JP6319616B2 - Scanning laser ophthalmoscope - Google Patents

Description

  The present invention relates to a scanning laser ophthalmoscope for photographing the fundus of a subject's eye.

  Conventionally, a scanning laser ophthalmoscope that scans the laser beam on the fundus by rotating the laser beam emitted from the light source around a point near the pupil and receives the fundus reflection light to obtain a fundus image It has been known.

  Patent Document 1 describes an apparatus that can mount a wide-angle lens attachment in the vicinity of an inspection window. In this apparatus, the size of the irradiation range of the laser light is switched between a state where the attachment is attached and a state where the attachment is removed. For this reason, fundus images having different shooting angles of view can be obtained between the state in which the attachment is attached and the state in which the attachment is removed.

JP 2009-011381 A

  However, in the apparatus described in Patent Document 1, the position of the turning center of the laser light is changed between the state where the attachment is attached and the state where the attachment is removed. For this reason, in order to irradiate the fundus with the laser beam well, it is necessary to adjust the positional relationship between the apparatus and the eye to be examined each time the attachment is attached or detached.

  An object of the present invention is to provide a scanning laser ophthalmoscope that can satisfactorily capture a fundus image by switching the field angle of view in view of the above-described problems of the prior art.

A scanning laser ophthalmoscope according to a first aspect of the present disclosure includes a light projecting optical system that projects laser light emitted from a light source onto the fundus of a subject's eye, and the laser light projected by the light projecting optical system. A scanning unit that changes a traveling direction of the laser light in order to scan on the fundus; and a light receiving optical system that receives a fundus reflected light of the laser light emitted from the light projecting optical system to the fundus using a light receiving element. A scanning laser ophthalmoscope comprising a photographing optical system for photographing a fundus image of an eye to be examined by laser scanning, comprising: a first convex lens; and a second convex lens positioned closer to the scanning unit than the first convex lens An objective lens optical system that includes at least a turning point of the laser light on the eye side to be examined with respect to the first convex lens, and that guides the laser light turned around the turning point to the fundus In the photographing optical system, by changing the arrangement of the first convex lens and the second convex lens, the photographing field angle in the photographing optical system is set to a first field angle and a second field angle wider than the first field angle. An angle-of-view switching mechanism that can be switched between, and the position of the turning point is maintained when the shooting angle of view is the first angle of view and when the angle of view is the second angle of view. The first convex lens and the second convex lens are arranged by the field angle switching mechanism .

  According to the present invention, the fundus image can be favorably captured by switching the photographing angle of view.

It is a schematic block diagram of the optical system which the ophthalmologic imaging device of this embodiment has. (A) is the schematic diagram which showed the objective-lens optical system in narrow-angle imaging | photography mode, (b) is the schematic diagram which showed the objective-lens optical system in wide-angle imaging | photography mode. It is the graph which showed typically the relation between a field angle of view and diopter (D) by an objective lens optical system on the conditions which make the position of the turning point to the eye to be examined constant. A table showing design values of the objective lens optical system in which the position of the turning point with respect to the eye to be examined and the diopter of the photographing optical system are maintained before and after the photographing field angle is switched between the first field angle and the second field angle. is there. It is the figure which showed the rotating plate seen from the arrow A direction of FIG. It is the graph which showed the filtering characteristic of the filter which a rotating plate has. It is the block diagram which showed the electrical structure of the ophthalmologic imaging device. It is the flowchart which showed the imaging | photography display process performed by CPU. It is the schematic diagram which showed an example of the display mode of a fundus image. It is the flowchart which showed the imaging | photography display process in 2nd Embodiment. It is a continuation of the flowchart shown in FIG. It is the flowchart which showed the 1st display control process in 2nd Embodiment. It is the schematic diagram which showed an example of the display mode of the fundus image in the second embodiment. (A) shows the lens arrangement in the narrow-angle shooting mode of the modified example of the objective lens optical system, and (b) shows the lens arrangement in the wide-angle shooting mode. It is the schematic diagram which showed. It is the figure which showed an example of the diopter correction part.

  Hereinafter, exemplary embodiments of the present invention will be described with reference to the drawings. First, a first embodiment will be described with reference to FIGS.

  FIG. 1 shows an optical system of the ophthalmologic photographing apparatus 1 according to the first embodiment. In this embodiment, the ophthalmologic photographing apparatus 1 has a scanning laser ophthalmoscope (SLO) as a basic configuration. The ophthalmologic imaging apparatus 1 may be an apparatus integrated with other ophthalmologic apparatuses such as an optical coherence tomography (OCT) and a perimeter.

  As an example, the ophthalmologic photographing apparatus 1 mainly includes a photographing optical system 2. In the ophthalmologic photographing apparatus 1 according to the first embodiment, the rotation unit 30 is provided. First, the photographing optical system 2 will be described. The imaging optical system 2 projects light onto the fundus Er of the eye E, and receives light emitted from each position of the fundus Er with the projected light by the light receiving element 25. Although details will be described later, the ophthalmologic photographing apparatus 1 acquires (photographs) a fundus image based on the light reception result of the light receiving element 25. The photographing optical system 2 has a light projecting optical system 3 and a light receiving optical system 4. The imaging optical system 2 is moved in the left-right direction (arrow X direction), the vertical direction (arrow Y direction), and the front-back direction (arrow Z direction) of the eye E by a driving mechanism 50 (see FIG. 7) described later. Moved.

  The light projecting optical system 3 projects light (illumination light or excitation light) to each position in the imaging range on the fundus Er of the eye E. In the present embodiment, the light projecting optical system 3 includes a laser light emitting unit 11, a perforated mirror 12, a lens 13, a lens 14, a scanning unit 15, and an objective lens optical system 16.

  The laser beam emitting unit 11 is a light source of the photographing optical system 2. The laser beam emitting unit 11 may emit, for example, at least a laser beam having a first wavelength (near wavelength 790 nm) and a laser beam having a second wavelength (near wavelength 490 nm). Of course, the laser beam emitting unit 11 may emit only monochromatic light. In this embodiment, the laser beam emitting unit 11 can emit two types of laser beams at the same time, or can emit only one of them.

  The laser light from the laser light emitting part 11 passes through the opening part of the perforated mirror 12 having an opening part in the center, passes through the lens 13 and the lens 14, and then goes to the scanning part 15. The light beam reflected by the scanning unit 15 passes through the objective lens optical system 16 and then converges on the fundus Er of the eye E to be examined. Light is emitted from the fundus Er as the laser beam is irradiated from the laser beam irradiation unit 11 to the fundus Er. For example, the laser light is scattered and reflected by the fundus Er. As a result, light scattered and reflected by the fundus Er (hereinafter referred to as fundus reflected light) is emitted from the pupil. Further, the laser light may excite a fluorescent substance present on the fundus Er. As a result, the fluorescence emitted from the fluorescent substance existing in the fundus Er may be emitted from the pupil.

  In the present embodiment, the lens 13 is configured to be movable in the optical axis direction L1 by the drive mechanism 13a. Depending on the position of the lens 13, the diopter of the photographing optical system 2 changes. For this reason, in the present embodiment, the diopter error of the eye E with respect to the normal eye is corrected (reduced) by adjusting the position of the lens 13. Note that the diopter error of the eye E may be corrected by displacing the lens 14.

  The scanning unit 15 is a unit that changes the traveling direction of the laser light guided from the laser light emitting unit 11 (deflects the laser light) in order to scan the laser light on the fundus. In the present embodiment, the scanning unit 15 includes a resonant scanner 15a and a galvano mirror 15b.

  As the scanning unit 15, for example, an acousto-optic device (AOM) that changes the traveling (deflection) direction of light may be used in addition to a reflection mirror (galvano mirror, polygon mirror, resonant scanner).

  In the present embodiment, the resonant scanner 15a deflects the laser light projected on the fundus of the eye E to be examined in a predetermined direction. As shown in FIG. 1, the light that has passed through the resonant scanner 15a travels to the galvanometer mirror 15b. In the present embodiment, the resonant scanner 15a is rotated by the motor 15c (see FIG. 7), so that the irradiation position (scan position) of the laser light on the fundus Er moves in the horizontal direction (that is, the X direction).

