Automatic dimension analyzer

• US 4,731,745 A
• Filed: 12/03/1984
• Issued: 03/15/1988
• Est. Priority Date: 11/09/1983
• Status: Expired due to Fees

• Current Assignee: Shin-Etsu Engineering Co., Ltd. (Shin-Etsu Chemical Company Limited)
• Original Assignee: Shin-Etsu Engineering Co., Ltd. (Shin-Etsu Chemical Company Limited)
• Inventors: Kasukawa, Kozo, Manabe, Shigenaga, Katagiri, Kiyoo
• Primary Examiner(s): Krass, Errol A.
• Assistant Examiner(s): Dixon, Joseph L.
• Application Number:
  US06/677,599
• Time in Patent Office: 1,198 Days
• Field of Search: 364/560, 364/562-564, 364/478, 364/513, 33/1 M, 33/503, 33/504, 356/372, 356/380, 356/383, 356/384, 382/25, 382/6, 382/8, 358/101, 358/106, 358/107
• US Class Current: 348/141
• CPC Class Codes: G01B 11/02 for measuring length, width or thickness G01B11/08 takes precedence
• CPC Class Codes: G01B 11/022 by means of tv-camera scanning

Abstract

An automatic dimension analyzer is disclosed which comprises a power driven table on which an object being measured is placed, the table being movable in orthogonal directions, and an optical system for forming an optical image of the object in a sample point field. The sample point field is electronically scanned in a rectangular raster format to produce sample point data bits each representing a sample point having a predetermined optical level. A cursor generator is synchronized with the raster to generate a cursor in the sample point field. A coincidence detector is provided to detect a coincidence between a sample point data bit and the cursor. Measurement instructions are stored in sequentially addressible locations of a memory through a data entry means. A microprocessor addresses the memory locations to retrieve the instructions to cause one of the table and the cursor to move relative to the other so that sample points derived from the object move toward the cursor and detect the position of the table or cursor relative to a reference upon the detection of a coincidence by the coincidence detector.

Claims

1. An automatic dimension analyzer comprising:

a power driven table on which an object under measurement is placed, the table being movable in orthogonal directions in a field defined by a pair of coordinate axes;

an optical system for forming an optical image of said object in a sample point field;

means for scanning said sample point field in a rectangular raster format to produce sample point data bits each representing a sample point having a predetermined optical level;

means for detecting a coincidence between at least one sample point data bit and a cursor defined in said sample point field parallel with one of said coordinate axes, said cursor being movable in said sample point field;

a memory;

data entry means for storing measurement instructions in sequentially addressable locations of said memory;

3. An automatic dimension analyzer as claimed in claim 1, wherein said means for generating left, right, upper and bottom window cursors comprises means for generating a plurality of signals each having a binary level corresponding to the binary level of said data bits, and wherein said coincidence detecting means includes means for detecting a coincidence between at least one sample point data bit and each of said signals to produce a coincidence output.

4. An automatic dimension analyzer as claimed in claim 1, wherein said data processing means is operable, in response to said instructions, for sequentially performing the steps of:

(a) causing said table to move at a given speed;

(b) reducing the speed of said table in response to the detection of a coincidence between a data bit and one of said window cursors by said coincidence detecting means when one edge of said object coincides with one of said window cursors; and

(c) detecting the position of said table in response to the detection of a coincidence between a data bit and the first-mentioned cursor by said coincidence detecting means when said edge coincides with the first-mentioned cursor.

5. An automatic dimension analyzer as claimed in claim 3, wherein said data processing means is further programmed to perform the steps of moving said table at a speed higher than said given speed, repeating the steps (a) to (c) to detect an opposite edge of said object opposite to the first-mentioned edge thereof and deriving a distance between the opposite edges of said object from the positions detected by the step (c) successively performed.

6. An automatic dimension analyzer as claimed in claim 3, wherein said coincidence detecting means comprises at least one flip-flop responsive to said data bits and said cursor signal to generate a coincidence signal.

7. An automatic dimension analyzer as claimed in claim 1, wherein said data processing means is programmed to perform the steps of:

inverting the binary levels of said data bits supplied from said scanning means so that said coincidence detecting means detects a coincidence between at least one inverted data bit and said cursor; and

detecting the position of said table at the instant the last-mentioned coincidence ceases to exist.

8. An automatic dimension analyzer as claimed in claim 1, wherein said optical system comprises a microscope for forming an optical image of a microscopic object.

9. An automatic dimension analyzer as claimed in claim 1, further comprising a movable support on which said optical system is mounted, said support being movable perpendicularly to said table, and means for moving said support, and said data processing means is programmed to move said support moving means to follow the surface contour of said object.

