JP2003088503A - Fundus camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently perform a rough positioning without requring the switch operation by a photographer by switching a fundus observation state to an anterior ocular segment observation state on the basis of the presence of receipt of the reflected image of an index projected to the anterior ocular segment of an eye to be tested. SOLUTION: When the photographer presses an anterior ocular segment/ fundus change-over switch in the anterior ocular segment observation state, and the anterior ocular segment observation state is changed to the fundus observation state, a processing is started. In step 100, the number of frames is set to n=0. In step 101, the detection of the reflected image of an alignment index is performed from a digital image of one frame stored in an image processing part. When the reflected image of the alignment index is not detected in step 102, the procedure is advanced to stop 103, where n=1+1 is set. In step 104, n>=T or not is judged. When n is a threshold T or more, the procedure is advanced to step 105, and the fundus observation state is switched to the anterior ocular segment observation state by an anterior ocular segment/ fundus switching control part.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a fundus camera used in an ophthalmology clinic or the like.

[0002]

2. Description of the Related Art Conventionally, in an ophthalmologic imaging apparatus such as a non-mydriasis fundus camera, when observing and photographing the fundus of a subject, first, roughly aligning the eye with the subject's eye while observing the anterior segment. Then, switch from the anterior segment observation state to the fundus observation state, observe the reflection image of the alignment index projected on the fundus of the eye to be examined on the television monitor, and this alignment index is projected at a predetermined position on the fundus. By moving the device body vertically and horizontally, the optical axes of the eye to be inspected and the fundus camera are precisely aligned.

However, in the fundus observation state, when the subject's face moves or the relative position with respect to the eye is greatly displaced during the fundus observation state, the alignment index is no longer observed. It is difficult to perform precise alignment with the eye to be examined.

Therefore, for example, in Japanese Unexamined Patent Publication No. 8-98805, a face movement detection means for the subject is provided, and in conjunction with the movement of the subject's face during the fundus observation state, the eye fundus observation state to the anterior segment observation state. There has been proposed an ophthalmologic photographing apparatus capable of performing rough alignment efficiently even if the photographer does not perform a switch operation by switching to.

[0005]

However, in the above-mentioned conventional example, since the alignment with the eye to be inspected during fundus observation is extremely delicate, there is no movement of the subject's face and only movement of the eye to be inspected. However, the alignment index may not be observed. Further, if the operator is not skilled in the alignment, the alignment index will not be observed even if the apparatus main body is moved in the vertical and horizontal directions too much. Therefore, it cannot be said that the above-described conventional example that supports only the face movement of the subject is sufficient.

An object of the present invention is to solve the above problems and to switch from a fundus oculi observation state to an anterior ocular segment observation state in association with an observation state of a reflection image of an alignment index projected on an anterior eye portion of an eye to be examined. Therefore, it is an object of the present invention to provide an ophthalmologic photographing apparatus capable of efficiently performing rough alignment without the photographer performing a switch operation.

[0007]

A fundus camera according to the present invention for achieving the above object comprises an anterior segment observation means for observing an anterior segment of an eye and a fundus observation for observing a fundus image of the eye. Means, switching means for switching the anterior segment observation state by the anterior segment observation unit and the fundus observation state by the fundus observation unit, projection means for projecting an index on the anterior segment of the eye to be examined, and the projection unit Light receiving means for receiving the reflected image of the index projected on the anterior segment of the optometry, and determination means for determining whether to switch from the fundus observation state to the anterior segment observation state depending on the presence or absence of light reception by the light receiving means. It is characterized by having.

Further, the fundus camera according to the present invention comprises an anterior ocular segment observing means for observing the anterior ocular segment of the subject's eye, a retinal observing device for observing a retinal image of the subject's eye, and the anterior ocular segment observing device. Switching means for switching between an eye observation state and a fundus observation state by the fundus observation means, projection means for projecting an index on the anterior eye part of the eye to be examined, and reflection of the index projected on the anterior eye part of the eye by the projection means. Light receiving means for receiving an image, input detecting means for detecting the presence / absence of input of an alignment operation in the fundus observation state, measuring means for measuring an elapsed time from the final input detected by the input detecting means, and the light receiving means. And a determination unit that determines whether or not to switch from the fundus oculi observation state to the anterior ocular segment observation state based on the presence or absence of light reception and the elapsed time by the measurement unit.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail based on the illustrated embodiments. FIG. 1 is a configuration diagram of a fundus camera. On the optical path behind the objective lens 1 facing the eye E to be inspected, an anterior ocular segment observation lens 2 which can be freely inserted into and removed from the optical path, a perforated mirror 3, and the perforated mirror. The photographing diaphragm 4 arranged in the hole of the mirror, the focus lens 5 for moving in the optical path direction to adjust the focus, the photographing lens 6, the switching mirror 7, and the still image capturing unit 8 are sequentially arranged. Further, the mirror 9, the field lens 10, and the imaging lens 1 are arranged in the reflection direction of the switching mirror 7.
1. Arrange the moving image capturing section 12. When the switching mirror 7 is removed from the optical path, a photographing optical system is configured to capture an image by the still image capturing unit 8. When the switching mirror 7 is inserted in the optical path, a capturing optical system is configured to capture a moving image capturing unit 12.
To image.

