Patent Description:
Typically, an objective lens unit is known that includes an objective lens with a correction ring, a rotary member that rotates the correction ring, and a drive motor that rotates the rotary member (e.g., Patent Literature <NUM>). For example, Patent Literature <NUM> discloses a microscope device that includes an objective lens with a correction ring, a power transmission mechanism such as a gear that engages with the correction gear, and a lens drive mechanism including a motor that drives the power transmission mechanism. Patent Literature <NUM> discloses an objective lens unit according to the preamble of claim <NUM>.

Patent Literature <NUM>, <NUM> and <NUM> establish technological background. They relate to a corrector ring driving device of a microscopic objective lens provided with a corrector ring, a microscope system, an objective lens unit and a microscope main body and a microscope device provided with a remote drive mechanism for operating an optical adjustment correction ring for objective lenses on the optical axis, from outside an object separated from the optical axis.

However, it is difficult for a typical microscope such as the microscope device disclosed in Patent Literature <NUM> to rotate the objective lens for detaching the objective lens from the microscope because the correction ring of the objective lens meshes with a gear of the motor. The objective lens, the gear, and the motor are integral in the typical microscope. As such, it is necessary to detach all of the objective lens, the gear, and the motor in replacement of the objective lens by for example an objective lens with different magnification.

The present invention has been made in view of the foregoing and has its object of providing an objective lens unit and a microscope with an objective lens that is capable of being replaced without necessity to remove a drive section from a microscope main body.

The present invention provides an objective lens unit according to claim <NUM> and a microscope according ot claim <NUM>.

In one aspect of the present invention, the first engagement portion may be provided as the one or more indentations. The second engagement portion may be provided as the one or more pins. The first rotary member includes a first plate with the outer peripheral surface and the first engagement portion. The second rotary member may include a second plate extending in a direction intersecting a rotation axis of the second rotary member. The second engagement portion may protrude from the second plate in a direction in which the rotation axis of the second rotary member extends.

In one aspect of the present invention, the objective lens may have a first end and a screw part. The first end may be located at an end in a first direction and may be to be opposite to an object. The screw may be located at an end in a second direction opposite to the first direction and may have a screw thread. The first plate is disposed on a side of the second plate in the first direction.

In one aspect of the present invention, the one or more indentations may each have paired inner side surfaces located so as to catch a corresponding one of the one or more pins. The paired inner side surfaces may be located substantially in parallel to each other so as to extend from an outer periphery of the first rotary member toward a central part of the first rotary member.

In one aspect of the present invention, the number of the one or more indentations may be the same as the number of the one or more pins.

In one aspect of the present invention, the objective lens may further include a detection section that detects a rotation position of the first rotary member being or not being positioned at a reference position. The reference position may be a position where the second engagement portion engages with the first engagement portion in rotation of the second rotary member from the retraction position to the engagement position.

According to the present invention, an objective lens unit and a microscope with an objective lens can be provided that includes an objective lens capable of being replaced without necessity to remove the drive section from the microscope main body.

The following describes an embodiment of the present invention with reference to the accompanying drawings. Note that elements that are the same or equivalent are indicated by the same reference signs in the drawings and description thereof is not repeated. In order to facilitate understanding, a Z axis is drawn in drawings as appropriate. In one example, the Z axis is parallel to the vertical direction. The positive direction of the Z axis indicates a vertically upward direction and the negative direction of the Z axis direction indicates a vertically downward direction.

With reference to <FIG>, description will be made of a microscope <NUM> including an objective lens unit <NUM> according to an embodiment of the present invention. <FIG> is a schematic side view of the microscope <NUM> including the objective lens unit <NUM> according to an embodiment of the present invention.

As illustrated in <FIG>, the microscope <NUM> of the present embodiment includes a microscope main body <NUM> and an objective lens unit <NUM> mounted on the microscope main body <NUM>. The microscope main body <NUM> includes a main body <NUM>, a stage <NUM> on which an object being an observation target is to be placed, a revolving nosepiece <NUM> on which objective lenses <NUM> are mounted, an eyepiece <NUM>, and an optical system (not illustrated).

The stage <NUM>, the revolving nosepiece <NUM>, and the eyepiece <NUM> are arranged at the main body <NUM>. The stage <NUM> may ascend and descend vertically, for example. The optical system (not illustrated) guides light entering the objective lens <NUM> to the eyepiece <NUM>. The optical system includes an imaging lens, a prism, and a reflection mirror, for example. The light from the objective lens <NUM> exits from the eyepiece <NUM>. This enable a user to observe a magnified image of the object through the eyepiece <NUM>.

<FIG> is a perspective view of a configuration around the revolving nosepiece <NUM> of the microscope <NUM> as viewed in a negative Z direction. As illustrated in <FIG>, a plurality of objective lenses <NUM> are attachably and detachably fitted to the revolving nosepiece <NUM> in the present embodiment. The revolving nosepiece <NUM> has a plurality of fitting holes (not illustrated) to which the objective lenses <NUM> are to be fitted. A screw thread (not illustrated) is formed on the inner circumferential surface of each fitting hole. In the present embodiment, the objective lens unit <NUM> is mounted on the revolving nosepiece <NUM> in addition to the objective lenses <NUM>. The revolving nosepiece <NUM> may be rotatable about the center line (not illustrated) thereof as a center. In the above configuration, the user can select one of the objective lenses <NUM> that is to be opposite to the object by rotating the revolving nosepiece <NUM>.

For example, an objective lens <NUM> used in the objective lens unit <NUM> has a larger magnification than the objective lenses <NUM> not used in the objective lens unit <NUM>. The magnification of the objective lens <NUM> used in the objective lens unit <NUM> is equal to or larger than <NUM>×, for example. By contrast, the magnification of the objective lenses <NUM> not used in the objective lens unit <NUM> is less than <NUM>×, for example. The objective lens <NUM> not used in the objective lens unit <NUM> may not be provided with correction ring, for example.

