Abstract: A printing apparatus that facilitate a checking operation of printed matter during printing and can avoid deterioration of quality of the printed matter. A printer unit executes a printing process according to an inputted print job. A determination unit determines, when the print job is interrupted during the printing process of the printer unit, whether the interruption requires a check printing. A control unit controls the printer unit to execute the check printing after removing the interruption of the print job using print data of the print job when the determination unit determines that the interruption requires the check printing.

Abstract: A chip mountable on a customer replaceable unit monitory (CRUM) unit used in an image forming job includes a central processing unit (CPU) to perform cryptographic data communication with a main body of an image forming apparatus, using an operating system (OS) of the CPU. The security of a unit on which the chip is mounted can thereby be reinforced and random changes of data of the unit can be prevented.

Abstract: An image processing apparatus restricts the use of functions on a user-by-user basis as well as easily suppresses the realization of a function that is equivalent to a restricted function by combining other functions. To accomplish this, an image processing system includes an image processing apparatus and an information processing apparatus that includes function restriction information for restricting, on a user-by-user basis, the use of functions provided by an image processing apparatus. Furthermore, the image processing apparatus acquires function restriction information corresponding to an authorized user, and if a function whose use is restricted by function restriction information can be realized by combining other functions, the image processing apparatus restricts the use of the other functions.

Abstract: A system for determining batch sizes for a print job may include a computing device and a computer-readable storage medium in communication with the computing device. The computer-readable storage medium may include one or more programming instructions for receiving a print job having a job size, receiving speed information for each of a plurality of document production devices in a production line, identifying a plurality of batches associated with the print job, performing a discrete event simulation to model a makespan for the print job in processing each of the plurality of batches on the plurality of document production devices using the speed information and repeating the identifying and performing until a plurality of final batches is determined, each having a unique final batch size.

Abstract: A wireless communication device can send and receive realtime facsimile transmissions over a data channel available to the device. The device can implement a real time facsimile protocol over the data channel, which can generally be a packet switched network connection, such as an IP connection. An image capture device can be employed to obtain an image of a document that can be facsimile transmitted from the wireless device over the data channel. The document image may be converted to a format generally usable with facsimile transmissions. The wireless device can be configured to transmit immediately following image capture, or after a desired number of images are captured. A contact list that may be included with the wireless device may be used to select a destination address for facsimile transmission. A printing device can be the destination address to permit wireless or mobile printing.

Abstract: A print management apparatus includes a writing-image processing unit and a job generation processing unit. The writing-image processing unit determines whether print data, to be printed using the print management apparatus, includes both color page and monochrome page, and generates writing-image data of the color page and writing-image data of the monochrome page from the print data. The job generation processing unit prepares a preliminary job ticket for printing the color page and a preliminary job ticket for printing the monochrome page based on an initial job ticket set for the print data when the writing-image processing unit determines that the writing-image data includes both color page and monochrome page.

Abstract: An image communication apparatus includes: a display; an input device displaying an address input dialogue on the display, receiving a user input to designate an address of a transmission destination of multicast transmission; storage storing multicast transmission history; an extracting device, connected to the input device and the storage, responsive to the input device receiving an input of an address of a transmission destination of multicast transmission, for extracting, from the multicast transmission history, a multicast transmission history record including the address received by the input device as a transmission destination, and extracting an address different from the address received by the input device, included in the extracted multicast transmission history record, as a candidate of multicast transmission destination; and a control device controlling the display such that the extracted candidate of multicast transmission destination is displayed in the address input dialogue.

Abstract: A configuration of an image forming system that includes an image forming apparatus and at least one of a paper feed apparatus and a post-process apparatus is defined based on system configuration information including a combination of identification information for the apparatuses and setting information for the order of arrangement of the apparatuses corresponding to the identification information without using a dedicated line connection.

Abstract: A printer selection system to select a printer for performing output from a plurality of printers includes: a mobile station moved along with a computer; a plurality of base stations fixedly disposed at known positions; and a server connected to the computer that enables data communication, the server including a positioning portion that determines a position of the computer based on a reception result of a radio wave for position detection transmitted from one of the base stations and the mobile station and received by the other, a printer position database portion storing information about positions of the printers, a distance determining portion that determines a distance between each of the printers and the computer, and a printer setting portion that sets a printer having the shortest distance as a printer that performs the output from the computer based on the distances between each of the printers and the computer.

