Abstract:
The present application relates to an eyepiece for use with a viewing device. The eyepiece is configured to change the distance between a first edge of the eyepiece and a lens near a second edge of the eyepiece. The eyepiece includes a first element having a pin extending therefrom and a rotational axis having a first axial direction and a second axial direction. The eyepiece further includes a second element having a groove, the second element sharing the rotational axis and configured to rotate about the rotational axis relative to the first element. The groove comprises a first pin movement section and a second pin movement section. The groove further comprises a pin stopping section, the pin stopping section located between the first pin movement section and the second pin movement section. The pin stopping section is configured to prevent the second element from rotating relative to the first element.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of prior application Ser. No. 10/629,241, filed Jul. 29, 2003. The entirety of application Ser. No. 10/629,241 is hereby incorporated by reference. 
    
    
     FIELD OF INVENTION 
     This present invention is a multi-step locking eye cup twist-up device and apparatus in the field of eyepieces, and more specifically, for application to optical and mechanical eyepieces such as those used in the fields of binoculars, monoculars, field glasses, telescopes, and focusing devices, to make it easy to adjust or maintain the focus in one or more selectable or discrete steps. 
     BACKGROUND OF THE INVENTION 
     With focusing devices, which include binoculars, monoculars, field glasses, and telescopes, there are different distances between the eyepiece lenses and eyeballs that are comfortable to the users due to the differences in their vision. Therefore, the eyepieces (the part that is in contact with eyes) of binoculars are often equipped with variable focusing devices (e.g., twist-up devices), that can adjust the distance between the eyepiece lenses and eyeballs. 
     A commonly used twist-up device is basically composed of a twist-up ring and a support ring that is often called a split-image suppressor ring. The twist-up ring has a longer twist-up adjustment groove, and the support ring is contained inside the twist-up ring, and it is equipped with the twist-up adjustment pins that are inserted into the above twist-up adjustment groove. The twist-up device moves the twist-up adjustment pins inside the twist-up adjustment groove along its circumference, and it twists up by moving the twist-up ring against the support ring in the adjustment groove. In so doing, the distance between the eyepiece lenses and eyeballs is made larger or smaller by the distance that the twist-up ring has moved. 
     The twist-up adjustment groove in the conventional twist-up ring is set in a straight line, diagonally from the opening at one end to the opening at the other end of the twist-up ring. For this reason, when the conventional twist-up device was operated by moving the twist-up ring against the support ring so that the pin slides along the groove to a desired position. However, there is no means known in the art to fix the twist-up ring at a fixed position. Consequently, when the twist-up ring is pressed against the eyeballs to look at something, the pin tends to slide in the groove and the twist-up ring consequently rotates, and it was not possible to maintain the desired position originally obtained by manipulating the twist-up device. As a result, a focusing device with the conventional twist-up devices known in the art fail to secure a proper distance between the eyepiece lenses and eyeballs which causes images to lose focus, difficulty in seeing desired objects and other inconveniences to the user. 
     In an attempt to resolve this limitation in the art, a twist-up device has been developed with a retaining section using a spring-operated retaining ball in the support ring, which can be pushed against the twist-up ring and held steady in the twist-up adjustment groove of the twist-up ring. With this twist-up device, when the twist-up ring is moved along the support ring in a set groove and the retaining ball comes to the set position in the retaining section and remains in the retaining section by the spring action. As a result, the retaining ball restricts the twist-up ring from moving to the direction of the groove. Thus, this twist-up device is able to prevent the movement of the twist-up ring when the user was looking at something through the focusing device, such as a binocular or other device as mentioned above. 
     However, there are limitations to the art of twist-up devices having a restraining ball and spring. The above retaining ball is held in place only the spring force. So, when a force applied to the focusing device is stronger than the spring force applied to the twist-up device, the retaining ball comes off of the retaining section, and the twist-up ring moves thereby failing to maintain the desired position obtained by manipulating the twist-up device, which is a significant shortcoming. 
     Another limitation to twist-up devices having a retaining ball and spring is the increased number of parts required for manufacturing the devices in addition to using the device. Additionally, a special manufacturing process is necessary to secure the above-mentioned retaining function. The increased number of parts complicates the manufacturing process, increases the manufacturing costs, and increase the number of components which may potentially fail. These are further shortcomings in the art. 
