JP4481976B2 - Geometric center position detection method for progressive multifocal spectacle lens - Google Patents

Description

  The present invention relates to a method for aligning a progressive multifocal spectacle lens in which a processing center position of a progressive multifocal spectacle lens is obtained and a processing jig is attached to the processing center position. The present invention relates to a method for detecting a position.

  When the unprocessed spectacle lens is mounted on the spectacle frame desired by the wearer, the spectacle lens is trimmed in accordance with the shape of the spectacle frame. At that time, the eyeglass lens eye point is processed as the processing center so that the pupil center of the wearer coincides with the eyepoint of the eyeglass lens. Since the eye point of the spectacle lens cannot be displayed directly on the lens surface, in the design of spectacle lenses, especially progressive multifocal lenses, a mark called a hidden mark is formed in advance at a predetermined distance from the geometric center. In addition, the geometric center of the lens, the optical center of the distance portion and the near portion, the position of the eye point, and the like can be derived from the position of the hidden mark. The hidden mark is formed in the form of minute irregularities of, for example, about 0.004 mm on the convex surface of the lens when the spectacle lens is molded.

  FIG. 9 shows an unprocessed progressive multifocal lens. 100 is a progressive multifocal lens made of plastic, 101 is a geometric center, 102 is a horizontal reference line passing through the geometric center 101, and 103a and 103b are hidden marks. The hidden marks 103a and 103b are formed in a combination of a circle and a letter or in the form of two circles at two locations on the horizontal reference line 102 and equidistant from the geometric center 101 (for example, 17 mm). .

  Below the hidden marks 103a and 103b, a numeral 104a representing the addition power of the progressive multifocal lens 100 (the difference between the outer vertex refractive power of the distance portion and the outer vertex refractive power of the near portion), and the lens type The identification mark 104b representing is formed in the form of minute irregularities like the hidden marks 103a and 103b. The number 104a representing the addition power is displayed as a three-digit number (for example, 300) under the hidden mark located on the ear side when worn. Therefore, it is possible to identify whether the lens is a left-eye lens or a right-eye lens by knowing whether the three-digit number 104a is formed below the left or right hidden mark. A progressive multifocal lens 100 shown in FIG. 9 is a lens for the right eye. One hidden mark 103a is circular, and the other hidden mark 103b is a letter “H” representing the manufacturer.

  In FIG. 9, 105 is a distance power measurement unit, 106 is a near power measurement unit, 107 is a distance unit for viewing a distance, 108 is a near unit for looking near, and 109 is a continuous frequency. 110 is an eye point. The eye point 110 is determined at a position above the geometric center 101 by a predetermined distance (for example, 2 mm). FIG. 10 shows another example of the progressive multifocal lens 100. The progressive multifocal lens 100 shown in FIG. 10 is a right-eye lens, and the hidden marks 103a and 103c are both circular.

  When searching for the position of the eye point 110 from the hidden marks 103a, 103b, and 103c, the progressive multifocal lens 100 is held over a light source such as a fluorescent lamp, and the hidden marks 103a, 103b, and 103c are visually found, and the positions are marked with the markers. Then, the progressive multifocal lens 100 is placed on a progressive multifocal lens sheet called a remark chart. The remark chart displays a full-scale progressive multifocal lens for each lens type in which the positions of the hidden mark, geometric center, distance power measurement unit, near power measurement unit, and eye point are described. .

  When the progressive multifocal lens 100 is placed on the remark chart, the positions of the hidden marks 103a, 103b, 103c marked on the lens 100 and the positions of the hidden marks of the same type of lenses described on the remark chart Are matched, and the position of the eye point described in the remark chart is set as the position of the eye point 110, and the same position of the progressive multifocal lens 100 is marked with a marker. Then, a processing jig (lens holder) is mounted at the position of the eye point 110 of the progressive multifocal lens 100, and the eye point 110 is set so that the center of the wearer's pupil coincides with the eye point 110 of the progressive multifocal lens 100. The progressive multifocal lens 100 is trimmed with the processing center as the processing center, and the outer shape of the lens 100 is matched with the frame shape of the spectacle frame (see, for example, Patent Document 1).

However, the method using the remark chart is inefficient because it is performed manually by the operator, and the burden on the operator is large, and the positioning error between the progressive multifocal lens 100 and the lens holder is large. there were.
Therefore, as a technique for detecting the hidden marks 103a, 103b, and 103c and automatically aligning the progressive multifocal lens 100 and the lens holder with high accuracy and automatically, the progressive multifocal lens 100 is optically enlarged and imaged. Then, the positions of the hidden marks 103a, 103b, and 103c are detected from the input image by template matching that compares the captured input image with a partial image (template) prepared in advance, and the position of the eye point 110 is calculated from this position. How to do is known.

