Patent Description:
In general, an endoscope comprises an elongated insertion part to be inserted into a body and a hand operating part connected to a base end side of the insertion part. The insertion part includes a distal end optical system on a distal end side, and displays an observation image of a subject captured from the distal end optical system on a display device, such as a monitor.

<CIT> (<CIT>) discloses an endoscope that performs focus adjustment by moving an objective lens forward and backward in an optical axis direction. With this endoscope, the objective lens is moved forward and backward in the optical axis direction by operating a focus adjustment knob of the hand operating part is to rotate a flexible shaft, converting the rotational movement into linear movement by a feed screw mechanism, and transmitting the converted linear movement to a lens frame.

Further, an endoscope disclosed in <CIT> moves a movable lens forward and backward in an optical axis direction by rotating a linear transmitting member by the power of a motor, converting the rotational movement into the linear movement by a feed screw mechanism, and transmitting the converted linear movement to a lens frame.

Since the endoscope disclosed in <CIT> (<CIT>) is an apparatus that moves the lens forward and backward by manually operating the focus adjustment knob, there is an advantage that costs (manufacturing cost and running cost) can be reduced as compared with the endoscope disclosed in <CIT> that moves the lens forward and backward by the motor. However, <CIT> (<CIT>) does not describe any zoom operation mechanism for efficiently transmitting an operation force of the focus adjustment knob to the shaft. That is, <CIT> (<CIT>) does not disclose at all the zoom operation mechanism for efficiently moving the distal end optical system forward and backward in the optical axis direction. <CIT> relates to a hard zoom endoscope as defined in the preamble of independent claim <NUM>.

An endoscope device according to the invention is provided as defined by claim <NUM>. Preferred embodiments of the invention are defined in the dependent claims <NUM> to <NUM>.

Hereinafter, embodiments of an endoscope according to the present invention will be described with reference to the accompanying drawings. <FIG> is an overall configuration diagram of an endoscope <NUM> according to the embodiment.

As shown in <FIG>, the endoscope <NUM> comprises an insertion part <NUM> and a hand operating part <NUM> to which a base end side of the insertion part <NUM> is connected. A base end of a universal cable <NUM> is connected to the hand operating part <NUM>. A connector device (not shown) connected to a processor device <NUM> is provided at the distal end of the universal cable <NUM>. The processor device <NUM> comprises a light source device <NUM> and an image processing device <NUM>. The light source device <NUM> comprises a processor-side connector (not shown) to which the connector device is connected. In addition, a display (not shown) that displays an image processed by the image processing device <NUM> is connected to the image processing device <NUM>. An endoscope system of the present example comprising the endoscope <NUM> and the processor device <NUM> has a configuration in which the power, the light signal, or the like is transmitted in a noncontact manner between the endoscope <NUM> and the processor device <NUM> via the connector portion composed of the connector device and the processor-side connector.

The hand operating part <NUM> is provided with an air supply/water supply button <NUM>, a suction button <NUM>, a shutter button <NUM>, a zoom operation knob <NUM>, a pair of bending operation knobs <NUM>, and a forceps insertion part <NUM> at predetermined positions, respectively.

The insertion part <NUM> has a longitudinal axis A, and includes a soft portion <NUM>, a bendable portion <NUM>, and a distal end hard portion <NUM> from the base end side toward a distal end side. The bending operation is performed on the bendable portion <NUM> remotely by rotationally operating the pair of bending operation knobs <NUM> provided on the hand operating part <NUM>. As a result, a distal end surface <NUM> of the distal end hard portion <NUM> can be directed in a desired direction.

<FIG> is a front view of the distal end surface <NUM> of the distal end hard portion <NUM>. As shown in <FIG>, on the distal end surface <NUM> of the distal end hard portion <NUM>, an observation window <NUM>, a pair of illumination windows 40A and 40B, an air supply/water supply nozzle <NUM>, and a forceps port <NUM> are arranged at predetermined positions, respectively. As an example, the observation window <NUM> is disposed substantially in the center of the distal end surface <NUM>, and the illumination windows 40A and 40B are arranged on both sides of the observation window <NUM>. In addition, the air supply/water supply nozzle <NUM> is arranged toward the observation window <NUM>, and the forceps port <NUM> is arranged in a space surrounded by the observation window <NUM>, the illumination window 40A, and the air supply/water supply nozzle <NUM>.