  In this embodiment, the galvanometer mirror 15b further deflects the laser light that has passed through the resonant scanner 15a in a direction different from that of the resonant scanner 15a. As shown in FIG. 1, the light that has passed through the galvanometer mirror 15 b travels toward the objective lens optical system 16. In the present embodiment, the galvano mirror 15b is rotated by the motor 15d (see FIG. 7), so that the irradiation position of the laser light on the fundus Er moves in the vertical direction (that is, the Y direction). As described above, the scanning unit 15 of the present embodiment scans the laser light two-dimensionally on the fundus Er by scanning the fundus Er in the X direction with the resonant scanner 15a and scanning in the Y direction with the galvano mirror 15b. .

  The objective lens optical system 16 allows the laser light that has passed through the scanning unit 15 to pass through the pupil position. In the present embodiment, the objective lens optical system 16 includes a first convex lens 16a and a second convex lens 16b. As shown in FIG. 1, the objective lens optical system 16 has these lenses arranged in series. The number of lenses of the objective lens optical system 16 is not limited to the above configuration, and may be an objective lens system including three or more lenses. In addition, each lens of the objective lens optical system 16 may be an aspheric lens, a compound lens composed of a plurality of lenses, or the like as required for aberration correction.

  The first convex lens 16 a is disposed closest to the eye to be examined among the lenses of the objective lens optical system 16. The second convex lens 16b is disposed closer to the scanning unit 15 than the first convex lens 16a. As shown in FIG. 1, in the present embodiment, a plano-convex lens having a convex surface facing the scanning unit 15 is used for the first convex lens 16a, and a biconvex lens is used for the second convex lens 16b. However, these lens shapes are merely examples, and it is sufficient that each has a positive power.

  In the present embodiment, the laser light that has passed through the objective lens optical system 16 is irradiated on the fundus Er through one point on the optical axis L3 of the objective lens optical system 16 (hereinafter referred to as a “turning point”). In the present embodiment, the position of the turning point is an optically conjugate position with the scanning unit 15 (for example, an intermediate point between the resonant scanner 15a and the galvanometer mirror 15b) via the objective lens optical system 16. For this reason, the chief ray of the laser light that has passed through the objective lens optical system 16 is turned around the turning point in accordance with the operation of the scanning unit 15. As a result, the laser beam is scanned two-dimensionally on the fundus oculi Er. By making the turning point of the laser beam coincide with the pupil position of the eye E in advance, vignetting in the iris is suppressed and the laser beam is guided well to the fundus. As a result, the fundus image is captured well.

  Further, the ophthalmologic photographing apparatus 1 of the present embodiment has a lens moving mechanism (view angle switching mechanism) 17 that moves each lens of the objective lens optical system 16. The lens moving mechanism 17 can move each lens of the objective lens optical system 16 by an arbitrary moving amount. For convenience of explanation, in the present embodiment, the lens moving mechanism 17 is described as a single device, but is not necessarily limited thereto. For example, the lens moving mechanism 17 may be a plurality of devices that each move one lens.

  In the present embodiment, the arrangement of the lenses in the objective lens optical system 16 is changed by the lens moving mechanism 17, so that the irradiation range of the laser light projected from the light projecting optical system 3, that is, the ophthalmologic photographing apparatus 1 ( Alternatively, the shooting angle of view in the shooting optical system 2) is changed. The ophthalmologic photographing apparatus 1 according to the present embodiment can switch the photographing angle of view to at least two types of a first angle of view and a second angle of view wider than the first angle of view. In this embodiment, the arrangement of the lenses 16a and 16b when the shooting angle of view is the first angle of view is shown in FIG. 2A, and the lenses 16a and 16b when the shooting angle of view is the second angle of view. The arrangement of is shown in FIG. Hereinafter, the state of the ophthalmologic photographing apparatus 1 when the photographing angle of view is the first angle of view is referred to as a narrow angle photographing mode, and the state of the ophthalmic photographing apparatus 1 when the angle of view is the second angle of view is referred to as a wide angle photographing mode. .

  As shown in FIGS. 2A and 2B, in the present embodiment, control described later is performed so that the position of the turning point with respect to the ophthalmologic photographing apparatus 1 is maintained even when the laser light irradiation range is changed. Each lens of the objective lens optical system 16 is arranged by the unit 90. In this embodiment, as an example, the first convex lens 16a and the second convex lens 16b are displaced in the same direction along the optical axis L3, so that the first field angle and the second field angle are mutually different. The case where it changes is shown (refer Fig.2 (a), FIG.2 (b)).

  For example, in the present embodiment, when the shooting angle of view is increased from the first angle of view to the second angle of view, each of the two convex lenses 16a and 16b is brought closer to the eye E side along the optical axis L3 (FIG. 2). (A) → FIG. 2 (b)). In the present embodiment, the second convex lens 16b is moved larger than the first convex lens 16a. That is, the two convex lenses 16a and 16b are moved so that the distance between the lenses is smaller than that in the case of the first angle of view. Thereby, the incident height of the laser light incident on the convex lenses 16a and 16b becomes higher than that in the case of the first angle of view. As a result, the converging action of the two convex lenses 16a and 16b is larger than that in the case of the first angle of view, and is widened in comparison with the case of the first angle of view. In this embodiment, the first convex lens 16a is moved with a smaller displacement than the second convex lens 16b, so that the turning point can be made closer to the first convex lens 16a than in the case of the first angle of view. As a result, in this apparatus, the position of the turning point with respect to the eye to be examined is maintained before and after the shooting angle of view is switched from the first angle of view to the second angle of view.

  On the other hand, in the present embodiment, when the shooting angle of view is narrowed from the second angle of view to the first angle of view, each lens of the objective lens optical system 16 is moved in the opposite direction to the case of widening the shooting angle of view. (FIG. 2 (b) → FIG. 2 (a)). As a result, the incident height of the laser light incident on the two convex lenses 16a and 16b is made lower than in the case of the second angle of view. Thereby, the convergence effect of each convex lens 16a, 16b is reduced with respect to the second field angle, and is narrowed with respect to the second field angle. At this time, the first convex lens 16a is moved to the scanning unit 15 side with a smaller displacement than the second convex lens 16b, so that the turning point moves away from the first convex lens 16a with respect to the case of the second angle of view. As a result, in this apparatus, the position of the turning point with respect to the eye to be examined is maintained before and after the shooting angle of view is switched from the second angle of view to the first angle of view.

  As described above, in the ophthalmologic photographing apparatus 1 according to the present embodiment, the position of the turning point of the laser beam is maintained with respect to the eye to be examined in the case where the photographing angle of view is the first angle of view and the second angle of view. Is done. For this reason, it is not always necessary to redo the positional relationship between the apparatus and the eye E so that the turning point is positioned near the pupil of the eye E when the shooting angle of view is changed. That is, the ophthalmologic photographing apparatus 1 of the present embodiment can photograph fundus images having different photographing angles while keeping the positional relationship between the eye E and the apparatus constant. Therefore, the ophthalmologic photographing apparatus 1 according to the present embodiment can favorably photograph fundus images having different photographing angles.

  By the way, under the condition that the position of the turning point with respect to the eye to be examined is kept constant, the diopter of the photographing optical system 2 changes with the photographing field angle of the objective lens optical system 16. The diopter (D) corresponding to each shooting angle of view when the position of the turning point is constant is schematically shown in the graph of FIG. That is, in the graph with the vertical axis representing the diopter (D) and the horizontal axis representing the shooting angle of view, the diopter (D) corresponding to each shooting angle of view has a negative value (D) as the minimum value, Shown as a convex curve. As shown in FIG. 3, the objective lens optical system 16 including the two convex lenses 16a and 16b has the same diopter (D) at two different shooting angles. For example, the diopter by the objective lens optical system 2 is 0 (D) in each of the case where the shooting angle of view is θ1 and the case where θ2 (θ1 <θ2).

  Therefore, for example, in the ophthalmologic photographing apparatus 1, the diopter in the narrow-angle photographing mode (that is, when the photographing field angle is the first angle of view, see FIG. 2A) and the wide-angle photographing mode (that is, When the shooting angle of view is the second angle of view, the first angle of view and the second angle of view are set such that the diopter of FIG. 2B is a constant value (for example, 0 (D)). May be set. In this case, in the ophthalmologic apparatus 1, when the shooting angle of view is switched between the first angle of view and the second angle of view, the diopter of the imaging optical system 2 is maintained in addition to the position of the turning point with respect to the eye to be examined. Thus, the two convex lenses 16 a and 16 b are arranged by the lens moving mechanism 17.