10. An automatic dimension analyzer as claimed in claim 8, wherein said data processing means is programmed to perform the steps of:

(a) causing said support moving means to move said support in a direction toward or away from said object;

(b) successively detecting the number of sample points having said predetermined binary level within a preselected area of said sample point field at successive locations of said support; and

(c) causing said support moving means to stop said support at a location in which the number of sample points having said predetermined binary level is maximum.

11. An automatic dimension analyzer as claimed in claim 9, wherein the data processing means is programmed to include in step (c) the further steps of:

(c₁) successively dividing said number by the number of all sample points in said predetermined area to derive average values;

(c₂) successively detecting a difference between said average values and storing said difference in a specified location of said memory corresponding to said location of said support;

(c₃) detecting a predetermined sign of said difference which indicates that the average value derived at a succeeding location is smaller than the average value derived at a preceding location;

(c₄) if said predetermined sign is not detected, repeating the steps (c₁) and (c₂) until said sign is detected;

(c₅) if said predetermined sign is detected, detecting said difference which is greater than a predetermined value;

(c₆) if said last-mentioned difference is not detected, repeating the steps (c₁) to (c₅);

(c₇) if said last-mentioned difference is reached, causing said support moving means to stop said support;

(c₈) determining the position of said support with respect to a reference point;

(c₉) successively addressing said memory locations beginning with the location in which the most recently derived difference is stored until said predetermined sign is detected;

(c₁₀) determining the position of said support corresponding to the memory location in which said predetermined sign is detected; and

(c₁₁) causing said support moving means to move said support in an opposite direction to the position determined by the step (c₁₀).

12. An automatic dimension analyzer as claimed in claim 1, further comprising a visual display means for providing a display of said sample point field on a viewing screen.

14. An automatic dimension analyzer as claimed in claim 12, further comprising means for counting the number of data bits which coincide with one of said first and second cursors.

2. data processing means for addressing said memory locations to retrieve said instructions, causing one of said table and said cursor to move with respect to the other in accordance with the retrieved instructions and detecting the position of said table or said cursor relative to a reference position upon the detection of a coincidence by said coincidence detecting means,

wherein said coincidence detecting means comprises means for generating left, right, upper and bottom window cursors in said sample point field to define a rectangular window therein, the first-mentioned cursor being located in said rectangular window, and

means for detecting a coincidence between said sample point data bits and each one of said window cursors,

further comprising means for counting the number of data bits derived from sample points located in said window.

13. An automatic dimension analyzer comprising:

a power driven table on which an object under measurement is placed, the table being movable in orthogonal directions in a field defined by a pair of coordinate axes;

an optical system for forming an optical image of said object in a sample point field;

means for scanning said sample point field in a rectangular raster format to produce sample point data bits each representing a sample point having a predetermined optical level;

means for detecting a coincidence between at least one sample point data bit and a cursor defined in said sample point field parallel with one of said coordinate axes, said cursor being movable in said sample point field;

a memory;

data entry means for storing measurement instructions in sequentially addressable locations of said memory; and

data processing means for addressing said memory locations to retrieve said instructions, causing one of said table and said cursor to move with respect to the other in accordance with the retrieved instructions and detecting the position of said table or said cursor relative to a reference position upon the detection of a coincidence by said coincidence detecting means,

wherein said coincidence detecting means includes means for generating a second cursor in said sample point field orthogonally intersecting the first-mentioned cursor and means for detecting a coincidence of at least one data bit simultaneously with said first and second cursors, and wherein said data processing means is programmed to perform the step of detecting the position of said table in response to the detection of the last-mentioned coincidence when one edge of said object coincides with an intersection of said first and second cursors.

15. An automatic dimension analyzer comprising:

a power driven table on which an object under measurement is placed, the table being movable in orthogonal directions in a field defined by a pair of coordinate axes;

an optical system for forming an optical image of said object in a sample point field;

means for scanning said sample point field in a rectangular raster format to produce sample point data bits each representing a sample point having a predetermined optical level;

means for detecting a coincidence between at least one sample point data bit and a cursor defined in said sample point field parallel with one of said coordinate axes, said cursor being movable in said sample point field;

a memory;

data entry means for storing measurement instructions in sequentially addressable locations of said memory; and

data processing means for addressing said memory locations to retrieve said instructions, causing one of said table and said cursor to move with respect to the other in accordance with the retrieved instructions and detecting the position of said table or said cursor relative to a reference position upon the detection of a coincidence by said coincidence detecting means,

wherein said data processing means is programmed to perform the steps of causing said cursor to move from a predetermined position to a measurement point on said object and determining the displacement of said measurement point with respect to said predetermined position in response to the detection of a coincidence between a data bit and said cursor by said coincidence detecting means when said cursor coincides with said measurement point.

