JP5745943B2 - Ophthalmic equipment - Google Patents

Description

  The present invention relates to an ophthalmologic apparatus for examining a subject's eye.

  2. Description of the Related Art An ophthalmologic measurement apparatus that measures a subject's eye by projecting a measurement light beam onto the fundus of the subject's eye and receiving the reflected light is known. For example, an autorefractometer can be mentioned.

  Moreover, in the ophthalmologic apparatus as described above, an apparatus that can capture an intra-pupil image (so-called transillumination image) by illuminating the inside of the pupil with fundus reflection light is known (see Patent Document 1). Thereby, the turbid state of a crystalline lens is confirmed.

JP-A-8-112254

  In the case of the conventional apparatus, when the entire captured image including the transillumination image is printed, the entire captured image is printed in a printable area of the printing paper so as to be reduced. In addition, if the corneal bright spot and the optical axis are deviated at the time of transillumination, the position of the pupil portion deviates from the center position of the image. For this reason, when the entire image is not printed and the print image is extracted with reference to the center of the image, the whole illumination image may not be printed.

  In view of the above problems, an object of the present invention is to provide an ophthalmologic apparatus capable of printing a transillumination image that is easy to observe.

  In order to solve the above problems, the present invention is characterized by having the following configuration.

(1) An inspection means for inspecting the eye to be examined and an imaging device having an imaging surface arranged at a position substantially conjugate with the anterior eye portion of the eye to be examined, projecting light to the fundus of the eye to be examined, An imaging optical system that captures a transillumination image by fundus reflected light, a storage unit that stores a captured image captured by the imaging optical system, and an image that includes an outer edge of a pupil from the captured image stored in the storage unit A control means for extracting an area and causing the printing means to print the extracted image;
The transillumination image is captured in a state where the corneal apex of the eye to be examined and the imaging optical axis of the imaging optical system are deviated, and the control means is printed on the paper in black on the outside of the pupil portion in the captured image. The position of the outer edge of the pupil in the image extracted by the process is set so as to be within the printable range on the paper, the printing process is performed , and the paper is processed by the printing process. With respect to the image printed above, the outside of the pupil portion in the captured image is different from the anterior ocular segment image .
(2) An inspection means for inspecting the eye to be inspected, and an imaging element having an imaging surface arranged at a position substantially conjugate with the anterior eye portion to be inspected, and projecting light onto the fundus of the eye to be inspected, An imaging optical system that captures a transillumination image by fundus reflected light, a storage unit that stores a captured image captured by the imaging optical system, and a predetermined image including a transillumination image from the captured image stored in the storage unit Control means for extracting an image of the range, the transillumination image is imaged in a state in which the corneal vertex of the eye to be examined and the imaging optical axis of the imaging optical system are shifted, and the control means Alignment is performed so that the image fits within the printing paper and the center of the transillumination image overlaps the center of the paper in the horizontal direction , and printing processing is performed.

  According to the present invention, it is possible to print a transillumination image that is easy to observe.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram of an optical system and a control system of the present apparatus. The following optical system is built in a housing (not shown). Further, the housing may be moved three-dimensionally with respect to the subject's eye E by a known alignment moving mechanism. Moreover, a hand-held type (handy type) may be used.

  The measurement optical system 10 includes a projection optical system 10a that projects a spot-like measurement index on the fundus oculi Ef of the eye E via the pupil central portion of the eye E, and fundus reflected light reflected from the fundus oculi Ef via the pupil periphery. And a light receiving optical system 10b for picking up a ring-shaped fundus reflection image on the two-dimensional imaging device.

  The projection optical system 10 a includes a measurement light source 11, a relay lens 12, a hall mirror 13, and an objective lens 14 that are disposed on the optical axis L <b> 1 of the measurement optical system 10. The light source 11 is optically conjugate with the fundus oculi Ef of the normal eye. The opening of the Hall mirror 13 is optically conjugate with the pupil of the eye E.

  In the light receiving optical system 10b, the objective lens 14 and the hall mirror 13 of the projection optical system 10a are shared, and the relay lens 16 and the total reflection mirror 17 disposed on the optical axis L1 in the reflection direction of the hall mirror 13 are totally reflected. It includes a two-dimensional imaging device 22 including a light receiving stop 18, a collimator lens 19, a ring lens 20, and an area CCD disposed on the optical axis L <b> 1 in the reflection direction of the mirror 17. The light receiving aperture 18 and the image sensor 22 are in a positional relationship optically conjugate with the fundus oculi Ef. The ring lens 20 includes a lens portion formed in a ring shape and a light shielding portion in which a region other than the lens portion is coated with a light shielding coating, and has a positional relationship optically conjugate with the pupil of the eye E. ing. The output from the image sensor 22 is input to the control unit 70 via the memory 75.

