JP7002192B2 - Ophthalmologic photography equipment - Google Patents

Description

The present invention relates to an ophthalmologic imaging apparatus.

Diagnostic imaging occupies an important position in the field of ophthalmology, and in recent years, the use of scanning laser ophthalmoscope (SLO) has been advancing. The SLO is a device that forms an image by scanning the fundus of the eye at high speed with a weak laser beam using a confocal optical system, and is used for screening and diagnosis of eye diseases.

Ghosts (flares) caused by various noise lights are mixed in the SLO image. The noise light that causes ghosts includes reflected light from an optical element such as an objective lens and reflected light from an eye tissue such as a cornea.

Japanese Unexamined Patent Publication No. 2016-28687

An object of the present invention is to provide a new technique for removing ghosts from SLO images.

The first aspect of the ophthalmologic imaging apparatus according to the embodiment is an ophthalmologic imaging apparatus that scans the fundus of the eye to be inspected with light to form an image, and collects data in both an orthogonal Nicol state and a parallel Nicol state. A first image is formed based on the first image collected by the optical system in the orthogonal Nicol state and the second data collected by the optical system in the parallel Nicol state. A partial region specification that identifies an image forming unit that forms a second image and a first central region in the first image, and specifies a second central region that is a region of the second image corresponding to the first central region. The unit, the first peripheral region which is the region excluding the first central region in the first image, and the second peripheral region which is the region excluding the second central region in the second image are added and averaged. A composite image of the summed averaging compositing unit, the first central region, and the summed averaging composite image formed by the summing and averaging of the first peripheral region and the second peripheral region by the summing and averaging compositing unit. It is provided with an image compositing unit to be formed.
A second aspect of the ophthalmologic imaging apparatus according to the embodiment is characterized in that the optical system sequentially collects data in the orthogonal Nicol state and data in the parallel Nicol state.
A third aspect of the ophthalmologic imaging apparatus according to the embodiment is characterized in that the optical system collects data in the orthogonal Nicol state and collects data in the parallel Nicol state in parallel.
A fourth aspect of the ophthalmologic imaging apparatus according to the embodiment is characterized in that the optical system scans the fundus with linearly polarized light.

According to embodiments, new techniques for removing ghosts can be provided.

It is a schematic diagram which shows an example of the structure of the ophthalmologic imaging apparatus which concerns on embodiment. It is a schematic diagram which shows an example of the structure of the ophthalmologic imaging apparatus which concerns on embodiment. It is a schematic diagram which shows an example of the structure of the ophthalmologic imaging apparatus which concerns on embodiment. It is a schematic diagram for demonstrating an example of the process performed by the ophthalmologic imaging apparatus which concerns on embodiment. It is a schematic diagram for demonstrating an example of the process performed by the ophthalmologic imaging apparatus which concerns on embodiment. It is a schematic diagram for demonstrating an example of the process performed by the ophthalmologic imaging apparatus which concerns on embodiment. It is a schematic diagram for demonstrating an example of the process performed by the ophthalmologic imaging apparatus which concerns on embodiment. It is a schematic diagram for demonstrating an example of the process performed by the ophthalmologic imaging apparatus which concerns on embodiment. It is a schematic diagram for demonstrating an example of the process performed by the ophthalmologic imaging apparatus which concerns on embodiment. It is a schematic diagram for demonstrating an example of the process performed by the ophthalmologic imaging apparatus which concerns on embodiment. It is a schematic diagram for demonstrating an example of the process performed by the ophthalmologic imaging apparatus which concerns on embodiment. It is a flowchart which shows the outline of an example of the operation performed by the ophthalmologic imaging apparatus which concerns on embodiment. It is a schematic diagram which shows an example of the structure of the ophthalmologic imaging apparatus which concerns on embodiment. It is a schematic diagram which shows an example of the structure of the ophthalmologic imaging apparatus which concerns on embodiment. It is a schematic diagram which shows an example of the structure of the ophthalmologic imaging apparatus which concerns on embodiment. It is a schematic diagram which shows an example of the structure of the ophthalmologic imaging apparatus which concerns on embodiment. It is a schematic diagram which shows an example of the structure of the ophthalmologic imaging apparatus which concerns on embodiment. It is a schematic diagram which shows an example of the structure of the ophthalmologic imaging apparatus which concerns on embodiment. It is a schematic diagram which shows an example of the structure of the ophthalmologic imaging apparatus which concerns on embodiment. It is a flowchart which shows the outline of an example of the operation performed by the ophthalmologic imaging apparatus which concerns on embodiment. It is a schematic diagram which shows an example of the structure of the ophthalmologic imaging apparatus which concerns on embodiment. It is a schematic diagram which shows an example of the structure of the ophthalmologic imaging apparatus which concerns on embodiment.

An exemplary embodiment of the ophthalmologic imaging apparatus will be described below. The contents of the cited document and publicly known techniques can be incorporated into embodiments.

The ophthalmologic imaging apparatus according to the embodiment is an SLO that scans the fundus with a light beam to form an image. The ophthalmologic imaging apparatus according to the embodiment may have only the SLO function, or may further have other functions. The other function may be any photographing function or measurement function. In a typical embodiment, the ophthalmologic imaging device may include an SLO function and an optical coherence tomography (OCT) function.

Hereinafter, unless otherwise specified, the direction along the optical axis of the objective lens is the Z direction, the predetermined direction orthogonal to the Z direction is the X direction, and the direction orthogonal to both the X direction and the Z direction is the Y direction. Typically, the left-right direction with respect to the subject can be the X direction, and the vertical direction can be the Y direction. The X, Y and Z directions define a three-dimensional Cartesian coordinate system.

<First Embodiment>
The ophthalmologic imaging apparatus according to the first embodiment scans the fundus of the eye to be inspected with light (scanning system), and among the return light from the eye to be inspected, the first and second polarization components that are different from each other are sequentially selected. (Detection system), a first image is formed based on the detection result of the first polarization component, a second image is formed based on the detection result of the second polarization component, and the first image and the second image are combined. Form a composite image of. In a typical example, the polarization axis of the first polarization component and the polarization axis of the second polarization component are orthogonal to each other, but the embodiment is not limited to this.

In the first embodiment, the fundus is sequentially scanned by linearly polarized light having a different polarization axis (polarization direction). That is, the scanning system scans the fundus with the first scanning light which is the linearly polarized light of the first polarization axis, and the second scanning light which is the linearly polarized light of the second polarization axis different from the first polarization axis. Scan the fundus with. The detection system detects a predetermined polarization component of the return light of the first scanning light as the first polarization component, and detects a predetermined polarization component of the return light of the second scanning light as the second polarization component. In a typical example, the first polarization axis and the second polarization axis are orthogonal to each other, but the embodiment is not limited to this. Further, the polarization axis of the predetermined polarization component detected as the first polarization component and the polarization axis of the predetermined polarization component detected as the second polarization component may be arbitrary.

Further, in the first embodiment, at least a part of the light source unit that outputs linearly polarized light is rotated about the optical axis of the scanning system to switch between the first scanning light and the second scanning light. The light source unit includes at least a light source that generates light. When the light output from the light source is linearly polarized, the light source unit includes, for example, only this light source. When the light source unit includes only the light source, the entire light source unit (that is, the light source) is rotated to switch between the first scanning light and the second scanning light. On the other hand, when the light output from the light source is not linearly polarized light, an optical element (polarizer) for converting this light into linearly polarized light is also included in the light source unit. In this case, at least the stator is rotated to switch between the first scanning light and the second scanning light.

In the first embodiment, in the process of forming a composite image, a first region which is at least a part of the first image and a second region which is a region of the second image corresponding to the first region are added and averaged. It may include the processing to be performed. Further, the process of forming the composite image is a part of the first partial region which is a part of the first image (or the second image) and a part of the second image (or the first image) corresponding to the first partial region. It may include a process of specifying the second subregion.

<Structure>
Examples of the configuration of the ophthalmologic imaging apparatus according to the first embodiment are shown in FIGS. 1 to 3. FIG. 1 shows an example of an optical system. FIG. 2 shows an example of an optical element (optical path synthesis member) that synthesizes an optical path of a scanning system and an optical path of a detection system. FIG. 3 shows an example of a processing system.

<Optical system>
The optical system shown in FIG. 1 scans the fundus Ef of the eye E to be inspected with a light beam and collects data. To this end, the optical system includes a scanning system that scans the fundus Ef with a light beam and a detection system that detects the return light of the light beam from the eye E to be inspected. An image of the fundus Ef is constructed based on the output from the detection system (ie, the data collected by the optical system).

In other embodiments, in addition to such an SLO optical system, an OCT optical system for performing an OCT scan, an anterior ocular segment imaging system for observing and photographing the anterior segment of the eye, and a fixation target on the fundus Ef. An index projection system for projecting an alignment index or a focus index may be provided. The optical system may be movable in the X, Y, and Z directions. As a result, it is possible to perform alignment and tracking of the optical system.

In the optical system schematically shown in FIG. 1, the scanning system includes a first light source 1A, a first collimating lens 2A, a first polarizing element 3A, a second light source 1B, a second collimating lens 2B, and a second polarization. Includes child 3B, dichroic mirror (or half mirror, etc.) 4, optical path synthesis member 5, lens 6, reflection mirror 7, lens 8, optical scanner 9, relay lens 10, and objective lens 11. ..

