Abstract: A digital camera apparatus has a sensing surface that captures images at a first resolution. A derivative of the captured image is displayed at a viewfinder or stored in a memory, after encoding, with a second, generally lower resolution. The resolutions are related by a downscale ratio. A method for digitally imaging a scene includes providing an imaging lens and a digital image sensing surface such as a CCD sensing surface, and changing a focusing of the lens with respect to the sensing surface in correspondence with a variance of a parameter that relates a captured image at the sensing surface and another image deriving from the captured image. Preferably, the variance of the parameter is the downscale ratio. The focusing of the lens with respect to the sensing surface may be changed by changing the physical distance or by changing a shape of the lens, for example. Apparatus and computer program products are also detailed.

Abstract: Methods to improve autofocus in digital imaging systems, such as digital cameras, are disclosed. Embodiments may include, in response to locking of lens focus on a subject image, determining an initial subject focus distance and an initial attitude, and in response to a request for an exposure, determining a final attitude. Embodiments may also include determining a final target subject distance based on the initial subject focus distance and a focus correction distance, where the focus correction distance is based on the difference between the initial attitude and the final attitude. Embodiments may also include focusing the lens at the final target subject distance. Further embodiments may include after focusing the lens at the final target subject distance, exposing an image. Other embodiments may include determining the initial and final attitude with a micro-electro-mechanical (MEMS)-based sensor or other sensor.

Abstract: A camera (210) for providing an adjusted image (214) of a scene (12) includes an apparatus frame (224), an optical assembly (222), a capturing system (226), and a control system (232). The optical assembly (222) is adjustable to alternatively be focused on a first focal area (356A) and a second focal area (356B) that is different than the first focal area (356A). The capturing system (226) captures a first captured image (360A) when the optical assembly (222) is focused at the first focal area (356A) and captures a second captured image (360B) when the optical assembly (222) is focused at the second focal area (356B). The control system (232) provides the adjusted image (214) of the scene (12) based upon the first captured image (360A) and the second captured image (360B). Additionally, the control system (232) can perform object depth extraction of one or more objects (16) (18) (20) in the scene (12).

Abstract: A focus-controlling apparatus adjusts a focus in an optical system. The apparatus includes a focus detecting unit, a storage unit, a focus area switching unit, and a drive control unit. The focus detecting unit detects de-focusing amounts of the optical system with respect to a plurality of objects that lie in a plurality of focus areas, respectively. The storage unit stores the de-focusing amounts detected for the respective focus areas. The focus area switching unit switches the focus areas, from one to another, in an order based on the de-focusing amounts stored in the storage unit. The drive control unit moves the optical system to a focus position corresponding to the de-focusing amount at any focus area switched by the focus area switching unit.

Abstract: An optical system is provided for allowing regional focus control. The system uses a variable power optical component system as two optical shear plates that can be laterally displaced with respect to each other to adjust and alter the field curvature of the optical system. This changing of the field curvature creates an area of focus whose particular size and shape within the field of view is controlled through manipulation of the shear plates with respect to each other and the field of view. The area of focus can be repositioned to any point within the field of view so that the area of focus can affect the image light coinciding with that particular region. The shear plates are preferably positioned at the intermediate focal plane of the optical system, between the camera body and the taking lens. The image which has been altered, by the shear plates is then transposed to the camera body by a relay lens and recorded by film at the primary film plane located within the camera body.

Abstract: A lens-controlling device controls a first lens unit which moves for zooming and a second lens unit which moves for correcting the displacement of an image plane caused by zooming and for focusing. The lens-controlling device includes a memory which stores data for obtaining target-position information representing a target position to which the second lens unit is to be moved, the target position corresponding to a position to which the first lens unit is moved from a current position and a controller which generates the target-position information on the basis of the data and controls the movement of the second lens unit on the basis of position information of the first lens unit and the target-position information.

Abstract: A camera described herein captures a plurality of images at different focus settings to improve the probability that the camera captures a clear representation of a desired object in a potentially ambiguous scene. According to one exemplary embodiment, the camera selects a plurality of focus settings corresponding to different focal points in a range of focal points. Subsequently, the camera automatically captures successive images of the scene at the selected focus settings in response to a single activation of a shutter control. The user may select one or more of the captured images for storage, transmission to a remote device, and/or further processing.

