JP4668581B2 - Surgical microscope - Google Patents

Description

  The present invention relates to a surgical microscope used for observing or imaging an object at a fine site in, for example, neurosurgery.

  Generally, in the field of neurosurgery, a surgical microscope is used for magnifying and observing a surgical site. Such a surgical microscope includes a microscope unit in which a mirror (optical unit) having a stereoscopic optical system for stereoscopic observation of an operation part is disposed, and a pedestal that supports the microscope part movably with respect to the operation part It is made up of.

  In recent years, various surgical microscopes have been proposed in which an operation part is three-dimensionally photographed by an imaging unit such as a TV camera, and three-dimensional observation is performed using an image obtained thereby (see, for example, Patent Document 1).

  By the way, in such a surgical microscope, both the macroscopic observation and the image observation method have an objective optical system for magnifying (imaging) the surgical part and a focus (focusing) for focusing on the surgical part. Is provided. With regard to the configuration for this focusing, those provided with a so-called autofocus (automatic focusing) mechanism have been proposed in order to reduce the trouble of focusing during surgery (for example, Patent Document 2 and Patent Document 3). reference.).

  Here, the principle of focusing by the autofocus mechanism will be described with reference to FIGS. 13, 14, and 15. FIG.

  That is, the objective lens 71 is disposed on the mirror body 70 of the surgical microscope. The optical axes of the left and right observation optical paths 72L and 72R of the objective lens 71 are coincident with each other at the focal position P of the surgical microscope, and the focal position P is the highest resolution position of the left and right observation optical paths 72L and 72R ( (See FIG. 13). Such an autofocus mechanism is generally controlled so that the focal position P coincides with the subject (distance measurement target) position.

  Here, the distance S from the objective lens 71 to the focal position P is a so-called focal distance. With respect to the focal position P of the surgical microscope, there is a relationship between the resolution and the case where the observation object is displaced in the front-rear direction (focus shift) as shown in FIG.

  In this way, the highest position of the resolving power is set as the focal position P (= focal length S), and the depth of field W that is a range that can be recognized as being in focus by the observer in the actual operation is the focal position. It is set to be distributed approximately symmetrically with P (focal length S) as the center.

By the way, in the operation using such a surgical microscope, generally, there are many usage forms such as observing the bottom of a hole through a small opening as shown in FIG. Are combined (P = Q), the portion shallower than the operation portion Q (near side) appears to be in focus up to half the depth of field W (W / 2). In other words, although there is a depth of field of W / 2 in a direction deeper than the observation point, this range is an unobservable region (unnecessary region). That is, in surgery using a conventional surgical microscope, observation using half of the depth of field W effectively is performed.
JP 2003-272760 A Japanese Unexamined Patent Publication No. 8-136683 Japanese Patent Laid-Open No. 5-107447

  However, since only half of the depth of field is effectively used in the above operating microscope, the frequency of adjustment is large when observing a wide range, and it takes a lot of time for adjustment. There is a problem that the usability is inferior.

  The present invention has been made in view of the above circumstances, and provides a surgical microscope with a simple configuration and capable of realizing high-accuracy observation over a wide range to improve usability. Objective.

This invention relates to an optical system for acquiring an optical image of the Target object, the optical system is engaged, the relationship between the distance resolution characteristic to the object from the optical system, having a substantially flat predetermined range electronic imaging device for acquiring an observation image of the optical image, and including electronic imaging section the monitor as a component for displaying an observation image acquired by the electronic image pickup device, the focus of the optical system to be engaged with the electronic imaging device A focus position at which the resolving power of the optical system by the autofocusing means is the highest within the range of depth of field in a predetermined range in which the resolving power characteristics of the electronic image pickup device are substantially flat. And a control means for variably setting the position away from the object by a predetermined distance.

According to the above construction, when performing surgery operations, by the control means, the focal position, a predetermined distance from the object, by Rukoto be variably set deviation position, compared to the case of acquiring an observation image to an optical Thus, a wider depth of field can be effectively used . As a result, even when the work position (observation target position) changes in the front-rear direction in surgery, for example, the frequency of focus adjustment can be reduced, and the object can be easily identified with minimum focus adjustment. Usability can be improved, and surgical operations can be speeded up.

  As described above, according to the present invention, it is possible to provide a surgical microscope that is easy to use and can realize high-accuracy observation over a wide range with a simple configuration.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(First embodiment)
FIG. 1 shows an external configuration in which a surgical microscope according to a first embodiment of the present invention is applied to an optical observation configuration. A base 1a is moved on, for example, the floor of a clinical room on a gantry 1 A support column 1b on which a power supply unit for a microscope (not shown) is arranged is erected on the base 1a.