17. An automatic dimension analyzer as claimed in claim 15, wherein said data processing means is futher programmed to perform the step of causing said at least one pair of said window cursors to move relative to one another by moving inwardly toward each other to said opposite edges of the optical image of said object, said predetermined positions being located outside the area of said object in said sample point field.

18. An automatic dimension analyzer as claimed in claim 15, wherein said data processing means is further programmed to perform the step of causing said at least one pair of said window cursors to move relative to one another by moving outwardly in directions away from each other to said opposite edges of the optical image of said object, said predetermined positions being located within the area of said object.

16. An automatic dimension analyzer comprising:

a power driven table on which an object under measurement is placed, the table being movable in orthogonal directions in a field defined by a pair of coordinate axes;

an optical system for forming an optical image of said object in a sample point field;

means for scanning said sample point field in a rectangular raster format to produce sample point data bits each representing a sample point having a predetermined optical level;

means for detecting a coincidence between at least one sample point data bit and a cursor defined in said sample point field parallel with one of said coordinate axes, said cursor being movable in said sample point field;

a memory;

data entry means for storing measurement instruction in sequentially addressable locations of said memory; and

data processing means for addressing said memory locations to retrieve said instructions, causing one of said table and said cursor to move with respect to the other in accordance with the retrieved instructions and detecting the position of said table or said cursor relative to a reference position upon the detection of a coincidence by said coincidence detecting means,

wherein said coincidence detecting means comprises means for generating left, right, upper and bottom window cursors in said sample point field to define a rectangular window therein, the first-mentioned cursor being located in said rectangular window, and

means for detecting a coincidence between said sample point data bits and each one of said window cursors,

each of said window cursors being movable in said sample point field, said data processing means being programmed to perform the steps of;

(a) causing at least one pair of said window cursors to move relative to one another to opposite edges of the optical image of said object from predetermined positions which are defined by the area of said object;

(b) determining the positions of said opposite edges in response to the successive detection of a coincidence between a data bit and each of the cursors of the pair by said coincidence detector when said window cursors of said pair coincide with each of the opposite edges of said object; and

(c) deriving a distance between said opposite edges from the positions determined by the step (b).

19. An automatic dimension analyzer comprising:

a power driven table on which an object under measurement is placed, the table being movable in orthogonal directions in a field defined by a pair of coordinate axes;

an optical system for forming an optical image of said object in a sample point field;

means for scanning said sample point field in a rectangular raster format to produce sample point data bits each representing a sample point having a predetermined optical level;

means for detecting a coincidence between at least one sample point data bit and a cursor defined in said sample point field parallel with one of said coordinate axes, said cursor being movable in said sample point field;

a memory;

data entry means for storing measurement instructions in sequentially addressable locations of said memory; and

data processing means for addressing said memory locations to retrieve said instructions, causing one of said table and said cursor to move with respect to the other in accordance with the retrieved instructions and detecting the position of said table or said cursor relative to a reference position upon the detection of a coincidence by said coincidence detecting means,

wherein said coincidence detecting means comprises a clock source, counter means for counting clock pulses from said clock source for generating an address code, and read-write memory means, wherein said data processing means is programmed to perform the steps of addressing said memory means to write binary 1'"'"'s in a series of locations specified by said retrieved instructions and addressing locations specified by said address codes to read the binary 1'"'"'s from said memory means.

20. An automatic dimension analyzer comprising:

a power driven table on which an object under measurement is placed, the table being movable in orthogonal directions in a field defined by a pair of coordinate axes;

an optical system for forming an optical image of said object in a sample point field;

means for scanning said sample point field in a rectangular raster format to produce sample point data bits each representing a sample point having a predetermined optical level;

means for detecting a coincidence between at least one sample point data bit and a cursor defined in said sample point field parallel with one of said coordinate axes, said cursor being movable in said sample point field;

a memory;

data entry means for storing measurement instructions in sequentially addressable locations of said memory; and

data processing means for addressing said memory locations to retrieve said instructions, causing one of said table and said cursor to move with respect to the other in accordance with the retrieve instructions and detecting the position of said table or said cursor relative to a reference position upon the detection of a coincidence by said coincidence detecting means,

wherein said scanning means comprises a solid-state image sensor on which said optical image is formed and means for causing said sensor to scan the optical image in rectangular raster format.

