Binoculars

Interpupillary distance of binoculars is adjusted by relatively rotating a pair of lens barrels about a predetermined axis. A click position setting mechanism sets a click position at an arbitrary angle of rotation of said pair of lens barrels and includes a rotating member rotatable about the predetermined axis. A lock/unlock member locks and unlocks the rotation of the rotating member.

TECHNICAL FIELD

The present invention relates to binoculars.

BACKGROUND ART

Japanese Patent Application Laid-Open Publication No. H11-14893 discloses horizontal movement type binoculars including: a click plate having a click portion provided in at least one part and being slidable in a direction orthogonal to a direction of an optical axis along a fixed body; an interpupillary distance click spring fitted to a movable body slidably movable in the direction orthogonal to the direction of the optical axis with respect to the fixed body and being capable of engaging with the click portion; and a lock mechanism being capable of locking and unlocking the click plate in an arbitrary position.

According to the conventional horizontal movement type binoculars, a position of the interpupillary distance at which a sense of clicking is obtained can be arbitrarily set and, besides, can be changed without canceling this set position.

PRIOR ART DOCUMENT

Patent Document

SUMMARY OF THE INVENTION

Problems to be Solved by the Invention

However, the conventional binoculars adopt a structure disabling the click plate from being operated directly. Therefore, in order to set the click plate in an arbitrary position, a user has to locate the click plate in a desired position and to thus set the click position by engaging the interpupillary distance click spring with a recessed portion of the click plate while sliding the movable body in an unlocked state of the lock mechanism and moving the movable body in the way of bringing the click plate together. Accordingly, realization of such an operation entails severely adjusting frictions of the respective portions and spring force as well, and the adjustments thereof are hard to attain.

This point will be specifically described in conformity with an embodiment in Japanese Patent Application Laid-Open Publication No. H11-14893.

Japanese Patent Application Laid-Open Publication No. H11-14893 discloses a structure disabling a “click plate21” provided with a “recessed portion21a” from being directly operated as shown inFIG. 5thereof, and discloses also a configuration that the “click plate21” being held on an “upper base plate17” and sliding in the direction orthogonal to the optical axis is sandwiched in between a “click spring23” and the “upper base plate17”.

This structure causes an increase in friction of the “click plate21” against the “click spring23” because if the spring force of the “click spring23” is strong and when a “movable body15” is moved in an increasing direction of the interpupillary distance from an interpupillary distance accommodated state, i.e., a state of the “click plate21” being in a minimum interpupillary distance position, the “click plate21” is pressed against the “upper base plate17” by the “click spring23”. On this occasion, the frictional force between the “click plate21” and the “click spring23” overcomes the frictional force between the “click plate21” and the “upper base plate17”, in which case even when the “click spring23” does not engage with the recessed portion21a”, it follows that the “click plate21” moves together with the movement of the “click spring23”.

Whereas if the spring force of the “click spring23” is made weak to such a degree that the “click plate21” does not move together with the movement of the “click spring23” and when force causing the“click spring23” to run on the “recessed portion21a” is inferior to the frictional force between the “click plate21” and the “upper base plate17” after the “click spring23” drops in the “recessed portion21a” of the “click plate21”, it follows that the “click plate21” does not move irrespective of the movement of the “click spring23” even though the “click spring23” engages with the “recessed portion21a”.

Thus, if the frictional force among the respective portions and the spring force of the “click spring23” are not severely adjusted, it is impossible to drop the “click spring23” in the “recessed portion21a” of the “click plate21” by moving the “movable body15” in the increasing direction of the interpupillary distance and thereafter to move the “click spring23” in the way of bringing the “click plate21” together. Namely, Japanese Patent Application Laid-Open Publication No. H11-14893 has difficulty to adjust the frictions among the respective portions and the spring force in order to perform an objective operation.

The present invention is made in view of such circumstances and aims at providing binoculars capable of arbitrarily setting a position of an interpupillary distance at which a sense of clicking can be obtained, changing the position of the interpupillary distance without canceling the set position and, besides, eliminating a necessity for severe adjustments of the respective portions for causing desired operations.