The microscope main body <NUM> includes a revolving nosepiece drive section <NUM> that rotates the revolving nosepiece <NUM> in the present embodiment. The revolving nosepiece drive section <NUM> includes a motor 15a and a drive gear 15b. The revolving nosepiece <NUM> includes a revolving nosepiece gear 13a engaging with the drive gear 15b. As a result of driving the revolving nosepiece drive section <NUM>, the revolving nosepiece <NUM> is rotated.

<FIG> is a perspective view of the configuration of the objective lens unit <NUM> as viewed from a positive A direction. <FIG> is a perspective view of the configuration of the objective lens unit <NUM> as viewed from a negative A direction. <FIG> is a perspective view of each configuration of the objective lens <NUM>, a first rotary member <NUM>, a second rotary member <NUM>, and a drive section <NUM> of the objective lens unit <NUM> as viewed from the negative A direction. <FIG> is an exploded perspective view of each configuration of the objective lens <NUM> and the first rotary member <NUM> of the objective lens unit <NUM> as viewed from the positive A direction. The A direction is a direction in which the optical axis of the objective lens <NUM> extends. In one example, the A direction is parallel to the vertical direction in a state in which the objective lens <NUM> is placed opposite to the object (observation target). The positive A direction is a substantially upward direction and the negative A direction is a substantially downward direction.

As illustrated in <FIG> and <FIG>, the objective lens unit <NUM> includes an objective lens <NUM> provided with a correction ring 55a (see <FIG>), a first rotary member <NUM> mounted on the objective lens <NUM>, a second rotary member <NUM> that engages with the first rotary member <NUM>, and a drive section <NUM> that rotates the second rotary member <NUM>. In the present embodiment, the objective lens unit <NUM> further includes a support member <NUM> that supports the second rotary member <NUM> and the drive section <NUM>.

As illustrated in <FIG> and <FIG>, the objective lens <NUM> has a first end 55b located at an end in the negative A direction thereof and a screw part 55c located at the other end in the positive A direction thereof. Note that the negative A direction is an example of a "first direction" in the present embodiment. Also, the positive A direction is an example of a "second direction" in the present embodiment.

The correction ring 55a (see <FIG>) is disposed at a substantially central part between the first end 55b and the screw part 55c. The correction ring 55a has an outer circumferential surface with projections and recesses (not illustrated) in the circumferential direction thereof. Rotation of the correction ring 55a moves the optical system such as a lens disposed inside the objective lens <NUM> in the optical axis direction. Through the above, aberration (spherical aberration) can be corrected.

The first end 55b is to be opposite to the object. Light from the object enters the first end 55b. The screw part 55c has a screw thread. The screw part 55c is attachably and detachably fitted in a fitting hole (not illustrated) of the revolving nosepiece <NUM>.

The first rotary member <NUM> rotates together with the correction ring 55a. Specifically, the first rotary member <NUM> includes a first plate <NUM> with first engagement portions <NUM> and a fixing part <NUM> that fixes the first plate <NUM> to the objective lens <NUM>.

The fixing part <NUM> is disposed around the correction ring 55a. The fixing part <NUM> includes a band <NUM> and a fastening section <NUM> that fastens the band <NUM> around the objective lens <NUM>. Note that the fastening section <NUM> includes a bolt and a nut in the present embodiment. Fastening the band <NUM> by the fastening section <NUM> fixes the fixing part <NUM> to the correction ring 55a. The first rotary member <NUM> accordingly rotates together with the correction ring 55a. Note that the band <NUM> is made of a metal sheet, for example.

The first plate <NUM> is arc-shaped or fan-shaped, for example. The inner rim of the first plate <NUM> is fixed to the band <NUM>. Note that the first plate <NUM> is made of a metal sheet, for example.

Furthermore, the first plate <NUM> has an outer peripheral surface 210a and first engagement portions <NUM> formed in the outer peripheral surface 210a. In the present embodiment, the first plate <NUM> includes a plurality of (<NUM> in this case) first engagement portions <NUM>. The first engagement portions <NUM> are spaced at equal angular intervals in the circumferential direction of the first plate <NUM>. Furthermore, each of the first engagement portions <NUM> has an indented shape. In other words, the first engagement portions <NUM> are indentations. Accordingly, the first engagement portions <NUM> can be easily formed in the first plate <NUM> made of a metal sheet.

<FIG> is a diagram illustrating each configuration of the objective lens <NUM> and the first rotary member <NUM> of the objective lens unit <NUM> as viewed from the negative A direction. The first engagement portions <NUM> are U-shaped, for example. Specifically, each first engagement portion <NUM> has paired inner side surfaces 211a and a connection surface 211b. Here, the paired inner side surfaces 211a are located so as to catch a later-described second engagement portion <NUM> and the connection surface 211b connects the paired inner side surfaces 211a to each other (see <FIG>). The paired inner side surfaces 211a extend toward the center from the outer periphery of the first rotary member <NUM>. The paired inner side surfaces 211a are arranged substantially in parallel to each other. The connection surface 211b has a semicircular arc shape, for example.

As illustrated in <FIG>, the first rotary member <NUM> includes a to-be-detected portion <NUM>. The to-be-detected portion <NUM> is a portion of the first rotary member <NUM> that is to be detected by a later described first detection section <NUM>. The to-be-detected portion <NUM> is not limited specifically, and may be located on the outer periphery of the first plate <NUM>, for example. Furthermore, the to-be-detected portion <NUM> protrudes in a direction (A direction) intersecting with the first plate <NUM>. The first plate <NUM> and the to-be-detected portion <NUM> are constituted by a single member in the present embodiment.

