JP2009015346A - Lens barrel, collapsible mount type lens barrel, and zoom lens barrel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To contrive arrangement of a shutter unit equipped with a notched surface parallel with an optical axis to an imaging device, so that strength of the guide holding part of a lens barrel substrate is secured while keeping extending amount of a rear lens group long by effectively using limited bow-shaped space between the notched surface and a cam mechanism, and to arrange a shutter flexible substrate so as to curve and get into the bow-shaped space, so that the length is secured and rolling-in is prevented, and to cover the bow-shaped space with a front lens frame, so that stray light is intercepted. <P>SOLUTION: The shutter 5 has constitution where the notched surface 5a parallel with the optical axis is formed on the outer periphery of a nearly disk-shaped body, and is fixed to the front lens frame 2A so that the notched surface can be nearly parallel with a diagonal of a rectangular imaging device 6, and constituted so that a lead screw 7a and a guide holding part 1a get into space surrounded by the inner wall of a cam mechanism C and the notched surface of the shutter when the front lens frame moves backward. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a technology for downsizing a lens barrel in a camera such as a silver salt camera or a digital camera, and in particular, by devising the arrangement of various components such as a shutter unit, a shutter flexible printed circuit board, and a motor constituting the lens barrel. The present invention relates to a lens barrel, a collapsible lens barrel, and a zoom lens barrel that are miniaturized.

In recent years, along with miniaturization of various cameras, particularly digital cameras, lens barrels have been rapidly miniaturized. As a mechanism for projecting a small lens barrel attached to the camera body, a collapsible lens barrel mechanism that uses a rotating cam that retracts during non-shooting while zooming in the direction of the subject during shooting is common. . This collapsible lens barrel mechanism includes a cam barrel having a cam (groove or the like) extending in the circumferential direction for moving a plurality of lens groups arranged in the optical axis direction in the optical axis direction, and an engagement with the cam of the cam barrel. Cam followers (pins, etc.) provided in each lens frame, and rectilinear cylinders having rectilinear grooves that move the lens group straightly in the optical axis direction by engaging with the cam followers. A cam mechanism that moves each lens group with high accuracy through cooperation is provided. Furthermore, as a means for moving the other lens group, a lead screw driven by a drive source independent of the cam mechanism is provided.
The lens group mainly includes one or a plurality of zoom lens groups (front lens group) that performs zooming and a focus lens group (rear lens group) that performs focusing. The zoom lens group is driven by a cam mechanism, and the focus lens group is driven by a lead screw that is rotationally driven by a drive source independent of the cam mechanism.
When not in use, the lens unit is made compact by retracting the distance between the lens groups to the minimum.
By the way, the focus lens group driven by the lead screw has a nut that engages with the lead screw in the lens frame portion thereof, goes straight by the rotation of the lead screw, and further guides the focus lens group in the optical axis direction. Can stably move forward and backward in the optical axis direction.
Further, the focus lens group requires as much movement as possible in order to photograph a subject at a short distance. In order to increase the amount of movement of the focus lens group, a long lead screw and guide shaft are required. To ensure the distance between the lead group and the guide shaft is sufficient, the distance between the lens groups is minimized. In addition, a configuration is known in which a space for allowing the lead screw and the guide shaft to enter is secured to the side of the zoom lens group in front of the focus lens group. In general, a substantially disc-shaped shutter unit including a shutter mechanism and a diaphragm mechanism for photographing is fixed at an appropriate position of the front lens group, and an outer cylinder constituting a cam mechanism is provided on the outer periphery of the shutter unit. A notch surface parallel to the optical axis is formed in order to secure a space for the lead screw and the guide shaft to enter.
Conventionally, as disclosed in Japanese Patent Application Laid-Open No. 2002-286888, the cutout surface of the shutter unit is positioned substantially parallel to one side edge of the rectangular imaging element, and the lens barrel is retracted. Sometimes, the lead screw, the guide shaft of the focus lens group, and the lens barrel substrate to hold them in the arcuate space formed by the cylindrical inner wall of the cam mechanism and the shutter notch surface, The protruding guide holding part is configured to enter. However, when the notch surface formed on the outer periphery of the shutter unit is substantially parallel to one end edge of the rectangular imaging surface as in this conventional example, the direction away from the top of the space in the arcuate shape when viewed from the subject side. Since the space becomes narrower toward the surface, the thickness of the pillar portion of the guide holding portion protruding into the space cannot be made sufficiently large, and the strength is weakened. Even if an attempt is made to secure a large arcuate space by increasing the notch width of the shutter unit, there is a limit to the size of the space limited by the outer shape of the image sensor fixed to the lens barrel substrate. It was difficult to ensure sufficient strength.
JP 2002-286888 A

