Abstract: A fixing device that fixes, to a light emitting device that emits light, a lens barrel included in a projection optical device and holding a plurality of lenses includes a first tube member, a contact section provided on an outer side of the first tube member and in contact with a holding section included in the light emitting device, and a pressing mechanism provided to be opposed to the contact section and configured to press the holding section toward the contact section when the fixing device is attached to the light emitting device.

Abstract: The disclosure relates to the technical field of projection auto-focusing, and embodiments particularly disclose a projection focusing method, a projection focusing apparatus, a projector, and a readable storage medium. According to the projection focusing method provided by this application, an initial position of a focused motor is roughly determined based on a current projection distance, a focusing direction is determined according to the current projection distance and a projection distance corresponding to the current motor position, a position of a clearest projection picture can be found by traversing a few motor positions, and the speed and precision of projection focusing are greatly increased.

Abstract: There is a skin analysis device for attachment to an electronic device of a human user, the electronic device having at least one skin characteristic measurement device, the skin analysis device comprising an enclosure comprising an enclosure body, configured to be removably connected to the electronic device and one or more skin characteristic measurement assisters, connected to the enclosure and configured to assist one or more skin characteristic measurement devices take a skin characteristic sample of a skin characteristic of the human user.

Abstract: An integrated image sensor and lens assembly including an image sensor, a lens barrel, and a lens element. The lens barrel configured to direct light to the image sensor. The lens barrel is a multiple segment lens barrel or a multiple subsection lens barrel. The multiple segment lens barrel or the multiple section lens barrel includes: a first segment or a first subsection, and a second segment or a second subsection. The lens element located within the lens barrel. The first segment or the first subsection is movable relative to the second segment or the second subsection.

Abstract: A light emitting device comprises a plurality of coherent light sources, and a plurality of light scattering structures. Each light scattering structure is located in an optical path for light output from a different corresponding one of the coherent light sources. Each light scattering structure comprises an arrangement of nanoantennas embedded in an electrically responsive material and electrical contacts by which to apply a voltage to the electrically responsive material. Application of a time varying electrical signal causes the refractive index of the electrically responsive material in a light scattering structure to vary and thereby varies light scattering by the nanoantennas in the light scattering structure. This effect may be used to reduce speckle caused by interference of light output by the coherent light sources.

Abstract: An electronic device is provided. The electronic device includes a function module, a body, and a motor assembly. The body includes an accommodation space for accommodating the function module. The motor assembly includes a drive motor, a gear, a rotation output shaft, a displacement mechanism, and a latch. The drive motor includes a shaft. The gear is fixedly attached to the shaft. The rotation output shaft includes a gear teeth portion. The gear teeth portion is coupled to the gear. The rotation output shaft is connected to the function module and is configured to drive the function module to rotate. The displacement mechanism synchronizes with the shaft and is separated from the rotation output shaft. The displacement mechanism includes a linear motion component. The latch is connected to the linear motion component, and is configured to engage the function module.

Abstract: An image light generation module includes a first display element configured to emit first image light, a second display element configured to emit second image light, a third display element configured to emit third image light, a combining prism configured to emit combined image light combined from the first image light, the second image light, and the third image light, and a first gap defining member that defines a first gap between the first display element and the combining prism, a second gap defining member that defines a second gap between the second display element and the combining prism, and a third gap defining member that defines a third gap between the third display element and the combining prism, in which at least one of the first gap, the second gap, and the third gap is different in size from another of the gaps.

Abstract: The laser radar includes: a light source configured to emit laser light; an optical system configured to shape the laser light into a line beam that is long in one direction, and project the line beam; a scanner configured to perform scanning with the line beam in a short side direction of the line beam; and a configuration for causing light intensity of the line beam to be different in a long side direction of the line beam. The light intensity of the line beam is caused to be different, for example, by a controller controlling emission power of a plurality of light emitting portions disposed in the light source along a direction corresponding to the long side direction of the line beam.

Abstract: A projection device and a household appliance are provided. The projection device includes a casing, a lens component, and a pattern lighting module. An opening is disposed at a front end of the casing. The lens component is disposed inside an accommodating space of the casing and fixed on the casing, and the lens component corresponds to the opening. The pattern lighting module is disposed inside the accommodating space of the casing and fixed on the casing, and the pattern lighting module corresponds to the lens component. The pattern lighting module emits at least one patterned light beam that passes through the lens component and the opening sequentially.

