Software is under development at Teledyne Brown Engineering to represent a lens configuration as a y-ybar or Delano diagram. The program determines third-order Seidel and chromatic aberrations for each configuration. It performs a global search through all valid permutations of configuration space and determines, to within a step increment of the space, the configuration with smallest third-order aberrations. The program was developed to generate first-order optical layouts which promised to reach global minima during subsequent conventional optimization. Other operations allowed by the program are: add or delete surfaces, couple surfaces (for Mangin mirrors), shift the stop position, and display first-order properties and the optical layout (surface radii and thicknesses) for subsequent entry into a conventional lens-design program with automatic optimization. Algorithms for performing some of the key functions, not covered by previous authors, are discussed in this paper.

Optical instruments designed for use with large telescopes need to be tested before being installed at their work site. This is especially true for space-based instruments. To perform these tests, an auxiliary optical system is required which simulates the telescope exit pupil. Two-mirror projection systems can be used for this purpose. In this paper the first-order geometric properties and third-order aberrations of the general two-mirror system used at finite conjugates are examined. Relations are given in terms of five design parameters: object distance, image distance, exit pupil size, and the two mirror magnifications. A particular application of these relations is presented for a system designed to simulate the HST, for ground testing of the next generation of scientific instruments to be installed in the observatory. We show that a sufficient number of degrees of freedom are available to meet requirements when both mirrors are conics.

Two-component zoom systems are a basic part of all zoom systems. The first zoom systems appeared at the end of the 19th century in Germany. Dunouer has shown the possibility of creating two-component zoom converters with a definite magnification range and the appropriate correlation between the optical powers of the components. After Dunouer several types of the two-component zoom objective lenses have been designed. Typically, they had small magnification range (less than 2X) and were more complex than was necessary. In the 1970s designers began to pay more attention to the creation of two-component zoom projection systems. Most recently, special telecinema zoom projection systems have been created. An optical telecinema system consists of a zoom projection system and a prism splitter to split the beam into three color channels. Its purpose is to project 8, 16, and 35 mm movies in a television. Such a zoom system is supposed to have telecentric chief rays in image space and a long distance from the last surface to the image. The creation of new zoom systems has to be founded on the general theory of first- and third-order design to find the optimum parameters of the system.

Dichromated gelatin layers (DCG) facilitate the design and fabrication of large-format (1 m2) holographic optical elements (HOE) that exhibit high optical quality and diffraction efficiency. The subject matter of this report is the presentation of an optimized design and fabrication technique for the manufacturing of large-format diffractive optics. The emphasis is placed on the realization of homogeneous diffraction efficiency distribution across the aperture of the HOE. The nature of the holographic process requires precise control of the mechanical properties of the DCG layer such as moisture content, shrinking, swelling, hardness, and elasticity of the film, which specify the slant angle, the mean index of refraction, and the amplitude of the refractive index modulation. These properties ensure the attainment of the desired diffraction efficiency, bandwidth, and Bragg-shift. The results achieved in the development and fabrication of such layers are presented and their applicability as holographic solar concentrators is explained. The emphasis is also placed upon the development and realization of a novel copying technique for the batch reproduction and inexpensive manufacturing of large-format transmissive holograms that are used as focusing lenses in solar concentrators.

Quantities which are necessary for ray tracing in any case are used to calculate the geometrical and optical path differences. Proceeding from the optical path difference, the coefficients of the power series of the wave-aberration function are fitted by a method of least squares up to the eighth degree. For a triplet the surface contributions of the different terms of the aberration function and their sums are represented graphically and numerically. Different checks of validity show not only the accuracy but also the uncertainty of the method in each special case.

Recently, a group of glasses has been investigated that have high refractive index and low dispersion. These glasses are known as reluctant glass formers and lie in the 'forbidden' region of the conventional glass map. Research is continuing to develop means and techniques to produce usable sizes and optical characteristics. Since these glasses have unusual optical properties, a study was performed to gain an understanding of the impact such glasses could have on optical design and to establish desired baseline optical properties as objectives for the material scientists. Several generic optical configurations were explored to determine if a meaningful improvement could be realized. Study results are presented and discussed to illustrate that a notable enhancement in optical performance is attainable.

Mathematical expressions are presented to relate object and image plane tilts in nonaxially symmetric systems. Examples that illustrate the use of these expressions are given. Keystone distortion is described and quantified as a function of image plane tilt.

