DE19616572C2 - Method and device for measuring a spectacle frame or a spectacle lens or a shaped pane - Google Patents

Description

The invention relates to a method and an apparatus for Measuring a facet groove in an eyeglass lens opening Eyeglass frame or a predetermined, non-circular shape having spectacle lenses or a shaped disc in one CNC-controlled spectacle lens edge grinding machine with at least a grinding wheel and a rotatable, relative to the Radially and axially adjustable grinding wheel Spectacle lens holding shaft.

In European patent application 0 143 468 there is one Device for measuring an eyeglass frame described, the a spectacle frame holder in the area of a Spectacle lens holding shaft and a probe on the Has lens holder shaft. The glasses frame is fixed, while the probe rotates with the lens holder shaft. Accordingly, the probe is with respect to the axis of rotation  Eyeglass lens shaft can be moved radially.

Furthermore, it is described in this document that the Spectacle lens after pre-grinding and / or after finishing is measured with regard to its radius values, these measured Radius values in a computer to control the Spectacle lens edge grinding machine stored target values are compared and, if necessary, a correction is carried out if the shaped lens is still too big.

The one used to measure the pre-ground lens Device is a probe attached to an arm for the device Eyeglass lens shaft is pivoted. With this The probe can also be the space curves of the front edge and the Measure the rear edge of the shaped lens. Because of the arrangement and design of this known Devices for scanning an eyeglass frame and They are a pre-ground spectacle lens Devices with their transducers completely independent from the controller to the shape grinding of a lens Spectacle lens edge grinding machine and therefore very complicated built and operated.

In U.S. Patent 4,217,736 there is one Spectacle lens edge grinding machine in connection with a  Scanning device for an eyeglass frame described, in which the glasses frame clamped in a holder Drive connection with an eyeglass lens shaft and with this is rotated. One in the faceted groove of the glasses frame led stylus transmits its through the shape of the Glasses opening in the glasses frame caused during the rotation Deflection on a pen that outlines the contour of the facet groove on a base arranged on the lens holding shaft, the rotates with the eyeglass lens shaft. The on the Underlined contour of the eyeglass frame opening is then opto-electronically scanned and used to control the Shape grinding of the clamped in the lens holder shaft Glasses used.

In the German patent 33 48 102 a device for Scanning a glass opening of a spectacle frame or one of the Glass opening of a spectacle frame corresponding template Obtaining the outline shape of one in the glass opening reflecting glasses and into one Electronic data storage transferable data for control a spectacle lens edge grinding machine described by a a motor rotatable holder for the template, one through the Motor rotatable bracket for the glasses frame, one device for detecting the angle of rotation of the eyeglass frame or the  Template and a linearly moving probe for detecting the a radius of rotation assigned to a certain angle of rotation Glass opening in the glasses frame or the template has. This known device is in terms of the drive for the rotatable holder for the glasses frame and the template as well of the linearly moving probe from the Spectacle lens edge grinding machine in which the recorded data be entered, completely separate and proportionate complicated structure.

Methods and devices are also known with which it is checked whether a circular Lens blank of a given diameter is suitable, in the form of a frame corresponding to a selected frame Glasses to be cut.

In the European patent applications 0 206 860 and 0 363 281 described devices are devices for centering a lens blank and for attaching one Blocks or suction cups on the lens blank.  

In the device according to European patent application 0 206 860 is displayed on a flat screen Spectacle frame for glasses to be ground accordingly including the decentration values of the glasses wearer pictured. Then the circular one is selected Diameter lens blank on the screen like this hung up that its optical center with the optical The center of the lens to be ground coincides. It it is checked whether the image of the spectacle lens to be ground is on never protrudes beyond the circumference of the lens blank and, if not, it becomes a block or sucker attached to the lens blank. Then the Spectacle lens blank using the suction cup in one Spectacle lens holding shaft of a spectacle lens edge grinding machine clamped and in the given one, a selected one Glasses frame corresponding shape ground.

In contrast, in European patent application 0 363 281 a device for centering and attaching a block or Sucker on a lens blank described the one Screen on which there is a circular Spectacle lens blank with a selected diameter and a according to the shape of a selected eyeglass frame grinding lens with the decentration values of the Eyeglass wearer possibly the axis position of a prismatic or  cylindrical cut and / or the values of the position of a Let the near part be overlaid, so that an assessment it is possible whether the diameter of the selected Spectacle lens blanks for the shape of the one selected Spectacle frame for glasses to be ground is sufficient.

In this device, the lens blank is placed on one Carrier placed and according to the decentration values of the Glasses wearer, possibly the axis position of a prismatic or cylindrical cut and / or the location of a near part aligned and provided with a block or sucker to then in an eyeglass lens edge grinding machine to be edited.

With one in European patent application 0 160 985 described, CNC-controlled eyeglass lens grinding machine is testing whether a certain diameter having a circular lens blank in the shape of a selected glasses frame can be ground on one into a spectacle lens holding shaft of the spectacle lens edge grinding machine clamped spectacle lens blank performed in such a way that a feeler on the clamped lens blank lowered and in this way the radius of the clamped Spectacle lens blank is measured. This measured radius of the  Eyeglass lens blanks are included in the control of the Spectacle edge grinding machine entered data of the selected glasses frame to be ground accordingly Eyeglass lenses including the decentration values of the Glasses wearer, possibly the axis position of a prismatic or cylindrical cut and / or the values of the position of a Compared and checked whether the radius of the Eyeglass lens blanks at least equal to that for each angle value corresponding radius of the spectacle lens to be ground. Is this test is positive, the grinding of the Spectacle lens blanks in the selected shape without the To unclamp the spectacle lens blank.

