CA1273820A - Color measuring and control device - Google Patents
Color measuring and control deviceInfo
- Publication number
- CA1273820A CA1273820A CA000510553A CA510553A CA1273820A CA 1273820 A CA1273820 A CA 1273820A CA 000510553 A CA000510553 A CA 000510553A CA 510553 A CA510553 A CA 510553A CA 1273820 A CA1273820 A CA 1273820A
- Authority
- CA
- Canada
- Prior art keywords
- product
- head
- color
- arm
- light
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 230000003534 oscillatory effect Effects 0.000 abstract 1
- 238000000034 method Methods 0.000 description 7
- 230000003287 optical effect Effects 0.000 description 4
- 238000010438 heat treatment Methods 0.000 description 3
- 206010033546 Pallor Diseases 0.000 description 2
- 244000061456 Solanum tuberosum Species 0.000 description 2
- 235000002595 Solanum tuberosum Nutrition 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 238000001514 detection method Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 239000003517 fume Substances 0.000 description 2
- 235000012015 potatoes Nutrition 0.000 description 2
- 244000105624 Arachis hypogaea Species 0.000 description 1
- BSYNRYMUTXBXSQ-UHFFFAOYSA-N Aspirin Chemical compound CC(=O)OC1=CC=CC=C1C(O)=O BSYNRYMUTXBXSQ-UHFFFAOYSA-N 0.000 description 1
- 238000009825 accumulation Methods 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 230000009977 dual effect Effects 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 235000013305 food Nutrition 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000010355 oscillation Effects 0.000 description 1
- 235000020232 peanut Nutrition 0.000 description 1
- 238000004886 process control Methods 0.000 description 1
- 230000000246 remedial effect Effects 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 238000010408 sweeping Methods 0.000 description 1
- 230000001960 triggered effect Effects 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
- G01J3/00—Spectrometry; Spectrophotometry; Monochromators; Measuring colours
- G01J3/02—Details
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B07—SEPARATING SOLIDS FROM SOLIDS; SORTING
- B07C—POSTAL SORTING; SORTING INDIVIDUAL ARTICLES, OR BULK MATERIAL FIT TO BE SORTED PIECE-MEAL, e.g. BY PICKING
- B07C5/00—Sorting according to a characteristic or feature of the articles or material being sorted, e.g. by control effected by devices which detect or measure such characteristic or feature; Sorting by manually actuated devices, e.g. switches
- B07C5/34—Sorting according to other particular properties
- B07C5/342—Sorting according to other particular properties according to optical properties, e.g. colour
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
- G01J3/00—Spectrometry; Spectrophotometry; Monochromators; Measuring colours
- G01J3/02—Details
- G01J3/0278—Control or determination of height or angle information for sensors or receivers
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
- G01J3/00—Spectrometry; Spectrophotometry; Monochromators; Measuring colours
- G01J3/02—Details
- G01J3/0291—Housings; Spectrometer accessories; Spatial arrangement of elements, e.g. folded path arrangements
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/84—Systems specially adapted for particular applications
- G01N2021/845—Objects on a conveyor
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2201/00—Features of devices classified in G01N21/00
- G01N2201/12—Circuits of general importance; Signal processing
- G01N2201/127—Calibration; base line adjustment; drift compensation
- G01N2201/12723—Self check capacity; automatic, periodic step of checking
Abstract
ABSTRACT
A color detecting device comprising a head (14) supported on an arm (30) for oscillatory motion over the product (11) being color measured to render a signal responsive to the average color of the product. A height detector (44) provides a signal indicating the distance between the product and head and is used to modify the color signal accordingly. A temperature sensor (39) in the head indicates an overtemperature condition for causing movement of the head away from the product. The screen (17) transparency is measured by the indicator (47, 48) to indicate when the screen is dirty.
A color detecting device comprising a head (14) supported on an arm (30) for oscillatory motion over the product (11) being color measured to render a signal responsive to the average color of the product. A height detector (44) provides a signal indicating the distance between the product and head and is used to modify the color signal accordingly. A temperature sensor (39) in the head indicates an overtemperature condition for causing movement of the head away from the product. The screen (17) transparency is measured by the indicator (47, 48) to indicate when the screen is dirty.
Description
~;~73~
Inventor: Charles W. Coatnev Title: Color Measurin~ and ContLol Device Field of the Invention A device for detecting the color of articles by directing different wavelengths of light, such as red and green, thereon and detecting the reflected light to mea6ure the color of the articles.
Back~round of the Invention This invention relates primarily to apparatus especially useful in the controlling of continuously operating proce6sing maohinery such as equipment for blanching or roasting of peanuts, french fried potatoes, or for peeling potatoes and the like. In such controlled proaesses, the color of the product is detected as it leaves the processing area. Since the color changes with the degree of processing such as heating, blanching, peeling and the like, detection of the product aolor can be relied upon to lndicate whether the procedure iB satlsfactory. Thereafter, the timing or temperature usually can be altered to optimize the process. Past color detectors have included a light emittlng head whlch ls statlonary over the product. The product is carried by a oonveyor through a heating oven or the like and thereafter beneath the head of the color detector. Because the product is heated and in the process of being cooked it gives off variou6 gases and radiates heat. If the color detecting head is exposed to an overtemperature conditlon or if vapor carried matter aollects on the lens lt can be rendered inoperative.
Because the product ls stacked on a conveyor for movement through a heating prooeæsor, the distance between the head and the produot can vary due to changes ln the depth of the product on the conveyor. This variance in spacing between the head and the product, as well as the degree to which the conveyor is covered by the product, can change significantly the detected color.
Thus, ln the case of the processor being controlled by a . '~
- - . , .
, .
'~ `
1 ~ 7~
signal responsive to this color, erroneou~ control signals are generated.