The baseline mission concept of the Geostationary Earth Observatory (GEO) calls for five Earth Science Geostationary Platforms (three by NASA, one by Europe, and one by Japan) to be deployed around the earth. This paper discusses the science goals of the GEO, the GEO platform concept, the instrument complement proposed for the GEO mission, and the various optical technology issues involved in the instrument operation. The instruments proposed include the Geostationary Microwave Precipitation Radiometer, the Geostationary Atmospheric Profiler, the Geostationary Earth Processes Spectrometer, the Advanced Lightning Mapper, and the High Resolution Earth Processses Imager. The instruments' design diagrams are included.

Geometric parameters such as fill-factor, pixel shape, and array symmetry strongly affect the performance of membrane light modulators. A set of modeling tools that allow device performance evaluation as a function of these parameters have been developed. The models predict the effect of varying a given parameter and allow visualization of the result. The current modeling results are in good agreement with experimental observation and have formed the basis for computer-aided design of future generations of such devices.

The techniques used for the analysis of thermally induced structural distortions of optical components such as scanning mirrors and telescope optics are outlined. Particular attention is given to the methodology used in the thermal and structural analysis of the GOES scan mirror, the optical analysis using Zernike coefficients, and the optical system performance evaluation. It is pointed out that the use of Zernike coefficients allows an accurate, effective, and simple linkage between thermal/mechanical effects and the optical design.

A novel concept on the construction of high-resolution objectives is outlined. Although similar to binary optics technology, this approach brings additional degrees of freedom to the optical design as far as achieving a finer balance of phase curvature via refractive properties and relative thickness of the multilayer stack. The differential coating objective can be used in conjunction with diffractive surfaces to optimize the transmission efficiency and control the secondary spectrum correction. The basic equations describing the monochromatic and three- color achromat predesign are presented.

An original plastic-lens array molded integrally as one block having a function of forming a unit-magnification erect image has been developed. The lens array consists of eight lens devices. The lens device has a roof prism, a reflecting v-groove, and a pair of convex-lens surfaces. A prototype of the lens arrays are arranged side by side. Thickness of the lens array is 4.5 mm, distance between object and image planes is 14.4 mm, array pitch is 1.3 mm, and the effective imaging region is 220 mm. The average modulation transfer function (MTF) at 41 p/mm of the lens array is 76% in the row direction (Y-direction) and 80% in the direction (X-direction) normal to Y-direction. The average F/NO in line-scanning is 1.8. The average irradience unevenness in line-scanning is 17%. The focal depth is +/- 0.6 mm in the area with the MTF being 60% or more. With this prototype a high-resolution image was attained. So, the lens arrays can be applied to imaging devices for use in a compact facsimile, image scanner, LED printer, and so on.

An original plastic-lens array molded integrally as one block having a function of forming a unit-magnification erect image has been developed. The lens array consists of eight lens devices. The lens device has a roof prism, a reflecting v-groove, and a pair of convex-lens surfaces. A prototype of the lens arrays are arranged side by side. Thickness of the lens array is 4.5 mm, distance between object and image planes is 14.4 mm, array pitch is 1.3 mm, and the effective imaging region is 220 mm. The average modulation transfer function (MTF) at 41 p/mm of the lens array is 76% in the row direction (Y-direction) and 80% in the direction (X-direction) normal to Y-direction. The average F/NO in line-scanning is 1.8. The average irradience unevenness in line-scanning is 17%. The focal depth is +/- 0.6 mm in the area with the MTF being 60% or more. With this prototype a high-resolution image was attained. So, the lens arrays can be applied to imaging devices for use in a compact facsimile, image scanner, LED printer, and so on.

High-resolution space-based imaging applications are limited by the difficulty of placing large monolithic mirrors in space and by technology limitations on the diameter achievable in monolithic mirrors. Multiple-mirror imaging systems can overcome these limitations but require precise alignment-error sensing and correcting schemes to maintain all elements in phase. When a wide field of view is desired, the complexity increases substantially since significant error terms will be a function of field angle. Approaches which can reduce the complexity of the error sensing/correcting schemes are thus of great interest. By sampling selected spatial frequencies, representative of both the individual subapertures and errors between subapertures, measurement of all error terms except absolute piston can be achieved. A technique which places a nonredundant mask in the compacted pupil plane of a phased-array imager and senses the selected spatial-frequency magnitude and phase in the focal plane has been analyzed. This technique can reduce complexity in the local error-sensing system while accounting for all tilt, geometry, magnification, and relative piston errors.