The first light source 1A and / or the second light source 1B may be an external light source that is not included in the scanning system (ophthalmologic photographing apparatus). In this case, for example, the light generated by the first light source 1A (or the second light source 1B) is guided to the scanning system through an optical fiber (not shown). Similarly, the first collimating lens 2A, the first polarizing element 3A, the second collimating lens 2B, the second polarizing element 3B, and the like may be provided outside the scanning system.

The number of light sources is not limited to two, and may be any number of one or more. Further, the wavelength of the light output from the light source is also arbitrary. For example, the light source may include at least one of an infrared light source of any wavelength band and a visible light source of any wavelength band.

In one example, the first light source 1A is a visible light source that outputs light having a wavelength of 532 nm, and the second light source 1B is a near-infrared light source that outputs light having a wavelength of 800 nm. Each of the first light source 1A and the second light source 1B includes, for example, a laser diode, a super luminescent diode, a laser driven light source, and the like. In a state where the alignment is suitable, each of the first light source 1A and the second light source 1B is arranged at a position (or in the vicinity thereof) optically conjugate to the fundus Ef.

The first collimating lens 2A converts the light output from the first light source 1A into a parallel luminous flux. The first polarizing element 3A generates linearly polarized light having a predetermined polarization axis from the parallel light flux generated by the first collimating lens 2A. The generated linearly polarized light (scanning light) is guided to the dichroic mirror 4. The optical path (first scanning optical path) from the first light source 1A to the dichroic mirror 4 is indicated by reference numeral OP1. When the first light source 1A outputs linearly polarized light, it is not necessary to provide the first polarizing element 3A.

Similarly, the second collimating lens 2B converts the light output from the second light source 1B into a parallel luminous flux. The second polarizing element 3B generates linearly polarized light having a predetermined polarization axis from the parallel light flux generated by the second collimating lens 2B. The generated linearly polarized light (scanning light) is guided to the dichroic mirror 4. The optical path (second scanning optical path) from the second light source 1B to the dichroic mirror 4 is indicated by reference numeral OP2. When the second light source 1B outputs linearly polarized light, it is not necessary to provide the second polarizing element 3B.

The dichroic mirror 4 synthesizes the first scanning optical path OP1 and the second scanning optical path OP2. In other words, the dichroic mirror 4 transmits the scanning light incident from the first scanning optical path OP1 and reflects the scanning light incident from the second scanning optical path OP2. On the contrary, it is also possible to apply a configuration using a dichroic mirror (or a half mirror or the like) that reflects the scanning light incident from the first scanning optical path OP1 and transmits the scanning light incident from the second scanning optical path OP2. .. The optical path between the dichroic mirror 4 and the optical path synthesis member 5 (that is, the combined optical path of the first scanning optical path OP1 and the second scanning optical path OP2 formed by the dichroic mirror 4) is referred to as a scanning optical path OP3.

In this example, the dichroic mirror 4 synthesizes the optical axis of the first scanning optical path OP1 and the optical axis of the second scanning optical path OP2. In other words, the dichroic mirror 4 coaxially synthesizes the first scanning optical path OP1 and the second scanning optical path OP2. The scanning light that has passed through the first polarizing element 3A travels on and near the optical axis of the first scanning optical path OP1, passes through the dichroic mirror 4, travels on and near the optical axis of the scanning optical path OP3, and travels in the optical path. It is projected onto the synthetic member 5. Similarly, the scanning light that has passed through the second polarizing element 3B travels on and near the optical axis of the second scanning optical path OP2, is reflected by the dichroic mirror 4, and travels on and near the optical axis of the scanning optical path OP3. Then, it is projected onto the optical path synthesis member 5.

The optical path synthesizing member 5 synthesizes the optical path of the scanning system and the optical path of the detection system. In this example, the optical path synthesizing member 5 synthesizes the scanning optical path OP3 and the detection optical path OP5 described later. The optical path synthesizing member 5 reflects the scanning light incident from the scanning optical path OP3 and causes it to enter the optical path OP4 toward the eye E to be inspected. Further, the optical path synthesizing member 5 transmits the return light from the eye E to be inspected incident from the optical path OP4 and causes the optical path to be incident on the detected optical path OP5. An example of such an optical path synthesis member 5 is shown in FIG. In another embodiment, the optical path synthesizing member may be configured and / or arranged so as to transmit scanning light and reflect return light from the eye E to be inspected.

The optical path synthesis member 5 shown in FIG. 2 includes a shielding portion 5a, a transmitting portion 5b, and a reflecting portion 5c. In this example, the reflective portion 5c is formed in a disk shape and the transmissive portion 5b is formed in an annular shape, but these may have other shapes.

The reflecting unit 5c reflects the scanning light incident from the scanning optical path OP3 in order to guide it to the eye E to be inspected. The reflecting portion 5c may be, for example, a reflecting mirror, or a thin film or a coating having a light reflecting action. The center of the disc-shaped reflecting portion 5c is substantially arranged on the optical axis of the scanning optical path OP3. The reflecting portion 5c is designed, for example, to have a size capable of reflecting the entire beam cross section of the scanning light. The scanning light traveling on or near the optical axis of the optical path OP3 is reflected by the optical path synthesizing member 5 and travels on or near the optical axis of the optical path OP4.

The transmitting portion 5b is provided around the reflecting portion 5c as described above, and is for guiding the return light from the eye E to be inspected incident from the optical path OP4 to the photodetectors 16A and 16B (described later) of the detection system. Make it transparent. The transmissive portion 5b may be formed of, for example, a material having translucency, or may be formed as an annular opening. The transmitting portion 5b is designed, for example, to have a size that allows a predetermined region of the beam cross section of the return light from the eye E to be inspected to pass through. Noise light such as reflected light from the optical element and reflected light from the eye tissue is mixed in the return light from the eye E to be inspected, and the noise light travels on or near the optical axis of the optical path OP4. The size of the circle inside the transmissive portion 5b can be designed so that at least a part of this noise light is sufficiently shielded.

The shielding portion 5a may be made of a light-shielding material, or may be a thin film, a coating, or the like having a light-shielding effect.

Typically, the optical path synthesis member 5 is created by forming a thin film or the like that functions as a shielding portion 5a and a thin film or the like that functions as a reflecting portion 5c on a transparent substrate made of glass, synthetic resin, or the like. It may be a member. In another example, the optical path synthesis member 5 is a member created by combining a reflection member that functions as a reflection portion 5c, a light-transmitting member that functions as a transmission portion 5b, and a light-shielding member that functions as a shielding portion 5a. It may be there. It should be noted that these are examples, and the optical path synthesizing member 5 may have an arbitrary configuration capable of synthesizing the optical path of the scanning system and the optical path of the detection system.

As described above, in another embodiment, the optical path synthesizing member that synthesizes the optical path of the scanning system and the optical path of the detection system is configured to transmit the scanning light and reflect the return light from the eye E to be inspected. It's okay. In this case, for example, it is possible to use an optical path synthesis member in which the region indicated by reference numeral 5b in FIG. 2 is configured as a reflecting portion and the region indicated by reference numeral 5a is configured as a translucent portion.

The scanning light (parallel light beam) incident on the optical path OP4 via the optical path synthesizing member 5 becomes convergent light by the lens 6, is reflected by the reflection mirror 7, is refracted by the lens 8, and is guided to the optical scanner 9.

The optical scanner 9 two-dimensionally deflects the scanning light. For example, the optical scanner 9 includes a first optical scanner that deflects light in the X direction and a second optical scanner that deflects light in the Y direction. Typically, one of the first optical scanner and the second optical scanner is a low-speed scanner (galvano mirror or the like), and the other is a high-speed scanner (resonant mirror, polygon mirror, MEMS mirror or the like). When the alignment is suitable, the optical scanner 9 (for example, the reflective surface of the first optical scanner, the reflective surface of the second optical scanner, or a predetermined position between the first optical scanner and the second optical scanner) is covered. It is placed at (or near) an optically conjugate position with respect to the pupil of the eye examination E. As a result, the scanning light can be swayed around a point (or its vicinity) in the pupil of the eye E to be inspected, and a wide range of the fundus Ef can be scanned.

The scanning light that has passed through the optical scanner 9 is refracted by the relay lens 10 and imaged on the eye E to be inspected by the objective lens 11. When alignment is preferred, the scanning light is imaged, for example, on the surface of the fundus Ef. Further, by moving the objective lens 11 in the direction along the optical axis of the optical path OP4, the focus adjustment (and diopter correction) of the scanning system and the detection system can be performed. It is also possible to provide a dedicated lens for adjusting the focus.

The scanning light is reflected and scattered at the fundus Ef. The light emitted from the eye to be inspected E includes not only the reflected light from the surface of the fundus Ef, but also the scattered light in the fundus Ef, the reflected light from the crystalline lens, the reflected light from the surface of the corneal membrane, and the like. For example, a part of the scanning light reflected by the rear surface of the objective lens 11 (the surface on the relay lens 10 side) is further mixed with the light emitted from the eye E to be inspected. Such return light travels in the optical path OP4 in the direction opposite to that of the scanning light, and is guided to the optical path synthesis member 5.

