JPH0248614A - Close-up photographing device - Google Patents

Abstract

PURPOSE:To change photographing magnification under keeping a photographing distance or an object distance constant and to improve operability by detecting the extension and contraction quantity of an intermediate device as the change of a space between a photographic camera mount part and a photographic lens mount part and moving a lens based on the changing quantity of the space. CONSTITUTION:A photographic lens A and a camera C are mounted and held on the intermediate device B through mount supporting members 51 and 52, which move back and forth along a guide rail 50 with the operation of normal and reverse rotation by knobs 54 and 58, so that the space between them extends and contracts. The supporting members 51 and 52 and the photographic lens A are linked as an interlocking member by a pantagraph 80 through three pins 1A, 51A and 52A. When the supporting member 52 is moved back and forth by a guide rail 50 with the operation of the normal and reverse rotation by the knob 58 in order to set the magnification as desired one, the pantagraph 80 extends and contracts. Then, the outer device 1 of the photographic lens A moves in an optical axis direction with respect to a guide barrel and the magnification can be automatically changed with force which works to the interlocking pin 1A of the photographic lens A.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a close-up photographing device used for close-up or enlarged photographing of a photographic subject using a camera.

(Prior Art) Conventionally, when performing so-called close-up photography at a photographic magnification of more than 0.2 times and up to about 10 times, an intermediate device has been used to widen the distance between the camera and the photographing lens. Generally, the intermediate device is a bellows-type feeding device that telescopically connects the camera mounting part and the wL shadow lens mounting part with a light-shielding bellows, or a so-called intermediate tube interposed between the camera and the photographic lens. It is widely used. Shooting magnification is determined by the amount of extension of the shooting lens, so
In the case of the former bellows type, the amount of expansion and contraction of the bellows is adjusted, and in the case of the latter tube, the desired imaging magnification is obtained by changing the length of the tube.

Figure 4 (a), (b), and (e) show green exposure f of the photographic lens.
It is a correlation model diagram between id and imaging magnification β.

is the photographing lens with focal length @f, F is the film plane as the imaging plane, Y is the subject, Y is the image formed, a is the subject pressure M (
Photographing lens LH subject Y. distance), b is the distance maintained Il! (
Photographing lens L → imaging plane F opening path 111), fi is photographing distance m
<Subject Y. 4-4 The distance between F and F is a).

(a) In the figure, the amount of extension of the photographing lens L is d=o, that is, the focal point of the lens L is located on the imaging plane F, and the photographing magnification β=l.
/oo is shown. Figures (b) and (C) each show a state in which the lens L is extended, and the photographing magnification β in figure (b) is approximately 1x, and in figure (e) it is 2x.

The imaging magnification β, the imaging distance 1lIIL, and the object distance a are each expressed by the following relational expressions.

β=Y/Yo=b/a=d/f...(1) 1=f(1
+β)2/β ・ ・ ・ ・ ・ (2) a=f
(1+1/β) ・ ・ ・ ・ ・ ・ (3)
From equation (1), J! ! Since the shadow magnification β is proportional to the lens extension id, in order to obtain the desired imaging magnification β, the lens extension f
The size of the id will be adjusted. Specifically, as mentioned above, a snake Jffl-type or tube-type feeding device is interposed between the camera and the photographic lens, and by adjusting the amount of expansion and contraction of the bellows and changing the length of the tube, the camera (focal plane of the camera) can be adjusted. Photographing is performed at a desired photographing magnification β by adjusting the amount by which the photographic lens is extended.

(Problems to be Solved by the Invention) However, conventional steering type or tube type simple edging devices have the following functional limitations or problems.

■If you change the shooting magnification β, the shooting distance will be ll! IIl changes. Therefore, it is necessary to perform an operation to change the camera position at the same time.

That is, when the photographing magnification β is changed by changing the lens extension amount d, the photographing distance 1111j2 changes according to the equation (2). This is the distance from the subject Y0 to the film F plane @j
Q: This means that the camera position must also be changed. When taking close-up shots, camera shake is likely to occur due to the high magnification β, and it is also difficult to capture minute objects within the shooting frame. It is common to shoot with the camera fixed. Therefore, the operation of moving the camera position and adjusting the focus in response to changes in the shooting distance of 111ffi due to changes in shooting magnification means moving the position of the stabilizing device itself, such as a tripod; , the camera and photographic lens installed in it,
It is a cumbersome operation to move the total weight of the entire intermediate device for close-up photography, and as a result of this movement, the minute subject falls outside the shooting frame, and all pre-shooting preparations such as determining the composition and adjusting the focus must be redone. This will cause inconvenience.