Abstract: An optical image capture structure is provided, which includes a substrate, a frame, a photosensitive element, a first axial actuator, a second axial actuator, and a third axial actuator. The frame moves relative to the substrate, and the photosensitive element is mounted in the frame for capturing an optical image. The first axial actuator is connected between the frame and the photosensitive element, the second axial actuator is connected between the frame and the photosensitive element, and the third axial actuator is connected between the frame and the substrate. The first axial actuator, the second axial actuator, and the third axial actuator are used for moving the photosensitive element in a first axial direction, a second axial direction, and a third axial direction, thereby making the photosensitive element to move as an optical axis changes, thereby clearly imaging the optical image on the photosensitive element.

Abstract: This stereo camera system is constituted of a stereo optical module which acquires a stereo image, a central control unit which evaluates an object as a target based on the stereo image acquired by the stereo optical module, and a communication line through which stereo image data output from the stereo optical module is input to the central control unit. Further, in this stereo camera system, an image output processing circuit which performs predetermined image processing with respect to the stereo image acquired by the stereo optical module is provided in the stereo optical module, whereby this image output processing circuit performs a correction arithmetic operation which corrects unbalance at the time of capturing the stereo image.

Abstract: A method for automatically estimating the spatial positions between cameras in a camera network utilizes unique identifying signals, such as RFID signals, transmitting between nearby cameras to estimate the relative distances or positions between cameras from received signal strength (RSS), time of arrival (TOA), or time difference of arrival (TDOA) measurements to thereby determine the neighboring relationship among the cameras. A discover-locate process can be used to discover, from the estimated relative distances, unknown cameras in the vicinity of at least three cameras at known locations. Absolute locations of the discovered unknown cameras can then be calculated using a geometric calculation. The discover-locate process can be cascaded throughout the network to discover and locate all unknown cameras automatically using previously discovered and located cameras.

Abstract: There is disclosed a lens barrel including a fixed frame, a rotary frame rotatable with respect to the fixed frame to advance or retract in an optical axis direction, and a rectilinear guide frame rotatable relative to the rotary frame to displace integrally with the rotary frame in the optical axis direction. In this structure, a front end portion of the rectilinear guide frame on a subject side in the optical axis direction is exposed from the rotary frame.

Abstract: A method for calculating distance and actual size of a shot object is provided, which is applicable to an image capture device, and includes the following steps. First, a table of the corresponding relationship of the focus pulse and an object distance (distance between the image capture device and the shot object) is established. After being focused, the actual object distance is obtained by looking up the table. Under the circumstance of the known object distance and image distance, the image height of the shot object is obtained by calculating the corresponding pixel size of the image capture device, and thus the object height (actual size of the shot object) is easily calculated with the equation of “object distance/object height=image distance/image height”.

Abstract: A lens module includes a frame, a guide bar, a lever, a first lens and a second lens. The frame is for carrying an image sensor with a photosensitive surface. The guide bar is disposed on one side of the frame and parallel to a normal of the photosensitive surface. The lever includes a pivot part coupled with the frame and an extended part capable of rotating around the pivot part. The first lens and the second lens coupled with the guide bar are leaned against the extended part. When the extended part rotates around the pivot part, the extended part drives the first lens and the second lens to slide along the guide bar, for changing a first distance between the first lens and the photosensitive surface and changing a second distance between the second lens and the photosensitive surface.

Abstract: The pseudo depth information of a subject is generated from multiple images of the subject captured with and without illumination or under various illumination intensities. A pseudo 3D image generating apparatus generates a pseudo 3D image. It includes an image storing unit that stores the images, and a depth computing unit that computes pseudo depth values of the subject based on operations between the pixel values of corresponding pixels in the images. A compact and handy 3D image generating apparatus is provided.

Abstract: An image sensing apparatus has a light flux splitter disposed between a lens that focuses light flux of an object image on an image sensing surface and that image sensing surface and that branches the light flux of the object image out of an image sensing light path, a light receiving unit that receives the light flux of the object image branched by the light flux splitter and obtains a signal for focusing control of the lens, and a holding unit that holds the light flux splitter at either an effective position within the image sensing light path or at a retracted position outside the image sensing light path. The image sensing apparatus automatically holds the light flux splitter at either the effective position or the retracted position depending on image sensing conditions.