An anterior ocular segment illumination light source 13 is arranged near the objective lens 1, and a fundus illumination optical system (not shown) is provided in the incident direction of the perforated mirror 3. When the anterior segment observation lens 2 is inserted in the optical path, the observation optical system constitutes an anterior segment observation means, and when the anterior segment observation lens 2 is separated from the optical path, the fundus. It constitutes an observation means.

The ends of the optical fibers 14a and 14b are arranged on both sides of the photographing diaphragm 4 in the hole of the perforated mirror 3,
The other ends of the optical fibers 14a and 14b are connected to alignment index illumination light sources 15a and 15b that emit infrared light to form an index illumination optical system.

Still image pickup unit 8 and moving image pickup unit 12
Is connected to the image controller 21 having the memory 21a, and the output of the image controller 21 is connected to the television monitor 22 and the image processor 23. The image processing unit 23 is connected to the anterior segment / fundus switching control unit 25 via the anterior segment / fundus switching determination unit 24. The outputs of the anterior segment / fundus switching control unit 25 are the alignment illumination light sources 15a and 15b, and the anterior segment illumination light source 1
3. Connect to the anterior segment observation lens 2. Further, the anterior segment / fundus changeover determination unit 24 is connected to an anterior segment / fundus changeover switch (not shown).

When the anterior ocular segment observation lens 2 is inserted in the optical path, the infrared light emitted from the anterior ocular segment illumination light source 13 is reflected from the anterior ocular segment by the objective lens 1 and the anterior ocular segment. Section observation lens 2, photographing diaphragm 4, focus lens 5, photographing lens 6, switching mirror 7, mirror 9, field lens 10,
An image is captured as an anterior segment image by the moving image capturing unit 12 via the imaging lens 11, and is displayed on the television monitor 22 via the image control unit 21.

When the anterior ocular segment observation lens 2 is separated from the optical path, infrared light emitted from the fundus illumination optical system (not shown) is reflected from the fundus Er, and the objective lens 1 and the photographing diaphragm 4 are used. Focus lens 5, photographing lens 6, switching mirror 7, mirror 9, field lens 10, imaging lens 11
The image is picked up as a fundus image by the moving image pick-up unit 12 and displayed on the television monitor 22. When the anterior segment observation lens 2 is separated from the optical path, the light from the alignment index illuminating light sources 15a and 15b is guided by the optical fibers 14a and 14b, and is emitted from the hole of the perforated mirror 3. The fundus Er is illuminated through the objective lens 1. The reflected light from the fundus Er is similarly picked up by the moving image pick-up unit 12 and displayed on the television monitor 22.

The image control unit 21 A / D-converts the signal obtained by the still image pickup unit 8 and stores it in the memory 21a as a digital image at the time of photographing with the switching mirror 7 removed from the optical path. Further, in the image control unit 21, during observation with the switching mirror 7 inserted in the optical path, the signal output from the moving image capturing unit 12 is A / D converted in real time and stored in the memory 21a as a digital image for each frame. Store.

In such a structure, when the photographer presses the anterior segment / fundus changeover switch (not shown) in the fundus observation state, the anterior segment / fundus switching determination unit 24 changes the fundus observation state to the anterior segment observation state. It is determined to switch, the anterior segment / fundus switching control unit 25 inserts the anterior segment observation lens 2 into the optical path, turns on the anterior segment illumination light source 13, and turns off the alignment index illumination light sources 15a and 15b. .

In the anterior segment observation state, the photographer roughly aligns with the subject's eye E while observing the anterior segment. When this alignment is completed and the photographer presses the anterior segment / fundus changeover switch in the anterior segment observation state, the anterior segment /
The fundus switching determination unit 24 determines to switch from the anterior segment observation state to the fundus observation state, and the anterior segment / fundus switching control unit 25 removes the anterior segment observation lens 2 from the optical path and anterior segment illumination. The light source 13 is turned off. Further, as will be described later, the alignment index illuminating light sources 15a and 15b are flickered by a half cycle.

