Abstract:
A lens assembly for obtaining an image of an object is provided. The lens assembly includes a lens device receiving a reflected light from the object, a circuit board carrying thereon the lens device, a spacer mounted on the circuit board, and a sensor mounted on the spacer, receiving the reflected light from the lens device and converting the reflected light into a digital signal, thereby generating the image.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention is related to a lens assembly, and more particularly to a lens assembly used for different sizes or standards of sensors without changing any lens devices of the lens assembly.  
       BACKGROUND OF THE INVENTION  
       [0002]     Please refer to  FIG. 1 , which is a schematic view showing a conventional lens structure. The conventional lens structure includes a lens device  10 , a circuit board  13  and a sensor  14 . Further, the lens device  10  includes a lens tube  11  and a lens base  12 , and the sensor  14  is mounted on the circuit board  13 . The lens tube  11  further includes an end having a receptacle portion  15  for containing the sensor  13 , and the end of the lens tube  11  is mounted on the circuit board  13 . Moreover, the circuit board  13  is further used for mounting the lens base  12  thereon.  
         [0003]     According to the general imaging theory, a plurality of reflected lights from an object would be received by the lens device  10 , and a plurality of focused lights would be generated within the lens device  10 , i.e. the reflected lights are focused on the sensor  14 , by a plurality of lenses of the lens tube  11 . Further, the sensor  14  could convert these focused lights into various digital signals. Then, these digital signals would be transferred to other devices by the circuit board  13  to process the following steps for showing an image or storing the image.  
         [0004]     However, various researches for the arrangement between the lens device and the lenses have been developed by the optical lens manufacturers to provide digital images with a better definition and introduce more functions, such as an auto-focus function, a macro-mode photo function, multi-apertures, a zoom lens with a mechanical shutter and zoom ratio, etc. Such researches not only involves complex optical, optomechanical and electrical control techniques, but the expense therefor is very high. Therefore, the price for the optical lens, i.e. the lens device  10 , usually is very expensive.  
         [0005]     Besides, these techniques, such as adjustments for the alignment, the position or the focus between the optical lens and the sensor, are also quite important, and the image quality would be enhanced according to the above adjustments. In addition, the optical lens manufacturers often suggest that the size or standard of the sensor should be chosen according to the type of the optical lens. Further, these optical lenses would be used in various products, such as a digital camera, a visualizer or a digital video camera. Accordingly, most product manufacturers often accept the optical lens manufacturers&#39; suggestion to adopt a designated size or standard of sensor in a designated optical lens.  
         [0006]     While the product with a particular standard or size of sensor is produced by the product manufacturer, the corresponding optical lenses must be particularly provided by the optical lens manufacturer. However, the charge for re-designing and producing the particular optical lens is very costly. Therefore, the manufacturing cost and the price for the products may go up quite substantially and there will be no market for these products.  
         [0007]     Therefore, the purpose of the present invention is to develop a lens assembly to deal with the above situations encountered in the prior art.  
       SUMMARY OF THE INVENTION  
       [0008]     It is therefore a first aspect of the present invention to provide a lens assembly suitable for various sensors without changing the lens devices therein, in which the position of the sensor in the lens device could be adjusted according to the size or standard of the sensor, and the manufacturing cost for the product with the lens assembly would be decreased therewith.  
         [0009]     It is therefore a second aspect of the present invention to provide a lens assembly with an additional spacer to change a focal length of the sensor for use in various sensors, so that the charge for re-designing and producing various optical lenses could be saved.  
         [0010]     According to an aspect of the present invention, a lens assembly for obtaining an image of an object is provided. The lens assembly includes a lens device receiving a reflected light from the object, a circuit board carrying thereon the lens device, a spacer mounted on the circuit board, and a sensor mounted on the spacer, receiving the reflected light from the lens device and converting the reflected light into a digital signal, thereby generating the image.  
         [0011]     Preferably, the lens assembly further includes a connector mounted between the circuit board and the spacer for conducting signals and currents coming from one of the circuit board and the space.  
         [0012]     Preferably, the connector is one of a conducting pillar and a conducting wire.  
         [0013]     Preferably, the lens device includes a lens tube and a lens base, and the lens base is used for mounting the lens tube on the circuit board.  
         [0014]     Preferably, the lens tube includes a plurality of lenses.  
         [0015]     Preferably, the lens tube further includes an end having a receptacle portion.  
         [0016]     Preferably, the end of the lens tube is mounted on the circuit board.  
         [0017]     Preferably, the receptacle portion is a notch.  
         [0018]     Preferably, the sensor is one of a CMOS optical sensor and a CCD optical sensor.  
         [0019]     Preferably, the lens assembly is an objective lens for a visualizer.  
         [0020]     Preferably, the spacer is a printed circuit board (PCB).  
         [0021]     Preferably, the circuit board and the spacer form a printed circuit board assembly (PCBA).  
         [0022]     According to another aspect of the present invention, a lens assembly is provided. The lens assembly includes a circuit board, a lens tube including a plurality of lenses, a lens base including a first end and a second end, the first end mounting thereon the lens tube and the second end mounted on the circuit board, wherein the second end further includes a receptacle portion, a spacer horizontally mounted above the circuit board and within the receptacle portion, and a sensor mounted above the spacer and receiving a focused light formed from the plurality of lenses.  
