Abstract: An apparatus and method for interrogating fiber optic sensors non-intrusively sensing fluid flow within a pipe is provided. The apparatus includes a two-beam interferometer which comprises an optical circuit for generating a series of discrete light pulses that are directed at sensors positioned between pairs of low reflectivity fiber Bragg gratings. The successive light pulses are split into first light pulses and second light pulses, and the second light pulses are delayed a known time period relative to the first pulses. The first and second light pulses are combined onto a single optical fiber and directed through the low reflectivity gratings and the sensors positioned between the gratings. Reflected pulses from the series of pulses impinge on a photo receiver and interrogator, wherein the phase shift between the reflected first light pulses from a particular grating and the reflected second light pulses from the preceding grating, for each sensor are determined.

Abstract: This invention relates to an apparatus and method for positioning dual stages during semiconductor wafer processing. More particularly, the invention facilitates the use of interferometers to determine the positions of both wafer stages at all times during processing. While the movement of a typical twin stage apparatus causes one of the stages to eclipse the other and requires the addition of a significant number of additional interferometers, this invention minimizes the number of interferometers necessary through dimensioning the stages so that one stage never totally eclipses the other.

Abstract: A wavefront measuring apparatus and a wavefront measuring method are capable of performing optical measurement on a test optical system, including an immersion optical system, with comparable ease of handling to that of the conventional measuring method using a concave member, and substantially independently of reflection that may occur at the surface closest to the test optical system among the surfaces of an optical member for reflecting light exiting from the test optical system. The wavefront measuring apparatus has a light source, a reference light path in which a reference member for producing reference light is disposed, and a test light path in which the test optical system is disposed. A plano-convex optical member with a wall thickness approximately equal to the radius of curvature of a convex surface thereof is disposed in the test light path in such a manner that a plane surface thereof faces toward the test optical system.

Abstract: A system and method for measuring the profile of an external surface of a part is provided. The system includes a source of light that directs light onto a region of the external surface of the part. The system also includes a linear, light-sensitive sensor, and a lens used to image locations within the region onto the sensor. The source of light and the sensor are located substantially within the same plane such that the sensor detects substantially only light scattered, diffracted, or reflected from the region and travelling substantially within the plane. The system additionally includes a re-positionable mirror that re-directs the light emitted from the source of light to the plurality of locations within the region and re-directs light scattered, diffracted, or reflected from the plurality of locations within the region to the lens and the sensor.

Abstract: An offset measuring board is formed of a rectangular metal plate which can be positioned at a component mounting position by a positioning device and which has at least in proximity to one corner portion thereof a recognition through hole, serving as a recognition mark, having a black bottom face within a recessed portion.

Abstract: A method of using high yielding spectra scatterometry measurements to control semiconductor manufacturing processes and systems for accomplishing same is disclosed. In one embodiment, the method comprises providing a library comprised of at least one target optical characteristic trace of a grating structure comprised of a plurality of gate stacks, the target trace corresponding to a semiconductor device having at least one desired electrical performance characteristic, providing a substrate having at least one grating structure formed thereabove, the formed grating structure comprised of a plurality of gate stacks, illuminating at least one grating structure formed above said substrate, measuring light reflected off of the grating structure formed above the substrate to generate an optical characteristic trace for the formed grating structure, and comparing the generated optical characteristic trace to the target trace.

Abstract: A jet of water in a cylindrical form is supplied from a jet nozzle onto a measurement surface of a substrate to form a column of the water extending between the nozzle and the measurement surface. Light is emitted from an irradiation fiber and transmitted through the column of water to the measurement surface. The light reflected by the measurement surface is received by a light-receiving fiber through the column of water. A measurement calculation unit measures the thickness of a film formed on the substrate, based on the intensity of the reflected light.

Abstract: A laser beam position sensing arrangement using two similar sensors where, instead of the first sensor being aligned normal to the beam scan path, the angle which bisects the two sensors is aligned normal to the beam scan path. The average of times T1 and T2 at which the laser beam is incident the respective sensors is used for the horizontal or start of scan value, and the difference (T2−T1) is proportional to the vertical or process direction value. From the difference between the two determined times, the longitudinal beam position may be determined.