Means for Solving the Problems

To solve the problems given above, the present invention provides binoculars that includes: a pair of lens barrels each having a telescopic optical system; and interconnecting portion interconnecting the pair of lens barrels so as to be relatively rotatable about an axis of an axial member that is parallel to an optical axis of each of the telescopic optical systems, an interpupillary distance being adjusted by relatively rotating the pair of lens barrels about the axial member,

the binoculars including: (a) a click position setting mechanism serving to set a click position at a predetermined angle of rotation of the pair of lens barrels, the click position setting mechanism being configured to include: a rotating member being provided on the axial member so as to be rotatable about the axis of the axial member and facing the interconnecting portion in a direction of the axis of the axial member; a protruded portion being provided on any one of the interconnecting portion and the rotating member; and a recessed portion being provided on the other of the interconnecting portion and the rotating member and being capable of engaging with the protruded portion; and (b) a lock/unlock member locking the rotation of the rotating member with respect to the axial member and unlocking the locked rotation thereof.

In the binoculars according to a preferable aspect of the present invention, a plurality of click positions are provided.

In the binoculars according to another preferable aspect of the present invention, at least one click position of the plurality of click positions is different in terms of a sense of clicking from other click positions.

In the binoculars according to still another preferable aspect of the present invention, the protruded portion protrudes in an axial direction of the axial member.

In the binoculars according to yet another preferable aspect of the present invention, the protruded portion is configured by a ball biased in a direction of the protrusion by an elastic member.

In the binoculars according to a further preferable aspect of the present invention, the lock/unlock member is a member screwed to the axial member, locking the rotation of the rotating member by fastening the rotating member in the axial direction of the axial member through making a rotation in a predetermined direction, and unlocking the locked rotation of the rotating member by slackening the fastened rotating member through making the rotation in a reversed direction.

The binoculars according to a still further preferable aspect of the present invention further include a member screwed to the axial member and having a portion positioned on a side opposite to the rotating member with respect to the lock/unlock member.

In the binoculars according to a yet further preferable aspect of the present invention, the lock/unlock member serves also as a decorative cover that covers one side of the rotating member in the axial direction.

Effect of the Invention

According to the present invention, it is feasible to provide the binoculars capable of arbitrarily setting the position of the interpupillary distance at which the sense of clicking can be obtained, changing the position of the interpupillary distance without canceling the set position and, besides, eliminating the necessity for the severe adjustments of the respective portions for causing the desired operations.

EMBODIMENTS FOR CARRYING OUT THE INVENTION

Binoculars according to the present invention will hereinafter be described with reference to the drawings.

First Embodiment

FIG. 1is schematic plan view showing binoculars1according to a first embodiment of the present invention.FIG. 2is a schematic front view showing the binoculars1illustrated inFIG. 1.FIGS. 1 and 2depict a state where an interpupillary distance is adjusted to a maximum interpupillary distance A.FIG. 3is a view of portions in the vicinity of an axis MA inFIG. 1, with these portions being illustrated in enlargement and the majority thereof being illustrated as being broken.FIG. 4is a view of a first axial member22inFIG. 3as viewed in a direction of the axis MA from a side of an eyepiece12.FIG. 4depicts only the first axial member22.

The binoculars1according to the first embodiment of the present invention include: a pair of right and left lens barrels2R,2L each incorporating a telescopic optical system; and an interconnecting unit3to interconnect these two lens barrels2R,2L in the way of being relatively rotatable about the axis MA parallel to optical axes OR, OL thereof, a configuration being such that the interpupillary distance is adjusted by relatively rotating the lens barrels2R,2L about the axis MA. As shown inFIG. 1, the axis MA is positioned between the optical axes OR, OL as viewed on plane.

Each of the lens barrels2R,2L includes an objective lens11, an eyepiece12and an erecting prism13disposed in an optical path between the objective lens11and the eyepiece12, these lens elements configuring the telescopic optical systems. A focus knob14for focusing of each telescopic optical system is provided on the side of the eyepiece12in the direction of the axis MA of the interconnecting unit3.