Hereinafter, a configuration of an observation optical system <NUM> including the observation window <NUM> provided in the distal end hard portion <NUM> will be described. <FIG> is a vertical cross-sectional view of the distal end hard portion <NUM> along the longitudinal axis A. <FIG> is a vertical cross-sectional view of the observation optical system <NUM> along an optical axis P of the observation optical system <NUM>. It should be noted that the longitudinal axis A and the optical axis P are parallel to each other.

As shown in <FIG>, the observation window <NUM> is attached to a distal end part body <NUM>. The distal end part body <NUM> is formed in a substantially cylindrical shape, and is formed with a through-hole 46A in a direction of the longitudinal axis A. The observation window <NUM> is inserted into the through-hole 46A from a base end side to a distal end side of the through-hole 46A, and then is fixed to the distal end part body <NUM> by a screw <NUM>. It should be noted that, in the distal end hard portion <NUM>, after the contents, such as the observation window <NUM>, are fixed to the distal end part body <NUM>, an outer peripheral surface of the distal end part body <NUM> is covered with an outer cover <NUM>, and the distal end surface of the distal end part body <NUM> is equipped with a cap <NUM>.

As shown in <FIG>, the observation optical system <NUM> comprises stationary lens groups 54F and <NUM> and movable lens groups 56F and <NUM>, and these lens groups are accommodated in a housing <NUM>. The stationary lens groups 54F and <NUM> and the movable lens groups 56F and <NUM> are each composed of one or several lenses.

The stationary lens groups 54F and <NUM> are mounted on stationary lens frames 58F and <NUM>, respectively, and are fixed to the housing <NUM> via the stationary lens frames 58F and <NUM>. The stationary lens frames 58F and <NUM> are disposed at intervals in a direction of the optical axis P shown in <FIG>.

The movable lens groups 56F and <NUM> are disposed between the stationary lens group 54F and the stationary lens group <NUM> on the optical axis P and are held by movable lens frames 60F and <NUM>, respectively. Arms 64F and <NUM> are installed consecutively to the movable lens frames 60F and <NUM>, and ring parts 66F and <NUM> are formed at the distal ends of the arms 64F and <NUM>. A cam shaft <NUM> is inserted into the ring parts 66F and <NUM>, and the ring parts 66F and <NUM> are slidably supported by the cam shaft <NUM>. In addition, cam pins 70F and <NUM> are projected on the ring parts 66F and <NUM> toward the inside of the ring parts 66F and <NUM>, and the cam pins 70F and <NUM> are engaged with cam grooves 68F and <NUM> spirally formed on an outer surface of the cam shaft <NUM>. Therefore, by rotating the cam shaft <NUM> about an axial center of the cam shaft <NUM>, the ring parts 66F and <NUM> move to the distal end side (right direction side in <FIG>) or the base end side (left direction side in <FIG>), and the movable lens groups 56F and <NUM> move forward and backward along the direction of the optical axis P. In this case, the movable lens groups 56F and <NUM> move in a direction close to or away from each other, whereby the focus adjustment or the zoom operation is performed. It should be noted that the lens configuration of the observation optical system <NUM> shown in <FIG> and <FIG> is not limited to the embodiment described above, and for example, an embodiment may be adopted in which the stationary lens group may be composed of one group or the movable lens group may be composed of one group or three groups. The movable lens groups 56F and <NUM> of the present example are examples of a distal end optical system according to the embodiment of the present invention, and are provided on the distal end side of the insertion part <NUM>.

In the cam shaft <NUM>, the axial center of the cam shaft <NUM> is disposed parallel to the optical axis P of the observation optical system <NUM>, and is supported by the housing <NUM> in a rotationally movable manner. A flexible shaft <NUM> is attached to a base end part of the cam shaft <NUM> via a linking tool <NUM>.