Abstract: An information processing apparatus serves as a host unit for communicating with a plurality of printing apparatuses via a network. Each of the plurality of printing apparatuses is in a print-ready state or a second power state, in which power consumption is less than that of the print-ready state. The information processing apparatus includes a request unit adapted to request status information of each of the plurality of printing apparatuses, a reception unit adapted to receive the status information of each of the plurality of printing apparatuses requested by the request unit, an identifying unit for identifying each of the plurality of printing apparatuses as being either in the print-ready state or the second power state, based on the status information received by the reception unit, and a user interface unit adapted to control a display of a plurality of printer states.

Abstract: An image data storing system, and more particularly a video capture controller to capture raw video image data from a peripheral unit and to provide compressed video image data to a document image management server. The video capture controller includes a control processor, a first memory, and a second memory. The first memory stores raw video image data from the peripheral unit under control of the control processor. The raw video image data stored in the first memory is then converted into compressed video image data, and is then stored in the second memory, again under control of the control processor. Then, the compressed video image data from the second memory is transferred to the image management server.

Abstract: There is provided a facsimile apparatus which transmits image data so that the image quality level of the received image can be kept in a range appropriate to the transmission signal rate without extending the transmission period of time in consideration of the data transmission rate varying with the communication conditions between transmitting and receiving facsimile apparatuses. A document is read by an image reading unit as an image having halftone densities so that the image of the document is converted into binary image data having different two or more gradients in a binary processing unit. A central processing unit conducts signal rate matching of the data transmission rate of the image data between the transmitting and receiving facsimile apparatuses through a communication line, line control unit and a modem.

Abstract: A computer system includes workstations and a peripheral having a processor. The workstations and the peripheral communicate via email over a network. Email messages include commands and requests that control access to status and reconfiguration of the peripheral, establish subscriptions to status of the peripheral, and invoke reconfiguration of the peripheral. Email messages also include publications of the status of the peripheral according to reporting criteria. Reporting criteria identify a report of process or state variables, define publication criteria for directing the monitoring of state variables, and define delivery criteria to avoid network undesirable network traffic and irritating addressees of subscriptions.

Abstract: A portable printer for printing a second interface onto a second surface, in response to first indicating data received from a sensing device in the form of a stylus. The first indicating data is sensed by the stylus from first coded data. A first interface is disposed on a first surface, and includes the first coded data. The printer includes an input module and a printing module. The input module is configured to receive the first indicating data from the stylus, the first indicating data being at least partially indicative of response data. The input module generates second indicating data based on the first indicating data, the second indicating data being at least partially indicative of the response data. The second indicating data is sent to a computer system. The printing module includes a printing mechanism configured to receive the response data from the computer system. The second interface is based at least partially on the response data.

Abstract: This invention provides a facsimile apparatus having an E-mail transmission/reception function, which can correctly transmit the contents of a file attached to E-mail even when the file cannot be opened on the other party side. A document file as a file attached to E-mail is transmitted from a transmitting facsimile apparatus and received by a receiving facsimile apparatus. If the attached file cannot be normally opened by viewer software or another application of the facsimile apparatus, the apparatus transmits, as a reply to the received E-mail, an error message containing contents representing that the error has occurred, and a facsimile number to be used by the other party for retransmission to the transmitting facsimile apparatus. When the received E-mail contains an error message, the transmitting facsimile apparatus searches for the attached file to be retransmitted by referring to, e.g., the mail title or mail text.

Abstract: A POP access section accesses a POP3 server using a first user ID/password registered in a user ID registration table, fetches message information from a mailbox of the user ID, and stores it to RAM. A message information extracting section extracts necessary information from the message information, and stores it to be associated with the user ID. Thereafter, a reception list generating section reads message information of all user IDs from RAM, and generates a reception list. Sequentially, the reception list generating section outputs the generated reception list. A user, who has seen the reception list, instructs the POP access section to fetch an e-mail message from a panel control section. This improves communication concealment.

Abstract: A system and method for providing a printer capable of generating a hard copy of at least one image is disclosed. The at least one image is stored in an image file on a removable memory. In one aspect, the method and system include a graphical user interface for allowing a user to view at least a portion of the image and a printing device coupled with the graphical user interface for printing the hard copy of the at least one image. In a second aspect, the method and system include means for storing the at least one image in a second format and a printing device coupled with the storing means for printing the hard copy of the at least one image. In a third aspect, the method and system include means for modifying the at least one image, means coupled with the modifying means for storing the at modified at least one image in the first format, and a printing device coupled with the storing means for printing the hard copy of the at least one image.