The present invention has been made in view of the above, and includes a front lens group driven by a cam mechanism, a rear lens group driven by a lead screw independently of the front lens group, and a front lens group just before the rear lens group. A shutter unit fixed to the front lens group and having a notch surface parallel to the optical axis, and forward from the lens barrel substrate to guide the lead screw and the rear lens group when the rear lens group moves rearward In the lens barrel in which the protruding guide holding portion enters the arcuate space surrounded by the notch surface of the shutter unit and the inner wall of the cam mechanism, the notch surface of the shutter unit is substantially parallel to the diagonal line of the rectangular imaging device. The projected shape seen from the subject side of the space surrounded by the notch surface of the shutter unit and the inner wall of the cam mechanism is cut at two adjacent edges (corner corners) of the image sensor. It has a lacking shape, the lead screw can be placed on one edge side of the image sensor, the guide holding part can be placed near the apex of the arcuate space, and the space for placing the guide holding part is increased to increase the strength of the guide part. Objective.
Furthermore, when the flexible printed circuit board of the shutter is inserted into the space surrounded by the notch surface of the guide holding portion and the shutter unit and the inner surface of the cam mechanism, when the guide holding portion is stably fixed and the shutter is extended forward. Another purpose is to secure the required length.

In order to solve the above-mentioned problems, the invention of claim 1 is directed to at least one front lens group, a cam mechanism for moving the front lens group straight in the optical axis direction, and straight in the optical axis direction behind the front lens group. A rear lens group that is movably disposed and driven by a lead screw independently of the front lens group, and a front lens frame that holds a front lens group disposed immediately in front of the rear lens group. In a lens barrel comprising a shutter, a lens barrel substrate having a guide holding portion protruding forward to guide the rear lens group, and a rectangular imaging device disposed behind the lens barrel substrate, The shutter has a configuration in which a notch surface parallel to the optical axis is formed on the outer periphery of a substantially disk-shaped body having an incident hole in the center, and the notch surface is substantially the same as a diagonal line of the imaging element having a rectangular shape. common The lead screw and the guide in a space surrounded by the inner wall of the cam mechanism and the notch surface of the shutter when the front lens frame is moved rearward. The holding part is configured to enter.
According to the present invention, the projected shape when the arcuate space surrounded by the notch surface of the shutter unit and the inner wall of the cam mechanism (fixed cylinder) is viewed from the subject side has two adjacent edges (corner corners) of the image sensor. Part), the lead screw can be placed on one edge of the image sensor, the guide holder can be placed near the apex of the bow, and the guide holder can be made larger by taking up a large space for the guide holder. The strength of can be increased. Further, when the front lens frame moves rearward, the lead screw and the guide holding part are inserted into the space surrounded by the inner wall of the cam mechanism and the notch surface of the shutter unit, so that the lead screw and the guide holding part The length of the lens group can be made long, and the lens group can be extended by a large amount without increasing the size of the lens barrel.
According to a second aspect of the present invention, in the first aspect, the motor for driving the lead screw is disposed on the lens barrel substrate so that the center of the motor body is located at the center position of one end edge of the rectangular imaging element. It is characterized by being.
According to the present invention, the mechanism for driving the lead screw without using gears or other reduction system components can be configured with the minimum and minimum components, and is surrounded by the edge of the image sensor on the lens barrel substrate and the inside of the cam mechanism. The motor is arranged in the optimum portion of the arcuate space, and the motor can be arranged in the lens barrel without increasing the diameter of the cam mechanism, thereby reducing the size of the lens barrel.
According to a third aspect of the present invention, there is provided the flexible printed circuit board according to the first or second aspect, wherein the flexible printed circuit board supplies a signal to the shutter unit, and the flexible printed circuit board is surrounded by the guide holding portion and the notch surface of the shutter. It is characterized by being curved into the open space.
According to the present invention, it is possible to sufficiently secure the length of the flexible printed circuit board when the shutter unit is extended to the subject side.
According to a fourth aspect of the present invention, in the first, second, or third aspect, the front lens frame includes a light shielding portion that covers at least a part of a space formed by the notch surface of the shutter and the inner wall of the cam mechanism. Is protruded forward.
According to this, stray light among the light rays incident from the subject side can be shielded by the front lens frame, and flare that is a cause of deteriorating image performance can be reduced.