Further, vibrations generated when a stabilizing device such as a tripod is moved may cause the minute object to move, which tends to cause problems that disturb the set state for photographing.

(2) If the photographing magnification β is changed, the subject pressure ala will change according to equation (3) above. In other words, the distance l11a from the subject Yo to the photographic lens L must be changed.

In close-up photography, the subject pressure 11ia is much smaller than in general photography, and the photographing lens L is focused on the minute subject Y.

Because the object is extremely close to the subject, moving the photographic lens position relative to the subject after focusing etc. on the subject is likely to cause the tip of the photographic lens to hit the subject, which may cause the subject to shift and move. Accidents can easily occur where the composition is distorted or the subject or photographic lens is damaged.

In addition, in order to illuminate the subject in this state, a lighting device such as a tungsten lamp or strobe is placed in a position where the illumination light is not eclipsed by the photographic lens and the subject is uniformly or in the desired light distribution, and then the amount of illumination light is must be determined.

In many cases, a plurality of illumination devices are used instead of just one, and an illumination device attached to the tip of the photographic lens is sometimes used. Therefore, changing the distance j11a between the subject and the photographic lens after determining the illumination state tends to cause the inconvenience of having to reset the illumination device and its light amount.

An object of the present invention is to provide a close-up photographing device that solves the above-mentioned problems.

(Means for Solving the Problems) The present invention comprises a camera, a photographic lens, and a camera, a photographic lens, and a camera, a camera, a photographic lens, and the like, in which both are held after feeding with their optical axes substantially aligned, and the distance between the two in the optical axis direction is set to a desired value for photographing. It has an intermediate device that changes the size depending on the magnification, and the intermediate device communicates between a camera mounting part and a photographic lens mounting part that can move relatively away from each other in the optical axis direction and a photographing lens mounting part, and the two mounting parts. The intermediate device is a telescopic device having a telescopically configured dark casing, the photographing lens being a variable focal length photographing lens, and the photographing lens mounting portion of the intermediate device having the variable focal length &
When the engraving lens is kept attached and the intermediate device is operated to extend or contract in order to set a desired photographic magnification, the amount of expansion or contraction of the intermediate device is detected as a change in the distance between the photographing camera mounting portion and the photographing lens mounting portion. and a moving means for moving the lens related to the focal length change of the photographing lens to an appropriate position in the optical axis direction based on the amount of change in the interval.
This is a close-up photographing device characterized by the following.

(Operation) Figures 1 (1) and (2) are graphs qualitatively explaining the principle and operation of the device of the present invention.

(A) The graph in Figure 1 (1) is obtained by solving the above optical formula (2), that is, It=f (1+β)2/β... (2) with the shooting distance @i as a constant value. The focal length f of the photographing lens is changed from increasing to decreasing in conjunction with an increase in the lens extension amount d (the increase in the distance between the photographing lens and the film (focal plane) when the photographing magnification is 1/ω). By doing so, the photographing magnification β can be monotonically increased without changing the photographing distance β.

Since the above-mentioned optical system (2) is an image forming system, the photographing focus will not shift even if the green exposure amount d is changed.

Therefore, if f is changed in conjunction with the change in d along the graph in FIG. It is possible to eliminate all the various inconveniences associated with moving a tripod for changing magnification.

Figure 2 shows variable focal length photographic lens A as a photographic lens.
This is an example optical system model diagram of L1L2 and L3.
-L4 is a lens group each composed of one or more lenses, and D is an aperture. 2nd lens group L1 ・2nd lens group L2 ・3rd lens group L3 ・4th lens group
By moving the lens group L4 and the aperture D, the focal length is changed, that is, the magnification is changed.

