Patent Publication Number: US-2013250311-A1

Title: Detecting device and method for detecting a transparent grating structure

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a detecting device and a method for detecting a transparent grating structure, and more specifically, to a detecting device and a method for detecting a transparent grating structure by an optical intensity signal. 
     2. Description of the Prior Art 
     In conventional procedure for producing stereoscopic images, because a grating plate is made of transparent material, it is hard to detect and locate the grating plate. Therefore a common method is to print the stereoscopic image on an opaque substrate, such as photographic paper or cards, and so on. And then the transparent grating plate can be glued on the substrate for detection and position, so as to produce a stereoscopic visual effect. The interlaced pattern on the grating plate is designed according to parameters of the grating plate, such as a width and a density of gratings on the grating plate. Grates on the grating plate need to align with the corresponding image, so as to present the precise stereoscopic image. However, it results in manufacturing difficulty of the stereoscopic image and increase of manufacturing cost. 
     SUMMARY OF THE INVENTION 
     The present invention is to provide a detecting device and a method for detecting a transparent grating structure to solve above problems. 
     According to the disclosure, a detecting device includes an actuating unit, a light source, a light sensor, a transforming circuit and a processing unit. The actuating unit is for driving a transparent grating structure. The light source is for emitting light to the transparent grating structure driven by the actuating unit. The light sensor is for sensing the light emitted from the light source as the transparent grating structure is moved to different positions relative to the light source so as to generate a corresponding optical intensity signal. The transforming circuit is coupled to the light sensor for transforming the optical intensity signal into a transforming signal. The processing unit is coupled to the transforming circuit for determining a position of the transparent grating structure according to the transforming signal transmitted from the transforming circuit. 
     According to the disclosure, the light source is a light emitting diode, and the light sensor is an optical interrupter sensor for sensing the light emitted from the light source and passing through the transparent grating structure so as to generate the corresponding optical intensity signal. 
     According to the disclosure, the light source is disposed at a planar side of the transparent grating structure, and the light sensor is disposed at a cylindrical side of the transparent grating structure. 
     According to the disclosure, the light sensor generates the maximum optical intensity signal when a top of the transparent grating structure is moved to a position between the light source and the light sensor. 
     According to the disclosure, the light sensor generates the minimum optical intensity signal when an edge of the transparent grating structure is moved to a position between the light source and the light sensor. 
     According to the disclosure, the light source is a light emitting diode, and the light sensor is an optical reflective sensor for sensing the light emitted from the light source and reflected by the transparent grating structure so as to generate the corresponding optical intensity signal. 
     According to the disclosure, the light source and the light sensor are disposed at a cylindrical side of the transparent grating structure. 
     According to the disclosure, the light sensor generates the minimum optical intensity signal when a top of the transparent grating structure is moved to a position relative to the light source. 
     According to the disclosure, the transforming circuit is for amplifying level changes of the optical intensity signal so as to generate the transforming signal. 
     According to the disclosure, a direction of movement of the transparent grating structure driven by the actuating unit is substantially vertical to a direction of the light emitted from the light source. 
     According to the disclosure, a method for detecting a transparent grating structure including following steps: driving the transparent grating structure, a light source emitting light to the transparent grating structure, a light sensor sensing the light emitted from the light source as the transparent grating structure is moved to different positions relative to the light source so as to generate a corresponding optical intensity signal, transforming the optical intensity signal generated by the light sensor into a transforming signal, and determining a position of the transparent grating structure according to the transforming signal. 
     The detecting device and the detecting method of the present invention can utilize the light sensor and the transforming circuit to detect and locate the transparent grating structure directly. Therefore, there is no need to print the stereoscopic image on an opaque substrate, such as photographic paper or cards and so on, and then to stick the transparent grating plate on the substrate. That is, the step of configuring the substrate and sticking the transparent grating plate on the substrate can be omitted. For example, the stereoscopic image can be directly printed on the planar side of the transparent grating plate, so as to reduce manufacturing difficulty and cost greatly. 
     These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagram of a detecting device according to a preferred embodiment of the present invention. 
         FIG. 2  is a flowchart of detecting a transparent grating structure according to the preferred embodiment of the present invention. 
