JP6830654B2 - Lens meter - Google Patents

Description

The present invention relates to, for example, a lens meter capable of measuring optical characteristics such as spherical lens power of spectacle lenses and contact lenses.

Conventionally, various progressive power lenses have been commercially available for correcting visual acuity of presbyopia and for reducing eye strain when working on a personal computer. In addition to the addition value, these progressive power lenses have hidden marks for identifying the manufacturer and laying out the spectacle frame. These hidden marks are usually difficult to see because they are slightly raised or slightly depressed and processed into a progressive power lens. Therefore, skill was required to visually recognize these hidden marks.

Patent Document 1 discloses a device that detects a hidden mark on an spectacle lens by irradiating the spectacle lens with a target pattern composed of a pattern in which opaque and transparent squares alternate. When the target pattern is applied to the spectacle lens, the direction of the light beam crossing the region having a slight refractive power (hidden mark) deviates, and the hidden mark appears as a bright region against a dark background or a dark region against a bright background. There is.

Japanese Patent No. 3133430

As described above, Patent Document 1 discloses a hidden mark detecting device that makes a hidden mark easily visible. However, the device disclosed in Patent Document 1 is a device only for detecting a hidden mark, and in order to measure optical characteristics such as a value of the refractive power of a progressive power lens which is a test lens, a lens is used. It is necessary to prepare a meter separately.

Further, the pitch of the target pattern is important when detecting the hidden mark, but when the target pattern is irradiated to the test lens, the pitch of the target pattern is expanded or reduced due to the refractive power of the test lens. There is a problem that the hidden mark may not be detected under the optimum conditions.

The present invention has been made to solve the above problems, and makes it possible to control the pitch of the target pattern displayed on the monitor to be enlarged or reduced according to the measured refractive power value of the lens to be inspected. It is an object of the present invention to provide a lens meter that can always visually recognize the hidden mark of the test lens under the optimum conditions.

In order to achieve the above object, the lens meter according to claim 1 irradiates the test lens with the light emitted from the light projecting unit, receives the light transmitted through the test lens at the light receiving unit, and receives the optics of the test lens. In a lens meter for measuring characteristics, there are at least two different types of storage means for storing the measured optical characteristic values of the test lens and display means for displaying the optical characteristic values of the test lens stored in the storage means. A display control means and a display means for displaying a hidden mark visual recognition screen on a display means, which is a target pattern composed of colors and in which a target pattern whose pitch can be freely changed to visually recognize the hidden mark of the test lens is displayed. A screen switching means for switching between a measurement screen on which the value of the optical characteristic of the test lens is displayed and a hidden mark visual recognition screen is provided, and the display control means corresponds to the optical characteristic of the test lens stored in the storage means. The feature is that the pitch of the target pattern is enlarged / reduced so that the pitch seen through the test lens becomes equal to the optimum target pitch for visually recognizing the hidden mark .

In the lens meter according to claim 2 , the optimum target pitch for visually recognizing the hidden mark in the lens meter according to claim 1 can be changed according to the size of the hidden mark and the degree of ridge or depression. It is characterized by.

Lens meter according to claim 3 is the lens meter according to claim 1 or 2, the target pattern for viewing the hidden marks, characterized in that it is a lattice pattern. The lens meter according to claim 4 is the lens meter according to claim 1 or 2 , wherein the target pattern for visually recognizing the hidden mark is a striped pattern. The lens meter according to claim 5 is the lens meter according to claim 1 or 2, wherein the target pattern for visually recognizing the hidden mark is a checkered pattern.

In the lens meter according to claim 1, in order to display a target pattern composed of at least two different colors for detecting a hidden mark of the lens to be inspected by a display means (monitor) provided in the lens meter, Patent Document 1 It does not require a device just for detecting hidden marks as disclosed in.

In addition, since the pitch of the target pattern is magnified / reduced according to the measured optical characteristic value of the test lens, the hidden mark of the test lens is always detected under the optimum conditions (target pattern with the optimum pitch). can do.

