Abstract: A projection apparatus includes a first, a second and a third light sources, a first reflective element, a first and a second dichroic mirrors, a light-homogenizing element, a light valve and a projection lens. The first reflective element is configured to reflect the first light beam, and the first dichroic mirror is configured to reflect the second light beam and to transmit the first light beam transmitted from the first reflective element. The second dichroic mirror is configured to reflect the first and the second light beams transmitted from the first dichroic mirror and to transmit the third light beam. The light-homogenizing element is used for homogenizing the combined light beam, and the light valve is used for modulating the combined light beam to form an image beam. The projection lens is used for receiving and then projecting the image beam.

Abstract: The present invention is to provide a laser irradiation technique for irradiating the irradiation surface with the laser beam having homogeneous intensity distribution using a cylindrical lens array without being affected by the intensity distribution of the original beam. A laser beam emitted from a laser oscillator is divided by two kinds of cylindrical lens arrays into a plurality of beams, which are two kinds of linear laser beams with their energy intensity distribution inverted each other, and the two kinds of linear laser beams are superposed in a minor-axis direction. This can form the linear laser beam having homogeneous intensity distribution on the irradiation surface.

Abstract: The present invention can provide an optical device, an optical uniform device, an optical sheet and a backlight unit and a display apparatus. In the present invention, a lamp image can be removed by uniformly emitting incident light from a plurality of light sources. Further, even if a distance between a light source and an optical device and between a light source and an optical uniform device are short, warpage due to heat generated from a light source does not occur.

Abstract: Systems and methods for forming a time-averaged line image having a relatively high amount of intensity uniformity along its length is disclosed. The method includes forming at an image plane a line image having a first amount of intensity non-uniformity in a long-axis direction and forming a secondary image that at least partially overlaps the primary image. The method also includes scanning the secondary image over at least a portion of the primary image and in the long-axis direction according to a scan profile to form a time-average modified line image having a second amount of intensity non-uniformity in the long-axis direction that is less than the first amount. For laser annealing a semiconductor wafer, the amount of line-image overlap for adjacent scans of a wafer scan path is substantially reduced, thereby increasing wafer throughput.

Abstract: A scanning technique for imaging sites in an array includes illuminating or irradiating sites in lines of the array, and collecting returned radiation from the sites for imaging. The sites are sequentially scanned by means of confocally directed radiation lines from source optics. The orientation of the radiation lines with respect to the lines of sites in the array is such that the distance between nearest edges of sites in adjacent lines is greater than lines through those edges in a direction parallel to the radiation lines used for scanning. The resulting system experiences less crosstalk and a greater ability to distinguish between neighboring sites in resulting images.

Abstract: A method of manufacturing a light source device includes: preparing a holder for a semiconductor laser and a coupling lens having a first side confronting the semiconductor laser and a second side opposite to the first side, a photopolymerizable resin being provided on the holder at least at a location between the coupling lens and the holder; locating a light source for emitting a curing light for curing the photopolymerizable resin on an opposite side of the semiconductor laser with respect to the coupling lens, a reflecting member being provided on an opposite side of the light source with respect to the coupling lens; and curing the photopolymerizable resin by irradiating the curing light from the light source directly on a part of the photopolymerizable resin, and also on another remaining part of the photopolymerizable resin by reflecting the curing light on the reflecting member irradiating the curing light.

Abstract: Systems and methods for imaging a distant light source at an enhanced resolution is provided. An evanescent field generator an evanescent field generator that receives an incident electromagnetic field representing at least one distant light source and restores high spatial frequency components to the incident electromagnetic field, resulting in an evanescent field. A negative refractive index lens assembly focuses the evanescent field onto a focal plane. A photodetector assembly located in the focal plane detects the focused evanescent field as an image of the at least one distant light source.

Abstract: Described are new magnifying apparatus based on two dimensional arrays of micro magnifying modules (MMMs) positioned along a plane perpendicular to the axis of the magnifying apparatus. In addition, the structure may include a two dimensional array of micro beam multipliers (MBMs) to improve the quality of the magnified image. The micro beam multipliers are positioned along a plane parallel to the array of micro magnifying modules. The structure also may include a two dimensional array of ray angle adjusters (RAAs) to extend the view angle. The ray angle adjusters are positioned along a plane parallel to the array of micro magnifying modules. The array of micro magnifying modules, with or without the micro beam multipliers and/or ray angle adjusters, may be constructed as a thin plate with a thickness of a few millimeters, through which the object is viewed.

