JP6936090B2 - Ophthalmic device and its control method - Google Patents

Description

The present invention relates to an ophthalmic apparatus and a method for controlling the same.

As an ophthalmic apparatus, one capable of measuring the refractive power of the eye to be inspected is known. For example, in Patent Document 1, a measurement pattern is projected onto the fundus of the eye to be inspected, the reflected light from the fundus is extracted from the center of the pupil, and the optical power value is calculated from the size of the acquired pattern image and the degree of deformation. The ophthalmic apparatus to be used is disclosed.

In such an ophthalmic apparatus, provisional measurement is performed for the purpose of predetermining the amount of movement of the focusing portion according to the accommodation force of the eye to be inspected. For example, in Patent Document 2, based on the amount of movement of the in-focus portion obtained by the provisional measurement, the in-focus portion is moved so that the measurement pattern image is substantially in focus on the fundus of the eye to be inspected, and further covered. An ophthalmic apparatus for measuring the accurate optical power of an eye to be inspected by carrying out this measurement after making the eye to be viewed as cloudy is disclosed.

Japanese Unexamined Patent Publication No. 2016-187461 Japanese Unexamined Patent Publication No. 2007-159850

When the line width of the pattern image projected on the fundus of the eye to be inspected is thick, even if the in-focus part is moved based on the amount of movement of the in-focus part obtained by the provisional measurement, the pattern image on the sensor before and after the movement. The change in brightness (illuminance) is small. Therefore, when the main measurement is performed under the measurement conditions determined by the provisional measurement, the measurement accuracy does not matter.

On the other hand, when the line width of the pattern image projected on the fundus is narrowed and the brightness is increased, the edge portion of the obtained pattern image becomes steep, so that the measured luminous flux is less affected by eclipse in the eye. From this, stable measurement is possible even for an eye to be inspected having opacity in the eye such as a cataract eye. However, when the line width of the pattern image is narrow and the brightness is high, the change in the brightness of the pattern image before and after the movement of the focusing portion becomes large. Therefore, when the main measurement is performed under the measurement conditions determined by the tentative measurement, a sufficient S / N ratio for image detection may not be obtained, and the measurement accuracy may be lowered.

The present invention has been made in view of such circumstances, and an object of the present invention is to reduce the measurement accuracy even when the line width of the pattern image for measuring the optical refractive power of the eye to be inspected is narrow and the brightness is high. It is an object of the present invention to provide an ophthalmic apparatus capable of suppressing the above-mentioned problems and a method for controlling the same.

In the first aspect of the embodiment, a pattern light based on the light from the light source is projected onto the eye to be inspected, and the return light of the pattern light from the eye to be inspected is an image pickup element via a focusing lens whose focal position can be changed. The optical system that receives light, the analysis unit that calculates the optical power value of the eye to be inspected based on the pattern image obtained by the imaging element, and the light source based on the first pattern image obtained by the imaging element. A first measurement condition including at least one of the amount of light, the exposure time of the image pickup element, the detection sensitivity of the image pickup element, and the control content for the focusing lens is determined, and the image pickup element determines the first measurement condition under the first measurement condition. Based on the obtained second pattern image, a second measurement condition including at least one of the light amount, the exposure time, the detection sensitivity, and the control content is determined, and the eye to be inspected under the second measurement condition. This is an ophthalmic apparatus including a control unit that causes the analysis unit to calculate the optical power value based on a third pattern image obtained by the image pickup element in a state of cloud fog.

Further, in the second aspect of the embodiment, in the first aspect, the light source is arranged so as to be optically coupled to the fundus of the eye to be inspected, and the optical system is optically connected to the pupil of the eye to be inspected. A throttle having a light-transmitting portion formed at a position substantially conjugate with the light source and a deflecting member for deflecting the light from the light source and guiding the light from the light-transmitting portion to the light-transmitting portion. The light transmitted through the light portion may be projected onto the eye to be inspected as the pattern light.

Further, in the third aspect of the embodiment, in the first aspect or the second aspect, the control unit executes the first brightness reduction control when the brightness of the first pattern image is high, and the brightness of the first pattern image is increased. When the brightness is low, the first brightness increase control is executed, when the brightness of the second pattern image is high, the second brightness decrease control is executed, and when the brightness of the second pattern image is low, the second brightness increase control is executed. May be good.

Further, in the fourth aspect of the embodiment, in the third aspect, at least one of the first luminance reduction control and the second luminance reduction control is a pattern image by lowering the detection sensitivity based on the brightness of the pattern image. After the first detection sensitivity control for lowering the brightness of the pattern image, the first exposure time control for lowering the brightness of the pattern image may be performed by shortening the exposure time.

Further, in the fifth aspect of the embodiment, in the fourth aspect, at least one of the first luminance reduction control and the second luminance reduction control is a pattern image by reducing the amount of light after the first exposure time control. The first light amount control for lowering the brightness of the light may be performed.

Further, in the sixth aspect of the embodiment, in the fourth or fifth aspect, the optical system includes a rotary prism arranged in the optical path of the pattern light, and the first exposure time control is performed by the rotary prism. The exposure time may be shortened so as to be equal to or longer than the lower limit time defined by the rotation speed.

Further, in the seventh aspect of the embodiment, in any one of the third to sixth aspects, at least one of the first luminance increase control and the second luminance increase control is a pattern image obtained by increasing the amount of light. After the second light amount control for increasing the brightness, the second exposure time control for increasing the brightness of the pattern image may be performed by lengthening the exposure time.

Further, in the eighth aspect of the embodiment, in the seventh aspect, at least one of the first luminance increase control and the second luminance increase control is patterned by increasing the detection sensitivity after the second exposure time control. The second detection sensitivity control that raises the brightness of the image may be performed.

Further, in the ninth aspect of the embodiment, in any of the first to eighth aspects, the pattern light may be ring-shaped light.

In the tenth aspect of the embodiment, a pattern light based on the light from the light source is projected onto the eye to be inspected, and the return light of the pattern light from the eye to be inspected is an image pickup element via a focusing lens whose focal position can be changed. It is a control method of an ophthalmic apparatus that measures the refractive power of the eye to be inspected by receiving light, and based on the first pattern image obtained by the imaging element, the amount of light of the light source, the exposure time of the imaging element, and the above. The first measurement condition determination step for determining the detection sensitivity of the image pickup element and the first measurement condition including at least one of the control contents for the focusing lens, and the image pickup element obtained under the first measurement condition. A second measurement condition determination step for determining a second measurement condition including at least one of the light amount, the exposure time, the detection sensitivity, and the control content based on the second pattern image, and the second measurement condition. It is a control method of an ophthalmic apparatus including a cloud fog control step in which the eye to be inspected is viewed as cloud fog, and a measurement step in which the refractive power is measured in the cloud fog control step in a state where the eye to be inspected is viewed as cloud fog.

Further, in the eleventh aspect of the embodiment, in the tenth aspect, at least one of the first measurement condition determination step and the second measurement condition determination step is the first determination for determining whether or not the brightness of the pattern image is high. In the step, the second determination step of determining whether or not the detection sensitivity is equal to or higher than the first threshold value when the brightness is determined to be high in the first determination step, and the detection sensitivity in the second determination step. When it is determined that is equal to or higher than the first threshold value, the first detection sensitivity control step for lowering the detection sensitivity and when it is determined in the second determination step that the detection sensitivity is less than the first threshold value, When it is determined in the third determination step for determining whether or not the exposure time is equal to or greater than the second threshold value and the exposure time is determined to be equal to or greater than the second threshold value in the third determination step, the exposure time is shortened. When it is determined in the first exposure time control step and the third determination step that the detection sensitivity is less than the second threshold value, a fourth determination is made to determine whether or not the amount of light is equal to or greater than the third threshold value. A step and a first light amount control step for lowering the light amount when it is determined in the fourth determination step that the light amount is equal to or higher than the third threshold value may be included.

Further, in the twelfth aspect of the embodiment, in the eleventh aspect, the ophthalmic apparatus includes a rotary prism arranged in the optical path of the pattern light, and the second threshold value is defined by the rotation speed of the rotary prism. It may be equal to or longer than the lower limit time.

Further, in the thirteenth aspect of the embodiment, in any one of the tenth to twelfth aspects, whether or not the brightness of the pattern image is low in at least one of the first measurement condition determination step and the second measurement condition determination step. A fifth determination step for determining whether or not the brightness is low, and a sixth determination step for determining whether or not the amount of light is equal to or less than the fourth threshold value when the brightness is determined to be low in the fifth determination step, and the sixth determination step. When it is determined in the determination step that the amount of light is equal to or less than the fourth threshold value, the second light amount control step for increasing the amount of light, and when it is determined in the sixth determination step that the amount of light exceeds the fourth threshold value. When it is determined in the seventh determination step of determining whether or not the exposure time is equal to or less than the fifth threshold value and the exposure time is determined to be equal to or less than the fifth threshold value in the seventh determination step, the exposure time is determined. When it is determined in the second exposure time control step to be lengthened and the seventh determination step that the exposure time exceeds the fifth threshold value, an eighth determination is made as to whether or not the detection sensitivity is equal to or less than the sixth threshold value. A determination step and a second detection sensitivity control step for increasing the detection sensitivity when the detection sensitivity is determined to be equal to or lower than the sixth threshold value in the eighth determination step may be included.

Further, in the fourteenth aspect of the embodiment, the light source is arranged so as to be optically coupled to the fundus of the eye to be examined, and the ophthalmic apparatus is located at a position optically substantially coupled to the pupil of the eye to be examined. A throttle formed in a light-transmitting portion for transmitting light from the light source, and a deflecting member for deflecting light from the light source and guiding the light from the light-transmitting portion to the light-transmitting portion, and transmitting the light-transmitting portion. The light may be projected onto the eye to be inspected as the pattern light.

It is the schematic which shows the structural example of the optical system of the ophthalmic apparatus which concerns on embodiment. It is the schematic which shows the structural example of the optical system of the ophthalmic apparatus which concerns on embodiment. It is the schematic which shows the structural example of the optical system of the ophthalmic apparatus which concerns on embodiment. It is the schematic which shows the structural example of the processing system of the ophthalmic apparatus which concerns on embodiment. It is the schematic which shows the structural example of the processing system of the ophthalmic apparatus which concerns on embodiment. It is the schematic which shows the flow of the operation example of the ophthalmic apparatus which concerns on embodiment. It is the schematic which shows the flow of the operation example of the ophthalmic apparatus which concerns on embodiment. It is the schematic which shows the flow of the operation example of the ophthalmic apparatus which concerns on embodiment. It is the schematic which shows the flow of the operation example of the ophthalmic apparatus which concerns on embodiment. It is the schematic which shows the flow of the operation example of the ophthalmic apparatus which concerns on embodiment. It is the schematic which shows the structural example of the optical system of the ophthalmic apparatus which concerns on the modification of embodiment. It is the schematic which shows the structural example of the optical system of the ophthalmic apparatus which concerns on the modification of embodiment.

An example of an embodiment of the ophthalmic apparatus according to the present invention will be described in detail with reference to the drawings. It should be noted that the description contents of the documents cited in this specification and arbitrary known techniques can be incorporated into the following embodiments.

The ophthalmic apparatus according to the embodiment can perform objective measurement and subjective examination. Objective measurement is a measurement method for acquiring information about an eye to be examined mainly by using a physical method without referring to a response from the subject.

Objective measurement includes measurement for acquiring the characteristics of the eye to be inspected and photographing for acquiring an image of the eye to be inspected. Objective measurement includes objective refraction measurement, corneal shape measurement, intraocular pressure measurement, fundus photography, optical interference measurement and the like. On the other hand, the subjective test is a measurement method for acquiring information by using the response from the subject. The subjective test includes a distance test, a near test, a contrast test, a glare test, and other subjective refraction measurements, and a visual field test.

The ophthalmic apparatus according to the embodiment can at least measure the objective refractive power, and in addition, any subjective test and any other objective measurement can be performed.

Hereinafter, the fundus conjugate position is a position that is optically conjugate with the fundus of the eye to be inspected in the state where the alignment is completed, and means a position that is optically conjugate to the fundus of the eye to be inspected or its vicinity. Similarly, the pupil conjugate position is a position that is optically conjugate with the pupil of the eye to be inspected in the state where the alignment is completed, and means a position that is optically conjugate with the pupil of the eye to be inspected or its vicinity. ..

<Composition of optical system>
FIG. 1 shows a configuration example of an optical system of an ophthalmic apparatus according to an embodiment. The ophthalmic apparatus 1000 includes a Z alignment system 1, an XY alignment system 2, a kerato measurement system 3, an optotype projection system 4, an anterior eye observation system 5, and a reflex measurement projection system as optical systems for inspecting the eye E to be inspected. 6 and a reflex measurement light receiving system 7 are included.

(Anterior segment observation system 5)
The anterior segment observation system 5 captures a moving image of the anterior segment of the eye E to be inspected. In the optical system that passes through the anterior segment observation system 5, the image pickup surface of the image pickup device 59 is arranged at the pupil conjugate position Q. The anterior segment illumination light source 51 irradiates the anterior segment of the eye E to be inspected with illumination light (for example, infrared light). The light reflected by the anterior segment of the eye E to be inspected passes through the objective lens 52, passes through the dichroic mirror 53, passes through the half mirror 54, passes through the relay lenses 55 and 56, and passes through the dichroic mirror 57. .. The light transmitted through the dichroic mirror 57 is imaged on the image pickup surface of the image pickup element 59 (area sensor) by the image pickup lens 58. The image sensor 59 performs image pickup and signal output at a predetermined rate. The output (video signal) of the image sensor 59 is input to the processing unit 9 described later. The processing unit 9 displays the image of the anterior eye portion based on this video signal on the display screen of the display unit described later. The anterior segment image is, for example, an infrared moving image.

(Z alignment system 1)
The Z alignment system 1 projects light (infrared light) for alignment in the optical axis direction (front-back direction, Z direction) of the anterior eye portion observation system 5 onto the eye E to be inspected. The light output from the Z alignment light source 11 is projected onto the cornea of the eye E to be inspected, reflected by the cornea, and imaged on the sensor surface of the line sensor 13 by the imaging lens 12. When the position of the corneal apex changes in the optical axis direction of the anterior eye observation system 5, the light projection position on the sensor surface of the line sensor 13 changes. The processing unit 9 obtains the position of the corneal apex of the eye E to be inspected based on the light projection position on the sensor surface of the line sensor 13, and controls the mechanism for moving the optical system based on this to execute Z alignment.

(XY alignment system 2)
The XY alignment system 2 emits light (infrared light) for alignment in a direction orthogonal to the optical axis of the anterior segment observation system 5 (horizontal direction (X direction), vertical direction (Y direction)). Irradiate to. The XY alignment system 2 includes an XY alignment light source 21 provided in an optical path branched from the anterior eye observation system 5 by a half mirror 54. The light output from the XY alignment light source 21 is reflected by the half mirror 54 and projected onto the eye E to be inspected through the anterior eye observation system 5. The light reflected by the cornea of the eye E to be inspected is guided to the image sensor 59 through the anterior eye observation system 5.

An image based on this reflected light (bright spot image) is included in the anterior segment image. The processing unit 9 displays the front eye portion image including the bright spot image and the alignment mark on the display screen of the display unit. When manually performing XY alignment, the user moves the optical system so as to guide the bright spot image within the alignment mark. When the alignment is performed automatically, the processing unit 9 controls a mechanism for moving the optical system so that the displacement of the bright spot image with respect to the alignment mark is cancelled.

(Kerato measurement system 3)
The kerato measurement system 3 projects a ring-shaped luminous flux (infrared light) for measuring the shape of the cornea of the eye E to be inspected onto the cornea. The kerato plate 31 is arranged between the objective lens 52 and the eye E to be inspected. A keratling light source (not shown) is provided on the back side (objective lens 52 side) of the kerato plate 31. By illuminating the kerato plate 31 with the light from the kerat ring light source, a ring-shaped luminous flux is projected onto the cornea of the eye E to be inspected. The reflected light (keratling image) from the cornea of the eye E to be inspected is detected by the image sensor 59 together with the anterior eye image. The processing unit 9 calculates a corneal shape parameter representing the shape of the cornea by performing a known calculation based on this keratling image.

(Optimal projection system 4)
The optotype projection system 4 presents various optotypes such as a fixation target and a target for subjective examination to the eye E to be inspected. The light (visible light) output from the light source 41 is converted into a parallel luminous flux by the collimating lens 42 and is irradiated on the optotype chart 43. The optotype chart 43 includes, for example, a transmissive liquid crystal panel and displays a pattern representing the optotype. The light transmitted through the optotype chart 43 passes through the relay lenses 44 and 45, is reflected by the reflection mirror 46, is transmitted through the dichroic mirror 68, and is reflected by the dichroic mirror 53. The light reflected by the dichroic mirror 53 passes through the objective lens 52 and is projected onto the fundus Ef. The light source 41, the collimating lens 42, and the optotype chart 43 can be integrally moved in the optical axis direction.

When performing the subjective test, the processing unit 9 controls the optotype chart 43 by moving the light source 41, the collimating lens 42, and the optotype chart 43 in the optical axis direction based on the result of the objective measurement. The processing unit 9 displays the optotype selected by the examiner or the processing unit 9 on the optotype chart 43. As a result, the target is presented to the subject. The subject responds to the optotype. Upon receiving the input of the response content, the processing unit 9 further controls and calculates the subjective test value. For example, in the visual acuity measurement, the processing unit 9 selects and presents the next visual acuity based on the response to the Randold ring or the like, and repeatedly repeats this to determine the visual acuity value.

(Ref measurement projection system 6, reflex measurement light receiving system 7)
The reflex measurement projection system 6 and the reflex measurement light receiving system 7 are used for objective refraction measurement (refraction measurement). The reflex measurement projection system 6 projects a ring-shaped luminous flux (infrared light) for objective measurement onto the fundus Ef. The reflex measurement light receiving system 7 receives the return light of the ring-shaped luminous flux from the eye E to be inspected.

The ref measurement light source 61 may be an SLD (Superluminescent Diode) light source, which is a high-intensity light source having a light emitting diameter of a predetermined size or less. The reflex measurement light source 61 is movable in the optical axis direction and is arranged at the fundus conjugate position P. The ring diaphragm 65 (specifically, the translucent portion) is arranged at the pupil conjugate position Q. The focusing lens 74 is movable in the optical axis direction. The focusing lens 74 may be a known varifocal lens that can change the focal position under the control of the main control unit 111 described later. In the optical system that passes through the reflex measurement light receiving system 7, the image pickup surface of the image pickup device 59 is arranged at the fundus conjugate position P.

The light output from the reflex measurement light source 61 passes through the relay lens 62 and is incident on the conical surface of the conical prism 63. The light incident on the conical surface is deflected and emitted from the bottom surface of the conical prism 63. The light emitted from the bottom surface of the conical prism 63 passes through the field lens 64 and passes through the translucent portion formed in a ring shape on the ring diaphragm 65. The light (ring-shaped luminous flux) that has passed through the translucent portion of the ring diaphragm 65 is reflected by the reflecting surface of the perforated prism 66, passes through the rotary prism 67, and is reflected by the dichroic mirror 68. The light reflected by the dichroic mirror 68 is reflected by the dichroic mirror 53, passes through the objective lens 52, and is projected onto the eye E to be inspected. The rotary prism 67 is used for averaging the light amount distribution of the ring-shaped luminous flux with respect to the blood vessel or the diseased part of the fundus Ef and reducing the speckle noise caused by the light source.

It is desirable that the conical prism 63 is arranged as close as possible to the pupil conjugate position Q.

FIG. 2 schematically shows a cross-sectional view of the field lens 64. For example, as shown in FIG. 2, the ring diaphragm 65 may be attached to the lens surface of the field lens 64 on the side of the eye to be inspected E. In this case, for example, a light-shielding film is vapor-deposited on the lens surface of the field lens 64 so that a ring-shaped translucent portion is formed.

Further, the reflex measurement projection system 6 may have a configuration in which the field lens 64 is omitted.

FIG. 3 schematically shows a cross-sectional view of the conical prism 63. For example, as shown in FIG. 3, the ring diaphragm 65 may be attached to the bottom surface 63b of the conical prism 63 in which the light passing through the relay lens 62 is incident on the conical surface 63a. In this case, for example, a light-shielding film is vapor-deposited on the bottom surface 63b of the conical prism 63 so that a ring-shaped translucent portion is formed. Further, the ring diaphragm may be on the side of the conical surface 63a of the conical prism 63.

The ring diaphragm 65 may be a diaphragm in which a translucent portion having a shape corresponding to a predetermined measurement pattern is formed. A light transmitting portion may be formed in this diaphragm at a position eccentric with respect to the optical axis of the reflex measurement projection system 6. Further, the diaphragm may have two or more translucent portions.

The return light of the ring-shaped luminous flux projected on the fundus Ef passes through the objective lens 52 and is reflected by the dichroic mirror 53 and the dichroic mirror 68. The return light reflected by the dichroic mirror 68 passes through the rotary prism 67, passes through the hole portion of the perforated prism 66, passes through the relay lens 71, is reflected by the reflection mirror 72, and is reflected by the relay lens 73 and the focusing lens. Pass through 74. The light that has passed through the focusing lens 74 is reflected by the reflection mirror 75, reflected by the dichroic mirror 57, and imaged on the imaging surface of the imaging element 59 by the imaging lens 58. The processing unit 9 calculates the refractive power value of the eye E to be inspected by performing a known calculation based on the output from the image sensor 59. For example, the refractive power value includes spherical power, astigmatic power, and astigmatic axis angle.

A diaphragm that limits the diameter of the light flux on the pupil is arranged between the perforated prism 66 and the relay lens 71. The translucent portion of this diaphragm is arranged at the pupil conjugate position.

Based on the calculated refractive power value, the processing unit 9 sets the reflex measurement light source 61 and the focusing lens 74 so that the fundus Ef, the reflex measurement light source 61, and the image pickup surface of the image sensor 59 are optically coupled. Are moved in the direction of the optical axis. Further, the processing unit 9 moves the optotype unit in the optical axis direction in conjunction with the movement of the reflex measurement light source 61 and the focusing lens 74. The optotype unit including the light source 41, the collimating lens 42, and the optotype chart 43, the ref measurement light source 61, and the focusing lens 74 may be movable in the respective optical axis directions in conjunction with each other.

<Processing system configuration>
The configuration of the processing system of the ophthalmic apparatus 1000 will be described. Examples of the functional configuration of the processing system of the ophthalmic apparatus 1000 are shown in FIGS. 4 and 5. FIG. 4 shows an example of a functional block diagram of the processing system of the ophthalmic apparatus 1000. FIG. 5 shows an example of a functional block diagram of the arithmetic processing unit 120 of FIG.

The processing unit 9 controls each unit of the ophthalmic apparatus 1000. In addition, the processing unit 9 can execute various arithmetic processes. The processing unit 9 includes a processor. The functions of the processor include, for example, a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), an ASIC (Application Specific Integrated Circuit), a programmable logic device (for example, a SPLD (Simple Programmable)) , FPGA (Field Programmable Gate Array)) and the like. The processing unit 9 realizes the function according to the embodiment by reading and executing, for example, a program stored in a storage circuit or a storage device.

The processing unit 9 includes a control unit 110 and an arithmetic processing unit 120. Further, the ophthalmic apparatus 1000 includes a display unit 170, an operation unit 180, and a communication unit 190.

(Control unit 110)
The control unit 110 controls each unit of the ophthalmic apparatus 1000. The control unit 110 includes a main control unit 111 and a storage unit 112.

The main control unit 111 controls the ophthalmic apparatus 1000 in various ways. The main control unit 111 controls the Z alignment light source 11 of the Z alignment system 1, the line sensor 13, the XY alignment light source 21 of the XY alignment system 2, and the keratling light source of the kerato measurement system 3. As a result, the amount of light output from the Z alignment light source 11, the XY alignment light source 21, or the keratling light source is changed, and lighting or non-lighting is switched. In addition, the signal detected by the line sensor 13 is captured, and alignment control or the like is performed based on the captured signal.

The main control unit 111 controls the light source 41 of the optotype projection system 4 and the optotype chart 43. As a result, the amount of light output from the light source 41 is changed, and lighting or non-lighting is switched. In addition, the display of the optotype and the fixation target on the optotype chart 43 can be turned on / off, and the optotype and the fixation target can be switched. Further, the main control unit 111 can control a moving mechanism (not shown) for moving the optotype unit including the light source 41, the collimating lens 42, and the optotype chart 43 in the optical axis direction.

The main control unit 111 controls the anterior eye portion illumination light source 51 and the image pickup element 59 of the anterior eye portion observation system 5. As a result, the amount of light output from the anterior eye illumination light source 51 is changed, and lighting or non-lighting is switched. Further, the exposure time of the image sensor 59 is changed, and the detection sensitivity is changed by controlling the gain of the amplifier included in the image sensor 59. In addition, the signal acquired by the image sensor 59 is taken in, and the arithmetic processing unit 120 forms an image or the like.

The main control unit 111 controls the reflex measurement light source 61 of the reflex measurement projection system 6, the rotary prism 67, and the focusing lens 74 of the reflex measurement light receiving system 7. As a result, the amount of light output from the reflex measurement light source 61 is changed, and lighting or non-lighting is switched. Further, the rotation speed of the rotary prism 67 is changed, and the rotation operation is switched on / off. Further, the position of the focusing lens 74 in the optical axis direction is changed. Further, the main control unit 111 can control a moving mechanism (not shown) that moves the reflex measuring light source 61 and the focusing lens 74 in the optical axis direction. When the focusing lens 74 is a varifocal lens, the main control unit 111 can change the focal position of the focusing lens 74 by controlling the focusing lens 74.

In this embodiment, the main control unit 111 is a moving mechanism including an optotype unit including a light source 41, a collimating lens 42, and an optotype chart 43, a ref measuring light source 61, and a holding member for holding the focusing lens 74. It is possible to control. The moving mechanism is provided with an actuator that generates a driving force for moving the holding member and a transmission mechanism that transmits the driving force. The actuator is composed of, for example, a pulse motor. The transmission mechanism is composed of, for example, a combination of gears or a rack and pinion. By controlling such a moving mechanism, the main control unit 111 can move each of them in the optical axis direction.

The main control unit 111 controls the optotype projection system 4, the anterior segment observation system 5, the reflex measurement projection system 6, the reflex measurement light receiving system, and the arithmetic processing unit 120 to execute the provisional measurement twice or more. It is possible to carry out the main measurement under the measurement conditions determined by the last provisional measurement. The measurement conditions of the same type may be determined or different types of measurement conditions may be determined by each provisional measurement so that the measurement conditions converge each time the provisional measurement is repeated. In this embodiment, the main measurement is performed after two provisional measurements. For example, in each provisional measurement, the amount of light output from the reflex measurement light source 61 (the amount of light of the reflex measurement light source 61), the exposure time of the image pickup element 59, and the detection sensitivity of the image pickup element 59 based on the obtained ring image. , And at least one of the control contents for the focusing lens 74 may be determined.

Further, the main control unit 111 performs a process of writing data to the storage unit 112 and a process of reading data from the storage unit 112.

The storage unit 112 stores various types of data. The data stored in the storage unit 112 includes the measurement information obtained by the kerato measurement system 3, the measurement information obtained by the reflex measurement projection system 6 and the reflex measurement light receiving system 7, and the image of the image acquired by the image pickup element 59. There are data, eye examination information, etc. The eye test information includes information about the subject such as the patient ID and name, and information about the test eye such as left eye / right eye identification information. The measurement information obtained by the kerato measurement system 3 is stored in the storage unit 112 when the kerato measurement of the eye E to be inspected is performed by the ophthalmic apparatus 1000. The measurement information obtained by the reflex measurement projection system 6 and the reflex measurement light receiving system 7 is stored in the storage unit 112 when the reflex measurement of the eye E to be inspected is performed by the ophthalmic apparatus 1000. The storage unit 112 may be used as a working memory for the calculation process of the corneal shape parameter and the calculation process of the optical power value. In addition, various programs and data for operating the ophthalmic apparatus 1000 are stored in the storage unit 112.

(Calculation processing unit 120)
The calculation processing unit 120 executes various calculations for obtaining parameters representing the eye refractive power, such as a corneal shape parameter and an eye refractive power value. The arithmetic processing unit 120 includes an analysis unit 121.

The analysis unit 121 analyzes the ring image (pattern image) obtained by the image sensor 59 receiving the return light of the ring-shaped luminous flux (ring-shaped measurement pattern) projected on the fundus Ef by the reflex measurement projection system 6. do. For example, the analysis unit 121 obtains the position of the center of gravity of the ring image from the brightness distribution in the image in which the obtained ring image is drawn, obtains the brightness distribution along a plurality of scanning directions extending radially from the position of the center of gravity, and obtains the brightness. Identify the ring image from the distribution. The analysis unit 121 can determine whether or not the brightness (ring brightness) of the specified ring image is within a predetermined brightness range. The analysis unit 121 may determine whether or not the S / N ratio of the specified ring image is within a predetermined numerical range.

The analysis unit 121 can obtain the approximate ellipse of the specified ring image, and by substituting the major axis and the minor axis of the approximate ellipse into a known equation, the spherical power, the astigmatism power, and the astigmatism axis angle can be obtained. Alternatively, the analysis unit 121 can obtain the spherical power, the astigmatic power, and the astigmatic axis angle based on the specified ring image (approximate ellipse) and the control content (for example, the amount of movement) for the focusing lens 74. be. Alternatively, the analysis unit 121 can obtain the parameter of the optical power based on the deformation and displacement of the ring image with respect to the reference pattern.

In addition, the analysis unit 121 calculates the corneal refractive power, the corneal astigmatism degree, and the corneal astigmatism axis angle based on the keratling image acquired by the anterior eye observation system 5. For example, the analysis unit 121 calculates the radius of curvature of the cornea of the strong main meridian and the weak main meridian on the anterior surface of the cornea by analyzing the keratling image, and calculates the above parameters based on the radius of curvature of the cornea.

(Display unit 170, operation unit 180)
The display unit 170 displays information under the control of the control unit 110. The operation unit 180 is used for operating the ophthalmic apparatus 1000 and inputting information. The operation unit 180 includes various hardware keys (joysticks, buttons, switches, etc.) and / or various software keys (buttons, icons, menus, etc.) presented on the display unit 170.

(Communication unit 190)
The communication unit 190 has a function of communicating with an external device. The communication unit 190 includes a communication interface according to the connection form with the external device. An example of an external device is a spectacle lens measuring device for measuring the optical characteristics of a lens. The spectacle lens measuring device measures the power of the spectacle lens worn by the subject, and inputs this measurement data to the ophthalmic device 1000. Further, the external device may be an arbitrary ophthalmic device, a device (reader) for reading information from a recording medium, a device (writer) for writing information on a recording medium, or the like. Further, the external device may be a hospital information system (HIS) server, a DICOM (Digital Imaging and Communication in Medicine) server, a doctor terminal, a mobile terminal, a personal terminal, a cloud server, or the like.

In the ophthalmic apparatus 1000, the reflex measurement light source 61 is arranged at the fundus conjugate position P, the ring aperture 65 is arranged at the pupil conjugate position Q, and the conical prism 63 is arranged near the pupil conjugate position Q. It becomes possible to project a ring-shaped measurement pattern that is thin (the width of the inner diameter and the outer diameter is narrow) and has high brightness on the Ef. Therefore, the total amount of the measured luminous flux incident on the eye E to be inspected can be reduced, and the measured pattern luminous flux having high brightness can be projected onto the eye to be inspected while reducing the burden on the subject. As a result, it becomes possible to obtain a highly reliable ocular refractive power value. In addition, since the profile of the ring image on the fundus becomes steep, the effect of blocking the incident luminous flux at the opaque portion of the crystalline lens caused by eyelashes and cataracts is small, and the occurrence of measurement errors can be suppressed.

The reflex measurement light source 61 is an example of the “light source” according to the embodiment. The ring-shaped luminous flux projected onto the eye E to be inspected by the reflex measurement projection system 6 is an example of the “patterned light” according to the embodiment. The anterior eye observation system 5, the reflex measurement projection system 6, and the reflex measurement light receiving system 7 are examples of the “optical system” according to the embodiment. The ring image is an example of the "pattern image" according to the embodiment. The ring diaphragm 65 is an example of the “diaphragm” according to the embodiment. The conical prism 63 is an example of the “deflection member” according to the embodiment.

<Operation example>
The operation of the ophthalmic apparatus 1000 according to the embodiment will be described. An example of the operation of the ophthalmic apparatus 1000 is shown in FIGS. 6 to 10. FIG. 6 shows a flow chart of an operation example of the ophthalmic apparatus 1000. FIG. 7 shows a flow chart of an operation example of step S3 of FIG. FIG. 8 shows a flow chart of an operation example of step S14 or step S20 of FIG. FIG. 9 shows a flow chart of an operation example of step S32 of FIG. FIG. 10 shows a flow chart of an operation example of step S34 in FIG. In the following, it is assumed that the optotype unit including the light source 41, the collimating lens 42, and the optotype chart 43 is moved in the optical axis direction.

First, an operation example of the ophthalmic apparatus 1000 will be described with reference to FIG.

(S1: Alignment)
When the examiner performs a predetermined operation on the operation unit 180 with the subject's face fixed to the face receiving portion (not shown), the ophthalmic apparatus 1000 is fixedly fixed by the light source 41 and the optotype chart 43. The target is projected onto the eye E to be inspected and alignment is performed.

Specifically, the main control unit 111 lights the Z alignment light source 11, the XY alignment light source 21, and the light source 41. Further, the anterior eye portion illumination light source 51 is turned on. A kerato light source may be turned on instead of the anterior eye illumination light source. The processing unit 9 acquires an image pickup signal of the front eye portion image on the image pickup surface of the image pickup element 59, and causes the display unit 170 to display the front eye portion image. After that, the optical system shown in FIG. 1 is moved to the inspection position of the eye E to be inspected. The examination position is a position where the examination of the eye E to be inspected can be performed with sufficient accuracy. The eye E to be inspected is placed at the examination position via the above-mentioned alignment (alignment by the Z alignment system 1 and the XY alignment system 2 and the anterior eye observation system 5). The movement of the optical system is executed by the main control unit 111 according to an operation or instruction by the user or an instruction by the main control unit 111. That is, the movement of the optical system to the examination position of the eye E to be inspected and the preparation for performing the objective measurement are performed.

Further, the main control unit 111 moves the reflex measurement light source 61, the focusing lens 74, and the optotype unit to the position of the origin (for example, the position corresponding to 0D) along the respective optical axes.

(S2: Kerato measurement)
The main control unit 111 projects a bright spot as a fixation target on the eye E to be inspected by the light source 41 and the optotype chart 43, and causes the kerato measurement to be executed.

That is, the main control unit 111 turns on the keratling light source. When light is output from the keratling light source, a ring-shaped luminous flux for measuring the shape of the cornea is projected onto the cornea of the eye E to be inspected. The analysis unit 121 calculates the radius of curvature of the cornea by performing arithmetic processing on the image acquired by the image pickup element 59, and calculates the corneal refractive power, the degree of corneal astigmatism, and the angle of the axis of corneal astigmatism from the calculated radius of curvature of the cornea. calculate. In the control unit 110, the calculated corneal refractive power and the like are stored in the storage unit 112. The operation of the ophthalmic apparatus 1000 shifts to step S3 by the instruction from the main control unit 111 or the user's operation or instruction to the operation unit 180.

(S3: Ref measurement)
The main control unit 111 turns on the reflex measurement light source 61 to execute the reflex measurement. The details of step S3 will be described later.

In the control unit 110, the moving amount of the focusing lens 74 after the reflex measurement in step S3, the spherical power calculated from the shape of the ring image, and the like are stored in the storage unit 112. The operation of the ophthalmic apparatus 1000 shifts to step S4 according to the instruction from the main control unit 111 or the user's operation or instruction to the operation unit 180. This completes the operation of the ophthalmic apparatus 1000 (end).

[Ref measurement]
As shown in FIGS. 7 to 10, the ophthalmologic apparatus 1000 performs the reflex measurement in step S3 of FIG.

(S11: Initialization of provisional measurement conditions)
Prior to the first provisional measurement, the main control unit 111 sets the amount of light output from the reflex measurement light source 61 (the amount of light of the reflex measurement light source 61), the exposure time of the image pickup element 59, and the detection sensitivity as initial values. do.

(S12: Temporary measurement (first time))
The main control unit 111 executes the first provisional measurement with the focusing lens arranged at the reference position (0D position). Specifically, the main control unit 111 turns on the reflex measurement light source 61, projects a ring-shaped luminous flux onto the fundus Ef onto the reflex measurement projection system 6, and captures the return light of the ring-shaped luminous flux from the fundus Ef as an image pickup element. Let 59 receive light. As a result, an image in which a ring image based on the ring-shaped luminous flux projected on the fundus Ef is drawn is acquired.

(S13: Is the brightness appropriate?)
The main control unit 111 causes the analysis unit 121 to perform a ring brightness check on the ring image obtained from the light receiving result of the image sensor 59 in step S12. The analysis unit 121 obtains the position of the center of gravity of the ring image from the brightness distribution in the image obtained by the image sensor 59, obtains the brightness distribution along a plurality of scanning directions radially extending from the position of the center of gravity, and obtains the brightness distribution along a plurality of scanning directions extending radially from the center of gravity position, and obtains the brightness distribution along a plurality of scanning directions extending radially from the center of gravity position. To identify. The analysis unit 121 determines whether or not the brightness of the ring image is appropriate by determining whether or not the brightness of the specified ring image is within a predetermined brightness range. When it is determined that the brightness of the ring image is within the predetermined brightness range (S13: Y), the operation of the ophthalmic apparatus 1000 shifts to step S15. When it is determined that the brightness of the ring image is not within the predetermined brightness range (S13: N), the operation of the ophthalmic apparatus 1000 shifts to step S14.

(S14: Measurement condition change control)
When it is determined in step S13 that the brightness of the ring image is not within the predetermined brightness range (S13: N), the main control unit 111 executes the measurement condition change control. In the measurement condition change control in step S14, the light intensity of the reflex measurement light source 61, the exposure time of the image sensor 59, and the detection sensitivity of the image sensor 59 are changed so that the brightness of the acquired ring image is changed. The details of step S14 will be described later.

When the step S14 is completed, the operation of the ophthalmic apparatus 1000 shifts to the step S12. That is, the image acquisition (first provisional measurement) in step S12 and the brightness check of the ring image in step S13 are repeated until the brightness of the ring image falls within a predetermined brightness range.

(S15: Calculate the temporary refractive power value)
When it is determined in step S13 that the brightness of the ring image is within the predetermined brightness range (S13: Y), the main control unit 111 has a false refractive power value (equivalent spherical refraction) based on the image acquired in step S12. Force value) is calculated by the analysis unit 121. As described above, the analysis unit 121 obtains an approximate ellipse of the ring image specified in the acquired image, and calculates a false refractive power value from the approximate ellipse.

(S16: Focus control)
Next, the main control unit 111 controls the actuator that moves the focusing lens 74 so that the ring image acquired in step S12 is in focus based on the optical power value obtained in step S15. decide. In this embodiment, the main control unit 111 determines the control content of the actuator corresponding to the movement direction and the movement amount of the focusing lens 74 in the optical axis direction. For example, the corresponding information in which the optical power value is associated with the moving direction and the moving amount in the optical axis direction of the focusing lens 74 is stored in advance in the storage unit 112, and the main control unit 111 is stored in the storage unit 112. The control content of the actuator is determined by referring to the corresponding information provided.

The main control unit 111 controls the actuator based on the determined control content to arrange the focusing lens 74 at a position corresponding to the eye refractive power value obtained in step S15.

When the focusing lens 74 is a variable focus lens, the main control unit 111 can similarly determine the control content for the focusing lens 74. That is, the correspondence information in which the ocular refractive power value and the control content for the focusing lens 74 are associated is stored in advance in the storage unit 112, and the main control unit 111 refers to the correspondence information stored in the storage unit 112. By doing so, the control content for the focusing lens 74 is determined. The main control unit 111 can change the focal position to a desired position by controlling the focusing lens 74 based on the determined control content. At the same time, the fixation target unit including the light source 61, the light source 41, the collimating lens 42, and the target chart 42 is moved. This movement may be driven by a common actuator, may be driven as a unit, or may be driven individually by individual actuators.

(S17: Determination of the next provisional measurement condition)
Next, the main control unit 111 sets the measurement conditions for executing the second provisional measurement. This measurement condition may be the measurement condition at the time when step S16 is completed. Further, the main control unit 111 may specify a new measurement condition from the measurement condition at the time when step S16 is completed. Since the brightness (luminance) of the ring image changes depending on the amount of movement of the focusing lens 74, the amount of light of the light source 61 may be changed based on the amount of movement. The relationship between the amount of movement of the focusing lens 74 and the amount of light of the light source 61 may be derived by a mathematical formula or may be stored as table information. The mathematical formula may be a linear formula or a quadratic formula derived from experimental results or the like.

(S18: Temporary measurement (second time))
The main control unit 111 executes the second provisional measurement. Step S18 is substantially the same as step S12.

(S19: Is the brightness appropriate?)
Similar to step S13, the main control unit 111 causes the analysis unit 121 to check the brightness of the ring image with respect to the ring image obtained in step S18. The brightness range in the ring brightness check in step S19 may be the same as or different from the brightness range in the brightness check of the ring image in step S13.

When it is determined that the brightness of the ring image is within the predetermined brightness range (S19: Y), the operation of the ophthalmic apparatus 1000 shifts to step S21. When it is determined that the brightness of the ring image is not within the predetermined range (S19: N), the operation of the ophthalmic apparatus 1000 shifts to step S20.

(S20: Measurement condition change control)
When it is determined in step S19 that the brightness of the ring image is not within the predetermined range (S19: N), the main control unit 111 executes the measurement condition change control. The measurement condition change control in step S20 is the same as in step S14.

When the step S20 is completed, the operation of the ophthalmic apparatus 1000 shifts to the step S18. That is, the image acquisition (second provisional measurement) in step S18 and the brightness check of the ring image in step S19 are repeated until the brightness of the ring image falls within a predetermined range.

(S21: Calculate the temporary refractive power value)
When it is determined in step S19 that the brightness of the ring image is within the predetermined brightness range (S19: Y), the main control unit 111 uses the ring specified in the image acquired in step S18 as in step S15. The analysis unit 121 is made to calculate the pseudo-refractive power value based on the image (for example, the shape of the ring image and the amount of movement of the focusing lens 74 with respect to the ring image).

(S22: Focus control)
Similar to step S16, the main control unit 111 refers to the actuator that moves the focusing lens 74 so that the ring image acquired in step S18 is in focus based on the optical power value obtained in step S21. Determine the control content.

The main control unit 111 controls the actuator based on the determined control content to arrange the focusing lens 74 at a position corresponding to the temporary refractive power value obtained in step S21.

(S23: Cloud fog control)
Next, the main control unit 111 sets the measurement conditions for executing the main measurement. This measurement condition may be the measurement condition at the time when step S22 is completed. Further, the main control unit 111 may specify a new measurement condition from the measurement conditions at the time when step S22 is completed. In particular, when the amount of movement of the focusing lens 74 is large, the change in the brightness of the ring image may be large, and new measurement conditions may be obtained in consideration of this change.

Subsequently, the main control unit 111 executes control for making the eye E to be inspected look cloudy. Specifically, the main control unit 111 moves the fixed index unit including the light source 41, the collimating lens 42, and the optotype chart 53 by a predetermined amount of movement by controlling the actuator. In a configuration in which the light source 61 and the focusing lens 74 are driven integrally, they also move at the same time.

(S24: main measurement)
The main control unit 111 executes this measurement. Specifically, the main control unit 111 turns on the reflex measurement light source 61, projects a ring-shaped luminous flux onto the fundus Ef onto the reflex measurement projection system 6, and captures the return light of the ring-shaped luminous flux from the fundus Ef as an image pickup element. Let 59 receive light. As a result, an image in which a ring image based on the ring-shaped luminous flux projected on the fundus Ef is drawn is acquired.

(S25: Calculate the optical power value)
The main control unit 111 obtains an approximate ellipse of the ring image specified in the image acquired in step S24, and analyzes the amount of movement of the focusing lens 74 and the spherical power, astigmatism power, and astigmatism axis angle from the approximate ellipse. To calculate. This completes the operation of the ophthalmic apparatus 1000 (end).

[Measurement condition change control]
The ophthalmic apparatus 1000 executes step S14 or step S20 of FIG. 7, as shown in FIGS. 8 to 10. In addition, either one of step S14 and step S20 may be executed as shown in FIGS. 8 to 10.

(S31: Is the brightness high?)
The main control unit 111 determines whether or not the brightness of the ring image is high. When the brightness of the ring image is equal to or greater than the upper limit of the predetermined brightness range, the main control unit 111 determines that the brightness of the ring image is high. When it is determined that the brightness of the ring image is high (S31: Y), the operation of the ophthalmic apparatus 1000 shifts to step S32. When it is not determined that the brightness of the ring image is high (S31: N), the operation of the ophthalmic apparatus 1000 shifts to step S33.

(S32: Brightness reduction control)
When it is determined in step S31 that the brightness of the ring image is high (S31: Y), the main control unit 111 executes the brightness reduction control. In the brightness reduction control in step S32, the amount of light of the reflex measurement light source 61 is changed, or the exposure time of the image sensor 59 and the detection sensitivity of the image sensor 59 are changed so that the brightness of the acquired ring image is reduced. Details of step S32 will be described later.

When step S32 ends, the operation of step S14 or step S20 of the ophthalmic apparatus 1000 ends (end).

(S33: Is the brightness low?)
When it is not determined in step S31 that the brightness of the ring image is high (S31: N), the main control unit 111 determines whether or not the brightness of the ring image is low. When the brightness of the ring image is equal to or less than the lower limit of the predetermined brightness range, the main control unit 111 determines that the brightness of the ring image is low. When it is determined that the brightness of the ring image is low (S33: Y), the operation of the ophthalmic apparatus 1000 shifts to step S34. When it is not determined that the brightness of the ring image is low (S33: N), the operation of step S14 or step S20 of the ophthalmic apparatus 1000 ends (end).

(S34: Brightness increase control)
When it is determined in step S33 that the brightness of the ring image is low (S33: Y), the main control unit 111 executes the brightness increase control. In the brightness increase control in step S34, the light amount of the reflex measurement light source 61 is changed, the exposure time of the image pickup element 59, the detection sensitivity of the image pickup element 59, and the focusing lens 74 so that the brightness of the acquired ring image is increased. The amount of movement is changed. Details of step S34 will be described later.

When step S34 is completed, the operation of step S14 or step S20 of the ophthalmic apparatus 1000 ends (end).

[Brightness reduction control]
As shown in FIG. 9, the ophthalmic apparatus 1000 executes the brightness reduction control in step S32 of FIG. In the brightness reduction control according to the embodiment, the first detection sensitivity that lowers the apparent brightness of the ring image by lowering the detection sensitivity of the image sensor 59 based on the brightness of the obtained ring image (that is, the amount to be reduced). After the control is performed, the first exposure time control for lowering the brightness of the ring image is performed by shortening the exposure time of the image sensor 59. Further, after the first exposure time control, the first light amount control for lowering the brightness of the ring image is performed by lowering the light amount of the reflex measurement light source 61.

For example, in the brightness reduction control, after the first detection sensitivity control for lowering the apparent brightness of the ring image is performed within a predetermined first brightness range, the upper limit is within the second brightness range which is equal to or less than the lower limit of the first brightness range. The first exposure time control is performed to reduce the apparent brightness of the ring image. Further, after the first exposure time control, the first light amount control for lowering the brightness of the ring image is performed within the third brightness range in which the upper limit is equal to or less than the lower limit of the second brightness range.

(S41: Determine the amount of decrease in brightness)
First, the main control unit 111 determines the amount of decrease in the brightness of the ring image. The amount of reduction may be a predetermined amount.

Further, the amount of reduction may be an amount corresponding to the amount of saturated light of the image sensor 59 or the amount of saturation due to A / D conversion. In this case, the main control unit 111 causes the analysis unit 121 to calculate the amount of decrease in the brightness of the ring image. The analysis unit 121 can predict the brightness of the ring image after moving the focusing lens 74, and can obtain the amount of decrease in brightness from the predicted value. For example, the analysis unit 121 controls the difference between the brightness of the ring image and the upper limit of the brightness range in step S31, the amount of light of the reflex measurement light source 61, the exposure time of the image pickup element 59, or the detection sensitivity of the image pickup element 59. The brightness after movement is specified based on the movement amount of the focusing lens 74 determined by the provisional measurement.

(S42: Detection sensitivity ≥ TH1?)
Next, the main control unit 111 specifies the detection sensitivity (gain) of the image sensor 59, and determines whether or not the specified detection sensitivity is equal to or higher than the first threshold value TH1. The main control unit 111 may specify the detection sensitivity from the control content for the image sensor 59, or may specify the detection sensitivity from the content set in the image sensor 59. When it is determined that the detection sensitivity is equal to or higher than the first threshold value TH1 (S42: Y), the operation of the ophthalmic apparatus 1000 shifts to step S43. When it is determined that the detection sensitivity is less than the first threshold value TH1 (S42: N), the operation of the ophthalmic apparatus 1000 shifts to step S44.

(S43: Decrease the detection sensitivity)
When it is determined in step S42 that the detection sensitivity is equal to or higher than the first threshold value TH1 (S42: Y), the main control unit 111 controls the image sensor 59 so as to lower the detection sensitivity. The main control unit 111 can reduce the detection sensitivity by a predetermined amount or a predetermined ratio.

In this way, the first detection sensitivity control is performed in step S42 and step S43. When step S43 is completed, the operation of step S32 of the ophthalmic apparatus 1000 ends (end).

(S44: Exposure time ≥ TH2?)
When it is determined in step S42 that the detection sensitivity is less than the first threshold value TH1 (S42: N), the main control unit 111 specifies the exposure time of the image sensor 59, and the specified exposure time is the second threshold value TH2. It is determined whether or not it is the above. The main control unit 111 may specify the exposure time from the control content for the image sensor 59, or may specify the exposure time from the content set in the image sensor 59.

When the exposure time is shortened, it becomes possible to suppress the occurrence of measurement error due to the movement of the eye E to be inspected. However, in order to obtain the effect of averaging the light amount distribution by the rotary prism 67, it is desirable that the exposure time of the image sensor 59 is equal to or longer than the time (lower limit time) for the rotary prism 67 to rotate a predetermined number of times. Therefore, the second threshold value TH2 may be the lower limit time corresponding to the rotation speed of the rotary prism 67.

When it is determined that the exposure time of the image pickup device 59 is equal to or greater than the second threshold value TH2 (S44: Y), the operation of the ophthalmic apparatus 1000 shifts to step S45. When it is determined that the exposure time of the image pickup device 59 is less than the second threshold value TH2 (S44: N), the operation of the ophthalmologic apparatus 1000 shifts to step S46.

(S45: Shorten the exposure time)
When it is determined in step S44 that the exposure time is equal to or greater than the second threshold value TH2 (S44: Y), the main control unit 111 controls the image sensor 59 so as to shorten the exposure time. The main control unit 111 can shorten the exposure time by a predetermined amount or a predetermined ratio.

In this way, the first exposure time control is performed in steps S44 and S45. When step S45 is completed, the operation of step S32 of the ophthalmic apparatus 1000 ends (end).

(S46: Light intensity ≥ TH3?)
When it is determined in step S44 that the exposure time is less than the second threshold value TH2 (S44: N), the main control unit 111 specifies the amount of light of the reflex measurement light source 61, and the specified amount of light is equal to or greater than the third threshold value TH3. It is determined whether or not it is. The main control unit 111 may specify the amount of light from the control content for the reflex measurement light source 61, or may specify the amount of light from the content set in the reflex measurement light source 61.

When it is determined that the amount of light of the reflex measurement light source 61 is equal to or higher than the third threshold value TH3 (S46: Y), the operation of the ophthalmic apparatus 1000 shifts to step S47. When it is determined that the amount of light of the reflex measurement light source 61 is less than the third threshold value TH3 (S46: N), the operation of the ophthalmic apparatus 1000 shifts to step S48.

(S47: Decrease the amount of light)
When it is determined in step S46 that the amount of light of the reflex measurement light source 61 is equal to or greater than the third threshold value TH3 (S46: Y), the main control unit 111 controls the reflex measurement light source 61 so as to reduce the amount of light. The main control unit 111 can reduce the amount of light by a predetermined amount or a predetermined rate.

In this way, the first light quantity control is performed in step S46 and step S47. When step S47 is completed, the operation of step S32 of the ophthalmic apparatus 1000 ends (end).

(S48: Error handling)
When it is determined in step S46 that the amount of light of the reflex measurement light source 61 is less than the third threshold value TH3 (S46: N), the main control unit 111 causes the main control unit 111 to execute a predetermined error process. The predetermined error processing includes an error display process for the display unit 170 and the like. If it is determined that the brightness of the ring image is high, but it is determined that the detection sensitivity of the image sensor 59, the exposure time, and the amount of light of the reflex measurement light source 61 cannot be controlled, error processing is executed. When step S48 is completed, the reflex measurement by the ophthalmologic apparatus 1000 is completed (end).

As described above, by repeatedly executing the brightness reduction control, the first detection sensitivity control is preferentially executed, and then the first exposure time control is executed to supplement the first detection sensitivity control. Finally, the first detection sensitivity control is executed to supplement the first exposure time control.

The first detection sensitivity control has less influence on the measurement environment than the first exposure time control and the first light amount control. On the other hand, the first exposure time control is advantageous for the movement of the eye E to be inspected as described above, but the effect of the rotary prism 67 cannot be obtained. Therefore, by performing the first exposure time control after the first detection sensitivity control, it is possible to suppress a decrease in the measurement accuracy of the reflex measurement while obtaining the effect of the rotary prism 67 even when the brightness of the ring image is high. become. Further, since the first light intensity control is performed after the first exposure time control, the influence on the measurement environment can be minimized.

[Brightness increase control]
As shown in FIG. 10, the ophthalmic apparatus 1000 executes the brightness increase control in step S34 of FIG. In the brightness increase control according to the embodiment, the second light amount control for increasing the brightness of the ring image by increasing the light amount of the reflex measurement light source 61 is performed based on the brightness of the obtained ring image (that is, the amount to be increased). After that, the second exposure time control for increasing the apparent brightness of the ring image is performed by lengthening the exposure time of the image pickup element 59. Further, after the second exposure time control, the second detection sensitivity control for increasing the apparent brightness of the ring image is performed by increasing the detection sensitivity of the image sensor 59.

For example, in the brightness increase control, after the second light amount control for increasing the brightness of the ring image within a predetermined fourth brightness range is performed, the ring image is within the fifth brightness range in which the lower limit is equal to or higher than the upper limit of the fourth brightness range. The second exposure time control for increasing the brightness of is performed. Further, after the second exposure time control, the second detection sensitivity control for increasing the brightness of the ring image is performed within the sixth luminance range in which the lower limit is equal to or higher than the upper limit of the fifth luminance range.

(S51: Determine the amount of brightness increase)
First, the main control unit 111 determines the amount of increase in the brightness of the ring image. The amount of increase may be a predetermined amount.

Further, the main control unit 111 may have the analysis unit 121 calculate the amount of increase in the brightness of the ring image. For example, the analysis unit 121 controls the difference between the brightness of the ring image and the lower limit of the brightness range in step S33, the amount of light of the reflex measurement light source 61, the exposure time of the image sensor 59, or the detection sensitivity of the image sensor 59. And the amount of increase may be obtained based on the amount of movement of the focusing lens 74.

(S52: Light intensity ≤ TH4?)
Next, the main control unit 111 specifies the amount of light of the reflex measurement light source 61, and determines whether or not the specified amount of light is equal to or less than the fourth threshold value TH4. It is desirable that the fourth threshold value TH4 is an amount of light in consideration of the visibility of the measurement pattern image by the subject and the safety of the subject. When it is determined that the amount of light is equal to or less than the fourth threshold value (S52: Y), the operation of the ophthalmic apparatus 1000 shifts to step S53. When it is determined that the amount of light exceeds the fourth threshold value TH4 (S52: N), the operation of the ophthalmic apparatus 1000 shifts to step S54.

(S53: Increase the amount of light)
When it is determined in step S52 that the amount of light is equal to or less than the fourth threshold value TH4 (S52: Y), the main control unit 111 controls the reflex measurement light source 61 so as to increase the amount of light. The main control unit 111 can reduce the amount of light by a predetermined amount or a predetermined rate.

In this way, the second light quantity control is performed in steps S52 and S53. When step S53 is completed, the operation of step S34 of the ophthalmic apparatus 1000 ends (end).

(S54: Exposure time ≥ TH5?)
When it is determined in step S52 that the amount of light exceeds the fourth threshold value TH4 (S52: N), the main control unit 111 specifies the exposure time of the image sensor 59, and the specified exposure time is equal to or less than the fifth threshold value TH5. Determine if it exists.

When the exposure time is long, a measurement error due to the movement of the eye E to be inspected is likely to occur. Therefore, the fifth threshold value TH5 may be a predetermined time as the time during which the movement of the eye E to be inspected does not occur.

When it is determined that the exposure time of the image pickup device 59 is equal to or less than the fifth threshold value TH5 (S54: Y), the operation of the ophthalmic apparatus 1000 shifts to step S55. When it is determined that the exposure time of the image pickup device 59 exceeds the fifth threshold value TH5 (S54: N), the operation of the ophthalmologic apparatus 1000 shifts to step S56.

(S55: Increase the exposure time)
When it is determined in step S54 that the exposure time is equal to or less than the fifth threshold value TH5 (S54: Y), the main control unit 111 controls the image sensor 59 so as to lengthen the exposure time. The main control unit 111 can lengthen the exposure time by a predetermined amount or a predetermined ratio.

In this way, the second exposure time control is performed in steps S54 and S55. When step S55 is completed, the operation of step S34 of the ophthalmic apparatus 1000 ends (end).

(S56: Detection sensitivity ≤ TH6?)
When it is determined in step S54 that the exposure time exceeds the fifth threshold value TH5 (S54: N), the main control unit 111 specifies the detection sensitivity of the image sensor 59, and the specified detection sensitivity is equal to or less than the sixth threshold value TH6. It is determined whether or not it is.

When it is determined that the detection sensitivity of the image sensor 59 is equal to or less than the sixth threshold value TH6 (S56: Y), the operation of the ophthalmic apparatus 1000 shifts to step S57. When it is determined that the detection sensitivity of the image pickup device 59 exceeds the sixth threshold value TH6 (S56: N), the operation of the ophthalmic apparatus 1000 shifts to step S58.

(S57: Increase detection sensitivity)
When it is determined in step S56 that the detection sensitivity of the image sensor 59 is equal to or less than the sixth threshold value TH6 (S56: Y), the main control unit 111 controls the image sensor 59 so as to increase the detection sensitivity. The main control unit 111 can increase the detection sensitivity by a predetermined amount or a predetermined rate.

In this way, the second detection sensitivity control is performed in step S56 and step S57. When step S57 is completed, the operation of step S34 of the ophthalmic apparatus 1000 ends (end).

(S58: Focus control execution?)
When it is determined in step S56 that the detection sensitivity of the image sensor 59 exceeds the sixth threshold value TH6 (S56: N), the main control unit 111 determines whether or not to execute the focusing control by the focusing lens 74. .. The main control unit 111 can determine whether or not to execute the focusing control based on the control content for the focusing lens 74 (actuator) and the position of the focusing lens 74. When it is determined that the focusing control by the focusing lens 74 is executed (S58: Y), the operation of the ophthalmic apparatus 1000 shifts to step S59. When it is determined that the focusing control by the focusing lens 74 is not executed (S58: N), the operation of the ophthalmic apparatus 1000 shifts to step S60.

(S59: Focus control)
When it is determined in step S58 that the focusing control by the focusing lens 74 is executed (S58: Y), the main control unit 111 moves the focusing lens 74 by a predetermined movement amount by controlling the actuator. The main control unit 111 can repeat the control in step S59 while changing the moving direction so that the brightness of the ring image increases. When step S59 is completed, the operation of step S34 of the ophthalmic apparatus 1000 ends (end).

(S60: Error handling)
When it is determined in step S58 that the focusing control by the focusing lens 74 is not executed (S58: N), the main control unit 111 causes the main control unit 111 to execute a predetermined error process. The predetermined error processing includes an error display process for the display unit 170 and the like. Error processing when it is determined that the detection sensitivity and exposure time of the image sensor 59, the amount of light of the reflex measurement light source 61, and the focusing lens 74 cannot be controlled even though the brightness of the ring image is determined to be low. Is executed. When step S60 is completed, the reflex measurement by the ophthalmic apparatus 1000 is completed (end).

As described above, by repeatedly executing the brightness increase control, the second light amount control is preferentially executed, and then the second exposure time control is executed to supplement the second light amount control. Then, the second detection sensitivity control is executed to supplement the second exposure time control, and finally the focusing control is executed to supplement the second detection sensitivity control.

If the light intensity of the reflex measurement light source 61 is increased by the second light intensity control, the ring-shaped luminous flux projected on the eye E to be inspected may be visually recognized by the subject, and the subject may gaze at it to make cloud fog difficult. Therefore, after increasing the light intensity to a certain extent by the second light intensity control, the exposure time is controlled by the second exposure time control, which makes it difficult for the subject to see the measurement pattern, which facilitates cloud fog and measures. It is possible to prevent the occurrence of errors.

Further, the execution of the second exposure time control means that the measurement time is lengthened. The second detection sensitivity control may amplify a noise component and deteriorate the image quality. Therefore, by performing the second exposure time control after the second light amount control, it is possible to avoid a long measurement time. By performing the second detection sensitivity control after the second exposure time control, the deterioration of the image quality can be suppressed as much as possible.

Further, in the brightness decrease control shown in FIG. 9 or the brightness increase control shown in FIG. 10, the detection sensitivity control is prioritized over the exposure time control in order to shorten the measurement time, or only the detection sensitivity control is performed. May be good. Further, steps S58 and S59 in FIG. 10 may not be executed in step S14 (first provisional measurement) of FIG. 7, but may be executed only in step S20 (second provisional measurement) of FIG.

Step S14 is an example of the “first measurement condition determination step” according to the embodiment. Step S20 is an example of the “second measurement condition determination step” according to the embodiment. Step S23 is an example of the "cloud fog control step" according to the embodiment. Step S24 is an example of the “measurement step” according to the embodiment.

Step S31 is an example of the "first determination step" according to the embodiment. Step S42 is an example of the “second determination step” according to the embodiment. Step S43 is an example of the “first detection sensitivity control step” according to the embodiment. Step S44 is an example of the "third determination step" according to the embodiment. Step S45 is an example of the "first exposure time control step" according to the embodiment. Step S46 is an example of the "fourth determination step" according to the embodiment. Step S47 is an example of the “first light intensity control step” according to the embodiment.

Step S33 is an example of the "fifth determination step" according to the embodiment. Step S52 is an example of the "sixth determination step" according to the embodiment. Step S53 is an example of the "second light intensity control step" according to the embodiment. Step S54 is an example of the "seventh determination step" according to the embodiment. Step S55 is an example of the “second exposure time control step” according to the embodiment. Step S56 is an example of the "eighth determination step" according to the embodiment. Step S57 is an example of the “second detection sensitivity control step” according to the embodiment.

[Modification example]
The configuration of the optical system of the ophthalmic apparatus 1000 according to the embodiment is not limited to the configuration shown in FIG.

FIG. 11 shows a configuration example of the optical system of the ophthalmic apparatus according to the modified example of the embodiment. In FIG. 11, the same parts as those in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted as appropriate.

The configuration of the ophthalmic apparatus 1000a according to the modified example is different from the configuration of the ophthalmic apparatus 1000 in that the reflex measurement projection system 6a is provided instead of the reflex measurement projection system 6. The configuration of the reflex measurement projection system 6a differs from the configuration of the reflex measurement projection system 6 in that a ring lens 69 is provided in place of the conical prism 63 and the field lens 64. The ring lens 69 includes a central region formed as a light-shielding region and a lens portion formed in a ring shape around the central region. The ring lens 69 functions as an optical element in which a field lens and a conical prism are combined.

In this modification, it is desirable that the ring lens 69 is arranged as close as possible to the pupil conjugate position Q while avoiding an increase in the size of the reflex measurement projection system 6a.

FIG. 12 schematically shows a cross-sectional view of the ring lens 69. For example, as shown in FIG. 12, the ring diaphragm 65 is attached to the lens surface of the ring lens 69 on the side of the eye to be inspected E.

Since the operation of the ophthalmic apparatus 1000a according to this modification is the same as that of the embodiment, detailed description thereof will be omitted.

In this modification as well, as in the embodiment, the amount of light incident on the eye E to be inspected can be reduced, and a pattern having a narrow line width and high brightness can be projected onto the eye E to be inspected. Therefore, it becomes possible to obtain a highly reliable eye refractive power value while reducing the burden on the subject. In addition, since a thin ring-shaped luminous flux can also be incident on the pupil, the effect of blocking the incident luminous flux at the opaque portion of the crystalline lens caused by eyelashes and cataracts is small, and the occurrence of measurement errors can be suppressed. ..

[Action / Effect]
The operation and effect of the ophthalmic apparatus according to the embodiment or the modified example will be described.

The ophthalmic apparatus (1000, 1000a) according to the embodiment includes an optical system (anterior eye observation system 5, reflex measurement projection system 6 or reflex measurement projection system 6a, reflex measurement light receiving system 7), an analysis unit 121, and a control unit. (110, main control unit 111) and the like. The optical system projects a pattern light (ring-shaped luminous flux) based on the light from the light source (ref measurement light source 61) onto the eye to be inspected (E), and the return light from the eye to be inspected can be changed in the focal position. Light is received by the image pickup element (59) via the focusing lens (74). The analysis unit calculates the optical power value of the eye to be inspected based on the pattern image (ring image) obtained by the image sensor. The control unit includes the first measurement condition including at least one of the light amount of the light source, the exposure time of the image sensor, the detection sensitivity of the image sensor, and the control content for the focusing lens based on the first pattern image obtained by the image sensor. The second measurement condition including at least one of the light amount, the exposure time, the detection sensitivity, and the control content is determined based on the second pattern image obtained by the image sensor under the first measurement condition. 2 The analysis unit is made to calculate the ocular refractive force value based on the third pattern image obtained by the image sensor with the subject to be viewed as cloudy under the measurement conditions.

According to such a configuration, the provisional measurement is performed to determine the first measurement condition, and the provisional measurement is performed again under the determined first measurement condition to determine the second measurement condition, and the second measurement condition is determined. Since the optical power value is acquired below, the optical power can be measured with higher accuracy than before even when the brightness of the pattern image is high.

Further, in the ophthalmic apparatus according to the embodiment, the light source is arranged so as to be substantially conjugate with the fundus (Ef) of the eye to be inspected, and the optical system is located at a position substantially conjugate with the pupil of the eye to be inspected (). A diaphragm (ring diaphragm 65) arranged in Q) and formed with a light-transmitting portion that transmits light from a light source, and a deflection member (conical prism 63, ring lens 69) that deflects light from the light source and guides it to the light-transmitting portion. ), And the light transmitted through the translucent portion may be projected onto the eye to be inspected as pattern light.

According to such a configuration, it becomes possible to project a thin pattern light (the width between the inner diameter and the outer diameter is narrow) on the fundus, and therefore, the acquired pattern is obtained by projecting the pattern light having high brightness. The image analysis accuracy can be improved. As a result, the pattern image with high brightness and the execution of the provisional measurement a plurality of times make it possible to measure the refractive power of the eye with higher accuracy than before.

Further, in the ophthalmic apparatus according to the embodiment, the control unit executes the first luminance reduction control (step S14, step S32) when the brightness of the first pattern image is high, and the first when the brightness of the first pattern image is low. The brightness increase control (step S14, step S34) is executed, the second brightness decrease control (step S20, step S32) is executed when the brightness of the second pattern image is high, and the second pattern image is low in brightness. Luminance increase control (step S20, step S34) may be executed.

According to such a configuration, the first measurement condition and the second measurement condition are determined so that the brightness of the pattern image falls within a predetermined brightness range, so that the measurement is performed even when the brightness of the pattern image is high. It becomes possible to measure the optical power with higher accuracy than before without lowering the accuracy.

Further, in the ophthalmic apparatus according to the embodiment, at least one of the first brightness reduction control and the second brightness reduction control is the first detection sensitivity that lowers the brightness of the pattern image by lowering the detection sensitivity based on the brightness of the pattern image. After the control (step S43), the first exposure time control (step S45) may be performed to reduce the brightness of the pattern image by shortening the exposure time.

According to such a configuration, when the brightness of the pattern image is high, it is possible to suppress a decrease in measurement accuracy without significantly affecting the measurement environment.

Further, in the ophthalmic apparatus according to the embodiment, at least one of the first brightness reduction control and the second brightness reduction control lowers the brightness of the pattern image by lowering the amount of light after the first exposure time control (step S45). 1 Light intensity control (step S47) may be performed.

According to such a configuration, when the brightness of the pattern image is high, it is possible to suppress the occurrence of measurement errors due to the movement of the eye to be inspected and to minimize the influence on the measurement environment.

Further, in the ophthalmic apparatus according to the embodiment, the optical system includes a rotary prism (67) arranged in the optical path of the pattern light, and the first exposure time control is set to a lower limit time or more defined by the rotation speed of the rotary prism. The exposure time may be shortened so as to be.

According to such a configuration, it is possible to suppress a decrease in measurement accuracy while obtaining the effect of averaging the light amount distribution by the rotary prism.

Further, in the ophthalmic apparatus according to the embodiment, at least one of the first brightness increase control and the second brightness increase control is exposed after the second light amount control (step S53) in which the brightness of the pattern image is increased by increasing the light amount. The second exposure time control (step S55) may be performed to increase the brightness of the pattern image by lengthening the time.

According to such a configuration, it is possible to facilitate the fixation of the eye to be inspected without the pattern light being visually recognized by the subject, and to prevent the measurement accuracy from being lowered.

Further, in the ophthalmic apparatus according to the embodiment, at least one of the first luminance increase control and the second luminance increase control increases the brightness of the pattern image by increasing the detection sensitivity after the second exposure time control (step S55). The second detection sensitivity control (step S57) may be performed.

According to such a configuration, it is possible to avoid a long measurement time and suppress deterioration of image quality due to amplification of noise components as much as possible.

Further, in the ophthalmic apparatus according to the embodiment, the pattern light may be a ring-shaped light.

According to such a configuration, even when the brightness of the ring image based on the ring-shaped light is high, the refractive power of the eye can be measured with higher accuracy than in the conventional case.

Further, in the control method of the ophthalmic apparatus according to the embodiment, a pattern light (ring-shaped luminous flux) based on the light from the light source (ref measurement light source 61) is projected onto the eye to be inspected (E), and the pattern light is returned from the eye to be inspected. This is a method for measuring the refractive power of an eye to be inspected by receiving light with an image pickup element (59) via a focusing lens (74) whose focal position can be changed. The control method of the ophthalmic apparatus includes a first measurement condition step (step S14), a second measurement condition step (step S20), a cloud fog control step (step S23), and a measurement step (step S24). The first measurement condition step includes at least one of the amount of light of the light source, the exposure time of the image sensor, the detection sensitivity of the image sensor, and the control content for the focusing lens based on the first pattern image obtained by the image sensor. The first measurement condition is determined. The second measurement condition determination step is based on the second pattern image obtained by the image sensor under the first measurement condition, and includes at least one of the light amount, the exposure time, the detection sensitivity, and the control content. To determine. The cloud fog control step causes the subject to be viewed as cloud fog under the second measurement condition. In the measurement step, the refractive power is measured in the cloud fog control step with the eye to be inspected viewed as cloud fog.

According to such a configuration, the first measurement condition is determined in the first measurement condition determination step, the second measurement condition is determined in the second measurement condition determination step under the determined first measurement condition, and the second measurement condition is determined. Since the optical power value is acquired under the measurement conditions, the optical power can be measured with higher accuracy than before even when the brightness of the pattern image is high.

Further, in the control method of the ophthalmic apparatus according to the embodiment, at least one of the first measurement condition determination step and the second measurement condition determination step includes a first determination step (step S31) and a second determination step (step S42). , The first detection sensitivity control step (step S43), the third determination step (step S44), the first exposure time control step (step S45), the fourth determination step (step S46), and the first light intensity control step. (Step S47) and may be included. The first determination step determines whether or not the brightness of the pattern image is high. The second determination step determines whether or not the detection sensitivity is equal to or higher than the first threshold value (TH1) when the brightness is determined to be high in the first determination step. The first detection sensitivity control step lowers the detection sensitivity when it is determined in the second determination step that the detection sensitivity is equal to or higher than the first threshold value. The third determination step determines whether or not the exposure time is equal to or greater than the second threshold value (TH2) when the detection sensitivity is determined to be less than the first threshold value in the second determination step. The first exposure time control step shortens the exposure time when it is determined in the third determination step that the exposure time is equal to or greater than the second threshold value. The fourth determination step determines whether or not the amount of light is equal to or greater than the third threshold value (TH3) when the detection sensitivity is determined to be less than the second threshold value in the third determination step. The first light amount control step reduces the light amount when it is determined in the fourth determination step that the light amount is equal to or greater than the third threshold value.

According to such a configuration, when the brightness of the pattern image is high, the detection sensitivity is first lowered, then the exposure time is shortened, and the amount of light is lowered. It becomes possible to minimize the decrease in measurement accuracy with respect to the movement of the optometry.

Further, in the control method of the ophthalmic apparatus according to the embodiment, the ophthalmic apparatus includes a rotary prism (67) arranged in the optical path of the pattern light, and the second threshold value is equal to or longer than the lower limit time defined by the rotation speed of the rotary prism. It may be.

According to such a configuration, it is possible to suppress a decrease in measurement accuracy while obtaining the effect of averaging the light amount distribution by the rotary prism.

Further, in the control method of the ophthalmic apparatus according to the embodiment, at least one of the first measurement condition determination step and the second measurement condition determination step includes a fifth determination step (step S33) and a sixth determination step (step S52). , The second light intensity control step (step S53), the seventh determination step (step S54), the second exposure time control step (step S55), the eighth determination step (step S56), and the second detection sensitivity control step. (Step S57) and may be included. The fifth determination step determines whether or not the brightness of the pattern image is low. The sixth determination step determines whether or not the amount of light is equal to or less than the fourth threshold value (TH4) when the brightness is determined to be low in the fifth determination step. The second light amount control step increases the light amount when it is determined in the sixth determination step that the light amount is equal to or less than the fourth threshold value. The seventh determination step determines whether or not the exposure time is equal to or less than the fifth threshold value (TH5) when it is determined in the sixth determination step that the amount of light exceeds the fourth threshold value. The second exposure time control step increases the exposure time when it is determined in the seventh determination step that the exposure time is equal to or less than the fifth threshold value. The eighth determination step determines whether or not the detection sensitivity is equal to or less than the sixth threshold value (TH6) when the exposure time is determined to exceed the fifth threshold value in the seventh determination step. The second detection sensitivity control step raises the detection sensitivity when it is determined in the eighth determination step that the detection sensitivity is equal to or less than the sixth threshold value.

According to such a configuration, when the brightness of the pattern image is low, the amount of light is first increased, then the exposure time is lengthened to increase the detection sensitivity, so that the noise component is increased by increasing the detection sensitivity. While suppressing it, it becomes possible to minimize a decrease in measurement accuracy with respect to the movement of the eye to be inspected.

Further, in the control method of the ophthalmic apparatus according to the embodiment, the light source is arranged so as to be optically substantially coupled to the fundus (Ef) of the eye to be inspected, and the ophthalmic apparatus is optically substantially coupled to the pupil of the eye to be inspected. A throttle (ring throttle 65) having a light-transmitting portion formed at a suitable position (Q) and transmitting light from a light source, and a deflection member (conical prism 63, conical prism 63, which deflects light from a light source and guides the light from the light-transmitting portion to the light-transmitting portion. The light transmitted through the translucent portion including the ring lens 69) may be projected onto the eye to be inspected as pattern light.

According to such a configuration, it becomes possible to project a thin pattern light (the width between the inner diameter and the outer diameter is narrow) on the fundus, and therefore, the acquired pattern is obtained by projecting the pattern light having high brightness. The image analysis accuracy can be improved. As a result, the pattern image with high brightness and the execution of the provisional measurement a plurality of times make it possible to measure the refractive power of the eye with higher accuracy than before.

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

In the above-described embodiment, the case where the transmissive liquid crystal panel is used as the optotype chart 43 has been described, but the configuration of the ophthalmic apparatus according to the embodiment is not limited to this. The optotype chart 43 may be an optical chart.

Instead of changing the exposure time of the image pickup device 59 in the above-described embodiment, the number of superposed images obtained by the image pickup device 59 may be changed. In this case, the arithmetic processing unit 120 (analysis unit 121) can perform the superposition processing of the image obtained by the image sensor 59 with the number of superpositions designated by the main control unit 111.

1 Z alignment system 2 XY alignment system 3 kerato measurement system 4 optotype projection system 5 anterior eye observation system 6, 6a reflex measurement projection system 7 reflex measurement light receiving system 9 processing unit 63 conical prism 64 field lens 65 ring aperture 69 ring lens 110 Control unit 111 Main control unit 121 Analysis unit 1000, 1000a Ophthalmic device

Claims (14)

An optical system that projects pattern light based on light from a light source onto an eye to be inspected and receives the return light of the pattern light from the eye to be inspected by an imaging element via a focusing lens whose focal position can be changed.
An analysis unit that calculates the optical power value of the eye to be inspected based on the pattern image obtained by the image sensor, and an analysis unit.
Based on the first pattern image obtained by the image sensor, the first measurement including at least one of the light intensity of the light source, the exposure time of the image sensor, the detection sensitivity of the image sensor, and the control content for the focusing lens. A second that includes at least one of the light intensity, the exposure time, the detection sensitivity, and the control content based on the second pattern image obtained by the image sensor under the first measurement condition after determining the conditions. The measurement conditions are determined, and the analysis unit is made to calculate the eye refractive force value based on the third pattern image obtained by the image sensor in a state where the eye to be inspected is viewed as cloud fog under the second measurement condition. Control unit and
Ophthalmic equipment including. The light source is arranged so as to be substantially conjugated with the fundus of the eye to be inspected.
The optical system is
An aperture that is arranged at a position optically conjugate with the pupil of the eye to be inspected and has a translucent portion that transmits light from the light source.
A deflecting member that deflects light from the light source and guides it to the translucent portion.
Including
The ophthalmologic apparatus according to claim 1, wherein the light transmitted through the translucent portion is projected onto the eye to be inspected as the pattern light. The control unit executes the first brightness decrease control when the brightness of the first pattern image is high, executes the first brightness increase control when the brightness of the first pattern image is low, and executes the brightness of the second pattern image. The ophthalmic apparatus according to claim 1 or 2, wherein the second luminance decrease control is executed when the brightness is high, and the second luminance increase control is executed when the brightness of the second pattern image is low. At least one of the first brightness reduction control and the second brightness reduction control is the exposure time after the first detection sensitivity control that lowers the brightness of the pattern image by lowering the detection sensitivity based on the brightness of the pattern image. The ophthalmic apparatus according to claim 3, wherein the first exposure time control for lowering the brightness of the pattern image is performed by shortening. At least one of the first brightness reduction control and the second brightness reduction control is characterized in that after the first exposure time control, the first light amount control for lowering the brightness of the pattern image by lowering the light amount is performed. The ophthalmic apparatus according to claim 4. The optical system includes a rotary prism arranged in the optical path of the pattern light.
The ophthalmic apparatus according to claim 4 or 5, wherein the first exposure time control shortens the exposure time so as to be equal to or greater than a lower limit time defined by the rotation speed of the rotary prism. At least one of the first brightness increase control and the second brightness increase control increases the brightness of the pattern image by increasing the exposure time after the second light amount control that increases the brightness of the pattern image by increasing the amount of light. The ophthalmic apparatus according to any one of claims 3 to 6, wherein a second exposure time control is performed. At least one of the first brightness increase control and the second brightness increase control is characterized in that after the second exposure time control, the second detection sensitivity control for increasing the brightness of the pattern image by increasing the detection sensitivity is performed. The ophthalmic apparatus according to claim 7. The ophthalmic apparatus according to any one of claims 1 to 8, wherein the pattern light is ring-shaped light. A pattern light based on the light from the light source is projected onto the eye to be inspected, and the return light of the pattern light from the eye to be inspected is received by the image pickup element through a focusing lens whose focal position can be changed. It is a control method of an ophthalmic device that measures refractive power.
Based on the first pattern image obtained by the image sensor, a first pattern including at least one of the amount of light of the light source, the exposure time of the image sensor, the detection sensitivity of the image sensor, and the control content for the focusing lens. The first measurement condition determination step for determining the measurement conditions and
Based on the second pattern image obtained by the image pickup device under the first measurement condition, the second measurement condition including at least one of the light amount, the exposure time, the detection sensitivity, and the control content is determined. The second measurement condition determination step to be performed and
A cloud fog control step that causes the eye to be examined to be viewed as cloud fog under the second measurement condition,
In the cloud fog control step, a measurement step of measuring the refractive power with the eye to be inspected viewed as cloud fog, and a measurement step.
Methods of controlling ophthalmic devices, including. At least one of the first measurement condition determination step and the second measurement condition determination step is
The first determination step of determining whether or not the brightness of the pattern image is high, and
When the brightness is determined to be high in the first determination step, the second determination step of determining whether or not the detection sensitivity is equal to or higher than the first threshold value.
When the detection sensitivity is determined to be equal to or higher than the first threshold value in the second determination step, the first detection sensitivity control step for lowering the detection sensitivity and the first detection sensitivity control step.
When it is determined in the second determination step that the detection sensitivity is less than the first threshold value, the third determination step of determining whether or not the exposure time is equal to or greater than the second threshold value.
When it is determined in the third determination step that the exposure time is equal to or greater than the second threshold value, the first exposure time control step for shortening the exposure time and the first exposure time control step.
When it is determined in the third determination step that the detection sensitivity is less than the second threshold value, the fourth determination step of determining whether or not the amount of light is equal to or greater than the third threshold value.
When it is determined in the fourth determination step that the amount of light is equal to or greater than the third threshold value, the first light amount control step for lowering the amount of light and the first light amount control step
10. The method for controlling an ophthalmic apparatus according to claim 10. The ophthalmic apparatus includes a rotary prism arranged in the optical path of the pattern light.
The method for controlling an ophthalmic apparatus according to claim 11, wherein the second threshold value is equal to or longer than a lower limit time defined by the rotation speed of the rotary prism. At least one of the first measurement condition determination step and the second measurement condition determination step is
The fifth determination step of determining whether or not the brightness of the pattern image is low, and
When the brightness is determined to be low in the fifth determination step, the sixth determination step of determining whether or not the amount of light is equal to or less than the fourth threshold value is used.
When it is determined in the sixth determination step that the amount of light is equal to or less than the fourth threshold value, the second light amount control step for increasing the amount of light and the second light amount control step
When it is determined in the sixth determination step that the amount of light exceeds the fourth threshold value, the seventh determination step of determining whether or not the exposure time is equal to or less than the fifth threshold value.
When it is determined in the seventh determination step that the exposure time is equal to or less than the fifth threshold value, the second exposure time control step for lengthening the exposure time and the second exposure time control step.
When it is determined in the 7th determination step that the exposure time exceeds the 5th threshold value, the 8th determination step for determining whether or not the detection sensitivity is equal to or less than the 6th threshold value.
When it is determined in the eighth determination step that the detection sensitivity is equal to or less than the sixth threshold value, the second detection sensitivity control step for increasing the detection sensitivity and the second detection sensitivity control step.
The method for controlling an ophthalmic apparatus according to any one of claims 10 to 12, wherein the method for controlling an ophthalmic apparatus. The light source is arranged so as to be substantially conjugated with the fundus of the eye to be inspected.
The ophthalmic device
An aperture that is arranged at a position optically conjugate with the pupil of the eye to be inspected and has a translucent portion that transmits light from the light source.
A deflecting member that deflects light from the light source and guides it to the translucent portion.
Including
The control method for an ophthalmic apparatus according to any one of claims 10 to 13, wherein the light transmitted through the translucent portion is projected onto the eye to be inspected as the pattern light.

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