The photographer uses the alignment index illuminating light sources 15a and 15b to observe the eye E to be examined in the fundus observation state.
The reflection image of the alignment index projected on the fundus Er of the device is observed by the television monitor 22, and the device body is moved in the vertical and horizontal directions so that the reflection image of the alignment index is projected at a predetermined position of the fundus Er, The eye E to be inspected and the optical axis of the fundus camera are precisely aligned.

In this embodiment, while the photographer is performing precise alignment in the fundus observing state, the reflection image of the alignment index projected on the fundus Er by the alignment index illuminating light sources 15a and 15b is displayed on the television monitor. 22
It is configured to switch from the fundus observation state to the anterior segment observation state when it is determined that the alignment has been greatly deviated when the reflected image is not within the observation field of view for a certain number of frames or more. is doing.

In order to detect that the reflection image of the alignment index is not observed by the television monitor 22,
For the digital image stored in the memory 21a by the image controller 21, it is necessary to detect the reflection image of the alignment index for each frame. However, if the alignment index illuminating light sources 15a and 15b are blinked at the same cycle, for example, even when the reflection image of the alignment index is within the observation field of view, it is impossible to detect the reflection image of the alignment index when both are turned off at the same time. Therefore, it is impossible to determine whether or not the reflection image of the alignment index is within the observation visual field. Therefore, as described above, the alignment index illuminating light sources 15a and 15b are shifted by a half cycle and blinked.

Alignment index illumination light sources 15a, 15
As the observation state of the reflection images 15a ′ and 15b ′ of b, when both the reflection images 15a ′ and 15b ′ are within the observation visual field, when only one of them is within the observation visual field,
It is conceivable that neither of them is within the observation field.

Alignment index illumination light sources 15a, 15
When both the reflection images of b are within the observation visual field,
As shown in (a), the alignment index illumination light source 15a
Only the reflected image 15a 'of the alignment index illuminating light source 15a is received and observed in the time zone A during which only the light is illuminated. During the time period B when only the alignment index illumination light source 15b is turned on, the alignment index illumination light source 15
Only the reflected image 15b 'of b is received and observed. In this way, since either the reflection image 15a 'or 15b' of the alignment index is always received, it is possible to always detect the reflection image 15a 'or 15b' of the alignment index.

Alignment index illumination light sources 15a, 15
When only one of the reflection images 15a ′ and 15b ′ of b is in the observation field of view, for example, when only the reflection image 15a ′ of the alignment index illumination light source 15a is in the observation field of view, As shown in FIG. 2B, in the time period A in which only the alignment index illumination light source 15a is turned on, the reflection image 15 of the alignment index illumination light source 15a is reflected.
Only a'is received and observed. In the time period B in which only the alignment index illumination light source 15b is turned on, the alignment index reflection image 15b 'is not received and is not observed. Therefore, it is possible to detect the reflection image 15a 'or 15b' of the alignment index only while the light source for illuminating the alignment index in the observation visual field is on.

Alignment index illumination light sources 15a, 15
When the reflection images of b are not both within the observation field of view,
As shown in FIG. 2C, the reflection of the alignment index occurs in both the time period A in which only the alignment index illumination light source 15a is on and the time period B in which only the alignment index illumination light source 15b is on. Image 15a ', 15
b'is not received and is not observed. Therefore, the reflection images 15a ′ and 15b ′ of the alignment index cannot always be detected.

From the above, when the alignment index reflection images 15a 'and 15b' are not detected while the alignment index illumination light sources 15a and 15b exceed at least half a blinking cycle, the alignment index reflection image 15 is detected.
It is considered that neither a ′ nor 15b ′ is within the observation visual field.

The flowchart of FIG. 3 shows the processing procedure of the anterior segment / fundus switching determination section 24 based on these items. In the anterior segment observation state, the photographer presses the anterior segment / fundus changeover switch to start the process when the anterior segment observation state is switched to the fundus observation state.

In step 100, n = 0. Here, n is the number of frames in which no reflection image of the alignment index is continuously detected.

In step 101, the image processing section 23 detects the reflection image of the alignment index from the digital image of one frame stored in the memory 21a. In step 102, when the reflected image of the alignment index is detected in step 101, the process returns to step 100. If the reflection image of the alignment index is not detected,
Go to step 103.