Abstract: A system and method for facilitating facsimile transmissions has one or more store and forward facilities, each associated with a plurality of subscriber facsimile machines, typically coupled over the switched telephone network. The store and forward facilities include a computer for controlling operations and mass data storage equipment. A subscriber to the system delivers an outgoing facsimile message to the store and forward facility with which it is associated, which records the fax message together with data as to originating facsimile machine and destination facsimile machine. The store and forward facility then delivers the facsimile message to the intended receiver facsimile machine, either directly or through another store and forward facility. If unsuccessful on an initial attempt, the store and forward facility periodically retrys to send the facsimile message.

Abstract: A data processing apparatus includes a connection unit for connecting a plurality of terminals, a storage unit for storing respective processing abilities of the plurality of terminals, a reception unit for receiving data via a line, a converting unit for converting the data received by the reception unit in accordance with the processing abilities stored in the storage unit, and a transfer unit for transferring the data converted by the converting unit to one of the plurality of terminals via the connection unit. A method of controlling a data processing apparatus capable of connecting a plurality of terminals, includes the steps of storing respective processing abilities of the plurality of terminals, receiving data via a line, converting the received data in accordance with the stored processing abilities, and transferring the converted data to one of the plurality of terminals.

Abstract: The network facsimile apparatus switches a status icon registered in a structured document for displaying a status icon, corresponding to a status change, while transmitting the structured document corresponding to a request from a client. Thus the apparatus enables the client to observe the latest status icon in homepage format.

Abstract: A digital scanner for scanning sheet document along transport path. The scanner includes a transport mechanism for moving the document along the transport path and a platen. The transport path is designed to minimize sticking or jamming of the document at the platen and for providing a high quality digital scan of the document.

Abstract: Collage making apparatus for assisting in the production of a collage by duplication apparatus may comprise a layout area contained within the collage making apparatus. The layout area accommodates at least one object that is to be contained in the collage. The collage making apparatus is convertible between a layout mode and a duplication mode. During the layout mode, the layout area is observable by a user so that the user may observe an arrangement of the at least one object within the layout area. During the duplication mode, the layout area is reproducible by the duplication apparatus so that the duplication apparatus produces a copy of the arrangement of the at least one object within the layout area.

Abstract: An image reading apparatus individually reads a predetermined white reference plate by flickering light sources of the respective colors before an original image is read by sequentially turning on the light sources during one line sync period. The flickering duty ratio of the light source obtained when the white reference plate is read is set for each color so as to maximize the output value from an A/D converter within its predetermined conversion range. When an original is read, the image reading apparatus changes the emission color by switching the light source to be flickered every line sync period, and turns on the light sources of the respective colors in accordance with different duty ratios set for these colors.

Abstract: Featured is a method for driving a CCD imaging device, including a plurality of photodetector columns each including a vertical array of photodetectors, a plurality of vertical CCDs, and a horizontal CCD, in a monitoring mode where only the signal charges from some of the photodetectors are used. The method includes reading a first signal charge from any one of said some photodetectors into a corresponding first packet of a corresponding one of the vertical CCDs, dividing the first signal charge in the first packet into smaller portions and placing one or more of the signal charge portions of the first signal charge into one or more second empty packets of the corresponding one of the vertical CCDs, and vertically transferring the signal charge portions in the first and the one or more second packets by the total number of the first and second packets.

Abstract: In an optical scanning device and image forming apparatus according to the present invention, a light source emits a light beam, and a scanning optical unit deflects the light beam from the light source and focuses the deflected light beam to form a light spot on a scanned surface, the scanned surface being scanned by the light beam from the scanning optical unit. A temperature detection unit detects a temperature of the scanning optical unit and its neighboring locations. A temperature compensation unit adjusts a focal-point position of the light beam on the scanned surface in accordance with a change in the temperature detected by the temperature detection unit, the temperature compensation unit adjusting the focal-point position of the light beam by directly varying a focusing effect of a corrector lens on the light beam from the light source by a controlled amount of movement of the corrector lens along its optical axis that corresponds to the temperature change.

Abstract: An optical scanner having a simple structure in which the light quantities of a plurality of light beams are not varied by differences in polarization direction among the light beams. The optical scanner scans a surface by means of a plurality of light beams in which the polarization direction of at least one of the light beams is different from the polarization directions of the other light beams. An optical element having a surface with a reflectance for s-polarized light and a reflectance for p-polarized light that are substantially the same at a given incident angle is provided in the optical paths of the light beams.