The lens position states of (a), (b) and (C) in Figure 2 are the focal lengths f and -f2 on the graph in Figure 1 (1), respectively.
- Shows the position state at f3. (a) and (C)
has an optically conjugate arrangement, f, = f3.1/
Since β,=β3, β2=×1. In other words, the second lens group L2, the third lens group L3, and the diaphragm D move linearly as a unit. The lens group L1 and the fourth lens group L4 are the second lens group L2, the third lens group L3, and the aperture D.
(b)
The distance between each lens is the closest. Furthermore, the movements on the optical axis of the second lens group and the fourth lens group relative to the second lens group L2, the third lens group L3, and the aperture D are the movements from photographing magnification β1 to β2 (equal magnification) and from β3 to It is configured so that the movements up to β2 (same magnification) are equal. In other words, the second lens group L2, the third lens group L3,
The lens group L1 and the fourth lens group L4 for the aperture D
The position at the bowl magnification is shown in FIG. Furthermore, at each magnification and at any imaging magnification between them, the distance between the subject and the intended imaging plane is always constant, and once focused, there is no need to focus again even if the magnification is changed.

(B) The graph in Figure 1 (2) is based on the optical formula (3), that is, a=f (1+l/β)...
(3) is solved by assuming that the subject distance 111a is a constant value, and the lens extension ff1d (imaging magnification 110
If the focal length f of the photographic lens is monotonically increased in conjunction with the increase in the distance between the photographic lens and the film (focal plane) relative to time o, the photographic magnification β can be increased without changing the subject distance @a. It can be monotonically increased. Above optical type (3)
is an image forming type, so by changing the lens extension ID,
The shooting focus will not shift. Therefore, if f is changed in conjunction with the change in d along the graph in Figure 1 (3), the above (
Problems to be Solved by the Invention) The disadvantages described in item 0 of the section ``Problems to be Solved by the Invention'', such as movement of the subject caused by moving the photographic lens, damage to the subject or the photographic lens, and resetting of the lighting device, can be avoided. It is possible to eliminate all of them. The movement of the optical system of the variable focal length photographing lens, which is the photographing lens, changes from a short focus state as shown in FIG. 3(a) to as shown in FIG. It is sufficient if it is of the type that moves to a long focal state.

(Embodiment) FIGS. 5 to 9 are side views of an apparatus according to an embodiment of the present invention that satisfies the relationship shown in FIG. 1 (1), and A is a variable focal length photographing lens ( Hereinafter, it is abbreviated as a photographing lens), B is a general code for an intermediate device (bellows), and C is a camera. Regarding camera C, the outline is shown by 2 points and 3n lines, and the detailed structure is omitted.

■The configuration of the photographic lens A is mainly shown in 1.
2 is an exterior ring, and 2 is a guide tube that is fitted concentrically into this exterior ring. The exterior ring 1 is freely slidable in the direction of the optical axis 0-O with respect to the guide tube. Reference numeral 3 denotes a front group cam cylinder which is fitted concentrically into the guide cylinder, and is rotatable forward and backward around the optical axis inside the guide cylinder. Reference numeral 4 denotes a fixed lens barrel which is integrally bolted to the rear end of the guide tube 2 concentrically with the guide tube and protrudes rearward from the rear end of the exterior ring 1, and 5 is provided concentrically with the fixed lens barrel. This is a rear group cam barrel that is fitted onto the outside of the fixed lens barrel, and can freely rotate forward and backward around the optical axis on the outside of the fixed lens barrel. Reference numeral 6 designates an annular mount that is integrally attached and fixed to the distal end flange portion of the fixed m-cylinder 4 at the rear end position of the outer ring 1, and is for attachment to an intermediate device B, which will be described later. Therefore, the three members, the guide tube 2, the fixed m tube 4, and the mount 6, are integral with each other.

Reference numeral 7 denotes a lens barrel holding the lens group L1, which is fitted inside the front group cam barrel 3 at the tip end side thereof and concentrically with the cam barrel. Reference numeral 8 denotes a second lens group barrel holding the second lens group L2, which is integrally mounted and supported at the tip of the fixed lens barrel 4, and is mounted inside the cam barrel 3 on the rear end side of the front group cam barrel 3. It is located concentrically with the cam cylinder.

Reference numeral 9 denotes a third lens group l! which is integrally molded within the fixed lens barrel on the distal end side of the fixed lens barrel 4, concentrically with the lens barrel. It is a cylinder and holds the third lens group L3. 1
0 is a fourth lens group lens barrel fitted inside the rear end side of the fixed lens barrel 4, and holds the fourth lens group L4. Reference numeral 11 denotes an aperture unit that is integrally mounted and supported on the fixed lens barrel 4 side in the open position with the second and third lens group barrels 8 and 9, and includes a stepping motor lla. The aperture D is driven.

12 and 12a (FIG. 8) are first and second linear grooves parallel to the optical axis provided in the guide tube 2, and 15 and 15a are provided in the cylindrical surface of the front group cam tube 3. first and second hemline cam slots. 16 is a pin shaft installed in the lens group lens barrel 7, and is located at the intersection of the first edge cam slot 15 of the surface group cam barrel 3 and the first rectilinear slot 12 of the guide barrel 2. Throughly engaged. Reference numeral 1a denotes a pin shaft implanted in the exterior ring 1, which is penetratingly engaged with the intersection of the second linear groove 12 of the guide tube 2 and the second edge cam groove 15a of the front group cam tube 3. ing.

21 is a linear groove parallel to the optical axis provided on the cylindrical surface of the fixed lens barrel 4; 22 is a helical cam slot provided on the cylindrical surface of the rear group cam tube; 23 is a groove provided on the fourth lens group barrel 10. This is a pin shaft that is implanted, and this pin shaft is penetratingly engaged with the intersecting portion of both the slots 21 and 22 mentioned above.

A key member 25 has one end fixed to the outer surface of the front end side of the rear group cam cylinder 5 and the other end fitted into a notch groove 26 formed in the rear end flange of the front group cam cylinder 3. Front group cam tube 3
When the is rotated in the forward or reverse direction, the rotational force is applied to the key member 25.
is transmitted to the rear group cam cylinder 5 through the rear group cam cylinder 5, and the rear group cam cylinder 5 rotates in the forward and reverse directions relative to the rear group cam cylinder 3.

28 is an electric signal bin assembly provided on the mounting mount 6; 29 is a circuit unit fixed to the outer surface of the guide tube and housed in the gap space between the outer ring l and the guide tube 2;
The aforementioned aperture unit 11 and electric signal bin assembly 28
It is electrically coupled to via a lead wire (not shown).

Reference numeral 32 denotes a fixed index attached to the outer surface of the rear end side of the exterior ring 1, and serves as an alignment mark when attaching the photographing lens A to an intermediate device B, which will be described later.

Reference numeral 1A denotes an interlocking pin that is integrally implanted on the upper surface of the exterior ring 1 and moves the exterior ring forward and backward in the optical axis direction with respect to the guide tube 2.

Thus, in the photographing lens A in this embodiment, the outer ring l moves forward and backward in the optical axis direction with respect to the guide tube 2.
This causes the internal lens to move and change the focal length.

In the vertical cross-sectional view of the photographing lens A in FIG. 8, the optical axis is 0-0.
In the upper half from the optical axis, the outer ring 1 is moved backward in the optical axis direction with respect to the guide M2, and the internal lens groups L1 to L4 are converted into a short focal length state (magnification β1). In the lower half of the array from the optical axis, the outer ring 1 is moved forward in the optical axis direction with respect to the guide tube 2 to form an internal lens group, and ~L4 is a lens converted to a long focal length state (magnification β2). It shows a group arrangement.

That is, when the exterior ring 1 is moved forward with respect to the guide tube 2, the front group cam tube 3 moves along the optical axis within the guide tube 2 due to the engagement between the pin shaft 1a and the second edge cam slot 15a. In conjunction with the normal rotation of the front group cam barrel 3, the first lens group lens barrel 7, that is, the first lens group L1 fitted inside the cam barrel 3, rotates in the forward direction. Due to the engagement of the pin shaft 16 with the helical cam slot 15 and the first rectilinear slot 12 of the guide tube 2, the lens is moved backward in the direction approaching the second lens group L2. In addition, as the front group cam cylinder 3 rotates forward around the optical axis, the rear group cam cylinder 5, which is connected by the key member 25, is fixed integrally with the front group cam cylinder 3. After that, in conjunction with the forward rotation of the group cam barrel 5, the fourth lens group barrel 10, that is, the fourth lens group L4, which is fitted inside the fixed lens barrel 4, moves in the straight groove of the fixed lens barrel 4. The engagement of the pin shaft 23 with the hole 21 and the edge cam slot 22 of the rear group cam cylinder 5 causes the lens to move forward in the direction approaching the third lens group L3. As a result, the internal lens group of photographing lens A, ~L4
From the optical axis 〇-〇 in Fig. 8, the upper half has a short focal length state (Fig. 2(a), magnification β1), and the lower half has a long focal length state (Fig. 2(b), magnification β2). It has been converted to an even shorter focal length! ! 3 ((C) in the same figure, β3).

