United States Patent 19
`Polidor et al.
`
`54 SURFACE LLUMINATOR WITH MEANS
`FOR ADJUSTING ORIENTATION AND
`NCLINATION OF INCIDENT
`LLUMNATON
`75) Inventors: Edward T. Polidor. Webster; Albert G.
`Choate, Rush; Terry L. Herbeck,
`Rochester, all of N.Y.
`73) Assignee: Optical Gaging Products, Inc.,
`Rochester, N.Y.
`
`21) Appl. No.: 645,382
`22 Filed:
`May 13, 1996
`6
`51) int. Cl. ............................................ F21W 500
`52 U.S.C. ... 362,244; 362251362800
`362/804; 359,387,359,388
`(58. Field of Search ...........
`............... 362/251, 252,
`362,244, 33, 800, 804, 32,359/355, 387,
`388
`4.
`References Cited
`U.S. PATENT DOCUMENTS
`1/1986 Choate ..................................... 362/32
`
`4,567,551
`
`56)
`
`
`
`US005690417A
`Patent Number:
`11
`45 Date of Patent:
`
`5,690,417
`Nov. 25, 1997
`
`1/1990 Arnold .................................... 362/252
`4,893,223
`8/1991 Koch et al. ............................. 362/252
`5,038,258
`Primary Examiner-James C. Yeung
`Attorney; Agent, or Firm-Shlesinger, Fitzsimmons &
`Shlesinger
`ABSTRACT
`57
`A plurality of light emitting diodes are secured coaxially
`around the lower end of a cylindrical objective lens housing
`in radially spaced, circular arrays or rings disposed coaxially
`of the housing. The diodes in each ring are equi-angularly
`spaced from each other about the axis of the housing; and
`their light emitting ends overlie a work table so as to direct
`beams of light obliquely downwardly onto an object sup
`ported thereon. The diodes are energizable in generally
`pie-shaped sectors disposed coaxially of the housing so that
`arcuate clusters of diodes in a given segment may be
`illuminated to enable the orientation of the resultant illumi
`nation to be varied. The diodes of each ring may have their
`beam axes inclined at different angles to the axis of the
`housing so that the inclination of the projected illumination
`may be varied by selected energization of the rings; and a
`collimating lens may be secured over the light emitting end
`of each diode.
`9 Claims, 3 Drawing Sheets
`
`Petitioner's Exhibit 1010
`Page 1 of 8
`
`

`

`U.S. Patent
`US. Patent
`
`
`
`Sheet 1 of 3
`Sheet 1 of 3
`
`5,690,417
`5,690,417
`
`Nov. 25, 1997
`Nov. 25, 1997
`
`S3 FIG. 2
`
`
`
`FIG.
`
`2
`
`Petitioner's Exhibit 1010
`Page 2 of 8
`
`Petitioner's Exhibit 1010
`Page 2 of 8
`
`

`

`U.S. Patent
`
`Nov. 25, 1997
`
`Sheet 2 of 3
`
`5,690,417
`
`
`
`
`
`SHRHS
`%N. V. V.
`NSSSN-2
`2 Sticist- CXXXX-2
`
`F
`
`32
`
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`
`
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`BRH-I-II
`Muuuuu-Duuuuu%
`
`Petitioner's Exhibit 1010
`Page 3 of 8
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`

`

`U.S. Patent
`
`Nov. 25, 1997
`
`Sheet 3 of 3
`
`5,690,417
`
`
`
`PROCESSOR
`CONTROLLER
`F.G. 6
`
`Petitioner's Exhibit 1010
`Page 4 of 8
`
`

