Abstract:
An exemplary embodiment of notebook computer includes a main body, a display, and a proximity sensor. The display is pivotably connected to the main body. The proximity sensor is installed in the main body and includes an emitter and a receiver. The emitter is configured for emitting an emission. The receiver is configure for receiving the emission, determining if an included angle between the main body and the display is in a predetermined range based upon the received emission, and, if yes, generating a signal indicative of placing the notebook computer in the sleep mode.

Description:
BACKGROUND 
     1. Technical Field 
     The present disclosure relates to notebook computers and, particularly, to a sleep mode of notebook computer. 
     2. Description of Related Art 
     To manually force most current notebook computers to enter into a sleep mode, the display must be folded completely to the main body so as to push a sleep mode button installed in the main body using a protrusion on the side of a display. However, it may not always be convenient or desirable to completely close the notebook computer to put it to sleep, and to do so through complicated menu operations is not convenient either. 
     Therefore, it is desirable to provide a notebook computer to overcome the above-mentioned problems. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic view of a notebook computer, according to an exemplary embodiment of the present disclosure. 
         FIG. 2  is a top view of a main body of the notebook computer of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIG. 1 , a notebook computer  100 , according to an exemplary embodiment of the present disclosure, includes a main body  10 , a display  20 , and a proximity sensor  30 . 
     Also referring to  FIG. 2 , the main body  10  includes a cuboid casing  12  which has a rectangular upper surface  12   s , a main circuit board  14  accommodated within the casing  12 , and a keyboard  10   k  generally mounted in the center of the upper surface  12   s . The main circuit board  14  is configured for controlling various aspects of the notebook computer  100 , including a work mode of the notebook computer  100 , e.g., a normal mode or a sleep mode. 
     In particular, the upper surface  12   s  includes a connecting edge  12   c  and a side edge  12   e  perpendicularly connecting to the connecting edge  12   c . The main body  10  also defines a small cavity  16 , e.g., a conic cavity, in the upper surface  12   s , outside the keyboard  10   k  and generally on a corner of an intersection of the connecting edge  12   c  and the side edge  12   e , and further includes a sleep mode button  18  received within the cavity  16 , which is exposed via the cavity  16  and electrically coupled to the main circuit board  14 . In detail, the button  18  can be directly disposed on the main circuit board or indirectly connected to the main circuit board  14  via wires or a connecting circuit board (not shown). In this embodiment the button  18  is directly disposed on the main circuit board  18 . 
     It should be understood that the positions and the shapes of the cavity  16  and the button  18  should not be limited to this embodiment, but can be changed depending on requirements. For example, in alternative embodiments, the cavity  16  can be a cylindrical cavity. 
     The display  20 , such as a liquid crystal display (LCD), is a rectangular panel shaped and sized corresponding to the main body  10  and has one of four edges thereof pivotably connected to the connecting edge  12   c . As such, the notebook computer  100  can be folded or unfolded by pivoting the display  20  towards or away from the main body  10 . The display  20  has a displaying surface  22  that contacts the upper surface  12   s  when the notebook computer  100  is folded completely and, corresponding to the cavity  16 , has a protrusion  24  protruding from the displaying surface  22 . As such, when the notebook computer  100  is closed completely, the protrusion  24  fits into the small cavity  16  and pushes the button  18  causing the main circuit board  14  controls the notebook computer  100  to enter into the sleep mode. 
     In other alternative embodiments, the cavity  16  and the button  18  can be formed on the display  20  and the protrusion  24  is formed on the main body  10 . The button  18  is connected to the main circuit board  14  via wires (not shown). In such a variant of the notebook computer  100 , the sleep mode also can be activated when the notebook computer  100  is closed completely. 
     The proximity sensor  30  includes an emitter  32  and a receiver  34 . Both of the emitter  32  and the receiver  34  are embedded into the upper surface  12   s . The emitter  32  is configured for emitting an electromagnetic or electrostatic field, or a beam of electromagnetic radiation (infrared, for instance) along a direction substantially perpendicular to the upper surface  12   s . Advantageously, to avoid interference between the emission of the emitter  32  and the emission of the display  20  (visible light), in this embodiment, the emitter  32  emits infrared light. The receiver  34  is electrically connected to the main circuit board  14  and is configured for receiving the emission of the emitter  32  and informing the main circuit board  14  to control the notebook computer  100  to enter into the sleep mode, when the emission is received. 
     Similar to the electrical connection between the button  18  and the main circuit board  14 , the receiver  34  can be directly disposed on the main circuit board  14  or, alternatively, indirectly connected to the main circuit board  14  via wires or a connecting circuit board (not shown). 
     In particular, the emitter  32  and the receiver  34  are also located on the corner of the intersection of the connecting edge  12   c  and the side edge  12   e , outside the keyboard  10   k . The cavity  16 , the emitter  32 , and the receiver  34  are arranged in a line generally parallel to the side edge  12   e  and in this order from a near-end to a far-end of the connecting edge  12   c . The emitter  32  has a physical area in the plane of the upper surface  12   s  substantially equal to an emission area thereof. The distance between the emitter  32  and the connecting edge  12   c  is represented as L. The physical area of the receiver  34  in the plane of the upper surface  12   s  is strip-shaped and connects the physical area of the emitter  32  in that plane. The receiver  34  is oriented substantially parallel to the side edge  12   e  and has a length X. As such, if an included angle θ between the main body  10  and the display  20  satisfies the following formula: L*tan θ*tan 2θ&lt;X, the emission of the emitter  32  will be reflected by the displaying surface  22  onto the receiver  34 . The formula can be transformed into: 
               θ   &lt;       tan     -   1       ⁢       (     X     L   -   X       )           ,         
which indicates that, provided appropriate L and X, when θ is smaller than
 
