JPH0197801A - Measuring apparatus of center thickness and curvature of lens - Google Patents

Abstract

PURPOSE:To measure the center thickness and curvature of a lens simultaneously and thereby to improve the efficiency of operation, by a method wherein a curvature measuring element measuring the sagital height of a lens is combined with a center thickness measuring element measuring the amount of transfer of the curvature measuring element from a reference point. CONSTITUTION:A curvature measuring element 30 measuring the curvature of a lens 31 to be measured is constructed of a cylindrical body 32 having an inner diameter D, a spindle 33 and a dial gage 34. A measuring apparatus is constituted by combining this element with a center thickness measuring element 40 measuring the amount of transfer of said cylindrical body 32 from a reference point A. When the curvature is measured, an opening part 32a of the cylindrical body 32 is made to contact with the lens 31. Then the spindle 33 is displaced by a sagital height (h), and the radius of curvature R=D<2>/8h+h/2 is calculated from the amount of the displacement. A spindle 41 of the center thickness measuring element 40 is displaced by a distance lbetween the opening part 32a and the reference point A, and a center thickness (t) is determined by adding the displacement amount (h) to said distance. Accordingly, the curvature and the center thickness can be determined simultaneously with excellent efficiency.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a lens thickness and curvature measurement device that can simultaneously measure the thickness and curvature of a lens to be measured.

[Prior Art] Conventionally, among the characteristic elements of a lens, the thickness and curvature have been measured separately using a medium thickness measuring device and a curvature measuring device. FIG. 5 is a side view showing the above-mentioned medium thickness measuring device.
A linear magnetic scale 4 for measuring the inside thickness of the lens 3 to be measured is provided, and a measuring stand 6 equipped with a mounting portion 5 for the lens 3 to be measured is provided on the base plate 2b at the bottom of the pedestal 2. This mounting section 5 is provided so as to be positioned on the axis of a contact terminal 4b which is provided on 4a of the linear magnetic scale 4 so as to be movable up and down, and makes contact with the middle thickness of the mounted lens 3 to be measured. terminal 4
The displacement amount b is measured, and this displacement amount can be displayed on a display section 7 provided on the linear magnetic scale 4.

When measuring the medium thickness of a lens to be measured 3 using the medium thickness measuring device 1, first, a straight line is formed with the mounting surface 5a of the mounting section 5 of the measurement table 6 in a state where the lens to be measured 3 is not placed. The displacement amount of the contact terminal 4b of the equation scale 4 is adjusted to 0. That is, the contact terminal 4b is lowered to the JJiffi section 5 where the lens 3 to be measured does not exist, and brought into contact with the mounting surface 5a, and the displacement amount of the contact terminal 4b on the display section 7 at this time is adjusted to 0. .

Thereafter, the contact terminal 4b is raised, and the mounting portion 5 of the measurement table 6 is
The lens to be measured 3 is placed on. Then, the lens to be measured 3
The contact terminal 4b is brought into contact with the contact terminal 4b, and the displacement amount of the contact terminal 4b is read by the display section 7 to measure the inner thickness of the lens 3 to be measured.

FIG. 6 is a partially cutaway front view showing the curvature measuring device. In the figure, 8 indicates a dial gauge, and this dial gauge 8 is equipped with a terminal 9 that can be moved up and down, and a grip l fixed to the dial gauge 8.
A holding cylinder 11 is provided so as to be able to come into contact with the lens to be measured 3 at an opening 11a via an opening 11a. The terminal 9 is located in the holding tube 11 at the axis of the holding tube 11, and displays the amount of displacement between the holding tube 11 and the terminal 9 on the dial gauge 8, as well as the contact of the terminal 9 with the lens 3 to be measured. The end 9a is rounded so as not to damage the surface of the lens 3 to be measured.

When measuring the curvature of the lens 3 to be measured using such a curvature measuring device, first, a master lens (not shown) having a desired curvature is held at the opening 11 of the fml.
Press a with your hand.

In such a case, the terminal 9 inside the holding tube 11 is pushed by the curved surface (lens surface) of the master lens, and the opening 1'l of the holding tube 11 is pressed against the curved surface (lens surface) of the master lens.
The difference between a and the terminal 7a is displayed as a numerical value on the scale of the dial gauge 8 as the amount of displacement. Then, this display is adjusted by operating the dial gauge 8 so that the scale of the dial gauge 8 is in a state of ±0.

Next, the lens to be measured 3 is placed on the holding cylinder 11 in the same manner as above.
The dial gauge 8 displays the difference between the displacement amount and the desired curvature of the master lens, and indirectly measures the difference between the curvature of the lens 3 to be measured.