A part of the return light projected on the optical path synthesis member 5 passes through the annular transmission portion 5b and is incident on the detection optical path OP5. At this time, the noise light (reflected light from the crystal body, the cornea, the objective lens 11 and the like) contained on the optical axis of the optical path OP4 and in the vicinity thereof is on the back surface of the reflecting portion 5c (the opposite side of the surface reflecting the scanning light). Since it is projected onto the surface of the light path OP5, it does not enter the detection optical path OP5. That is, the noise light (at least a part of) included in the return light from the eye E to be inspected is removed by the optical path synthesizing member 5.

The return light incident on the detection optical path OP5 is projected onto the dichroic mirror (or half mirror or the like) 12. The dichroic mirror 12 divides the detection optical path OP5 into a first detection optical path OP6 and a second detection optical path OP7. When the fundus Ef is scanned by the scanning light from the first scanning optical path OP1, the return light passes through the dichroic mirror 12 and is incident on the first detection optical path OP6. On the other hand, when the fundus Ef is scanned by the scanning light from the second scanning optical path OP2, the return light is reflected by the dichroic mirror 12 and is incident on the second detection optical path OP7.

The return light incident on the first detection optical path OP6 is guided to the first linear transducer 13A. The first linear polarizing element 13A is an optical element that converts return light into linearly polarized light, that is, an optical element that extracts a predetermined polarization component contained in the return light. As the first linear splitter 13A, for example, a polarizing beam splitter or a polarizing plate is used.

The linearly polarized light generated by the first linear splitter 13A is refracted by the first condenser lens 14A and projected onto the first confocal diaphragm 15A. In a state where the alignment is suitable, the first confocal diaphragm 15A is arranged at a position optically conjugate with the fundus Ef (or in the vicinity thereof). The first confocal diaphragm 15A acts to block at least a part of noise light (fund scattered light and the like) contained in the linearly polarized light and selectively pass the reflected light from the surface of the fundus Ef.

The linearly polarized light that has passed through the first confocal diaphragm 15A is detected by the first photodetector 16A. The first photodetector 16A includes, for example, an avalanche photodiode or a photomultiplier tube.

On the other hand, the return light incident on the second detection optical path OP7 is guided to the second linear transducer 13B. The second linear splitter 13B is an optical element that converts return light into linearly polarized light, and is, for example, a polarizing beam splitter or a polarizing plate.

The linearly polarized light generated by the second linear polarizing element 13B is refracted by the second condenser lens 14B and projected onto the second confocal diaphragm 15B. In a state where the alignment is suitable, the second confocal diaphragm 15B is arranged at a position optically conjugate with the fundus Ef (or in the vicinity thereof). The second confocal diaphragm 15B blocks at least a part of noise light (fund scattered light and the like) contained in the linearly polarized light, and acts to selectively pass the reflected light from the surface of the fundus Ef.

The linearly polarized light that has passed through the second confocal diaphragm 15B is detected by the second photodetector 16B. The second photodetector 16B includes, for example, an avalanche photodiode or a photomultiplier tube.

In this example, the detection system includes an objective lens 11, a relay lens 10, an optical scanner 9, a lens 8, a reflection mirror 7, a lens 6, an optical path synthesis member 5, a dichroic mirror 12, and a first straight line. The extruder 13A, the first condensing lens 14A, the first confocal aperture 15A, the first light detector 16A, the second linear polarizing element 13B, the second condensing lens 14B, and the second confocal aperture. Includes 15B and a second light detector 16B.

<Processing system>
FIG. 3 shows a configuration example of the processing system of the ophthalmologic imaging apparatus according to the first embodiment. The processing system includes one or more processors for performing various data processing (signal processing, image processing, calculation, control, storage, etc.).

The "processor" includes, for example, a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), an ASIC (Application Specific Integrated Circuit), a programmable logic device (for example, a SPLD (Simple It means a circuit such as Device), FPGA (Field Programmable Gate Array)). The processor realizes the function according to the embodiment by reading and executing, for example, a computer program stored in a storage circuit or a storage device.

The processing system of the ophthalmologic imaging apparatus according to the first embodiment includes the optical system shown in FIG. 1, such as the first light source 1A, the second light source 1B, the optical scanner 9, the first photodetector 16A, and the second photodetector 16B. Includes some of the included elements. Further, the processing system includes a scanning light rotation driving unit 30, a control unit 100, an image forming unit 110, a data processing unit 120, and a user interface unit 130.

<Scanning light rotation drive unit 30>
As described above, the scanning light for scanning the fundus Ef is linearly polarized light. The scanning light rotation driving unit 30 drives an optical element of the scanning system to rotate the polarization direction (polarization axis) of the scanning light. In this example, at least the first extruder 3A is rotated. The rotatable range may be arbitrary, for example 90 degrees.

Under the control of the control unit 100 (main control unit 101) or in response to a manual operation, the scanning light rotation drive unit 30 sets the first polarizing element 3A into the first rotation state and the second rotation state. You can switch. Thereby, the first scanning light, which is the linearly polarized light of the first polarizing axis, and the second scanning light, which is the linearly polarized light of the second polarizing axis different from the first polarizing axis, are selectively generated. Can be done.

Similarly, the second polarizing element 3B is also rotated by the scanning light rotation drive unit 30. By switching the second polarizing element 3B between the first rotation state and the second rotation state, the first scanning light which is the linearly polarized light of the first polarization axis and the straight line of the second polarization axis different from the first polarization axis. The second scanning light, which is polarized light, can be selectively generated.

When the first polarizing element 3A is not provided, that is, when the first light source 1A generates linearly polarized light, the scanning light rotation drive unit 30 is configured to rotate the first light source 1A. In this case, under the control of the control unit 100 (main control unit 101) or in response to a manual operation, the scanning light rotation drive unit 30 sets the first light source 1A (and the first collimating lens 2A) to the first light source. It is possible to switch between the one-rotation state and the second rotation state. Thereby, the first scanning light, which is the linearly polarized light of the first polarizing axis, and the second scanning light, which is the linearly polarized light of the second polarizing axis different from the first polarizing axis, are selectively generated. Can be done. The same applies to the case where the second polarizing element 3B is not provided.

The scanning light rotation drive unit 30 has an arbitrary configuration for rotating a rotation target (an optical element such as a first polarizing element 3A, a light source such as a first light source 1A, or the like). In a typical example, the scanning light rotation drive unit 30 has an actuator that generates a driving force according to a control signal from the control unit 100 (main control unit 101) and a rotation target according to the driving force generated from the actuator. Includes a rotating mechanism. The actuator is, for example, a pulse motor.

<Control unit 100>
The control unit 100 includes a configuration for controlling each unit of the ophthalmologic imaging apparatus. The control unit 100 includes a main control unit 101 and a storage unit 102. The function of the main control unit 101 is realized by one or more processors and the like. Various data, various information, various computer programs, and the like are stored in the storage unit 102. The storage unit 102 includes a semiconductor memory, a magnetic storage device, and the like.

The processing executed by the ophthalmologic imaging device is realized by the cooperation of hardware resources (processor etc.) and software (computer program etc.). In addition, actuators are provided in at least a part of various mechanisms provided in the ophthalmologic photographing apparatus. The main control unit 101 sends a control signal to each actuator.

<Main control unit 101>
The main control unit 101 includes a processor and generates and transmits various control signals. Thereby, each part of the ophthalmologic photographing apparatus is controlled. For example, the main control unit 101 controls the first light source 1A, the second light source 1B, the optical scanner 9, the first photodetector 16A, the second photodetector 16B, the scanning light rotation drive unit 30, and the like.

The control of the first light source 1A and the second light source 1B includes lighting, extinguishing, adjusting the amount of light, and the like. The control of the optical scanner 9 includes a control of a scanning position, a control of a scanning range, a control of a scanning pattern, a control of a scanning speed, and the like. The control of the first photodetector 16A and the second photodetector 16B includes exposure adjustment, gain adjustment, detection rate (detection repetition frequency) adjustment, and the like.

Although not shown, the ophthalmologic photographing apparatus may include an optical system moving mechanism for moving the optical system in the X direction, the Y direction, and the Z direction. The control of the optical system movement mechanism is performed in alignment or the like.

When performing SLO shooting, the main control unit 101 turns on (blinks) the first light source 1A (or the second light source 1B) at a predetermined timing, and sets the optical scanner 9 according to a predetermined scanning pattern (for example, raster scan). Control.

<Storage 102>
The storage unit 102 stores information, data, computer programs, and the like used by the ophthalmologic photographing apparatus. Further, the storage unit 102 stores data acquired by the ophthalmologic photographing apparatus and data acquired from the outside.

<Image forming unit 110>
The image forming unit 110 forms an image of the fundus Ef based on the data collected by the optical system. More specifically, the image forming unit 110 has the detection signal input from the first photodetector 16A (or the second photodetector 16B) and the pixels input from the control unit 100, as in the conventional SLO. An image is formed based on the position signal.

As described above, in the first embodiment, by rotating the first polarizing element 3A and the like, scanning with the first scanning light, which is linearly polarized light of the first polarizing axis, and scanning with the first scanning light, which is different from the first polarizing axis, are performed. It is possible to switch between scanning with the second scanning light, which is linearly polarized light with two polarization axes.

The image forming unit 110 forms the first image based on the data collected by scanning the fundus Ef with the first scanning light. That is, the image forming unit 110 forms the first image based on the detection data of the first polarizing component which is a predetermined polarizing component of the return light from the eye E to be scanned for the first scanning light.

