JP2010220654A - Ophthalmologic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ophthalmologic apparatus having a simple configuration which allows a user to observe and photograph a fundus image formed by means of an objective lens. <P>SOLUTION: A fundus image 1b formed by the objective lens 4 is imaged on an imaging surface 14a of an imaging apparatus 14 via a second lens 13. A focusing indicator 17 is projected by a first lens 12 to form an indicator image 17a. The first and the second lenses are linked and moved together so that the indicator and the imaging surface are always in a conjugate relationship with each other. By moving the first lens, the indicator image 17a is focused and placed approximately on a fundus image 1b formed via the objective lens. The fundus image is then photographed via the second lens moved cooperatively with the movement of the first lens. With such a configuration, an operator can adjust the focus of a fundus image while observing the fundus image 1b and the projected indicator image 17a. In addition, a visibility correction and adjustment mechanism for an eyepiece becomes unnecessary because the fundus image and the indicator image can be observed without using the eyepiece lens. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an ophthalmologic apparatus, and more particularly to an ophthalmologic apparatus for observing and photographing a fundus image of a subject's eye that is imaged through a separate objective lens.

  Forming an inverted aerial image of the fundus of the eye to be examined using an objective lens (inverted mirror lens), and observing the fundus through this aerial image is one of the basic examinations in ophthalmic practice, and an ophthalmologic apparatus It is widely done in general.

  Since fundus observation using such an objective lens has a wider observation field of view than direct image observation in which the fundus of the eye to be examined is observed as an erect image without using an objective lens, observation of the fundus periphery and the like is easy. However, the magnification rate of the inverted image is small, and in order to obtain a clear observation image (retinal image) or to photograph it, it is necessary to acquire a certain skill.

  2. Description of the Related Art Conventionally, a configuration is known in which a fundus image is observed through an eyepiece chart and an eyepiece lens, and an image medium is arranged on a conjugate plane of the eyepiece chart to capture the fundus image (Patent Documents 1 and 2).

  In addition, a hand-held ophthalmic apparatus that improves workability by integrating an inverted image lens with the ophthalmic apparatus has been proposed (Patent Document 3).

JP-A-11-89798 JP-A-51-69629 Japanese Patent Laid-Open No. 11-9553

  However, in the configurations as described in Patent Documents 1 and 2, the fundus image is observed through the eyepiece lens, and thus the diopter of the eyepiece lens is used to make the examiner's fundus and eyepiece chart conjugate. A correction adjustment mechanism is required, and the examiner must always adjust the diopter and observe the fundus image to focus.

  Further, in the apparatus described in Patent Document 3, the observation optical system including the inversion lens is integrally fixed to the housing of the ophthalmologic apparatus. When changing, it is necessary to move each ophthalmologic apparatus (in the past, the illumination light source or the like is moved), which impairs simplicity during fundus examination using a hand-held inverted image lens.

  In addition, although an inverted image of the fundus observation site is visible to the examiner who operates the ophthalmologic apparatus, when the fundus observation site is photographed, the desired fundus image is not included in the screen after the image capture, or the fundus image is Even if the image is captured, the outline is blurred (so-called out-of-focus), and acquisition of an observation image (photographing operation) requires a predetermined skill.

  The present invention has been made in view of the above problems, and an object thereof is to provide an ophthalmologic apparatus capable of observing and photographing a fundus image formed by an objective lens with a simple configuration.

The present invention
An ophthalmic apparatus for observing and photographing a fundus image of a subject's eye imaged through a separate objective lens,
An indicator plate on which an index for focusing is formed;
A first lens that projects an index of the index plate to form an index image;
An imaging device for capturing the fundus image;
A second lens that forms the fundus image on an imaging surface of an imaging device;
A moving mechanism that moves the first and second lenses in an interlocked manner so that the index and the imaging surface are in a conjugate relationship with respect to the first and second lenses,
The first lens is moved so that the index image substantially coincides with the fundus image formed through the objective lens, and the second lens is moved in conjunction with the movement of the first lens. And taking a fundus image.

In addition, the present invention includes a moving mechanism that moves the index and the imaging surface in association with each other so that the index and the imaging surface have a conjugate relationship with respect to the first and second lenses,
The index image is moved so that the index image substantially coincides with the fundus image formed through the objective lens, and the imaging surface is moved in conjunction with the movement of the index to capture the fundus image. And

  In such a configuration, the first lens that forms the index image and the second lens that forms the fundus image on the imaging surface of the imaging apparatus are interlocked so that the index and the imaging surface are always in a conjugate relationship. Moved. The first lens is moved and focused so that the index image substantially matches the fundus image formed through the objective lens, and the index image moves in conjunction with the movement of the first lens. A fundus image is taken through the second lens. Therefore, the examiner can observe the fundus image and the projection index, and can focus the fundus image captured by the imaging device, and can focus by looking at the fundus image displayed on the separately provided image display unit. Therefore, it is easy to focus and a good fundus image can be acquired.