`

`5,690,417
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`O
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`15
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`20
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`25
`
`1
`SURFACE LLUMNATOR WITH MEANS
`FOR ADJUSTING ORDENTATION AND
`NCLINATION OF INCIDENT
`LLUMINATION
`BACKGROUND OF THE INVENTION
`This invention relates to surface illuminators designed to
`illuminate objects that are being inspected by contour
`projectors, optical comparators, microscopes and the like.
`Even more particularly this invention is related to an
`improved oblique surface illuminator having novel means
`for adjusting orientation and inclination of incident illumi
`nation directed onto an object.
`As noted in U.S. Pat. No. 4,567.551, which is assigned to
`the same assignee as the instant application, proper illumi
`nation of an object which is being inspected is most impor
`tant when the image of the object is to be magnified and
`observed by a lens system of the type employed in inspec
`tion systems of the type noted above. In the U.S. Pat No.
`4.567,551, for example, there is disclosed an oblique or
`multi-directional surface illuminator in which illumination
`is projected in a number of different directions onto the
`surface of the object which is to be inspected via an
`objective lens system. More specifically, this prior art appa
`ratus comprises a plurality (four in the illustrated
`embodiment) of light sources arranged at 90° intervals
`around an objective lens housing to project light onto four
`registering, reflective surfaces, which are inclined to the axis
`of the lens housing to reflect illumination onto a Fresnel lens
`that surrounds the objective lens. The Fresnel lens then
`projects illumination obliquely onto the surface of the object
`that is to be inspected.
`One of the principal advantages of this prior art system is
`that the light which is reflected onto the Fresnel lens is
`directed by the latter transversely of the image path of the
`object that is to be inspected. As a consequence the oblique
`rays from the Fresnel lens do not interfere with the light
`reflected directly from the object along the image axis.
`Although this prior art construction has the advantage that it
`permits the intensity of each of the four light sources to be
`adjusted as desired, nevertheless the orientation and incli
`nation of incident illumination that is directed onto the
`object that is to be inspected, remain fixed.
`It is an object of this invention, therefore, to provide an
`improved multi-directional surface illuminator which
`includes novel means for effecting adjustment of both the
`orientation and the inclination of incident illumination that
`is directed obliquely onto a workpiece that is to be inspected.
`A more specific object of this invention is to provide an
`improved multi-directional surface illuminator having a
`plurality of light sources arrayed in such manner that the
`inclination of the angle of incidence can be readily adjusted
`simply by selectively energizing only certain of the light
`SOUCCS.
`Still another object of this invention is to provide an
`improved multi-directional surface illuminator having a
`plurality of selectively energizable light sources arrayed in
`such manner as to enable adjustment of the orientation and
`angle of incidence of the illumination produced thereby.
`Other objects of this invention will become apparent
`hereinafter from the specification and from the recital of the
`appended claims particularly when read in conjunction with
`the accompanying drawings.
`SUMMARY OF THE INVENTION
`An annular lamp housing, which is secured coaxially
`around the lower end of a cylindrical objective lens housing,
`
`2
`contains a plurality of lamps arranged in radially spaced,
`circular arrays or rings disposed coaxially of the lens hous
`ing; and with the lamps in each ring being angularly spaced
`from each other about the axial centerline of the housings.
`The light emitting ends of the lamps overlie a work table so
`as to direct beams of light downwardly onto an object
`supported on the table. The lamps are controlled by circuits
`which are operable selectively to light the lamps in generally
`pie-shaped sectors disposed coaxially of the housings'
`centerline, whereby clusters of lamps in a given segment of
`a ring of lamps in a particular sector may be illuminated,
`thus enabling the orientation of the resultant illumination to
`be varied.
`Also, in one embodiment the lamps of each ring have their
`beam axes inclined to the centerline of the housing so that
`the inclination of the projected illumination may be varied
`by selected energization of the rings of lamps. In other
`embodiments the lamps are mounted with their axes extend
`ing parallel to the centerline of the housing, and are directed
`by a Fresnel lens onto a workpiece. Also, a preferred lamp
`is a light-emitting diode (LED) of the type having a colli
`mating lens secured over the light emitting end thereof.
`THE DRAWINGS
`FIG. 1 is a side elevational view of an improved surface
`illuminator having coaxially mounted on one end of its
`objective lens system an annular lamp housing containing a
`plurality of radially spaced, circular arrays of light sources,
`the angles of incidence of the beams emitted from these
`sources being shown as they appear when directed onto a
`workpiece that is shown in phantom by broken lines, and the
`lamp housing being shown partially in section as seen when
`taken along the line 1-1 in FIG. 2;
`FIG. 2 is a bottom plan view of the surface illuminator and
`its objective lens system, and illustrating one manner in
`which the circular arrays of light sources can be considered
`to form eight, similar, pie-shaped sectors of illumination;
`FIG.3 is a modified form of the surface illuminator shown
`in FIG. 1, but with portions thereof cut away and shown in
`section;
`FIG. 4 is a view similar to FIG.3 but showing still another
`modification of this surface illuminator;
`F.G. 5 is a schematic wiring diagram illustrating one
`manner in which arcuate clusters of light sources of a
`respective sector of illumination can be selectively ener
`gized; and
`F.G. 6 is a schematic diagram illustrating one manner in
`which selective illumination of the light sources may be
`controlled.
`
`50
`
`55
`
`65
`
`DETALED DESCRIPTION OF THE
`PREFERRED EMBOOMENTS
`Referring now to the drawings by numerals of reference,
`and first to FIGS. 1 and 2, 10 denotes generally a surface
`illuminator of the type having a cylindrical lens housing 12
`containing a conventional objective lens system (not
`illustrated). Secured to and surrounding the lower end of
`housing 12 is an annular, generally disc-shaped lamp sup
`porting housing 14. Surface illuminator 10 is adapted to be
`mounted in a conventional manner above a work table 16,
`which, as shown in phantom by broken lines in FIG. 1, is
`adapted to have supported thereon the object or workpiece
`W which is to be inspected.
`In the embodiment shown in FIGS. 1 and 2, housing 14
`has mounted therein two hundred lamps L., which are
`
`Petitioner's Exhibit 1010
`Page 5 of 8
`
`

