JP2005037224A - Conveyance device and conveyance method of lens - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable unmanned continuous operation of a lens processing line without imposing a large economical burden, and to enable undispersed uniform lens measurement, by enabling measurement of an external shape such as the diameter or the roundness of a lens before or after being processed on a processing line of the lens without installing an exclusive measuring device. <P>SOLUTION: This lens conveyance device is equipped with two driving sources (generally servomotors) 15, 16 controlled by an NC device 21 so that a conveyance head 14 can be moved successively on the two-dimensional plane on a work stand. A detection end for lens external shape measurement is provided on the conveyance head 14, and the processed lens or edges of centering plates sandwiching the lens are detected by the detection end 22, to thereby measure the external shape of the lens. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a lens conveyance device and a lens conveyance method provided in a lens processing line, and relates to a conveyance device and a conveyance method that enable measurement of the outer shape of a lens during lens conveyance.

  A lens processing line is provided with a lens outer periphery processing device, and a conveying device for carrying in and out the lens is provided in the outer periphery processing device. In general lens processing, first, the spherical surface of the lens is processed, and then the outer periphery of the lens is processed with reference to the optical axis determined by the spherical surface. An apparatus for processing the outer periphery of the lens is generally called a lens centering machine.

  In machining, it is unavoidable that machining errors occur due to tool wear or thermal deformation of the machine. Even when processing the outer periphery of a lens using a lens centering machine, it is necessary to inspect whether the error in the lens diameter and roundness is caused by changes in the grinding wheel wear and other processing conditions, and that the error falls within the allowable accuracy. There is.

  In a conventional general lens processing line, a sampled inspection of a processed lens is performed manually. In other words, the lens whose outer periphery has been processed with a centering machine is appropriately removed, the operator measures the diameter in multiple directions with a dial gauge, and the lens diameter and roundness are determined from the measured values to determine the pass / fail of the lens. Was.

On the other hand, a measuring apparatus that automatically measures the outer shape of a lens has also been proposed.
JP 62-137510 A

  In the conventional means of manually inspecting processed lenses by sampling inspection, there is a risk of scratching the lens and generating defective products during measurement work such as removing the lens and applying a dial gauge, processing and transporting the lens Even if it is automated, it is necessary to arrange a worker for the inspection of the lens, so it is difficult to operate continuously at night, and in manual measurement, the measurement value varies depending on the individual difference and skill level of the worker There was a problem such as.

  Such a problem can be solved by providing an automatic lens measuring device in the lens processing line. However, the installation of such a measuring device causes an increase in equipment costs and a lens processing unit cost. There is a problem of increasing.

  In addition, when measuring the outer shape of the lens at the lens processing position, it is necessary to hold the lens at the processing position during the measurement time, so there is a problem that a measurement waiting time is generated during the processing cycle and the processing efficiency is lowered. .

  The present invention provides a great economic advantage by providing a technical means that enables measurement of an outer shape such as a diameter and roundness of a processed lens before processing or on a lens processing line without providing a dedicated measuring device. It is an object to enable unmanned continuous operation of a lens processing line without causing a burden on the lens and to measure a uniform lens without variation.

  The present invention solves the above-described problems by providing a lens conveyance device that carries in and / or out a lens at a processing position of a lens processing machine to have a lens outer shape measuring function. The work table (stocker) of the lens processing machine is equipped with a large number of lenses, and the lens transport device provided in the lens processing machine reciprocates between the work table and the processing position of the processing machine. The lens is handed over to the processing position. Accordingly, since the lens conveying device of the lens processing machine needs to sequentially convey the lenses arranged on the work table, the conveying head 14 can be moved sequentially in a two-dimensional plane on the work table. In addition, two drive sources (generally servo motors) 15 and 16 controlled by the NC device 21 are provided.

  The present invention has been made by paying attention to the fact that the lens transport device provided in the lens processing machine has the above-described structure. The transport head 14 having the lens holder 20 and the transport head are the first. 1 and a numerically controllable drive source 15 and 16 for moving in a second direction substantially orthogonal to the first direction, and a numerical control device 21 for controlling these drive sources, and the lens In a lens transport device that is held by a lens holder and transports from the first position to the second position, the lens placed at a predetermined position on the transport head or the edge of the member 24 that contacts the lens is preferably a light beam. The numerical control device is equipped with detection means for detecting a position signal of each of the drive sources when the detection end detects the edge, and the detected position signal. Providing a conveying device of a lens and a calculating means for calculating a contour of the lens from the multivalued, is obtained by allowing to perform morphometric lens during transport of the lens by the lens conveying device.