According to a fifth aspect of the present invention, in the first to fourth aspects, the lead screw is disposed on an edge side where a terminal of the rectangular imaging element is disposed.
According to the present invention, the cam mechanism can be made small by arranging the lead screw close to the image pickup element while securing the image pickup element fixing portion for fixing the image pickup element to the lens barrel substrate. Can be
The invention of claim 6 is characterized in that the motor of claim 2 is a pulse motor.
According to the present invention, the lens barrel can be made small and easily controlled.
The invention of claim 7 is the flexible printed circuit board holding portion protruding in the imaging surface direction from the front lens frame so as to form a space between the guide holding portion and the guide holding portion, and is curved into the space. A fixing member that sandwiches and fixes a part of the flexible printed circuit board that is inserted at the distal end of the flexible printed circuit board holding part, and a fixing plate member that fixes the flexible printed circuit board so as to be sandwiched between the guide holding part, It is provided with.
When the front lens group is extended, the flexible printed circuit board is extended in the optical axis direction while being held by the fixing member and the fixing plate member, and when the front lens group is extended toward the lens barrel substrate from that state. Since the flexible printed circuit board is held by the fixing member and the fixed plate member, the flexible printed circuit board can smoothly enter the space between the guide section and the flexible printed circuit board holding section while being curved in accordance with the flexible printed circuit board. Can be prevented from entering.
The invention of claim 8 is characterized in that, in the first to seventh aspects, when not in use, the lens groups approach each other and are in a retracted state.
According to the present invention, it is possible to provide a retractable lens barrel in which the rear lens group is extended and retracted in a small size when stored.
The invention of claim 9 is characterized by comprising either the lens barrel of claims 1 to 7 or the retractable lens barrel of claim 8.
According to the present invention, the amount of lens movement due to zooming can be increased, and a small zoom lens barrel can be provided.
The invention of claim 10 is characterized in that, in claim 9, the rear lens group is a focus lens, and the front lens group is a zoom lens for zooming.
According to the present invention, the focus lens can be controlled independently and the amount of focus lens extension can be increased, so that the photographing distance range can be increased.

