JP2016140390A - Ophthalmic measurement device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ophthalmic measurement device having a compact device configuration.SOLUTION: A flood light optical system of an ophthalmic measurement device includes a scanning unit in which a light source and a polygon mirror are positioned at a predetermined positional relationship, and scans a measurement light at an ocular fundus using the polygon mirror. Also, a light-receiving optical system of the ophthalmic measurement device includes a light-receiving unit 37 on which light-receiving elements 37a-37r are arranged in conjugation with a cornea, and receives the measurement light reflected at the ocular fundus using the light-receiving elements 37a-37r. Further, a control unit of the ophthalmic measurement device obtains refractive power of a subject eye at cornea parts in a meridian direction corresponding to the scanning direction of the measurement light based on a phase difference signal output from the light receiving element 37a-37r corresponding to each of the cornea parts. Further, the control unit drives the polygon mirror and a drive unit in combination to control scanning of the measurement light, and obtains a distribution of the refractive force of the subject eye at the cornea parts in a plurality of meridian directions.SELECTED DRAWING: Figure 2

Description

  The present disclosure relates to an ophthalmologic measurement apparatus that measures a refractive distribution of a subject's eye.

  Conventionally, an apparatus for measuring an eye refraction distribution (including wavefront aberration) over a wide range of an eye to be examined is known. As such an apparatus, while scanning the fundus of the eye to be examined with a slit light beam, the slit light beam reflected by the fundus is received using a plurality of light receiving elements arranged at a position substantially conjugate with the cornea, and the phase difference of each light receiving element is detected. Devices that obtain the refractive power of an eye to be examined that change in the meridian direction based on a signal are known.

  Patent Document 1 discloses an apparatus in which a cylindrical rotating sector having a plurality of slits is provided so as to surround a measurement light source in order to scan a slit light beam. The rotating sector of this device is arranged so that the central axis of the cylinder is perpendicular to the measuring optical axis. When measuring the eye refraction distribution, the rotating sector rotates about the central axis of the cylinder and also rotates about the measuring optical axis, so that the slit light flux is scanned in each meridian direction.

Japanese Patent Laid-Open No. 10-108837

  For example, in the apparatus described in Patent Document 1, a rotating sector having a size surrounding the measurement light source is required, and in order to rotate the rotating sector around the measurement optical axis, a unit including the rotating sector and its driving mechanism is provided in the housing. Because of this, a large space was required. As a result, it was difficult to make the apparatus compact. Further, it has been an obstacle to providing an optical system for performing measurement different from the eye refraction distribution measurement in the same housing.

  The present disclosure has been made in view of the problems of the prior art, and an object of the present disclosure is to provide an ophthalmic measurement apparatus that can easily make the apparatus configuration compact.

  An ophthalmologic measurement apparatus according to a first aspect of the present disclosure projects a measurement light emitted from a light source onto a subject's eye, a projection optical system that scans the fundus of the subject's eye using the measurement light, a subject's eye cornea, It has a light receiving unit in which two or more pairs of light receiving elements arranged symmetrically with respect to the optical axis at a conjugate position, and receives measurement light reflected from the fundus of the eye to be examined using the light receiving element. And the refractive power of the eye to be examined in the corneal region in the meridian direction corresponding to the scanning direction of the measurement light based on the phase difference signal output from the light receiving element corresponding to each corneal region An ophthalmic measurement apparatus comprising: an arithmetic control unit that obtains the projection optical system, the light source, and an optical scanner that changes the traveling direction of the measurement light by deflecting the measurement light emitted from the light source; Is in a fixed positional relationship And a driving unit that rotates the scanning unit around a measurement optical axis in the projection optical system, and the arithmetic control unit combines the optical scanner and the driving unit. To drive the measurement light, thereby obtaining the refractive power distribution of the eye to be examined at the corneal site in a plurality of meridian directions.

  According to the present disclosure, the apparatus configuration can be easily configured in a compact manner.

It is the figure which showed the outline | summary of the optical system in the ophthalmic measurement apparatus of this embodiment. It is the figure which showed the structure of the light-receiving unit. It is the figure which showed the outline | summary of the electrical structure in the ophthalmic measurement apparatus of this embodiment. It is the figure which showed the output signal strength from each light receiving element when a polygon mirror was rotated with respect to the 2nd rotating shaft. It is a figure for showing the phase difference signal output at the time of changing the position of a stop.