It is the purpose of the present invention to provide an improved device for reading the color of a product.
Summary of the Inven~ion An apparatus for measuring the color of a product supported on a substantially horizontal surface compri 6 ing a head with means for directing light, usually in the red and green or possibly blue wavelength regions, onto the product and means for deteating the light reflected from the product. The reflected light is changed to an electronic signal indicating the color of the product.
To obtain an average color, the head is translated along a horizontal path back and forth above the product.
Means are provided within the head for measuring the temperature thereof and if the temperature exceeds a predetermined limit, an emergency circuit is triggered to move the head away from the product so it will not become overheated and damaged. The temperature measured is also used to compensate the color lndlcating signal to make it more accurate.
Additionally, a height measuring device is incorporated in the head to detect the distance between the head and the product. An electrical signal indicating this distance is used to modify the color indicating signal to also make it more accurate and delete any variances due to a change in the distance between the head and product. A special combination of light sources and lens is also provided to maximize the effective viewing area. The light sources and lens are temperature controlled and maintained clear of foreign matter to enhance the life and accuracy of the apparatus.
.
-' '' ' ' .' ' ~ ~ :' , ~738;~) 2a The invention therefore relates to a color ser.sor for detecting the color of a product carried on a top surface of a support, the sensor comprising:
5means to generate a light beam including selected color wavelengths, a head for transmitting the light beam onto the product, means supporting the head for translating movement 10over the support top surface along a path generally parallel to the top surface, detector means in the head for detecting the reflected light from the product, means to analyze the reflected light to generate an 15output signal responsive to the color of the product;
means for generating a distance signal responsive to the distance between the product and the head, and means to modulate the output signal responsive to the distance signal to adjust for light changes due to 20changes in the distance between the product and the head.
The invention still further relates to a color sensor for detecting the color of a product carried on the top surface of a support, the senor comprising:
a color sensing head including means for directing 25light of a predetermined wavelength onto the product;
a first arm supporting at one end the color sensing ~., - ~ ~
1~738~V
2b head, a second arm rotatably fixed at one end to the other end of the first arm, means rotatably supporting the second arm other end;
and, means for rotating the first arm to oscillate the head back and forth over the support to detect an average color of the product.
~,,,JI ':
. .
' ' . . ' ' ' ': ~,, ' . - . . ' -., : . :'' . .. -' ' ' .
1~7~8~(~
Des~ri~tiQn o~ the Invention Figure 1 i8 a perspeotive view of a color measuring device lncorporating the present invention, Figure 2 i6 a block diagram showing the electronic components of the inventlon, Flgure 3 show6 the mannsr in which the color mea6uring head is actuated acro~s the product; and Figure 4 is a cross sectional view of the color detector head.
De6cri~tion of the Drawin~
Apparatus incorporating the subject invention is shown in Figure 1 wherein a conveyor 10 carries the product 11, usually a food product, from an oven or other form of processing station past a color measuring lS apparatus 12. The color measuring apparatus tests the color of the product as it pas6es and while not shown in the drawing, a signal therefrom is used to adjust the process so the color falls within a predetermined range thereby indicating that a proper processing procedure is 2Q being achieved. Usually the temperature or belt speed is ad~usted to optimize the process.
The product is tested by exposing it to light in a predetermined frequency range or ranges. The reflected light is then measured to determine the color of the product in those ranges. For this purpose a head 14 is suspended over the product such that light source6 lS and 16 are positioned to direct light down on the conveyor (Fig. 4). The head comprises a housing 16 preferably made of opague material and with a bottom wall 17 including a transparent window 17A. By proper energization, light in predetermined frequenay ranges, suoh as red and green is directed onto the product with the reflected light passing baok through an aspheric lens 18A in an optical 6ystem 18 contained in a light proof enolosure 19. The light is transmitted through a . . - , ~
.
. .
. . . :: .
~ , , ` ` ., ' ` .
: .:
': ' : ` ` -` ' lZ738XO
dichroic reflector 20 or other means which separates the light ranges by passing light in one range and reflecting light in another range. Separation of the light ranges can also be accomplished by use of fiber optics, etc.
Thus, the separated red and green ranges are represented by the arrows 21 and 22 respectively, with an electrical signal being generated responsive thereto by the respective photodiodes 24 and 25. The electrical signal generated by the photodiodes is responsive to the magnitude of light in eaah range and thus indicates the color of the product in these light frequencies. For a more complete description of the operation of this portion of a typical system, reference can be made to United States Patent No. 4,057,352, Color Grading Apparatus Utllizing Infra-red Light Source, issued on November 8, 1977.
One of the problems with prior art devices is the inability to gain an accurate average reading for the width of the product passing thereby. If the head i8 raised sufficiently to view the overall product width it is u6ually far enough from the product to allow other variances ~uch as ambient light, etc. to affect the reading. If the head is placed closer to the product a smaller area is viewed and a less than average reading is gained. The subject invention allows for an average reading to be achieved for the total width of the product stream. Another problem encountered in prior art devices 18 the damaging of the detecting head by overtemperature conditions. Also, fumes frequently rise from the heated product and fog up the optical components of a detecting head and, if not remedied, will result in faulty readings being obtained.
In accordance with the present invention, the head is traversed across the product as the product is moved past and for that purpose, is mounted on a supporting arm ~ F `
, - - ~ -:
- . . ..
. ~ , . . . -- - . .
. . - .
. - :. .
