Abstract:
A target lens shape measuring device for measuring a target lens shape of an eyeglass lens has a measuring section including: a template feeler contactable with a periphery of a template; a first supporting base to which the template feeler is attached; a first motor and a link mechanism that move the template feeler and the first supporting base between a measuring position and a retracted position, wherein the link mechanism located between the measuring position and the retracted position is engaged with the first supporting base, and the link mechanism located at the measuring position is disengaged with the first supporting base; a second motor that moves the template feeler and the first supporting base in a radius vector direction of the template; and a first encoder that detect an amount of movement of the template feeler and the first supporting base in the radius vector direction of the template. A calculating section obtains radius vector information of the template based on the amount of movement detected by the first encoder.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a target-lens-shape measuring device for measuring a target lens shape of a template (including a dummy lens) obtained by tracing the shape of a lens frame of an eyeglass frame, and an eyeglass-lens processing apparatus having the same. 
     As target-lens-shape measuring devices, those disclosed in, for example, U.S. Pat. No. 5,138,770, European Patent 0868969 (US 09/050,977) and the like are known. In this type of device, after an eyeglass frame is held by a holding means, a feeler (frame-measuring feeler) is inserted into and moved along a frame groove, so that the amount of movement of the feeler is detected to measure the target lens shape of the lens frame. In addition, this device is so arranged to be able to measure a template by using (using in common) a detecting mechanism for detecting the amount of movement of the feeler. In the measurement of the template, a measuring pin (template feeler) which is to be brought into contact with an outer periphery of the template is attached to a measuring mechanism section so as to effect the measurement. After completion of the template measurement, the measuring pin is removed from the measuring mechanism section so that it will not hinder the measurement of the eyeglass frame. 
     With the device as described above, however, the operator must manually attach and detach the measuring pin on each occasion of the template measurement, so that the operation is time-consuming and troublesome. In addition, since the measuring pin is unnecessary other than during the template measurement, the measuring pin must be removed and stored separately. However, the storage is troublesome, and the measuring pin may be lost. 
     SUMMARY OF THE INVENTION 
     In view of the above-described problems, an object of the invention is to provide a target-lens-shape measuring device which eliminates the troublesomeness of attaching and detaching the measuring pin and makes it possible to effect template measurement speedily. Another object of the present invention is to provide an eyeglass-lens processing apparatus having such target-lent-shape measuring device. 
     To overcome the above-described problems, the invention provides the following construction. 
     A target lens shape measuring device for measuring a target lens shape of an eyeglass lens, comprising: 
     a template feeler contactable with a periphery of a template; 
     first moving means for moving the template feeler in a radius vector direction of the template along a guide; 
     template measuring means for detecting movement of the template feeler, and obtaining radius vector information of the template based on a result of detection thereof; 
     second moving means for moving the template feeler between a measuring position and a retracted position, the second moving means including a driving power source and a transmitting mechanism for transmitting power of the driving power source, wherein the transmitting mechanism moves the template feeler from one of the measuring position and the retracted position to the other of the measuring position and the retracted position in a state in which the transmitting mechanism is engaged with a member of the first moving means, and the transmitting mechanism is disengaged from the member of the first moving means upon the template feeler reaches the measuring position; and 
     detecting means for detecting a state in which the template feeler is located at the measuring position. 
     The device of the present invention, further comprising: 
     control means for operating the first moving means to measure the template based on a result of detection by the detecting means. 
     The device of the present invention, further comprising: 
     fixing means for fixing the template at a predetermined position. 
     The device of the present invention, further comprising: 
     an eyeglass frame holding unit including a pair of sliders contactable respectively with an upper end surface and a lower end surface of an eyeglass frame, clamp pins provided on the sliders and adapted to clamp the eyeglass frame, and urging means for urging the sliders toward each other, 
     wherein the template is measured using a space that is defined when the sliders are located away from each other at a predetermined distance against an urging force of the urging means. 
     The present invention also includes: 
     fixing means for fixing the template at a predetermined position, 
     wherein the sliders are fixed to have the predetermined distance therebetween when the template is fixed at the position by the fixing means. 
     The present invention further comprises: 
     slider detecting means for detecting whether or not the sliders are located to have the predetermined distance therebetween; and 
     mode detecting means for detecting, based on a result of detection by the slider detecting means, a template measuring mode in which the template is to be measured. 
     The present invention further comprises: 
     a frame feeler contactable with a frame groove of a lens frame of an eyeglass frame; 
     third moving means for moving the frame feeler in a radius vector direction of the lens frame; and 
     frame measuring means for detecting movement of the frame feeler, and obtaining radius vector information of the lens frame based on a result of detection thereof; 
     wherein the first moving means and the third moving means have a common moving mechanism. 
     In addition, the template measuring means and the frame measuring means have a common movement detecting mechanism. 
     An eyeglass lens processing apparatus, provided with the target lens shape measuring device of the present invention, for processing the eyeglass lens based on the obtained target lens shape, the apparatus comprising: 
     lens processing means having a rotatable abrasive wheel and a lens rotating shaft adapted to hold and rotate the lens; and 
     processing control means for controlling the lens processing means based on the obtained target lens shape. 