  One end of the first arm 2 is attached to the upper end of the column 1b of the gantry 1 so as to be rotatable around a vertical axis 0a. The first arm 2 incorporates a microscope light source (not shown). The other end of the first arm 2 is connected to a second arm 3 constituted by, for example, a link mechanism so as to be rotatable about a vertical axis 0b and to be vertically movable around a horizontal axis 0c. At one end of the second arm 3, one end of the lifting arm 4 is attached to be rotatable about the axis 0 d and rotatable about the axes 0 e and 0 f.

  The shafts Oa to Of are provided with electromagnetic brakes (not shown) capable of fixing / releasing rotation around the respective shafts.

  Further, a microscope unit 7 is disposed on the lifting arm 4. The microscope unit 7 is configured by assembling an observation barrel 6 to a mirror unit 5. Among these, the mirror body portion 5 is provided with an operation handle 8, and is disposed so as to be movable to a spatially free position via the handle 8. The handle 8 is provided with a lock-free switch 8a (FIG. 4), which will be described later, and the electromagnetic brake (not shown) is controlled in response to the operation of the lock-free switch 8a. Switching between moving / fixing is performed.

  Further, the microscope unit 7 incorporates an illumination optical system (not shown). The illumination optical system (not shown) includes a microscope light source (not shown) provided in the first arm 2. The illumination light is guided by light transmission means such as a light guide (not shown), and irradiates the illumination light to a target object such as an operation part as a target object.

  At the end of the microscope section 7, a variable focal length objective optical system 9 having an optical axis 23 is disposed as shown in FIG. This variable focal length objective optical system 9 includes a lens group whose focal length can be changed by a lens moving means (not shown), and is used to operate an input switch 26 (see FIG. 4) such as a foot switch, which will be described in detail later. In response, the lens moving means (not shown) is driven and controlled, and the focal distance is variably set by changing the lens interval of the lens group (not shown).

  The variable focal length objective optical system 9 is formed with a pair of left and right observation optical axes 15L and 15R corresponding to the optical axis 23, and a pair of left and right variable magnification optical systems 10L and 15R are formed on the observation optical axes 15L and 15R. 10R is arranged. The variable magnification optical systems 10L and 10R are provided with a lens moving means (not shown), and the interval between the lens groups is variably adjusted through the lens moving means (not shown) to variably set the observation magnification. Here, the positions of the pair of left and right observation optical axes 15L and 15R where the respective resolving powers are maximum coincide with each other on the optical axis 23, and these positions form a focal position P.

  In the observation barrel 6, a pair of left and right imaging lenses 11L and 11R and a pair of left and right eyepieces 12L and 12R constituting a stereoscopic eyepiece optical system correspond to the pair of left and right variable magnification optical systems 10L and 10R. Are provided in order.

  In the mirror part 5, an infrared light emitting element 13 for emitting an infrared projection index constituting an autofocus mechanism is disposed on the optical axis 23 of the focal length variable objective optical system 9 via a light emitting optical system 14 and a mirror 16. It is arranged. Thereby, the infrared light emitted from the infrared light emitting element 13 is guided to the optical axis 23 of the focal length variable objective optical system 9 via the light emitting optical system 14 and the mirror 16 and projected onto the surgical site Q. In this autofocus mechanism, the active method of irradiating the surgical site Q with infrared light emitted from the infrared light emitting element 13 can be used to quickly move the focal point to the target position.

  A photoelectric conversion element 18 that receives reflected light of infrared light from the surgical part Q is disposed via a light receiving optical system 17 at a side position of the mirror body 5 away from the infrared light emitting element 13. Is done. A dichroic prism 19 is disposed at a position where the central axis (the light receiving optical axis 22) of the light receiving optical system 17 intersects the left observation optical axis 15L. The dichroic prism 19 totally transmits visible light at the reflection surface 20 and totally reflects infrared light toward the light receiving optical system 17. Here, the focal position P coincides with the focus position and intersection of the pair of left and right observation optical axes 15L and 15R, and the reference position T on the photoelectric conversion element 18 is set in an optically conjugate positional relationship. ing.

  As shown in FIG. 3, the autofocus mechanism configured in this way always has a deviation position F that is farther away from the focal point P (the focus position and intersection of the pair of left and right observation optical axes 15L and 15R) by a distance D. Is operated so as to coincide with the object to be observed (the surgical site Q in the case of surgery).

