Abstract: Electrochemical/electrically controllable device having variable optical and/or energetic properties, including a first carrier substrate provided with an electrically conductive layer associated with a first stack of electrically active layers and a second carrier substrate provided with an electrically conductive layer associated with a second stack of electrically active layers, wherein the first and second stacks each function optically in series on at least a portion of their surface and are separated by an electrically insulating means, which is a gas, or is a vacuum.

Abstract: Methods of writing display data to MEMS display elements are configured to minimize charge buildup and differential aging. Simultaneous to writing rows of image data, a pre-write operation is performed on a next row. The pre-write operation writes either image data or the inverse of the image data to the next row. In some embodiments, the selection between writing image data and writing inverse image data is performed in a random or pseudo-random manner.

Abstract: An optical module, which is arranged in an optical transmission path, includes an optical amplifying unit configured with a semiconductor, wherein the optical amplifying unit amplifies light input from the optical transmission path, and an optical element configured with a semiconductor, wherein the optical element propagates the light amplified by the optical amplifying unit to the optical transmission path.

Abstract: Embodiments include methods and devices for controlling the spectral profile and color gamut of light produced by an interferometric display. Such devices include illuminating a display with selected wavelengths of light. Embodiments also include a display comprising separate sections that output different predetermined colors of light. Other embodiments include methods of making the aforementioned devices.

Abstract: A reflective spatial light modulator device features two pairs of electrodes formed on different metallization layers. Elevation of the upper electrode pair reduces its distance from the overlying reflecting surface, thereby requiring a smaller applied voltage to generate an equivalent electrostatic attractive force for altering or maintaining physical orientation of the reflecting surface relative to incident light. In one embodiment, the reduced distance between the electrode and reflecting surface allows operation at lower voltages, reducing the possibility of breakdown and avoiding the need for complex device designs to eliminate such breakdown. In another embodiment, the reduced distance between the electrode and the reflecting surface allows the use of stiffer hinges for the reflecting surface, thereby increasing the speed of device operation. Other embodiments can employ both reduced voltage operation and the use of stiffer hinge structures.

Abstract: An automatic drying apparatus and a method of controlling the same is disclosed, enabling exact drying by using a humidity sensor (37) provided at a location having a stabilized output characteristic for automatic drying, the automatic drying apparatus including a heating apparatus (31) for heating air supplied into a drum into which a drying object is introduced, a fan (32) for forcibly drawing air into the drum; and a humidity sensor (37) provided between the fan (32) and the heating apparatus (37) such that a sensing surface is positioned to be parallel to a flowing direction of air passed through the fan (32), for outputting a sensing voltage value for determining dryness of the drying object.

Abstract: For displaying a color image by recombination of several single color images, parasitic noise like speckles due to scattering within the system, in particular when laser light is involved, with the invention a significant improvement with a low number of parts can be realized by use of a color wheel that comprises in radially divided zones refractive elements for redirecting light beams incoming at different impinging angles and redistributing elements, e.g. a hologram, that provide for a defined output beam in an optical axis. The sequence of the individual light processing zones on the color wheel are synchronized with respective laser sources. The invention combines the functionality of plural elements, reduces speckles and avoids losses.

Abstract: A transflective display device has a viewing side (7) and a rear side (8) and comprises a plurality of electrowetting elements (2) having a first support plate (5) facing the viewing side and a second support plate (6) facing the rear side. Each electrowetting element comprises a space (10) between the first support plate and the second support plate and includes a first fluid (11) and a second fluid (12) immiscible with each other. The second fluid absorbs at least a part of the optical spectrum. The position of the second fluid is controllable to cover a predetermined area (30) of the cross-section (29) of the space in the plane of the second support plate. A structured reflector (18) is arranged on the second support plate, comprising within the cross-section an area (33, 34) transparent for light incident from the rear side and an area (35, 36) reflective for light incident from the viewing side.

Abstract: Ink having the optimum contact angle relative to a partition wall is selected for forming a pixel, based on the relationship with an inclination angle of the partition wall. The ink applied to the opening of the partition wall is dried to form the pixel such that an outer edge in contact with the partition wall has a thickness of at least 35% of the maximum height of the partition wall and a difference between the maximum thickness and the average thickness and a difference between the minimum thickness and the average thickness are not larger than 35% of the average thickness in an effective pixel area.

