JP5015429B2 - Lens meter - Google Patents

Description

  The present invention relates to a lens meter that measures optical characteristics of a lens to be examined.

A lens meter is known in which a measurement light beam is projected onto a test lens, a measurement light beam transmitted through the test lens is detected by a light receiving element, and optical characteristics of the test lens are obtained based on the detection result. In this type of conventional lens meter, a nose pad member is brought into contact with the nose pad of the spectacle frame, and between the optical centers of the left and right lenses framed in the spectacle frame based on the left and right movement positions of the nose pad member. A lens having a function of measuring a distance (distance between eyepoints in the distance portion in the progressive lens, hereinafter abbreviated as PD) is known (see Patent Document 1).
JP-A-9-54014

When performing PD measurement of a progressive lens with a lens meter having such a PD measurement function, it is necessary to first determine the distance area and then further determine the distance power measurement position (eye point). there were. However, such work is troublesome and takes time.
In view of the above-described problems of the prior art, it is an object of the present invention to provide a lens meter that can easily measure PD in the left and right progressive lenses framed in a spectacle frame and has excellent operability.

In order to solve the above problems, the present invention is characterized by having the following configuration.
(1) A measurement optical system is provided that projects a measurement light beam onto a test lens placed on the nosepiece, and receives the measurement light beam passing through the opening of the nosepiece through the test lens by a light receiving element. In a lens meter that measures the optical characteristics of the test lens based on the output signal of the light receiving element, when the test lens is a progressive lens, the test lens based on the output signal of the light receiving element A distance portion area determining means for determining whether or not the current measurement position of the lens is within the distance portion area, and the measurement position of the test lens is within the distance portion area by the distance portion area determining means A first distance for obtaining a first distance in the left-right direction from the current test lens measurement position to the distance power measurement position based on the output signal of the light receiving element at the measurement position of the test lens. Calculation means and spectacle frame A nose pad member that is in contact with the nose pad of the camera and movable in the left-right direction, and calculates a second distance from the current measured lens position to the nose pad member based on the amount of movement of the nose pad member The distance from the bridge center of the spectacle frame to the distance power measurement position of the lens to be measured is added by summing the distances calculated by the second distance calculating means and the first distance calculating means and the second distance calculating means. 3rd distance calculation means which calculates | requires the 3rd distance of the left-right direction, and the display means which displays the said 3rd distance calculated | required by this 3rd distance calculation means, The said display means is a measurement position of the said test lens. The distance to be displayed is the second distance calculated by the second distance calculating means until at least the distance enters the distance portion area.
(2) In the lens meter according to (1), the display means is configured so that the third means is independent of the moving position of the test lens while the measurement position of the test lens is located within the distance portion. The third distance obtained by the distance calculating means is displayed.
(3) In the lens meter of (2), after the display means displays the third distance obtained by the third distance calculation means, guidance for further guiding the current measurement position to the distance power measurement position A mark is displayed.

  According to the present invention, it is excellent in operability, and the PD in the left and right progressive lenses framed in the spectacle frame can be measured efficiently.

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic external view of a lens meter device according to an embodiment.
Reference numeral 1 denotes a lens meter main body. Reference numeral 2 denotes a display composed of an LCD or the like, which displays information necessary for measurement such as measurement results and alignment targets. Reference numeral 3 denotes an input switch unit, and by pressing a switch corresponding to the switch display displayed on the display 2, a necessary input instruction such as switching of the measurement mode can be performed. Reference numeral 4 denotes a nosepiece as a mounting member on which the test lens LE is mounted. Reference numeral 5 denotes a lens presser, and the lens LE placed on the nosepiece 4 can be stably held by lowering the lens presser.

  Reference numeral 6 denotes a lens pad that is movable in the front-rear direction. In the measurement of the lens LE framed in the spectacle frame 100, the lower ends of the left and right frames (in the present specification, the spectacle frame and the upper and lower sides of the lens indicate that the spectacles are worn It is used to mean the upper and lower sides of the glass) and plays a role in stabilizing. The lens pad 6 is held so as to be movable in the front-rear direction with respect to the apparatus. Reference numeral 7 denotes a nasal pad (a nose pad member) that is brought into contact with the nose pad of the spectacle frame when measuring the lens LE to be tested that is framed in the spectacle frame 100. Is held movable.