Abstract: A camera including a lens barrel, lens elements, and an image sensor. The lens barrel includes a first subsection, a second subsection, and a spacer located between the first subsection and the second subsection. The lens elements are located in the first subsection and other lens elements located in the second subsection. The image sensor is aligned along an optical axis that extends through the first subsection and the second subsection of the lens barrel. The first subsection and the second subsection are separate pieces that are in communication by the spacer being sandwiched between the first subsection and the second subsection.

Abstract: A projection apparatus having a light modulation element includes a main body; an optical unit that is rotatably supported by the main body and includes a projection optical system for projecting the spatially modulated light onto the projection surface, a first rotation member rotatably supported to the main body and a second rotation member rotatably supported to the first rotation member; a first sensor; a second sensor; a controller; and a regulation mechanism, and the regulation mechanism includes a moving member that is movable between a regulation position for regulating the rotation and a regulation release position for releasing the regulating of the rotation, and fixes the moving member at the regulation position in a case where the controller determines that the first rotation member and the second rotation member are in the predetermined specific rotation state.

Abstract: A projection apparatus includes a light valve, a lens module, a distance measuring module, a lens position detection module and a processor. The light valve forms an image beam. The lens module projects the image beam onto a display surface. The distance measuring module detects a distance between the lens module and the display surface to obtain a first distance value. The lens position detection module detects a position of the lens module to obtain a second distance value. The processor receives the first distance value from the distance measuring module, receives the second distance value from the lens position detection module and obtains an effective focus range according to the second distance value.

Abstract: The invention provides a projection device which includes a rotating module and an imaging module. The rotating module is assembled on a mounting surface and includes a rotating part and an assembling part which are integrally formed. The rotating part is parallel to the mounting surface, and the assembling part is perpendicular to the mounting surface. The imaging module is assembled on the assembling part of the rotating module. When the rotating module rotates by taking an axis perpendicular to the mounting surface as an axial center, the rotating module drives the imaging module to rotate so as to change a projection direction of the imaging module. The projection device of the invention adjusts the projection direction without using a tool.

Abstract: A system of camera calibration includes at least one first equipment and at least one second equipment, wherein a camera of at least one camera includes at least two image capturing groups, each image capturing group of the at least two image capturing groups includes at least two image capturers. Each first equipment provides at least one first calibration pattern, and the at least one first calibration pattern is utilized to calibrate first images including the at least one first calibration pattern captured by a plurality of corresponding image capturers of the at least two image capturing groups. Each second equipment provides at least one second calibration pattern, and the at least one second calibration pattern is utilized to calibrate second images including the at least one second calibration pattern captured by two corresponding adjacent image capturers of the at least two image capturing groups.

Abstract: An integrated image sensor and lens assembly comprises a lens barrel holding camera lenses coupled to a lens mount. The lens mount is further coupled to an image sensor substrate that has an image sensor lying on an image plane. The optical distance between lenses and the image sensor is tuned such that the focal plane of the lenses coincides with the image plane. Due to thermal expansion, this optical distance may vary thereby to cause the focal plane of the lenses to shift away from the image plane. The integrated image sensor and lens assembly further comprises spacers that couple one or more lens elements to the lens barrel. The spacers and the lens elements are configured such that the optical distance is maintained to be constant or substantially constant.

Abstract: According to an embodiment of the present technology, an image display apparatus includes a light source; an image generation unit; and a projection optical system. The image generation unit generates image light by modulating a light beam emitted from the light source. The projection optical system includes a first lens group that is disposed on an optical axis of the generated image light and has a first refractive power, a second lens group that is disposed on the optical axis and has a second refractive power, a first movement mechanism that moves the first lens group, and a second movement mechanism that moves the second lens group corresponding to the first refractive power, the second refractive power, and the movement of the first lens group.

Abstract: There is disclosed a portably suspended retractable shelf for storing furniture-side items that includes a horizontal platform having an inner portion and an outer portion. In various embodiments, the inner portion is adapted to be slidably captured between an upper cushion and a lower supporting structure. At least one of a projector insert rotationally adjustable to a plurality of orientations and the following upward-facing compartments is disposed on the outer portion of the horizontal platform and is accessible to a user on the furniture: a collapsible basin, a hanging flexible pocket, and a foldable box. A cutout hole is configured to hold the projector insert or the compartments in a suspended configuration through the shelf. A downward-facing sliding drawer compartment is mounted and/or supported underneath the outer portion of the shelf. A storage container extends from a leading surface of the portable suspended retractable shelf. Other embodiments are also disclosed.