  Here, 22 and 22 'in FIG. 3 indicate the light receiving optical axis at the focal position P and the deviation position F, and the light receiving optical axis 22 is partially the same as the observation optical path 15L. The position T ′ on the photoelectric conversion element 18 is a position that is optically conjugate with the deviation position F. The distance Δd between the position T and the position T ′ (a reference conjugate with the focal position P) of the photoelectric conversion element 18 corresponds to the distance D on the object side. This distance D is set, for example, at a position shifted by ¼ of the depth of field range W far from the focal position P via a distance calculation circuit 25 (see FIG. 4) described later.

  Next, the microscope control system will be described with reference to FIG. That is, the input switch 26 is provided with, for example, a not-shown (manual) focusing, zooming, and autofocusing operator, and each output terminal thereof has a zooming drive circuit 27 constituting a zooming means, a focusing. The focusing drive circuit 29 constituting the means is connected to the input terminal of the distance measuring circuit 25 constituting the control means in the automatic focusing means. The variable magnification drive circuit 27 has an output terminal connected to the variable magnification drive motor 28, generates a drive signal based on the operation signal from the input switch 26, and outputs the drive signal to the variable magnification drive motor 28. The variable magnification drive motor 28 drives lens moving means (not shown) in the variable magnification optical systems 10L and 10R in response to the drive signal.

  An encoder 24 is provided at the output portion of the zoom drive motor 28, and a magnification detection circuit 31 is connected to the encoder 24. The encoder 24 detects the drive amount of the variable power drive motor 28 and outputs it to the magnification detection circuit 31. The magnification detection circuit 31 is connected to the distance calculation circuit 25, generates an observation magnification signal corresponding to the lens displacement in the variable magnification optical system 10 based on the detection signal from the encoder 24, and outputs the observation magnification signal to the distance calculation circuit 25. The variable magnification optical systems 10L and 10R are variably controlled.

    The focusing drive circuit 29 is connected to the focusing drive motor 30, generates a drive signal based on the operation signal from the input switch 26, and drives and controls the focusing drive motor 30. The focusing drive motor 30 drives and controls a lens moving means (not shown) of the focal length variable objective optical system 9 based on a drive signal.

  A lock-free switch 8a is connected to the distance measurement calculation circuit 25 via an input circuit 21, and a brake drive circuit 32 connected to the electromagnetic brake (not shown) is connected to the input circuit 21. . The input circuit 21 outputs a drive signal to the brake drive circuit 32 to drive and control the electromagnetic brake (not shown) while the lock-free switch 8a is pressed, so that the lock-free switch 8a is pressed. When it is released and turned off, an off signal is output to the distance measuring circuit 25.

  The distance calculation circuit 25 is connected to a light emitting circuit 35 and a light receiving circuit 33 that constitute distance measuring means. Among these, the light emitting circuit 35 receives a drive signal from the distance measurement calculation circuit 25 when the lock free switch 8 a and the input switch 26 are operated and each operation signal is input to the distance calculation circuit 25. Then, the light emitting circuit 35 outputs a light emission signal to the infrared light emitting element 13 in response to the drive signal, and drives the infrared light emitting element 13 to light. The other light receiving circuit 33 is composed of a drive circuit and an amplification circuit that receive an output from the photoelectric conversion element 18 and performs an amplification process, and generates a distance information signal based on the output from the photoelectric conversion element 18 to measure the distance. The result is output to the arithmetic circuit 25.

  Furthermore, the distance calculation circuit 25 is connected to the input terminal of the focusing drive circuit 29. The ranging calculation circuit 25 generates a focusing signal based on the observation magnification signal, the distance information signal, and the depth of field data described above, and outputs the focusing signal to the focusing drive circuit 29. The focusing drive circuit 29 drives and controls the focusing drive motor 30 based on the input control drive signal to drive a lens moving means (not shown) of the variable focal length objective optical system 9.

  Further, the distance calculation circuit 25 is connected to a memory 34 as storage means, and the memory 34 stores depth of field data corresponding to the observation magnification.

  In the above configuration, when performing stereoscopic observation of the surgical site Q, the surgical site Q is irradiated with illumination light by an illumination optical system (not shown) built in the microscope unit 7. Then, the light reflected by the surgical site Q passes through the variable focal length objective optical system 9, the pair of left and right variable magnification optical systems 10L and 10R, the pair of left and right imaging lenses 11L and 11R, and the pair of left and right eyepieces 12L and 12R. The eye reaches the surgeon's eye E and is observed as a stereoscopic image.

  Here, the observation magnification of the stereoscopic image is variably set to a desired value suitable for the operation by the input switch 26. In this magnification setting, the magnification detection circuit 31 calculates the observation magnification of the mirror unit 5 based on the detection value of the encoder 24 and outputs it to the distance measurement calculation circuit 25 during the magnification operation by the magnification optical system 10. .