     The objectives of the present invention are to solve or avoid the above shortcomings held by the conventional twist-up devices. In other words, the objectives of the present invention are to make it possible to securely maintain the adjustment position obtained by manipulating the twist-up device even when a force is applied while focusing device is in use, to limit the number of parts to as few as possible, to enhance the ability of the focus device to remain in focus with increased force applied to the focusing device, and to provide a twist-up device with its manufacturing cost kept low. 
     SUMMARY OF THE INVENTION 
     The present invention teaches a twist-up device having a support ring equipped with one or more twist-up adjustment pins that protrude toward the outer circumference, and one or more twist-up adjustment grooves that hold the above twist-up adjustment pins in such a way as to allow them to move in a set groove. A twist-up ring is installed in the twist-up device in such a way as to allow it to move in a set groove around the outer circumference of the said support ring, while letting these twist-up adjustment pins move in a set groove inside the said twist-up adjustment grooves. The twist-up device features these twist-up adjustment grooves installed in multiple steps. 
     The present invention also teaches a twist-up device having a support ring with one or more twist-up adjustment pins that protrude toward the outer circumference, and of one or more twist-up adjustment grooves that hold the above twist-up adjustment pins in such a way to allow them to move in a set groove. At least one twist-up ring is installed in the twist-up device in such a way as to allow the twist-up ring to move in a set groove around the outer circumference of the said support ring, while letting the twist-up adjustment pin move in a set groove inside the said twist-up adjustment grooves. The twist-up device features the following components: (1) at least one pin movement section that allows at least one twist-up adjustment groove to make the twist-up adjustment pin move in a desired set-groove direction; (2) at least one pin-stopping section that is installed next to the said pin-movement section to engage the at least one above-mentioned twist-up adjustment pins to prevent the said twist-up ring from moving in a direction of the set movement groove. Furthermore, in one embodiment of the present invention, to give a proper style to the twist-up device, the pin-movement section is installed so that it extends diagonally from the first opening to the second opening of the twist-up ring, and the above pin-stopping section is installed in the direction from the end of the second opening of the above pin-movement section to the circumference perpendicular to the axis line of the above twist-up ring, or to the direction of the first opening mentioned above. In the preferred embodiment of the present invention, the twist-up adjustment grooves contain the following sections:
     1 A first pin-movement section.   2 A first pin-stopping section that is installed in the direction from the end of the second opening of the above pin-movement section to the above-mentioned first opening.   3 A second pin-movement section that is installed in the direction from the end of the first opening of the first pin-stopping section to the second opening.   4 A second pin-stopping section that is installed in the direction from the end of the second opening of the second pin-movement section to the first opening.   5 A third pin-movement section that is installed in the direction from the end of the first opening of the pin-stopping section to the direction of the second opening.   6 A third pin-stopping section installed in the direction from the end of the second opening of the third pin-movement section to the circumference that is perpendicular to the axis line of the above twist-up ring.   

     The twist-up ring has an angled contact section that contacts the twist-up adjustment pin at the end of the pin-movement section from the opening side in extension from the end to the pin-movement section. The support ring fits inside the inner circumference of the twist-up ring and it has a resisting part that gives a required resistance force against the movement of the twist-up ring when the twist-up device is operated. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       The nature, objects and advantages of the invention will be more fully understood from the following description of the preferred embodiments shown by way of example in the accompanying drawings in which: 
         FIG. 1  is a front view of a preferred embodiment of the twist-up device  1 , in accordance with the present invention. 
         FIG. 2  is an exploded side view of the twist-up device in  FIG. 1 . 
         FIG. 3  is a front view of the twist-up device in  FIG. 1 , showing a detail of its use when the twist-up adjustment pin  4  is at Position A of the twist-up adjustment groove. 
         FIG. 4  is a front view of the twist-up device in  FIG. 1 , showing a detail of its use when the twist-up adjustment pin  4  is at Position B 1  of the twist-up adjustment groove. 
         FIG. 5  is a front view of the twist-up device in  FIG. 1 , showing a detail of its use when the twist-up adjustment pin  4  is at Position B 2  of the twist-up adjustment groove. 
         FIG. 6  is a front view of the twist-up device in  FIG. 1 , showing a detail of its use when the twist-up adjustment pin  4  is at Position D 1  of the twist-up adjustment groove. 
         FIG. 7  is a front view of the twist-up device in  FIG. 1 , showing a detail of its use when the twist-up adjustment pin  4  is at Position D 1  of the twist-up adjustment groove. 