Abstract: An apparatus for a camera with a lens barrel and a barrel driving unit. The apparatus includes an eye-shaped lens barrel, a vertical driving unit, a horizontal driving unit, a rotation-position sensing unit, a coordinate input unit, and a controller. The vertical driving unit rotates the eye-shaped lens barrel about a vertical axis in response to a vertical rotation control signal. The horizontal driving unit rotates the eye-shaped lens barrel about a horizontal axis in response to a horizontal rotation control signal. The rotation-position sensing unit generates a rotation-position data in response to the rotation of the eye-shaped lens barrel. The coordinate input unit generates an input coordinate data according to a manipulating action of a user. The controller generates the vertical rotation control signal and the horizontal rotation control signal according to the input coordinate data and the rotation-position data.

Abstract: In order to perform personal identification by matching a first body image that is obtained in advance by an image taking process with a second body image that is obtained when the identification is performed, an image taking device (1) for obtaining the second body image includes a shooting condition storage portion (203) for storing a shooting condition for each person in connection with an ID given to the person, the shooting condition being used when a body image of the person is taken for obtaining the first body image, an interface (24) for entering the ID of a person to be an object of the identification, and a shooting control portion (201) for controlling to take the body image under the shooting condition corresponding to the entered ID for obtaining the second body image of the person to be an object of the identification.

Abstract: A connection structure for a camera module with an auto-focus feature and a module connector that eliminates the need for wires and FPCs for connection between motor signal terminals and a printed circuit substrate, as will as the need for solder connection operations is also eliminated. A cameras module with an auto-focus feature is equipped with a module base on which is disposed a camera signal contact terminal, and a main module unit on which is disposed a motor signal terminal extending from a side surface. A module connector includes an installation cavity for installing the camera module. A motor signal contact is disposed on the module connector, and the motor signal terminals are formed with a contact, which comes into contact with contacts of the motor signal contact when the camera module is installed in the installation cavity.

Abstract: According to an aspect of the invention, there is provided an information processing apparatus including: a display unit configured to display a plurality of informations having a plurality of hierarchies; a focus control unit configured to focus at least one of the plurality of informations to be displayed by the display unit; a recognition unit configured to recognize whether or not a focus movement speed in at least one of the plurality of informations controlled by the focus control unit is smaller than a prescribed reference value; and a first control unit configured to control the display unit to display at least one of the plurality of informations according to the recognition result by the recognition unit.

Abstract: A lens barren assembly for a camera is disclosed. The lens barrel assembly comprises a lens barrel, at least one optical element disposed within the lens barrel, and an actuator configured to move the optical element. The actuator can be disposed entirely or partially within the lens barrel. The actuator can be a MEMS actuator, such as a MEMS actuator that is formed at least partially of silicon. The optical element can be a lens.

Abstract: Disclosed herein is a liquid-lens assembly using an electrowetting method. The liquid-lens assembly includes a liquid-lens module, a barrel supporting the liquid-lens module, and a housing coupled to the barrel and having an image sensor. Electrodes are provided on the barrel and the housing, so that current is applied to the liquid-lens module through the electrodes.

Abstract: Described are an electronic device, a camera, and a method for determining an orientation of a camera in an electronic device. The method includes measuring a position of the lens at rest within the lens cavity (680), determining a pointing direction of the camera based on the position of the lens (684), and moving the lens to a new or adjusted starting position for an auto-focus function based on the pointing direction (688). The lens is biased to a predetermined position within the lens cavity when the camera is oriented in a predetermined pointing direction. A lens position sensor can measure a position of the lens to record a measured position. By evaluating the measured lens position, the camera orientation can be determined. The auto-focus of the camera can be started at a starting position based on the camera orientation.

Abstract: Imaging systems and methods for calibrating imaging systems are provided. The imaging system has a body, a scene image capture system that captures images using a taking lens system that can be set to a plurality of different focus distances, and a rangefinder that is capable of determining a distance between the imaging system and at least one portion of a field of view of the taking lens system. The method comprises: automatically capturing a first calibration image of a first field of view through the taking lens system with the taking lens system set to a first focus distance setting; identifying a portion of the first calibration image having a predetermined degree of focus; using the rangefinder to determine a first calibration distance from the imaging device to the identified portion. A focus correlation is determined based upon the first calibration distance and the first focus distance setting.