1~738~0 30 (see Figures 3 and 4) whioh is pivotally attachsd to a second arm 31. The arm 31 i6 attached at one end to the top of a standard 32 (Fig. 1) extending vertically and adjacent the conveyor 11. Preferably the arm 31 extends 5 to the mid-portion of the conveyor and the arm 30 is slightly longer than one half the width of the conveyor to allow the head 14 to be traversed across the complete width of the belt. A drive motor 34 positloned the top of the standard drives chain or belt 35 extending around a sprocket 36 on the drive motor and a second sprocket 37 fixed to the supporting spindle 30A of the arm 30. By driving the belt 35 the arm 30 can be actuated to swing the head 14 through an arcuate path indicated by the dotted line 38 (Fig. 3) across the width of the conveyor lS belt. By oscillation of the arm to move the head across the belt continuously, an average color reading of the product can be achieved since the head traverses the width of the product stream as the stream proceeds past the head. Other supports for the head will achieve equal result6 as long as the head is traver6ed acros6 the product6 preferably in a continuous motion.
AS an added feature of the invention there is located within the head one or more temperature sensors 39 which indicate the temperature to which the head is heated. When an overtemperature condition exists for the head, a signal is transmitted back to the control to actuate the motor 34 and move the head immediately over a pad 40 spaced (Fig. 3) laterally from the conveyor belt. In this manner the head is removed from the immediate proximity of the product and the overtemperature condition is alleviated before the head is damaged.
AB a second feature of the invention, the device is calibrated while in the position laterally spaced from the conveyor and 6uch calibration is affected ,. ~. . - .
- , ~ ' . .
'' ' , ' : ' ` `
' .' ~ " :. - ' 1~738~
periodically to assure accurate read~ngs. Calibration is achieved by positioning one or more color calibrating targets 42 (Fig. 3) beside the conveyor on a holder 41 over which the head can be positioned periodically.
With the head so positioned calibration can then be achieved in a suitable manner such as is described in United States Patent No. 4,259,020 entitled Automatic Calibration Control for Color Grading Apparatus is 8 ued on March 31, 1981.
Another feature of the invention allows for the detection of ambient light and adjustment of the readant signal from the color detecting system responsive to the level of ambient llght. For this purpose a light detector 43 i8 provided for detecting the ambient light surrounding the head 14. By generating a signal responsive to this ambient light and U8 i ng that ambient llght signal to modify the product color signal a more accurate indication of the product is generalized.
In accordance with another feature of the invention the height of the head above the product is constantly measured so as to provide for modification of the color signal to accommodate changes in height. For this purpose a sonlc measuring device 44 (Flg. 4) is fixed to the head 14 to provide a signal indicative of the distance between the product and the head. One device which function satisfactorily in thi6 manner is the Polaroid R Sonic Position Measuring device which is available commercially. With the signal provided by this device the color signal is reduced or increased depending upon the variance in the height of the head from a normal or predetermined height above the product. The depth of the produ,ct on the conveyor changes this height. The mea6urlng device preferably has a long time aonstant so as to average the height as the head translates across the conveyor.
~, .
: . . : . : , - . . .
- - : -, -1;~73 In accordance wlth another feature of the invention there is provided a lens sensor which senses the accumulation of foreign matter on the screen 17 of the head. For this purpose a light detector 47 is positioned S within the head 14 (Figure 4). The light detector 8 uppl i es a signal indicating the light from the ~ource 15 and 16 reflected back from the transparent window 17A.
Thus a~ dust and the like accumulates on the viewing 6creen and begins to diminish the transparency of the screen the reflected light increases to a predetermined amount causing an alarm signal to be sounded indicating that the screen should be cleaned.
Illustrated in Figure 2 is a block diagram of the electrioal circuit of the subject invention. The sensor head 14 is supported by the actuating arm 30 and driven by the oscillator drive 34 which i8 under control of a position control 51. The signals from the ~ensor head are fed through the conductors 26 to an analog to digital converter 52 which has the primary function of transposing the analog signals to digital form for proper processing in a micro computer 54. The signal from the height sensor 44 is fed through the digltal interface 45 to this computer as well as the signals from the temperature sensor and the lens sensor 48. Each of the signals is utilized to modulate or modify the primary signal received from the 6ensor head optical system. The head sensor signal also serves to deteot operational limits beyond which the head cignal should not be utilized.
The micro computer 54 ~oins these signal6 for the purpose of generating a composite signal reflecting the respective input from those modifying conditions. The arm position sensor 55 for detecting the general position of the head relative to the conveyor is shown in Figure 4. This sensor comprises a disk 53 fixed to rotate with ..~' ~. ., . ' ' ~ :
. .
- - .
;~. - . - - .` `
1 ~73~
the spindle 30A to indicate the physical positioning of the arm 30 relative to the arm 31. An optical ~yBtem 55A
detects the rotative posltion of the disk in any of several well known methods and supplies a signal which is compared with that of the microcomputer to indicate a desired position and to generate a signal for energizing the oscillator drive 34. The position control 51 thereby regulates the drive 34 for oscillating and positioning the sensor head 14. A similar system is provided for the arm 31.
The output from the microcomputer 54 is fed to a microcomputer 58 including the serial interface 57 and a micro processor 59. The computer 58 includes a series of limit and sensor tables 60 which receive the height, lS temperature and dirt sensor signals and by use of a standard table look-up program, ~upplies a modifying slgnal, where appropriate, to alter the color signal received from the sensor head 14. Limits are also provided by the limit detector 60 which includes limits for the temperature sensor 39 and the lens sensor 48. If such limits are exceeded an alarm 64 is energized by an alarm output circuit 61. Additionally, a diagnostic control is energized to analyze the system in the usual manner. As described before, the calibration circuit 66 is also provided and a chart recorder 65 energized by a current loop output circuit 66, and a printer 67 provide printouts of the operation of the color measuring and control device. Also the microprocessor 59 can supply a signal to regulate the processor (not shown) that is processing the product on the conveyor.
In the manner described, there is provided a color detector which senses the overall color of the product passing on the conveyor for generation of a signal which ultimately is utilized for process control, etc. This signal can be modified by the varying height of the .