  The progressive multifocal lens 100 is optically magnified and imaged when the hidden marks 103a, 103b, and 103c are imaged without being optically magnified. This is because a size of at least about 10 × 10 pixels is required when using the. According to the method using template matching, the progressive multifocal lens 100 and the lens holder can be aligned with high accuracy. Of the above background technologies, the method using template matching is not known in the literature as far as the applicant knows at the time of filing.

JP-A-8-297262

In the method using template matching, an enlargement optical system for optically enlarging and imaging the progressive multifocal lens 100 is required, which increases the cost and further requires time for template matching.
The present invention has been made to solve the above-described problems. In a method for aligning a progressive multifocal spectacle lens and a processing jig such as a lens holder, a hidden mark is efficiently and shortly made at a lower cost than in the past. An object of the present invention is to provide a method for detecting the geometric center position of a progressive multifocal spectacle lens that can be detected in time and the geometric center position of the spectacle lens can be obtained from the position of the hidden mark.

The present invention relates to a photographing means for photographing an image of a progressive multifocal spectacle lens to be processed, an image processing means for processing the image to obtain a geometric center position of the spectacle lens, and the geometric center position. Geometric center of progressive multifocal spectacle lens for detecting the geometric center position in a layout block device having a calculation means for obtaining a processing center position of the spectacle lens and a mechanism for attaching a processing jig to the processing center position A position detection method, wherein a binarization process for binarizing an input image photographed by the photographing means and a geometric feature parameter of each figure included in the image after the binarization process are extracted Then, an extraction process for extracting a figure in which the characteristic parameter satisfies a predetermined condition as an image of a hidden mark formed in advance on the eyeglass lens to be processed, and the extracted Whether or not there are two mark marks is determined. If there are two mark marks, the number determination process returns to the binarization process. If there are two extracted hidden marks, the distance between the two hidden marks is a predetermined value. A distance determination process for returning to the binarization process when the distance between the hidden marks is not within a predetermined range centered on a predetermined value; When the distance between the hidden marks is within a certain range centered on a predetermined value, a calculation process for calculating the position of the intermediate point between the two hidden marks as the geometric center position of the eyeglass lens to be processed; It is what you have. Since there is a positional definition common to all spectacle lenses between the hidden mark and the reference position (geometric center in the case of a progressive multifocal lens), if the hidden mark is detected by image processing, the spectacle lens A reference position can be obtained. The relationship between the reference position and the processing center position differs for each spectacle lens.
In addition, according to the configuration example of the geometric center position detection method of the progressive multifocal spectacle lens of the present invention, the elapsed time of the binarization process, the extraction process, the number determination process, and the distance determination process is further a predetermined time. When it exceeds the above-mentioned range, it has a process of discharging the eyeglass lens to be processed from the layout block device.

  According to the present invention, an image of a spectacle lens to be processed is captured and binarized, and a geometric feature parameter of each figure included in the binarized image is extracted. Because the figure that fits the image is extracted as a hidden mark image, the time required to detect the hidden mark can be reduced compared to the conventional method using template matching, and the magnification optical system required for template matching is not required. Thus, the cost can be reduced. In the present invention, it is determined whether there are two extracted hidden marks, and further, it is determined whether the distance between the two hidden marks is within a certain range centered on a predetermined value. And when the distance between the hidden marks is within a certain range centered on the predetermined value, the position of the hidden mark is calculated as the position of the intermediate point between the two hidden marks. From this, the geometric center position of the spectacle lens can be obtained. The processing center position of the spectacle lens can be obtained from this geometric center position. As a result, in the present invention, compared with the case where an operator manually aligns a spectacle lens and a processing jig such as a lens holder, highly accurate alignment can be realized, and the burden on the operator is significantly reduced. It is possible to reduce the amount, and highly accurate alignment of the spectacle lens and the processing jig can be performed efficiently and in a short time.

  Next, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing the configuration of a progressive multifocal lens layout block device according to an embodiment of the present invention. The progressive multifocal lens layout block device according to the present embodiment is installed adjacent to an edge trimming device (not shown). The progressive multifocal lens 100 is imaged and based on the captured image. At the same time as determining the left and right of the progressive multifocal lens 100, layout processing for calculating the attachment position and attachment angle of a processing jig (hereinafter referred to as a lens holder) attached to the progressive multifocal lens 100, and the lens holder as a progressive multifocal lens Block processing attached to the processing center of 100 is performed, and the progressive multifocal lens 100 after the lens holder is attached is conveyed to the edging apparatus.