Abstract: An image recording system includes a print data processing unit for performing a control for recording a predetermined recording failure check pattern after print data is recorded on a recording medium for each job, and a recording failure checking unit for determining whether or not there is a recording failure in a check image based on a recording failure check pattern obtained by capturing the check image with a check image obtaining unit.

Abstract: A document transmission apparatus reduces troublesome labor of an operator when transmitting document data, inputted from a scanner or the like, by various transmission methods such as electronic mail, facsimile, remote printing and file transfer. An address book containing a receiver and a plurality of transmission methods for transmitting document data to the receiver is generated. Upon transmission instruction, an appropriate transmission method is selected by the receiver, then document data is converted into data of an appropriate data format, and the converted data is transmitted. Further, a notice of transmission indicating that the document data has been transmitted is transmitted to the receiver of the document data by a method different from the transmission method of the document data. Thus, the document data can be reliably delivered to the receiver.

Abstract: In a digital multi-function peripheral, a QR code generation section generates image data of a QR code on the basis of first data for security of obtained image data. An encryption section encrypts second data for security of the image data. A micro gradation generation section generates a micro gradation (a gradation pattern) on the basis of the second data having been encrypted by the encryption section and history data, and adds the micro gradation to the image data of the QR code generated by the micro gradation QR code generation section.

Abstract: An image processing apparatus includes a recording control unit for recording, by a recording head, a recording position adjustment chart including a pattern for adjusting a recording position of the recording head discharging ink and a mark formed in a position different from that of the pattern, a reading unit for reading the recording position adjustment chart as image data, a first detection unit for detecting a position and inclination of the recording position adjustment chart when reading the recording position adjustment chart based on the mark, a second detection unit for detecting the position of the pattern based on the position and the inclination detected by the first detection unit, and a determination unit for determining adjustment values for the recording position adjustment based on the image data of the recording position adjustment chart in which the position of the pattern has been detected by the second detection unit.

Abstract: In an image forming apparatus having various and may functions, in order to easily set a function based on a scanned document, a CPU of an MFP executes a program including: when a document is scanned by a user (YES at S3200), the step of displaying a preview image of the scanned document (S3202); the step of OCR-processing the document data (S3204); when the scanned document has been registered in a document-by-document recommended functions list (YES at S3210), the step of reading the document-by-document recommended functions list from an HDD and displaying the document type and recommended menu on a touch-panel display (S3212); the step of setting the function registered in the recommended functions list in the MFP (S3222) unless the setting of recommended menu is changed (NO at S3218); and the step of executing copy/transmission process based on the set function (S3224).

Abstract: There is provided an image processing method which determines the area of a document from an image read on a transparent platen, the image processing method also determines a single object area or a plurality of object areas from the image on the transparent platen, and when the luminance of the area in which the object area is removed from the image on the transparent platen is detected to determine the document area, the image processing method detects whether or not an image of a shadow exists around the periphery of the object area on the image of the transparent platen, and the threshold value used for determining the document area is different depending on whether a shadow is detected.

Abstract: It is an object to provide an image reading apparatus, an image reading method, and a program, in which in the case of reading both of a reflecting original and a transmitting original by one image reading apparatus, an average scanning time in the scan of a plurality of number of times can be shortened without increasing costs. In the image reading apparatus, whether the read original is the reflecting original or the transmitting original is discriminated based on a part of data read as a reflecting original by a reflecting original reading unit. If it is determined that the original is the transmitting original, the original is read as a transmitting original by a transmitting original reading unit. If it is determined that the original is the reflecting original, the data which has been read before is used.

Abstract: A photosensitive chip, including: a plurality of sets of photosensors arranged along an X direction, the photosensors within each set of photosensors aligned in a Y direction, perpendicular to the X direction, and the photosensors within said each set being off-set, in the Y direction, relative to the photosensors of an adjacent set of photosensors by a distance less than a length of a photosensor. In an example embodiment, the plurality of sets of photosensors includes a first number of sets and the distance is about equal to the length of a photosensor divided by the first number.

Abstract: For the problem of blurring at a boundary in a scanned illustration, a method of separating and vectorizing color regions accurately is realized by identification of a labeled region corresponding to the blurring and combining processing with another neighboring region. An image input unit, a color region dividing unit dividing an input image into the color regions, a labeling unit providing an individual label to the color region, a labeled region shape analysis unit obtaining labeled region shape information including information representing a shape feature of a labeled region which is the color region provided with the label, a micro-region determination unit determining whether the labeled region provided with the label is a micro-region or not according to the labeled region shape information, and a micro-region combining unit combining the region determined to be the micro-region with a neighboring region, are comprised.

