TWI421465B - Lens thickness measuring device - Google Patents

Description

Lens thickness gauge

The invention relates to a thickness gauge, in particular to a lens thickness gauge for measuring the center thickness of a lens and a method for measuring the thickness of the lens center.

In recent years, with the development of optical products, the application range of optical lenses has continued to expand, such as digital cameras and mobile phones with camera functions. The optical lens and the lens module including the optical lens require high precision. Optical lenses are typically injection molded. Production of products by injection molding greatly increases production efficiency and output, and reduces costs.

During the production process, the lens needs to be tested for its center thickness (thickness of the lens center) after injection molding to ensure the accuracy of the product. A lens, etc. is disclosed in A Novel Optical Method of Dimension Measurement of Objects with Circular Cross-section by Tomas Fischer et al., 2006 Instrumentation and Measurement Technology Conference. Height detection method for optical components.

Referring to FIG. 1, at present, a contact surface profiler 2 is generally used in the production process, which uses the surface profiler 2 to contact the surface of a lens 1 and move on the surface of the lens 1, and then calculates the difference between the highest point and the lowest point during the movement. The value is found to be the center thickness of the lens 1. However, the contact surface profiler 2 is expensive, and when the lens 1 is easily placed tilted, measurement errors are caused.

Referring to FIG. 2, the height gauge 3 is also used to measure the center thickness of the lens 1. The height gauge 3 includes a measuring stage 32 and a contact head 31. When measuring, the lens 1 is placed on the carrying table 32, one surface of the lens 1 is in contact with the carrying table 32, and the end surface of the contact head 31 and the lens 1 are different. A surface contact, at which time the height gauge 3 reads the distance between the carrier 32 and the contact head 31, that is, the center thickness of the lens 1.

However, generally, the surface of the carrying platform 32 and the end surface of the contact head 31 are both flat. When the lens 1 is measured, the lens 1 cannot be effectively fixed, which is liable to cause measurement error. In addition, the surface of the loading table 32 and the end surface of the contact head 31 and the surface of the lens 1 are The contact surface is relatively small. When the contact head 31 is in contact with the surface of the lens 1, the lens 1 is easily deformed locally, and the measurement accuracy is deteriorated.

In view of this, it is necessary to provide a lens thickness gauge with high measurement accuracy.

A lens thickness gauge for measuring a center flesh thickness of a lens, the lens thickness gauge comprising a lens carrier and a scale, the scale being disposed opposite to the lens carrier, the lens carrier having a receiving groove for receiving the lens The lens carrier is provided with a contact unit and a control unit, the contact unit and the scale are located on opposite sides of the lens carrier, and the contact unit and the scale can move away from and close to the receiving groove, The control unit controls the movement of the contact unit.

Compared with the prior art, the lens thickness gauge adopts a contact unit and a lens carrier, and the lens carrier has a receiving groove for accommodating the lens, and is transparent when measuring the thickness of the lens center. The lens is firmly received in the accommodating groove, the contact unit is in contact with one surface of the lens, and the scale is in contact with the other side of the lens. When the lens is used to measure the lens, the force area of the lens is large, thereby avoiding The measurement error caused by the local deformation of the lens caused by deformation.

32, 11‧‧ ‧ carrying platform

31‧‧‧Contact head

3‧‧‧ height gauge

2‧‧‧Surface profiler

10‧‧‧Lens Thickness Gauge

1, 20‧ ‧ lens

201‧‧‧ first surface

202‧‧‧ second surface

12‧‧‧ bracket

13‧‧‧ scale

14‧‧‧ lens carrier

16‧‧‧Contact unit

111‧‧‧ bearing surface

141‧‧‧ accommodating slots

19‧‧‧Pumping unit

142‧‧‧ first hole

143‧‧‧ second hole

17‧‧‧First connecting rod

15‧‧‧Second connecting rod

18‧‧‧Control unit

Figure 1 is a schematic view of a prior art contact surface profiler with a lens.

Figure 2 is a schematic view of a prior art height gauge and lens fit.

3 is a schematic structural view of a lens thickness gauge according to an embodiment of the present invention.

4 to 5 are schematic views of measuring the thickness of the lens using the lens thickness gauge of Fig. 3.

The invention will be further described in detail below with reference to the accompanying drawings.

Referring to FIG. 3, an embodiment of the present invention provides a lens thickness gauge 10 for measuring the center thickness of a lens 20. In this embodiment, the lens 20 is a lenticular lens having a first surface 201 and a second surface opposite thereto. Surface 202.

The lens thickness gauge 10 includes a loading platform 11, a bracket 12 for vertically fixing the loading platform 11, a scale 13 disposed on the bracket 12, and a set on the loading platform 11 at a position opposite to the scale 13 The lens carrier 14 and a contact unit 16 disposed on the lens carrier 14 have a scale 13 and a contact unit 16 on either side of the lens carrier 14.

The carrier 11 has a bearing surface 111 on which the lens carrier 14 is disposed. The lens carrier 14 has a receiving groove 141 for accommodating the lens 20 and an air extracting unit 19, and the air extracting unit 19 communicates with the receiving groove 141. In this embodiment, the receiving slot 141 is wrapped. The first hole 142 and the second hole 143 are coaxially disposed. The diameter of the first hole 142 is larger than the diameter of the second hole 143, and the diameter of the first hole 142 is equal to the size of the lens 20. The center of the scale 13, the contact unit 16 and the accommodating groove 141 are located on the same straight line to ensure that the measurement result is the center thickness of the lens 20.

