 3  is a partial, isometric view of the 3D glasses of  FIG. 1  in use. 
     
    
    
     DETAILED DESCRIPTION 
     As shown in  FIG. 1  and  FIG. 2 , 3D glasses  10  of one embodiment include two lenses  11 , a frame  12 , a power unit  16  and a circuit board  18 . 
     The lenses  11  may be photoelectric units, such as display screens or liquid crystal shutters, but are not limited thereto. 
     The frame  12  includes two rims  128  respectively holding the two lenses  11 , a bridge  121  connecting the two rims  128 , two connection bases  124  respectively connected to the two rims  128 , and two temples  125  respectively connected to the two connection bases  124 . Each connection base  124  and each temple  125  respectively defines a first hollow  120  and a second hollow  140  therein, and the first hollow  120  and the second hollow  140  cooperatively form a cavity. The two temples  125  may be respectively connected to the two connection bases  124  through rotation shafts or hinges, so the temples  125  are rotatable against the connection bases  124 . Accordingly, the temples  125  can bend toward the lenses  11  to be stored or can be unfolded for use. The two temples  125  may be respectively fixed to the two connection bases  124  through other means, or may just be received in the two connection bases  124  in other embodiments. The connection bases  124  may be fixedly connected or rotatable to the rims  128  through any means. 
     The circuit board  18  is stored in the first hollow  120  of one connection base  124 , and can be screwed to the connection base  124 . The circuit board  18  includes electric elements and circuits to actively control the two lenses  11 , so different images or shutters are provided for each side and 3D stereoscopic images are generated. The power unit  16  includes a battery  160 , a control switch  162  and a lead wire  164 . The battery  160  is also stored in the first hollow  120  of the connection base  124 , and is located on the circuit board  18 . The battery  160  is electrically connected to the control switch  162  and the circuit board  18  to supply electric power to the circuit board  18 . 
     The control switch  162  is located on one of the temples  125 . The temple  125  has an inner surface  144  and defines an opening  1440  in the inner surface  144 . The opening  1440  communicates the second hollow  140  and the surroundings. The control switch  162  is aligned with the opening  1440 . A portion of the control switch  162  is stored in the second hollow  140 , and a portion of the control switch  162  extends through the opening  1440  of the temple  125 . The control switch  162  includes a base  1622  stored in the second hollow  140  of the temple  125 , an electrical contact  1626  surrounded by the base  1622  and extending through the base  1622 , and an elastic protrusion  1624  extending from both the base  1622  and the opening  1440  of the temple  125 . 
     The base  1622  may be screwed to or adhered to a sidewall of the temple  125 , and faces the opening  1440 . The base  1622  surrounds the electrical contact  1626 , and can retain the positions of the electrical contact  1626  and the elastic protrusion  1624 , so the elastic protrusion  1624  can always face the electrical contact  1626 . The elastic protrusion  1624  includes a convex outer surface and a concave inner surface. The elastic protrusion  1624  is contoured to be activated by touch or press, so it is located right above the electrical contact  1626 . Accordingly, the outer surface of the elastic protrusion  1624  is also the outer surface of the control switch  162 , and the elastic protrusion  1624  extends from the inner surface  144  of the temple  125 . 
     The lead wire  164  is electrically connected to the electrical contact  1626  and the battery  160 . The lead wire  164  may include two wires to electrically connect the battery  160  and the control switch  162 . One of the wires may electrically connect the electrical contact  1626  and an anode or a cathode of the battery  160 , and the other wire may electrically connect the other electrode of the battery  160  and a portion of the control switch  162  that will contact the electrical contact  1626  when the elastic protrusion  1624  is contacted. 
     When the control switch  162  is not contacted, the elastic protrusion  1624  does not bias the electrical contact  1626 , so the circuit between the battery  160  and the circuit board  18  remains open. Since the control switch  162  is located on the inner surface  144  of the temple  125 , when not worn, the 3D glasses  10  automatically turn off, and no electric power of the battery  160  is expended. With no additional step required to turn off the 3D glasses  10 , no additional mechanism is needed to detect the operation of the 3D glasses  10 , and costs are conserved. 
     As shown in  FIG. 3 , when the 3D glasses  10  are worn, the 3D glasses  10  are mounted on the head  20  (marked by the dotted line in  FIG. 3 ), and the temples  125  contact the head  20 . The control switch  162  located on the inner surface  144  is automatically contacted, and the elastic protrusions  1624  biased. Accordingly, the elastic protrusion  1624  activates the electrical contact  1626  to complete the circuit between the battery  160  and the circuit board  18  and power is supplied to the circuit board  18  and the lenses  11  operate. Thus, once the 3D glasses  10  are worn, the 3D glasses  10  are automatically turned on, and no additional step is needed to turn on the 3D glasses  10 . 
     When the 3D glasses  10  are removed, force of the elastic protrusion  1624  automatically recovers shape and position thereof, whereby the control switch  162  again extends from the inner surface  144  of the frame  12 , and the 3D glasses  10  are automatically turned off. 
     Compared to the relative art, supply and stop of the electric power are automatically switched according to the wear of the 3D glasses of the present disclosure. Once the 3D glasses are worn, the 3D glasses are turned on; and once the 3D glasses are taken off, the 3D glasses are turned off. Thus, the electric power is effectively saved, and the usage of the 3D glasses is convenient. Furthermore, the 3D glasses of the present disclosure can have a simpler structure then the relative 3D glasses including other power-saving unit. 
     It is believed that the present embodiment and their advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the disclosure or sacrificing all of its material advantages, the examples hereinbefore described merely being exemplary embodiments of the disclosure.