  Reference numeral 8 denotes a marking mechanism used when the marking work is performed. Reference numeral 9 denotes a READ switch for reading optical characteristic data of the lens LE. When the switch 9 is pressed, the measured value is held on the display 2 and stored in the memory inside the apparatus. Reference numeral 10 denotes a power switch for turning on the apparatus. Reference numeral 11 denotes a moving lever for moving the lens pad 6 in the front-rear direction.

FIG. 2 is a view for explaining the moving position detection mechanism 200 in the front-rear direction and the left-right direction of the lens LE.
Reference numeral 50 denotes a rack fixed to the back plate 6a of the lens pad 6. The rack 50 is held inside the apparatus so as to be movable back and forth. A pinion 51 is meshed with the rack 50, and a shaft 52 is fixed through the pinion 51. A moving lever 11 is fixed to one end of the shaft 52, and a potentiometer 54 is attached to the other end via a flexible cup 53. When the moving lever 11 is turned, the rack 50 moves back and forth with the lens pad 6 by the rotation of the pinion 51, and the rotation is transmitted to the potentiometer 54. Therefore, when the test lens LE is moved together with the lens pad 6, the amount of movement in the front-rear direction is detected by the potentiometer 54.

  Two rails 55 extending in parallel in the left-right direction are fixed to the lens backing plate 6 a via fixing members, and the nose pad 7 is a sliding member 56 that can move along the rails 55. Are integrally held. Reference numeral 6b denotes a lens abutting front plate, and a linear resistor 58a and a conductor 58b are held on the back surface thereof. A brush 57 is fixed to the sliding member 56, and the lens abutting front plate 6b is attached to the lens abutting back plate 6a so that one arm abuts the linear resistor 58a and the other arm abuts the conductor 58b. It is done. By detecting a change in voltage caused by the brush 57 sliding on the linear resistor 58a, the amount of movement in the left-right direction of the test lens that moves with the nose pad 7 (from the nose pad to the current measurement position of the test lens). ) Is detected. In other words, the distance from the bridge center of the spectacle frame to the current measurement position of the lens to be examined can be obtained.

  FIG. 3 is a schematic configuration diagram of the optical system and the control system. Reference numeral 20 denotes a measurement optical system, and L1 denotes its measurement optical axis. The measurement optical system 20 includes a measurement light source 21 such as an LED, a collimating lens 22, a mirror 23, a grid plate 24 that is a measurement index plate on which a measurement index is formed, and a two-dimensional light receiving sensor 25. The grid plate 24 is held by the holding member 26 of the main body 1, and the opening 4 a of the nose piece 4 is positioned on the grid plate 24. The opening 4a is circular with a diameter of 8 mm. As shown in FIG. 4, the grid plate 24 is formed with a measurement index 30 including a large number of circular holes. In this embodiment, the measurement index 30 includes a center hole 31 having a diameter of 0.4 mm formed at the center position through which the measurement optical axis L1 passes, and a large number of small holes 32 having a diameter of 0.2 mm arranged around the center hole 31. Consists of. The small holes 22 are distributed in a lattice shape at a pitch of 0.5 mm. The center hole 31 is used as a reference index for specifying the correspondence relationship of the other holes 31.

  The light beam from the measurement light source 21 is converted into a parallel light beam by the collimating lens 22, reflected by the mirror 23, and projected onto the lens LE placed on the nosepiece 4. Of the light transmitted through the lens LE, the light beam that has passed through the center hole 31 and the small hole 32 of the grid plate 24 enters the light receiving sensor 25.

  An output signal from the light receiving sensor 25 is input to the control unit 40. Connected to the control unit 40 is a memory 41 for storing the coordinates of the “0D reference” dot image, measurement information, and the like detected without the lens LE when the apparatus is turned on. When the lens LE is not placed, the control unit 40 uses the coordinate position of the dot image of each small hole 32 incident on the light receiving sensor 25 as a reference, and sets each dot image when the lens LE having refractive power is placed. The optical characteristics (spherical power S, columnar power C, astigmatism axis angle A, prism amount Δ) of the lens LE are calculated from the position change. For example, when a lens LE having only a spherical power is placed, each dot image is enlarged and reduced at an equal distance in a circular shape from the optical center of the lens LE, compared to the case where there is no lens LE. A spherical power S is obtained based on the amount of enlargement or reduction. Further, when the lens LE having the columnar power C is placed, each dot image is enlarged or reduced in an elliptical shape from the axial center of the lens LE, compared to the case where there is no lens LE. Based on the amount of enlargement or reduction, the column surface frequency C and the astigmatic axis angle A are obtained. The prism amount Δ is obtained from the parallel movement amount of the center dot image of the lens LE or the dot image in the vicinity thereof. A lens having a spherical power, a columnar power, and a prism may be considered as a composite of these (see Japanese Patent Laid-Open No. 50-145249).