  FIG. 4 shows the focal lengths of the convex lenses 16a and 16b that can maintain the diopter and the position of the turning point when the shooting field angle is switched between the first field angle of about 50 ° and the second field angle of about 110 °. The arrangement of the convex lenses 16a and 16b is shown as an example. In the example shown in FIG. 4, the focal length of the first convex lens 16a is 42.6 mm, and the focal length of the second convex lens 16b is 70.5 mm.

  When the shooting angle of view is set to the first angle of view (about 50 °), the second convex lens 16b has an eye to be examined of 115.3 mm from the scanning unit 15 (in this embodiment, an intermediate point between the resonant scanner 15a and the galvanometer mirror 15b). Located apart on the E side. In addition, the first convex lens 16a is disposed further away from the second convex lens 16b toward the eye E to be examined by 66.5 mm. As a result, the position of the turning point is 31.1 mm away from the first convex lens 16a toward the eye E to be examined. That is, the distance from the scanning unit 15 to the turning point when the shooting angle of view is 50 ° is 212.9 mm. Further, the diopter by the objective lens optical system 16 is 0 (D).

  On the other hand, when the shooting angle of view is set to the second angle of view (about 110 °), the second convex lens 16b is disposed away from the scanning unit 15 toward the subject eye E 177.1 mm. In addition, the first convex lens 16a is further arranged away from the second convex lens 16b toward the eye E to be examined by 4.8 mm. As a result, the position of the turning point is 30.9 mm away from the first convex lens 16a toward the eye E to be examined. That is, the distance from the scanning unit 15 to the turning point when the shooting angle of view is 110 ° is 212.8 mm. As described above, in the example of FIG. 4, from the scanning unit 15 to the turning point when the shooting angle of view is the first angle of view (about 50 °) and when the angle of view is the second angle of view (about 110 °). Are substantially the same distance. Further, when the convex lenses 16a and 16b are arranged as described above so that the shooting field angle becomes the second field angle (about 110 °), the diopter of the objective lens optical system 16 becomes 0 (D). Therefore, in the example of FIG. 4, the diopter of the photographic optical system 2 is maintained between the first field angle (about 50 °) and the second field angle (about 110 °). Is done. It should be noted that the diopter maintained when the shooting angle of view is changed is not necessarily 0 (D). For example, each parameter of FIG. 4 can be set so that the diopter at the first angle of view and the second angle of view is −2D. Further, the focal lengths and specific positions of the lenses 16a and 16b are not limited to those illustrated in FIG. The focal lengths and specific positions of the lenses 16a and 16b can be determined as appropriate according to the required shooting angle of view.

  As described above, if the diopter of the photographing optical system 2 is maintained in addition to the position of the turning point with respect to the eye to be examined before and after the photographing field angle is switched between the first field angle and the second field angle. There is no need to adjust the diopter after switching the angle of view. Therefore, fundus images having different shooting angles can be taken even better.

  Note that the diopter of the photographing optical system 2 may not be maintained when the photographing field angle is switched between the first field angle and the second field angle. In this case, the apparatus may use a diopter correction mechanism provided in the photographing optical system 2, for example. More specifically, the change in the diopter due to the switching of the shooting angle of view between the first angle of view and the second angle of view is on the common optical path of the light projecting optical system 3 and the light receiving optical system 4. Correction may be made by displacing at least one lens (eg, lens 13). When correcting the change in diopter by displacing the lens 13, the lens 13 and the drive mechanism 13a function as a diopter correction mechanism.

  In the present embodiment, the lens movement mechanism 17 moves the respective lenses of the objective lens optical system 16 to switch the shooting angle of view in the shooting optical system 2, but the present invention is not necessarily limited thereto. For example, in the ophthalmologic photographing apparatus 1, a plurality of objective lens optical systems that set different photographing angles of view in the photographing optical system 2 and an image in which one of the plurality of optical systems is alternatively arranged on the optical path of the laser light. And a corner switching mechanism. However, by switching a plurality of objective lens systems in front of the eye E to be examined, a lens (in this embodiment) included in one optical system, as in this embodiment, rather than a device that switches the shooting angle of view. The device that moves the position of each lens of the objective lens optical system 16 is easier to configure in a compact manner.

  Next, the light receiving optical system 4 will be described. The light receiving optical system 4 receives light from the fundus oculi Er associated with the laser light from the light projecting optical system 3 (that is, fundus reflected light during normal photographing and fluorescence generated in the fundus Er during fluorescent photographing). In the light receiving optical system 4 of the present embodiment, each member arranged from the perforated mirror 12 to the objective lens optical system 16 on the optical path L1 of the light projecting optical system 3 is shared with the light projecting optical system 3. . The light receiving optical system 4 of the present embodiment includes a lens 22, a pinhole plate 23, a lens 24, and a light receiving element 25.

  When laser light is irradiated on the fundus of the eye E, the light reflected or emitted from the fundus Er based on the laser light travels backward through the light projecting optical system 3 and is reflected by the perforated mirror 12. Guided to the lens 22. Note that the pupil position of the eye E and the opening of the perforated mirror 12 have an optically conjugate relationship. On the downstream side of the lens 22, the light from the fundus Er is focused at the pinhole of the pinhole plate 23 and received by the light receiving element 25 through the lens 24. In the present embodiment, an APD (avalanche photodiode) having sensitivity in the visible region and the infrared region is used as the light receiving element 25.

  The rotating plate unit 30 selects the wavelength of light received by the light receiving element 25. The rotating plate unit 30 includes a rotating plate 31, a pulse motor 32, and a sensor 33.

  The rotating plate 31 has a plurality of types of barrier filters for observing fluorescence generated in the fundus Er. The rotating plate 31 is placed so that the plate surface is orthogonal to the optical axis L2. Further, the optical axis L2 of the light receiving optical system 4 passes through a part of the rotating plate away from the rotating shaft. The rotating plate 31 is rotated by a pulse motor 32. Here, as shown in FIG. 5, the rotary plate 31 is provided with a filter 31b, a filter 32c, and an opening 31d. The filter 31b, the filter 32c, and the opening 31d are all disposed on a locus through which the imaging region Lz of the light receiving optical system 4 passes when the rotating plate 31 is rotated. For this reason, any one of the filter 31b, the filter 32c, and the opening 31d is set in the imaging region Lz of the imaging region Lz of the light receiving optical system 4 as the rotating plate 31 rotates. Note that the type of filter to be set in the rotating plate 31 is adjusted based on the rotation angle detected by the sensor 33.

The filter 31b is a barrier filter for infrared fluorescence photography. The filter 31b has the spectral characteristics shown in FIG. The filter 31b can be used for, for example, ICG (indocyanine-green-fundus-angiography) imaging, which is one of infrared fluorescence imaging. ICG imaging is fluorescence imaging using indocyanine green as a fluorescent fundus contrast medium. In the ophthalmologic photographing apparatus 1 of the present embodiment, photographing is performed by irradiating the first light (near wavelength 790 nm) from the laser light emitting unit 11. ICG imaging is mainly used for observation of choroidal blood vessels.

The filter 31c is a barrier filter for visible fluorescence photography. The filter 31c has the spectral characteristics shown in FIG. The filter 31c can be used for, for example, FAF (fundus-auto-fluorescence) imaging performed by irradiating the fundus with a laser beam having a second wavelength (visible laser beam). Note that the autofluorescence imaging exemplified here utilizes the principle that the lipofuscin of the retinal pigment epithelium exhibits autofluorescence (wavelength near 500 nm to wavelength 750 nm) when irradiated with the second light (wavelength near 490 nm). In addition, by providing a light source and a filter in accordance with the fluorescence characteristics of the fluorescent substance to be emitted, the fundus can be photographed by exciting the fluorescent substances other than those exemplified above.

  The opening 31d is placed on the imaging region Lz, for example, when aligning the eye E with the apparatus and during normal fundus observation. At this time, the opening 31 d transmits all the light from the fundus Er and guides it to the light receiving element 25. In the present embodiment, the size of the opening 31d is designed to substantially match the size of the imaging region Lz of the light receiving optical system 4.

