JP2001149315A - Device and method of objective measurement - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device and a method of objective measurement capable of optimizing the timing of measurement and the fogging effect by measuring a subject's eye according to the condition of the eye such as the fixation or release of the adjustment power at the time of the measurement. SOLUTION: This device of objective measurement comprises a measuring optical system 1 for objectively measuring the refracting power of an eye E to be examined, a fixation target projecting optical system 2 for projecting a fixation target 22 to the eye E, a fixation target moving part 4, and a control part 8. The fixation target moving part 4 moves the fixation target 22 of the fixation target projecting optical system 2 from a proximal position to a distal position to the far point of the eye E, and produces the fogging condition for the eye E when the fixation target 22 is moved to the distal position. The control part 8 controls the fixation target moving part 4, etc., according to the result of monitoring executed by a fixation monitoring means for monitoring the fixation condition of the eye E.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an objective measurement apparatus and an objective measurement method for objectively measuring the refractive power of an eye to be inspected, and more particularly, to the fixation and accommodation power of the subject during measurement. The present invention relates to an objective measurement device and an objective measurement method having a feature in, for example, canceling of the object.

[0002]

2. Description of the Related Art Conventionally, objective measurement for objectively measuring the refractive power (spherical refractive power S, cylindrical surface refractive power C, astigmatism axial degree A, etc.) of an eye to be inspected based on the principle of a radiographic method or the like. The device is widely used. In such an objective measurement apparatus, in order to accurately measure the refractive power, a predetermined operation for guiding the eye to be examined to a position and state suitable for the measurement is performed prior to the measurement.

Specifically, first, a fixation target for guiding the line of sight of the eye to be examined in a predetermined direction with respect to the device is projected. Further, when the fixation target is projected in this manner, since the subject easily adjusts to the eye to be examined in order to gaze at the fixation target, it is necessary to reduce or cancel the accommodation force. A fog condition is generated. The generation of cloud fog state means that the fixation target is moved farther than the far limit position (far point) where the subject's eye can see, so that the fixation target is blurred to the subject and fog and clouds are generated. As a state in which the eye appears to have been applied (cloudy state), the accommodation power of the eye to be examined is reduced or released.

[0004] The projection of the fixation target and the generation of the cloudy fog are automatically performed before the refractive power measurement after the start of the measurement is instructed by the examiner. Was incorporated. The procedure from the measurement instruction to the completion of the measurement will be specifically described. First, the objective measurement device is arranged in front of the subject's eye, and the start of the measurement is instructed by pressing the measurement start button by the examiner. Then, the projection of the fixation target and the generation of the fog state are automatically performed. The relative positional relationship (alignment state) between the objective measurement apparatus and the subject's eye is monitored by predetermined means in the apparatus, and after the generation of the fog state is completed, when the alignment state becomes appropriate. The refractive power of the eye to be examined is measured, the result of this measurement is output, and the measurement is completed. Such a measurement procedure is the same for all the eyes to be examined, and the projection of the fixation target and the generation of the cloudy state are automatically performed for all the eyes to be examined.

[0005]

However, in such a conventional objective measuring apparatus, the fogging state is simply generated for all the eyes to be examined, and therefore, the following problem arises. First, depending on the subject, fixation may not be possible or fixation may be difficult. For example, infants aged 0 to 3 years, subjects undergoing surgery represented by cataracts, subjects suffering from diseases represented by nystagmus, animals other than humans, etc., have uncertain gazes. Fixation is often impossible. However, conventionally, the fogging state was generated for these subjects as well as other subjects, so that extra time was required for the measurement, and the subjects suffered more than necessary. There was a problem of forcing.

[0006] Further, since the fog state is generated up to such a case, a slight measurement chance may be missed. That is, as described above, when performing measurement of a subject having difficulty in fixation or the like, or because the stability of the device is poor as measured by a hand-held objective measurement device provided in recent years, the eye and the eye to be inspected are compared. When the relative position is not determined, fixation becomes unstable and the alignment state rarely becomes proper. In the conventional apparatus, even if the alignment state is proper, the measurement is not performed unless the generation of the fog state is completed. And other problems.

In order to solve the problem that measurement chances are missed, the present applicant has proposed a new objective measuring apparatus (Japanese Patent Application Laid-Open No. Hei 8-191795). This device is provided with a fog operation stop switch for instructing stop of generation of the fog state, and when the fog stop switch is pressed, the fog state is not generated after the projection of the fixation target. The measurement is performed immediately when the alignment state becomes appropriate. According to such a device,
Measurement can be performed without missing a small measurement chance. However, in such an objective measurement device having the fog operation stop switch, the examiner needs to switch between generating the fog state and stopping the generation of the fog state, and the operation is troublesome. Was. Further, there is a risk that an operation error may occur, for example, when the fogging state is generated and the adjusting force is to be released, the fogging state is erroneously stopped.

In addition, in the conventional objective measurement apparatus, when the generation of the cloudy state is completed, the measurement is immediately performed when the alignment state becomes appropriate regardless of the state of the eye. There is a possibility that the measurement may be performed even though the release of the adjusting force of the suffix is not sufficient.
In other words, depending on the eye to be examined, it takes time until the accommodation power is relaxed, and even after the generation of the cloudy state is completed, the accommodation power may still remain. If the measurement is performed, the measurement is performed in a state where the adjusting force remains, and there is a problem that a correct measured value cannot be obtained.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems in the conventional objective measuring apparatus and objective measuring method. It is an object of the present invention to provide an objective measurement apparatus and an objective measurement method capable of optimizing the measurement timing and the fogging effect by performing a measurement in accordance therewith.