  Next, when the observation visual field is moved during the operation, the operator holds the handle 8 and presses the lock-free switch 8a. Then, an electromagnetic brake (not shown) is released via the input circuit 21 and the brake drive circuit 32. Thereby, the fixation of the first arm 2, the second arm 3, and the lifting arm 4 is released, and the microscope unit 7 can be freely moved. The operator operates the handle 8 to move the observation mirror unit 7 to a desired position. It can be moved to a position. For example, the eyepieces 12L and 12R of the observation barrel 6 are looked into and moved so that the observation object comes to the center of the observation field.

  After the microscope unit 7 is moved in this way and the field of view is adjusted to the target position, the lock-free switch 8a is turned off or the input switch 26 is operated with the autofocus operator. .

  That is, when the lock-free switch 8a is opened and turned off, an off signal is input to the distance measuring circuit 25 via the input circuit 21, or when the autofocus operator of the input switch 26 is operated, A focus operation signal is input to the distance measuring circuit 25. Then, the distance measurement calculation circuit 25 outputs a drive signal to the light emitting circuit 35, and the light emitting circuit 35 is configured to project a predetermined minute infrared index on the surgical part Q in order to project the infrared light emitting element 13. Lights up. The infrared projection index emitted by the infrared light emitting element 13 is reflected in the direction of the surgical site Q by the mirror 16 through the light emitting optical system 14, and the surgical site Q through the focal length variable objective optical system 9. Is irradiated. The infrared light emitting element 13 always emits light continuously during autofocus operation.

  The infrared projection index reflected by the surgical part Q is incident on the variable focal length objective optical system 9 and guided to the reflection surface 20 of the dichroic prism 19 disposed on one observation optical axis 15L for reflection. Then, an optical image is formed on the light receiving surface of the photoelectric conversion element 18 via the light receiving optical system 17. The photoelectric conversion element 18 photoelectrically converts the incident light image to generate an electrical signal, and outputs it to the light receiving circuit 33.

  Here, the principle of distance measurement up to the surgical site Q will be described. That is, the autofocus mechanism is in a state in which the operating portion Q is far away from the focal position P (out of the depth of field W) and out of focus, like the light projecting optical system and the light receiving optical system shown in FIG. It operates to move the deviation position F so as to coincide with the surgical site Q. Here, the deviation position F and the surgical site Q have light receiving optical axes 22 ′ and 22 ″, and are conjugate with the positions T ′ and T ″ on the light receiving surface of the photoelectric conversion element 18. The distance Δu between the position T ′ and the position T ″ on the photoelectric conversion element 18 corresponds to the distance U between the deviation position F and the surgical site Q.

  An output signal corresponding to the position T ″ on the photoelectric conversion element 18 is input to the light receiving circuit 33, and the input signal is subjected to signal processing to generate a distance information signal, which is output to the distance measurement calculation circuit 25. Then, the distance calculation circuit 25 first calls depth-of-field information (= depth-of-field W at the current magnification) corresponding to the magnification information signal input from the magnification detection circuit 31 from the memory 34 and performs the current observation. The distance D (= W / 4) corresponding to the magnification is calculated, and then the distance calculation circuit 25 calculates the (virtual position) T ′ position on the photoelectric conversion element 18 based on the calculated distance D information. Then, the positional deviation amount “ΔU” between the calculated position information of T ′ and the position information of (light receiving position) T ″ on the conversion element 18 in the operating part Q to be focused, which is input from the light receiving circuit 33. Is calculated.

  Further, the distance measuring circuit 25 generates a drive signal corresponding to the sign of the shift amount “Δu” and outputs it to the focusing drive circuit 29. Then, based on this output, the focusing driving circuit 29 drives the focusing driving motor 30 to drive a lens driving means (not shown) of the variable focal length objective optical system 9. As a result, the lens group constituting the lens group is moved, and the focal length by the variable focal length objective optical system 9 is changed.

  Then, the distance calculation circuit 25 calculates the amount of deviation “Δu” based on the position information of T ″ input from the light receiving circuit 33 one by one, and the deviation position F in FIG. Until this is done, that is, until the value of “Δu” becomes zero, a drive signal is output to the focusing drive motor 30 via the focusing drive circuit 29 to control the movement of the variable focal length objective optical system 9. Then, when the value of the deviation “Δu” becomes zero (0), the distance measurement calculation circuit 25 stops the calculation process, stops the light emission of the infrared light emitting element 13, and performs the distance measurement and focusing operation. Exit.

  The focus position deviation amount “Δu” is controlled so as to be a fixed ratio with respect to the depth of field range, so that the surgeon can adjust the focus deviation or the like even if the depth of field changes due to the magnification. It can be used without a sense of incongruity.

  Here, the microscope unit 7 is set to a position where the focal position P is separated by a distance D with respect to the surgical site Q as shown in FIG. Thereby, the surgeon can observe in a state where the focus is within the range of 3 W / 4 from the surgical site Q (X in FIG. 3). In this observation, the depth of field that was effectively used for actual observation in the conventional autofocus was W / 2. The frequency of focusing can be reduced, which can contribute to shortening of the operation time.

  Thus, the surgical microscope automatically focuses the focus of the variable focus objective optical system 9 that acquires an optical image of the surgical site Q via the autofocus mechanism, and within the depth of field range thereof, The focus position with the highest resolving power of the focusing variable objective optical system 9 by the autofocus mechanism is variably set at a position separated from the surgical site Q by a predetermined distance.

  According to this, when performing a surgical operation, the focal position is set to a predetermined position deviating from the surgical part Q where the depth of field W becomes deep, and the observation range that can be observed at once in the front-rear direction is expanded. By setting as described above, it is possible to specify an object such as a surgical site in a wide range. As a result, during surgery, for example, even when the work position (observation target position) changes in the front-rear direction, the focus adjustment frequency can be reduced, and the surgical site Q can be easily identified with the minimum focus adjustment. As a result, the usability can be improved, and the surgical operation can be speeded up.

(Second Embodiment)
FIG. 6 shows a surgical microscope according to the second embodiment, and shows an external configuration applied to an image observation configuration. However, in the second embodiment including FIG. 6, the same reference numerals are given to the same parts configured in the same manner as the first embodiment, and the detailed description thereof is omitted.

  That is, the second embodiment is different in the configuration of the autofocus optical system and the distance measurement calculation means associated therewith, and a pair of left and right CCDs 42L and 42R (see FIG. 8) to be described later is provided in the mirror unit 39. Arranged. The CCDs 42L and 42R are connected to a 3D display 37 as a display device via a known image processing device 38.

  Here, prior to describing the second embodiment, a difference in resolving power between optical observation and image observation will be described with reference to FIG. That is, in the figure, the vertical axis represents the resolving power, and the horizontal axis represents the distance from the focal length variable objective optical system 9 (see FIG. 7) to the observation position. A line A indicates the resolution characteristic of optical observation, and a line B indicates the resolution characteristic of image observation. The resolving power characteristic B for image observation is greatly affected by the number of pixels of the CCDs 42L and 42R, which are connected imaging means, and the resolving power of the 3D display 37.

  Currently, since the CCD pixel pitch is generally larger than the optical resolution, the image observation has a lower center resolution than the optical observation. A range C in the figure shows a range in which the change in the resolution is difficult to be recognized on the observation image even if the optical resolution changes due to the focus shift in the surgical microscope for image observation. In the second embodiment, This range C is set as the depth of field W.

  Note that the resolution limit value varies depending on the image sensor (CCD), and can be arbitrarily set.

  That is, as shown in FIG. 7, the pair of left and right CCDs 42L and 42R of the mirror unit 39 includes the imaging lenses 40L and 40R on the pair of left and right photographing optical axes 41L and 41R of the focusing variable objective optical system 9. The 3D display 37 is connected to the image forming position via an image processing device 38.

  On the optical axis 23 of the focal length variable objective optical system 9, a distance measuring objective lens 43 and a mirror 44 constituting the light receiving side of a so-called passive focus mechanism are disposed. On the optical axis reflected by the mirror 44, a distance measuring optical system 48 including a field lens 45, a separator lens 46, and a line sensor 47 (detection element) constituting a distance measuring unit is disposed. In this distance measuring optical system 48, the distance measuring light beam from the surgical part Q that has passed through the focal length variable objective optical system 9 is guided by the distance measuring objective lens 43 to the mirror 44 and reflected, and then is near the field lens 45. The formed image is guided to the separator lens 46 through the field lens 45, separated into two by the separator lens 46, and formed at two positions on the line sensor 47.

  In other words, the detection principle of the distance measuring optical system 48 is re-imaged on the line sensor 47 in accordance with the imaging position shift (shift amount Δ) from the in-focus position of the image formed near the field lens 45. The interval h (pitch) between the two images is changed, and the shift amount Δ is calculated based on the interval h. The focal length variable objective optical system 9 is driven so that the shift amount Δ is within a predetermined range to perform automatic focusing.

  When the focus is shifted, the surgical site Q is separated from the focal position P by a distance G as shown in FIG. Therefore, in this second embodiment, focusing is performed so that the deviation position F that is separated from the focal position P by the distance K coincides with the surgical part Q that is the observation target.