         FIG. 8  is a perspective view of an alternative embodiment of the twist-up device of  FIG. 1 . 
         FIG. 9  is a perspective view of an alternative embodiment of the twist-up device of  FIGS. 1 and 8 . 
         FIG. 10  is a front view of the alternative embodiment of the twist-up device of  FIGS. 8 and 9 . 
         FIG. 11  is a front view of the alternative embodiment of the twist-up device of  FIGS. 8 and 9 , showing the section line A-A went the pin is at the top. 
         FIG. 12  is a rear view of the alternative embodiment of the twist-up device of  FIGS. 8 and 9 . 
         FIG. 13  is a right side view of the alternative embodiment of the twist-up device of  FIGS. 8 and 9 . 
         FIG. 14  is a left side view of the alternative embodiment of the twist-up device of  FIGS. 8 and 9 . 
         FIG. 15  is a front view of the alternative embodiment of the twist-up device of  FIGS. 8 and 9 , showing the section line B-B went the pin is at the bottom. 
         FIG. 16  is a bottom view of the alternative embodiment of the twist-up device of  FIGS. 8 and 9 . 
         FIG. 17  is a top view of the alternative embodiment of the twist-up device of  FIGS. 8 and 9 . 
         FIG. 18  is a sectional view of the alternative embodiment of the twist-up device of  FIG. 11 , of the section A-A. 
         FIG. 19  is a sectional view of the alternative embodiment of the twist-up device of  FIG. 15 , of the section B-B. 
         FIG. 20  is a front view of the preferred embodiment of the twist-up device of  FIG. 1 . 
         FIG. 21  is a rear view of the preferred embodiment of the twist-up device of  FIG. 1 . 
         FIG. 22  is a right side view of the preferred embodiment of the twist-up device of  FIG. 1 . 
         FIG. 23  is a left side view of the preferred embodiment of the twist-up device of  FIG. 1 . 
         FIG. 24  is a bottom view of the preferred embodiment of the twist-up device of  FIG. 1 . 
         FIG. 25  is a top view of the preferred embodiment of the twist-up device of  FIG. 1 . 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIG. 1  shows a front view of the twist-up device  1 , which is one example of the twist-up device to embody this concept. The twist-up device  1  consists of the twist-up ring  2 , the support ring  3 , the twist-up adjustment pins  4  and the resistance part  5 . The twist-up device  1  is formed by these parts combined in one unit. 
       FIG. 2  is a side overview of the twist-up ring  2 , the support ring  3 , the twist-up adjustment pins  4  and the resistance part  5  respectively before they are combined. It will be appreciated that the present invention may be practiced with as few as one adjustment pin  4 , or may include as many adjustment pins  4  as might be desired, even exceeding the number of adjustment pins  4  shown in the preferred embodiment in  FIG. 2 . 
     The twist-up ring  2  is a part that moves in a groove against the support ring  3  when the twist-up device  1  is operated. The twist-up ring  2  has a first opening  9  and a second opening  10 , which are located at each respective end of the ring  2 , and three twist-up adjustment grooves  6  that are made around its circumference in equal distance. It will be appreciated that the present invention may be practiced with as few as one adjustment groove  6  or may include as many adjustment grooves  6  as might be desired, even exceeding the three adjustment grooves  6  shown in the preferred embodiment in  FIG. 2 . 
     The twist-up adjustment groove  6  holds the twist-up adjustment pin  4 , and by regulating the motion of the twist-up adjustment pin  4  when the twist-up device is operated, the groove  6  has a function to determine the motion of the twist-up ring  2  toward the support ring  3 . 
     The twist-up adjustment grooves  6  are shaped with multiple steps  6   a , as shown in  FIGS. 1 and 2 . The twist-up adjustment grooves  6  consist of the pin movement sections  7  and the pin stopping sections  8 , both of which are placed alternately in the twist-up adjustment grooves  6 . 
     The pin movement sections  7  enable the twist-up adjustment pins  4 , which are inserted into the twist-up adjustment grooves  6 , to move in the groove  6  direction or to the opening  9  or  10  of the twist-up ring  2 . Three pin movement sections  7  are set up to hold the pin stopping sections between them. In other words, the pin movement sections  7  consist of the pin movement sections  7   a ,  7   b  and  7   c  from the opening  9 . Each pin movement section  7  is set in a straight line diagonally with the same incline from the opening  9  to the opening  10  of the twist-up ring  2 . Here, “a straight line” means that it is a straight line in the direction of the axis line of the twist-up ring  2 . 
