JPH07143963A - Ophthalmologic apparatus - Google Patents

Abstract

PURPOSE:To enable visual checking to determine whether alignment is completed or not. CONSTITUTION:This apparatus is provided with a light projection optical system 7 to project light for alignment toward an eye 3 to be inspected and imaging optical systems 4, 13, 11 and 15 to introduce an luminance image formed by the light for alignment reflected on the eye 3 to be inspected and an interior ocular segment image of the eye to be inspected onto an image pickup tube 16. Moreover, a monitor 26 is provided to display the luminance image and the anterior ocular segment image based on a signal from the image pickup tube 16 and a video signal detection circuit 25, a square wave detection circuit 32, an arithmetic circuit 33 and a judging circuit 34 are arranged to detect the position of the luminance image based on a video signal from the image pickup tube 16, thereby achieving a determination of whether alignment is completed or not photoelectrically.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of an ophthalmologic apparatus.

[0002]

2. Description of the Related Art In an ophthalmologic apparatus such as an objective eye refractive power measuring apparatus, a measuring light projecting optical system projects measuring light toward an eye to be inspected, and based on the measuring light, the eye refractive power, the intraocular pressure, etc. are measured. Although the measurement is performed, if the measurement light is not properly set on the eye to be inspected, an error occurs in the measurement.
Therefore, conventionally, the ophthalmologic apparatus has been provided with an alignment detecting means for detecting the position of the measurement optical system with respect to the eye to be inspected.

[0003]

By the way, the alignment detecting means includes an alignment light projection optical system for projecting the alignment light toward the eye to be examined and a light receiving optical system for receiving the alignment light reflected by the eye to be examined. And a system for detecting alignment light reflected by the eye to be inspected using a detector of the light receiving optical system,
It is determined whether or not the alignment adjustment is completed. For example, as an ophthalmologic apparatus, an alignment light projection optical system and a light receiving optical system are incorporated in a measurement optical system, and the alignment light is projected toward an eye to be inspected through an objective lens of the measurement optical system. The alignment light is imaged at the corneal curvature center of the optometry, and the imaged alignment light is guided through the objective lens to the detector of the light receiving optical system incorporated in the measurement optical system to form an image. Although the alignment is adjusted based on the amount of light detected by the detector, the alignment detecting means of the conventional ophthalmologic apparatus has a drawback that the completion of alignment cannot be visually confirmed.

The present invention has been made in view of the above problems, and an object thereof is to provide an ophthalmologic apparatus capable of visually confirming whether or not alignment is completed.

[0005]

In order to achieve the above object, the present invention comprises an alignment light projection optical system for projecting alignment light onto an eye to be inspected and an alignment light reflected by the eye to be inspected. An imaging optical system for guiding the bright spot image and the anterior segment image of the subject's eye onto the image pickup device, and displaying the bright spot image and the anterior segment image based on a signal from the image pickup device. A display device and an alignment detection system for photoelectrically detecting whether or not alignment has been performed by detecting the position of the bright spot image based on a video signal from the image pickup device.

[0006]

With the above arrangement, the alignment light projection optical system projects the alignment light toward the eye to be inspected, and the alignment light reflected by the eye to be inspected causes the bright spot image and the anterior eye of the eye to be inspected. A partial image is formed on the imaging device, the bright spot image and the anterior ocular segment image are displayed on a display device based on a signal from the imaging device, and the bright spot is based on a video signal from the imaging device. An alignment detection system photoelectrically detects whether or not alignment has been performed by detecting the position of the image.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an eye refractive power measuring device which is an ophthalmologic apparatus according to the present invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 1 is a measurement target image projection optical system of an eye refractive power measuring apparatus, 2 is an objective lens thereof, and the measurement target image projection optical system 1 is a measurement light for measuring an eye to be inspected. Has a function of projecting a measurement target image toward the eye 3 to be inspected, and the measurement target image is a half mirror.
An image is formed on the fundus 5 of the eye 3 to be examined via
The measurement target image formed on the fundus 5 is again guided to the target image projection optical system 1 via the Hafmylar-4, and the eye refractive power measuring device is based on the measurement target image. The eye refracting power of the eye 3 to be inspected is measured and its detailed configuration is already known. Therefore, the description thereof will be omitted.

The half mirror 4 is arranged on the measurement optical axis ι of the measurement target image projection optical system 1 and constitutes a part of the observation optical system 6. The observation optical system 6 includes an alignment light projection optical system 7 that projects alignment light and a light receiving optical system 8 that receives the alignment light reflected by the eye 3 to be examined. The alignment light projection optical system 7 is roughly composed of a light emitting element 9, a condenser lens 10, a perforated mirror 11, a half mirror 12, and an imaging lens 13. The light emitting element 9 generates the alignment light, and the condenser lens 10 has a function of converting the alignment light into a parallel light beam. The alignment light passes through the hole 11a of the perforated mirror 11 and the half mirror. The alignment light guided to −12 is formed as a bright spot image on the corneal surface 14 of the eye 3 to be inspected.