[0010]

In order to achieve the above object, the present invention according to claim 1 relates to an objective measuring apparatus for objectively measuring the refractive power of an eye to be examined. Measuring means, a fixation target projecting means for projecting a fixation target to the eye to be inspected, and a fixation target of the fixation target projection means from a position closer to the far point of the eye to be examined to the far point of the eye to be examined. It moves to an arbitrary position to a more distant position, and when moving to the distant position, monitors the fixation target moving means for generating a fog state for the eye to be inspected, and monitors the fixation state of the eye to be inspected And a control means for controlling the measurement means and / or the fixation target moving means in accordance with the monitoring result of the fixation monitoring means.

In this objective measurement apparatus, the fixation state of the subject's eye is monitored by fixation monitoring means prior to measurement. Then, the operation of generating the fog state, the timing of measurement, and the like are controlled according to the monitoring result. Therefore,
Measurement can be performed at an optimal timing according to the state of the subject (eye to be inspected), or an optimal fog effect can be obtained. Therefore, the measurement time can be minimized and the subject is not unnecessarily distressed, and the measurement is performed in an optimal state, so that the reliability of the measurement value can be improved.

Further, the objective measurement device according to claim 2 is
The fixation monitoring means determines whether or not fixation of the subject's eye is possible by determining whether the position of the subject's eye is within a predetermined fixable area in a plane orthogonal to the measurement optical axis. When the eye to be examined is located in the fixation-possible region, the time during which the subject's eye remains within the fixation-possible region is measured. By comparing, the fixation quality determining unit that determines whether fixation is performed well, measures the entire time that the subject's eye is located within the fixable area, and determines the effect of this time. The apparatus is provided with at least one of a cloud fogging effect determination unit that determines whether or not the adjustment of the subject's eye is sufficiently released by comparing with the reference time.

Various types of monitoring can be considered as specific monitoring contents by the fixation monitoring means. Here, first, the fixation possibility determination unit determines whether or not fixation is possible, thereby obtaining an eye to be inspected. Can be identified simply by moving around without performing any fixation. In addition, by determining whether the fixation is good or bad by the fixation goodness determination unit, it is possible to identify a case where the subject's eye moves around with little fixation, although there is a possibility of fixation. Further, by determining the release state of the adjusting force by the fog effect determination unit,
It is possible to identify a case where the subject's eye is fixated, but the accommodation power has not yet been sufficiently released. Then, appropriate measurement can be performed according to the identification results.

Further, the objective measurement device according to claim 3 is
The above-mentioned control means starts a fog stop mode in which the refractive power is measured without generating the fog state, starts the fog state, and enables the measurement of the refractive power during and / or after the completion of the fog state. After the completion of the generation of the cloud fog state, the measurement priority mode for performing the measurement at the point in time when the measurement is completed, and the measurement of the refractive power is performed when the entire time during which the subject's eye is located within the fixable area reaches the above-described effect determination reference time. Controlling the measuring means and / or the fixation target moving means so as to perform the measurement in at least one of the fog extension mode to be performed and the normal measurement mode for measuring the refractive power immediately after the completion of generation of the fog state. It is composed of

The control means may be controlled in various ways. In this case, in addition to the normal measurement mode as in the prior art, a fog stop mode in which no fog state is generated and a fog state are generated. The measurement is performed in one of a measurement priority mode in which measurement is prioritized, and a fog extension mode in which the fog state is maintained until the adjusting force is released. Therefore, the measurement can be performed at an optimal timing according to the state of the eye to be inspected, and when possible, with the accommodation force sufficiently released.

In the objective measuring apparatus according to the fourth aspect, the control means determines that the fixation possibility determining unit determines that the eye to be inspected cannot be fixed. The measurement is performed in the mode, and when it is determined that fixation of the subject's eye is possible in the fixation possibility determination unit, the fixation quality determination unit performs determination by the fixation quality determination unit. When it is determined that fixation is not performed well, measurement is performed in the measurement priority mode, and when it is determined that fixation is performed well in the fixation quality determination unit. The cloud fogging effect determination unit performs the determination, and when it is determined that the adjustment of the subject's eye is not sufficiently released by the cloud fogging effect determination unit, the measurement is performed in the cloud fogging extension mode, and the cloud fogging effect is measured. When the determination unit determines that the adjustment of the subject's eye has been sufficiently released. Is to perform the measurement in the normal measurement mode, configured to control said measuring means and or the fixation target moving means.

There are various possible combinations of the monitoring contents of the fixation monitoring unit and the control contents of the control unit, but the above combination enables the most effective measurement.
For example, when there is no possibility of fixation, the measurement is performed without generating the fog state, so that the measurement time can be shortened and the subject does not have to uselessly suffer. Alternatively, when the fixation is not good, the measurement is prioritized over the generation of the cloudy state, so that the measurement can be performed without missing a slight measurement chance. Furthermore, when fixation is not sufficient but the fixation is not sufficient, the measurement is performed after the adjustment is sufficiently released by extending the fog state, so the measurement reliability is improved. I do. Furthermore,
When the adjusting force has been sufficiently released, the measurement can be performed at the same timing as in the related art.

Further, the objective measurement device according to claim 5 is
There is provided a mode switching means for arbitrarily selecting which of the fog stop mode, the measurement priority mode, the fog extension mode, and / or the normal measurement mode to perform measurement. The examiner can select an arbitrary mode via the mode switching means. Therefore, for example, when the state of the subject (eye to be inspected) is known in advance, the measurement mode corresponding to this state is selected, thereby eliminating the time required for automatically selecting the measurement mode and the selection error. can do.

The objective measurement device according to claim 6 is
An output unit is provided for presenting a mode used for measurement to the examiner among the fog stop mode, the measurement priority mode, the fog extension mode, and / or the normal measurement mode. By outputting the mode to the output unit in this manner, the examiner can easily grasp the measurement mode, and can refer to the reliability of the measurement and the behavior of the eye E. Alternatively, it is possible to switch to a desired mode, for example, when the measurement is about to be performed in a mode not intended by the examiner.