Abstract: A light modulator device includes a first electrical conduit, a second electrical conduit electrically isolated from the first conduit, a first display element, and a second display element. The first display element is in an actuated state when a voltage difference between the first conduit and the second conduit has a magnitude greater than a first actuation voltage and is in a released state when the voltage difference has a magnitude less than a first release voltage. The second display element is in an actuated state when the voltage difference has a magnitude greater than a second actuation voltage and is in a released state when the voltage difference has a magnitude less than a second release voltage. Either the actuation voltages are substantially equal and the release voltages are different, or the actuation voltages are different and the release voltages are substantially equal.

Abstract: A light control apparatus may include a substrate, a first reflection layer provided on the substrate, a light modulating film provided on the first reflection layer, a second reflection layer provided on the light modulating film, and a pair of electrodes which applies an electric field to the light modulating film. The light modulating film ma have a refractive index controlled by the electric field.

Abstract: A method of calculating an aerial image of a spatial light modulator array includes calculating pair-wise interference between pixels of the spatial light modulator array; calculating effective graytones corresponding to modulation states of the pixels; and calculating the aerial image based on the pair-wise interference and the effective graytones. The graytones depend only on the modulation states of the pixels. The pair-wise interference depends only on position variables. The position variables are position in an image plane and position in a plane of a source of electromagnetic radiation. The pair-wise interference can be represented by a matrix of functions. The pair-wise interference can be represented by a four dimensional matrix. The effective graytones are approximated using sinc functions, or using polynomial functions.

Abstract: Embodiments of exemplary MEMS interferometric modulators are arranged at intersections of rows and columns of electrodes. In certain embodiments, the column electrode has a lower electrical resistance than the row electrode. A driving circuit applies a potential difference of a first polarity across electrodes during a first phase and then quickly transition to applying a bias voltage having a polarity opposite to the first polarity during a second phase. In certain embodiments, an absolute value of the difference between the voltages applied to the row electrode is less than an absolute value of the difference between the voltages applied to the column electrode during the first and second phases.

Abstract: There is disclosed a spatial light modulating unit comprising, a spatial light modulator having a plurality of optical elements arrayed two-dimensionally and controlled individually, and an exit-side optical system which guides light having traveled via the plurality of optical elements of the spatial light modulator, wherein the exit-side optical system is configured so that zero-order light having traveled via a surface portion other than the plurality of optical elements and approximately parallel to an array plane where the plurality of optical elements are arrayed, does not pass through an entrance pupil of the exit-side optical system.

Abstract: A projector includes a projecting module for projecting a projecting image on a screen panel, an image sensor for capturing an image of an object which is located outside of the projecting module and faces toward the lens module, a light director, and a controlling unit. The projecting module has a lens module and a light source for emitting light transmitting through the lens module. The light director is movable between a first position where the light director is located outside of a light path associated with the lens module, and a second position where the light director is configured for directing light of the object through the lens module to be incident on the image sensor. The controlling unit controls the light director to move between the first and second positions.

Abstract: A stereo projection optical system includes a first polarizing beam splitter, a transmission-type light modulator positioned to receive the first polarized light component from the first polarizing light splitter and an image assimilator positioned to receive an emergent light of the transmission-type light modulator. The image assimilator includes a second polarized light splitter and first, second reflective spatial light modulators. The stereo projection optical systems provide viewers three-dimensional images formed by two alternative polarization light beams whose polarizations are perpendicular to each other utilizing the transmission-type light modulators to form “3-D” images.

Abstract: A projector includes: a light source unit which supplies coherent light; a spatial light modulating unit which modulates the coherent light supplied from the light source unit according to an image signal; a projection optical system which projects light modulated by the spatial light modulating unit; and a light shifting unit disposed on an optical path of the projection optical system to shift light in a direction substantially perpendicular to an optical axis.

Abstract: In a pulse generator of very high resolution phase and/or intensity profiles, an active mode-locking laser source (1) emits a first train of optical pulses according to a determined period (To), which is intensity-modulated pulse-by-pulse by a modulator (2). The modulated pulses are transmitted to an optical loop (3) via a coupler (4). The optical length of the optical loop is slightly different from the period (To) of the source. The modulated pulses are transmitted to input B of the coupler. The optical loop connects output D to input A of the coupler. This coupler is commanded such that, according to a first command (k=0), it transmits the light received on its two inputs A, B towards output d, and according to a second command (K=1), it transmits the light received on its input (A) towards output (C).