22. An automatic dimension analyzer as claimed in claim 20, wherein said second means comprises a clock source, counter means for counting clock pulses from said clock source for generating an address code, and read-write memory means, wherein said data processing means is programmed to perform the steps of addressing said memory means to write binary 1'"'"'s in a series of locations specified by said retrieved instructions and addressing said memory means to read the binary 1'"'"'s from locations specified by said address code.

23. An automatic dimension analyzer as claimed in claim 20, wherein said optical system comprises a microscope for forming an optical image of a microscopic object.

24. An automatic dimension analyzer as claimed in claim 20, further comprising a movable support on which said optical system is mounted, said support being movable perpendicularly to said table, and means for moving said support, and said data processing means is programmed to move said support moving means to follow the surface contour of said object.

25. An automatic dimension analyzer as claimed in claim 23, wherein said data processing means is programmed to perform the steps of:

(a) causing said support moving means to move said support in a direction toward or away from said object;

(b) successively detecting the number of sample points having said predetermined binary level within a preselected area of said sample point field at successive locations of said support; and

(c) causing said support moving means to stop said support at a location in which the number of sample points having said predetermined binary level is maximum.

27. An automatic dimension analyzer as claimed in claim 25, wherein said data processing means is further programmed to perform the steps of moving said table at a speed higher than said given speed subsequent to the step (c) over a preset distance, repeating the steps (a) to (c) to detect another edge of said object opposite to the first-mentioned edge thereof by successive occurrences of coincidence between said another edge of said column and row cursors and said one of said X and Y cursors, and the step of deriving a distance between the opposite edges of the object from the positions detected by the step (c) successively performed.

28. An automatic dimension analyzer as claimed in claim 25, wherein said second means comprises means for generating a plurality of cursor signals each having a binary level corresponding to the binary level of said data bits, and means for detecting a coincidence between at least one sample point data bit and each one of said cursor signals to produce a coincidence output.

29. An automatic dimension analyzer as claimed in claim 27, wherein said second means comprises at least one flip-flop responsive to said data bits and each of said cursor signals to generate a coincidence signal.

31. An automatic dimension analyzer as claimed in claim 29, wherein said data processing means is further programmed to perform the step of causing said at least one pair of said window cursors to move relative to one another by moving inwardly toward each other to said opposite edges of said object, said predetermined positions being located outside the area of said object in said sample point field.

32. An automatic dimension analyzer as claimed in claim 29, wherein said data processing means is further programmed to perform the step of causing said at least one pair of said window cursors to move relative to one another by moving outwardly in directions away from each other to said opposite edges of said object, said predetermined positions being located within the area of said object.

34. A method as claimed in claim 32, further comprising the step of inverting all the sample points in said sample point field so that the inverted data bits represent a background of said object, wherein the step (e) comprises detecting a coincidence between at least one inverted data bit and said cursor and detecting when said coincidence ceases to exist, and wherein the step (f) comprises the step of detecting the position of said table when the cessation of said coincidence is detected.

35. A method as claimed in claim 32, further comprising the step of forming a second cursor orthogonally intersecting the first-mentioned cursor, wherein the step (c) comprises moving said table so that the data bits representing said object approach an intersection of said first and second cursors, and the step (d) comprises detecting a coincidence between a sample point defining an edge of said object and said intersection.

36. A method as claimed in claim 32, further comprising the step of forming a second movable cursor parallel with and spaced from the first-mentioned cursor, wherein the step (c) comprises moving said first and second cursors inwardly to each other toward peripheral edges of the data bits representing said object from predetermined positions, and the step (d) comprises detecting when said first and second cursors coincide with sample points defining said peripheral edges, and the step (e) comprises detecting the positions of said first and second cursors upon the occurrence of said coincidences of said first and second cursors with said data bits, and wherein the method further includes the step of deriving the distance between said first and second cursors from said detected positions.

37. A method as claimed in claim 32, further comprising the step of forming a second movable cursor parallel with and spaced from the first-mentioned cursor, wherein the step (c) comprises moving said first and second cursors outwardly from each other toward peripheral edges of the data bits representing said object from predetermined positions, and the step (d) comprises detecting when said first and second cursors coincide with sample points defining said peripheral edges, and the step (e) comprises detecting the positions of said first and second cursors upon the occurrence of said coincidences of said first and second cursors with said data bits, and wherein the method further includes the step of deriving the distance between said first and second cursors from said detected positions.