The flexible shaft <NUM> has a shaft axis B, and is provided from the hand operating part <NUM> to the insertion part <NUM> in <FIG>. The flexible shaft <NUM> is configured to rotate in a rotation direction about the shaft axis B by linking a distal end side with the cam shaft <NUM> via the linking tool <NUM> and linking a base end side with a linking tool <NUM> (see <FIG>), which will be described below, as shown in <FIG>. In a case in which the flexible shaft <NUM> rotates in the rotation direction described above, the cam shaft <NUM> is rotated about the axial center. As a result, the movable lens groups 56F and <NUM> are moved in the direction of the optical axis P, and the focus adjustment or the zoom operation is performed. The flexible shaft <NUM> of the present example is an example of a shaft according to the embodiment of the present invention, and is composed of a close contact coil spring as an example. It should be noted that an operation member or the like for rotationally operating the flexible shaft <NUM> will be described below.

As shown in <FIG>, a distal end side of a protective tube <NUM> is fixed to a base end side of the housing <NUM>. The flexible shaft <NUM> is protected by being inserted into the protective tube <NUM>, and other contents (light guide, signal cable, air supply/water supply tube, and the like) contained in the insertion part <NUM> (see <FIG>) are prevented from coming into contact with the flexible shaft <NUM>. Similarly to the flexible shaft <NUM>, the protective tube <NUM> is provided from the hand operating part <NUM> to the insertion part <NUM> of <FIG>.

In addition, an imaging apparatus <NUM> is attached to the housing <NUM>. The imaging apparatus <NUM> is disposed on the hand operating part <NUM> (see <FIG>) side with respect to the stationary lens frame <NUM>. The imaging apparatus <NUM> mainly includes a prism <NUM> that bends an optical path of the observation optical system <NUM> by <NUM>°, and a solid-state imaging element <NUM> that is disposed at an image-forming position of the observation optical system <NUM>. The imaging apparatus <NUM> is attached to the observation optical system <NUM> by fixing a lens barrel holder <NUM>, which is adhered to the prism <NUM>, to the housing <NUM>.

Hereinafter, some embodiments (first and second embodiments) of the zoom operation mechanism that rotates the flexible shaft <NUM> about the shaft axis B for performing the zoom operation will be described.

<FIG> is an explanatory diagram showing a configuration of a zoom operation mechanism <NUM> according to the first embodiment. As shown in <FIG>, the zoom operation mechanism <NUM> according to the first embodiment comprises a zoom operation knob <NUM>, a slider <NUM>, and a power conversion transmission mechanism <NUM>. The zoom operation knob <NUM>, the slider <NUM>, and the power conversion transmission mechanism <NUM> are each provided in the hand operating part <NUM>.

As shown in <FIG>, the zoom operation knob <NUM> is provided to be exposed to the outside of the hand operating part <NUM>, and is manually operated by an operator who operates the endoscope <NUM>. The zoom operation knob <NUM> is configured to rotate by being rotatably supported by a frame <NUM> of the hand operating part <NUM> shown in <FIG>. Further, as an example, a rotation axis C of the zoom operation knob <NUM> is disposed coaxially with a rotation axis D (see <FIG>) of the bending operation knob <NUM> (see <FIG>). With such a configuration, the zoom operation knob <NUM> can be easily operated with the finger of the operator who operates the bending operation knob <NUM>. In addition, since the rotation axis C is shared with the rotation axis D, it is not necessary to separately provide the rotation axis C, so that the zoom operation mechanism <NUM> can be simplified. The zoom operation knob <NUM> is an example of an operation member according to the present invention, and is an example of a rotational operation member.

The slider <NUM> shown in <FIG> moves forward and backward in the direction of the shaft axis B according to the rotational operation of the zoom operation knob <NUM>. Hereinafter, an example of a transmission mechanism <NUM> for transmitting a rotational operation force of the zoom operation knob <NUM> to the slider <NUM> will be described.