Abstract: There are provided an optical element which can reduce an assembly cost by simplifying focus adjustment of the optical element, decreasing the number of parts required for the adjustment, and shortening the adjustment time, and an optical scanning device using the element. The optical element has a plurality of sets of positioning references for defining the position of the element in the optical axis direction. The plurality of sets of positioning references respectively define different positions in the optical axis direction.

Abstract: A pivotable optical element that may be fully deflected in a plurality of positions is disclosed. The fully deflected positions of the optical element may be defined against linear segments on a platform or against linear segments on the optical element.

Abstract: A laser countermeasure system uses a fluence trigger along an optical path between an entrance and a detector at an output. The fluence trigger detects laser radiation and blocks the passage thereof beyond the trigger. A shutter at the front end can be operated in response to detection by the trigger. A threat analyzer also receives radiation and automatically breaks the radiation into spectral components for correlation to appropriate filters to remove the harmful coherent radiation. A tunable filter and/or a filter wheel is interposed along the optical path and is controlled by an adjustment system, illustratively servo controls. The adjustment system responds to the threat analyzer to select and interpose automatically the proper filter(s) to attenuate or block the coherent radiation. Thereafter, the fluence trigger and/or shutter operate to restore full operation along the optical path. The system and method provide look-through capability and mission continuity in the face of unknown laser threats.

Abstract: The present invention provides, in one aspect, an optical device, a method of manufacture therefor, and an optical system including the same. The optical device may include a membrane configured to be electrically deformable and reflective. The membrane may further be positioned over a cavity located within a substrate. The device may additionally include a transmissive spacer coupled to the substrate, and a lens coupled to the transmissive spacer and optically aligned with the membrane.

Abstract: An optical modulator and an image projection display apparatus using it can reduce a size of a system and improve efficiency, by attaching a reflection plane on a nonlinear matter. The optical modulator in accordance with the present invention includes a nonlinear matter which is divided into predetermined regions having a direction of a polarization which is periodically reversed, an electrode which is joined with the upper and lower sides of the nonlinear matter, for applying an electric field to the polarization region at the lower portion of the nonlinear matter and a reflection plane which is joined to the rear surface of the nonlinear matter, for reflect an incident light to an incident region again.

Abstract: Described is an optical element having plural electrodes and, disposed therebetween, a stimuli-responsive polymer gel, a liquid which can be absorbed therein and an ion supplying material. As the ion supplying material, preferred is a material showing a volumetric change, in the form of the element, of 0 to 100% under external stimuli. According to the present invention, a novel optical element showing a large change in light transmittance, reflectance or absorption amount and exhibits stable optical properties in repetition can be provided.

Abstract: The invention describes an electrochromic display element in the form of an electrically dimmable mirror, an optical filter having an electrically alterable transparency or a display element which contains an electrochromic liquid between two electrode sheets, where at least one of the electrode sheets is transparent and has a transparent, electrically conductive layer and the transparent electrode sheet has a pattern of strips or grid made of a material having metallic conductivity in order to produce a uniform coloration of the electrochromic liquid.

Abstract: A Faraday rotator of multilayer film type is provided in which satisfactory optical characteristics are obtained with a small number of layers. In the Faraday rotator, a first periodic dielectric multilayer film made of silicon dioxide SiO2 and tantalum pentaoxide Ta2O5 is formed on a substrate, then a magneto-optical thin film, and a second periodic dielectric multilayer film made of tantalum pentaoxide Ta2O5 and silicon dioxide SiO2 are formed sequentially. The first and second periodic dielectric multilayer films sandwich the magneto-optical thin film such that their respective higher refractive dielectric thin films are in contact with the magneto-optical thin film. The number of layers of the first periodic dielectric multilayer film is larger than that of the second periodic dielectric multilayer film.

Abstract: An optical cross-connect is fabricated on a substrate using individual MEMs dice with mirrors that rotate into and out of an optical beam path. Each die can be aligned to a single (input-output) pair of collimators in a fiber-optic switching system. An individually accessible magnetic drive on each die provides low power consumption when re-configuring the array in addition to fast switching speeds. The state of each die can be electronically sensed to verify proper array configuration and operation of each die.

