JP2019097944A - Ophthalmologic imaging apparatus - Google Patents

Abstract

To provide an ophthalmologic apparatus in which two or more of a plurality of optical systems can satisfactorily exhibit their functions or performance.SOLUTION: An ophthalmologic apparatus 1 includes: an OCT optical system 100; an anterior eye part imaging optical system 300 sharing an objective optical system with the OCT optical system 100; an optical path coupling unit 158 for coupling optical paths of the OCT optical system 100 and the anterior eye part imaging optical system 300; and an attachment unit 160 for switching an imaging condition of the OTC optical system 100 by changing optical power of the objective optical system and switching an optical arrangement in an independent optical path of the anterior eye part imaging optical system 300 according to the change in the optical power of the objective optical system.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to an ophthalmologic imaging apparatus.

  Various apparatuses such as an optical coherence tomography (OCT), a fundus camera, and a scanning laser ophthalmoscope (SLO apparatus) are known as an ophthalmologic imaging apparatus.

  For example, in an ophthalmologic imaging apparatus, an apparatus is known in which optical paths of a plurality of optical systems having different functions are combined while sharing an objective optical system. As an example, in Patent Document 1, the optical path of the fundus imaging optical system for obtaining a front image of the fundus, and the optical path of the anterior segment observation optical system for obtaining an anterior segment observation image are the optical paths of measurement light of the OCT optical system It is combined.

  Further, Patent Document 1 discloses a device in which a region photographed by an OCT optical system, which is one of a plurality of optical systems possessed by the device, is switched between an anterior segment and a fundus. In Patent Document 1, the lens system is inserted and withdrawn between the apparatus main body and the eye to be examined, whereby the power of the objective optical system is switched, whereby the region to be photographed is switched between the anterior segment and the fundus. .

  Further, Patent Document 2 discloses an apparatus in which the region on the fundus imaged by the SLO optical system is switched between a first angle of view and a larger second angle of view. In Patent Document 2, a lens system is inserted between an apparatus main body and an eye to be examined, and thereby the power of the objective optical system is switched to increase or decrease the imaging range.

JP, 2011-147612, A JP, 2016-123467, A

  In an apparatus in which an objective optical system is shared by a plurality of optical systems, for one of the optical systems, the power of the objective optical system is switched to enable imaging of a desired area. It also receives an optical system. As a result, it is conceivable that the function or performance of the other optical system is lost either before or after the power of the objective optical system is changed.

  The present disclosure solves at least one of the technical problems in the prior art, and in an ophthalmologic imaging apparatus in which an objective optical system is shared by a plurality of optical systems, two or more of the plurality of optical systems exhibit good function or performance. The purpose is to

  In order to solve the above-mentioned subject, this indication comprises the following composition.

  For example, the ophthalmologic apparatus according to the first aspect irradiates imaging light to an eye to be examined through an objective optical system, and the first imaging optical system captures an image of the eye based on return light of the imaging light; A second photographing optical system which shares an optical system with the first photographing optical system and photographs the subject eye with a photographing method different from the first photographing optical system, the first photographing optical system, and the second photographing optical system The optical path coupling portion for coupling the optical path with the system, and the imaging power of the first imaging optical system is switched by changing the optical power of the objective optical system, and the optical power of the objective optical system is changed. And switching means for switching an optical arrangement in an independent optical path of the second photographing optical system.

  An ophthalmologic apparatus according to a second aspect of the present disclosure has a first irradiation optical system that irradiates imaging light to an eye through an objective optical system, and captures an image of the eye based on return light of the imaging light. A second irradiation optical system which shares an optical system and the objective optical system with the photographing optical system and irradiates the second light which is any one of the measurement light, the treatment light, the stimulation light, and the second photographing light And an optical path coupling unit for coupling the optical path of the imaging light and the optical path of the second light, and changing the optical power of the objective optical system to switch the imaging condition of the imaging optical system. And switching means for switching the optical arrangement in the independent optical path of the second irradiation optical system in accordance with the change of the optical power of the objective optical system.

  According to the present disclosure, when the objective optical system is shared by the plurality of optical systems, two or more of the plurality of optical systems can exhibit the function or performance well.

"Overview"
An exemplary embodiment of the present disclosure will be described. In addition, the item classified by <> below may be used independently or in connection.

First Embodiment
The ophthalmologic apparatus according to the first embodiment at least includes a first imaging optical system, a second imaging optical system, an optical path coupling unit, and a switching unit.

  The first photographing optical system irradiates photographing light to the eye to be examined through the objective optical system, and photographs the eye to be examined based on return light of the photographing light. The imaging light may be simultaneously irradiated to the entire imaging range or may be scanned over the imaging range.

  The second photographing optical system shares the objective optical system with the first photographing optical system, and photographs the eye to be examined by a photographing method different from the first photographing optical system. The second imaging optical system may be usable as an observation optical system used to capture an observation image of the anterior segment or the fundus. The difference in photographing method includes, for example, the difference in photographing principle, the difference in wavelength of photographing light, the difference in polarization, the difference in angle of view, and the difference between the first photographing optical system and the second photographing optical system. The position of the image plane may be different, or the like.

  In the present embodiment, at least one of emission and reception of imaging light in the first imaging optical system and at least one of emission and reception of imaging light in the second imaging optical system are performed via the objective optical system. Thus, the objective optical system is shared between the first imaging optical system and the second imaging optical system.