1~73~;~0 detector head relative to the product. Other variables such as the temperature of the head and the dirt deposits on the head screen are also detected to indicate when remedial action should be taken.
Additional measures ar~ also taken to provide an accurate indication of the product color. A film of air is blown along the lower face of the transparent screen 17A as indicated by the arrow. This air is circulated through the arms 31 and 30 for cooling the electronic and mechanical components therein as indicatea by the arrow6 71. The air originates at a pressured air source (not shown) and after pas6age through the arms, flows around the housing 19 and out of the port 72 adjacent the transparent screen. Thus the circulated air is used for the dual purpose of cooling the device and sweeping aontaminated fumes from the vicinity of the screen.
Inventor: Charles W. Coatnev Title: Color Measurin~ and ContLol Device Field of the Invention A device for detecting the color of articles by directing different wavelengths of light, such as red and green, thereon and detecting the reflected light to mea6ure the color of the articles.
Back~round of the Invention This invention relates primarily to apparatus especially useful in the controlling of continuously operating proce6sing maohinery such as equipment for blanching or roasting of peanuts, french fried potatoes, or for peeling potatoes and the like. In such controlled proaesses, the color of the product is detected as it leaves the processing area. Since the color changes with the degree of processing such as heating, blanching, peeling and the like, detection of the product aolor can be relied upon to lndicate whether the procedure iB satlsfactory. Thereafter, the timing or temperature usually can be altered to optimize the process. Past color detectors have included a light emittlng head whlch ls statlonary over the product. The product is carried by a oonveyor through a heating oven or the like and thereafter beneath the head of the color detector. Because the product is heated and in the process of being cooked it gives off variou6 gases and radiates heat. If the color detecting head is exposed to an overtemperature conditlon or if vapor carried matter aollects on the lens lt can be rendered inoperative.
Because the product ls stacked on a conveyor for movement through a heating prooeæsor, the distance between the head and the produot can vary due to changes ln the depth of the product on the conveyor. This variance in spacing between the head and the product, as well as the degree to which the conveyor is covered by the product, can change significantly the detected color.
Thus, ln the case of the processor being controlled by a . '~
- - . , .
, .
'~ `
1 ~ 7~
signal responsive to this color, erroneou~ control signals are generated.
It is the purpose of the present invention to provide an improved device for reading the color of a product.
Summary of the Inven~ion An apparatus for measuring the color of a product supported on a substantially horizontal surface compri 6 ing a head with means for directing light, usually in the red and green or possibly blue wavelength regions, onto the product and means for deteating the light reflected from the product. The reflected light is changed to an electronic signal indicating the color of the product.
To obtain an average color, the head is translated along a horizontal path back and forth above the product.
Means are provided within the head for measuring the temperature thereof and if the temperature exceeds a predetermined limit, an emergency circuit is triggered to move the head away from the product so it will not become overheated and damaged. The temperature measured is also used to compensate the color lndlcating signal to make it more accurate.
Additionally, a height measuring device is incorporated in the head to detect the distance between the head and the product. An electrical signal indicating this distance is used to modify the color indicating signal to also make it more accurate and delete any variances due to a change in the distance between the head and product. A special combination of light sources and lens is also provided to maximize the effective viewing area. The light sources and lens are temperature controlled and maintained clear of foreign matter to enhance the life and accuracy of the apparatus.
.
-' '' ' ' .' ' ~ ~ :' , ~738;~) 2a The invention therefore relates to a color ser.sor for detecting the color of a product carried on a top surface of a support, the sensor comprising:
5means to generate a light beam including selected color wavelengths, a head for transmitting the light beam onto the product, means supporting the head for translating movement 10over the support top surface along a path generally parallel to the top surface, detector means in the head for detecting the reflected light from the product, means to analyze the reflected light to generate an 15output signal responsive to the color of the product;
means for generating a distance signal responsive to the distance between the product and the head, and means to modulate the output signal responsive to the distance signal to adjust for light changes due to 20changes in the distance between the product and the head.
The invention still further relates to a color sensor for detecting the color of a product carried on the top surface of a support, the senor comprising:
a color sensing head including means for directing 25light of a predetermined wavelength onto the product;
a first arm supporting at one end the color sensing ~., - ~ ~
1~738~V
2b head, a second arm rotatably fixed at one end to the other end of the first arm, means rotatably supporting the second arm other end;
and, means for rotating the first arm to oscillate the head back and forth over the support to detect an average color of the product.
~,,,JI ':
. .
' ' . . ' ' ' ': ~,, ' . - . . ' -., : . :'' . .. -' ' ' .
1~7~8~(~
Des~ri~tiQn o~ the Invention Figure 1 i8 a perspeotive view of a color measuring device lncorporating the present invention, Figure 2 i6 a block diagram showing the electronic components of the inventlon, Flgure 3 show6 the mannsr in which the color mea6uring head is actuated acro~s the product; and Figure 4 is a cross sectional view of the color detector head.
De6cri~tion of the Drawin~
Apparatus incorporating the subject invention is shown in Figure 1 wherein a conveyor 10 carries the product 11, usually a food product, from an oven or other form of processing station past a color measuring lS apparatus 12. The color measuring apparatus tests the color of the product as it pas6es and while not shown in the drawing, a signal therefrom is used to adjust the process so the color falls within a predetermined range thereby indicating that a proper processing procedure is 2Q being achieved. Usually the temperature or belt speed is ad~usted to optimize the process.