The transmission mechanism <NUM> of the present example includes a swing member <NUM> and a link member <NUM>. The swing member <NUM> is a rotating ring <NUM> that is integrally configured with the zoom operation knob <NUM>, and is configured as a protruding portion that protrudes from an outer peripheral portion of the rotating ring <NUM> that is rotatable about the rotation axis C. With such a configuration, in a case in which the zoom operation knob <NUM> is rotationally operated in a direction indicated by an arrow E in <FIG>, the swing member <NUM> can swing in a direction of an arrow F about the rotation axis C. The swing member <NUM> is an example of a swing member according to the embodiment of the present invention.

The link member <NUM> links the swing member <NUM> with the slider <NUM>. Specifically, in <FIG>, a left end of the link member <NUM> is supported pivotally by the swing member <NUM> via a pin <NUM>, and a right end of the link member <NUM> is supported pivotally by the slider <NUM> via a pin <NUM>. With such a configuration, in a case in which the swing member <NUM> swings in a clockwise direction about the rotation axis C, the link member <NUM> can linearly move the slider <NUM> in a right direction in <FIG> in the direction of the shaft axis B. Further, in a case in which the swing member <NUM> swings in a counterclockwise direction about the rotation axis C, the link member <NUM> can linearly move the slider <NUM> in a left direction in <FIG> in the direction of the shaft axis B. As a result, the link member <NUM> functions as a member that moves the slider <NUM> forward and backward in the direction of the shaft axis B. The link member <NUM> is an example of a link member according to the embodiment of the present invention.

The power conversion transmission mechanism <NUM> shown in <FIG> rotates the flexible shaft <NUM> about the shaft axis B by the forward and backward movement of the slider <NUM>. Hereinafter, a specific configuration of the power conversion transmission mechanism <NUM> will be described with reference to <FIG>.

<FIG> is an overall perspective view of the power conversion transmission mechanism <NUM>. <FIG> is a perspective view of a nut <NUM>, which is one of components of the power conversion transmission mechanism <NUM>. <FIG> is a perspective view of a screw shaft <NUM>, which is one of the components of the power conversion transmission mechanism <NUM>. As shown in <FIG>, the power conversion transmission mechanism <NUM> includes the nut <NUM> and the screw shaft <NUM>.

As shown in <FIG>, the nut <NUM> is provided on the slider <NUM>. The nut <NUM> is configured as a substantially tubular body including a nut axis G, and a female screw <NUM> is spirally formed on an inner peripheral surface thereof along a direction of the nut axis G. The nut <NUM> is an example of an engagement member according to the embodiment of the present invention. It should be noted that the slider <NUM> of the present example is configured as a substantially tubular body that covers an outer surface (excluding a flat bottom surface 110A of <FIG>) of the nut <NUM>.

As shown in <FIG>, the screw shaft <NUM> is a shaft body having an axial center H, and a male screw <NUM> is spirally formed on an outer peripheral surface thereof along a direction of the axial center H. The male screw <NUM> and the female screw <NUM> of the nut <NUM> (see <FIG>) are engaged (screwed) to configure the power conversion transmission mechanism <NUM> of the present example as shown in <FIG>. The power conversion transmission mechanism <NUM> is an example of a power conversion transmission mechanism according to the embodiment of the present invention. The screw shaft <NUM> is an example of a shaft member according to the embodiment of the present invention, and the male screw <NUM> is an example of an engaged part according to the embodiment of the present invention.

As an example, the power conversion transmission mechanism <NUM> configured as described above is provided in the hand operating part <NUM> as follows. That is, as shown in <FIG>, after the axial center H of the screw shaft <NUM> is disposed on an extension line of the shaft axis B of the flexible shaft <NUM>, a distal end (right end 112A of <FIG>) of the screw shaft <NUM> is linked with the base end of the flexible shaft <NUM> via the linking tool <NUM>. Also, a base end (left end 112B in <FIG>) of the screw shaft <NUM> is attached to the frame <NUM> via a bearing (not shown). As a result, the power conversion transmission mechanism <NUM> is provided in the hand operating part <NUM>. Further, with the power conversion transmission mechanism <NUM> of the present example, in a case in which the slider <NUM> moves forward and backward by the rotational operation of the zoom operation knob <NUM>, the nut <NUM> linearly moves with the forward and backward movement of the slider <NUM>. Then, in a case in which the linear movement of the nut <NUM> is converted into the rotational movement by the female screw <NUM> and the male screw <NUM>, the screw shaft <NUM> rotates in the rotation direction about the shaft axis B. As a result, the rotation of the screw shaft <NUM> is transmitted to the flexible shaft <NUM> via the linking tool <NUM>, and the flexible shaft <NUM> rotates about the shaft axis B.