Abstract: A system and method for reconfiguring a plurality of electromagnetic beams to take advantage of various wavelength beam combining techniques. The reconfiguring of beams includes individual rotation and selective repositioning of one or more beams with respect to beam's original input position.

Abstract: Embodiments of the present invention are directed to single prism beamsplitters and compound beamsplitters formed from combining one or more of the single prism beamsplitters. In one embodiment, the beamsplitters can be configured to produce one or more split beams of light that can emerge at angles other than 90° to one another. The prisms of the beamsplitter embodiments are configured so that light propagating through prisms encounter one or more intermediate planar surfaces at various angles with respect to the path of the light. A certain number of the intermediate planar surfaces can be angled so that the light transmitted along a particular path undergoes total internal reflection within the prism. A number of other intermediate planar surfaces are angled so that the light transmitted along a particular path does not undergo total internal reflection.

Abstract: An optical system and method are presented to produce a desired illuminating light pattern. The system comprises a light source system configured and operable to produce structured light in the form of a plurality of spatially separated light beams; and a beam shaping arrangement. The beam shaping arrangement is configured as a diffractive optical unit configured and operable to carry out at least one of the following: (i) combining an array of the spatially separated light beams into a single light beam thereby significantly increasing intensity of the illuminating light; (ii) affecting intensity profile of the light beam to provide the illuminating light of a substantially rectangular uniform intensity profile.

Abstract: One optical system comprises a first optical surface, a faceted second optical surface, and a faceted third optical surface. The optical system is operative to convert a first bundle of rays that is continuous in phase space outside the first optical surface into a second bundle of rays that is continuous in phase space outside the third optical surface. Between the second and third optical surfaces the rays making up the first and second bundles form discrete sub-bundles each passing from a facet of the second optical surface to a facet of the third optical surface. The sub-bundles do not form a continuous bundle in a phase space that has dimensions representing the position and angle at which rays cross a surface transverse to the bundle of rays.

Abstract: An illuminating device is provided. The illuminating device includes a light source, a dividing unit, an optical unit and a light-distribution control unit. The dividing unit is configured to divide light emitted from the light source into light beams. The optical unit is configured to allow at least one of a travelling direction and a focal length of the light beams divided by the dividing unit to be variable. The light-distribution control unit is configured to control at least one of the travelling direction and focal length of light beams by acting on the optical unit.

Abstract: There is provided a light source unit which includes a luminescent light source which receives excitation light so as to emit light of a predetermined wavelength band, excitation light sources which shine excitation light on to the luminescent light source, a reflection space having the luminescent light source in an interior thereof and an emission space which emits luminescent light source light emitted from the reflection space from an emission port whose area is made smaller than the area of the luminescent light source and a projector which employs the light source unit.

Abstract: The invention provides an optical device, including a light-transmitting substrate, optical means for coupling light into the substrate by total internal reflection, and a plurality of partially reflecting surfaces carried by the substrate, characterized in that the partially reflecting surfaces are parallel to each other and are not parallel to any of the edges of the substrate.

Abstract: An optical arrangement has a laser configured to emit a laser beam, an amplitude mask and a focusing element. The amplitude mask is disposed between the laser and the focusing element in a path of the laser beam such that the laser beam hits the amplitude mask before being modified by the focusing element so as to direct the laser beam to a focal point within a photosensitive material.

Abstract: A monolithic frame for optics used in interferometers where the material of the monolithic frame may have a substantially different coefficient of thermal expansion from the beamsplitter and compensator without warping, bending or distorting the optics. This is accomplished through providing a securing apparatus holding the optics in place while isolating the expansion thereof from the expansion of the frame. Stability in optical alignment is therefore achieved without requiring a single material or materials of essentially identical coefficients of thermal expansion. The present invention provides stability in situations where it is not possible to utilize a single material for every component of the interferometer.

Abstract: In order to increase the depth of field of an optical system, there is provision to add a phase object, interposed between an object (O) to be imaged and an image plane (8) of the optical system. The phase object is interposed although a chromatic aberration of the system is not yet corrected. After interposition, the measured optical signal is corrected complementarily so as to eliminate the chromatic aberrations therefrom. It is shown that if a parameter of the expansion of the expression, a function of pupil dependency, that the difference in path length of the optical system possesses a significant value of higher order than that of the defocus, then an increase in the depth of field is obtained.

