Abstract: The display panel is a display panel that is flexible, including: an EL structure layer including a plurality of EL elements arranged two-dimensionally; a foamed resin layer on a side of the EL structure layer that is opposite to a light emitting surface of the EL structure layer; a metal layer provided between the EL structure layer and the foamed resin layer; and a first adhesive layer provided between the EL structure layer and the metal layer and comprises an adhesive having an elastic modulus of 90 kPa or more.

Abstract: An accessory that is attachable to a device comprises an image sensor and a beam splitter having a first surface and a second surface. The beam splitter is configured to impinge light upon the first surface, and split the light impinging upon the first surface into at least a first beam, a second beam, and a third beam. The first beam travels from a first opening of the device to a second opening of the device along an optical path when the accessory is attached to the device, the second beam travels from the first surface to the image sensor, and the third beam travels from the second surface to the image sensor or a beam dump.

Abstract: A laser driving device and a method for enabling a uniform light field, wherein the laser driving device is a high-power laser driving device that enables a uniform light field on the basis of a narrow-band low-spatial-coherence light and is provided for laser fusion. The narrow-band low-spatial-coherence light is configured as a seed of the laser driving device, an amplification and transmission unit amplifies the seed, a frequency conversion unit converts a frequency of the laser, and a focusing component is configured for laser focusing and uniform illumination.

Abstract: Provided is a camera module and a photosensitive component thereof and a manufacturing method thereof, said photosensitive component comprising: a circuit board, a photosensitive element, and a molding base; the molding base is integrally formed on the circuit board and photosensitive element to form a light window; a first end side corresponding to the molding base adjacent to the flexible region has a first side surface facing the light window; said first side surface comprises a first partial surface arranged adjacent to the photosensitive element and a second partial surface connected to said first portion surface; a first angle between said first partial surface and the optical axis of the camera module is greater than a second angle between the second partial surface and the optical axis; a second end side opposite to and away from the flexible region of the molding base has a second side surface facing the light window; said second side surface comprises a third partial surface arranged adjacent to the

Abstract: Provided is a periscope lens module, including: a prism; a bearing member including a bearing frame; a ball; a supporting member including a prism bracket, a driving bracket, and a rotating bracket in rotation-fit with the ball; an elastic member; and a driving member. The elastic member includes a first elastic bracket including a first abutting portion, and a second elastic bracket including a second abutting portion. The first and second abutting portions are spaced from each other and abut against a top of the rotating bracket from two sides of the ball, in such a manner that the rotating bracket and the ball abut against the bearing frame. The driving member is connected between the bearing member and the driving bracket for driving the supporting member to drive the prism to rotate. This leads to a simple structure while achieving image stabilization.

Abstract: A maintenance tool for gas turbine engine includes a rail system having a plurality of rail segments insertable through one or more inspection holes of the gas turbine engine for assembly within a core air flowpath of the gas turbine engine. The maintenance tool additionally includes a maintenance head movable along the plurality of rail segments of the rail system for performing maintenance operations within the core air flowpath.

Abstract: A light blocking sheet having a central axis includes a central hole and a plurality of inner extended portions. The central axis passes through the central hole, which is enclosed by a hole inner surface. The hole inner surface has a first corresponding circle and a second corresponding circle, wherein a diameter of the first corresponding circle is greater than a diameter of the second corresponding circle. The inner extended portions are adjacent to and surround the central hole, wherein each of the inner extended portions is extended and tapered from the first corresponding circle towards the second corresponding circle and includes an inner surface, and the inner surface includes a line pair. The line pair includes two line sections, wherein one end of one line section thereof and one end of the other line section thereof are towards the second corresponding circle and approach to each other.

Abstract: A translucent solar module assembly for integration with a greenhouse having a frame with a plurality of roof supports includes a pair of brackets attachable to each of the plurality of roof supports, a bi-facial solar panel attachable to the pair of brackets, and a pair of reflector rails attachable to each of the plurality of roof supports. A dichroic reflector is attachable to the pair of reflector rails.

Abstract: An optical element is ring-shaped and has an inner peripheral face. The inner peripheral face is formed with a bumpy section. The bumpy section is formed with a plurality of grooves. The grooves are disposed around an axial direction of the optical element. A rib is formed between any adjacent two of the grooves. Each of the grooves has a fifth end and a sixth end along the axial direction. A width of each of the grooves along a circumferential direction is increasing from the sixth end toward the fifth end so that a third angle between two lateral walls of each of the grooves is larger than 0 degree but smaller than 90 degrees.