<Optical path coupling>
The first imaging optical system and the second imaging optical system share at least a part of the objective optical system. That is, the optical path of the first imaging optical system and the optical path of the second imaging optical system are coupled by the optical path coupling portion, and at least the optical element closest to the eye to be examined in the objective optical system is disposed on the common optical path. Ru. This optical element has positive or negative power. A lens or a curved mirror is mentioned as an example of this optical element.

<Switching unit>
The switching unit changes the optical power (also simply referred to as power) of the objective optical system. By changing the optical power of the objective optical system, the imaging conditions of the first imaging optical system are switched. In changing the optical power of the objective optical system, the switching unit may switch the power of an optical element (for example, a lens) included in the objective optical system, for example, and the objective optical system includes a plurality of optical elements. In this case, the arrangement between the optical elements may be switched, or the number of optical elements (e.g., lenses) may be switched. At this time, the optical power of the entire objective optical system may be changed by changing the power of the optical element disposed between the optical path coupling portion and the eye to be examined.

  The imaging condition may be a condensing condition of imaging light. The focusing condition referred to herein is a condition regarding focusing of light beams having different light heights on the optical surface, and does not necessarily correspond to the condition regarding focusing. In detail, the focusing condition may be a condition regarding at least one of a focusing position of shooting light that has passed through the objective optical system and a condition regarding an irradiation range ((angle of view) of the shooting light. That is, in accordance with the change of the focusing condition, the position or the size of the region to be photographed in the eye to be examined is changed.

  The switching unit may switch the optical power of the objective optical system by inserting and removing the optical element. In this case, the optical power of the objective optical system may be switched by selectively arranging the first group and the second group each including one or more optical elements on the optical path of the photographing light.

  Further, at least one of the optical elements disposed on the optical path of the photographing light in the first photographing optical system is movably provided, and the angle of view in the first photographing optical system is provided by displacing the optical element. The diopter, working distance, etc. may be adjustable.

  In the present embodiment, in accordance with the change of the optical power of the objective optical system, the optical arrangement in the independent optical path of the second imaging optical system is switched by the switching unit. As a result, the imaging condition in the second imaging optical system can be appropriately set before or after the change of the optical power of the objective optical system. Therefore, the eye to be examined can be well photographed by the second photographing optical system both before and after the optical power of the objective optical system is changed.

  For example, it is possible to properly set the area on the subject's eye photographed by the second photographing optical system to a desired area both before and after the optical power of the objective optical system is changed. More specifically, a predetermined part (for example, an anterior segment) can be photographed by the second photographing optical system both before and after the optical power of the objective optical system is changed. In addition, at least one of a change in the angle of view in the second imaging optical system, a change in the focusing state, and a change in the focusing position based on a change in the optical power of the objective optical system Accordingly, correction may be made by switching the optical arrangement in the independent optical path of the second imaging optical system.

  In addition, before and after the optical power of the objective optical system is changed by the switching unit, the area photographed by the second photographing optical system is not maintained, but the area photographed by the second photographing optical system is positively As changed, the optical arrangement in the independent light path of the second imaging optical system may be switched. For example, the switching unit may switch the angle of view in the first imaging optical system and switch the imaging position in the optical axis direction in the second imaging optical system.

  Here, the second imaging optical system may be a front imaging optical system that captures a front image of the anterior segment or the fundus. The front image may be an observation image used for alignment between the optical axis of the first imaging optical system and the eye to be examined. Here, the change in the imaging condition of the second imaging optical system accompanying the change of the optical power of the objective optical system by the switching unit is corrected (for example, suppressed) by switching the optical arrangement in the independent optical path of the second imaging optical system It may be done.

  In this case, alignment and the like based on the front image can be favorably performed before and after the imaging conditions in the first imaging optical system are switched. In this case, the ophthalmologic imaging apparatus may have a control unit that performs control related to alignment. The control regarding alignment may be drive control of an actuator that changes the positional relationship between the optical axis of the first imaging optical system and the eye to be examined. In the case of the manual alignment, it may be an output of guide information for guiding an operation to the alignment target position on the monitor. In addition, control operations other than these may be performed.

  In addition, the first imaging optical system may be an OCT optical system that acquires OCT data of an eye to be examined by imaging, and the switching unit is configured to obtain a depth region in which the OCT data is acquired In order to switch between them, the power of the objective optical system may be changed, and the imaging conditions in the first imaging optical system may be changed.

  On the other hand, at this time, in the second photographing optical system, the front image of the anterior segment is properly photographed both before and after the power of the objective optical system is changed, according to the change of the power of the objective optical system. The optical arrangement in the independent optical path of the second imaging optical system may be switched.

  In addition, the switching unit changes the power of the objective optical system and the independent optical path of the second imaging optical system so that the front image in the depth region imaged by the first imaging optical system is captured by the second imaging optical system. The optical arrangement at may be switched. At this time, the switching unit converts the relation between the entrance pupil and the exit pupil and the relation between the object and the image so that they alternate with each other. The front image can be used for focus adjustment and the like in addition to the alignment described above.

  Moreover, when using a 2nd imaging | photography optical system for alignment, a 2nd imaging | photography optical system is not necessarily limited to what image | photographs the front image of an anterior ocular segment. The second imaging optical system may, for example, image a face image of the subject. Specifically, at least a part of the face including the eye is photographed as a face image.

