Abstract:
An eyeglass lens processing system, including: a data input unit, which inputs frame shape data for processing a lens to be fitted to an eyeglass frame and layout data for providing a layout of the lens with respect to a frame shape; a lens processing unit, having two shafts for clamping the lens, for grinding a periphery of the lens; a first conveying unit, which conveys a tray on which the lens is placed and to which a management code is applied, the management code interrelating the lens placed on the tray to the data inputted by the data input unit; a lens measuring unit, which obtains at least an optical center position of the lens; a second conveying unit that picks and holds the lens, disposes the lens at a predetermined position of the lens measuring unit, and mounts the lens to the shafts of the lens processing unit after measurement by the lens measuring unit; and an arithmetic unit, which obtains processing data based on: (1) data, read out based on the management code applied to the tray from the data inputted by the data input unit, and (2) measurement data obtained by the lens measuring unit, the arithmetic unit being connected to the lens processing unit.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to an eyeglass lens processing system for grinding a peripheral edge of a subject lens. 
     Conventionally, in a case where the peripheral edge of a subject lens is ground, processing is performed after a cup serving as a processing jig (a flared suction cup or the like) is attached to the optical center of the lens. A primary purpose of using the cup is to fix the lens so that the lens will not move due to the load applied from a grinding wheel during processing. The followings are other purposes. 
     When a monofocal lens is processed, a marked point is preliminarily applied to the optical center of the lens by using a lens meter, and the cup is attached to the lens through a cup attaching device, i.e., a so-called aligner, with that marked point used as a reference mark. Subsequently, a cup portion is mounted on a cup holder of a lens chuck shaft provided in a processing apparatus, and the lens is chucked to perform processing. As a result, the processing apparatus is able to effect processing while managing the relationship between the rotational center of the lens and the optical center thereof. 
     In contrast, to attach the lens directly to the processing apparatus without using the cup, it is necessary to attach the lens by aligning the marked point on the lens and the center of the lens chuck shaft, and it is extremely difficult to enable it in the light of the structure of the apparatus. 
     In recent years, processing centers have been established where the lens processing which has been conventionally performed by optical shops is performed intensively. The processing centers have come to perform large volumes of lens processing in a concentrated manner in response to requests from optical shops. In such processing centers, there has been a demand for automation of processing so as to effect processing efficiently by saving the trouble of the operator as much as possible. 
     However, as mentioned above, the lens processing requires, the above-described cup attaching operation as a preliminary step before the processing and the cup removing operation as a subsequent step after the processing, which has been a difficult factor in realizing the automation of processing. In addition, since these operations have been performed manually by the operator, the operating efficiency has been poor. 
     SUMMARY OF THE INVENTION 
     In view of the above-described problems of the conventional art, it is an object of the present invention to provide a processing system which makes it possible to effect processing while managing the relationship between the rotational center and the optical center (and the angle of the cylinder axis) of the lens during processing without using the cup as a processing jig. 
     According to one aspect of the present invention, there is provided: 
     An eyeglass lens processing system including: 
     a data input unit, which inputs frame shape data for processing a lens to be fitted to an eyeglass frame, and layout data for providing a layout of the lens with respect to a frame shape; 
     a lens processing unit, having two shafts for clamping the lens, the processing unit rotates the shafts synchronously for grinding a periphery of the lens, at least one of the shafts has an end to which is provided a holding portion for holding the lens by directly contacting the lens surface without a cup as a processing jig; 
     a first conveying unit, that conveys a tray on which the lens is placed and to which a management code is applied, the management code interrelating the lens placed on the tray to the data inputted by the data input unit; 
     a lens measuring unit, which measures at least an optical center position of the lens by detecting and processing an image of a measurement index; 
     a second conveying unit having a hand part for holding the lens and a moving unit for moving the hand part, wherein the second conveying unit picks and holds the lens from the tray using the hand part, disposes the lens at a predetermined position of the lens measuring unit, and mounts the lens to at least one of the shafts of the lens processing unit after measurement by the lens measuring unit; and 
     an arithmetic unit, which obtains processing data based on the management code applied to the tray from the data inputted by the data input unit. 