The actual measured value of the curvature of the lens 3 to be measured can be determined by measuring the displacement jlH between the opening 11a of the holding cylinder 11 and the terminal 9 using the dial gauge 8 in the cross section showing the measurement state in FIG. , can be determined by the following formula.

R” = (D/2) items (R-H) I R=D”/(8H) + (H/2) Here, R is the radius of curvature, and D is the inner diameter of the holding cylinder.

[Problems to be Solved by the Invention] However, in measuring the medium thickness and curvature of the lens described above, each is measured individually, so the lens to be measured must be transported between the respective measuring devices. There was an unavoidable problem. Therefore, manual transportation requires time and labor, and automation of transportation requires an expensive transportation device, which poses a cost problem. Furthermore, during measurement, measurement time for medium thickness, transportation time, and time for measuring curvature are required individually, and the measurement time for medium thickness and curvature is the total time for each of the above measurement times, which deteriorates the work efficiency of measurement. There was a problem.

Therefore, the present invention has been made in view of the above-mentioned problems, and it eliminates the need to transport the lens to be measured between the medium thickness measuring device and the curvature measuring device by simultaneously measuring the medium thickness and curvature of the lens to be measured. An object of the present invention is to provide a lens medium thickness and curvature measurement device that can shorten measurement time and improve measurement work efficiency.

[Means for Solving the Problems] The lens medium thickness and curvature measuring device of the present invention, as shown in the conceptual diagram of FIG. Using the spindle 22 of a measuring device that is placed in contact with the axis of the cylinder 20, the dimension (height of the notch) between the opening 20a of the cylinder 20 and the tip 22b of the spindle 22 is determined by the absolute height of the lens to be measured. A curvature measurement unit 24 measures the displacement of the cylindrical body 20 from the reference point A of the lens 21 to be measured by measuring the curvature by measuring the value or measuring the comparative value with a master lens, etc.
It is composed of a medium thickness measuring section 25 that measures the distance l between the contact portions of a and the contact portions.

[Function] According to the above configuration, when the opening 20a of the cylindrical body 20 comes into contact with the lens 21 to be measured, the spindle 22 is displaced by the height of the notch. Then, by measuring this displacement ff1h, the radius of curvature R of the lens 21 to be measured can be determined as R=D"/(8H)+(h/2), where the inner diameter of the cylindrical body 20 is D. .

Further, the spindle 26 of the medium thickness measuring section 25 is attached to the cylindrical body 20.
is displaced by the distance g between the opening 20a and the reference point A of the lens 21 to be measured. Then, this displacement amount l and the above displacement 1t
By adding h, the middle thickness (center thickness) t of the lens 21 to be measured can be determined.

[Example] Embodiments of the present invention will be described in detail below with reference to the drawings.

(First Embodiment) FIG. 2 shows a first embodiment of the medium thickness and curvature measuring device according to the present invention.

In the figure, reference numeral 30 indicates a curvature measuring section for measuring the curvature of the lens 31 to be measured. A dial gauge 34 is provided with a spindle 33 that is positioned on the axis a of a cylinder 32 and is movable up and down, and is fixed together with a grip 35. This cylindrical body 32 has a tip portion 32a that comes into contact with the lens 31 to be measured.
A guide member 3 is provided and fixed to the grip 35.
6 so as to be slidable in the vertical direction.

The guide member 36 is slidably supported in the vertical direction by a guide rod 37, and the guide rod 37 is erected and fixed on a base 38 provided with a mounting portion 38a for the lens 31 to be measured.

On the other hand, reference numeral 40 in the figure is a medium thickness measuring section for measuring the medium thickness of the lens 31 to be measured, and this medium thickness measuring section 40 has a spindle 41 that can come into contact with the lower surface 36a of the guide member 36. The dial gauge 42 is held via a grip 43, and this grip 43 is supported by a fixing member 44 fixed to the guide rod 37. The fixing member 44 is slidably provided on the guide rod 37 between the guide member 36 and the base 38, and is attached to the dial gauge 42.
can be fixed at a desired position.

Next, a case will be described in which the medium thickness and curvature of the lens to be measured 31 are measured using the medium thickness and curvature measuring device having the above configuration.

First, a master lens (not shown) with a known medium thickness and curvature is placed on the lens placement portion 38a of the base 38, and the cylindrical body
2 is lowered from above to bring the tip 32a of the cylindrical body 32 into contact with the master lens. The spindles 33 and 41 are connected to the master lens 31 and the guide member 36.
Dial gauges 34 and 42 pressed and displayed
Adjust the scale to ±0.