It is a figure explaining the whole structure of the lens meter which concerns on embodiment of this invention. It is a figure explaining the optical system of the lens meter which concerns on embodiment of this invention. It is a figure explaining the example of the pattern plate used in the lens meter which concerns on embodiment of this invention. It is a figure explaining the operation flow of the lens meter which concerns on embodiment of this invention. It is a figure explaining the example of (a) the display screen of the measured value, (b) the display screen of a checkered pattern as a target pattern, which is displayed on the monitor of the lens meter which concerns on embodiment of this invention. It is a figure explaining the control of the pitch of the checkered pattern displayed on the monitor of the lens meter which concerns on embodiment of this invention. It is a figure explaining the display screen of the lattice pattern as another example of the target pattern to be displayed on the monitor of the lens meter which concerns on embodiment of this invention. It is a figure explaining (a) the striped pattern (vertical) display screen, (b) the striped pattern (horizontal) display screen as another example of the target pattern to be displayed on the monitor of the lens meter which concerns on embodiment of this invention. ..

Hereinafter, the lens meter 1 according to the embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a diagram showing the overall configuration of the lens meter 1 according to the embodiment of the present invention, and FIG. 2 is a diagram showing an optical system of the lens meter 1 according to the embodiment of the present invention.

As shown in FIG. 1, the lens meter 1 according to the embodiment includes an optical system 10 and a main body 100. The optical system 10 includes a measuring light source 11 for measuring the refractive power of the lens to be inspected, an RGB type CMOS image sensor 26, and the like.

The main body 100 is composed of a calculation / control processing unit 101, a monitor 102, a touch panel 103, a switch button 104, a printer 105, a memory 106, and the like. The control signal from the calculation / control processing unit 101 controls the lighting / extinguishing of the measurement light source 11 and the control of the CMOS image sensor 26. Further, the image data acquired by the CMOS image sensor 26 is input to the calculation / control processing unit 101. Then, the image data input to the calculation / control processing unit 101 is subjected to calculation processing to calculate the value of the refractive power of the lens under test. The calculation / control processing unit 101 stores the calculated result in the memory 106 and displays it on the monitor 102.

Next, the optical system 10 will be described with reference to FIG. The optical system 10 includes a light projecting unit including a measurement light source 11 and the like, and a light receiving unit including a CMOS image sensor 26 and the like.

In the present embodiment, for example, a green light LED having a wavelength of 535 nm is adopted as the measurement light source 11. Since the refractive power of the spectacle lens is priced by the d-line (587.56 nm) or e-line (546.07 nm), which is the reference wavelength, in this embodiment, green light of 535 nm, which is close to these reference wavelengths, is adopted. However, the present invention is not limited to this, and an LED of red light having a wavelength longer than that of green light may be adopted. The error caused by the difference from the reference wavelength is corrected by the calibration work using the reference lens.

The green light (hereinafter referred to as “measurement light”) emitted from the measurement light source 11 is incident on the diaphragm 16 and the collimator lens 17. The diaphragm 16 is a thin flat plate provided with a circular through hole, and limits the luminous flux diameter of the light emitted to the lens 18 to be inspected. If the light beam diameter of the light emitted to the test lens 18 is too large, another component (not shown) arranged between the collimator lens 17 and the test lens 18 is irradiated, and the reflected light is emitted from the test lens 18. There is a risk of getting in. The diaphragm 16 limits the luminous flux diameter of the light irradiating the test lens 18 to prevent the reflected light from other components from entering the test lens 18.

Further, the measurement light source 11 is arranged at a position of the rear side focal length (back focus) of the collimator lens 17. As a result, the measurement light becomes parallel light by the collimator lens 17 and irradiates the test lens 18 perpendicularly. The lens receiver 19 is a stand on which the lens 18 to be tested is placed, and the lens 18 to be tested is arranged by the lens receiver 19 at a certain distance from the CMOS image sensor 26 which is a light receiving element, and has a refractive power or the like. Optical properties are measured.

