Abstract: Disclosed herein is an imaging device having a lens including a zoom lens and a focus lens; an image sensor for outputting an imaging result of an optical image formed by the lens; a signal processor for processing the imaging result to output a video signal; a detector for processing the video signal to output an evaluation value indicative of the degree of focusing; a memory for storing data of an imaging range where a focused image is ensured, by using a cam curve of the lens; and a controller for moving the focus lens in concert with the zoom lens; wherein when a focal depth detected according to a current position of the zoom lens is less than the imaging range at the current position of the zoom lens, the controller performs autofocus control using the evaluation value to move the focus lens; and when the focal depth is greater than the imaging range at the current position of the zoom lens, the controller performs focus control by the cam curve to move the focus lens.

Abstract: A digital camera module (100) with an auto-focusing function is adapted for use in a foldable electronic device. The digital camera module includes a lens mount (10), a lens barrel (20), a voice coil actuator (40), and an image pick-up module (50). The lens barrel receives at least one lens (24) therein and is mounted on/in the lens mount. The lens barrel is made of a composite material including a magnetic metallic nano-powder. The voice coil actuator is adapted for cooperating with the lens barrel to form a magnetic loop. The image pick-up module is disposed under the lens mount and is configured for receiving an image from the at least one lens and converting that image to an electrical signal.

Abstract: A variable-magnification optical system has, from the object side to the image side, at least a first lens group having a positive optical power, a second lens group having a negative optical power, and a third lens group having a positive optical power. The first lens group includes an optical prism that changes the optical path, and a prescribed conditional formula is fulfilled.

Abstract: A push-pull type camera module for a portable wireless terminal in which a hollow outer lens barrel is installed in the portable wireless terminal, a push-pull switch is installed in the outer barrel, an inner barrel is installed in the outer barrel, the inner barrel extending from or retracting to the outer barrel by the push-pull switch, a lens assembly is exposed at an outer surface of the inner barrel, the lens assembly taking a picture when the inner barrel is extended, a first switching module detects the extension and retraction of the inner barrel, and a second switching module detects rotation of the extended inner barrel.

Abstract: The present invention is directed to a lens barrel that is simplified in structure with the reduced number of components and is facilitated in assembly and associated adjustment. The lens barrel enables an appropriate frictional force against the rotation force caused by manipulating rotary operation rings such as a zooming ring and a focusing ring to effect the optimum operating force on the rotary operation rings.

Abstract: There is disclosed a zoom lens system comprising, in order from an object side: a first lens unit having a positive refractive power; a second lens unit having a negative refractive power; a third lens unit having a positive refractive power; and a fourth lens unit having a negative refractive power. During zooming from a wide-angle end to a telephoto end, a space between the first lens unit and the second lens unit enlarges, a space between the second lens unit and the third lens unit narrows, a space between the third lens unit and the fourth lens unit changes, and all of the first to fourth lens units move along an optical axis. The zoom lens system further comprises an aperture stop which moves integrally with the third lens unit during the zooming.

Abstract: An imaging apparatus including a first lens unit with positive power in which the most object-side surface is concave and the most image-side surface is convex, an aperture stop, a second lens unit with positive power in which the most object-side surface is convex and the most image-side surface is concave, and a third lens unit with positive power; and an image sensor. Air spacing between the second lens unit and the third lens unit assumes the shape of a biconvex air lens. The imaging apparatus satisfies the following condition: 1.4?|r 2R|/IH?15.0 where IH is the maximum photographic image height, which is a half of the diagonal length, in an effective imaging area, of the image sensor, and r 2R is the radius of curvature, measured along the optical axis, of the most image-side surface of the second lens unit.

Abstract: The invention relates to photographing process, where zooming is carried out. In a method an image is formed through imaging optics onto a light sensitive image sensor in an imaging device and wherein the device is capable of both optical and digital zooming. The method comprises steps of determining an amount of available illumination, determining, according to the amount of available illumination, a ratio between the optical zooming and the digital zooming, and performing, according to which ratio, the optical and the digital zooming. The invention also relates to a device, controller, a computer executable program and a medium.

Abstract: Embodiments of the present invention comprise systems and methods for compensating for motion of a viewer relative to a display device.