According to the present invention, the cutout surface parallel to the optical axis formed on the outer periphery of the shutter unit is inclined and arranged so as to be parallel to the diagonal line of the rectangular image sensor (a state that obliquely intersects the edge). Thus, the limited arcuate space between the notch surface and the cam mechanism can be effectively used, and the strength of the guide holding portion of the lens barrel substrate can be ensured while taking the amount of extension of the rear lens group long. . Furthermore, by arranging the shutter flexible substrate so as to be curved and enter the arcuate space, the length can be secured and the entrainment can be prevented. Further, stray light can be shielded by forming the arcuate space with the front lens frame.
In the first aspect of the invention, the shutter unit is fixed to the lens frame of the front lens group disposed immediately before the rear lens group, and has a guide holding portion protruding forward to guide the rear lens group. In the lens barrel provided with the above-described lens barrel substrate, the outer diameter of the shutter unit is a substantially half-moon shape in which a notch surface parallel to the optical axis is formed on the outer periphery of the substantially disk-shaped body, and the notch surface is rectangular. A subject in an arcuate space surrounded by the notch surface of the shutter unit and the inner surface of the cam mechanism by being fixed so as to be inclined with respect to the edge of the image sensor while being substantially parallel (parallel) to the diagonal of the element (CCD) The projected shape seen from the side is a shape that is cut out at two adjacent edges of the image sensor (a shape in which the corners of the image sensor protrude from the intermediate position of the cut surface). For this reason, a lead screw projecting forward to drive the rear lens group is arranged on one narrow end side of the image sensor, and a guide holding part holding a guide shaft for guiding the second lens group is formed at the apex of the arcuate space. The guide holder can be disposed close (wide space), and the strength of the guide holder can be increased by taking a large space for arranging the guide holder. In addition, when the front lens frame moves rearward, the lead screw and the guide holding portion enter the space surrounded by the inner surface of the cam mechanism and the notch surface of the shutter unit, so that the length of the lead screw and the guide holding portion is increased. The length of the lens group can be extended, and the amount of extension of the lens group can be secured long.
In the invention of claim 2, the lead screw is driven directly from the motor, and the center of the motor body is arranged on the lens barrel substrate on the bisector of the one end edge at a position along the one end edge of the image pickup element when viewed from the subject side. As a result, it can be configured with the minimum and minimum components that drive the lead screw without using gears or other reduction system components, and is surrounded by the edge of the image sensor on the lens barrel substrate and the inner surface of the cam mechanism. Since the motor is arranged at the apex of the arcuate space, the motor can be arranged in the lens barrel without increasing the diameter of the cam mechanism, and the size of the lens barrel can be reduced.

According to the third aspect of the present invention, the flexible printed circuit board that supplies a signal to the shutter unit is curved and enters the space surrounded by the guide holding portion, the cutout surface of the shutter unit, and the inner diameter of the cam mechanism, so that the shutter unit is A sufficient length of the flexible printed circuit board when extended to the subject side can be secured.
According to the invention of claim 4, a light shielding portion is provided in the lens frame of the front lens group so as to cover the space formed by the cutout surface of the shutter unit and the inner diameter of the cam mechanism from the front side, so that the subject side Stray light can be shielded by the front lens frame among the light rays incident from the light source, and flare which is a cause of deteriorating image performance can be reduced.
According to the fifth aspect of the present invention, the lead screw is disposed on the edge side where the terminal of the image sensor is disposed (or at a position along one edge of the rectangular image sensor), whereby the image sensor is The cam mechanism can be made small by arranging the lead screw in the vicinity of the image sensor while securing the image sensor fixing portion to be fixed to the lens barrel substrate. As a result, the lens barrel can be miniaturized.
According to the sixth aspect of the present invention, since the motor is a pulse motor, the lens barrel can be made small and easily controlled.