The measurement light transmitted through the test lens 18 is incident on the cover glass 20, the pattern plate 21, and the condenser lenses 22, 23, 24, and then on the CMOS image sensor 26.

Here, the cover glass 20 is a flat plate-shaped flat glass arranged to protect the light receiving portion from dust and the like, and in the present embodiment, the measurement light, the ultraviolet light, and the blue light transmitted through the test lens 18 are approximately 100. Multi-coating for anti-reflection is applied to both the upper surface and the lower surface so that the light can be transmitted at a transmittance of%. It should be noted that the multi-coating is not indispensable, and an appropriate antireflection coating may be applied as needed.

As the pattern plate 21, for example, a disk-shaped flat plate provided with four circular through holes 21a, 21b, 21c, and 21d centered on each apex of the square as shown in FIG. 3A can be adopted. The measurement light transmitted through the test lens 18 is refracted according to the refractive power of the test lens 18 and incident on the pattern plate 21 to become four separated lights. The four separated lights are condensed by the condenser lenses 22, 23 and 24 and imaged on the light receiving surface of the CMOS image sensor 26.

Since the positions where the four lights are imaged on the light receiving surface of the CMOS image sensor 26 change according to the refractive power of the lens 18 to be inspected, the positions of the center of gravity (coordinate positions) of the four lights are the image data of the CMOS image sensor 26. By calculating from, the value of the refractive power of the lens 18 to be examined can be calculated. A method for calculating the values of optical characteristics such as the spherical power S, the cylindrical power C, and the astigmatic angle A from the four coordinate positions is disclosed in Japanese Patent No. 3150404 and the like, and details thereof will be omitted here.

Further, the measurement light in this embodiment is green light as described above. Therefore, the calculation / control processing unit 101 selectively extracts the electric signal received on the G light receiving surface from the R light receiving surface (red), the G light receiving surface (green), and the B light receiving surface (blue) of the CMOS image sensor 26. The optical characteristics such as the refractive power of the lens 18 to be inspected can be obtained by processing with. That is, by adopting the RGB type CMOS image sensor 26 as the light receiving element as in the present embodiment, it is not necessary to arrange a filter or the like for selectively receiving the measurement light.

Next, the operation method in this embodiment will be described with reference to FIG. FIG. 4 shows an example of the operation flow of the lens meter according to the embodiment of the present invention.

First, in step S10, the measurement light source 11 is turned on. When the lens under test is placed on the lens receiver 19 in step S12 (Y), the calculation of the refractive power of the lens under test 18 is started in step S14. The calculation of the refractive power of the lens 18 to be examined is always performed after the lens 18 to be examined is inserted, and each time the lens 18 is stored in the memory 106 and displayed on the monitor 102.

The process proceeds to step S16 to perform alignment. The alignment moves left, right, front and back with the lens 18 placed on the lens receiver 19 so that the optical center of the lens 18 comes to the measurement optical axis. Specifically, the alignment is performed by moving the test lens so that the target displayed on the monitor 102 comes to the center of the coordinates.

FIG. 5A is an example of a measurement screen displayed on the monitor 102 of the lens meter 1. The target area 116 is displayed in the center of the screen, and the target mark (+) 117 is displayed in the target area 116. The target mark (+) 117 represents the position of the optical center of the lens 18 to be inspected, the center 118 of the target area 116 represents the center of the optical axis of the optical system 10, and the target mark (+) displayed on the monitor 102. The operator moves the test lens 18 left, right, front and back with the lens receiver 19 placed on the lens receiver 19 so that 117 comes to the center 118 of the target area 116, and performs alignment.