  FIG. 7 is a block diagram showing a control system of the ophthalmologic photographing apparatus 1 in the present embodiment. Main control of the ophthalmologic photographing apparatus 1 is performed by the control unit 90. The control unit 90 is a processing device having an electronic circuit that performs control processing of each unit of the ophthalmologic photographing apparatus 1 and calculation processing of measurement results.

  In the present embodiment, the control unit 90 includes an HDD (hard disk) 95, an image processing IC 96, a laser beam emitting unit 11, a driving mechanism 13a, a resonant scanner driving motor 15c, a galvano mirror driving motor 15d, a lens moving mechanism 17, and a light receiving unit. It is connected to the element 25, the pulse motor 32, the drive mechanism 50, the operation unit 60, the monitor 70, and the like.

  The control unit 90 includes a CPU 91, a ROM 92, and a RAM 93. The CPU 91 is a processing device for executing various processes related to the ophthalmologic photographing apparatus 1. The ROM 92 is a nonvolatile storage device that stores a control program, fixed data, and the like. The RAM 93 is a rewritable volatile storage device. The RAM 93 stores, for example, temporary data used for photographing and measuring the eye E by the ophthalmologic photographing apparatus 1.

  The HDD 95 is a rewritable nonvolatile storage device. The HDD 95 stores at least a program for causing the control unit 90 to execute a shooting display process described later. Further, the HDD 95 stores a fundus image (fundus photographed image) photographed by the ophthalmologic photographing apparatus 1.

  The image processing IC 96 is a processing device that generates image data of a fundus image photographed using the photographing optical system 2 based on a light reception signal from the light receiving element 25. Here, when the fundus Er is scanned two-dimensionally with laser light as the scanning unit 15 is driven, the light receiving element 25 sequentially receives fundus reflected light corresponding to the scanning position of the laser light on the fundus Er. As a result, the light reception signal from the light receiving element 25 is sequentially output to the image processing IC 96. In the image processing IC 96 of this embodiment, the received light reception signal is converted into image data and stored in a buffer (not shown). Therefore, when a light reception signal for one frame (one fundus image) is input to the image processing IC 96, the image data for one frame is stored in the buffer of the image processing IC 96.

  The operation unit 60 is provided with an input device such as a switch operated by an examiner. In the present embodiment, a joystick 60a, a shooting switch 60b, a shooting field angle switch 60c, and various switches such as a shooting mode switch 60d are prepared.

  The joystick 60a is an input device that is operated by the examiner to designate the imaging range of the fundus oculi Er. The control unit 90 drives the drive mechanism 50 according to the operation of the joystick 60a to move the ophthalmologic photographing apparatus 1 with respect to the eye E. Note that the position adjustment of the photographing optical system 2 is not limited to the case where the control unit 90 is controlled by the drive control of the drive mechanism 50. For example, it may be configured to include a drive mechanism for the examiner to manually move the position of the photographing optical system 2 and adjust the position of the photographing optical system 2.

  The imaging switch 60b is a switch operated to capture (capture) a fundus image.

  The shooting field angle switch 60 c is a switch operated to switch the shooting field angle (shooting range) of the shooting optical system 2. In the present embodiment, the size of the shooting range is selected by the examiner from at least two types of ranges (first view angle and second view angle) through the shooting view angle changeover switch 60c. The control unit 90 arranges each lens included in the objective lens optical system 16 in accordance with an operation on the photographing field angle switch 60c. In the present embodiment, when the first angle of view is selected, the control unit 90 drives the lens moving mechanism 17 so that each lens of the objective lens optical system 16 is set in the arrangement shown in FIG. To do. On the other hand, when the second angle of view is selected, the control unit 90 drives the lens moving mechanism 17 so that the lenses of the objective lens optical system 16 are set in the arrangement shown in FIG. . Accordingly, in the present embodiment, each lens 16a to 16a of the objective lens optical system 16 is maintained so that the position of the turning point is maintained in the case where the shooting field angle is the first field angle and the second field angle. 16c is arranged.

  The mode changeover switch 60d is a switch for switching the photographing mode of the ophthalmologic photographing apparatus 1 executed by the control unit 90 among the manual photographing mode, the FAF photographing mode, and the IGC photographing mode. Although details will be described later, the manual mode is a mode for observing the fundus with infrared fundus reflected light. The FAF imaging mode is a mode for observing spontaneous fluorescence emitted from the fundus Er. The IGC imaging mode is a mode for observing fluorescence from a fluorescent contrast agent administered to the fundus Er. When the mode changeover switch 60d is operated, the wavelength of the light output from the laser light emitting unit 11 and the barrier filter set in the pass region of the optical axis are switched according to the newly set photographing mode.

  The monitor 70 is a display device having a display for displaying an image of the eye E to be examined taken by the ophthalmologic photographing apparatus 1 and various measurement results.

  Next, the operation of the ophthalmologic photographing apparatus 1 having the above configuration will be described.

  First, the examiner operates the mode changeover switch 60d to select the manual photographing mode. Accordingly, the control unit 90 drives the pulse motor 32 to adjust the rotation angle of the rotating plate 31 so that the opening 31d of the rotating plate 31 is positioned on the optical axis L2. In addition, when the manual photographing mode is selected, the control unit 90 sets the lighting state in which the laser light emitting unit 11 emits the first wavelength laser light (infrared light). Thereby, the examiner can perform the alignment of the photographing optical system 1 performed thereafter while viewing the image photographed by the fundus reflection light. The image captured by the fundus reflection light is easier to grasp the captured state than the image captured by the fluorescence, so that the position is easily adjusted by the examiner.

  Next, the examiner performs alignment of the photographing optical system 2 and photographs a photographed image using the ophthalmologic photographing apparatus 1. Although illustration is omitted, in this embodiment, it is assumed that the scanning unit 15 is continuously driven by the control unit 90 until at least the alignment process is performed and the captured image is captured. That is, the fundus Er is continuously scanned by the laser beam according to a predetermined procedure.

  Next, the examiner observes a live image (fundus observation image) photographed using fundus reflected light, and causes the apparatus to acquire the photographed image. The operation of the ophthalmologic photographing apparatus 1 at this time will be described with reference to the flowchart of FIG. The live image here is displayed not only in the fundus image displayed simultaneously with the shooting timing (that is, in real time), but also after a slight lag (for example, several milliseconds or seconds) from the shooting timing. The fundus image is included.

  In the ophthalmologic photographing apparatus 1 of the present embodiment, photographing and display of the fundus image is performed by photographing display processing. In the photographing display process, first, the processes of S11 and S12 are executed by the CPU 91. As a result, the fundus image captured by the ophthalmologic photographing apparatus 1 is displayed in the display area D of the monitor 70.

  In the process of S11, the CPU 91 acquires image data of a fundus image for one frame from the image processing IC 96 (S11). For example, in this embodiment, the image data is acquired by transferring the image data stored in the buffer of the image processing IC 96 to the RAM 93. This process is on standby until image data for one frame is accumulated in the buffer of the image processing IC 96.

  Next, the CPU 91 executes a first display control process (S12). In the first display control process (S12), the CPU 96 displays the fundus image for one frame newly acquired by the ophthalmologic photographing apparatus 1 in the first display area D1 (see FIG. 9). As will be described later, this processing is repeatedly executed until the photographing of the fundus photographed image is completed. As a result, live images (observation images) composed of continuous fundus images are sequentially displayed in the first display area D1 by the first display control process (S12). Therefore, the examiner can align the photographing optical system 2 so that a desired photographed image can be obtained by operating the joystick 60a while confirming the display content of the first display area D1. In the present embodiment, the movement process (drive control of the drive mechanism 50) of the photographing optical system 2 performed in accordance with the operation of the joystick 60a is a process performed in parallel with the photographing display process in the control unit 90. Alternatively, it may be a process (not shown) that is appropriately executed by the control unit 90 during the standby time when acquiring image data from the image processing IC 96.

  Note that there may be a case where the number of pixels of the fundus image (so-called number of image pixels) acquired by the processing of S11 is larger than the number of pixels of the first display region D1 on the monitor 70 (so-called number of device pixels). In this case, in the first display process (S12), for example, the CPU 91 may perform a process of compressing (reducing) the fundus image according to the number of pixels of the first display area D1.