A novel beam path in the test leg of an amplitude division interferometer is presented, which has application to the testing of thin visibly opaque windows. Its function and applications are discussed, alignment methods explained, and scaling factors given.

With many optical systems the method that is used to align the optical system needs to be an integral portion of the system design and not an afterthought. Once all the pieces are in fabrication it may be too late to implement a cost-effective alignment procedure for both prototype and production designs. This is especially true with catadioptric systems where the mirror alignment tends to be very critical as far as system performance is concerned. This paper describes the design and use of an aspheric null mirror for the alignment of a two mirror subsystem to a lens cell. The optical system to be aligned was a six-in. EFL, F/2 system working in the 3-5 micrometers bandpass. It consisted of two aspheric mirrors, one aspheric lens, and two spherical lenses.

The schematic of a real-time holographic microscope featuring a phase-conjugate mirror for retroreflection and a scanning module is reported. The instrument is provided with Epi- and Dia- brightfield capabilities, video/photosensing output, and optional optoelectronic processing. An analysis of the real-time restoration process in comparison with conventional holography is presented. The paper reviews the merits and drawbacks of the setup and concludes with a brief discussion on 2-D scanning options.

An application of Fourier transform lenses to surface topography detection is investigated. The field is illuminated in parallel using an array of three different wavelength laser diodes, and relative phase alteration is read out between cross-correlated electronic pixels. Diffraction theory of image formation is used to interpret the modulation in contrast. Speckle sensitivity to wavelength provides the basic technique for noise filtering.

An analysis of the measuring accuracy that can be obtained using critical angle refractometry as a direct and an indirect method is made. The working conditions required to get the highest accuracy are discussed.

The authors developed a new advanced laser scanning range finder. The width gauge consists of a pair of these range finders. Conventional gauges cannot measure the effective width of complexly shaped plate edges. However, the gauge measures both side profiles of a plate and calculates the effective width with an accuracy of +/- 1.5 mm. This new type of width gauge has been developed and tested at the plate rolling mill at Kashima Steel Works of Sumitomo Metal Industries Ltd.

Laser micromachining with ten level resist kinoforms, manufactured by electron-beam lithography, is presented. The kinoforms were shown to have a diffraction efficiency of 68%. One kinoform was used to drill nine diffraction-limited holes simultaneously in a 0.10 mm thick stainless-steel plate. Marking in a silicon wafer was also done.

The transformation of laser beams passing through optical systems is analyzed using a TEM modal decomposition. The laser beam is decomposed and the optical system is described by a matrix that relates the modal composition of the input and output beams. The hard aperture and the parabolic and Gaussian soft apertures are given a typical examples. The matrices that characterize these apertures allow analysis of the losses of laser resonators, including finite and/or variable reflectivity mirrors. The modal decomposition is used for defining modified ABCD matrices that include any kind of apertures.

A tutorial on the subject of interferometer fringe scaling factors is offered. Various approaches are pursued in the hope of reaching a broad audience. The distinction between fringes and waves is established and maintained, and a procedure for interpreting interferograms is provided. Scale factors for various cases are shown.

The theory of nondiffracting beam propagation and experimental evidence for nearly-nondiffractive Bessel beam propagation are reviewed. The experimental results are reinterpreted using simple optics formulas, which show that the observed propagation distances are characteristic of the optical systems used to generate the beams and do not depend upon the initial beam profiles. A set of simple experiments are described which support this interpretation. It is concluded that nondiffracting Bessel beam propagation has not yet been experimentally demonstrated.

It has been shown that the Admittance Diagram along with the Quarterwave Rule can be used in the design and characterization of optical thin film coatings. However, this same tool may be utilized in the design and characterization of some microwave components as well. A simple design example of a Wilkinson power divider is presented to illustrate the utility of this optical technique for microwave circuit design and analysis.

This paper reports the behavior of an XeCl laser having two independent preionizers which generate UV radiation into the discharge region in the perpendicular and parallel direction to the electrode surfaces. Output energy and other parameters have been measured using a single preionizer and both preionizers, changing the power-supply polarity and varying the delay time between the preionization and the main discharge. When the preionization system generated photons only in the direction perpendicular to the electrode surfaces and a negative power supply was used, a high discharge current and a high output laser energy were obtained. Besides, the diffusion coefficient of the photo-preionized electrons played an important role in the laser behavior, particularly when a consistent delay time between the onset time of the preionization and the main discharge was present. During the breakdown the discharge impedance is time dependent and its value changes as the preionizers change position. By comparing the experimental results obtained by the equation of the discharge electric circuit, it is possible to get exactly the electric element value which simulates the discharge impedance.