  The measurement optical system 10 is not limited to the above, and a ring-shaped measurement index is projected from the periphery of the pupil to the fundus oculi Ef, the fundus reflection light is extracted from the center of the pupil, and the ring-shaped fundus reflection is reflected on the two-dimensional imaging device. Well-known ones such as a configuration for receiving an image can be used.

  Note that the measurement optical system 10 is not limited to the above-described one, and a light projecting optical system that projects measurement light toward the fundus of the subject's eye and a fundus reflection light from the measurement light by a two-dimensional light receiving element. And a light receiving optical system that receives light as a measuring optical system. For example, the optical power measurement optical system may be configured to include a Shack-Hartmann sensor.

  Between the objective lens 14 and the hall mirror 13, the fixation target luminous flux from the fixation target presenting optical system 30 is guided to the eye E, and the reflected light from the anterior eye part of the eye E to be examined is guided to the observation optical system 50. A dichroic mirror 29 is arranged. The dichroic mirror 29 transmits the wavelength of the measurement light beam used in the measurement optical system 10.

  The fixation target presenting optical system 30 is a fixation optical system having a fixation light source for fixing a subject's eye. The fixation target presentation optical system 30 includes a fixation target presentation visible light source 31, a fixation target plate 32 having a fixation target, a light projection lens 33, a dichroic mirror 29, and an objective lens 14. The light source 31 and the fixation target plate 32 are moved in the direction of the optical axis L2, thereby performing clouding of the eye E.

  A ring index projection optical system 45 that emits near-infrared light for projecting a ring index onto the cornea Ec of the eye E and an infinite distance index onto the cornea Ec of the eye E are projected in front of the anterior segment of the eye E. Accordingly, the working distance index projection optical system 46 that emits near-infrared light for detecting the alignment state in the working distance direction with respect to the eye to be examined is arranged symmetrically with respect to the observation optical axis. The ring projection optical system 45 is also used as anterior segment illumination for illuminating the anterior segment of the eye E. It can also be used as an index for corneal shape measurement.

  The observation optical system (imaging optical system) 50 shares the objective lens 14 and the dichroic mirror 29 of the fixation target presentation optical system 30, and includes a half mirror 35, an imaging lens 51, and a two-dimensional imaging element 52. The imaging device 52 has an imaging surface disposed at a position substantially conjugate with the anterior eye portion to be examined, and an output from the imaging device 52 is input to the control unit 70. As a result, the anterior segment image of the eye E is captured by the two-dimensional image sensor 52 and displayed on the monitor 7. The observation optical system 50 also serves as an optical system that detects an alignment index image formed on the cornea of the eye E, and the position of the alignment index image is detected by the control unit 70.

  The arithmetic control unit 70 (hereinafter referred to as the control unit 70) includes an image sensor 52, a memory 75, a monitor 7, an operation unit 90 for performing various input operations by an examiner, a roll paper specialized for measurement results, transillumination images, and the like. A small printer (for example, a small thermal printer) 91 for printing out is connected. Note that the width of the printing paper is about 58 mm. The control unit 70 controls the entire apparatus, calculates an eye refraction value, calculates a corneal shape, and the like. In the memory 75, a first mode in which the eye refractive power is measured by analyzing a ring image captured by the image sensor 22, and a captured image including a transillumination image that is an intra-pupil image by the observation optical system 50 are stored. It is possible to store a second mode calculation program or the like for imaging.

<First mode>
The measurement operation of the apparatus having the above configuration will be described. First, the face of the subject is fixed to a face support unit (not shown), and after instructing to fixate the fixation target 32, alignment with the eye to be examined is performed.

  The controller 70 turns on the light source 11 based on the input of the measurement start signal. The measurement light emitted from the light source 11 is projected onto the fundus oculi Ef via the relay lens 12 to the objective lens 14 to form a spot-like point light source image that rotates on the fundus oculi Ef.

  The light of the point light source image formed on the fundus oculi Ef is reflected and scattered, exits the subject eye E, is collected by the objective lens 14, and passes through the dichroic mirror 29 through the total reflection mirror 17 to the light receiving stop 18. The light is condensed again on the aperture, converted into a substantially parallel light beam (in the case of a normal eye) by the collimator lens 19, extracted as a ring-shaped light beam by the ring lens 20, and received by the image sensor 22 as a ring image.

  At this time, preliminary measurement of eye refractive power is first performed, and the light source 31 and the fixation target plate 32 are moved in the direction of the optical axis L2 based on the result of the preliminary measurement. It is done. Thereafter, the eye refractive power is measured for the eye to be inspected with cloud fog.