The interconnecting unit3includes: an interconnecting member21R serving as an arm unit provided integrally with the lens barrel2R; an interconnecting member21L serving as an arm unit provided integrally with the lens barrel2L; a first cylindrical axial member22having a flange portion22a; and a second cylindrical axial member23having a flange portion23abeing large in wall thickness.

In the first embodiment, the interconnecting member21R is connected to the interconnecting member21L via the first and second axial members22,23each being coaxial with the axis MA so that the interconnecting members21R,21L can relatively rotate about the axis MA. The interconnecting members21R,21L are formed with holes21Ra,21La each extending in the direction of the axis MA. The hole21Ra of the interconnecting member21R and the hole21La of the interconnecting member21L are disposed in a side-by-side relationship coaxially with the axis MA, and receive, as will be described later on, insertions of the first and second axial members22,23being screwed to each other. As will be described later on, the first and second axial members22,23are fixed integrally with the interconnecting member21R. On the other hand, the interconnecting member21L is supported rotatably on the first axial member22inserted into the hole21La thereof and is thereby rotatable about the first and second axial members22,23. This configuration being thus made, the interconnecting members21R,21L can relatively rotate about the axis MA.

In the following description, for the explanatory convenience, a direction on the side of the eyepiece12, i.e., the direction toward the eyepiece12in the direction of the axis MA is referred to as an upper side or an upward direction inFIG. 3, while a direction on the side of the objective lens11, i.e., the direction toward the objective lens11in the direction of the axis MA is referred to as a lower side or a downward direction inFIG. 3as the case may be.

The first axial member22is inserted into the holes21Ra,21La of the interconnecting members21R,21L in the side-by-side relationship on the axis MA from the upper side inFIG. 3, with its flange portion22abeing directed on the upper side inFIG. 3. An upper portion of the hole21Ra inFIG. 3is configured with its diameter being expanded in a shape capable of receiving just the flange portion22a, and a lower surface of the flange portion22ainFIG. 3abuts on an abutment surface21Rb of the interconnecting member21R, thereby regulating a downward movement of the first axial member22inFIG. 3with respect to the interconnecting member21R. As shown inFIG. 4, the flange portion22aof the first axial member22is formed with a notch22b. A protrusion (not shown) of the interconnecting member21R fits in this notch22b, thereby regulating a rotation of the first axial member22about the axis MA with respect to the interconnecting member21R.

The second axial member23is inserted into the first axial member22from the lower side inFIG. 3, with its flange portion23abeing directed on the lower side inFIG. 3. A male thread portion23bformed along an outer periphery of the upper portion of the second axial member23inFIG. 3, is screwed into a female thread portion22cformed along an inner periphery of the first axial member22, and an upper surface of the flange portion23aof the second axial member23inFIG. 3abuts on an end surface of the interconnecting member21R on the side of the objective lens11in the direction of the main axis MA. With this abutment, the flange portion22aof the first axial member22and the flange portion23aof the second axial member23pinch the interconnecting member21R respectively from upward and downward inFIG. 3, thereby regulating the movements of the second axial member23with respect to the first axial member22and further the interconnecting member21R in the upper and lower directions inFIG. 3.

The flange portion23aof the second axial member23is formed with a screw hole23cthrough the flange portion23ain the direction of the axis MA. A screw24is screwed into the screw hole23c, and an upper end of the screw24in FIG.3is pressed against an end surface of the interconnecting member21R on the side of the objective lens11in the direction of the axis MA. This configuration regulates the rotation of the second axial member23about the axis MA with respect to the interconnecting member21R and the first axial member22, and inhibits a screw-engagement between the male thread portion23bformed along the outer periphery of the second axial member23and the female thread portion22cformed along the inner periphery of the first axial member22from slackening. Note that the second axial member23is formed with a hole23dcapable of receiving an insertion of a tool (unillustrated) for making the screw-engagement of the second axial member23.