According to the seventh aspect of the present invention, the space between the guide holding unit and the flexible printed circuit board holding unit that holds the flexible printed circuit board that protrudes in the imaging surface direction of the front lens frame provided to face the guide holding unit. A fixing member for fixing the flexible printed circuit board so that the flexible printed circuit board is inserted in a curved manner and the flexible printed circuit board holding part is sandwiched and fixed between the shutter flexible printed circuit board and the guide holding part; Thus, when the front lens group is extended, the flexible printed circuit board is extended in the optical axis direction while being held by the fixing member and the fixing plate member, and from this state, the front lens group becomes the lens barrel substrate. When retracting to the side, the flexible printed circuit board is held by the fixing member and the fixing plate member. Because it is, it is possible to enter smoothly into space between the guide holding portion and the flexible printed circuit board holding unit while being curved so as to follow it, enters into the other space can be prevented.
According to the invention of claim 8, when the lens barrel according to any one of claims 1 to 7 is not in use, the lens groups approach each other and enter a retracted state, so that the rear lens group is extended and the storage is small. A retractable lens barrel that can be retracted can be provided.
According to the ninth aspect of the present invention, by using either the lens barrel of the first to seventh aspects or the retractable lens barrel of the eighth aspect of the present invention as a zoom lens barrel, the amount of lens movement due to zooming can be reduced. A large zoom lens barrel can be provided.
According to a tenth aspect of the present invention, in the zoom lens barrel according to the ninth aspect, the rear lens group is a focus lens, and the front lens group and the other lens group are zoom lenses that perform zooming. Can be controlled independently, and the amount of extension of the focus lens can be increased, so that the photographing distance range can be increased.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
FIG. 1 is a sectional view of a lens barrel according to an embodiment of the present invention, and FIG. 2 is an exploded perspective view.
The lens barrel according to this embodiment includes a first lens group 3 and a second lens group 2 (both zoom lens group = front lens group) that perform zooming, and a third lens group (focus lens group) that performs focusing. = Rear lens group) 4, cam mechanism C for linearly driving the front lens group including the first and second lens groups 3 and 2 in the optical axis direction, and the rear lens group 4 as the third lens group Is schematically provided with a motor 7 (lead screw 7a) for moving the lens in the direction of the optical axis, a CCD (imaging device) 6, a lens barrel substrate 1, and the like.
The cam mechanism C includes a cam cylinder 8, a fixed cylinder 9, drive pins 10, 11 and the like.
A fixed cylinder 9 is fixed to the front surface of the lens barrel substrate 1, and a cam cylinder 8 is rotatably supported coaxially on the outer diameter side of the fixed cylinder 9 and is driven to rotate by a drive source (not shown). The cam cylinder 8 is provided with a first group cam groove 8a and a second group cam groove 8b which are engaged with the drive pins 10 and 11 to determine the position of the first lens group 3 and extend in an oblique circumferential direction. The first lens group 3 and the second lens group 2 are supported by a first lens group driving pin 10 and a second lens group driving pin 11, respectively. Further, the fixed cylinder 9 is engaged with the first lens group driving pin 10 and the second lens group driving pin 11, respectively, and linearly moves in the optical axis direction without rotating the front lens groups 3 and 2. Guide grooves 9a and 9b are provided. By rotating the cam cylinder 8 in this way, the front lens groups 3 and 2 can move forward and backward in the optical axis direction without changing the rotation while creating the positional relationship required according to the cam grooves.
On the other hand, in the third lens group 4 for focusing, a guided hole or the like provided in the lens frame is fitted to the guide shafts 12 and 13 protruding forward from the lens barrel substrate 1 and is movable in the optical axis direction. The stepping motor 7 is screwed with a lead screw (output shaft) 7a protruding forward from a stepping motor 7 fixed to the lens barrel substrate 1 and a nut 14 fixed to the lens frame. It is possible to move forward and backward in the direction of the optical axis with high accuracy by the pulse given to. Images formed by the lens groups 3, 2, and 4 are photoelectrically converted by the CCD 6 fixed to the lens barrel substrate 1 by the CCD fixing member 18 from the rear, and recorded as image information on the camera body side.
The lens barrel of this embodiment can be miniaturized by reducing the distance between the lens groups when not in use and retracting. In front of the second lens group 2, a shutter unit 5 having an entrance hole 5A and for performing a diaphragm and a shutter is fixed, and moves together with the second lens group 2 in the optical axis direction.