Hereinafter, an action of the zoom operation mechanism <NUM> according to the first embodiment will be described.

In a case in which the zoom operation knob <NUM> shown by a solid line in <FIG> is rotationally operated in a counterclockwise direction about the rotation axis C, the swing member <NUM> and the rotating ring <NUM> swing in a counterclockwise direction from the position shown by the solid line. As a result, the link member <NUM> linked with the swing member <NUM> is pulled by the swing member <NUM> and moves in the left direction in <FIG>, and the slider <NUM> linked with the link member <NUM> moves in the left direction in <FIG>.

Then, the nut <NUM> (see <FIG>) linearly moves in the left direction with the movement of the slider <NUM> in the left direction. Then, the linear movement of the nut <NUM> in the left direction is converted into the rotational movement by the female screw <NUM> (see <FIG>) of the nut <NUM> and the male screw <NUM> (see <FIG>) of the screw shaft <NUM>. As a result, the screw shaft <NUM> smoothly rotates in the rotation direction about the shaft axis B (for example, in a clockwise direction CW as the screw shaft <NUM> is viewed from the left end 112B in <FIG>), the rotation of the screw shaft <NUM> is transmitted to the flexible shaft <NUM> via the linking tool <NUM>, and the flexible shaft <NUM> rotates about the shaft axis B. As a result, by rotating the cam shaft <NUM> shown in <FIG>, the movable lens groups 56F and <NUM> are moved in the direction of the optical axis P, and the zoom operation is performed, for example, on a wide side.

On the contrary, in a case in which the zoom operation knob <NUM> shown by a two-dot chain line in <FIG> is rotationally operated in a clockwise direction about the rotation axis C, the swing member <NUM> and the rotating ring <NUM> swing in a clockwise direction from the position shown by the two-dot chain line. As a result, the link member <NUM> linked with the swing member <NUM> is pushed by the swing member <NUM> and moves in the right direction in <FIG>, and the slider <NUM> linked with the link member <NUM> moves in the right direction in <FIG>.

Then, the nut <NUM> linearly moves in the right direction with the movement of the slider <NUM> in the right direction. Then, the linear movement of the nut <NUM> in the right direction is converted into the rotational movement by the female screw <NUM> (see <FIG>) of the nut <NUM> and the male screw <NUM> (see <FIG>) of the screw shaft <NUM>. As a result, the screw shaft <NUM> smoothly rotates in the rotation direction about the shaft axis B (for example, in a counterclockwise direction CCW as the screw shaft <NUM> is viewed from the left end 112B in <FIG>), the rotation of the screw shaft <NUM> is transmitted to the flexible shaft <NUM> via the linking tool <NUM>, and the flexible shaft <NUM> rotates about the shaft axis B. As a result, by rotating the cam shaft <NUM> shown in <FIG>, the movable lens groups 56F and <NUM> are moved in the direction of the optical axis P, and the zoom operation is performed, for example, on a telephoto side.

Therefore, with the zoom operation mechanism <NUM> of the first embodiment, since the configuration is adopted in which the slider <NUM> is moved forward and backward in the direction of the shaft axis B according to the rotational operation of the zoom operation knob <NUM>, and the flexible shaft <NUM> is rotated by the power conversion transmission mechanism <NUM> by the forward and backward movement of the slider <NUM>, the movable lens groups 56F and <NUM> can be efficiently moved forward and backward in the direction of the optical axis P. In addition, since the feed screw mechanism including the nut <NUM> and the screw shaft <NUM> is adopted as the power conversion transmission mechanism <NUM>, the linear movement of the slider <NUM> can be effectively converted into the rotational movement.

<FIG> is an explanatory diagram showing a configuration of a zoom operation mechanism <NUM> according to the second embodiment.