Abstract: A system and method for locking the relative phase of multiple coherent optical signals, which compensates for optical phase changes induced by vibration or thermal changes in the environment.

Abstract: A single-channel optical processing system for an energetic-beam instrument has separate sources for processing radiation and illumination radiation. The processing radiation and the illumination radiation are combined in a single optical path and directed to a sample surface inside the energetic-beam instrument through a self-focusing rod lens. The self-focusing rod lens thus has a working distance from the sample surface that will not interfere with typical arrangements of ion beams and electron beams in such instruments. A combination of polarizers and beam splitters allows separation of the combined incident radiation and the combined radiation reflected from the sample surface and returned through the same optical channel, so that the reflected radiation may be directed to an optical detector, such as a camera or spectrometer. In other embodiments, additional illumination of the sample surface is provided at an angle to the central axis of the self-focusing rod lens.

Abstract: In an optical etalon with a fixed FSR determined by the cavity length, the time delay is adjusted by an etalon surface coating. The proper cavity length is chosen to achieve a desired FSR, and the coating is independently selected to obtain a desired time delay.

Abstract: A system for inspecting a specimen is provided. The system includes an illumination subsystem configured to produce a plurality of channels of light energy, each channel of light energy produced having differing characteristics (type, wavelength, etc.) from at least one other channel of light energy. Optics are configured to receive the plurality of channels of light energy and combine them into a spatially separated combined light energy beam and direct it toward the specimen. A data acquisition subsystem comprising at least one detector is provided, configured to separate reflected light energy into a plurality of received channels corresponding to the plurality of channels of light energy and detect the received channels.

Abstract: A laser beam source device includes: a first light emission element which has a light emission portion for emitting a laser beam; a second light emission element which has a light emission portion for emitting a laser beam; a control member which has a flat surface on which the first light emission element is disposed and a curved surface having a convexed part; and a holding member which has a concaved portion formed in correspondence with the curved surface for engagement between the concaved portion and the control member, wherein the first light emission element and the second light emission element are disposed such that light emitted from the light emission portion of each of the first and second light emission elements enter the light emission portion of the other light emission element.

Abstract: A laser beam source device includes: a first light emission element; a second light emission element; and first and second dividing units, wherein the first light emission portion of the first light emission element and the first light emission portion of the second light emission element, having a first clearance, are disposed such that the laser beam emitted from each of the light emission portions can enter the other light emission portion, the second light emission portion of the first light emission element and the second light emission portion of the second light emission element, having a second clearance, are disposed such that the laser beam emitted from each of the light emission portions enters the other light emission portion, and the first clearance is longer than the second clearance.

Abstract: Optical filters tunable for both center wavelength and bandwidth, having applications such as in astronomy, remote sensing, laser spectroscopy, and other laser-based sensing applications, using Michelson interferometers or Mach-Zehnder interferometers modified with Gires-Tournois interferometers (“GTIs”) are disclosed. A GTI nominally has unity magnitude reflectance as a function of wavelength and has a phase response based on its resonator characteristics. Replacing the end mirrors of a Michelson interferometer or the fold mirrors of a Mach-Zehnder interferometer with GTIs results in both high visibility throughput as well as the ability to tune the phase response characteristics to change the width of the bandpass/notch filters. A range of bandpass/bandreject optical filter modes, including a Fabry-Perot (“FP”) mode, a wideband, low-ripple FP mode, a narrowband notch/bandpass mode, and a wideband notch/bandpass mode, are all tunable and wavelength addressable.

Abstract: A multi-laser module includes two compartments arranged one above the other. The lower compartment includes four lasers and four corresponding beam-steering mirrors arranged to direct corresponding laser beams into the upper compartment. The upper compartment includes a regular pentagonal prism and four other beam-steering mirrors each arranged to receive one of the laser beams and direct that beam to the prism. The beam prism has three dichroic-coated surfaces and two antireflection-coated surfaces. Each of three of the beams enter the prism via a corresponding one of the dichroic-coated surfaces. The fourth beam enters the prism via one of the antireflection coated surfaces, and all of the beams exit the prism via the other antireflection coated surface along a common path.