  This layout block device includes a holder supply device 1 for supplying a lens holder, a seal supply device 2 for supplying an elastic seal described later, a lens supply device 3 for supplying a progressive multifocal lens 100 to be processed, and a holder supply. A holder holding device 4 for attaching the lens holder supplied by the apparatus 1 to the processing center of the progressive multifocal lens 100, a lens meter 5 serving as a photographing means for photographing the progressive multifocal lens 100, and an image photographed by the lens meter 5. The image processing device 6 that determines the left and right of the progressive multifocal lens 100 based on the above and calculates the attachment position and attachment angle of the lens holder, and the progressive multifocal lens 100 after the lens holder is attached to the edging device. A lens transport device 7 for transport, a control device 8 for controlling the entire layout block device, A calculating means for controlling the out-block apparatus and edger and a host computer 9.

  FIG. 2 is a side view showing a state in which a lens holder is attached to the progressive multifocal lens 100 via an elastic seal based on the result of image processing by the image processing device 6. The lens holder 200 made of a metal such as stainless steel is molded into a cylindrical body with a flange. The surface of the lens holder 200 to which the elastic seal 201 is attached (the lower surface of the holder 200) is a concave spherical lens holding surface corresponding to the convex lens surface of the progressive multifocal lens 100.

  In this case, when the lens holding surface corresponding to the convex curve is formed for each lens, the type of the lens holder 200 increases. Therefore, by changing the radius of curvature of the lens holding surface in stages, the type of the lens holder 200 is increased. The number of progressive multifocal lenses 100 having different convex curves can be held by one type of lens holder 200.

  The elastic seal 201 is made of a thin rubber having a thickness of about 0.5 to 0.6 mm, and has an outer diameter larger than the outer diameter of the lens holding surface of the lens holder 200 (about 22 mmφ) and an inner diameter larger than the hole diameter of the lens holder 200. A small (about 8 mm) shaped ring is used, with both sides coated with an adhesive.

  FIG. 3 is a block diagram showing the configuration of the lens meter 5. The lens meter 5 includes a light source 31 that illuminates the progressive multifocal lens 100, a condenser lens 32 disposed in the optical path between the light source 31 and the progressive multifocal lens 100, a diaphragm 33, a half mirror 34, A lens holding device 35 for sucking and fixing the progressive multifocal lens 100, a rotary screen 36 on which images of hidden marks 103a and 103b, a numerical value 104a indicating addition power and an identification mark 104b of the progressive multifocal lens 100 are projected, and this rotation Condensing lenses 37, 38 disposed between the screen 36 and the progressive multifocal lens 100, a projection lens 39, an imaging device 40 such as a CCD camera that captures reflected light from the rotating screen 36, and the rotating screen 36 And a motor 41 that rotates the motor.

  As the light source 31 used for the projection of the progressive multifocal lens 100, light having a narrow emission spectrum width, for example, a red LED is used so that the hidden marks 103a and 103b, the numeral 104a, and the identification mark 104b can be projected satisfactorily. The progressive multifocal lens 100 is disposed on the convex surface side. For example, the half mirror 34 having a transmittance of 70% and a reflectance of 30% is used, and the imaging device 40 is disposed correspondingly.

The rotating screen 36 has a reflective sheet coated with fine powder such as glass or aluminum on its surface in order to increase the reflectance. Further, in order to make the brightness of the surface uniform, the rotary screen 36 is rotated at a high speed (for example, 3400 rpm) by the motor 41.
The cylindrical lens holding device 35 that holds the progressive multifocal lens 100 has a sufficiently small outer diameter (for example, 8 mmφ) so as not to hinder photographing of the hidden marks 103a and 103b, the numeral 104a, and the identification mark 104b. Yes.

4 to 6 are flowcharts showing the operation of the layout block device of FIG. Hereinafter, the operation of the layout block device will be described with reference to FIGS.
First, under the control of the control device 8, the lens supply device 3 causes the lens meter 5 to have one progressive multifocal lens 100 (hereinafter referred to as a processing target lens 100) to be edged with its convex surface facing upward. Placed on the lens holding device 35. The lens holding device 35 sucks and fixes the processing target lens 100 to the upper surface opening of the lens support tube by evacuating the inside of the lens support tube (step S1 in FIG. 4).

The holder supply device 1 supplies the lens holders 200 one by one to the holder holding device 4 under the control of the control device 8.
The elastic seal 201 is loaded in the seal supply device 2 in the form of a roll. This roll has a surface covered with protective paper. The seal supply device 2 supplies the elastic seal 201 to the holder holding device 4 in a state where the protective paper is peeled one by one under the control of the control device 8.

  Upon receiving the lens holder 200 and the elastic seal 201, the holder holding device 4 holds the lens holder 200, affixes the elastic seal 201 to the lens holding surface of the lens holder 200, and the lens holder 200 to the processing target lens 100. In preparation for mounting, the standby state is set (step S2).

  Next, the control device 8 turns on the light source 31 of the lens meter 5 (step S3). Subsequently, the image processing device 6 resets and starts the time-up timer for image processing to 0 in accordance with an instruction from the control device 8, and starts time measurement (step S4). This time-up timer is for measuring the elapsed time of image processing related to one processing target lens 100.

