Source: http://www.google.com/patents/US20090116026?ie=ISO-8859-1&dq=ininventor:oliver+ininventor:steele
Timestamp: 2014-03-14 06:23:34
Document Index: 648574400

Matched Legal Cases: ['art 2', 'art 2', 'art 3', 'art 2', 'art 3', 'art 3', 'art 2', 'art 3', 'art 2', 'art 4', 'art 4', 'art 2', 'art 4', 'art 3', 'art 7', 'art 2', 'art 7']

Patent US20090116026 - Reflection characteristic measuring apparatus for sheet specimen, method of ... - Google PatentsSearch Images Maps Play YouTube News Gmail Drive More »Sign inAdvanced Patent SearchPatentsA reflection characteristic measuring apparatus capable of scanning a specimen surface of a sheet specimen at a high speed is provided. The reflection characteristic measuring apparatus includes a group of illuminating and light-receiving systems for directing illuminating light onto the specimen surface...http://www.google.com/patents/US20090116026?utm_source=gb-gplus-sharePatent US20090116026 - Reflection characteristic measuring apparatus for sheet specimen, method of calibrating reflection characteristic measuring apparatus for sheet specimen, and calibration reference plate for use in calibration of reflection characteristic measuring apparatus for sheet specimenAdvanced Patent SearchPublication numberUS20090116026 A1Publication typeApplicationApplication numberUS 12/290,868Publication dateMay 7, 2009Filing dateNov 4, 2008Priority dateNov 6, 2007Also published asUS7973935, US8130371, US20110222065Publication number12290868, 290868, US 2009/0116026 A1, US 2009/116026 A1, US 20090116026 A1, US 20090116026A1, US 2009116026 A1, US 2009116026A1, US-A1-20090116026, US-A1-2009116026, US2009/0116026A1, US2009/116026A1, US20090116026 A1, US20090116026A1, US2009116026 A1, US2009116026A1InventorsKenji ImuraOriginal AssigneeKonica Minolta Sensing, Inc.Export CitationBiBTeX, EndNote, RefManClassifications (5), Legal Events (1) External Links: USPTO, USPTO Assignment, EspacenetReflection characteristic measuring apparatus for sheet specimen, method of calibrating reflection characteristic measuring apparatus for sheet specimen, and calibration reference plate for use in calibration of reflection characteristic measuring apparatus for sheet specimenUS 20090116026 A1Abstract A reflection characteristic measuring apparatus capable of scanning a specimen surface of a sheet specimen at a high speed is provided. The reflection characteristic measuring apparatus includes a group of illuminating and light-receiving systems for directing illuminating light onto the specimen surface of the sheet specimen held by a specimen holding roller pair and for receiving reflected light from the specimen surface. The illuminating and light-receiving systems measure a spectral characteristic of the received reflected light. The illuminating and light-receiving systems are disposed over one-dimensional arrays of color samples which extend in the longitudinal direction of the sheet specimen, and scan the one-dimensional arrays in a direction opposite to a direction in which the sheet specimen is transported.