Abstract: Methods and apparatuses for harvesting light from displays. In one embodiment, the invention relates to a substrate having a first and a second surface, an edge and a luminescent dye. A photovoltaic transducer is positioned adjacent the substrate. Light passing through both the first and second surfaces of the substrate is polarized and light constrained within and traveling through the substrate interacts with the photovoltaic transducer to produce electric current. In one embodiment, the method of harvesting light from an illuminated electronic display including the steps of providing a light source, providing a substrate having a first and a second surface and an edge; and a luminescent dye; and providing a photovoltaic transducer positioned adjacent the substrate. Light passing through both the first and second surfaces of the substrate is polarized, and light constrained within and traveling through the substrate interacts with the photovoltaic transducer to produce electric current.

Abstract: A light valve unit may include a first conductive layer and a second conductive layer disposed on opposite sides of each other with respect to a plurality of cells in which at least some of the cells include a first material and a second material. The first material may have a lower light transmissivity property than the second material and a position of the first material within a corresponding cell may be changeable responsive to application of an electric field between the first and second conductive layers. The second conductive layer may include at least two electrodes and a gap defined between the two electrodes. A portion of the light valve unit adjacent to the gap may be configured to have a transmissivity that is substantially less than transmissivity of a portion of the light valve unit adjacent to cells across which the electric field is applied, but greater than or equal to transmissivity of a portion of the light valve unit adjacent to cells across which the electric field is not applied.

Abstract: An optical device includes: a light modulation unit configured to modulate a light according to image information, including an element substrate having a pixel electrode and a switching element connected with the pixel electrode, and an opposed substrate disposed opposed to the element substrate; a frame configured to hold the light modulation unit; and an incident side dustproof glass disposed in close contact with a light incident side end surface of the opposed substrate, the incident side dustproof glass having the plane size larger than the plane size of the opposed substrate is disposed on the light incident side of the frame.

Abstract: A lithography method is provided. The method includes generating a beam of radiation, patterning portions of the beam of radiation, projecting the patterned beam of radiation towards a substrate, and blocking scattered light from the beam of radiation from the substrate.

Abstract: A method for operating an optical transmitter for transmission of an optical signal over a dispersive fiber optic media to a remote receiver. The method includes the steps of providing a respective bias level of a first RF signal and a second RF signal input to an optical modulator that modulates the optical signal; determining an output level of the optical modulator in response to the provided bias levels and adjusting a bias level of at least one of the first and second RF input signals based upon the determined output level and an expected output level at a configuration set point for the provided respective bias levels.

Abstract: A laser source is disclosed with coherent recombination of N spatial monomode laser beams having N phase shifters controlled by a phase-lock device (3). The phase-lock device has an optical device (30) capable of taking at least a portion of each of the N beams. The optical device has an optical element (32) capable of applying a phase deformation, and at least one matrix (M1) of detectors capable of detecting a first image (im) of a wave surface corresponding to the N beams. The matrix (M1) of detectors also detects a second image (imd) deformed by the optical element (32). Processing means (31) are provided for processing the first and second images. The processing means are configured so as to measure the phase pistons between on the sub-pupils (spj) corresponding to the N beams and to apply phase corrections c(?) to each of the N beams, by means of said N phase shifters so as to minimize the phase pistons.

Abstract: An electro-optic device with a doped semiconductor base and a plurality of pixels on the semiconductor base. Pixels include oppositely doped semiconductor layer and a top electrode formed on the oppositely doped semiconductor layer. The top electrode has a grid pattern with at least one busbar and a plurality of fingers extending from the busbar, and spacing between the fingers decreases with distance from the bondpad along the busbar. Each pixel can also include a multiple quantum well formed on the semiconductor base. The top electrode shape produces an approximately uniform lateral resistance in the pixel. An embodiment is a large area modulator for modulating retro-reflector systems, which typically use large area surface-normal modulators with large lateral current flow. Uniform resistance to each part of the modulator decreases location dependence of frequency response. A chirped grid electrode balances semiconductor sheet resistance and metal line resistance components of the series resistance.

Abstract: An illumination apparatus includes a plate-like separation optical element having a dichroic surface and a PBS surface. The dichroic surface reflects green component light and transmits yellow component light. The PBS surface transmits P polarization component light and reflects S polarization component light. The separation optical element combines red component light entering from a certain direction and transmitted through the dichroic surface, with yellow component light entering from a different direction and reflected by the PBS surface, and leads a combined light towards a red liquid crystal panel. The separation optical element combines green component light entering from the certain direction and reflected by the dichroic surface, with yellow component light entering from the different direction and transmitted through the PBS surface, and leads a combined light towards a green liquid crystal panel.

Abstract: An Interferometric Modulator (IMod) is a microelectromechanical device for modulating light using interference. The colors of these devices may be determined in a spatial fashion, and their inherent color shift may be compensated for using several optical compensation mechanisms. Brightness, addressing, and driving of IMods may be accomplished in a variety of ways with appropriate packaging, and peripheral electronics which can be attached and/or fabricated using one of many techniques. The devices may be used in both embedded and directly perceived applications, the latter providing multiple viewing modes as well as a multitude of product concepts ranging in size from microscopic to architectural in scope.

Abstract: A modulator drive circuit provides a modulator drive signal to modulate an optical signal for transport across a network infrastructure. The modulator drive circuit powered by an adjustable voltage source, such that the modulator drive signal is generated from a data signal and the adjustable voltage source, an AC component of the modulator drive signal being derived from the data signal while a DC component of the modulator drive signal being derived from the adjustable voltage source. An array of such modulator drive circuits are provided on a single substrate.

Abstract: A system for making small modifications to the pattern in standard processed semiconductor devices. The modifications are made to create a small variable part of the pattern against a large constant part of the same pattern. In a preferred embodiment the exposure of the variable and constant parts are done with the same wavelength in the same combined stepper and code-writer. The invention devices a way of writing variable parts of the chip that is automatic, inexpensive and risk-free. A system for automatic design and production of die-unique patterns is also shown.

Abstract: Even in an image-forming apparatus including an optical deflection apparatus using a light source such as a high-power laser light source, a variation in temperature of an optical deflector due to modulation of deflected light based on drawing data is compensated to maintain a preferable oscillation state of the optical deflection apparatus. The optical deflection apparatus includes an optical deflector in which an oscillator is supported by an elastic support member to be oscillatable about a support substrate and at least one light source, and the optical deflection apparatus is controlled such that total power of light emitted from the light source to the optical deflector within each of a plurality of divided time regions corresponding to specific times of equal lengths becomes a predetermined power.

Abstract: Embodiments of the present invention provide arrays of electrical circuits having one or more chirped elements or components for providing output signals to corresponding arrays of electro-optic devices. Certain embodiments of the present invention include a plurality of modulator driver circuits, each of the plurality of driver circuits configured to be substantially identical to each other and provide a corresponding one of a plurality of modulator drive signals to a respective one of a plurality of electro-optic modulators, each of the plurality of modulator driver circuits being chirped to provide a desired output to the corresponding electro-optic modulator for enhanced operation.

Abstract: According to one embodiment, a projection system includes a color wheel operable to filter light into a passed component and a reflected component. The projection system also includes a digital micromirror device comprising a plurality of micromirrors each operable to receive the passed component and the reflected component. Each micromirror is selectively positionable to direct, at approximately the same time, the passed component and the reflected component to desired locations. The projection system also includes an optical system operable to direct the passed component and the reflected component from the color wheel to the digital micromirror device at approximately the same time.

Abstract: An image projector comprises a plurality of flexible reflective analog modulators (FRAMs), an illumination optics for focusing at least one light source thereon, a conversion optics for converting the variations in divergence of the beams reflected therefrom into variations in intensity, and a scanning mechanism coupled to a projection optics for displaying an image, constructed of intensity modulated light dots or pixels, on a screen. FRAM curvatures, responsible for determining the divergence of the reflected beams, and ultimately the intensity of each pixel, are varied by an actuation voltage that can be modulated using waveforms that minimize the FRAM response times. For multicolor images, three laser light sources operating at different wavelengths are used in conjunction with three linear FRAM arrays.

Abstract: A semiconductor image sensing element has a semiconductor element including an image sensing area, a peripheral circuit region, a plurality of electrode portions provided in the peripheral circuit region, and a plurality of micro-lenses provided on the image sensing area and an optical member having a configuration covering at least the image sensing area and bonded over the micro-lenses via a transparent bonding member. The side surface region of the optical member is formed with a light shielding film for preventing the irradiation of the image sensing area with a reflected light beam or a scattered light beam from the side surface region.