The bracket 12 is provided with a first connecting rod 17 of a parallel bearing surface 111. The scale 13 is disposed on the bracket 12 via a first connecting rod 17, and the scale 13 has a precise scale.

The lens carrier 14 is provided with a second connecting rod 15 , and the contact unit 16 is connected to the lens carrier 14 via the second connecting rod 15 , and the contact unit 16 can move up and down with respect to the second connecting rod 15 , that is, the contact unit 16 can be away from And moving in the direction of the accommodating groove 141. One end of the contact unit 16 near the accommodating groove 141 is a flat surface. The second connecting rod 15 is provided with a control unit 18, which can control the rise or fall of the contact unit 16, and the control unit 18 can be a stepping motor, a hydraulic motor or the like.

When the center of the lens 20 is measured, the suction of the accommodating groove 141 by the pumping unit 19 allows the lens 20 to be firmly received in the accommodating groove 141, and the contact unit 16 is in contact with the second surface 202, and the scale 13 is When the first surface 201 is in contact, the force area of the lens 20 is large, so that the measurement error caused by the local deformation of the lens 20 can be avoided.

Referring to FIG. 4 and FIG. 5 together, the first method for measuring the center thickness of the lens 20 by using the lens thickness gauge 10 includes the following steps:

1) The lens 20 is placed in the accommodating groove 141, and the venting unit 19 is opened to evacuate the accommodating groove 141 to firmly adsorb the lens 20 on the wall of the accommodating groove 141. The contact unit 16 is operated by the control unit 18. Contact with the second surface 202 of the lens 20.

2) the scale 13 descends in contact with the first surface 201 of the lens 20, and records this moment The scale value of the scale 13 is recorded as the first scale.

3) After the scale 13 is away from the lens 20, the lens 20 is taken out, and then the scale 13 is brought into contact with the contact unit 16, and the scale value of the scale 13 at this time is recorded, and this scale is recorded as the second scale.

4) Calculate the difference between the second scale value and the first scale value, which is the center thickness of the lens 20.

Of course, a plurality of sets of differences can be measured, and the average value thereof is taken as the center flesh thickness of the lens 20.

A second method of measuring the center flesh thickness of the lens 20 using the lens thickness gauge 10 is as follows: first, the lens 20 is squared on the lens carrier 14, the contact unit 16 is brought into contact with the second surface 202, and then the lens 20 is taken out. The scale 13 is brought into contact with the contact unit 16, the first scale value of the scale 13 is recorded, and the lens 20 is placed in the accommodating groove 141, so that the scale 13 is in contact with the first surface 201, and the scale 13 is recorded. The second scale value, the difference between the second scale value and the first scale value is the center thickness of the lens 20.

A third method of measuring the center flesh thickness of the lens 20 by the lens thickness gauge 10: first, the lens 20 is placed on the lens carrier 14, so that the scale 13 contacts the first surface 201, so that the contact unit 16 and the second The surface 202 is in contact, and the first scale value of the scale 13 is recorded. Then, the lens 20 is taken out, the scale 13 is brought into contact with the contact unit 16, and the second scale of the scale 13 is recorded. The second scale value and the first scale value are recorded. The difference is the center thickness of the lens 20.

When the second surface 202 is a concave surface, one end of the contact unit 16 adjacent to the receiving groove 141 is a convex structure, and the second surface 202 is in contact with the contact unit 16, and the first surface 201 is in contact with the scale 13.

In summary, the present invention has indeed met the requirements of the invention patent, and has filed a patent application according to law. However, the above description is only a preferred embodiment of the present invention, and it is not possible to limit the scope of the patent application of the present invention. Equivalent modifications or variations made by persons skilled in the art in light of the spirit of the invention are intended to be included within the scope of the following claims.

10‧‧‧Lens Thickness Gauge

11‧‧‧Loading station

20‧‧‧ lens

12‧‧‧ bracket

13‧‧‧ scale

14‧‧‧ lens carrier

16‧‧‧Contact unit

17‧‧‧First connecting rod

15‧‧‧Second connecting rod

18‧‧‧Control unit

19‧‧‧Pumping unit

201‧‧‧ first surface

202‧‧‧ second surface

111‧‧‧ bearing surface

141‧‧‧ accommodating slots

142‧‧‧ first hole

143‧‧‧ second hole

Claims (7)

A lens thickness gauge for measuring a central flesh thickness of a lens, the lens thickness gauge comprising a lens carrier and a scale, the scale being disposed opposite to the lens carrier, wherein the lens holder has a lens for receiving the lens The lens carrier is provided with a contact unit and a control unit. The contact unit and the scale are located on opposite sides of the lens carrier. The contact unit and the scale can be moved away from and close to the receiving slot. The direction moves, and the control unit controls the movement of the contact unit. The lens thickness gauge of claim 1, wherein the size of the receiving groove is equal to the size of the lens. The lens thickness gauge of claim 1, wherein the portion of the contact unit that is in contact with the lens is a planar or protruding structure. The lens thickness gauge of any one of claims 1 to 3, wherein the lens thickness gauge further comprises a carrier, the lens carrier being disposed on the carrier. The lens thickness gauge of claim 4, wherein the lens thickness gauge further comprises a bracket vertically disposed on the carrier, the scale being coupled to the bracket by a first connecting rod. The lens thickness gauge of claim 5, wherein the lens thickness gauge further comprises a second connecting rod, the contact unit is disposed on the lens carrier through the second connecting rod, the control unit It is disposed on the second connecting rod. The lens thickness gauge of claim 6, wherein: the lens carrier is provided with an air extraction unit.