According to a seventh aspect of the present invention, there is provided an objective measurement method for objectively measuring the refractive power of an eye to be inspected, the method comprising: projecting a fixation target onto the eye to be inspected; After the projection procedure, by determining whether or not the position of the subject's eye is within a predetermined fixable area in a plane orthogonal to the measurement optical axis, whether or not fixation of the subject's eye is possible is determined. The fixation possibility determination procedure to be determined, and when it is determined that fixation of the subject's eye is not possible in the fixation possibility determination procedure, measurement of refractive power is performed without generating a cloudy state for the subject's eye. Performing, when it is determined that fixation of the subject's eye is possible in the fixation possibility determination procedure, when the subject's eye is located in the fixation possible area, Measure the time during which the subject's eye remains and compare this time with the predetermined reference time By this, the fixation good / bad judgment procedure for judging whether or not the fixation is well performed, and if it is judged that the fixation is not good in the fixation good / bad judgment procedure, During the generation of the fog state and / or after the completion of the generation of the fog state, the measurement is started when the measurement of the refractive power becomes possible, and the fixation is performed well in the fixation good / bad judgment procedure. If it is determined that the eye to be inspected is measured for the entire time during which the eye to be examined is located within the fixable area, and this time is compared with a predetermined effect determination reference time to adjust the eye to be examined. Fog effect determination procedure to determine whether or not has been sufficiently released, and if it is determined that the adjustment of the subject's eye is not sufficiently released in the fog effect determination procedure, after the completion of generation of the fog state, The subject's eye is located within the fixable area When it is determined that the adjustment of the eye to be examined is sufficiently released in the procedure for measuring the refractive power at the time when the entire time reaches the effect determination reference time and the fogging effect determination procedure, Measuring the refractive power immediately after the completion of the generation of the state.
According to this method, the measurement timing and the fogging effect can be optimized as in the above-described operation.

[0021]

(Embodiment 1) Hereinafter, an embodiment 1 of an objective measurement apparatus and an objective measurement method of the present invention will be described in detail with reference to the drawings. FIG. 1 is a view (partially cut away) of the objective measurement device according to the present embodiment viewed from the side, FIG. 2 is a view taken along the line AA in FIG. 1, and FIG. 3 shows a mode changeover switch. FIG. 4 is a block diagram showing an electrical configuration of a control unit of the objective measurement device. FIG. 5 is a flowchart of a measurement operation by the objective measurement device. In this embodiment, a case will be described in which the present invention is applied to a hand-held type objective measurement device. However, the present invention can be similarly applied to a stationary type objective measurement device.

First, the configuration of the objective measurement device will be described, and then the measurement operation by the objective measurement device will be described. As shown in FIG. 1, the objective measurement device includes a measurement optical system 1, a fixation target projection optical system 2, an imaging optical system 3, a fixation target moving unit 4, an input unit 5, an output unit 6, a storage unit 7, and The control unit 8 is entirely or partially housed in a housing 9.

The measuring optical system 1 constitutes a part of the measuring means for measuring the refractive power of the eye to be examined by the same principle (contrast method in the present embodiment) and configuration as the conventional objective measuring apparatus. That is, the measuring light is projected onto the eye E, and the measuring light reflected by the eye E is received. Specifically, the measurement optical system 1 includes an infrared light source 11, lenses 12 to 14, a chopper 15, a half mirror 16, a diaphragm 17, and a light receiver 18. Then, the measurement light emitted from the infrared light source 11 is scanned by the chopper 15 via the lens 12, and the scanned measurement light is guided to the eye E through the lens 13 and the half mirror 16, and further scanned. The measurement light reflected by the optometry E passes through the half mirror 16, the lens 14, and the aperture 17, and
The light is received at 8.

As shown in FIG. 2, the photodetector 18 includes four photoelectric conversion elements 18a to 18d and
e is arranged. A pair of photoelectric conversion elements 18a, 18
b is vertically symmetrically arranged about the measurement optical axis 19, and the pair of photoelectric conversion elements 18 c and 18 d are arranged symmetrically about the measurement optical axis 19. When the measurement light is received by the photoelectric conversion elements 18a to 18d, a signal is output from the photoelectric conversion elements 18a to 18d to a measurement value calculation unit 81, which will be described later, of the control unit 8. A measurement value is calculated based on the phase difference between the measurement light received by the photoelectric conversion elements 18a and 18b and the measurement light received by the pair of photoelectric conversion elements 18c and 18d.

As shown in FIG. 2, the four elements of the four-division light receiving element 18e are arranged at equal positions around the measurement optical axis 19, and When the measurement light is received, the four-divided light receiving element 18e
A signal is output from the control unit 8 to an eye position calculating unit 82, which will be described later, of the control unit 8. In the eye position calculating unit 82, a signal is output based on the difference in the amount of measurement light received by each of the four-divided light receiving elements 18e. The position of the subject's eye E with respect to the objective measurement device is calculated. Here, the position of the eye E is a position in a plane parallel to the light receiving surface of the four-divided light receiving element 18e (a surface orthogonal to the measurement optical axis 19, hereinafter, a light receiving surface).

As shown in FIG. 1, the fixation target projection optical system 2 includes a visible light source 21, a fixation target 22, a total reflection mirror 23, a lens 24, and a die that reflects visible light and transmits infrared light. Fixation light emitted from the visible light source 21 and transmitted through the fixation target 22 is projected onto the eye E through the total reflection mirror 23, the lens 24 and the dichroic mirror 25. You. Imaging optical system 3
Is provided with a half mirror 31 and a CCD camera 32, and the image of the subject's eye reflected by the dichroic mirror 25 is reflected by the CCD camera 32 via the half mirror 31.
Is imaged.

The fixation target moving section 4 is a fixation target moving means for moving the fixation target 22 in a direction parallel to the measurement optical axis 19.
In the present embodiment, the motor 41 is configured. The fixation target 22 is moved by the motor 41 from the position closer to the subject's eye E than the far point to an arbitrary position from the far point to the far point. In particular, by moving the fixation target 22 to a position farther than the far point, the subject is provided with the fixation target 2.
A state (cloud fog state) is generated in which 2 is blurred and looks like fog or cloud.

The input unit 5 is provided with a measurement switch 51 shown in FIG.
And a mode changeover switch 52. The measurement switch 51 is for instructing the start of measurement of the eye E. This measurement switch 51
It is provided on the front surface of a handle 9 a provided below the housing 9. The mode changeover switch 52 arbitrarily selects one of a plurality of measurement modes set for performing measurement at an optimum measurement timing, or
This is operation means for selecting a mode (automatic mode) in which a plurality of measurement modes are automatically switched. Although specific contents of the plurality of measurement modes will be described later, in the present embodiment, a fog stop mode, a measurement priority mode, a fog extension mode, and a normal measurement mode are provided. As shown in FIGS. 1 and 3, the mode changeover switch 52 is provided as a dial-type switch on the upper surface of the housing 9, rotates the dial 52 a, and moves the indicator 52 b provided on the upper surface of the dial 52 a to The mode switching described above can be performed by matching one of the indexes of the automatic mode, the fog stop mode, the measurement priority mode, the fog extension mode, and the normal measurement mode. However, the specific configuration and position of the mode changeover switch 52 can be arbitrarily determined.

The output unit 6 includes the monitor 61 and the printer 62 shown in FIG. The monitor 61 displays an image of the eye to be inspected captured by the CCD camera 32, a measured value measured via the measuring optical system 1, and the like. The printer 62 prints measured values and the like measured via the measuring optical system 1 and the like. In particular, in the present embodiment, the measurement mode used at the time of measurement is displayed and printed. This will be described later.

The storage unit 7 includes a ROM (Read Only Memory) for storing various programs and basic data, and a RAM (Random Access Memory) for temporarily storing measurement results and the like.
y). Illustration of these ROM and RAM is omitted.

As shown in FIGS. 1 and 4, the control unit 8 includes an infrared light source 11, a chopper 15, a light receiver 18, a visible light source 21,
Motor 41, CCD camera 32, measurement switch 51, mode changeover switch 52, monitor 61, printer 6
And control means for electrically controlling the electrical components such as the storage unit 7 and the like to control them (in FIG. 1, some electrical lines leading to the control unit 8 are omitted). . The control unit 8 is, specifically, a CPU (Central
Processing Unit) and a control program operating on the CPU. In addition, all or a part of the control unit 8 can be configured by wired logic.

As shown in FIG. 4, the control unit 8 includes a measurement value calculation unit 81, a subject eye position calculation unit 82,
A fixation monitoring section 83 and a measurement mode selection section 84 are provided. The measurement value calculation unit 81 includes the light receiving elements 18a to 18a.
The phase difference is calculated based on the light receiving signal from 18d, and the refractive power of the eye E is calculated based on the phase difference and the principle of the image analysis method. That is, the measurement value calculation unit 81 constitutes a measurement unit that measures the refractive power of the eye E in cooperation with the measurement optical system 1. Further, the subject's eye position calculation unit 82
The position of the eye E with respect to the objective measurement device is calculated based on the difference in the amount of measurement light received by each element of the four-division light receiving element 18e.

The fixation monitoring unit 83 monitors the fixation state of the eye E, and determines the fixation state of the eye E based on the measurement result of the eye position calculation unit 82. The fixation monitoring unit 83 includes a fixation possibility determining unit 85, a fixation good / bad determination unit 86, and a fog effect determination unit 87.

The fixation possibility determining section 85 determines whether or not the position of the eye E measured by the eye position calculation section 82 is within a predetermined fixable area on the light receiving surface. It is determined whether fixation of the subject's eye E is possible or not. The fixable region is a region virtually set in the light receiving surface as a range in which the eye E can be recognized as being fixed (acceptable for measuring the refractive power of the eye E). It is. For example, as shown by an imaginary line in FIG.
Can be set as a circular area that is slightly smaller than the light receiving surface.

As a criterion for determining whether or not the position of the subject's eye E is within the fixable area, various criteria for determining / estimating the possibility of whether or not the subject's eye E can be properly fixed can be determined. Can be used. As an example, within a predetermined time starting from a predetermined timing after the fixation target 22 is projected (for example, immediately after the projection of the fixation target 22 or immediately after the determination in the determination step S5 of the measurement mode described later, 2-3se
If the position of the subject's eye falls within the fixable area even within a moment, it is determined that the position of the subject's eye E is in the fixable area. In addition, for example, the reference may be based on the fact that the position of the eye to be examined is continuously in the fixable area for a predetermined time or more. Alternatively, the speed at which the subject's eye position passes through the fixable area may be calculated, and the speed may be determined to be equal to or lower than a predetermined speed, or the speed may be attenuated at a predetermined rate or higher. That is, any criterion that can determine the possibility of performing fixation can be used.

When it is determined based on such a criterion that the position of the eye E is not within the fixable area, it is impossible to perform fixation because the subject has not seen fixation at all. It is possible, and it can be determined that it is not necessary to generate the fog state. On the other hand, when it is determined that the position of the subject's eye E is within the fixation-possible region, the subject can fixate because the subject is looking at fixation for at least a moment, and furthermore, the cloudy state It can be expected that the adjustment force will be released by generating.

When the eye E is located in the fixable area, the fixation good / bad judgment unit 86 determines whether the eye E is within a predetermined reference time starting from a predetermined timing (for example, immediately after completion of the fixation possibility judgment). (Within 5 to 6 seconds), the time during which the eye E remains within the fixation-possible region is measured, and this time is compared with a predetermined reference time (a pass / fail judgment reference time, for example, 3 seconds) to fixate. It is determined whether or not is performed well. That is, if the time during which the subject's eye E remains does not satisfy the pass / fail judgment reference time, the subject has no intention of fixation, and the subject's eye E simply moves around. It can be determined that the measurement chance is small. On the other hand, if the time is equal to or longer than the pass / fail judgment reference time, the subject has a fixation intention and the fixation is performed favorably, so that it is determined that there is sufficient measurement chance even when the cloudy state is generated. be able to.

Here, the time during which the subject's eye E stays within the fixable area is the time during which the subject's eye E continuously stays within the fixable area (continuous time) or the time when the subject's eye E stays within the fixable area. When intermittently entering and exiting the fixable area, a time (accumulated time) obtained by accumulating the time during which the eye E remains in the fixable area can be adopted. When the former continuous time is measured, while fixation is performed almost satisfactorily,
If the subject's eye E is out of the fixable area even for a moment,
Since it may be determined that fixation is not good, the accumulated time is measured in the present embodiment.

Further, the fogging effect determination section 87 measures the total time during which the subject's eye E has been located in the fixable area at the time when the generation of the fogging state is completed, and determines this time as a predetermined time. Reference time (effect determination reference time, for example, 2-3
By comparing with (sec), it is determined whether or not the adjustment of the eye E has been sufficiently released. In this determination, if the total time is less than the effect determination reference time, it can be said that the subject did not sufficiently look at the fixation, there is a possibility that the release of accommodation power has not been performed sufficiently, Further, it can be determined that the cloudy state should be continued. On the other hand, if the total time is equal to or longer than the effect determination reference time, the subject has sufficiently watched his fixation, the accommodation power has been sufficiently released, and the subject is ready for proper measurement. You can judge. In the measurement by the fogging effect determination section 87, it is conceivable to measure the continuous time, the accumulated time, and the like. However, in the present embodiment, the accumulated time is measured for the same reason as described above.

The fixation possibility determining unit 85, fixation good / bad determination unit 86, and cloud fog effect determination unit 87 are:
A part thereof can be omitted, or a determination means for determining the state of fixation of the eye E and the release of accommodation power based on other criteria can be further provided.

The measurement mode selection unit 84 includes a fixation monitoring unit 83
The measurement mode is selected according to the monitoring result of. As the measurement mode, as shown in FIG.
Four modes are set: a measurement priority mode, a fog extension mode, and a normal measurement mode. Although FIG. 4 shows each mode, each of these modes is generally described as a numerical condition in a control program. Among these, the fog stop mode is a mode in which the fog state is not generated, and the measurement is performed when the refractive power can be measured (hereinafter, a measurable state). here,
The measurable state refers to a state in which the position of the eye E calculated by the eye position calculator is within a predetermined measurable region. As the measurable area, the same area as the fixable area can be set, or an area different from the fixable area can be set.

The measurement priority mode is a mode in which the generation of the fog state is started, and the measurement is performed when the fogging state becomes measurable during or after the completion of the generation. Next, in the fog extension mode, a fog state is generated, and after the generation is completed, measurement can be performed after the entire time during which the subject's eye E is located within the fixable area reaches the above-described effect determination reference time. This is a mode in which measurement is performed when the state is reached. In other words, even if the generation of the cloudy state is completed, the measurement is not performed if the total time has not reached the effect determination reference time, and the measurement is performed after waiting until the effect determination reference time is reached. In the normal measurement mode, the cloudy state is generated, and after the generation of the cloudy state, measurement is performed at the time when the eye E enters the measurable state irrespective of the entire time in which the eye E is located within the fixable area. Mode.

It should be noted that a part of the fog stop mode, the measurement priority mode, the fog extension mode, and the normal measurement mode can be partially omitted, or the fixation projection and the fog state can be performed depending on other operation contents. The modes for performing the generation may be further combined. In addition, the fixation possibility determining unit 85, the fixation quality determining unit 86, and the fog effect determining unit 87
The combination of the fog stop mode, the measurement priority mode, the fog extension mode, and the normal measurement mode is arbitrary. For example, when the fixation possibility determining unit 85 determines that there is no possibility of fixation, the measurement may be performed in the cloud fog stop mode or the measurement in the measurement priority mode. The following measurement operation is an example of this combination.

Hereinafter, the measuring operation by the objective measuring device configured as described above will be described with reference to FIG. First, this operation starts when the examiner turns on the power of the objective measurement device (Step S).
1). Then, the examiner operates the mode changeover switch 52 to arbitrarily select one of the plurality of measurement modes or the automatic changeover mode (step S2). The mode switching operation can be performed at any timing before the power is turned on and before the measurement switch 51 is pressed. Naturally, if there is no need to change the mode, the mode switching operation can be omitted. Thereafter, the examiner places the objective measurement device at a substantially appropriate position in front of one of the left and right eyes E to be examined. Here, the control unit 8 monitors whether or not the measurement switch 51 is pressed (step S3). When the measurement switch 51 is pressed, the fixation target projection optical system 2 projects the fixation target 22. (Step S4).

Then, the state of the mode changeover switch 52 is identified by the control unit 8, and it is determined whether any of the measurement modes is selected (step S5).
First, a case where the automatic mode is selected will be described. In this case, first, the fixation possibility determining unit 85 sets the position of the subject's eye within the fixable area within a predetermined time starting from a predetermined timing after the fixation target 22 is projected as described above. It is monitored whether it has entered even for a moment. If it does not enter, it is determined that there is no possibility of fixation,
If it does, it is determined that there is a possibility of fixation (step S6).

If it is determined in step S6 that there is no possibility of fixation, it can be determined that there is no need to generate a fog state, so that measurement is performed in the fog stop mode (step S7). ). That is, the cloud fog state is not generated, and the measurement is performed immediately when the state becomes measurable. Therefore, the cloudy fog state is not generated even when fixation cannot be performed, so that the examinee is not imposed an unnecessary burden.