Further, the image forming unit 110 forms the second image based on the data collected by scanning the fundus Ef with the second scanning light. That is, the image forming unit 110 forms the second image based on the detection data of the second polarizing component, which is a predetermined polarizing component of the return light from the eye E to be scanned for the second scanning light.

In this example, since the first linear splitter 13A (second linear splitter 13B) is not rotated, the polarization axis of the light detected by the first photodetector 16A (second photodetector 16B) is the first scan. It is the same in the case of light and the case of the second scanning light. However, since the polarization axis of the first scanning light (first polarization axis) and the polarization axis of the second scanning light (second polarization axis) are different from each other, the detection data (first polarization component) in the case of the first scanning light. And the detection data (second polarization component) in the case of the second scanning light are different from each other. The rotation state of the first linear splitter 13A (second linear splitter 13B) may be switched between the case of the first scanning light and the case of the second scanning light. That is, the first polarization component and the second polarization component whose polarization axes are different from each other may be detected in the case of the first scanning light and the case of the second scanning light.

In a typical example, the relationship between the polarization direction of the scanning light and the polarization direction of the first linear polarizing element 13A (second linear polarizing element 13B) can be switched between the orthogonal Nicol state and the parallel Nicol state. For example, in the case of the first scanning light, the polarization axis of the first scanning light (first polarization axis) and the polarization axis of the first linear polarizing element 13A (second linear polarizing element 13B) are orthogonal to each other. , The rotational state of the first polarizing element 3A (second polarizing element 3B) and the arrangement of the first linear polarizing element 13A (second linear polarizing element 13B) are determined (orthogonal Nicol state). Further, in the case of the second scanning light, the polarization axis of the second scanning light (second polarization axis) and the polarization axis of the first linear polarizing element 13A (second linear polarizing element 13B) are parallel to each other. In addition, the rotational state of the first polarizing element 3A (second polarizing element 3B) and the arrangement of the first linear polarizing element 13A (second linear polarizing element 13B) are determined.

<Data processing unit 120>
The data processing unit 120 executes various data processing. As an example of data processing, there is processing for image data formed by the image forming unit 110 or another device. Examples of this processing include various image processing, analysis processing for images, and diagnostic support processing such as image evaluation based on image data.

In the first embodiment, the data processing unit 120 forms a composite image of the first image and the second image formed by the image forming unit 110. Therefore, the data processing unit 120 includes a partial area specifying unit 121, an averaging synthesizing unit 122, and a synthesizing processing unit 123.

Hereinafter, as a typical example, a case where the orthogonal Nicol state is applied in the case of the first scanning light and the parallel Nicol state is applied in the case of the second scanning light will be described. However, the mode of SLO imaging in the first embodiment is not limited to this. In the case of other embodiments, the same processing as described below can be applied.

An example of the image (first image) obtained in the orthogonal Nicol state is shown in FIG. 4A. An example of the image (second image) obtained in the parallel Nicol state is shown in FIG. 4B. As shown in FIG. 4A, the first image G1 obtained in the orthogonal Nicol state has a hyperbolic dark region (signal) in the peripheral portion of the image due to the influence of the polarization characteristics of the eye (mainly the cornea and the retinal nerve fiber layer). The part that cannot be obtained) occurs.

In general, the polarization axis of the return light from the portion corresponding to this dark region is substantially parallel to the polarization axis of the light reflected by the objective lens. In fact, in the second image G2 shown in FIG. 4B, the reflected light by the objective lens (the bright region in the center of the image) and the image of the portion corresponding to the hyperbolic dark region in the first image G1 are drawn. There is. The portion of the fundus Ef depicted in the first image G1 is not depicted in the second image G2 (that is, it is a dark region of the second image G2).

Therefore, when linearly polarized light is used, it is difficult to acquire a signal from the entire scanning region of the fundus at one time while preventing reflection from the objective lens. Therefore, although the details will be described later, in the embodiment using linear polarization as in the first embodiment, the image is in the orthogonal Nicol state not including the reflection from the objective lens and the parallel Nicol state including the reflection from the objective lens, respectively. And by synthesizing these images, an image without ghosts and in which the entire scanning region of the fundus is depicted is acquired.

In addition, before forming the composite image of the first image G1 and the second image G2, or in the process of forming the composite image (that is, the composite image is a part of the formation process), the data processing unit 120 is used. Alignment (registration) between the first image G1 and the second image G2 can be performed.

Registration comprises, for example, the following treatments: (1) feature regions in the first image G1 corresponding to predetermined feature sites of the fundus Ef (optic disc, macula, vascular disease, diseased part, laser treatment scars, etc.). (2) Processing to specify a feature region in the second image G2 corresponding to the same feature region; (3) Between the first image G1 and the second image G2 so as to match these feature regions. The process of finding the transformation parameters of (for example, the Affin transformation matrix). The registration method is not limited to this, and any known method for aligning a plurality of images representing the same object can be applied.

The time interval between the scan for forming the first image G1 and the scan for forming the second image G2 may be sufficiently shorter than the time required for the eye movement of the eye E to be inspected. .. For example, as in the embodiment described later, a polarization beam splitter may be used to simultaneously detect the first polarization component and the second polarization component. In such a case, since the eye movement of the eye E to be inspected can be substantially ignored, a natural correspondence can be set between the pixels of the first image G1 and the pixels of the second image G2.

<Partial area identification part 121>
In a typical embodiment, the first image and the second image formed by the image forming unit 110 are input to the partial region specifying unit 121. The partial region specifying portion 121 includes a first partial region that is a part of one of the first image and the second image, and a second partial region that is a region of the other image corresponding to the first partial region. To identify.

The case where the first image G1 (image obtained in the orthogonal Nicol state) shown in FIG. 4A and the second image G2 (image obtained in the parallel Nicol state) shown in FIG. 4B are input will be described. For example, the partial region specifying portion 121 specifies the partial region (central region) H2 so as to include a ghost (reflection from the objective lens 11 or the like) drawn in the central portion of the second image G2.

The range (position, size, etc.) in which the ghost caused by the reflection from the objective lens 11 is reflected is determined by the design of the optical system of the ophthalmologic imaging apparatus and the actual structure. Therefore, for example, the range of the central region H2 can be set in advance by performing a simulation such as ray tracing or performing an actual measurement. The partial area specifying unit 121 can specify the predetermined range in the second image G2 as the central area H2. The simulation can be performed at any time, for example, at the time of designing, manufacturing, pre-shipment, post-installation, etc. of the ophthalmologic imaging apparatus. In addition, the actual measurement can be performed at any time such as at the time of manufacturing the ophthalmologic imaging apparatus, before shipping, and after installation.

The partial region specifying unit 121 further identifies the partial region (central region) H1 of the first image G1 corresponding to the central region H2 of the second image G2. In one specific example, the partial region specifying unit 121 can specify the partial region of the first image G1 corresponding to the above-mentioned predetermined range as the central region H1. In another specific example, the partial region specifying unit 121 identifies the partial region of the first image G1 corresponding to the specified central region H2 based on the registration result, and sets this partial region as the central region H1. be able to.

<Additional average synthesizer 122>
In a typical embodiment, the result of the specific processing executed by the partial region identification unit 121 is input to the addition average composition unit 122. The partial region specifying portion 121 includes a first partial region that is a part of one of the first image and the second image, and a second partial region that is a region of the other image corresponding to the first partial region. When the above is specified, the addition average synthesis unit 122 includes a third partial region which is a region of the first image different from the first partial region, and a fourth partial region which is a region of the second image corresponding to the third partial region. Is added and averaged.

The case where the central region H2 shown in FIG. 5 is specified from the second image G2 and the central region H1 shown in FIG. 6 is specified from the first image G1 will be described. For example, the averaging synthesis unit 122 includes a partial region (peripheral region) J1 excluding the central region H1 in the first image G1 (see FIG. 7) and a partial region (peripheral region) excluding the central region H2 in the second image G2. Region) J2 and (see FIG. 8) are added and averaged.

The third partial region may be a region different from the first partial region in the first image. For example, the third sub-region may be a complement of the first sub-region in the first image, a part of this complement, or at least a part of this complement and at least a part of the first sub-region. It may be the union of. The same applies to the fourth subregion.

The averaging composition is a process of finding the average value of the corresponding pixel values and setting the pixel value of a new image (addition averaging image). In the example shown in FIGS. 7 and 8, a one-to-one correspondence relationship is given between the pixel group included in the peripheral region J1 and the pixel group included in the peripheral region J2 by registration or the like. The addition average synthesizing unit 122 sets the value of the first pixel (brightness value, etc.) for each combination of the pixel (first pixel) of the peripheral region J1 and the pixel (second pixel) of the peripheral region J2 associated with each other. The value of the second pixel (brightness value, etc.) is added, and the sum value obtained thereby is divided by 2. As a result, the values of the pixels of the averaging image corresponding to the first pixel and the second pixel can be obtained.

An example of the averaging image obtained in this way is shown in FIG. The averaging image G3 shown in FIG. 9 is an image obtained by averaging the peripheral region J1 of the first image G1 and the peripheral region J2 of the second image G2. As described above, the portion of the fundus Ef corresponding to the dark region in the first image G1 (peripheral region J1) is depicted in the second image G2 (peripheral region J2), and conversely, the second image G2 (peripheral region J1). The portion of the fundus Ef corresponding to the dark region in the region J2) is visualized in the first image G1 (peripheral region J1). Therefore, by adding and averaging the peripheral region J1 and the peripheral region J2, the fundus Ef is suitably visualized over the entire peripheral region.

<Composite processing unit 123>
In a typical embodiment, the result of the specific processing executed by the partial region specifying unit 121 and the averaging image obtained by the averaging averaging unit 122 are input to the synthesizing unit 123. The composition processing unit 123 forms a composite image by synthesizing one of the first partial region and the second partial region specified by the partial region specifying unit 121 and the averaging image formed by the averaging averaging unit 122. do.

In the example shown in FIGS. 4A to 9, the synthesis processing unit 123 is the center of the central region H1 in the first image G1 and the central region H2 in the second image G2, which does not include reflection by the objective lens 11. Select region H1. The selected partial region is preset, and the partial region on the side where the reflection by the objective lens 11 is (relatively) not included is selected, for example, the partial region in the image obtained in the orthogonal Nicol state. ..

Alternatively, by analyzing the brightness (luminance value, etc.) of the first image and the second image, an image that does not (relatively) include reflection by the objective lens 11 is selected, and a partial region in this image is selected. be able to.

The compositing processing unit 123 specifies, for example, a partial region (excluded region) corresponding to the predetermined range (range of the central region H1 and the central region H2) in the summing average image formed by the additive average compositing unit 122. Further, the synthesis processing unit 123 can replace the exclusion region specified from the averaging image with a partial region selected from the first partial region and the second partial region. Alternatively, the synthesis processing unit 123 can superimpose a partial region selected from the first partial region and the second partial region on the exclusion region specified from the averaging image.

In the example shown in FIGS. 4A to 9, the synthesis processing unit 123 synthesizes the central region H1 shown in FIG. 6 with the central region of the averaging image G3 shown in FIG. As a result, the composite image G as shown in FIG. 10 is formed.

In addition, in "forming a composite image", not only a single image data (composite image) is formed based on the first image and the second image as described above, but also the first image and the second image are formed. It also includes displaying an image composite based on the image. As an example of the latter, the central region H1 and the averaging image G3 (further, the positional relationship between them) are acquired, and the central region H1 is overlaid on the averaging image G3 by using a layer display function or the like. Can be done.

The compositing processing unit 123 can perform image processing on the compositing image. For example, processing for making the boundary between the central region H1 and the averaging image G3 inconspicuous can be performed. This processing may include, for example, image processing for matching the signal-to-noise ratio (SNR) of the first partial region H1 with the SNR of the averaging image G3. The processing applied to the composite image is not limited to this, and for example, corrections and adjustments can be made regarding arbitrary conditions (characteristics) such as luminance and contrast.

<User interface unit 130>
The user interface (UI) unit 130 has a function for exchanging information between the user and the ophthalmologic photographing apparatus. The user interface unit 130 includes a display device and an operation device (input device). Display devices include, for example, a liquid crystal display (LCD). The operating device includes various hardware keys and / or software keys. The control unit 100 receives the operation content for the operation device and outputs a control signal corresponding to the operation content to each unit. It is possible to integrally configure at least a part of the operating device and at least a part of the display device. The touch panel display is one example.

<Operation>
The operation of the ophthalmologic imaging apparatus according to the first embodiment will be described. An example of the operation in the first embodiment is shown in FIG. In this operation example, the images and processes shown in FIGS. 4A to 10 will be described as examples.

(S1: Observe the anterior segment of the eye)
First, the examiner observes the anterior segment of the eye E to be inspected. The observation of the anterior segment of the eye is performed using, for example, the above-mentioned anterior segment imaging system (not shown).

(S2: Alignment)
The optical system (scanning system, detection system) is aligned with the eye E to be inspected by using the image obtained by the anterior eye portion photographing system and the index projection system (not shown) described above. This alignment method may be, for example, the same auto alignment or manual alignment as before.

(S3: Preliminary shooting)
When the alignment in step S2 is completed, preliminary imaging is performed. Preliminary imaging is performed using, for example, a near-infrared light source (second light source 1B). In the preliminary imaging, for example, a raster scan using near-infrared light is repeatedly performed. As a result, a near-infrared moving image of the fundus Ef can be obtained.

(S4: Align in focus direction)
Alignment in the focus direction (depth direction of fundus Ef, axial direction of scanning light) is performed based on the near-infrared moving image obtained in step S3. For example, in parallel with the preliminary imaging, the focus index is projected onto the fundus Ef by the index projection system, and auto-focusing or manual focusing is performed based on the image of the focus index drawn on the near-infrared moving image. Alternatively, auto-focusing or manual focusing is performed so that a near-infrared moving image having a suitable image quality can be obtained while evaluating the image quality of the near-infrared moving image obtained by preliminary photography.

(S5: Taken in the orthogonal Nicol state)
When the alignment in step S4 is completed, the main control unit 101 controls the scanning light rotation drive unit 30 to set the optical system to the orthogonal Nicol state, if necessary. The main control unit 101 controls the first light source 1A (visible light source), the optical scanner 9, the first photodetector 16A, and the like to perform photographing (data collection) in an orthogonal Nicol state. The image forming unit 110 forms the first image G1 based on the collected data (see FIG. 4A).

(S6: Rotate the polarization axis of the scanning light)
After the imaging in the orthogonal Nicol state in step S5 is completed, the main control unit 101 sets the optical system to the parallel Nicol state by controlling the scanning light rotation drive unit 30.

(S7: Shoot in parallel Nicol state)
The main control unit 101 controls the first light source 1A (visible light source), the optical scanner 9, the first photodetector 16A, and the like to perform photographing (data collection) in a parallel Nicol state. The collected data is sent to the image forming unit 110. The image forming unit 110 forms the second image G2 based on the collected data (see FIG. 4B).

In this example, the image is taken in the parallel Nicol state after the image in the orthogonal Nicol state, but the image in the orthogonal Nicol state may be performed after the image in the parallel Nicol state.

(S8: Specify the central area)
The partial region specifying unit 121 identifies the central region H1 of the first image G1 obtained in step S5 (see FIG. 6). Further, the partial region specifying unit 121 identifies the central region H2 of the second image G2 obtained in step S7 (see FIG. 5).

(S9: Form an averaging image)
The averaging synthesis unit 122 synthesizes the peripheral region J1 of the first image G1 (see FIG. 7) and the peripheral region J2 of the second image G2 (see FIG. 8) by averaging. As a result, the averaging image G3 shown in FIG. 9 is formed.

(S10: Combine the central area and the averaging image)
The synthesizing unit 123 synthesizes the central region H1 specified from the first image G1 in step S8 and the averaging image G3 formed in step S9. As a result, the composite image G shown in FIG. 10 is formed.

The main control unit 101 can display the composite image G or the like on the display device of the user interface unit 130. Further, the main control unit 101 stores the composite image G or the like in the storage unit 102, records the composite image G on a recording medium, or stores the composite image G in a server (image archiving device or the like) on the communication line. Can be sent.

<Action / effect>
Some examples will be described with respect to the actions and effects of the ophthalmologic imaging apparatus according to the first embodiment.

The ophthalmologic imaging apparatus according to the first embodiment includes a scanning system, a detection system, an image forming unit (for example, an image forming unit 110), and an image synthesizing unit (for example, a data processing unit 120). The scanning system scans the fundus of the eye to be inspected with light. The detection system detects a first polarization component and a second polarization component that are different from each other in the return light of the scanning light from the eye to be inspected. The image forming unit forms the first image based on the detection result of the first polarization component, and forms the second image based on the detection result of the second polarization component. The image composition unit forms a composite image of the first image and the second image.

In the first embodiment, the scanning system can scan the fundus with linearly polarized light. Further, in the first embodiment, the angle formed by the polarization axis of the linearly polarized light and the polarization axis of the first polarization component (for example, the orthogonal Nicol state), the polarization axis of the linearly polarized light, and the polarization axis of the second polarization component. The angle formed by (for example, the parallel Nicol state) is different.

In the first embodiment, the scanning system scans the fundus with the first scanning light, which is the linearly polarized light of the first polarization axis, and is the linearly polarized light of the second polarization axis different from the first polarization axis. The fundus is scanned with the second scanning light. The detection system detects a predetermined polarization component of the return light of the first scanning light from the eye to be inspected as the first polarization component, and a second polarization component of the return light of the second scanning light from the eye to be inspected. It can be detected as a polarization component. Here, scanning with the first scanning light and detection of the first polarizing component correspond to, for example, imaging in an orthogonal Nicol state, and scanning with the second scanning light and detection of the second polarizing component are, for example, in a parallel Nicol state. Equivalent to shooting in.

In the first embodiment, the scanning system may include a light source unit that outputs linearly polarized light. The light source unit includes, for example, a first light source 1A, a first collimating lens 2A, and a first polarizing element 3A. Further, the ophthalmologic imaging apparatus according to the first embodiment may include a first drive unit and a first control unit. The first drive unit can rotate at least a part of the light source unit about the optical axis of the scanning system. The first drive unit includes, for example, a scanning light rotation drive unit 30 that rotates the first polarizing element 3A. By controlling the first driving unit, the first control unit can switch between scanning with the first scanning light and scanning with the second scanning light. The first control unit includes, for example, a control unit 100 (main control unit 101).

The image synthesizing unit (for example, the data processing unit 120) of the ophthalmologic photographing apparatus according to the first embodiment may include an averaging synthesizing unit (for example, an averaging unit 122). The additive averaging unit includes a first region (for example, peripheral region J1) which is at least a part of the first image and a second region (for example, peripheral region J2) which is a region of the second image corresponding to the first region. Additive average synthesis is possible.