  Hereinafter, exemplary embodiments of the present disclosure will be described with reference to the drawings. FIG. 1 shows a schematic configuration of an ophthalmologic measurement apparatus 1 according to the embodiment. The ophthalmologic measurement apparatus 1 is used for analyzing an eye refractive power distribution. In the present embodiment, it is also used for analyzing a detailed distribution of the corneal shape.

<Description of optical system>
First, the optical system of the ophthalmic measurement apparatus 1 will be described. The ophthalmologic measurement apparatus 1 includes a projection optical system 20 and a light receiving optical system 30 as an optical system (eye refractive power distribution measurement optical system) for measuring an eye refractive power distribution.

  The projection optical system 20 projects (projects) the measurement light from the light source 21a onto the eye E. In this case, the projection optical system 20 scans the fundus of the eye E using the measurement light. In the present embodiment, the projection optical system 20 includes a scanning unit 21, a light projecting lens 23, and a beam splitter 24.

  The scanning unit 21 is a unit in which at least a light source 21a and a polygon mirror 21b (an optical scanner in the present embodiment) are arranged. The polygon mirror 21b reflects the measurement light emitted from the light source 21a and changes the traveling direction of the measurement light. The polygon mirror 21b rotates by driving a drive mechanism 21c (for example, a motor or the like, see FIG. 2), and scans the measurement light in one direction (in this embodiment, the rotation direction of the polygon mirror 21b). In the present embodiment, the scanning unit 21 is rotated around the measurement optical axis L1 when the drive mechanism 22 is driven. In this case, the relative positional relationship between the light source 21a and the polygon mirror 21b is maintained even when the scanning unit 21 rotates.

  As shown in FIG. 1, the measurement light emitted from the light source 21 a passes through the light projection lens 23 and the beam splitter 24 through the scanning unit 21 and is irradiated to the eye E. In FIG. 1, a beam splitter 51 (details will be described later) is disposed between the eye E and the beam splitter 24. In the present embodiment, the beam splitter 51 does not prevent the measurement light from being projected and received.

  The light receiving optical system 30 includes a light receiving unit 37 that receives measurement light reflected by the fundus of the eye to be examined. In addition, the light receiving optical system 30 includes a detection lens 31, a first diaphragm 32, a mirror 33, a second diaphragm 34, a third diaphragm 34, and a filter 36. Each of these members is disposed on the reflection side of the beam splitter 24. In the light receiving optical system 30 configured as described above, the measurement light reflected from the fundus is reflected by the beam splitter 24 and guided to the detection lens 31. Then, the measurement light is reflected by the mirror 33 and is irradiated to the light receiving unit 37 via any one of the diaphragms 32, 34, and 35 and the filter 36.

  The diaphragms 32, 34, and 35 are used for obtaining a signal corresponding to the phase from the measurement light reflected from the fundus of the eye to be examined. The diaphragms 32, 34, and 35 remove light that becomes noise of the phase difference signal as a result of being arranged in the optical path of the measurement light. In the present embodiment, any one of the diaphragms 32, 34, and 35 is inserted into the light receiving optical path of the measurement light and used for measurement. The drive mechanisms 32a, 34a, 35a (see FIG. 6) for moving the respective diaphragms 32, 34, 35 are controlled by the control unit 70, whereby the position of the diaphragm in the light receiving optical path is switched. In this case, the second aperture stop 34 is disposed at the fundus conjugate position of the normal eye (eye with diopter error OD). The first diaphragm 32 is disposed at the fundus conjugate position of a myopic eye (for example, an eye having a diopter error of minus 6D), and the third diaphragm 35 is a hyperopic eye (for example, an eye having a diopter error of plus 7D). ) At the fundus conjugate position. The configuration for switching the position of the diaphragm is not limited to the above configuration. For example, the position of the diaphragm may be switched using a mechanism that displaces the diaphragm along the light receiving optical axis. In the present disclosure, “conjugate” is not necessarily limited to a complete conjugate relationship. In the present disclosure, the “conjugate” relationship may be a positional relationship deviated from the complete conjugate relationship within an allowable accuracy range in addition to the complete conjugate relationship. The filter 36 has a characteristic of transmitting the measurement light and blocking the other light.

