1. A calibration plate for measuring calibration of a digital microscope, the calibration plate comprising at least one calibration area formed with a surface structure which includes a plurality of grid cells arranged periodically, wherein at least part of a boundary or at least part of an apex of each grid cell can be identified by an optical imaging system of the digital microscope.
2. The calibration plate according to claim 1, wherein the grid cells have equal size and identical shape.
3. The calibration plate according to claim 2, wherein each grid cell is in the shape of a square.
4. The calibration plate according to claim 3, wherein the plurality of grid cells are arranged in a chessboard-like pattern.
5. The calibration plate according to claim 1, wherein the plurality of grid cells are stripes arranged in one-dimensional direction.
6. The calibration plate according to claim 1, wherein the reflection rates at opposite sides of the at least part of the boundary of each grid cell that can be identified by the optical imaging system of the digital microscope are different from each other.
7. The calibration plate according to claim 6, wherein each whole grid cell has a different reflection rate from adjoining areas or adjoining grid cells.
8. The calibration plate according to claim 7, wherein each grid cell and adjoining areas or adjoining grid cells have different surfaces formed with different reflection rates by photoetching.
9. The calibration plate according to claim 1, wherein the calibration plate includes a plurality of different calibration areas, and the grid cells in any one calibration area have different size from those in other calibration areas.
10. The calibration plate according to claim 1, wherein a sub-surface structure is formed in at least one grid cell of at least one calibration area and wherein the sub-surface structure also includes a plurality of grid cells arranged periodically, wherein at least part of a boundary or at least part of an apex of each grid cell of the sub-surface structure can be identified by the optical imaging system of the digital microscope.
11. The calibration plate according to claim 1, further including an even reflection area which exhibits equal reflection rate for visible lights of all the wavelengths.
12. The calibration plate according to claim 11, wherein the even reflection area is formed by a metallic coating or an optical reflective coating formed on a surface of the calibration plate.
13. A digital microscope system, comprising a digital microscope and a calibration plate, the calibration plate comprising at least one calibration area formed with a surface structure which includes a plurality of grid cells arranged periodically, wherein at least part of a boundary or at least part of an apex of each grid cell can be identified by an optical imaging system of the digital microscope.
14. The digital microscope system according to claim 13, wherein the digital microscope has a movable stage, and the calibration plate is mounted on the stage and is able to be moved along with the stage to place the calibration area thereof within a objective visual field of the digital microscope.
15. A method for measuring calibration of a digital microscope by using a calibration plate comprising at least one calibration area formed with a surface structure which includes a plurality of grid cells arranged periodically, wherein at least part of a boundary or at least part of an apex of each grid cell can be identified by an optical imaging system of the digital microscope, the method comprising:
a) placing one calibration area of the calibration plate, as a target calibration area, within the objective visual field of the digital microscope, and generating a digital image of the target calibration area by the digital microscope, wherein an optical imaging system of the digital microscope identifies at least part of boundary andor at least part of apexes of each grid cell andor at least part of joint points of the grid cells in the target calibration area and reflects in the digital image the at least part of boundary andor of apexes andor of joint points of the grid cells;
b) determining image positions or relative image position relationship of the identified at least part of boundary andor of apexes andor of joint points of the grid cells in the digital image;
c) deriving a magnification of the digital microscope by computation based on the image positions or relative image position relationship of the identified at least part of boundary andor of apexes andor of joint points of the grid cells and preset positions or relative preset position relationship of the identified at least part of boundary andor of apexes andor of joint points of the grid cells, such that the digital microscope is calibrated.
16. The method according to claim 15, wherein in a case where the calibration plate includes a plurality of different calibration areas respectively having grid cells of different sizes, the method further includes prior to the step a): moving the calibration plate to select one from the plurality of different calibration areas thereof as the target calibration area that is to be placed within the objective visual field, wherein the number of the grid cells in the objective visual field of the selected calibration area is within a predetermined range.
17. The method according to claim 15, wherein in a case where at least one grid cell of the target calibration area includes a sub-surface structure, when the number of the grid cells in the objective visual field of the sub-surface structure is within a predetermined range, image positions or relative image position relationship of the identified at least part of boundary andor of apexes andor of junction points of the grid cells of the sub-surface structure in the digital image are determined in the step b) as the image positions or relative image position relationship used in the step c).
18. The method according to claim 15, wherein preset positions of apexes or of junction points of the grid cells in the target calibration area are recorded as numerical value matrix Greal;
boundaries or apexes or junction points of the grid cells are identified in the step a) by the optical imaging system of the digital microscope; image positions of the identified junction points or apexes of the grid cells are recorded in the step b) as a numerical value matrix Gimage; and a magnification of the digital microscope is calculated using a root-mean-square of (M*Greal\u2212Gimage) minimum.
19. The method according to claim 18, wherein in the step b) the image positions Gimage of the junction points are computed by a differential and edge feature extraction algorithm according to the identified boundaries or apexes of the grid cells.
20. A method for measuring calibration of a digital microscope by using a calibration plate comprising at least one calibration area formed with a surface structure which includes a plurality of grid cells arranged periodically, wherein at least part of a boundary or at least part of an apex of each grid cell can be identified by an optical imaging system of the digital microscope, the method comprising:
(a) recognizing and marking straight portions of the boundary of the grid cells in the digital image by a Canny edge detection algorithm so as to obtain a plurality of possibly discontinuous line segments;
(b) processing the line segments obtained in step (a) by a Probabilistic Hough Transform algorithm to calculate a possible skewing angle of the digital image;
(c) de-skewing the digital image based on the skewing angle calculated in step (b);
(d) finding the discontinuous line segments in the de-skewed digital image by a Probabilistic Hough Transform algorithm, and connecting the discontinuous line segments to form continuous horizontal and vertical lines by using a Clustering algorithm;
(e) determining, based on the continuous horizontal and vertical lines obtained in the step (d), an average value of an average distance among the horizontal lines and an average distance among the vertical lines in the digital image, and calculating the magnification M of the digital microscope by dividing the average value by a preset side-length of the grid cells.
