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公开(公告)号：DE1573575A1
公开(公告)日：1970-06-18
申请号：DEJ0028449
申请日：1965-06-26
Applicant: IBM
Inventor： FLEISHER HAROLD , MAX KOSANKE KURT , T SINCERBOX GLENN
Abstract: 1, 070, 336. Photo-electric inspection of coatings. INTERNATIONAL BUSINESS MACHINES CORPORATION. May 25, 1965 [June 29, 1964], No. 22033/65. Heading G1A. [Also in Divisions G2 and H4] The continuity of a reflective coating on a transparent strip is detected by reflecting light off the coated strip and detecting when, in the absence of the coating, interference occurs between light reflected from the two surfaces of the strip. White light from a source 22 is polarized at 24 before entering a monochromator 25 producing an output beam the wavelength of which varies cyclicly at high frequency. This beam is scanned across the strip by a mirror drum 27 or an electro-optic light deflector. Light reflected by the coating is of substantially constant intensity and gives a D. C. output from the photo-cell 62, but when the coating is missing, an A. C. signal results as the wavelength of the incident beam passes through those wavelengths at which constructive and destructive interference occurs between the surfaces of the strip. A high-pass filter 64 detects this A. C. signal and operates a defect marker 32 through an appropriate delay 31. The mirror drum 27 may be omitted and the strip scanned by a linear beam of light transverse to strip. The monochromator may operate utilizing the rotary dispersion of an optically active crystal in combination with an electrooptical rotator as polarizer or analyzer. (See Division G2).
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公开(公告)号：DE1547378A1
公开(公告)日：1969-12-11
申请号：DE1547378
申请日：1966-12-15
Applicant: IBM DEUTSCHLAND
Inventor： LEONARD DUDA WILLIAM , MAX KOSANKE KURT , WOLFGANG KULCKE DR WERNER , ERHARD MAX DR
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Patent Agency Ranking
公开(公告)号：DE1472141A1
公开(公告)日：1969-01-09
申请号：DE1472141
申请日：1965-06-28
Applicant: IBM
Inventor： FLEISHER HAROLD , MAX KOSANKE KURT , W KULCKE DR WERNER , ERHARD MAX DR
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公开(公告)号：DE1639269A1
公开(公告)日：1972-03-16
申请号：DEI0035501
申请日：1968-01-13
Applicant: IBM DEUTSCHLAND
Abstract: 1,138,985. Multi-frequency light deflectors. INTERNATIONAL BUSINESS MACHINES CORP. 6 Oct., 1967 [16 Jan., 1967], No. 45641/67. Heading H4F. [Also in Division G2] A plane polarized polychromatic light beam is separated into two or more spatially separated and preferably parallel output beams each comprising one or more of the plurality of wavelengths of the polychromatic light beam by means of polarization control means for orienting the polarization plane of at least one of the wavelengths perpendicular to the polarization plane of the other wavelengths, and beam splitting means adapted to separate wavelengths having mutually perpendicular polarization planes. As shown, Fig. 1, a plane polarized light beam from a light source 10 having a plurality of wavelengths # 1 , # 2 , # 3 and # 4 is separated into two parallel spaced outputs beams comprising wavelengths # 1 , # 2 and # 3 , # 4 respectively by means of dispersion rotator 12 of optically active material such as quartz, which separates the four wavelengths into pairs polarized in two mutually perpendicular polarization directions, an electro-optic crystal assembly 14 which works as a polarization switch for a mutual exchange of the two polarization directions when the voltage is applied to those shown by the wavelength designations in the brackets, and a totally internal reflecting polarization dependent beam splitter 16. Beam splitter 16 includes a birefringent plate 22 e.g. calcite or sodium nitrate crystal, the optic axis of which is parallel to its reflecting surface and perpendicular to the plane of the drawing, the plate being inclined at an angle which is greater than the critical angle for a total reflection of light polarized perpendicular to the plane of the drawing. Beam splitter 16 also includes an alignment plate 24 with its reflecting surface parallel to plate 22. Plate 24 may be made of glass or sodium fluoride which has a refractive index less than or equal to the low index of refraction of the material of plate 22 so that external reflection occurs. The dispersion rotator may be replaced by a dispersive phase plate and the beam splitter by a pair of Wollaston prisms (Fig. 2, not shown). The two Wollaston prisms are deflection direction