In one from European patent application 0 603 074 Known device is testing whether the diameter of a Glass blank is sufficient to be in the shape of a Spectacle lenses for a selected spectacle frame to be grinded in such a way that the Spectacle lens blank into a spectacle lens holding shaft Eyeglass lens grinder clamped and on a stationary, but freely rotatable grinding wheel of the Eyeglass lens edge grinding machine is placed. On a free one There is a shaped disc at the end of the lens holder shaft, which is the perimeter contour of a selected eyeglass frame has glasses to be ground accordingly, and this  Shaped disc comes into contact with a contact shoe when the Radius of the shaped disc is the same in a certain angular position or greater than the radius of the shaft in the eyeglass lens clamped and resting on the grinding wheel Eyeglass lens blank. This creates an electrical contact closed, which triggers a signal, so that by a slow rotation of the lens blank and the shaped disc can determine whether and where the molded disc the contact shoe touched and can be judged from this signal whether the Diameter of the lens blank for grinding into one given form is sufficient.

In practice it has been shown that the devices for Scanning eyeglass frames in order to add a lot of data win that to control the shaping of a lens are usable, are complex, even if it is not to be separate from the lens edge grinding machine Fixtures, but around in the spectacle lens edge grinding machine integrated devices. This also applies if instead an eyeglass frame a shaped disc that already has the shape of the has to be ground to be scanned should.

Another problem also has a big problem in practice Meaning that occurs frequently. If a wearer of glasses  wants to change the eyeglass frame for purely aesthetic reasons, it is desirable - if the optical values of the for the Eyeglass wearers have not changed the required glasses have - the glasses of the old frame in the new one Use glasses frame. It also often happens that a damaged spectacle frame or a damaged spectacle lens in an eyeglass frame is taken, another Select glasses frame, the glasses of the damaged Glasses frame or the undamaged glasses from the old one However, to reuse the eyeglass frame.

Already cut into a predetermined, non-circular shape Reuse lenses for a selected lens can, however, has the condition that the radius of the existing glasses for at least the same for each angle value the corresponding radius of the spectacle lens to be ground and that there is a possibility for such an examination.

The invention is therefore based on the problem of a method and a device for measuring a facet groove in a Spectacle lens opening of a spectacle frame or one predetermined, out-of-round shape glasses or one To create a shaped disk with which these measurements can be carried out quickly, easily and without complicated additional equipment and if necessary check whether an eyeglass lens for regrinding in the shape of a selected, different glasses frame appropriate glasses is suitable.  

Based on this problem, a procedure is developed that consists of the following steps:

• - Clamp the glasses frame in one with the Spectacle lens rotating shaft, with respect to the Spectacle lens holding shaft fixed bracket or clamping the Glasses or the shaped disc in the lens holding shaft,
• - Insert one with a bearing for the grinding wheel largely rigidly connected, with respect to the grinding wheel fixed probe in the faceted groove of the glasses frame or placing the spectacle lens or the shaped lens on one largely rigid with the bearing for the grinding wheel connected, fixed with respect to the grinding wheel Measuring shoe,
• - Rotate the glasses frame or the glasses or the Shaped disc by means of the lens holder shaft, the Probe with the faceted groove or the measuring shoe with the Spectacle lens or the shaped lens are kept in contact,  
• - Recording the value pairs radius r _{n of} the facet groove or the spectacle lens or the shaped disc and angle of rotation (ρ _n ) of the spectacle lens holding shaft by means of a displacement sensor on a bearing for the spectacle lens holding shaft or on the bearing for the grinding wheel and an angle encoder on the spectacle lens holding shaft and
• - Transfer of the value pairs into the control of the Spectacle lens edge grinding machine.

The invention is based on the consideration that on a CNC-controlled spectacle lens edge grinding machine all elements for Recording the measured values, for storing these measured values, for Processing the measured values and controlling the shape grinding of an eyeglass lens are present and therefore the measurements particularly easy and fast and without additional effort have it carried out.

Because the grinding of a roof facet on a form-ground Eyeglass lens using a CNC controlled Eyeglass lens edge grinding machine in such a way that the Course of the space curve of the roof facet by a controlled Displacement of the glasses in the axial direction with respect to the Grinding wheel takes place, the spatial course of the Faceted groove or a roof facet on the circumference of one  measuring glasses by means of a Parallel shift of the spectacle lens holding shaft compared to the Position sensor for every angle of rotation record and to control the Glasses edge grinding machine transferred.

To a deformation of the glasses frame during measurement and / or Damage to the eyeglass lens or the Avoiding the shaped disk when measuring can affect the contact force of the probe in the facet groove or the one to be measured Glasses or the shaped disc on the measuring shoe during the Measuring process against the contact force during the Shape grinding process can be reduced.

On the other hand, to accelerate the measuring process, the Speed of the lens holding shaft higher during the measurement process than being during shape grinding.

The method of measuring a predetermined, out-of-round Shape glasses to check whether this Eyeglass lens for grinding into the shape of a selected, other glasses frame corresponding Glasses, can consist of the following steps:

• - Enter the data of a selected glasses frame  correspondingly to be ground glasses, the Decentration values of the glasses wearer, possibly the axis position a prismatic or cylindrical cut and / or the Values of the location of a near part in the control of the CNC controlled eyeglass lens grinding machine,
• - Clamping the glasses to be measured in the Spectacle lens holding shaft of the spectacle lens edge grinding machine,
• - placing the clamped spectacle lens on the measuring shoe,
• - turning the lens,
• Recording of the value pairs radius r _n and angle of rotation ρ _n and, if appropriate, also the parallel displacement z _n when the spectacle lens is rotated by means of the displacement and angle sensors,
• - Transfer the values to the control of the Spectacle lens edge grinding machine,
• - Compare these pairs of values with those in the controller entered data and values,
• - Check whether the radius values r _{n of} the measured spectacle lens are at any point on the circumference smaller than the corresponding radius values of the entered spectacle lens and
• - Grinding the spectacle lens into the specified shape if none of the radius values r _{n are} smaller than the corresponding radius values of the entered spectacle lens.

With the method according to the invention, this check is successful as quickly as possible using those on a CNC-controlled Glasses edge grinding machine already existing control and Sensors without the glasses to be measured, if it is appropriate to be manipulated.