  FIG. 2 is a ring image captured by the image sensor 22 during measurement. The output signal from the image sensor 22 is stored in the memory 75 as image data (measurement image). Thereafter, the control unit 70 specifies (detects) the position of the ring image in each meridian direction based on the measurement image stored in the memory 75. In this case, the control unit 70 specifies the position of the ring image by edge detection. The position of the ring image is determined by cutting the waveform of the luminance signal at a predetermined threshold, and determining the waveform intermediate point, the peak of the luminance signal waveform, the barycentric position of the luminance signal, etc. Also good. Next, the control unit 70 approximates an ellipse using the least square method or the like based on the image position of the specified ring image. And the control part 70 calculates | requires the refraction error of each meridian direction from the approximate ellipse shape, and based on this, the eye refraction value of the eye to be examined, S (spherical power), C (column surface power), A (astigmatic axis) Each value of (angle) is calculated, and the measurement result is displayed on the monitor 7.

  Moreover, the fundus reflection light by the measurement light is received, and the presence or absence of turbidity of the subject eye translucent body is determined based on the light reception result. For example, in the case of a measurement optical system having a light receiving optical system that receives fundus reflected light as a two-dimensional pattern image by a two-dimensional light receiving element, the control unit 70 receives fundus reflected light from the measurement light by the light receiving element. Based on the received two-dimensional pattern image, the presence or absence of turbidity of the subject's eye transparent body is determined. Then, switching to the second mode is performed according to the determination result.

  The turbidity determination and control operation will be described below. First, the control unit 70 detects edges in each meridian direction sequentially in the 360 degree direction with reference to the center coordinates of the ring image. FIG. 3 illustrates a ring image (left diagram) captured by the image sensor 22 and luminance distribution (right diagram) acquired for performing edge detection in the direction of the line L1 from the center of the ring image. FIG. FIG. 3A shows a ring image and a luminance distribution when the eye to be examined is not turbid. FIGS. 3B and 3C show the ring image and the luminance distribution when the eye to be examined has turbidity and the ring image is missing or blurred due to turbidity.

  When there is no turbidity in the eye E as shown in FIG. 3A, a ring image (left figure) having no chipping or blurring is formed. And when the luminance distribution (right figure) of the line L1 direction is acquired, a high luminance value is obtained. As a result, a high luminance value is obtained as a whole for the luminance distribution in each meridian direction. Further, the half width W with respect to the peak value of the luminance distribution becomes narrow. Also in each meridian direction, the full width at half maximum W is narrow.

  When the eye E is turbid due to a lesion such as a cataract, the ring image is chipped or blurred. For example, as shown in FIG. 3B, a ring image (left figure) in which chipping has occurred is formed. And when the luminance distribution (right figure) of the line L1 direction is acquired, a luminance value hardly raises. Therefore, in the luminance distribution in each meridian direction, an increase in the luminance value is hardly detected in a region where a defect occurs.

  Further, as shown in FIG. 3C, a ring image (left figure) in which a blur has occurred is formed. When blurring occurs, a lower luminance value is obtained when the luminance distribution (right figure) in the direction of the line L1 is acquired than when there is no turbidity. Accordingly, with respect to the luminance distribution in each meridian direction, a lower luminance value is obtained in a region where blur occurs than when there is no turbidity. Further, the half width W is widened. Therefore, in each meridian direction, the area where the blur occurs is in a state where the half width W is wide.

  It should be noted that the reason why the region with the ring image is missing is that when the measurement light beam passes through the eye to be examined, the light beam is almost lost due to the severe opacity of the cataract, and the light beam is not condensed on the image sensor 22. is there.

  The reason why the ring image is blurred is that when the measurement light beam passes through the eye to be inspected, the light beam is scattered due to turbidity of cataract, etc., and the ring image spreads and forms an image when imaged on the image sensor 22. Because it will do.

  By utilizing these characteristics, in the following determination, a threshold value S1 is set so that a peak value when there is turbidity and a peak value when there is no turbidity can be determined, and the peak value of each luminance distribution is The presence or absence of turbidity in the meridian direction is determined by the control unit 70 depending on whether or not it exceeds S1. Further, a threshold value S2 is set so that the half-value width when there is turbidity and the half-value width when there is no turbidity can be discriminated, and whether or not there is turbidity in the meridian direction depending on whether or not the peak value of each luminance distribution exceeds the threshold value S1. Is determined by the control unit 70. Furthermore, the control unit 70 determines the opacity of the entire eye to be examined based on the presence or absence of turbidity in each meridian direction.

<Second mode>
As described above, when it is determined that there is turbidity, the control unit 70 issues a switching signal to the second mode (transillumination image observation mode) for observing the transillumination image by the observation optical system 50.

  It should be noted that a mode change switch is provided, and the control unit 70 displays a display on the monitor 7 that it is better to observe the transillumination image, and prompts the examiner to guide the mode change. And the control part 70 is good also as a structure which switches a mode from a 1st mode to a 2nd mode, when the predetermined | prescribed mode change switch for shifting to a 2nd mode is selected.