Here, if the curvature of the master lens is RO+, the middle thickness is to, and the contact diameter of the cylinder 32 with the master lens, that is, the inner diameter of the tip 32a of the cylinder 32 is D, then the tip 32a of the cylinder 32 and the dial The distance h0 between the tip 33a of the spindle 33 of the gauge 34 and the distance 10 between the tip 32a of the cylinder 32 and the mounting surface of the base 38 are: h,=R,-i is required.

Next, the lens 31 to be measured is placed on the placement part 38a of the base 38, and the top surface of the lens 31 is brought into contact with the tip 32a of the cylinder 32. At this time, the scale of the dial gauge 34 is Δh
, when the scale of the dial gauge 42 measures 6 g, the distance between the tip 32a of the cylinder 32 and the tip 33a of the spindle 33, and the distance between the tip 32a of the cylinder 32 and the lens 31 to be measured between the base 38. Distance to the mounting surface! h, h
=h, +Δh (1) 1=1. 1Δl (2).

Therefore, the radius of curvature R and the middle thickness t of the lens 31 to be measured are R=D/(8h)+(h/2) (3')t=
h+1 (4).

Note that the above explanation was based on the case where the curvature and medium thickness of the lens to be measured 31 were determined by measuring comparative values with the master lens. ).

According to (4), the curvature and medium thickness of the lens to be measured can be determined.

According to this embodiment, it is possible to easily and simultaneously measure the medium thickness and curvature of the characteristic elements of the lens.

(Second Embodiment) FIG. 3 shows a second embodiment of the lens medium thickness and curvature measuring device according to the present invention.
This shows an example.

The thickness and curvature measuring device of this embodiment is constructed by replacing the dial gauges 34 and 42 in the first embodiment with linear magnetic scales.

That is, in the figure, 50 indicates a linear magnetic scale provided in the curvature measuring section 30, and 51 indicates a linear magnetic scale provided in the medium thickness measuring section 40.

This linear magnetic scale 50.51 calculates the radius of curvature R9, medium thickness t, using the above equations (1) to (4) using signals that electrically output the displacement Δh and ΔI of the spindle 33.41 of the linear magnetic scale. A calculation unit 53 that performs calculation processing is connected to the calculation unit 53, and a display unit 54 that displays the calculated numerical value is connected to the calculation unit 53. The rest of the structure is the same as that of the first embodiment, so the same parts are given the same numbers and the explanation thereof will be omitted. Further, since the steps of measuring the curvature and the medium thickness are the same as those in the above embodiment, the explanation thereof will be omitted.

According to this embodiment, the same functions and effects as those of the first embodiment described above can be obtained. Furthermore, the radius of curvature and the medium thickness of the lens to be measured can be immediately known, and these values can be easily fed back to the lens processing machine, allowing the lens to be reprocessed quickly.

Further, by using it together with a conveyance device for conveying the lens to be measured and a control device, it can be used as an automatic medium thickness and curvature measuring device.

(Third Embodiment) FIG. 4 shows the third embodiment of the lens medium thickness and curvature measuring device according to the present invention.
This shows an example.

The medium thickness and curvature measuring device of this embodiment is configured to be able to simultaneously measure the curvature and medium thickness of both surfaces of the lens to be measured.

That is, the apparatus of this embodiment includes an upper surface curvature measuring section 61 that measures the curvature of one surface (the upper surface in the figure) of the lens 60 to be measured, and a lower surface curvature measuring section 62 that measures the curvature of the lower surface of the lens 60 to be measured. It is composed of a curvature measuring section 63. In this embodiment, the top surface curvature measuring section 61 and the middle thickness measuring section 63 are constructed in the same manner as the curvature measuring section 30 and the middle thickness measuring section 40 of the second embodiment, so the same portions have the same structure. They are numbered and their explanations are omitted.

The lower surface curvature measuring unit 62 is a linear magnetic type having a cylinder 64 having an outer diameter smaller than the outer diameter of the lens 60 to be measured, and a spindle 65 positioned at the axis of the cylinder 64 and movable up and down. A scale 66 is fixed together with a grip 67, and a contact portion 64a is formed in the upper part of the cylindrical body 64 to come into contact with (place on) the lower surface of the lens 60 to be measured.

The lower surface curvature measuring section 62 is fixed to the base 38 with the axis a of the cylinder 32 of the upper surface curvature measuring section 61 aligned with the axis A of the cylinder 64.