A high-speed, high-precision laser plotter, the Super Laser Photo Plotter (S-LPP) has been developed. S-LPP has a flat table so that both photographic plates and films can be used, and it is capable of writing fine patterns for print circuit boards (PCBs), lead frames for IC, etc., over the area of 640 mm X 819 mm with a minimum line width of 10 micrometers in 60 min. It has achieved more than fifty-times faster speed than that of a conventional plotter which has almost the same specifications as S-LPP. Several important optical techniques that have given S-LPP its own features are described.

The author proposes a new noise power-spectrum estimation method for mark-dimension fluctuation in optical disks. Diffraction by marks was modeled using Fraunhofer diffraction theory, and mark-dimension fluctuations were taken into account through statistical averaging. The calculated and experimental results agreed well. Fluctuations in the mark edge position mainly contributed to noise.

The results of intracavity application of soft or apodized apertures (AA) with smooth transmission profiles decreasing from the center to the edges are presented. Photooxidation (PhO) AA, made of CaF2:Pr crystals were used. The approximately 3-4 mm diameter of PhO AA with bell-like transmission profiles as placed inside the 2.94 micrometers and 1.06 micrometers resonators of master oscillators. The tendency of the order of magnitude of 1.3 - 1.8 times increasing in output energy and diminishing in beam divergence in single-mode lasing as compared with hard-edge aperture have been observed in the experiment described.

Matrices of optical components (like LEDs, microlenses, microzone plates, microspatial filters) are used in some arrangements to obtain the optical transformation from an area of a frontal plane to a point and vice versa. By use of these matrices the following arrangement are established: a matrix optical relay-system, a multichannel optoelectronic hybrid computer, an optical system for pattern recognition by spatial multichannel filtering, and uniform illumination system. The established relationships are applied to calculate the positions, the component sizes, and the system performance. Matrix configuration is shown to be advantageous for maximizing the performance for plane-point correlation and, also, for a miniature solution.

A method of investigation of the optical properties of anisotropic materials using modulation of the light polarization is presented. Measuring set-up was constructed and used to examine the optical properties of interesting tetragonal semiconducting Zn₃P₂ compound.

A new approach to the fringe formation in the interference of light incident on a plane parallel plate is introduced. It is shown that for a particular angle of incidence, which depends only on the refractive index, the interfringes are minimum. It is proved that in an angular interval of few arc degrees around this particular incident angle the interfringes are equal to a high accuracy. It is shown that this feature can be exploited to produce an interference grating with an arbitrary transparent-to-opaque groove ratio, and to measure the wavelength of light and the fine structures of a spectrum with a precision considerably higher than can be obtained in the other similar interferometric methods.

The main parts of the imaging spectrometer for observing ocean color (OCM system) are: the scan subsystem, the pre-position telescope, the dispersion element, and the spectrometer which should be determined according to the science requirements of ocean color observation and the correspondent specifications of the optical design. The authors analyzed the optical systems of the MODIS-T proposed by NASA/Goddard Space Flight Center and found some problems in them. Based on this the authors designed a reflection-refraction hybrid optical system by autocollimation grating. The results are better than the improved MODIS-T optical design in some points--the minimal optical MTF value of the design at the Niquist frequency is better than 0.96, the construction is much more compact.

The authors developed a zoom lens design expert system intended to operate with little user intervention. The paper emphasizes the knowledge representation, system architecture, reasoning, and control strategy of the system MEX-1.

The spherical aberration coefficient (SAC) can be divided into : intrinsic and derivative coefficients. The former occurs on certain boundaries without incident beam aberration, and the latter is the variant of spherical aberration (SA) which is caused by aberration of the incident beam on certain boundaries. The third, fifth, and seventh order intrinsic SACs can be obtained by enlarging the SAC of the incident beam without aberration (L=1, SinU=u). The aberration of the incident beam is expressed as Δl=L-1 and Δy=L · SinU-1 · u (where 1 and L are the intersecting distance of paraxial and nonparaxial beams, respectively). Then the fifth and seventh order derivative SACs can be derived from differentiating and intrinsic SAC with respect to aberration of the incident beam.