Furthermore, the first plate <NUM> is located on the side of the later-described second plate <NUM> in the negative A direction in the present embodiment as illustrated in <FIG> and <FIG>.

The second rotary member <NUM> engages with the first rotary member <NUM> to rotate the first rotary member <NUM>. Specifically, the second rotary member <NUM> includes a second plate <NUM> and second engagement portions <NUM> that each are to engage with corresponding one of the first engagement portions <NUM> of the first rotary member <NUM>. Note that the second plate <NUM> is made of a metal sheet, for example. Furthermore, the second engagement portions <NUM> each are a bar member made of metal, for example.

The second plate <NUM> extends in a direction (radial direction) intersecting with a rotation axis L310 of the second rotary member <NUM>. The shape of the second plate <NUM> is not limited specifically and may be a disc shape, for example. The rotation axis L310 passes through the center of the second plate <NUM>. The second rotary member <NUM> is rotatable about the rotation axis L310.

The second engagement portions <NUM> are arranged on a part in the circumferential direction of the second rotary member300. The second engagement portions <NUM> are arranged on a part in the circumferential direction of the outer peripheral part of the second plate <NUM>. In the above configuration, the second rotary member <NUM> rotates to position each second engagement portion <NUM> at an engagement position or a retraction position. Here, the engagement position is a position where at least one of the second engagement portions <NUM> engages with a corresponding one of the first engagement portions <NUM> and the retraction position is a position where the second engagement portions <NUM> retract from the first engagement portions <NUM>.

The second engagement portions <NUM> are each formed so as to protrude from the second plate <NUM> to engage with a corresponding one of the first engagement portions <NUM>, for example. The second engagement portions <NUM> each include a pin that engages with a corresponding one of the first engagement portions <NUM> (indentations) in the present embodiment. The shape of the second engagement portions <NUM> is not limited specifically and is a columnar or cylindrical shape in the present embodiment. The second engagement portions <NUM> have a length longer than the thickness of the first engagement portions <NUM> in the A direction, for example. In other words, the second engagement portions <NUM> protrude in both the positive A direction and the negative A direction from the first engagement portion <NUM>.

The second engagement portions <NUM> protrude from the second plate <NUM> in a direction in which the rotation axis L310 extends (see <FIG>). The second engagement portions <NUM> protrude from the second plate <NUM> in the negative A direction in the present embodiment.

The second rotary member <NUM> includes a plurality of second engagement portions <NUM> in the present embodiment. Furthermore, the number of the first engagement portions <NUM> is the same as the number of the second engagement portions <NUM> in the present embodiment. The second engagement portions <NUM> are disposed at equal angular intervals in the circumferential direction.

The second rotary member <NUM> includes a to-be-detected portion <NUM>. The to-be-detected portion <NUM> is a portion of the second rotary member <NUM> that is to be detected by a later-described second detection section <NUM>. The to-be-detected portion <NUM> is not limited specifically and may be disposed on a surface 310a in the positive A direction of the second plate <NUM>, for example. Note that the to-be-detected portion <NUM> may be disposed on a part of the second plate <NUM> other than the surface 310a thereof or on any of the second engagement portions <NUM>. Alternatively, the to-be-detected portion <NUM> may be constituted by a part of the second plate <NUM> or a part of the second engagement portion <NUM>. That is, the to-be-detected portion <NUM> and the second plate <NUM> may be constituted by a single member or the to-be-detected portion <NUM> and the second engagement portion <NUM> may be constituted by a single member.

The to-be-detected portion <NUM> is formed for example by bending a metal piece. The to-be-detected portion <NUM> includes a mount portion <NUM> mounted on the second plate <NUM>, an extension portion <NUM> extending from the mount portion <NUM> in the A direction, and an end portion <NUM> extending in parallel to the second plate <NUM> from the extension portion <NUM>.

The drive section <NUM> rotates the second rotary member <NUM> in the positive and negative directions by a specific angle, for example. The drive section <NUM> rotates the second rotary member <NUM> through a non-illustrated gear or the like, for example. The drive section <NUM> includes a motor such as a stepper motor, for example. Note that the drive section <NUM> may not include the motor as long as it is capable of rotating the second rotary member <NUM> in the positive and negative directions by the specific angle. Furthermore, the drive section <NUM> is disposed along the rotation axis L310 (see <FIG>), for example.

The support member <NUM> is formed by bending a metal sheet. The support member <NUM> includes a mount portion <NUM> mounted on the revolving nosepiece <NUM>, an extension portion <NUM> extending in the negative A direction from the mount portion <NUM>, and a support portion <NUM> extending in a direction intersecting with the extension portion <NUM>. The drive section <NUM> is fixed to the support portion <NUM>, and the second rotary member <NUM> is rotatable relative to the support portion <NUM>.

The objective lens unit <NUM> further includes a first detection section <NUM> and a second detection section <NUM>. The first detection section <NUM> is fixed to the support member <NUM>. In the present embodiment, the first detection section <NUM> is fixed to the mount portion <NUM> of the support member <NUM> through a connection piece <NUM>. The second detection section <NUM> is fixed to the support member <NUM>. The second detection section <NUM> is fixed to the extension portion <NUM> of the support member <NUM> in the present embodiment. Note that the first detection section <NUM> is an example of a "detection section" in the present invention.