  A detailed configuration of the light receiving unit 37 will be described with reference to FIG. The light receiving unit 37 shown in FIG. 5 includes a plurality (10 as an example in FIG. 5) of light receiving elements 37a to 37r. Each of the light receiving elements 37a to 37r is disposed at a position conjugate with the cornea of the eye E with respect to the detection lens 31 and the diaphragms 32, 34, and 35. (For example, a position that is strictly conjugated with each of the light receiving elements 37a to 37r may be allowed even if it is shifted to the fundus side from the apex of the cornea to about 4 mm, for example). As shown in FIG. 5, the optical elements 37 a to 37 p are arranged on one straight line that intersects the optical axis L <b> 2 of the light receiving optical system 30 (hereinafter referred to as the light receiving optical axis L <b> 2). In the example of FIG. 5, the light receiving elements 37a and 37i, the light receiving elements 37b and 37j,... (Omitted)..., And the light receiving elements 37h and 37p are respectively paired with respect to the light receiving optical axis L2. They are arranged symmetrically. The arrangement distances of the eight pairs of light receiving elements are set so as to obtain refractive powers of different parts in the meridian direction of the cornea. On the other hand, the light receiving elements 37q and 37r are arranged with the light receiving optical axis L2 interposed therebetween so as to be arranged orthogonal to the arrangement direction of the light receiving elements 37a to 37p. Further, the light receiving unit 37 rotates around a rotation axis (third rotation axis) set coaxially with the light reception optical axis L2 by driving a drive mechanism 38 (for example, a motor or the like, see FIG. 2). . The light receiving unit 37 can rotate in synchronization with the rotational movement (first rotation axis) of the light projection optical axis L1 in the scanning unit 21 (that is, with the same amount of angular displacement).

  The ophthalmologic measurement apparatus 1 includes a placido ring projection optical system 40 (hereinafter abbreviated as the projection optical system 40) and an imaging optical system 50 as an optical system (that is, a corneal shape measurement optical system) for measuring a corneal shape. And comprising. The projection optical system 40 projects a plurality of annular index images formed concentrically on the cornea of the eye to be examined. In the present embodiment, as an example, the projection optical system 40 includes a platide plate 41, a visible light source 42, and a reflection plate 43. On the platide plate 41, a large number of annular indicators are formed concentrically. The visible light source 42 illuminates the placido plate 41 from behind. The imaging optical system 50 mainly includes an imaging element 54 (for example, a CCD camera or the like) that captures an index image reflected by the cornea of the eye to be examined. In the present embodiment, the imaging optical system 50 includes beam splitters 51 and 52 and a photographing lens 53 in addition to the imaging element 54. In the present embodiment, the anterior ocular segment can be observed or photographed using the imaging optical system 50. That is, the imaging optical system 50 can also be used as an anterior ocular segment imaging optical system.

  The ophthalmologic measurement apparatus 1 includes a fixation optical system 60. The fixation optical system 60 includes a visible light source 61, a fixation target 62, and a lens 63. The lens 63 is movable in the optical axis direction by controlling the drive mechanism 63a (see FIG. 3) by the control unit 70. The movement of the lens 63 is performed, for example, when eye refractive power measurement is performed. In this case, cloud fog is generated by the movement of the lens 63.

<Description of electrical configuration>
Next, the electrical configuration of the ophthalmologic measurement apparatus 1 will be described with reference to FIG. The ophthalmologic measurement apparatus 1 includes a control unit 70 (calculation control unit). The control unit 70 is a processor that performs overall control and arithmetic processing in the ophthalmic measurement apparatus 1. In the present embodiment, the control unit 70 calculates a corneal corneal refractive power distribution (corneal curvature distribution) and an eye refractive power distribution of the entire eye. Further, the control unit 70 calculates an intraocular refractive power distribution from the corneal refractive power distribution and the ocular refractive power distribution. The control unit 70 is composed of, for example, a combination of a CPU and a memory. In the present embodiment, the control unit 70 also serves as an image processing unit that performs various types of image processing on the image of the eye to be examined acquired via the optical system. However, the present invention is not necessarily limited to this, and a circuit that performs various types of image processing may be provided separately from the control unit 70.