The revisions of enlarging all the aberrations related to aperture to the seventh order for the Seidel aberration theory have been proposed in this paper. The practice of the revised theory in the range of small viewing field and large aperture (for example, the lens of microscope and telescope) has proven that the theory is applicable in this scale.

The relationship between aberration and the aberration coefficient is the basic formulation in the field of aberration theory. The Seidel's formulations can only be used in the case of low performance (small aperture and small field), so that a set of correct relations between spherical aberration (SA) and spherical aberration coefficient (SAC) must be derived for the application of large aperture and small viewing field.

The expressions of the Seidel aberration theory are comparatively simple and easy to use due to its characteristics and prerequisites. Meanwhile, the effective range of the theory is limited also due to its prerequisites. The possibility for enlarging its effective range is analyzed in this paper.

A new type of Galilean binoculars is presented. The objective lenses are composed of a cemented doublet and a positive meniscus, and the eyepiece is a negative thick meniscus. In addition, all of the surfaces except the gluing surface are concave toward the eye-side of the system. So the structure is suitable for both increasing the field of view and decreasing the dimensions. It increases the vision angle by 46.5% and reduced the dimensions approx 2.33 times. The characteristics are: the magnifying power, 2.3; the object vision angle, 32 deg when its interpupillary distance is 6 mm, 27,36 deg when its interpupillary distance is 8 mm; the total of the telescope 29 mm; and the full objective aperture, (Phi) 35 mm.

A simple spatial filtering is added in moire deflectometry (MD) which raises the sensitivity, improves the contrast of moire patterns, and makes the viewing plate conjugate to the phase objects under test. This modified system is called moire interferometer (MI). Using the Fourier method, this paper analyzes the measurement principle of MI and obtains a strict relationship between a tested wave function and the shift of moire fringes.

This paper puts forward a new large-aperture high-accuracy interferometer for flow visualization and optical shop testing. The interferometer uses a Twyman-Green interferometer as a beam splitter, and a grating as a detector. Using this interferometer to measure the flow fields in a shock tunnel and to test optical elements obtained some satisfactory results.

The optical layout, the application, and the working principle of a large-aperture long-range moire interferometer (MI) for the quantitative measurement of flow properties are introduced. The interferometer is easily converted from a schlieren, and is easily tuned by practitioners of experimental flow mechanics.

A new, simple method for on-line rapid testing of the optical transfer function (OTF) of camera lenses has been developed in which the digital fast Fourier transform method is employed using a linear array CCD for sampling the linear spread function (LSF) of the lens under test. The main advantage of the new method is that for the test of off-axis OTF neither the lens under test nor the collimator need to be rotated. Obviously, this method is different from the present complicated test methods. Therefore, this method is simple and easy to accomplish on-line automatic test of OTF. The time required for testing a nine-position OTF such as on-axis +/- 0.7 and +/- 1 viewfields in both meridional and sagittal planes is less than 2-3 min. An OTF testing formula relative to the testing factors has been established. Based on it, the testing accuracy of OTF is discussed with the idea of relative accuracy for the first time. The theoretical results are in agreement with the experiments. Precision is 1-2%. The relative errors of both the modulation transfer function (MTF) and phase transfer function (PTF), which change with spatial frequency f, are about 10% and 3% at f equals 50 c/mm, respectively.

The mechanism of laser-induced damage to thin films is described and a definition of laser breakdown threshold to thin film, and optical breakdown threshold, is presented. The new definition is clearer than the existing one. The measurement results and comparison for various samples are given on the basis of the two above-mentioned definitions.

The design principles of a large-aperture high-sensitivity and high-precision moire deflector in which two error-correction methods of real-time holography are used to make grating are presented. Theories and experiments show that this moire deflector has high sensitivity and high precision in measurement, and its system errors are eliminated.

To further use of optical devices in a more critical environment it is necessary to research the image-stabilization theory of reflecting prisms in the case of a finite angular perturbation. This article gives conception of standard conjugate pairs of the object and image spaces of stabilization, establishes general image-stabilizing formulas either in the relative or absolute coordinate system, and analyzes the one-freedom image stabilization of single ISRP in the collimated light that is located in or before the optical system. Some useful conclusions and compensation formulas are given.

This paper presents a new idea for the optimization of an initial lens structure type from an optical lens database on the basis of introducing optical lens database (OLDB) and computer- aided optical design (CAOD) systems. Using image-quality target parameters as conditional search parameters of optimization of initial lens structure type from database, and evaluating selected lens quality with surface relative aperture (h/r), the authors were able to obtain a good effectiveness in practice.