Based on what is configured so far, the first axial member22and the second axial member23are fixed integrally with the interconnecting member21R.

The interconnecting member21L is, as described above, rotatable with respect to the first axial member22and the second axial member23. By dint of the screw-engagement between the first axial member22and the second axial member23, the interconnecting member21L is pressed, via a washer (unillustrated), against the interconnecting member21R in the direction of the main axis MA, resulting in occurrence of a predetermined magnitude of frictional force among the interconnecting member21R, the washer and the interconnecting member21L. This frictional force has the magnitude being large enough to overcome weights of the right and left lens barrels2R,2L, to enable an angle made by the right and left lens barrels2R,2L to be set to an arbitrary value, i.e., enable these right and left lens barrels2R,2L to be held at an arbitrary interpupillary distance, and to enable the right and left lens barrels2R,2L to rotate relatively about the axis MA by applying a predetermined magnitude of external force to the lens barrels2R,2L. Accordingly, the interpupillary distance can be adjusted by relatively rotating the right and left lens barrels2R,2L about the axis MA.

Then, the binoculars1according to the first embodiment further include: a ball31being provided on one lens barrel2L and serving as a protrusion for clicking; an operation member41being rotatable about the axis MA through a rotating operation and having a V-shaped groove41aengaging with the ball31and serving as one recessed portion for clicking, the operation member41setting a click position corresponding to a rotating position; a lock/unlock member51to lock the rotation and unlock the locked rotation of the operation member41with respect to the other lens barrel2R in a way that corresponds to the operation; and a decorative cover61.

FIG. 5is a plan view showing the operation member41inFIGS. 1 to 3. Namely,FIG. 5is the view of the operation member41as viewed in the direction of the axis MA from the upper side inFIG. 3.FIG. 6is a sectional view taken along the arrow line A-A′ inFIG. 5.FIG. 7is a sectional view taken along the line B-B′ inFIG. 5.

In the first embodiment, the operation member41is configured as an annular member. A one-sided surface (an upper surface inFIG. 3) of the operation member41in the axial direction is formed with a radially-extended V-shaped groove, i.e., the groove41ataking the V shape in section as one recessed portion for clicking. As a matter of course, the recessed portion for clicking is, if capable of a click engagement, not limited to the V-shaped groove. Further, the operation member41is formed with a plurality of through-holes41bpassing through between the inner periphery and the outer periphery in order to be provided with pins42that will be mentioned below.

The operation member41is fitted, with a surface formed with the V-shaped groove41abeing directed on the upper side inFIG. 3, on the outer periphery of the flange portion23aof the second axial member23, and is thus supported on the flange portion23aso as to be freely rotatable about the axis MA. An engagement groove23eis formed over an entire length of the outer periphery of the flange portion23a. The pins42are press-fitted into the through-holes41bof the operation member41so as to protrude on the side of the inner periphery of the operation member41. This pin42engages with the engagement groove23eof the flange portion23aof the second axial member23, thereby regulating a movement of the operation member41in the direction of the axis MA with respect to flange portion23a. With this configuration, the operation member41becomes rotatable about the axis MA with respect to the second axial member23in a state of facing the interconnecting member21R with a slight gap in the direction of the axis MA. An outer periphery of the operation member41is exposed to the outside, and a user performs a rotating operation to apply rotating force acting about the axis MA to the outer periphery of the operation member41, whereby the operation member41can be rotated about the axis MA.