Abstract: A laser beam source device includes: a first light emission element and a second light emission element each of which has a light emission portion for emitting a laser beam having a fundamental wavelength, wherein the first light emission element and the second light emission element are disposed such that light emitted from the light emission portion of each of the first light emission element and the second light emission element can enter the light emission portion of the other light emission element, at least either the first light emission element or the second light emission element has the plural light emission portions, and the areas of the plural light emission portions are not uniform.

Abstract: A digital display system is disclosed, wherein the display system generally includes a recording mechanism, such as a digital camera, a processing mechanism for processing and saving at least one image; software for interlacing the image; software for processing slides and movies comprised of multiple images; a digital display device for receiving, storing and displaying the image, and a lenticular screen overlaid upon the digital display device for viewing the interlaced images in three dimensions. A method of manufacturing a lenticular sheet is also disclosed as having as its primary steps the provision of a substantially transparent substrate material; forming a plurality of lenses on a first side of the substrate; and shaping the substrate to correspond to a display area of the display device, wherein the plurality of lenses are angled to correspond to the pixel size and pitch of the display area.

Abstract: A printing medium includes: a rectangular lens sheet that has a surface formed in a predetermined lens shape; and a thin base that is fixed to a rear surface of the lens sheet on which no lens is formed and has an extending portion extending from one side of the lens sheet to the outside. In the printing medium, when a region corresponding to the rear surface of the lens sheet is referred to as a unit region, the extending portion includes a plurality of unit regions adjacent to one another with adjacent portions, which are common sides, interposed therebetween, and a first printing surface and a second printing surface having predetermined images formed thereon are formed in corresponding unit regions on one surface of the base that is fixed to the rear surface of the lens sheet or the other surface of the base. In addition, at least one unit region is additionally interposed between the unit region where the first printing surface is formed and the unit region where the second printing surface is formed.

Abstract: Disclosed herein are systems that divert images for image capture devices. An image diversion system includes a deviating optical element to provide a first view to an imager of an image capture device and to provide at least a second view to the imager. An image diversion system includes a first deviating optical element and a second deviating optical element optically coupled to the first deviating optical element. The first deviating optical element provides a first view and at least a second view to an imager of an image capture device. An image diversion system includes a first deviating optical element, a second deviating optical element, and at least one corrective lens. The image diversion system is contained within a housing that is attachable to a housing portion of an image capture device.

Abstract: According to one embodiment of the present invention, a system for illuminating a target includes a light source configured to emit one or more light beams with a first divergence. The system further includes a lens separated from the light source. The lens is configured to substantially satisfy the sine condition without removing spherical aberrations from the one or more light beams. The lens is further configured to receive the one or more light beams with the first divergence. The lens is further configured to change the first divergence of the one or more light beams to a second divergence. The second divergence is less than the first divergence. The second divergence is greater than zero. The lens is further configured to transmit the one or more light beams with the second divergence.

Abstract: A unit for measuring a power of randomly polarized light beam is configured with spaced first and second beam splitters having respective reflective surfaces which face one another and configured to sequentially reflect a fraction of randomly polarized beam which is incident upon the first splitter. The beam splitters are dimensioned and shaped so that an output beam, reflected from the second beam splitter, has a power independent from the state of polarization of the randomly polarized beam.

Abstract: A camera module that can be made thinner and achieves a beautiful image over an entire image region regardless of a subject distance is provided.

Abstract: The present invention relates to a laser processing method and laser processing apparatus for enabling improvement and maintenance of homogenization of a beam intensity distribution in an irradiated region. The laser processing apparatus comprises, at least, an ASE light generation section for emitting ASE light, and a homogenizer for splitting the ASE light into multiple beams. The ASE generation section for emitting the ASE light as processing laser light is provided, and whereby the deterioration of homogenization due to inter-beam interference is suppressed. The homogenization of beam intensity distribution is improved by locating a condenser lens relative to an object such that the object is shifted from a focus position of the condenser lens in the homogenizer, by intentionally deteriorating a beam quality M2 of the ASE light itself emitted from the ASE light generation section to about 2 to 10, or by a combination of these, in laser processing.

Abstract: Various embodiments described herein comprise mixers comprising a light pipe having input and output ends and a central region therebetween. An optical path extends in a longitudinal direction from the input end through the central region to the output end. The central region of the light pipe comprises one or more rippled reflective sidewalls having a plurality of elongate ridges and valleys and sloping surfaces therebetween. Light from the input end propagating along the optical path reflects from the sloping surfaces and is redirected at a different azimuthal direction toward the output end thereby mixing the light at the output end. Illuminance and/or color mixing can therefore be provided.