  As another configuration, the index and the imaging surface are moved in association with each other so that the index and the imaging surface are in a conjugate relationship with respect to the first and second lenses. Since the index is moved so that it substantially coincides with the fundus image formed in this way, and the fundus image is captured on the imaging surface that moves in conjunction with the movement of the index, the same effect as described above can be obtained. be able to.

  Further, according to the present invention, the fundus image and the index image can be observed without using an eyepiece lens, so that an effect that a diopter correction adjustment mechanism for the eyepiece lens is not required is obtained.

It is a block diagram explaining the Example of the ophthalmologic apparatus of this invention. It is an optical diagram showing an optical system built in the ophthalmologic apparatus of the present invention. (A) is an optical diagram showing a light beam path when a fundus image is captured, and (b) is an optical diagram showing a light beam path when an index image is projected. (A) is an explanatory view showing an index image when the photographed fundus image is not in focus, and (b) is an explanatory view showing an index image when it is in focus. It is explanatory drawing which showed the moving mechanism which moves two lenses interlockingly.

  Embodiments of the present invention will be described below in detail with reference to the drawings.

  FIG. 1 shows an embodiment of an ophthalmologic apparatus 10 of the present invention for observing and photographing a fundus image. The ophthalmologic apparatus 10 has a form that can be grasped by the examiner 2 who performs fundus observation with one hand 3 (right hand in the illustrated example), and includes an imaging device 14 (CCD camera) that captures a fundus image. . The ophthalmologic apparatus 10 incorporates an observation photographing optical system, an index, a light source for illuminating the index, and the like (not shown in FIG. 1).

  The ophthalmologic apparatus 10 is provided with a shutter switch 10a that can be operated (for example, a sliding operation with a thumb) while being held by the examiner 2 with one hand 3, and a focus knob 10b that can be focused. A fundus illumination light source 5 made of, for example, a light emitting diode is disposed on the surface facing the eye 1 to be examined, and a finder 6 is disposed on the surface on the examiner 2 side.

  Further, an inversion mirror 7 having a built-in objective lens 4 (also referred to as a front lens or an inversion mirror lens) separate from the ophthalmologic apparatus 10 is prepared. When observing the fundus of the eye 1 to be examined, the examiner 2 holds the inverted mirror 7 with the other hand (or left hand when the one hand 3 is the right hand), and the optical axis 4a of the objective lens 4 is the eye axis of the eye 1 to be examined. It arrange | positions in the front part of the eye 1 to be examined so that it may correspond substantially. The examiner 2 holds the ophthalmologic apparatus 10 in a direction substantially orthogonal to the optical axis 4a of the objective lens 4, and observes the fundus image with the viewfinder 6 aligned with the optical axis 4a.

  The ophthalmologic apparatus 10 is mounted with a fundus illumination light source 5 that illuminates the fundus of the subject's eye so that the fundus illumination light source 5 is located above the optical axis 4a. It has a U-shaped cross-sectional shape so that it does not enter (does not enter).

  The fundus of the subject eye 1 illuminated by the fundus illumination light source 5 is formed as an inverted image in the air by the objective lens 4, and the examiner 2 observes the inverted fundus image through the finder 6.

  The ophthalmologic apparatus 10 is connected to a control unit 22 including a computer with a built-in power supply via a power cable 21a and a signal line 21b. Power is supplied to an index illumination light source, which will be described later. Also, the video signal from the imaging device 14 and the shutter signal from the shutter switch 10a are input to the control unit 22 via the signal line 21b.

  A power switch 22 a is provided in the housing of the control unit 22, and the fundus image 1 c acquired by the imaging device 14 is displayed on the image display unit 23 connected to the control unit 22.

  FIG. 2 illustrates configurations of an optical system, an imaging device, and the like housed in the ophthalmologic apparatus 10. In the ophthalmologic apparatus 10, a transparent indicator plate 11, an indicator illumination light source 16 that illuminates the indicator plate 11, a first lens 12, and a flat plate-like shape having first and second reflecting surfaces 15a and 15b that are parallel to each other. The half mirror 15, the second lens 13, and the imaging device 14 are accommodated so as to coincide with the optical axis 10c extending in the vertical direction of the device at the center thereof.