compensated i.e. the two beams which leave the first Wollaston prism divergently are made parallel by the action of the second Wollaston prism. The beam splitter may alternatively comprise a birefringent single crystal with special orientation. By using two such multi-frequency light deflectors four spatially separate output beams may be obtained (the second dispersion rotator being designed to make mutually perpendicular polarization pairs # 1 , # 3 and # 2 , # 4 ). Instead of using a dispersion rotator in combination with an electrooptic polarization switch, electric field controlled liquid crystal cells may be used, Fig. 5 (Figs. 6 and 7, not shown), each of which enables a single light frequency to be changed in its polarization direction such that it will be perpendicular to the remaining light frequencies in a polychromatic light beam. If a voltage is applied to a first electrode pair 76, 78 the molecules of the liquid crystal material will align in the direction of the electric field and birefringence will be exhibited. If a voltage is applied to electrodes 84 and 86 instead of electrodes 76 and 78 no birefringence occurs. For four wavelengths the number of combinations of polarization directions which can be achieved by three liquid crystal cells is eight, but by the addition of an achromatic electro-optic switch sixteen different combinations may be obtained (Fig. 6, not shown).
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公开(公告)号：DE1639267A1
公开(公告)日：1971-02-04
申请号：DE1639267
申请日：1968-01-12
Applicant: IBM DEUTSCHLAND
Abstract: 1,153,934. Light deflectors. INTERNATIONAL BUSINESS MACHINES CORP. Oct.2, 1967 [Jan. 16, 1967], No.44708/67. Heading G2J. [Also in Division H4] A light deflector for deflecting a beam containing light of two different wavelengths so that ordinary polarized light is transmitted without deviation while extraordinary light polarized is displaced, comprises a first birefringement crystal I which causes the wavelengths to be deflected by different amounts, and a second birefringement crystal I which recombines the two wavelengths. As shown Fig. 2 light of two wavelengths is passed through a Kerr cell 10 and then through the crystals; when the light is polarized in the first direction by the Kerr cell both wavelengths pass through the crystals as ordinary rays and remain colinear leaving the second crystal at the first point; when the light is polarized perpendicular to the first direction both beams travel as extraordinary rays and are recombined at the second point corresponding to a deflection b.
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公开(公告)号：DE1499723A1
公开(公告)日：1970-04-30
申请号：DE1499723
申请日：1966-10-11
Applicant: IBM DEUTSCHLAND
Inventor： JEROME HARRIS THOMAS , WOLFGANG KULCKE WERNER , MAX KOSANKE KURT , MAX ERHARD
Abstract: 1,104,163. Optical information storage system. INTERNATIONAL BUSINESS MACHINES CORPORATION. 11 Oct., 1966 [14 Jan., 1966], No. 45364/66. Heading G4A. An optical information storage system includes scanning means responsive to binary address signals for illuminating a selected area of an optical information record by deflecting a light beam appropriately over the record, and monitoring means responsive to the parity of each address applied to the scanning means for subtracting the emanation from the selected area of the record from that from another similar area of the record to provide an information indicating output. High intensity light from a monochromatic light source 10 is passed through a collimating lens 12, through a linear polarizer and through an aperture in a plate to a first unit 14 of a light deflection unit 14 including a plurality of deflection stages. Each stage comprises a birefringent means (22, Fig. 2, not shown) preceded by an electro optic element which provides an output beam polarized either in a first direction or a second direction at 90 degrees to the first, the birefringent means allowing one beam to pass through normally but causing the second beam to be diffracted and to leave the means at a position spatially separated from the first beam. Deflection stages are arranged in increasing order of deflection by a factor of two, the unit 14 causing deflections in the x position being followed by a unit 16 causing deflections in the y direction. An optical memory is then read by the light beam. The light beam is directed to the appropriate spot in the optical memory by X position address and Y position address signals which are converted into X