In step 103, n = n + 1.
That is, the number n of frames in which the reflection image of the alignment index is not continuously detected is increased by one. Step 104
Then, it is determined whether or not n> = T. Here, T is a threshold value for determining whether to switch from the fundus observation state to the anterior segment observation state.

As described above, the threshold value T is a value that exceeds the number of frames corresponding to a half cycle of blinking of the alignment index illuminating light sources 15a and 15b. However, if the threshold value T is too small, when the observer is performing precise alignment, the state in which the reflection image of the alignment index is not within the observation field of view continues for a short time, and It switches to the eye observation state. Therefore, it is necessary to set the threshold value T so that the photographer wants to switch from the fundus observation state to the anterior segment observation state.

When n is less than T, the process returns to step 101 and the reflection image of the alignment index is detected for the next frame. When n is T or more, the process proceeds to step 105. In step 105, the anterior segment / fundus switching control unit 25
Thus, the fundus observation state is switched to the anterior segment observation state.

With the above configuration, when the reflection image of the alignment index is not observed for T frames or more in the fundus observation state, that is, when the alignment is largely deviated, the anterior segment observation is automatically performed. State, without pressing the anterior segment / fundus changeover switch,
It is possible to efficiently perform rough alignment.

If the state in which the reflection image of the alignment index is not observed immediately after switching from the anterior segment observation state to the fundus observation state, rough alignment in the anterior segment observation state is insufficient. It is thought that Therefore, in the anterior ocular segment / fundus switching determination unit 24, the threshold value T is set to be smaller than that at other times only immediately after the anterior ocular segment observation state is switched to the ocular fundus observation state. If the alignment is insufficient, it is possible to immediately return to the anterior ocular segment observation state, so that it is possible to efficiently perform rough alignment.

Even when the reflection image of the alignment index is not observed for more than T frames, if the photographer is performing the alignment operation, it is considered that the alignment operation is possible and the photographer performs the alignment operation. When the operation is stopped, it is considered that the alignment is impossible and the operation is stopped.

Therefore, in the anterior segment / fundus switching determination unit 24 of the previous embodiment, even when the reflection image of the alignment index is not observed for more than T frames,
Without immediately switching from the fundus observation state to the anterior segment observation state,
It is also effective to switch from the fundus observation state to the anterior segment observation state when the state in which the alignment index is not observed continues for T frames or more and the state in which the photographer does not perform the alignment operation continues for a certain time or longer. .

FIG. 4 is a block diagram of another embodiment, in which a timer control unit 31 having a memory 31a is connected to the anterior eye segment / fundus switching determination unit 24 as compared with the embodiment shown in FIG. A timer 32 is connected to the timer control unit 31.

In this structure, the timer control section 31 performs the processing shown in the flowchart of FIG. In the anterior segment observation state, the photographer presses an anterior segment / fundus changeover switch (not shown) to start the process when the anterior segment observation state is switched to the fundus observation state.

In step 200, the timer value 0 is stored in the memory 31a and the timer 32 is started. In step 201, it is determined whether or not this processing is to be ended. When the eye fundus observation state is switched to the anterior segment observation state, this process is terminated. If it is in the fundus oculi observation state, the process proceeds to step 202 without ending this process.

In step 202, whether or not an input relating to the alignment operation is input is detected by an input detection unit (not shown). In step 203, if an input regarding the alignment operation is detected in step 202, the process proceeds to step 204. If no input related to the alignment operation is detected, the process proceeds to step 205.

In step 204, the timer value 0 is stored in the memory 31a, the timer 32 is reset, and the process returns to step 201. In step 205, the current timer value is acquired from the timer 32, stored in the memory 31a, and the process returns to step 201.

Simultaneously with the processing of the timer control section 31, the anterior segment / fundus switching determination section 24 carries out the processing according to the flowchart shown in FIG. When the photographer observes the anterior segment,
When an anterior ocular segment / fundus changeover switch (not shown) is pressed to switch from the anterior ocular segment observation state to the ocular fundus observation state, processing is started.

In step 300, n = 0. In step 301, the image processing unit 23 detects the reflection image of the alignment index. In step 302, when the reflected image of the alignment index is detected in step 301, the process returns to step 300. When the reflected image of the alignment index is not detected, the process proceeds to step 303.

At step 303, n = n + 1.
That is, the number n of frames in which the reflection image of the alignment index is not continuously detected is increased by one. Step 304
Then, the timer value is acquired from the memory 31a. In step 305, it is determined whether n> = T and the timer value> = Time.