Abstract: In a photographing apparatus, while a deterioration of a contrast characteristic caused by an optical zooming operation is prevented, superior photographic images are continuously acquired. Magnification set by an optical zooming function is acquired, and a gamma curve, namely gradation correcting information is set to a gamma lookup table, while the gamma curve is applied during a photographing operation based upon the acquired set magnification. A gamma correcting unit corrects gradation of image data (namely, RAW data) outputted from an imaging element by employing gradation correcting information set in this gamma lookup table.

Abstract: A lens apparatus is disclosed, which is capable of keeping the engagement of a protruding portion of a first member and a cam groove portion of a second member even if an external force acts on the apparatus. The lens apparatus comprises: a first member including first and second protruding portions; and a second member including a first groove portion with which the first protruding portion engages, and a second groove portion into which the second protruding portion is inserted. The second protruding portion and the second groove portion are away from each other in a case where the first and second members are located in a specified positional relationship, and come into contact with each other in a case where the first and second members are located in another positional relationship.

Abstract: An object of the present invention is to provide a compact size variable power optical system capable of producing a high quality image. The variable power optical system comprises a plurality of lens groups for forming an optical image on an image surface of an image pickup device. Among the plurality of lens groups, the first lens group, which is disposed in the most subject side has a negative refraction power, includes at least a lens having a negative refraction power and a reflective optical element for bending the optical axis. When varying the variable power, the axial distance between the first lens group and the image surface varies. When Nd denotes the refraction power of the lens having negative refraction power at d-line, the refraction power satisfies the conditional formula Nd>1.81.

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 light shielding structure of a zoom lens barrel includes an outer ring, an intermediate ring and an inner ring which are concentrically arranged, the intermediate ring being movable relative to the outer ring and including at least one through-slot, the inner ring being movable relative to the intermediate ring, and the inner ring including at least one projection which is formed on an outer peripheral surface of the inner ring to be engaged in the through-slot. The light shielding structure is in the form of a light shielding sheet including a fixing portion which is fixed to the inner ring, and at least one resilient light-shielding tongue which projects radially outwards from the fixing portion to pass through the through-slot so that a radially outer end portion of the resilient light-shielding tongue comes in contact with an inner peripheral surface of the outer ring.

Abstract: A zoom lens with a reduced overall length having a color separating prism therein and a telecentric property with a first lens group (GI) having a positive refractive power and having a fixed position, a second lens group (GII) of the variable magnification type having a negative refractive power and having a position movable for magnification variation, a third lens group (GIII) having a positive refractive power and having a fixed position and a fourth lens group (GIV) having a positive refractive power and having a position variable for adjustment of a focal position upon magnification variation and upon focusing are disposed in order from an object side. At least one face of the two convex lenses in the fourth lens group is formed from an aspheric face.

Abstract: An improved lens mount and related lens and lens barrel positioning methods are provided. In one example, a lens mount for use with a miniature camera can include a ring member having a substantially cylindrical interior surface defining a substantially cylindrical interior space. A plurality of elongate ribs are disposed on the interior surface of the ring member and are adapted to exert pressure against an external surface of a lens barrel received by the ring member. In another example, a method of positioning a lens barrel includes inserting a lens barrel into a ring member having a substantially cylindrical interior surface. Pressure can be exerted against an external surface of the lens barrel from a plurality of elongate ribs disposed on the interior surface of the ring member. The pressure can prevent rotation of the lens barrel along at least three axes of rotational freedom.

Abstract: An assembly-stage focus adjustment mechanism of a zoom lens barrel including a plurality of lens groups which are moved while distances therebetween are changed to perform a zooming operation, the assembly-stage focus adjustment mechanism including two lens fixing frames to which two of the plurality of lens groups are fixed, respectively; two moving frames which linearly move in an optical axis direction during the zooming operation, the two moving frames being respectively screw-engaged with the two lens fixing frames; and a rotational-direction integrating device which makes the two lens fixing frames rotate as one integral body in a direction of rotation relative to the two moving frames when an assembly-stage focus adjustment operation is performed.

Abstract: A lens module (10) includes a lens barrel (11), at least one fixed focus lens (12) fixed in the lens barrel, and at least two variable focus lenses (13) fixed in the lens barrel. Each variable focus lens includes two electrodes (151) and an electro-optical material (153) between the electrodes. Each electrode is electrically connected to a voltage supply so as to be able to selectively apply a voltage to the electro-optical material and to thus selectively control the refractive index of that material. By changing the refractive index, a concordant change in the focus of a given variable focus lens is possible, without modifying the position and/or shape thereof.