The first detection section <NUM> is a member to detect the rotation position of the first rotary member <NUM> being or not being positioned at a later-described first reference position P100. The first detection section <NUM> is a sensor, for example. The first detection section <NUM> transmits a detection signal to a later-described controller 2a. The first detection section <NUM> detects the to-be-detected portion <NUM> in the present embodiment. Specifically, the first detection section <NUM> includes a light projector <NUM> that projects light and a light receiver <NUM> that receives the light from the light projector <NUM>. When the to-be-detected portion <NUM> is positioned between the light projector <NUM> and the light receiver <NUM>, the light projected from the light projector <NUM> is blocked by the to-be-detected portion <NUM> and is not received by the light receiver <NUM>. The controller 2a determines whether or not the to-be-detected portion <NUM> is positioned between the light projector <NUM> and the light receiver <NUM> based on the detection signal from the first detection section <NUM>. In the present embodiment, the rotation position of the first rotary member <NUM> when the to-be-detected portion <NUM> is positioned between the light projector <NUM> and the light receiver <NUM> corresponds to a later-described first reference position P100. That is, it is possible to detect the rotation position of the first rotary member <NUM> being or not being positioned at the first reference position P100 based on a result of detection of the to-be-detected portion <NUM> by the first detection section <NUM>.

The second detection section <NUM> is a member for detecting the rotation position of the second rotary member <NUM> being or not being positioned at a later-described second reference position P200. The second detection section <NUM> is a sensor, for example. The second detection section <NUM> transmits a detection signal to the later-described controller 2a. In the present embodiment, the second detection section <NUM> detects the to-be-detected portion <NUM>. Specifically, the second detection section <NUM> includes a light projector <NUM> that projects light and a light receiver <NUM> that receives the light from the light projector <NUM>, for example. When the end portion <NUM> of the to-be-detected portion <NUM> is positioned between the light projector <NUM> and the light receiver <NUM>, the light projected from the light projector <NUM> is blocked by the to-be-detected portion <NUM> and is not received by the light receiver <NUM>. The controller 2a determines whether or not the to-be-detected portion <NUM> is located between the light projector <NUM> and the light receiver <NUM> based on a signal from the second detection section <NUM>. In the present embodiment, the rotation position of the second rotary member <NUM> when the to-be-detected portion <NUM> is positioned between the light projector <NUM> and the light receiver <NUM> corresponds to the later-described second reference position P200. That is, it is possible to detect the rotation position of the second rotary member <NUM> being or not being positioned at the second reference position P200 based on a result of detection of the to-be-detected portion <NUM> by the second detection section <NUM>.

With reference to <FIG>, engagement between the first rotary member <NUM> and the second rotary member <NUM> will be described next in detail. <FIG> is a diagram illustrating a state in which the first rotary member <NUM> is positioned at the first reference position P100 as viewed from the negative A direction. <FIG> is a diagram illustrating a state in which the first rotary member <NUM> is positioned at the first reference position P100 as viewed from the negative A direction. <FIG> is a diagram illustrating a state in which a first engagement portion <NUM> and a second engagement portion <NUM> engage with each other as viewed from the negative A direction. <FIG> is a diagram illustrating a state in which a first engagement portion <NUM> and a second engagement portion <NUM> engage with each other as viewed from the negative A direction. <FIG> is a diagram illustrating a state in which the first rotary member <NUM> is positioned at the first reference position P100 and the second rotary member <NUM> is positioned at the second reference position P200 as viewed from the negative A direction. Note that only the objective lens <NUM>, the first rotary member <NUM>, the second rotary member <NUM>, and the drive section <NUM> are illustrated in <FIG> in order to facilitate understanding.

The first engagement portions <NUM> of the first rotary member <NUM> and the second engagement portions <NUM> of the second rotary member <NUM> engage with each other. In the present embodiment, the three second engagement portions <NUM> sequentially engage with the corresponding three first engagement portions <NUM> by rotation of the second rotary member <NUM> about the rotation axis L310. Specifically, a second engagement portion 320a engages with a first engagement portion 2110a as illustrated in <FIG>. A second engagement portion 320b engages with a first engagement portion 2110b. A second engagement portion 320c engages with a first engagement portion 2110c.

Here, the second rotary member <NUM> rotates to be positioned at an engagement position or a retraction position. The engagement position is a rotation position of the second rotary member <NUM> when a second engagement portion <NUM> and a first engagement portion <NUM> engage with each other. The retraction position is a rotation position of the second rotary member <NUM> when the second engagement portions <NUM> retract from the first engagement portions <NUM>. In the present embodiment, the engagement position is a rotation position of the second rotary member <NUM> when a second engagement portion <NUM> is in contact with a first rotary member <NUM>. The retraction position is a rotation position of the second rotary member <NUM> when the second engagement portions <NUM> separate from the first rotary member <NUM>. The engagement position includes the positions illustrated in <FIG>, for example. The retraction position includes the position illustrated in <FIG>, for example.

When the second rotary member <NUM> is rotated in a state in which the second rotary member <NUM> is positioned at the engagement position, the first rotary member <NUM> is also rotated. However, due to the load of the drive section <NUM>, the first rotary member <NUM> and the second rotary member <NUM> are not rotated even when the first rotary member <NUM> is tried to rotate. Furthermore, in a state in which the second rotary member <NUM> is positioned at the retraction position, one of the first rotary member <NUM> and the second rotary member <NUM> is not rotated even if the other of the first rotary member <NUM> and the second rotary member <NUM> is rotated. That is, when the second rotary member <NUM> is positioned at the retraction position, the objective lens <NUM> and the first rotary member <NUM> can be rotated for attachment and detachment thereof to and from the revolving nosepiece <NUM>.

The second reference position P200 is a rotation position of the second rotary member <NUM>. Specifically, the second reference position P200 is a rotation position at which the second rotary member <NUM> is positioned in attachment of the objective lens <NUM> and the first rotary member <NUM> to the revolving nosepiece <NUM>. In the present embodiment, the second reference position P200 is a rotation position at which the second rotary member <NUM> is positioned in detachment of the objective lens <NUM> and the first rotary member <NUM> from the revolving nosepiece <NUM>. The second reference position P200 is included in the retraction position.