<Coupling of the bypass optical path to the second imaging optical system>
The switching unit switches the optical power in the objective optical system to switch the imaging condition of the first imaging optical system and increases or decreases the independent optical path of the second imaging optical system, thereby the independent optical path of the second imaging optical system You may switch the optical arrangement in. Hereinafter, for the sake of convenience, the portion to be increased or decreased is referred to as a "bypass light path". Also, an optical system forming a bypass optical path is referred to as a "bypass optical system".

  The switching unit adds an optical element disposed on the independent optical path of the second imaging optical system by coupling the bypass optical path to the optical path of the second imaging optical system. One or more optical elements may be arranged in advance on the bypass optical path. In addition, the bypass optical coupler may further include a bypass coupler that couples the bypass optical path to the optical path of the second imaging optical system. The bypass coupler may be a beam splitter or the like. The bypass coupling unit may couple the bypass optical path to the optical path of the second imaging optical system or may be separated from the optical path of the second imaging optical system by inserting and removing the optical path of the second imaging optical system. it can. One bypass coupling may be provided at each of the beginning and the end of the bypass light path.

  The bypass optics may relay the object-image relationship. For example, before and after the insertion and removal of the bypass optical system, the same portion (the same portion in the direction of the optical axis) of the eye to be examined is imaged on a predetermined intermediate image plane of the second imaging optical system. At this time, erecting / inverting of the image plane may be reversed before and after insertion and removal of the bypass optical system.

<Switching by attachment unit>
The switching unit may include, for example, an attachment unit that is removable from the housing of the ophthalmologic apparatus. The attachment unit includes, for example, an optical element for changing the optical power of the objective optical system and switching imaging conditions in the first imaging optical system, and an optical element disposed on an independent optical path of the second imaging optical system. May be included. For example, the above-described bypass optical path may be formed inside the attachment unit, separated from the optical path of the imaging light from the first imaging optical system, and even if the optical element is disposed on the bypass optical path Good. In this case, the bypass optical path is coupled / separated to the optical path of the second imaging optical system in accordance with the attachment / detachment of the attachment unit.

Second Embodiment
The ophthalmologic apparatus according to the second embodiment is the ophthalmologic apparatus according to the first embodiment in which the second imaging optical system is replaced by a second irradiation optical system. That is, the ophthalmologic apparatus according to the second embodiment at least includes the first imaging optical system, the second irradiation optical system, the optical path coupling unit, and the switching unit.

  The second irradiation optical system irradiates one of the measurement light, the treatment light, the stimulation light, and the second imaging light to the eye to be examined. Here, the measurement light may be used to measure the eye characteristics, dimensions, and the like of the subject's eye. The treatment light may be, for example, a laser emitted from a laser treatment unit. As a laser treatment part, you may use what is disclosed by Unexamined-Japanese-Patent No. 2017-153751, for example. Stimulation light may be used, for example, to stimulate tissue that forms vision (eg, retinal tissue) to examine visual sensitivity. The second imaging light may be used for imaging the imaging region of the first imaging optical system by a different imaging method, and is used for imaging a region different from the imaging region of the first imaging optical system It may be done.

  The detailed configuration of the second embodiment will be omitted because the description of the first embodiment described above can be used by appropriately replacing “second imaging optical system” with “second irradiation optical system”. In the second embodiment, the region irradiated with the light by the second irradiation optical system can be appropriately set to the desired region both before and after the imaging conditions in the first imaging optical system are switched.

Third Embodiment
The ophthalmologic apparatus according to the third embodiment divides the photographing light of the photographing optical system into the first divided light and the second divided light, and transmits each of the divided lights via different optical systems to each other. Irradiate the fundus of the eye Then, based on the return light from the fundus, an image of the fundus different in imaging conditions is captured for each of the divided imaging light.

  The ophthalmologic apparatus according to the third embodiment at least includes a photographing optical system and a dividing unit. The dividing unit is provided on the light path of the photographing light of the photographing optical system. The dividing unit may be, for example, an optical element that divides a light beam, may be a half mirror, may be a prism, or may be another member. In the photographing optical system, a first divided optical system and a second divided optical system are formed in parallel, and the first divided light is transmitted to the first divided optical system, and the second divided light is transmitted to the second divided optical system. It is led to the optical system, respectively.

  Further, the fundus reflected light of the first split light and the fundus reflected light of the second split light can be distinguished optically or by signal processing after light reception by the light receiving element, and a fundus image can be individually formed.

  At least one of the first divided optical system and the second divided optical system is different from each other in angle of view, focus, optical path length, incident position of light beam on the pupil, diameter of light beam on the pupil, and the like. In addition, the ophthalmologic apparatus of the third embodiment may have an image processing unit that synthesizes the fundus oculi image passed through the first divided optical system and the fundus oculi image transmitted through the second divided optical system.

  Here, when the angle of view is different between the first divisional optical system and the second divisional optical system, it is possible to obtain fundus images having mutually different imaging ranges and resolutions. As a result of combining these, it is possible to obtain, for example, fundus images having different resolutions depending on places (for example, between the center and the periphery).

  In addition, the ophthalmologic apparatus of the third embodiment may have an image processing unit that synthesizes the fundus oculi image passed through the first divided optical system and the fundus oculi image transmitted through the second divided optical system. For example, when the angle of view is different between the first divisional optical system and the second divisional optical system, it is possible to obtain a fundus image having different resolution (for example, between the central portion and the peripheral portion) depending on the location.

  Further, when the first divided optical system and the second divided optical system are different in focus, it is possible to obtain a fundus image in which different depth positions are in focus. By combining these, it is possible to generate a composite image in which information of different regions in the depth direction is well contained.