  According to the lens transport method of the present invention realized by the above apparatus, the transport head 14 is moved and positioned in the first direction and the second direction substantially perpendicular to the first direction. The lens holder 20 and the detection end 22 for detecting the edge of the lens are attached to the lens holder 20, and when the lens placed at a predetermined position is transported to another position, the lens is held by the holder before the lens is held. The transport head 14 is moved so that the detection end crosses the predetermined position at least in the first direction and the second direction substantially orthogonal to the first direction, and the detection end detects the edge of the lens during the movement. In this case, the coordinate values of the two-dimensional coordinates of the transport head 14 are read, and the outer shape of the lens immediately before the transport is measured from the read coordinate values.

  According to a third aspect of the present invention, the lens transport method includes disposing a receiving base 23 having a centering plate 24 that clamps the lens in the radial direction in the moving region of the transport head 14. A detection end 22 for detecting the edge of the centering plate is mounted, a lens being transported is placed on the cradle, the lens is sandwiched by the centering plate, and the detection end is placed on the cradle on the centering plate. The transport head 14 is moved so as to cross in the clamping direction, and the coordinate value of the transport head 14 is read when the detection end detects the edge of the centering plate during the movement, and the coordinate value of the transport head 14 is read from the plurality of read coordinate values. The outer shape of the lens is measured, and then the lens is conveyed from the cradle 23 to a desired position.

  The lens outer shape measurement by the above method is performed on a cradle 23 that holds the outer periphery of the lens in a protruding state. Since the lens holders 5 and 6 provided at the processing position of the lens centering machine are smaller in diameter than the outer diameter of the lens, the outer shape of the lens can be measured by the above method on the lens holder. If time is taken, a processing cycle will be extended and processing efficiency will fall. If the lens can be measured on the work table, the processed lens can be immediately taken out to the work table and measured, so there is no risk of extending the processing cycle. Depending on the shape of the pallet being held, measurement is impossible or the lens posture is not stable, resulting in a large measurement error.

  One preferred method is to provide a cradle 23 for temporarily holding the lens in the middle of the transport path of the lens transport device, and immediately after processing the processed lens, it is unloaded from the processing position and placed on the cradle 23. An external shape is measured on the cradle. If the error is within the allowable range, the lens is carried out from the cradle 23 to the work table. If the error is outside the allowable range on the small diameter side (− side), the defective product box 25 The lens that is unloaded to the large diameter side (+ side) is supplied again to the processing position of the processing machine and reprocessed.

  According to such a structure in which the temporary cradle 23 is provided, since the lens can be measured during the outer periphery processing of the lens by the lens processing machine, there is no possibility of reducing the processing efficiency and the dedicated cradle 23 is provided. Therefore, the shape of the cradle 23 and the lens holding means can be most suitable for measurement. Since the conveyance of the lens onto the cradle 23 is performed by a lens conveyance device for supplying the lens to the processing machine, an increase in the apparatus cost is slight.

  The number of measurement points at the time of measurement varies depending on the accuracy required for the lens. If measurement of roundness is not required, the outer diameter can be measured by measuring three points on the outer periphery of the lens. When measuring through a centering plate provided with a V-shaped side, the outer diameter can be measured by detecting two points. When high-precision measurement is required for the diameter and roundness of each direction of the lens, it is necessary to take a large number of measurement points. The detection end 22 is caused to travel in a plurality of directions, and the lens is measured at a large number of measurement points. The edge coordinates need to be read.

  The detection end 22 is most preferably moved in the diameter direction of the lens to be measured, but the movement locus itself does not need to be so accurate. When the lens edge is directly detected and measured, it is important that the detected value of the two-dimensional coordinates at each detected point is accurate. For this purpose, it is preferable to read the two-dimensional coordinates when the edge of the lens is detected while moving the detection end 22 in a direction orthogonal to the edge of the lens to be measured.

  As a characteristic of the sensor, when the detection end 22 is moved in the direction toward the lens and when the detection end 22 is moved in the direction away from the lens, there is a deviation in the measured value. The correction value corresponding to the direction is obtained in advance, and the read coordinate value is corrected, or only the detection value when the detection end is moving in the direction correctly detected is used as the measurement data. Of course, it is necessary to take action.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view of a main part schematically showing an example of a lens centering machine provided with an XY type lens conveyance device. In the figure, 1 is a main part of the lens centering machine, and 2 is a main part of the lens conveying device. Reference numeral 3 denotes a processing position of the lens 4, and upper and lower work shafts 7 and 8 having cup-shaped lens holders 5 and 6 mounted on opposite ends enable the upper work shaft 7 to move up and down, and are provided on the same rotational axis. ing. The lens 4 carried into the processing position 3 is sandwiched between the upper and lower lens holders 5 and 6 by the downward movement of the upper work shaft 7, and is rotationally driven by the synchronous rotation of the upper and lower work shafts 7 and 8. The outer peripheral 4d is ground by the rotating grindstone 9 thus formed.

  A plurality of pallets 11 on which a large number of lenses 4 are mounted in a matrix are placed on a work table 10 provided adjacent to the work processing position 3. A fixed guide beam 12 is mounted above the right rear side in the drawing of the work table 10, and a base end of an arm 13 is mounted so as to be movable along the guide beam. The arm 13 is supported at the base end by the guide beam 12, extends forward toward the workpiece machining position 3, and a transport head 14 is mounted along the arm 13 so as to be movable. That is, the guide beam 12 is provided with a guide rail and a feed screw that is rotationally driven by the first servo motor 15 along its longitudinal direction, and the base end of the arm 13 is screwed with the feed screw, The first servo motor 15 reciprocates in parallel along the guide beam 12 by forward and reverse rotation. On the other hand, the arm 13 is provided with a guide rail and a feed screw that is rotationally driven by a second servo motor 16 along the longitudinal direction thereof. The motor 16 reciprocates along the arm 13 by forward and reverse rotation.

  Two lifting cylinders 17 are mounted in parallel on the front surface of the transport head 14 (the surface facing the workpiece machining position 3 side), and long and short fingers 18 and 19 that are individually moved up and down by each lifting cylinder are provided. ing. At the tip of each finger 18, 19 is attached a holder 20 that holds the upper surface of the lens by suction. One of the two holders 20 is for conveying the lens before processing, and the other is for conveying the processed lens. The reason why the two lens holders 20 are arranged in the longitudinal direction of the arm 13 with the fingers 18 and 19 being long and short is that the operation of picking up the processed lens from the processing position 3 and placing the lens before processing is carried out. This is because it is performed only by movement in the direction along the arm 13.

  The first and second servo motors 15 and 16 are controlled by the NC device 21, and the NC device 21 recognizes the position of the transport head 14 from the rotation amount from the origin of each servo motor 15 and 16. An optical fiber sensor 22 is mounted on the transport head 14 downward, and a signal from the optical fiber sensor is sent to the NC device 21.

  A pedestal 23 for temporarily placing the lens is provided in an appropriate position in the moving region of the lens holder 20 and in the moving region of the optical fiber sensor 22. The pedestal 23 has a structure capable of attracting the lens with a negative pressure if necessary, and is provided with a relative positional relationship with the processing position 3 in an accurate positional relationship. On both sides of the upper surface of the cradle 23, there are provided a pair of centering plates 24 with their V-shaped tip sides facing each other, and a cylinder (not shown) that opens and closes the centering plates synchronously. The lens on the cradle 23 is positioned at a fixed position on the cradle 23 by sandwiching the outer periphery with the centering plate.

  The illustrated apparatus includes two cradles 23 and four defective product boxes 25 so that two types of lenses having different diameters can be processed in parallel.

  Next, with reference to FIG. 2 thru | or 4, the external shape measurement of the processed lens by this invention is demonstrated. As shown in FIG. 2, the unprocessed lens 4 b is attracted by the lens holder 20 from the pallet 11 b on which the unprocessed lens is mounted, and is conveyed onto the cradle 23. The lens placed on the cradle 23 is centered by being pinched by the centering plate 24, is attracted to the lens holder 20 again, and is transported to the processing position 3. As shown in FIG. 2, the lens transported to the processing position is rotationally driven while being held between the upper and lower lens holders 5, 6 by the lowering operation of the upper work shaft 7. Peripheral machining. When the processing is completed, the upper work shaft 7 is moved upward, and the processed lens is conveyed onto the receiving table 23 by the lens holder 20. Since the lens to be processed is accurately centered at the lens processing position 3, if the relative positional relationship between the cradle 23 and the processing position 3 is set accurately, the servo motors 15 and 16 are controlled by the NC device 21. Thus, the processed lens 4a can be accurately placed on the cradle 23.

  After the processed lens 4a is placed on the cradle 23, the transport head 14 moves so that the optical fiber sensor 22 is on the cradle 23 as shown in FIG. Then, as shown in FIG. 4, the optical fiber sensor 22 is moved in the direction of the arrow in FIG. 4 by the movement of the transport head 14 under the control of the servo motors 15 and 16, and the movement locus and the edge of the processed lens 4a intersect. Thus, a lens edge detection signal is sent from the optical fiber sensor 22 to the NC device 21. Here, FIG. 4A is a diagram showing an example of measuring four points on the edge of the lens, and FIG. 4B is a diagram showing an example of measuring eight points. As described above, in order to perform highly accurate measurement, more measurement points are required. When a lens edge detection signal is output from the optical fiber sensor 22, the NC device 21 reads the coordinates of the transport head 14, thereby reading the relative positional relationship between the plurality of measurement points on the two-dimensional coordinates. be able to. The diameter and roundness of the lens 4a to be measured can be obtained by mathematical calculation from the relative two-dimensional coordinates of a plurality of measurement points.

  The centering machine shown in FIG. 1 is provided with a pair of centering plates 24 for centering the lens on the cradle 23. Therefore, the outer shape of the lens is measured with the lens sandwiched between the centering plates 24. It can also be done. FIG. 5 is a plan view showing an example thereof. The processed lens 4a placed on the cradle 23 is sandwiched between the opposite ends of the V-shaped centering plate 24, and the transport head 14 is placed in a direction parallel to the sandwiching direction. Move. As a result, the optical fiber sensor 22 moves in the direction of the arrow in FIG. 5, and a detection signal is sent from the optical fiber sensor 22 to the NC device 21 at the point where the movement locus and the edge of the centering plate 24 intersect.

  Practically, the intersection distance E on both sides is measured in advance with a master lens having an accurate outer shape and stored in the NC device, and the difference between the intersection distance when the processed lens 4a is measured and the stored value is calculated. Calculate the outer diameter error of the lens. If the apex angle of the V-shape of the tip side of the centering plate 24 is 120 degrees, the lens outer diameter error is obtained by multiplying the deviation from the stored value of the intersection interval E by the square root of 3, and dividing by 2. Become.

  By measuring the outer shape, a lens whose error is within an allowable range is carried out by the lens holder 20 to the processed lens pallet 11a. The defective lens that cannot be reprocessed is discharged to the defective product box 25 by the lens holder 20. By repeating such an operation while shifting the lens take-out position from the pre-processing lens pallet 11b by one pitch and shifting the carry-out position to the processed lens pallet 11a by one pitch, a large number of lenses can be processed. External shape measurement is performed.

  When the outer shape of the lens is extracted and inspected, for example, if there are 10 lenses, the processed lens is mounted on the receiving table 23 for every 10 and the measurement is performed. The lens for which measurement is not performed is returned directly from the processing position 3 to the processed lens pallet 11a. If the number of measurement points of the lens is increased, it is possible to measure the lens with high accuracy, but the measurement takes time. If a cradle for centering the lens before processing is provided separately from the cradle 23 for external measurement, the lens to be measured is placed on the cradle 23 until the lens to be inspected next is processed. Since it is possible to leave it in place, it is possible to reduce the machining efficiency even when the measurement time is longer than the machining time by dividing and measuring multiple measurement points using the time that the lens transport device is waiting for machining. It is possible to carry out a sampling inspection with high accuracy.

The perspective view which shows the principal part of an Example apparatus. Schematic side view showing lens conveyance in the apparatus of FIG. Side view of detection end and lens during lens measurement Plan view explaining the movement of the detection end during lens measurement FIG. 3 is a plan view for explaining measurement in a different mode from FIG.

Explanation of symbols

14 Transport head
15 1st servo motor
16 2nd servo motor
20 Holder
21 NC unit
22 Optical fiber sensor

Claims (3)

  A transport head (14) having a lens holder (20), and a numerically controllable drive source (15) for moving the transport head in a first direction and a second direction substantially orthogonal to the first direction. , 16) and a numerical controller (21) for controlling these drive sources, and a lens transport device for transporting the lens from the first position to the second position by holding the lens with the lens holder, A detection end (22) for detecting an edge of a lens placed in a predetermined position on the transport head or a member (24) abutting on the lens is mounted, and the numerical control device detects when the detection end detects the edge. A lens conveying apparatus, further comprising: detecting means for detecting a position signal of each of the driving sources; and calculating means for calculating the outer shape of the lens from a plurality of values of the detected position signal.   The conveyance head (14) moved and positioned in the first direction and the second direction substantially orthogonal to the first direction is equipped with a lens holder (20) and a detection end (22) for detecting the edge of the lens. When the lens placed at a predetermined position is transported to another position, the detection end moves the predetermined position at least in the first direction and the first prior to holding the lens by the holder. The transport head (14) is moved so as to cross in the second direction substantially orthogonal to the direction, and the coordinate value of the two-dimensional coordinates of the transport head (14) when the detection end detects the edge of the lens at the time of the movement is obtained. A method for conveying a lens, comprising: reading and measuring an outer shape of the lens immediately before conveyance from the plurality of read coordinate values.   A cradle (23) having a centering plate (24) that clamps the lens in the radial direction is disposed in a moving region of the transport head (14), and the lens holder (20) and the core are disposed on the transport head (14). A detection end (22) for detecting the edge of the centering plate is mounted, the lens being transported is placed on the cradle, the lens is sandwiched by the centering plate, and the detection end is centered on the cradle. The transport head (14) is moved so as to cross in the clamping direction, and the coordinate value of the transport head (14) when the detection end detects the edge of the centering plate during the movement is read, and the plurality of coordinates read A lens transport method, comprising: measuring an outer shape of a lens on a cradle from a value, and then transporting the lens from the cradle to a desired position.

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