Abstract: The invention relates to techniques for speckle reduction in holographic optical systems, in particular holographic image display systems. We describe a holographic image display system for displaying an image holographically on a display surface, the system including: a spatial light modulator (SLM) to display a hologram; a light source to illuminate said displayed hologram; projection optics to project light from said illuminated displayed hologram onto said display surface to form a holographically generated two-dimensional image, said projection optics being configured to form, at an intermediate image surface, an intermediate two-dimensional image corresponding to said holographically generated image; a diffuser located at said intermediate image surface; and an actuator mechanically coupled to said diffuser to, in operation, move said diffuser to randomise phases over pixels of said intermediate image to reduce speckle in an image displayed by the system.

Abstract: The invention comprises a pattern generation unit (20), a programmable lighting means and a holographic screen (28) that together make a holographic volumetric display. The holographic screen contains a pre-recorded set of volume elements or voxels (32) in three dimensional space outside the plane of the holographic screen. The holographic screen comprises a series of sub-holograms where each sub-hologram is associated with a voxel such that the voxel may be reconstructed when the sub-hologram is illuminated. A sub-hologram is a sampled hologram of a voxel and sub-holograms are spatially multiplexed and interleaved across the surface of the holographic screen. The programmable lighting means may be provided by a colour digital projected unit (28) and the pattern generation unit which can illuminate any number of sub-holograms on the holographic screen. In this way, a volumetric display with holographic voxels can be made.

Abstract: A method for producing true three dimension imagery includes positioning an object to be imaged and directing imaging laser beams to impinge upon the object. Splitting the imaging laser beams after the imaging laser beams have impinged upon the object is then accomplished, while redirecting the split imaging beams to a recording substrate.

Abstract: A method of adjusting a resonance frequency in an optical scanning device, containing: providing the optical scanning device, having: a substrate composed of a substrate main body and two cantilever beam portions; a drive source; a mirror portion; and a supporting component for fixing the substrate main body at a fixed end; and reducing an area of the substrate which protrudes from the fixed end to an outside of the supporting component, thereby to increase the resonance frequency; or alternatively, increasing the area of the substrate which protrudes from the fixed end to the outside of the supporting component, thereby to reduce the resonance frequency.

Abstract: A light controlling apparatus includes a substrate having an aperture, a light controlling section which includes at least one incident-light controlling means, having a magnet joined to a position of a center of rotation, and which rotates in a plane perpendicular to an optical axial direction, on the substrate, and at least one coil which imparts a rotational force to the magnet. The incident-light controlling means is displaced to a retracted position of being retracted from the position of the aperture, by supplying an electric power supply, and in the light controlling apparatus in which, incident light which passes through the aperture is controlled, the coil is disposed to be extended in a direction parallel to the optical axis.

Abstract: According to a first embodiment the invention provides for increasing the throughput and reducing the striping due to imperfections in the microlens and/or confocal aperture arrays of a Laser Confocal Scanning Microscope by increasing the number of repeat patterns in the microlens and confocal aperture arrays to more than one, and incorporating an intensity modulation function that ensures constant integrated image intensities at the image detector independent of the instantaneous speed of scanning. According to a second embodiment the invention provides for reducing the striping in a Laser Confocal Scanning Microscope by introducing a second galvanometer mirror such that the emitted laser light beam is descanned at the image (sample) plane.

Abstract: A polarization-separation device includes: a beam splitter that includes a beam-separating surface, on which a light beam that contains a first light beam and a second light beam impinges, wherein polarization direction of the first light beam and polarization direction of the second light beam are perpendicular to each other, and incident angle of the first light beam and incident angle of the second beam vary independently while incident into the beam-separating surface; a first polarizer arranged in an optical path of light beams having transmitted through the beam splitter, and allows the first light beam to transmit therethrough; and a second polarizer arranged in an optical path of light beams reflected from the beam splitter, and allows the second light beam to transmit therethrough.

Abstract: Disclosed is a polarization element which, by utilizing the fact that the plasmon resonance frequency of a metal piece varies according to the polarization direction of a light irradiated on the metal piece, is constituted by a polarizer comprising such an aggregate of metal pieces that the plasmon resonance frequency in a predetermined direction of a metal piece is substantially equal to the frequency of light irradiated on a polarization element, and the real part and the imaginary part of permittivity at the plasmon resonance frequency of a metal material constituting the metal piece and the refractive index (na) of a dielectric layer satisfy a particular relation.