Preferably, an image of the entered lens and the measured eyeglass overlaid on a screen are represented and can be checked on the basis of this representation.

It is also possible that the computer an acoustic or gives an optical warning signal if the measured lens is not is suitable in the form of a selected glasses frame appropriate glasses to be sharpened.

Finally, the data of the measured and the numerically display grinding glasses and  juxtaposition so that based on these numerical values a It is possible to assess whether the measured lens is suitable is in the shape of a selected eyeglass frame appropriate glasses to be sharpened.

Depending on the type of computer program for the CNC control, this can Spectacle lens to be measured, for example by means of a simple handling device without block or sucker between the Glasses holding shaft are used and clamped there, without it being important to exactly measure the spectacle lens to be arranged in the optical center. When measuring the Spectacles can namely the computer from the measured values Recognize the position of the lens and with the entered data for another, from the eyeglass to be measured compare the glasses to be sanded and the sanding according to the position of the lens to be measured control precisely after the computer has determined that the eyeglass lens to be measured is suitable for regrinding.

However, it is also possible to measure the spectacle lens in the to clamp the optical center in the lens holding shaft, so that the decentration values of the glasses wearer, possibly the Axis position of a prismatic or cylindrical section and / or the values of the location of a near part arithmetically be taken into account.  

It is also possible to decenter the eyeglass lens to be measured according to the decentration values of the eyeglass wearer, possibly the axis position of a prismatic or cylindrical section and / or the values of the position of a near part in the eyeglass lens holding shaft, so that the measured radius values r _n and angle values ρ _n are directly suitable for displaying the measured spectacle lens on the screen.

The method according to the invention is also suitable for a Dimensional accuracy of the ground lens afterwards to the measuring process checking the shape grinding process perform by re-fitting the shaped lens the support and, if it is still too large, one undergoes further finishing touches.

Based on the problem mentioned above, the further a device for measuring a facet groove in a spectacle lens opening of a spectacle frame or a predetermined, out-of-round shape glasses or one Shaped disc in a lens grinder with at least one grinding wheel, a rotatable one, relative to that Radially and axially adjustable grinding wheel Spectacle lens holding shaft, one with the spectacle lens holding shaft  rotatably coupled, with respect to the lens holding shaft fixed bracket for the glasses frame, one with a Bearing for the grinding wheel largely rigidly connected, fixed with respect to the grinding wheel, for engaging in the Facet groove can be used to measure the facet groove with regard to their radius value and possibly their axial value and / or at least one axially offset next to the grinding wheel arranged, fixed with respect to the grinding wheel, touching with a contour-cut lens interacting measuring shoe for measuring a shaped disk or the lens contour of the lens with respect to your Radius value and possibly the axial value of a roof facet on Spectacle lens, a travel sensor for recording the radius values of the Faceted groove of the glasses frame or the glasses or the Shaped wheel on the bearing for the grinding wheel or the Spectacle lens holding shaft, an angle encoder for receiving the Angle of rotation of the lens holding shaft, possibly a displacement sensor to Recording the axial values of the facet groove or the roof facet, a computer for storing the measured values and for controlling the Spectacle edge grinding machine proposed.

The only change to a CNC controlled Eyeglass lens edge grinding machine that is required to the To use the device according to the invention thus exists inside, a rotatable bracket for the glasses frame  to be provided which are rotatably coupled with the spectacle lens holding shaft, however, is fixed with respect to the lens-retaining shaft, and on a bearing for the grinding wheel with respect to the Fixed grinding wheel, for engaging in the facet groove of the eyeglass frame bring probe. The Measure the facet groove in the spectacle lens opening Eyeglass frame can then be used on a CNC-controlled eyeglass lens edge grinding machine anyway existing displacement and angle encoders as well as the calculator on simple Perform wisely and quickly.

A predetermined, non-circular shape is even easier measuring spectacle lens or a shaped disc, as it it is sufficient to clamp this in the spectacle lens holding shaft an axially offset next to the grinding wheel, fixed with respect to the grinding wheel, touching the Glasses interacting measuring shoe to put the measurement to be carried out in the same way as with the spectacle frame.

If the drives for axial and radial adjustment of the Spectacle lens holding shaft relative to the grinding wheel as well as to Rotating the lens holding shaft consist of stepper motors, can they also function as pathfinders and Fulfill angle encoders.  

It is also possible to go from the drives to the radial and axial adjustment of the lens holding shaft relative to the Grinding wheel and for rotating the lens holder shaft to provide independent position sensors and angle sensors.

The holder for the eyeglass frame can preferably be made from a rotatable on a with respect to the lens holder shaft fixed console axially parallel to the lens holder shaft and the grinding wheel arranged support ring with a central Opening through which one with storage for the Grinding wheel and with respect to this fixed probe tip in the faceted groove of the eyeglass frame held on the support ring intervenes.

A particularly simple structure of the device can be reach if the support ring is coaxial to the lens holding shaft and the probe tip are arranged on an arm, the arm in a space between the console and the storage for the grinding wheel protrudes.

To deform the eyeglass frame to be measured or Grinding marks on the spectacle lens to be measured and one to avoid the resulting falsification of the measurement results, can interact with the drive and with regard to its transmissible torque adjustable clutch and a die  Coupling in terms of its torque to accommodate the radius and Angle values of the spectacle frame or the spectacle lens or the mold switching device can be provided.

If the grinding wheel with its drive can be moved on one Cross slide relative to the rotatable in the machine frame arranged glass holding shaft is arranged, the Arrange the position sensor so that it adjusts the displacement of the Cross slide in the machine frame with reference to the contour of the Faceted groove or the contoured lens or measure the shaped washer.

Since the cross slide in the machine frame outside one Coolant and the pan collecting the abrasion is arranged, the transducers are not by the im Area of the grinding wheels of the spectacle lens to be ground prevailing atmosphere adversely affected.