Here, Time is a threshold value for whether or not to switch from the fundus oculi observation state to the anterior ocular segment observation state with respect to the time when no input relating to the alignment operation is made. Time
Is preferably longer than the time required to process an image for T frames. When n> = T and the timer value> = Time, the process proceeds to step 306. Otherwise, the process returns to step 301, and the reflected image of the alignment index is detected for the next frame. In step 306, the anterior segment /
The fundus switching control unit 25 switches the fundus observation state to the anterior segment observation state.

As described above, the state in which the reflection image of the alignment index is not observed continues for T frames or more, that is, the alignment is largely deviated, and the anterior segment observation state is automatically set when the photographer stops the alignment operation. Therefore, it is possible to efficiently perform rough alignment without pressing the anterior segment / fundus changeover switch.

In this embodiment, the image processing unit 23
The method of detecting the reflected image of the alignment index was explained by using, but the wavelength of the fundus illumination system light source and the wavelength of the alignment index illumination light source are made to differ, and the wavelength of the fundus illumination system light source is transmitted on the optical path for alignment index illumination. You may arrange | position the mirror which permeate | transmits a part of wavelength of a light source, and reflects the other, arrange | position a sensor in the reflection direction, and this sensor may detect the reflected image of an alignment index.

[0047]

As described above, in the fundus camera according to the present invention, in the fundus observation state, it is determined whether or not the reflected image of the projected index is observed, and the state automatically becomes the anterior segment observation state. Therefore, if the subject's face moves, the subject's eye moves, the operator is not skilled in alignment, and the device body is moved too far in the vertical and horizontal directions, etc. Since the anterior segment observation state is achieved, the rough alignment can be efficiently performed without pressing the anterior segment / fundus changeover switch.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a fundus camera of an embodiment.

FIG. 2 is an explanatory diagram of an observation state of a reflection image of an alignment index.

FIG. 3 is an operation flowchart of an anterior segment / fundus switching determination unit.

FIG. 4 is a configuration diagram of a fundus camera according to another embodiment.

FIG. 5 is an operation flowchart of a timer control unit.

FIG. 6 is an operation flowchart of the anterior segment / fundus switching determination unit.

[Explanation of symbols]

1 Objective lens 2 Anterior segment observation lens 3 perforated mirror 4 Shooting aperture 5 Focus lens 6 Shooting lens 7 Switching mirror 8 Still image capturing unit 11 Imaging lens 12 Image capture unit for moving images 13 Light source for anterior segment illumination 14a, 14b optical fiber 15a, 15b Light source for alignment index illumination 21 Image controller 22 TV monitor 23 Image Processor 24 Anterior / fundus switching determination unit 25 Anterior / fundus switching controller 31 Timer control unit 32 timer

Claims (4)

[Claims] 1. An anterior segment observation means for observing an anterior segment of an eye to be inspected, a fundus observation unit for observing a fundus image of the eye to be inspected, an anterior segment observation state by the anterior segment observation unit, and the fundus observation. Switching means for switching the fundus observation state by means, projection means for projecting an index on the anterior segment of the eye to be inspected, light receiving means for receiving the reflected image of the index projected on the anterior segment of the eye by the projecting means, A fundus camera, comprising: a determination unit that determines whether to switch from the fundus observation state to the anterior segment observation state based on whether or not the light receiving unit receives light. 2. A storage unit for storing a predetermined number of light reception states in the past in the light receiving unit, wherein the determining unit determines the fundus observation state based on the light reception presence or absence states in the past predetermined number stored in the storage unit. The fundus camera according to claim 1, wherein it is determined whether or not to switch to the anterior ocular segment observation state. 3. An anterior segment observation means for observing the anterior segment of the subject's eye, a fundus observation unit for observing a fundus image of the subject's eye, an anterior segment observation state by the anterior segment observation unit, and the fundus observation. Switching means for switching the fundus observation state by means, projection means for projecting an index on the anterior segment of the eye to be inspected, light receiving means for receiving the reflected image of the index projected on the anterior segment of the eye by the projecting means, Input detecting means for detecting whether or not an alignment operation is input in the fundus observation state, measuring means for measuring an elapsed time from the final input detected by the input detecting means, presence or absence of light reception in the light receiving means, and the measuring means A fundus camera, which determines whether or not to switch from the fundus observation state to the anterior segment observation state according to the elapsed time. 4. The fundus observing state is provided by the determining means, which has a storage means for storing the light receiving presence / absence state of a predetermined number of past times in the light receiving means, and the light receiving presence / absence state of the past predetermined number of times stored in the storage means. The fundus camera according to claim 3, wherein it is determined whether or not to switch to the anterior ocular segment observation state.