Abstract: An electrochromic material including at least one compound represented by Chemical Formulas 1 to 3: wherein Z1 to Z3 are each independently selected from a substituted or unsubstituted C6 to C30 arylene group, a substituted or unsubstituted C2 to C30 heteroarylene group, a substituted or unsubstituted C3 to C30 cycloalkylene group or a combination thereof, R1 to R3 are each independently selected from a single bond, a substituted or unsubstituted C1 to C30 alkylene group, a substituted or unsubstituted C3 to C30 cycloalkylene group, a substituted or unsubstituted C6 to C30 arylene group, a substituted or unsubstituted C2 to C30 heteroarylene group or a combination thereof.

Abstract: Electro-optic elements are becoming commonplace in a number of vehicular and architectural applications. Various electro-optic element configurations provide variable transmittance and or variable reflectance for windows and mirrors. The present invention relates to various thin-film coatings, electro-optic elements and assemblies incorporating these elements.

Abstract: An optical clock for generating a series of optical clock pulses, comprises a laser source for generating output having a plurality of spectral components ?1, ?2, . . . ?N, an amplitude-modulator arranged to cooperate with the laser source to produce a series of intermediate optical pulses each having the plurality of spectral components, and optical fibre arranged to provide dispersion of each intermediate optical pulse to form a plurality of component pulses each corresponding to a spectral component and to compress each component pulse, the spectral width of each spectral component being sufficient to inhibit stimulated Brillouin scattering (SBS) of the component pulses within the optical fibre. The optical clock may be used for analogue-to-digital conversion of an electrical signal, in which application pulses of respective spectral components are demultiplexed and subsequently detected and digitised in parallel, providing for faster conversion.

Abstract: An electrophoretic display and a display medium are provided. The electrophoretic display has a plurality of micro-cells and a display medium filled therein. The display medium includes a plurality of particles and a continuous phase solution. Each of the particles has a deformable polymer shell and a filling liquid. The polymer shell has at least an airtight space and the filling liquid is filled in the airtight space. Additionally, the particles are distributed in the continuous phase solution, wherein a density of the particles is substantially equal to a density of the continuous phase solution.

Abstract: A radial power combination system is provided. The system comprises a radial divider comprising ports in the form of rectangular waveguides on the periphery, a radial combiner superposed on the radial divider, comprising ports in the form of rectangular waveguides on the periphery, a first, input transition transmitting a first signal to the center of the radial divider, a second, output transition capturing the first signal amplified to the output of the radial combiner, at least two amplifying channels comprising a third, input transition capable of interacting with the guides, a fourth, output transition capable of interacting with the guides and at least one amplifier, and means for adjusting the positioning of the amplifying channels, thus making it possible to adjust the phase shift of the various channels.

Abstract: A catadioptric projection optical system for forming a reduced image of a first surface (R) on a second surface (W) is a relatively compact projection optical system having excellent imaging performance as well corrected for various aberrations, such as chromatic aberration and curvature of field, and being capable of securing a large effective image-side numerical aperture while suitably suppressing reflection loss on optical surfaces. The projection optical system comprises at least two reflecting mirrors (CM1, CM2), and a boundary lens (Lb) whose surface on the first surface side has a positive refracting power, and an optical path between the boundary lens and the second surface is filled with a medium (Lm) having a refractive index larger than 1.1.

Abstract: A microscope system includes: an illumination unit; a light control direction unit specifying quantity of light output from the illumination unit; a storage unit storing voltage-related information in which a direction value specified by the light control direction unit and a voltage value to be applied to the illumination unit are associated with each other and are set, the direction value being in an entire range that can be specified by the light control direction unit under each observation condition, the voltage value corresponding to the direction value; a light quantity control unit controlling the quantity of the emitted light; and a control unit acquiring the voltage value corresponding to the specified direction value from the voltage-related information corresponding to the observation condition, and allowing the light quantity control unit to control the quantity of light based on the acquired voltage value.

Abstract: Provided is a magnified-projection optical system, which can retain a considerably long back focus although a focal length is short and which has a small chromatic aberration. The optical system comprises a projecting optical system, a relay optical system and a display element, which are sequentially arrayed from a screen side along the optical axis. The projecting optical system enlarges and projects the image, which has been linearly focused by the relay optical system, on the screen, and includes a negative group and a positive group arrayed sequentially from the screen side and having a negative optical power and a positive optical power, respectively. The optical system satisfies the following conditional relations of |Fb/F|>10 and 0.5<|F/Fp|<2.