     The pin stopping sections  8  are set up to stop and prevent the twist-up pins  4  from moving in a groove  6  toward the opening  9  or  10  of the twist-up ring  2 . 
     The pin stopping sections  8  are set at the ends of the opening  10  of each pin movement section  7  at three places. It will be appreciated that the present invention may be practiced with one or more the pin stopping sections  8 . In other words, as shown in the preferred embodiment, the pin stopping sections  8  are composed of the following three parts: 
     As to the first part, The pin stopping section  8   a , set so as to connect the side end of the opening  10  of the pin movement section  7   a  and the side end of the opening  9  of the pin movement section  7   b . As to the second part, the pin stopping section  8   b , set so as to connect the side end of the opening  10  of the pin movement section  7   b  and the side end of the opening  9  of the pin movement section  7   c , and As to the third part, the pin stopping section  8   c , set at the side end of the opening  10  of the pin movement section  7   c . The pin stopping section  8   a  is set with a slight incline from the side end of the opening  10  of the pin movement section  7   a  toward the opening  9 . The pin stopping section  8   b  is also set with a slight incline from the side end of the opening  10  of the pin movement section  7   b  toward the opening  9 . The pin stopping section  8   c  is set parallel from the side end of the opening  10  of the pin movement section  7   c  to the openings  9  and  10 , or toward the circumference of the circle perpendicular to the axis line of the twist-up ring  2 . 
     As shown in  FIG. 1  with respect to the depiction of the twist-up adjustment groove  6 , the twist-up ring  2  contains the following parts: A lower stopping section  18   a  and the upper stopping section  19   a , which form the pin stopping section  8   a , A lower stopping section  18   b  and the upper stopping section  19   b , which form the pin stopping section  8   b , and A lower stopping section  18   c  and the upper stopping section  19   c , which form the pin stopping section  8   c . The twist-up ring  2  has the following four angled contact sections  20   a ,  20   b ,  21   a  and  21   b : An upper angled contact section  21   a , which can contact the twist-up adjustment pin  4 , located at the side end of the opening  10  of the pin movement section, from the opening  9  in the direction that the pin movement section extends from its end, An upper angled contact section  21   b , which can contact the twist-up adjustment pin  4 , located at the side end of the opening  10  of the pin movement section  7   b , from the side of the opening  9 , A lower angled contact section  20   a , which can contact the twist-up adjustment pin  4 , located at the side end of the opening  9  of the pin movement section  7   b , from the side of the opening  10 , and A lower angled contact section  20   b , which can contact the twist-up adjustment pin  4 , located at the side end of the opening  9  of the pin movement section  7   c , from the side of the opening  10 . The width of the pin movement section  7  and of the pin stopping section  8 , or the width of the twist-up adjustment groove  6 , is determined by the size of the twist-up adjustment pin  4  that can move in the groove of the twist-up adjustment groove  6 . In particular, the distance between the lower angled contact section  20   a  and the upper angled contact section  21   a , and the distance between lower angled contact section  20   b  and the upper angled contact section  21   b  are set at the size that allows the twist-up adjustment pins  4  to pass between them only after a certain strong force is applied to the twist-up ring  2 . 
     The length of the pin movement section  7  is determined by the extent that allows effective adjustments in the twist-up 1 operation. The length of the pin stopping section  8  is determined by the extent that allows the twist-up adjustment pins  4  to stop, prevents them to move in the direction of the groove and yet creates no trouble in the twist-up operation. 
     As for the material of the twist-up ring  2 , there is no special restriction as long as it can perform the above functions. For example, metal and plastics are recommended. Materials may be selected which demonstrate characteristics for strength and low wear with repeated use. 
     The support ring  3  is fixed to the eyepiece, such as a binocular, monocular, field glasses, telescope, or other focusing device, and supports the twist-up ring  2 . On the outer circumference of the support ring  3 , this part moves the twist-up ring  2  in the groove. The support ring  3  is contained inside the twist-up ring  2  of the twist-up device  1 . 