21. An automatic dimension analyzer comprising:

a power driven table on which an object under measurement is placed, the table being movable in orthogonal directions in a field defined by a pair of coordinate axes;

an optical system for forming an optical image of said object in a sample point field;

first means for scanning said sample point field in a rectangular raster format to produce sample point data bits each representing a sample point having a predetermined optical level;

second means for defining a pair of X and Y cursors orthogonally intersecting each other in said sample point field respectively parallel with said coordinate axes and detecting a coincidence between at least one sample point data bit and each one of said X and Y cursors;

a memory;

data entry means for storing measurement instructions in sequentially addressable locations of said memory; and

data processing means for addressing said memory locations to retrieve said instructions, causing said table to move with respect to said cursor in accordance with the retrieved instructions and detecting the position of said table relative to a reference point upon the detection of a coincidence by said second means

wherein said data processing means is programmed to perform the steps of;

inverting the binary levels of said data bits supplied from said first means so that said second means detects a coincidence between at least one inverted data bit and one of said X and Y cursors; and

detecting the position of said table at the instant the last mentioned coincidence ceases to exist.

26. An automatic dimension analyzer comprising:

a power driven table on which an object under measurement is placed, the table being movable in orthogonal directions in a field defined by a pair of coordinate axes;

an optical system for forming an optical image of said object in a sample point field;

first means for scanning said sample point field in a rectangular raster format to produce sample point data bits each representing a sample point having a predetermined optical level;

second means for defining a pair of X and Y cursors orthogonally intersecting each other in said sample point field respectively parallel with said coordinate axes and detecting a coincidence between at least one sample point data bit and each one of said X and Y cursors;

a memory;

data entry means for storing measurement instructions in sequentially addressable locations of said memory; and

data processing means for addressing said memory locations to retrieve said instructions, causing said table to move with respect to said cursor in accordance with the retrieved instructions and detecting the position of said table relative to a reference point upon the detection of a coincidence by said second means,

where in said second means comprises means for generating a pair of column cursors parallel with the oppositely spaced from said X cursor and a pair of row cursors parallel with and oppositely spaced from said Y cursor, said column and row cursors defining a window in said sample point field, and means for detecting a coincidence between said data bit and each one of said column and row cursors, said data processing means being programmed to sequentially perform the steps of;

(a) causing said table to move at a given speed in a direction parallel with one of said coordinate axes;

(b) reducing the speed of said table in response to the detection of a coincidence between a data bit and one of said column and row cursors by said coincidence detecting means when one edge of said object coincides with said window; and

(c) detecting the position of said table in response to the detection of a coincidence between a data bit and one of said X and Y cursors by said coincidence detecting means when said one edge of the object coincides with said X or Y cursor.

30. An automatic dimension analyzer comprising:

an optical system for forming an optical image of an object under measurement in a sample point field;

means for scanning said sample point field in a rectangular raster format to produce sample point data bits each representing a sample point having a predetermined optical level;

means for generating a pair of spaced-apart column window cursors and a pair of spaced-apart row window cursors forming with said column window cursors a rectangular window in said sample point field, each of said window cursors being movable with respect to the other of the same pair to vary the size of said rectangular window;

means coupled to said cursor generating means and to said scanning means for detecting a coincidence between at least one sample point data bit and each one of said window cursors;

a memory;

data entry means for storing measurement instructions in sequentially addressable locations of said memory; and

data processing means for addressing said memory locations to recall said instructions, causing one of said window cursors to move with respect to the other of the same pair in accordance with the recalled instructions and detecting the position of said moved cursor relative to a reference point upon the detection of a coincidence by said coincidence detecting means,

wherein said data processing means is programmed to perform the steps of;

(a) causing at least one pair of said window cursors to move relative to one another to opposite edges of said object from predetermined positions which are defined by the area of said object;

(b) determining the positions of said opposite edges in response to the successive detection of a coincidence between a data bit and each of the cursors of the pair by said coincidence detector when said window cursors of said pair coincide with each of the opposite edges of said object; and

(c) deriving a distance between said opposite edges from the positions determined by the step (b).

33. A method of analyzing the dimensions of an object placed on a movable table, comprising the steps of:

(a) forming an optical image of said object on a sample point field;

(b) scanning said sample point field in a rectangular raster format and generating sample point data bits each representing a sample point having a predetermined optical level;

(c) moving one of said table and a cursor relative to the other so that the sample points representing said object move toward said cursor, said cursor being defined in said sample point field parallel with one of coordinate axes of said field and movable therein;

(d) detecting a coincidence between at least one data bit and said cursor; and

(e) detecting the position of said table or the position of said cursor with respect to a reference point upon the detection of a coincidence by the step (d),

and further

(f) forming a second cursor parallel with and spaced from the first-mentioned cursor,

said step (c) comprising moving said table toward said second cursor at a higher speed at first, then at a lower speed when said one data bit coincides with said second cursor and moving said table toward said first cursor at the lower speed until said one data bit coincides with the first-mentioned cursor.