  In the present embodiment, the storage unit 71, the operation input unit 72, and the monitor 75 are electrically connected to the control unit 70. In addition, various light sources (that is, the light source 21, the light source 42, and the light source 61) and various light receiving elements (that is, the light receiving element 37, the imaging element 54, and the like) are electrically connected to the control unit 70. Yes. In the present embodiment, the driving mechanism 22 for rotating the scanning unit 21, the driving mechanism 21 c for rotating the polygon mirror 21 b, the driving mechanism 33 a for rotating the light receiving unit 37, each diaphragm 32, The control unit 70 also has a drive mechanism 32a, 34a, 35a for inserting and removing 34, 35 and a drive mechanism 63a for moving the lens 63 (both not shown). Connected.

  In the present embodiment, the storage unit 71, the operation input unit 72, and the monitor 75 are electrically connected to the control unit 70. In addition, various light sources (that is, the light source 21a, the light source 42, the light source 61, and the like) and various light receiving elements (that is, the light receiving element 37, the imaging element 54, and the like) are electrically connected to the control unit 70. Yes. In the present embodiment, the drive mechanism 22 for rotating the scanning unit 21 around the measurement optical axis L1, the drive mechanism 21c for rotating the polygon mirror 21b, and the drive mechanism for rotating the light receiving unit 37 are further provided. 33a, drive mechanisms 32a, 34a, 35a for inserting / removing the diaphragms 32, 34, 35, and a drive mechanism 63a for moving the lens 63 (none of which is shown). However, the control unit 70 is connected.

  The storage unit 71 stores various control programs and fixed data. Further, the storage unit 71 may store an image taken by the ophthalmologic measurement apparatus 1, temporary data, and the like.

  The control unit 70 controls each member described above based on the operation signal output from the operation input unit 72. The operation input unit 72 includes operation members such as a mouse and a keyboard as operation members operated by the examiner.

  The monitor 75 may be a display monitor mounted on the ophthalmic measurement apparatus 1 (that is, a housing-integrated display), or may be a general-purpose display monitor that is separate from the ophthalmic measurement apparatus 1. Moreover, the structure in which these were used together may be sufficient. The monitor 75 can display various calculation results by the control unit 70 (for example, analysis results on the refraction and shape of the eye to be examined). The monitor 75 can display an image (for example, an anterior ocular segment image) taken by the ophthalmologic measurement apparatus 1.

<Operation of the device>
Next, the operation of the ophthalmic measurement apparatus 1 having the above-described configuration will be described.

<Measurement of eye refraction distribution>
Next, the operation of the apparatus in the measurement of the eye refractive power distribution will be described. In the measurement, the eye E and the apparatus may be aligned in advance using the corneal reflection bright spot of the light source 21a.

  First, in the ophthalmologic measurement apparatus 1 of the present embodiment, a method for obtaining eye refractive power at a corneal region corresponding to one measurement meridian (here, a method using a phase difference method) will be described. The measurement meridian is determined by the rotation direction of the polygon mirror 21b. In the present embodiment, the direction of the measurement meridian is the rotation direction of the polygon mirror 21b.

  In the measurement, the control unit 70 matches the arrangement direction of the light receiving elements 37a to 37p in the light receiving unit 37 with the direction of the measurement meridian (that is, the rotation direction of the polygon mirror 21b). In addition, the control unit 70 emits measurement light from the light source 21a and rotates the polygon mirror 21b around the second rotation axis. As a result, the measurement light is scanned on the fundus of the eye E. Then, the reflected light is received by the light receiving unit 37.

Based on the light reception result of the light receiving unit 37 that has received the measurement light in this way, the control unit 70 obtains the eye refractive power at the corneal region corresponding to one measurement meridian. First, the corneal center (or visual axis center) in the meridian direction in which the light receiving elements 37a to 37p are located is obtained from the phase difference between the output signals of the light receiving elements 37q and 37r arranged in the direction orthogonal to the measurement meridian. . Then, by obtaining the phase difference between the cornea corresponding position and the cornea center in each of the light receiving elements 37a to 37p, the refractive power at the cornea portion corresponding to each of the light receiving elements 37a to 37p is obtained (for more details of signal processing). (See, for example, JP-A-10-10883)
Here, the graph of the output signal in each of the light receiving elements 37a to 37r when the polygon mirror 21b is rotated about the second rotation axis is shown by the graph of FIG. In the graph of FIG. 4, the horizontal axis represents the rotation angle of the polygon mirror 21b. When the polygon mirror 21b rotates at a constant speed, it can be converted into time. The vertical axis indicates the intensity of the output signal. The signal intensity shown in the graph of FIG. 4 is a value obtained by simulation by the inventor by appropriately setting the design value of the optical system.

  When the refractive power is measured by the phase difference method outlined above, it is necessary to define a phase reference (that is, output timing reference) for each output signal. For example, the timing at which the output signal becomes maximum (or the rotation angle of the polygon mirror 21b, etc.) can be used as the phase reference. If the phase reference is appropriate, good measurement accuracy can be achieved. Here, as shown in FIG. 4, the waveform of the output signal obtained by the measurement method of the present embodiment has a comparatively gentle way of bending around the peak, and in some cases, the peak may be flattened. is there. Therefore, if the location where the intensity is the highest in the waveform is used as the phase reference, the phase difference cannot be obtained with high accuracy, and as a result, sufficient refractive power measurement accuracy may not be obtained. It is done.

  On the other hand, in the present embodiment, two timings at which a signal intensity of a predetermined ratio with respect to the maximum intensity of the output signal is output are obtained, and the midpoint is used as a phase reference in the output signal. According to this method, even if the output signal has a collapsed peak, the phase reference can be set more appropriately. Therefore, good measurement accuracy can be realized.

  FIG. 5 (a) shows the phase simulation values for the axial refractive aberration model eyes (22D, 18D, 6D, 0D, minus 4D, minus 22D) having different frequencies. However, in the graph of FIG. 5A, the phase values of the signals from the two light receiving elements (more specifically, 37d and 37l) that are paired and are offset by the phase value of 0D are shown. . FIG. 5A shows a signal when the diaphragm 34 is arranged at the fundus conjugate position in the normal eye. FIG. 5B shows a signal when the diaphragm 32 is arranged at the fundus conjugate position in the plus 7D myopic eye.

  According to the simulation result shown in FIG. 5A, it is confirmed that the phase value of the signal from the light receiving element 37d wraps around the phase value in a certain diopter (about 0D in FIG. 5A). It was. As a result, it is difficult to uniquely determine the eye refractive power with respect to the phase value. For example, when plus 2 deg is obtained as the phase value of the signal from the light receiving element 371, according to the graph of FIG. 5A, the refractive power is approximately minus 4D and approximately plus 6D. You will get both.

  On the other hand, in this embodiment, after the position of the diaphragm arranged on the light receiving optical axis L2 is arranged at the first position to obtain the phase difference output, the second position different from the first position is obtained. A diaphragm is arranged to obtain a phase difference output, and a value of eye refractive power is determined based on a change in the phase difference output. For example, as described above, when the diaphragm is arranged at the fundus conjugate position of the normal eye as the first position and the refractive power is measured, the diaphragm 32 is arranged at the plus 7D position as the second position and the refractive power is measured. May be measured. In this case, as shown in FIG. 5B, a graph obtained by shifting the graph of FIG. 5A to the right side is obtained. That is, the phase difference (the difference indicated by the arrow A) of the output signals from the light receiving element 37d and the light receiving element 37l corresponding to about minus 4D is increased in FIG. 5B compared to FIG. . On the other hand, the phase difference (difference indicated by the arrow B) of the output signals from the light receiving element 37d and the light receiving element 37l corresponding to about 6D is reduced in FIG. 5B compared to FIG. Therefore, if about minus 4D is the true value of the refractive power, the phase difference is increased by changing the stop arrangement as described above. On the other hand, if approximately plus 6D is the true value of the refractive power, the phase difference is reduced by changing the stop arrangement as described above. Therefore, the control unit 70 can determine the true value of the refractive power based on the change in the phase difference accompanying the change in the arrangement of the diaphragm. As the second position, the diaphragm 35 may be arranged at a position of minus 6D. In this case, the phase graph is obtained by shifting FIG. 5A to the left side. Then, the phase difference between the output signals from the light receiving element 37d and the light receiving element 37l corresponding to about minus 4D is reduced with respect to FIG. 5A, and the phase difference corresponding to about 6D is shown in FIG. 5A. In contrast, it increases.

  As described above, the ocular refractive power at the corneal region corresponding to one measurement meridian is obtained. Therefore, the control unit 70 measures the eye refractive power as described above at each step position while rotating the scanning unit 21 and the light receiving unit 37 around the measurement optical axis, for example, by one step. Here, the step position is a rotational position of the scanning unit 21 corresponding to each step and is a position with respect to the measurement optical axis L1. In addition, after the step position is changed by one degree (that is, one step) around the measurement optical axis L1, the measurement is performed with one measurement meridian. However, it is not necessarily limited to this. For example, the measurement at a certain step position may be performed by driving the polygon mirror 21b for at least one scan while rotating around the measurement optical axis L1 by one degree.

  As a result of the measurement performed at each step position, the control unit 70 can obtain an eye refractive power distribution for each measurement meridian corresponding to each rotation step (that is, an eye refractive power distribution at each portion of the cornea). When such an eye refractive power distribution is obtained, the control unit 70 performs, for example, predetermined processing on the eye refractive power in each meridian direction with a diameter of 3 mm, thereby obtaining a spherical power S, an astigmatic power C, an astigmatic axis. The angle A can be obtained. The eye refractive power distribution (and spherical power S, astigmatism power C, astigmatic axis angle A) is a value of refraction error with respect to the normal eye in the whole eye when the cornea to the retina are considered as one optical system. can get.

  As described above, according to the ophthalmologic measurement apparatus 1 of the present embodiment, the scanning unit 21 can be configured with relatively small space using the optical scanner such as the polygon mirror 21b, the light source 21a, and the driving mechanisms 21b and 22 thereof. In the ophthalmologic measuring apparatus 1, the space required for the operation of the scanning unit 21 is suppressed. Therefore, it is possible to realize a compact device with good measurement accuracy. In addition, the fact that the space for the scanning unit 21 and its operation is suppressed is advantageous in incorporating an optical system for performing measurement different from eye refractive power measurement in the housing, which is a measurement related to the eye to be examined. (For example, an axial length measurement optical system, an interference optical system used for tomographic imaging, an anterior ocular segment imaging optical system, a fundus imaging optical system, etc.).

<Measurement of corneal shape>
Next, corneal shape measurement will be described. In the measurement, the eye E and the apparatus may be aligned in advance using the corneal reflection bright spot of the light source 21a. The controller 70 projects the placido ring on the cornea by turning on the light source 42. The control unit 70 captures a placido ring image by the image sensor 54. Then, corneal shape measurement data is obtained by subjecting the obtained image to image processing. As the corneal shape measurement data, for example, a corneal curvature distribution (for example, a distribution indicating the corneal curvature for each step with respect to the corneal center) based on the corneal center (the bright spot by the light source 21a) can be obtained. .

  The corneal curvature distribution data can be converted into corneal refractive power distribution data by a known process. For example, the intraocular refractive power distribution that is the refractive power in the eye from the posterior corneal surface to the retina can be calculated from the corneal refractive power distribution data and the ocular refractive power distribution data. The control unit 70 may display any one or two or more of the eye refractive distribution, corneal refractive power distribution, and intraocular refractive power distribution obtained as described above on the monitor 75 as a map.

  Although the description has been given based on the embodiment, the embodiment can be appropriately modified based on the knowledge that a person skilled in the art normally has.

  For example, in the above embodiment, the case where the scanning unit 21 is provided with the polygon mirror 21b as an optical scanner has been described. However, the present invention is not necessarily limited to this, and various optical scanners can be employed. More specifically, it may be an optical scanner that reflects or diffracts the measurement light emitted from the light source 21a to change the traveling direction of the measurement light. In this case, for example, a reflective optical scanner such as a galvanometer mirror or a resonant scanner may be used, or a diffractive optical scanner such as an acousto-optic element (AOM) may be used.

  Moreover, although the said embodiment demonstrated the case where eye refractive power was acquired based on the phase difference signal output from several light receiving element 37a-37r arrange | positioned in a predetermined position, it is not necessarily restricted to this. Absent. For example, instead of the plurality of light receiving elements 37a to 37r, a two-dimensional light receiving element (as a specific example, a two-dimensional CCD or the like) may be used. In this case, if a position corresponding to each part of the cornea is predetermined on the light receiving surface of the two-dimensional light receiving element, a phase difference signal output can be obtained as a phase difference of the light reception signal at each position. In this case, information on the position corresponding to each part of the cornea in the two-dimensional light receiving element is such that the control unit 70 can identify which part in the cornea the signal output from the two-dimensional light receiving element corresponds to. The structure memorize | stored in the memory | storage part 71 may be sufficient.

  Further, when the two-dimensional light receiving element is provided in the light receiving unit, it is not always necessary to rotate the light receiving unit 37 together with the scanning unit 21 when measuring the eye refractive power. The coordinates of the position corresponding to each part of the cornea in the two-dimensional light receiving element may be changed (rotated) in synchronization with the rotation of the scanning unit 21 around the optical axis L1.

  Further, the measurement light projected from the scanning unit 21 toward the eye E may be slit light. In this case, for example, slit light may be formed using the line LED as the light source 21a. Further, slit light may be formed by arranging a slit plate between the light source 21a and the polygon mirror 21b. In these cases, the direction of the slit in the longitudinal direction may be a direction intersecting (for example, orthogonal to) the scanning direction of the polygon mirror 21b.

20 Projection optical system 21 Scanning unit 21b Polygon mirror 22 Drive mechanism 30 Light receiving optical system 37 Light receiving units 37a to 37r Light receiving element 38 Drive mechanism 70 Control unit

Claims (5)

A projection optical system that projects measurement light emitted from a light source onto the eye to be examined and scans the fundus of the eye to be examined using the measurement light;
A light receiving optical system having a light receiving unit in which a light receiving element is arranged at a position conjugate with the eye cornea to be examined, and for receiving measurement light reflected by the fundus of the eye to be examined using the light receiving element;
Calculation control means for obtaining the refractive power of the eye to be examined in the corneal region in the meridian direction corresponding to the scanning direction of the measurement light based on the phase difference signal output from the light receiving element corresponding to each corneal region; An ophthalmic measuring device comprising:
The projection optical system is
A scanning unit in which the light source and an optical scanner that deflects measurement light emitted from the light source and changes a traveling direction of the measurement light are arranged in a fixed positional relationship;
A drive unit that rotates the scanning unit around a measurement optical axis in the projection optical system,
The arithmetic control means controls the scanning of the measurement light by driving the optical scanner and the driving unit in combination, and obtains the refractive power distribution of the eye to be examined at the corneal site in a plurality of meridian directions. Ophthalmic measuring device.   When the refractive power distribution is obtained, the arithmetic control unit drives the scanning unit around the measurement optical axis at a predetermined angle step, and at least one period of time by the optical scanner at each step position. The ophthalmic measurement apparatus according to claim 1, wherein optical scanning is performed. A second drive unit for rotating the light receiving unit around a light receiving optical axis of the light receiving optical system;
The arithmetic control unit controls the drive unit and the second drive unit so that the rotation of the scanning unit with respect to the measurement optical axis is synchronized with the rotation of the light receiving element with respect to the light receiving optical axis. The ophthalmic measurement apparatus according to claim 1 or 2.   The arithmetic control means outputs a phase difference signal output from two different light receiving elements in the light receiving unit to a position between two midpoints indicating a predetermined ratio of intensity with respect to an intensity peak in the signal output waveform of each light receiving element. The ophthalmic measurement apparatus according to any one of claims 1 to 3, wherein the ophthalmic measurement apparatus is detected as a signal output corresponding to a phase difference.   The arithmetic control unit arranges the position of the stop arranged on the optical axis of the light receiving optical system at the first position to obtain a phase difference output, and then sets the stop to a second position different from the first position. The eye refractive power value is determined based on a change in the phase difference output between the first position and the second position. The ophthalmic measurement apparatus according to any one of the above.