Patent Publication Number: US-2007103700-A1

Title: Moving device

Description:
TECHNICAL FIELD  
      The present invention generally relates to accurate moving devices and, more particularly, to an accurate moving device for use in precision machinery.  
     BACKGROUND  
      With the development of accurate manufacturing, accurate moving devices are widely used in precision machinery for mounting work pieces. As the precision required in the manufacturing of working piece becomes higher and higher, so the requirement for moving precision of accurate moving device has also increased. In a typical precision machine, moving precision is generally improved by improving the manufacturing precision and the assembly of components of the precision machine. However, as the manufacturing precision and the assembling precision of components are improved, the precision machine itself may also become more expensive.  
      In addition, when the precision machine is used for a period of time, the moving precision of the accurate moving device will be decreased by misuse, abrasion of components, and by general wear-and-tear. In most cases this can only be fixed by replacing the damaged parts. Therefore, the accurate moving device used in the typical precision machine cannot achieve a stable level of precision, and in addition is not capable of acting in real time.  
      What is needed, therefore, is a moving device for use in precision machinery which can be used for real time control, and can achieve stable high moving precision.  
     SUMMARY  
      In one preferred embodiment thereof, a moving device for use in precision machinery includes a moving member, a light emitter, a light receiver, and a driving element. The light emitter is disposed on the moving member in a manner so as to emit light. The light receiver is configured for receiving the light and thereby generating a position signal of the moving member corresponding to the light, the signal is used for controlling the moving member. The driving element is configured for driving the moving member to move along a first axis and a second axis perpendicular to the first axis.  
      Other advantages and novel features of a preferred embodiment of the present accurate moving device and its applications will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      Many aspects of the moving device and their applications can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the moving device. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.  
       FIG. 1  is a schematic view of a moving device in accordance with a preferred embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
      Referring to  FIG. 1 , in a preferred embodiment, a moving device  100  includes a moving member  10 , a light emitter  20  disposed on the moving member  10 , and a light receiver  30  and a driving element  40 . The accurate moving device  100  is used in a precision machine (not shown) such as a computerized numerical control (CNC) device. The precision machine has a processor for controlling adjusting a position of the moving member  10 . The processor stores a series of required moving values when the moving member  10  moves normally.  
      The moving member  10  is substantially a square stage having a working plate  101  parallel to a X-Y plane, a first sidewall  103 , and a second side wall  105  perpendicularly connecting to the first sidewall  103 . The first sidewall  103  and the second sidewall  105  are both perpendicular to the working plate  101 . An engaging structure (not shown) is disposed below the moving member  10  for engaging with the driving element  40  so that the moving member  10  can be driven to move along an X direction or along a Y direction.  
      The light emitter  20  includes two light sources disposed with one at either of the first sidewall  103  and the second side wall  105  of the moving member  10 . Each of the light sources can emit a collimated light such as a laser beam. In this preferred embodiment, the collimated light is emitted horizontally from the two light sources.  
      The light receiver  30  has two image sensors disposed adjacent to the first sidewall  103  and the second side wall  105  of the moving member  10 . The image sensors are selected from charge coupled devices (CCD) and complementary metal-oxide semiconductors (CMOS). One of the image sensors is parallel to the first sidewall  103 , and the other one is parallel to the second sidewall  105 . Each of the image sensors is connected to the processor of the precision machine. The image sensors of the light receiver  30  receive the light emitting from the light emitter  20 , and send a position signal of the moving member  10  to the processor. The processor changes the position signal into a coordinate value. The processor then calculates a total departure value of the moving member  10  according to the required moving value.  
      The driving element  40  includes two motors  31 , two screw structures  33 , and a controller (not shown). One end of each screw structure  32  engages with the engaging structure of the moving member  10  and the other end of each screw structure  33  is connected to one of the motors  31 . One of the motors  31  drives the moving member  10  to move along an X direction and the other motor  31  drives the moving member  10  to move along a Y direction. The X direction is perpendicular to the Y direction. The controller is connected with the motors  31  and the processor of the precision machine.  
      In use, when the moving member  10  needs to move along a required moving route, the light source on the first sidewall  103  emits a collimated light to the image sensor parallel to the first sidewall  103 . Then, the image sensor parallel to the first sidewall  103  receives the light and sends a position signal of the moving member  10  to the processor so that the processor can receive a coordinate value along X direction, for example X 1 . The light source on the second sidewall  105  also emits a collimated light to the image sensor parallel to the second sidewall  105 . Then, the image sensor the parallel to the second sidewall  103  receives the light and sends a position signal of the moving member  10  to the processor so that the processor can receive a coordinate value along Y direction, for example Y 1 . If the X coordinate value of one object position of the required moving route is X 0 , and the Y coordinate value of such position is Y 0 , the total departure value of the moving member  10  according to the object position is X 0 -X 1  along the X direction, and Y 0 -Y 1  along the Y direction. Then, the processor  302  sends a moving signal to the controller of the driving element  40  according to the total departure value X 0 -X 1 , Y 0 -Y 1  so as to reach the object position. In the same way, the moving member  10  can move to other object positions of the required moving route.  
      Acting in co-operation with the screw structure  32 , the motor  31  drives the moving member  10  to move according to the moving signal so that the moving member  10  moves along a required moving route. Therefore, the moving device  100  can achieve real time control by compensating the for the departure value, thus, the moving member  10  can move along a required moving route and achieves stable high moving precision.  
      In the alternative embodiment, the moving member  10  can be of a shape other than square and the light emitter  20  can have more than two light sources.  
      It is believed that the embodiments 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 invention or sacrificing all of its material advantages, the examples hereinbefore described merely being preferred or exemplary embodiments of the invention.