JPH02201305A - Wiring structure in lens barrel for optical lens - Google Patents

Abstract

PURPOSE:To reduce the size of the lens barrel while preventing an optical lens from decreasing performance by laminating flexible printed wiring boards in the lens barrel and inserting them into one insertion hole formed in the peripheral wall of the lens barrel. CONSTITUTION:The flexible printed board 1 for a zoom encoder has a pattern contact 1a at its one end and a contact piece 10 moves on it to generate various signals. A connection part is formed at the other end and the signals are trans mitted to the camera control part of a microcomputer, etc. A shutter wiring board which is soldered to a shutter block 3 by an annular part 2a is interposed between a zoom signal board 1 which has a link part 2i2 fixed to a metallic fixture 1l and this metallic fixture 1l through the link part 2i1 and further led to a camera body side together with the link part 1l2 of a zoom signal board 1 one over the other. Consequently, plural wiring boards can be arranged in the lens barrel without deteriorating the performance of the optical lens and the lens barrel is reducible in size.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to an arrangement structure of a plurality of flexible printed wiring boards arranged for transmitting electrical signals within the barrel of an optical lens.

[Prior art and its problems]

Conventionally, in autofocus cameras equipped with zoom lenses, exposure control and focus adjustment are generally performed in response to various zooming positions. Therefore, specific signals are set in advance for various zooming positions, and the microcomputer installed in the camera body performs arithmetic processing based on the specific signals generated at the zooming position when shooting. is being carried out. A zoom encoder is installed on the lens barrel to send such signals to the camera. For example, the zoom encoder may be provided with a flexible printed wiring board having a patterned contact made of a conductive part and an insulating part on the fixed lens barrel, and a zoom ring with many contacts that slide on it. A suitable contact piece is provided. By the way, in order to perform complex controls such as focusing and exposure control, as in an automatic focus camera, a variety of information is required, and for this purpose, it is necessary to combine a large number of signals. Therefore, the above-mentioned zoom encoder requires a contact piece that provides many contact points, and accordingly, the signal board having pattern contacts and, by extension, the zoom encoder itself also needs to be large. Regarding the place to install such a zoom encoder, if it is installed outside the lens barrel, the lens barrel itself will become larger, or depending on the configuration of the lens barrel, it may not be possible to install it, so the preferred embodiment is It cannot be said that the composition of On the other hand, if the empty space inside the lens barrel is used to place it inside the lens barrel, a flexible printed wiring board is conventionally installed inside the lens barrel to transmit commands from the camera control section and perform exposure. Therefore, in this case, a total of two wiring boards must be provided within the lens barrel. Therefore, in order to pull these flexible printed wiring boards out from inside the lens barrel, the number of insertion holes in the board formed in the lens barrel must be increased accordingly, but this causes the problem of reduced strength of the lens barrel. arise. There are many fixed and movable objects inside the lens barrel.
Fixed objects and movable objects, and fixed objects and fixed objects must be installed so that they do not interfere with each other. In other words, this flexible printed wiring board must be placed so that it does not interfere with other fixed objects or movable objects, so in order to pull it out from inside the lens barrel, it is necessary to avoid interference with fixed objects or movable objects. An insertion hole (escape) must be made. Therefore, if two wiring boards are provided, the number of insertion holes must be increased accordingly, and the angle occupied by the insertion holes in the entire circumference (360°) of the lens barrel increases. If this happens, not only will there be serious problems such as reduced strength and accuracy of the lens barrel, but also there will be major restrictions in terms of design and layout because nothing else can be provided in the area where the board is located or the white insertion area. In order to eliminate such reductions in strength and precision, as well as restrictions on design and layout, it is necessary to increase the wall thickness of the lens barrel or enlarge the entire lens barrel. Furthermore, there is a risk that light leakage will increase from the increased number of insertion holes, and furthermore, the amount of light reflected within the lens barrel by the flexible printed wiring board will increase, affecting the optical path and causing flare. The present invention has been devised to effectively solve the conventional technical problems as described above. Therefore, the purpose is to overcome design and layout constraints,
A wiring structure inside the lens barrel of an optical lens that can reduce the size of the lens barrel while preventing performance deterioration of the optical lens such as a decrease in strength and accuracy, an increase in light leakage from the insertion port, and an increase in the amount of reflected light on the inner surface of the lens. Our goal is to provide the following.