Abstract: A semiconductor laser device including a submount having a front surface and a back surface corresponding to the opposing face that are in parallel with each other and a visible light transmittance of 60% or more; a connection electrode that is formed on the front surface; and a semiconductor laser element that is packaged on the submount through the connection electrode, and is allowed to emit a laser beam in a direction parallel to the front surface.

Abstract: At least one exemplary embodiment is directed to a display optical system which includes a first optical system configured to form a magnified image of an image displayed on an image display element, the first optical system including an optical member, a second optical system configured to magnify and guide light of the magnified image from the first optical system to one of an observer or a projection surface, the second optical system including a decentered reflecting surface, and an adjusting mechanism configured to displace the optical member of the first optical system in such a way as to have a component in a direction perpendicular to an optical axis of the first optical system.

Abstract: An original laser-radiation beam having a symmetrical M2 but poor beam quality is sliced in one transverse axis, by a fanned-out stack of parallel transparent plates, into a plurality of beam slices. The beam-slices are also spread by the stack of plates in another transverse axis perpendicular to the first axis. A fanned-out stack of glass blocks aligns the spread beam-slices in the first axis to form what is effectively a single beam having an asymmetric M2, with beam quality improved in one axis and degraded in the other compared with the original beam. The effective single beam is projected into a line of radiation by a cylindrical lens, or by a homogenizing projector including spaced apart cylindrical lens arrays followed by a spherical condenser lens.

Abstract: An external laser light introducing device is constructed to introduce laser light from outside of an optical apparatus into inside so that the laser light is condensed on a target by a condenser lens located inside the optical apparatus. In this case, the external laser light introducing device comprises a pupil projection optical system for projecting the entrance pupil of the condenser lens on an external pupil located outside the optical apparatus and an optical axis aligning mechanism for practically aligning the optical axis of the laser light with that of the external pupil.

Abstract: An illuminator (10) for producing a radiation spot (120) on a workpiece (110) comprises a laser light source (20) and a beam-shearing optical system (30). Fine structure (160) generated by an integrator (80) of laser light source (20) in integrated beams (90) as a result of path length differences among coherent light beams (70) from emitters (60) of lasers (40) is sheared by the inclusion of beam-shearing optical system (30) into illuminator (10). Beam-shearing optical system (30) allows illuminator (10) to produce a radiation spot (120) in which the fine structure (160) is spread so that scanning of radiation spot (120) does not produce the striations (140) in scanned patch (170) that are obtained with prior art illuminators.

Abstract: An illumination optical apparatus, used in a projection exposure apparatus for projecting and exposing a pattern arranged in a first plane to a second plane, for supplying the first surface with illumination light from a light source comprises an optical path combiner arranged in an optical path between the light source and the first surface, for combining a plurality of light beams different from each other from the light source such that the first and second light beams illuminate the first surface closely to each other. The optical path combiner includes a discrete point positioned on or near a third surface optically conjugate with the first surface. The plurality of light beams travel by way of a plurality of regions sectioned by the discrete point, respectively.

Abstract: The disclosure relates to an optical integrator configured to produce a plurality of secondary light sources in an illumination system of a microlithographic projection exposure apparatus. The disclosure also relates to a method of manufacturing an array of elongated microlenses for use in such an illumination system. Arrays of elongated microlenses are often contained in optical integrators or scattering plates of such illumination systems.

Abstract: Optical filters tunable for both center wavelength and bandwidth, having applications such as in astronomy, remote sensing, laser spectroscopy, and other laser-based sensing applications, using Michelson interferometers or Mach-Zehnder interferometers modified with Gires-Tournois interferometers (“GTIs”) are disclosed. A GTI nominally has unity magnitude reflectance as a function of wavelength and has a phase response based on its resonator characteristics. Replacing the end mirrors of a Michelson interferometer or the fold minors of a Mach-Zehnder interferometer with GTIs results in both high visibility throughput as well as the ability to tune the phase response characteristics to change the width of the bandpass/notch filters. A range of bandpass/bandreject optical filter modes, including a Fabry-Perot (“FP”) mode, a wideband, low-ripple FP mode, a narrowband notch/bandpass mode, and a wideband notch/bandpass mode, are all tunable and wavelength addressable.