Abstract: A lens adjustment mechanism according to an embodiment of the present disclosure includes: a base section; a lens holding section that holds a lens having an optical axis in a Z-axis direction; an intermediate member disposed between the base section and the lens holding section; a first rotating cam that is disposed between the base section and the intermediate member, and is rotated about an optical axis of the lens; and a second rotating cam that is disposed between the intermediate member and the lens holding section, and is rotated about the optical axis of the lens. The intermediate member moves in a Y-axis direction together with the lens holding section during rotation of the first rotating cam, and restricts movement in the Y-axis direction of the lens holding section during rotation of the second rotating cam.

Abstract: An adjustable carrier structure for a lamp is described. Said adjustable carrier structure comprises an optical component carrier on which an optical component may be fastened, a coupling device for fastening the carrier structure on the lamp, and at least one threaded spindle. The latter comprises a first threaded spindle end that is mounted in an axially-fixed and non-rotatable manner on the optical component carrier, and is connected to the coupling device via a threaded socket that cooperates with the threaded spindle. In this case, the threaded socket is connected to the coupling device in an axially-fixed and rotatable manner. The threaded spindle extends essentially parallel to an optical axis of the adjustable carrier structure. A distance may be set between the first threaded spindle end and the coupling device by means of rotating the threaded socket. Moreover, a lamp having a carrier structure of this type is proposed.

Abstract: The projection image adjustment system includes: projection display apparatuses for projecting projection images; a first and a second imaging apparatus for shooting the projection images; and a controller. The controller includes: an imaging-apparatus selecting unit, a shooting-region setting unit, a pattern projection unit, and a shot-image display unit. The imaging-apparatus selecting unit selects the first or the second imaging apparatus. The shooting-region setting unit sets a first and a second charge-of-shoot region for a projection display apparatus. The first and the second imaging apparatus are respectively in charge of shooting the first and the second charge-of-shoot region. At least one projection display apparatus is shared by the first and second charge-of-shoot regions. The pattern projection unit projects a format pattern of the projection display apparatus corresponding to the first or the second charge-of-shoot region.

Abstract: A free-form surface lens is made of a transparent resin forming an oblique projection optical system including a free-form surface mirror in a projection type video display apparatus, this lens includes a lens effective region having a surface on which a predetermined free-form surface is formed, and an edge surface formed to surround the lens effective region, the lens effective region and the edge surface in a part of a circumference surrounding the lens effective region where the edge surface is not formed are joined to each other by at least either one of a curved surface and a flat surface set so as not to change a direction of a tilt of the lens effective region in vicinity of the lens effective region, and an end surface including at least either one of the curved surface and the flat surface is set as a tapered surface.

Abstract: Described are a ranging method, and an automatic focusing method and device. The ranging method comprises: acquiring a coefficient of relationship between the number of pixels and the object distance within a range of a distance between a camera and a projection lens on the basis of a preset calibrated object distance; and calculating an actual object distance according to the acquired coefficient of relationship.

Abstract: Provided is a technique capable of achieving a manually-operated lens shift mechanism in a space-saving manner in regard to a projection type image display apparatus. The lens shift mechanism includes a first base, a second base, a third base to which a projection lens is fixed, a first shift portion moves the projection lens in a vertical direction by moving the second base in the vertical direction with respect to the first base, and a second shift portion which moves the projection lens in a horizontal direction by moving the third base in the horizontal direction with respect to the second base. The first shift portion is arranged along the vertical direction to be coaxial with a first manual operation portion and a first rotation shaft. The second shift portion is arranged along the vertical direction to be coaxial with a second manual operation portion and a second rotation shaft.

Abstract: A decorative light apparatus has a housing 12, a dome 20, a power supply, a motor 30, a light board 36 having LEDs 46 surrounding the motor, a multi-surface refractive lens and a beam-splitter lens light shade. The light disk 36 supports the motor 30 directly so that alignment of the LEDs, lens and motor are always correct. The motor may further transmit vibrations into the light board which can provide a slight shimmering effect of the light passing through the lens.