  Further, when the incident position of the light beam on the pupil is different between the first divisional optical system and the second divisional optical system, a fundus oculi image in which at least one of the degree of artifact and the distribution is different can be obtained. Therefore, for example, a composite image with few artifacts can be generated by combining (for example, averaging) these.

  In addition, when the light beam diameter on the pupil is different between the first divisional optical system and the second divisional optical system, the fundus reflection light of the first division light and the fundus reflection light of the second division light may be used. Based on this, it is possible to obtain fundus images having different resolutions.

  In addition, when the imaging optical system is an OCT optical system, OCT data of different depth regions can be simultaneously acquired by making the optical path lengths different between the first divisional optical system and the second divisional optical system. By combining these, OCT data of a wide depth region is generated.

<Example>
Next, an embodiment will be described with reference to the drawings. The ophthalmologic apparatus according to the embodiment is an optical coherence tomography (OCT) apparatus shown in FIG. The OCT apparatus 1 according to the present embodiment basically has, for example, a spectral domain OCT (SD-OCT).

  The OCT apparatus 1 includes an interference optical system 100, an anterior eye imaging optical system 300 (an example of a second imaging optical system), an optical path coupling unit 158, and an attachment unit 160 (an example of a switching unit).

  Furthermore, the OCT apparatus 1 includes a light source 102, an interference optical system (OCT optical system) 100, and a calculation controller (calculation control unit) 70 (see FIG. 2). In addition, the memory 72, the display unit 75, and a fixation target projection system (not shown) may be provided in the OCT apparatus. The arithmetic controller (hereinafter, control unit) 70 is connected to the light source 102, the interference optical system 100, the memory 72, and the display unit 75.

  The interference optical system 100 guides the measurement light to the eye E by the light guide optical system 150. The interference optical system 100 guides the reference light to the reference optical system 110. The interference optical system 100 causes the detector (light receiving element) 120 to receive interference signal light acquired by interference between the measurement light reflected by the eye E and the reference light. The interference optical system 100 is mounted in a case (not shown) (not shown), and moves the case three-dimensionally with respect to the eye E by a known alignment moving mechanism via an operation member such as a joystick. Alignment to the subject eye may be performed by

  For the interference optical system 100, the SD-OCT method is used. As the light source 102, one emitting a light beam with a low coherent length is used, and as the detector 120, a spectral detector for separating and detecting a spectral interference signal for each wavelength component is used.

  The coupler (splitter) 104 is used as a first light splitter, and splits the light emitted from the light source 102 into a measurement light path and a reference light path. For example, the coupler 104 guides the light from the light source 102 to the optical fiber 152 on the measurement light path side, and guides the light to the reference optical system 110 on the reference light path side.

<Light guiding optical system>
The light guide optical system 150 is provided to guide the measurement light to the eye E. For example, an optical fiber 152, a collimator lens 154, a variable beam expander 155, a light scanner 156, and an objective lens system 158 (objective optical system in the present embodiment) may be sequentially provided in the light guide optical system 150. In this case, the measurement light is emitted from the emission end of the optical fiber 152 and is collimated by the collimator lens 154. Thereafter, the light beam is directed to the optical scanner 156 in a state where the desired beam diameter is obtained by the variable beam expander 155. The light passing through the light scanner 156 is irradiated to the eye E through the objective lens 159. A first pivot point P1 is formed at a position conjugate to the optical scanner 156 with respect to the objective lens system 159. When the anterior segment is positioned at the pivot point P1, the measurement light reaches the fundus without vignetting. Further, the measurement light is scanned on the fundus according to the operation of the optical scanner 156. At this time, the measurement light is scattered and reflected by the tissue of the fundus.

  The light scanner 156 may scan the measurement light in the X and Y directions (transverse direction) on the eye E. The light scanner 156 is, for example, two galvanometer mirrors, and the reflection angle thereof is arbitrarily adjusted by the drive mechanism. The light beam emitted from the light source 102 has its reflection (traveling) direction changed, and is scanned in any direction on the fundus. As the light scanner 156, for example, in addition to a reflection mirror (galvano mirror, polygon mirror, resonant scanner), an acoustooptic device (AOM) or the like for changing the traveling (deflection) direction of light may be used.

  Scattered light (reflected light) from the eye E due to the measurement light travels the path at the time of light projection, is incident on the optical fiber 152, and reaches the coupler 104. Coupler 104 directs the light from optical fiber 152 into the light path towards detector 120.

  In the present embodiment, a dichroic mirror 158 (an example of an optical path coupling unit) is disposed on the optical path of the measurement light between the optical scanner 156 and the objective lens 159. The dichroic mirror 158 is a type of beam splitter, and combines and branches an optical path of measurement light (specifically, an optical path of the light guiding optical system 150) and an optical path of the anterior eye imaging optical system 300. In the example of FIG. 1, the reflected light from the anterior segment of the second imaging light is reflected by the dichroic mirror 158, and the measurement light is transmitted through the dichroic mirror 158. The optical path of the measurement light and the optical path of the anterior eye part imaging optical system 300 are combined at least once by the dichroic mirror 158 disposed on the optical path of the measurement light of the OCT apparatus 1. As a result, at least between the dichroic mirror 158 and the lens 159, a common optical path is formed between the optical path of the measurement light and the optical path of the anterior eye imaging optical system 300. The measurement light and the second imaging light have different wavelength ranges.