Abstract: A focusing device includes a first focus-position determining unit configured to determine a focus position based on a change in a radio-frequency component in an image signal obtained with movement of a focusing lens, a second focus-position determining unit configured to determine a focus position by using a different process from a process performed by the first focus-position determining unit, a mode setting unit configured to select at least a first mode which uses a result with the first focusing-position determining unit together with the second focusing-position determining unit or a second mode which uses a result with the first focus-position determining unit without the second focus-position determining unit, and a control unit configured to control driving of the focusing lens according to selection by the mode setting unit such that the focusing lens is driven in the first mode at a higher speed than in the second mode.

Abstract: A photographing apparatus includes a drive portion driving a focus lens included in a photographing optical system in a focus adjustment direction when a shutter button is pressed, a photographing portion continuously and sequentially outputting images of an object formed on an image forming surface through the photographing optical system as the shutter button is pressed once, as image data corresponding to the number of all pixels, an in-focus position detection portion detecting an in-focus position of the focus lens based on the image data sequentially output from the photographing portion, an in-focus control portion maintaining the focus lens at the in-focus position by controlling the drive portion based on a result of the detection by the in-focus position detecting portion, and a recording portion sequentially recording the image data output from the photographing portion during which the focus lens is maintained at the in-focus position after the shutter button is pressed.

Abstract: A method of and an apparatus for determining a depth map utilizing a movable lens and an image sensor are described herein. The depth information is acquired by moving the lens a short distance and acquiring multiple images with different blur quantities. An improved method of simulating gaussian blur and an approximation equation that relates a known gaussian blur quantity to a known pillbox quantity are used in conjunction with a non-linear blur difference equation. The blur quantity difference is able to be calculated and then used to determine the depth map. Many applications are possible using the method and system described herein, such as autofocusing, surveillance, robot/computer vision, autonomous vehicle navigation, multi-dimensional imaging and data compression.

Abstract: An image-capturing device including a shutter button for capturing an image and a focus button for focusing an image is provided. The focus button is disposed in a range where a user may press the shutter button. Before pressing the shutter button to capture an image, the user triggers the focus button firstly to focus the image.

Abstract: A camera capable of displaying a live view is disclosed, which has a movable reflecting mirror movable between a viewing position for reflecting a light beam from a photographing lens to guide the light beam to a finder optical system, and a position retracted from an area through which the light beam from the photographing lens passes, and which is configured such that, upon focusing the photographing lens from the state of the live view display, the movable reflecting mirror is driven without charging a shutter.

Abstract: A method of evaluating effective sampling steps of auto focus is provided. By utilizing the depth-of-field feature, many sampling steps are ignored and some representative steps in the depth-of-field range are used as the effective sampling steps. Since the sampling steps are minimized, the search time is largely reduced without deteriorating the search effectiveness.

Abstract: A camera having a depth of field which can be modified to produce desired photographic effects. The camera determines the depth of field for a subject when the subject is focused upon. A modification to the depth of field is determined based upon the distance to the subject, and the depth of field is modified to produce the desired photographic effect. In one embodiment, the depth of field is reduced, while, in another embodiment, the depth of field is shifted to place the subject slightly out of focus and to alter the focus of the background.

Abstract: A focus adjustment device includes an image sensor that includes imaging pixels for capturing an image formed via an imaging optical system and focus detection pixels for detecting a focus adjustment state at the imaging optical system, a focus detector that detects a focus adjustment state at the imaging optical system, and a focus adjustment controller that executes focus adjustment for the imaging optical system based upon the focus adjustment states detected with the image sensor and the focus detector.

Abstract: A method of blurring an image includes acquiring two images of nominally a same scene taken at a different light exposure levels. At least one region of one of the images includes pixels having saturated intensity values. For at least one of the saturated pixels, values are extrapolated from the other image. At least a portion of a third image is blurred and re-scaled including pixels having the extrapolated values.

Abstract: An image capturing apparatus includes: a focal position adjusting device operable to adjust a focal position of an optical system to a predetermined position in a first image capture period and change the focal position of the optical system in a second image capture period; a display operable to display an image captured in the first image capture period; a distribution generator operable to generate a distribution of sharpness corresponding to focal positions based on an image captured in the second image capture period; and a focused position detector operable to detect the focal position of the optical system, at which an image of a subject is in focus, based on the generated distribution of sharpness.

Abstract: A fixed-focus camera module includes an image sensor, a lens for focusing an image onto the image sensor, and a positioning structure for maintaining an alignment of the lens and image sensor. The alignment provides a desired image quality of the image focussed onto the image sensor. The positioning structure includes a first unthreaded member coupled to the lens and a second unthreaded member coupled to the image sensor. One of the first and the second members is configured to be inserted into the other of the members to provide an adjustable relative position of the lens and the image sensor.