Abstract: A projection correction method adapted to a projector. The projection correction method includes: sensing a temperature of a body of the projector, so as to obtain a first temperature value, where a focusing gear of the projector is located at a first gear position; determining whether the temperature of the body of the projector is changed, and when the temperature of the body of the projector is changed from the first temperature value to a second temperature value, the focusing gear is rotated by a predetermined distance to rotate the focusing gear to a second gear position; and determining whether a storage device stores a target gear position corresponding to the second temperature value, so as to rotate the focusing gear to the target gear position. Moreover, a projector using the aforementioned projection correction method is also provided.

Abstract: A projector includes a projection lens, a projector body, and an angle adjustment unit. In the projection lens, a U-shaped optical path is formed of optical axes CL1 to CL3. A lens barrel is a U-shaped barrel. The angle adjustment unit includes a fitting portion, a mounting flange, a fixing unit, a mount ring, and bearings. The projection lens is supported so as to be rotationally movable around the optical axis CL1. The fixing unit includes a mounting hole, a fixing screw, and a screw hole. The mounting hole is formed in the shape of an arc. The fixing screw is screwed with the screw hole through the mounting hole, so that the lens barrel is fixed to a housing.

Abstract: A projection system including a processing device and a plurality of projectors is provided. The projectors are disposed above a projection plane or below the projection plane. The processing device determines whether the projectors are disposed above the projection plane or below the projection plane according to a firmware setting of each of the projectors. When one of the projectors disposed above the projection plane projects a projection mode determination image, the processing device analyzes captured images captured by remainders of the projectors in respective image capture areas of the projection plane to determine projection modes of the projectors. In addition, an automatic setting method is also provided. The projection system of the invention may be readily set up based on various projection requirements.

Abstract: A lens moving mechanism includes a guide section which supports a lens mount unit on which a lens for projecting light is mounted and guides the lens mount unit in three orthogonal axis directions including an optical axis direction of the light, and a base member which supports a saddle guide unit of the guide section and is fixed to a projector main body. The saddle guide unit includes first linear motion guide devices which are fixed to the base member and guide the lens mount unit in an orthogonal-to-optical axis direction orthogonal to the optical axis direction.

Abstract: The multiple function LED project light is a hand-held and powered by DC power, and the project light has front lens has project magnify lens fit-into or install-on or built-in on center position. The project lens has below position outer-tube set assembled together so outer-tube can envelope or surrounded the lower position separated inner-tube which has image-forming unit within. While the project head move away from the project light neck by screw-thread or other extend construction to make distance between the magnify lens and image forming-unit changed to get focus adjustment functions. The said Project light may has self-prong, or project light fit within the hold-base which has prong-set both get AC current through the AC-to-DC circuit to get desired DC power for LED or SMD-LEDs or Dip-LEDs or COB-LED or other DC operated electric components to use.

Abstract: An integrated image sensor and lens assembly comprises a lens barrel holding camera lenses coupled to a lens mount. The lens mount is further coupled to an image sensor substrate that has an image sensor lying on an image plane. The optical distance between lenses and the image sensor is tuned such that the focal plane of the lenses coincides with the image plane. Due to thermal expansion, this optical distance may vary thereby to cause the focal plane of the lenses to shift away from the image plane. The integrated image sensor and lens assembly further comprises spacers that couple one or more lens elements to the lens barrel. The spacers and the lens elements are configured such that the optical distance is maintained to be constant or substantially constant.

Abstract: Provided is a lens alignment adjustment device capable of suitably correcting an angle accuracy of an optical axis of a lens unit with respect to a projector main body. A lens alignment adjustment device is provided to a projector to retain a projection lens, and is capable of adjusting inclination of an optical axis of the projection lens with respect to the projector. The lens alignment adjustment device includes: a base plate which is retained in a predetermined posture with respect to the projector; and a lens fixing plate to which the projection lens is fixed. The lens fixing plate is rockably coupled to the base plate through intermediation of a first center pin orthogonal to an optical axis of the projection lens. First adjusting means for setting an inclination angle of the lens fixing plate with respect to the base plate about the first center pin is provided.