Here, a difference in configuration between the second embodiment shown in <FIG> and the first embodiment shown in <FIG> will be described. The feed screw mechanism including the nut <NUM> and the screw shaft <NUM> is adopted as the power conversion transmission mechanism <NUM> of the first embodiment, whereas a cam mechanism including a cam pin <NUM> (see <FIG>) and a cam shaft <NUM> is adopted as a power conversion transmission mechanism <NUM> of the second embodiment shown in <FIG>. Since the other configurations (zoom operation knob <NUM>, slider <NUM>, swing member <NUM>, and link member <NUM>) are the same, in the description of the zoom operation mechanism <NUM> of the second embodiment, the power conversion transmission mechanism <NUM> shown in <FIG> will be mainly described.

<FIG> is an overall perspective view of the power conversion transmission mechanism <NUM>. <FIG> is a perspective view of a pair of cam pins <NUM> which are one of the components of the power conversion transmission mechanism <NUM>. <FIG> is a perspective view of the cam shaft <NUM>, which is one of the components of the power conversion transmission mechanism <NUM>. As shown in <FIG>, the power conversion transmission mechanism <NUM> includes the pair of cam pins <NUM> and the cam shaft <NUM>.

As shown in <FIG>, the slider <NUM> is formed in a tubular shape, and the pair of cam pins <NUM> are projected from the inner peripheral surface of the slider <NUM> to face each other. The cam pin <NUM> is an example of an engagement member according to the embodiment of the present invention.

As shown in <FIG>, the cam shaft <NUM> is a shaft body having an axial center J, and a cam groove <NUM> is spirally formed on an outer peripheral surface thereof along a direction of the axial center J. The cam groove <NUM> and the pair of cam pins <NUM> (see <FIG>) are engaged with each other to configure the power conversion transmission mechanism <NUM> of the present example as shown in <FIG>. The power conversion transmission mechanism <NUM> is an example of a power conversion transmission mechanism according to the embodiment of the present invention. The cam shaft <NUM> is an example of a shaft member according to the embodiment of the present invention, and the cam groove <NUM> is an example of an engaged part according to the embodiment of the present invention.

As an example, the power conversion transmission mechanism <NUM> configured as described above is provided in the hand operating part <NUM> as follows. That is, as shown in <FIG>, after the axial center J of the cam shaft <NUM> is disposed on an extension line of the shaft axis B of the flexible shaft <NUM>, a distal end (right end 134A of <FIG>) of the cam shaft <NUM> is linked with the base end of the flexible shaft <NUM> via the linking tool <NUM>. Also, a base end of the cam shaft <NUM> (left end 134B in <FIG>) is attached to the frame <NUM> via a bearing (not shown). As a result, the power conversion transmission mechanism <NUM> is provided in the hand operating part <NUM>. Further, with the power conversion transmission mechanism <NUM> of the present example, in a case in which the slider <NUM> moves forward and backward by the rotational operation of the zoom operation knob <NUM>, the pair of cam pins <NUM> linearly move with the forward and backward movement of the slider <NUM>. Further, in a case in which the linear movement of the pair of cam pins <NUM> is converted into the rotational movement by the cam groove <NUM>, the cam shaft <NUM> rotates in the rotation direction about the shaft axis B. As a result, the rotation of the cam shaft <NUM> is transmitted to the flexible shaft <NUM> via the linking tool <NUM>, and the flexible shaft <NUM> rotates about the shaft axis B.

Hereinafter, an action of the zoom operation mechanism <NUM> according to the second embodiment will be described. It should be noted that a point that overlaps with the action of the zoom operation mechanism <NUM> of the first embodiment will be described repeatedly.

Then, the pair of cam pins <NUM> linearly move in the left direction with the movement of the slider <NUM> in the left direction. Then, the linear movement of the pair of cam pins <NUM> in the left direction is converted into the rotational movement by the cam groove <NUM> (see <FIG>) of the cam shaft <NUM>. As a result, the cam shaft <NUM> smoothly rotates in the rotation direction about the shaft axis B (for example, in the clockwise direction CW as the cam shaft <NUM> is viewed from the left end 134B in <FIG>), the rotation of the cam shaft <NUM> is transmitted to the flexible shaft <NUM> via the linking tool <NUM>, and the flexible shaft <NUM> rotates about the shaft axis B. As a result, by rotating the cam shaft <NUM> shown in <FIG>, the movable lens groups 56F and <NUM> are moved in the direction of the optical axis P, and the zoom operation is performed, for example, on the wide side.