     The present disclosure relates to the subject matter contained in Japanese patent application No. Hei 10-275031 (filed Sep. 29, 1998). 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the accompanying drawings: 
     FIG. 1 is a diagram illustrating a schematic external view of an eyeglass lens automatic processing system in accordance with the present invention; 
     FIG. 2 is a diagram explaining the configuration of a lens conveying apparatus; 
     FIG. 3 is a diagram explaining the configuration of a distal end portion of a first hand; 
     FIG. 4 is a diagram explaining the configuration of a distal end portion of a second hand; 
     FIG. 5 is a diagram illustrating a measuring optical system and a control system of an eccentricity measuring apparatus; 
     FIG. 6 is a diagram explaining a method of detecting the position of an optical center of a lens LE; 
     FIG. 7 is a diagram explaining the configuration of the processing apparatus; 
     FIG. 8 is a diagram explaining the configuration of the distal end side of a chuck shaft of the processing apparatus; 
     FIG. 9 is a diagram illustrating a system configuration concerning the order for lenses from an optical shop as well as the acceptance of orders and control processing in the grinding process at a processing center where the eyeglass lens automatic processing system in accordance with the present invention is installed; and 
     FIG. 10 is a diagram explaining a method of determining processing data for correcting a portion of eccentricity of the optical center with respect to a rotational axis L 3 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Hereafter, a description will be given of an embodiment of the present invention with reference to the drawings. FIG. 1 is a diagram illustrating a schematic external view of the eyeglass lens automatic processing system in accordance with the present invention. The processing system includes a processing apparatus  100  for grinding an eyeglass lens; a tray conveying apparatus  500  for conveying trays  400 , on each of which a pair of left and right subject lenses are placed, to a predetermined delivering position; a lens conveying apparatus  200  for holding the lens to convey the lens between a tray disposed at the predetermined delivering position and the processing apparatus  100 ; and an eccentricity measuring apparatus  300  for detecting the optical center of the lens held by the conveying apparatus  200  and for measuring its eccentric position. Hereafter, the configurations of the respective apparatuses will be described in order. 
     &lt;Lens Conveying Apparatus&gt; 
     First, the configuration of the conveying apparatus  200  will be described with reference to FIGS. 2 to  4 . Reference numeral  201  denotes a conveying base which extends in parallel to the processing apparatus  100 , the measuring apparatus  300 , and the conveying apparatus  500 . An X-moving base  210  which moves in the left-and-right direction (in the X-direction) is mounted on a pair of rails  202  provided on the base  201 . A ball screw  204  is connected to a rotating shaft of a motor  203  attached to the base  201 , and a connecting block  211  fixed to a base  210  is threadedly engaged with the screw  204 . As the motor  203  is rotatively driven, the base  210  moves over the base  201  in the X-direction. 
     A Y-moving base  220  which moves in the back-and-forth direction (in the Y-direction) along two guide shafts  212  is mounted on the base  210 . A ball screw  215  connected to a rotating shaft of a motor  214  is threadedly engaged with a lower portion of the base  220 , and the base  220  moves in the Y-direction as the motor  214  is rotatively driven. A holder  222  having a first hand  230  for sucking and holding an unprocessed lens LE and a second hand  240  for sucking and holding a processed lens LE′ is mounted on the base  220  in such a manner as to be capable of swiveling, so that the holder  222  is adapted to swivel 180 degrees via an unillustrated gear by a motor  221  accommodated in the base  220 . The first hand  230  and the second hand  240  are held by the holder  222  in such a manner as to be movable in the vertical direction (in the Z-direction) by motors  231  and  241 , respectively. 
     A sucking base  232  is fixed to an end portion of the first hand  230 , and its distal end portion is formed substantially in a U-shape, as shown in FIG. 3, so as to secure a range of passage of a beam for measurement by the measuring apparatus  300  which will be described later. Further, three suckers  233  projecting downward for sucking the surface of the lens LE are provided on the sucking base  232  at equal intervals by using as a center a holding reference axis L 1  for the X-Y direction which the first hand  230  has. Each sucker  233  has a suction hole, and the suction hole communicates with a tube  235  through air passages formed inside the sucking base  232  and the first hand  230 . The tube  235  is connected to a pump unit  236  which effects the suction and delivery of air, and as the pump unit  236  is driven and sucks, the lens LE is sucked and held by the three suckers  233 , while as the pump unit  236  delivers air to the contrary, the suction and holding are canceled. 