  Illumination light from the light source 31 passes through the condenser lens 32, the diaphragm 33, and the half mirror 34 and is irradiated onto the processing target lens 100. Thereby, the images of the hidden marks 103a and 103b, the numbers 104a and the identification marks 104b formed on the surface of the processing target lens 100 are condensed by the condenser lenses 37 and 38 and projected onto the rotary screen 36 by the projection lens 39. Is done. The image projected on the rotary screen 36 is reflected by the half mirror 34 through the projection lens 39 and the condenser lenses 38 and 37 and projected onto the light receiving surface of the imaging device 40. The imaging device 40 photoelectrically converts the image projected on the light receiving surface and outputs an image signal.

The image processing device 6 A / D converts the image signal output from the imaging device 40 of the lens meter 5 and temporarily stores the image data after the A / D conversion in an internal memory (step S5).
Subsequently, the image processing device 6 starts image processing on the input image stored in the memory. 7 and 8 are explanatory diagrams showing the state of image processing by the image processing apparatus 6.

  First, the image processing apparatus 6 compares the input image shown in FIG. 7A with a predetermined first threshold value, and extracts a pixel having a luminance value equal to or higher than the first threshold value from the input image as it is. For a pixel having a luminance value less than the first threshold value, a static threshold value process is performed to set the luminance value to 0, thereby removing a background area from the input image and extracting a lens area. Are stored in the memory (step S6).

  Subsequently, the image processing device 6 calculates, for each pixel, the difference between the image after smoothing the static threshold processing image stored in the memory and blurring the image and the image after the static threshold processing. Thus, a value of “1” is set for a pixel whose calculated difference is equal to or greater than a predetermined second threshold value, and a value of “0” is set for a pixel whose difference is less than the second threshold value. By performing threshold processing, the image after the static threshold processing is binarized (step S7).

  In this dynamic threshold processing, the contour is sharpened by difference processing, where the difference output is large, that is, the portion that seems to be the contour of the object is set to “1”, and other portions are set to “0”. Even if there is slight illumination unevenness or halation when the processing target lens 100 is photographed, it is possible to extract the shapes of the hidden marks 103a and 103b, the numerals 104a, and the identification marks 104b. By this dynamic threshold processing, an image as shown in FIG. 7B is obtained. The image processing device 6 stores the image after the dynamic threshold processing in the memory.

  The binarized image includes dust, dirt, and the like on the surface of the processing target lens 100, and the binarized hidden mark itself is often partially missing. Therefore, since the hidden marks 103a and 103b cannot be detected with the binarized image obtained by the dynamic threshold processing, the noise components are removed and the defects of the hidden marks 103a and 103b are repaired as follows. Etc. to detect the hidden marks 103a and 103b.

  The image processing apparatus 6 regards a group of pixels “1” connected in the binarized image after the dynamic threshold processing as one connected component, and each pixel in the same connected component has the same label (number). Or, after performing a labeling process that gives a name), geometric feature parameters of each connected component are extracted and stored in a memory. Here, as the characteristic parameters of each connected component, the area (number of pixels of the connected component) S of the connected component shown in FIG. 7C and the ratio (L1 / L2) of the major axis L1 and the minor axis L2 are extracted. In FIG. 7C and after FIG. 7C, the area of the pixel “1” is indicated by hatching.

  Then, the image processing apparatus 6 is configured such that the area S is in the first area range set in advance and the ratio between the major axis L1 and the minor axis L2 is equal to or less than a preset ratio threshold (for example, 1.2). Is extracted as a candidate region for a circular hidden mark (hereinafter referred to as a “similar region”), and the position of this extracted “similar region” is stored in the memory (step S8). In this way, for example, a similar region as shown in FIG. 7D can be extracted.

  ○ The similar area includes a protruding noise component. Therefore, the image processing apparatus 6 once shrinks the extracted ○ similar region by a predetermined number of pixels, and then expands it by the same number of pixels and restores it to the original. ○ When the similar region is shrunk, the protruding noise component disappears. Therefore, if the similar region after the shrinking process is expanded and restored, the protruding noise component can be removed from the similar region ( Step S9).

  Further, the ○ similar region includes noise components such as holes and defects. Therefore, the image processing device 6 removes noise components such as holes and defects from the similar region by expanding the ○ similar region after removing the protruding noise component by a predetermined number of pixels, thereby reducing the shape. Correction is performed (step S10). Thereby, the ○ similar region after the shape correction as shown in FIG.

  Subsequently, the image processing device 6 fills the interior of each ○ similar region after shape correction with the pixel “1” as shown in FIG. 7F, and then extracts the geometric feature parameters of each ○ similar region. And store it in memory. Also here, as the characteristic parameters, the area S of each of the similar regions and the ratio of the major axis L1 and the minor axis L2 are extracted.