Abstract: The present invention provides improved MEMS devices and methods for use with fiber-optic communications systems. In one embodiment, an apparatus (100) for steering light has a base layer (110), a beam layer (114) and a folded flexure assembly (120) coupled therebetween. The folded flexure assembly complete underlies the beam layer, and facilitates rotation of the beam layer relative to the base layer. The flexure assemblies further provide a counter rotation force to help prevent the beam layer from sticking in an actuated position. In one aspect, the base layer includes raised portions (140, 142) which operate as mechanical stops for the beam layer. In this manner, the counter rotation force helps prevent the beam layer from sticking to the base layer or the raised portions.

Abstract: Wavelength conversion apparatus is described that utilizes a Kerr cell to modulate the polarization of a pump laser beam having a first wavelength before the beam is input to an optical parametric oscillator/amplifier wavelength converter to generate a laser beam having a second wavelength. By modulating the polarization of the pump laser beam using the Kerr cell, the optical wavelength converter can be controlled to switch on and off or otherwise amplitude modulate the second wavelength laser beam output from the converter, and to correspondingly amplitude modulate the first wavelength and all other laser beams being output from the converter. In addition, with the pump laser beam and the second wavelength laser beam always being output from said wavelength converter there is a substantially constant thermal load on said wavelength converter creating substantially constant thermal lensing in the wavelength converter crystal that may be easily compensated using optical means.

Abstract: Method and system for providing laser light that is tunable over a relatively wide mid-infrared wavelength range, such as 2-17 &mgr;m. A first noncritically phase matched nonlinear crystal receives a laser light beam and converts the light to a first cavity beam having a first selected wavelength, using optical parametric oscillation techniques. A second noncritically phase matched nonlinear crystal receives the first cavity beam and converts the light to a second cavity beam having a second selected wavelength. Where the first wavelength is tuned (e.g., by temperature change or effective path length change) over a wavelength range of 2-5 &mgr;m, the second wavelength can vary over a higher and broader wavelength range, such as 3-17 &mgr;m.

Abstract: The present invention aims at providing a method for controlling wavelength characteristics of optical transmission powers by Raman amplification, in which the wavelength characteristics of optical transmission powers are automatically compensated without giving any losses to channel lights to thereby improve transmission characteristics, and an apparatus adopting the same. To this end, the method for controlling wavelength characteristics of optical transmission powers by Raman amplification according to the present invention supplies Raman pump light to an optical transmission path (Raman amplifying medium); compensates the wavelength characteristics of optical transmission powers caused by transmission of WDM signal light through the optical transmission path, by gain wavelength characteristics of generated Raman amplification; and monitors the wavelength characteristics of optical transmission powers after Raman amplification to thereby control the gain wavelength characteristics of Raman amplification.

Abstract: Disclosed is a dispersion-compensated optical-fiber amplifier including a circulator for outputting an optical signal received at a first terminal to a second terminal, while outputting an optical signal received at the second terminal to a third terminal; a first amplifier for amplifying the optical signal from the second terminal and an optical signal reapplied thereto; a dispersion-compensating fiber for compensating for a dispersion occurring in the optical signal received from the first amplifier and an optical signal reapplied thereto; a second amplifier for amplifying the optical signal from the dispersion-compensating fiber and an optical signal reapplied thereto; a splitter installed on the dispersion-compensating fiber and adapted to output to the dispersion-compensating fiber, an optical signal applied thereto and an optical signal reapplied thereto, while outputting a pumping light applied to one end thereof and adapted to pump both the first and second amplifiers to the other end thereof without

Abstract: An infrared transparent optical element for use as an optical window for an infrared imaging camera includes an infrared transparent substrate, an antireflection film, and a protective film of a polymer material. The infrared transparent substrate has first and second major surfaces opposite each other, and the antireflection film is disposed on each of the first and second major surfaces of the substrate. The protective film is on an outer surface of the antireflection film on the first major surface of the substrate.

Abstract: There is disclosed a microscope focusing apparatus comprising a light illuminator, an objective lens, an observation tube, a holder which holds these, a focusing main body including a focusing movable portion which linearly and vertically moves, and an attaching portion, formed in the focusing movable portion, which fixes the holder, wherein the holder comprises a first holder including a first support, the first support disposed on an observation optical axis, which supports the light illuminator, and a second holder including a second support, the second support disposed outside the observation optical axis, which supports the light illuminator, and one of the first and second holders can be selectively attached to the attaching portion.