Abstract: A projection system includes a first lens group that does not move when the projection magnification is changed with the aid of the zoom function, and the first lens group includes a correction lens group that is moved in the direction of the optical axis to correct worsened astigmatism. The projection system satisfies the following conditional expressions (1) and (2): |?BF20|<P×FNO×?2??(1) 1.5<|f1/f|??(2) where P represents the pixel pitch in an image displayed by liquid crystal panels, FNO represents the F number of the entire lens system, ?BF represents the amount of movement of the back focus position in a case where the correction lens group is moved by the amount of movement for correction of the aberration that changes when the temperature changes by 20° C., f represents the focal length of the entire lens system, and f1 represents the focal length of the correction lens group.

Abstract: A lighting device for producing scenographic light effects has a light source mounted on the frame; a light guide coupled to the light source to define an optical path along a longitudinal axis; a first mirror (5) arranged along the longitudinal axis facing the light source to reflect the light beam towards the light source; a second mirror movable with respect to the frame and facing the first mirror to reflect the light beam reflected by the first mirror.

Abstract: A lighting device for producing scenographic light effects has a light source mounted on the frame; a light guide coupled to the light source to define an optical path along a longitudinal axis; a first mirror (5) arranged along the longitudinal axis facing the light source to reflect the light beam towards the light source; a second mirror movable with respect to the frame and facing the first mirror to reflect the light beam reflected by the first mirror.

Abstract: A projector including a light source, a power supply section, a power supply control section that controls power supply from the power supply section, a projection lens that projects an image, and a projection system driver that moves the projection lens, wherein the power supply control section performs, as power supply modes, an operation mode in which power is supplied to the light source section to allow the light source section to output light and a first standby mode in which the power supply to the light source section is terminated, and in the first standby mode, power is supplied to the projection system driver to allow the projection lens to move to an attachment/detachment position where the projection lens is attachable and detachable.

Abstract: An image projection apparatus includes an acquirer configured to acquire information on a lens unit, and a controller configured to set, based on the information on the lens unit, at least one of an image orientation of a projection image and a shift direction of the lens unit.

Abstract: A microlithographic apparatus comprises an optical wavefront manipulator. The latter includes an optical element and a gas-tight cavity that is partly confined by the optical element or contains it. A gas inlet device directs a gas jet towards the optical element. The location, where the gas jet impinges on the optical element after it has passed through the cavity, is variable in response to a control signal supplied by a control unit. A gas outlet is in fluid connection with the vacuum pump so that, upon operation of the vacuum pump, the pressure within the cavity is less than 10 mbar even if the gas jet passes through the cavity.

Abstract: Systems and methods for machine vision are presented. Such machine vision includes ego-motion, as well as the segmentation and/or classification of image data of one or more targets of interest. The projection and detection of scanning light beams that generate a pattern are employed. Real-time continuous and accurate spatial-temporal 3D sensing is achieved. The relative motion between an observer and a projection surface is determined. A combination of visible and non-visible patterns, as well as a combination of visible and non-visible sensor arrays is employed to sense 3D coordinates of target features, as well as acquire color image data to generate 3D color images of targets. Stereoscopic pairs of cameras are employed to generate 3D image data. Such cameras are dynamically aligned and calibrated. Information may be encoded in the transmitted patterns. The information is decoded upon detection of the pattern and employed to determine features of the reflecting surface.

Abstract: A head-mounted display apparatus may include: a main frame, one surface of which faces a user's face; and a support part coupled to at least part of the main frame to fix the main frame to the user's face, wherein the main frame has a cavity structure such that an electronic device is mounted on an opposite surface thereof and includes a position adjustment part for adjusting the position of an electronic device, and a structure for preventing the electronic device from being tilted during the position adjustment is included in the interior of the main frame.

Abstract: A kit for creating a flat folding projection device is provided and includes a lens and a sheet defining at least a first, second, third and fourth panels, each panel separated from the other panels by at least one fold. A hole is positioned in the first panel, the hole defining an edge. A cut is positioned in the first panel adjacent to the hole such that the first panel on either side of the cut can be separated to create a space configured to receive and hold the lens therein. Further includes is one of: a light source, a translucent sheet or a light source and a translucent sheet. An envelope contains the foregoing such that a thickness of the envelope is less than ½ inches.

Abstract: There is provided a projection optical system capable of projecting an image formed on an image forming unit on a projection plane, which has an extremely short projection distance and a small size.