The ball31serving as the protrusion for clicking to engage with the V-shaped groove41aof the operation member41, is disposed in a position enabling a face-to-face relationship with the V-shaped groove41aof the operation member41through the rotation of the operation member41. This ball31is biased toward the downward direction inFIG. 3by a compression spring32accommodated in a hole21Lb extending in the direction of the axis MA, the hole being formed with an opening in a lower-sided surface of the interconnecting member21L inFIG. 3, i.e., the surface facing the operation member41. Most of the ball31is also accommodated in the hole21Lb. With this arrangement, the ball31is provided on the side of the interconnecting member21L and, though movable in the direction of the axis MA with respect to the interconnecting member21L, rotates about the axis MA together with the interconnecting member21L. When the ball31faces the V-shaped groove41aof the operation member41corresponding to the rotating position about the axis MA of the operation member41relative to the interconnecting member21L, the ball31drops into the V-shaped groove41aof the operation member41, thus attaining a click-engagement.FIGS. 2 and 3illustrate a state where the ball31click-engages with the V-shaped groove41a. Whereas when the ball31does not face the V-shaped groove41aof the operation member41corresponding to the rotating position about the axis MA of the operation member41relative to the interconnecting member21L, the ball31is freed from the click-engagement with the V-shaped groove41aand runs on the upper surface of the operation member41inFIG. 3. Note that the protrusion for clicking may involve, without being limited to the ball31biased by the compression spring32, using a protrusion provided on a plate spring.

In the first embodiment, the lock/unlock member51is configured as an annular member and is disposed coaxially with the operation member41on the lower side of the operation member41inFIG. 3. A female thread portion51aformed along the inner periphery of the lock/unlock member51is screwed to a male thread portion23fformed along the outer periphery of the flange portion23aof the second axial member23. The outer periphery of the lock/unlock member51is exposed to the outside, and the user can rotate the lock/unlock member51in a predetermined direction and in a reversed direction about the axis MA by performing the rotating operation through applying the rotating force acting about the axis MA to the outer periphery of the lock/unlock member51. With this operation, the lock/unlock member51, upon being rotated in the predetermined direction about the axis MA, locks the rotation of the operation member41by fastening the operation member41in the direction of the axis MA, herein, in the upward direction inFIG. 3, and thus the lock/unlock member51disables the operation member41from rotating; and the lock/unlock member51, upon being rotated in the reversed direction, unlocks the rotation of the operation member41by slackening the fastened operation member41, and thus the lock/unlock member51enables the operation member41to rotate. As a matter of course, the first embodiment may adopt a member(s) based on some other lock mechanisms by way of a lock/unlock member in place of the lock/unlock member51.

In the first embodiment, the decorative cover61includes a disc-like cover portion61aand a shaft portion61bbeing protruded at the center of the cover portion61a. A male thread portion61cformed along the outer periphery of the shaft portion61bis screwed in a female thread portion23gformed along the inner periphery of the flange portion23aof the second axial member23. With this arrangement, the cover portion61aof the decorative cover61covers an end portion of the lower side of the lock/unlock member51inFIG. 3and also covers the lower side of the second axial member23inFIG. 3.

Thus, in the first embodiment, the decorative cover61is screwed to the second axial member23and becomes a member including a portion positioned on the side opposite to the operation member41with respect to the lock/unlock member51, i.e., herein, becomes a member including the cover portion61a. The outer periphery of the cover portion61aof the decorative cover61is exposed to the outside, and the user can rotate the decorative cover61in the predetermined direction and in the reversed direction about the axis MA by performing the rotating operation through applying the rotating force acting about the axis MA to the outer periphery of the cover portion61a. With this operation, the decorative cover61, upon being rotated about the axis MA in the predetermined direction, fastens the lock/unlock member51in the direction of the axis MA, herein, in the upward direction inFIG. 3; and the decorative cover61, upon being rotated in the reversed direction, slackens the fastened lock/unlock member51.

In the case of unlocking the locked rotation of the operation member41, after slackening the decorative cover61, it may be sufficient that the lock/unlock member51is slackened. Whereas in the case of locking the rotation of the operation member41, after fastening the lock/unlock member51, it may be sufficient that the decorative cover61is fastened. Thus, the decorative cover61in cooperation with the lock/unlock member51realizes a state similar to a double nut, and can further surely prevent the lock/unlock member51from being unlocked due to unintentional slackening thereof when the rotation of the operation member41is being locked. As a matter of course, according to the present invention, the decorative cover61does not necessarily need to be provided but may be removed. In this case, the female thread portion23gof the second axial member23can be utilized as, e.g., a screw for fixing a tripod.