     Meanwhile, a sucking base  242  is fixed to an end portion of the second hand  240 , and a flared sucker  243  projecting downward is provided on its distal end side by using as a center a holding reference axis L 2  for the X-Y direction which the second hand  240  has, as shown in FIG.  4 . This sucker  243  is also provided with a suction hole, through which the sucker  243  is connected to a pump unit  246  via a tube  245  in the same way as the first hand  230 , and the suction and holding of the lens LE′ by the sucker  243  and its cancellation are effected. 
     It should be noted that the mechanism for holding the lenses LE and LE′ may be arranged to nip the peripheral edges of the lenses. 
     &lt;Eccentricity Measuring Apparatus&gt; 
     A casing  301  of the measuring apparatus  300  has a substantially U-shaped side surface, and a measuring optical system and a control system shown in FIG. 5 are disposed in the casing  301 . In FIG. 5, reference numeral  302  denotes an illuminating light source;  303 , a collimator lens; and  305 , a screen plate formed of a semitransparent material (e.g., ground glass). Numeral  304  denotes an index plate with a predetermined pattern formed thereon, and the index plate  304  is supported by a supporting member  304   a  embedded in the screen plate  305  so as to be located approximately 15 mm above the screen plate  305 . The index plate  304  in this embodiment is arranged such that a grid index of black dots arranged at 0.5 mm-pitch intervals within the range of a 20-mm square by using as a center an optical axis L 0  of measurement by the collimator lens  303  is formed on the transparent glass plate. It should be noted that this index plate  304  may be disposed on the light source  302  side with respect to the lens LE which is mounted as shown in FIG. 5 at the time of measurement. Numeral  307  denotes a CCD camera. 
     The lens LE is held by the first hand  230  which the aforementioned conveying apparatus  200  has, and the lens LE is disposed with its X-Y direction positioned such that the reference axis L 1  of the first hand  230  becomes aligned with the optical axis L 0  of measurement. In addition, the heightwise direction (Z-direction) of the lens LE is set in such a manner as to assume a predetermined heightwise distance with respect to the index plate  304 . 
     The illuminating light from the light source  302  is converted to a substantially parallel beam of light by the collimator lens  303 , and is projected onto the lens LE. The light beam which passed through the lens LE further illuminates the index plate  304 , an image of the grid index subjected to the prismatic action of the refractive power of the lens LE is projected onto the screen plate  305 , and this image is picked up by the camera  307 . An image signal from the camera  307  is inputted to an image processing unit  311 , and the processing unit  311  processes the obtained image, detects the position of the index image, and inputs its detection signal to a control unit  310 . On the basis of the inputted detection signal, the control unit  310  determines the position of the optical center and the direction of the cylinder axis of the lens LE. 
     A description will be given of a method of determining the position of the optical center and the direction of the cylinder axis of the lens LE on the basis of the image obtained from the camera  307 . 
     In the case where the lens LE is not mounted, since the grid index of the index plate  304  is illuminated by the parallel beam of light, the index image is projected as it is onto the screen plate  305 . The control unit  310  stores in advance the coordinate positions of dot images at this time which are detected by the processing unit  311 . If the lens LE is mounted, the dot image located immediately below the vicinity of the optical center of the lens remains at the same position irrespective of the presence or absence of the lens, but the coordinate positions of the dots images at portions which are not at the optical center move due to the prismatic action of the lens. Accordingly, to detect the optical center, a change in the coordinate position of each dot image with the lens LE mounted with respect to the coordinate position of each dot image with the lens LE removed is examined, and the position from or toward which the dot images diverge or converge as the center is determined. Namely, the center of this divergence or convergence can be detected as the optical center. In the example shown in FIG. 6, for instance, since the coordinate positions of dot images P with the lens LE removed converge at P 0  as the center, the coordinate position of this P 0  can be detected as the optical center. Even if the optical center is located between dots, it suffices if the center of movement is determined by interpolating the center of movement on the basis of the moving directions of the dot images and the amounts of their movement. 
     According to such a method, the position of the optical center can be detected accurately irrespective of the powers of the lenses, and the amount of eccentricity with respect to the optical axis L 0  of measurement can be easily transformed into an absolute coordinate. 
     In a case where the lens LE has cylindrical power, the dot images move in a direction toward (or away from) a generating line of the lens. Hence, the direction of the cylinder axis can be similarly detected by examining in which direction the dot images are moving with respect to the coordinate positions of the dot images with the lens LE removed. 