Abstract: An image processing apparatus displays a realistic image depending on a user's viewpoint. A sensor control unit 41 detects a user's viewpoint and a point of interest based on signals from various sensors, and outputs the detected viewpoint and point to a depth-of-field adjusting unit. The depth-of-field adjusting unit reads, from the image database, a depth of field set beforehand (or designated each time) and image data of images captured from different positions according to user's viewpoints, and outputs the read depth of field and data to an image combining unit. The image combining unit combines a plurality of image data items output from the depth-of-field adjusting unit and displays a combined image on a display. The present invention is applicable to a television apparatus.

Abstract: An automatic focusing system comprises at least one micromirror array lens, an image sensor, and a signal processor. The micromirror array lens images an object and focuses the image on the image sensor. The image sensor receives the light and converts the photo energy of the light to electrical energy in the form of an electrical signal. The image sensor sends the electrical signal, which carries image data concerning the object, to the signal processor. The signal processor receives the electrical signal, compares the image quality of the image data to its focus criteria, and generates a control signal, which it sends to the micromirror array lens to adjust the focal length of the micromirror array lens. This iterative process is continued until the quality of the image data meets the focus criteria, and the process is completed within the afterimage speed of the human eye.

Abstract: The present invention provides an AF evaluation value calculating device in which speed of AF control does not deteriorate even when a number of AF areas are set. The AF evaluation value calculating device for calculating an AF evaluation value used for AF (auto-focus) control of a digital camera, includes: at least one AF evaluation value calculating unit 13 for calculating an AF evaluation value in each of a plurality of AF areas which are set in an image area of image data supplied; and a data transmitter (17a and ch0) for transmitting the AF evaluation value calculated by the AF evaluation value calculator 13 into a predetermined memory by DMA (Direct Memory Access).

Abstract: A camera includes: an image-capturing element that captures a subject image through a photographic lens having a focusing lens; an evaluation value calculation unit that calculates focus evaluation values at a plurality of lens positions assumed by the focusing lens based upon an image-capturing signal output by the image-capturing element; a weighting unit that weights the focus evaluation values calculated by the evaluation value calculation unit in correspondence to the lens positions of the focusing lens assumed when the focus evaluation values are calculated respectively; and a focusing operation unit that performs a focusing operation for the photographic lens based upon the weighted focus evaluation values.

Abstract: A worm gear is provided on a rotating shaft of an AF motor. A first supporting cylinder includes a gear portion and a receiving portion. A wheel gear, which is in engagement with the worm gear, is formed on an outer surface of the gear portion. A slit is formed at the receiving portion. A second supporting cylinder includes a supported portion which is placed in the receiving portion of the first supporting cylinder, and a receiving portion which supports an AF coupler. A gear is in engagement with a portion which connects the supported portion and the receiving portion of the 2nd supporting cylinder. A clutch spring is wound around the supported portion, being in contact with the outer surface of the supported portion. Both ends of the clutch spring cross each other and are in engagement with a pair of walls, of the slit, which are parallel to an axis of the receiving portion.

Abstract: A lens system has an optical path through a lens that is in contact with a liquid. The focal length of the lens system can be changed through introduction of a bubble in the optical path at the lens-liquid interface. The bubble changes the refractive index difference at the lens surface and thereby changes the focal length of the lens system. In a camera, the lens system can operate in a macro mode corresponding to a shorter focal length or a normal mode corresponding to a longer focal length.

Abstract: A lens assembly in a camera includes a first meniscus lens (10) and a second meniscus lens (11) respectively having a first radius of curvature (A,A?) and a second radius of curvature (B,B?) larger than that of the first radius of curvature A,A?), a concave lens (12) having a first radius of curvature (C) and a second radius of curvature (C?) smaller than the first radius of curvature (C), and a convex lens (13) having two opposite sides with a radius of curvature so that after a distance between the lens to the object is determined, a clear image is presented.

Abstract: Flash emission is required when image data have a low luminance value and when it is determined that flash emission is not prohibited, the built-in flash is used for autofocus (AF). An AF evaluation value is obtained under the flash emission, and the lens is driven based on this value. This operation is repeated until it is determined that the lens is focused, and accurate AF is executed even in dark conditions.