         FIG. 3  to  FIG. 6  are respectively diagrams of a light source, a light sensor and the transparent grating structure in different positions according to the preferred embodiment of the present invention. 
         FIG. 7  is a diagram of transforming an optical intensity signal into a transforming signal according to the preferred embodiment of the present invention. 
         FIG. 8  is a diagram of the detecting device according to another embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Please refer to  FIG. 1 .  FIG. 1  is a diagram of a detecting device  50  according to a preferred embodiment of the present invention. The detecting device  50  is for detecting position of gratings of a transparent grating structure  52 , so as to be a basis of following location and printing. The transparent grating structure  52  can be made of transparent material, such as acrylic, PVC, PET and so on, and the transparent grating structure  52  includes a planar side  521  and a cylindrical side  523 . A stereoscopic image, such as an interlaced image, can be directly printed on the planar side  521 . A plurality of cylindrical structures is formed on the cylindrical side  523  with equal spacing, and a plurality of convex lens is formed by convexes of the cylindrical structures so as to present different stereoscopic visual effects in different view angles. The detecting device  50  includes an actuating unit  54  for driving the transparent grating structure  52  to move in the X direction. The detecting device  50  further includes a light source  56  for emitting light in the Y direction to the transparent grating structure  52  driven by the actuating unit  54 . A direction (X direction) of the transparent grating structure  52  driven by the actuating unit  54  can be substantially vertical to a direction (Y direction) of the light emitted from the light source  56 . The light source  56  can be a light emitting diode. 
     The detecting device  50  further includes alight sensor  58  for sensing the light emitted from the light source  56  as the transparent grating structure  52  is moved to different positions relative to the light source  56 , so as to generate a corresponding optical intensity signal. The light sensor  58  can be an optical interrupter sensor or an optical reflective sensor. The detecting device  50  further includes a transforming circuit  60  coupled to the light sensor  58 . The transforming circuit  60  is for transforming the optical intensity signal generated by the light sensor  58  into a transforming signal, such as transforming an analog signal into a recognizable digital signal. For example, level changes of the optical intensity signal generated by the light sensor  58  are weak, so the transforming circuit  60  can be utilized for amplifying the level changes of the optical intensity signal so as to generate the transforming signal. In addition, the detecting device  50  further includes a processing unit  62  coupled to the transforming circuit  60  for determining every position of the grating of the transparent grating structure  52  according to the transforming signal transmitted from the transforming circuit  60 . 
     Please refer to  FIG. 2 .  FIG. 2  is a flowchart of detecting the transparent grating structure  52  according to the preferred embodiment of the present invention. The method includes following steps: 
     Step  100 : The actuating unit  54  drives the transparent grating structure  52  to move in the X direction. 
     Step  102 : The light source  56  emits the light in the Y direction to the transparent grating structure  52  driven by the actuating unit  54 . 
     Step  104 : The light sensor  58  senses the light emitted from the light source  56  so as to generate the corresponding optical intensity signal. 
     Step  106 : The transforming circuit  60  transforms the optical intensity signal generated by the light sensor  58  into the transforming signal. 
     Step  108 : The processing unit  62  determines every position of the grating of the transparent grating structure  52  according to the transforming signal transmitted from the transforming circuit  60 . 
     Step  110 : The end. 