     A target lens shape measuring device for measuring a target lens shape of an eyeglass lens, comprising: 
     a measuring section including: 
     a template feeler contactable with a periphery of a template; 
     a first supporting base to which the template feeler is attached; 
     a first motor and a link mechanism that move the template feeler and the first supporting base between a measuring position and a retracted position, wherein the link mechanism located between the measuring position and the retracted position is engaged with the first supporting base, and the link mechanism located at the measuring position is disengaged with the first supporting base; 
     a second motor that moves the template feeler and the first supporting base in a radius vector direction of the template; and 
     a first encoder that detect an amount of movement of the template feeler and the first supporting base in the radius vector direction of the template; and 
     a calculating section that obtains radius vector information of the template based on the amount of movement detected by the first encoder. 
     Also, the measuring section further includes a sensor that detects a state in which the template feeler and the first supporting base are located at the measuring position. 
     The device also has: 
     a control section that drives the second motor based on a result of detection by the sensor to measure the template. 
     The measuring section further includes a guide along which the template feeler and the first supporting base are moved in the radius vector direction of the template. 
     The measuring section further includes: 
     a frame feeler contactable with a frame groove of a lens frame of an eyeglass frame; 
     a second supporting base to which the frame feeler is attached; 
     a third motor that moves the frame feeler and the second supporting base in a radius vector direction of the lens frame; and 
     a second encoder that detects an amount of movement of the frame feeler and the second supporting base, 
     wherein the calculating section obtains radius vector information of the lens frame based on the amount of movement detected by the second encoder. 
     The invention also has: 
     at least one of the template feeler and the first supporting base is movably held on the second supporting base; 
     the second motor and the third motor are constructed as a common motor; and 
     the first encoder and the second encoder are constructed as a common encoder. 
     An eyeglass lens processing apparatus, provided with the target lens shape measuring device of the present invention, for processing the eyeglass lens based on the obtained target lens shape, the apparatus comprising: 
     a lens processing section having a rotatable abrasive wheel and a lens rotating shaft adapted to hold and rotate the lens; and 
     a processing control section that controls the lens processing section based on the obtained target lens shape. 
     The present disclosure relates to the subject matter contained in Japanese patent application No. Hei. 11-220089 (filed on Aug. 3, 1999), which is expressly incorporated herein by reference in its entirety. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a diagram of the external configuration of an eyeglass-lens processing apparatus in accordance with the invention; 
     FIG. 2 is a perspective view illustrating the arrangement of a lens processing section disposed in a casing of a main body of the apparatus; 
     FIG. 3 is a plan view of a frame holding section of an target-lens-shape measuring device; 
     FIG. 4 is a cross-sectional view taken along line A—A in FIG.  3  and illustrating an essential portion; 
     FIG. 5 is a plan view of a measuring section of the target-lens-shape measuring device; 
     FIG. 6 is a side elevational view for explaining a feeler unit; 
     FIG. 7 is a view taken in the direction of arrow C in FIG. 6; 
     FIG. 8 is a view taken in the direction of arrow D in FIG. 6; 
     FIG. 9 is a perspective view of a template holder in a state in which a template holding portion for mounting a template thereon is oriented upward; 
     FIG. 10 is a perspective view of the template holder in a state in which a cup holding portion for mounting a dummy lens thereon is oriented upward; 
     FIG. 11 is a longitudinal cross-sectional view of the template holder; 
     FIG. 12 is a control system block diagram of the apparatus; 
     FIG. 13 is a side elevational view for explaining a modification of the feeler unit; and 
     FIG. 14 is a view taken in the direction of arrow D in FIG.  13 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Hereafter, a description will be given of an embodiment of the invention. 
     (1) Overall Construction 
     FIG. 1 is a diagram illustrating the external configuration of an eyeglass-lens processing apparatus in accordance with the invention. A target-lens-shape measuring device, i.e. an eyeglass-frame-shape measuring device,  2  is incorporated in an upper right-hand rear portion of a main body  1  of the apparatus. The target-lens-shape measuring device  2  is disposed in such a manner as to be inclined toward a front side along the inclination of the upper surface of the casing of the main body  1  so as to facilitate the setting of an eyeglass frame on a frame holding section  200  which will be described later. A switch panel section  410  having switches for operating the target-lens-shape measuring device  2  and a display  415  for displaying processing information and the like are disposed in front of the target-lens-shape measuring device  2 . Further, reference numeral  420  denotes a switch panel section having various switches for inputting processing conditions and the like and for giving instructions for processing, and numeral  402  denotes an openable window for a processing chamber. 
     FIG. 2 is a perspective view illustrating the arrangement of a lens processing section disposed in the casing of the main body  1 . A carriage unit  700  is mounted on a base  10 , and a subject lens LE clamped by a pair of lens chuck shafts  702 L and  702 R of a carriage  701  is ground by a group of abrasive wheels  602  attached to a rotating shaft  601 . The group of abrasive wheels  602  include a rough abrasive wheel  602   a  for glass lenses, a rough abrasive wheel  602   b  for plastic lenses, and a finishing abrasive wheel  602   c  for beveling processing and flat processing. The rotating shaft  601  is rotatably attached to the base  10  by a spindle  603 . A pulley  604  is attached to an end of the rotating shaft  601 , and is linked through a belt  605  to a pulley  607  which is attached to a rotating shaft of an abrasive-wheel rotating motor  606 . A lens-shape measuring section  500  is provided in the rear of the carriage  701 . 