  The image processing apparatus 6 has an area S within a preset second area range and the ratio of the major axis L1 to the minor axis L2 is equal to or less than the ratio threshold value. Extracted as the most promising candidate region (hereinafter referred to as “O region”), and the position of the extracted O region is stored in the memory (step S11). Then, the image processing device 6 counts the number of the extracted ○ regions and stores it in the memory (step S12).

  Next, the image processing apparatus 6 performs a labeling process on the binarized image after the dynamic threshold process, and then extracts a geometric feature parameter of each connected component and stores it in a memory. . Here, the area S, the major axis L1, and the minor axis L2 of the connected component are extracted as characteristic parameters of each connected component.

  The image processing apparatus 6 has a rod-like shape in which the area S is in a preset third area range, the major axis L1 is in a preset major axis range, and the minor axis L2 is in a preset minor axis range. The connected component is extracted as a region that seems to be a component of the H-shaped hidden mark, and the position of the extracted bar-shaped connected component is stored in the memory (step S13). Thus, for example, an area as shown in FIG. 7G can be extracted.

  The three rod-shaped regions shown in FIG. 7 (g) are shaped like an H shape but are not connected. Therefore, the image processing apparatus 6 expands the extracted bar-shaped area by a predetermined number of pixels (for example, about 2 pixels) to connect these areas, and thereby H-shaped hidden mark candidate areas (hereinafter referred to as “hidden mark candidate areas”). , Referred to as an H-similar region) (step S14). Thereby, the H-similar region after shape correction as shown in FIG.

  Subsequently, the image processing device 6 once shrinks the H-like region after shape correction by a predetermined number of pixels, and then expands the same by the same number of pixels and restores the original shape, thereby projecting noise from the H-like region. The component is removed (step S15), and the geometric feature parameter of the H-similar region after removing the noise component is extracted and stored in the memory. Here, as the characteristic parameters of the H-similar region, the ratio (HT / W) between the height HT and the width W of the H-similar region shown in FIG. 7 (i) and the convexity (showing the hollow shape of the figure in the two-dimensional plane) Degree), the diameter D of the circle circumscribing the H-similar region, and the distance from the circle region. The convexity is less than 1 when the circle has a dent or hole.

  The image processing device 6 has a ratio of the height HT to the width W within a preset ratio range, the convexity is within a predetermined range (for example, 0.6 to 0.7), and the diameter D of the circumscribed circle is set in advance. An H-similar region within the set diameter range and the distance from the region is within a preset distance range is extracted as the most promising candidate region of the H-shaped hidden mark (hereinafter referred to as the H region). The position of the extracted H area is stored in the memory (step S16). Then, the image processing device 6 counts the number of extracted H regions and stores it in the memory (step S17).

  Next, the image processing apparatus 6 determines whether or not the number of ○ areas counted in Step S12 is 2 (Step S18). If the number of ○ areas is not 2, it determines whether or not the number of ○ areas is 1 (Step S19). ) If the number of regions is 1, it is determined whether the number of H regions counted in step S17 is 1 (step S20). When the number of areas is neither 2 nor 1, or when the number of areas is 1 and the number of H areas is not 1, the image processing apparatus 6 sets the elapsed time during measurement by the time-up timer to a predetermined second (for example, 4 seconds). It is determined whether it has been exceeded (step S21).

  If the elapsed time does not exceed the predetermined second, the image processing device 6 executes the processes of steps S5 to S20 again. Thus, when the number of areas is neither 2 nor 1, or when the number of areas is 1 and the number of H areas is not 1 (that is, when something other than the hidden marks 103a and 103b is detected), the elapsed time is a predetermined number of seconds. If not exceeded, the processes in steps S5 to S20 are repeatedly executed.

  When the elapsed time exceeds the predetermined second in step S21, the image processing device 6 determines that the hidden marks 103a and 103b cannot be detected by the image processing, and indicates that the image processing is impossible. The image processing impossible error processing notified to the is performed. Upon receiving the notification, the control device 8 performs processing such as discharging the processing target lens 100 in which the image processing incapable error has occurred from the layout / block device.

  On the other hand, when the number of ○ regions is 2, or when both the ○ region number and the H region number are 1, the image processing device 6 calculates the distance between the two ○ regions or the distance between the ○ region and the H region, It is determined whether or not this distance is within a certain range centered on a predetermined value (for example, 34 mm) (step S22). If the obtained distance is not within a certain range centered on the predetermined value, the process proceeds to step S21.

  Next, when the obtained distance is within a certain range centered on a predetermined value and both the number of ○ areas and the number of H areas are 1 (YES in step S23 in FIG. 5), the image processing apparatus 6 The center of the smallest circumscribed circle of the region is the center of the region ○, the center of the smallest circumscribed circle of the H region is the center of the H region, and the center coordinate of the region and the center coordinate of the H region are calculated and stored in the memory. (Step S24).