and Y switch addresses by exclusive OR circuits 24, 28, an address of 111 requiring a diffraction of 7 positions thus requiring a switch address of 001 since the operation of the first electro-optic element will leave the beam polarized such that all succeeding birefringent means will cause diffraction of the beam. Examination of the switch addresses shows that the parity of the signal indicates from which quadrant of the memory the light beam will emerge, e.g. if the y parity is odd the light beam emerges from quadrant 1 or 2, if even from 3 or 4. Parity check circuits 30, 32 emit signals X1, X2, Y1, Y2 (X1, Y1 for even parity) which are applied to AND gates 50, 52, 54, 56 which indicate which quadrant the light beam is in. The four quadrants are examined by photo-cells 36, 38, 40, 42, one to each quadrant with the outputs of 38, 40, examining quadrants 2, 3 being applied to one difference amplifier 44 and the outputs of the other photo-cells being applied to a difference amplifier 46. It is assumed that the quadrants 1, 4 have the same noise signal produced by extraneous light, and similarly for quadrants 2, 3 so that the difference amplifier acts to subtract the signal due to noise from the data output signal. The resulting signal is then applied via inverters I, if necessary, AND gates 58, 60, 62, 64 and OR gates to the output.
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公开(公告)号：DE1547359A1
公开(公告)日：1969-11-20
申请号：DE1547359
申请日：1966-07-21
Applicant: IBM DEUTSCHLAND
Abstract: 1,134,373. Optical alignment apparatus. INTERNATIONAL BUSINESS MACHINES CORP. July 20, 1967 [July 21, 1966], No.33299/67. Heading G2J. Apparatus for optically aligning an object such as a semi-conductor wafer 1 with a reference mark 6 comprises an optical deflecting system 15, 16 which transmits a beam of radiation from a reflecting reference mark 5 on wafer 1 towards mark 6, control devices 18, 19 causing deflecting systems 15, 16 to scan the beam over the plane 17 containing mark 6 in accordance with a predetermined raster, a photo-cell 20 interrupting the scanning operation when the beam is incident on mark 6. Printed circuit patterns 22 are to be projected successively on to the photo-sensitized surface of wafer 1, and the wafer is first roughly aligned with the projection axis by screws 3, 4. The optical axis is then finally adjusted relative to the wafer using a subsidiary monochromatic light source 8 to which the wafer surface is insensitive, and a light switch 7. Light polarized at 11 passes via beam-splitter 12, lenses 13, 4 and devices 7, 15, 16 on to the area containing mark 5 and is reflected back through the system on to reference mark plane 17. When alignment of the projection axis is achieved, radiation from source 8 is cut off by switch 7 and the wafer is exposed to the pattern 22 which may be in hologram form using polarizing laser 24. Light switch 7 comprises an electro-optical crystal (31), Fig. 2 (not shown), to which a voltage (V) may be applied whereby the plane of polarization of a monochromatic light beam is rotated through 90 degrees, a birefringent plate (32) and a reflecting plate (33). Polarizer (34) passes light polarised in direction (41) only which is that of light beam (40) from source 8. Beam (44) from the laser is polarized at 90 degrees to direction (41) and is therefore only passed when crystal (31) is energized. Beams (40), (44) correspond to the extraordinary and ordinary beams for plate (32). Deflection units 15, 16 operating in X and Y directions are similar to switch 7 and comprise five electro-optical elements each followed by a birefringent element through which light may pass, depending on the state of the electro-optical elements, either as an ordinary or a deflected extraordinary beam. Each birefringent element is twice the thickness of its preceding element. The scanning deflections of the beam are obtained by activating the electro-optical elements in succession through five inter-connected bi-stable devices each with a switching frequency half that of the preceding device. The outputs of these devices are fed to the electro-optical elements through a logic circuit whereby each may be activated without affecting its neighbours. Rotational adjustment of wafer 1 is possible by using a Piezo-electric torsional support whereby the wafer may be rotated until moirÚ patterns due to lines on the wafer and reference mark reach a standard setting as sensed by photo-cells.
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