The image synthesis unit (for example, the data processing unit 120) of the ophthalmologic photographing apparatus according to the first embodiment may include a partial region specifying unit (for example, a partial region specifying unit 121). The partial region specifying portion is a region of the first partial region (for example, the central region H2) which is a part of one of the first image and the second image, and the region of the other image corresponding to the first partial region. A second subregion (eg, central region H1) can be identified. In this case, the image composition unit can form a composite image including only one of the first partial region and the second partial region (for example, the central region H1).

In the first embodiment, a synthesis processing section (123) is provided in addition to the partial region specifying section (121) and the addition average synthesis section (122). The partial region specifying portion is a region of the first partial region (for example, the central region H2) which is a part of one of the first image and the second image, and the region of the other image corresponding to the first partial region. Identify a second subregion (eg, central region H1). The additive averaging unit includes a third partial region (for example, peripheral region J2) which is a region of the first image different from the first partial region, and a fourth partial region (for example, a region of the second image corresponding to the third partial region). For example, the peripheral region J1) and the peripheral region J1) are added and averaged. The synthesizing unit forms a composite image by synthesizing one of the first partial region and the second partial region (for example, the central region H1) and the averaging image (G3) formed by the averaging synthesizing unit (FIG. See 10).

According to such a first embodiment, it is possible to detect a first polarization component and a second polarization component that are different from each other, form a first image and a second image based on these, and form a composite image thereof. can. For example, according to the first embodiment, the images are taken in the orthogonal Nicol state and the parallel Nicol state, respectively, and the first image G1 in the orthogonal Nicol state and the second image G2 in the parallel Nicol state are combined (specification of a partial region). , Additive average composition, etc.), an image without ghosts (with reduced ghosts) can be obtained. Further, it is also possible to acquire an image in which the entire scanning area is depicted.

<Second Embodiment>
The ophthalmologic imaging apparatus according to the second embodiment will be described. 12 and 13 show an example of the configuration of the ophthalmologic imaging apparatus according to the second embodiment. FIG. 12 shows an example of an optical system. FIG. 13 shows an example of a processing system. Unless otherwise specified, the elements of the ophthalmologic imaging apparatus according to the present embodiment may be the same as those of the first embodiment.

The ophthalmologic imaging apparatus according to the second embodiment is provided with a 1/2 wavelength plate (λ / 2 plate) 21 between the first splitter 3A and the dichroic mirror (or half mirror or the like) 4 (FIG.). 12) and the point that the processing system is provided with the scanning light rotation drive unit 31 (see FIG. 13), which is different from the first embodiment. It is possible to provide the same configuration on the second scanning optical path OP2 side.

The scanning light rotation drive unit 31 rotates the 1/2 wave plate 21 around the optical axis of the scanning system (the optical axis of the first scanning optical path OP1). Alternatively, the scanning light rotation drive unit 31 inserts / removes the 1/2 wavelength plate 21 from the optical path (first scanning optical path OP1) of the scanning system.

The scanning light rotation drive unit 31 for rotating the 1/2 wave plate 21 is a 1/2 wave plate 21 under the control of the control unit 100 (main control unit 101) or in response to a manual operation. Can be switched between the first rotation state and the second rotation state. Thereby, the direction of the linear polarization generated by the first polarizing element 3A can be controlled according to the rotational state of the 1/2 wave plate 21. Therefore, as in the first embodiment, the first scanning light, which is the linearly polarized light of the first polarizing axis, and the second scanning light, which is the linearly polarized light of the second polarizing axis different from the first polarizing axis, are combined. , Can be selectively generated. In a typical example, the scanning light rotation drive unit 31 has an actuator that generates a driving force according to a control signal from the control unit 100 (main control unit 101) and a 1/2 according to the driving force generated from this actuator. It includes a mechanism for rotating the wave plate 21. The actuator is, for example, a pulse motor.

The scanning light rotation drive unit 31 for inserting and removing the 1/2 wave plate 21 is the first scanning optical path OP1 under the control of the control unit 100 (main control unit 101) or in response to a manual operation. The 1/2 wave plate 21 can be inserted and removed. As a result, the direction of the linear polarization generated by the first polarizing element 3A is set in the arrangement state of the 1/2 wave plate 21 (the state in which it is arranged in the scanning optical path OP1 or the state in which it is retracted from the scanning optical path OP1). Can be controlled according to. Therefore, as in the first embodiment, the first scanning light, which is the linearly polarized light of the first polarizing axis, and the second scanning light, which is the linearly polarized light of the second polarizing axis different from the first polarizing axis, are combined. , Can be selectively generated. In a typical example, the scanning light rotation drive unit 31 has an actuator that generates a driving force according to a control signal from the control unit 100 (main control unit 101) and a 1/2 according to the driving force generated from this actuator. It includes a mechanism for moving the wave plate 21. The actuator is, for example, a solenoid coil.

The operation of the ophthalmologic imaging apparatus according to the second embodiment will be described. The operation in the second embodiment is executed, for example, in the same flow as in FIG. However, in the second embodiment, in step S6, the main control unit 101 controls the scanning light rotation drive unit 31 to rotate or insert / remove the 1/2 wave plate 21 to change the state of the optical system into orthogonal Nicols. Switch from the state to the parallel Nicol state (or switch the state of the optical system from the parallel Nicol state to the orthogonal Nicol state).

As described above, the scanning system of the ophthalmologic imaging apparatus according to the second embodiment includes the 1/2 wave plate (21). Further, the ophthalmologic imaging apparatus according to the second embodiment includes a second drive unit (for example, a scanning light rotation drive unit 31) and a second control unit (for example, a control unit 100). The second drive unit can rotate the 1/2 wave plate around the optical axis of the scanning system, or can insert / remove the 1/2 wave plate from the optical path of the scanning system. The second control unit can switch between scanning with the first scanning light and scanning with the second scanning light by controlling the second driving unit.

According to such a second embodiment, it is possible to obtain an image without ghosts (with reduced ghosts) as in the first embodiment. Further, it is also possible to acquire an image in which the entire scanning area is depicted.

<Third Embodiment>
The ophthalmologic imaging apparatus according to the third embodiment will be described. 14 and 15 show an example of the configuration of the ophthalmologic imaging apparatus according to the third embodiment. FIG. 14 shows an example of an optical system. FIG. 15 shows an example of a processing system. Unless otherwise specified, the elements of the ophthalmologic imaging apparatus according to the present embodiment may be the same as those of the first embodiment and the like.

The ophthalmologic photographing apparatus according to the third embodiment is provided with a polarizing rotor 22 between the first splitter 3A and the dichroic mirror (or half mirror or the like) 4 (see FIGS. 14 and 15).
Is different from the first embodiment. It is possible to provide the same configuration on the second scanning optical path OP2 side.

The polarization rotator 22 operates under the control of the control unit 100. The polarization rotator 22 may have an action of rotating the polarization axis of linearly polarized light, and its specific configuration is not limited. Examples of the polarizing rotor 22 include those using a liquid crystal element and those using acoustic optical technology.

The operation of the ophthalmologic imaging apparatus according to the third embodiment will be described. The operation in the third embodiment is executed, for example, in the same flow as in FIG. However, in the third embodiment, in step S6, the main control unit 101 switches the state of the optical system from the orthogonal Nicol state to the parallel Nicol state (or changes the state of the optical system) by controlling the polarizing rotor 22. Switch from the parallel optics state to the orthogonal optics state).

As described above, the scanning system of the ophthalmologic imaging apparatus according to the third embodiment includes a polarization rotator (22) that rotates the polarization axis of linearly polarized light, and a third control unit (for example, control unit 100) that controls the polarization rotator (22). And include. By controlling the polarization rotator, the third control unit can switch between scanning with the first scanning light and scanning with the second scanning light.

According to such a third embodiment, it is possible to obtain an image without ghosts (with reduced ghosts) as in the first embodiment. Further, it is also possible to acquire an image in which the entire scanning area is depicted.

<Fourth Embodiment>
The ophthalmologic imaging apparatus according to the fourth embodiment will be described. The ophthalmologic imaging apparatus according to the fourth embodiment may include an optical system similar to that of the first embodiment (see FIG. 1). FIG. 16 shows an example of the configuration of the processing system of the ophthalmologic imaging apparatus according to the fourth embodiment. Unless otherwise specified, the elements of the ophthalmologic imaging apparatus according to the present embodiment may be the same as those of the first embodiment and the like.

The scanning system of the ophthalmologic imaging apparatus according to the fourth embodiment scans the fundus Ef with light of linearly polarized light in a predetermined direction defined by the first polarizing element 3A or the like. The detection system detects the first polarization component and the second polarization component of the return light from the eye E to be inspected for the linearly polarized scanning light. The first polarization component is a polarization component forming a first angle with respect to the polarization axis (the predetermined direction) of the scanning light. On the other hand, the second polarization component is a polarization component that forms a second angle (the second angle is different from the first angle) with respect to the polarization axis of the scanning light.

The detection light rotation drive unit 32 shown in FIG. 16 has a first linear polarizing element 13A that converts the return light from the eye E to be linearly polarized light into the optical axis of the detection system (the optical axis of the first detection optical path OP6). Rotate around. It is possible to provide the same configuration on the second scanning optical path OP2 side.