3 is a front view showing the positional relationship between the shutter unit 5, the CCD (imaging device) 6, the CCD pressing member 18 and the stepping motor 7 according to this embodiment. FIG. 4 is a front view showing the shutter unit 5, the second lens group 2, and the stepping. 3 is a perspective view showing a positional relationship between the motor 7 and the lens barrel substrate 1. FIG. The shutter unit has a substantially disc-like appearance having an aperture mechanism and a shutter mechanism inside, has an incident hole 5A in the center, and a notch surface 5a as a flat surface parallel to the optical axis on the outer periphery. Prepare. This notch surface 5a is fixed to the second lens group 2 so that the front shape is substantially parallel to the diagonal line of the CCD 6 having a rectangular shape.
The notch surface 5a is parallel (or parallel) to the diagonal line of the CCD 6. For example, as shown in FIG. 3 and the like, the notch surface 5a is an upper right corner of the CCD 6 whose front shape is a rectangle. Are arranged so as to cross over two edges (upper edge and right vertical edge) which are adjacent (orthogonal) via the, and are almost parallel to the diagonal line connecting the upper left corner and the lower right corner of the CCD 6 It is intended to include a state where they are arranged so that they do not have to be parallel in a strict sense.
As described above, in the conventional lens barrel, the notch surface 5a viewed from the front (subject side) is arranged so as to be parallel to the upper or lower edge of the rectangular CCD 6, so the notch The space becomes narrower in the direction away from the top (the center of the arc) of the arcuate space formed between the surface 5a and the fixed cylinder 9 in the left-right direction. While this space cannot be expanded beyond a predetermined limit due to restrictions on the size of the CCD 6, the thickness of the pillar portion of the guide holding portion protruding into the space cannot be made sufficiently large and the strength is weakened. There was a problem.
The shutter unit 5 is formed in a substantially discoid outer case by forming a notch surface 5a into a substantially half-moon shape (the notch surface 5a is at a position avoiding the incident hole). The cut-out surface 5a is in a state where the upper right corner, the upper edge and the right vertical edge of the CCD 6 are partially exposed, and a substantially arcuate space is formed between the inner periphery of the fixed cylinder 9.

In the present invention, the notch surface 5a is not parallel to one end edge of the CCD 6, but crosses diagonally, so that the upper right corner of the CCD 6 is L in the arcuate space from the center of the notch surface 5a. It is in a state protruding in a letter shape. Accordingly, symmetrical spaces are formed on the left and right of the upper right corner of the CCD 6. While the motor 7 is disposed at a position on the left side in this space (the center of the upper edge of the CCD), a guide having a sufficient size in a sufficiently wide space between the upper right corner of the CCD and the top of the arcuate space. It became possible to accommodate the holding | maintenance part 1a. Therefore, the thickness of the hollow guide holding portion 1a can be sufficiently increased to increase its strength.
5 (a) and 5 (b) are comparative views of the conventional example and the present invention. The positional relationship between the upper edge (lead terminal forming side) of the CCD and the notch surface of the shutter unit, and the arcuate space are shown in FIGS. The layout of components that can be stored is shown.
When the shutter unit is arranged so that the notch surface 5a is parallel to the upper mold edge of the CCD 6 as shown in FIG. 5A, if the motor 7 is arranged at the position shown in the figure, the arcuate space is formed. The space for arranging the guide holding portion 1a is limited, and the guide holding portion cannot be configured to be large.
On the other hand, when the notch surface 5a is arranged obliquely so as to intersect the upper mold edge of the CCD 6 and the right vertical side as in the configuration example of the present invention shown in FIG. While it can arrange | position toward the corner which is a narrow space of arcuate space, the space which arrange | positions other components including the guide holding | maintenance part 1a expands. Therefore, not only can the guide holding portion 1a be configured to be large to increase its strength, but also the light shielding wall 2a ′ of the second lens group 2 and the shutter FPC 19 can be accommodated.

Next, FIG. 6 is a front view showing the positional relationship among the shutter unit 5, the lens barrel substrate 1, the stepping motor 7, the third lens group 4, and the guide shaft 12, and FIGS. 7 and 8 are perspective views thereof. Each figure shows a state when stored, and the third lens group 4 is placed in an arcuate space surrounded by the notch surface 5a of the shutter unit 5 and the inner surface of the fixed cylinder 9 which is a part of the cam mechanism C. A guide shaft 12 for guiding, a guide holding portion 1a that protrudes from the lens barrel substrate 1 and holds the guide shaft 12, a lead screw 7a that rotates by the output of the stepping motor 7, and a flexible printed circuit board (FPC) 19 for the shutter unit enter. Yes.
The stepping motor 7 provided with the lead screw 7a is arranged so that the center of the motor body is positioned on the bisector of the edge 6a (FIG. 3) on the terminal forming side of the CCD 6, By fixing the motor body 7 at a position where the width of the arcuate space surrounded by the inner surface of the fixed tube 9 and one edge of the CCD 6 is the minimum width while securing the space for the lens barrel substrate fixing portion 15a. The diameter of the tube 9 can be reduced.
By arranging the guide shaft 12 and the guide holding portion 1a at a position where the arcuate space surrounded by the notch surface 5a of the shutter unit 5 and the inside of the fixed cylinder 9 becomes the maximum width, the outer wall of the guide holding portion 1a is arranged. The surface 1b along the inside of the fixed cylinder 9 and the surface 1c parallel to the edge of the CCD 6 can be formed in a substantially V shape, and sufficient strength to hold the guide shaft 12 can be ensured.
A spring 15 for biasing the third lens group 4 to the nut 14 is inserted inside the guide holding portion 1a.