Abstract: A screen includes: a substrate; and a first color material layer disposed on one surface of the substrate, wherein the first color material layer includes a first color material adapted to absorb light with a part of wavelengths of an incident light, and the first color material has a peak absorption wavelength in a visible light range, and a size of causing Mie scattering on the light in the visible light range.

Abstract: The present invention is directed to a rear-projection screen which encompasses 1) a flexible light-diffusive first film having a substantially smooth first surface and an opposing substantially smooth second surface, and comprising a wax-free amorphous thermoplastic matrix having a plurality of light-diffusing particles dispersed therein and which is lens-free; and 2) an opposing flexible light-absorption second film having a first surface and an opposing second surface, and comprising a thermoplastic matrix having a plurality of light-absorbing particles dispersed therein, wherein the first and second films are adapted to be 3) bonded together in direct contact with each other and then, affixed as a laminate to one or more transparent rigid substrates or 4) affixed individually to a transparent rigid substrate.

Abstract: A three-dimension display suitable for a viewer wearing a pair of eyeglasses is disclosed. The eyeglasses have two circular polarized eyeglass lenses with different polarizations. The three-dimension display includes a flat display panel, a quarter-wave plate and a patterned half-wave plate. The flat display panel has a plurality of pixels arranged in an array, wherein the flat display panel is suitable to display a linear polarized image. The quarter-wave plate is disposed between the flat display panel and the eyeglasses. The patterned half-wave plate is disposed between the flat display panel and the eyeglasses, wherein the patterned half-wave plate corresponds to a part of the pixels. The present invention also provides a fabrication method of a three-dimension display.

Abstract: A three-dimensional 3D image formation device includes a mounting box, an image source device, a plurality of transparent reflecting lenses and a top panel. Reflection principles are used for reflecting a plurality of image sources of the image source device onto the transparent reflecting lenses tilted at an angle of 45 degrees, such that a viewer can view a 3D image floating in the air from any angle, and the 3D image formation device gives a lively 3D perception of the image to enhance the value of the product.

Abstract: The present disclosure relates to a polarization converting device and a method for manufacturing the same, wherein the polarization converting device includes a polarization separation unit aligned with a plurality of unit blocks including an optical separator transmitting a first polarization between an upper surface and a lower surface and reflecting a second polarization, and a phase retarder aligned in correspondence to an upper surface of each unit block of the polarization separation unit where a first region and a second region are alternately formed, wherein any one of the first and second regions of the phase retarder converts the polarized light while the other region emits the polarized light as it is.

Abstract: An imaging apparatus includes a light receiving device array having light receiving devices two-dimensionally arranged in both a row direction and a column direction, and a light transmissive filter disposed in front of the light receiving device array, wherein the light transmissive filter includes plural types of band-shape light transmissive sections having respective, different light transmissive characteristics, and the plural types of band-shape light transmissive sections are arranged in sequence in a width direction thereof.

Abstract: An optical element having an anti-reflection function includes a base having a main surface, and a plurality of projecting or recessed structures arranged on the main surface of the base at a fine pitch equal to or less than the wavelength of visible light, wherein the main surface of the base, the main surface having the structures thereon, has hydrophilicity, and a contact angle of the main surface of the base, the main surface having the structures thereon, to pure water is 30° or less.

Abstract: A line generator according to the present invention includes a light source, a first lens group, and a second lens group. An optical axis is set to a position of a light beam which travels orthogonal to incidence surfaces of both the first and second lens groups and the first lens group is configured such that light beams from the light source are not collimated in a first direction in a plane orthogonal to the optical axis and are collimated or focused only in a second direction orthogonal to the first direction in the plane orthogonal to the optical axis and the second lens group is configured such that the light beams which have passed through the first group form a line.

Abstract: Disclosed herein is a zoom lens, including: an object side lens group disposed on the object side and including a first variable lens having a deformation surface, the object side lens group having a focal length varied by deformation of the first variable lens; an image side lens group disposed on the image side with respect to the object side lens group with an aperture stop sandwiched therebetween and including a second variable lens having a deformation surface, the image side lens group having a focal length varied by deformation of the second variable lens; and a lens group disposed between the object side lens group and the image side lens group and including the aperture stop. The deformation of the first and second variable lenses is controlled to carry out power variation and carry out image surface movement compensation and focusing by the power variation.