  That is, the dial switch, which will be described later, determines how far the object (displacement position F) is set from the focal position P, in other words, what percentage of the depth of field W the value of the distance K is set to. 51 (see FIG. 10) is used for input operation. In actual observation, when the focal position P and the deviation position F are separated by a distance K, the image on the line sensor 47 corresponding to the deviation position F is formed by being separated by Δk. Here, the images on the line sensor 47 corresponding to the surgical site Q are formed separated by Δg.

  Here, the passive autofocus mechanism will be described with reference to FIG. In FIG. 10, the same parts as those in FIG. 4 described in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. That is, the distance calculation circuit 50 is connected to the line sensor 47 via the light receiving circuit 49 as shown in FIG. The distance calculation circuit 50 is connected to the dial switch 51 that allows the operator to arbitrarily set the ratio of shifting the observation position F and the focus position P.

  An output shaft (not shown) of the focusing drive motor 30 is provided with an encoder 53 (not shown) for detecting a lens position (not shown) of the variable focal length objective optical system 9. The encoder 53 is a focusing distance detection circuit 54. Connected to. The focusing distance detection circuit 54 is connected to the distance calculation circuit 50, calculates focal distance information based on detection information of the encoder 53, and outputs the focal distance information to the distance calculation circuit 50.

  The distance measurement calculation circuit 50 receives the observation magnification signal, the distance information signal, and the depth of field data as well as the focal length information, and calculates a drive signal based on the observation magnification signal, the distance information signal, and the focusing drive circuit 29. Drive control.

  With the above configuration, the image of the surgical site Q is separated by Δg on the line sensor 47 via the variable focal length objective optical system 9, the distance measuring objective lens 43, the mirror 44, the field lens 45, and the separator lens 46. Imaged. When the observation visual field is moved, when the lock-free switch 8a or the input switch 26 is operated, an operation signal is input to the distance measurement calculation circuit 50 in substantially the same manner as in the first embodiment. At the same time, the distance calculation circuit 50 receives distance information corresponding to Δg calculated by the light receiving circuit 49 based on the output information of the line sensor 47.

  Here, the distance measurement calculation circuit 50 first calls the depth of field W (that is, the depth of field in the current observation state) corresponding to the magnification information from the magnification detection circuit 31 from the memory 34, and dial switch 51. The distance K to be shifted between the focal position P and the deviation position F is calculated with respect to the depth of field W in accordance with the “setting value” corresponding to the operation amount. For example, when the depth of field at the desired magnification is Y and the dial switch 51 is set to “10%”, the distance calculation circuit 50 calculates the value “distance K = Y / 10”.

  Subsequently, when there is an object at the set deviation position F, the distance measurement calculation circuit 50 calculates the virtual displacement amount Δk of the image when the object is imaged on the line sensor 47 and is inputted. The information of Δg and Δk are compared, the drive amount of the variable focal length objective optical system 9 is calculated so that this difference becomes zero (Δg = Δk), and the drive signal is output to the focusing drive circuit 29. The focusing drive circuit 29 drives the focusing drive motor 30 based on the input information, and drives lens driving means (not shown) of the focal length variable objective optical system 9. As a result, the lens group constituting the lens group is moved, the focal length by the variable focal length objective optical system 9 is changed, and the deviation position F coincides with the surgical site Q.

  In the above description, the value of the distance K is 10% of the depth of field, but the present invention is not limited to this, and the operator can arbitrarily set and use it according to the operation. This makes it possible to make optimal settings according to the surgical style and to maximize the effective use of the depth-of-field range for observation regardless of the surgical procedure, thus improving the usability and speeding up the surgical operation. Can be achieved.

  In addition, according to the second embodiment, the use of the passive focus mechanism without the light emitting means as the distance measuring means simplifies the mirror body 39, thereby reducing the size of the microscope section. Can be achieved.

  Furthermore, according to the second embodiment, there is no so-called feedback in which distance information to the surgical site Q is input at the start of autofocus and a predetermined amount of focus is moved with respect to this information. This makes it possible to quickly move the focal position to a desired position.

  Moreover, since the depth of field is deep by adopting the electronic image observation type microscope configuration, the action of expanding the depth of field is further expanded.

(Third embodiment)
11 and 12 show a surgical microscope according to a third embodiment of the present invention. However, in the description of FIGS. 11 and 12, the same reference numerals are given to the same components as those in FIGS. 7 and 10 described in the second embodiment, and the detailed description thereof is omitted. .