Analogously, the transducers can also be Arrange the glass holding shaft if it is relative to the machine frame axially and radially movable to the rotating grinding wheel only is stored to the data of the glasses frame or the Measure glasses or the shaped lens. Preferably leaves use a digital sensor, whose measured values direct to the computer and processed there.  

Based on the problem mentioned above, a device for measuring a predetermined non-circular shape spectacle lens on a spectacle lens edge grinding machine with at least one grinding wheel, a rotatable, radially and axially adjustable spectacle lens holding shaft is proposed, the at least one axially offset next to the grinding wheel arranged with respect to the grinding wheel, in contact with a circumferentially contour-ground spectacle lens measuring shoe for measuring the lens contour of an eyeglass lens with respect to the radius values r _n and possibly the axial values z _{n of} a roof facet on the eyeglass lens, the eyeglass lens grinding machine having at least one computer with a device for controlling the axial position of the spectacle lens holding shaft with the spectacle lens relative to the grinding wheel in accordance with the axial course of the spectacle lens contour and for converting the spectacle Englases on the measuring shoe, an input device for entering the data of a spectacle lens to be ground according to a selected spectacle frame, the decentration values of the spectacle wearer, possibly the axial position of a prismatic or cylindrical ground section and / or the values of the position of the near part with a memory and a displacement sensor for Recording the radius values r _n and possibly a displacement sensor for recording the axial values z _{n of} the spectacle lens and the computer compares the desired values of the radius values of the spectacle lens to be ground with the measured actual radius values r _{n of} the spectacle lens and only then a grinding process triggers if the radius values r _{n of} the measured spectacle lens are at no point smaller than the corresponding radius values of the entered spectacle lens to be ground.

The measuring shoe can preferably be placed next to the grinding wheel be arranged a bearing neck for the shaft and one cylindrical circular section and possibly a faceted groove as Support with a diameter of the grinding wheel have the appropriate diameter.

The invention is described below with reference to a drawing illustrated embodiment of the closer explained. In the Show drawing:

Fig. 1 is a schematic front view of a spectacle lens edge grinding machine according to the invention with sectional view of a device for measuring the bevel groove in the lens opening of a spectacle frame,

Fig. 2 is a schematic side view, partially in section, of the spectacle-lens edge grinding machine according to Fig. 1,

Fig. 3 is a schematic sectional view of a spectacle lens edge grinding machine according to the invention showing their Meßschuhs and transducer,

Fig. 4 is a perspective view of a splash guard surrounding the grinding wheels of the machine with a measuring shoe and an eyeglass lens holding shaft arranged in front thereof with an eyeglass lens to be measured and

Fig. 5 a connected to a computer screen showing a to be measured and a to be ground spectacle lens.

The spectacle lens edge grinding machine shown in FIG. 1 has a housing 13 with a grinding chamber 38 , in which a pre-grinding wheel 11 with a cylindrical circumference and two facet grinding wheels 12 with facet grooves are arranged on a shaft 10 . Arranged parallel to the shaft 10 with the grinding wheels 11 , 12 is a spectacle lens holding shaft composed of two halves 14 , 14 a, of which the half shaft 14 can be axially displaced by means of a handle 37 in order to clamp a spectacle lens blank 35 . On the half shaft 14 , a holding head 36 is arranged, the z. B. can be made of rubber to hold the lens blank 35 securely during grinding against twisting and moving. The grinding chamber 38 is closed during the grinding process by means of a hinged cover, not shown.

For grinding the shaft 10 with the grinding wheel 11 is offset 12 in a fast rotation while rotating slowly by the spectacle lens holding shaft 14, 14 a lens blank held 35th The distance between the spectacle lens holding shaft 14 , 14 a from the shaft 10 with the grinding wheels 11 , 12 is controlled by a computer 16 by storing control data for grinding the spectacle lens blank 35 in accordance with the shape of a selected spectacle frame. An input keyboard 39 and a screen 40 are also arranged on the housing 13 . Using the input keyboard 39 , stored spectacle lens contours can be called up in a known manner and sent to the control of the spectacle lens edge grinding machine for processing the spectacle lens.

Furthermore, it is possible to enter 39 personal data of the glasses wearer using the input keyboard, e.g. B. the pupil distance, the axial position of a cylindrical or prismatic cut of the lens or the position of a near part.

The screen 31 serves to display the entered data. Furthermore, the circular eyeglass lens blank 35 and / or an eyeglass lens 24 , 25 shaped according to the entered data can be displayed on the screen 31 .

A bracket 41 , shown in section, is fastened to the side of the housing 13 and serves as a carrier for a rotatable spectacle frame support ring 45 . A spectacle frame 51 can be fastened to the spectacle frame support ring 45 by means of clips 46 , which can be clamped by means of knurled nuts 47 . An opening 42 in the eyeglass frame 45 allows a probe tip 44 attached to an arm 43 to be guided up to a facet groove 52 in an eyeglass lens opening 53 of the eyeglass frame 51 in order to scan this facet groove 52 , as is described in detail with reference to FIG. 2 .

The eyeglass support ring 45 is via a gear 48 , which is arranged on a shaft 49 , via a drive connection 50 , the z. B. may consist of a toothed belt, rotated by the support shaft 14 a, so that there is a clear relationship between the angular position 15 recorded by the angle encoder of the lens holder shaft 14 , 14 a and the angular position of the eyeglass frame of the support ring 45 .

With reference to FIG. 2 it can be seen that a cross slide is arranged on a machine frame 1 , the slide part 3 of which has guide rods 4 , which in bores 5 of lugs 6 of a slide part 7 radially to the spectacle lens holding shaft 14 , 14 a with one of them held, to be measured glasses 25 are slidably mounted.

The slide part 7 is displaceably arranged on guide rails 8 on the machine frame 1 in a direction parallel to the spectacle lens holding shaft 14 and a shaft 10 for a pre-grinding wheel 11 and a finishing and / or facet grinding wheel 12 arranged coaxially therewith.