On the other hand, when it is determined in step S6 that there is a possibility of fixation, the process proceeds to the determination by the fixation quality determining section 86, and the subject's eye E is placed in the fixable area as described above. The time during which the optometry E remains is measured, and this time is compared with a pass / fail judgment reference time. If this time is less than the pass / fail judgment reference time, it is determined that fixation is not good, and if it is equal to or longer than the pass / fail judgment reference time, it is judged that fixation is good (step S8).

If it is determined in this step S8 that fixation is not good, it can be determined that there is little chance of measurement, so that measurement is performed in the measurement priority mode (step S9). That is, the generation of the fog state is started, and whether or not the measurement is possible is constantly monitored. When the measurement is possible, the measurement is performed regardless of whether the generation of the fog state is completed. Done. Therefore, even in a state where the fixation is not stable, the measurement can be performed without missing a slight measurement chance (in addition,
In FIG. 5, the steps of generation and termination of generation of the fog state at this time are omitted.

On the other hand, if it is determined in step S8 that the fixation is good, the generation of the fog state is started (step S10), and after the generation of the fog state is completed (step S11), the fog effect determination is performed. The determination by the unit 87 is performed (step S12). In this determination, the total time during which the subject's eye E was located within the fixable area was measured,
This time is compared with the effect determination reference time. If the total time is less than the effect determination reference time, it is determined that the fogging effect is insufficient and that the adjustment of the eye E is not sufficiently released. On the other hand, if the total time is equal to or longer than the effect determination reference time, it is determined that the fog effect is sufficient and the adjustment of the eye E is sufficiently released.

If it is determined in step S12 that the adjustment of the eye E has not been sufficiently released, the measurement is performed in the fog extension mode (step S13). That is, while the fixation target 22 is maintained at the position where the cloudy state is generated, the measurement of the time during which the subject's eye E is located within the fixable area is continued, and the entire time is longer than the effect determination reference time. After that, the measurement is performed when the measurement is possible. Therefore, the measurement is performed when the accommodation power of the eye E is sufficiently released, so that the reliability of the measurement is further improved. On the other hand, when it is determined in step S12 that the adjustment of the eye E has been sufficiently released, the measurement is performed in the normal measurement mode (step S14). That is, the measurement is performed immediately when the measurement is possible.

In the determination of the measurement mode in step 5, if any one of the measurement modes is manually selected, the measurement is performed in the selected mode (step S15). Specifically, when the fog stop mode is selected, the measurement is immediately performed when the measurement is possible without generating the fog state,
When the measurement priority mode is selected, the generation of the fog state is started, and the measurement is performed immediately when the measurement is possible. Further, when the fog extension mode is selected, after the generation of the fog state is completed, and the entire time during which the subject's eye E is located within the fixable area has reached the effect determination reference time. Later, the measurement is performed when the measurement is possible. In addition, when the normal measurement mode is selected, the measurement is performed at the time when the cloudy state is completed and the measurement becomes possible after the generation. As described above, the examiner can perform measurement in an arbitrary measurement mode by himself / herself determining the state or the like of the subject.

After the first measurement is performed in the automatic mode or the measurement mode selected by the examiner,
Each time the state becomes measurable, the measurement is repeated a predetermined number of times. Then, an average value of a plurality of measurement values obtained by the plurality of measurements is calculated, and the average value is a final measurement value.
This final measured value is displayed on the monitor 61 (step S16). FIG. 6 shows an example of a screen output on the monitor. As shown in FIG.
In 1, character information superimposed by a character superimposition circuit (not shown) on the eye E to be inspected captured by the CCD camera 32 is displayed.

In FIG. 6, as an example, the character 61a of "RIGHT" indicating that the measured eye E is the right eye E and the measured spherical refractive power are displayed on the monitor 61, as in the prior art. Character 6 of "S +3.50" (unit: diopter)
1b, a character 61c of "C-0.50" (unit: diopter) indicating the measured cylindrical surface refractive power, and a character 61d of "A 160" (unit: degree) indicating the measured astigmatic axis degree are displayed. . In particular, unlike the related art, the monitor 61 displays an "automatic mode" character 61e indicating that the measurement was performed in the automatic mode. As described above, the mode used for the measurement is displayed on the monitor 61. In addition, for example, when the fog stop mode is manually selected and measurement is performed, characters such as “fog stop mode” are displayed. The display of the mode content is preferably performed immediately after the determination of the mode selected in step S5 is performed. In this case, the mode can be notified to the examiner before the measurement is completed. .

In FIG. 5, after the above measurement is performed on both the left and right eyes E, the final two measured values are printed by the printer 62 (step S).
17). FIG. 7 shows an example of a print sheet printed by a printer. As shown in FIG. 7, the print sheet 62a
After the measurement date and time 62b, a measurement value 62c for the right eye E and a measurement value 62d for the left eye E are printed after the measurement date 62b. In particular, printing sheet 6
2a, a character 62e of "automatic mode" indicating that the measurement was performed in the automatic mode is displayed.

Such a monitor 61 and a printer 62
The specific display format and print format in can be arbitrarily determined. For example, in addition to characters, figures and symbols representing the contents of the measurement mode can be displayed and printed. That is, it is sufficient that at least the contents of the mode in which the measurement is performed can be recognized by the examiner. Further, any output form other than the display by the monitor 61 and the printing by the printer 62 can be adopted, and for example, the output by voice may be performed. By performing such output, the measured mode can be easily grasped by the examiner, so that it is possible to refer to the reliability of the measurement or to refer to the behavior of the eye E to be examined, or If the measurement is about to be performed in a mode not intended by the examiner, the mode can be switched to a desired mode. After the printing is completed, the measurement operation is completed (Step S18).

(Embodiment 2) Next, Embodiment 2 of the objective measurement apparatus of the present invention will be described in detail with reference to the drawings. However, the configuration, processing, and the like, which are not particularly described, are the same as those in the above-described first embodiment, and the same configuration and processing are denoted by the same reference numerals as in the first embodiment. FIG. 8 is a flowchart of the measurement operation by the objective measurement device according to the present embodiment. The present embodiment generally relates to an objective measurement apparatus in which a measurement mode is simplified.

