Abstract:
A media size detection device for detecting a size of a media held in a media tray is provided. The device includes a width adjuster and a length adjuster, a first magnetic member indicates width and a second magnetic member indicates length, and a plurality of magnetic sensors arranged on a lower surface of the media tray generates signals as to respective proximities of the first and second magnetic members, the act of placing and securing the media within the media tray enables the automatic calculation of the size of the media. A media size detection method is also provided.

Description:
REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims all benefits accruing under 35 U.S.C. §119 from Taiwan Patent Application No. 101123801, filed on Jul. 2, 2012 in the Taiwan Intellectual Property Office, the contents of the Taiwan Application are hereby incorporated by reference. 
       BACKGROUND 
       [0002]    1. Technical Field 
         [0003]    The present disclosure relates to media size detection devices and methods for detecting a size of a media in an image formation device. 
         [0004]    2. Description of Related Art 
         [0005]    Image formation devices, such as printers, often include adjustable media trays to accommodate media of different sizes. In these types of image formation devices, when a user places a media in the media tray, it is necessary for the user to select a correct size of the media via a user interface (UI) on the image formation devices. However, it may be difficult for the user to correctly determine the size of the media held in the media tray. 
         [0006]    Therefore, there is room for improvement within the art. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]    Many aspects of the embodiments 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 embodiments. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views. 
           [0008]      FIG. 1  is an exploded, isometric view of a media size detection device in accordance with an embodiment. 
           [0009]      FIG. 2  is an enlarged view of circled part II of the  FIG. 1 . 
           [0010]      FIG. 3  is an enlarged view of circled part III of the  FIG. 1 . 
           [0011]      FIG. 4  is a top view of a mounting plate of the media size detection device of  FIG. 1 . 
           [0012]      FIG. 5  is an assembled view of the media size detection device of  FIG. 1 . 
           [0013]      FIG. 6  is similar to  FIG. 5 , but viewed from a different aspect. 
           [0014]      FIG. 7  is an example of a size mapping table in accordance with an embodiment. 
           [0015]      FIG. 8  is a flowchart of a media size detection method in accordance with an embodiment. 
       
    
    