The shaft 10 is supported on the slide part 3 by means of bearing supports 9 . The grinding wheels 11 , 12 with their shaft 10 and the spectacle lens holding shaft 14 , 14 a are surrounded by the housing 13 , which has a tub, not shown in detail below, which prevents coolant and grinding abrasion from the grinding chamber 38 into the area of the cross slide 2 reached.

A displacement sensor 17 is arranged on the slide part 7 and absorbs the radial displacement of the slide part 3 with respect to the spectacle lens holding shaft 14 , 14 a. This displacement sensor 17 is connected to the computer 16 .

The radial displacement of the slide part 3 is brought about by a drive motor 18 which is controlled by the computer 16 via control lines 21 and which is in drive connection with the guide rods 4 via an electromagnetic clutch 19 .

In a target value memory 20 , circumferential contour values for the most varied lens shapes can be entered and stored as polar coordinates.

To grind a predeterminable spectacle lens circumference contour 24 , a circular spectacle lens blank 35 is clamped into the spectacle lens holding shaft 14 , 14 a and brought into contact with the pre-grinding disc 11 . The contact pressure that arises from the setting of the electromagnetic clutch 19 and can be set differently depending on various parameters, for. B. for spectacle lenses made of plastic or silicate glass or according to the edge thickness of the spectacle lens depending on the optical values of the spectacle lens 25 .

The spectacle lens 25 is rotated with its shaft 14 , 14 a in a known manner, the speed of rotation usually being at 10 to 13 rpm. The angle encoder 15 transmits the computer 16 at equal angular intervals, for. B. in increments of 6 ° a pulse, which causes the computer 16 to set the associated radius to be ground of the peripheral contour 24 via the drive motor 18 . During the grinding of the peripheral contour 24 on the roughing wheel 11, the slide member 7 and thus the grinding wheel 11 in an oscillating movement are offset parallel to the axis of rotation of the spectacle lens 25, which is respectively reversed in the opposite direction at the edge of the roughing. 11 This movement is controlled by a drive, not shown, for the slide part 7 , which is also connected to the computer 16 .

On both sides of the pre-grinding wheel 11 , ring segments 23 are arranged, which are fastened to a splash guard 22 which surrounds the pre-grinding wheel 11 and the finished grinding wheel 12 and is only open in the area of contact with the spectacle lens 24 . The ring segments 23 form a probe and are connected to a sensor 26 shown schematically in FIG. 4, which in turn is connected to the computer 16 via a control line 27 . The oscillating movements of the slide part 7 and thus of the grinding wheels 11 , 12 and the surrounding protection 22 are controlled by the sensor 26 in the manner described in German Patent 38 42 601 and at the same time serve to measure the circumferential contour 24 with respect to the spatial curve of the front and back and the glass thickness to be measured. These measured values are used to grind a facet to the circumferentially contoured spectacle lens by means of the finished grinding wheel 12 , the course of which can be controlled by the computer 16 .

The axial movement of the grinding wheels 11 , 12 is detected by the slide part 7 by means of a displacement sensor 54 and passed on to the computer 16 .

Before the grinding is carried out in this way, the contour of a spectacle lens opening 53 in a spectacle frame 51 is first determined by fastening it to the spectacle frame support ring 45 by means of the clamps 46 and the knurled nuts 47 . The arm 43 with the probe tip 44 is attached to a bearing neck 28 for the shaft 10 on the bearing support 9 and therefore with the bearing support 9 both in the direction of the guide rods 4 , ie in the X direction and in the direction of the guide rails 8 , ie in Z Direction movable and therefore follows the facet groove 33 when the spectacle frame 51 is rotated with the spectacle frame support ring 47 . As already mentioned, this rotation is transmitted via the drive connection 50 , the shaft 49 and the gear 48 from the spectacle lens holding shaft 14 , 14 a, so that a single amount of rotation of the spectacle frame 51 results in a data volume r _n , z _n and ρ _n , which represents the spatial curve of the facet groove 52 of the spectacle lens opening 53 in the spectacle frame 51 . The values recorded by the displacement sensors 17 , 54 and the angle sensor 15 reach the computer 16 , are stored there and can be used for grinding an eyeglass lens blank 35 according to the shape of the eyeglass frame.

Before this form grinding is carried out, the spectacle frame is of course released from the spectacle frame support ring 45 in order not to hinder the grinding process.

When shaping an eyeglass lens, the same displacement sensors 17 , 54 and the angle transmitter 15 are used to control the drives for the corresponding movements of the grinding wheel 11 , 12 and the rotation of the eyeglass lens holding shaft 14 , 14 a in accordance with the recorded data.

If, instead of the grinding wheel 11 , 12, the spectacle lens holding shaft 14 , 14 a is mounted so that it can be moved radially and axially, the measuring process proceeds in the same way, only the displacement and angle sensors are then located on the guides for the spectacle lens holding shaft 14 , 14 a.

From Fig. 2 it can be seen that the spectacle frame support ring 45 is arranged coaxially to the spectacle lens holding shaft 14 , 14 a. Since a drive connection is required anyway between the spectacle lens holding shaft 14 , 14 a and the spectacle frame support ring 45 , the spectacle frame support ring 45 can also be used elsewhere, e.g. B. be arranged coaxially to the shaft 10 of the grinding wheels 11 , 12 or at any point between the spectacle lens holding shaft 14 , 14 a and the shaft 10 , however the spectacle frame support ring 45 with the bracket 41 must always be fixed with respect to the spectacle lens holding shaft 14 , 14 a.

If a pre-ground spectacle lens 25 or a shaped disk is to be measured, it is clamped between the half-shafts 14 , 14 a and placed on a measuring shoe 29 which is fastened to a bearing neck 28 of the bearing support 9 by means of fastening screws 30 and a cylindrical measuring surface with the radius 11 , 12 has.