Abstract: An imaging optical element set has an optical axis, and includes an object-side lens element, an image-side lens element and a light blocking sheet. The light blocking sheet is interposed between the object-side lens element and the image-side lens element, and includes an object-side outer surface, an image-side outer surface, an outer diameter portion, an inner diameter portion and a height compensation structure. The image-side outer surface is opposite to the object-side outer surface. The outer diameter portion has an outer diameter surface connected to the object-side outer surface and the image-side outer surface. The inner diameter portion has an inner diameter surface connected to the object-side outer surface and the image-side outer surface. The height compensation structure is in full circle form, and is for adjusting a height difference between the inner diameter surface and the outer diameter surface along a direction parallel to the optical axis.

Abstract: A network of scopes, including one or more lead scopes and one or more follower scopes, is provided to allow the respective scopes to track the same presumed target. A lead scope locates a target and communicates target position data of the presumed target to the follower scope. The follower scope uses the target position data and its own position data to generate electronic control signals for use by follower scope to make position movements so as to re-position the follower scope from its current target position to move towards the target position defined by the target position data received from the lead scope. At least the second scope is mounted to, or integrated into, a vehicle, which uses the target position data to move to a new location so as to allow the second scope to better view the target.

Abstract: A camera head includes: a mount detachably connected to an eyepiece of an endoscope; an imager configured to capture a subject image emitted from the eyepiece; and a housing configured to house the imager, the housing including an interior portion including the imager thereinside, and an exterior portion arranged on an outer side of the interior portion, wherein the interior portion and the exterior portion are separated from each other in at least a part of an outer surface.

Abstract: A system and method for vaporizing space debris in space. The system includes a spacecraft body, a primary solar concentrator mounted to the spacecraft body that collects and focuses solar flux from the sun, and a secondary solar concentrator positioned at a focal point of the primary solar concentrator that refocuses the focused solar flux. A manipulator arm coupled to the spacecraft body grabs the space debris in space and positions it at a location where the refocused solar flux vaporizes the debris. The secondary solar concentrator can be a point-source concentrator, the primary solar concentrator can be a parabolic mirror, a Fresnel lens or a light focusing element or assembly, and the space debris can be a retired spacecraft or launch vehicle upper stage or component.

Abstract: A system for use in maintaining a turbine assembly includes a plurality of blades and a plurality of vanes. The system includes an insertion apparatus including an insertion end, a steering end opposite the insertion end, and a body extending from the insertion end to the steering end. The insertion end is positionable proximate at least one blade of the plurality of blades using a steering interface. The system also includes a service apparatus for use in maintaining the turbine assembly. The service apparatus includes at least one maintenance device and an anchoring feature. The service apparatus is proximate the insertion end of the insertion apparatus and is positionable in a plurality of orientations via the steering interface. The anchoring feature is configured to releasably couple the service apparatus to at least one blade of the plurality of blades.

Abstract: Integrated telescopes are described that are stable and compact, and include optics pieces that are susceptible to stray light. One example telescope includes an optics piece formed of a transparent optical material and two surfaces with each surface including a reflector surface and a baffle. The baffles may be formed in a groove in one of the surfaces of the optics piece. The baffle may have an index of refraction that is approximately the same as an index of refraction of the optics piece. The baffle may include a blackened epoxy, a carbon black material, or a powdered black spinel. The integrated telescope may include a short-wave infrared image sensor fixed in position relative to the optics piece.

Abstract: An coronagraph optical system and method for continuously imaging a wide field of view that includes the Sun. Examples of the coronagraph optical system include an all-reflective foreoptics assembly that receives light rays from a viewed scene and a direct solar image of the Sun, a sensor assembly configured to produce an image of the viewed scene, an all-reflective relay optics assembly configured to receive the light rays from the foreoptics assembly and to reflect the light rays to the sensor assembly, and a solar rejection optical component positioned between the foreoptics assembly and the relay optics assembly and dynamically configurable such that the direct solar image of the Sun is reflected away from the relay optics assembly and the light rays are reflected to the relay optics assembly while an entrance aperture of the foreoptics assembly is continuously positioned towards the Sun.