A case in which the curvature and medium thickness of the lens to be measured 60 are measured using the measuring device having the above configuration will be described below.

First, the lens to be measured 60 is held between the cylinders 32 and 64, and the displacement h1 between the cylinder 32 and the tip 33a of the spindle 33 and the displacement between the cylinder 64 and the tip 65a of the spindle 65 are measured using the linear magnetic scale 50. and 66. This displacement flh can be determined by measuring a comparative value (Δ)11+Δht) with the master lens or by measuring an absolute value (h+, h*) of the lens to be measured. Also,
The distance l between the cylindrical body 32 and the cylindrical body 64 is measured using a linear magnetic scale 5.
Measured according to 1.

Then, the measured values are input to the calculation unit 53 in the same manner as in the second embodiment, and the curvature radius R, , R of the lens 60 to be measured is
, and medium thickness t are calculated, and the results of these calculations are displayed on the display section 54, respectively.

In addition, the above-mentioned medium thickness t is obtained by t=r+hl+hf, and in this formula, the sign of is the spindle 3.
The direction in which the tip 33a of No. 3 protrudes from the tip 32a of the cylindrical body 32 is negative (-), and the same applies to h.

Although the present embodiment is illustrated for the case where the lens 60 to be measured is a biconcave lens, it can be similarly implemented with a convex lens or a concave-convex lens.

According to this embodiment, the above first. This embodiment has the same functions and effects as the second embodiment, and can simultaneously measure the curvatures of both surfaces of the lens to be measured.

[Effects of the Invention] As described above, according to the lens medium thickness and curvature measuring device of the present invention, the medium thickness and curvature, which are characteristic elements of a lens, can be measured simultaneously. Therefore, it is possible to shorten the measurement time, and since the measuring devices for medium thickness and curvature are integrated, there is no need to transport the lens to be measured between the above devices, and it is not necessary to transport the lens manually or by a transport device. This eliminates the need for additional means, making it possible to improve work efficiency and reduce costs in the measurement process.

[Brief explanation of the drawing]

FIG. 1 is a conceptual diagram of a medium thickness and curvature measuring device according to the present invention, FIG. 2 is an explanatory diagram showing a first embodiment of the present invention, and FIG. 3 is an explanatory diagram showing a second embodiment of the present invention. FIG. 4 is an explanatory diagram showing a third embodiment of the present invention, and FIGS. 5 to 7 are explanatory diagrams of the prior art. 20.32.64...Cylinder 22.33.65...Spindle 24.30.61...Curvature measurement part 25.40.63...Medium thickness measurement part 26.41...Spindle 34 .42...Dial gauge 50.51.66...Linear magnetic scale 53...
Calculation section 54...Display section D...Cylinder diameter h...Displacement N (ball cutout height)! ...Distance (movement amount) R...Radius of curvature t...Medium thickness A...Reference point Fig. 3 Fig. 7 Fig. 1. Indication of the case 1986 Patent Application No. 255608 2, Name of the invention Lens thickness, curvature measuring device 3, Person making the correction Relationship to the case Patent applicant address 2-43-2 Hatagaya, Shibuya-ku, Tokyo Title name
(037) Representative of Olympus Optical Industry Co., Ltd.
Satoshi Yama, Department 4, Agent 105 Address: 706-6 Hamamatsucho Dia Heights, 2-2-15 Hamamatsucho, Minato-ku, Tokyo Subject of amendment −
'-''-7, Contents of correction (1) "D is the inner diameter of the holding cylinder" written on page 5, line 6 of the specification is corrected to "D is the contact diameter between the holding cylinder and the lens curvature part." do. (2) “Tip portion 22” stated on page 6, line 13 of the specification.
b” is corrected to be “tip portion 22a”. (3) "Master lens 31" written in the 13th to 14th lines of page 9 of the specification is corrected to "master lens."that's all

Claims (2)

[Claims] (1) A lens medium thickness and curvature measuring device characterized by comprising a curvature measuring section that measures the notch height of the lens, and a medium thickness measuring section that measures the amount of movement of the curvature measuring section from a reference point. . (2) A curvature measuring section that measures the height of the notch of the lens, a medium thickness measuring section that measures the amount of displacement of this curvature measuring section, and calculation processing of the curvature and medium thickness of the lens based on the measured values of both measurement sections. What is claimed is: 1. An apparatus for measuring the inside thickness and curvature of a lens, comprising: a calculation section that calculates the calculation results; and a display section that displays the calculation results of the calculation section.