  This will be described more specifically. When the mode switching signal is issued, the control unit 70 turns off the light source of the ring index projection optical system 45 and the light source of the working distance index projection optical system 46 and turns on the measurement light source 11. At this time, the control unit 70 changes the light amount of the measurement light source 11 based on the mode switching signal. Further, the gain of the image sensor 52 is changed (described later). In the case of the present embodiment, the measurement light source 11 also serves as a fundus illumination light source, but a light source for transillumination may be provided separately.

  A light beam is emitted from the light source 11 and projected onto the fundus. Then, the fundus reflection light is emitted from the pupil after illuminating the crystalline lens of the eye E. The fundus reflection light emitted from the pupil is reflected by the half mirror 35, picked up by the image pickup device 52 as a picked-up image including a transillumination image (in-pupil image), and displayed on the monitor 7. Thereby, in the site | part K with a cataract or opacity, a dark shadow is confirmed (refer FIG. 4).

  When a transillumination image is captured, it is better to image the transillumination image by moving the apparatus main body relative to the eye E so that the corneal apex of the eye to be examined and the observation optical axis of the observation optical system 50 are shifted. For example, when the second mode is set, the control unit 70 controls a driving unit (not shown) so that the corneal apex is shifted from the observation optical axis, and the image sensor 52 captures a transillumination image.

  This is because when an attempt is made to capture a transillumination image, a corneal bright spot from the measurement light source 11 is reflected in the center of the transillumination image, so that the opacity is hidden by the corneal bright spot, and the examiner observes the transillumination image. It becomes difficult. In addition, the examiner may mistake the cloudy part and the corneal bright spot. Therefore, by shifting the corneal apex from the imaging optical axis, the brightness of the corneal bright spot is reduced, and the examiner can easily observe the transillumination image, and the possibility of misperception is reduced.

  Further, when switching to the second mode is performed based on a switching signal from the control unit 70, at least one of the light amount of the fundus illumination light source and the gain of the image sensor is controlled. For example, when the switching signal to the second mode is output, the control unit 70 increases the light amount of the fundus illumination light source to the light amount necessary for the transillumination photographing. The light amount level for this transillumination image photographing is, for example, a light amount increased from a light amount for normal eye refractive power measurement. In addition, the gain of the image sensor is increased more than the gain of eye refractive power measurement. This makes it possible to more clearly observe the turbid portion that has been overlooked due to the low luminance value with the amount of light required when measuring the eye refractive power.

  In the present embodiment, both the light amount of the fundus illumination light source and the gain of the image sensor are changed. However, the present invention is not limited to this. For example, the structure which changes either one may be sufficient.

  Further, when switching to the second mode is performed based on the switching signal from the control unit 70, the control unit 70 refracts the amount of light emitted from the visible light source (fixation light source) 31 of the fixation target presenting optical system 30. A predetermined amount of light is dimmed from the light intensity at the time of force measurement. By reducing the amount of illumination light, the pupil is in an open state, so that shooting is performed without a miosis. Therefore, it is possible to take a transillumination image of a wider area, and it is possible to satisfactorily observe the cataract even in the eye to be examined such as when the cataract is in the periphery of the lens.

  In the above description, the illumination light quantity is reduced by a predetermined amount, but the present invention is not limited to this. For example, the fixation target presenting visible light source 31 may be turned off. The configuration may be such that the examiner can change the light level of the visible light source 31.

<Printing the illumination image>
When a predetermined switch of the operation unit 90 is operated, a captured image including a transillumination image captured by the observation optical system 50 is stored in the memory 75. Further, such a captured image is output to the monitor 70, the printer 91, and the like. In the present invention, an image is acquired by a predetermined switch. However, a configuration may be adopted in which shooting is automatically performed.

  Here, when outputting to the printer 91 or the like, the control unit 70 extracts an image in a predetermined range including a transillumination image from the captured image stored in the memory 75. The control unit 70 detects an edge due to the pupil based on the captured image, and extracts an image region corresponding to the pupil part. And the control part 70 extracts the image area | region containing the outer edge part of a pupil, and prints the extracted image on paper. At this time, printing is performed so that the outer edge of the pupil in the extracted image is within the printable range on the paper. In addition, a process is performed in which the transillumination image of the captured image fits within the print paper and the center of the transillumination image overlaps the paper center.

  Hereinafter, a processing method when outputting the illumination image will be described with reference to the flowchart of FIG. When a transillumination image is shot and a print switch provided in the operation unit 90 is operated, an output signal is transferred to the control unit 70, and the control unit 70 performs image processing of the acquired captured image.

  First, the control unit 70 detects the center coordinate of the illumination image from the acquired captured image. The control unit 70 scans the center position in the X direction (horizontal direction) and the center position in the Y direction (vertical direction) of the captured image, and acquires the luminance distribution. FIG. 6 shows a luminance distribution acquired by performing luminance detection in the line X direction and the line Y direction with respect to the image center of the acquired captured image and the transillumination image.