Abstract: A thin flash module for a camera uses a flexible circuit as a support surface. A blue GaN-based flip chip LED die is mounted on the flex circuit. The LED die has a thick transparent substrate forming a “top” exit window so at least 40% of the light emitted from the die is side light. A phosphor layer conformally coats the die and a top surface of the flex circuit. A stamped reflector having a knife edge rectangular opening surrounds the die. Curved surfaces extending from the opening reflect the light from the side surfaces to form a generally rectangular beam. A generally rectangular lens is affixed to the top of the reflector. The lens has a generally rectangular convex surface extending toward the die, wherein a beam of light emitted from the lens has a generally rectangular shape corresponding to an aspect ratio of the camera's field of view.

Abstract: Anti-fogging system for an endoscope including an endoscope having an outer housing, an imaging arrangement, and a distal window. A filter lens is located at the distal window, with the filter lens allowing a first portion of electromagnetic light to pass therethrough while absorbing a second portion of electromagnetic light in order to heat the filter lens.

Abstract: A Cassegrain telescope design consists of a silicon primary mirror bonded into a silicon-carbide (SiC) telescope metering tube. A secondary mirror is bonded directly to the telescope window. The window sits in a SiC bezel that is bonded to the SiC telescope tube. A graphite snout is bonded to the rear of the primary mirror and extends forward into the telescope. The snout incorporates a field stop that blocks stray light and sources outside the acquisition field of view (FOV). A lens cell threads into the snout and holds two lenses that collimate the light exiting that end of the telescope.

Abstract: An annular optical element having an optical axis includes an outer diameter surface, an inner annular surface, an object-side surface and an image-side surface. The object-side surface includes an annular reflecting surface, an annular auxiliary surface and a connecting surface. The annular reflecting surface is inclined with the optical axis. The annular auxiliary surface is closer to the optical axis than the annular reflecting surface is to the optical axis. The connecting surface is for connecting to an optical element, wherein the connecting surface is closer to the optical axis than the annular auxiliary surface is to the optical axis. The image-side surface is located opposite to the object-side surface and includes an annular optical surface. A V-shaped groove is formed by the annular auxiliary surface and the annular reflecting surface of the object-side surface.

Abstract: An exposure apparatus includes an exposure unit for exposing a wafer. The exposure unit includes an illumination system and masks. The illumination system includes a light-homogenizing unit. The light-homogenizing unit includes a light-homogenizing quartz rod having a regular hexagonal cross section. Each of the masks has a regular hexagonal shape matching with the cross section of the light-homogenizing quartz rod. A field of exposure resulting from this arrangement is less affected by objective field of view distortion and allows a higher useful depth of focus (UDoF) when compared to other fields of exposure of the same size. In addition, with the same projection objective DoF, a greater field of exposure can be obtained.

Abstract: This invention comprises an adaptor device for connecting an electronic device having a camera to a range of optical devices, including but not limited to binoculars, monoculars, riflescopes, spotting scopes, telescopes, and microscopes. This adaptor device has a plurality of protrusion that provide a self-centering and fitted connection between the electronic and optical device, so that the optical axes are aligned so that the user may take images or video on their electronic device through the optical device. The structure of the adaptor device allows the adaptor to fit a range of differently sized optical device, denoted by the diameter of the eyepiece end of the optical device.

Abstract: A transparent vehicle lamp includes at least one lens having a main body portion and a first light input portion. An optical axis extends through the main body portion in a front-rear direction. The main body portion has a reflecting surface intersecting with the optical axis, a coupling surface connected to a periphery of the reflecting surface and a light output surface spaced apart from the reflecting surface and the coupling surface along the optical axis such that the image of a scenery toward which the coupling surface faces is formed on the light output surface.

Abstract: A video endoscope including: a endoscope shaft; a hermetically enclosed video-optical unit arranged in the endoscope shaft, wherein the video-optical unit comprises an enclosure including a substantially cylindrical, hermetically sealed housing having a distally arranged entry window, an objective lens, an image sensor unit, and one or more signal lines, the housing being connected to an outer jacket tube in a rotationally fixed manner, wherein the image sensor unit is mounted in the housing rotatably about a longitudinal axis of the endoscope shaft and comprises at least one image sensor, wherein, in order to rotate the image sensor unit, a magnetic coupling with an outer magnet and an inner magnet operationally connected to the outer magnet in a magnetic manner, is arranged in the area of the distal tip of the endoscope shaft.

Abstract: An optical inspection probe for obtaining and providing images of an object to be inspected. The optical inspection probe comprises an imaging assembly for capturing an image of an object and an illumination assembly for producing a light beam directed toward the object. The optical inspection probe is configured such that the light beam converges to a focal point at a first focal plane.

Abstract: Embodiments of the invention generally relate to laser annealing systems with optics for imaging a pattern on a substrate. The optics may comprise an aperture or plurality of apertures which shape an image to be exposed on a surface of a substrate. The image may be determined by the shape of an aperture within the optics system.

Abstract: A beam diffusing module including a light incident terminal, a light emitting terminal, a first reflective plate and a second reflective plate is provided. The first reflective plate and the second reflective plate are disposed on a transmission path of a laser beam. At least one of the first reflective plate and the second reflective plate has a plurality of reflective micorstructures. The reflective micorstructures are arranged along a second direction from the light incident terminal towards the light emitting terminal. At least a part of the laser beam enters the beam diffusing module through the light incident terminal and emerges from the light emitting terminals after being reflected repeatedly by the first reflective plate and the second reflective plate to cause an M squared of the laser beam to be redistributed along a first direction. A beam generating system is also provided.

Abstract: An annular optical spacer includes an outer annular surface, an inner annular surface, a first side surface, a second side surface and a plurality of protruding structures. The inner annular surface surrounds a central axis of the annular optical spacer and is opposite to the outer annular surface. The first side surface connects the outer annular surface with the inner annular surface. The second side surface connects the outer annular surface with the inner annular surface and is opposite to the first side surface. The protruding structures are regularly disposed on the inner annular surface. Each of the protruding structures extends along a direction from the first side surface to the second side surface and is integrated with the inner annular surface.

Abstract: The present invention is generally directed toward a laryngoscope having a handle, a rigid tube, and an optical subassembly. The handle has a distal end and a proximate end. The tube is hollow and also has a distal end having a distal opening and a proximate end having a proximate opening. The optical subassembly includes a light source located within the handle, a power source located within the handle and in communication with the light source and a light carrier extending between the handle and the tube and in communication with the light source and providing light inside and along the entire length of the tube.

Abstract: A drive assembly for a centrifugal processing system is provided for rotating the yoke assembly (36) about a first axis at a first angular velocity and rotating the chamber assembly (30 coaxially with the yoke assembly at a second angular velocity A drive motor (54) is provided for rotating the yoke assembly at the first angular velocity and simultaneously rotating the chamber assembly at the second angular velocity by means of a stationary first gear (64), a second gear (68) mounted to the yoke assembly that operatively engages the first gear, a third gear (74) rotatably mounted to the yoke assembly so as to synchronously rotate with the second gear, and a fourth gear (76) fixed to the chamber assembly that operatively engages the third gear so as to rotate the chamber assembly (30) relative to the yoke assembly (36) upon rotation of the yoke assembly about the first gear.

Abstract: A system and method for focusing electromagnetic radiation is presented. A lens has an outside perimeter. A curved lens surface is located inside the outside perimeter. The curved lens surface is to bend at least one wavelength of electromagnetic energy passing through the curved surface. One (or more) mounting surface(s) are located between the outer perimeter and the curved lens surface. The mounting surface has at least one flat surface.

Abstract: An optical imaging lens includes a lens barrel, a front lens element, plural intermediate lens elements, and a rear lens element. The front lens element has a first central lens portion and a first assembly portion. The first assembly portion has a first front abutting section, a first front slanting surface section, and a first rear slanting surface section. Each of the intermediate lens elements has a second central lens portion and a second assembly portion. The second assembly portion has a second front slanting surface section and a second rear slanting surface section. The rear lens element has a third central lens portion and a third assembly portion. The third assembly portion has a third front slanting surface section.

Abstract: A first lens includes, on end surfaces of both ends in a direction along an optical axis, a first lens surface, a second lens surface, lens outer edges formed on outer peripheral sides of the first and second lens surfaces, and a lens side surface that is adjacent to the lens outer edges and serves as an outermost surface in a direction orthogonal to the optical axis. The first lens is provided so as to be mountable on a lens holding frame. In the first lens, a first abutment surface provided within one plane orthogonal to the optical axis is provided on at least one of the lens outer edges. A second projection is formed on at least one of the lens outer edges so as to protrude in the direction along the optical axis from a position closer to an inner peripheral side than the lens side surface, and the second projection has a reference cylindrical surface provided in a fixed positional relationship with the optical axis in the direction orthogonal to the optical axis.