  Here, the optical characteristics of the lens LE are calculated by setting four adjacent (at least three) dot images as one set. Accordingly, information on a plurality of measurement positions can be obtained at once in the nosepiece opening 4a, and an optical characteristic distribution in the nosepiece opening 4a can be obtained. For this reason, in the progressive lens, whether the current measurement position is in the distance portion, similarly, whether the current measurement position is in the near portion, or whether it is in the progressive zone, etc. However, it can be detected efficiently. The control unit 40 controls the display of the alignment screen of the display 2 based on the detection result of the alignment state. Further, the control unit 40 continuously obtains the refractive power distribution at predetermined time intervals based on the output of the light receiving sensor 25.

  In the lens meter having the above-described configuration, the description will focus on the distance measurement and the method of obtaining the eye point interval (PD) of the distance portions of the left and right test lenses LE framed in the spectacle lens. First, the examiner selects the measurement mode of the single focus lens or the measurement mode of the progressive lens and designates whether the lens to be measured is the right lens or the left lens by the input of the switch unit 3. The right lens or the left lens can also be automatically determined according to the position of the nose pad in the horizontal direction with respect to the nose piece when the nose pad is brought into contact with the nose pad of the spectacle frame.

Hereinafter, a case where the right-eye lens is first selected in the progressive lens measurement mode will be described. The current measurement position used in the present embodiment means the center of the measurement optical axis L1 shown in FIG. 3 among the plurality of measurement positions.
As shown in FIG. 1, the nose pad is brought into contact with the nose pad 7, and the lower side of the frame is brought into contact with the lens pad 6. In addition, the lens holder 5 is used to stabilize the test lens. The eyeglass frame 100 is adjusted up and down (front and rear relative to the apparatus) and left and right movements together with the lens pad 6 and the nose pad 7 so that the lens LE to be measured (here, the right lens) measured in this state is placed on the nosepiece 4. Start the measurement. When the test lens LE is positioned on the measurement optical axis L1 shown in FIG. 2, the current measurement position is displayed on the alignment screen 2a of the display 2 in addition to the lens mark 300 having a progressive band graphic that makes a progressive lens image. A cross line 301 shown, a target 302 showing an approximate distance power measurement position, and a guide 303 for guiding the test lens to the distance portion are displayed (see FIG. 5A).

  Since the near power measurement position of the progressive lens is located on the inward side (nose side) by about 2 mm with respect to the distance power measurement position, when the right eye lens is designated, the progressive band on the lens mark 300 is designated. The figure is displayed as a graphic slightly inclined to the left (see FIGS. 1 and 5). The lens mark 300 is moved and displayed as the alignment state changes due to the movement of the lens LE. On the other hand, the cross line 301 is fixedly displayed in a state of intersecting at the center of the screen 2a.

  When the lens LE is placed on the nosepiece 4, based on the optical characteristic distribution measured in the nosepiece opening 4 a, which position of the lens LE the current measurement position is (roughly aligned with the measurement optical axis) It is determined by the control unit 40. That is, if there is a change in optical characteristics such as SE value and spherical power S with respect to the vertical direction of the lens LE, it is determined that the current measurement position is near the lens center position (progressive zone center). If there is no change in the addition power or the column surface power C in the vertical and horizontal directions of the lens LE and the horizontal prism value (prism value in the horizontal direction) is substantially 0, it is determined that the measurement position is in the vicinity of the distance portion area. . At this time, the control unit 40 stores the SE value or the spherical power S and the prism amount distribution information in the memory 42.