  FIG. 9 is a vertical cross-sectional view showing a storage state of a flexible substrate (FPC) 19 for the shutter unit (some components are not shown). An FPC 19 is accommodated in a space formed between the guide holder 1a and the FCP holder 2a. The FPC 19 once extends toward the CCD side along the lower surface of the FPC holding portion 2a protruding from the lens frame 2A of the second lens group 2 toward the CCD side, and then the clip-like FPC fixing member 16 at the tip of the FPC holding portion 2a. Is fixed by being sandwiched between the FPC holding portion 2a. The FPC 19 is bent and inverted along the FPC holding portion 2a at the tip of the FPC holding portion 2a, and is extended in the subject direction. Here, the FPC 19 enters a space surrounded by the notch surface 5a of the shutter unit 5, the guide holding portion 1a, and the fixed cylinder 9, and curves upwards and reverses in the vicinity of the tip of the guide holding portion 1a to lower the lower surface of the guide holding portion. Is extended to the outside of the lens barrel substrate 1 in the direction of the CCD along the plane 1c, and is fixed by being sandwiched between the L-shaped FPC fixing plate member 17 and the plane 1c of the guide holding member 1a. Has been. That is, the FPC 19 extends rearward along the lower surface of the FPC holding portion 2a with the lower end portion fixed by the lens frame 2A of the second lens group, and then is fixed upward at the tip of the FPC holding portion 2a. Inverted and extended forward along the upper surface of the FPC holding portion 2a, and further inverted backward and extended backward along the plane 1c of the guide holding member, and the other end at the rear end portion of the guide holding member 1a Has been fixed. Therefore, in the process in which the second lens group 2 including the lens frame 2A advances and retracts in the optical axis direction with respect to the guide holding member 1a, the FPC 19 can smoothly expand and contract.

FIG. 10 is a longitudinal sectional view showing a state in which the second lens group 2 is extended forward from the lens barrel substrate 1 (parts are not shown). When the second lens group 2 is extended, the FPC 19 has its lower end and upper end fixed by the lens frame 2A and the guide holding member 1a, respectively, while maintaining the curvature of the intermediate curved portion substantially constant. Therefore, it is possible to prevent problems such as breakage and entrainment due to feeding and drawing-in, and it is possible to ensure the necessary length during feeding by being bent into an S shape in the retracted state shown in FIG. .
Further, as shown in FIG. 4, the lens frame 2 </ b> A of the second lens group 2 has a light shielding portion 2 a ′ that covers from the subject side the arcuate space surrounded by the notch surface 5 a of the shutter unit 5 and the inner surface of the fixed cylinder 9. Thus, stray light deviating from the outside of the effective ray that has passed through the first lens groups 3 and 2 is shielded so as not to pass through the arcuate space and reach the imaging surface of the CCD 6. Thereby, it is possible to prevent the image performance from being deteriorated due to flare or the like.
As described above, the rear lens is assembled by assembling the shutter unit 5 to the second lens group 2 in a state where the notch surface 5a of the shutter is tilted so as to be parallel to the diagonal line of the CCD 6 having a rectangular front shape. It is possible to secure a sufficiently large strength of the guide holding portion 1a of the lens barrel substrate 1 while taking a sufficiently long feeding amount of the group 4, and to arrange the shutter flexible substrate so as to be curved and enter the arcuate space. Thus, the length can be secured and the entrainment can be prevented. Moreover, stray light can be shielded by covering the front surface of the arcuate space with a light shielding portion 2a ′ provided in a part of the lens frame 2A of the second lens group 2.