Abstract: A camera lens is formed with a casing and a lens stack having at least one lens element, the lens stack arranged within the casing. A spring arrangement is pre-compressed to exert a clamping force between the casing and the lens stark basically in a direction of an optical axis of the at least one lens element.

Abstract: An optical module for an electro-optical device with a functional element, in particular for a camera device, and to an electro-optical device with such a module. The optical module includes a lens substrate portion with at least one lens element, and a spacer. The spacer serves to keep the lens substrate at a well defined axial distance from a base substrate portion of the fully assembled electro-optical device. In order to ensure improved performance of the functional element, an EMC shield is provided. The spacer is at least in parts electrically conductive and thus forms the EMC shield or a part thereof. A method of manufacturing a plurality of such modules on a wafer scale is also provided.

Abstract: A system includes a light detector, optics, a telescope camera mount, a plurality of spacers, and a retainer. The optics are configured to focus light on the light detector. The telescope camera mount is configured to at least partially support the optics. The plurality of spacers are positioned between the optics and the light detector. A retainer is coupled to the plurality of spacers.

Abstract: A method for manufacturing a plurality of optical devices comprising the steps of:—Providing a replication tool (1), the replication tool comprising a replication surface defining an array of replication cells, each replication cell comprising a lens replication portion (2) and a spacer replication portion (3), wherein the spacer replication portion on the replication tool is more indented than the lens replication portion,—Bringing the replication tool and a support (6) in contact with each other with replication material (11) between the replication surface and the support,—Causing the replication material to harden,—Wherein the lens replication sections are caused to be kept at a distance from the support when the support rests against the replication tool,—Removing the replication tool, and—Separating the hardened replication material into individual optical devices, each device having a replicated surface portion with a structure corresponding to a negative of a replication cell and comprising a spacer p

Abstract: Various techniques are disclosed for providing systems and methods for orienting one or more lenses or other optical elements in a lens sleeve. For example, a system may include a lens sleeve defining an interior lens cavity. A plurality of lens positioning features extend from the lens sleeve adjacent the interior lens cavity. A first lens is secured in the lens cavity at a first position relative to the lens sleeve. A first set of the lens positioning features are located at a second position relative to the lens sleeve, and a second set of the lens positioning features are located at a third position relative to the lens sleeve. A second lens engages either the first set or the second set of the plurality of lens positioning features depending on a desired distance between the first lens and the second lens.

Abstract: Provided is an imaging lens, in which a space holding portion is formed outside the effective aperture of one or both of junction type compound lenses facing each other in order to hold the space between the junction type compound lenses. A mating face formed on the space holding portion which is made of the same material as that of a lens portion is brought in direct contact with a mating face provided on the other among the junction type compound lenses facing each other at the position facing the mating face of the space holding portion, outside the effective aperture of the other junction type compound lens. Alternatively, mating faces which are formed on confronting surfaces of the space holding portions formed on the facing junction type compound lenses are brought in direct contact with each other.

Abstract: A lens module includes a lens barrel, a first lens, a second lens, and a spacer. The lens barrel includes an object-side end and an image-side end opposite to the object-side end. The first lens is received in the lens barrel, and adjacent to the object-side end. The second lens is received in the lens barrel, and adjacent to the image-side end in relative to the first lens. The spacer is an annular plate, and includes an object-side surface, an image-side surface opposite to the object-side surface, and an inner sidewall. The spacer is positioned between the first lens and the second lens. The object-side surface faces the first lens, and the image-side surface faces the second lens. The intersection of the object-side surface and the inner sidewall forms a chamfer.

Abstract: A lens module includes a lens barrel, a first lens, a second lens, a third lens, and two spacers. The lens barrel includes an object-side end and an image-side end. The first, second, and third lenses are received in the lens barrel and arranged in that order from the object-side to the image-side. One of the two spacers is positioned between the first lens and the second lens, and the other of the two spacers is positioned between the second lens and the third lens. Each of the spacers is chamfered to prevent the ingress of unwanted light.