  Subsequently, the image processing apparatus 6 calculates the coordinates of an intermediate point (reference position) C between the center of the region O and the center of the region H as shown in FIG. 8A and stores it in the memory (step S25). A line segment connecting the center of the region and the center of the H region (vector from the region to the H region) V is obtained, and an angle formed by the vector V and the horizontal reference line 102 of the layout block device (with respect to the horizontal reference line 102) The rotation angle θ of the processing target lens 100 is calculated and stored in the memory (step S26). In the processing target lens 100, an angular deviation occurs at the time of supply with respect to the original position on the layout block device. The process of step S26 is a process for obtaining this angular deviation.

  Next, the image processing apparatus 6 is located on either the left or right side (left side in the present embodiment) when viewing the H region from the ○ region, and is a vector from the center of each of the ○ region and the H region. Two rectangular areas A1 and A2 having a preset size that are separated by a preset distance in a direction perpendicular to V are cut out from the binarized image after the dynamic threshold processing (step S27).

  The image processing apparatus 6 then rotates the rectangular areas A1 and A2 by the rotation angle θ so that the two rectangular areas A1 and A2 that are cut out are inclined by the rotation angle θ and the horizontal reference line 102. Parallel to each other (step S28). The reason why the rectangular areas A1 and A2 are rotated is to make it possible to cut out characters in the next character count process.

  The image processing apparatus 6 cuts out the characters in the rectangular areas A1 and A2 after the rotation processing one by one, thereby counting the number of characters in the rectangular areas A1 and A2 and storing them in the memory (step S29). The size and character pitch of characters formed on the progressive multifocal lens 100 as numbers 104a and identification marks 104b are known. Therefore, the image processing apparatus 6 shrinks the images in the rectangular areas A1 and A2 only in the horizontal direction to remove noise components such as short-circuits between characters, and then performs a preprocessing technique used in the character recognition technique. Use to cut out characters. That is, the image processing device 6 detects a space between characters based on the character pitch, detects a character region based on the character size, and determines a character cut-out position.

  Next, the image processing apparatus 6 determines whether the processing target lens 100 is a right-eye lens or a left-eye lens (Step S30). In the progressive multifocal lens 100 in which the circular hidden mark 103a and the H-shaped hidden mark 103b are formed in advance, the hidden mark 103a and the number 104a indicating the addition power are provided on the ear side, and the hidden mark 103b and the lens are provided on the nose side. There is an identification mark 104b indicating the type of the. Therefore, when looking at the H region from the ○ region, if the numeral 104a and the identification mark 104b are on the right side, the lens is for the right eye (FIG. 9), and if the numeral 104a and the identification mark 104b are on the left side, the left eye This is a lens for use (FIG. 8A).

  In the present embodiment, the rectangular areas A1 and A2 on the left side when the H area is viewed from the ◯ area are cut out by the processing in step S27. Therefore, the image processing apparatus 6 determines that the lens is for the left eye when the number of characters counted in step S29 is within a certain range (for example, 3 to 7 characters), and when the number of characters is not within the certain range. It is determined that the lens is for the right eye. In the case of a right-eye lens, the number of characters in the rectangular areas A1 and A2 should be 0, and in the case of a left-eye lens, the number of characters should be 5. If the number of characters is within a certain range, it is determined that the lens is for the left eye.

  Next, the image processing apparatus 6 determines whether the numeral 104a and the identification mark 104b are below the hidden marks 103a and 103b (step S31). For example, when it is determined in step S30 that the lens is for the right eye, the numeral 104a and the identification mark 104b are below the hidden marks 103a and 103b if the vector V is facing right, and are hidden if the vector V is facing left. Above the marks 103a and 103b. When it is determined that the lens is for the left eye, the numeral 104a and the identification mark 104b are below the hidden marks 103a and 103b when the vector V is facing left, and the hidden marks 103a and 103b when the vector V is facing right. It is on the upper side.

  When the number 104a and the identification mark 104b are above the hidden marks 103a and 103b, the image processing device 6 notifies the control device 8 that the processing target lens 100 is upside down and out of the allowable range of the layout block device. Perform upside down error processing. Upon receiving the notification, the control device 8 performs processing such as discharging the processing target lens 100 in which the upside-down error has occurred from the layout block device.

  When the number 104a and the identification mark 104b are below the hidden marks 103a and 103b, the image processing device 6 determines whether the rotation angle θ is within a preset range (for example, ± 60 °) ( Step S32). If the rotation angle θ is not within the preset range, the image processing device 6 notifies the control device 8 that the rotation angle of the lens 100 to be processed is outside the allowable range of the layout / block device. I do. Upon receiving the notification, the control device 8 performs processing such as discharging the processing target lens 100 in which the angle over error has occurred from the layout / block device.