The light receiving optical system 8 has an image forming lens 15 and an image pickup tube (image pickup device) 16. The anterior ocular segment reflected light reflected by the anterior ocular segment of the eye 3 to be inspected is picked up on the image pickup surface 16a of the image pickup tube 16 by means of the Hahmira-4, the imaging lens 13, the Hahmira-12, and the perforated Mira-11. The alignment light reflected by the corneal surface 14 while being guided through the lens is imaged as an anterior ocular segment image, and the harmylar-4, the imaging lens 13, the harmylar-12, and the perforated mirror-11. And is imaged as a bright spot image. Then, the half mirror-4, the imaging lens 13, and the perforated mirror-1.
1 and the imaging lens 15 to pick up a bright spot image and an anterior segment image on the image pickup tube
An image forming optical system for forming an image is formed.

The half mirror 12 constitutes a part of the reference scale image projection optical system 17, and the reference scale projection optical system 17 includes an illumination light source 18, a condenser lens 19, and a reference. It has a scale pattern plate 20 and a projection lens 21. A reference pattern 22 is formed on the reference scale pattern plate 20 as shown in FIG. The reference pattern 22 is formed of arcuate transmission parts 23 and 24 which are arranged at target positions with the center O as a boundary. The reference scale light emitted from the reference scale image projection optical system 17 is fed to the image pickup tube 16 as a half mirror 12 and a perforated mirror-1.
First, it is guided through the imaging lens 15 and is formed as a reference scale image together with the bright spot image and the anterior segment image.

The observation optical system 6 is for displaying and visually observing the anterior segment image and the bright spot image. The image pickup tube 16 is provided with a video signal extraction circuit 25 as shown in FIG. A television monitor 26 as a display device is connected. On the display surface 27 of the television monitor 26, as shown in FIG. 3, an anterior ocular segment image 28, a bright spot image 29 and a reference scale image 30 are displayed. The examiner visually confirms the anterior segment image 28, the bright spot image 29, and the reference scale image 30 to perform rough alignment and fine adjustment of the alignment of the target image projection optical system 1 with respect to the subject's eye 3. It is something to do. The video signal extraction circuit 25 has a function of sequentially extracting a video signal corresponding to a predetermined scanning line based on the extraction command signal of the extraction command circuit 31, and its output signal is the rectangular wave generation circuit 3.
It is entered in 2. As shown in FIG. 4, the extraction command circuit 31 has a function of outputting an extraction command signal corresponding to predetermined scanning lines n1, n2, n3 to the video signal extraction circuit 25. The scanning lines n1, n2, and n3 used are within a predetermined range ι ', and the scanning lines n1 and n1 are symmetrical with respect to the scanning line n2. The scanning lines n1, n2, and n3 are bright spot images 29.
The waveform of the video signal output from the video signal extraction circuit 25 changes depending on the position where the video signal corresponding to the scanning line n2 is rectangular wave. 5B shows that the video signal corresponding to the scanning line n1 is converted into a rectangular wave, and FIG. 5C shows the image corresponding to the scanning line n3. It shows the signal converted to a square wave. Whether or not the alignment is completed is determined based on the rectangular wave signal. When the alignment of the eye 3 to be examined in the horizontal direction is completed, the absolute value of the difference between the intervals ι1 and ι2 is │ι1−ι2│ <ε1. It is determined by whether or not

This is because it can be considered that the bright spot image 29 exists in the horizontal center if the distance ι1 and the distance ι2 are substantially equal. Completion of vertical alignment of the eye 3 to be inspected
It is determined by whether or not three rectangular waves are detected for all the scanning lines n1, n2 and n3. This is because the position where each scanning line crosses the reference scale image 30 is determined, and when the position of the bright spot image 29 is deviated from the center of the reference scale image 30, one of the scanning lines is determined. This is because the number of rectangular waves of the rectangular wave signal corresponding to one becomes two. Completion of the working distance adjustment in the measurement optical axis direction is determined by the size of the bright spot image as the focused state, and here, the interval from the leading edge to the trailing edge of the rectangular wave L is ι3 <ε2. It is determined by whether or not. This is because the size of the bright spot image 29 is minimized when the focused state is in focus.

The output of the rectangular wave generation circuit 32 is the arithmetic circuit 33.
And the output of the arithmetic circuit 33 is input to the determination circuit 34. The arithmetic circuit 33 determines the interval
The determination circuit 34 has a function of calculating 1, ι2, ι3 and | ι1−ι2 | by calculating each scanning line n1, based on a calculation signal output from the calculation circuit 33. n2, n3
The alignment state is detected by discriminating whether or not three rectangular waves are detected for all of the above and whether or not | ι1−ι2 | <ε1. In addition, the determination circuit 34 uses | ι3 | <ε2
It also has a function of determining whether the working distance is adjusted or not and detecting the working distance adjustment state.