The product is tested by exposing it to light in a predetermined frequency range or ranges. The reflected light is then measured to determine the color of the product in those ranges. For this purpose a head 14 is suspended over the product such that light source6 lS and 16 are positioned to direct light down on the conveyor (Fig. 4). The head comprises a housing 16 preferably made of opague material and with a bottom wall 17 including a transparent window 17A. By proper energization, light in predetermined frequenay ranges, suoh as red and green is directed onto the product with the reflected light passing baok through an aspheric lens 18A in an optical 6ystem 18 contained in a light proof enolosure 19. The light is transmitted through a . . - , ~
.
. .
. . . :: .
~ , , ` ` ., ' ` .
: .:
': ' : ` ` -` ' lZ738XO
dichroic reflector 20 or other means which separates the light ranges by passing light in one range and reflecting light in another range. Separation of the light ranges can also be accomplished by use of fiber optics, etc.
Thus, the separated red and green ranges are represented by the arrows 21 and 22 respectively, with an electrical signal being generated responsive thereto by the respective photodiodes 24 and 25. The electrical signal generated by the photodiodes is responsive to the magnitude of light in eaah range and thus indicates the color of the product in these light frequencies. For a more complete description of the operation of this portion of a typical system, reference can be made to United States Patent No. 4,057,352, Color Grading Apparatus Utllizing Infra-red Light Source, issued on November 8, 1977.
One of the problems with prior art devices is the inability to gain an accurate average reading for the width of the product passing thereby. If the head i8 raised sufficiently to view the overall product width it is u6ually far enough from the product to allow other variances ~uch as ambient light, etc. to affect the reading. If the head is placed closer to the product a smaller area is viewed and a less than average reading is gained. The subject invention allows for an average reading to be achieved for the total width of the product stream. Another problem encountered in prior art devices 18 the damaging of the detecting head by overtemperature conditions. Also, fumes frequently rise from the heated product and fog up the optical components of a detecting head and, if not remedied, will result in faulty readings being obtained.
In accordance with the present invention, the head is traversed across the product as the product is moved past and for that purpose, is mounted on a supporting arm ~ F `
, - - ~ -:
- . . ..
. ~ , . . . -- - . .
. . - .
. - :. .
1~738~0 30 (see Figures 3 and 4) whioh is pivotally attachsd to a second arm 31. The arm 31 i6 attached at one end to the top of a standard 32 (Fig. 1) extending vertically and adjacent the conveyor 11. Preferably the arm 31 extends 5 to the mid-portion of the conveyor and the arm 30 is slightly longer than one half the width of the conveyor to allow the head 14 to be traversed across the complete width of the belt. A drive motor 34 positloned the top of the standard drives chain or belt 35 extending around a sprocket 36 on the drive motor and a second sprocket 37 fixed to the supporting spindle 30A of the arm 30. By driving the belt 35 the arm 30 can be actuated to swing the head 14 through an arcuate path indicated by the dotted line 38 (Fig. 3) across the width of the conveyor lS belt. By oscillation of the arm to move the head across the belt continuously, an average color reading of the product can be achieved since the head traverses the width of the product stream as the stream proceeds past the head. Other supports for the head will achieve equal result6 as long as the head is traver6ed acros6 the product6 preferably in a continuous motion.
AS an added feature of the invention there is located within the head one or more temperature sensors 39 which indicate the temperature to which the head is heated. When an overtemperature condition exists for the head, a signal is transmitted back to the control to actuate the motor 34 and move the head immediately over a pad 40 spaced (Fig. 3) laterally from the conveyor belt. In this manner the head is removed from the immediate proximity of the product and the overtemperature condition is alleviated before the head is damaged.
AB a second feature of the invention, the device is calibrated while in the position laterally spaced from the conveyor and 6uch calibration is affected ,. ~. . - .
- , ~ ' . .
'' ' , ' : ' ` `
' .' ~ " :. - ' 1~738~
periodically to assure accurate read~ngs. Calibration is achieved by positioning one or more color calibrating targets 42 (Fig. 3) beside the conveyor on a holder 41 over which the head can be positioned periodically.
With the head so positioned calibration can then be achieved in a suitable manner such as is described in United States Patent No. 4,259,020 entitled Automatic Calibration Control for Color Grading Apparatus is 8 ued on March 31, 1981.
Another feature of the invention allows for the detection of ambient light and adjustment of the readant signal from the color detecting system responsive to the level of ambient llght. For this purpose a light detector 43 i8 provided for detecting the ambient light surrounding the head 14. By generating a signal responsive to this ambient light and U8 i ng that ambient llght signal to modify the product color signal a more accurate indication of the product is generalized.
In accordance with another feature of the invention the height of the head above the product is constantly measured so as to provide for modification of the color signal to accommodate changes in height. For this purpose a sonlc measuring device 44 (Flg. 4) is fixed to the head 14 to provide a signal indicative of the distance between the product and the head. One device which function satisfactorily in thi6 manner is the Polaroid R Sonic Position Measuring device which is available commercially. With the signal provided by this device the color signal is reduced or increased depending upon the variance in the height of the head from a normal or predetermined height above the product. The depth of the produ,ct on the conveyor changes this height. The mea6urlng device preferably has a long time aonstant so as to average the height as the head translates across the conveyor.
~, .
: . . : . : , - . . .
- - : -, -1;~73 In accordance wlth another feature of the invention there is provided a lens sensor which senses the accumulation of foreign matter on the screen 17 of the head. For this purpose a light detector 47 is positioned S within the head 14 (Figure 4). The light detector 8 uppl i es a signal indicating the light from the ~ource 15 and 16 reflected back from the transparent window 17A.
Thus a~ dust and the like accumulates on the viewing 6creen and begins to diminish the transparency of the screen the reflected light increases to a predetermined amount causing an alarm signal to be sounded indicating that the screen should be cleaned.