                 tan     -   1       ⁢       (     X     L   -   X       )         ,         
the receiver  34  receives the emission of the emitter  32  and the notebook computer  100  enters into the sleep mode.
 
     In use, the included angle θ must be in a range of 0°-45°. When the included angle θ is 0°, the emission of the emitter  32  is reflected back to the emitter  32  itself. When the included angle θ is equal to or greater than 45°, the emission of the emitter  32  is directly reflected outside the notebook computer  100 . 
     Given the range of 0°-45° of θ, it is still beneficial to appropriately determine L and X, to maximally reduce the physical areas of the emitter  32  and the receiver  34  in the plane of the upper surface  22 . 
     To increase the sensitivity of the proximity sensor  10 , a high-reflective film  26  for the emission of the emitter  32  may be formed on an appropriate position of the displaying surface  22 . 
     It should be mentioned that the proximity sensor  30 , including the shapes, the positions and the position relationship of the emitter  32  and the receiver  34 , is not limited to this embodiment. Other structures and/or arrangements of the proximity sensor  30  which can determine if the included angle θ in a desired range can be used too. For example, in other alternative embodiments, if a gap exist between the upper surface  12   s  and the displaying surface  22 , the emitter  32  can be installed so that the emission thereof is slightly tilted toward the receiver  34 . As such, even when the notebook computer  100  is completely folded (i.e., the included angle θ is 0°), the emission still can reach the receiver  34 , and activation of the sleep mode can be done by the proximity sensor  30  without the button  18 . Therefore, the structure of the cavity  16  and the protrusion  24  can be omitted. 
     Further, in other alternative embodiments, the proximity sensor  30  can be installed in the display  20 . 
     With regard to ambient interference, it is beneficial to include a comparing unit  14   c  in the main circuit board  14 . The comparing unit  14   c  is configured for comparing the received emission of the receiver  34  with a predetermined threshold. If the received emission of the receiver  34  is smaller than the predetermined threshold, it is deemed that the received emission is ambient noise. Otherwise, it is deemed that the received emission is from the emitter  32 . 
     While various exemplary and preferred embodiments have been described, it is to be understood that the disclosure is not limited thereto. To the contrary, various modifications and similar arrangements (as would be apparent to those skilled in the art) are intended to also be covered. Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.