In order to be able to determine the spatial course of a roof facet 34 on the spectacle lens 25 by absorbing the axial displacement of the spectacle lens holding shaft 14 , 14 a, the measuring shoe 29 has a facet groove 33 into which the roof facet 34 can be inserted without play. When the spectacle lens holding shaft 14 , 14 a is rotated with the spectacle lens 25 , the radius values r _n , the axial values z _n and the corresponding angle values ρ _n are thus recorded by the displacement transducers 17 , 54 and the angle encoder 15 and entered into the computer.

This data can then be used to grind spectacle lenses of the same shape or to grind the measured spectacle lens 25 onto a spectacle lens contour entered into the computer and to be ground in accordance with a selected spectacle frame.

In order to be able to check whether this regrinding is possible, the circumferential contour of the measured spectacle lens 25 is displayed on this screen on a screen 31 connected to the computer 16 , which furthermore (shown in dashed lines) provides an image of the circumferential contour 24 entered, which is the target Value memory 20 is stored and is superimposed on the measured spectacle lens 25 . On the screen 31 are a coordinate system of the X axis and the Y axis, the optical center 32 of the measured spectacle lens 25 and the spectacle lens 24 to be ground, and the decentration values e _x , e _y with reference to the X axis and the Y axis shown. From the display on the screen 31, it can be seen immediately whether the radius of the spectacle lens 24 to be ground at any point exceeds the radius of the measured spectacle lens 25 or not. In the example shown, this is the case in the area of the upper right and lower quadrants, so that it results that the existing spectacle lens 25 is not suitable for being cut into a different shape.

On the other hand, it follows from this representation that the entire circumferential contour of the spectacle lens 24 to be ground is within the circumferential contour of the measured spectacle lens 25 , the grinding process can be initiated by first converting the measured spectacle lens 25 onto the pre-grinding wheel 11 and there into a circumferential contour corresponding to that to be sharpened spectacle lens 24 .

With regard to its optical center 32 , the spectacle lens 25 to be measured can be centered in the spectacle lens holding shaft 14 if the decentration values are taken into account by the computer 16 . It is also possible to clamp the spectacle lens 25 to be measured already with the decentration values e _x , e _y in the spectacle lens holding shaft 14 . In both cases, the image of the measured spectacle lens 25 appears decentered on the screen 31 in the same way as the image of the spectacle lens 24 to be ground, which, together with all data, including the decentration values of the spectacle wearer, possibly the axis position of a prismatic or cylindrical cut, and / or the values of the location of a near part were entered into the computer 16 .

Even if the spectacle lens 25 is clamped relatively imprecisely into the spectacle lens holding shaft 14 , 14 a, the computer 16 is able, on the basis of the measured values recorded, to assign the measured data to the stored data and to display the images on the screen with precise angles.

The decision of whether it is a predetermined, non-circular shape having spectacle lens in the shape of a selected one Spectacle frame for glasses to be ground can be looped around, even without representation on a Screen done by a signal that is acoustic or visual gives an indication of whether regrinding is possible or not.

Furthermore, instead of or in addition to the screen display, it is possible to numerically specify the values and the angular position of those radius regions of the spectacle lens 24 to be ground, which extend beyond the circumferential contour of the measured spectacle lens 25 , in order to be able to decide whether a slight change in the decentration values e _x , e _y a regrinding is made possible.

After the eyeglass lens contour has been ground according to the illustration in FIG. 1 by means of the pre-grinding disk 11 , the eyeglass lens is automatically converted onto the finish grinding disk 12 and positioned precisely in relation to the facet groove. The spectacle lens has sufficient machining allowance for finish grinding.

After the final grinding, the spectacle lens, which is re-cut onto the circumferential contour 24 , controlled by the computer 16 , is again placed in the correct position on the measuring shoe 29 . The computer 16 determines which point of the spectacle lens 24 is put on using input commands. In the simplest case, it is sufficient to carry out a single distance measurement, determine the deviation of the actual value from the corresponding target value, which is stored in the target value memory 20 , for this point, and one by the computer 16 when a predeterminable deviation is exceeded carry out another fine adjustment with correction of this deviation. This method with detection of only one measuring point presupposes that the deviations on the entire circumferential contour are essentially the same everywhere.

More precise is a re-measurement carried out over a complete revolution of the spectacle lens 24 with contact with the measuring shoe 29 . The distance values of the spectacle lens re-grinded onto the peripheral contour 24 are recorded by means of the measurement sensor 17 and fed into the computer 16 , where the comparison with the target values is carried out.

The most accurate measurement is obtained when the roof facet is inserted into the facet groove 53 in the measuring shoe 29 after the final grinding, which is then also measured the axial component z _n caused by the spatial profile of the roof facet.

If the comparison of the actual values with the target values results in an impermissible deviation on the contour of the spectacle lens circumference, then the computer 16 can either average this deviation over the circumference and set a corrective grinding according to this mean value or the deviations are registered point by point with the corresponding target values are compared, whereupon the correction grinding is carried out only where a deviation has actually occurred.

Of course, the circumferential contour 24 of the re-sharpened spectacle lens can be remeasured after the pre-grinding on the pre-grinding disc 11 . This is advantageous if the pre-grinding wheel 11 wears out faster than the fine grinding wheel 13 . Possibly. it is then no longer necessary to measure the circumferential contour again after finishing. However, even after the final sanding, the circumferential contour can be remeasured and, if necessary, corrected.

The machine according to the invention is a fully automatic CNC-controlled spectacle lens edge grinding machine. In these spectacle lens edge grinding machines, the stored nominal values of the peripheral contour serve to control the cross slide 2 carrying the grinding wheels 11 and 12 in such a way that the required spectacle lens peripheral contour 24 is created directly.

When measuring a spectacle frame 51 or the spectacle lens 25 before grinding or after grinding the entered circumferential contour 24 , the rotational speed of the spectacle lens holding shaft 14 can be increased in order to be able to carry out the measurement more quickly. A control command can be given to the clutch 19 via the computer 16 , which reduces the contact pressure during measurement compared to the grinding pressure, so that deformation of the spectacle frame 51 or wear or scoring on the measuring shoe 29 or on the circumference of the spectacle lens is avoided.