The detection light rotation drive unit 32 sets the first linear splitter 13A in the first rotation state and the second rotation state under the control of the control unit 100 (main control unit 101) or in response to a manual operation. Can be switched to. Thereby, the direction (polarization axis) of the polarization component to be detected by the first photodetector 16A can be controlled according to the rotational state of the first linear polarizing element 13A. Therefore, similarly to the first embodiment, it is possible to selectively detect the first polarization component and the second polarization component that are different from each other. In a typical example, the detection light rotation drive unit 32 has an actuator that generates a driving force according to a control signal from the control unit 100 (main control unit 101) and a first linear line according to the driving force generated from the actuator. It includes a mechanism for rotating the stator 13A. The actuator is, for example, a pulse motor.

The operation of the ophthalmologic imaging apparatus according to the fourth embodiment will be described. The operation in the fourth embodiment is executed, for example, in the same flow as in FIG. However, in the fourth embodiment, in step S6, the main control unit 101 controls the detection light rotation drive unit 32 to rotate the first linear splitter 13A, thereby detecting the first polarization component and the second polarization. Switch between component detection and. Thereby, for example, the state of the optical system can be switched from the orthogonal Nicol state to the parallel Nicol state, or the state of the optical system can be switched from the parallel Nicol state to the orthogonal Nicol state.

As described above, in the ophthalmologic imaging apparatus according to the fourth embodiment, the detection system includes a linear splitter (first linear splitter 13A) and a photodetector (first photodetector 16A). The linear deflector converts the return light from the eye to be inspected into linearly polarized light. The photodetector detects linearly polarized light produced by the linearly polarized light. Further, the ophthalmologic imaging apparatus according to the fourth embodiment includes a third drive unit (for example, a detection light rotation drive unit 32) and a fourth control unit (for example, a control unit 100). The third drive unit can rotate the linear polarizing element around the optical axis of the detection system. The fourth control unit can switch between the detection of the first polarization component and the detection of the second polarization component by controlling the third drive unit.

According to such a fourth embodiment, it is possible to obtain an image without ghosts (with reduced ghosts) as in the first embodiment. Further, it is also possible to acquire an image in which the entire scanning area is depicted.

The method for changing the polarization axis of the detected light is not limited to rotating the first linear polarizing element 13A. For example, a configuration in which a 1/2 wave plate is arranged in the first detection optical path OP6 and is rotated can be applied. Alternatively, a configuration in which the 1/2 wave plate is inserted / removed from the first detection optical path OP6 can be applied. In another example, it is possible to apply a configuration in which a polarizing rotor using a liquid crystal element, acoustic optical technology, or the like is arranged in the first detection optical path OP6 and controlled thereof.

<Fifth Embodiment>
The ophthalmologic imaging apparatus according to the fifth embodiment will be described. 17 and 18 show an example of the configuration of the ophthalmologic imaging apparatus according to the fifth embodiment. FIG. 17 shows an example of an optical system. FIG. 18 shows an example of a processing system. Unless otherwise specified, the elements of the ophthalmologic imaging apparatus according to the present embodiment may be the same as those of the first embodiment and the like.

The ophthalmologic imaging apparatus according to the fifth embodiment performs detection of the first polarization component and detection of the second polarization component in parallel (that is, at the same time). As illustrated in FIG. 17, the ophthalmologic imaging apparatus according to the fifth embodiment is different from the first embodiment in the configuration provided in the first detection optical path OP6 formed by the dichroic mirror 12.

First, the first detection optical path OP6 is provided with a polarization beam splitter 17A. The polarization beam splitter 17A splits the return light from the eye E incident on the first detection optical path OP6 into two polarization components.

The polarization component (for example, the P polarization component) transmitted through the polarization beam splitter 17A is incident on the detection optical path OP61. On the other hand, the polarization component (for example, the S polarization component) reflected by the polarization beam splitter 17A is incident on the detection optical path OP62.

The P-polarized component incident on the detection optical path OP61 is refracted by the condenser lens 14C and projected onto the confocal diaphragm 15C. When the alignment is suitable, the confocal diaphragm 15C is arranged at a position (or near) optically conjugate with the fundus Ef. The confocal diaphragm 15C acts to block at least a part of noise light (such as scattered light in the fundus) contained in the P polarization component and selectively pass the reflected light from the surface of the fundus Ef. The P-polarized component that has passed through the confocal diaphragm 15C is detected by the photodetector 16C.

Similarly, the S-polarized component incident on the detection optical path OP62 is refracted by the condenser lens 14D and projected onto the confocal diaphragm 15D. When the alignment is suitable, the confocal diaphragm 15D is arranged at a position (or in the vicinity thereof) optically conjugate to the fundus Ef. The confocal diaphragm 15D acts to block at least a part of noise light (such as scattered light from the fundus) contained in the S polarization component and selectively pass the reflected light from the surface of the fundus Ef. The S-polarized component that has passed through the confocal diaphragm 15D is detected by the photodetector 16D.

The data collected by the photodetector 16C and the data collected by the photodetector 16D are input to the image forming unit 110, respectively. The image forming unit 110 forms an image (for example, the first image G1 shown in FIG. 4A) based on the data collected by the photodetector 16C. Further, the image forming unit 110 forms an image (for example, the second image G2 shown in FIG. 4B) based on the data collected by the photodetector 16D.

The polarization component detected by the photodetector 16C and the polarization component detected by the photodetector 16D are orthogonal to each other. Therefore, according to the fifth embodiment, it is possible to simultaneously detect the first polarization component and the second polarization component that are different from each other in the return light from the eye E to be inspected. Typically, the photodetector 16C is used for imaging in the orthogonal Nicol state (or parallel Nicol state), and the photodetector 16D is used for imaging in the parallel Nicol state (or orthogonal Nicol state). ..

The operation of the ophthalmologic imaging apparatus according to the fifth embodiment will be described. An example of the operation in the fifth embodiment is shown in FIG. Steps S1 to S4 are executed in the same manner as in the first embodiment (see FIG. 11).

In this operation example, step S21 is executed instead of steps S5 to S7 in FIG. That is, in the first to fourth embodiments, the detection of the first polarization component and the detection of the second polarization component (for example, shooting in the orthogonal Nicol state and shooting in the parallel Nicol state) are sequentially executed, but the fifth. In the embodiment, these are executed in parallel (that is, at the same time).

When the first image and the second image are acquired based on such parallel photographing, steps S8 to S10 are executed in the same manner as in the first embodiment.

As described above, in the ophthalmologic imaging apparatus according to the fifth embodiment, the detection system includes a first polarization beam splitter (for example, a polarization beam splitter 17A), a first photodetector (for example, a photodetector 16C), and a second light. Includes a detector (eg, photodetector 16D). The first polarization beam splitter can split the return light from the eye to be inspected into two polarization components. The first photodetector can detect one of the two polarization components generated by the first polarization beam splitter as the first polarization component. The second photodetector can detect the other of these two polarization components as the second polarization component.

According to such a fifth embodiment, it is possible to obtain an image without ghosts (with reduced ghosts) as in the first embodiment. Further, it is also possible to acquire an image in which the entire scanning area is depicted.

Further, according to the fifth embodiment, since the detection of the first polarization component and the detection of the second polarization component can be executed in parallel, the detection of the first polarization component and the detection of the second polarization component are sequentially executed. It is possible to shorten the shooting time as compared with the case of

Further, according to the fifth embodiment, it is not necessary to provide a mechanism for switching between the detection of the first polarization component and the detection of the second polarization component, so that the mechanism and control can be simplified.

<Sixth Embodiment>
In the sixth embodiment, an example of scanning the fundus with circularly polarized or elliptically polarized light will be described. FIG. 20 shows an example of the configuration of the optical system of the ophthalmologic imaging apparatus according to the sixth embodiment. The processing system may be, for example, the same as that of the fourth embodiment (see FIG. 16). Unless otherwise specified, the elements of the ophthalmologic imaging apparatus according to the present embodiment may be the same as those of the first embodiment and the like.

As shown in FIG. 20, in the ophthalmologic imaging apparatus according to the sixth embodiment, a wavelength plate (for example, λ / 4 plate) 23 is provided between the first polarizing element 3A and the dichroic mirror (or half mirror or the like) 4. This is different from the first embodiment in that a wave plate (for example, a λ / 4 plate) 24 is provided between the dichroic mirror 12 and the first linear splitter 13A. Further, the processing system according to the sixth embodiment is provided with the same detection light rotation drive unit 32 as the fourth embodiment. It is possible to provide the same configuration on the second scanning optical path OP2 side and the second detection optical path OP2 side.

When the λ / 4 plate is applied as the wavelength plate 23 arranged in the first scanning optical path OP1, the wavelength plate 23 converts the linearly polarized light formed by the first splitter 3A into circularly polarized light. In this case, the light that has become circularly polarized when it has passed through the wave plate 23 (λ / 4 plate) is incident on the eye E to be inspected due to the polarization characteristics and phase characteristics of the optical elements arranged in the scanning system. It becomes elliptically polarized. In such a case, the fundus Ef is scanned with the scanning light of elliptically polarized light.