  Since the transillumination image has a different amount of light depending on the luminance distribution in the X direction, the edge of the transillumination image can be detected, and further, the center position from the transillumination image edge detection, that is, the center of the transillumination image in the horizontal direction. Can be obtained. Similarly, since the transillumination image has a different amount of light depending on the luminance distribution in the Y direction, the edge of the transillumination image can be detected, and further, the center position of the transillumination image edge detection, that is, the center of the pupil in the vertical direction can be detected. Can be obtained. Therefore, the center coordinates of the transillumination image can be obtained from both.

  When the center coordinates are detected as described above. Next, an area to be printed on the paper of the printer 91 is extracted based on the position of the center coordinates.

  The control unit 70 extracts an area corresponding to a rectangular area centered on the center coordinate of the transillumination image as a print area of the printer 91. The quadrangular area indicates an area having one side at a position equidistant from the center coordinate in the vertical and horizontal directions. In this embodiment, the setting criterion for one side is a range (for example, 400 pixels) that falls within the printable range on the paper by the printer 91. For example, when the printable range is an area of 400 × 400 pixels, if one side of the extraction area is 400 pixels, the printable area is just within the printable area.

  When the extraction of the rectangular area including the illumination image is completed, the control unit 70 outputs an output signal for starting output to the printer 91. When receiving the output signal, the printer 91 starts printing the extracted image data.

  At this time, the control unit 70 performs printing so that the pupil center in the extracted image is arranged at a predetermined position on the paper. For example, the position is set so that the center of the transillumination image comes to the center of the printing paper in the horizontal direction, and printing is performed.

  As described above, by extracting and printing a transillumination image, it is possible to output the transillumination image on the printing paper without cutting it out without performing reduction processing and outputting the reduced image. As a result, the turbidity of the transillumination image can be observed with a size that can be easily discriminated.

  Further, since the center of the transillumination image is detected and the image is extracted based on the center coordinates of the transillumination image, even when the observation optical axis of the observation optical system 50 and the corneal bright spot are shifted, The transillumination image is always output so as to be positioned at the center, and the transillumination image is not cut and printed. Therefore, it becomes possible to observe the whole illumination image satisfactorily (see FIG. 7).

  In the above configuration, the image extraction process is performed and the extracted region is printed. However, the present invention is not limited to this. For example, the configuration may be such that the examiner can arbitrarily select whether to print the extraction region or the entire captured image.

  In the present embodiment, the control unit 70 sets the position so that the center of the transillumination image comes to the center of the printing paper in the horizontal direction, and printing is performed. However, the present invention is not limited to this. For example, printing may be performed so that the printable range on the paper and each side of the extracted image substantially match. In other words, the transillumination image is printed so that the extraction area is within the printable area of the printing paper.

  In this embodiment, the central portion of the transillumination image is printed at the center of the printing paper during printing by the printer 91. However, the control unit 70 displays the extracted image on the screen and extracts it. Display may be made so that the outer edge of the pupil in the printed image is within the printable range on the paper. In this case, the control unit 70 moves the center of the transillumination image to the center of the monitor 7 when displaying the transillumination image on the monitor 7 after taking the transillumination image. For example, when the corneal bright spot is shifted from the center of the transillumination image, the apparatus is moved slightly from the imaging optical axis to perform imaging. In this case, the photographed transillumination image is shifted from the center of the monitor 7 because it is shifted from the optical axis. At this time, by detecting the center of the transillumination image and moving the transillumination image to the center of the monitor 7, even if the transillumination image is enlarged and observed, the possibility that the image is cut off from the monitor 7 is low. Become.

  In the case of the eye E having a very large pupil, the transillumination image area becomes wider than the original extraction area, and the entire transillumination image may not be printed. Therefore, the control unit 70 calculates the pupil diameter of the eye E by image processing based on the anterior segment image. Then, when the calculated pupil diameter exceeds the predetermined pupil diameter, the control unit 70 enlarges the image extraction area and prints the extracted area so that the extracted area falls within the printable range. May be. In this case, the predetermined pupil diameter is set in order to determine the eye E whose transillumination image area is wider than the predetermined extraction area.

  The display method of the transillumination image of the monitor 7 may be configured to be arbitrarily set by the examiner. For example, it is possible to set whether to display the entire captured image or only the extraction region, A configuration may be adopted in which image processing such as enlargement / reduction can be performed and displayed.

  In this embodiment, the mode switching to the second mode is performed based on the determination result of the ring image, but the present invention is not limited to this. For example, the configuration may be such that determination is performed based on the transillumination image acquired at the same time as the eye refractive power is measured, and the mode is switched. Note that the transillumination image at the time of eye refractive power measurement is not suitable for an observation image because the light amount of the light source 1 is set low, but it is possible to determine the presence or absence of turbidity to some extent. Therefore, for example, the area of the light shielding region (part where the light amount level is low) in the pupil is calculated by image processing, and whether or not there is turbidity is determined based on whether or not the calculated area is within an allowable range.

  In this embodiment, a scale or the like that can estimate the size of the illumination image may be displayed together with the illumination image. When the scale is displayed together with the transillumination image, when the image is enlarged / reduced, the control unit 70 changes the size of the scale or the dimension value of the scale according to the changed magnification.

  In the present embodiment, when the mode is switched, it may be configured to display the fact on the monitor 7.

  In the present embodiment, when the mode is switched, the function of one switch may be switched according to the mode. For example, in the first mode, when a switch for starting measurement is switched to the second mode, it is switched to a switch for starting photographing.

  In the above description, the eye refractive power measuring device has been described as an example of the inspection means for inspecting the eye to be examined. However, the present invention is not limited to this. That is, in an ophthalmologic apparatus equipped with an inspection optical system that projects a measurement light beam onto the fundus and receives the reflected light to inspect the eye to be examined, the inside of the pupil is illuminated with the fundus reflected light, so The present invention can be applied as long as it has a configuration capable of capturing a transillumination image. For example, an axial length measuring device that measures the axial length by an optical interference optical system can be considered.

The interference optical system includes, for example, a light source that emits low-coherent light, a beam splitter that divides the light emitted from the light source, and a light-projecting optical system that projects one of the divided lights toward the fundus. A light receiving optical system that guides interference light (measurement light) generated by combining the reflected one light and the other light to the light receiving element, in the optical axis direction to adjust the optical path difference between the one light and the other light And an optical member that is movably disposed. The control unit connected to the interference optical system measures the axial length based on the interference signal output from the light receiving element. As for the detailed configuration, for example, the control unit described in JP-T-2002-531205, for example, the S / N ratio (SNR: Signal to Noise ratio) of the interference signal acquired while measuring the axial length. ) To determine the presence or absence of turbidity. The S / N ratio is the ratio of noise to the interference signal output from the light receiving element. The S / N ratio indicates that the higher the numerical value, the lower the noise and the higher the quality signal. When the S / N ratio is smaller than the predetermined value, the control unit issues a switching signal from the first mode for measuring the axial length to the second mode for observing the transillumination image.

<Printing method>
In printing by the printer, portions other than the pupil portion are printed in black, so it takes time to complete the printing. The control unit 70 acquires a printing image in which the luminance value of the captured image captured by the observation optical system 50 is increased, and controls the printer 91 to print the printing image. If printing is performed after adjusting the brightness value of the image data, the printing time can be shortened, so that shooting can be completed smoothly. For this reason, the time taken for printing is shortened by adjusting the brightness value of the photographed image and reducing the area to be printed in black.

  A case where a thermal printer is used as the printer 91 will be described as an example. The thermal printer has a print head for blackening a thermal paper as a print paper, and performs a print operation by moving the print head in the vertical and horizontal directions on the print paper.

  A thermal printer, which is a type of thermal printer, prints by applying a heated print head to special paper (thermal paper). In order to print an image on printing paper, the control unit 70 applies current to the print head to cause the print head to generate heat. The controller 70 applies the heated print head to the special paper (thermal paper) to change the color of the thermal paper to black. The control unit 70 expresses the color shade by forming a dot pattern by increasing or decreasing the number of pixels in a certain region. Within a certain area, the number of pixels and the pixel position for changing the color are adjusted, and a predetermined pattern is formed by a plurality of pixels.

  For example, the dot pattern is set for every 256 gradations in order to express 256 gradations. For example, in the case of 100 gradations on the monitor 7, 24 pixels of the 8 × 8 (64) pixel area on the thermal paper are changed to black. In the case of 200 gradations on the monitor 7, 48 pixels of the 8 × 8 (64) pixel area on the thermal paper are changed to black.

  When the color when printed on thermal paper is made darker (blackened), the number of pixels to be changed to black is increased in a certain area, and a dot pattern expressing black is formed. Further, when the color printed on the thermal paper is made lighter (whitened), the number of pixels to be changed to black is reduced within a certain area, and a dot pattern expressing white is formed. That is, when expressing white, it is not necessary to change the color of the pixel. As described above, the lightness / darkness of the color is adjusted.

  As described above, when the region that is darker black on the monitor 7 is expressed on the thermal paper, it is necessary to increase the number of pixels that are changed to black in a certain region. .

  Hereinafter, means for shortening the printing time by adjusting the brightness value will be described. For example, a case will be described as an example in which a region corresponding to a quadrangular region centered on the center coordinate of the illumination image is extracted and printed on a print sheet.

  When the extraction of the square area including the illumination image is completed, the control unit 70 outputs an output signal for outputting the extracted image data to the printer 91. When the output signal is output, the control unit 70 adjusts the luminance value of the image data.

  The control unit 70 distinguishes the captured image into a first image region P1 inside the pupil outer edge and a second image region P2 outside the pupil outer edge using the luminance value of the pixel that generates the captured image, A print image including the first image region P1 and having the brightness value of the second image region P2 increased is acquired by image processing (see FIG. 9).

  In the present embodiment, the first image region P1 and the second image region P2 are distinguished by comparing each luminance value of the captured image with a predetermined threshold value. First, the control unit 70 detects the brightness distribution of the transillumination image from the acquired image data. The control unit 70 scans the captured image in the X direction (lateral direction) and acquires a luminance distribution. Of course, the luminance distribution may be acquired by scanning in the Y direction (vertical direction). FIG. 8 shows the luminance distribution of the acquired scanning line SL obtained by scanning the extracted image data in the line X direction.

  After acquiring the luminance distribution, the control unit 70 determines whether or not to adjust the luminance value in the region of the scanning line SL. The determination is performed, for example, by determining whether the luminance value is higher than a predetermined threshold B for each pixel of the scanning line SL or for each predetermined pixel range.

  The iris portion of the eye to be examined is captured by the image sensor as a dark image in order to shield the fundus reflection light. In the turbid portion due to cataract or the like, the fundus reflection light is scattered by the turbidity when the fundus reflection light passes through the turbid portion. The fundus reflection light is dimmed and becomes an image darker than other regions in the pupil, and is captured by the image sensor. The turbid portion inside the pupil has a lower luminance value than the non-turbid region inside the pupil, and a higher luminance value than the region other than the pupil portion.

  For example, the predetermined threshold B is set to be smaller than the luminance value when there is turbidity due to cataract and the like, and larger than the luminance value of the region outside the pupil part. By setting the threshold value B in this way, a shadow caused by turbidity due to cataract or the like is not erroneously determined as a region other than the pupil portion, and a region other than the pupil portion is classified.

  Note that, by setting the threshold value as described above, the rising portion of the luminance value due to the pupil portion is lower than the luminance value inside the pupil in the luminance distribution, so that it is printed darker than the inside of the pupil. Thereby, even when printing is performed after the luminance value adjustment, the outer edge of the pupil is printed. Note that the threshold value S is calculated in advance by performing experiments and simulations using a model eye or the like.

  The controller 70 determines whether or not the luminance value of each pixel of the scanning line SL is higher than a predetermined threshold value B. When it is determined that the luminance value of the pixel is higher than the predetermined threshold B, the control unit 70 does not adjust the luminance value. Further, when it is determined that the luminance value of the pixel is lower than the predetermined threshold value B, the control unit 70 performs luminance value adjustment.

  In the present embodiment, the image displayed on the monitor 7 displays brightness data in 256 gradations. The luminance value is adjusted by changing the gradation (luminance value) within 256 gradations. The luminance value is set between 0 and 255, and the color becomes lighter as the parameter is closer to the 255 parameter, and becomes darker as the parameter is closer to 0.

  In the present embodiment, when it is determined that the luminance value of the pixel of the image is lower than the predetermined threshold B, the control unit 70 sets the luminance value for the region lower than the predetermined threshold B in each predetermined region. By raising it, the image is whitened. For example, the parameter of the brightness value is adjusted to 255. Thereby, in the area other than the pupil part, the luminance value is whitened and changed from black to white.

  Similarly, the luminance distribution is acquired for each scanning line, and the luminance value is adjusted on all the scanning lines. As a result, as shown in FIG. 9, the brightness value of the region P excluding the pupil is adjusted from black (dark color) to white (light color). When the brightness value adjustment on all scanning lines is completed on the transilluminated image, the control unit 70 outputs the image data after the brightness value adjustment to the printer 91 and starts printing. When printing is started, the control unit 70 converts image data in order to express an image expressed in 256 gradations as a dot pattern. At this time, it is possible to shorten the printing time for the whitened region by adjusting the luminance value (see FIG. 10).

  As described above, by adjusting the brightness value before printing, it is possible to eliminate printing of areas that are not necessary for observation, such as outside the pupil, shorten the printing time, and perform shooting smoothly. As well as being able to reduce the stress of the examiner. In addition, since the burden on the print head during printing is reduced, the probability of failure can be reduced.

  As for the method for shortening the printing time, the luminance value is exemplified by extracting a region corresponding to a rectangular region centered on the center coordinate of the transillumination image as shown in FIG. 7 as a printing region. Although adjustment was demonstrated, it is not limited to this. The present invention can be applied to an image obtained by extracting a predetermined range image including a transillumination image from a captured image. For example, an image region obtained by extracting a region inside the outer edge of the pupil may be used. Further, the present invention can be applied to printing the entire captured image, not the extracted image.

  In the present embodiment, a thermal printer is taken as an example, but the present invention is not limited to this. For example, the present invention can be applied to an inject printer that performs printing using an ink ribbon or the like. In this case, since the black portion of the transillumination image can be reduced by adjusting the brightness value, the area where it is necessary to apply ink and print black is reduced, and the printing time can be shortened. Also, ink consumption can be reduced.

  In this embodiment, the brightness value adjustment is performed on the image area outside the pupil to shorten the printing time. However, the present invention is not limited to this. For example, the brightness of the image area identified as the first image area may be further increased. In this case, the image in the pupil may be brightened by increasing a constant parameter with respect to the gradation parameter for each pixel of the image in the pupil. Alternatively, a parameter change table may be used to change a predetermined parameter to a certain parameter (for example, 60 for 30 to 40, 75 for 50 to 60, etc.). Thus, it is possible to shorten the printing time by brightening the image in the pupil. Of course, adjusting the luminance values of both the image inside the pupil and the image outside the pupil is more effective for shortening the printing time. It should be noted that in the adjustment of the luminance value of the image in the pupil, it is necessary to adjust the luminance value to such an extent that the shadow of turbidity due to cataracts can be identified. For example, a parameter that does not allow the shadow of turbidity to be detected is calculated in advance through experiments, simulations, or the like, and the luminance value is adjusted so as not to exceed that parameter.

  In the present embodiment, the luminance value is adjusted to make the black region white. However, the present invention is not limited to this. Any structure may be used as long as it is whitened. For example, it is possible to shorten the printing time even if adjustment is made to make the black area gray by increasing the luminance value of the black area by a certain amount. The controller 70 increases the amount of increase in the brightness of the second image region P2 over the first image region P1. It is necessary to adjust the contrast between the color of the region in the pupil and the color of the region other than the pupil so that the pupil region and the region other than the pupil can be identified.

  The method for acquiring the image for printing including the first image region P1 and increasing the luminance value of the second image region P2 by image processing is not limited to the above method. For example, the first image region P1 and the second image region P2 may be distinguished by detecting a pupil edge in the captured image, and the print image may be acquired by extracting the first image region from the captured image.

It is a schematic block diagram of the optical system and control system of this apparatus. It is a figure which shows the ring image imaged by the imaging device in the case of a measurement. It is a figure explaining the ring image imaged by the image pick-up element, and the luminance distribution of the ring image. It is a figure which shows the captured image containing the captured illumination image. It is a flowchart which shows the processing method at the time of outputting a transillumination image. It is the figure which showed the luminance distribution acquired by carrying out the brightness | luminance detection in the line X direction and the line Y direction about the image center of the acquired captured image and a transillumination image. It is a figure which shows the transillumination image printed on the printing paper. The luminance distribution of the scanning line acquired by scanning the extracted image data in the line X direction is shown. It is a figure explaining the adjustment of the luminance value of the area | region except a pupil part. It is a figure which shows the transillumination image printed on the printing paper after luminance value adjustment.

7 monitor 10 measurement optical system 11 light source 10a projection optical system 10b light receiving optical system 22 two-dimensional image sensor 30 fixation target presentation optical system 45 ring index projection optical system 46 working distance index projection optical system 50 observation optical system 52 image sensor 70 control Section 75 Memory 90 Operation section 91 Printer

Claims (2)

An inspection means for inspecting the eye to be examined;
An imaging optical system having an imaging element having an imaging surface arranged at a position substantially conjugate with the anterior ocular segment to be examined, projecting light onto the fundus of the eye to be examined, and imaging a transillumination image by the fundus reflection light,
Storage means for storing a captured image captured by the imaging optical system;
The image region extracting including an outer edge of the pupil from the captured image stored in the storage means, and a control means to print the extracted image to the printing unit, and
The transillumination image is captured in a state where the corneal vertex of the eye to be examined and the imaging optical axis of the imaging optical system are shifted,
The control means performs a process of reducing a black printed area on the paper outside the pupil portion in the captured image, and an outer edge portion of the pupil in the image extracted by the processing is a printable range on the paper. After the position is set so as to fit in the image , a printing process is performed , and an image printed on the sheet by the printing process is different from the anterior eye part image outside the pupil part in the captured image. Ophthalmic equipment. An inspection means for inspecting the eye to be examined;
An imaging optical system having an imaging element having an imaging surface arranged at a position substantially conjugate with the anterior ocular segment to be examined, projecting light onto the fundus of the eye to be examined, and imaging a transillumination image by the fundus reflection light,
Storage means for storing a captured image captured by the imaging optical system;
And a control means for extracting an image of a predetermined range including the retroillumination from stored the captured image in the storage means,
The transillumination image is captured in a state where the corneal vertex of the eye to be examined and the imaging optical axis of the imaging optical system are shifted,
The control unit performs an alignment process so that the transillumination image of the captured image fits in the printing paper and the center of the transillumination image overlaps the central portion in the horizontal direction of the paper, and print processing is performed. apparatus.