  When the examiner moves the lens LE to the back side of the apparatus in order to bring the target 302 to the cross line 301 in the display state of FIG. 5A, the class line fixedly displayed at the center as shown in FIG. 5B. With respect to 301, the lens mark 300 and the target 302 are displayed so as to move upward (the display position changes) on the screen. When the test lens LE is moved, the numerical value of the prism amount and the optical characteristic changes. Therefore, the control unit 40 is based on the Prentice equation [Eccentric amount (mm) = (Prism amount / Frequency) × 10]. The movement distance from the memorized measurement position is calculated. Then, the lens mark 300 and the target 302 are moved together as needed based on the calculated moving distance (the display position is changed). Note that while the current measurement position of the lens LE is not located in the distance portion area, the control unit 40 uses the distance information obtained from the movement position detection mechanism 200 as the temporary right PD value 310 and displays the display 2. Is displayed as needed (see FIG. 6A).

  The examiner moves the lens so that the target 302 is positioned at the intersection of the cross lines 301 in order to align the distance region of the lens LE with the measurement optical axis L1. From the change in the SE value or the spherical power S obtained at the center of the measurement optical axis, the control unit 40 determines that it is a far field region when entering the region where the addition power is almost lost, as shown in FIG. The moving position of the lens mark 300 is moved so that the target 302 is positioned at the intersection of the cross lines 301, the guide 303 is turned off, and the target 302 is changed to the cross mark 304. As a result, the examiner is notified that alignment of the distance portion is completed.

At this time, the control unit 40 determines the distance (deviation amount) in the left-right direction from the current measurement position to the position where the prism value in the horizontal direction becomes 0 based on the prism value detected at the current measurement position and the frequency. Is obtained by calculation (when there is no column surface frequency). Then, the deviation amount obtained by the arithmetic processing is added to the distance between the measurement optical axis L1 obtained from the moving position detection mechanism 200 and the nose pad 7, and the distance after this addition is displayed on the display 2 as the right PD value 310 '. Displayed (see FIG. 6B). In addition, while the measurement position is located in the area of the distance portion, the control unit 40 determines the distance obtained by the moving position detection mechanism 200 and the distance to the position where the horizontal prism value obtained by the calculation becomes zero. Is always displayed as the right PD value. In addition, the examiner presses the switch 9 to hold the measured value (frequency, PD value, etc.) on the display 2 and to store it in the memory 41 inside the apparatus. When the distance C is present in the distance portion, the distance from the current measurement position is determined based on the optical characteristics (S, C, A) and prism values (horizontal and vertical prism values) obtained by measurement. The distance in the left-right direction to the main meridian passing through the power measurement position is obtained by calculation processing, and this distance is treated as the above-described deviation amount.
As described above, when the PD value is obtained, the PD value is calculated by the calculation process at the time of entering the area of the distance portion without accurately matching the eye point position (distance power measurement position) of the distance portion of the test lens. Therefore, measurement can be performed efficiently without taking time.

  When the subject lens LE enters the distance portion area, the control unit 40 displays a distance indicator 305 for performing detailed alignment in the left-right direction on the alignment screen 2a for the marking operation (FIG. 5). (See (c)). When the marking operation is necessary, the examiner moves the lens LE to the left and right while looking at the distance indicator 305 shown in FIG. When the test lens LE moves to a position where the amount of horizontal prism becomes 0 (the position of the main meridian passing through the distance power measurement position when there is a column surface power), the control unit 40 displays the distance indicator from the alignment screen 2a. The display of 305 is turned off. Thus, the examiner can confirm that the measurement position of the test lens LE is the position of the eye point in the distance portion. When the distance indicator 305 is no longer displayed on the alignment screen 2a, the examiner marks the subject lens LE using the marking mechanism 8.

Measurement of the near portion starts after the measurement value obtained at the distance portion is stored and then the lens LE is moved to a position (progressive zone) where the measurement position can obtain a predetermined addition power. To do.
When moving to the measuring step for the near portion, as shown in FIG. 7A, the control unit 40 erases the cross mark 304 indicating the far portion, and the new target 306 is correlated with the display of the progressive zone graphic. The lens mark 300 is displayed at a location corresponding to the near portion. At the same time, a guide 307 for guiding the movement of the lens is displayed. This time, in order to measure the optical characteristics of the near portion, the lens LE to be measured is moved to the front side of the apparatus so that the target 306 is located at the intersection of the cross lines 301. At this time, the control unit 40 calculates the moving distance from the distance portion based on the prism amount and the optical characteristics in the distance portion stored in the memory 41. Based on the calculated movement distance, the target 306 and the lens mark 300 are moved and displayed so as to go to the cross line 301 (the display position is changed). When the measurement position of the test lens LE is in the progressive zone, the control unit 40 turns off the guide 307 and displays the near indicator 308 on the top, bottom, left and right of the target 306 to indicate the direction in which the lens is moved (see FIG. 7B). ).