`

`5,690,417
`
`10
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`15
`
`35
`
`45
`
`3
`secured or mounted at their inner ends in the housing 14, and
`which project at their outer, light emitting ends, downwardly
`from housing 14 toward a substantially common point in the
`object plane, and in the direction of the work table 16. As
`shown more clearly in FIG. 2, the lamps L are mounted in
`housing 14 in five circular arrays or rings disposed coaxilly
`of the axial centerline of the housings 12 and 14. Adjacent
`arrays or rings of the lamps are equispaced radially from
`each other, and the respective lamps Lin each circular array
`thereof are equiangularly spaced from each other about the
`axis of housings 12 and 14. Thus, as shown in the drawings,
`the innermost ring of lamps contains twenty-four equiangu
`larly spaced lamps L., the light emitting ends of which lie in
`a circle at a radius R1 from the centerline of the lens housing
`12. The next ring of lamps comprises thirty-two lamps the
`light emitting ends of which lie at a radius R2 from the
`housing centerline; the next array contains forty lamps
`disposed at a radius R3 from the centerline of the housing;
`the next outer ring comprises forty-eight lamps the light
`emitting ends of which lie on a circle located at a radius R4
`from the centerline of the housing 12; and the last or
`outermost ring of lamps L comprises fifty-six lamps, the
`light emitting ends of which lie in a circle located at a radius
`RS from the housing centerline.
`Referring still to FIG. 2, it will be noted that, in addition
`to being mounted in housing 14 in circular arrays, the
`equispaced lamps L also can be, arbitrarily, divided into
`eight equiangular sectors identified as S1 through S8. These
`sectors, as noted hereinafter, are selected to enable selective
`illumination of certain of the lamps Lin certain areas of the
`housing 14, so that illumination from the light sources can
`be directed selectively from different directions onto a
`workpiece W that is being inspected.
`For example, as shown in F.G. 5, the lamps in sector S1
`are controlled by five different circuits denoted S1-1, S1-2,
`S1-3, S1-4 and S1-5. Those circuits are connected through
`switches R1S1, R2S1, R3S1, R4S1 and RSS1, respectively,
`to a power supply which is denoted at PS in FIG. 5. The
`switches R1S1 through RSS1 are shown in their normally
`opened mode. Whenever any one of those switches is closed,
`the power is supplied to the associated circuit S1-1 through
`S1-5, and thereby energizes the associated lamps L., which
`in the case of the circuit S1-1 will energize all three of the
`lamps L connected in parallel therewith, and which happen
`to be located at the distance R1 from the centerline of
`housing 14. In a similar manner the lamps controlled by
`circuits S1-2, S1-3, S1-4 and S1-5 can be selectively ener
`gized. Although FIG. 5 has been explained in connection
`with only section S1 of the lamps L shown in FIG. 2, it will
`be understood that seven similar such circuits will be
`utilized for selectively energizing the lamps Lin each of the
`seven remaining sectors S2 through S8.
`For example, as shown in FIG. 6, the illustrated
`microprocessor/controller can be utilized for selectively
`supplying power to a selected group of lamps in each of the
`sectors S1 through S8. As shown in FIG.6, SS1 through SS8
`illustrate manually operable switches, any one or more of
`which can be closed manually by an operator to select a
`particular sector, certain lamps of which (for example a
`cluster of lamps) are to be energized. SR1 through SR5
`denote manually operable switches which can be selectively
`closed to denote the particular ring of lamps a particular
`segment or cluster of which lamps in a given sector are to be
`energized, each such cluster being located at one of the
`radial distances R1 through R5 from the centerline of the
`housing. The switches SS1 through SS8, and the switches