Illustrated in Figure 2 is a block diagram of the electrioal circuit of the subject invention. The sensor head 14 is supported by the actuating arm 30 and driven by the oscillator drive 34 which i8 under control of a position control 51. The signals from the ~ensor head are fed through the conductors 26 to an analog to digital converter 52 which has the primary function of transposing the analog signals to digital form for proper processing in a micro computer 54. The signal from the height sensor 44 is fed through the digltal interface 45 to this computer as well as the signals from the temperature sensor and the lens sensor 48. Each of the signals is utilized to modulate or modify the primary signal received from the 6ensor head optical system. The head sensor signal also serves to deteot operational limits beyond which the head cignal should not be utilized.
The micro computer 54 ~oins these signal6 for the purpose of generating a composite signal reflecting the respective input from those modifying conditions. The arm position sensor 55 for detecting the general position of the head relative to the conveyor is shown in Figure 4. This sensor comprises a disk 53 fixed to rotate with ..~' ~. ., . ' ' ~ :
. .
- - .
;~. - . - - .` `
1 ~73~
the spindle 30A to indicate the physical positioning of the arm 30 relative to the arm 31. An optical ~yBtem 55A
detects the rotative posltion of the disk in any of several well known methods and supplies a signal which is compared with that of the microcomputer to indicate a desired position and to generate a signal for energizing the oscillator drive 34. The position control 51 thereby regulates the drive 34 for oscillating and positioning the sensor head 14. A similar system is provided for the arm 31.
The output from the microcomputer 54 is fed to a microcomputer 58 including the serial interface 57 and a micro processor 59. The computer 58 includes a series of limit and sensor tables 60 which receive the height, lS temperature and dirt sensor signals and by use of a standard table look-up program, ~upplies a modifying slgnal, where appropriate, to alter the color signal received from the sensor head 14. Limits are also provided by the limit detector 60 which includes limits for the temperature sensor 39 and the lens sensor 48. If such limits are exceeded an alarm 64 is energized by an alarm output circuit 61. Additionally, a diagnostic control is energized to analyze the system in the usual manner. As described before, the calibration circuit 66 is also provided and a chart recorder 65 energized by a current loop output circuit 66, and a printer 67 provide printouts of the operation of the color measuring and control device. Also the microprocessor 59 can supply a signal to regulate the processor (not shown) that is processing the product on the conveyor.
In the manner described, there is provided a color detector which senses the overall color of the product passing on the conveyor for generation of a signal which ultimately is utilized for process control, etc. This signal can be modified by the varying height of the .
1~73~;~0 detector head relative to the product. Other variables such as the temperature of the head and the dirt deposits on the head screen are also detected to indicate when remedial action should be taken.
Additional measures ar~ also taken to provide an accurate indication of the product color. A film of air is blown along the lower face of the transparent screen 17A as indicated by the arrow. This air is circulated through the arms 31 and 30 for cooling the electronic and mechanical components therein as indicatea by the arrow6 71. The air originates at a pressured air source (not shown) and after pas6age through the arms, flows around the housing 19 and out of the port 72 adjacent the transparent screen. Thus the circulated air is used for the dual purpose of cooling the device and sweeping aontaminated fumes from the vicinity of the screen.
Claims (2)
1. A color sensor for detecting the color of a product carried on a top surface of a support, said sensor comprising:
means to generate a light beam including selected color wavelengths, a head for transmitting said light beam onto said product, means supporting said head for translating movement over said support top surface along a path generally parallel to said top surface, detector means in said head for detecting the reflected light from said product, means to analyze said reflected light to generate an output signal responsive to the color of said product;
means for generating a distance signal responsive to the distance between the product and said head, and means to modulate said output signal responsive to said distance signal to adjust for light changes due to changes in the distance between the product and the head.
means to generate a light beam including selected color wavelengths, a head for transmitting said light beam onto said product, means supporting said head for translating movement over said support top surface along a path generally parallel to said top surface, detector means in said head for detecting the reflected light from said product, means to analyze said reflected light to generate an output signal responsive to the color of said product;
means for generating a distance signal responsive to the distance between the product and said head, and means to modulate said output signal responsive to said distance signal to adjust for light changes due to changes in the distance between the product and the head.
2. A color sensor for detecting the color of a product carried on the top surface of a support, said sensor comprising:
a color sensing head including means for directing light of a predetermined wavelength onto said product;
a first arm supporting at one end said color sensing head, a second arm rotatably fixed at one end to the other end of said first arm, means rotatably supporting said second arm other end; and, means for rotating said first arm to oscillate said head back and forth over said support to detect an average color of said product.