Abstract: A zoom lens driving apparatus achieves the object of driving multiple lens groups by a single motor and low production cost. When a first lens group, which includes a first lens, moves along guide rods, a leading cam of a leading member drives a leading pin of a follower, so that the follower moves a guide pin, and moves a second lens group, which includes a second lens, along the guide rods. The relative distance between the first lens group and the second lens group is controlled by the leading cam.

Abstract: A zoom lens including front and rear elements, the front elements is set up so that the front elements are disposed at a position to satisfy the formula: T 1 ? Ha 1 + HH 1 + L + HH 2 + f 2 ? ( f 1 - L ) f 1 + f 2 - L + f 1 2 m - f 1 , where a length from the top of the front elements on the optical axis to the front main point of the front elements: Ha1, a main point of the front elements: HH1, a length from the rear main point of the front elements to the front main point of the rear elements: L, a main point of the rear elements: HH2, a focal length of the front elements: f1, a focal length of the rear elements: f2, a length from the object at the time of photography to the front main point of the front elements: m, and a length from the top of the front elements on the optical axis to the imaging plane: T1.

Abstract: A zoom lens with a reduced thickness and size in the depthwise direction consists of a plurality of lens groups (GR1 to GR5), so that it varies in power in response to variation in intervals between the lens groups. The zoom lens also has a prism G2 to bend the optical axis passing through the lens groups (GR1 to GR5). The last lens group G5 (counted from the object side) is composed of a negative lens group and a positive lens group, with an air layer interposed between them (arranged sequentially from the object side). The present invention also provides an imaging device equipped with an imaging element to convert the optical images formed by said zoom lens into electrical signals.

Abstract: Luminance components of image profile portions are extracted from luminance components (Y components) included in image data corresponding to an image within a focus frame. A profile component evaluation value is obtained by totalizing the absolute values of two-dimensionally-differentiated values of the extracted components. A distribution graph of a focus lens position and the profile component evaluation value is generated. A finder image is displayed by combining a photo-object image and the distribution graph. At this time, a bar corresponding to a current focus lens position is displayed in a different color from that of other bars in the distribution graph.

Abstract: The casing of the camera module is composed of two housings. The first housing has a base part provided with an opening for attaching a object side fixed lens and a first and second side walls extending from the base part, large cutout openings being formed between the side walls. Moving lens holders are inserted from the open side facing the base part of the first housing to be assembled to the first housing. A driving motor is bonded to a side wall of the second housing. After the first housing to which the lens moving mechanism, etc. are assembled and the second housing to which the driving motor is fixed, adjustment the lens moving mechanism, etc. can be done easily. The first and second housing are joined together with a single bolt and a single joining part joining by means of an adhesive agent.

Abstract: A device includes a housing capable of forming an internal space during operation of the device. The device also includes a camera having an optical zoom portion provided within the housing. The optical zoom portion is capable of expanding into the internal space when the camera is in use.

Abstract: A lens retraction mechanism slantways retracts a lens from a shooting position to a receiving space. The lens retraction mechanism includes a base body, which includes a substrate, a guide wall disposed on the substrate and the receiving space, a lens guiding frame moveable with respect to the base body in the direction of an optical axis of the lens group, a pair of guiding shafts having one end fixed to the guiding frame, and a lens holding frame that fixes a lens group and includes a pair of slippage portions moveable with respect to the guide wall. When the lens retracts, the guiding frame draws the guiding shaft to move towards the substrate in the direction of the optical axis, and the lens holding frame moves along the guide means and also along the guiding shaft, and finally falls into the receiving space. The lens retraction mechanism retracts the lens group stably and securely.

Abstract: A lens drive mechanism, enabled to move lens holding member in a stable state, is disclosed. The lens drive mechanism comprises: first and second guide members, each extending in a predetermined direction; a first lens holding member holding a first lens and including a first cam follower portion and a first sleeve portion which engages with the first guide member and is guided in the predetermined direction; a second lens holding member holding a second lens and including a second cam follower portion and a second sleeve portion, which engages with the second guide member and is guided in the predetermined direction; and a cam member engaging with the first and second cam follower portions and driving the first and second lens holding members.

Abstract: A zoom lens having five lens groups arranged in succession. The zoom lens is configured such that when zooming from a short focal length end toward a long focal length end, the second lens group lens moves toward the third lens group and the fourth lens group moves toward a side of the third lens group, and the fifth lens group corrects the zooming and a shift in a position of an imaging plane of the zoom lens caused by movement of the third lens group and the fourth lens group.

