JPH0320726B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a lens barrel with a built-in turret filter, and more particularly to a lens barrel with a built-in polarizing filter in which at least one of the holding filters is a polarizing filter.

A turret type filter has a turret type filter frame whose rotation center is outside the optical axis of the lens, and holds multiple filters that can be moved along the optical axis as the filter frame rotates. It is mainly built into short-focus interchangeable lenses.
There are no particular restrictions on the type of filter that can be held in this filter frame, but in conventional devices, the filter is fixed to the filter frame, so polarizing filters that need to be rotated during use cannot be held due to their nature. I stopped talking. In other words, there was no idea to incorporate a polarizing filter into a turret filter. Therefore, when using a polarizing filter, the only way to use it is to fit it into the filter frame at the front end of the lens and rotate it while visually checking the effect with the filter.Furthermore, the front element of the lens is moved far forward like an ultra-wide-angle lens. In some cases, lenses that protrude cannot be used.

The present invention reconsiders the conventional wisdom regarding such turret-type filters, that is, the fixed idea that the filter is fixed to a frame and cannot be rotated, and makes the turret-type filter hold the polarizing filter. This was created based on a new idea, in which at least one of the holding filters of the turret type filter frame is a polarizing filter, which can be rotated with respect to the filter frame, and this polarizing filter and the turret type filter It is characterized by providing a rotation means for separately rotating the frame.

The invention will now be described with reference to the illustrated embodiments. 1 to 5 show a first embodiment of the present invention, in which reference numeral 11 indicates a fixed lens barrel 12 attached to the camera body, and a focus ring 13 rotatably supported by the fixed lens barrel 11 has a helicoid attached thereto. The lens barrel is screwed together through a lens barrel 14, and a front frame 15 is integrally screwed to the front part of the lens barrel. Therefore, the lens barrel 12
The front frame 15 moves back and forth in the optical axis direction following the helicoid 14 as the focus ring 13 rotates.

The turret type filter frame 16 has a disk shape, and its center is rotatably supported by the lens barrel 12 by a shaft screw 17 at a position off the optical axis of the lens. A plurality of different types of filters 18 are supported on the circumferential surface of the turret type filter frame 16, which move along the optical axis as the turret type filter frame 16 rotates. One of the filters 18 is a polarizing filter 20 fixed to a polarizing filter frame 19,
Polarizing filter frame 19 is turret type filter frame 1
6, and an engaging surface 21 is formed on the front surface of this polarizing filter frame 19.

The turret type filter frame 16 integrally has a filter conversion gear 22 in its center, and this filter conversion gear 22 is bored with radial interlocking grooves 23 of a number corresponding to the number of holding filters of the turret type filter frame 16. It is set up. The radial interlocking groove 23 is engaged with the interlocking pin 25 of the filter conversion tube 24 which is rotatably fitted into the inner surface of the lens barrel 12, and as the filter conversion tube 24 rotates, the radial interlocking groove 23, that is, the turret type filter frame is engaged. 16 is configured to rotate.

On the other hand, on the inner surface of the lens barrel 12, a polarizing filter rotating barrel 26 is supported so as to be rotatable around the optical axis and movable in the optical axis direction, and the rear end thereof is connected to the engaging surface 21 of the end face of the polarizing filter frame 19. An engageable cylindrical engagement surface 27 is formed. This engagement surface 2
1 and 27 are formed into knurled shapes in this embodiment, but when they come into contact, the filter conversion cylinder 24
Any surface or material can be used as long as the rotation of the polarizing filter frame 19 is transmitted to the polarizing filter frame 19.
Reference numerals 28 and 29 in FIG. 1 indicate a click ball and its biasing spring for stopping the turret type filter frame 16 with the filter 18 correctly positioned on the optical axis.

Therefore, according to the above configuration, when the filter conversion cylinder 24 is rotated, the turret type filter frame 16
is rotated to replace the filter 18 located on the optical axis, and with the polarizing filter 20 positioned on the optical axis, the polarizing filter rotating cylinder 26 is moved rearward in FIG. 1 to engage its engaging surface 27. By bringing it into contact with the mating surface 21 and then rotating the rotary cylinder 26, the polarizing filter 20 will rotate.

However, in this embodiment, the filter conversion tube 24
The rotation and movement and rotation of the polarizing filter rotary barrel 26 in the optical axis direction are performed by a single filter operation ring 30 supported on the lens barrel 12 so as to be rotatable and movable in the optical axis direction. A radial interlocking pin 31 is implanted in the filter conversion tube 24, and this interlocking pin 31 passes through a circumferential groove 32 bored in the lens tube 12 and into a filter conversion groove 33 of the filter operation ring 30. It is embedded. The filter conversion groove 33 consists of an escape groove 33a in the circumferential direction and an interlocking groove 33b in the optical axis direction, and when the filter operation ring 30 is moved forward in the optical axis direction (to the left in FIG. 1), the interlocking groove 33b In the state in which the interlocking pin 31 is fitted, the filter operation ring 30 and the filter conversion cylinder 24 rotate together. On the other hand, the filter operation ring 30 is moved rearward and the relief groove 3
When the interlocking pin 31 is fitted into 3a, the rotation of the filter operation ring 30 is not transmitted to the filter conversion cylinder 24.

On the other hand, the radial interlocking pin 35 installed in the polarizing filter rotation tube 26 passes through the planar dogleg-shaped guide groove 36 bored in the lens tube 12 and connects to the polarization filter rotation groove 37 of the filter operation ring 30. It is embedded in Similar to the filter conversion groove 33, the polarizing filter rotation groove 37 is a circumferential relief groove 37.
a and an interlocking groove 37b in the optical axis direction, and when the filter operation ring 30 is moved backward in the optical axis direction (to the right in FIG. 1) and the interlocking pin 35 is fitted into the interlocking groove 37b, the filter Operation ring 3
When the filter operating ring 30 is moved forward and the interlocking pin 35 is fitted into the escape groove 37a, the rotation of the filter operating ring 30 is caused by the rotation of the polarizing filter rotating barrel 26. It is no longer being transmitted. That is, the filter operation ring 30 integrally rotates the filter converting cylinder 24 at the forward sliding end, and integrally rotates the polarizing filter rotating cylinder 26 at the rearward sliding end. Note that the filter operating ring 30 can be biased to slide forward, for example, in FIG. 1.

As is clear from FIG. 5, the guide groove 36 moves the polarizing filter rotating barrel 26 in the optical axis direction until its engaging surface 27 engages with the engaging surface 21 when the polarizing filter rotating barrel 26 rotates. inclined guide groove 36
a and a circumferential groove 36b that interlocks with the circumferential groove 36b. The length a of the inclined guide groove 36a in the optical axis direction is
The distance a is equal to the distance a required for the engagement surface 27 of the polarizing filter rotating barrel 26 to come into contact with the engagement surface 21 of the polarizing filter frame 19 . Here, when the filter operation ring 30 moves rearward, the interlocking pin 35 is inserted into the axial groove 37b.
When the filter operation ring 30 is inserted into the guide groove 36 and then rotated, it moves rearward while rotating along the circumferential groove 36b. In order to maintain the filter operation ring 30, the rearward movement amount b (see FIGS. 3 and 4) is set to be longer than the length a of the inclined guide groove 36a in the optical axis direction.

Therefore, in this device having the above configuration, when the filter operation ring 30 is rotated when it is at the forward sliding end as shown in FIG. Accordingly, the turret type filter frame 16 is rotated by the interlocking pin 25 and the radial interlocking groove 23, and the filter 18 located on the optical axis is replaced. With the polarizing filter 20 positioned on the optical axis, when the filter operating ring 30 is moved rearward and then rotated, the polarizing filter rotating cylinder is 26
moves rearward while rotating, and its engaging surface 27 engages with the engaging surface 21 of the polarizing filter frame 19. When the filter operating ring 30 is further rotated, the polarizing filter rotating cylinder 26 rotates together with this. As a result, the polarizing filter 20 rotates.

6 to 8 show another embodiment of the present invention. This embodiment differs from the first embodiment in that the groove 40 for the interlocking pin 35 drilled in the lens barrel 12 is replaced by two guide grooves 41, 42 in the circumferential direction, front and rear, as shown in FIG. And this guide groove 4
1 and 42, and an interlocking hole in the filter operation ring 30 that allows the filter operation ring 30 and the polarizing filter rotation tube 26 to always move together in the optical axis direction and the circumferential direction. This is the point where 44 was formed. The length a of the optical axis direction groove 43 is set equal to the distance a required to bring the engagement surface 27 into contact with the engagement surface 21. Further, when the interlocking pin 35 is in the circumferential groove 41, the interlocking pin 31 is located in the escape groove 33a, and when it is in the circumferential groove 42, the interlocking pin 31 is located in the interlocking groove 33b, and the interlocking pin 31 is located in the relief groove 33a. The positions of each element are set so that when the filter 35 is located within the optical axis direction groove 43, the polarizing filter 20 is located on the optical axis. Other points are the same as in the first embodiment, and the same parts are given the same reference numerals.

In other words, in the device configured as described above, when the filter operating ring 30 is rotated when it is at the front sliding end shown in FIG. The filter 18 located on the shaft takes its place. At this time, the interlocking pin 35 moves within the circumferential groove 41. When the interlocking pin 35 reaches the optical axis groove 43, the polarizing filter 20 is positioned on the optical axis.
When the filter operation ring 30 is pulled rearward in this state, the polarizing filter rotary cylinder 26 moves together with it, and its engaging surface 27 comes into contact with the engaging surface 21 of the polarizing filter frame 19. From this state, the circumferential groove Rotating the filter operating ring 30 along 42 rotates the polarizing filter 20. In this case, the interlocking pin 31
is located within the relief groove 33a, so the filter conversion cylinder 24 does not rotate.

In all of the above embodiments, the rotation of the turret type filter frame 16 and the rotation of the polarizing filter 20 are performed using a single filter operation ring 30, and the filter conversion and rotation of the polarizing filter can be performed with one hand. However, even if the rotation of the turret type filter frame 16 and the rotation of the polarizing filter 20 are performed by separate operation rings, it is possible to incorporate the polarizing filter into the turret type filter and rotate the polarizing filter. The greatest effect of the present invention is not lost.

In the above embodiment, the filter conversion tube 24, the polarizing filter rotation tube 26, and the filter operation ring 30 are fitted inside and outside the lens barrel 2, but depending on the lens structure, these may be fitted into a fixed lens barrel. In short, these can be fitted into a wide range of "lens barrels".

As described above, in a lens barrel having a turret type filter, the present invention rotatably supports the polarizing filter in the turret type filter frame and provides a means for rotating it, so that only the polarizing filter that requires rotational operation can be removed. There is no longer a need to attach a special filter to the front of the lens, and it is also possible to use a polarizing filter on lenses with a protruding front element, such as ultra-wide-angle lenses. Moreover, since the diameter is small, it is possible to reduce costs overall.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing an embodiment of a lens barrel with a built-in polarizing filter according to the present invention, and FIG.
3 and 4 are cross-sectional views taken from the - line in FIG. 1 in mutually different operating states; FIG. 5 is a view taken in the direction of the arrow in FIG. 1;
The figure is a longitudinal sectional view similar to FIG. 1 showing another embodiment of the present invention, FIG. 7 is a sectional view taken along the line - in FIG. 6, and FIG. 8 is a sectional view taken along the line - This is an expanded diagram. DESCRIPTION OF SYMBOLS 11... Fixed lens barrel, 12... Lens barrel, 18... Filter, 19... Polarizing filter frame, 20... Polarizing filter, 21... Engaging surface, 22... Filter conversion gear, 2
4... Filter conversion tube, 26... Polarizing filter rotation tube, 27... Engagement surface, 30... Filter operation ring,
31... Interlocking pin, 33... Filter conversion groove, 35
...Interlocking pin, 36...Guide groove, 37...Polarizing filter rotation groove.

Claims (1)

[Scope of Claims] 1. A lens barrel with a built-in polarizing filter, in which a turret-type filter frame having a rotation center outside the optical axis of the lens holds a plurality of filters that can be moved on the optical axis as the filter frame rotates. At least one of the holding filters of the turret type filter frame is a polarizing filter, the polarizing filter is rotatably supported on the turret type filter frame, and the rotating operation means for the turret type filter frame and the polarizing filter A lens barrel with a built-in polarizing filter, characterized in that it is provided with a filter rotation operation means. 2. In claim 1, the polarizing filter rotating means has an engaging surface that can come into contact with and separate from the engaging surface of the frame of the polarizing filter, and has an engaging surface that can be moved toward and away from the engaging surface of the frame of the polarizing filter. It consists of a polarizing filter rotating tube that is movably fitted, and a filter operating ring that is fitted to the outside of the lens barrel so as to be rotatable and movable in the optical axis direction, which moves and rotates the polarizing filter rotating tube in the axial direction. A lens barrel with a built-in polarizing filter. 3. In claim 2, the filter operating ring is configured to operate on the turret type filter frame when the filter operating ring is moved to a position in the optical axis direction where the engaging surface of the polarizing filter rotating barrel abuts the engaging surface of the polarizing filter frame. A lens barrel with a built-in polarizing filter is rotatable with respect to the turret type filter frame and is interlocked with the turret type filter frame so as to rotate together with the turret type filter frame when the two engaging surfaces are moved to positions in the optical axis direction where they are separated.