Note that in order to facilitate the rotating operations for the operation member41, the lock/unlock member51, and the decorative cover61, the surfaces thereof may be subjected to knurling and may also be provided with materials such as a rubber exhibiting a high frictional coefficient according to the necessity.

Referring next toFIGS. 8 to 12, an operational example of the binoculars1according to the first embodiment will be described.FIGS. 8 to 12are schematic front views each showing an operational state of the binoculars1according to the first embodiment, and correspond toFIG. 2. In these drawings throughout, the interpupillary distance A denotes a maximum interpupillary distance, an interpupillary distance B represents an arbitrary interpupillary distance, and an interpupillary distance C designates a minimum interpupillary distance. Herein, a relationship between these interpupillary distances is given such as A≥B≥C. It is to be noted that for facilitating the understanding, inFIGS. 8 to 12, the lens barrel2R and the interconnecting member21R are illustrated as being fixed in the same direction in these drawings. It is assumed that the indications of the up/down and right/left in the following description correspond to the up/down and right/left inFIGS. 8 to 12.

In the case of setting an interpupillary distance for obtaining a sense of clicking to the interpupillary distance B, to start with, the rotating operation of the operation member41is set in an enabled state. Namely, the lock/unlock member51is slackened after slackening the decorative cover61, thereby unlocking the locked rotation, about the axis MA, of the operation member41with respect to the lens barrel2R, the interconnecting member21R and the first and second axial members22,23and thus setting the rotation of the operation member41in the enabled state.FIG. 8shows an example in which the rotating operation of the operation member41is set in the enabled state, in which the interpupillary distance is set to the maximum interpupillary distance A. In the example illustrated inFIG. 8, the V-shaped groove41aof the operation member41is positioned under the axis MA, and the ball31provided on the side of the interconnecting member21L is positioned on the right side of the axis MA.

Next, while the rotating operation of the operation member41remains in the enabled state, the lens barrels2R,2L are rotated relatively about the axis MA, thereby changing the interpupillary distance to the desired interpupillary distance B.FIG. 9illustrates a state of changing the interpupillary distance to the interpupillary distance B from the state shown inFIG. 8. InFIG. 9, the V-shaped groove41aof the operation member41remains positioned under the axis MA, and, by contrast, the ball31provided on the side of the interconnecting member21L is shifted to a position existing obliquely rightward and downward of the axis MA corresponding to the rotations, about the axis MA, of the lens barrel2L and the interconnecting member21L with respect to the lens barrel2R and the interconnecting member21R.

Thereafter, the rotating operation of the operation member41is stopped in the rotating position in which the sense of clicking is obtained by performing the rotating operation of the operation member41, thereby click-engaging the V-shaped groove41aof the operation member41with the ball31provided on the side of the interconnecting member21L and further locking the rotation of the operation member41. Namely, the decorative cover61is fastened after fastening the lock/unlock member51, thus the rotation, about the axis MA, of the operation member41with respect to the lens barrel2R, the interconnecting member21R and the first and second axial members22,23is locked.FIG. 10illustrates a state in which the V-shaped groove41aof the operation member41brought into the click-engagement with the ball31provided on the side of the interconnecting member21L from the state shown inFIG. 9, and further the rotation of the operation member41is locked. InFIG. 10, the ball31provided on the side of the interconnecting member21L remains positioned obliquely rightward and downward of the axis MA, and the V-shaped groove41aof the operation member41is shifted to the same position as that of the ball31.

The operation of setting the interpupillary distance for obtaining the sense of clicking to the interpupillary distance B terminates so far. In the description made above, the initial state of the setting operation is set in the state where the interpupillary distance is the maximum interpupillary distance A, and may also adopt other arbitrary interpupillary distances.