     &lt;Tray Conveying Apparatus&gt; 
     In FIG. 1, the conveying apparatus  500  is constituted by a belt conveyor  501 , and the trays  400  on the belt conveyor  501  are consecutively moved in the direction of arrow A. The conveyance of the trays  400  is stopped at a predetermined position Q 1  where the acceptance and delivery of the lens LE (LE′) are effected by the conveying apparatus  200 . An ID tag  401  on which the work number of the pair of left and right lenses has been recorded is attached to each tray  400 , and the work number of the ID tag of the tray  400  stopped t the position Q 1  is read by an ID tag reader  502 . 
     &lt;Processing Apparatus&gt; 
     Next, a description will be given of the configuration of the processing apparatus  100  with reference to FIGS. 7 and 8. The processing apparatus  100  nips and holds the lens LE by means of an upper chuck shaft  111  and a lower chuck shaft  121  which extend vertically. The upper chuck shaft  111  is moved vertically by a chuck upper portion mechanism  110  provided in the center of a sub-base  102 , and is rotated by a pulse motor  113  attached to a holder  112 . A lens holder  115  is attached to a lower end of the upper chuck shaft  111  (see FIG.  8 ). 
     The lower chuck shaft  121  is rotatably held by a holder  120  fixed to a main base  101 , and is rotated by a pulse motor  123  in synchronism with the upper chuck shaft  111 . A sucking member  130  having a rubber-made sucking portion  130   a  is attached to an upper end of the lower chuck shaft  121  (see FIG.  8 ). The sucking portion  130   a  is formed in a flared shape whose central portion is concave, and a suction hole is provided in a central portion thereof, to which is connected a pump unit  135  for effecting the suction and delivery of air through an air passage  131  formed inside the lower chuck shaft  121 . After the lens LE is set on the sucking member  130  by the conveying apparatus  200 , the upper chuck shaft  111  is lowered, and the sucking operation of the pump unit  135  is started, thereby making it possible to hold the lens LE so that the lens LE does not move during processing. When the lens LE is removed, its suction and holding can be canceled by delivering air to the sucking member  130 . 
     The lens LE held by the upper and lower chuck shafts is ground from two directions by left and right lens grinding portions  150 R and  150 L each having a group of grinding wheels  151  (a plastic rough grinding wheel, a finishing grinding wheel having a beveling groove, etc.) on its grinding-wheel rotating shaft. The grinding portions  150 R and  150 L are bilaterally symmetrical, and are respectively moved vertically and horizontally by moving mechanisms provided on the sub-base  102 . 
     In addition, a lens measuring portion  160  is accommodated on a farther side in the center of the sub-base  102 , and the measuring operation of this measuring portion  160 , the movement of the grinding portions  150 R and  150 L, and the angles of rotation of the upper and lower chuck shafts are controlled on the basis of data inputted to the control unit  160  which will be described later. It should be noted that since the configuration excluding the lower chuck shaft portion is basically similar to the one disclosed in Japanese Patent Unexamined Publication No. 97445/1996 (U.S. Pat. No. 5,803,793) filed by the present applicant, reference is had to be made to this publication for details. 
     Next, the operation of the eyeglass lens automatic processing system having the above-described configuration will be described with reference to a system configuration diagram shown in FIG.  9 . FIG. 9 is a diagram illustrating the system configuration concerning the order for lenses from an optical shop as well as the acceptance of orders and control processing in the grinding process at the processing center where the processing system in accordance with the present invention is installed. 
     An ordering terminal  10  and an eyeglasses-frame measuring apparatus  11  are installed in the optical shop, and lens order data including the data on the eyeglasses frame shape measured by the apparatus  11 , layout data of the lenses for the eyeglasses frame (the pupillary distance of a client, the distance between geometric centers of the eyeglasses frame, the height of the optical center from the geometric center, etc.), the lens type, lens prescription data (spherical power, cylindrical power, angle of the cylinder axis), and the like are inputted online from the ordering terminal  10  to a host computer (hereafter, a host PC)  30  at the processing center through a public communication line  20 . 
     At the processing center, a work number is allotted to each of a multiplicity of pieces of order data inputted to the host PC  30 , and the work number is registered for the ID tag  401  on each tray  400 . A pair of left and right lenses LE of the specification read out from the host PC  30  is set on each tray  400  on the basis of the work number. At this time, each lens is set in such a manner that an approximate center of each lens is located at a predetermined point on the tray  400 . Subsequently, the trays  400  with the lenses LE set thereon are consecutively placed on the belt conveyor  501  of the conveying apparatus  500  (these steps may be performed by the operator, but if an arrangement is adopted in which the steps are automatically performed by a robot, further automation can be realized). 