Abstract: A lens module includes a first lens and a first spacer. The first lens includes a first optical portion and a first support portion surrounding the first optical portion. The first support portion includes a first upper surface facing an object side of the lens module and a first lower surface facing an image side of the lens module. The first lower surface includes a first annular portion, a slanted annular portion and an inner annular portion. The slanted annular portion is obliquely interconnected between the outer annular portion and the inner annular portion. The first annular portion and the inner annular portion are perpendicular to the optical axis of the lens module. The slanted annular portion faces inwardly of the first lens. The outer shield portion covers the first annular portion. The intermediate shield portion covers the slanted annular portion. The inner shield portion covers the inner annular portion.

Abstract: One embodiment may take the form of a system for reducing the appearance of optical effects in a display. The system may include an enclosure with a first surface and a second surface. Furthermore, the system may include spacers that may be deposited on the bottom face of the first surface and/or the top face of the second surface, where the first surface may be a touch panel and/or cover lens and the second surface may be a display module. The spacers may be deposited in one layer with an anti-reflection coating. The thickness of the coating may be less than the diameter of the spacers.

Abstract: A wafer level lens module includes a first optical layer, a spacer layer and a second optical layer. The spacer layer is disposed upon the first optical layer, having a hole through the spacer layer for light passage, wherein a surface of the hole substantially avoids light reflection. And the second optical layer is disposed upon the spacer layer.

Abstract: An operation microscope includes a microscope body having an illumination optical system which illuminates a subject, a lens barrel, and a main observation optical system which observes the subject, an assistant's microscope unit attached to the microscope body, and a guide rail which is disposed in the lens barrel of the microscope body, and extends in a circumferential direction about a center of an optical axis of an objective lens of the microscope body. The assistant's microscope unit is disposed in the guide rail to be movable between a usage position and a non-usage position in a circumferential direction of the lens barrel.

Abstract: Provided is an imaging lens, in which a space holding portion is formed outside the effective aperture of one or both of junction type compound lenses facing each other in order to hold the space between the junction type compound lenses. A mating face formed on the space holding portion which is made of the same material as that of a lens portion is brought in direct contact with a mating face provided on the other among the junction type compound lenses facing each other at the position facing the mating face of the space holding portion, outside the effective aperture of the other junction type compound lens. Alternatively, mating faces which are formed on confronting surfaces of the space holding portions formed on the facing junction type compound lenses are brought in direct contact with each other.

Abstract: An optical component is provided. The optical component includes an optical-path portion including an arm-connecting portion and a lower portion, a first arm extending from a first end of the arm-connecting portion, and a second arm extending from a second end of the arm-connecting portion. The first arm has at least one resting feature and the second arm has at least one resting feature. The optical-path portion has an input surface. When the resting features of the first arm and the second arm are positioned on a top surface at short edges of a trench in a trench system, the optical-path portion is vertically aligned in the trench.

Abstract: An adjustable optical mount adapted for use with an optical table defining a reference plane includes a hollow housing with openings in the side walls to allow passage of an optical beam therethrough, a gimbal base fixed on the top of the housing, a gimbal plate adjustably mounted under the gimbal base, and a carrier bracket fixed to the gimbal plate for holding preselected optical elements within the housing along the path of the beam. Adjustment mechanisms are provided to tilt and rotate the gimbal plate so as to align the optical element on a selected axis relative to the reference plane.

Abstract: The disclosure pertains to an optical apparatus, in particular for microlithography, that includes an optical module, a support structure and a connection apparatus. The connection apparatus includes at least one connection unit which includes a first connector part and a second connector part. The first connector part is connected to the optical module, and the second connector part is connected to the support structure.

Abstract: Disclosed are a wafer-level lens array, a method of manufacturing a wafer-level lens array, a lens module, and an imaging unit that can prevent the influence of, for example, the shrinkage of a forming material, prevent the positional deviation between lenses when the wafer-level lens arrays overlap each other or when the wafer-level lens array overlaps an imaging element array, and be easily designed. A method of manufacturing a wafer-level lens array including a substrate unit and a plurality of lens units that is arranged on the substrate unit includes: forming the substrate unit; and integrally forming the lens units that are made of a resin having substantially the same optical characteristics as a material forming the substrate unit with the substrate unit.