The examiner moves the lens LE so that the target 306 approaches the cross line 301 with reference to the guidance display of the near indicator 308. If the addition (or SE value) detected at the measurement position in the vertical direction around the measurement optical axis rises and becomes almost constant at a certain point, the control unit 40 determines that the vertical measurement position is in the near part. Determined. Further, in the left-right direction, if the amount of optical distortion at the measurement position at the center of the optical axis becomes the minimum value, it is determined that the position in the left-right direction is also in the near portion. When it is determined that the current measurement position is the near power measurement position, the control unit 40 turns off the display of the near indicator 308 and moves the lens mark 300 so that the target 306 is located at the intersection of the cross lines 301. Move and display. Thereby, the examiner can know the completion of the alignment to the near portion, and when the examiner presses the switch 9, the measurement value at the near power measurement position is stored in the memory 41 (with the alignment completed) The near-use measurement value may be automatically stored in the memory 41). As a result, the near power measurement position can be determined, so that it is possible to check the inset amount with respect to the distance power measurement position and the layout during the frame processing.
By performing this operation not only on the right lens but also on the left lens in the same manner, the right and left PD values of the distance portion and the binocular PD can be easily obtained.

  In the present embodiment, the calculation of the near-field power measurement position in the left-right direction is a position where the optical distortion amount at the measurement position at the center of the optical axis is the minimum value, but is not limited to this. It is only necessary to obtain a condition such that the near-field power measurement position can be understood. For example, the position where the addition power is the highest in the left-right direction and the position where the absolute value of the column surface power is the lowest in the left-right direction can be set as the near-field power measurement position in the left-right direction.

It is the figure which showed the external appearance of the lens meter in this embodiment. It is the figure which showed the structure of the movement position detection mechanism in this embodiment. It is the figure which showed the optical system and control system of the lens meter in this embodiment. It is the figure which showed the structure of the grit board. It is the figure which showed the flow of distance part position alignment in a progressive lens. It is the figure which showed the example of a display on a display. It is the figure which showed the flow of near part position alignment in a sales trial lens.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Lens meter main body 2 Display 4 Nosepiece 7 Nasal pad 20 Measurement optical system 24 Grit board 25 Two-dimensional light receiving sensor 40 Control part 41 Memory 200 Moving position detection mechanism

Claims (3)

A measurement optical system that projects a measurement light beam onto a test lens placed on the nosepiece, and receives the measurement light beam that passes through the opening of the nosepiece through the test lens by a light receiving element; In a lens meter that measures the optical characteristics of the test lens based on the output signal of the light receiving element, when the test lens is a progressive lens, the current of the test lens based on the output signal of the light receiving element The distance portion area determining means for determining whether the measurement position is within the distance portion area, and the distance portion area determining means determines that the measurement position of the lens to be measured is within the distance portion area. First distance calculation means for obtaining a first distance in the left-right direction from the current test lens measurement position to the distance power measurement position based on an output signal of the light receiving element at the measurement position of the test lens. The glasses frame Against the has a nose pad member movable in contact the lateral direction, the second distance to calculate a second distance to the nose pad member from the current of the lens measurement position based on the movement amount of the nasal contact member By adding the distances calculated by the calculation means and the first distance calculation means and the second distance calculation means, the first in the left-right direction from the bridge center of the spectacle frame to the distance power measurement position of the lens to be examined is calculated. A third distance calculating means for obtaining three distances; and a display means for displaying the third distance obtained by the third distance calculating means, wherein the display means has a measurement position of the lens to be measured at least the far distance. The lens meter is characterized in that the distance to be displayed is the second distance calculated by the second distance calculating means until entering the use area. 2. The lens meter according to claim 1, wherein the display unit is configured to calculate the third distance regardless of the movement position of the lens to be measured while the measurement position of the lens to be measured is located in the distance portion. 3. A lens meter characterized by displaying the third distance obtained in (1). 3. The lens meter according to claim 2, wherein the display means displays a third distance obtained by the third distance calculation means, and further displays a guidance mark for guiding the current measurement position to the distance power measurement position. A lens meter characterized by: