JPH0410584Y2 - - Google Patents

Description

[Detailed explanation of the invention] "Technical field" This invention is an AF (Auto Focus) SLR camera that can be attached between the body of a single-lens reflex camera and an interchangeable lens that does not have an AF function to enable automatic focusing. do
Regarding AF rear adapter.

"Prior Art and its Problems" In a normal AF single-lens reflex camera, a focus adjustment system built into the interchangeable lens is driven by a drive system on the body side to adjust the focus. In contrast, the rear adapter that is the object of the present invention is equipped with a focus adjustment lens itself, and by moving this focus adjustment lens in the optical axis direction by a drive system on the body side, Automatic focusing is also possible for interchangeable lenses that do not have a mechanism. In other words, for automatic focus adjustment, the focus adjustment lens on the interchangeable lens side is not used. On the other hand, the diaphragm device uses the diaphragm device on the interchangeable lens side and drives it by a drive mechanism on the body side.

In this AF rear adapter, it is necessary to adjust the position of the focusing lens to the correct position during assembly, and conventional products also have some kind of adjustment mechanism. However, most of the conventional mechanisms utilize a screw mechanism or insert washers of different thicknesses, and the adjustment work is complicated.

"Purpose of the invention" Therefore, the present invention makes it possible to easily adjust the position of the focusing lens during assembly and adjustment.
The purpose is to obtain an AF rear adapter.

"Summary of the invention" This invention is a single-lens reflex camera equipped with a focusing lens that is attached between the body of an autofocus single-lens reflex camera and an interchangeable lens, and is moved in the optical axis direction by a drive system on the body side. In the AF rear adapter for reflex cameras, there is a fixed tube attached between the body and the interchangeable lens; a reed tube that is integrated into this fixed tube; a focusing lens is fixed and rotates around the inner circumference of this lead tube. and a lens barrel fitted so as to be movable in the optical axis direction; a guide roller protruding from this lens barrel; this guide roller fitted, and the lens barrel moved in the optical axis direction as the lens barrel rotates. a lead groove or a cam groove formed on the lead cylinder; a drive mechanism that rotates the lens cylinder by a drive system on the body side; a circle that fixes the lead cylinder in an adjustable angular position with respect to the fixed cylinder; It is characterized by having a circumferentially long fixing hole and a fixing means consisting of a fixing screw.

According to this configuration, by adjusting the angular position of the lead barrel with respect to the fixed barrel and then fixing both, the initial position of the focusing lens in the optical axis direction can be easily adjusted.

``Embodiments of the invention'' The invention will be described below with reference to illustrated embodiments. Figure 9 is a front view of body B of an AF single-lens reflex camera.
The body side mount 11 is provided with a joint shaft 12 that is rotationally driven by a drive system (not shown), and on a part of the inner circumference of the body side mount 11,
An aperture drive member 13 is provided that moves in the direction of arrow A when the shutter is released.

Figure 10 is a rear view of an interchangeable lens L that enables AF using the rear adapter that is the object of the present invention.
The lens side mount 14 includes an aperture drive member 13.
An automatic diaphragm member 15 is provided which is driven by. Further, an aperture value transmitting protrusion 16 that rotates together with the aperture value setting ring of the interchangeable lens is provided, and this aperture value transmitting protrusion 16 engages with an aperture value reading protrusion 17 when attached to the body B. However, joint axis 12
There is no focus adjustment joint (driven shaft) that engages the two.

As is well known, when the shutter button is pressed, the aperture drive member 13 moves in the direction of arrow A before the shutter is released, and moves the automatic aperture member 15 in the same direction to set the aperture mechanism inside the interchangeable lens. It works to narrow down the aperture to the specified aperture value. Many such automatic diaphragm mechanisms are known in the past.

1 to 8 show an embodiment of an AF rear adapter 20 according to the present invention. This rear adapter has interchangeable lenses L at the front and rear of the fixed barrel 21, respectively.
A body side mount 11A to which the lens side mount 14 of the body B is attached, and a body side mount 11 of the body B.
It has a lens side mount 14A that is attached to the lens. 2
3 is a decorative ring fixed to the outer periphery of the fixed cylinder 21.
The lens side mount 14A includes a driven shaft 32 that engages with the joint shaft 12 on the body B side, an automatic aperture member 15a that engages with the aperture drive member 13, and an aperture value transmission protrusion that engages with the aperture value reading protrusion 17. 16a are provided.

A reed tube 25 having a lead groove (or cam groove) 25a is fixed to the inner circumference of the fixed tube 21 via a fixing screw 24, and a lens tube 26 is attached to the inner circumference of the lead tube 25 so as to rotate and rotate the optical axis. Supported for directional movement. A focusing lens 27 is fixed to the lens barrel 26. Further, a focus adjusting rotary tube 28 is rotatably supported on the outer periphery of the lead tube 25, and on the inner surface of the focus adjusting rotary tube 28,
A drive groove 28a parallel to the optical axis is cut. The guide roller 30 protruding from the outer periphery of the lens barrel 26 is fitted into both the lead groove 25a of the lead barrel 25 and the drive groove 28a of the focus adjusting rotary barrel 28. Therefore, when the focusing rotary barrel 28 is rotated, the lens barrel 26 is rotated and moved in the optical axis direction according to the relationship between the drive groove 28a and the lead groove 25a. Note that the focusing rotary tube 28 is sandwiched between the outer peripheral flange 25b of the lead tube 25 and the retaining ring 29, and is prevented from moving in the optical axis direction, and is only free to rotate.

According to the above-mentioned lens barrel structure, when the rotationally fixed position of the lead barrel 25 with respect to the fixed barrel 21 is changed, the lead groove 25a and the guide roller 3 fitted into the lead groove 25a are formed.
Since the lens barrel 26 is fixed at 0, the position of the lens barrel 26, that is, the focusing lens 27 in the optical axis direction changes.

The present invention attempts to adjust the position of the focusing lens 27 during assembly by utilizing this relationship, and for this reason, the fixing hole 21a drilled in the fixing tube 21 through which the fixing screw 24 is inserted is the third As shown in the figure, it is a long hole in the circumferential direction. Therefore, during assembly and adjustment, the lead tube 25 is rotated relative to the fixed tube 21 within the fixed hole 21a so that the focusing lens 27 is located at the reference position, for example, the infinity photographing position, and after adjustment, both are fixed. This will easily complete the adjustment.

A sector gear 31 is fixed to the focus adjustment rotating barrel 28, and this sector gear 31 meshes with a driven shaft 32 that engages with the joint shaft 12 of the body B and a gear train 34 that meshes with the driven shaft 32 (see FIG. 5). (See Figure 7). As shown in FIGS. 7 and 8, the driven shaft 32 is provided on the lens side mount 14A, and when the lens side mount 14A is attached to the body side mount 11 of the body B, it meshes with the joint shaft 12. The rotation is transmitted.

Both ends of the sector gear 31 are used as stoppers that restrict the rotation range of the focus adjusting rotation barrel 28. That is, as shown in FIG. 4, the fixed cylinder 21 is provided with a cylindrical rib 21b corresponding to the position of the sector gear 31.
A notch 21c is provided at b to engage with both ends of the sector gear 31 to restrict its rotation range.
Therefore, the infinity photographing position, which is one of the rotational ranges of the focusing rotary barrel 28, is regulated at the position where the right end of the sector gear 31 in FIG. 4 abuts the right end of the notch 21c, and the shortest photographing position is , the left end of the sector gear 31 is regulated at a position where it comes into contact with the left end of the notch 21c. According to this rotation range limiting mechanism, existing members are used without increasing the number of parts.

An aperture interlocking rod 36 extending in a direction parallel to the optical axis is fixed to the aperture driving rotary tube 35, and this aperture interlocking rod 36
The end on the body B side constitutes an automatic diaphragm member 15a that engages with the diaphragm drive member 13, and the end on the interchangeable lens L side constitutes the diaphragm drive member 13 that engages with the automatic diaphragm member 15.
constitute a.

This aperture drive rotating barrel 35 is the focus adjustment rotating barrel 2.
It is rotatably supported on the annular V-groove 37 of 8. A slope 38 corresponding to one slope of this V-groove 37 is formed on the diaphragm driving rotary cylinder 35.
The slope 4 formed on this slope 38 and the retaining ring 39
0 constitutes a V-groove 41 facing the V-groove 37. A ball 42 and a spacer 43 are inserted between the V grooves 37 and 41 to enable smooth rotation of the diaphragm driving rotary tube 35 on the focusing rotary tube 28. The spacer 43 is made of a low-friction synthetic resin material, and the spacer 43 is made of a synthetic resin material with low friction.
The number of can be reduced. However, V groove 37
All balls 42 may be inserted between and 41.

Further, on the inner periphery of the fixed barrel 21, a rotating barrel 44 for transmitting the aperture value is rotatably supported, and an aperture value interlocking rod 45 is fixed to the rotating barrel 44 for transmitting the aperture value. (See Figure 5). The aperture value interlocking rod 45 has an aperture value transmission protrusion 16a whose end on the body side engages with the aperture value reading protrusion 17, and an aperture value transmission protrusion 16a whose end on the lens L side engages with the aperture value transmission protrusion 16. This constitutes a value reading protrusion 17a.

Therefore, when the present AF rear adapter 20 having the above configuration is properly installed between the body B and the interchangeable lens L, its driven shaft 32 meshes with the joint shaft 12. Further, the automatic diaphragm member 15a of the diaphragm interlocking rod 36 engages with the diaphragm drive member 13, and the diaphragm drive member 13a
engages with the automatic aperture member 15 of the interchangeable lens L.
Furthermore, the aperture value transmission protrusion 16a engages with the aperture value reading protrusion 17, and the aperture value reading protrusion 17a engages with the aperture value transmission protrusion 16 of the interchangeable lens L.

In this state, if you press the shutter button,
First, the joint shaft 12 is rotationally driven by a drive signal from the AF control system, and the focus adjustment rotary barrel 28 is rotated by the interlocking system, and as a result, the lens barrel 26 (focus adjustment lens 27) is rotated. It moves in the direction of the optical axis and reaches the in-focus position. That is, by the composite lens system of the interchangeable lens L and the focusing lens 27,
In focus.

After that, or at the same time, the aperture drive member 13 moves in the direction of arrow A. Then, the automatic diaphragm member 15a (diaphragm interlocking rod 36) receives the force and integrally moves the diaphragm driving rotary tube 35 to the focus adjustment rotary tube 28.
The automatic diaphragm member 15 of the interchangeable lens L is driven via the diaphragm drive member 13a. Therefore, the aperture mechanism of the interchangeable lens L is instantaneously stopped down to the set aperture value. The shutter is then released.

``Effects of the invention'' As described above, this invention is an AF system for single-lens reflex cameras.
In the rear adapter, the angular position of the fixed barrel installed between the body and the interchangeable lens and the lead barrel that has a lead groove or cam groove that moves the lens barrel in the optical axis direction as the lens barrel rotates is adjusted. Since we made it possible and fixed it, just by adjusting its angular position,
The position of the lens barrel, that is, the focusing lens in the optical axis direction when assembled, can be adjusted. Therefore, with a simple adjustment system, it is possible to improve work efficiency and reduce the number of parts.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal cross-sectional view showing an embodiment of the AF rear adapter of the present invention, Fig. 2 is an exploded view showing the relationship between the lead groove of the lead cylinder and the drive groove of the focus adjustment rotary cylinder, Figs. Figure 4 is a sectional view taken along the - line and - line in Figure 1, Figure 5 is an exploded perspective view showing how the focus adjusting rotary barrel and the aperture drive rotary barrel are supported, and Figure 6 is the same assembled state. Figure 7 is a cross-sectional view showing the power transmission system from the driven shaft to the sector gear, Figure 8 is a rear view of the AF rear adapter of the present invention, and Figure 9 is the AF rear adapter.
Figure 10 is a front view of the body of a single-lens reflex camera, and a rear view of an interchangeable lens without an AF function that is attached to this body. B...Body, L...Interchangeable lens, 11, 11
A...Body side mount, 12...Joint shaft, 13, 13a...Aperture drive member, 14, 14A
... Lens side mount, 15, 15a ... Automatic aperture member, 16, 16a ... Aperture value transmission projection, 17, 1
7a...Aperture reading projection, 20...AF rear adapter, 21...Fixed tube, 25...Lead tube, 25a
... Lead groove, 26 ... Lens tube, 27 ... Focus adjustment lens, 28 ... Focus adjustment rotary tube, 28a
... Drive groove, 30 ... Guide roller, 31 ... Sector gear, 32 ... Driven shaft, 35 ... Rotating cylinder for diaphragm drive, 36 ... Aperture interlocking rod, 37, 41 ... V groove,
38, 40...slope, 42...ball, 43...
Spacer, 44... Rotating cylinder for aperture value transmission, 45...
Aperture value linked rod.

Claims (1)

[Scope of utility model registration claim] The body of an autofocus single-lens reflex camera,
An AF rear adapter for single-lens reflex cameras with a focusing lens that is attached between the interchangeable lenses and moved in the optical axis direction by a drive system on the body side. A barrel; A lead barrel that is integrated with the fixed barrel; A lens barrel to which the focusing lens is fixed and fitted onto the inner periphery of the lead barrel so as to be rotatable and movable in the optical axis direction; a guide roller protruding from; a lead groove or cam groove formed in the lead tube into which the guide roller is fitted and moves the lens tube in the optical axis direction as the lens tube rotates; a lead groove or a cam groove formed in the lead tube; a drive mechanism for rotating the reed tube by a drive system on the body side; and a fixing means consisting of a circumferentially long fixing hole and a fixing screw, which fixes the lead tube to the fixed tube in an adjustable angular position. AF for single-lens reflex cameras featuring;
Rear adapter.