21. A method for measuring calibration of a digital microscope by using a calibration plate comprising at least one calibration area formed with a surface structure which includes a plurality of grid cells arranged periodically, wherein at least part of a boundary or at least part of an apex of each grid cell can be identified by an optical imaging system of the digital microscope, the method comprising:
(a) recognizing and marking straight portions of the boundary of the grid cells in the digital image by a Canny edge detection algorithm so as to obtain a plurality of possibly discontinuous line segments;
(b) processing the line segments obtained in the step (a) by a Probabilistic Hough Transform algorithm to calculate a possible skewing angle of the digital image;
(c) de-skewing the digital image based on the skewing angle calculated in step (b);
(d) finding the discontinuous line segments in the de-skewed digital image by a Probabilistic Hough Transform algorithm, and connecting the discontinuous line segments to form continuous horizontal and vertical lines by using a Clustering algorithm;
(e) determining image positions of junction points among the continuous horizontal and vertical lines obtained in the digital image and recording them as a numerical value matrix Gimage, and in conjunction with a numerical value matrix Greal representing preset positions of junction points among straight lines formed by connecting boundaries of the grid cells, calculating a magnification of the digital microscope using a root-mean-square of (M*Greal\u2212Gimage) of the grid cells minimum.
22. The method according to claim 20, further comprising:
generating a number of horizontal and vertical straight lines randomly across the grid cells, converting the straight lines into short line segments falling in the grid cells by using a thresholding algorithm, and calculating an average length of these short line segments; and
filtering out in step (d) the line segments that have a length longer or shorter than the average length of the short line segments by more than a predetermined value.
23. The method according to claim 21, further comprising:
generating a number of horizontal and vertical straight lines randomly across the grid cells, converting the straight lines into short line segments falling in the grid cells by using a thresholding algorithm, and calculating an average length of these short line segments; and
filtering out in step (d) the line segments that have a length longer or shorter than the average length of the short line segments by more than a predetermined value.
24. The method according to claim 15, wherein the image positions or relative image position relationship is measured by pixel.
25. The method according to claim 20, wherein the image positions or relative image position relationship is measured by pixel.
26. The method according to claim 21, wherein the image positions or relative image position relationship is measured by pixel.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A comminution apparatus for reducing a particle size of a material, the comminution apparatus comprising:
a cutting chamber defining an interior volume, the cutting chamber comprising a first member and a second member forming an angle therebetween, wherein each of the first member and the second member include a plurality of slots therethrough providing access to the interior volume; and
rotatable arbor disposed outside the interior volume of the cutting chamber and supporting a plurality of toothed blades thereon such that during rotation of the arbor a portion of each of the blades enters an interior volume of the cutting chamber through the slots in the first member and exits the interior volume of the cutting chamber through the slots in the second member.
2. The comminution apparatus of claim 1, wherein the cutting chamber includes two end supports, each end support having a first recess and a second recess for receiving an end of the first member and the second member, respectively.
3. The comminution apparatus of claim 1, wherein the first member includes an insert through which are formed the plurality of slots in the first member.
4. The comminution apparatus of claim 1, further comprising a housing enclosing the cutting chamber and the arbor.
5. The comminution apparatus of claim 4, wherein the housing is adapted to be supported on a table of a milling machine, and wherein the, milling machine selectively rotates the arbor.
6. The comminution apparatus of claim 4, further comprising a cleaning roller rotatably supported on the housing and contacting the blades during rotation.
7. The comminution apparatus of claim 1, wherein the first member includes at least one coolant channel therein.
8. The comminution apparatus of claim 4, wherein the housing includes an inlet for introduction of an inert gas into the housing.
9. The comminution apparatus of claim 1, wherein the blades are separated on the arbor by spacers disposed intermediate adjacent blades.
10. The comminution apparatus of claim 1, further comprising a collection hopper communicating with and receiving processed material from the interior volume of the cutting chamber.
11. The comminution apparatus of claim 1, wherein the plurality of slots in the first member and the plurality of slots in the second member provide access to a bottom portion of the interior volume of the cutting chamber.
12. A method for reducing a particle size of a feed material, the method comprising:
providing a comminution apparatus comprising
a cutting chamber defining an interior volume, the cutting chamber comprising a first member and a second member forming an angle therebetween, wherein each of the first member and the second member include a plurality of slots therethrough providing access to the interior volume, and
a rotatable arbor disposed outside the interior volume of the cutting chamber and supporting a plurality of toothed blades thereon such that during rotation of the arbor a portion of each of the blades enters an interior volume of the cutting chamber through the slots in the first member and exits the interior volume of the cutting chamber through the slots in the second member;
introducing the feed material into the interior volume of the cutting chamber; and
rotating the arbor to thereby rotate the plurality of blades and agitate and comminute the feed material within the interior volume of the cutting chamber.
13. The method of claim 12, wherein the feed material is selected from the group consisting of zirconium, titanium, magnesium, niobium, calcium, copper, potassium, hafnium and aluminum.
14. The method of claim 12, wherein rotating the plurality of blades reduces a particle size of the feed material to no greater than mesh size 10.