On the contrary, when the outer ring 1 or the guide tube 2 is moved backward, an operation opposite to that described in -F occurs and the inner lens group ~L4 opens from the short focus state β3 to Fig. 8. Optical axis 0-
0, the state is converted to the short focal length state β1 of the lower half through the long focal length state β2 of the lower half.

II. Structure of intermediate device B In the side view of the device in FIG. 5, the plan view in FIG. 6, and the sectional view in FIG.
51 a is a rack fixedly provided along the longitudinal direction of the upper surface;
is a support member (hereinafter referred to as the first support member) on which the photographing lens is attached, and is placed on the guide rail member 5'0 so that the base side engages with the rail member in a dovetail groove and extends along the length of the rail member. It allows for smooth and stable forward and reverse sliding movement. Reference numeral 52 denotes a support member (hereinafter referred to as a second support member) for mounting the camera, and on the rear side of the first support member 51, a dovetail groove engages with the guide rail member 50F on the base side with the rail member. This allows the rail member to be mounted so that it can smoothly and stably slide forward and backward along the length of the rail member.

Reference numeral 53 denotes a drive knob shaft disposed on the base side of the first support member 51 so as to pass through the member in the left-right direction and be freely rotatably supported;
54, 54 are knobs fixed to both left and right ends of the knob shaft;
Reference numeral 5 designates pinion gears fixed to intermediate portions of the knob shaft. Therefore, when the knob 54 is rotated in the forward and reverse directions, the pinion gear 55 and the rack 50a on the guide rail member 50 side are engaged with each other, so that the first member 51 is rotated toward the rail member 50.
It slides forward and backward along.

Similarly, regarding the second support member 52, a drive knob shaft 57 is disposed through the base side of the second support member 52 so as to be freely rotatably supported, and a drive knob shaft 57 is disposed in the middle thereof to be engaged with the rack 50a on the guide rail member 50 side. A matching pinion gear 59 is provided, and by rotating knobs 58 fixed to both left and right ends of the knob shaft 57 in forward and reverse directions, the second member 52 slides forward and backward along the rail member 50.

Reference numeral 66 indicates a fixed index attached to the outer surface of the uppermost part of the lens mounting mount, which is attached to the front surface of the first support member 51 as a support member, and is connected to the fixed index 32 attached to the side of the photographic lens A. This is the alignment mark.

The camera is mounted on the second support member 52 as a support member, and 68 is an annular mount for mounting the camera fixed concentrically with the opening for mounting the camera on the back side of the member 52.

69 is interposed between the first support member 51 and the second member 52, with the front end fixed to the first support member 51 and the rear end fixed to the second support member 52. It is a bellows serving as a dark casing with an expandable and retractable structure in which the photographing lens fitting opening on the side and the camera mounting phase opening on the second support member 52 side are communicated in the nine-light axis direction.

Reference numeral 70 denotes an electric signal bin assembly mounted on the annular mount 68 for mounting the camera marked -F.

By engaging a facing mount (not shown) on the camera C side with the mount 68, the camera C is firmly mounted and supported on the second support member 52.

When the camera C is properly mounted and supported on the second support member 52 via the mount 68, the mount 68
An electrical signal bin assembly (not shown) on the camera C side comes into corresponding contact with the electrical signal bin assembly 70 on the side, and the two assemblies are in electrical communication with each other.

Electrical signal bin assembly 70 on the second support member 52 side
and the same assembly (not shown) on the first support member 51 side.
are electrically connected via lead wires (not shown). Therefore, the photographic lens A is attached to the first support member 51 of the intermediate device B.
When the cameras C are properly mounted and supported on the second support members 52, the electric circuit on the camera C side and the photographic lens A are connected to each other.
The electrical circuits on both sides are in contact with each other.

The bellows 69 moves the first support member 51 and/or the second support member 52 forward and backward along the guide rail member 50 by forward and reverse rotation operations of the knobs 54 and 58, thereby increasing and decreasing the mutual spacing between the members 51 and 52. When changed, it expands and contracts depending on the size of the mutual spacing, and the opening for fitting the photographing lens on the first support member 51 side and the opening for attaching the camera on the second support member 52 side have a dark path along the optical axis. Always communicated.