Abstract: A lens module includes: a base unit, a first lens unit, a spacer unit, a second lens unit and a cap unit. The base unit has a first through hole having a first tapered portion. The first lens unit has a first peripheral portion having second and third tapered portions. The second and third tapered portions taper in opposite directions. The second tapered portion is engaged in the first tapered portion of the first through hole of the base unit. The spacer unit has a second through hole having fourth and fifth tapered portions. The fourth and fifth tapered portions taper in opposite directions. The fourth tapered portion is engaged in the third tapered portion. The second lens unit has a second peripheral portion having a sixth tapered portion. The sixth tapered portion is engaged in the fifth tapered portion of the second through hole of the spacer unit.

Abstract: A light guide system for receiving and transporting ambient light by means of light guides, which system comprises at least one light collecting unit for receiving light and light transporting means to transport the received light to a location remote from the unit, is described wherein the said light collecting unit comprises a number of light guides, the light receiving ends of which are arranged in a two dimensional array of rows and columns whilst downstream these ends the light guides stepwise compose to a number of outgoing transport light guides, which number is substantially lower than the number of light receiving ends and which transport light guides constitute said light transport means. The system has a large light-collecting capability and can be made very compact and is especially very suitable for a road marking system.

Abstract: An imaging device and method of a bonding apparatus in which the imaging device includes: a high-magnification optical system having first and second high-magnification optical paths that extend to multiple imaging planes through a high-magnification lens and have different optical path lengths from the high-magnification lens to the respective imaging planes correspondingly to multiple subject imaging ranges which are at different distances from the high-magnification lens; and a low-magnification optical system having a low-magnification optical path that extends to an imaging plane through a low-magnification lens and having a field of view wider than those of the high-magnification optical paths. The imaging elements on the respective imaging planes in the high-magnification optical system are adapted to image semiconductor chips, while the imaging element on the imaging plane in the low-magnification optical system is adapted to image a lead frame.

Abstract: A pulse stretcher includes a beam splitter configured to split an input light beam into first and second beams, a con-focal resonator including first and second con-focal mirrors, and a fold mirror. The beam splitter, con-focal resonator, and fold mirror are optically arranged such that at least a portion of the first beam is recombined with the second beam into a modified beam after an optical delay of the first beam caused by the optical arrangement. The apparatus further includes one or more optical elements in an optical path of the input light beam prior to the beam splitter such that a focal point of the first beam is foamed at a distance away from the fold mirror preventing energy density-related damage to the fold mirror. The apparatus can further include one or more additional optical elements to provide re-conditioning of the modified beam. A related method is also disclosed.

Abstract: A curve representing a characteristic of a blue-light reflecting dichroic film DB and a curve representing a characteristic of a red-light reflecting dichroic film DR are configured to have shapes that track an ideal spectral characteristic of green. Accordingly, it is possible to obtain a characteristic approximated to the ideal spectral characteristic without using a trimming filter having a dichroic film in an exiting surface of a prism. Since it is not necessary to use the trimming filter having the dichroic film, it is possible to prevent ghost and flare from occurring due to the dichroic film of the trimming filter. Accordingly, it is possible to embody an imaging apparatus having the ideal spectral characteristic with ghost and flare being reduced.

Abstract: Substrate-guided relays that employ light guiding substrates to relay images from sources to viewers in optical display systems. The substrate-guided relays are comprised of an input coupler, an intermediate substrate, and an output coupler. In some embodiments, the output coupler is formed in a separate substrate that is coupled to the intermediate substrate. The output coupler may be placed in front of or behind the intermediate substrate, and may employ two or more partially reflective surfaces to couple light from the coupler. In some embodiments, the input coupler is coupled to the intermediate substrate in a manner that the optical axis of the input coupler intersects the optical axis of the intermediate substrate at a non-perpendicular angle.

Abstract: A light source module for a scanning projection apparatus is provided. The light source module includes a plurality of point light sources and at least one light blocking unit. Each point light source is capable of providing a color light beam. The color light beams are combined into a combined light beam and the colors of the color light beams are different. The at least one light blocking unit is capable of being inserted into a transmission path of at least one of the color light beams at a fixed frequency to block a portion of the color light beam.