BACKGROUND

1. Technical Field

The present disclosure relates to a polishing device for creating a flat surface.

2. Description of Related Art

A polishing device is typically employed to process a surface of a workpiece for complete flatness and for aesthetic reasons. The polishing device includes a polishing head and a movable base for holding the polishing head. The movable base carries the polishing head to polish the surface. In a polishing process, dust, scraps, and debris are accumulated on the surface being polishing and adversely affect the polishing. In addition, abrasion of the polishing head also degrades the polishing.

What is needed therefore is a polishing device addressing the limitations described.

BRIEF DESCRIPTION OF THE DRAWINGS

The components of the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the embodiments of the present disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout several views.

FIG. 1 is a schematic view of a polishing device, according to a first exemplary embodiment of the present disclosure.

FIG. 2 is a schematic view of a flatness detecting unit of the polishing device of FIG. 1.

FIG. 3 is a schematic view of a polishing device, according to a second exemplary embodiment of the present disclosure.

FIG. 4 is a schematic view a flatness detecting unit of the polishing device of FIG. 3.

DETAILED DESCRIPTION

Referring to FIGS. 1-2, a polishing device 100, according to a first exemplary embodiment, is shown. The polishing device 100 polishes a surface of a workpiece 200. The polishing device 100 includes a movable base 10, a polishing head 20 fixed on the movable base 10, and a flatness detecting unit 30 fixed on the movable base 10.

The movable base 10 carries the polishing head 20 and the flatness detecting unit 30, moving along a direction that is substantially parallel with the surface of the workpiece 200. The flatness detecting unit 30 moves along with the polishing head 20. The movable base 10 can be driven to move by a driving motor (not shown).

The polishing head 20 polishes the surface of the workpiece 200. The polishing head 20 includes a blade 21 at its distal end. In a polishing process, the blade 21 pares off protrusions of the surface of the workpiece 200 to improve flatness of the surface. A material of the polishing head 20 depends on a material of the workpiece 200. In this embodiment, the workpiece 200 is an insert of an injection mold (not shown), a copper or nickel layer is coated on an outer surface of the workpiece 200, and the blade 21 of the polishing head 20 includes small diamonds.

The flatness detecting unit 30 detects the flatness of the surface and determines whether the flatness of the surface is acceptable. The flatness detecting unit 30 includes a coherent light source 31, a light splitting member 32, a reflector 33, a receiving member 34, and an analyzing member 35 electrically connected to the receiving member 34.

The coherent light source 31 emits a first light beam L1 of a single frequency, which is transmitted along a direction that is substantially parallel with a movement direction of the polishing head 20. The coherent light source 31 is a laser generator.

The light splitting member 32 is positioned on an optical path of the first light beam L1 for splitting the first light beam L1 into a second light beam L2 and a third light beam L3. The second light beam L2 is reflected by the light splitting member 32 to project on the surface of the workpiece 200, and the second light beam L2 is reflected back to the light splitting member 32 by the workpiece 200. The second light beam L2 reflected by the workpiece 200 is split into a fourth light beam L4 by the light splitting member 32, and the fourth light beam L4 passes through the light splitting member 32. The third light beam L3 passes through the light splitting member 32 and is then projected on the reflector 33. The second light beam L2 is substantially perpendicular to the third light beam L3.

The reflector 33 is positioned on an optical path of the third light beam L3 for reflecting the third light beam L3 into the light splitting member 32. The third light beam L3 reflected by the reflector 33 is split into a fifth light beam L5 by the light splitting member 32, and the fifth light beam L5 is reflected by the light splitting member 32. The fourth light beam L4 and the fifth light beam L5 are made to coincide, thus the fourth light beam L4 and the fifth light beam L5 mutually interfere . An interference pattern is generated from any interference between the fourth light beam L4 and the fifth light beam L5. The reflector 33 can be moved toward or away from the light splitting member 32 to adjust a phase difference between the fourth light beam L4 and the fifth light beam L5.