`SR1 through SR5, when closed, are designed to apply a
`
`4
`signal to a switching matrix denoted generally by the
`numeral 20 in F.G. 6. As noted diagrammatically by matrix
`20, the simultaneous closing or selection of the switches SS1
`and SR1 are designed to apply a signal which closes switch
`R1S1 (FIG. 5) to supply power to the cluster of lamps L
`which are located in sector 1 at a radial distance R1 from the
`centerline of housing 14. Obviously if all of the switches
`SR1 through SR5 were closed simultaneously with switch
`SS1, all lamps L in the sector S1 would be illuminated.
`However, selective operation of the switches SR1 through
`SR5 at a time when the switch SS1 is closed, will provide
`selective energization of one or more of the five clusters of
`lamps located in sector 1.
`Although not described in detail above, it will be apparent
`that similar switching effects for each of the remaining
`sectors S2 through S8 can be achieved by selective operation
`of the switches SS2 through SS8, and the particular switches
`which select the desired circular array-i.e., switches SR1
`through SR5.
`In FIG. 6the microprocessor/controller is designed also to
`control the intensity of the illumination emitted by the lamps
`L. For this reason a circuit denoted at C in FIG. 6 can be
`controlled by the controller to function as a global intensity
`control, so that the overall intensity of the illumination from
`lamps L. can be controlled as desired. Thus, when employing
`an array of lamps as shown in FGS. 1 and 2, and as
`controlled by the means shown in FIGS. 5 and 6, it is
`possible to control the orientation of the illumination around
`the object that is being inspected.
`In addition to being able to vary the orientation of the
`illumination that is directed on the object that is to be
`inspected, it is possible also selectively to vary the angle of
`inclination of the illumination that is directed onto a Work
`place. For example, as shown in F.G. 1, although each of the
`five rings or circular arrays of lamps L that surround the lens
`housing 12 is radially spaced a different distance from the
`centerline of the housing, the axial centerlines of the five
`rings, A1 through A5, respectively, are inclined at different
`angles to the axial centerline of the lens housing. In the
`embodiment illustrated, it will be noted that the angle of
`incidence is least for the beam of light centered upon axis
`A1, and is the greatest for the beam transmitted along the
`axis A5. Thus, by selectively energizing the lamps Lin each
`of the arrays R1 through RS, it is possible to vary the angle
`of inclination of illumination directed onto the workpiece W.
`With the embodiment shown in FIG. 1, therefore, it is
`possible selectively to vary both the orientation and the
`inclination of the light directed onto the workpiece W.
`Obviously the respective angle of inclination of the illumi
`nation directed onto the workpiece by the lamps L in a
`respective ring or array corresponding R1,R2, R3, R4 or R5,
`can be varied, as desired, simply by mounting associated
`lamps Lin the housing 14 so that the axes of the light beams
`emitted therefrom form the desired angle of incidence with
`the workpiece that is being examined.
`Referring now to the embodiment as shown in FIG. 3,
`wherein like numerals are employed to denote elements
`similar to those shown in the first embodiment, 39 denotes
`generally a modified illuminator in which the five circular
`arrays or rings of lamps L., again denoted by the designations
`R1 through R5, are mounted in housing 14 with their axes
`A1 through AS extending parallel to the axis of the lens
`housing 12, rather than being inclined thereto. This con
`struction has the advantage that the lamps L. can be simply
`mounted in a common plane in housing 14. An additional
`difference in this embodiment is that the modified illumi
`nator 30 has an annular Fresnel lens 32 mounted beneath the
`
`55
`
`65
`
`Petitioner's Exhibit 1010
`Page 6 of 8
`
`