a specimen holding part for holding a sheet specimen; a group of illuminating and light-receiving systems for directing illuminating light onto a specimen surface of the sheet specimen held by said specimen holding part and for receiving reflected light from the specimen surface of the sheet specimen to measure the received reflected light; and a scanning part for causing the sheet specimen held by said specimen holding part and said group of illuminating and light-receiving systems to move relative to each other, thereby causing said group of illuminating and light-receiving systems to scan the specimen surface of the sheet specimen, wherein said group of illuminating and light-receiving systems are discretely arranged in a direction nonparallel to a scanning direction in which said group of illuminating and light-receiving systems scan the specimen surface of the sheet specimen. 2. The reflection characteristic measuring apparatus according to claim 1, wherein
said specimen holding part includes: a first contact member for contacting the specimen surface of the sheet specimen, said first contact member being configured so that the position of a contact area in which said first contact member contacts the specimen surface of the sheet specimen is fixed relative to said group of illuminating and light-receiving systems; and a second contact member for contacting a back surface of the sheet specimen opposite the specimen surface to press the back surface of the sheet specimen toward said first contact member. 3. The reflection characteristic measuring apparatus according to claim 2, wherein
said first contact member is a first roller rotating about a first rotary shaft, and said second contact member is a second roller rotating about a second rotary shaft and opposed to said first roller, with the sheet specimen therebetween. 4. The reflection characteristic measuring apparatus according to claim 3, wherein
said first roller includes an assembly of small rollers contacting the specimen surface of the sheet specimen outside an measurement area to be subjected to the measurement by said group of illuminating and light-receiving systems. 5. The reflection characteristic measuring apparatus according to claim 3, wherein
said scanning part rotates at least one of said first and second rollers to transport said sheet specimen. 6. The reflection characteristic measuring apparatus according to claim 1, wherein
said group of illuminating and light-receiving systems are discretely arranged also in a direction parallel to the scanning direction in which said group of illuminating and light-receiving systems scan the specimen surface of the sheet specimen. 7. A method of calibrating a group of illuminating and light-receiving systems provided in a reflection characteristic measuring apparatus for a sheet specimen, said group of illuminating and light-receiving systems directing illuminating light onto a specimen surface of the sheet specimen and receiving reflected light from the specimen surface of the sheet specimen to measure the received reflected light, said method comprising the steps of:
(a) measuring a first reference area included in a calibration reference plate with a first illuminating and light-receiving system included among said group of illuminating and light-receiving systems; (b) measuring a second reference area other than the first reference area included in the calibration reference plate with said first illuminating and light-receiving system; (c) calibrating said first illuminating and light-receiving system, based on a result of measurement of the first reference area in said step (a); (d) applying a result of calibration in said step (c) to determine a reflection characteristic of the second reference area from a result of measurement of the second reference area in said step (b); (e) measuring the second reference area with a second illuminating and light-receiving system other than said first illuminating and light-receiving system included among said illuminating and light-receiving systems; and (f) calibrating said second illuminating and light-receiving system, based on the reflection characteristic determined in said step (d) and a result of measurement in said step (e). 8. The method according to claim 7, wherein
the calibration reference plate in which the first reference area and the second reference area are arranged in a first direction is used; said steps (a) and (b) are executed by transporting the calibration reference plate in the first direction to cause the first reference area and the second reference area to pass through a measurement area of said first illuminating and light-receiving system; and said step (e) is executed by transporting the calibration reference plate in a second direction to cause the second reference area to pass through a measurement area of said second illuminating and light-receiving system. 9. A calibration reference plate for use in calibrating a group of illuminating and light-receiving systems provided in a reflection characteristic measuring apparatus for a sheet specimen, said group of illuminating and light-receiving systems directing illuminating light onto a specimen surface of the sheet specimen and receiving reflected light from the specimen surface of the sheet specimen to measure the received reflected light, said calibration reference plate comprising:
a first reference area to be measured with a first illuminating and light-receiving system included among said group of illuminating and light-receiving systems, said first reference area having a previously assigned reflection characteristic; and a second reference area to be measured with said first illuminating and light-receiving system and a second illuminating and light-receiving system other than said first illuminating and light-receiving system included among said group of illuminating and light-receiving systems. 10. The calibration reference plate according to claim 9, wherein
said calibration reference plate being a white plastic plate with a white inorganic plate embedded in the position of the first reference area. 11. The calibration reference plate according to claim 9, further comprising
a position detecting mark spaced apart from the first reference area and the second reference area. Description
FIG. 13 is a plan view of the sheet specimen 971. As shown in FIG. 13, the sheet specimen 971 has a specimen surface 972 on which a multiplicity of (typically, hundreds of) color samples 981 having different color tones and different densities are printed. The color samples 981 are typically rectangular or square in shape, and are arranged in a regular array both in the longitudinal direction and in the transverse direction of the sheet specimen 971. Such a sheet specimen 971 is also known as a �color patch chart� or the like.