The receiving member 34 is positioned on an optical path of the fourth light beam L4 and the fifth light beam L5 for receiving the interference pattern. The receiving member 34 can be a charge-coupled device (CCD) or a complementary metal oxide semiconductor (CMOS). In this embodiment, the receiving member 34 is a CCD.

The analyzing member 35 analyses the interference pattern received by the receiving member 34 and determines a flatness of the polished surface of the workpiece 200. The analyzing member 35 includes a storage unit 351 and a processor 352 electrically connected to the storage unit 351. The storage unit 351 stores a number of interference patterns, and each interference pattern represents a degree of flatness of a surface. The processor 352 analyses the interference pattern received by the receiving member 35, compares the pattern to the patterns stored in the storage unit 351, and then determines the flatness of the polished surface of the workpiece 200. The analyzing member 35 can output the determination of flatness to a display device (not shown), and/or the analyzing member 35 can compute an adjusting quantity of the polishing head 20 according to the determined flatness of the polished surface, and the adjusting quantity is then fed back to the driving motor of the movable base 10.

Before the polishing process, the polishing head 20 is adjusted to a predetermined position in relation to the workpiece 200 to set a polishing position and a polishing depth of the polishing head 20. The flatness detecting unit 30 is also adjusted to a predetermined state and location. In detail, the movable base 10 and the flatness detecting unit 30 start to polish a predetermined area of the surface of the workpiece 200. The coherent light source 31 emits a first light beam L1 to the light splitting member 32, the first light beam L1 is split into a second light beam L2 and a third light beam L3 by the light splitting member 32. The second light beam L2 is reflected by the light splitting member 32 and then projected onto the surface of the workpiece 200, the second light beam L2 is reflected by the surface and split into a fourth light beam L4 by the light splitting member 32. The third light beam L3 is reflected by the reflector 33 and split into a fifth light beam L5. The fourth light beam L4 and the fifth light beam L5 are coherent light, and thus able to generate an interference pattern. The interference pattern is received by the receiving member 34. In adjusting, the reflector 33 is moved toward or away from the light splitting member 32 to adjust any phase difference of the fourth light beam L4 and the fifth light beam L5, thus generating a predetermined pattern of the interference patterns. Then, the reflector 33 is fixed relative to the light splitting member 32. Then the polishing device 100 can start a polishing process.

During the polishing process, if the flatness of the polished surface is not uniform, the phase difference of the fourth light beam L4 and the fifth light beam L5 accordingly changes, therefore, the interference pattern is changed. The processor 35 can generate an adjusting quantity of the polishing head 20 according to the changing of the interference pattern, and can generate an adjusting quantity of the polishing head 20. The polishing head 20 can be then adjusted to a proper position. Therefore, the flatness of the polished surface of the workpiece 200 can be timely adjusted to decrease any non-uniformity in the flatness of the polished surface.

Referring to FIGS. 3-4, a polishing device 300, according to a second exemplary embodiment, is shown. The polishing device 300 in the second exemplary embodiment is similar to the polishing device 100 in the first exemplary embodiment, except that the first light beam L1 emitted form the coherent light source 31 is substantially perpendicular to a movement direction of the movable base 10 in the second exemplary embodiment. The light splitting member 32 splits the first light beam L1 into the second light beam L2 and the third light beam L3, the second light beam L2 is reflected by the light splitting member 32 and projected on to the reflector 33, and the third light beam L3 passes through the light splitting member 32 and is then projected onto the surface of the workpiece 200. The second light beam L2 is reflected to the light splitting member 32 by the reflector 33, and then the second light beam L2 is split into the fourth light beam L4. The third light beam L3 is reflected to the light splitting member 32 by the surface of the workpiece 200, and then the third light beam L3 is split into the fifth light beam L5. The fourth light beam L4 and the fifth light beam L5 are made to coincide. The receiving member 34 is positioned on an optical path of the fourth light beam L4 and the fifth light beam L5 to receive any interference pattern of the fourth light beam L4 and the fifth light beam L5.

It is believed that the present embodiments and their advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the disclosure or sacrificing all of its material advantages, the examples hereinbefore described merely being preferred or exemplary embodiments of the disclosure.