Then, the pair of cam pins <NUM> linearly move in the right direction with the movement of the slider <NUM> in the right direction. Then, the linear movement of the pair of cam pins <NUM> in the right direction is converted into the rotational movement by the cam groove <NUM> (see <FIG>) of the cam shaft <NUM>. As a result, the cam shaft <NUM> smoothly rotates in the rotation direction about the shaft axis B (for example, in the counterclockwise direction CCW as the cam shaft <NUM> is viewed from the left end 135B in <FIG>), the rotation of the cam shaft <NUM> is transmitted to the flexible shaft <NUM> via the linking tool <NUM>, and the flexible shaft <NUM> rotates about the shaft axis B. As a result, by rotating the cam shaft <NUM> shown in <FIG>, the movable lens groups 56F and <NUM> are moved in the direction of the optical axis P, and the zoom operation is performed, for example, on the telephoto side.

Therefore, with the zoom operation mechanism <NUM> of the second embodiment, since the configuration is adopted in which the slider <NUM> is moved forward and backward in the direction of the shaft axis B according to the rotational operation of the zoom operation knob <NUM>, and the flexible shaft <NUM> is rotated by the power conversion transmission mechanism <NUM> by the forward and backward movement of the slider <NUM>, the movable lens groups 56F and <NUM> can be efficiently moved forward and backward in the direction of the optical axis P. Further, since the cam mechanism including the pair of cam pins <NUM> and the cam shaft <NUM> is adopted as the power conversion transmission mechanism <NUM>, the linear movement of the slider <NUM> can be effectively converted into the rotational movement.

Here, a rotary encoder <NUM> is also provided in the first embodiment shown in <FIG> and the second embodiment shown in <FIG>. The rotary encoder <NUM> detects a rotation angle of the flexible shaft <NUM>, is linked with the left end 112B (see <FIG>) of the screw shaft <NUM> as an example in the first embodiment of <FIG>, and is linked with the left end 134B (see <FIG>) of the cam shaft <NUM> as an example in the second embodiment of <FIG>. The rotary encoder <NUM> is an example of a rotation detection unit according to the embodiment of the present invention.

A detection signal output from the rotary encoder <NUM> is input to the processor device <NUM> (see <FIG>) of the endoscope <NUM> as an example. <FIG> is a functional block diagram showing a configuration of the processor device <NUM>. The processor device <NUM> comprises a processor <NUM> and a memory <NUM>.

As shown in <FIG>, the processor <NUM> includes an encoder signal acquisition unit <NUM> that acquires the detection signal output from the rotary encoder <NUM>, an imaging magnification acquisition unit <NUM> that acquires information indicating an imaging magnification corresponding to the detection signal acquired by the encoder signal acquisition unit <NUM> from the memory <NUM>, a shutter speed setting unit <NUM> that sets a shutter speed corresponding to the imaging magnification acquired by the imaging magnification acquisition unit <NUM>, and a light amount setting unit <NUM> that sets a light amount corresponding to the imaging magnification acquired by the imaging magnification acquisition unit <NUM>.

The shutter speed setting unit <NUM> sets the shutter speed corresponding to the imaging magnification to a shutter controller <NUM>, and the shutter controller <NUM> controls a shutter <NUM> at the set shutter speed. In addition, the light amount setting unit <NUM> sets the light amount corresponding to the imaging magnification to a light source controller <NUM> of the light source device <NUM>, and the light source controller <NUM> controls the light source <NUM> with the set light amount.