If the rotation angle θ is within a preset range, the image processing device 6 proceeds to step S44 in FIG.
On the other hand, if the distance obtained in step S22 is within a certain range centered on the predetermined value and the number of ◯ areas is 2 (NO in step S23 in FIG. 5), the image processing device 6 Using the center of the smallest circumscribed circle as the center of each circle area, the center coordinates of the two circle areas are calculated and stored in the memory (step S33).

  Subsequently, the image processing device 6 calculates the coordinates of the intermediate point C (geometric center 101) between the centers of the two ○ regions as shown in FIG. 8B and stores them in the memory (step S34). A line segment V connecting the centers of the two circle regions is obtained, and an angle (rotation angle) θ formed by the line segment V and the horizontal reference line 102 is calculated and stored in the memory (step S35).

  Next, the image processing apparatus 6 is one of four rectangular regions B1 to B4 having a predetermined size that is separated from the center of each of the regions by a predetermined distance in a direction perpendicular to the line segment V. Is cut out from the binarized image after the dynamic threshold processing (step S36). Then, the image processing apparatus 6 rotates the cut out rectangular area by the rotation angle θ so as to be parallel to the horizontal reference line 102 (step S37).

The image processing apparatus 6 counts the number of characters in the rectangular area after the rotation process in the same manner as in step S29 and stores it in the memory (step S38).
Next, the image processing apparatus 6 determines whether or not the number of characters counted in step S38 is 3 (step S39). When the number of characters is not 3, the image processing apparatus 6 selects another rectangular area from the four rectangular areas B1 to B4 (steps S40 and S41), and performs the processes of steps S36 to S39.

  As a result of sequentially counting the number of characters in the four rectangular areas B1 to B4, if there is no rectangular area with three characters, the image processing apparatus 6 determines that the left / right determination by image processing is impossible and notifies the host computer 9 in advance. After performing the RL determination impossibility process for determining whether the processing target lens 100 is a right eye lens or a left eye lens based on the processed information, the process proceeds to step S32.

  On the other hand, when the number of characters is 3 in any of the rectangular areas B1 to B4, the image processing apparatus 6 determines whether the processing target lens 100 is a right-eye lens or a left-eye lens (Step S42). ). In the progressive multifocal lens 100 in which two circular hidden marks 103a and 103c are formed in advance, the ear side has a three-digit number 104a representing the addition power, and the nose side has an identification mark 104b representing the lens type. is there. Therefore, if the rectangular area with 3 characters is one of the rectangular areas B1 and B3 shown in FIG. 8B, it is the lens for the right eye (FIG. 21), and if it is one of the rectangular areas B2 and B4, the left It is an eye lens (FIG. 8B).

  Next, the image processing apparatus 6 determines whether the numeral 104a and the identification mark 104b are below the hidden marks 103a and 103c (step S43). The number 104a and the identification mark 104b are located below the hidden marks 103a and 103c if the three-character rectangular area is one of the rectangular areas B3 and B4, and the three-character rectangular area is one of the rectangular areas B1 and B2. If it is, it is above the hidden marks 103a and 103c.

When the number 104a and the identification mark 104b are above the hidden marks 103a and 103c, the image processing apparatus 6 performs the upside down error process as described above.
If the number 104a and the identification mark 104b are below the hidden marks 103a and 103c, the image processing device 6 performs the process of step S32 described above.

  Next, in step S44, the image processing device 6 transmits the result of the left / right determination of the processing target lens 100, the calculated coordinates of the intermediate point C, and the rotation angle θ to the control device 8, and the control device 8 The result of the left / right determination of the lens 100 and the rotation angle θ are transmitted to the host computer 9. Further, the control device 8 turns off the light source 31 of the lens meter 5 (step S45).

  The host computer 9 reads the barcode attached to the tray of the processing target lens 100 when supplied to the layout block device with a barcode reader, so that the processing target lens 100 is for the right eye or the left eye. The lens is recognized in advance. The host computer 9 collates the result read from the bar code with the result of the left / right determination sent from the control device 8, so that the content represented by the bar code and the actual processing target lens 100 placed on the tray are determined. You can check if they match.

  Then, the host computer 9 stores the layout data of the lens 100 to be processed (data indicating the positional relationship between the geometric center 101, the hidden marks 103a and 103b, and the eye point 110) stored in advance according to the rotation angle θ. After the angle correction, block data (data representing the position of the eye point 110 with reference to the geometric center 101) is calculated based on the layout data after the angle correction and transmitted to the control device 8 (step S46).