[Means to solve the problem]

The wiring structure within the lens barrel of the optical lens according to the present invention is configured as follows in order to achieve the above-mentioned object. That is, a plurality of flexible printed wiring boards for transmitting the control signals are arranged in a stacked manner within the lens barrel.
It is inserted into one insertion hole formed in the peripheral wall of the lens barrel.

[Action/effect]

In the above configuration, compared to when multiple flexible printed wiring boards are inserted through the same number of insertion holes, the angle of the insertion holes in the entire circumference of the lens barrel is smaller, and there are no restrictions on design and layout. strength and strength without increasing the size.
Decrease in accuracy can be prevented. In other words, when two substrates are stacked and inserted through the peripheral wall of the lens barrel, the width (angle) in the circumferential direction occupied by the insertion hole remains the same compared to when only one substrate is used, so multiple insertion holes are formed. The strength of the lens barrel is
The strength can be maintained close to that of the case where an insertion hole through which only one board is inserted is formed. The same applies to light leakage, and it is possible to minimize the increase in light leakage. Furthermore, the reflected field within the lens barrel will not increase unless the area of the substrate changes. Therefore, the possibility of flare occurring can be kept at the same level as before. As described above, multiple wiring boards can be placed inside the lens barrel without degrading the performance of the optical lens.
It is possible to downsize the lens barrel.