As shown in the flowchart of FIG.
In the present embodiment, the step of determination by the fixation possibility determining unit (S6 of FIG. 5), the step of measurement in the fog stop mode (S7 of FIG. 5), and the step of measurement in the fog extension mode (FIG. 5) S13) is omitted.

Then, the measurement mode selected by the examiner is determined (step S5). If the selected mode is the automatic mode, first, the fixation is determined (step S8). . If it is determined that the fixation is not good, the measurement is performed in the measurement priority mode.
According to such a processing flow, measurement is performed in the measurement priority mode even when there is no possibility of fixation. In this case, although the generation of the fog state is started, regardless of the completion of the generation of the fog state, the measurement is performed at the time when the state becomes the measurable state.
The measurement can be performed without imposing a large burden on the subject. In this case, the time required for determining the fixability can be omitted.

In step S8, it is determined that the fixation is good, and the generation of the fog state is started (step S10). After the generation is completed (step S11),
In the fogging effect determination section 87, it is monitored whether or not the entire time during which the subject's eye E is located in the fixable area has reached the effect determination reference time (step S20). Then, the cloudy state is maintained until the entire time reaches the effect determination reference time, and when the effect determination reference time has been reached, measurement is performed in the normal measurement mode (step S21). In this processing flow, when the entire fixation time has not reached the effect determination reference time, the measurement is performed after waiting until the entire time has elapsed, so that the measurement is substantially the same as the measurement in the fog extension mode. Is performed.

As described above, it is also possible to omit some of the plurality of measurement modes shown in the first embodiment. In this case, a mode that can be manually selected can also be partially omitted. Alternatively, the plurality of measurement modes selected in the automatic mode and the plurality of measurement modes that can be manually selected may be different from each other.
When the processing flow is changed in this way, the configuration of the mode changeover switch 52 and the configuration of the control unit 8 are also appropriately changed in accordance with the processing flow.

Although the first and second embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, but may be variously modified within the scope of the technical idea. It may be implemented. For example, as the control content of the control unit according to the monitoring result of the fixation monitoring unit, different content besides the measurement in each mode described above can be adopted. For example, in each measurement mode other than the fog stop mode among the above measurement modes, the fixation target is moved in a direction away from the subject's eye in order to generate a fog state. When a defect such as the eye being separated from the fixation target is monitored, it is possible to perform control such that the fixation target that has once been moved away is returned to the vicinity of the subject's eye.

[0062]

As described above, according to the objective measuring apparatus of the first aspect, the measurement can be performed at an optimal timing according to the state of the subject (eye to be examined). An optimal fog effect can be obtained. Therefore,
The measurement time can be minimized so that the subject is not unnecessarily distressed, and the measurement is performed in an optimal state, so that the reliability of the measurement value can be improved.

According to the objective measuring apparatus of the second aspect, when the subject's eye simply moves around without performing fixation at all, the subject's eye hardly performs fixation although there is a possibility of fixation. When the subject moves around, the subject's eyes fixate, but the accommodation power is not sufficiently released, and the accommodation power is sufficiently released. It can be performed.

According to the objective measurement device of the third aspect, in addition to the normal measurement mode, a mode in which the fog state is not generated, a mode in which the fog state is generated but the measurement is prioritized, and the adjusting power is not sufficient. The measurement is performed in one of the modes that maintain the cloudy fog state until it is released, etc., and the measurement is performed at the optimal timing according to the state of the eye to be examined, and when possible, with the accommodation power fully released. It can be carried out.

According to the objective measurement apparatus of the fourth aspect, the most effective measurement can be performed by optimally combining the monitoring content of the fixation monitoring unit and the control content of the control unit. . For example, when there is no possibility of fixation, the measurement time can be shortened by performing measurement without generating a cloudy fog state, and the subject does not needlessly suffer. Alternatively, when fixation is not good, by giving priority to measurement, measurement can be performed without missing a measurement chance. Further, when the release of the adjusting force is insufficient, the measurement is performed after the releasing of the adjusting force, thereby improving the reliability of the measurement. Further, when the adjusting force is sufficiently released, the measurement can be performed at the same timing as in the related art.

According to the objective measuring apparatus of the fifth aspect, the examiner can select an arbitrary mode via the mode switching means. Therefore, for example, when the state of the subject (eye to be inspected) is known in advance, the measurement mode corresponding to this state is selected, thereby eliminating the time required for automatically selecting the measurement mode and the selection error. can do.

According to the objective measurement apparatus of the sixth aspect, the mode is output to the output means, so that the examiner can easily grasp the measurement mode and can refer to the reliability of the measurement. This can be used as a reference for grasping the behavior of the eye E. Alternatively, it is possible to switch to a desired mode, for example, when the measurement is about to be performed in a mode not intended by the examiner.

According to the objective measurement method of the present invention, the measurement operation and the fogging effect can be optimized by performing the same measurement operation as that of the objective measurement apparatus described above.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an objective measurement device according to Embodiment 1 of the present invention when viewed from a side.

FIG. 2 is a view taken along the line AA of FIG. 1;

FIG. 3 is a diagram showing a mode change switch.

FIG. 4 is a block diagram illustrating an electrical configuration of a control unit of the objective measurement device.

FIG. 5 is a flowchart of a measurement operation performed by the objective measurement device.

FIG. 6 shows an example of a screen output on a monitor.

FIG. 7 shows an example of a print sheet printed by a printer.

FIG. 8 is a flowchart of a measurement operation performed by the objective measurement device according to the second embodiment of the present invention.