Abstract: An image signal output device for use in a passive range finder. The device can correct the sensitivities of sensor arrays according to the amount of incident light. The output device has line sensor portions that produce pixel outputs. An A/D converter portion A/D converts these pixel outputs. At this time, the A/D conversion range of the A/D converter portion is modified according to the difference in sensitivity between the line sensor portions.

Abstract: A color scannerless range imaging system comprises four component systems, including an illumination system, an image capture device, an optical assembly and a controller for interconnecting and controlling the component systems. The illumination system separately illuminates a scene with modulated and unmodulated illumination, while the image capture device is positioned in an optical path of the reflected illumination from the scene for capturing a plurality of images thereof, including (a) at least one image of the reflected modulated illumination, whereby the modulation of the reflected modulated illumination incorporates a phase delay corresponding to the distance of objects in the scene from the range imaging system, and (b) at least one color image of the reflected unmodulated illumination.

Abstract: A camera of the present invention comprises a sensor unit for measuring a distance to a subject. Moreover, the sensor unit includes a photoelectric conversion element, a housing with which the photoelectric conversion element is covered and in which a first through hole is formed in a predetermined position, and an electric substrate which is electrically connected to the photoelectric conversion element and in which a second through hole is formed in the predetermined position. Furthermore, the second through hole formed in the electric substrate is disposed opposite to the first through hole formed in the housing in a state in which the electric substrate is electrically connected to the photoelectric conversion element.

Abstract: An electronic camera includes a camera main body and a lens barrel arranged on the front face of the camera main body to extend forward therefrom, and to hold an image-pickup lens therein. A U-shaped protruding cover is attached to the lens barrel to extend downward therefrom. The bottoms of the camera main body and the protruding cover are level with each other. First and second windows are arranged on the front face of the protruding cover. A lamp for emitting an auto-focus assist light is arranged in the protruding cover to face the first window. A sensor for receiving a light signal from a remote control is arranged in the protruding cover to face the second window.

Abstract: A sterile, disposable camera system which is always sterilized for use and avoids the need to sterilize the camera or camera mounting system for re-usage includes a sterile camera unit which is easily, removably mounted on a sterile mounting apparatus which is constructed to be collapsible. The camera mounting system is disposable such that after the camera system has been used, the sterile camera unit is easily removed from the sterile mounting apparatus and the mounting apparatus can be discarded as waste. The mounting apparatus is arranged to support the sterile camera unit relative to a subject to be photographed such that the camera quickly obtains in-focus close-up photographs of subjects of interest. The system includes a mini-crowbar like tool for safe removal of the film cartridge after camera use.

Abstract: The present invention relates to an image pick-up apparatus having a focus detection mechanism capable of improving an AF speed at low costs and in a space-saving way without adding any new mechanism or optical system and ensuring an accurate focus adjustment and capable of preventing a picture-taking image quality being deteriorated. An image pick-up device of the image pick-up apparatus of the present invention has a focus detection area and image pick-up area and, since no image data is obtained at the focus detection area, interpolation processing is done with image data of a peripheral image pick-up area. In the case where a color filter is provided in the image pick-up area, interpolation processing is done with image data of an image pick-up area and image data of a peripheral area.

Abstract: A subject selection device comprises a light source and an imaging device, such as a CCD, having a plurality of photo-diodes. The light source radiates a distance measuring light beam toward a plurality of objects. A reflected light beam, generated by the objects due to the distance measuring light beam, is received by the, photo-diodes. A signal charge is integrated in each of the photo-diodes, so that three-dimensional information, which includes distances from the camera to each point on a surface of the objects, is obtained. A histogram indicating a distribution of the distances is generated. Based on a peak value of the histogram, a subject to be photographed is selected from the objects. An in-focus portion indicating device indicates a portion of the subject, which is in focus, based on the peak value.

Abstract: A switching mechanism of a lens barrel includes a stationary barrel having a stop groove; a lens holding ring, a distance adjustment ring and an AF/MF switching ring, each positioned concentrically with the stationary barrel. The AF/MF switching ring is prevented from rotating relative to the stationary barrel by engagement of the engaging member with the stop groove while a driving force is transferred from a power source to the distance adjustment ring to move the lens holding ring along the optical axis when the AF/MF switching ring is in the AF position. Rotation of the AF/MF switching ring is transferred to the distance adjustment ring to move the lens holding ring along the optical axis while the driving force is prevented from being transferred from the power source to the distance adjustment ring when the AF/MF switching ring is in the MF position.