【Example】

An embodiment of the present invention will be described below with reference to FIGS. 1 to 7. Fig. 1 is an exploded perspective view of a lens barrel of a zoom lens having a wiring structure according to an embodiment of the present invention, Fig. 2 is a partial perspective view showing a wiring board insertion hole, and Fig. 3 shows the lens barrel in a wide-angle state. FIG. 4 is a longitudinal sectional view when the lens barrel is in a telephoto state, and FIG. 5 is a longitudinal sectional view showing the relationship between the lens barrel and the film winding and rewinding gear box. First, the configuration of the lens barrel will be explained below. As shown in FIG. 3, the lune frame 4 that holds the lune group is screwed into the lune frame holding member 19 by a vericoid screw formed on its outer periphery. And this holding cylinder I9
is attached to a shutter block 3 that performs focusing and exposure. At that time, although not shown, a rotatable lever in the shutter block 3 and a recess formed in the lens frame 4 engage with each other. When this lever rotates, the lens frame 4 also rotates, and at the same time moves in the optical axis direction by the action of the helicoid screw, thereby focusing on the subject. Further, the shutter block 3 includes a cylindrical portion 5b and a flange portion 5.
It is screwed to the advancing cylinder 5 so as to operate integrally with the advancing cylinder 5 consisting of the cylinder 5. The second lens frame 7 holding the second lens group has a conical first cam follower 8 fitted to a cam dK 5 a formed on the peripheral wall of the cylindrical portion of the forward barrel 5 inside the forward barrel 5. Later, it is held in the forward cylinder 5 by screwing it. The cam grooves 5a are spirally formed at three locations on the peripheral wall of the forward cylinder 5, and are wider on the outer circumferential surface side than on the inner circumferential surface side. The peripheral wall of the forward cylinder 5 is inserted into a rotating ring 9 having a zoom encoder contact piece 10 attached to its outer peripheral surface. The inner circumferential surface of the rotating ring 9 has an inner diameter along the axial direction.
I9b is formed, and this inner groove 9b engages with the above-mentioned first cam follower 8 located within the cam groove 5a of the forward cylinder 5. On the other hand, an outer 'tR9a in the direction along the axial direction is formed on the outer circumferential surface of the rotating ring 9;
tR9a engages with a projection (not shown) formed on the inner circumferential wall of the rotary forward cylinder 13, which will be described later, and thereby the rotation of the rotary forward cylinder 13 is transmitted to the rotary ring 9. The rotating ring 9 is held in the forward barrel 5 with only rotation allowed, by fixing the stopper 12 and the metal fitting II to the forward barrel 5 with screws. A metal fitting 1 fixed around the cylindrical portion 5b of the forward cylinder 5! A flexible printed wiring board 1 for a zoom encoder shown in FIG. 6 is fixed on the inner surface of the flexible printed wiring board 1 for a zoom encoder, and various lens position signals are generated by sliding this and the above-mentioned contact piece lO. The advancing barrel 5 holding the first lens group, the second lens group, and the zoom encoder in the above-described configuration is held inside the rotating advancing barrel 13 having a cylindrical shape. A substantially spiral cam IWt13b is provided on the inner circumferential surface of the rotation forward cylinder 13.
is formed so as to divide the circumferential surface into three equal parts. This cam groove 13b is a rotating forward cylinder! The groove does not penetrate through the thickness of the third piece, but is formed as a bottomed groove on the inner surface so that the width on the opening side is wider than the width of the groove bottom. Here, as shown in FIG. 1, the cam groove 13b
3 to form an opening. The forward barrel 5 is configured such that after a conical second cam follower 6 to be engaged with the cam groove 13b is attached to a boss 5d formed around the flange portion 5c, the cam follower 6 rotates to the subject of the forward barrel 13. It is guided into the cam groove tab from the side (left side in FIG. 3) and stored inside the cam groove tab. Although not shown, a ring for preventing the forward movement cylinder from being pulled out is attached to the rear end of the rotation forward movement cylinder 13. As shown in FIG. 1, a boss 13c is formed at a position dividing the outer periphery of the rotationally advancing cylinder 13 into three equal parts.
A third cam follower 14, which is the same as that attached to the forward cylinder 5, is attached to c. The rotation forward barrel 13 is housed inside the cylindrical fixed lens barrel I5 by engaging the attached third cam follower 14 with cam grooves 15a formed at three locations on the inner circumferential surface of the cylindrical fixed lens barrel I5. The cam 115a is connected to the cam groove 13 of the rotation forward cylinder 13 described above.
Like b, it is a spiral groove with a bottom, and the opening side is wider than the groove bottom. Further, as shown in the figure, the cam M15a is moved toward the front end of the cylinder by the fixed lens barrel I5.
The opening is formed by penetrating the end of the opening. After the rotating advance barrel 13 is inserted into the fixed lens barrel 15,
A retaining ring (not shown) is attached. A gear portion 13a is formed on the outer circumferential surface of the rotary forward barrel 13 in order to rotate the rotary forward barrel 13 by meshing with a gear connected to a zoom motor (not shown). Further, as shown in FIG. 5, a part of the fixed lens barrel is cut out and a film winding/rewinding gear hook 18 is disposed therein. This arrangement prevents the lens barrel from becoming too large. Incidentally, since the rotary advance barrel I3 moves along a cam groove 15a with respect to the fixed lens barrel 15 as will be explained later, the gear portion 13a is also formed in a spiral shape along this locus. Further, as shown in FIG. 3, the rotary forward cylinder 13 is formed with a notch +3d so as not to interfere with the flexible printed wiring board 1.2. A flange portion of a guide ring 16 composed of a cylindrical portion and a flange portion is fixed to the end portion of the fixed lens barrel 15 on the camera body side with screws. The cylindrical portion of this guide ring 16 fits into the inner circumferential surface of the rotary forward barrel 13, and the fixed lens barrel 15
The rotationally advancing cylinder 13 is held between the two. Further, inside this cylindrical portion, a groove portion 12 formed at the peripheral end of the stopper 12 is provided.
A guide member 17 that engages with a is fixed. This guide member 17 is connected to the flexible printed wiring board 1.2.
It is placed so that it does not interfere with the Regarding the zoom lens barrel configured as above,
The operation will be explained below. However, in this case, the initial state is set to the wide-angle side shown in FIG. As a premise of the zoom operation, when the zoom switch is turned on, the rotation of the motor is transmitted to a gear (not shown) attached to the fixed lens barrel 15 via a reduction gear train (not shown). Therefore, the rotary advance barrel 13 rotates within the fixed lens barrel 15 due to the action of the gear portion 13a, but the third cam follower 14 moves along the cam groove 15a, thereby moving the lens group, the second lens group, etc. It also moves in the optical axis direction together with the held forward barrel 5. By the way, the guide member 17 integrally included in the guide ring 16 screwed to the fixed lens barrel 15 is connected to the stopper 12 screwed to the forward barrel 5.