Of course, the invention can be done in an analogous manner can also be used with an eyeglass lens grinding machine where the grinding wheels only turn, but are otherwise stationary, while the eyeglass lens shaft is radially and axially movable is stored with respect to the grinding wheels.

Claims (20)

1. A method for measuring a facet groove in a spectacle lens opening of a spectacle frame or a spectacle lens or a shaping disc having a predetermined, non-circular shape in a CNC-controlled spectacle lens edge grinding machine with at least one grinding wheel, a rotatable, relative to the grinding wheel radially and axially adjustable spectacle lens holding shaft with the steps :

• - Clamping the spectacle frame in a holder which is rotatably coupled to the spectacle lens holding shaft and is fixed with respect to the spectacle lens holding shaft, or clamping the spectacle lens or the shaped disk in the spectacle lens holding shaft,
• Inserting a probe, which is largely rigidly connected to a mounting for the grinding wheel and is fixed with respect to the grinding wheel, into the facet groove of the spectacle frame or fitting the spectacle lens or the shaped disk onto a measuring shoe which is largely rigidly connected to the mounting for the grinding wheel and fixed with respect to the grinding wheel,
• - Rotating the spectacle frame or the spectacle lens or the shaped disc by means of the spectacle lens holding shaft, the probe head with the facet groove or the measuring shoe being held in contact with the spectacle lens or the shaped disc,
• - Recording the pairs of values radius (r _n ) of the facet groove or the spectacle lens or the shaped disc and angle of rotation (ρ _n ) of the spectacle lens holding shaft by means of a displacement sensor on a bearing for the spectacle lens holding shaft or on the bearing for the grinding wheel and an angle encoder on but the spectacle lens holding shaft and
• - Transfer of the value pairs into the control of the spectacle lens edge grinding machine.

2. The method according to claim 1, characterized in that in addition to the pair of values (r _n ) and (ρ _n ) also the spatial profile of the facet groove or a roof facet on the circumference of the spectacle lens by means of a parallel displacement (z _n ) of the spectacle lens holding shaft relative to the grinding wheel receiving encoder for each angle of rotation (ρ _n ) is recorded and transmitted to the control of the lens edge grinding machine. 3. The method according to claim 1 or 2, characterized in that the contact force of the probe in the faceted groove or the measuring glasses or the shaped disc on the  Measuring shoe during the measuring process against the contact force is reduced during the form grinding process. 4. The method according to claim 1, 2 or 3, characterized in that the speed of the lens shaft during the Measuring process is higher than during the form grinding process. 5. The method according to one or more of claims 1 to 4 with the steps:

• Entering the data of a spectacle lens to be ground in accordance with a selected spectacle frame, the decentration values of the spectacle wearer, possibly the axis position of a prismatic or cylindrical grinding and / or the values of the position of a near part in the control of the CNC-controlled spectacle lens edge grinding machine,
• Clamping the spectacle lens to be measured in the spectacle lens holding shaft of the spectacle lens edge grinding machine,
• - placing the clamped spectacle lens on the measuring shoe,
• - turning the lens,
• Recording the value pairs radius (r _n ) and angle of rotation (ρ _n ) and possibly also the parallel displacement (z _n ) when rotating the spectacle lens by means of the displacement and angle sensors,
• - transfer of the values into the control of the eyeglass lens grinding machine,
• - comparing these value pairs with the data and values entered into the control,
• - Check whether the radius values (r _n ) of the measured spectacle lens are at any point on the circumference smaller than the corresponding radius values of the entered spectacle lens and
• - Grinding the spectacle lens into the specified shape if none of the radius values (r _n ) are smaller than the corresponding radius values of the entered spectacle lens.

6. The method according to claim 5, characterized in that an image of the entered lens and the measured Eyeglass is shown overlaid on a screen and can be checked on the basis of this figure. 7. The method according to one or more of claims 1 to 6, characterized in that the spectacle lens to be measured in optical center clamped in the lens holding shaft becomes. 8. The method according to one or more of claims 1 to 6, characterized in that the spectacle lens to be measured decentred according to the decentration values of the Glasses wearer, possibly the axis position of a prismatic or cylindrical cut and / or the values of the position of a Is clamped into the spectacle lens holding shaft. 9. The method according to one or more of claims 1 to 8, characterized in that the lens after completion of the Shape grinding process is measured again on the support and  possibly subjected to a further fine-tuning. 10. Device for measuring a facet groove in an eyeglass lens opening of an eyeglass frame or an eyeglass lens having a predetermined, non-circular shape or a shaped disk in an eyeglass lens edge grinding machine

• - at least one grinding wheel ( 11 ; 12 ),
• - A rotatable, relative to the grinding wheel ( 11 ; 12 ) radially and axially adjustable spectacle lens holding shaft ( 14 , 14 a),
• - a (a 14, 14) drehgekuppelten with the spectacle lens holding shaft with respect to the spectacle lens holding shaft (14, 14 a) fixed support (45, 46, 47) for the spectacle frame (51),
• - With a bearing ( 9 , 28 ) for the grinding wheel ( 11 , 12 ) largely rigidly connected, with respect to the grinding wheel ( 11 , 12 ) fixed for engagement in the facet groove ( 52 ) can be brought probe ( 43 , 44 ) for measuring the facet groove ( 52 ) with regard to their radius value (r _n ) and possibly their axial value (z _n ) and / or at least one axially offset next to the grinding wheel ( 11 ; 12 ), which is fixed with respect to the grinding wheel ( 11 ; 12 ), touching with a circumferential contour ground lens (25) cooperating measuring shoe (29) for measuring a forming wheel or the spectacle lens contour of the spectacle lens (25) with respect to its radius value (R _n) and optionally the Axialwertes (z _n) of a roof facet (34) on the spectacle glass (25),
• - A displacement sensor ( 17 ) for receiving the radius values (r _n ) of the facet groove ( 52 ) of the spectacle frame ( 51 ) or the spectacle lens ( 25 ) or the shaped disk on the bearing ( 9 , 28 ) for the grinding disk ( 11 , 12 ) or the spectacle lens holding shaft ( 14 , 14 a),
• - an angle encoder ( 15 ) for recording the angle of rotation (ρ _n ) of the spectacle lens holding shaft ( 14 , 14 a),
• - if necessary, a displacement sensor ( 54 ) for recording the axial values (z _n ) of the facet groove ( 52 ) or the roof facet ( 34 ),
• - A computer ( 16 ) for storing the measured values (r _n , z _n , ρ _n ) and for controlling the lens edge grinding machine.