  When observing and photographing the fundus image of the subject eye 1 imaged by the objective lens 4, as shown in FIG. 2, the optical axis 4a of the objective lens 4 and the optical axis 10c of the apparatus 10 are almost orthogonal to each other. The examiner 2 places the eye fundus to be examined in such a manner that the center of the half mirror 15 arranged at an angle of about 45 degrees with respect to the optical axis 10c coincides with the optical axis 4a. Observe.

  In the center of the lower surface 11a of the indicator plate 11, a cross indicator (chart) 17 for focusing is formed. The indicator plate 11 is arranged so that the indicator 17 is positioned inside the focal point of the first lens 12, and when the indicator plate 17 is illuminated by the indicator illumination light source 16, a virtual image of the indicator 17 is provided by the first lens 12. The virtual image can be observed by the examiner 2 through the first reflecting surface 15a of the half mirror 15.

  The fundus image formed by the objective lens 4 is reflected by the second reflecting surface 15 b of the half mirror 15 and guided to the second lens 13, and the second lens 13 is formed by the objective lens 4. The formed fundus image is re-imaged on the imaging surface 14 a of the imaging device 14.

  In this embodiment, the focal lengths of the first lens 12 and the second lens 13 are set to be the same, and the first lens 12 is operated by operating the focus knob 10b (FIG. 1). It is movable along the axis 10c. When the focus knob 10b is operated to move the first lens 12, the examiner 2 observes that the index image of the index 17 moves along the optical axis 4a. Further, the second lens 13 is configured to move along the optical axis 10 c in conjunction with the first lens 12. At this time, the lower surface 11a of the index plate 11 (that is, the surface on which the index 17 is formed) and the imaging surface 14a of the imaging device 14 have a conjugate relationship with respect to the optical system including the first and second lenses 12 and 13. This conjugate relationship is maintained regardless of the movement of the first and second lenses 12 and 13. Therefore, even if the first and second lenses are moved by operating the focus knob 10b, the index 17 of the index plate 11 is always conjugate with the imaging surface 14a of the imaging device 14.

  FIG. 5 shows a moving mechanism for moving the first and second lenses 12 and 13 in association with each other and maintaining the conjugate relationship. The first lens 12 is held by the lens barrel 12a, and the second lens 13 is held by the lens barrel 13a. The lens barrels 12a and 13a are movable along the guide cylinder 30, and racks 12b and 13b indicated by a one-dot chain line are formed in a part of the lens barrel. The portions of the guide cylinder 30 facing the racks 12b and 13b are notched, and the rack 12b and the rack 13b are engaged with the gear 31 and the gear 34, respectively. The rotation of the gear 31 is transmitted to the gear 34 via the gear 32. The gear 31 and the gear 34 are the same gear, that is, have the same diameter and the same number of teeth.

  When the focus knob 10b is operated, the gear 31 rotates, for example, in the direction indicated by the arrow in FIG. 5, and the gear 31 and the rack 12b are engaged with each other. It moves downward along the shaft 10c. Further, since the rotation of the gear 31 is transmitted to the gear 34 via the gear 32, the gear 34 rotates in the direction of the arrow, that is, the lens barrel 13 a in which the rack 13 b meshing with the gear 34 is formed, that is, the second lens 13. Moves coaxially along the optical axis 10c and moves downward by the same distance as the first lens 12, as indicated by the arrows. Similarly, when the focus knob 10b is operated in the opposite direction, the first and second lenses 12 and 13 move the same distance in the same direction (the direction opposite to the direction indicated by the arrow in FIG. 5, that is, the upward direction). .

  As described above, the second lens 13 moves the same distance in the same direction in conjunction with the movement of the first lens 12, and therefore, when the focal lengths of the first and second lenses are the same, the index 17 and the imaging are performed. The surface 14a can maintain a conjugate relationship even when the first and second lenses 12 and 13 move in conjunction with each other. When the focal lengths of the first and second lenses are different from each other, the movement amounts of the first and second lenses are calculated so that the index 17 and the imaging surface 14a maintain a conjugate relationship, and the gears are geared accordingly. A gear ratio of 31 to 34 is set.

  Although the first and second lenses 12 and 13 are illustrated as single lenses, they may be composed of a plurality of lens groups. Therefore, the first lens 12 is constituted by a single lens or a plurality of lenses, and the second lens 13 is also constituted by a single lens or a plurality of lenses.

  In the case of observing and photographing the fundus oculi to be examined with the ophthalmologic apparatus 10 configured as described above, the power switch 22a is turned on to light the fundus illumination light source 5, and the imaging device 14 is activated. As shown in FIG. 1, the examiner 2 holds the inverted mirror 7 including the objective lens 4 with one hand so that the optical axis 4 a of the objective lens 4 substantially coincides with the eye axis of the eye 1 to be examined. It arrange | positions in the front part of the optometry 1. FIG. The examiner 2 holds the ophthalmologic apparatus 10 with the other hand 3 so that the optical axis 10c thereof is substantially orthogonal to the optical axis 4a of the objective lens 4, and the finder 6 coincides with the optical axis 4a. Thus, the position and inclination of the ophthalmologic apparatus 10 are adjusted.

  As shown in FIG. 3A, the light beam from the fundus illumination light source 5 illuminates the fundus 1 a of the subject eye 1 through the objective lens 4. The fundus 1a illuminated by the light source 5 is imaged as a fundus image 1b inverted in the air by the objective lens 4. As described above, the optical axis 4a of the objective lens 4 is substantially coincident with the eye axis of the eye 1 to be examined, the optical axes 4a and 10c are substantially orthogonal, and the viewfinder 6 is coincident with the optical axis 4a. When the optometry 1, the objective lens 4, and the ophthalmologic apparatus 10 are aligned (aligned), the examiner 2 displays the aerial fundus image 1b inverted in the housing 7a of the inversion mirror 7, as shown in FIG. It can be observed through the half mirror 15.

  In this state, the fundus image 1 b is reflected by the second reflecting surface 15 b of the half mirror 15 and formed on the imaging surface 14 a of the imaging device 14 by the second lens 13. However, since the in-focus state of the fundus image 1c formed on the imaging surface 14a varies depending on the position of the ophthalmologic apparatus 10, it is not necessarily an in-focus image.

  Therefore, as shown in FIG. 3B, the indicator illumination light source 16 is turned on, the indicator 17 is illuminated, and an image is formed by the first lens 12. The index 17 becomes an index image 17a and can be observed by the examiner 2 as a virtual image. When the focus knob 10b is operated, the first lens 12 moves along the optical axis 10c, and the index image 17a also moves along the optical axis 4a accordingly. Therefore, the index image 17a matches the fundus image 1b. Thus, the focus knob 10b is adjusted. By adjusting the focus knob 10b, the second lens 13 also moves along the optical axis 10c in conjunction with the first lens 12.

  FIGS. 4A and 4B show how the index image 17a is observed from the examiner when the focus knob 10b is operated. When the index image 17a does not coincide with the fundus oculi image 1b, the index image 17a is observed in a blurred manner as shown by a dotted line as shown in FIG. When the first lens 12 is moved back and forth, the index image 17a can be clearly observed as shown by the solid line in FIG. Since the image magnification of the index image 17a varies depending on the position where it is formed, the size of the index image 17a illustrated in FIGS. 4A and 4B is different.

  When it is confirmed that the index image 17a is clear and coincides with the fundus oculi image 1b as shown in FIG. 4B, the index image 17a and the index 17 of the index plate 11 are in a conjugate relationship. In addition, the index 17 and the imaging surface 14a of the imaging device 14 are always in a conjugate relationship even when the first and second lenses 12 and 13 are moved. Therefore, the match between the fundus image 1b and the index image 17a means that the fundus image 1b and the index 17 are conjugated, that is, the fundus image 1b and the imaging surface 14a are conjugated. A focused fundus image 1c is formed.

  Thus, when the alignment and focusing are completed, the index illumination light source 16 is turned off, and the fundus image 1c formed on the imaging surface 14a is imaged by operating the shutter switch 10a. The captured fundus image 1c is captured by the control unit 22 via the signal line 21b, and is displayed on the image display unit 23 after being subjected to a predetermined image display process.

  As described above, the examiner observes the fundus oculi image and the projection index image, adjusts the position and inclination of the ophthalmic apparatus so that the centers of the two images overlap each other, and further adjusts the position of the light. When the first lens is moved and adjusted so that the two aerial images of the fundus image 1b in the direction of the axis 4a and the projection index image 17a coincide with each other, the fundus image captured by the imaging apparatus can be aligned and focused. . Therefore, it is not necessary to perform positioning and focusing by looking at the fundus image displayed on a separate image display unit, which facilitates positioning and focusing, and reduces the burden on the examiner. Can be obtained.