Abstract: An optical modulator is provided with a stripe-shaped optical waveguide, which has an upper clad layer, a lower clad layer formed between the upper clad layer and a substrate, and an undoped core layer which is arranged between the upper clad layer and the lower clad layer and has a complex refractive index that changes corresponding to the intensity of an applied electric field, to a signal light propagating inside. On both sides of the stripe-shaped optical waveguide, conductor walls are configured by arranging a pair of parallel blocking flat boards with an insulating wall in between. Thus, the semiconductor optical modulator having a high optical modulation efficiency is provided.

Abstract: An electrochromic display is disclosed which comprises an array-side substrate (10) in which a pixel electrode (15) and an electrochromic layer (30) are formed, a color filter-side substrate (50) in which a counter electrode (53) and an electrochromic layer (54) are formed, and an electrolytic layer (80) injected between the array-side substrate (10) and the color filter-side substrate (50). By forming a partition wall (23) on the periphery of the pixel electrode (15) and the electrochromic layer (30), there can be prevented short-circuits between pixel electrodes (15) and short-circuits between electrochromic layers (30) between adjacent pixels, thereby realizing an electrochromic display with higher precision.

Abstract: A system comprises two or more light sources comprising a first light source and a second light source, each light source of the two or more light sources configured to provide light of a particular wavelength, wherein a first wavelength of a first light provided by the first light source differs from a second wavelength of a second light provided by the second light source, and wherein the first light has a first radiant energy that experiences roll-off. The system further comprises a controller configured to modulate an attribute of each light source to compensate for the roll-off, the modulation comprising modulating an attribute of the first light source, and the modulation further comprising modulating an attribute of the second light source, the modulation of the second attribute being different from the modulation of the first attribute.

Abstract: Light in the visible spectrum is modulated using an array of modulation elements, and control circuitry connected to the array for controlling each of the modulation elements independently, each of the modulation elements having a surface which is caused to exhibit a predetermined impedance characteristic to particular frequencies of light. The amplitude of light delivered by each of the modulation elements is controlled independently by pulse code modulation. Each modulation element has a deformable portion held under tensile stress, and the control circuitry controls the deformation of the deformable portion. Each deformable element has a deformation mechanism and an optical portion, the deformation mechanism and the optical portion independently imparting to the element respectively a controlled deformation characteristic and a controlled modulation characteristic. The deformable modulation element may be a non-metal.

Abstract: The invention relates to a spot-generator (10) having: an entrance surface (12) for receiving an incident light beam (20) and an exit surface (14) for transmitting the light beam, the entrance surface defining an entrance side (16) and the exit surface defining an exit side (18), wherein the spot generator is designed to modulate the incident light beam to generate on the exit side a plurality of separate light spots. According to the invention, the plurality of light spots comprises a first light spot (22) generated in a first focal plane (24) and a second light spot (26) generated in a second focal plane (28), the first focal plane and the second focal plane being essentially perpendicular to the mean propagation direction of the exit light beam, and wherein the first light spot (22) differs from every other light spot generated on the exit side by the spot generator in the projection of its position on a plane essentially perpendicular to the mean propagation direction of the exit light beam.

Abstract: An optical arrangement includes a focusing lens and a plurality of light sources. The focusing lens is configured to focus a plurality of light beams to form an array of virtual light sources in an image plane. The plurality of light sources are configured to emit the plurality of light beams such that the light beams cross each other in a plane.

Abstract: An optical system which includes some or all of the following parts: a laser light source which illuminates a spatial light modulator such that optical characteristics are preserved; a stereoscopic display which has a polarization-switching light source; a stereoscopic display which includes two infrared lasers, two optical parametric oscillators, and six second harmonic generators; two light sources processed by two parts of the same spatial light modulator; a method of assembly using an alignment plate to align kinematic rollers on a holding plate; an optical support structure which includes stacked, compartmented layers; a collimated optical beam between an optical parametric oscillator and a second harmonic generator; a laser gain module with two retroreflective mirrors; an optical tap which keeps the monitored beam co-linear; an optical coupler which includes an optical fiber and a rotating diffuser; and an optical fiber that has a core with at least one flat side.

Abstract: Provided are a processing method and a processing apparatus which are capable of suppressing a disturbance attributable to a surface wave in a processing by interfered laser beams, in particular, a processing by the interfered laser beams of a pulsed laser having a pulse width of equal to or more than 1 fs and of equal to or less than 1 ps, in which the wavelength of a surface wave that propagates in a direction of the interference of the laser is made longer than a pitch of the interference of the laser on a surface of an object to be processed to process the object.

