JPH0727096B2 - Lens barrel - Google Patents

Description

The present invention relates to a lens barrel detachable from a main body,
In particular, it relates to a detachable lens barrel for a single-lens reflex camera having a double-sided printed circuit board on which an electric circuit is mounted.

[Prior Art] In recent years, single-lens reflex cameras have come to be equipped with multi-functional automation such as incorporating an auto-focus mechanism, and interchangeable lenses for single-lens reflex cameras are also used for various motors such as focus drive motors and electromagnetic diaphragms. , The electric circuit scale tends to be large and complicated.

On the other hand, since the shape of the camera and the interchangeable lens tends to be small, or if they have the same shape, various complicated mechanisms are likely to be housed, so that a space where the electric circuit can be installed is often small.

Therefore, in such a single-lens reflex camera and interchangeable lens, the electric circuit is mounted on the flexible printed circuit board,
This electric circuit unit has been mounted in a small gap between the internal mechanism and the exterior cover.

As an example, the same applicant as the present case has already proposed a method of mounting an electric circuit as shown in FIGS. 8 to 10 on a lens barrel.

In FIG. 8, 110 is a cylindrical housing such as a lens barrel, 1
Reference numeral 01 is a first flexible printed circuit board, and 102 is a second flexible printed circuit board, which are schematically shown before being mounted on the cylindrical casing 110.

The first flexible printed circuit board 101 has a first main area 101a.
And the first connection area connected to the lead-out section 101d
And 101b. The first main area 101a is connected to an aperture driving motor (not shown) and an actuator for zooming, and is housed in the casing 110 at a position parallel to the axial direction of the cylinder.

The first connection portion region 101b has a connection pattern portion 101e for electrically connecting to another printed circuit board and a positioning hole 101c for positioning, and projects out of the housing 110.

The second flexible printed circuit board 102 has a second main area 102a.
And the second connection area connected to the drawer 102d
102b and. The second main region 102a has a donut shape, and electric parts 102f such as ICs, resistors and capacitors are placed on the surface of the donut shape and formed in a direction orthogonal to the axial direction of the housing 110. It is placed and held on the formed step surface 110a. The second connection portion region 102b has a positioning hole 102c for positioning with a connection pattern portion 102e for electrically connecting with the first flexible printed circuit board 101.

The second main portion region 102a is fitted in a plane shape orthogonal to the axial direction of the casing 110, and at this time, the second connecting portion region 102b projects out from the casing 110 as shown in FIG. It is set so as to be in contact with the first connection portion region 101b of the flexible printed circuit board 101 outside the housing 110. In this state, the first connecting portion region 101b and the second connecting portion region 102b are positioned by using the positioning holes of 101c and 102c by a jig and tool (not shown), and at the same time, the connecting patterns 101e and 102e of the two are connected by the solder 103 or the like. Connect electrically. After the connection, as shown in FIG. 10, both connection part regions 101b and 102b at the outer position of the housing are bent inwardly of the housing and accommodated so as to overlap on the surface of the second main part area 102a.

After that, the lens mount 104 and the makeup cylinder 105 are fitted.

[Problems to be Solved by the Invention] However, in the above-mentioned conventional example, since the circuit board 102 does not have a land for inspecting or adjusting the electrical characteristics, the board 102 is assembled and fixed in the lens barrel. After that, when there is a problem with the operation of the lens or camera and you want to inspect or adjust the circuit board, you had to remove the circuit board from the lens barrel and disassemble part of the circuit board. .

[Means and Actions for Solving the Problem] A first invention of the present application is to electrically connect a lens, a circuit board, a controlled part controlled by using the circuit board, and the circuit board and the controlled part. In a lens barrel having a connecting portion for connecting and a mount for attachment / detachment to / from a main body, an inspection portion for inspecting a circuit is formed on one surface of the circuit board, and the circuit board is perpendicular to an optical axis. It is arranged in the vicinity of the mount along a flat plane, and the one surface of the circuit board is provided on the mount side.

A second invention of the present application is to attach and detach a lens, a circuit board, a controlled section controlled by using the circuit board, a connecting section electrically connecting the circuit board and the controlled section, and a main body. In the lens barrel having a mount for adjusting the circuit, an adjusting portion for adjusting a circuit is formed on one surface of the circuit board, and the circuit board is arranged near the mount along a plane perpendicular to the optical axis. However, the one surface of the circuit board is provided on the mount side.

In the first and second inventions of the present application, an inspection section or an adjustment section for inspecting or adjusting a circuit is formed on one surface of the circuit board, and the circuit board is provided in the vicinity of the mount so as to be along a plane perpendicular to the optical axis. Since the one surface of the circuit board is directed to the mount side, electrical check and repair can be easily performed only by removing the lens mount.