  The intermediate point C detected by the image processing apparatus 6 is the geometric center 101 of the lens 100 to be processed. At this time, the intermediate point C is the horizontal direction (left-right direction in FIG. 8) and the vertical direction (up-down direction in FIG. 8). (Position) is displaced from the position that should be originally on the layout block device. That is, the processing target lens 100 is displaced in the horizontal direction and the vertical direction. On the other hand, the block data is calculated on the assumption that the angular deviation of the processing target lens 100 is corrected as described above, but the positional deviation in the horizontal direction and the vertical direction has no positional deviation.

  Therefore, when the control device 8 transports the processing target lens 100 from the lens meter 5 to a predetermined lens holding position by the lens supply device 3, the position shift of the processing target lens 100 in the horizontal direction and the vertical direction is determined at the intermediate point C. After correcting based on the coordinates, the lens supply device 3 is set so that the eye point 110 of the processing target lens 100 is directly below the lens holder 200 held by the holder holding device 4 based on the block data from the host computer 9. Control (step S47).

  Subsequently, the control device 8 controls the holder holding device 4 and corrects the angle by rotating the lens holder 200 by the rotation angle θ in order to correct the angle shift at the time of supplying the processing target lens 100 (step). S48). Then, the control device 8 controls the holder holding device 4 to lower the lens holder 200 and press the elastic seal 201 attached to the lens holder 200 against the processing target lens 100 so as to be in close contact therewith. Thereby, as shown in FIG. 2, the lens holder 200 is attached to the processing center (eye point 110) of the processing target lens 100 via the elastic seal 201 (step S49).

The control device 8 controls the holder holding device 4 to convey the lens holder 200 together with the processing target lens 100 to a predetermined removal position (step S50), and then controls the lens conveyance device 7 to remove the removal position. The processing target lens 100 is conveyed to the edging apparatus (step S51).
Thus, the process of the layout block device for one processing target lens 100 is completed.

  The lens to be processed 100 sent to the edging device is subjected to edging processing such as beveling based on the lens frame shape data and the wearer's prescription data by the edging processing device. A matching spectacle lens is produced.

  The present invention can be applied to a technique for detecting the geometric center position of a progressive multifocal spectacle lens.

It is a block diagram which shows the structure of the layout block apparatus for progressive multifocal lenses used as embodiment of this invention. It is a side view which shows the state which attached the lens holder to the progressive multifocal lens through the elastic seal | sticker. It is a block diagram which shows the structure of the lens meter of the layout block apparatus of FIG. It is a flowchart figure which shows operation | movement of the layout block apparatus of FIG. It is a flowchart figure which shows operation | movement of the layout block apparatus of FIG. It is a flowchart figure which shows operation | movement of the layout block apparatus of FIG. FIG. 2 is an explanatory diagram showing a state of image processing by the image processing device of the layout block device of FIG. 1. FIG. 2 is an explanatory diagram showing a state of image processing by the image processing device of the layout block device of FIG. 1. It is a top view which shows the positional relationship of a hidden mark, a geometric center, etc. of a progressive multifocal lens. It is a top view which shows the other example of a progressive multifocal lens.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Holder supply apparatus, 2 ... Seal supply apparatus, 3 ... Lens supply apparatus, 4 ... Holder holding apparatus, 5 ... Lens meter, 6 ... Image processing apparatus, 7 ... Lens conveyance apparatus, 8 ... Control apparatus, 9 ... Host computer .

Claims (2)

Imaging means for taking an image of a progressive multifocal spectacle lens to be processed, image processing means for processing the image to obtain a geometric center position of the spectacle lens, and the spectacle lens based on the geometric center position In a layout block device having a calculation means for obtaining a machining center position and a mechanism for attaching a machining jig to the machining center position, the geometric center position detection method for a progressive multifocal spectacle lens that detects the geometric center position There,
A binarization process for binarizing the input image captured by the imaging unit;
A geometric feature parameter of each figure included in the image after the binarization processing is extracted, and a hidden mark formed in advance on the eyeglass lens to be processed is a figure in which the feature parameter satisfies a predetermined condition. Extraction processing to extract as an image of,
A number determination process for determining whether there are two extracted hidden marks and returning to the binarization process if not two;
When there are two extracted hidden marks, it is determined whether the distance between the two hidden marks is within a certain range centered on a predetermined value, and the distance between the hidden marks is centered on the predetermined value A distance determination process for returning to the binarization process when the predetermined range is not satisfied,
When the distance between the hidden marks is within a certain range centered on a predetermined value, a calculation process for calculating a position of an intermediate point between the two hidden marks as a geometric center position of the eyeglass lens to be processed; A method for detecting a geometric center position of a progressive multifocal spectacle lens, comprising: The method of detecting a geometric center position of a progressive multifocal spectacle lens according to claim 1,
Furthermore, when the elapsed time of the binarization process, the extraction process, the number determination process, and the distance determination process exceeds a predetermined time, a process of discharging the eyeglass lens to be processed from the layout block device A method for detecting a geometric center position of a progressive multifocal spectacle lens, comprising:

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