  In the third embodiment, in addition to the configuration of the second embodiment, between the variable magnification optical systems 10L and 10R and the CCDs 42L and 42R on the left and right observation optical paths 15L and 15R, Variable aperture stops 50L and 50R are respectively provided. The aperture stops 50L and 50R are connected to each other, and are provided so that the aperture diameter can be changed and adjusted by an operation knob (not shown). Further, for example, an encoder 57 (see FIG. 12) constituting the aperture diameter detecting means is assembled to the operation knob (not shown), and the encoder 57 corresponds to the aperture diameter of the aperture stops 50L and 50R. The operation amount is detected.

  A diaphragm aperture diameter detection circuit 59 is connected to the encoder 57. The aperture calculation circuit 50 is connected to the aperture diameter detection circuit 59, and the aperture diameters of the aperture diaphragms 50L and 50R are calculated based on the detection information of the encoder 57 and output to the distance measurement circuit 50.

  Further, the distance calculation circuit 50 is connected to a memory 60 that constitutes a storage means, and this memory 60 corresponds to the aperture diameters of the aperture stops 50L and 50R together with the depth of field information corresponding to the observation magnification. The depth of field information is stored.

  With the above configuration, the distance calculation circuit 50 stores the depth of field information according to the observation magnification and the depth of field information based on the aperture diameters of the aperture stops 50L and 50R input from the aperture information detection circuit 59. The distance K between the focal position P and the deviation position F is calculated based on each depth-of-field information and the operator's setting value by the dial switch 51.

  Here, when the object is present at the set deviation position F, the distance measurement calculation circuit 50 is an image when the object is imaged on the line sensor 47 in substantially the same manner as in the second embodiment. Is calculated, the input Δg information is compared with Δk, and the driving amount of the focal length variable objective optical system 9 is calculated so that the difference becomes zero (Δg = Δk). A drive signal is output to the focusing drive circuit 29 (see FIG. 9). Then, the focusing drive circuit 29 drives the focusing drive motor 30 based on the input information, and drives a lens driving means (not shown) of the variable focal length objective optical system 9.

  As a result, the lens group constituting the lens group is moved, the focal length by the variable focal length objective optical system 9 is changed, and the deviation position F coincides with the surgical site Q.

  According to the third embodiment, by providing the aperture stops 50L and 50R, it becomes possible to set an arbitrary depth of field even in normal surgery, so that the usability can be further improved. The speed of the operation can be promoted.

  Therefore, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention in the implementation stage. Further, the above embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements.

  For example, even if some constituent elements are deleted from all the constituent elements shown in the embodiment, the problem described in the column of the problem to be solved by the invention can be solved, and the effect described in the effect of the invention can be obtained. In some cases, a configuration from which this configuration requirement is deleted can be extracted as an invention.

  Moreover, according to each of the embodiments described above, the present invention can also constitute the following surgical microscope.

(Appendix 1)
A mirror provided with a pair of optical systems for obtaining an optical image of the target object;
Automatic focusing means for focusing the pair of optical systems of the mirror body;
Within the depth of field range of the pair of optical systems, the focal position where the resolving power of the pair of optical systems is the highest by the automatic focusing means is variably set to a position separated from the object by a predetermined distance. Control means;
A surgical microscope characterized by comprising:

(Appendix 2)
The operating microscope according to claim 1, wherein the control means sets a focal position by the automatic focusing means to a near point side of the object.

(Appendix 3)
The control unit includes an input unit, and is configured to be able to variably set a focal position by the automatic focusing unit in response to an input operation of the input unit within the depth of field. The surgical microscope according to 1 or 2.

(Appendix 4)
The automatic focusing means includes a distance measuring means for detecting a distance to a symmetrical object, a focusing means for changing a focal length of the stereoscopic observation or stereoscopic imaging optical system, and the stereoscopic observation or stereoscopic imaging optics. A magnification detecting means for detecting the magnification of the system,
The control means includes a storage means in which depth of field according to the magnification is stored in advance, performs calculation based on depth of field information from the storage means and information from the distance measurement means, The surgical microscope according to any one of appendices 1 to 3, wherein the focusing means is driven by a predetermined amount.

(Appendix 5)
The automatic focusing means includes a distance measuring means for detecting a distance to a symmetrical object, a focusing means for changing a focal length of the stereoscopic observation or stereoscopic imaging optical system, and the stereoscopic observation or stereoscopic imaging optics. Magnification detection means for detecting the magnification of the system, an aperture stop capable of changing the depth of field of the stereoscopic observation or stereoscopic imaging optical system, and an aperture diameter detection means for detecting aperture diameter information of the aperture stop And
The control unit includes a storage unit that stores a depth of field corresponding to a magnification and an aperture diameter in advance, and based on depth-of-field information from the storage unit and information from the ranging unit, The surgical microscope according to any one of appendices 1 to 3, wherein the operation microscope is operated to drive the focusing means by a predetermined amount.