[Examples] The present invention will be described below in detail based on the examples shown in the drawings.

FIG. 1 shows a sectional view of an embodiment of a lens barrel according to the present invention.

In the figure, reference numeral 1 indicates a fixed cylinder, and a bayonet mount 1A for coupling with a camera (not shown) is attached to one end of the fixed cylinder. The adjustment of the back focus at this time will be described with reference to FIGS.

In FIG. 2, 1A is a mount to be mounted on the fixed barrel 1, and the thickness D of the fastening flange portion 1Aa of the mount 1A.
Is the final thickness d considering the back focus adjustment method.
It is formed so as to be thicker in advance. The back surface of the fastening flange portion 1Aa serves as a reference surface 1Ab for back focus measurement and back focus adjustment, and a screw insertion hole (dumb hole) opening in the reference surface 1Ab is provided through the fastening flange portion 1Aa. The mount 1A has a front shape and a cross-sectional shape as shown in FIGS. 4 and 5, and has the same structure as a known mount.

The fixed cylinder 1 that is fastened to the mount 1A has a screw hole on the rear end face thereof that matches the screw insertion hole of the mount 1A, and the screw 1B is screwed into the screw hole through the screw insertion hole to mount the mount. 1A and the fixed cylinder 1 are fastened.

Here, as the fixed barrel 1, a structure in which the distance ring and the helicoid barrel are integrated is manufactured, and the work for adjusting the back focus of the lens barrel is performed as follows.

That is, after the dummy mount 1A having the reference thickness dimension D is temporarily fastened to the fixed barrel with the screw 1B as shown in FIG. 2, the fixed barrel 1 is attached to the collimator and the back focus BF is measured. In this case, as described above, the thickness D of the fastening flange portion 1Aa of the dummy mount 1A is designed to be thicker than the thickness d corresponding to the back focus value obtained by the measurement (thickness d is determined for each back focus measurement value). It is found that a mount having a size of d = D-1 in which the thickness of the fastening flange portion 1Aa of the mount 1A is reduced by an excessive thickness of 1 is suitable. So dummy mount
After removing 1A from the fixed cylinder 1, as shown in FIG. 3, the joint surface of the fastening flange portion 1A'a of a separate mount 1A 'of the same type is cut to make the thickness of the fastening flange portion 1A'a a predetermined value d. To The cutting is performed by mounting the mount 1A 'on a lathe or a milling machine and using the reference surface 1A'b as a reference.

If the mount 1A 'having the thickness of the fastening flange portion 1A'a cut to d is fastened to the fixed barrel 1 as shown in FIG. 3, a lens barrel assembly adjusted to a predetermined back focus can be obtained. It will be.

In FIG. 1, the 2 first moving ring, 4 represents a second moving ring, holds the lens _{L 4 ~L 6, L 1 ~L} 3 for focusing each. The outer peripheral surface of the second moving ring 4 has a fitting portion 4a that fits with the inner diameter portion 2a of the first moving ring 2 and a fixing means for fixing the second moving ring 4 to the moving ring 2. The fixing means engages the plurality of protrusions 4b protruding on the outer periphery of the second moving ring 4 with the engaging portions 2b provided on the inner diameter surface of the first moving ring 2.

Reference numeral 6 denotes a motor held by the fixed cylinder 1, which is composed of yokes 6a ₁ and 6a ₂ fixed to the fixed cylinder 1, a stator including permanent magnets (not shown), and a rotor including a coil, a rotating shaft 6b, and the like. . G ₁ ～Gn indicates gear group constituting the gear mechanism to increase or decrease the rotational speed in conjunction with the rotation shaft 6b, the gear group is axially supported by the main plate 8 fixed to the fixed tube 1.

Reference numeral 10 denotes a rotating ring that rotates at a fixed position of the fixed cylinder 1, and the rotating ring 10 is provided with a hercoid portion 10a that is screwed with a helicoid portion 2c formed on the outer periphery of the first moving ring 2 on the inner diameter, and further, A V-shaped ball race groove 10b for receiving the bearing balls 12 is formed on the outer periphery of the rotating ring 10.

The bearing balls 12 are arranged in the ball race groove 10b of the rotating ring 10 either continuously with each other by the ball spacers 14 or at regular intervals by the spacers 14 and are fitted into the inner circumference of the fixed cylinder 1 to provide an inclined surface at one end. It is held by the first ball receiving ring 16 and the second ball receiving ring 18 that is screwed into the threaded portion 1a on the inner surface of the fixed barrel 1.