a color sensing head including means for directing light of a predetermined wavelength onto said product;
a first arm supporting at one end said color sensing head, a second arm rotatably fixed at one end to the other end of said first arm, means rotatably supporting said second arm other end; and, means for rotating said first arm to oscillate said head back and forth over said support to detect an average color of said product.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US06/740,622 US4707138A (en) | 1985-06-03 | 1985-06-03 | Color measuring and control device |
| US740,622 | 1985-06-03 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1273820A true CA1273820A (en) | 1990-09-11 |
Family
ID=24977351
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000510553A Expired CA1273820A (en) | 1985-06-03 | 1986-06-02 | Color measuring and control device |
Country Status (3)
| Country | Link |
|---|---|
| US (1) | US4707138A (en) |
| EP (1) | EP0204547A3 (en) |
| CA (1) | CA1273820A (en) |
Families Citing this family (47)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4853879A (en) * | 1987-04-03 | 1989-08-01 | Matzoll Jr Robert J | Automated paint film characterization system |
| DE3723701A1 (en) * | 1987-07-17 | 1989-02-02 | Krzyminski Harald | HAND MEASURING DEVICE FOR OPTICAL REFLECTION MEASUREMENT |
| US5077806A (en) * | 1989-06-01 | 1991-12-31 | Accuron Corporation | Machine vision analysis apparatus |
| US5073857A (en) * | 1989-06-01 | 1991-12-17 | Accuron Corporation | Method and apparatus for cell analysis |
| DE9002437U1 (en) * | 1990-03-02 | 1990-05-03 | Man Roland Druckmaschinen Ag, 6050 Offenbach, De | |
| US5117101A (en) * | 1990-08-13 | 1992-05-26 | Technostics Corporation | Tristimulus color recognition system with means for compensating for variations in light source color |
| ES2075361T3 (en) * | 1991-09-03 | 1995-10-01 | Sortex Ltd | CLASSIFICATION MACHINE. |
| WO1995018360A1 (en) * | 1993-12-29 | 1995-07-06 | Milliken Research Corporation | Method and apparatus for determining directional variation of shade of pile and napped materials |
| JPH07270238A (en) * | 1994-03-30 | 1995-10-20 | Minolta Co Ltd | Colorimetry device |
| GB9508632D0 (en) * | 1995-04-28 | 1995-06-14 | Chipper 2000 Ltd | Colour detection method |
| DE19532724A1 (en) * | 1995-09-05 | 1997-03-06 | Tampoprint Gmbh | Multi-color printing device |
| US5759030A (en) | 1996-01-02 | 1998-06-02 | Lj Laboratories, L.L.C. | Method for determing optical characteristics of teeth |
| US6307629B1 (en) | 1997-08-12 | 2001-10-23 | Lj Laboratories, L.L.C. | Apparatus and method for measuring optical characteristics of an object |
| US6239868B1 (en) | 1996-01-02 | 2001-05-29 | Lj Laboratories, L.L.C. | Apparatus and method for measuring optical characteristics of an object |
| US6254385B1 (en) | 1997-01-02 | 2001-07-03 | Lj Laboratories, Llc | Apparatus and method for measuring optical characteristics of teeth |
| US6373573B1 (en) | 2000-03-13 | 2002-04-16 | Lj Laboratories L.L.C. | Apparatus for measuring optical characteristics of a substrate and pigments applied thereto |
| JPH09288007A (en) * | 1996-04-22 | 1997-11-04 | Minolta Co Ltd | Spectral colorimeter |
| US6301004B1 (en) | 2000-05-31 | 2001-10-09 | Lj Laboratories, L.L.C. | Apparatus and method for measuring optical characteristics of an object |
| US6501542B2 (en) | 1998-06-30 | 2002-12-31 | Lj Laboratories, Llc | Apparatus and method for measuring optical characteristics of an object |
| US6870616B2 (en) | 1998-06-30 | 2005-03-22 | Jjl Technologies Llc | Spectrometer apparatus for determining an optical characteristic of an object or material having one or more sensors for determining a physical position or non-color property |
| US6449041B1 (en) | 1997-07-01 | 2002-09-10 | Lj Laboratories, Llc | Apparatus and method for measuring optical characteristics of an object |
| US7285300B1 (en) * | 1997-11-11 | 2007-10-23 | Group 32 Development & Engineering, Inc. | Roasting system |
| US6106877A (en) * | 1998-05-01 | 2000-08-22 | Fresh Roast Systems, Inc. | Method of terminating roasting of bulk materials in real time on basis of objectively determined color of materials |
| US6104494A (en) * | 1998-05-01 | 2000-08-15 | Fresh Roast Systems, Inc. | Reflectometer for a roasting system |
| US6573984B2 (en) | 1998-06-30 | 2003-06-03 | Lj Laboratories Llc | Apparatus and method for measuring optical characteristics of teeth |
| US6249348B1 (en) | 1998-11-23 | 2001-06-19 | Lj Laboratories, L.L.C. | Integrated spectrometer assembly and methods |
| US6538726B2 (en) | 1998-07-10 | 2003-03-25 | Lj Laboratories, Llc | Apparatus and method for measuring optical characteristics of an object |
| DE19857896C1 (en) * | 1998-12-15 | 2000-08-31 | Siemens Ag | Method and device for evaluating spectroscopic measurements on solid materials with spatially and / or temporally varying surfaces |
| ATE283472T1 (en) | 1999-01-08 | 2004-12-15 | Ibsen Photonics As | SPECTROMETER |
| US6362888B1 (en) | 1999-12-23 | 2002-03-26 | Lj Laboratories, L.L.C. | Spectrometer assembly |
| US6519037B2 (en) | 1999-12-23 | 2003-02-11 | Lj Laboratories, Llc | Spectrometer having optical unit including a randomized fiber optic implement |
| US6414750B2 (en) | 2000-01-10 | 2002-07-02 | Lj Laboratories, L.L.C. | Spectrometric apparatus and method for measuring optical characteristics of an object |
| US6573994B2 (en) * | 2001-02-16 | 2003-06-03 | Ganado Research, L.L.C. | Optical method to monitor the processing of a starch-containing material |
| DE10127909A1 (en) * | 2001-06-08 | 2002-12-12 | Nexpress Solutions Llc | Method and device for determining a measured value in the area of a printing device |
| US6586759B1 (en) | 2001-07-03 | 2003-07-01 | Lexmark International, Inc. | Method and apparatus for aligning an optical detecting device |