     (2) Construction of Various Sections 
     (A) Target-Lens-Shape Measuring Device 
     A description will be given of the major configuration of the target-lens-shape measuring device  2  by dividing it into the frame holding section, a measuring section, and a template holder. 
     &lt;Frame Holding Section&gt; 
     Referring to FIGS. 3 and 4, a description will be given of the construction of the frame holding section  200 . FIG. 3 is a plan view of the frame holding section  200 , and FIG. 4 is a cross-sectional view taken along line A—A in FIG.  3  and illustrating an essential portion. 
     A front slider  202  and a rear slider  203  for holding an eyeglass frame are slidably placed on a pair of guide rails  204  and  205  arranged on the rightand left-hand sides of a holding section base  201 . Pulleys  207  and  208  are rotatably attached respectively to a front-side block  206   a  and a rear-side block  206   b  that support the guide rail  204 . An endless wire  209  is suspended on the pulleys  207  and  208 . An upper side of the wire  209  is secured to a pin  210  attached to a right end member  203 R extending from the rear slider  203 , while a lower side of the wire  209  is secured to a pin  211  attached to a right end member  202 R extending from the front slider  202 . Further, a spring  213  is stretched between the rear-side block  206   b  and the right end member  202 R using a mounting plate  212 , so that the front slider  202  is constantly urged in the direction in which the spring  213  contracts. Owing to this arrangement, the front slider  202  and the rear slider  203  are slid in a symmetrically opposing manner with respect to a reference line L 1  at the center therebetween, and are constantly pulled in directions toward that center (reference line L 1 ) by the spring  213 . Accordingly, if one of the front slider  202  and the rear slider  203  is slid in the opening direction, a distance therebetween for holding the frame can be secured, and if the front slider  202  and the rear slider  203  are in a free state, the distance therebetween is reduced by the urging force of the spring  213 . 
     The frame is clamped by clamp pins  230  arranged at total four locations, i.e. by clamp pins  230  at right and left two locations of the front slider  202  and clamp pins  230  at right and left locations of the rear slider  203 , so as to be held in a reference plane for measurement. 
     The opening and closing of these clamp pins  230  are effected by driving a clamp motor  223  which is fixed on the reverse side of the holding section base  201 . A worm gear  224  attached to a rotating shaft of the motor  223  is in mesh with a wheel gear  221  of a shaft  220  which is rotatably held between the block  206   a  and the block  206   b,  so that the rotation of the motor  223  is transmitted to the shaft  220 . The shaft  220  is passed through the right end member  202 R and the right end member  203 R. Inside the right end member  202 R, an unillustrated wire for opening and closing the clamp pins  230  is attached to the shaft  220 , and as the wire is pulled by the rotation of the shaft  220 , the opening and closing operation of the clamp pins  230  are effected simultaneously. Inside the right end member  203 R as well, an unillustrated similar wire is also attached to the shaft  220 , and the opening and closing operation of the clamp pins  230  are effected simultaneously by the rotation of the shaft  220 . Further, brake pads for securing the opening and closing of the front slider  202  and the rear slider  203  due to the rotation of the shaft  220  are respectively provided inside the right end member  202 R and the right end member  203 R. As the arrangement of the mechanism for opening and closing the clamp pins  230 , it is possible to use the arrangement disclosed in U.S. Pat. No. 5,228,242 commonly assigned to the present assignee, so that reference is had to made thereto for details. 
     Further, an attaching plate  300  for attaching a template holder  310  (described later), which is used at the time of measuring a template  350  (or a dummy lens), is fixed at the center on the front side of the holding section base  201  as shown in FIG.  4 . The attaching plate  300  has an inverse L-shaped cross section, and the template holder  310  is used upon being placed on the upper surface of the attaching plate  300 . A magnet  301  is provided in the center of the upper surface of the attaching plate  300 , and two holes  302  for positioning the template holder  310  are formed in the attaching plate  300  on the left- and right-hand sides of the magnet  301 . 
     &lt;Measuring Section&gt; 
     Referring to FIGS. 5 to  8 , a description will be given of the construction of the measuring section  240 . FIG. 5 is a plan view of the measuring section  240 . In FIG. 5, a transversely movable base  241  is supported in such a manner as to be transversely slidable along two rails  242  and  243  which are axially supported by the holding section base  201  and extend in the transverse direction (in the arrow B direction). The transverse movement of the transversely movable base  241  is effected by the driving of a motor  244  attached to the holding section base  201 . A ball screw  245  is connected to a rotating shaft of the motor  244 , and as the ball screw  245  meshes with an internally threaded member  246  fixed on the lower side of the transversely movable base  241 , the transversely movable base  241  is moved in the transverse direction (in the arrow B direction) by the forward and reverse rotation of the motor  244 . 
     A rotating base  250  is rotatably held on the transversely movable base  241  by rollers  251  provided at three positions. As shown in FIG. 6, a geared portion  250   a  is formed around a circumference of the rotating base  250 , and an angular or tapered guide rail  250   b  projecting in a radially outward direction is formed below the geared portion  250   a.  This guide rail  250   b  is brought into contact with a V-shaped groove of each roller  251 , and the rotating base  250  rotates while being held by the three rollers  251 . The geared portion  250   a  of the rotating base  250  meshes with an idle gear  252 , and the idle gear  252  meshes with a gear  253  attached to a rotating shaft of a pulse motor  254  secured to the lower side of the transversely movable base  241 . As a result, the rotation of the motor  254  is transmitted to the rotating base  250 . A feeler unit  255  is attached to the underside of the rotating base  250 . 