Reference numeral 20 denotes a plate-shaped spacer provided between the first ball receiving ring 16 and the fixed cylinder 1, and the pressing of the ball 12 is adjusted by changing the plate thickness. Reference numeral 22 is a position detector such as an encoder arranged in the gear mechanism.

A part of the outer circumference of the rotating ring 10 has a small diameter, and the small diameter portion
A gear ring 24 is fixed to the outer periphery of 10c, and the gear ring 24 meshes with the output gears of the gears G _{1 to} Gn.

In the above structure, a space is formed between the movable ring 2 and the fixed cylinder 1 so that the motor 6 and the gear mechanisms G _{1 to} Gn can be housed and arranged, and this space is fixed between the fixed cylinder 1 and the movable ring 2. The balls 12 are held by the bearing constituent members 10, 16, 18 of the balls 12, 12.

D is a diaphragm unit fixed to the inner peripheral surface of the moving ring 2 and the wall surface 2e of the small diameter portion, EMD is a motor for driving the diaphragm unit D, and the motor EMD is fixed to the inner peripheral surface of the moving ring 2.

Reference numeral 30 is a hard double-sided printed board on which a circuit for controlling the drive of the motor 6 and the EMD is mounted, and is arranged in the gap between the wall surface 2e of the small diameter portion of the moving ring 2 and the front surface of the optical axis of the mount 1A. It is fixed at 1. Reference numeral 31 is a contact block for exchanging electrical signals with the camera body (not shown).

The rigid double-sided printed board 30 and the above-mentioned motor 6, EMD, and contact block 31 are electrically connected by flexible printed boards 32a, 32b, 32c.

The flexible printed board 32b is electrically connected to the motor 6 and the EMD at one end, changes the phase around the optical axis along the wall surface of the diaphragm unit D, and is pulled out from the inside of the moving ring 2.
After having an appropriate slack, the hard printed board 30 is extended to the surface 30a, and the other end is electrically connected.

By providing this slack, the change in the gap of the fixed barrel 2 due to the movement of the moving ring 2 in the optical axis direction is absorbed.

The flexible pudding plate 32c electrically connects between the rigid double-sided printed board 30 and the contact block 31, and the rigid double-sided printed board 30 by back adjustment described in detail in FIGS.
The change in the gap between the contact block 31 and the contact block 31 is absorbed.

As will be described later, on the rigid double-sided printed board 30, an electric circuit element such as an IC is provided with a surface 30b facing the small diameter wall surface 2e of the moving ring 2.

By configuring as described above, a rigid double-sided printed board
Since the surface of 30a of 30 has few protrusions, it is possible to make a large gap with the small-diameter wall surface 2e of the moving ring 2 by simply providing a gap in consideration of the slight back adjustment amount described above. Can also be arranged.

Further, if the movable ring 2 is made of a molded product, when the strength is insufficient due to the small wall thickness of the small diameter wall surface 2e, it is possible to increase the wall thickness of the portion where the electric circuit element described later escapes.

Reference numeral 29 is a back cover fitted to the inner diameter of the mount 1A.

FIGS. 6 (a) and 6 (b) show the element mounting surface, that is, the front surface 30b and the back surface 30a of the rigid double-sided printed board 30 of FIG.
In the plan view of the pattern, the thick line shows the outline, the thin line shows the copper foil pattern, the two-dot chain line shows the opening of the solder resist, and the copper foil pattern other than the part surrounded by the two-dot chain line is covered with the solder resist. ing. The small-diameter holes shown in bold in the copper foil pattern are through-hole plated holes,
The circuit patterns of 30b and the back surface 30a are connected. The sixth
(B) The back surface pattern is shown in a perspective view from the front for easy understanding.

In FIG. 6 (a), 33 and 34 are ICs forming a lens control circuit, 35 is a transistor array for driving a motor EMD, and 36
Is a transistor array for driving the motor 6, 37 is an external chip resistor, 38 is an external melf type resistor, 39 is a tantalum capacitor, 40 is a diode, 41 is a ceramic oscillator, and 42 is a semi-fixed volume. All of them are SMT (surface mount type) electric circuit elements and are electrically connected to the exposed conductor portions of the surface pattern of the surface 30b of the hard double-sided printed board 30 by known reflow soldering.

In FIG. 6 (b), 43 is a flexible printed board 32.
Exposed part for connecting c, 44 is an exposed part of the connection pattern of the flexible printed board 32b, 45 and 46 are exposed parts of the connection pattern of the flexible printed board 32a, and 47 is a connected flexible printed board with a switch (not shown). It is a pattern exposed portion for performing. Here, the outer shape of the flexible printed board is shown by a one-dot chain line, and is drawn from the cutout portions 30A, 30B, 30D of the hard double-sided printed board 30 to the back surface (30a side). Reference numeral 48 denotes a pattern exposure portion that constitutes an adjustment portion that electrically adjusts the lens depending on whether or not the pattern of this portion is short-circuited after the hard double-sided printed board 30 is mounted in the lens barrel, and other pattern exposure portions. Reference numeral 49 is a portion for raising a probe pin for checking and adjusting the electric circuit. Reference numeral 50 is a hole provided under the semi-fixed volume 42, which allows the rear half fixed volume 42 to be adjusted from the back surface 30a, that is, inside the lens barrel.