Front eye imaging optical system
The anterior eye photographing optical system 300 irradiates the second photographing light to the anterior eye of the eye to be examined, and photographs the front image of the anterior eye based on the reflected light from the anterior eye of the second photographing light. The anterior segment imaging optical system 300 includes an imaging element. In addition to this, the anterior eye part imaging optical system 300 may have a member such as a light source for the second imaging light, a lens, and the like. At least light reflected by the anterior segment of the second imaging light passes (that is, is reflected) through the dichroic mirror 158 and is imaged by an imaging device (not shown) provided in the anterior segment imaging optical system 300.

  The anterior eye imaging optical system 300 may further include an anterior eye imaging light source as a light source of the second imaging light. In the present embodiment, the anterior segment imaging light source is shared with the index light source (light source 600 or light source 700 in FIG. 1) in the alignment index projection optical system. The alignment index projection optical system is used to align the optical system with the eye E. In the present embodiment, a plurality of index light sources are provided concentrically with the optical axis L at the center. The anterior segment imaging light source may be disposed independently of the index light source. The light source 600 is used as an index light source when the attachment unit described later is not mounted.

<Attachment unit>
In the OCT apparatus 1 of the embodiment, the attachment unit 160 is attached to and detached from the housing surface of the apparatus main body, and on the optical path of measurement light between the objective lens 159 and the eye to be examined based on attachment and detachment. The angle of view switching optical system 160A is inserted and removed. The attachment unit 160 is mounted on the housing surface of the apparatus main body, whereby the angle-of-view switching optical system 160A forms a part of the objective optical system.

  The attachment unit 160 includes an angle of view switching optical system 160A and a bypass optical system 160B. Further, in the present embodiment, the attachment unit 160 may have the light source 700. The optical path of the bypass optical system 160B is the bypass optical path in the present embodiment.

  The angle-of-view switching optical system 160A switches the imaging conditions in the OCT. In the present embodiment, the angle-of-view switching optical system 160 switches the shooting angle of view which is one of the shooting conditions. The imaging angle of view is a scannable range of the measurement light on the fundus.

  The field angle switching lens 164 provided in the field angle switching optical system 160A is arranged (inserted) on the measurement light path based on the attachment of the attachment unit 160, whereby the imaging field angle in OCT is increased. The angle-of-view switching lens 164 has the main power for switching the shooting angle of view. At least the lens 164 bends the measurement light having passed through the objective lens 158 through the pivot point P1 formed by the measurement light toward the optical axis L, whereby the optical scanner 156 with respect to the angle of view switching optical system 160A and the objective lens 158 The second pivot point P2 is formed at a position conjugate with the second pivot point P2. That is, the angle-of-view switching optical system 160A is an optical system that relays the turning point P1 to the turning point P2.

  As an example, in the present embodiment, the shooting angle of view (solid angle of the measurement light at the turning point P1 in FIG. 1) when the attachment unit 160 is not attached is about φ60 °, while the attachment unit 160 is attached. The shooting angle of view in the case (solid angle of measurement light at the turning point Q in FIG. 1) can be increased to φ90 ° or more.

  In addition to the angle of view switching lens 164, the angle of view switching optical system 160A includes an aberration correction lens 162 (aberration correction optical system). The aberration correction lens 162 reduces various aberrations that increase as the angle of view switching optical system 160 is attached. For example, it may be used for chromatic aberration correction in measurement light, or may be used for correction of astigmatism, curvature, and the like.

  On the optical path of the angle-of-view switching optical system 160A, bypass coupling portions 161 and 163 for coupling bypass optical paths are disposed. Each of the bypass coupling units 161 and 163 is a dichroic mirror, and in FIG. 1 has a characteristic of transmitting the measurement light and reflecting the second imaging light. The bypass coupling portions 161 and 163 are both disposed between the objective lens 161 and the angle of view switching lens 164, whereby the angle of view switching lens 164 passes not only the measurement light but also the second imaging light.

  Here, assuming that there is no bypass optical system 160B and the angle of view switching optical system 160A is a common optical path between the measurement light and the second imaging light, the imaging angle of view of the anterior eye imaging optical system 300 is The attachment of the attachment unit 160 is considered to be narrow, making it difficult to use for alignment and the like.

  On the other hand, in the present embodiment, a plurality of lenses are disposed on the bypass optical system 160B, whereby the imaging conditions for the second imaging light are set independently of the change in the imaging conditions of the OCT. Ru. In the present embodiment, the bypass optical system 160B relays the image plane located in the anterior segment to the same intermediate image plane as the attachment unit 160 in the non-mounted state.

  As an example, in the present embodiment, the bypass optical path is set so that the imaging range of the anterior segment by the anterior segment imaging optical system 300 is substantially the same between attachment and non-attachment of the attachment unit 160. The lens is arranged appropriately. As a result, when the attachment unit 160 is attached or not attached, the subject eye and the apparatus can be properly aligned based on the front image of the anterior segment.

  When the light source 700 is provided in the attachment unit 160, this may be used as an anterior ocular segment photographing light source when the attachment unit is attached. The light source 700 may be disposed on a housing surface on the eye side of the attachment unit 160. In this case, the light source 700 may be used as an alignment index light source when the attachment unit is attached. Thereby, even if the subject's eye is moved away from the apparatus main body by the attachment of the attachment unit 160, the imaging light for imaging the anterior segment can be favorably irradiated to the anterior segment.

<Reference optical system>
The reference optical system 110 generates reference light that is combined with the fundus reflection light of the measurement light. The reference light passing through the reference optical system 110 is combined with the light from the measurement light path by the coupler 148 and interferes. The reference optical system 110 may be a Michelson type or a Mach-Zehnder type.

  The reference optical system 110 shown in FIG. 1 is formed of a transmission optical system. In this case, the reference optical system 110 guides the light from the coupler 104 to the detector 120 by transmitting the light without returning it. For example, the reference optical system 110 may be formed by a reflection optical system, and the light from the coupler 104 may be guided to the detector 120 by being reflected by the reflection optical system.

  In the present embodiment, the reference optical system 110 may be provided with a plurality of reference light paths. For example, in FIG. 1, the optical path through which the reference optical path passes through the fiber 141 by the coupler 140 (the first branch optical path in the present embodiment) and the optical path through the fiber 142 (the second branch optical path in the present embodiment) It is branched. The fiber 141 and the fiber 142 are connected to the coupler 143, whereby the two branched optical paths are coupled and enter the coupler 148 via the optical path length difference adjustment unit 145.

  In the present embodiment, the reference light from the coupler 104 is guided by the coupler 143 simultaneously to the fiber 141 and the fiber 142. The light passing through any of the fiber 141 and the fiber 142 is multiplexed with the measurement light (fundus reflected light) at the coupler 148.

  The optical path length difference between the fiber 141 and the fiber 142, that is, the optical path length difference between the first branch optical path and the second branch optical path may be a fixed value. In this embodiment, there is an optical path length difference which is substantially the same as the optical path length of the angle of view switching optical system 160A.

  An optical member for adjusting an optical path length difference between the measurement light and the reference light may be disposed in at least one of the measurement optical path and the reference optical path. As an example, in the optical system shown in FIG. 1, a reference light path adjustment unit 145 is provided. Various configurations can be applied as the reference light path adjustment unit 145.

  Here, in the present embodiment, the reference optical path adjustment unit 145 is provided on the optical path between the coupler 143 and the coupler 148, that is, on the common optical path of the first branch optical path and the second branch optical path. Adjusting the optical path length difference between the measurement optical path and the reference optical path, wherein the adjustment regarding the individual difference of the axial length is collectively performed on both the first branch optical path and the second branch optical path It becomes possible.

  The adjustment range of the optical path length in the reference optical path adjustment unit 145 is the optical path length difference between the fiber 141 and the fiber 142 (in other words, the optical path length difference between the first branch optical path and the second branch optical path) It is preferable to set sufficiently short.

<Photodetector>
A detector 120 is provided to detect interference from the light from the measurement path and the light from the reference path. In the present embodiment, the detector 120 is a spectral detector, for example, includes a spectroscope and a line sensor, and the measurement light and the reference light multiplexed by the coupler 148 are dispersed by the spectroscope, Light is received by different regions (pixels) of the line sensor for each wavelength. As a result, the output for each pixel is obtained as a spectral interference signal.

  The curvature of the fundus does not necessarily coincide with the imaging plane of the measurement light, and in the insertion state of the angle-of-view switching optical system 160A, the divergence between the two increases in at least one of the central portion and the peripheral portion of the fundus. In the photodetector, it is preferable that a sufficient depth range in consideration of the deviation is secured. For example, in SD-OCT, it is preferable that a line camera with a sufficient number of pixels for a desired depth range be employed. Further, a configuration described later as <Modification> may be further adopted.

<Acquisition of depth information>
The control unit 70 processes (Fourier analysis) the spectrum signal detected by the detector 120 to obtain OCT data of the eye to be examined.

  The spectral signal (spectral data) may be rewritten as a function of the wavelength λ and transformed to the function I (k) equally spaced with respect to the wavenumber k (= 2π / λ). Alternatively, it may be obtained from the beginning as an equidistant function I (k) with respect to the wave number k (K-CLOCK technique). The arithmetic controller may obtain OCT data in the depth (Z) region by Fourier transforming a spectral signal in the wavenumber k space.

  Furthermore, information after Fourier transform may be represented as a signal including real and imaginary components in Z space. The control unit 70 may obtain OCT data by obtaining absolute values of real and imaginary components of the signal in the Z space.

  Here, the reference light passing through the first branch light path and the reference light passing through the second branch light path are simultaneously guided to the coupler 148, and each is multiplexed with the measurement light. Since a large difference in optical path length, which is approximately the same as the optical path length of the angle of view switching optical system 160, exists between the first branch optical path and the second branch optical path, the reference light via the first branch optical path Of the reference light that has passed through the second branch light path, one is likely to cause interference with the measurement light, but the other is unlikely to cause interference. Although the spectral interference signal from the detector 120 includes a component by the reference light passing through the first branch light path and a component by the reference light passing through the second branch light path, of the two types of components One according to the state of the light guide optical system 150 is obtained as a significantly stronger signal than the other. As a result, good OCT data can be obtained regardless of the state of the light guide optical system 150. That is, by having a plurality of reference optical paths having an optical path length difference corresponding to the angle of view switching optical system 160A, the OCT apparatus according to the embodiment is a variation of the optical path length difference between the measurement optical path and the reference optical path. The amount of change associated with A insertion / removal of the angle-of-view switching optical system 160 is compensated regardless of the state of the light guide optical system 150.

  In addition, it is necessary to control the reference light path adjustment unit 145 to adjust in advance the light path length difference between the measurement light path and the reference light path, which is the optical axis length of the eye E to be examined. When the adjustment range of the optical path length in the reference optical path adjustment unit 145 is sufficiently smaller than the optical path length difference between the first branch optical path and the second branch optical path, interference signals in the adjustment range of the reference optical path adjustment unit 145 The position at which the intensity peak of the light source can be uniquely identified.

  In the insertion state, the fundus reflection light of the measurement light from the periphery of the fundus becomes weak relative to the reflection light from the center of the fundus, so the zero delay position of the measurement optical path and the reference optical path is at the fundus peripheral part. The optical path length difference between the measurement optical path and the reference optical path may be adjusted by the reference optical path adjustment unit 145 so as to overlap with a desired fundus tissue (for example, the retina, choroid, sclera etc.).

<Control system>
The control unit 70 may include a CPU (processor), a RAM, a ROM, and the like (see FIG. 2). For example, the CPU of the control unit 70 may control the OCT apparatus. The RAM temporarily stores various information. The ROM of the control unit 70 may store various programs for controlling the operation of the OCT apparatus, initial values, and the like.

  The control unit 70 may be electrically connected to a non-volatile memory (hereinafter, abbreviated to a memory) 72 as a storage unit, the display unit 75, and the like. The memory 72 may use a non-transitory storage medium that can retain stored contents even when the supply of power is shut off. For example, a hard disk drive, a flash ROM, and a USB memory detachably attached to the OCT apparatus can be used as the memory 72. The memory 72 may store a control program for controlling acquisition of OCT data and imaging of an OCT image. In addition to the OCT image generated from the OCT data, the memory 72 may store various information related to imaging. The display unit 75 may display an OCT image generated from OCT data.

  Note that an insertion / removal detection unit that automatically detects whether or not the angle-of-view switching optical system 160A is inserted into the light guide optical system may be provided, and based on a detection signal from the detection unit, the control unit The control of each part in the OCT optical system 100 may be executed. For example, the switching control of the beam diameter by the variable beam expander 155, the setting control of the zero delay position by the reference light path adjustment unit 145, the change processing of the dispersion amount of the optical system between the measurement light path and the reference light, etc. It may be implemented as appropriate. In addition to this, processing such as distortion correction amount changing processing, tracking reference changing processing, optical scanner scanning range changing processing, switching processing of a fixation lamp presentation position and presentation size may be executed.

  The insertion detection unit may be a sensor disposed in the vicinity of the objective optical system 158.

  Of course, the examiner inputs information for specifying the state of the light guide optical system (insertion state / retraction state of the angle-of-view switching optical system) to the UI (user interface) of the OCT apparatus. Based on the control unit, the control of each unit in the OCT optical system 100 may be executed.

<Modification example>
<Form a plurality of reference light paths corresponding to the insertion state>
In the above description, only one reference light path corresponding to the insertion state of the angle-of-view switching optical system is set. However, the present invention is not limited to this, and a plurality of reference light paths may be set.

  Specifically, the first reference optical path having an optical path length set to obtain OCT data including the central part of the fundus, and the optical path length set to acquire OCT data including the peripheral part of the fundus The OCT optical system may be provided with a second reference light path different from the reference light path of the second optical path as a reference light path corresponding to the insertion state. When a reference light path corresponding to each state is provided for each state of the light guide optical system (here, for each of two types of states of the insertion state and the retraction state of the angle of view switching optical system), the OCT optical The system will be provided with three or more reference light paths.

  The optical path length difference between the first reference optical path and the second reference optical path may be set corresponding to the optical path length difference of the measurement light between the central portion of the fundus and the peripheral portion of the fundus. In addition, in consideration of the curvature of the eyeball, for example, the second reference light path may be set to have a shorter optical path length than the first reference light path.

  In this case, for example, the image processor may obtain OCT data including the center of the fundus based on an interference signal between the measurement light guided to the center of the fundus and the reference light from the first reference light path. OCT data including the periphery of the fundus may be obtained based on an interference signal between the measurement light guided to the periphery of the fundus and the reference light from the second reference light path. In this case, for example, the OCT data including the central part of the fundus and the OCT data including the peripheral part of the fundus may be continuous in at least one of the transverse direction and the depth direction.

  According to this, for example, by providing the reference optical path corresponding to the central part of the fundus and the reference optical path corresponding to the peripheral part of the fundus, for example, OCT data in a wide angle area can be acquired with good signal strength.

  The image processor may obtain wide-angle OCT data of the fundus of the eye to be examined by combining the OCT data including the central part of the fundus and the OCT data including the peripheral part of the fundus. This makes it possible to obtain one wide-angle OCT data.

  In this case, the light scanning unit may scan a wide-angle area including the central area of the fundus and the peripheral area of the fundus by scanning the measurement light in one scanning direction on the fundus. In this case, for example, the scan area at the center of the fundus and the scan area at the periphery of the fundus may be continuous in the transverse direction. In addition, the light scanning unit may be configured to scan the measurement light to a scan angle that can scan a wide-angle area on the fundus, for example. The light scanning unit may be disposed, for example, at a position substantially conjugate with the pupil of the eye to be examined, and may measure the measurement light with the pupil center as a turning point.

  When the light scanning unit is provided, the measurement light is scanned in a wide angle area including the central area of the fundus and the peripheral area of the fundus by one B-scan by the optical scanning section, and the OCT data including the central area of the fundus and the peripheral area of the fundus are included. OCT data may be obtained. By this, for example, OCT data in the wide angle region can be acquired smoothly.

  The OCT optical system may include, for example, a first detector corresponding to the central portion of the fundus and a second detector corresponding to the peripheral portion of the fundus. In this case, the OCT optical system includes a first detector for detecting an interference signal between the measurement light guided to the center of the fundus and the reference light from the first reference light path, and a first detector A second different detector may be provided, for detecting an interference signal between the measurement light guided to the periphery of the fundus and the reference light from the second reference light path. According to this, for example, since the first detector and the second detector can be used in parallel, it is possible to reliably detect the OCT data of the central part of the fundus and the peripheral part of the fundus, and each OCT Data can be acquired smoothly and with good signal strength.

  In addition, although the Example of SD-OCT was shown in the said description, it is not limited to this, This Example may be applied in SS-OCT.

  In the above description, although an OCT apparatus for photographing an eye to be examined is taken as an example, the present invention is not limited to this, and the present embodiment is applied to an OCT apparatus for photographing OCT data of a subject It is also good. Further, the test object may be, for example, an eye (an anterior segment, a fundus, etc.), a living body such as skin, or a material other than a living body.

It is a figure which shows an example of the optical system of the OCT apparatus which concerns on a present Example. It is a figure which shows an example of the control system of the OCT apparatus which concerns on a present Example. It is a figure which shows an example of the B scan image of the ocular fundus image | photographed in the insertion state,

70 arithmetic controller 100 OCT optical system 104 coupler 110 reference optical system 120 detector 141, 142 fiber 150 light guiding optical system 159 lens 160 attachment optical system P1, P2 pivot point

Claims (12)

A first imaging optical system which irradiates imaging light to the subject's eye through the objective optical system and captures an image of the subject's eye based on return light of the imaging light;
A second photographing optical system which shares the objective optical system with the first photographing optical system and photographs the subject eye by a photographing method different from the first photographing optical system;
An optical path coupling unit that couples optical paths of the first imaging optical system and the second imaging optical system;
While changing the imaging condition of the first imaging optical system by changing the optical power of the objective optical system, the optical arrangement in the independent optical path of the second imaging optical system according to the change of the optical power of the objective optical system And o switching means for switching.   The switching unit corrects a change in angle of view of the second imaging optical system based on a change in optical power of the objective optical system by switching an optical arrangement in an independent optical path of the second imaging optical system. Ophthalmic device.   The switching unit corrects the change of the photographing position in the second photographing optical system based on the change of the optical power of the objective optical system by switching the optical arrangement in the independent optical path of the second photographing optical system. Or the ophthalmologic apparatus according to 2.   The switching unit corrects a change in focus state of the second imaging optical system based on a change in optical power of the objective optical system by switching an optical arrangement in an independent optical path of the second imaging optical system. The ophthalmologic apparatus according to any one of to 3. The first photographing optical system is a fundus photographing optical system for photographing a fundus, and
The ophthalmologic apparatus according to any one of claims 2 to 4, wherein the second photographing optical system is a front photographing optical system for photographing a front image of an anterior segment.   The ophthalmologic apparatus according to claim 5, wherein the switching unit switches an angle of view in the first imaging optical system by changing an optical power of the objective optical system. The second photographing optical system is a front photographing optical system for photographing a front image of an anterior segment or a fundus, wherein
The ophthalmologic apparatus according to any one of claims 1 to 6, further comprising control means for controlling alignment of the optical axis of the first photographing optical system and the eye to be examined based on the front image. .   The switching means couples the bypass optical path independent of the optical path of the first imaging optical system to the optical path of the second imaging optical system together with the change of the optical power of the objective optical system, or the second imaging The ophthalmologic apparatus according to any one of claims 1 to 7, wherein the optical arrangement in the independent optical path of the second imaging optical system is switched by being separated from the optical path of the optical system.   The switching means inserts the bypass optical path independent of the optical path of the first imaging optical system into and out of the optical path of the second imaging optical system, thereby forming the bypass optical path of the second imaging optical system. The ophthalmologic apparatus according to claim 8, wherein the ophthalmologic apparatus is coupled to the light path or separated from the light path of the second imaging optical system.   The switching unit includes an optical element for changing the optical power of the objective optical system, and a bypass optical system forming the bypass optical path, and is an attachment unit which is attached to and detached from the apparatus main body. The ophthalmic apparatus according to 8 or 9. The attachment unit has an illumination light source on a surface facing the subject's eye in a state of being attached to the apparatus main body,
The second photographing optical system is an anterior eye photographing optical system for photographing a front image of the anterior eye based on light reflected from the anterior eye by light from the illumination light source,
The ophthalmologic apparatus according to claim 10, further comprising: control means for performing control relating to alignment of the optical axis of the first photographing optical system and the eye to be examined based on the front image. An imaging optical system having a first irradiation optical system that irradiates imaging light to the eye through the objective optical system, and imaging the eye based on return light of the imaging light;
A second irradiation optical system which shares the objective optical system with the photographing optical system and irradiates the second light which is any one of the measurement light, the treatment light, the stimulation light, and the second photographing light;
An optical path coupling unit that couples the optical path of the imaging light and the optical path of the second light;
By changing the optical power of the objective optical system, the imaging conditions of the imaging optical system are switched, and in accordance with the change of the optical power of the objective optical system, the optical arrangement in the independent optical path of the second irradiation optical system is switched And o switching means.

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