Since the rotary forward barrel 13 is engaged with the groove 12a of the fixed lens barrel 15, it moves forward while rotating with respect to the fixed lens barrel 15.
The forward barrel 5 only moves linearly with respect to the fixed lens barrel 15. Therefore, the rotation forward cylinder 13 and the forward movement cylinder 5 rotate relative to each other. As a result, the second cam follower 6 attached to the outer periphery of the flange portion 5c of the forward-moving cylinder 5 is connected to the cam groove on the inner periphery of the rotating forward-moving cylinder 13.
3b, the advancing section 5 itself moves further forward along the optical axis within the rotary advancing cylinder 13, and moves from the lun group by the same distance as this movement. At this time, the rotary ring 9 located around the cylindrical portion 5b of the forwarding tube 5 moves integrally with the forwarding tube 5 in the optical axis direction, but the outer groove 9a and the protrusion (unshaped) of the rotating forwarding tube 13 move in the optical axis direction. (Illustrated)
Since the forward cylinder 5 is engaged with the rotary forward cylinder 13, the forward cylinder 5 rotates together with the rotating forward cylinder 13. As the rotating ring 9 rotates relative to the forward cylinder 5, the cam groove 5
The first cam follower 8 located within the cam groove 5a
move along. In other words, the second lens group moves in the optical axis direction at this time as well, and the total amount of movement of the second lens group from the wide-angle side to the telephoto side is equal to the cam 17115a. 13b, inside 5a, three cam followers, -14,68
can be said to be the sum of the amounts moved along the optical axis. In this way, when zooming from the wide-angle side to the telephoto side, the second lens group is
The first cam follower 8 moves in the optical axis direction by an amount corresponding to the amount of movement in the optical axis direction. Here, a printed wiring board used in the wiring structure according to the present invention will be explained using FIGS. 6 and 7. FIG. 6 shows a flexible printed wiring board 1 for a zoom encoder (hereinafter referred to as a zoom signal board). As shown in the figure, this zoom signal board 1 has a pattern contact 1a at one end thereof, and various signals are generated by moving the above-mentioned contact piece 10 over this. A connecting portion 1k is formed at the other end, where it is connected to another board and signals are transmitted to a camera control unit such as a microcomputer. Holes Ib and lc formed around the pattern contacts
. ld, it is positioned and attached to the back surface of the metal fitting 11. On the other hand, a hole 1e is formed at the right end of the figure. The position of the Ir is regulated by engaging with a protrusion (not shown) formed on the fixed lens barrel. Also, the hole 1g at the top end. Holes lh are for positioning with other boards connected to this board, and holes 1 i and I j are holes for connecting with other boards. FIG. 7 shows a flexible printed wiring board 2 for shutter operation (hereinafter referred to as a shutter wiring board). This shutter wiring board 2 has at one end an annular portion 2a having an inner diameter and an outer diameter a that are substantially the same as those of the shutter block 3. This annular portion 2a is soldered and electrically connected to the shutter block 3. Further, a connecting portion 2r is formed at the other end, and is connected to another board here to transmit a signal from the camera control portion to the shutter. The holes 2b and 2c formed at the left end in the figure are engaged with protrusions (not shown) formed on the fixed lens barrel, and their positions are regulated. Further, the holes 2d and 2h at the upper end are for positioning with other boards connected to this board, and the holes 2e and 2h are for positioning with other boards connected to this board.
2g is a hole for connection to another board. Below, the wiring structure using these boards will be explained again in the first part.
This will be explained with reference to FIG. 4. The glossy wiring board 2 soldered to the shutter block 3 at the annular portion 2a passes through the connecting portion 2i+ and is then connected to the connecting portion 21. is inserted between the zoom signal board fixed to the metal fitting 11 and this metal fitting 11, and from then on, the zoom signal board 1
It overlaps with the communication part +12 and is guided to the camera body side. Therefore, the space (angle) in the circumferential direction that the communication portion 21°1i2 occupies on the lens barrel is the space for one lens. The overlapping communication portion 1ρ12+z passes through 1 (is, 2 L), and is bent at In, 2 m at the insertion opening 20 formed by the notches 15b and 16a, as shown in FIG. 2, and taken out of the lens barrel. Here, the communication part 2 i3. I Q, is the rotating surface
It passes through a notch 13d formed in , and the proportion of this notch +3d to the entire circumference of the rotary bending cylinder 13 is only one substrate. In addition, the guide member 17
As mentioned above, there is a constraint that it must be placed so as not to interfere with the board, but this constraint can also be achieved with a space that accommodates one board. FIG. 3 shows the state of each substrate 1.2 when the lens barrel is in a wide-angle state, and FIG. 4 shows the state of each substrate 1.2 when the lens barrel is in a telephoto state. There is. As shown in the figure, each substrate 1.2 is in an extended state in the telephoto state, and is folded and stored between the guide ring 16 and the metal fitting 11 in the wide-angle state. With the above configuration, during zooming, the rotary ring 9 holding the contact piece lO and the metal fitting 1 holding the zoom signal board l
1 rotates relatively. Therefore, the contact piece 10 moves on the zoom signal board 1, and various signals generated thereby are guided outside the lens barrel along the wiring path of the zoom signal board 1 and transmitted to the camera control section. The arithmetic-processed control signal follows the same path on the shutter wiring board 2 and is transmitted to the shutter. As explained above, in the above configuration, even if a plurality of boards are arranged for camera control, it is only necessary to form one insertion hole, and the space (angle) that the insertion hole occupies in the circumferential direction is ) may be the same as that of the insertion opening when only one board is inserted, and the space (angle) in the circumferential direction occupied by the board within the lens barrel is also the same as that for one board. Therefore, compared to forming as many insertion holes as there are substrates, the insertion holes of the present invention reduce the strength of the lens barrel to a very small degree. In addition, it is extremely small because only one board is required due to the constraints of arranging other parts avoiding a certain position on the board and providing relief parts for other parts so that the board can pass through. For these reasons, strength and accuracy can be maintained without the need to increase the size of the lens barrel. In addition, the gap that exists around the inserted board hardly increases compared to when only one board is inserted, and the amount of light leaking from there is smaller than when only one board is inserted. There will be no increase in comparison. In addition, the surface on which the substrate reflects light within the lens barrel does not increase as long as the surface area of the substrate is the same as in the case of one substrate. Not at all. In this way, according to the above configuration, a plurality of wiring boards can be disposed within the lens barrel without deteriorating the performance as an optical lens, and therefore the lens barrel can be downsized.