Abstract: A viewing device (10) adapted to be held at eye level by an apparatus (14) comprises a housing (16) designed to fit within a tray (12) of the apparatus (14), two eyepieces (22) mounted to a proximal end (24) of the housing, a magnification mechanism (26), and a focus mechanism (28). The device (10) also includes an objective lens (18) and a video screen (19) mounted to a distal end (20) of the housing (16). The housing (16) preferably includes a substantially flat bottom (30) and two substantially flat sides (32) and is preferably secured to the tray (12) by a threaded fastener (36). The eyepieces (22) are preferably flexible and padded to provide a comfortable fit. The eyepieces (22) may be either contoured or substantially flat. The contoured eyepieces (22) fit against a user's face. The substantially flat eyepieces (22) fit against the user's eyeglasses.

Abstract: A projection apparatus is disclosed for displaying an image projected by a projector. The projection screen apparatus includes a frame, a screen, and a screen coupler configured to couple the screen to the frame.

Abstract: A rear-projection screen 3, including at least a lenticular lens sheet 32 and a Fresnel lens sheet 31, is configured so that the lenticular lens sheet 32 contains, in a base material thereof made of a resin, light diffusing microparticles made of a resin having a refractive index different from a refractive index of the base material, and the light diffusing microparticles satisfy 0.5 &mgr;m≦&Dgr;N1×d1≦0.9 &mgr;m, where &Dgr;N1 represents a difference between a refractive index of the light diffusing microparticles and a refractive index of the base material of the lenticular lens sheet, and d1 represents an average particle diameter of the light diffusing microparticles. With this, a rear-projection screen with small wavelength dependency of diffusion characteristics can be provided utilizing only resins with general properties.

Abstract: An illumination system for a reflective display is particularly useful for microdisplays that use reflective displays. The light source and the reflective image display unit are mounted in a coplanar manner, thus permitting the light source and the display unit to be mounted on a single board, or even on a single substrate. The display unit may include a first light source directing light generally along a first axis and a reflective image display unit disposed with an optical axis substantially parallel to the first axis. A reflective polarizing film is disposed to direct light from the first light source to the reflective image light display unit.

Abstract: A polarizing device, such as a wire-grid polarizer, includes a substantial mono-layer of a corrosion inhibitor without adversely affecting the optical properties of the polarizing device. The polarizing device can include an optical element and a nano-structure, such as an array of a plurality of spaced-apart, elongated elements disposed on a substrate. The corrosion inhibitor is chemically bonded to surfaces of the elements to form the mono-layer. The mono-layer can have a thickness less than 100 Angstroms. A method of forming the substantial mono-layer can include treating the polarizing device with an amino phosphonate, such as a nitrilotris (methylene) triphosphonic acid.

Abstract: Stress-induced photoelastic birefringence compensates for intrinsic birefringence of cubic crystalline structures in deep ultraviolet (less than 200 nm) microlithographic imaging systems. Both the photoelastic birefringence and the intrinsic birefringence are expressed in a tensor format simplified by the symmetries of cubic crystalline structures. The stress-induced photoelastic birefringence can be sized to individually compensate for intrinsic birefringence exhibited in the same optical elements or preferably to collectively compensate for the cumulative effects of intrinsic birefringence in other optical elements in the lithography system.

Abstract: A multilayer optical interference filter having a multiplicity of optical cavities separated by a dielectric reflector stacks to achieve either a very narrow passband region or sharp transition between the passband and reflective region is substantially free of stress to preserve the desired optical performance upon fabrication into miniature discrete filter elements. The substantial stress reduction is achieved by removing the filter from the substrate used in the deposition process in a controlled manner to preserve the structural integrity of the resulting free standing multilayer film structure. The structure can be further bonded or attached to other optical components to suppress a thermal shift in center wavelength without reintroducing stress or interposing a massive substrate in the optical path through the filter.

Abstract: A lens adapted for securement to a holder, for transmission of light, comprising a lens body, defining an axis, threading on the lens body extending about said axis, for reception in threading associated with the holder.

Abstract: An optical magnifier is provided. One general form of one example embodiment includes two lens elements, at least two aspheric surfaces, and at least one diffractive surface. Another general form of another example embodiment includes three lens elements, and at least three aspheric surfaces. At least two of the aspheric surfaces can be simple conics. The optical magnifier, suitable for use in an electronic display system, has an apparent field of view of at least +/−10 degrees; a magnification of at least 15×; a back focal length of at least 5 mm; and an eye relief greater than the effective focal length of the optical magnifier. The lens elements can be made from plastic.