Reference numeral 80 includes a first support member 51 as a support member for mounting the J1 shadow lens, a photographic lens A mounted and supported by this first support member 51, and a second support member 52 as a support member for mounting the camera. This is a pantograph-type link structure (hereinafter referred to as a pantograph) as an interlocking member that connects two parts. Three engagement holes 81, 82, 83, first to third, are provided at the tip, middle, and rear end of the pantograph 80, and the upper surfaces of the first and second support members 51, 52 Interlocking bins 51A and 52A are respectively installed upwardly in approximately the center. Then, the interlocking bin IA of the photographing lens A attached to the first support member 51, the first and second support members 51
・3 bins IA of 52 above-mentioned interlocking bins 51A and 52A
- By fitting and engaging the three engagement holes 81, 82, and 83 of the pantograph 80 with 51A and 52A, respectively, the three members of the photographing lens A, the first support member 51, and the second support member 52 are connected. The pantograph 80 is connected to the pantograph 80.

For the photographic lens A, insert the rear group cam cylinder 5 portion of the photographic lens A into the photographic lens insertion opening of the first support member 51,
The rotation angle posture of the photographic lens A is adjusted so that the fixed index 32 on the photographic lens A side corresponds to the fixed index 66 on the first support member 51 side, and the mount 6 on the photographic lens A side is attached to the first support member 51. Place the photographic lens A in contact with the mount 61 on the side.
is sufficiently rotated clockwise (approximately 60°) until further rotation is prevented by a stopper portion (not shown). As a result, the photographing lens A is stably mounted and supported on the first support member 51 by the mutual engagement of the mounts 6 and 61. In the normal mounting state, the photographing lens A has the interlocking bottle IA installed, and the surface portion thereof is the upper surface, and the interlocking bottle IA is in an upward state.
The pantograph 80, which is an interlocking member, can be attached and connected to the photographic lens A and the first and second support members 51 and 52.

84 (FIG. 6) is a magnification calculation scale plate provided along the longitudinal direction on the upper surface of the guide rail member 50.

(2) Interlock between intermediate device B and photographic lens A. Photographic lens A is connected to first support member 51 of bellows B,
Cameras C are respectively attached to the support member 52, and photographic lenses A,
As described above, the pantograph 80 is engaged and attached to each of the upward interlocking bins IA, 51A, and 52A of the three members, the first support member 51 and the second support member 52.
1 and 52 are connected, when the second support member 52 of the bellows B is slid forward and backward along the guide rail member 50 by rotating the knob 58 in the forward and reverse directions, the pantograph 80 expands and contracts.

In this case, the pantograph 80 has a distance LA between the engagement hole 81 engaged with the interlocking pin IA of the photographic lens A and the engagement hole 82 engaged with the interlocking pin 51A of the first support member 51.
The ratio of the distance RLa between the engagement hole 82 engaged with the interlocking pin 51A of the first support member 51 and the engagement hole 83 engaged with the interlocking pin 52A of the second support member 52 is It always expands and contracts in a constant manner. In conjunction with the movement operation of the second supporting member 52 along the guide rail member 50, the Jail shadow lens mounted and supported on the first supporting member 52 is moved in the front-rear direction via the pantograph 80. Push and pull forces act to move the exterior ring 1 of the photographic lens A forward and backward relative to the guide tube 2 in the optical axis direction, and automatic changes in #i & shadow magnification (β1 β2 β3) are performed.

Specifically, as shown by the solid line in FIGS. 5 and 6, the first support member 51
is located at the tip side of the guide rail member 50, and the second
When the support member 52 is positioned closest to the first support member 51, the photographic lens A is in the lens array state of short focus state β1 (shown on the lower half side from the optical axis in FIG. 8). The lens arrangement state is shown in FIG. 2(a).

The knob 58 of the second support member 52 is reversely rotated to move it backward along the guide rail member 50 in the direction away from the first support member 5 as shown by the two-dot sn line and the three-dot chain line. Then, the outer ring 1 of the photographic lens A
is moved forward (extended) in the optical axis direction with respect to the guide tube 2, and the photographing lens A is in the lens arrangement state of the long focus state β2 (the lens arrangement state shown in the lower half side of the optical axis in Fig. 8). , FIG. 2(b)), and then further converted to the short focus state β3 (FIG. 2(C)). That is, photographing magnification change β1→β
2 → β3 is done. Conversely, the second support member 52 is moved along the guide rail member 50 by rotating the knob 58 in the forward direction.
By moving forward in the direction approaching the support member 51, the exterior ring 1 of the photographing lens A moves toward the guide tube 2.
As the photographing lens A is moved backward (retracted) in the optical axis direction, the lens arrangement state is changed to short focus β3→long focus β2→short focus β1.