`

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`lowerlight emitting ends of the lamps L., and coaxially of the
`lens housing 12. Fresnel lens 32, which may be generally of
`the type employed in the above-noted U.S. Pat. No. 4,567,
`551, is secured around its outer peripheral surface in the
`lower end of a circular camp or ring 33, the upper end of
`which is secured to the outer peripheral surface of housing
`14, so that lens 32 is supported beneath and in registering
`relation with the lamps L in the illuminator 30. As noted in
`the U.S. Pat. No. 4567,551 lens 32 can be made from two
`identical, annular plastic or glass elements having grooved
`sides thereof cemented together. With this construction the
`Fresnel lens 32 can be designed so that it redirects the
`illumination from the numerous lamps L in the illuminator
`30 downwardly in FIG. 3 toward a workpiece (not
`illustrated) in a manner similar to that shown in FIG. 1.
`Referring now to the embodiment shown in FIG. 4, 40
`denotes generally still another form of surface illuminator
`comprising a lamp supporting housing 14, again secured
`coaxially on the lens housing 12 adjacent the lower end
`thereof, and containing a plurality of lamps L which are
`mounted in housing 14 in a manner similar to those shown
`in FIG. 3-i.e., with the axial centerlines of their beams
`extending parallel to the axis of the lens housing 12. Also as
`in the embodiment shown in FIG. 3, a ring clamp 43 is
`secured coaxially at its upper end around the outer periph
`eral surface of housing 14, and projects axially downwardly
`beneath housing 14 and has secured in its lower end a
`Fresnel lens 32. Also mounted within ring 43 between the
`Fresnel lens 32 and the lower ends of the lamps L is an
`annular diffusing element 44, which lies in a plane spaced
`slightly above and parallel to lens 32, and slightly beneath
`the lower ends of the lamps L in the illuminator 40. The
`advantage of using the diffusing element as shown in FIG.
`35
`4 is that it makes the illumination, which is directed at the
`work (not illustrated), more uniform both angularly and
`spacially.
`One of the preferred types of lamps L employed in the
`foregoing embodiments is of the type known as a light
`emitting diode (LED) which has a collimating lens molded
`over the output end of the lamp-i.e., the end of the lamp L
`directed toward the workpiece W, as shown for example in
`FIG. 1, and corresponding to the lower ends of the lamps L
`45
`as shown in FIGS.3 and 4. Each lamp thus serves as a source
`of essentially collimated light with small angular spread
`from the axial centerline of the light beam, for example in
`the range of 7. In those embodiments in which the Fresnel
`lens is employed, such beams are then redirected and
`focused onto the object plane (the plane of the workpiece) by
`the Fresnel lens. LED's of the type described are offered for
`sale by Hewlett Packard under the designation HLMA
`CHOOf-CLOO.
`55
`It will be apparent to one skilled in the art however, that
`other light sources, such as for example light pipes, con
`ventional incandescent lamps, or similar beam-emitting
`devices, with or without associated collimated lenses can be
`employed without departing from this invention. Moreover
`although in the illustrated embodiments only five circular
`arrays of lamps have been illustrated, it will be readily
`apparent that any number of circular arrays can be employed
`and the overall number of lamps employed can be increased
`or decreased without departing from this invention. For
`example, the number of lamps employed in a surface illu
`
`65
`
`6
`minator of the type described above may include circular
`arrays ranging from R1 to any desired upper limit RN, while
`the number of sectors likewise could range anywhere from
`S1 to any desired upper limit as SN. Likewise, if desired, the
`angular spacing of adjacent lamps in an array thereof need
`not be equiangular, nor need the arrays be equispaced
`radially from each other.
`While this invention has been illustrated and described in