     Referring to FIGS. 6 and 8, a description will be given of the construction of the feeler unit  255 . FIG. 6 is a side elevational view for explaining the feeler unit  255 , FIG. 7 is a view taken in the direction of arrow C in FIG. 6, and FIG. 8 is a view taken in the direction of arrow D in FIG.  6 . 
     A fixed block  256  is fixed to the underside of the rotating base  250 . A guide rail receiver  256   a  is attached to a side surface of the fixed block  256  in such a manner as to extend in the planar direction of the rotating base  250 . A transversely movable supporting base  260  having a slide rail  261  is slidably attached to the guide rail receiver  256   a.  A DC motor  257  for moving the transversely movable supporting base  260  and an encoder  258  for detecting the amount of its movement are attached to a side of the fixed block  256  which is opposite to its side where the guide rail receiver  256   a  is attached. A gear  257   a  attached to a rotating shaft of the motor  257  meshes with a rack  262  fixed to a lower portion of the transversely movable supporting base  260 , and the transversely movable supporting base  260  is moved in the left-and-right direction (in the arrow F direction) in FIG. 6 by the rotation of the motor  257 . Further, the rotation of the gear  257   a  attached to the rotating shaft of the motor  257  is transmitted to the encoder  258  through an idle gear  259 , and the amount of movement of the transversely movable supporting base  260  is detected from this amount of rotation. 
     A vertically movable supporting base  265  is supported by the transversely movable supporting base  260  to be movable in the vertical direction (in the arrow G direction). As for its moving mechanism, in the same way as the transversely movable supporting base  260 , a slide rail (not shown) attached to the vertically movable supporting base  265  is slidably held on a guide rail receiver  266  attached to the transversely movable supporting base  260  and extending in the vertical direction. A vertically extending rack  268  is secured to the vertically movable supporting base  265 , a gear  270   a  of a DC motor  270  attached to the transversely movable supporting base  260  by means of a fixing metal plate meshes with the rack  268 , and as the motor  270  rotates, the vertically movable supporting base  265  is moved vertically. Further, the rotation of the motor  270  is transmitted through an idle gear  271  to an encoder  272  attached to the transversely movable supporting base  260  by means of a fixing metal plate, and the encoder  272  detects the amount of movement of the vertically movable supporting base  265 . Incidentally, a downward load of the vertically movable supporting base  265  is reduced by a power spring  275  attached to the transversely movable supporting base  260 , thereby rendering the vertical movement of the vertically movable supporting base  265  smooth. 
     Further, a shaft  276  is rotatably held on the vertically movable supporting base  265 , an L-shaped attaching member  277  is provided at its upper end, and a feeler  280  is fixed to an upper portion of the attaching member  277 . The tip of the feeler  280  is aligned with a rotational axis of the shaft  216 , and the tip of the feeler  280  is to be brought into contact with a frame groove of the frame F. 
     A limiting member  281  is attached to a lower end of the shaft  276 . This limiting member  281  has a substantially hollow cylindrical shape, and a protrusion  281   a  is formed on its side surface along the vertical direction (the arrow G direction), while another protrusion  281   a  is formed on the opposite side opposite with respect to the paper surface of FIG.  6 . As these two protrusions  281   a  respectively abut against notched surfaces  265   a  (the illustrated notched surface  265   a,  and a similar notched surface  265   a  that is provided on the opposite side with respect to the paper surface of FIG. 6) formed in the vertically movable supporting base  265 , the rotation of the shaft  276  (i.e., the rotation of the feeler  280 ) is limited to a certain range. An obliquely cut slanting surface is formed on a lower portion of the limiting member  281 . When the limiting member  281  is lowered together with the shaft  276  due to the downward movement of the vertically movable supporting base  265 , this slanting surface abuts against a slanting surface of a block  263  secured to the transversely movable supporting base  260 . As a result, the rotation of the limiting member  281  is guided to the state shown in FIG. 6, thereby correcting the orientation of the tip of the feeler  280 . 
     In FIG. 6, a measuring pin, i.e. a template measuring feeler,  290  is vertically slidably held on a right-hand side portion of the transversely movable supporting base  260 . Here, if consideration is given to a mechanism for vertically moving the measuring pin  290 , a mechanism is conceivable in which a motor is attached to the transversely movable supporting base  260 , and the measuring pin  290  is vertically moved by such as a mechanism including a rack and a pinion. However, since the arrangement in which the motor, the rack, the pinion, and the like are merely attached to the transversely movable supporting base  260  adds weight of these components, an inertial force becomes large when the transversely movable supporting base  260  is moved. Consequently, the measurement accuracy becomes poor, and speedily measurement becomes impossible. Accordingly, the apparatus of the invention is so arranged that the motor for vertically moving the measuring pin  290  is not mounted on the transversely movable supporting base  260 . Hereafter, a description will be given of the mechanism for vertically moving the measuring pin  290 . 