The first reference position P100 is a rotation position of the first rotary member <NUM>. Specifically, the first reference position P100 is a rotation position at which the first rotary member <NUM> is positioned in engagement of the second rotary member <NUM> with the first rotary member <NUM>. The first reference position P100 ranges from the position illustrated in <FIG> to the position illustrated in <FIG>. For example, even when the first rotary member <NUM> is positioned at the rotation position illustrated in <FIG> or the rotation position illustrated in <FIG>, a second engagement portion <NUM> engages with a first engagement portion <NUM> by rotating the second rotary member <NUM> in the clockwise direction. In the present embodiment, the rotation positions of the first rotary member <NUM> differ by approximately <NUM> degrees to <NUM> degrees between <FIG> and <FIG>. That is, control of the rotation position of the first rotary member <NUM> with an accuracy of ±<NUM> degrees to ±<NUM> degrees can prevent the second engagement portions <NUM> from coming into contact with a part of the first rotary member <NUM> that is other than the corresponding first engagement portions <NUM>. Accordingly, control of the rotation position of the first rotary member <NUM> with an accuracy of ±<NUM> degrees to ±<NUM> degrees can facilitate engagement of a second engagement portion <NUM> with a first engagement portion <NUM>.

<FIG> is a block diagram of a configuration of the microscope <NUM>. As illustrated in <FIG>, the microscope <NUM> further includes a control device <NUM>, a notification section <NUM>, and an input section <NUM>. The control device <NUM> controls various operations of the microscope <NUM>. The control device <NUM> includes a controller 2a and storage 2b. The controller 2a includes a processor. The controller 2a includes a central processing unit (CPU), for example.

The storage 2b stores data and computer programs therein. The storage 2b includes a main storage device and an auxiliary storage device. The main storage device is semiconductor memory, for example. The auxiliary storage device includes either or both semiconductor memory and a hard disk drive, for example. The storage 2b may include a removable medium.

The controller 2a executes the computer programs stored in the storage 2b to perform the operation of the microscope <NUM>. The controller 2a transmits a first position signal to the notification section <NUM> based on the detection signal from the first detection section <NUM>. The first position signal is a signal indicating whether or not the first rotary member <NUM> is positioned at the first reference position P100. The controller 2a further transmits a second position signal to the notification section <NUM> based on the detection signal from the second detection section <NUM>. The second position signal is a signal indicating whether or not the second rotary member <NUM> is positioned at the second reference position P200.

The notification section <NUM> notifies that the first rotary member <NUM> is or is not positioned at the first reference position P100 based on the first position signal from the controller 2a. The notification section <NUM> also notifies that the second rotary member <NUM> is or is not positioned at the second reference position P200 based on the second position signal from the controller 2a. The notification section <NUM> is not limited specifically, and includes a display screen that displays notification content, for example. Note that the notification section <NUM> may include an indictor lamp or a speaker that emits sound, for example.

The input section <NUM> includes an operation section that the user operates. The input section <NUM> includes a switching section 4a, an adjusting section 4b, and a revolving nosepiece rotating section 4c. The switching section 4a is a member for switching the rotation position of the second rotary member <NUM> between the retraction position and the engagement position, for example. The adjusting section 4b is a member for adjusting the rotation position of the second rotary member <NUM>, for example. The adjusting section 4b can rotate the second rotary member <NUM> for example by a specific angle in the positive and negative directions. The revolving nosepiece rotating section 4c is a member for rotating the revolving nosepiece <NUM>. The switching section 4a, the adjusting section 4b, and the revolving nosepiece rotating section 4c each include any of a switch, a button, a lever, or a dial, for example.

The controller 2a controls the rotation position of the second rotary member <NUM> based on a signal from the switching section 4a. The controller 2a controls the rotation position of the second rotary member <NUM> based on a signal from the adjusting section 4b. The controller 2a controls the rotation position of the revolving nosepiece <NUM> based on a signal from the revolving nosepiece rotating section 4c.

With reference to <FIG>, a method for replacing the objective lens <NUM> of the objective lens unit <NUM> will be described next. <FIG> is a flowchart depicting an example of the method for replacing the objective lens <NUM> of the objective lens unit <NUM>.

As depicted in <FIG>, the second rotary member <NUM> is set at the retraction position in Step S1. Specifically, the user operates the switching section 4a to move the second rotary member <NUM> from the engagement position to the retraction position. The controller 2a drives the drive section <NUM> to rotate the second rotary member <NUM>. As a result, the second rotary member <NUM> is moved from the engagement position illustrated in for example <FIG> or <FIG> to the retraction position illustrated in <FIG>. In doing so, the second rotary member <NUM> is rotated until the second detection section <NUM> detects the to-be-detected portion <NUM> in the present embodiment. This sets the second rotary member <NUM> at the second reference position P200. Note that the second rotary member <NUM> may be positioned at a retraction position other than the second reference position P200 in Step S1.

Next in Step S2, the objective lens <NUM> is detached from the microscope <NUM>. Specifically, the user rotates the objective lens <NUM> and the first rotary member <NUM> to detach them from the revolving nosepiece <NUM>. In doing so, the first rotary member <NUM> and the second rotary member <NUM> are out of contact with each other because the second rotary member <NUM> is positioned at the retraction position. Therefore, the objective lens <NUM> can be detached from the microscope <NUM> without the need to detach the second rotary member <NUM> and the drive section <NUM> from the microscope <NUM>.

Next in Step S3, an objective lens <NUM> with a magnification different from that of the objective lens <NUM> having detached in Step S2 is attached to the microscope <NUM>. In the following, the objective lens <NUM> with a magnification different from that of the objective lens <NUM> having detached in Step S2 may be referred to as "different objective lens <NUM>". Specifically, the first rotary member <NUM> is fixed to the different objective lens <NUM>. The user rotates the different objective lens <NUM> and the first rotary member <NUM> to attach them to the revolving nosepiece <NUM>. In doing so, the first rotary member <NUM> and the second rotary member <NUM> do not engage with each other due to the second rotary member <NUM> being positioned at the retraction position. Therefore, the different objective lens <NUM> can be attached to the microscope <NUM> in a state in which the second rotary member <NUM> and the drive section <NUM> are left mounted on the microscope <NUM>.