  Further, in the present invention, the fundus image and the index can be observed through the half mirror 15 without using an eyepiece lens, so that a diopter correction adjustment mechanism for the eyepiece lens becomes unnecessary.

  The indicator illumination light source 16 may be turned on / off by providing a dedicated switch below the shutter switch 10a, or the indicator illumination light source 16 may be turned on in conjunction with the operation of the focus knob 10b. You may make it light-extinguish according to operation of switch 10a. At this time, in order to prevent the index from being mistakenly photographed, imaging is performed after the index illumination light source 16 is turned off.

Further, the half mirror 15 is configured to be detachable, and the index illumination light source 16 is turned on and / or the imaging device 14 is activated (powered) in conjunction with the insertion of the half mirror 15 into the optical axis 10c. You may comprise. At this time, the indicator illumination light source 16 is turned off according to the operation of the shutter switch 10a.
In addition, as described above, the first and second lenses are not moved in association with each other so that the index 17 and the imaging surface 14a have a conjugate relationship with respect to the first and second lenses 12 and 13. The index 17 and the imaging surface 14a may be moved in conjunction so that the index 17 and the imaging surface 14a have a coaxial and conjugate relationship with respect to the first and second lenses 12 and 13. Even in such a configuration, when the examiner moves the index 17 so that the index image and the fundus image formed through the objective lens substantially coincide with each other, the conjugate relationship is maintained in conjunction with the movement of the index. However, the imaging surface 14a also moves. Since the imaging surface 14a is conjugated with the index 17 (conjugated with the fundus image), a clear fundus image can be captured by the imaging device 14, and similar effects can be obtained.

  The interlocking relationship between the index and the imaging surface as described above is such that a gear mechanism including gears 31, 32, and 34 as shown in FIG. 5 is provided, and the gear 31 is attached to the rack formed on the casing that holds the index plate 11. This can be realized by meshing, or by meshing the gear 34 with a rack formed in a housing that holds the imaging device 14. If the gears 31, 32, and 34 are rotated according to the operation of the focus knob 1b, the above focusing can be performed.

DESCRIPTION OF SYMBOLS 4 Objective lens 5 Fundus illumination light source 10 Ophthalmology apparatus 10a Shutter switch 10b Focus knob 11 Index plate 12 First lens 13 Second lens 14 Imaging device (CCD camera)
14a Imaging surface 15 Half mirror 16 Index illumination light source 17 Index

Claims (6)

An ophthalmic apparatus for observing and photographing a fundus image of a subject's eye imaged through a separate objective lens,
An indicator plate on which an index for focusing is formed;
A first lens that projects an index of the index plate to form an index image;
An imaging device for capturing the fundus image;
A second lens that forms the fundus image on an imaging surface of an imaging device;
A moving mechanism that moves the first and second lenses in an interlocked manner so that the index and the imaging surface are in a conjugate relationship with respect to the first and second lenses,
The first lens is moved so that the index image substantially coincides with the fundus image formed through the objective lens, and the second lens is moved in conjunction with the movement of the first lens. An ophthalmologic apparatus characterized by taking a fundus image. An ophthalmic apparatus for observing and photographing a fundus image of a subject's eye imaged through a separate objective lens,
An indicator plate on which an index for focusing is formed;
A first lens that projects an index of the index plate to form an index image;
An imaging device for capturing the fundus image;
A second lens that forms the fundus image on an imaging surface of an imaging device;
A moving mechanism for moving the index and the imaging surface in an interlocking manner so that the index and the imaging surface are coaxially and conjugately related to the first and second lenses;
The index image is moved so that the index image substantially coincides with the fundus image formed through the objective lens, and the imaging surface is moved in conjunction with the movement of the index to capture the fundus image. Ophthalmic device.   The optical axes of the first and second lenses are substantially orthogonal to the optical axis of the objective lens, and the fundus image can be observed through a half mirror disposed in the optical path between the first and second lenses. The ophthalmologic apparatus according to claim 1 or 2.   4. The ophthalmologic apparatus according to claim 3, wherein the index image is observed through a first reflecting surface of a half mirror, and the fundus image is guided to an imaging device through a second reflecting surface of the half mirror. .   The half mirror is detachable, and when the half mirror is inserted into the optical path between the first and second lenses, the light source that illuminates the index is turned on and / or the imaging device is activated. The ophthalmologic apparatus according to any one of claims 1 to 4.   The ophthalmologic apparatus according to claim 1, wherein a light source that illuminates the index is turned off during fundus photography.

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