In step S18, it is determined whether or not the alignment is completed. If the alignment is completed (Y: alignment is OK), the value of the refractive power of the lens 18 to be inspected at the end of the alignment is stored in the memory 106 and displayed on the monitor 102 in step S20. If the alignment is not completed (N: alignment NG), the process returns to step S14, and the calculation of the refractive power of the lens 18 to be examined is repeated.

In step S22, the value of the refractive power of the lens 18 to be inspected displayed on the monitor 102 is confirmed, and if it is determined to be OK (Y: measured value OK), the process proceeds to step S24. If there is a problem with the displayed refractive power value of the test lens 18 (N: measured value NG), the process returns to step S14, and the calculation of the refractive power of the test lens 18 is restarted.

In step S24, the switch button 104, which is a screen switching button, is pressed. When the switch button 104 is pressed, in step S26, a target pattern for visually recognizing the hidden mark of the lens 18 to be inspected is displayed on the monitor 102. In the present embodiment, as an example of the target pattern, as shown in FIG. 5B, a checkered pattern 120 in which white and black squares are alternately described will be described.

Here, the pitch of the white and black squares displayed on the monitor 102 is calculated and determined by the calculation / control processing unit 101 based on the value of the refractive power of the lens 18 stored in the memory 106 in step S20. Will be done. The hidden mark is visually recognized by arranging the test lens 18 in front of the monitor 102 on which the checkered pattern 120 is displayed and viewing the checkered pattern 120 through the test lens 18. Since the checkered pattern 120 viewed through the test lens 18 is enlarged or reduced by the refractive power of the test lens 18, the hidden mark cannot be visually recognized at a constant pitch. Therefore, in the present embodiment, the pitch of the white and black squares is determined based on the measured refractive power value of the test lens 18 so that the pitch of the checkered pattern 120 viewed through the test lens 18 is always constant. Is displayed on the monitor 102.

In step S28, the hidden mark on the lens 18 to be inspected is visually recognized. As described above, the hidden mark can be visually recognized by viewing the checkered pattern 120 displayed on the monitor 102 through the test lens 18. That is, the hidden mark can be visually recognized as a dark region of a bright background (white square) or a bright region of a dark background (black square).

When the visibility of the hidden mark is completed, the switch button 104 is pressed again in step S30. When the switch button 104 is pressed, the measurement screen shown in FIG. 5A is displayed again on the monitor 102 in step S32.

In step S34, it is determined whether or not the measurement is completed. If the measurement is completed (Y), the operation is completed. In the case of measuring again (N), the process returns to step S14, and the calculation of the refractive power of the lens 18 to be examined is repeated.

The screen display shown in FIGS. 5A and 5B is an example and is not limited. The optimum screen display may be displayed on the monitor 102 as appropriate.

FIG. 6 is a diagram illustrating control of a checkered pitch displayed on a monitor of a lens meter according to an embodiment of the present invention. It is assumed that the optimum pitches d0 and d0 of the white and black squares of the checkered pattern 120 displayed on the monitor 102 of FIG. 6A are the optimum values for visually recognizing the hidden mark. For example, when the test lens 18 is a convex lens having a positive refractive power, the pitches d1 and d1 of the checkered pattern 120 seen through the test lens 18 are larger than the pitches d0 and d0 as shown in FIG. (D1> d0).

In the present embodiment, as shown in FIG. 6B, the checkered pattern 120 visible through the test lens 18 has a checkered pattern so that the pitches d2 and d2 are equal to the optimum pitches d0 and d0 (d2 = d0). The white and black square pitches d3 and d3 of 120 are reduced (d3 <d0) and displayed on the monitor 102. Here, the white and black square pitches d3 and d3 of the checkered pattern 120 displayed on the monitor 102 are calculated and controlled by the calculation / control processing unit 101 based on the measured refractive power values of the lens 18 as described above. Is calculated by.

As described above, according to the present embodiment, the hidden mark can be visually recognized with the optimum pitch of the white and black squares regardless of the refractive power of the lens 18 to be inspected.