     The support ring  3  has three pin insert grooves  11  and three holes covered with resistance material  12 . The pin insert grooves  11  fix the twist-up adjustment pins  4  inside by mating with the twist-up adjustment pins  4 . The three pin insertion grooves  11  are positioned so that the twist-up adjustment pins  4 , which are inserted into the pin insertion grooves  11 , can be inserted into the different twist-up adjustment grooves  6  respectively. The holes covered with resistance material  12  fix the resistance material  5  by mating with it. The holes covered with resistance material  12  are positioned so that, when the twist-up adjustment pins  4  fixed in the pin insertion grooves  11  are inserted into the different twist-up adjustment grooves  6  respectively, they do not stick out of the twist-up adjustment grooves  6 . The support ring  3  contains a spiral groove  13  in its inner circumference, which is used to fix the twist-up device  1  by spiral-fitting it into the eyepieces of a binocular. 
     As shown in  FIG. 2 , the support ring  3  has the openings  16  and  17 , and in the condition of being attached to the twist-up ring  2  as mentioned above, and when there is the twist-up adjustment pins  4  at the side end of the opening  9  of the twist-up adjustment groove  6 , the surface of the opening  16  of the support ring  3  and the surface of the opening  9  of the twist-up ring  2  form the same surface. 
     As for the material of the support ring  3 , there is no special restriction as long as it can perform the above functions. For example, metal and plastics are recommended. Materials may be selected which demonstrate characteristics for strength and low wear with repeated use. 
     In the preferred embodiment the adjustment pins  4  are shown as screws inserted into the pin insertion grooves  11  of the support ring  3 . Those skilled in the art will appreciate that present invention may also be practiced with adjustment pins  4  which are pegs which insert into grooves  11 , phalanges which are adhered to the support ring  3 , or phalanges or denticles which are formed as part of the support ring  3 . 
     The twist-up adjustment pin  4  is inserted into the twist-up adjustment groove  6  when the twist-up device is operated. By moving inside the twist-up adjustment groove  6 , these parts regulate the motion of the twist-up ring  2  against the support ring 
     A shown in  FIG. 2 , each of the twist-up adjustment pins  4  consists of at least one head  14  and one leg  15 , and the heads  14  are contained inside the twist-up adjustment groove  6 , and as the legs  15  are screwed into the pin insert grooves  11 , they are fixed to the support ring  3 . While the heads  14  are thus fixed into the support ring  3 , their size is such that they can move inside the twist-up adjustment groove  6  without sticking out of the surface of the outer circumference of the twist-up ring  2 . 
     Those skilled in the art will appreciate that the heads  14  may have any suitable shape which will fit into and move in the twist-up adjustment groove  6 , including circular, oval, square, rectangular, triangular, hexagonal, octagonal, n-gonal, or irregular shaped, having either smooth or defined edges and contours. Furthermore, the legs  15  may screw into the pin insert grooves  11  as shown, but may also snap into the pin insert groove  11  using a nob and fitting configuration, lock into the pin insert groove  11  using a lock and key configuration, be adhered into the pin insert groove using an appropriate epoxy or adhesive, or be wedged into the pin insert groove  11 , as might be desired. 
     As for the material of the twist-up adjustment pins  4 , there is no special restriction as long as it can perform the above functions. For example, metal and plastics are recommended. Materials may be selected which demonstrate characteristics for strength and low wear with repeated use. 
     The resistance part  5  gives a required resistance to the movement of the twist-up ring  2  in the groove against the support ring  3  when the twist-up device is operated. The resistance part  5  is mated to the grooves covered with the resistance material  12  of the support ring  3 , and its outer circumference slightly sticks out of that of the support ring  3 . Therefore, when the support ring  3  is inserted into the twist-up ring  2  with the resistance part  5  attached to the support ring  3 , the outer circumference of the resistance material sticking out from the surface of the outer circumference of the support ring  3  will contact the inner surface of the twist-up ring  2 . As a result, when the twist-up device is operated, a required resistance force is given to the groove motion of the twist-up ring  2 . 
     The size of the resistance part  5  is determined by the size of the resistance force given by the groove motion of the twist-up ring  2 . In other words, to increase the above resistance force, the portion that sticks out from the surface of the outer circumference of the support ring  3  is increased, and the resistance part  5  is made larger in order to strengthen its contact with the inner surface of the twist-up ring  2 . To reduce the above resistance force, the portion that sticks out from the surface of the outer circumference of the support ring  3  is decreased, and the resistance part  5  is made smaller in order to weaken its contact with the inner surface of the twist-up ring  2 . 
     As for the material of the resistance part  5 , there is no special restriction as long as it can perform the above functions. Any type of flexible material can be suitably used. For example, some metals and many kinds of plastics are recommended. Materials may be selected which demonstrate characteristics for strength and low wear with repeated use. 