DESCRIPTION OF THE PREFERRED EMBODIMENTS First Preferred Embodiment <1-1 Overview of Reflection Characteristic Measuring Apparatus 1> FIGS. 1 to 3 are schematic views of principal parts of a reflection characteristic measuring apparatus 1 according to a first preferred embodiment of the present invention. FIG. 1 is a perspective view of the reflection characteristic measuring apparatus 1. FIG. 2 is a sectional view of the reflection characteristic measuring apparatus 1 taken along the line II-II of FIG. 1. FIG. 3 is a sectional view of the reflection characteristic measuring apparatus 1 taken along the line III-III of FIG. 1. For convenience in illustration, FIGS. 1 to 3 include an XYZ rectangular coordinate system in which directions extending from front to rear, and vice versa, are defined as negative and positive X directions (�X directions), directions extending from right to left, and vice versa, are defined as negative and positive Y directions (�Y directions), and vertical directions extending from top to bottom, and vice versa, are defined as negative and positive Z directions (�Z directions). The reflection characteristic measuring apparatus 1 continuously measures the reflection characteristics of color samples 911 arranged in a two-dimensional array on a specimen surface 902 of a sheet specimen 901 shown in FIG. 5.
<1-2 Measuring Part 2> The measuring part 2 holds and transports the sheet specimen 901 carried from the paper feed part 3 while applying tension to the sheet specimen 901, and measures the reflection characteristics of the color samples 911 printed on the specimen surface 902. The measuring part 2 includes illuminating and light-receiving systems 201 to 208, a specimen holding roller pair 211, a drive motor 221, frames 231 and 232, and springs 241 and 242.
{Illuminating and Light-Receiving Systems 201 to 208} The illuminating and light-receiving systems 201 to 208 direct illuminating light onto the specimen surface 902 of the sheet specimen 901 held by the specimen holding roller pair 211, and receive reflected light from the specimen surface 902. The illuminating and light-receiving systems 201 to 208 also measure the spectral characteristics of the received reflected light.
The illuminating and light-receiving systems 201 to 208 are arranged in a line in the �X directions perpendicular to the transport direction of the sheet specimen 901 and parallel to the specimen surface 902. The illuminating and light-receiving systems 201 to 208 are equally spaced apart from each other, and the spacing therebetween is equal to the spacing at which the color samples 911 are arranged in the �X directions. The illuminating and light-receiving systems 201 to 208 are disposed over one-dimensional arrays 921 to 928, respectively, of the color samples 911 which extend in the longitudinal direction of the sheet specimen 901, and scan the one-dimensional arrays 921 to 928, respectively, in the −Y direction (referred to hereinafter as a �scanning direction�) opposite to the transport direction. The discrete arrangement of the plurality of illuminating and light-receiving systems 201 to 208 in the �X directions which are nonparallel to the scanning direction as described above allows the parallel scanning of the plurality of one-dimensional arrays 921 to 928 of the color samples 911, thereby accomplishing the high-speed measurement of the reflection characteristics of the color samples 911 arranged in the two-dimensional array. The term �nonparallel� used herein means that the plurality of illuminating and light-receiving systems 201 to 208 need not necessarily be arranged in a direction �perpendicular� to the scanning direction. Although the eight illuminating and light-receiving systems 201 to 208 are shown as disposed in FIGS. 1 to 3, the number of illuminating and light-receiving systems 201 to 208 is increased or decreased in accordance with the number of color samples 911 arranged in each column extending in the transverse direction of the sheet specimen 901.
{Specimen Holding Roller Pair 211} The specimen holding roller pair 211 includes a positioning roller 212 provided over a transport path and a pressure roller 213 provided under the transport path to nip the sheet specimen 901 therebetween, thereby holding the sheet specimen 901 in a position in which the reflection characteristics are to be measured. Further, the specimen holding roller pair 211 rotates the positioning roller 212 and the pressure roller 213 to thereby transport the sheet specimen 901 in the +Y direction while applying tension to the sheet specimen 901.