Reference numeral 51 is a hole for fixing the rigid double-sided printed board 30 to the moving ring 2 shown in FIG. 1 with screws.

Reference numeral 52 is a hole for positioning the hard double-sided printed board 30 with respect to the lens body when fixing with screws, and a positioning pin (not shown) implanted in the moving ring 2 is inserted therein.

53 is a flexible printed board (not shown) and a pattern exposed portion
A hole for positioning 43-47 when soldering them, or a jig / tool positioning hole for reflow soldering of the electric circuit element on the surface 30b.

The flexible printed boards 32a, 32b, 32c for connection and other flexible printed boards and the pattern exposed portions 43, 44, 45, 46, 47 of the hard double-sided printed board 30 are described in detail in the seventh (a),
It shows in (b), (c) figure. FIG. 7 (a) shows a positioning hole for the connecting portion between the hard printed board 30 and the flexible printed board 54.
It is a figure before it connects using 53 and is connected by soldering. Fig. 7 (b) is a diagram after connection by soldering.
(C) The figure is the cross section.

30 'is a copper foil pattern of the rigid printed board 30, 54a is a base film of the flexible printed board 54, 54b is a copper foil pattern of the flexible printed board 54, and 54c is a cover film of the flexible printed board 54.

Reference numeral 55 is a solder resist on the hard printed board 30, and reference numeral 56 is a solder for connection, which covers the copper foil pattern 30a so as to wrap the base film 54a so that electrical connection is made.

The circle shown by the broken line in FIG. 6 (b) shows the diameter of the end face of the mount 1A indicated by reference numeral 1Ac in FIG. 1, and the mount 1A and the rigid double-sided printed board are outside this circle. Since the gap of 30 is reduced, only the check land 49 is arranged as shown in the figure.
Since the clearance between the hard double-sided printed board 30 and the hard double-sided printed board 30 becomes large, connection lands for connection with the flexible printed board for electrical connection with the interface are arranged as shown in the figure.

[Effects of the Invention] As described above, according to the present invention, there is an effect that electrical check and repair of a circuit board can be easily performed only by removing a lens mount.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a lens barrel according to the present invention, FIGS. 2 to 5 are views for explaining back focus adjustment, and FIGS. 2 and 3 are sectional views. 4 is a plan view and FIG. 5 is a sectional view taken along the line IV-IV in FIG. FIG. 6 (a) is a plan view of the front surface side of the rigid double-sided printed circuit board, FIG. 6 (b) is a plan view of the back surface side thereof (a perspective view from the front surface side), FIG. 7 (a), and FIG. b) Figure, 7 (c)
FIG. 8 is a diagram for explaining a connection between a flexible printed circuit board and a rigid double-sided printed circuit board, and FIGS. 8 to 10 are diagrams for explaining a conventional example. 1 …… Fixed cylinder, 1A …… Mount 6, EMD …… Motor 30 …… Hard double-sided printed circuit board 31 …… Contact block 32 …… Flexible printed circuit board

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shoji Eguchi 770 Shimonoge, Takatsu-ku, Kawasaki City, Kanagawa Canon Inc. Tamagawa Business Office (56) References JP-A-61-270737 (JP, A) JP-A-60 -150698 (JP, A) Actual development Sho 56-70670 (JP, U)

Claims (2)

[Claims] 1. A lens, a circuit board, a controlled section controlled by using the circuit board, a connecting section for electrically connecting the circuit board and the controlled section, and attachment / detachment of a main body. In a lens barrel having a mount of, an inspection unit for inspecting a circuit is formed on one surface of the circuit board, and the circuit board is arranged in the vicinity of the mount along a plane perpendicular to the optical axis. A lens barrel, wherein the one surface of the circuit board is provided on the mount side. 2. A lens, a circuit board, a controlled section controlled by using the circuit board, a connecting section for electrically connecting the circuit board and the controlled section, and attachment / detachment to / from the main body. In a lens barrel having a mount of, an adjusting portion for adjusting a circuit is formed on one surface of the circuit board, and the circuit board is arranged in the vicinity of the mount along a plane perpendicular to the optical axis. A lens barrel, wherein the one surface of the circuit board is provided on the mount side.