     The twist-up device  1  works as follows with the above structure, as exemplified in  FIGS. 3 through 7 .  FIGS. 3 through 7  show the front view of the twist-up device  1 , and the positional relationship of the twist-up adjustment groove  6  and the twist-up adjustment pins  4 . However,  FIGS. 3 through 7  describe only one twist-up adjustment groove  6 , and it will be appreciated by those skilled in the art that invention may be practiced with only one or as many sets of twist-up grooves  6 , twist-up pins  4 , and related components as desired. 
     Turning to  FIGS. 3 through 7 , the following positions are depicted: 
     Position A: The side end of the opening  9  of the pin movement section  7   a  of the twist-up adjustment groove  6 . 
     Position B 1 : The side end of the opening  10  (the right end of the pin stopping section  8   a ) of the twist-up adjustment groove  7   a.    
     Position B 2 : The side end of the opening  9  (the left end of the pin stopping section  8   a ) of the twist-up adjustment groove  7   b.    
     Position C 1 : The side end of the opening  10  (the right end of the pin stopping section  8   a ) of the twist-up adjustment groove  7   b , similar to that as shown for Position B 1 . 
     Position C 2 : The side end of the opening  9  (the left end of the pin stopping section  8   c ) of the twist-up adjustment groove  7   c , similar to that as shown for Position B 2 . 
     Position D 1 : The side end of the opening  10  (the right end of the pin stopping section  8   c ) of the twist-up adjustment groove  7   c.    
     Position D 2 : The left end of the pin stopping section  8   c.    
     Below is an explanation of an example based on a case in which the twist-up device  1  is fixed to the eyepiece of a binocular, with the spiral-fitting section  13  of the support ring  3  in the twist-up device  1  screwed to the eyepiece of the binocular. Therefore, it is assumed that the eyepiece lens is fixed to the side of the opening  17  of the support ring  3 . 
     As indicated in  FIG. 3 , the embodiment of the invention is shown with twist-up adjustment pin  4  located at Position A of the twist-up adjustment groove  6 . In this situation, the support ring  3  takes the highest position with respect to the twist-up ring  2 , which takes the lowest position relative to the support ring  3 . In other words, the distance between the opening  9  of the twist-up ring  2  and the eyepiece lens is the shortest in this situation. 
     As shown in  FIG. 3 , when an upward force is applied to the twist-up ring  2  along the pin movement section  7   a , the twist-up ring  2  moves upward in the groove against the support ring  3 . The twist-up adjustment pin  4  moves in the twist-up adjustment groove  6  from Position A to Position B 1 . Before reaching from Position A to Position B, there is no means to stop the movement of the twist-up adjustment pin  4 . So, until the twist-up adjustment pin  4  has moved from Position A to Position B 1 , or to the extent that twist-up adjustment pin  4  can move inside the pin movement section  7   a , the twist-up ring  2  can smoothly move upward against the support ring  3  or to the direction of the groove. Therefore, in this segment the distance between the opening  9  of the twist-up ring  2  and the eyepiece lens is variable, and by the movement of the twist-up adjustment pin  4  from Position A to Position B 1 , the distance gets larger between the opening  9  of the twist-up ring  2  and the eyepiece lens. 
     As shown in  FIG. 4 , when the twist-up adjustment pin  4  arrives at Position B 1 , it comes into contact with the lower contact section  18   a . So the movement of the twist-up adjustment pin is stopped and as a result the upward movement of the twist-up ring  2  against the support ring  3  is also stopped. When the twist-up adjustment pin  4  is at Position B 1 , the twist-up adjustment pin  4  comes into contact with the upper angled contact section  21   a  as well. So, even when a downward force is applied to the twist-up ring  2  in the direction of the axis line, the movement of the twist-up ring  2  is stopped. Therefore, when the twist-up adjustment pin  4  is at Position B 1 , the twist-up ring  2  does not move unless a force is applied in the direction of the pin movement section  7   a  or of the pin stopping section  8   a . The distance between the lower angled contact section  20   a  and the upper angled contact section  21   a  is set in such a way that the twist-up adjustment pin cannot pass unless a fairly strong force is applied to the twist-up ring  2 . So the twist-up adjustment pin  4  will not move to Position B 2  unless a strong force is intentionally applied to the twist-up ring  2  in the direction to the pin stopping section  8   a , Thus, when the twist-up adjustment pin  4  is at Position B 1 , the position of the opening  9  of the twist-up ring  2  with respect to the support ring  3  is maintained constant. So it is possible to maintain the distance constant between the opening  9  of the twist-up ring  2  and the eyepiece lens. 
     When the twist-up adjustment pin  4  is at Position B 1  and a force is applied to the twist-up ring  2  in the direction along the pin stopping section  8   a , the twist-up adjustment pin  4  moves from Position B 1  to Position B 2 , as shown in  FIG. 5 . As described above, the distance between the lower angled contact section  20   a  and the upper angled contact section  21   a  is set so as to enable the twist-up adjustment pin  4  to pass only after a considerably strong force has been applied to the twist-up ring  2 , so that the twist-up device  1  can produce a click sound when the twist-up adjustment pin  4  moves from Position B 1  to Position B 2 . 
     The twist-up adjustment pin  4  works in the same manner when it is moving from Position B 2  to Position D 1  as when it is moving from Position A to Position B 2 . In other words, when it moves from Position B 2  to C 1 , and from C 2  to D 1 , the distance between the opening  9  of the twist-up ring  2  and the eyepiece lens becomes longer. Furthermore, as indicated at Position C 1  and D 1 , the distance between the opening  9  of the twist-up ring  2  and the eyepiece lens can be maintained constant. 
     As shown in  FIG. 6 , when the twist-up adjustment pin is at Position D 1 , it can be easily moved to Position D 2 , as shown in  FIG. 7 , by applying a force counter-clockwise to the twist-up ring  2  and rotating it. When the twist-up adjustment pin  4  is at Position D 1  or D 2 , the distance between the opening  9  of the twist-up ring  2  and the eyepiece lens is the greatest. 
     When the twist-up adjustment pin  4  is at Position D 2 , it is in contact with the lower contact section  18   c  and the upper contact section  19   c . So the twist-up ring  2  does not move upward or downward along the axis line. Therefore, when the twist-up adjustment pin  4  is at Position D 1 , the distance between the opening  9  of the twist-up ring  2  and the eyepiece lens can be maintained constant. 
     When the twist-up device is operated with the twist-up adjustment pin  4  at Position D 2 , a force is applied clockwise to the twist-up ring  2  to turn it and move the twist-up adjustment pin  4  to Position D 1 , and then a force is applied to the twist-up ring  2  to turn it so that the twist-up adjustment pin  4  moves along the pin movement section  7   c  and to Position C 2 . Thus, the distance between the opening  9  of the twist-up ring  2  and the eyepiece lens is made shorter. In Position C 2 , the twist-up adjustment pin  4  contacts the upper contact section  19   b  above the axis line, and the lower angled contact section  20   b  below the axis line, and so the twist-up ring  2  does not move even if a force is applied to it in the direction of the axis line. Therefore, when the twist-up adjustment pin  4  is at Position C 2 , the distance between the opening  9  of the twist-up ring  2  and the eyepiece lens can be maintained constant. 
     As can be seen, the twist-up adjustment pins  4  move in sequence, and until they reach Position A, they work the same way as previously described. 
     As explained above, in the twist-up device  1 , the twist-up ring  2  can take four positions against the support ring  3 ; in other words, these four positions correspond to positions of ring  2  when the twist-up adjustment pin  4  is in Positions A, B 1  or B 2 , C 1  or C 2 , and D 1  or D 2 . And in these four positions, the twist-up ring  2  does not move even if a force is applied in the direction of the axis line. 
     Since the twist-up device  1  is equipped with the resistance part  5 , the twist-up ring  2  moves with a proper amount of resistance feel when the twist-up device is operated. In other words, the twist-up device  1  can make the operation of the twist-up tube not too light or not too heavy, so that the twist-up operation is easy and provides a good feel. 
     A further and alternative embodiment of the twist-up device, is shown in the Reference  FIGS. 8 ,  9  and  10 . As indicated in  FIG. 8  the twist-up ring  31  is used in combination of Split-image suppressor ring  32 , having three Eyepiece-turning screws  33  and Torque Rubber  34 . The Torque Rubber  34  may be comprised of rubber, Mylar, nylon, flexible plastic, or some other suitably durable resilient material. 