The 60-cm diameter, f/2 DCWS telescope is a modified Ritchey Chretein configuration which collects radiation in three spectral bands, 0.4 to 0.9/micron (visible), 5.0 to 9.0/microns (MWIR), and 9.0 to 12.0 microns (LWIR). The visible and infrared radiation are separated by a dichroic beamsplitter and focused on to separate focal planes; the MWIR and LWIR radiation share a common focal plane with separate detector arrays residing side-by-side. The conic constants of the primary and secondary mirrors are that of a Ritchey Chretein telescope; to improve the image quality at the edges of the field of view, a set of zero power correcting optics have been introduced to each optical train. The Ritchey Chretein telescope is corrected to have zero third order spherical aberration and zero third order coma; the DCWS telescope is further configured such that the positive power in the primary mirror is approximately equal to the negative power in the secondary mirror, resulting in a telescope with very little field curvature.

The authors analyzed techniques for designing lenses consisting of conventional reflective or refractive elements used in conjunction with binary optical elements (BOEs), and reviewed the use of BOE correctors in systems with both rotational and bilateral symmetry. These systems add a large number of degrees of freedom, such that almost any arbitrary wavefront shape can be obtained. For this reason, automatic optimization with BOEs requires special considerations; especially, tilted or decentered systems, wide-waveband systems, or wide field-of-view systems. If caution is not exercised, one can easily consume large amounts of expensive cpu time only to converge on nonoptimal dead-end solutions. A typical situation that occurs is the convergence upon a solution where the performance is diffraction limited at the finite number of defined field points, but strongly aberrated at field points in between. The key to converging on an optimal solution is the proper use of user defined constraints. The authors studied how to select which BOE coefficients to vary and how to choose field points in order to increase the probability of converging on optimal solutions.

All-reflective, unobscured optical designs were developed to help identify a candidate first- generation system to be used in soft x-ray projection lithography. The resolution goal for all designs was 0.1 micrometers , or better, at a design wavelength of 13 nm. Different design aspects including usable field size, image distortion, number of mirrors, telecentricity, surface shape (spherical versus aspheric), and system packaging were explored. Trade-off studied between systems requiring scanning and full-format nonscanning systems were made. The tolerance sensitivity analysis for a representative design demonstrated that as-built performance will be driven by the mirror surface irregularity tolerance; the required tolerance levels are briefly discussed.

Specifications, design, and operation of an optical system that couples a high-power copper vapor laser beam into a large core, multimode fiber are described. The approach used and observations reported are applicable to fiberoptic delivery applications.

A novel optical distributed-wavelength filter for IC integration and chip-integrated spectroscopy is described. The filter structure is of Fabry-Perot character. It is comprised of a wedge-shaped dielectric film sandwiched between two reflecting thin films. The novel fabrication technology employed is IC batch compatible. The marriage of this novel filter with a distributed detector array is intended to provide a monolithic chip-integrated spectrometer. Such a spectrometer is expected to be of high performance, rugged, small, light weight and of low cost. Imaging structures using arrays of microfilters fabricated using the same technology are also targeted. The filter arrays are to provide wavelength-selective imaging. Experimental prototype visible-filter results have already exhibited approximately 40% transmission. Analytical results for additional prototypes are described. Certain prototypes indicate 80% transmission is achievable. Bandwidth and transmission features are determined by the design features and are very flexible. For the first time, manufacture of low-cost, light-weight, rugged monolithic chip spectrometers appears feasible.

A technique which automatically adjusts the optical axis of a CCD image sensor with the lens for a linear CCD image scanner is described. The error of the alignment is measured to the magnitude and pulse-width of the detected signal from the linear CCD image sensor, calculating the value of error by computer and driving the stepping motor to achieve the automatic adjustment.

Recent development ofG4 fax and scanner requires a high speed, high resolution, and high contrast second generation image sensor. This paper describes a silicon butting Contact Image Sensor (CIS) module which has been developed and produced to solve the problems encountered by using CCD image sensors. Due to the flexibility ofthe design, the CIS module can be made for the A6, A4 ,B4 or other paper sizes. This device can be operated at high speed (2 MHz or higher), high dynamic range (1000: 1) and high resolution (400DPI). By adding alayer ofcolor filter on top of the photosensor, it is also applicable for the color G4 facsimile and color scanner.