Abstract: An image formation optical unit is provided. In the image formation optical unit, a first shaft formed with a guide shaft and a drive shaft and a second shaft formed with a guide shaft and a drive shaft are disposed side by side so as to extend in parallel with a second optical axis direction. A free space is thus provided in the center and further two motors and are disposed in a free space at the rear of a prism, thereby making it possible to further reduce the dimensions in the height direction.

Abstract: The present invention provides an imaging lens which allows for an operation for adjusting a position of an adjusting lens to be carried out easily and which has an improved impact resistance. An imaging lens 100 comprises a lens frame 121 for supporting a lens 111 serving as an adjusting lens and a support frame 131 for supporting the lens frame 121. A contact section for support frame adjustment 134 operable to come into contact with the lens frame 121 is arranged in the support frame 131. A contact section for lens frame adjustment 124 operable to come into contact with the support frame 131 is arranged in the lens frame 121. The lens frame 121 is configured such that the fastening force generated between the lens frame 121 and the support frame 131 can be applied vertical with respect to the contact section for support frame adjustment 134 in a state of the contact section for lens frame adjustment 124 held in contact with the contact section for support frame adjustment 134.

Abstract: An optical assembly includes a barrel including a slot, a lens installed inside the barrel for magnifying an image, a magnification-adjusting mechanism installed outside and around the barrel including an adjusting loop installed outside the barrel in a rotatable manner including a groove on a side facing the barrel, and a roller installed between the adjusting loop and the barrel. The optical machine further includes a rod for adjusting the magnification of the lens. One end of the rod is installed inside the slot of the barrel in a slidable manner, and another end of the rod is installed inside the groove of the adjusting loop in a slidable manner.

Abstract: A lens moving mechanism which includes a moving lens for zooming or focusing; a lens holder holding the moving lens in a lens-barrel, and being supported freely movably into an optical axis direction of the moving lens; a guide shaft guiding the lens holder into the optical axis direction of the moving lens when the lens holder moves; a drive magnet attached to the lens holder; a drive coil fixed to the lens-barrel with at least part of the drive coil opposed to the drive magnet and giving an impelling force into the optical axis direction to the lens holder by being electrified; and a magnetic body fixed to the lens-barrel and located to oppose to the drive magnet on an opposite side of the drive magnet with at least a part of the drive coil put between the magnetic body and the drive magnet, and attracting the drive magnet.

Abstract: The lens unit includes an imaging lens including lenses, each of which includes a lens portion having an optical function and a flange portion on a periphery of the lens portion, and a ring-shaped lens holding member provided between the lenses and holds at least one of the lenses and a cylindrical-shaped lens-barrel including a lens holding portion that holds the imaging lens. The flange portion of each of the lenses is fittable to the flange portion of the other lens of the lenses, or the lens holding portion or an inner surface of the lens-barrel, and the lenses combined with each other through fitting to the flange portion of the other lens, the lens holding portion or the inner surface of the lens-barrel have respective shapes in which optical axes of the lenses coincide each other under a fitting state. The compact image pickup module includes the lens unit.

Abstract: An image-taking lens apparatus has an image sensor for converting an optical image of a subject into an electrical signal and an image-taking lens system for forming the optical image on the image sensor. The image-taking lens system includes a prism for bending the optical path, and the refractive index of the prism fulfills a prescribed conditional formula.

Abstract: A lens device in which a first movable lens holding frame and a second movable lens holding frame are moved along an optical axis by rotating a cam cylinder rotatably provided on a lens barrel, an escape channel for escapement of a portion of the second movable lens holding frame being formed in the first movable lens holding frame, the lens device comprising: a light shielding member moved along the optical axis by the rotation of the cam cylinder, the light shielding member being moved to a position at which the light shielding member closes the escape channel of the first movable lens holding frame.

Abstract: The casing of the camera module is composed of two housings. The first housing has a base part provided with an opening for attaching a object side fixed lens and a first and second side walls extending from the base part, large cutout openings being formed between the side walls. Moving lens holders are inserted from the open side facing the base part of the first housing to be assembled to the first housing. A driving motor is bonded to a side wall of the second housing. After the first housing to which the lens moving mechanism, etc. are assembled and the second housing to which the driving motor is fixed, adjustment the lens moving mechanism, etc. can be done easily. The first and second housing are joined together with a single bolt and a single joining part joining by means of an adhesive agent. The camera module can be constructed small in size and light in weight, and a user-friendly portable terminal equipped with the camera module having autofocusing and zooming function can be provided.