Here, the lens meter 1 is an example of a lens meter, the lens 18 to be examined is an example of a lens to be examined, the memory 106 is an example of storage means, the monitor 102 is an example of display means, and the checkered pattern 120. Is an example of a target pattern.

The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, the present invention is not limited to the one applied to the above-described embodiment, and may be applied to an embodiment in which these embodiments are appropriately combined, and the present invention is not particularly limited.

For example, in the above embodiment, the pattern plate 21 has the four holes shown in FIG. 3A, but the pattern plate is not limited to this. For example, it is also possible to adopt a Hartmann plate provided with a large number of through holes as in the pattern plate 210 of FIG. 3 (b). Further, although not shown in the present specification, a circular pattern may be adopted. That is, the patterns disclosed in various patent documents can be adopted.

Further, in the above embodiment, the checkered pattern 120 of white and black is displayed on the monitor 102, but the combination of light and dark colors is not limited to white and black, and various color combinations can be adopted. .. Further, it may be a combination of three or more colors. Various color combinations can be adopted as long as the color scheme is effective for visual recognition.

Further, in the above embodiment, the pitches d0 and d0 of the white and black squares are regarded as the optimum values, but this is also not limited to one value. The values of pitches d0 and d0 may be adjusted according to the size of the hidden mark and the degree of ridge or depression. For example, the values of pitch d0 and d0 may be adjusted by the enlargement / reduction button 121 of FIG. 5B, or may be adjusted by swiping, pinching out, or pinching in on the monitor.

Further, in the above embodiment, as an example of the target pattern, the checkered pattern 120 in which squares are alternately arranged as shown in FIG. 5B is displayed on the monitor 102, but the target pattern is not limited to this. For example, the eyes of the checkered pattern 120 may be rectangular instead of square. Further, the checkered pattern 122 as shown in FIG. 7 may be used, or the striped patterns 123 and 124 as shown in FIGS. 8A and 8B may be used.

Further, the target patterns shown in FIGS. 5 (b), 7 and 8 (a) and 8 (b) are patterns having boundaries in the vertical or horizontal direction with respect to the vertical direction of the monitor 102, but the present invention is limited to this. It may be a pattern having a boundary in the inclination direction instead of the one.

1 ・ ・ Lens meter 10 ・ ・ Optical system 11 ・ ・ Measurement light source 18 ・ ・ Lens to be inspected 26 ・ ・ CMOS image sensor 101 ・ ・ Calculation / control processing unit 102 ・ ・ Monitor 120 ・ ・ Checkered pattern

Claims (5)

The test lens is irradiated with the light emitted from the light projecting unit.
In a lens meter that measures the optical characteristics of the lens under test by receiving the light transmitted through the lens under test at the light receiving unit.
A storage means for storing the measured optical characteristic values of the lens to be inspected, and
A display means for displaying the optical characteristic value of the test lens stored in the storage means, and a display means.
A display for displaying a hidden mark viewing screen, which is a target pattern composed of at least two different colors and in which a target pattern whose pitch can be freely changed in order to visually recognize the hidden mark of the test lens is displayed. Control means and
A screen switching means for switching between a measurement screen on which the value of the optical characteristic of the test lens is displayed by the display means and the hidden mark visual recognition screen is provided.
The display control means has the target pattern so that the pitch seen through the test lens is equal to the optimum target pitch for visually recognizing the hidden mark according to the optical characteristics of the test lens stored in the storage means. A lens meter characterized by controlling the expansion / reduction of the pitch of the lens.
The lens meter according to claim 1, wherein the optimum target pitch for visually recognizing the hidden mark can be changed according to the size of the hidden mark and the degree of ridge or depression.
The lens meter according to claim 1 or 2 , wherein the target pattern is a checkerboard pattern. The lens meter according to claim 1 or 2 , wherein the target pattern is a striped pattern.
The lens meter according to claim 1 or 2, wherein the target pattern is a checkered pattern.