1 is a cross-sectional view of a lens barrel according to an embodiment of the present invention. The disassembled perspective view of the lens barrel of FIG. The front view which showed the positional relationship of the shutter unit of this embodiment, CCD (imaging element), a CCD pressing member, and a stepping motor. FIG. 4 is a perspective view showing the positional relationship among the shutter unit, the second lens group, the stepping motor, and the lens barrel substrate. The comparison figure of a prior art example and this invention. The front view which showed the positional relationship of a shutter unit, a lens-barrel board | substrate, a stepping motor, a 3rd lens group, and a guide shaft. The perspective view of FIG. The perspective view of FIG. The longitudinal cross-sectional view which shows the structure and operation | movement of FPC. The longitudinal cross-sectional view which shows the structure and operation | movement of FPC.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Lens substrate, 1a Guide holding part, 1b surface, 1c plane, 2nd lens group (zoom lens group = front lens group), 2A front lens frame, 2a FPC holding part, 2a 'light-shielding part, 3 1st lens Group (zoom lens group = front lens group), 4 third lens group (focus lens group = rear lens group), C cam mechanism, 5 shutter unit, 5A entrance hole, 5a notched surface, 6 CCD, 7 motor, 7a Lead screw, 8 cam cylinder, 9 fixed cylinder, 10, 11 drive pin, 12, 13 guide shaft, 14 nut, 19 flexible substrate (FPC)

Claims (10)

At least one front lens group, a cam mechanism that linearly moves the front lens group in the optical axis direction, and a rear screw that is arranged so as to be linearly movable in the optical axis direction behind the front lens group; Is a rear lens group driven independently, a shutter fixed to a front lens frame holding a front lens group disposed immediately in front of the rear lens group, and a front side for guiding the rear lens group In a lens barrel including a lens barrel substrate having a protruding guide holding portion, and a rectangular imaging element disposed behind the lens barrel substrate,
The shutter has a configuration in which a notch surface parallel to the optical axis is formed on the outer periphery of a substantially disk-shaped body having an incident hole in the center, and the notch surface is substantially the same as a diagonal line of the imaging element having a rectangular shape. Fixed to the front lens frame to be parallel,
The lead screw and the guide holding part are configured to enter the space surrounded by the inner wall of the cam mechanism and the notch surface of the shutter when the front lens frame moves rearward. Characteristic lens barrel.   2. The lens mirror according to claim 1, wherein the motor for driving the lead screw is disposed on the lens barrel substrate so that the center of the motor main body is located at the center position of one end edge of the rectangular imaging element. Torso.   2. A flexible printed circuit board for supplying a signal to the shutter unit, wherein the flexible printed circuit board is curved and enters a space surrounded by the guide holding portion and the cutout surface of the shutter. Or the lens barrel according to 2.   The front lens frame is provided with a light-shielding portion protruding forward so as to cover at least a part of a space formed by a notch surface of the shutter and an inner wall of the cam mechanism. Item 4. The lens barrel according to Item 1, 2 or 3.   The lens barrel according to any one of claims 1 to 4, wherein the lead screw is disposed on an edge side where a terminal of the rectangular imaging element is disposed.   3. The lens barrel according to claim 2, wherein the motor is a pulse motor.   A flexible printed circuit board holding part that protrudes in the imaging surface direction from the front lens frame so as to form a space between the guide holding part and a part of the flexible printed circuit board that is curved and entered into the space. The fixing member which clamps and fixes at the front-end | tip of a printed circuit board holding | maintenance part, and the fixing board member which fixes the flexible printed circuit board so that it may be inserted | pinched between the said guide holding | maintenance part, It is provided. Lens barrel.   The retractable lens barrel according to any one of claims 1 to 7, wherein when the lens is not in use, each lens group approaches and is in a retracted state.   A zoom lens barrel comprising either the lens barrel according to claim 1 or the retractable lens barrel according to claim 8.   The zoom lens barrel according to claim 9, wherein the rear lens group is a focus lens, and the front lens group is a zoom lens that performs zooming.

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