Abstract: An object is to provide an image pick up apparatus in which positioning of a lens barrel unit relative to a front cover with respect to the optical axis direction and directions perpendicular to the optical axis can be effected with high accuracy. In an image pick up apparatus including a lens barrel unit 201 having a photographing optical system, a structure 216 that holds the lens barrel unit 201 in such a way that the lens barrel unit 201 is movable in the direction of the optical axis of the photographing optical system and directions perpendicular to the optical axis and a front cover 205 that covers the front side of the image pick up apparatus, the position of the lens barrel unit 201 relative to the front cover with respect to directions perpendicular to the optical axis and with respect to the optical axis direction is determined by the front cover 205 when the front cover 205 is assembled.

Abstract: A guide bar used in a video lens barrel in the related art has problems of deterioration in supporting accuracy of the lens retaining frame, high manufacturing cost, and upsizing of the lens barrel. Also, in a cam pin type lens barrel, how the lens retaining frame is supported by the cam pins may not be clear. Therefore, by providing a plurality of guiding members on the inner surface of the fixed barrel of the lens barrel, and allowing a plurality of engaging portions on the lens retaining frames to engage the guiding members, the lens retaining frames are supported so as to be capable of moving in the direction of the optical axis. By differentiating the length of engagement of the respective engaging portions, the roles of the respective engaging portions on the lens retaining frames for supporting the lens unit in a space are clarified.

Abstract: An improved method and module for auto focusing utilizes a variable thickness focus element. A different thickness, and thus a different focus, is optically coupled to an image sensor by rotating the focus element. Movement along the optic axis is not required. This minimizes the amount of space required to provide the auto focusing function, allowing a mobile device utilizing the module to be smaller while still providing the auto focusing feature. In addition, the mechanism for rotating the focus element is smaller and/or less complex than a mechanism for moving a lens assembly along the optic axis, further allowing the device to be smaller. The focus element has less inertia than conventional lens assemblies and so required less power to move and allows for fast focusing.

Abstract: An image pickup apparatus includes a multifocal optical system in which first and second focal lengths on short and long focal length sides is optically selected; an image pickup device for converting an optical image into an image signal; an image processor which processes the image signal to form an original image; a trimming device for trimming the original image formed by the image processor; a drive controller for switching the optical focal length when the set angle-of-view of the trimming device changes between the second angle-of-view and a third angle-of-view which is smaller than the second angle-of-view; and a memory for storing an original image formed by the image processor at a focal length before the optical focal length is switched by the drive controller. The trimming device forms trimmed images of set angle-of-views while the optical focal length is switched.

Abstract: A lens barrel includes a distance adjustment ring for moving a movable lens group; a hand-operated ring and a motor for rotating the distance adjustment ring; a one-way rotational transfer mechanism which transfers torque of the hand-operated ring to the distance adjustment ring when the hand-operated ring is manually rotated, and prevents torque of the distance adjustment ring transferring to the hand-operated ring when the distance adjustment ring is rotated by the motor. A circumferentially-uneven-width-space forming portion formed on an annular overlapping portion of the hand-operated ring, is shaped so that a torque transfer member, installed in an accommodation space between the annular overlapping portion and-a torque transfer cylindrical surface on the distance adjustment ring, wedges between the circumferentially-uneven-width-space forming portion and the torque transfer cylindrical surface to transfer the torque of the manually rotated hand-operated ring to the distance adjustment ring.

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 barrel includes a rotatable ring, an outer annular member which is non-rotatable and supports the rotatable ring inside the outer annular member, and an optical element movable along the optical axis by a rotation of the rotatable ring; an advancing/retracting mechanism configured to move the rotatable ring along the optical axis between movement limits of the rotatable ring; a circumferential groove located on the inner peripheral surface of the outer annular member or the outer peripheral surface of the rotatable ring; and a rotation-guiding projection located on the inner peripheral surface of the outer annular member or the outer peripheral surface of the rotatable ring. The rotation-guiding projection is engaged in the circumferential groove such that the rotatable ring is rotatable without moving along the optical axis when the rotatable ring is moved to the front movement limit by the advancing/retracting mechanism.