     When the setting of the trays  400  is completed, a control unit  510  of the conveying apparatus  500  effects conveyance by operating the belt conveyor  501 , and when the tray  400  is brought to the predetermined position Q 1  for delivering and receiving the lenses, its movement is stopped. At this time, the work number on the ID tag  401  attached to the tray  400  is read by the reader  502 , and its signal is inputted to the host PC  30 . The host PC  30  transmits data concerning lens processing corresponding to this work number to the processing apparatus  100 . 
     Further, when the tray  400  is brought to the position Q 1 , the host PC  30  transmits an operation command signal to the conveying apparatus  200 . A control unit  250  of the conveying apparatus  200  conveys the lens LE to a position of measurement by the measuring apparatus  300  in the following manner by controlling the driving of each motor. First, the base  210  and the base  220  are moved so that the holding reference axis L 1  of the first hand  230  is brought to the predetermined point over the tray  400  where one lens LE is placed. Consequently, the optical center of the lens LE is located in the vicinity of the reference axis L 1  within the substantially U-shaped configuration formed in the sucking base  232 . Subsequently, the first hand  230  is lowered to the sucking position, and as the suction by the pump unit  236  is started, the lens LE (R) for the right eye is sucked and held by the three suckers  233 . 
     After the lens LE is thus held, the first hand  230  is temporarily raised, and the first hand  230  together with the holder  222  is then rotated through 180 degrees to cause the first hand  230  to be oriented on the measuring apparatus  300  side. Subsequently, the base  210  and the base  220  are moved, the lens LE is conveyed to the position where the holding reference axis L 1  of the first hand  230  is aligned with the measuring optical axis L 0  of the measuring apparatus  300 , and the lens LE is positioned at a predetermined height. This completes the disposition of the lens LE at the measuring position. 
     When the disposition of the lens LE is completed, a measurement starting signal is inputted from the host PC  30  to the measuring apparatus  300 , and the control unit  310  of the measuring apparatus  300  determines the optical center of the lens LE by the above-described method from the image of the index image obtained from the camera  307 , thereby obtaining eccentricity information with respect to the measuring optical axis L 0  (namely, this serves as information on the eccentric position of the first hand  230  with respect to the holding reference axis L 1 ). In addition, in a case where the lens LE has cylindrical power, the angle of the cylinder axis in the state in which the lens LE is held by the first hand  230  is obtained. The information on the eccentricity of the optical center (and the cylinder axial angle data) obtained by the control unit  310  is transmitted to the host PC  30 . 
     When the measurement by the measuring apparatus  300  is completed, the conveying apparatus  200  conveys the lens LE held by the first hand  230  up to the processing apparatus  100 . After the lens LE is placed such that a rotational axis L 3  of the chuck shaft of the processing apparatus  100  and the reference axis L 1  of the first hand  230  are aligned with each other, the lens LE is set on the sucking member  130  by the lowering operation of the first hand  230 . Subsequently, the suction on the first hand  230  side is canceled, and the rear surface side of the lens LE is sucked onto the sucking member  130  by the sucking operation of the pump unit  135 , thereby lowering the upper chuck shaft  111 . As a result, the lens LE is chucked in the state in which its state at the time of eccentricity measurement is maintained. The first hand  230  which canceled the suction of the lens LE is moved away from the processing apparatus  100 . 
     It should be noted that when the lens LE is set on the sucking member  130 , if the optical center of the lens LE is offset substantially from the rotational axis L 3  of the chuck shaft, there are cases where the accuracy of the processing shape is affected. As a countermeasure against this problem, it suffices if the host PC  30  determines whether the amount of eccentricity of the optical center obtained from the measuring apparatus  300  is within a predetermined range (e.g., 10 mm), and if the amount of eccentricity exceeds this range, the lens LE may be set by controlling the movement of the first hand  230  so as to correct that portion of eccentricity. 
     When the chucking of the lens LE is completed, the host PC  30  inputs the eccentricity information obtained by the measuring apparatus  300  to the processing apparatus  100  to start processing. The control unit  160  of the processing apparatus  100  determines processing data (this processing data may be obtained on the host PC  30  side) in which the portion of eccentricity of the optical center with respect to the rotational axis L 3  and a portion of offset in the angle of the cylinder axis are corrected, by incorporating the eccentricity information into the frame shape data, the layout data, the cylinder axial angle data of the lens prescription, and the like which have been inputted earlier. Namely, as shown in FIG. 10, the radial information (rn, θn) on the frame shape data using the geometric center F 0  of the frame shape as a reference is subjected to coordinate transformation using the rotational center G o  of the lens as a reference on the basis of the coordinate position of the optical center O 0  determined from the layout data with respect to the geometric center F 0  as well as the coordinate position of the rotational center G 0  of the lens determined from the eccentricity information with respect to this optical center O 0 , to thereby determine new radial information (r′n, θ′n) . In addition, the angle of the cylinder axis is determined by being transformed into radial information in which the frame shape is rotated about the optical center O 0  so as to correct the offset portion of the detected axial angle with respect to the axial angle data in the prescription. 
     Subsequently, on the basis of the determined processing data, the control unit  160  effects processing while controlling the rotational angle of the lens LE and the movement (axis-to-axis distance between the chuck shaft and the grinding wheel shaft and the axial position of the rotating shaft of the grinding wheel with respect to the lens LE) of the grinding portions  150 R and  150 L with respect to the lens LE. As a result, the lens LE is accurately processed to an intended shape without using a conventional cup as a processing jig. 
     It should be noted that, at the time of setting the lens LE at the position of chucking by the chuck shafts  111  and  121 , in addition to effect the setting as described above, the portion of eccentricity of the position of the optical center may be corrected by the control of X-Y movement of the first hand  230  (namely, such that the rotational center and the optical center of the lens are aligned with each other), or the frame center processing may also be effected such that the geometric center of the eyeglasses frame is aligned with the rotational center of the lens. 
     With respect to the rotational center of the lens, whether the reference axis L 1  of the first hand  230  is to be aligned, whether the optical center of the lens LE is to be aligned, or whether the geometric center of the eyeglasses frame is to be aligned may be selected in advance by the host PC  30 . Further, the host PC  30  may make the aforementioned determination and selection on the basis of the frame shape data and the layout data so that the processing shape will become stable. 
     In addition, in a case where a lens with an extremely eccentric layout or with a narrow vertical width is to be processed, if the lens is set as it is, there are cases where the chuck diameter of the processing apparatus  100  (the diameters of the sucking member  130  and the lens holder  115 ) projects outside the frame shape, causing interference in processing. In such a case as well, it suffices if the lens is set in such a manner as to avoid the interference in processing by offsetting the position of the lens chuck by controlling the X-Y movement of the first hand  230 . For instance, a selection is made as to which of the aforementioned positions the lens is to be set. 
     In the case where the lens LE is thus set by controlling the X-Y movement of the first hand  230 , the processing data is obtained on the host PC  30  side, and control of the movement is effected by the host PC  30 . 
     Upon completion of processing of the lens LE, a processing completion signal is transmitted to the host PC  30 . The host PC  30  causes the conveying apparatus  200  to operate again. The processed lens LE′ is conveyed by the second hand  240 . The second hand  240  is swiveled to the processing apparatus  100  side, and after the upper chuck shaft  111  on the processing apparatus  100  side has been raised, the second hand  240  moves to the position where the holding reference axis L 2  of the second hand  240  is aligned with the rotational axis L 3  of the chuck shaft. Subsequently, the suction on the lower chuck shaft  121  side is canceled, and the lens LE′ is sucked and held by the sucker  243  of the second hand  240 . After the lens LE′ is held, the lens LE′ is conveyed by the movement in the X-Y-Z direction and the swiveling motion of the second hand  240 , and is returned to the tray  400 . 
     When the processing of one lens is finished, the other lens is successively conveyed in a similar procedure, and processing is effected automatically. Thereafter, the conveyance and processing of the lens placed on each tray  400  is repeated automatically. 
     As described above, in accordance with the present invention, it is possible to effect processing accurately while managing the relationship between the rotational center and the optical center (and the angle of the cylinder axis) of the lens on the processing apparatus side without using the cup as a processing jig. As a result, the steps of the operation of inscribing a marked point on the lens by using the lens meter and the attachment and removal of the cup are made unnecessary, and automatic processing which saves the trouble of the operator can be effected very efficiently.