  Next, the CPU 91 performs processing for displaying a part (partial image) of the fundus image displayed in the first display area D1 in an area different from the first display area D1 (S13 to S17).

  First, the CPU 91 determines whether or not an operation for setting the attention range C has been accepted (S13). The attention range C is a range in which image processing is performed in the fundus image displayed in the first display region D1 (or in the region of the fundus Er indicated by the fundus image). The operation for setting the attention range C may be performed by the examiner specifying a position on the fundus image where the attention range C is desired to be set using, for example, a pointing device such as a mouse. In the present embodiment, the setting of the attention range C includes not only providing the attention range C, but also moving the setting position of the attention range C or changing the vertical and horizontal sizes.

  In the present embodiment, it is determined that the setting operation for the attention range C is not accepted by the process of S13 until the setting operation for the attention range C is performed by the examiner for the first time (S13: No). In this case, the CPU 91 executes the process of S15 without setting the attention range C.

  On the other hand, in the process of S13, when it is determined that an operation for setting the attention range C has been received (S13: Yes), the CPU 91 sets the attention range C in the range designated by the examiner through the setting operation (S14). . For example, in the present embodiment, the CPU 91 stores position information indicating the position occupied by the attention range C with respect to the photographing range of the fundus image in the RAM 93. Next, the CPU 91 executes the process of S15.

  As described above, in the present embodiment, the attention range C is described as being provided when there is an instruction from the examiner, but is not necessarily limited thereto. For example, the attention range C may be set to a predetermined range of the fundus image by the CPU 91 regardless of an instruction from the examiner. In the present embodiment, not only whether or not the attention range C is provided, but also the position, size, and the like of the attention range C will be described as being set by the CPU 91 in accordance with an instruction from the examiner. It is not limited to this configuration. For example, the apparatus may be configured such that the attention range C is always set at a certain position (for example, the center region of the fundus image) with respect to the fundus image.

  In the process of S15, the CPU 91 determines whether or not the attention range C is provided (S15). As described above, the attention range C is already provided when the setting operation of the attention range C is performed at least once. In this case, the CPU 91 executes the process of S16 (S15: Yes).

  In the process of S16, the CPU 91 acquires image data of the partial image (S16). In the present embodiment, the image data of the partial image is generated and acquired by the CPU 91 extracting data indicating the range of interest from the image data indicating the entire fundus image. In the present embodiment, the CPU 91 can extract the image data of the partial image from the image data indicating the entire fundus image based on the position information of the attention range C acquired in advance in the process of S14.

  Next, the CPU 91 executes a second display control process (S17). In the second display control process (S17), the CPU 91 displays the partial image from which the image data has been acquired in the process of S16 in the second display area D2 (see FIG. 9). Similar to the first display control process (S12), this process is repeatedly executed until the photographing of the fundus photographed image is completed. Therefore, a second live image composed of continuous partial images is displayed in the second display area D2 by the second display control process (S17).

  In the present embodiment, the second live image is described as being displayed in synchronization with the first live image, but the present invention is not necessarily limited thereto. For example, the display mode may be such that one of the first live image and the second live image is continuously displayed and the other is switched between display and non-display at intervals of several seconds. Further, the first live image and the second live image may be displayed alternately.

  Further, in the second display control process (S17) of the present embodiment, the CPU 91 displays a second live image enlarged from the attention range C on the first live image. For example, in the present embodiment, the second live image is displayed in the second display area D2 having the same size as the first display area D1 where the fundus image is displayed (see FIG. 9). Thereby, the examiner can observe the attention range C more easily using the second live image.

  Further, as described above, the number of pixels of the fundus image (number of image pixels) acquired by the device is larger than the number of pixels (number of device pixels) of the first display region D1, and the fundus image acquired by the device. A case where the compressed image of the image is displayed as the first live image is conceivable. In such a case, in the second display control process (S17), the second live image may be displayed with a higher resolution than the first live image. Note that the resolution in the present embodiment has a correlation with the resolution of the fundus tissue in the image. In this case, the attention range C in the fundus image is displayed in more detail in the second display area D2 than in the first display area D1. Therefore, the examiner can perform detailed observation of the attention range C satisfactorily.

  Next, the CPU 91 executes a discrimination display process (S18). By executing the process of S18, when the second live image is displayed in the second display area D2, the distinction display between the attention range C and other areas is performed on the first live image. The discrimination display may be a display that helps the examiner discriminate between the attention range C and other regions. In the present embodiment, as an example of the discrimination display, the attention range C is surrounded by a line on the first display area D1 (on the first live image) (see FIG. 9). Other examples of the discrimination display include a mode in which the attention area C is darker or thinner than the surrounding area, or the attention area C is shaded.

  Next, the CPU 91 determines whether or not a photographing operation for a photographed image (in this embodiment, an operation of the photographing switch 60b) has been received (S19). If the photographing operation has not been accepted (S19: No), the CPU 91 repeatedly executes the processes from S11 to S19. On the other hand, when the photographing operation from the examiner is accepted by the process of S19 (S19: Yes), the photographing process of S20 is executed. Through the photographing process (S20), the CPU 91 acquires a fundus photographed image. For example, the CPU 91 may newly acquire a fundus image from the image processing IC 96 and store the acquired fundus image as a fundus photographic image in the HDD 95 or the like. Note that the fundus image acquired from the image processing IC may be a plurality of images, and an addition average image of a plurality of fundus images captured continuously may be used as a fundus image. In the present embodiment, after the shooting process (S20), the shooting display process ends.

  Here, it returns to the process of S15 and continues description. If the setting operation for the attention range C has never been performed, the CPU 91 determines in step S15 that the attention range C is not set. In this case, the CPU 91 skips the processes from S16 to S18 and performs the processes after S19. Therefore, the second live image is not displayed in the display area D until the setting operation for the attention range C is performed by the examiner.

  In the above description, a case where a captured image captured using fundus reflection light is acquired has been described. However, a captured image captured using fluorescence from the fundus can also be acquired. For example, the examiner switches the photographing mode change-over switch 60d when the photographing optical system 2 is aligned while viewing the observation images (first live image and second live image) photographed using fundus reflected light. To switch the shooting mode to a mode (FAF shooting mode, IGG shooting mode) for shooting using fluorescence from the fundus, and then operate the shooting switch 60b.

  As described above, according to the ophthalmologic photographing apparatus 1 of the present embodiment, the first live image including a plurality of continuous fundus images is displayed on the monitor 70 by the first display control process (S12) that is sequentially executed. The Thereby, for example, the checker's confirmation omission for a characteristic part (for example, a nipple, a macula, a lesioned part, a blood vessel, etc.) existing in the photographing range of the fundus image is suppressed. Further, according to the ophthalmologic photographing apparatus 1 of the present embodiment, when the setting operation of the attention range C for the fundus image is performed in advance by the examiner, the second display control process (S17) performs attention from the fundus image. A partial image extracted as a range is generated, and a second live image including a plurality of continuous partial images is also displayed on the monitor 70. As a result, the examiner can easily perform detailed observation of the characteristic part existing in a part of the fundus image displayed as the second live image (the attention range C in the present embodiment). Therefore, in the ophthalmologic apparatus 1, it is easy for the examiner to observe in detail the photographing range of the fundus image using the live image of the fundus image without omission.

  Further, for example, when the position of the turning point of the laser beam is deviated from the pupil position of the eye E, a part of the light from the apparatus may be blocked by the iris (vignetting). In this case, the outer edge of the fundus image may be affected by vignetting light. This may be impossible for the examiner to confirm when only the second live image consisting of a part of the fundus image is displayed. Therefore, if only the second live image is confirmed and a captured image of the entire fundus image is acquired, a fundus image in which it is difficult to observe the outer edge portion or the like may be obtained. On the other hand, in the ophthalmologic apparatus 1 of the present embodiment, the first live image composed of the fundus image is displayed together with the second live image, so whether or not the outer edge of the fundus image is affected by the vignetting light. The examiner can easily confirm. For this reason, the examiner can cause the apparatus to acquire a captured image while confirming the first and second live images and aligning the photographic optical system 2 so that a desired captured image can be obtained. . Therefore, the ophthalmologic apparatus 1 according to the present embodiment can capture a good fundus image.

  Further, in the ophthalmologic photographing apparatus 1 of the present embodiment, the attention range C of the fundus image from which the partial image is extracted is set based on an instruction from the examiner (S14). A range desired by the examiner in the fundus image can be displayed as the second live image. As a result, it is easier for the examiner to observe the fundus.

  In the ophthalmologic photographing apparatus 1 of the present embodiment, when the second live image is displayed in the second display area D2, the attention range C and other areas are displayed on the first live image in the first display area D1. Is displayed (S18). Thereby, the examiner can easily understand the correspondence between the fundus image and the partial image.

  In the first embodiment, the case where the attention range C is set at a fixed position with respect to the display range (or imaging range) of the fundus image has been described. For example, in the ophthalmologic photographing apparatus 1 according to the first embodiment, the position of the attention range C on the first display region D1 does not change before and after the photographing range of the optical system on the fundus Er is changed by the alignment operation. . However, the attention range C may not be set at a fixed position with respect to the display range of the fundus image. For example, the attention range C may be set at a certain position of the fundus Er indicated by the fundus image. In this case, for example, when the imaging range on the fundus Er is moved by the fixation eye movement of the eye E, the attention range C on the first display area D1 tracks a certain position on the fundus Er. As an example, the following modification of the first embodiment will be described. In this modification, the CPU 91 may perform the attention area C setting process (S14) by acquiring a template image from a part of the fundus image. As the template image, an image extracted from a fundus image acquired in advance by the apparatus is used.

  In addition, the CPU 91 specifies an image region having a high correlation with the template image from the fundus image displayed in the first display region D1 at each timing. Thereby, the movement of the image area extracted as the second display area D2 is detected. The CPU 91 may correct a region extracted as a partial image from the fundus image according to the detection result, and perform the second display control process (S17) on the corrected region. Thereby, even if the imaging range in the fundus oculi Er is moved by fixation eye movement of the eye E, a certain part included in the template image is displayed in the second image region D2.

  Next, a second embodiment of the present invention will be described with reference to FIGS. As described above, the ophthalmologic photographing apparatus 1 according to the first embodiment displays a plurality of continuous live images in the first display area D1 of the monitor 70. The ophthalmologic photographing apparatus 1 displays a second live image that is a partial image of the fundus image displayed in the first display area D1 in the second display area D2 of the monitor 70.

  On the other hand, the ophthalmologic photographing apparatus 100 according to the second embodiment acquires a first fundus image and a second fundus image having different image resolutions, and monitors a composite image of the first fundus image and the second fundus image. 70 is displayed. In the present embodiment, the first fundus image is a fundus image captured with the shooting field angle of the shooting optical system 2 set to the second field angle (that is, in the wide-angle shooting mode), and the second fundus image is It is the partial image image | photographed regarding a part of 1st fundus image by setting the imaging field angle of the imaging optical system 2 to the first field angle (in the narrow-angle imaging mode). In the present embodiment, the second fundus image has a higher resolution because the shooting angle of view is narrower than that of the first fundus image. In the following description, the observation image and the captured image of the first fundus image are referred to as an observation image (wide) and the captured image (wide), respectively, and the observation image and the captured image of the second fundus image are respectively observed. It shall be described as an image (narrow) and a photographed image (narrow).

  The ophthalmologic photographing apparatus 100 according to the second embodiment has the same optical system as that of the ophthalmic photographing apparatus 1 according to the first embodiment. The ophthalmologic photographing apparatus 100 is assumed to have approximately the same control system as the control system of the ophthalmic photographing apparatus 1 of the first embodiment. However, the ophthalmologic photographing apparatus 100 is at least different from the ophthalmic photographing apparatus 1 of the first embodiment in the control program that defines the processing executed when photographing the fundus image.

  Hereinafter, the operation of the ophthalmologic photographing apparatus 100 when photographing a fundus image will be described with reference to the flowcharts of FIGS.

  First, the CPU 91 determines whether the shooting field angle (shooting magnification) of the shooting optical system 2 is the first field angle or a second field angle wider than the first field angle (S21). For example, in the present embodiment, the CPU 91 performs the determination based on a shooting angle of view (shooting magnification) that is set in advance according to the operation of the shooting angle of view switch 60c.

  When it is determined that the shooting angle of view is the second angle of view (S21: second angle of view), processing in the wide-angle shooting mode after S22 is executed. By the process of S22, the CPU 91 determines whether or not a photographing operation has been accepted (S22). When the CPU 91 determines that a shooting operation has been accepted (S22: Yes), the CPU 91 acquires image data for one frame from the image processing IC 96 (S23). Thereby, image data of a fundus image having a wide angle of view (second angle of view in the present embodiment) is acquired. This image data is displayed on the monitor 70 as a captured image (wide) by subsequent processing. In the present embodiment, the image data of the captured image (wide) acquired by the process of S23 is temporarily stored in the RAM 93 until a new captured image (wide) is captured. Note that the CPU 91 can also store the image data of the captured image acquired by the process of S23 in a nonvolatile storage device (for example, the HDD 95). After the process of S23, the CPU 91 executes a first display control process (S25).

  On the other hand, when it is determined by the CPU 91 that the photographing operation is not accepted (S21: No), image data for one frame is acquired from the image processing IC 96 (S24). This image data is displayed on the monitor 70 as an observation image (wide) by subsequent processing (S24). In the present embodiment, the image data of the observation image (wide) acquired by the process of S24 is temporarily stored in the RAM 93 until a new image of the observation image (wide) is taken. After the process of S23, the CPU 91 executes a first display control process (S25).

  In the wide-angle shooting mode, display control of the monitor 70 is performed by the first display control process (S25). In the first display control process (S25), the CPU 91 controls the display on the monitor 70 using the image data acquired in the process of S23 or S24 (S25). Here, the first display control process (S25) in the wide-angle shooting mode will be described with reference to FIG. In the first display control process (S25), first, the CPU 91 determines whether or not to display a captured image (wide) (S31). In the present embodiment, if the captured image (wide) is acquired in advance by the process of S23, the CPU 91 determines that the captured image (wide) is displayed (S31: Yes). On the other hand, if the captured image (wide) is not acquired in advance, the CPU 91 determines that the captured image (wide) is not displayed (S31: No). If it is determined by the process of S31 that the captured image (wide) is not displayed (S31: No), the display process of the monitor 70 is performed using the image data of the observation image (wide) acquired by the process of S24 immediately before. Is done. That is, in this case, a live image composed of an observation image (wide) is displayed. Here, in the present embodiment, it is determined in advance whether or not a captured image (narrow) has been captured (acquired) in the narrow-angle capturing mode (S32).

  If the captured image (narrow) has not been acquired in advance (S32: No), the CPU 91 displays the observation image (wide) in the display area D of the monitor 70 (S33).

  On the other hand, if the captured image (narrow) is acquired in advance (S32: Yes), the CPU 91 performs alignment between the observed image (wide) and the captured image (narrow) (S34). In this embodiment, the alignment (matching process) between the first fundus image (observation image (wide) or captured image (wide)) and the second fundus image (observation image (narrow) or captured image (narrow)) is performed. For example, it can be performed using the correlation between both images (for example, pattern matching). Thereby, even if the positional relationship of the imaging range between the first fundus image and the second fundus image is not constant due to fixation fixation or the like, image processing of both images described later can be performed appropriately. On the other hand, when the second fundus image is included in a certain position of the first fundus image, the CPU 91, based on the information indicating the imaging range (that is, the attention range C) of the second fundus image in the first fundus image, Image alignment can also be performed.

  In the present embodiment, the first fundus image and the second fundus image are photographed with the same number of pixels, although the photographing angle of view is different from each other. Therefore, in this embodiment, when the first fundus image and the second fundus image are aligned, the CPU 91 adjusts the enlargement / reduction magnification of each of the first fundus image and the second fundus image. For example, in the present embodiment, the second fundus image is aligned with respect to the enlarged image of the first fundus image in which the range of interest C in the first fundus image matches the size of the second fundus image. Note that the enlargement / reduction magnification of each of the first fundus image and the second fundus image is, for example, the shooting field angle (or shooting magnification) of the first fundus image and the shooting field angle (or shooting magnification) of the second fundus image. ).

  After completion of the alignment process of S34, the CPU 91 executes a composite image display process (S35). In the composite image display process (S35), the CPU 91 causes the monitor 70 to display a composite image obtained by combining the first fundus image and the second fundus image that have been aligned in advance by image processing. In the present embodiment, the CPU 91 displays a composite image of the enlarged image of the first fundus image and the second fundus image used for positioning on the monitor 70. Various image processing techniques can be used as the image processing for combining the first fundus image and the second fundus image. For example, a method of synthesizing by adding the first fundus image and the second fundus image can be used. Further, it is possible to use a method of replacing the attention range C of the first fundus image with the second fundus image.

  Returning to the processing of S31, description will be made. In the present embodiment, even when it is determined to display the captured image (wide) (S31: Yes), it is determined whether the captured image (narrow) is acquired in advance (S36). If the captured image (narrow) is not acquired in advance (S36: No), the captured image (wide) stored in the RAM 93 is displayed on the display area D of the monitor 70 by the CPU 91 (S38). On the other hand, if the captured image (narrow) has been acquired in advance (S31: Yes), the CPU 91 aligns the captured image (wide) and the captured image (narrow) (S38), and the captured image (wide). And a composite image of the captured image (narrow) is displayed in the display area D (S35). As described above, in this embodiment, when a captured image (wide) is stored in the RAM 93 in advance, the captured image (wide) in the RAM 93 is used as the first image portion of the composite image. As described above, in the present embodiment, when the captured image of the first fundus image is acquired in advance using the imaging optical system 2, the captured image is continuously displayed in the first fundus image portion of the composite image. The

  Note that the composite image of the captured image (wide) and the captured image (narrow) is not only displayed on the monitor 70, but also displayed on the print medium by printing on the print medium using a printer or the like. Good.

  In the process of S26, the CPU 91 determines whether or not to end this process (S26). For example, when an instruction to end the process is received from the examiner, the process ends (S30: Yes). On the other hand, when it determines with not complete | finishing (S30: No), CPU91 repeats a process from S21.

  Returning to S21, the description will be continued. When it is determined that the shooting angle of view is the first angle of view (S21: first angle of view), the CPU 91 executes processing in the narrow angle shooting mode (S27 to S29, S40).

  First, the CPU 91 executes the processing of S27 to S29, and acquires the second fundus image (observation image (narrow) or captured image (narrow)). First, the CPU 91 determines whether a shooting operation has been accepted (S27). When the CPU 91 determines that a shooting operation has been accepted (S27: Yes), the CPU 91 acquires image data for one frame from the image processing IC 96 as image data of a shot image (narrow) (S28). The image data of the captured image (narrow) is temporarily stored in the RAM 93 until a new captured image (narrow) is captured. After the process of S28, the CPU 91 executes a second display control process (S40).

  On the other hand, when it is determined by the CPU 91 that the photographing operation is not accepted (S27: No), the image data for one frame is acquired from the image processing IC 96 as the image data of the photographed image (narrow) (S29). Thereby, image data of a fundus image having a narrow angle of view (first angle of view in the present embodiment) is acquired. The image data of the observation image (narrow) is temporarily stored in the RAM 93 until a new image of the observation image (narrow) is taken. After the process of S23, the CPU 91 executes a second display control process (S40).

  In the narrow-angle shooting mode, the display control of the monitor 70 is performed by the second display control process (S40). In the second display control process (S40), the display of the monitor 70 is controlled using the image data of the second fundus image acquired in the process of S28 or S29. In the second control process (S40) of the present embodiment, a process according to each process of the first display control process (S25) is performed. Specifically, in each step of the flowchart shown in FIG. 12, the captured image (wide) and the captured image (narrow) are replaced with each other, and the observation image (wide) and the observed image (narrow) are replaced with each other. The second control process (S40) is executed. After executing the second control process (S40), returning to FIG. 10, the CPU 91 executes the process of S26.

  As described above, according to the ophthalmologic photographing apparatus 100 of the second embodiment, one of the first fundus image (fundus image) and the second fundus image (partial image) is acquired (captured) in advance. In this case, when the CPU 91 newly acquires (photographs) the other image, the CPU 91 displays a composite image of the first fundus image and the second fundus image in the display area D of the monitor 70. Here, the composite image is a composite image obtained by image processing of the second fundus image in the image area of the first fundus image corresponding to the second fundus image (in the present embodiment, the attention range C). Since the composite image has the same shooting angle of view as the first fundus image, the examiner can observe a wide range of the fundus through the composite image. Moreover, the second fundus image is taken at a higher resolution than the first fundus image. For this reason, the examiner can observe the fundus Er in detail through the region where the second fundus image is synthesized in the synthesized image. In addition, since the second fundus image is synthesized with the image area of the first fundus image corresponding to the second fundus image, this synthesized image is easily observed by the examiner. Therefore, according to the image processing apparatus of the first aspect, the state of the fundus oculi Er can be well understood by the examiner through the composite image displayed on the monitor 70.

  Further, according to the ophthalmologic photographing apparatus 100 of the present embodiment, when a composite image is generated in the first display control process (S25) or the second display control process (S40), the first fundus image and the second fundus image. Is matched (matching). As a result, the ophthalmologic photographing apparatus 100 can obtain an appropriate composite image.

  Further, according to the ophthalmologic photographing apparatus 100 of the present embodiment, the second fundus image is an enlarged image of the first fundus image in which the attention range C in the first fundus image matches the size of the second fundus image. It is synthesized by image processing. Thereby, each part of the fundus included in the imaging range of the fundus image can be displayed on the composite image without being hidden by the second fundus image. Therefore, the examiner can observe the characteristic part in the fundus without omission through the composite image.

  Further, according to the ophthalmologic photographing apparatus 100, when an observation image of one image corresponding to the photographing field angle of the photographing optical system 2 is photographed among the first fundus image and the second fundus image, the other image is captured. If a captured image is acquired in advance, the captured image and a live image composed of one image are combined by the CPU 91 and displayed on the monitor 70. Thereby, the examiner can observe the first fundus image and the second fundus image almost in real time through the composite image.

  In the ophthalmologic photographing apparatus 100 according to the second embodiment, the first fundus image and the second fundus image forming the composite image have been described as being images captured using fluorescence from the fundus. For at least one of the first fundus image and the second fundus image, a fluorescence image captured using fluorescence from the fundus may be used.

  In the second embodiment, the case where two types of fundus images (first fundus image and second fundus image) having different angles of view are captured by switching the arrangement of the objective lens optical system 16 has been described. However, it is not limited to this. For example, by adjusting the shake angle of the scanning unit 15 (resonant scanner 15a and galvano mirror 15b in the above embodiments) of the photographing optical system 2, two types of fundus images having different angles of view can be taken. At this time, for example, the scanning speed of the scanning member when capturing the second fundus image may be slower than when capturing the first fundus image. Accordingly, when the second fundus image is captured, the number of pixels acquired by scanning the fundus Er with the unit length is larger than that when the first fundus image is captured. The same effect as the embodiment can be obtained. In the second embodiment, switching of the shooting angle of view may be performed not by switching the lens arrangement of the objective lens optical system 16 but by attaching / detaching a wide-angle lens attachment that widens the shooting angle of view of the apparatus. .

  In the second embodiment, the case where the ophthalmologic photographing apparatus 1 generates a composite image of the first fundus image and the second fundus image (partial image) has been described. However, the present invention is not necessarily limited thereto. For example, a composite image may be generated also in a general-purpose computer (for example, a personal computer). For example, an analysis program for causing the computer processor to execute the processes of S34 and S35 of the imaging display process executed by the ophthalmologic imaging apparatus 1 of the above-described embodiment may be prepared on a hard disk of a computer or the like. In this case as well, a composite image of the first fundus image and the second fundus image (partial image) can be generated as in the ophthalmologic photographing apparatus 1 of the above embodiment.

  Further, in each of the above embodiments, the common light receiving element 25 is used for capturing a fundus image using reflected light from the fundus Er and for capturing a fundus image using fluorescence generated in the fundus Er. Although the case where it uses is demonstrated, a different light receiving element 25 can also be used in each case. For example, the optical path of the light receiving optical system 4 can be branched using a half mirror or the like, a light receiving element is provided at the end of each optical path, and photographing can be performed simultaneously using each light receiving element. By arranging the light receiving elements having different light receiving characteristics for each light receiving element, it is possible to simultaneously perform photographing with a plurality of wavelengths.