     DETAILED DESCRIPTION 
       [0016]    The disclosure is illustrated by way of example and not by way of limitation in the figures of the accompanying drawings in which like references indicate similar elements. It should be noted that references to “an” or “one” embodiment in this disclosure are not necessarily to the same embodiment, and such references mean “at least one.” 
         [0017]      FIGS. 1-6  show a media size detection device in accordance with an embodiment. The media size detection device includes a media tray  10 , a width adjuster  20 , and a length adjuster  30 . The media tray  10  includes a bottom plate  11 . The width adjuster  20  and the length adjuster  30  are located on an upper surface of the bottom plate  11 . 
         [0018]    The width adjuster  20  is movable in accordance with a widthwise dimension of the bottom plate  11 . The length adjuster  30  is movable in accordance with a lengthwise dimension of the bottom plate  11 . The bottom plate  11  together with the width adjuster  20  and the length adjuster  30  defines a media placing area for the placing of a media, such as a sheet of paper. The media tray  10  can support a range of media sizes by way of moving the width adjuster  20  and the length adjuster  30  to a variety of positions. 
         [0019]    The width adjuster  20  includes two limiting plates  22  and a linking member  23 . The two limiting plates  22  are parallel to each other and perpendicular to the bottom plate  11  of the media tray  10 . The linking member  23  interconnects the two limiting plates  22 . The distance between the two limiting plates  22  determines the width of the media placing area in the media tray  10 . 
         [0020]    The linking member  23  is located on a lower surface of the bottom plate  11  of the media tray  10 . The linking member  23  includes two toothed racks  231  and a gear  232  meshed with the two toothed racks  231 . Each of the two toothed racks  231  is connected to one of the two limiting plates  22 . The linking member  23  facilitates the movement of the two limiting plates  22  towards or away from each other. 
         [0021]    The media size detection device further includes a first magnetic member  21  and a second magnetic member  31 . The first magnetic member  21  is attached to the width adjuster  20  and can move together with the width adjuster  20 . The second magnetic member  31  is attached to the length width adjuster  30  and can move together with the length width adjuster  30 . 
         [0022]    The media size detection device further includes a first magnetic sensor  101 , a second magnetic sensor  102 , a third magnetic sensor  103 , and a fourth magnetic sensor  104 . 
         [0023]    The first magnetic sensor  101 , the second magnetic sensor  102 , the third magnetic sensor  103 , and the fourth magnetic sensor  104  are mounted to a mounting plate  12 . The mounting plate  12  is attached to a lower surface of the bottom plate  11  of the media tray  10 . The first magnetic sensor  101 , the second magnetic sensor  102 , the third magnetic sensor  103 , and the fourth magnetic sensor  104  are sandwiched between the mounting plate  12  and the bottom plate  11  of the media tray  10 . In one embodiment, each of the first magnetic sensor  101 , the second magnetic sensor  102 , the third magnetic sensor  103 , and the fourth magnetic sensor  104  includes a Hall effect sensor. 
         [0024]    The first magnetic sensor  101  and the second magnetic sensor  102  are arranged in a first line in accordance with the widthwise dimension of the bottom plate  11  and adapted to sense the proximity of the first magnetic member  21 . The third magnetic sensor  103  and the fourth magnetic sensor  104  are arranged in a second line in accordance with the lengthwise dimension of the bottom plate  11  and adapted to sense the proximity of the second magnetic member  31 . Each of the first magnetic sensor  101 , the second magnetic sensor  102 , the third magnetic sensor  103 , and the fourth magnetic sensor  104  is adapted to generate a position signal to indicate whether it senses any of the first magnetic member  21  and the second magnetic member  31  or not. For example, when the first magnetic sensor  101  senses the first magnetic member  21 , the first magnetic sensor  101  generate a position signal with a high electrical level to indicate that the first magnetic  21  and the width adjuster  20  are above or close to being above the first magnetic sensor  101 . In contrast, when the first magnetic sensor  101  does not sense the first magnetic member  21 , the first magnetic sensor  101  generates a position signal with a low electrical level to indicate that the first magnetic  21  and the width adjuster  20  are not yet above or close to being above the first magnetic sensor  101 . Thus, when the width adjuster  20  and the length adjuster  30  are moved to different positions, the first magnetic sensor  101 , the second magnetic sensor  102 , the third magnetic sensor  103 , and the fourth magnetic sensor  104  may generate different combinations of position signals. 
         [0025]    Referring to  FIG. 7 , an example of a size mapping table in accordance with an embodiment is shown. The size mapping table includes relationships between combinations of the position signals and predetermined media sizes. In the size mapping table, an integer 1 represents a position signal with a high electrical level, and an integer zero represents a position signal with a low electrical level. For example, when the position signal generated by the first magnetic sensor  101  is 1 and the other three position signals generated by the second magnetic sensor  102 , the third magnetic sensor  103 , and the fourth magnetic sensor  104  are all zero, the media size is determined to be A4 size. When the signals generated by the second magnetic sensor  102  and by the fourth magnetic sensor  104  are both 1 and the other two position signals generated by the first magnetic sensor  101  and the third magnetic sensor  103  are zero, the media size is determined to be Legal size. 
         [0026]    The media size detection device further includes a logic unit (not shown). The logic unit compares the respective signals generated by all the magnetic sensors  101 - 104  with the size mapping table and determines the size of the media. The logic unit can be embodied in either hardware or software. 
         [0027]    Referring to  FIG. 8 , a flowchart of a media size detection method is illustrated. The method comprises the following steps. 
         [0028]    In step S 802 , the bottom plate  11  together with the width adjuster  20  and the length adjuster  30  defines a media placing area for the placing of a media to receive a hard copy, such as a sheet of paper. 
         [0029]    In step S 804 , the first magnetic sensor  101 , the second magnetic sensor  102 , the third magnetic sensor  103 , and the fourth magnetic sensor  104  generates four position signals to indicate whether they senses any of the first magnetic member  21  and the second magnetic member  31  or not. 
         [0030]    In step S 806 , the logic unit compares the four position signals generated by the first magnetic sensor  101 , the second magnetic sensor  102 , the third magnetic sensor  103 , and the fourth magnetic sensor  104  with the size mapping table and thus determines the size of the media. 
         [0031]    It is to be understood however, that even though numerous characteristics and advantages have been set forth in the foregoing description of embodiments, together with details of the structures and functions of the embodiments, the disclosure is illustrative only and changes may be made in detail, especially in the matters of shape, size, and arrangement of parts within the principles of the disclosure to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed. 
         [0032]    In particular, depending on the embodiment, certain steps or methods described may be removed, others may be added, and the sequence of steps may be altered. The description and the claims drawn for or in relation to a method may give some indication in reference to certain steps. However, any indication given is only to be viewed for identification purposes, and is not necessarily a suggestion as to an order for the steps.