| US6903813B2 (en) | 2002-02-21 | 2005-06-07 | Jjl Technologies Llc | Miniaturized system and method for measuring optical characteristics |
| CN1581131B (en) * | 2003-10-07 | 2010-05-12 | 赵舜培 | Reading material capable of automatically identifying content |
| US7198265B2 (en) * | 2004-08-31 | 2007-04-03 | Lexmark International, Inc. | Imaging apparatus including a movable media sensor |
| EP1681541B1 (en) * | 2004-09-30 | 2011-05-04 | X-Rite Europe GmbH | Method and apparatus for improved colorimetry |
| US7372571B2 (en) | 2004-09-30 | 2008-05-13 | Gretegmacbeth, Llc | Color sensing apparatus |
| US7499163B2 (en) * | 2005-02-15 | 2009-03-03 | X-Rite Europe Gmbh | System and method for applying correction factors related to ambient conditions |
| US20070131060A1 (en) * | 2005-12-14 | 2007-06-14 | The Gillette Company | Automated control of razor blade colorization |
| DE502006008891D1 (en) * | 2006-12-21 | 2011-03-24 | X Rite Europe Gmbh | Scanning device with electronic distance control and without distance sensor |
| JP6335499B2 (en) | 2013-12-13 | 2018-05-30 | 株式会社イシダ | Optical inspection device |
| CN107321648A (en) * | 2017-08-31 | 2017-11-07 | 东北农业大学 | Potato multi-level sorting machine based on machine vision technique |
| CN107806930B (en) * | 2017-10-08 | 2020-06-16 | 内蒙古自治区农牧业科学院 | Method for rapidly judging colors of potato skins and potato pulp in field |
| JP6539371B1 (en) * | 2018-03-14 | 2019-07-03 | Ckd株式会社 | Inspection apparatus, PTP packaging machine, and inspection method |
Family Cites Families (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1917379A (en) * | 1928-08-02 | 1933-07-11 | Eastman Kodak Co | Automatic gloss meter |
| US3890049A (en) * | 1973-09-17 | 1975-06-17 | Howell Lab Inc | Glossmeter for providing a linear response corresponding to true gloss readings |
| US3998555A (en) * | 1973-10-18 | 1976-12-21 | Genevieve I. Hanscom | Color grading apparatus |
| US4057352A (en) * | 1976-05-13 | 1977-11-08 | Genevieve I. Hanscom | Color grading apparatus utilizing infrared light source |
| US4031752A (en) * | 1976-07-19 | 1977-06-28 | Art Sanders | Web process control apparatus |
| JPS591977B2 (en) * | 1978-01-25 | 1984-01-14 | 株式会社京都第一科学 | Analysis method using color test paper |
| US4259020A (en) * | 1978-10-30 | 1981-03-31 | Genevieve I. Hanscom | Automatic calibration control for color grading apparatus |
| US4498778A (en) * | 1981-03-30 | 1985-02-12 | Technical Arts Corporation | High speed scanning method and apparatus |
| US4591996A (en) * | 1981-05-18 | 1986-05-27 | Vachon Reginald I | Apparatus and method for determining stress and strain in pipes, pressure vessels, structural members and other deformable bodies |
| DE3146506A1 (en) * | 1981-11-24 | 1983-06-01 | Maschinenfabrik Alfred Schmermund Gmbh & Co, 5820 Gevelsberg | METHOD AND TEST DEVICE FOR CHECKING THE LEVEL OF FILLING OF CIGARETTE ENDS |
| US4435093A (en) * | 1981-12-08 | 1984-03-06 | Bethlehem Steel Corporation | Pyrometer with sighting window cleanliness monitor |
| US4486098A (en) * | 1982-02-23 | 1984-12-04 | Hauni-Werke Korber & Co. Kg | Method and apparatus for testing the ends of cigarettes or the like |
| KR940004652B1 (en) * | 1984-11-06 | 1994-05-27 | 매슈렉스 코포레이숀 | System for measuring the colour of a material |
-
1985
- 1985-06-03 US US06/740,622 patent/US4707138A/en not_active Expired - Fee Related
-
1986
- 1986-06-02 CA CA000510553A patent/CA1273820A/en not_active Expired
- 1986-06-03 EP EP86304222A patent/EP0204547A3/en not_active Withdrawn
Also Published As
| Publication number | Publication date |
|---|---|
| EP0204547A3 (en) | 1988-06-08 |
| EP0204547A2 (en) | 1986-12-10 |
| US4707138A (en) | 1987-11-17 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA1273820A (en) | Color measuring and control device | |
| CA1116427A (en) | Automatic calibration control for color grading apparatus | |
| US5073712A (en) | Light scanner web profile measurement apparatus and method | |
| KR101389582B1 (en) | In-line inspection system for vertically profiling plastic containers using multiple wavelength discrete spectral light | |
| US4648396A (en) | Respiration detector | |
| US3614450A (en) | Apparatus for measuring the amount of a substance that is associated with a base material | |
| US5416550A (en) | Photographic processing apparatus | |
| US4057352A (en) | Color grading apparatus utilizing infrared light source | |
| KR900000824B1 (en) | Temperature measuring device of heating system | |
| US4365165A (en) | Level measurement device | |
| US6414747B1 (en) | Infrared photodetector apparatus for measuring projectile velocity | |
| JPS58108428A (en) | Device for measuring temperature of coke | |
| CA2399632C (en) | Method and apparatus for measuring coating | |
| JPS60151550A (en) | Measuring device for fatigue of lining of furnace | |
| US3675019A (en) | Apparatus for measuring the amount of a substance that is associated with a base material | |
| NZ515737A (en) | Side multiple-lamp on-line inside quality inspecting device | |
| KR960024041A (en) | Automatic cooking control device and method thereof | |
| JPS6145445Y2 (en) | ||
| US6118107A (en) | Process and device for in-service measurement of temperature in at least one cooking zone of a cooking area with a glass ceramic plate | |
| IE53682B1 (en) | Method and apparatus for measuring moisture content | |
| US6443616B1 (en) | Material melting point determination apparatus | |
| JP3423518B2 (en) | Moisture content detection device / moisture content measurement method and moisture content measurement device | |
| EP0336208A1 (en) | Computed tomograph | |
| JPS59135350A (en) | Measuring device for water content in moving web | |
| JPS59208445A (en) | Method and device for measuring absorptive component quantity of sample |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKLA | Lapsed |