[Explanation of symbols]

 E Eye to be inspected 1 Measurement optical system 11 Infrared light source 12 to 14 Lens 15 Chopper 16 Half mirror 17 Aperture 18 Light receiver 18a to 18d Photoelectric conversion element 18e Quadrant light receiving element 19 Measurement optical axis 2 Fixation target projection optical system 21 Visible light source Reference Signs List 22 fixation target 23 total reflection mirror 24 lens 25 dichroic mirror 3 imaging optical system 31 half mirror 32 CCD camera 4 fixation target moving unit 41 motor 5 input unit 51 measurement switch 52 mode changeover switch 6 output unit 61 monitor 62 printer 7 Storage unit 8 Control unit 81 Measured value calculation unit 82 Eye position to be calculated calculation unit 83 Fixation monitoring unit 84 Measurement mode selection unit 85 Fixation possibility determination unit 86 Fixation goodness determination unit 87 Cloud fog effect determination unit 9 Casing

Claims (7)

[Claims] 1. A measuring means for objectively measuring a refractive power of an eye to be examined, a fixation target projecting means for projecting a fixation target to the eye to be examined, and a fixation target of the fixation target projecting means. It moves from a position near the far point of the subject's eye to an arbitrary position from the far point of the subject's eye to a position farther from the far point of the subject's eye. The generated fixation target moving means, the fixation monitoring means for monitoring the fixation state of the subject's eye, and the measuring means and / or the fixation target moving means are controlled in accordance with the monitoring result by the fixation monitoring means. An objective measurement device, comprising: control means. 2. The fixation monitoring means determines whether or not the position of the eye to be examined is within a predetermined fixable area in a plane orthogonal to the measurement optical axis.
A fixation possibility determining unit that determines whether fixation of the subject's eye is possible, and measures a time during which the subject's eye stays in the fixable region when the subject's eye is located in the fixable region. Then, by comparing this time with a predetermined reference quality determination reference time, a fixation quality determination unit that determines whether fixation is performed well, and the subject's eye is located within the fixation possible area. A cloud fog effect determination unit that determines whether or not the adjustment of the subject's eye has been sufficiently released by measuring the total time during which the subject's eye has been adjusted, and comparing this time with a predetermined effect determination reference time. The objective measurement device according to claim 1, wherein: 3. The fogging stop mode in which the refractive power is measured without generating the fog state, the fogging state is started, and the refracting power is generated during and / or after the fogging state is generated. The measurement priority mode in which the measurement is performed when the measurement of the eye becomes possible, after the completion of the generation of the cloudy state, the time when the entire time during which the subject's eye is located within the fixable area reaches the above-described effect determination reference time The measurement means and / or the fixation target moving so that the measurement is performed in at least one of the fog extension mode for measuring the refractive power and the normal measurement mode for measuring the refractive power immediately after the generation of the fog state is completed. 3. The objective measurement device according to claim 1, wherein the objective control device controls the means. 4. The control means, when the fixation possibility determining unit determines that fixation of the eye to be examined is not possible, performs measurement in the cloud fog stop mode, When it is determined that the fixation of the subject's eye is possible in the determination unit, the determination is further performed by the fixation quality determination unit, and that fixation is not properly performed by the fixation quality determination unit. When it is determined, the measurement is performed in the measurement priority mode, and when it is determined that the fixation is good, the fixation quality determination unit further performs the determination by the cloud fogging effect determination unit. When the fogging effect determination unit determines that the adjustment of the eye to be inspected is not sufficiently released, the measurement is performed in the fog extension mode, and the adjustment of the eye to be inspected is performed by the fogging effect determination unit. If it is determined that it has been released sufficiently, the normal measurement mode The objective measurement apparatus according to claim 3, wherein the measurement unit and / or the fixation target moving unit is controlled so as to perform the measurement by using a target. 5. A mode switching means for arbitrarily selecting any one of the fog stop mode, the measurement priority mode, the fog extension mode, and / or the normal measurement mode. The objective measurement device according to claim 3, wherein the objective measurement device is provided. 6. An output means for presenting a mode used for measurement to the examiner among the fog stop mode, the measurement priority mode, the fog extension mode, and / or the normal measurement mode. The objective measurement device according to any one of 3 to 5, wherein 7. An objective measurement method for objectively measuring a refractive power of an eye to be inspected, comprising: a projection step of projecting a fixation target onto the eye to be inspected; and a position of the eye to be inspected after the projection step. However, by determining whether or not within a predetermined fixable region in a plane orthogonal to the measurement optical axis, fixation possibility determination procedure to determine whether fixation of the subject's eye is possible, If it is determined in the fixation possibility determining procedure that fixation of the eye to be examined is not possible, a procedure of measuring refractive power without generating a cloudy state for the eye to be examined, and the fixation possibility determination If it is determined in the procedure that fixation of the subject's eye is possible, when the subject's eye is located in the fixable region, the time during which the subject's eye remains in the fixable region is measured. By comparing this time with a predetermined pass / fail judgment reference time, fixation can be improved. If the determining whether or not the fixation quality determination procedure has cracks, the fixation in the fixation quality determination procedure is determined not satisfactorily performed, start the generation of fogging condition,
During the generation of the cloudy fog state and / or after the completion of the generation, when the measurement of the refractive power becomes possible, it is determined that the fixation is performed favorably in the procedure for performing the measurement and the fixation quality determination procedure. In this case, whether the adjustment of the subject's eye has been sufficiently released by measuring the total time during which the subject's eye is located within the fixable area and comparing this time with a predetermined effect determination reference time In the fogging effect determination procedure for determining whether or not the eye fogging effect is determined, if it is determined that the adjustment of the subject's eye has not been sufficiently released, after the generation of the fogging state is completed, the subject's eye can fixate. When the refractive power is measured at the time when the total time within the area reaches the effect determination reference time, and when it is determined that the adjustment of the subject's eye is sufficiently released in the cloud fogging effect determination procedure In the generation of fog state Objective measuring method characterized by comprising: a procedure for measuring the refractive power After the completion, the.