Next in Step S4, the first rotary member <NUM> is positioned at the first reference position P100. Specifically, the user rotates the different objective lens <NUM> and the first rotary member <NUM> relative to the revolving nosepiece <NUM>. Upon the first detection section <NUM> detecting the to-be-detected portion <NUM> in doing so, the notification section <NUM> notifies the user of the first rotary member <NUM> being positioned at the first reference position P100. This makes the user to know that the first rotary member <NUM> has been positioned at the first reference position P100. The user then stops the rotation of the different objective lens <NUM> and the first rotary member <NUM>. As a result, the first rotary member <NUM> and the second rotary member <NUM> are in the state illustrated in <FIG>, for example.

Next in Step S5, the second rotary member <NUM> is caused to engage with the first rotary member <NUM>. Specifically, the user operates the switching section 4a to move the second rotary member <NUM> from the retraction position to the engagement position. The controller 2a drives the drive section <NUM> for example for a predetermined time to rotate the second rotary member <NUM>. This moves the second rotary member <NUM> to the engagement position illustrated in <FIG> from the retraction position illustrated for example in <FIG>. That is, a second engagement portion <NUM> of the second rotary member <NUM> engages with a first engagement portion <NUM> of the first rotary member <NUM>. The rotation position of the correction ring 55a can be adjusted as above through use of the adjusting section 4b.

The objective lens <NUM> is replaced in the manner described above.

Note that the revolving nosepiece <NUM> may be rotated in replacement of the objective lens <NUM>. That is, the objective lens <NUM> may be replaced in a state in which the objective lens <NUM> is retracted from the object by rotation of the revolving nosepiece <NUM>.

As has been described so far with reference to <FIG>, the second engagement portions <NUM> are arranged at a part in the circumferential direction of the second plate <NUM> and the second rotary member <NUM> rotates to be positioned at the engagement position where a second engagement portion <NUM> engages with a first engagement portion <NUM> or the retraction position where the second engagement portions <NUM> retract from the first engagement portions <NUM>. In the above configuration, when the second rotary member <NUM> is positioned at the retraction position, the objective lens <NUM> and the first rotary member <NUM> can be rotated to be attached to or detached from the revolving nosepiece <NUM>. Accordingly, the objective lens <NUM> can be replaced without the need to detach the second rotary member <NUM> and the drive section <NUM> from the microscope main body <NUM>.

Furthermore, the first engagement portions <NUM> and the second engagement portions <NUM> are respectively indentations and pins as described above. In the above configuration, the first engagement portions <NUM> and the second engagement portions <NUM> can be easily designed, as will be described later, as compared to a case for example in which the first engagement portions <NUM> and second engagement portions <NUM> are gears.

Furthermore, compared to a case in which the first engagement portions <NUM> and the second engagement portion <NUM> are gears, there is no need to increase relative positional accuracy between the first engagement portions <NUM> and the second engagement portions <NUM>. Furthermore, there is no need to form the first engagement portions <NUM> and the second engagement portions <NUM> for example along an involute curve, which facilitate production thereof.

As described above, the second engagement portions <NUM> protrude from the second plate <NUM> in the direction in which the rotation axis L310 extends. In the above configuration, an increase in size of the second rotary member <NUM> in a direction (radial direction) intersecting with the rotation axis L310 can be suppressed.

Furthermore, the first plate <NUM> is disposed on the side of the second plate <NUM> in the negative A direction. In the above configuration, the first plate <NUM> can be easily prevented from coming in contact with the second plate <NUM> in detachment of the objective lens <NUM> and the first rotary member <NUM>.

Furthermore, as described above, the paired inner side surfaces 211a are in parallel to each other so as to extend from the outer periphery toward the central part of the first rotary member <NUM>. In the above configuration, even when the second engagement portions <NUM> are moved in the radial direction of the first rotary member <NUM> along a first engagement portion <NUM>, for example, the contact state of the second engagement portion <NUM> to the first engagement portion <NUM> is prevented from changing. Therefore, there is no need to increase relative positional accuracy between the first rotary member <NUM> and the second rotary member <NUM>.

Furthermore, the number of the first engagement portions <NUM> is the same as the number of the second engagement portions <NUM> as described above. In the above configuration, the user can easily perceive which of the first engagement portions <NUM> corresponds to which of the second engagement portions <NUM>. Therefore, the user can easily check the first engagement portions <NUM> and the second engagement portions <NUM> being or not being correctly engage for example without <NUM>-pitch displacement.

Furthermore, as described above, the first detection section <NUM> is a member for detecting the rotation position of the first rotary member <NUM> being or not being positioned at the first reference position P100. As such, the first rotary member <NUM> can be easily positioned at the first reference position P100 through detection by the first detection section <NUM>. Therefore, rotation of the second rotary member <NUM> from the retraction position to the engagement position can easily cause engagement of a second engagement portion <NUM> with a first engagement portion <NUM>.

The positional relationship between the first engagement portions <NUM> and the second engagement portions <NUM> will be described next with reference to FISG. <NUM> and <NUM>. More specifically, description will be made of a method for calculating a movable range of the first rotary member <NUM>. <FIG> is a schematic diagram explaining the positional relationship between a first engagement portion <NUM> and a second engagement portion <NUM>. With reference to <FIG>, a case will be described first in which one first engagement portion <NUM> and one second engagement portion <NUM> are provided.