(Appendix 6)
The surgical microscope according to any one of appendices 1 to 5, wherein the automatic focusing means is an active type.

(Appendix 7)
The surgical microscope according to any one of appendices 1 to 5, wherein the automatic focusing means is a passive type.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a configuration explanatory view showing an external configuration of a surgical microscope according to a first embodiment of the present invention. It is the block diagram which showed the optical system of the microscope part of FIG. It is explanatory drawing shown in order to demonstrate operation | movement of the auto-focus mechanism of FIG. It is the block diagram which took out and showed the microscope control system of FIG. It is explanatory drawing shown in order to demonstrate the operation | movement principle of the focus position detection of FIG. It is composition explanatory drawing which showed the external appearance structure of the surgical microscope which concerns on 2nd Embodiment of this invention. It is the block diagram which showed the optical system of the microscope part of FIG. It is explanatory drawing shown in order to demonstrate the difference in the resolving power by the optical observation and image observation to which this invention is applied. It is explanatory drawing shown in order to demonstrate the operation | movement principle of the focus position detection of FIG. It is the block diagram which took out and showed the microscope control system of FIG. It is the block diagram which showed the optical system of the microscope part of the surgical microscope which concerns on 3rd Embodiment of this invention. It is the block part which took out and showed the microscope control system of FIG. It is explanatory drawing which showed the arrangement configuration of the conventional surgical microscope. It is the characteristic view which showed the relationship between the shift | offset | difference of the focus position in a surgical microscope, and resolution. It is explanatory drawing shown in order to demonstrate the problem of the conventional surgical microscope.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Base part, 1a ... Base, 1b ... Post, 2 ... 1st arm, 3 ... 2nd arm, 4 ... Lifting arm, 5 ... Body part, 6 ... Observation tube, 7 ... Microscope part, 8 ... Handle 8a, lock-free switch, 9 ... variable focal length objective optical system, 10L, 10R ... variable power optical system, 11L, 11R ... imaging lens, 12L, 12R ... eyepiece, 13 ... infrared light emitting element, 14 ... light emission Optical system, 15L, 15R ... observation optical axis, 16 ... mirror, 17 ... light receiving optical system, 18 ... photoelectric conversion element, 19 ... dichroic prism, 20 ... reflecting surface, 21 ... input circuit, 22, 22 '... light receiving optical axis , 23 ... Optical axis, 24 ... Encoder, 25 ... Ranging calculation circuit, 26 ... Input switch, 27 ... Variable power drive circuit, 28 ... Variable power drive motor, 29 ... Focus drive circuit, 30 ... Focus drive motor, 31 ... Magnification detection circuit, 32 ... Bray Drive circuit 33 ... Light receiving circuit 34 ... Memory 35 ... Light emitting circuit 37 ... 3D display 38 ... Image processing device 39 ... Mirror body part 40L, 40R ... Imaging lens, 41L, 41R ... Shooting optical axis, 42L, 42R ... CCD, 43 ... distance measuring objective lens, 44 ... mirror, 45 ... field lens, 46 ... separator lens, 47 ... line sensor, 48 ... distance measuring optical system, 49 ... light receiving circuit, 50 ... distance measuring arithmetic circuit , 50L, 50R ... aperture stop, 51 ... dial switch, 53 ... encoder, 54 ... focusing distance detection circuit, 57 ... encoder, 59 ... aperture diameter detection circuit, 60 ... memory.

Claims (3)

Optical system for acquiring an optical image of the Target object, the optical system is engaged, the resolution characteristics the optical system in relation to the distance to the object, the optical image having a substantially flat predetermined range electronic imaging device for acquiring an observation image, and including electronic imaging unit monitor for displaying an observation image acquired by the electronic image pickup element as a component,
Automatic focusing means for focusing the optical system that engages the electronic imaging device;
The focus position where the resolving power of the optical system is the highest by the autofocusing means within a predetermined depth range within a predetermined range where the resolving power characteristic of the electronic imaging device is substantially flat is separated from the object by a predetermined distance. Control means for variably setting the position,
A surgical microscope characterized by comprising:   The surgical microscope according to claim 1, wherein the control unit sets a focal position by the automatic focusing unit to a near point side of the object.   The control means includes an input means, and is configured to be capable of variably setting a focal position by the automatic focusing means in response to an input operation of the input means within the depth of field. Item 3. The surgical microscope according to Item 1 or 2.

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