  In the above embodiments, the control unit 90 is described as performing position control of each lens included in the objective lens optical system 16, but the present invention is not limited to this. For example, the turning point of the laser beam is maintained by the lens moving mechanism 17 configured to interlock the arrangement of the lenses of the objective lens optical system 16 when the shooting angle of view in the shooting optical system 2 is changed. Also good.

  In the above embodiment, the case where the objective lens optical system 16 includes two lenses (the first convex lens 16a and the second convex lens 16b) has been described. However, the objective lens optical system 16 includes three or more lenses. May be. As an example in which the objective lens optical system 16 includes three lenses, in addition to the first convex lens 16a and the second convex lens 16b described above, a lens having negative power is closer to the scanning unit 15 than the second convex lens 16b. May be provided. For example, as shown in FIG. 14, a concave lens 16c may be provided as a lens having negative power.

  In the example of FIG. 14, the concave lens 16 c is disposed with the concave surface facing the scanning unit 15 side. In the example of FIG. 14, a plano-concave lens is used as the concave lens 16c. However, the present invention is not limited to this. For example, a biconcave lens, a concave meniscus lens, an aspheric lens, a compound lens, or the like may be used. Good.

  By the concave lens 16c with the concave surface facing the scanning unit side, the laser light from the scanning unit 15 side that passes through other than the center of the concave lens 16c is refracted in a direction away from the optical axis L3 as compared with the case without the concave lens 16c. Therefore, the laser beam can be set to a required height at a position close to the scanning unit 15 with respect to the case where there is no concave lens 16c. That is, when a constant shooting angle of view is obtained, each of the two convex lenses 16a and 16b can be arranged closer to the scanning unit 15 side than when there is no concave lens 16c. Therefore, in the example of FIG. 14, the total length of the objective lens optical system 16 can be shortened as compared with the case where there is no concave lens 16 c. Therefore, the apparatus is easily configured compactly.

  In the example of FIG. 14, when the shooting angle of view of the shooting optical system 2 is the first angle of view (see FIG. 14A) and when it is the second angle of view (see FIG. 14B), The two convex lenses 16a and 16b are displaced by the lens moving mechanism 17 similarly to the example shown in FIG. At this time, the concave lens 16c may be displaced together with the two convex lenses 16a and 16b. For example, the two convex lenses 16a and 16b are used so that the diopter is maintained in addition to the position of the turning point with respect to the eye to be examined in the case where the photographing field angle is the first field angle and the second field angle. , And the concave lens 16 c may be arranged by the lens moving mechanism 17. As described above, when the objective lens optical system 2 includes the two convex lenses 16a and 16b, when the shooting field angle is switched between specific field angles corresponding to the design values of the two convex lenses 16a and 16b (for example, 4), the position of the turning point with respect to the eye to be examined and the diopter are not maintained before and after the switching of the shooting angle of view. On the other hand, in the example of FIG. 14, the change in diopter caused by the displacement of the two convex lenses 16a and 16b can be canceled by the displacement (movement) of the concave lens 16c. Therefore, in the example of FIG. 2, a good fundus image is easily captured even when the shooting angle of view is switched between specific angles of view. The position of the concave lens 16c can be appropriately determined based on the focal length of each of the lenses 16a to 16c, a required shooting angle of view, and the like. The concave lens 16c may be fixedly arranged on the optical axis L3.

  Further, in the configuration of the above-described embodiment, the diopter for correcting the change in the diopter by the objective lens optical system 16 according to the shooting angle of view or correcting the diopter error of the eye E with respect to the normal eye. The correction unit may be provided on a common optical path of the light projecting optical system 3 and the light receiving optical system 4 (for example, between the scanning unit 15 and the laser beam emitting unit 11). As a specific example, the diopter correction unit 18 will be described with reference to FIG. The diopter correction unit 18 performs diopter correction by adjusting the optical path length of the photographing optical system 2 between the scanning unit 15 and the laser beam emitting unit 11. The diopter correction unit 18 may include, for example, two mirrors 18a and 18b and a drive unit (not shown). The drive unit moves the two mirrors 18a and 18b in the arrow s direction while maintaining the positional relationship between the two mirrors 18a and 18b. As a result, the optical path length of the common part of the light projecting optical system 3 and the light receiving optical system 4 is changed.

  In the above embodiment, the first convex lens 16a and the second convex lens 16b are displaced in the same direction along the optical axis L3 in order to change the imaging angle of view so that the position of the turning point with respect to the eye to be examined is maintained. Explained the case. However, it is not necessarily limited to this. When switching the shooting angle of view while maintaining the position of the turning point with respect to the eye to be examined, at least the second convex lens 16b may be displaced along the optical axis L3 in a direction corresponding to enlargement or reduction of the shooting angle of view. . More specifically, when the shooting angle of view is widened, at least the second convex lens 16b may be displaced in a direction from the scanning unit 15 toward the eye E. Further, when the photographing field angle is narrowed, at least the second convex lens 16b may be displaced in a direction from the eye E toward the scanning unit 15. However, in this case, the first convex lens 16a is the same as the second convex lens 16b, depending on the design value of the objective lens optical system 16 and the required shooting angle of view (first shooting angle of view and second shooting angle of view). Not only the case of being displaced in the direction but also the case of being displaced in the direction opposite to the second convex lens 16b can be considered.

  In the above-described embodiment, the case has been described in which the photographing field angle in the photographing optical system 2 is switched between two stages of the first field angle and the second field angle wider than the first field angle. However, the photographing field angle in the photographing optical system 2 may be switched to more stages than two stages, and may be switched continuously instead of stepwise. In these cases, the technique of the above embodiment can be applied when the shooting angle of view is changed between arbitrary binary values.

  In the above embodiment, the ophthalmologic photographing apparatus 1 has been described as an SLO apparatus that two-dimensionally scans laser light on the fundus. However, the present invention is not limited to this. For example, the fundus imaging apparatus 1 may be a so-called line scan SLO. In this case, a line-shaped laser beam is scanned one-dimensionally on the fundus based on the operation of the scanning unit 15. Further, the ophthalmologic photographing apparatus 1 may be a fundus camera.

DESCRIPTION OF SYMBOLS 1,100 Ophthalmology imaging device 2 Shooting optical system 3 Light projection optical system 4 Light receiving optical system 16 Objective lens optical system 16a 1st convex lens 16b 2nd convex lens 16c Concave lens 17 Lens moving mechanism 25 Light receiving element 90 Control part 91 CPU
L3 optical axis

Claims (3)

A projection optical system that projects laser light emitted from a light source onto the fundus of the eye to be examined, and a traveling direction of the laser light for scanning the laser light projected by the projection optical system on the fundus A scanning section for changing, and a light receiving optical system for receiving the fundus reflection light of the laser light irradiated to the fundus from the light projecting optical system by a light receiving element, and photographing for photographing a fundus image of the eye to be examined by laser scanning A scanning laser ophthalmoscope equipped with an optical system,
It includes at least a first convex lens and a second convex lens located on the scanning unit side with respect to the first convex lens, and forms a turning point of the laser light on the eye side to be examined with respect to the first convex lens. An objective lens optical system that guides the laser light swiveled around the fundus to the fundus oculi.
By changing the arrangement of the first convex lens and the second convex lens, the photographing field angle in the photographing optical system can be switched between a first field angle and a second field angle wider than the first field angle. With a corner switching mechanism,
The first convex lens and the second convex lens are arranged so that the position of the turning point is maintained when the shooting field angle is the first field angle and when the second field angle is the second field angle. A scanning laser ophthalmoscope characterized by being arranged by a switching mechanism.   The angle-of-view switching mechanism displaces the first convex lens along the optical axis of the objective lens optical system, and displaces at least the second convex lens in a direction from the scanning unit toward the eye to be examined. The scanning laser ophthalmoscope according to claim 1, wherein the angle of view is changed from the first angle of view to the second angle of view.   The first convex lens and the second convex lens so that the diopter of the photographing optical system is maintained further when the photographing field angle is the first field angle and when the second field angle is the second field angle. The scanning laser ophthalmoscope according to claim 1, wherein the angle of view is arranged by the angle-of-view switching mechanism.