As illustrated in <FIG>, M1 denotes a track of the outer peripheral surface of the first plate <NUM> of the first rotary member <NUM>, M2 denotes an outermost track (also referred simply to below as "track") of the outer circumferential surface of the second engagement portion <NUM> of the second rotary member <NUM>, and m2 denotes a track of the center of the second engagement portion <NUM>. Furthermore, R1 denotes the radius of the track M1, R2 denotes the radius of the track M2, r2 denotes the radius of the track m2, and r3 denotes the radius of the second engagement portion <NUM>. A point A indicates an intersection point of the track M1 and the track M2, a point B indicates the rotational center of the second rotary member <NUM>, and a point C indicates the rotational center of the first rotary member <NUM>. Furthermore, L denotes the distance between the point B and the point C and W denotes the width of the first engagement portion <NUM>. Where the center of the second engagement portion <NUM> is located on the straight line connecting the point B and the point C (in a state illustrated in <FIG>), a point D indicates a contact point between the first engagement portion <NUM> and the outer circumferential surface of the second engagement portion <NUM>, an angle α indicates an angle DCB, an angle β indicates an angle DCA, and an angle C<NUM> indicates an angle ACB (= angle α + angle β).

Here, when the second engagement portion <NUM> rotates in the anticlockwise direction about the point B as a center from the state illustrated in <FIG>, the second engagement portion <NUM> is kept engaging with the first engagement portion <NUM> until the outer circumferential surface of the second engagement portion <NUM> reaches the point A. In other words, the movable range of the first rotary member <NUM> is an angle β (= angle C<NUM> - angle α) in anticlockwise rotation of the second engagement portion <NUM> from the state illustrated in <FIG>.

The following is met in accordance with the low of cosines.

Furthermore, the following is met in accordance with the trigonometric ratio.

In other words, the following is met.

Accordingly, the angle β (= angle C<NUM> - angle α) can be easily calculated.

For example, where R1 = <NUM>, R2 = <NUM>, r2 = <NUM>, L = <NUM>, r3 = <NUM>, and W = <NUM>, the following is met.

<FIG> is a bilaterally symmetrical diagram. As such, the movable range of the first rotary member <NUM> is accordingly <NUM>° × <NUM> = <NUM>°.

<FIG> is a schematic diagram explaining a positional relationship between first engagement portions <NUM> and second engagement portions <NUM>. Next, a case will be described with reference to <FIG> in which two first engagement portions <NUM> and two second engagement portions <NUM> are provided.

As illustrated in <FIG>, a point E and a point F indicate intersection points of the track M1 and the track m2. Furthermore, an angle C<NUM> indicates an angle ECB.

Here, the second engagement portion <NUM> positioned at the point E is in contact with the paired inner side surfaces 211a of the corresponding first engagement portion <NUM> in the state illustrated in <FIG>. When the second rotary member <NUM> rotates anticlockwise from the state illustrated in <FIG>, the second engagement portion <NUM> positioned at the point E moves outward from the inside of the corresponding first engagement portion <NUM>. This releases simultaneous contact of the outer circumferential surface of the second engagement portion <NUM> with the paired inner side surfaces 211a of the first engagement portion <NUM>. That is, a gap is generated between the second engagement portion <NUM> and the first engagement portion <NUM>. As such, when the rotation of the second rotary member <NUM> switches for example from the anticlockwise direction to the clockwise direction, the rotation of the first rotary member <NUM> is no longer accompanied by the rotation of the second rotary member <NUM> by the amount of the gap.

In view of the foregoing, the angular distance between the two second engagement portions <NUM> is set so that the center of one of the second engagement portions <NUM> is positioned at the point F when the center of the other second engagement portion <NUM> is positioned at the point E. In the above configuration, a phenomenon can be prevented in which the rotation of the second rotary member <NUM> is not accompanied by the rotation of the first rotary member <NUM>.

Specifically, the following is met in accordance with the low of cosines.

For example, where R1 = <NUM>, r2 = <NUM>, and L = <NUM> as above, the following is met.

<FIG> is a bilaterally symmetrical diagram. As such, the angular distance between the two second engagement portions <NUM> is approximately <NUM>° (= <NUM>° × <NUM>).

Next, an angular distance between the two first engagement portions <NUM> is calculated. Specifically, the following is met in accordance with the low of cosines.

<FIG> is a bilaterally symmetrical diagram. As such, the angular distance between the two first engagement portions <NUM> is approximately <NUM>° (= <NUM>° × <NUM>).

Furthermore, the movable range of the first rotary member <NUM> is a value obtained by adding approximately <NUM>° that is the angular distance between the two first engagement portions <NUM> to <NUM>° that is calculated in a case with one first engagement portion <NUM>. That is, the movable range of the first rotary member <NUM> is approximately <NUM>° = <NUM>° + approximately <NUM>°.

Note that in a case in which n first engagement portions <NUM> and n second engagement portions <NUM> are provide, the movable range of the first rotary member <NUM> is a value obtained by adding <NUM>° that is calculated in a case with one first engagement portion <NUM> and a value obtained by multiplying (n-<NUM>) by approximately <NUM>° that is the angular distance between the first engagement portions <NUM>. That is, the movable range of the first rotary member <NUM> is approximately <NUM>° + approximately <NUM>° × (n-<NUM>).

As has been described so far with reference to <FIG> and <FIG>, the first rotary member <NUM> and the second rotary member <NUM> can be easily designed in the present embodiment. Note that the present invention is not limited to the above example in which the movable range of the first rotary member <NUM> is calculated using the radius R1 of the track M1, the radius R2 of the track M2, the radius r2 of the track m2, the radius r3 of the second engagement portions <NUM>, the distance L between the point B and the point C, and the width W of the first engagement portions <NUM>. Needless to say, the radius R1, the radius R2, the radius r2, the radius r3, or the distance L can be calculated after the movable range of the first rotary member <NUM> is set.