[Brief explanation of the drawing]

1 is an exploded perspective view of a lens barrel of a zoom lens having a wiring structure according to an embodiment of the present invention, FIG. 2 is a partial perspective view showing a wiring board insertion hole, and FIG. 3 is a wide-angle lens barrel. Figure 4 is a vertical cross-sectional view when the lens barrel is in the telephoto state, Figure 5 is a vertical cross-sectional view showing the relationship between the lens barrel and the film winding and rewinding gear box, and Figure 6 is a vertical cross-sectional view when the lens barrel is in the telephoto state. A plan view of the flexible printed wiring board for the encoder, and FIG. 7 is a plan view of the flexible printed wiring board for shutter operation. ■...Flexible printed wiring board for zoom encoder, 2...Flexible printed wiring board for shutter operation, 3...Shutter block, 4...Second
Lens frame, 5... Advance amount, 5a... Cam groove, 5b.
... Cylindrical part, 5c... Flange part, 5d... Boss,
6... Second cam follower, 7... Second lens frame,
8... First cam follower, 9... Rotating ring, 9a
...Outer groove, 9b...Inner groove, lO...Zoom encoder contact piece, 11...Metal fitting, 12...Stopping metal fitting, 12
a...Groove portion, 13...Rotation forward cylinder, 13a...Gear portion, 13b cam groove, l 3c...Boss, 14
...Third cam follower 15...Fixed lens barrel, 15
a: cam groove, 15b: notch, 16: guide ring, 16a: notch, 17: linear guide member, 18: gear box, 19: second lens Frame holding cylinder, 20...Insertion port Patent applicant Minolta Camera Co., Ltd. Agent
Person Patent attorney Maeda Ao (and 1 other person) Figure 5 Figure 3

Claims (1)

[Claims] (1). A plurality of flexible printed wiring boards (1, 2) for transmitting control signals are arranged in a stacked manner within the lens barrel of the optical lens, and the wiring boards (1, 2) are formed on the peripheral wall of the lens barrel. 1. A wiring structure within a lens barrel of an optical lens, characterized in that the wiring is inserted through one insertion port (20).