     In FIG. 6, a pin moving supporting base  291  is attached to a lower end of the measuring pin  290  which is vertically slidably held on the transversely movable supporting base  260 . A plate  292  extending in a direction perpendicular to the plane of the drawing of FIG. 6 is attached to a lower end of the transversely movable supporting base  260 . A spring  293  is stretched between this plate  292  and a lower portion of the pin moving supporting base  291 , so that the measuring pin  290  is constantly urged in the downward direction. 
     In addition, a guide groove  288  is formed in the transversely movable supporting base  260  in the vertical direction (in the arrow G direction), and a pin  289  attached to the pin moving supporting base  291  is fitted in the guide groove  288  and serves for preventing relative rotation between the pin moving supporting base  291  and the measuring pin  290 . 
     As shown in FIG. 8, a slot  291   a  is formed in the pin moving supporting base  291 , and a pin  296  attached to an arm  295  which rotates about a shaft  294  is engaged with the slot  291   a.  A gear  297  is fixed to the arm  295 , and this gear  297  meshes with a gear  284  attached to a rotating shaft of a DC motor  283  attached to the fixed block  256 . As a result, the rotation of the motor  283  is transmitted to the gear  284 , and as the arm  295  rotates, the pin moving supporting base  291  is vertically moved. A fan-shaped slot  297   a  is formed in the gear  297 . A pin  298  attached to the fixed block  256  is inserted in the slot  297   a  so as to limit the angle of rotation of the gear  297 . 
     In addition, photosensors  286  and  287  are attached to the transversely movable supporting base  260  on upper and lower sides thereof, respectively, and as a light shielding plate  285  enters the photosensor  286  or  287 , it can be detected whether the measuring pin  290  is at the measuring position (at the position where the measuring pin  290  is at the most elevated position) or at the retreated position (at the most lowered position). In addition, only the photosensor  287  may be used so as to only detect whether or not the measuring pin  290  is at the measuring position. 
     A roller  279  is attached to the pin moving supporting base  291 . When the transversely movable supporting base  260  is moved leftward (in the direction of arrow D) from the state shown in FIG. 6, the roller  279 , while being subjected to a downwardly urging force by the spring  293 , rolls on a guide  282  attached to the rotating base  250 . Consequently, the measurement of the template is effected in a state in which the measuring pin  290  is at the measuring position, and is separated from the vertically moving mechanism including the motor  283 , the arm  295 , and the like. 
     &lt;Template Holder&gt; 
     Referring to FIGS. 9 to  11 , a description will be given of the construction of the template holder  310 . FIG. 9 is a perspective view of the template holder  310  in a state in which a template holding portion  320  for mounting a template  350  thereon is oriented upward. FIG. 10 is a perspective view of the template holder  310  in a state in which a cup holding portion  330  for mounting a dummy lens thereon is oriented upward. FIG. 11 is a longitudinal cross-sectional view of the template holder  310 . 
     The template holding portion  320  and the cup holding portion  330  are provided integrally on opposite surfaces, respectively, of a main body block  311  of the template holder  310  so that the template holding portion  320  and the cup holding portion  330  can be selectively used by inverting the template holder  310 . Pins  321   a  and  321   b  are implanted on the template holding portion  320 , an opening  322  is provided in the center, and a movable pin  323  projects from the opening  322 . As shown in FIG. 11, the movable pin  323  is fixed to a movable shaft  312  inserted in the main body block  311 , and the movable shaft  312  is constantly urged in the direction of arrow E in FIG. 11 by a spring  313 . A button  314  for performing a pushing operating is attached to a distal end of the movable shaft  312  projecting from the main body block  311 . Further, a recessed portion  324  is formed on the front side (right-hand side in FIG. 11) of the movable pin  323 . 
     A hole  331  for inserting a basal part  361  of a cup  360  with a dummy lens fixed thereon is formed in the cup holding portion  330 , and a projection  332  for fitting to a key groove  362  formed in the basal part  361  is formed inside the hole  331 . Further, a sliding member  327  is fixed to the movable shaft  312  inserted in the main body block  311 , and its front-side end face  327   a  is circular-arc shaped (a circular arc of the same diameter as that of the hole  331 ). 
     At the time of fixing the template  350 , after the button  314  is manually pushed in, the template  350  is positioned such that a central hole  351  is fitted over the movable pin  323  while two small holes  352  provided on both sides of the central hole  351  are engaged with the pins  321   a  and  321   b.  Subsequently, if the button  314  pushed in toward the main body block  311  side is released, the movable pin  323  is returned in the direction of arrow E by the urging force of the spring  313 , and its recessed portion  324  abuts against the wall of the central hole  351  in the template  350 , thereby fixing the template  350 . 
     At the time of fixing the cup  360  attached to the dummy lens, in the same way as with the template, after the button  314  is manually pushed in to open the sliding member  327 , the key groove  362  of the basal part  361  is fitted to the projection  332 . Upon releasing the button  314 , the sliding member  327  together with the movable shaft  312  is returned toward the hole  331  by the urging force of the spring  313 . As the basal part  361  of the cup  360  inserted in the hole  331  is pressed by the circular-arc shaped end face  327   a,  the cup  360  is fixed in the cup holding portion  330 . 
     A fitting portion  340  for fitting the template holder  310  to the attaching plate  300  of the holding section base  201  is provided on the rear side of the main body block  311 , and its obverse side (the template holding portion  320  side is assumed to be the obverse side) has the same configuration as the reverse side. Pins  342   a,    342   b  and  346   a,    346   b  for insertion into the two holes  302  formed in the upper surface of the attaching plate  300  are respectively implanted on the obverse surface  341  and the reverse surface  345  of the fitting portion  340 . Further, iron plates  343  and  347  are respectively embedded in the obverse surface  341  and the reverse surface  345 . Flanges  344  and  342  are respectively formed on the obverse surface  341  and the reverse surface  345  of the fitting portion  340 . 
     At the time of attaching the template holder  310  to the target-lens-shape measuring device  2 , after the front slider  202  is opened toward the front side (the rear slider  203  is also opened simultaneously), in the case of the template measurement, the template holding portion  320  side is oriented downward, and the pins  342   a  and  342   b  on the fitting portion  340  are engaged in the holes  302  in the attaching plate  300 . At this time, since the iron plate  343  is attracted by the magnet  301  provided on the upper surface of the attaching plate  300 , the template holder  310  can be easily fixed immovably to the upper surface of the attaching plate  300 . Further, the flange  344  of the template holder  310  abuts against a recessed surface  202   a  formed in the center of the front slider  202  to maintain the open state of the front slider  202  and the rear slider  203 . 
     (B) Carriage Section 
     Referring to FIG. 2, a description will be given of the construction of the carriage section  700 . The carriage  701  is capable of rotating the lens LE while chucking it with two lens chuck shafts (lens rotating shafts)  702 L and  702 R, and is rotatably slidable with respect to a carriage shaft  703  that is fixed to the base  10  and that extends in parallel to the abrasive-wheel rotating shaft  601 . Hereafter, a description will be given of a lens chuck mechanism and a lens rotating mechanism as well as an X-axis moving mechanism and a Y-axis moving mechanism of the carriage  701  by assuming that the direction in which the carriage  701  is moved in parallel to the abrasive-wheel rotating shaft  601  is the X axis, and the direction for changing the axis-to-axis distance between the chuck shafts ( 702 L,  702 R) and the abrasive-wheel rotating shaft  601  by the rotation of the carriage  701  is the Y axis. 
     &lt;Lens Chuck Mechanism and Lens Rotating Mechanism&gt; 
     The chuck shaft  702 L and the chuck shaft  702 R are rotatably held coaxially by a left arm  701 L and a right arm  701 R, respectively, of the carriage  701 . A chucking motor  710  is fixed to the center of the upper surface of the right arm  701 R of the carriage  701 . Using the rotation of the motor  701  as power source, the chuck shaft  702 R can be moved in the axial direction, so that the lens LE is clamped by the chuck shafts  702 L and  702 R. 
     A rotatable block  720  for attaching a motor, which is rotatable about the axis of the chuck shaft  702 L, is attached to a left-side end portion of the carriage  701 , and the chuck shaft  702 L is passed through the block  720 , a gear  721  being secured to the left end of the chuck shaft  702 L. A motor  722  for lens rotation is fixed to the block  720 , and as the motor  722  rotates the gear  721  through a gear  724 , the rotation of the motor  720  is transmitted to the chuck shaft  702 L. 
     &lt;X-axis Moving Mechanism and Y-axis Moving Mechanism of Carriage&gt; 
     The carriage shaft  703  is provided with a movable arm  740  which is slidable in its axial direction so that the arm  740  is movable in the X-axis direction (in the axial direction of the shaft  703 ) together with the carriage  701 . Further, the arm  740  at its front position is slidable on and along a guide shaft  741  that is secured to the base  10  in a parallel positional relation to the shaft  703 . A rack  743  extending in parallel to the shaft  703  is attached to a rear portion of the arm  740 , and this rack  743  meshes with a pinion  746  attached to a rotating shaft of a motor  745  for moving the carriage in the X-axis direction, the motor  745  being secured to the base  10 . By virtue of the above-described arrangement, the motor  745  is able to move the carriage  701  together with the arm  740  in the axial direction of the shaft  703  (in the X-axis direction). 
     A swingable block  750  is attached to the arm  740  in such a manner as to be rotatable about the axis which is in alignment with the rotational center of the abrasive wheels  602 . A Y-axis moving motor  751  is attached to the swingable block  750 , and the rotation of the motor  751  is transmitted through a belt  753  to a female screw  755  held rotatably in the swingable block  750 . A feed screw  756  is inserted in a threaded portion of the female screw  755  in mesh therewith, and the feed screw  756  is moved vertically by the rotation of the female screw  755 . 
     A guide block  760  which abuts against a lower end surface of the motor-attaching block  720  is fixed to an upper end of the feed screw  756 , and the guide block  760  moves along two guide shafts  758  implanted on the swingable block  750 . Accordingly, as the guide block  760  is vertically moved together with the feed screw  756  by the rotation of the motor  751 , it is possible to change the vertical position of the block  720  abutting against the guide block  760 . As a result, the vertical position of the carriage  701  attached to the block  720  can be also changed (namely, the carriage  701  rotates about the shaft  703  to change the axis-to-axis distance between the chuck shafts ( 702 L,  702 R) and the abrasive-wheel rotating shaft  601 ). 
     Next, referring to the control system block diagram of FIG. 12, a description will be given of the operation of the apparatus having the above-described construction. 
     When the template  350  is measured by the target-lens-shape measuring device  2 , the front slider  202  is pulled toward the front side, and the template holder  310  with the template  350  fixed thereto is attached to the upper surface of the attaching plate  300 . Since the flange  344  of the template holder  310  is engaged with the recessed surface  202   a  of the front slider  202 , the opening of the front slider  202  and the rear slider  203  is fixed. The open state of the front slider  202  is detected by a sensor plate  236  and a sensor  235 , so that the template measurement mode is detected. 
     After the setting of the template holder  310 , in a case where the template  350  to be measured is for the right use, a right trace switch  413  on the switch panel section  410  is pressed, whereas in a case where the template  350  is for the left use, a left trace switch  411  is pressed. In the case of both-eye trace the switch  412  is pressed. 
     A control unit  150  drives the motor  244  to position the measuring section  240  (the transversely movable supporting base  241 ) at the measuring position in the center. The initial position of the transversely movable supporting base  260  in the template measurement mode is set at the position where the transversely movable supporting base  260  abuts against an inner end face of the rotating base  250 , i.e., at the outermost position in the movable range of the transversely movable supporting base  260 . Accordingly, as shown in FIG. 6, the pin  296  attached to the arm  295  is engaged with the slot  291   a  formed in the pin moving supporting base  291 , and the measuring pin  290  and the vertically moving mechanism including the motor  283  and the like are in a linked state. 
     When the control unit  150 , upon receiving a tracing start signal, drives the motor  283 , the gear  297  in mesh with the gear  284  attached to the shaft of the motor  283  rotates, which in turn causes the arm  295  secured coaxially to the gear  297  through the shaft  294  to rotate in the direction of arrow H. As the arm  295  rotates in the direction of arrow H, the pin moving supporting base  291  is raised, so that the measuring pin  290  secured to the pin moving supporting base  291  is also raised. When the pin moving supporting base  291  has been raised most, the light shielding plate  285  attached to the pin moving supporting base  291  enters the photosensor  287 , so that the photosensor  287  detects that the measuring pin  290  has risen to the measuring position. Upon receiving this detection signal, the control unit  150  drives the motor  257  so as to allow the measuring pin  290  to be oriented toward the center (in the direction of arrow D) and move the transversely movable supporting base  260 . Consequently, the pin moving supporting base  291  (the slot  291   a ) is disengaged from the pin  296  attached to the arm  295 , the roller  279  rolls on the guide  282 , and the measuring pin  290  remains raised at the top (at the measuring position). 
     Accordingly, the measurement of the template  350  is effected in the state in which the measuring pin  290  is separated from the vertically moving mechanism including the motor  283  and the like, and the measuring pin  290  is placed at the measuring position. During the movement of the transversely movable supporting base  260 , the driving current to the motor  257  is controlled to provide a predetermined driving torque. In a state in which the measuring pin  290  abuts against the end face of the template  350 , the pulse motor  254  is rotated in accordance with each predetermined unit number of rotational pulses to rotate the feeler unit  255 . As a result of this rotation, the transversely movable supporting base  260  together with the measuring pin  290  slides in the leftward and rightward direction (in the direction of arrow F) in accordance with the radius vector of the template  350 , and the amount of its movement is detected by the encoder  258 , thereby measuring the target lens shape. Since the motor  283  large in weight is not mounted on the transversely movable supporting base  260 , the movement of the transversely movable supporting base  260  takes place smoothly, and the follow-up movement of the measuring pin  290  in accordance with the radius vector of the template  350  is not degraded. Accordingly, the measurement data can be obtained with high accuracy. 
     Upon completion of the measurement of the entire periphery of the template  350 , the transversely movable supporting base  260  is moved to its initial position under control by the control unit  150 . In this position, the roller  279  is disengaged from the guide  282 , and the pin  296  attached to the arm  295  comes into engagement with the slot  291   a  of the pin moving supporting base  291 . In addition, the arm  295  separated from the pin moving supporting base  291  during the target lens shape measurement, after the arm  295  may be lowered, and thereafter the power supply to the motor  283  may be cut off. The arm  295  may be raised again by rotating the motor  283  in response to the signal representing the completion of the measurement. 
     After the pin  296  is engaged with the slot  291   a,  the pin moving supporting base  291  and the measuring pin  290  are moved downward by the slight rotation of the arm  295  in the direction of arrow I with the motor  283  and by the urging force of the spring  293 . At the point of time when the pin moving supporting base  291  has been lowered, the light shielding plate  285  attached to the pin moving supporting base  291  enters the photosensor  286 , thereby detecting the fact that the measuring pin  290  has been lowered to the lower position (retreated position). 
     Next, a description will be given of a modification of the feeler unit  255 . FIG. 13 is a side elevational view for explaining the modification of the feeler unit  255 , and FIG. 14 is a view taken in the direction of arrow D in FIG.  13 . 
     The construction shown in FIG. 13 differs from the construction shown in FIG. 6 in that the plate  292  and the spring  293  are omitted, and a downward force acts on the pin moving supporting base  291  due to its own weight. The construction shown in FIG. 14 differs from the construction shown in FIG. 8 in that a pin  291   b  is provided on the pin moving supporting base  291  instead of the slot  291   a,  and the arm  295  is provided with pins  296   a  and  296   b  on its upper and lower sides, respectively, so that the pin  291   b  is interposed between the pins  296   a  and  296   b.    