Even after setting the interpupillary distance for obtaining the sense of clicking to the interpupillary distance B, the interpupillary distance can be changed to another arbitrary interpupillary distance by relatively rotating the lens barrels2R,2L about the axis MA.FIG. 11illustrates a state of changing the interpupillary distance to the maximum interpupillary distance A from the state shown inFIG. 10. InFIG. 11, the position of the V-shaped groove41aremains the same as inFIG. 10, however, the position of the ball31provided on the side of the interconnecting member21L is shifted to a position on the right side of the axis MA corresponding to the rotations, about the axis MA, of the lens barrel2L and interconnecting member21L with respect to the lens barrel2R and the interconnecting member21R.FIG. 12illustrates a state of changing the interpupillary distance to the minimum interpupillary distance C from the state shown inFIG. 10. InFIG. 12, the position of the V-shaped groove41aremains the same as inFIG. 10, however, the position of the ball31provided on the side of the interconnecting member21L is shifted to a position on the lower side than the V-shaped groove41acorresponding to the rotations, about the axis MA, of the lens barrel2L and interconnecting member21L with respect to the lens barrel2R and the interconnecting member21R.

In this way, in the case of returning to the interpupillary distance B at which the sense of clicking has been set after changing the interpupillary distance from the interpupillary distance B, the lens barrels2R,2L are rotated relatively about the axis MA in such a direction as to return to the interpupillary distance B, e.g., in a decreasing direction of the interpupillary distance when returning to the interpupillary distance B from the state illustrated inFIG. 11and in an increasing direction of the interpupillary distance when returning to the interpupillary distance B from the state illustrated inFIG. 12. Thereupon, when reaching the interpupillary distance B, the state shown inFIG. 10occurs, i.e., the ball31drops in the V-shaped groove41a, resulting in the state of the click-engagement between the ball31and the V-shaped groove41aand thereby obtaining the sense of clicking. Accordingly, the user can simply return the interpupillary distance to the previously arbitrarily set interpupillary distance B.

As described above, according to the first embodiment, it is feasible to arbitrarily set the position of the interpupillary distance at which the sense of clicking is obtained and, besides, the position of the interpupillary distance is changed without canceling the set position.

Then, in the first embodiment, such as when changing to the state illustrated inFIG. 10from the state shown inFIG. 9, the rotating position of the operation member41, i.e., the clicking position can be set by rotationally operating the operation member41directly. Hence, according to the first embodiment, for setting the rotating position of the operation member41, there is no necessity for making use of the following movement through the click-engagement as in the case of the binoculars1disclosed in Japanese Patent Application Laid-Open Publication No. H11-14893 and, in the first embodiment, the arrangement that the operation member41is operated following the rotation of the interconnecting member21L in the state where the ball31engages with the V-shaped groove41a. Therefore, the first embodiment has no necessity for severely adjusting the frictions of the respective portions and the spring force of the spring32.

By the way, in the binoculars disclosed in Japanese Patent Application Laid-Open Publication No. H11-14893 described above, the width of the click plate in the increasing direction of the interpupillary distance requires at least the length that is twice as long as the adjustment range of the interpupillary distance, resulting causing a restrain to the adjustment range of the interpupillary distance of the binoculars and causing increases in size both in widthwise direction and in the thicknesswise direction.

In this point, to give a specific description in accordance with the embodiment in Japanese Patent Application Laid-Open Publication No. H11-14893, according to the configuration of Japanese Patent Application Laid-Open Publication No. H11-14893, the “click spring23” needs to exist on the surface (including the recessed portion21a) of the “click plate21” on the side of the click spring within the movement range of the “movable body15” in the increasing direction of the interpupillary distance.

This means that when considering the state where the “click plate21” is frictionally seized and restricted from moving in the increasing direction of the interpupillary distance by the “interpupillary distance position lock lever20”, the width of the “click plate21” in the increasing direction of the interpupillary distance requires the width to the maximum side of the interpupillary distance when the “click spring23” drops in the “recessed portion21a” of the “click plate21” at the minimum interpupillary distance, and the width to the minimum side of the interpupillary distance when the “click spring23” drops in the “recessed portion21a” of the “click plate21” at the maximum interpupillary distance.