On the other hand, it is possible to design the scanning system so that it becomes circularly polarized when it is incident on the eye E to be inspected. For example, the phase difference characteristic of the wave plate 23 can be set to the phase difference obtained by subtracting the total amount of the phase difference given by the optical elements constituting the scanning system from λ / 4. As a result, a phase difference λ / 4 is imparted to the scanning light output from the first light source 1A by the entire scanning system, whereby the fundus Ef is scanned with (substantially) circularly polarized scanning light. It becomes possible.

The wave plate 24 (for example, λ / 4 plate) arranged in the first detection optical path OP6 converts the return light which is circularly polarized light or elliptically polarized light into linearly polarized light. In the sixth embodiment, the detection light rotation drive unit 32 can rotate the wave plate 24 around the optical axis of the first detection optical path OP6, for example. Alternatively, the detection light rotation drive unit 32 can rotate the first linear splitter 13A around the optical axis of the first detection optical path OP6. By such a rotation operation, it is possible to rotate the polarization axis of the light incident on the first photodetector 16A.

Thereby, the detection of the first polarization component and the detection of the second polarization component can be selectively performed. Typically, it is possible to switch between shooting in the orthogonal Nicol state and shooting in the parallel Nicol state. Further, the data processing unit 120 of the ophthalmologic imaging apparatus according to the sixth embodiment is similar to the first embodiment by synthesizing the first image and the second image acquired by such two-step imaging. It is possible to form a composite image.

As described above, in the ophthalmologic imaging apparatus according to the sixth embodiment, the scanning system can scan the fundus with each of the third scanning light and the fourth scanning light, which are circularly polarized light or elliptically polarized light. Further, the detection system detects a predetermined polarization component of the return light of the third scanning light from the eye to be inspected as the first polarization component, and detects a predetermined polarization component of the return light of the fourth scanning light from the eye to be inspected. It is detected as a second polarization component.

Typically, when the scanning system and the detection system are set to the orthogonal Nicol state (or parallel Nicol state), the fundus is scanned with a third scanning light of circularly polarized light or elliptically polarized light, and the return light thereof is predetermined. Detects the polarization component of. The first image is formed based on the data collected in this way. Further, when the scanning system and the detection system are set to the parallel Nicol state (or orthogonal Nicol state), the fundus is scanned with the fourth scanning light of circularly polarized light or elliptically polarized light, and a predetermined polarizing component of the return light thereof is scanned. Is detected. A second image is formed based on the data collected in this way. The ophthalmologic imaging apparatus according to the sixth embodiment forms a composite image of the first image and the second image thus obtained.

According to such a sixth embodiment, it is possible to obtain an image without ghosts (with reduced ghosts) as in the first embodiment. Further, it is also possible to acquire an image in which the entire scanning area is depicted.

<7th Embodiment>
Also in the seventh embodiment, an example of scanning the fundus with circularly polarized or elliptically polarized light will be described. FIG. 21 shows an example of the configuration of the optical system of the ophthalmologic imaging apparatus according to the seventh embodiment. Unless otherwise specified, the elements of the ophthalmologic imaging apparatus according to the present embodiment may be the same as those of the first embodiment and the like. The ophthalmologic imaging apparatus according to the seventh embodiment scans the fundus with light of circularly polarized light or elliptically polarized light, and detects the first polarized light component and the second polarized light component in parallel (that is, simultaneously). It is configured in.

Similar to the sixth embodiment, the ophthalmologic imaging apparatus according to the seventh embodiment includes a wave plate (for example, a λ / 4 plate) 23 between the first splitter 3A and the dichroic mirror (or half mirror or the like) 4. .. Further, the first detection optical path OP6 of the ophthalmologic imaging apparatus according to the seventh embodiment is provided with the same optical system as that of the fifth embodiment.

The polarization beam splitter 17A provided in the first detection optical path OP6 divides the return light of circular polarization or elliptically polarized light incident on the first detection optical path OP6 into two polarization components. The polarization component (for example, the P polarization component) transmitted through the polarization beam splitter 17A is incident on the detection optical path OP61. On the other hand, the polarization component (for example, the S polarization component) reflected by the polarization beam splitter 17A is incident on the detection optical path OP62.

The P-polarized component incident on the detection optical path OP61 is refracted by the condenser lens 14C and projected onto the confocal diaphragm 15C. The P-polarized component that has passed through the confocal diaphragm 15C is detected by the photodetector 16C.

Similarly, the S-polarized component incident on the detection optical path OP62 is refracted by the condenser lens 14D and projected onto the confocal diaphragm 15D. The S-polarized component that has passed through the confocal diaphragm 15D is detected by the photodetector 16D.

The data collected by the photodetector 16C and the data collected by the photodetector 16D are input to the image forming unit 110, respectively. The image forming unit 110 forms an image (for example, the first image G1 shown in FIG. 4A) based on the data collected by the photodetector 16C. Further, the image forming unit 110 forms an image (for example, the second image G2 shown in FIG. 4B) based on the data collected by the photodetector 16D.

The polarization component detected by the photodetector 16C and the polarization component detected by the photodetector 16D are orthogonal to each other. Therefore, according to the seventh embodiment, it is possible to simultaneously detect the first polarization component and the second polarization component that are different from each other in the return light from the eye E to be inspected. Typically, the photodetector 16C is used for imaging in the orthogonal Nicol state (or parallel Nicol state), and the photodetector 16D is used for imaging in the parallel Nicol state (or orthogonal Nicol state). ..

As described above, in the ophthalmologic imaging apparatus according to the seventh embodiment, the detection system includes a second polarization beam splitter (for example, a polarization beam splitter 17A), a third photodetector (for example, a photodetector 16C), and a fourth light. Includes a detector (eg, photodetector 16D). The second polarization beam splitter can split the return light of the circularly polarized or elliptically polarized scanning light from the eye to be examined into two polarization components. The third photodetector can detect one of the two polarization components generated by the second polarization beam splitter as the first polarization component. The fourth photodetector can detect the other of these two polarization components as the second polarization component.

According to such a seventh embodiment, it is possible to obtain an image without ghosts (with reduced ghosts) as in the first embodiment. Further, it is also possible to acquire an image in which the entire scanning area is depicted.

Further, according to the seventh embodiment, since the detection of the first polarization component and the detection of the second polarization component can be executed in parallel, the detection of the first polarization component and the detection of the second polarization component are sequentially executed. It is possible to shorten the shooting time as compared with the case of

Further, according to the seventh embodiment, it is not necessary to provide a mechanism for switching between the detection of the first polarization component and the detection of the second polarization component, so that the mechanism and control can be simplified.

<Modification example>
The first to seventh embodiments shown above are merely examples for carrying out the present invention. A person who intends to carry out the present invention can make arbitrary modifications, omissions, additions, etc. within the scope of the gist of the present invention.

In the first to seventh embodiments, both the detection of the first polarization component and the detection of the second polarization component are performed by using the scanning light having the same polarization characteristics, but the embodiment is not limited to this. For example, the linearly polarized scanning light can be used to detect the first polarization component, and the circularly polarized (or elliptically polarized) scanning light can be used to detect the second polarization component. On the contrary, the first polarization component can be detected by using the circularly polarized (or elliptically polarized) scanning light, and the second polarizing component can be detected by using the linearly polarized scanning light.

In the first to seventh embodiments, two different polarization components are detected, but it is also possible to detect three or more different polarization components. When detecting three or more polarized components, all of these polarized components may be detected sequentially, or at least a part of these polarized components may be detected at the same time. That is, the selection or combination of sequential detection and parallel detection may be arbitrary. Needless to say, embodiments for detecting three or more different polarization components are also included in the scope of the gist of the present invention.

1A 1st light source 3A 1st polarizing element 5 Optical path synthesizer 9 Optical scanner 11 Objective lens 12 Dycroic mirror 13A 1st linear polarizing element 16A 1st optical detector 16C Optical detector 16D Optical detector 17A Polarized beam splitter 21 1/2 Wave plate 22 Polarizing rotor 23 Wave plate 24 Wave plate 30 Scanning light rotation drive unit 31 Scanning light rotation drive unit 32 Detection light rotation drive unit 100 Control unit 110 Image forming unit 120 Data processing unit 121 Partial area identification unit 122 Addition average synthesis Part 123 Synthesis processing part

Claims (4)

An ophthalmologic imaging device that scans the fundus of the eye to be inspected with light to form an image.
An optical system capable of collecting data in both orthogonal and parallel Nicol states, and
An image that forms a first image based on the first data collected by the optical system in the orthogonal Nicol state and forms a second image based on the second data collected by the optical system in the parallel Nicol state. Forming part and
A partial region specifying portion that identifies the first central region in the first image and identifies the second central region that is the region of the second image corresponding to the first central region .
Additive averaging of the first peripheral region, which is the region excluding the first central region in the first image, and the second peripheral region, which is the region excluding the second central region in the second image, are added and averaged. Synthetic part and
The first central region and the image synthesizing unit forming a composite image of the averaging combined image formed by averaging the first peripheral region and the second peripheral region by the averaging synthesizing unit. Equipped with an ophthalmologic imaging device. The ophthalmologic imaging apparatus according to claim 1, wherein the optical system sequentially collects data in the orthogonal Nicol state and data in the parallel Nicol state. The ophthalmologic imaging apparatus according to claim 1, wherein the optical system collects data in the orthogonal Nicol state and collects data in the parallel Nicol state in parallel. The ophthalmologic photographing apparatus according to any one of claims 1 to 3, wherein the optical system scans the fundus with linearly polarized light.

Images