     As shown in FIG. 13, in the initial position of the transversely movable supporting base  260  in the template measurement mode, the pin  291   b  provided on the pin moving supporting base  291  is located between the pins  296   a  and  296   b  provided on the arm  295 , and the measuring pin  290  and the vertically moving mechanism including the motor  283  and the like are in a linked state. 
     When the control unit  150 , upon receiving a tracing start signal, rotates the motor  283 , the gear  297  is rotated, which, in turn, rotates the arm  295  in the direction of arrow H. The rotation of the arm  295  in the direction of arrow H causes the pin moving supporting base  291  to be moved upward, so that the measuring pin  290  secured to the pin moving supporting base  291  is also moved upward. Upon receiving a detection signal from the photosensor  287 , the control unit  150  drives the motor  257  to move the transversely movable supporting base  260  so that the measuring pin  290  is oriented toward the center (in the direction of arrow D). Consequently, the pin  291   b  is disengaged from a space between the pins  296   a  and  296   b,  the roller  279  rolls on the guide  282 , and the measuring pin  290  remains raised at the top (at the measuring position). Accordingly, the measurement of the template  350  is effected in the state in which the measuring pin  290  is separated from the vertically moving mechanism including the motor  283  and the like, and in the state in which the measuring pin  290  is placed at the measuring position. 
     Upon completion of the measurement of the entire periphery of the template  350 , the transversely movable supporting base  260  is moved to its initial position under control by the control unit  150 . In this position, the roller  279  is disengaged from the guide  282 , and the pin  291   b  enters the space between the pins  296   a  and  296   b.  After the pin  291   b  entered the space between the pins  296   a  and  296   b,  the pin moving supporting base  291  and the measuring pin  290  are moved downward by the slight rotation of the arm  295  in the direction of arrow I with the motor  283  and by the self-weight of the pin moving supporting base  291 , thereby positioning the pin  290  at the retreated position. 
     Next, a brief description will be given of the case where the eyeglass frame is measured. After the frame is set on the frame holding section  200 , the switch on the switch panel section  410  is pressed to start tracing. In the case of both-eye tracing, the control unit  150  drives the motor  244  to move the transversely movable base  241  so that the feeler  280  is located at a predetermined position on the right frame side of the eyeglass frame. Subsequently, the vertically movable supporting base  265  is raised by driving the motor  270  to position the feeler  280  at the height of the reference plane for measurement. 
     Subsequently, the control unit  150  drives the motor  257  to move the transversely movable supporting base  260  so that the tip of the feeler  280  is inserted into the frame groove of the frame. During this movement, since a DC motor is used as the motor  257 , the driving current (driving torque) to the motor  257  can be controlled to provide a predetermined driving torque. Therefore, it is possible to impart a weak pressing force of such a degree that the frame in not deformed and that the feeler  280  is not dislocated. Subsequently, the pulse motor  254  is rotated in accordance with each predetermined unit number of rotational pulses to rotate the feeler unit  255  together with the rotating base  250 . As a result of this rotation, the transversely movable supporting base  260  together with the feeler  280  moves along the direction of the rail of the guide rail receiver  256   a  (in the direction of arrow F) in accordance with the radius vector of the frame groove, and the amount of its movement is detected by the encoder  258 . Further, the vertically movable supporting base  265  together with the feeler  280  moves in accordance with the warp (curve) of the frame groove vertically along the direction of the rail of the guide rail receiver  266  (in the direction of arrow G), and the amount of its movement is detected by the encoder  272 . The lens frame shape is measured from the angle of rotation θ of the pulse motor  254 , the amount r detected by the encoder  258 , and the amount z detected by the encoder  272 . 
     During the measurement the eyeglass frame as well, since the weight of the motor  283  for vertically moving the measuring pin  290  is not applied to the transversely movable supporting base  260 , the inertial force at the time of movement does not become large. Therefore, the tip of the feeler  280  moves along the frame groove without being dislocated from the frame groove, and the target lens shape of the lens frame is measured with high accuracy. 
     Upon completion of the measurement of the target lens shape in the above-described manner, the operator presses a data switch  421  on the switch panel section  420 , so that the target lens shape data is transferred to a data memory  161 , and the target lens shape is graphically displayed on the display  415 . By operating switches for data input arranged on the switch panel section  420 , the operator enters layout data such as the PD value of the wearer, the frame PD, and positional data on the optical center height. Further, the operator enters data on the processing conditions such as the material of the frame, lens material, and the like. Subsequently, the operator allows the lens LE to be chucked by the chuck shafts  702 L and  702 R to perform processing. 
     When a start signal is inputted by a start switch  423 , a main control unit  160  of the lens processing apparatus executes the lens shape measurement by using the lens-shape measuring section  500  in accordance with a processing sequence program. Subsequently, on the basis of the processing data obtained in accordance with the inputted data, the driving of the respective motors of the lens processing section  800  is controlled to move the carriage  701  transversely (in the X direction) and vertically (in the Y direction), and bring the lens LE into pressure contact with a rotating abrasive wheel of a group of abrasive wheels  602  for processing. 
     As described above, in accordance with the invention, in the measurement of the shape of the template or the dummy lens, the troublesome attachment and detachment of the measuring pin can be eliminated, and high-accuracy measurement can be effected. In addition, in the measurement of the eyeglass frame as well, the feeler is prevented from being dislocated from the frame groove, and the measurement accuracy is not impaired.