`detail in connection with only certain embodiments, it will
`be apparent that it is capable of still further modification, and
`that this application is intended to cover any such modifi
`cations as may fall within the scope of one skilled in the art
`or the appended claims.
`We claim:
`1. A surface illuminator, comprising
`a first housing having therein an axial bore containing
`means for projecting through said bore the image of an
`object located in a predetermined position beyond one
`end of said first housing,
`a second housing surrounding said first housing and
`having an open end disposed coaxially of and adjacent
`to said one end of said first housing
`a plurality of collimated light sources each having a light
`emitting end,
`said light sources being mounted in said second housing
`in spaced relation to each other, and with said light
`emitting ends thereof disposed in radially spaced cir
`cular arrays surrounding said first housing coaxially of
`said bore, and lying in a common plane extending
`normal to the axis of said bore, each of said sources
`being operative, when energized, to direct a beam of
`light substantially parallel to said axis and toward the
`open end of said second housing.
`a Fresnel lens mounted in said open end of said second
`housing in confronting relation to the light emitting
`ends of said light sources whereby the light beams from
`said sources pass through said Fresnel lens and are
`thereby redirected toward and focused onto said object
`in said predetermined position, and
`control means for selectively energizing said light
`sources, thereby to control the amount and orientation
`of the illumination directed by said Fresnal lens onto
`said object.
`2. A surface illuminator as defined in claim 1, wherein
`said control means includes a plurality of electrical cir
`cuits each of which controls a predetermined number of
`adjacent light sources in each of said arrays thereof,
`each of said circuits includes switch means operable
`selectively to energize in one or more of said arrays
`said adjacent number of light sources controlled
`thereby,
`said predetermined number of adjacent light sources in
`each array controlled by a respective circuit increases
`progressively from a minimum number for the radial
`innermost of said arrays to a maximum number for the
`radial outermost of said arrays.
`3. A surface illuminator as defined in claim 2, wherein
`said predetermined minimum and maximum numbers of
`adjacent light sources in an array thereof are the same for
`each of said circuits.
`4. A surface illuminator as defined in claim 2, wherein
`each of said circuits for a respective one of said arrays
`controls an equal number of said light sources, and
`
`Petitioner's Exhibit 1010
`Page 7 of 8
`
`

`

`7
`the light beams emitted by the arrays of light sources
`controlled by said circuits are arranged in generally
`pie-shaped sectors.
`5. A surface illuminator as defined in claim 1, including a
`light diffusing element interposed between said light sources
`and said Fresnel lens.
`6. A surface illuminator as defined in claim 1, wherein
`said light sources comprise light emitting diodes having
`the light emitting ends thereof disposed in said com
`mon plane, and
`each of said light emitting diodes has a collimating lens
`secured over the light emitting end thereof.
`
`15
`
`5,690,417
`
`8
`7. A surface illuminator as defined in claim 1, wherein
`said circular arrays are radially spaced equal distances
`from each other, and
`the light sources in each of said arrays are equi-angularly
`spaced from each other about the axial centerline of
`said bore.
`8. A surface illuminator as defined in claim 7, wherein the
`total number of light sources in each circular array increases
`progressively from the radial innermost to the radial outer
`o most of said arrays.
`9. A surface illuminator as defined in claim 1, including
`means for selectively adjusting the global intensity of said
`light sources.
`
`Petitioner's Exhibit 1010
`Page 8 of 8
`
`