{Drive Motor 221} The drive motor 221 rotates the pressure roller 213. Thus, the drive motor 221 transports the sheet specimen 901 in contact with the pressure roller 213 in the +Y direction to cause the sheet specimen 901 and the illuminating and light-receiving systems 201 to 208 to move relative to each other in a direction parallel to the specimen surface 902, thereby causing the illuminating and light-receiving systems 201 to 208 to scan the specimen surface 902. Although only the drive motor 221 for rotating the pressure roller 213 is shown as provided in FIGS. 1 to 3, only a drive motor for rotating the positioning roller 212 may be provided in place of the drive motor 221 or the drive motor for rotating the positioning roller 212 may be provided together with the drive motor 221. In this manner, at least one of the pressure roller 213 and the positioning roller 212 is rotated to apply tension to the sheet specimen 901. This makes the sheet specimen 901 difficult to bend, thereby reducing errors of measurement of the reflection characteristics.
{Frame 231} The frame 231 holds the illuminating and light-receiving systems 201 to 208 and the positioning roller 212. When the illuminating and light-receiving systems 201 to 208 and the positioning roller 212 are held by the same frame 231 in this manner, the position of an area of contact (or the area of nipping) in which the positioning roller 212 (the small rollers 2121 to 2129) contacts the specimen surface 902 relative to the illuminating and light-receiving systems 201 to 208 is held fixed independently of the thickness of the sheet specimen 901 and the like. Then, pressing the sheet specimen 901 toward the positioning roller 212 which is positioned brings the specimen surface 902 into contact with the positioning roller 212, thereby maintaining the distance between the illuminating and light-receiving systems 201 to 208 and the specimen surface 902 constant. This reduces errors of measurement of the reflection characteristics. The frame 231 is fixed to an enclosure of the reflection characteristic measuring apparatus 1, and is provided over the transport path. The frame 231 has sufficient rigidity to prevent the contact area in which the positioning roller 212 contacts the specimen surface 902 from being out of position relative to the illuminating and light-receiving systems 201 to 208 due to the deformation thereof. Of course, the positional relationship between the illuminating and light-receiving systems 201 to 208 and the positioning roller 212 relative to each other may be fixed by other means than fixing to the same frame 231. For example, the illuminating and light-receiving systems 201 to 208 and the positioning roller 212 may be formed integrally to fix the positional relationship between the illuminating and light-receiving systems 201 to 208 and the positioning roller 212 relative to each other.
{Frame 232} The frame 232 holds the pressure roller 213 and the drive motor 221. The frame 232 is fixed to an enclosure 10 of the reflection characteristic measuring apparatus 1 with the springs 241 and 242, and is provided under the transport path.
{Springs 241 and 242} The springs 241 and 242 urge the frame 232 toward the back surface 903. Of course, an elastic body other than the springs 241 and 242 may be used to urge the frame 232 or an actuator may be used to urge the frame 232. By urging the frame 232 in this manner, the pressure roller 213 held by the frame 232 can press the back surface 903 of the sheet specimen 901 toward the positioning roller 212.
<1-3 Paper Feed Part 3> The paper feed part 3 feeds the supplied sheet specimen 901 to the measuring part 2. The paper feed part 3 includes a paper feed roller pair 311, a drive motor 321, and a frame 331.
{Paper Feed Roller Pair 311} The paper feed roller pair 311 includes a roller 312 provided over the transport path and a roller 313 provided under the transport path to nip the sheet specimen 901 therebetween, thereby transporting the sheet specimen 901 inserted in a gap between the rollers 312 and 313 in the +Y direction.
{Drive Motor 321} The drive motor 321 rotates the roller 313 to transport the sheet specimen 901 in contact with the roller 313 in the +Y direction. As in the measuring part 2, of course, only a drive motor for rotating the roller 312 may be provided in place of the drive motor 321 or the drive motor for rotating the roller 312 may be provided together with the drive motor 321.