Namely, this means that the width of the increasing direction of the interpupillary distance of the“click plate21” requires at least the length that is twice as long as the adjustment range of the interpupillary distance. For example, in the case of the binoculars that are 56 mm-72 mm in adjustment width of the interpupillary distance as the majority of general binoculars have, it follows that the width of the click plate in the increasing direction of the interpupillary distance needs to be equal to or larger than 32 mm. This leads to the restraint of the adjustment range of the interpupillary distance and to the restraints both in the widthwise direction and in the thicknesswise direction of the binoculars.

In contrast with this, in the binoculars1according to the first embodiment, the click position is set depending on the rotating position of the operation member41, and hence there are increases in terms of degree of freedom about the adjustment range of the interpupillary distance and about the size of the binoculars1.

In the first embodiment, as shown inFIGS. 5 to 7given above, the operation member41is formed with only one V-shaped groove41aas the recessed portion for clicking. In contrast with this, the operation member41may also be formed with a plurality of V-shaped grooves41aas a plurality of recessed portions for clicking.FIG. 13is a plan view showing a modified example of the operation member41, and corresponds toFIG. 5. The number of the V-shaped grooves41ais not limited, however, in an example illustrated inFIG. 13, the operation member41is formed with three V-shaped grooves41aat proper angle intervals. In this case, for example, the user sets a position from which the sense of clicking is obtained based on the central V-shaped groove41aas a desired interpupillary distance, and can recognize a warning of being very close to the desired interpupillary distance when obtaining the sense of clicking based on another V-shaped groove41a. Accordingly, the user can adjust more easily the interpupillary distance to the desired interpupillary distance.

Thus, in the case of forming the plurality of recessed portions for clicking on the operation member41, the plurality of recessed portions for clicking may be configured so that the sense of clicking through one recessed portion for clicking is different from the sense of clicking through any one of other recessed portions for clicking. For example, in the example illustrated inFIG. 13, the three V-shaped grooves41ahave the same depth and exhibits the same sense of clicking obtained therefrom, however, the sense of clicking based on the central V-shaped groove41amay also be differentiated from the senses of clicking based on two other V-shaped grooves41aby setting the depth of the central V-shaped groove41adeeper than the depths of two other V-shaped grooves41a. In this case, the sense of clicking related to the warning is different from the sense of clicking related to the desired interpupillary distance, and hence the user becomes easier to distinguish between these two senses of clicking. The user can therefore adjust the interpupillary distance to the desired interpupillary distance much more easily.

Second Embodiment

FIG. 14is a view of portions in the vicinity of the axis MA of binoculars101according to a second embodiment, and corresponds toFIG. 3. inFIG. 14, with these portions being illustrated in enlargement and the majority thereof being illustrated as being broken. InFIG. 14, the same or corresponding components as or to those inFIG. 3are marked with the same numerals and symbols, but their redundant explanations are omitted.

Only a difference between the binoculars101according to the second embodiment and the binoculars1according to the first embodiment is such a point that the lock/unlock member51is removed, and the decorative cover61serves as the lock/unlock member.

Namely, in the second embodiment, the decorative cover61, when rotated in the predetermined direction about the axis MA, fastens the operation member41in the direction of the axis MA, herein, in the upward direction inFIG. 14, thus locking the rotation of the operation member41, i.e., disabling the operation member41from rotating; and the decorative cover61, when rotated in the reversed direction, slackens the fastened operation member41, thus unlocking the locked rotation of the operation member41. Namely, the decorative cover61enables the operation member41to rotate.

The same advantages as those in the first embodiment are acquired from the second embodiment. Note that the operation member41may be formed with the plurality of V-shaped grooves41aalso in the second embodiment.

The respective embodiments of the present invention and the modified examples thereof have been described so far, however, the present invention is not limited to those embodiments and the modified examples.

For example, in the respective embodiments described above, the operation member41is formed with the V-shaped groove41aas the recessed portion for clicking, while the ball31serving as the protrusion for clicking is provided on the side of the lens barrel2L; and conversely the protrusion for clicking may be provided on the operation member41, while the recessed portion for clicking may be provided in the lens barrel2L.