Abstract: A directional display apparatus, comprising a spatial light modulator comprising an array of pixels and a lens array in which each respective section of the lens array is capable of directing light from a group of pixels aligned with the respective section into nominal viewing windows, is arranged such that each respective section is also capable of directing light from at least one adjacent group of pixels aligned with a section adjacent the respective section into the same nominal viewing windows. This may be achieved by a deflection element, such as a prism element or a hologram, or by each respective section of the lens array having at least one lens surface providing: at least one first region capable of directing light from said group of pixels aligned with the respective section into said nominal viewing windows; and at least one second region capable of directing light from said at least one adjacent group of pixels into the same nominal viewing windows.

Abstract: An afocal beam system corrects excess diffraction from phase error in microelectromechanical mirror offsets. One invention aspect interposes an opposing phase difference, between rays reflected at adjacent mirrors, varying the difference with mirror angle to make it roughly an integral number of waves. Mirror-array (not one-mirror) dimensions limit diffraction. Another aspect sharpens by generating and postprocessing signals to counteract phase difference. A third has, in the optical path, a nonlinear phase-shift device introducing a phase shift, optically convolves that shift with others from mirrors, then deconvolves to extract unshifted signals. A fourth varies mirror position in piston as a function of mirror angle to hold phase difference to an integral number of waves. A fifth aspect has, in the path, at least one delay element—whose delay varies as a function of mirror angle. A sixth has another mirror array in series with the first, matching their angles to introduce opposing phase difference.

Abstract: One inventive aspect relates to a display comprising a display element configured to selectively reflect light of a first wavelength in the infrared range and light of a second wavelength in the visible spectrum. Another inventive aspect relates to a color display comprising at least three reflective display elements. Each display element is configured to selectively reflect light of a different wavelength in the visible range. At least one of the three reflective display element is further configured to selectively reflect light of a wavelength in the infrared range.

Abstract: An electronic device and method are presented for creating at least one predetermined stimulus at the device output. The device comprises an electrically non-conductive holey structure carrying at least two active electrically conductive cores electrically insulated from one another along their lengths, for supplying a potential difference between them, and at least one stimulus creator configured to be affected by said potential difference to provide a predetermined output of the device.

Abstract: An optical deflection apparatus including a light source; an optical deflector including first and second oscillators and first and second torsion springs, the first torsion spring connecting the first and second oscillators, the second torsion spring being connected to the second oscillator, and the first and second torsion springs sharing a common torsion axis; and a driver that applies a driving force to the optical deflector; and a driving controller that supplies a driving signal to the driver. The driving controller sets a reference frequency on the basis of a resonant frequency of the optical deflector, calculates a target time at which one of the first and second oscillators makes a predetermined deflection angle on the basis of the reference frequency, and supplies such a driving signal that the one of the first and second oscillators passes through a point corresponding to the predetermined deflection angle at the target time.

Abstract: According to an aspect of an embodiment, an optical modulation device includes a Mach-Zehnder modulator and a controller. The Mach-Zehnder modulator is supplied a drive signal and a bias voltage. The Mach-Zehnder modulator modulates inputted light on the bases of the drive signal and the bias voltage. The drive signal selectively is superimposes a predetermined frequency signal. The bias voltage selectively is superimposes the predetermined frequency signal. The controller selects a superimposing target which is the drive signal or the bias voltage so as to change modulation formats.

Abstract: A light modulator includes: a holding member having a frame disposed around an opening; and a light modulation panel formed in such a way that the edge thereof is held by the frame and the outer surface of the portion corresponding to the opening is flush with the outer surface of the frame or positioned outside the outer surface of the frame.

Abstract: A light beam emitted from a light source (11) impinges on the spherical surface (20a) of a collimator lens (20) substantially perpendicularly thereto. A light beam making a small angle to the optical axis impinges on the ellipsoid (20c) and then it is refracted. The ellipsoid (20c) converts light beams diverging from a light source located at the first focal point thereof into parallel light beams. A light beam making a large angle to the optical axis impinges on an ellipsoid (20b) and then it is reflected totally off the ellipsoid (20b). A light beam diverging from a light source located at the first focal point of the ellipsoid (20b) is converted into a light beam being focused on the second focal point thereof. An ellipsoid (20d) converts the light beams focused on the second focal point thereof into parallel light beams.