     The twist-up ring  31  has three slide grooves  35 , which are set diagonally in steps from an opening at one end to another opening at the other end. The torque rubber  34  is contained in the hole  39  in the split-image suppressor ring  32 . A part of the torque rubber  34  sticks out from the outer surface of the split-image suppressor ring  32 . The split-image suppressor ring  32  is inserted to the inside of the twist-up ring  31 . At this time, as the torque rubber  34  is pressed against and adheres to the inner surface of the twist-up ring  31 , the split-image suppressor ring  32  is installed in the twist-up ring  31 . The three pieces of eyepiece-turning screws  33  are screwed into the screw holes  37  set in the split-image suppressor ring  32  so that each of the screw-heads is contained inside the respective slide grooves  35 . 
     In  FIG. 10  a front view of the twist-up ring  31  of twist-up device, generally indicated at  38 , is attached to the eyepiece of binoculars, monoculars, field glasses, telescopes, or focusing devices, with one end of the opening facing the eyepiece lens and the other end facing the eyeball. 
     Turning to the twist-up device  38 , when a force is applied to the twist-up ring  31  on the side of the eyepiece lens or of the eyeball, the twist-up ring  31  slides toward the eyepiece lens or the eyeball along the outer surface of the split-image suppressor ring  32 , shown in  FIG. 9 , while the torque rubber  34  is pressed against the inner surface of the twist-up ring  31  and the screw-head  36  moves inside the slide groove  35 . In the twist-up device  38 , when the twist-up ring  31  is moved toward the eyepiece lens, the distance between the eyepiece lens and the eyeball is shortened, when the twist-up ring  31  is moved toward the eyeball, and the distance between the eyepiece lens and the eyeball is increased. 
     The twist-up ring  31 , is also called a “Turn Slide.” 
     As described above, when twist-up device  38  when force is applied to the twist-up device  38 , the moves against the twist-up ring  31  based on its functions, which changes the relative position of the split-image suppressor ring  32  with respect to the twist-up ring  31 . The advantage of this alternative embodiment of the invention is that the screw-head  36  in the screw hole  37  moves along the slide groove  35  in the twist-up ring  31  any position along the slide groove  35  may be fixedly selected, as desired. 
     When the twist-up device  1  or  38  as shown in  FIG. 1  or  10 , respectively, is used in the eyepiece of the binoculars, monoculars, field glasses, telescopes, or focusing devices, the distance between the opening  9  of the twist-up ring  2  and the eyepiece lens can be adjusted to 4 stages, and at each stage the distance can be maintained, even if a force is applied to the twist-up ring  2  in the direction of the axis line. 
     The user of a binoculars, monoculars, field glasses, telescopes, or other focusing device in which the twist-up device  1  is used in the eyepiece, moves the twist-up ring  2  to adjust the distance between his eyeballs and the eyepiece lens, to the best-focused position of the 4 positions mentioned above. At this time, even if a force is applied to the twist-up ring  2  in the direction of the axis line, it does not move as explained above. So the best-focused distance between his eyeballs and the eyepiece lens can be maintained, even if a force is applied to the twist-up ring  2  in the direction of the axis line when he is looking through the binoculars, monoculars, field glasses, telescopes, or other focusing device. Therefore, it is very comfortable to use binoculars, monoculars, field glasses, telescopes, or other focusing devices in which the twist-up device  1  is used in the eyepiece. 
     The twist-up device taught in this invention is not restricted by the twist-up device  1 . As long as the above-mentioned functions are secured, it can adopt various forms. For example, the number of twist-up adjustment grooves may be any number, one or more, as desired. The number of adjustment steps in the twist-up adjustment pins  4  may be any number, one or more, as desired. Additionally, and the shape of the twist-up adjustment groove can vary in shape, angle, length or conformation, as may be desired, or corresponding to the number of steps desired. 
     Because the twist-up device in the present invention has twist-up adjustment grooves in multiple steps, it is possible to make twist-up adjustments in multiple steps. 
     Since these twist-up adjustment grooves are structured to stop the twist-up adjustment pins, it is possible to securely maintain a focused position obtained by twist-up operation. 
     The twist-up device in the present invention does not require springs or other parts, and it can be manufactured with a simple change to the shape of the conventional twist-up adjustment groove. So the manufacturing cost may be minimized. The twist-up device of this invention can be appropriately reinforced, to improve durability, strength, and minimize wear to the twist-up operation with the use variously selected material with the desired characteristics. Additionally, the present invention provides the user with a feel-response as it clicks into the desired position when the twist-up adjustment pins move along to each pin stopping-section.