With the above configuration, in other words, to attach the camera to the bellows B, rotate the lens-side drive knob 54 without operating the support member 52, and to attach the lens, widen the distance between the support member 51, and to attach the camera, to widen the distance between the support member 52. , the movement of each lens group and diaphragm D with respect to the mount 6 of the optical system of photographing lens A is shown in Figure 3, and the movement of each lens group and diaphragm D with respect to the planned imaging plane (film surface) is shown in Figure 2 (a). →(b)→(
C), and the relationship shown in FIG. 1 (1) is satisfied.

■, Other Examples (Fig. 10) This example satisfies the relationship shown in Fig. 1 (2) above.
FIG.

In this case, the optical system changes from a short focus state as shown in Figure 3 (a) to (b) as the amount of bellows B increases.
It suffices to use a type that moves to a long focus state such as , and the basic configurations of the photographing lens A and the bellows B may be the same as in the previous embodiment.

Here, the linear groove 21 of the fixed lens barrel 4, the first linear groove 12, the second linear groove 12a of the guide tube 2, and the cam groove of the rear group cam tube 5 in the photographic lens A 3 of the above-mentioned embodiment. 22, the first cam groove 15 and the second cam groove 15a of the front group cam cylinder 3 are respectively
0 figure 21'12' 12a 22'15'
By changing the shape to 15a', the focal length of the photographic lens A can be monotonically increased with respect to an increase in the amount of extension of the bellows B.

With this configuration, contrary to the previous embodiment, the lens of the bellows B is attached by rotating the camera-side drive knob 58 without operating the support member 51, and the lens is attached between the support member 51 and the camera is attached between the support member 52. When an operation is performed to widen the distance, the focal length of the photographing lens A increases monotonically, and conversely, the focal length of the photographic lens A increases
If an operation is performed to shorten the distance between the two, the focal length will decrease monotonically. Therefore, the relationship shown in FIG. 1(2) is satisfied, and the photographing magnification can be changed simply by adjusting the amount of extension of the bellows B without moving the photographing lens A.

(Effects of the Invention) According to the present invention, it is possible to change the photographing magnification while keeping the photographing distance or subject distance constant, so the above-mentioned problems are solved and the intended purpose is well achieved.

[Brief explanation of the drawing]

Figures 1 (1) and (2) are principle mode graphs for close-up photography, Figures 2 and 3 are optical system model diagrams of variable focal length photographing lenses, and Figures 4 (a) and (b). e) is a correlation model diagram of the lens extension amount and photographing magnification, Figures 5 to 9 show the example device, Figure 5 is a side view of the device, Figure 6 is a plan view, and Figure 7 is a 8 is a longitudinal sectional side view of the photographing lens, FIG. 9 is a developed view of the main parts, and FIG. io is a developed view of the main parts of the photographic lens of another embodiment. A is a photographic lens (focal length variable photographic lens), B is an intermediate device (bellows), C is a camera, L1 to L4 are first to fourth lens groups, D is a diaphragm, and 51 and 52 are photographic lenses of the intermediate device, respectively. Mounting is a support member (first support member), Gamera is mounted on a support member (second support member), 50 is a guide rail member,
54 and 58 are support member movement operation knobs. Meika patent applicant Canon Co., Ltd. Yizu

Claims (1)

[Claims] (1) It has a camera, a photographing lens, and an intermediate device that holds the two front and back with their optical axes substantially aligned, and that changes the distance between them in the optical axis direction depending on the desired photographic magnification. The intermediate device includes a camera mounting section and a photographic lens mounting section that can be moved relatively apart and toward each other in the optical axis direction, and a dark housing section that is freely extendable and retractable and that communicates between the two mounting sections. The intermediate device is a telescoping device having a telescopic device, wherein the photographing lens is a variable focal length photographing lens, and the variable focal length photographing lens is attached and held to the photographing lens mounting portion of the intermediate device, and the intermediate device is configured to set a desired photographic magnification. means for detecting the amount of expansion and contraction of the intermediate device as a change in the distance between the photographing camera mounting section and the photographing lens mounting section when the intermediate device is operated to extend or contract; having a moving means for moving the lens to an appropriate position in the optical axis direction;
A close-up photographing device characterized by: