JPH0545617U - Imaging-related member support device - Google Patents

Abstract

(57) [Abstract] [Purpose] To improve space efficiency when supporting imaging-related members, and reduce eccentricity and inclination between the imaging-related members disposed adjacent to each other. [Structure] The fitting portion 4a that slidably supports the fourth lens group 4F as a photographing-related member with respect to the reference shaft 1 has a sufficient fitting length L4. Fitting portions 3a and 5a slidable with respect to the fitting portion 4a are provided, and the third lens group 3 is formed by these fitting portions 3a and 5a.
Z and the fifth lens group 5Z are held. This reduces the tilt of each lens group and improves space efficiency. In addition, the eccentricity between adjacent imaging-related members is suppressed to be small.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an imaging-related member supporting device.

[0002]

[Prior Art]

 Recently, as imaging devices such as video movies have become smaller and lighter and have higher performance, their imaging lenses have also become smaller and lighter. Further, functionally, there is a demand for a high-magnification zoom, wide range expansion, and a lens with a small FNo, that is, a bright lens. In order to satisfy these requirements, for example, an imaging optical system having a 5-group structure in which the third lens group and the fifth lens group are each a zoom system and the fourth lens group is a focus system is considered as a small video movie. However, in this case, the third to fifth lens groups are very close to each other.

The above is a description of the lens group, but as the imaging-related members that need to be moved in the optical axis direction, there are other solid-state imaging devices such as CCDs, filters, diaphragm members, and the like. A conventional example of a member supporting device will be described below with reference to FIGS.

FIG. 8 is a longitudinal sectional view of a main part of a conventional supporting device for a photographing-related member represented by a third lens group 3Z, a fourth lens group 4F, and a fifth lens group 5Z. Therefore, only one lens will be shown as a representative. Now, one ends of the third lens group frame 3, the fourth lens group frame 4, and the fifth lens group frame 5 that hold the above-mentioned lens groups near the reference axis are respectively attached to the reference axis 1 as a fixed guide member. The fitting portions 3a1, 4a1, 5a1 and the other end are commonly supported by U-shaped grooves 3b, 4b, 5b respectively on guide shafts 9, 9A shown in FIG. The reference shaft 1 is supported by a fixed guide member support portion (hereinafter simply referred to as a support portion) 2 fixed to a camera body (not shown), and the solid-state image sensor 6 is mounted on the support portion 2. The optical axis is aligned with the lens group.

That is, since each lens group 3Z, 4F, 5Z is commonly supported by the pair of reference shafts 1 and the guide shaft 9 (see FIG. 10) as fixed guide members, the fixed guide members are exclusively used. The space is small and it is advantageous for downsizing.

FIG. 9 is a vertical cross-sectional view of a main part of another conventional example. A major difference from the conventional example of FIG. 8 is that the number of reference axes is increased to two. That is, the second reference axis 1A is provided in parallel with the reference axis 1, and the fitting portion 4A of the fourth lens group frame 4 for holding the fourth lens group 4F is provided on the reference axis 1A. I am trying to fit. Except for this point, there is no difference from the conventional example of FIG. 8 described above, and therefore, the same reference numerals are given to the same components and the description thereof is omitted.

According to the conventional example shown in FIG. 9, since the reference shafts are separately provided, the fitting length L21 of the fourth lens group 4F located in the middle can be sufficiently set.

In addition to the conventional example shown in FIGS. 8 and 9, for example, in Japanese Unexamined Patent Publication No. 61-116310, a first lens group is connected along the outer peripheral surface of a cylindrical cam as a fixed guide member. A technical means is disclosed in which the joined lens case and the guide rod to which the second lens group is joined along the inner peripheral surface slide respectively. According to this means, the multi-fitting structure improves the space efficiency.

[0009]

[Problems to be solved by the device]

 However, in the conventional example shown in FIG. 8, each lens group frame is commonly fitted to one reference shaft 1, so that, for example, the fitting length of the fourth lens group 4F arranged in the middle in FIG. L11 cannot be taken sufficiently. Therefore, the fourth lens group 4F may be tilted.

Next, in the conventional example shown in FIG. 9, since two reference shafts are provided, the space occupied by the fixed guide member becomes large. In addition to this, the optical axis shift of the fourth lens group 4F, that is, the shift Δd from the optical axis O of the line connecting the second reference axis 1A and the second guide axis 9A shown in FIG. 10, occurs. This will adversely affect the image quality during zooming.

Further, in the technical means disclosed in Japanese Patent Laid-Open No. 61-116310, for example, when the lens case is located on the rightmost side and the guide rod is located on the leftmost side, the first lens group and the second lens group are arranged. Assuming that the positions of the optical axes of the groups are the same, if the positions are in the opposite directions, the play will be integrated, resulting in a so-called two-stage play. Will end up.

Therefore, an object of the present invention is to solve the above-mentioned problems and to provide a photographing-related member supporting device which is small in eccentricity and inclination between adjacent photographing-related members and is space efficient.

[0013]

[Means for Solving the Problems]

 The imaging-related member supporting device of the present invention comprises a first guide member for mounting an imaging-related member slidable on a fixed guide member, and an imaging-related member slidable on the first guide member. And a second guide member for mounting, and a plurality of at least one of the first guide member and the second guide member is provided.

[0014]

[Action]

 In this imaging-related member support device, the first guide member for mounting the imaging-related member slides on the fixed guide member, and the second guide member slides on this first guide member.

[0015]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a vertical cross-sectional view of a main part of a photographing-related member supporting device according to a first embodiment of the present invention, which is often used in, for example, a small video movie, and adjacent lens groups are arranged very close to each other. In addition, in the zoom lens barrel having the five-group configuration, the third and fifth lens groups 3Z and 5Z for zooming operation and the fourth lens group 4F for focusing operation exemplify members related to photography. Each lens group is represented by one lens for simplicity.

At the tip of the fourth lens group frame 4 that holds the fourth lens group 4F near the reference axis, a hollow pipe structure that fits to the reference axis 1 as a fixed guide member has a fitting length of L4. A fitting portion (hereinafter referred to as a fourth group fitting portion) 4a of the fourth lens group frame 4 is provided. Further, the tip end of the third and fifth lens group frames 3 and 5 respectively holding the third and fifth lens groups 3Z and 5Z, which is close to the reference axis, has a hollow pipe structure fitted to the fourth group fitting portion 4a. , And the fitting portions (hereinafter, referred to as the third group fitting portion and the fifth group fitting portion) 3a and 5a of the third and fifth lens group frames 3 and 5 having the fitting lengths of L3 and L5, respectively. It is being touched.

That is, the first guide member for mounting the imaging-related member, which is slidable with respect to the reference shaft 1 as the fixed guide member, is provided by the fourth group fitting portion 4a and with respect to the first guide member. A second guide member for mounting an image-related member that is slidable by means of the third and fifth group fitting portions 3a, 5a is formed respectively. Then, at least one of the first guide member or the second guide member is plural, that is, the two 3, 5 group fitting portions 3a, 5a corresponding to the second guide member are It is provided on the fourth group fitting portion 4a as one guide member.

One end of the reference shaft 1 is supported by a support portion 2 fixed to a camera body (not shown), and a solid-state image sensor 6 such as a CCD is mounted on the support portion 2 by the third to fifth lens groups 3Z. , 4F, 5Z and the optical axis O can be aligned.

In the first embodiment thus constructed, the fourth group fitting portion which supports the fourth lens group 4F slidably in the optical axis direction with respect to the reference axis 1 as the fixed guide member. Since the fitting length L4 of 4a is sufficiently larger than the fitting length L11 in the conventional example (see FIG. 8), there is no fear that the lens group 4F tilts or decenters. On the other hand, the fitting lengths L3 and L5 of the third and fifth lens group fitting portions 3a and 5a supporting the third and fifth lens groups 3Z and 5Z are substantially equal to those of the conventional example.

In this case, since the third and fifth group fitting portions 3a and 5a slide on the fourth group fitting portion 4a that slides with respect to the reference axis 1 in the optical axis direction, they function as a first guide member. The fourth group fitting portion 4a and the third and fifth group fitting portions 3a and 5a as the second guide members, two of which are provided on the fourth group fitting portion 4a as the first guide member, If there is play with respect to the reference axis 1 as the fixed guide member, the lens groups 3Z held by the lens group frames 3, 4, 5 extending from the fitting portions 3a, 4a, 5b, respectively. , 4F, 5Z optical axes are deviated, causing a problem.

However, in this type of sliding mechanism, it is usually impossible to eliminate the play, and there is a problem whether the play of the first and second guide members is accumulated or canceled. This point will be described in detail in the second embodiment described later with reference to FIGS. 5 to 7 and will not be described further here.

According to the first embodiment described above, even in a zoom optical system for a small video movie in which adjacent lens groups are very close to each other, each lens group serves as each guide member for mounting each photographing-related member. Since the fitting lengths L3, L4, L5 of the fitting portions 3a, 4a, 5a with respect to the reference shaft 1 as the fixed guide member can be sufficiently obtained, the inclination of each lens group can be reduced. Further, the eccentricity between adjacent photographing-related members can be reduced, and the space of the entire optical system can be reduced.

2 (A) and 2 (B) are cross-sectional views of a main part of a supporting mechanism for supporting the reference shaft 1 of the fourth group fitting portion 4a in FIG. 1 above. Metal bearings are provided at the ends of the fourth group fitting portion 4a. 7 or 8 is press-fitted to reduce wear when the fourth group fitting portion 4a slides on the reference shaft 1. It should be noted that this kind of support mechanism can be similarly applied to a support mechanism for the fourth group fitting portion 4a of the third and fifth group fitting portions 3a, 5a.

FIG. 3 is a vertical cross-sectional view of a main part showing the drive mechanism of each lens group 3Z, 4F, 5Z in FIG. 1, and the same components as those in FIG. The description will be omitted and only different members will be described below.

In the drive mechanism shown in FIG. 3, the zoom drive system and the focus drive system are driven by separate drive sources. First, the zoom drive system meshes with the DC motor 18 as a drive source, the motor output gear 17 attached to the output shaft 18a of the motor 18, and the gear 17 to zoom the rotational force of the motor 18. The transmission gear 16 for transmitting to the cam shaft 11 for use, the first and second cylindrical cams 12 and 14 fixed to the cam shaft 11 and provided with spiral cam grooves 12a and 14a on the surface, respectively, The main parts are constituted by the first and second zoom drive pins 13 and 15 which are fitted into the cam grooves 12a and 14a and whose other ends are fixed to the third and fifth group fitting parts 3a and 5a, respectively. ing.

Next, the focus drive system is connected to a stepping motor 19 as a drive source, a U-shaped mounting bracket 20 fixed to the outer casing of the motor 19, and an output shaft of the motor 19. The lead screw 21 supported by the lead screw support portion 21a on the mounting bracket 20, the cam follower 22 engaged with the lead screw portion 21b of the lead screw 21, one end connected to the cam follower 22 and the other end fitted in four groups. The focusing drive pin 23 engaged with the U-shaped groove 4c of the joint portion 4a constitutes the main portion thereof.

First, the zooming operation in each of the above-described drive mechanisms configured as described above will be described. A control signal from a control unit (not shown) is applied to the DC motor 18 to rotate the motor 18, and accordingly, the first and second zoom cylindrical cams 12 and 14 rotate. Then, the zoom drive pins 13 and 15 are zoomed in the optical axis direction by being guided by the spiral cam grooves 12a and 14a provided on the surfaces of the first and second cylindrical cams 12 and 14, respectively. The zoom movement of the third and fifth lens groups 3Z and 5Z for zooming is performed.

Next, the focusing operation will be described. A drive pulse from a control unit (not shown) is applied to the stepping motor 19, and the lead screw 21 is rotated corresponding to the number of drive pulses. As a result, the fourth lens group 4F for focusing is driven by the cam follower 22 and the drive pin 23 for focusing to the in-focus point.

FIG. 4 is an end view of the main part in FIG. 3, and the same members as those in FIG. 3 are denoted by the same reference numerals, and the description thereof will be omitted. Only different members will be described below.

In FIG. 4, each drive system is arranged such that the focus drive pin 23 of the focus system and the zoom drive pin 13 (15) of the zoom system form an angle θ. Reference numeral 24 denotes a rotation stop shaft, which is a guide for driving the focus drive pin 23 in parallel with the optical axis O in response to the rotation of the lead screw 21.

The members on the left side of the reference axis 1 in FIG. 4, that is, the third lens group 3Z, the fourth lens group 4F, the fifth lens group 5Z, which are arranged along the optical axis O, and these respective lenses are arranged. Although not shown in FIG. 3, the U-shaped grooves 3b, 4b, 5b of each lens group frame holding the group and the guide shaft 9 into which the U-shaped grooves 3b, 4b, 5b are fitted are not shown in FIG. The members are arranged in the upper part of FIG.

5 and 6 are cross-sectional views of an essential part for explaining the second embodiment of the present invention, and FIG. 7 is a view in the direction of arrow A in FIG. In the description of the first embodiment, as shown in FIG. 5, the play Δd1 of the fourth group fitting portion 4a slidably fitted to the reference shaft 1 and the fourth group fitting portion 4a. When the backlash Δd 2 of the third and fifth group fitting portions 3a and 5a slidably fitted to is in the same direction, the backlash of the third and fifth group fitting portions 3a and 5a with respect to the reference shaft 1 is , .DELTA.dt is obtained by accumulating both the backlash and the backlash. Then, for example, the optical axis shift of the third and fifth lens groups 3Z and 5Z with respect to the solid-state image pickup device 6 (see FIG. 1) attached to the support portion 2 fixed to the main body of the camera will be Δdt. ..

Therefore, in the second embodiment, as shown in FIG. 6, the metal bearing 8a is press-fitted into the end of the fourth group fitting portion 4a, and the inner peripheral surface of the metal bearing 8a is pushed as a backlash member. A leaf spring 31 is provided in close proximity to the metal bearing 8b press-fitted to the ends of the third and fifth group fitting portions 3a, 5a, and a push leaf spring 32 is provided on the inner peripheral surface thereof. In this case, as shown in FIG. 7, the push plate spring 31 is attached so as to be 180 ° opposite to the push plate spring 32 with respect to the reference shaft 1. The biasing force of the push plate springs 31 and 32 causes the sliding of the fourth group fitting portion 4a with respect to the reference shaft 1 and the third and fifth group fitting portions 3a and 5a with respect to the fourth group fitting portion 4a. Shall be suppressed to the extent that it does not interfere with According to the second embodiment described above, the backlash of the fourth group fitting part 4a with respect to the reference shaft 1 and the backlash of the third and fifth group fitting parts 3a, 5a with respect to the fourth group fitting part 4a are not accumulated. Since it is canceled, the backlash of the third and fifth group fitting portions 3a, 5a with respect to the reference axis 1 can be reduced. Therefore, the optical axis shift of the third and fifth lens groups 3Z and 5Z with respect to the solid-state image sensor 6 (see FIG. 1) fixed to the support portion 2 provided on the camera body (not shown) can be suppressed to a low level. The decentering amounts of the third and fifth lens groups 3Z and 5Z with respect to the fourth lens group 4F are the same as those in the conventional example.

According to each of the above-described embodiments, even in the case of a zoom optical system for a small video movie in which adjacent lens groups are very close to each other, the number of reference axes is not one but is one. In addition, the fitting length of the fitting portion that supports each imaging-related member can be made sufficient, and rattling does not accumulate. Therefore, the inclination and eccentricity of each photographing-related member can be reduced, the image quality can be expected to be improved, and the space of the photographing-related member supporting device can be kept low.

[0035]

[Effect of the device]

 As described above, according to the present invention, the first guide member for mounting the photographing-related member that is slidable with respect to the fixed guide member, and the photographing-related member that is slidable with respect to the first guide member. Since at least one of the second guide members for mounting the members is provided in plural, space efficiency is improved, and eccentricity and inclination between the photographing-related members arranged adjacent to each other can be reduced. A remarkable effect is exhibited.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of an essential part of an imaging-related member support device showing a first embodiment of the present invention.

FIG. 2 is a sectional view of a main part of a support mechanism for each fitting part in FIG.

FIG. 3 is a vertical cross-sectional view of a main part in which the drive mechanism is also displayed on the supporting device shown in FIG.

FIG. 4 is an end view of a main part in FIG.

FIG. 5 is a view for explaining a backlash of each fitting portion with respect to a reference axis.

FIG. 6 is a vertical cross-sectional view of a main part of an imaging-related member support device showing a second embodiment of the present invention.

FIG. 7 is a view on arrow A in FIG.

FIG. 8 is a vertical cross-sectional view of a main part of a conventional imaging-related member support device.

FIG. 9 is a vertical cross-sectional view of a main part of still another conventional imaging-related member support device.

FIG. 10 is a view on arrow B in FIG. 9;

[Explanation of symbols]

 1 ... Reference axis (fixed guide member) 3a ... 3rd group fitting portion (second guide member) 4a ... 4th group fitting portion (first guide member) 5a ... 5th group fitting portion (first 2 guide member)

Claims (1)

[Scope of utility model registration request] 1. A first guide member for mounting an imaging-related member slidable with respect to a fixed guide member, and a second guide member for mounting an imaging-related member slidable with respect to the first guide member. An imaging-related member support device having a guide member, wherein at least one of the first guide member and the second guide member is provided in plural.