Next, an objective lens unit <NUM> according to a variation of the present invention will be described with reference to <FIG> is a diagram illustrating each configuration of an objective lens <NUM> and a first rotary member <NUM> of the objective lens unit <NUM> according to the variation of the present invention as viewed from the negative A direction.

As illustrated in <FIG>, first engagement portions <NUM> each have paired inner side surfaces 211c in the objective lens unit <NUM> of the variation of the present invention. The paired inner side surfaces 211c extend toward the central part from the outer periphery of the first rotary member <NUM>. Unlike the paired inner side surfaces 211a in the above embodiment, the paired inner side surfaces 211c are located so as to intersect each other. The first engagement portions <NUM> are V-shaped, for example.

The other configuration and the replacement method of the objective lens unit <NUM> of the variation of the present invention are the same as those in the above embodiment.

An embodiment of the present invention has been described so far with reference to the accompanying drawings. However, the present invention is not limited to the above embodiment and may be implemented in various manners within a scope not departing from the gist thereof. Various disclosures can be formed by appropriately combining elements of configuration disclosed in the above embodiment. For example, some elements of configuration may be omitted from all the elements of configuration indicated in the embodiment. Any elements of configuration in different embodiments may be combined as appropriate. The drawings schematically illustrate elements of configuration in order to facilitate understanding. Properties such as thickness, length, number, and intervals of elements of configuration illustrated in the drawings may differ from actual properties in order to facilitate preparation of the drawings. Furthermore, the material, shape, dimension, and the like of each element of configuration indicated in the above embodiment are examples and not particular limitations. Various alterations may be made so long as there is no substantial deviation from the effects of the present invention.

For example, example in which the first engagement portions <NUM> (indentations) are U-shaped and V-shaped have been presented above in the embodiment and the variation, respectively, which should not be taken to limit the present invention. The first engagement portions <NUM> (indentations) may have any shape other than the U-shape and the V-shape.

Furthermore, an example in which the first engagement portions <NUM> include indentations and the second engagement portions <NUM> include pins has been presented in the above embodiment, which should not be taken to limit the present invention. For example, the first engagement portions may include pins and the second engagement portions may include indentations.

Furthermore, an example in which the second engagement portions <NUM> are columnar or cylindrical in shape has been presented in the above embodiment, which should not be taken to limit the present invention. For example, the second engagement portions <NUM> may have a polygonal prism shape or an elliptical cylinder shape. However, it is preferable that a part of the surface of each second engagement portion <NUM> that is to come into contact with the inner side surface of the corresponding first engagement portion <NUM> is a curved surface.

Furthermore, an example in which the second engagement portions <NUM> protrude from the second plate <NUM> in the direction in which the rotation axis L310 extends has been presented in the above embodiment, which should not be taken to limit the present invention. For example, the second engagement portions may protrude from the second plate <NUM> in the direction (radial direction) intersecting the rotation axis L310.

Furthermore, an example in which the first plate <NUM> is disposed on the side of the second plate <NUM> in the negative A direction has been presented in the above embodiment, which should not be taken to limit the present invention. For example, the first plate <NUM> may be disposed on the side of the second plate <NUM> in the positive A direction. In this case, for example, an indentation through which the first plate is passable may be formed in the second plate <NUM> or the second plate <NUM> may formed into a semicircular shape or fan shape in order that the first plate <NUM> does not come into contact with the second plate <NUM>.

Furthermore, although an example in which the number of the indentations is the same as the number of the pins has been presented in the above embodiment, the number of the indentations may differ from the number of the pins.

Furthermore, an example in which the first detection section <NUM> is provided in order to detect the rotation position of the first rotary member <NUM> being or not being positioned at the first reference position P100 has been presented in the above embodiment, which should not be taken to limit the present invention. For example, the user may visually check the rotation position of the first rotary member <NUM> being or not being positioned at the first reference position P100.

Furthermore, an example in which the second detection section <NUM> is provided in order to detect the rotation position of the second rotary member <NUM> being or not being positioned at the second reference position P200 has been presented in the above embodiment, which should not be taken to limit the present invention. For example, the user may visually check the rotation position of the second rotary member <NUM> being or not being positioned at the second reference position P200.

Furthermore, an example in which the switching section 4a and the adjusting section 4b are provided in order to rotate the second rotary member <NUM> has been presented in the above embodiment, which should not be taken to limit the present invention. For example, the second rotary member <NUM> may be moved between the retraction position and the engagement position using the adjusting section 4b without providing the switching section 4a.

Furthermore, an example in which the objective lens <NUM> is disposed above the object has been presented in the above embodiment, which should not be taken to limit the present invention. For example, the objective lens <NUM> may be disposed below the object for observation of the object from below.

Claim 1:
An objective lens unit (<NUM>) comprising:
an objective lens (<NUM>) provided with a correction ring (55a);
a first rotary member (<NUM>) that is mounted on the objective lens and that rotates together with the correction ring;
a second rotary member (<NUM>) that engages with the first rotary member to rotate the first rotary member; and
a drive section (<NUM>) that rotates the second rotary member, wherein
the first rotary member has an outer peripheral surface (210a) and a first engagement portion (<NUM>) formed in the outer peripheral surface,
the second rotary member has a second engagement portion (<NUM>) that is to engage with the first engagement portion,
the second engagement portion is disposed at a part in a circumferential direction of the second rotary member,
the second rotary member rotates to be positioned at an engagement position or a retraction position, the engagement position being a position where the second engagement portion engages with the first engagement portion, the retraction position being a position where the second engagement portion retracts from the first engagement portion,
characterized in that
one of the first engagement portion and the second engagement portion is provided as one or more indentations, and
another of the first engagement portion and the second engagement portion is provided as one or more pins that are to engage with the one or more indentations.