11. The device according to claim 10, characterized in that the drives for the radial and axial adjustment of the spectacle lens holding shaft ( 14 , 14 a) relative to the grinding wheel ( 11 , 12 ) and for rotating the spectacle lens holding shaft ( 14 , 14 a) consist of stepper motors, which simultaneously fulfill the function of position sensors and angle sensors. 12. The apparatus according to claim 10, characterized in that independent of the drives for the radial and axial adjustment of the spectacle lens holding shaft ( 14 , 14 a) relative to the grinding wheel ( 11 , 12 ) and for rotating the spectacle lens holding shaft ( 14 , 14 a) ( 17 , 54 ) and angle sensors ( 15 ) are provided. 13. Device according to one of claims 10, 11 or 12, characterized in that the holder ( 45 , 46 , 47 ) from a rotatable on a with respect to the lens holding shaft ( 14 , 14 a) fixed bracket ( 41 ) axially parallel to the lens holding shaft ( 14th , 14 a) and the grinding wheel ( 11 , 12 ) arranged support ring ( 45 ) with a central opening ( 42 ) through which one with the bearing ( 9 , 28 ) for the grinding wheel ( 11 , 12 ) and with respect to this fixed probe tip ( 44 ) engages in the facet groove ( 52 ) of the eyeglass frame ( 51 ) held on the support ring ( 45 ). 14. The apparatus according to claim 13, characterized in that the support ring ( 45 ) coaxial to the spectacle lens holding shaft ( 14 , 14 a) and the probe tip ( 44 ) are arranged on an arm ( 43 ) which in an intermediate space between the console ( 41 ) and the bearing ( 9 , 28 ) for the grinding wheel ( 11 , 12 ) protrudes. 15. The device according to one or more of claims 10 to 14 with a drive ( 18 ) for the radial adjustment of the grinding wheel ( 11 ; 12 ) relative to the spectacle lens holding shaft ( 14 ), characterized by a with the drive ( 18 ) cooperating and with respect to their transmissible torque adjustable clutch ( 19 ) and a device which switches the clutch ( 19 ) with respect to its torque when recording the values (r _n , ρ _n ) of the spectacle frame ( 51 ) or the spectacle lens ( 25 ) or the shaped disk. 16. The device according to one or more of claims 10 to 15, wherein the grinding wheel ( 11 ; 12 ) with its drive is arranged displaceably on a cross slide ( 2 ) relative to the rotatable in the machine frame ( 1 ) arranged spectacle lens holding shaft ( 14 ), characterized that the displacement sensors ( 17 , 54 ) measure the radius and axial values (r _n , z _n ) of the spectacle frame ( 51 ) or of the spectacle lens ( 25 ) via the displacement of the cross slide ( 2 ) in the machine frame ( 1 ). 17. The device according to one or more of claims 10 to 16, characterized in that the displacement sensors ( 17 , 54 ) are digital transducers. 18. Device for measuring a predetermined, out-of-round shape spectacle lens in a spectacle lens edge grinding machine

• - at least one grinding wheel ( 11 ; 12 ),
• - a rotatable, relative to the grinding wheel ( 11 ; 12 ) radially and axially adjustable spectacle lens holding shaft ( 14 ),
• - at least one axially displaced in addition to the grinding wheel (11; 12) arranged, with respect to the grinding wheel (11; 12) fixed, touching cooperating with a circumferential contour ground spectacle glass (25) measuring shoe (29) with respect to the measurement of the lens shape of the spectacle lens (25) of their radius value (r _n ) and possibly the axial values (z _n ) of a roof facet ( 34 ) on the spectacle lens ( 25 ),
• - At least one computer ( 16 ) with a device for controlling the axial position of the spectacle lens holding shaft ( 14 ) with the spectacle lens ( 25 ) relative to the grinding wheel ( 11 ; 12 ) according to the axial course of the spectacle lens contour ( 24 ) and for converting the spectacle lens ( 25 ) on the measuring shoe ( 29 ),
• - An input device ( 39 ) for entering the data of a spectacle lens ( 24 ) to be ground in accordance with a selected spectacle frame, the decentration values (e _x , e _y ) of the spectacle wearer, possibly the axis position of a prismatic or cylindrical cut and / or the values of the position a near part with a memory ( 20 ),
• - A displacement sensor ( 17 ) for recording the radius values (r _n ) and possibly a displacement sensor ( 54 ) for recording the axial values (z _n ) of the spectacle lens ( 25 ), wherein
• - The computer ( 16 ) compares the desired values of the radius values of the spectacle lens ( 24 ) to be ground with the measured actual radius values of the spectacle lens ( 25 ) and only triggers a grinding process if the radius values (r _n ) of the measured spectacle lens ( 25 ) are at no point smaller than the corresponding radius values of the entered spectacle lens ( 24 ) to be ground.

19. The apparatus according to claim 18, characterized in that the measuring shoe ( 29 ) next to the grinding wheel ( 11 ; 12 ) is arranged on a bearing neck ( 28 ) for the shaft ( 10 ) and a cylindrical circular section and possibly a facet groove ( 33 ) as a support with a diameter corresponding to the diameter of the grinding wheel ( 11 ) or ( 12 ). 20. The apparatus of claim 18 or 19, characterized by a with the computer ( 16 ) connected to the screen ( 31 ) with a superimposed display of the measured spectacle lens ( 25 ) and the spectacle lens ( 24 ) to be ground.