         [0023]     Preferably, the lens assembly further includes a connector mounted between the circuit board and the spacer for conducting signals and currents coming from one of the circuit board and the spacer.  
         [0024]     Preferably, the sensor is contained within the receptacle portion.  
         [0025]     Preferably, the sensor and the spacer have a cooperative size smaller than a containing space of the receptacle portion.  
         [0026]     According to another aspect of the present invention, a lens assembly is provided. The lens assembly includes a circuit board, and lens device disposed on the circuit board and including a receptacle portion containing a spacer and a sensor disposed above the space.  
         [0027]     Preferably, the spacer is horizontally disposed above the circuit board.  
         [0028]     Preferably, the sensor receives a focused light from the lens device.  
         [0029]     The above contents and advantages of the present invention will become more readily apparent to those ordinarily skilled in the art after reviewing the following detailed descriptions and accompanying drawings, in which: 
     
    
     BRIEF DESCIPTION OF THE DRAWINGS  
       [0030]      FIG. 1  is a schematic view showing a conventional lens structure; and  
         [0031]      FIG. 2  is a schematic view showing a lens assembly according to a preferred embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0032]     The present invention will now be described more specifically with reference to the following embodiment. It is to be noted that the following descriptions of preferred embodiment of this invention are presented herein for purposes of illustration and description only; it is not intended to be exhaustive or to be limited to the precise form disclosed.  
         [0033]     Please refer to  FIG. 2 , which is a schematic view showing a lens assembly according to a preferred embodiment of the present invention. The lens assembly includes a lens device  20 , a circuit board  23 , a spacer  24  and a sensor  25 . Further, the lens device  20  includes a lens tube  21  and a lens base  22 . The lens base  22  includes a first end and a second end, wherein the lens tube  21  is mounted on the first end and the second end is mounted on the circuit board  23 , and the second end further includes a receptacle portion  26 . Moreover, the sensor  25  and the spacer  24  are contained within the receptacle portion  26 , the sensor  25  is mounted above the spacer  24 , and the spacer  24  is horizontally mounted above the circuit board  23 . In addition, the lens assembly further includes at least one connector  27  mounted between the circuit board  23  and the spacer  24  for conducting signals and currents coming from one of the circuit board  23  and the spacer  24 .  
         [0034]     While an image of an object is obtained by the lens assembly, a plurality of reflected lights from the object would be received by the lens tube  21 . According to the above conventional imaging theory, a plurality of focused lights would be generated by a plurality of lenses of the lens tube  21  and received by the sensor  24 . Thus, the sensor  24  could convert these focused lights into various digital signals. Then, these digital signals would be transferred to other devices by the spacer  24  and the circuit board  23  to process the following steps for showing or storing the image.  
         [0035]     Furthermore, the connector  27  can be a conducting pillar or a conducting wire, and the receptacle portion  26  can be a notch. Further, the sensor  25  is a CMOS optical sensor or a CCD optical sensor, and the sensor  25  and the spacer  24  have a cooperative size smaller than a containing space of the receptacle portion  26 . Moreover, the spacer  24  is a printed circuit board (PCB), and the circuit board  23  and the spacer  24  could form a printed circuit board assembly (PCBA). The lens assembly can be an objective lens for a visualizer.  
         [0036]     Therefore, various sensors could be used in the lens assembly by providing the spacer  24  to change the focal length thereof only if the sensor  25  has a size smaller than the containing space of the receptacle portion  26  in the lens device  20 . Further, the lens device  20  includes different imaging features according to the size or standard of the sensor  25  mounted thereon.  
         [0037]     Take an example, the conventional lens device only uses a ⅓-inch CCD optical sensor and cannot use other sizes or standards of sensors, such as a ¼-inch CCD optical sensor or a ¼-inch CMOS one. However, a ¼-inch CCD optical sensor or a ¼-inch CMOS one could be applied in the lens device  20  of the present lens assembly and the imaging result is still good and not affected. Thus, the spacer  24  could be contained within the receptacle portion  26  and the focal length of the sensor  25  would be adjusted by changing the location of the spacer  24  in the receptacle portion  26  to conform to the standard of the sensor  25 . Moreover, the manufacturing cost for the present lens assembly would not be greatly increased and digital images obtained by the present lens assembly have no distortion.  
         [0038]     According to the above description, the present invention could provide a universal lens assembly for use in various sensors without changing any lens devices, and various sensors could be used in one lens device. Furthermore, the present invention could be achieved by using an additional spacer to change the focal length of the sensor so as to effectively save the charge for re-designing and producing various lens devices. Moreover, the manufacturing cost for the product with the lens assembly would be effectively decreased.  
         [0039]     While the invention has been described in terms of what are presently considered to be the most practical and preferred embodiments, it is to be understood that the invention need not to be limited to the disclosed embodiment. On the contrary, it is intended to cover various modifications and similar arrangements included within the spirit and scope of the appended claims which are to be accorded with the broadest interpretation so as to encompass all such modifications and similar structures.