     Detail description of above procedure is described herein. As the light sensor  58  is an optical interrupter sensor, the light source  56  can be disposed in front of the planar side  521  of the transparent grating structure  52 , and the light sensor  58  can be disposed in front of the cylindrical side  523  of the transparent grating structure  52 . Please refer to  FIG. 3  to  FIG. 6 .  FIG. 3  to  FIG. 6  are respectively diagrams of the light source  56 , the light sensor  58  and the transparent grating structure  52  in different positions according to the preferred embodiment of the present invention. The actuating unit  54  can drive the transparent grating structure  52  to move in the X direction, so that every grating of the transparent grating structure  52  can pass between the light source  56  and the light sensor  58  one by one. The light source  56  can emit the light in the Y direction. Because the transparent grating structure  52  has a property of transparency, the light emitted from the light source  56  can penetrate the transparent grating structure  52  and can be sensed by the light sensor  58 . It is noticed that when an edge of the transparent grating structure  52  is moved to a position between the light source  56  and the light sensor  58 , the light emitted from the light source  56  will scatter in other directions, just because the edge of the transparent grating structure  52  is uneven and the light travels through the interface between different mediums. As a result, the light sensor  58  senses weak light so as to generate a minimum optical intensity signal. As shown in  FIG. 4  and  FIG. 6 , when a convex (but not the top) of the transparent grating structure  52  is moved to the position between the light source  56  and the light sensor  58 , the light emitted from the light source  56  will refract due to the convex of the transparent grating structure  52  so that the light sensor  58  also senses weak light and cannot generate a maximum optical intensity signal. As shown in  FIG. 5 , only when the top of the transparent grating structure  52  moves to the position between the light source  56  and the light sensor  58 , the light sensor  58  can sense strongest light, just because the light emitted from the light source  56  directly penetrates the top of the transparent grating structure  52  almost without refraction, so as to generate the maximum optical intensity signal. 
     Please refer to  FIG. 7 .  FIG. 7  is a diagram of transforming the optical intensity signal into the transforming signal according to the preferred embodiment of the present invention. Because the level changes of the optical intensity signal generated by the light sensor  58  are weak, in order to increase accuracy of determination, the transforming circuit  60  can be utilized for amplifying the level changes of the optical intensity signal so as to generate the transforming signal. And then the processing unit  62  can determine the position of every grating of the transparent grating structure  52  according to the transforming signal transmitted from the transforming circuit  60 . For example, every grating of the transparent grating structure  52  respectively corresponds to a level change of the optical intensity signal, which means that the top of the transparent grating structure  52  corresponds to the maximum optical intensity signal and the other portions of the transparent grating structure  52  correspond to weaker optical intensity signals. Positions and amounts of the gratings of the transparent grating structure  52  can be determined according to a waveform of level changes of the transforming signal, for providing a basis of locating and printing the stereoscopic image in following procedure. 
     Moreover, the light sensor  58  of the present invention can selectively be an optical reflective sensor. Please refer to  FIG. 8 .  FIG. 8  is a diagram of the detecting device  50  according to another embodiment of the present invention. The difference between this embodiment and previous one is that the light source  56  and the light sensor  58  are both disposed in front of the cylindrical side  523  of the transparent grating structure  52  in this embodiment. Similar to the previous embodiment, when the convex (not the top) of the transparent grating structure  52  is moved to a position corresponding to the light source  56 , the light sensor  58  senses stronger reflective light because the convex of the transparent grating structure  52  reflects the light emitted from the light source  56 , and therefore the light sensor  58  generates the stronger optical intensity signal. But when the top of the transparent grating structure  52  is moved to the position corresponding to the light source  56 , the light sensor  58  senses weaker light because most of the light emitted from the light source  56  penetrates the top of the transparent grating structure  52  and there is almost no reflective light, so that the light sensor  58  generates the minimum optical intensity signal. As for the operational principles of the transforming circuit  60  and the processing unit  62  are similar to the previous embodiment and are omitted herein. Furthermore, the positions and amounts of the light source  56  and the light sensor  58  are not limited to above embodiments. For example, the present invention can include multiple sets of light sources and light sensors, such as two sets, and those components can be disposed at two sides of the transparent grating structure or two ends of a travelling path of the transparent grating structure, so as to locate the transparent grating structure more accurately and to correct errors due to the inappropriate cut or skew of the transparent grating structure, and it depends on practical design demand. 
     In contrast to the prior art, the detecting device and the detecting method of the present invention can utilize the light sensor and the transforming circuit to detect and locate the transparent grating structure directly. Therefore, there is no need to print the stereoscopic image on an opaque substrate, such as photographic paper or cards and so on, and then to stick the transparent grating plate on the substrate. That is, the step of configuring the substrate and sticking the transparent grating plate on the substrate can be omitted. For example, the stereoscopic image can be directly printed on the planar side of the transparent grating plate, so as to reduce manufacturing difficulty and cost greatly. 
     Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.