Abrading – Precision device or process - or with condition responsive... – With indicating
Reexamination Certificate
2000-05-01
2001-12-04
Hail, III, Joseph J. (Department: 3723)
Abrading
Precision device or process - or with condition responsive...
With indicating
C451S042000, C451S044000, C451S384000
Reexamination Certificate
active
06325700
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to an eyeglass-frame-shape measuring device for measuring a lens frame shape such as a shape of a lens-fitting portion of an eyeglass frame, and an eyeglass-lens processing apparatus having the measuring device.
An eyeglass-frame-shape measuring device is disclosed, for instance, in U.S. Pat. No. 5,228,242. In the disclosed measuring device, a feeler is biased against the frame groove of a frame held by a frame holding section to be kept in contact with the frame groove, and the feeler thus kept in contact with the frame groove is moved along the frame groove. The measuring device obtains the information on movement of the feeler to measure the lens frame shape of the frame. The measuring device of this type uses an urging force of a spring to bias the feeler against the frame groove (i.e., in the direction of the radius vector of the frame shape (or the target lens shape)) in measurement.
However, the eyeglass-frame-shape measuring device suffers from the following problems.
(1) With the method of biasing the feeler using the spring, the spring expands and contracts depending on the radius vector of the frame, so that the urging or pressing force against the frame during measurement is not constant. To cope with frames of various shapes and eliminate the dislocation of the feeler from the frame groove during measurement, the force of a certain degree needs to be applied to the frame groove even in the state in which the spring is contracted (a portion whose length of the radius vector is long). If measurement is effected with the force of the spring thus determined, a large pressing force is applied to the frame groove in a portion whose length of the radius vector is short, which may causes deformation on a materially or structurally soft frame. To perform measurement without deforming the frame, it is desirable to apply such a pressing force as to be weak but not to cause the feeler to be dislocated, and to apply the pressing force to the frame groove constantly.
(2) With the method of biasing the feeler using of the spring, it is necessary to substantially horizontally maintain the holding of the frame by a frame holding section and a feeler moving mechanism section without tilting them, and therefore the degree of freedom in the layout of the device is restricted. Namely, if the feeler moving mechanism section is tilted, the pressing force of the feeler varies depending on the angular direction of the radius vector in measurement due to the effect of its own weight, so that the possibility of the deformation of the frame and the dislocation of the feeler from the frame groove becomes large.
(3) After the insertion of the feeler into the frame groove, the feeler is generally set in a free state so as to be movable vertically along the frame groove. Therefore, the feeler is likely to be dislocated in the case of a frame having large warp.
SUMMARY OF THE INVENTION
In view of the above-described problems of the background art, an object of the invention is to provide an eyeglass-frame-shape measuring device and/or an eyeglass-lens processing apparatus having the same, which makes it possible to reduce the possibility of deformation of the eyeglass frame and prevent the feeler from being dislocated from the frame groove in measurement.
Another object of the invention is to provide an eyeglass-frame-shape measuring device and/or an eyeglass-lens processing apparatus having the same, which has a high degree of freedom in the layout of the device.
The present invention provides the followings:
(1) An eyeglass-frame-shape measuring device for measuring a lens frame shape of an eyeglass frame, said device comprising:
holding means for holding the frame in a predetermined condition;
a feeler movable while being kept in contact with a frame groove of the frame held by the holding means;
measuring means for obtaining information on radius vector of the frame based on an amount of movement of the feeler;
first moving means having a first motor for moving the feeler in a direction of the radius vector of the frame;
control means for variably controlling driving of the first motor during measurement based on the information on the radius vector obtained by the measuring means.
(2) The device according to (1), wherein the control means estimates change of the radius vector of an unmeasured portion of the frame based on information on the radius vector of a measured portion of the frame, and variably controls the driving of the first motor based on the thus estimated change of the radius vector.
(3) The device according to (2), wherein the control means increases driving torque of the first motor if the radius vector of the unmeasured portion is estimated to be longer, and decreases the driving torque of the first motor if the radius vector of the unmeasured portion is estimated to be shorter.
(4) The device according to (1), further comprising:
circumferentially moving means for circumferentially moving the feeler while being kept in contact with the frame groove; and
first detection means for detecting an amount of movement of the feeler in the direction of the radius vector,
wherein the measuring means obtains information on the radius vector based on result of detection by the first detection means.
(5) The device according to (1), further comprising:
second moving means having a second motor for moving the feeler in a direction of warp of the frame, which is perpendicular to the direction of the radius vector,
wherein the measuring means obtains information on the warp of the frame based on an amount of movement of the feeler, and
wherein the control means variably controls driving of the second motor during measurement based on the information on the warp of the frame obtained by the measuring means.
(6) The device according to (5), wherein the control means estimates change of the warp of an unmeasured portion of the frame based on information on the warp of a measured portion of the frame, and variably controls the driving of the second motor based on the thus estimated change of the warp.
(7) The device according to (6), wherein the control means drives the second motor to move the feeler upward if the warp of the unmeasured portion is estimated to be changed upward, and drives the second motor to move the feeler downward if the warp of the unmeasured portion is estimated to be changed downward.
(8) The device according to (5), further comprising:
circumferentially moving means for circumferentially moving the feeler while being kept in contact with the frame groove; and
second detection means for detecting an amount of movement of the feeler in the direction of the warp,
wherein the measuring means obtains information on the warp based on result of detection by the second detection means.
(9) The device according to (1), wherein the holding means holds the frame along a measurement reference plane having a predetermined inclination with respect to a horizontal plane, the first motor is capable of moving the feeler in a direction along the measurement reference plane, and the control means variably controls the first motor during measurement based on a state of inclination of the measurement reference plane.
(10) An eyeglass-frame-shape measuring device for measuring a lens frame shape of an eyeglass frame, the device comprising:
holding means for holding the frame in a predetermined condition;
a feeler movable while being kept in contact with a frame groove of the frame held by the holding means;
measuring means for obtaining information on warp of the frame based on an amount of movement of the feeler;
moving means having a motor for moving the feeler in a direction of the warp of the frame, which is perpendicular to a direction of radius vector of the frame;
control means for variably controlling driving of the motor during measurement based on the information on the warp obtained by the measuring means.
(11) The device according to (10), wherein the control means estimates change of the warp of an unmeasured portion of
Kobayashi Masahiko
Matsuyama Yoshinori
Mizuno Toshiaki
Hail III Joseph J.
Nidek Co. Ltd.
Sughrue Mion Zinn Macpeak & Seas, PLLC
Thomas David B.
LandOfFree
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