{Frame 331} The frame 331 holds the rollers 312 and 313, and the drive motor 321.
<1-4 Paper Output Part 4> The paper output part 4 ejects the sheet specimen 901 transported from the measuring part 2. The paper output part 4 includes a paper output roller pair 411, a drive motor 421, and a frame 431 which are similar to the corresponding components of the paper feed part 3.
<1-5 Specimen Guide 5> The specimen guide 5 restricts the movement of the sheet specimen 901 lying in the transport path in the �X directions perpendicular to the transport direction, and guides the sheet specimen 901 lying in the transport path in the +Y direction.
<1-6 Control System> FIG. 4 is a block diagram illustrating a control system for the reflection characteristic measuring apparatus 1.
<1-7 White Calibration of Illuminating and Light-Receiving Systems 201 to 208> {White Calibration Reference Plate 941} FIGS. 6 and 7 are schematic views showing an example of a white calibration reference plate 941 for use in white calibration of the illuminating and light-receiving systems 201 to 208. FIG. 6 is a plan view of the white calibration reference plate 941. FIG. 7 is a sectional view of the white calibration reference plate 941 taken along the line VII-VII of FIG. 6.
{Procedure for White Calibration} FIG. 10 is a flow diagram illustrating a procedure for the white calibration.
K   1  ( λ ) = R   1  ( λ ) D   1  ( λ ) ( 1 ) where R1(λ) is a known spectral reflectance factor previously assigned for the reference area 961. The calibration reference disc 943 made of a hard material and embedded in the reference area 961 is suitable as a reference for the spectral reflectance factor because the calibration reference disc 943 has a scratch-resistant surface and exhibits small changes in spectral reflectance factor with time. Thus, the calibration factor K1(λ) calculated according to Equation (1) is used for the white calibration of the illuminating and light-receiving system 201. This allows the determination of the correct spectral reflectance factor R(λ) from the spectral intensity data D(λ) measured by the illuminating and light-receiving system 201.
Ri(λ)=K1(λ)�Di(λ) (i=2, 3, . . . , 8) (2)
Ki  ( λ ) = Ri  ( λ ) Ei  ( λ )   ( i = 2 , 3 , �  , 8 ) ( 3 ) Spectral reflectance factors R1 j(λ) to R8 j(λ) for a j-th color sample in the one-dimensional arrays 921 to 928 are calculated from the calibration factor K1 determined in Step S5 and the calibration factors K2(λ) to K8(λ) determined in Step S11, based on the results of measurement of spectral intensity data E1 j(λ) to E8 j(λ) about the j-th color sample in the one-dimensional arrays 921 to 928. This calculation is given according to Equation (4). In other words, the illuminating and light-receiving systems 202 to 208 are calibrated, based on the spectral reflectance factors R2(λ) to R8(λ) for the reference areas 962 to 968 determined in Step S6 and the result of measurement of the spectral intensity data E2(λ) to E8(λ) about the reference areas 962 to 968.
Rij(λ)=Ki(λ)�Eij(λ) (i=1, 2, . . . , 8; and j=1, 2, . . . , 9) (4)
2. Second Preferred Embodiment FIG. 11 is a schematic view of principal parts of a measuring part 7 according to a second preferred embodiment of the present invention which is usable in place of the measuring part 2 of the reflection characteristic measuring apparatus 1 according to the first preferred embodiment. FIG. 11 is a perspective view of the measuring part 7. For convenience in illustration, FIG. 11 includes an XYZ rectangular coordinate system in which directions extending from front to rear, and vice versa, are defined as negative and positive X directions (�X directions), directions extending from right to left, and vice versa, are defined as negative and positive Y directions (�Y directions), and vertical directions extending from top to bottom, and vice versa, are defined as negative and positive Z directions (�Z directions).