Abstract: An image display unit includes a first unit fixed to a receiving frame, a second unit, movably supported by the first unit, including an image generator to generate an image when light enters the image generator, and a first link unit to supportingly fix the first unit to the receiving frame, and a space between the first unit and the receiving frame adjustable by the first link unit.

Abstract: In a lens barrel of the present invention, a frame body holding an optical element is held in a frame body holding member, includes an adjuster for adjusting the position of the frame body with respect to a predetermined axis of the frame body holding member so as to be able to adjust at least one of the orientation of an optical axis in the optical element and the position of the optical element in a direction of the optical axis, and the adjuster is arranged at a position adjustable from an opening portion of a mounting member to be mounted on the frame body holding member.

Abstract: A projector includes a projection lens, a first imaging section adapted to take an image of the projection surface, and a second imaging section adapted to take an image of the projection surface with a field angle wider than a field angle of the first imaging section. The first imaging section is disposed at a first distance from an optical axis of the projection lens in a direction perpendicular to the optical axis, and the second imaging section is disposed at a second distance longer than the first distance from the optical axis of the projection lens in the direction perpendicular to the optical axis.

Abstract: A head-up display device includes a screen, a projector that projects a visual image to the screen using a projection lens, and a processor. The processor is programmed to generate a virtual image of the visual image from the projected visual image and determine an image-generation position at which the virtual image is to be generated. The screen and the projection lens are configured to be movable along an optical path of the projector. The processor is programmed to determine a screen position to which the screen is to be moved based on the decided image-generation position and determine a lens position to which the projection lens is to be moved based on the determined screen position. The projector includes a screen-drive motor that moves the screen to the determined screen position and a lens-drive motor that moves the projection lens to the determined lens position.

Abstract: An image processing apparatus includes a detection unit, a size changing unit, and a determining unit. The detection unit detects, from a first captured image obtained by capturing a projection image projected by a projection unit, a vertex of the projection image. The size changing unit reduces a size of the projection image in response to the detection unit not detecting a predetermined number of vertexes of the projection image from the first captured image. The determining unit determines a distortion correction parameter to be used for correcting a distortion of a projection image projected by the projection unit, in accordance with a detection result of vertexes by the detection unit for a second captured image obtained by capturing the size-reduced projection image in a case where the detection unit detects the predetermined number of vertexes of the size-reduced projection image from the second captured image.

Abstract: A projection apparatus includes a light source, an optical engine module, and a lens module. The lens module includes a plate having at least one through hole, a lens fixed to the plate, at least one slide assembly disposed between the plate and an optical engine housing of the optical engine module, and a position adjusting device including a movable guide member and at least one guide pillar. The plate is movably disposed on the optical engine housing through the slide assembly. The movable guide member is movably disposed between the plate and the optical engine housing. The guide pillar is disposed on the movable guide member and passes through the through hole. When the movable guide member is forced to move towards an axial direction, the guide pillar drives the plate to move on the slide assembly along the axial direction relative to the optical engine housing.

Abstract: A lens barrel includes: a first barrel; a second barrel that, with respect to the first barrel, is capable of relative movement in a direction orthogonal to the optical axis; an adjustment member for adjusting an amount of the relative movement; two adjustment member housing portions that are provided in a diametral space between the first barrel and the second barrel, are formed so as to be separate from each other in a circumferential direction and are capable of housing the adjustment member; a plurality of screws; a plurality of fastening portions for threadedly engaging and fastening the first barrel and the second barrel in parallel with the optical axis by means of the plurality of screws; and one washer member that is held in an integral manner between the plurality of screws and the plurality of fastening portions.

Abstract: An image projector includes an image forming element that is illuminated by a light from a light source, a projection optical system that projects a light output from the image forming element, a shifter that shifts the projection optical system with respect to the image forming element so as to shift a projection position, a deforming part that deforms an image formed on the image forming element, and a corrector that corrects a shift direction with the shifter on the basis of a deformation state by the deforming part.

Abstract: A scanner includes a platen having a surface supporting items for scanning, and a projector adjacent (e.g., above or below) the platen. The projector projects light displaying patterned alignment marks on the items located on the platen. The patterned alignment marks identify an alignment position for the items to be located on the platen for properly aligned scanning. The projector projects different patterned alignment marks based on different characteristics of different items to be scanned.