The processor <NUM> executes a command stored in the memory <NUM>. A hardware structure of the processor <NUM> is various processors as described below. Various processors include a central processing unit (CPU) as a general-purpose processor which acts as various function units by executing software (program), a graphics processing unit (GPU) as a processor specialized in image processing, a programmable logic device (PLD) as a processor of which a circuit configuration can be changed after manufacture, such as a field programmable gate array (FPGA), a dedicated electric circuit as a processor which has a circuit configuration specifically designed to execute specific processing, such as an application specific integrated circuit (ASIC), and the like.

One processing unit may be configured by using one of these various processors, or two or more processors of the same type or different types (for example, a plurality of FPGAs, or a combination of a CPU and an FPGA, or a combination of a CPU and a GPU). Moreover, a plurality of function units may be configured by using one processor. As a first example in which the plurality of function units are configured by using one processor, as represented by a computer such as a client or a server, there is a form in which one processor is configured by using a combination of one or more CPUs and software, and this processor acts as the plurality of function units. As a second example thereof, as represented by a system on chip (SoC), there is a form in which a processor, which implements the functions of the entire system including the plurality of function units by one integrated circuit (IC) chip, is used. As described above, various function units are configured by using one or more of the various processors described above as the hardware structure.

Further, the hardware structures of these various processors are, more specifically, an electric circuit (circuitry) in which circuit elements such as semiconductor elements are combined.

<FIG> is a flowchart showing a flow of processing of setting the shutter speed and setting the light amount by the processor <NUM> shown in <FIG>. As shown in <FIG>, in step S10, the encoder signal acquisition unit <NUM> (see <FIG>) acquires the detection signal from the rotary encoder <NUM> (see <FIG>). Next, in step S20, the imaging magnification acquisition unit <NUM> (see <FIG>) acquires the information indicating the imaging magnification corresponding to the detection signal acquired by the encoder signal acquisition unit <NUM> (see <FIG>) from the memory <NUM>. Then, in step S30, the shutter speed setting unit <NUM> (see <FIG>) sets the shutter speed corresponding to the imaging magnification acquired by the imaging magnification acquisition unit <NUM> (see <FIG>). Then, in step <NUM>, the light amount setting unit <NUM> (see <FIG>) sets the light amount corresponding to the imaging magnification acquired by the imaging magnification acquisition unit <NUM> (see <FIG>). The above description is the flow of processing of setting the shutter speed and setting the light amount by the processor <NUM>. It should be noted that step S30 and step S40 may be processed in parallel or may be processed in a different order.

The processing of the processor <NUM> will be briefly described. Since the image blur is likely to occur in a case in which the imaging magnification is increased by the zoom operation, the processor <NUM> sets the shutter speed to high speed, and sets the light amount for obtaining a sufficient light amount even at the shutter speed. As a result, it is possible to suppress image blur in a case in which the imaging magnification is increased.

Hereinafter, a modification example according to the "shaft" and the "operation member" which are the configuration requirements of the present invention will be described.

As the shaft, the flexible shaft <NUM> having a flexibility is described as an example in the embodiment. For example, a rigid (non-flexible) shaft may be applied as the shaft. In this case, the rigid shaft can be applied to a rigid mirror in which the insertion part is composed of a hard member.

Claim 1:
An endoscope (<NUM>) comprising:
a distal end optical system that is movable forward and backward in an optical axis direction;
a shaft (<NUM>) that has a shaft axis (B), is configured to rotate in a rotation direction about the shaft axis (B), and moves the distal end optical system in the optical axis direction in a case in which the shaft (<NUM>) rotates in the rotation direction;
an operation member;
a slider (<NUM>) that moves forward and backward in a direction of the shaft axis (B) according to an operation of the operation member;
a power conversion transmission mechanism (<NUM>) that rotates the shaft (<NUM>) by the forward and backward movement of the slider (<NUM>);
an insertion part (<NUM>); and
a hand operating part (<NUM>) that is connected to a base end side of the insertion part (<NUM>),
wherein the distal end optical system is provided on a distal end side of the insertion part (<NUM>); and
the operation member is provided on the hand operating part (<NUM>),
characterized in that
the slider (<NUM>) and the power conversion transmission mechanism (<NUM>) are provided on the hand operating part (<NUM>); and
the shaft (<NUM>) is provided from the hand operating part (<NUM>) to the insertion part (<NUM>).