The video signal extraction circuit 25, the rectangular wave generation circuit 32, the arithmetic circuit 33, and the determination circuit 34 detect the position of the bright spot image 29 and photoelectrically detect whether or not the bright spot image 29 is aligned. An alignment detection system is configured.

The output of the judgment circuit 34 is inputted to the output circuit 35, the output thereof is inputted to the television monitor 26, and the television monitor 26 displays whether or not alignment and working distance adjustment are completed. The video signal extraction circuit 25, the extraction command circuit 35, the rectangular wave generation circuit 32, the arithmetic circuit 33, and the determination circuit 34 include a video signal corresponding to the reference scale image and a video signal corresponding to the bright spot image. Based on the above, the relative position of the bright spot image with respect to the reference scale image and the in-focus state of this bright spot image are discriminated and whether or not the measurement optical system is aligned and the working distance is adjusted with respect to the eye 3 The discrimination processing circuit for discriminating is generally constituted.

By the way, the alignment is performed on the display screen 27.
Since the reference scale image 30, the bright spot image 29, and the anterior segment image 28 displayed on the display screen 27 can be visually confirmed, the alignment can be easily adjusted.

Whether or not the alignment is completed is determined by
Since the arithmetic circuit 33 and the determination circuit 34 determine the position of the bright spot image 29 based on the video signal output from the video signal extraction circuit 25, the alignment can be accurately detected.

Although the embodiment has been described above, the completion of the adjustment of the working distance in the measurement optical axis direction can be determined based on the output peak value of the rectangular wave corresponding to the light amount of the bright spot image. .

In the above embodiment, the completion of the vertical alignment is determined by the predetermined scanning lines n1, n2, n3.
Is determined by whether or not three rectangular waves are detected, all of the above are set to the alignment permissible width by setting the vertical length of the reference scale shown in FIG. The determination may be made depending on whether a rectangular wave is detected.

Regarding the horizontal alignment, the horizontal width of the reference scale shown in FIG. 4 is set to the alignment allowable width, and only the video signal in a range somewhat larger than the horizontal width of the reference scale is taken out. The determination may be made based on whether three rectangular waves are detected within the range.

[0022]

According to the present invention, the alignment light projection optical system for projecting the alignment light toward the eye to be examined, the bright spot image formed by the alignment light reflected by the eye to be examined and the eye to be examined. An image forming optical system for guiding the anterior segment image onto the imaging device, and a display device for displaying the bright spot image and the anterior segment image based on a signal from the imaging device,
Since it has an alignment detection system for photoelectrically detecting whether or not the position of the bright spot image is detected based on the image signal from the image pickup device and aligned, a bright spot image and an anterior segment image Is displayed on the display device, and the alignment adjustment and the fine adjustment can be roughly performed by observing the display device and visually confirming the bright spot image and the anterior segment image. Then, it is electrically detected whether or not the alignment is performed by the video signal from the imaging device used for the observation.

That is, the alignment can be roughly adjusted and finely adjusted based on the anterior segment image and the bright spot image by observation, and whether or not the alignment detection system is aligned by obtaining the position of the bright spot image. Since it is determined, the alignment can be accurately detected. In addition, since the bright spot image and the anterior segment image are displayed on the display device, they can be visually checked, and therefore the alignment can be easily adjusted.

[Brief description of drawings]

FIG. 1 is an optical system diagram of an embodiment of an eye refractive power measuring device according to the present invention.

2 is a plan view of a reference scale pattern plate of the reference scale image projection optical system shown in FIG.

3 is a plan view showing an anterior segment image, a bright spot image, and a reference scale image displayed on the display surface of the television monitor shown in FIG.

FIG. 4 is an explanatory diagram for explaining alignment determination of the eye refractive power measurement device.

5A shows a video signal corresponding to the scanning line n2 in FIG. 4 converted into a rectangular wave. (B) shows a video signal corresponding to the scanning line n1 in FIG. 4 converted into a rectangular wave. (C)
4 shows a video signal corresponding to the scanning line n3 converted into a rectangular wave.

[Explanation of symbols]

 3 ... Inspected eye 6 ... Observation optical system 7 ... Alignment optical projection optical system 8 ... Receiving optical system 16 ... Image pickup tube 26 ... TV monitor-27 ... Display surface 28 ... Anterior eye image 29 ... Bright spot image 32 ... Rectangular wave Generation circuit 33 ... Operation circuit 34 ... Judgment circuit

Claims (1)

[Claims] 1. An alignment light projection optical system for projecting alignment light onto an eye to be inspected, a bright spot image formed by the alignment light reflected by the eye to be inspected, and an anterior segment image of the eye to be inspected. An image forming optical system for guiding the image on the image pickup device, a display device for displaying the bright spot image and the anterior segment image based on the signal from the image pickup device, and the display device based on a video signal from the image pickup device. An ophthalmologic apparatus having an alignment detection system for photoelectrically detecting whether or not alignment has been performed by detecting the position of a bright spot image.