Abstract: A zoom lens includes, in order from an enlargement conjugate side to a reduction conjugate side, a first lens unit of negative refractive power; a second lens unit of positive refractive power; a third lens unit of positive refractive power, the third lens unit having at least three lens elements; a middle lens unit including at least one lens unit; and a last lens unit of positive refractive power. All the lens units, except the first lens unit and the last lens unit, move during zooming. The zoom lens satisfies appropriate conditions.

Abstract: A zoom lens includes sequentially from an object side, a positive first lens group; a negative second lens group; a diaphragm; a positive third lens group; a positive fourth lens group; and a positive fifth lens group, wherein a first condition 0.8?(SLM?(SLW+SLT)/2)/FW?2.0 and a second condition F14t?0 are satisfied. SLW is a distance from the diaphragm at a wide angle edge to an imaging plane; SLM is a distance from the diaphragm at an intermediate zoom position to the imaging plane; SLT is a distance from the diaphragm at a telephoto edge to the imaging plane; FW is optical system focal length for infinity at the wide angle edge; and F14t is a combined focal length for the first to the fourth lens groups at the telephoto edge.

Abstract: An optical system having a larger total lens length than a focal length includes lenses L and NL at least one of a magnification conjugate side and a reduction conjugate side with respect to an aperture stop. The lens L satisfies conditional expressions as follows, ?1.68×10?3·?L+0.590<?L<3.15×10?4·?L2?1.86×10?2·?L+0.878, and 5<?L<27, where ?L and ?L are an Abbe number and a gF-line partial dispersion ratio of the lens L. The refractive power of the lens L is positive when located at the magnification conjugate side, or negative when located at the reduction conjugate side.

Abstract: A zoom lens unit, including in order from an object side to an image side: a first lens group having a positive refracting power; a second lens group having a negative refracting power; a third lens group having a positive refracting power; and a fourth lens group having a positive refracting power, an aperture stop being disposed on an object side of the third lens group, wherein the third lens group has at least two positive lenses and one negative lens, wherein all the positive lenses of the third lens group satisfy the following formula: (1) ?0.005865?d3p+0.93226<?gF3p<?0.005865?d3p+0.95226, where, ?d3p represents an Abbe number of each of the positive lenses of the third lens group, and ?gF3p represents a partial dispersion ratio of each of the positive lenses of the third lens group, defined by the formula: ?gF3p=(ng?nF)/(nF?nC).

Abstract: A zoom lens includes a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, and a fourth lens group having a positive refractive power, which are disposed in order from an object side, and an aperture stop disposed at an object side of the third lens group. When changing the magnification from a wide angle end to a telephoto end, an interval between the first and second lens groups increases, an interval between the second and third lens groups decreases, and an interval between the third and fourth lens groups increases. The first lens group includes a negative lens, a positive lens, and a positive lens, in order from the object side. Predetermined conditions of a refractive index of the negative lens E1 for a d line, an Abbe number for d line, and a relative partial dispersion are satisfied.

Abstract: A zoom lens system, in order from an object side to an image side, comprising a first lens unit of positive power, a second lens unit of negative power, a third lens unit of positive power, and a fourth lens unit of positive power, wherein in zooming, the first to the fourth lens units are moved along the optical axis such that the air spaces between the individual lens units should vary, so that magnification change is achieved, and wherein the conditions: ?0.60<M2/fG2<?0.07, ?W?30, and fT/fW?4.5 (M2 is an amount of axial movement of the second lens unit in zooming, fG2 is a composite focal length of the second lens unit, ?W is a half view angle at a wide-angle limit, and fT and fW are focal lengths of the entire system at a telephoto limit and at a wide-angle limit, respectively) are satisfied, an imaging device and a camera are provided.

Abstract: A rotationally extendable structure of a lens barrel includes a stationary ring; a rotational ring, supported by the stationary ring to move in an optical axis direction while rotating and includes a peripheral gear at the rear end thereof; and a rotational-ring drive gear. The rotational-ring drive gear includes a long gear portion, formed long enough to mesh with the peripheral gear over an entire moving range of the rotational ring, and a large-diameter gear portion at the rear end of the long gear portion. The rotational ring is provided in a rear end thereof with a large-diameter-gear accommodating recess. When the rotational ring is moved to a rearward movement extremity in the optical axis direction, the large-diameter gear portion enters into the large-diameter-gear accommodating recess so that the large-diameter gear portion coincides with the peripheral gear with respect to the optical axis direction.