The four illuminating and light-receiving systems 701, 703, 705 and 707 are arranged in a line in the +X directions perpendicular to the transport direction and parallel to the specimen surface 902. The illuminating and light-receiving systems 701, 703, 705 and 707 are equally spaced apart from each other, and the spacing therebetween is equal to twice the spacing at which the color samples 911 are arranged in the �X directions. Thus, the illuminating and light-receiving systems 701, 703, 705 and 707 are disposed over the one-dimensional arrays 921, 923, 925 and 927, respectively, of the color samples 911 which extend in the transport direction, and are capable of scanning the one-dimensional arrays 921, 923, 925 and 927 of the color samples 911 on the specimen surface 902 in the scanning direction opposite to the transport direction.
The four illuminating and light-receiving systems 702, 704, 706 and 708, on the other hand, are arranged in a line in the +X directions perpendicular to the transport direction and parallel to the specimen surface 902. The illuminating and light-receiving systems 702, 704, 706 and 708 are equally spaced apart from each other, and the spacing therebetween is equal to twice the spacing at which the color samples 911 are arranged in the �X directions. Thus, the illuminating and light-receiving systems 702, 704, 706 and 708 are disposed over the one-dimensional arrays 922, 924, 926 and 928, respectively, of the color samples 911 which extend in the transport direction, and are capable of scanning the one-dimensional arrays 922, 924, 926 and 928 of the color samples 911 on the specimen surface 902 in the scanning direction opposite to the transport direction.
The arrangement of the eight illuminating and light-receiving systems 701 to 708 in two lines, rather than in one line, achieves the discrete arrangement of the illuminating and light-receiving systems 701 to 708 not only in a direction nonparallel to the scanning direction but also in a direction parallel to the scanning direction. Such an arrangement allows the measurement areas of the illuminating and light-receiving systems 701 to 708 to belong to the effective zone at different times. As a result, this achieves the increase in power supplied to the LEDs of the illuminating and light-receiving systems 701 to 708 at different times to suppress the peak of power consumption of the reflection characteristic measuring apparatus, thereby reducing power supply burdens and costs. Additionally, when a spacing between the illuminating and light-receiving systems 701, 703, 705 and 707 and the illuminating and light-receiving systems 702, 704, 706 and 708 in the scanning direction is {n+(�)} times the spacing at which the color samples 911 are arranged in the scanning direction, the peak current consumption of the reflection characteristic measuring apparatus is especially reduced.
3. Modifications The reflection characteristic measuring apparatus 1 is configured to transport the sheet specimen 901, with the illuminating and light-receiving systems 201 to 208 fixed, to cause the sheet specimen 901 and the illuminating and light-receiving systems 201 to 208 to move relative to each other, thereby causing the illuminating and light-receiving systems 201 to 208 to scan the specimen surface 902. Alternatively, the reflection characteristic measuring apparatus 1 may be configured to transport the illuminating and light-receiving systems 201 to 208, with the sheet specimen 901 fixed, to cause the sheet specimen 901 and the illuminating and light-receiving systems 201 to 208 to move relative to each other, thereby causing the illuminating and light-receiving systems 201 to 208 to scan the specimen surface 902. Transporting the sheet specimen 901, with the illuminating and light-receiving systems 201 to 208 fixed, is advantageous in eliminating the need to move the heavy-weight illuminating and light-receiving systems 201 to 208 for the scanning.
Classifications U.S. Classification356/447, 356/448International ClassificationG01N21/55Cooperative ClassificationG01N21/55European ClassificationG01N21/55Legal EventsDateCodeEventDescriptionNov 4, 2008ASAssignmentOwner name: KONICA MINOLTA SENSING, INC., JAPANFree format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:IMURA, KENJI;REEL/FRAME:021855/0452Effective date: 20081023RotateOriginal ImageGoogle Home - Sitemap - USPTO Bulk Downloads - Privacy Policy - Terms of Service - About Google Patents - Send FeedbackData provided by IFI CLAIMS Patent Services©2012 Google