Abstract: A cam mechanism includes a cam ring; and a linearly movable frame movable by the cam ring along an optical axis of an optical system, by engagement of a plurality of cam grooves located on the cam ring with a plurality of complementing cam followers located on the linearly movable frame when the cam ring is rotated, the linearly movable frame supporting at least one optical element of the optical system. The plurality of cam grooves are located at different positions in both the optical axis direction and a circumferential direction of the cam ring, and respectively trace substantially a same reference cam diagram. The plurality of complementing cam followers are located at different positions in both the optical axis direction and a circumferential direction of the linearly movable frame, and are engageable in the plurality of cam grooves, respectively.

Abstract: An optical element retracting mechanism includes a linearly movable ring; a swingable holder mounted supported inside the linearly movable ring; a position-controller holding the swingable holder; a support plate including first and second elongated holes; a support plate fixing device fixing the support plate to the linearly movable ring; first and second rotatable shafts extending substantially parallel to the optical axis having first and second eccentric pins engaged in the first and second elongated holes, wherein when the first or second rotatable shaft is rotated, a movement force is applied on the support plate in a direction generally orthogonal to the elongation direction of the elongated hole thereof; and a movement direction setting device which sets the movement direction of the support plate when the movement force is applied on the support plate by the rotation of the first or second rotatable shaft.

Abstract: A taking lens apparatus has a zoom lens system that is composed of a plurality of lens units and that achieves zooming by varying the distances between the lens units and an image sensor that converts the optical image formed by the zoom lens system into an electrical signal.

Abstract: A zoom lens barrel comprises an exterior unit, which mainly forms an exterior portion, an optical unit having an image pickup optical system built therein, and a control unit and can be detachably mounted on a single-lens reflex camera. The optical unit includes first and second group lenses as the image pickup optical system, which can move forward and rearward in zooming and focusing, and a third group lens which can move forward and rearward in zooming. Particularly, in focusing, a first group lens holding frame for holding the first group lens and a second group lens holding frame for holding the second group lens are driven forward and rearward in a different amount in an optical axis direction through a cam follower and two cam grooves by driving a focus ring in rotation, thereby focusing is executed. The lens barrel can cope with a forward/rearward movement required in zooming and focusing and can be reduced in size.

Abstract: An image capturing unit comprises a variable optical element, an optical unit, and a light-flux limiting section. The variable optical element includes a first liquid member, a second liquid member, and a container which contains the first liquid member and the second liquid member. An interfacial shape between the first liquid member and the second liquid member varies according to a voltage which is applied to the liquid members. The light-influx limiting section satisfies following condition 0.1<(??2×h)<20.0 where ? (mm) indicates a maximum diameter for an axial light-flux in the variable optical element and h (mm) indicates a highest position of the axial light-flux on the light-incident end of the variable optical element. By doing this, it is possible to restrict a flare light and a ghost light and prevent impurities in the liquid members from being observed in the captured image.

Abstract: A cam mechanism includes a cam ring, and a linearly movable frame movable supporting an optical element. The cam grooves are located at different positions in the optical axis direction and which trace a same reference cam diagram. All cam grooves are partial cam grooves each having at least one end opening at at least one of opposite ends of the cam ring, so as not to include an entire portion of the reference cam diagram. Cam followers are located at different positions at least in the optical axis direction and are respectively engageable in the cam grooves. At least one of the cam followers remains engaged in a corresponding cam groove while at least one of the other of the cam followers comes out of the end opening and is disengaged therefrom when the linearly movable frame moves to movement limit in the optical-axis direction.

Abstract: A lens barrel extending and retracting mechanism. A photographic optical axis and a central axis of a lens barrel are eccentric such that a first lens group and a second lens group are housed in a side of a CCD separated from the optical axis. The lens barrel is rotatably extended around the central axis thereof, and a picture is taken when lens optical axes of the first lens group and the second lens group coincide with the optical axis. The lens barrel extending and retracting mechanism prevents displacement and tilt of the lens optical axes of the first lens group and the second lens group, maintaining optical performance and reducing the size of the lens barrel in the housed position.

Abstract: A lens barrel includes a rotatable ring, a non-rotatable outer annular member having a circumferential groove located on the inner peripheral surface thereof, an advancing/retracting mechanism configured to move the rotatable ring along the optical axis between movement limits of the rotatable ring, a rotational projection located on the outer peripheral surface of the rotatable ring such that the projection is engaged in the circumferential groove when the rotatable ring is moved to one of the movement limits, and a stopper which is insertable into and removable from the circumferential groove at an intermediate point between opposite ends of the groove.