JP2023036436A - Target presentation apparatus and target presentation program - Google Patents

Abstract

To provide a target presentation apparatus and a target presentation program, capable of mitigating a load on a subject at the time of inspection.SOLUTION: A target presentation apparatus for presenting a target to a subject's eye comprises: display control means for making an inspection target be displayed on display means; and target creation means that on the basis of a changeover signal for changing over the inspection target from a first inspection target to a second inspection target differing from the first inspection target, starts creation of the second inspection target. The display control means continues display of the first inspection target for a predetermined time even after acquiring the changeover signal and makes the second inspection target be displayed at any timing after completion of the creation of the second inspection target based on the changeover signal.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to a target presenting device and a target presenting program for presenting a target to an eye to be examined.

A target presenting device for presenting a target to an eye to be examined is known. For example, in Patent Literature 1, test targets displayed on a display are switched by a target switching signal.

JP 2010-233964 A

In the above-described optotype presenting apparatus, when switching the test optotype, the display of the test optotype is erased for a certain period of time, and the next test optotype is displayed. By the way, in recent years, it has become possible to adopt a high-resolution display for the device, but since the high-resolution display expresses the test optotype in more detail, it may take time to generate the test optotype. In this case, the time required to switch to the next test target after erasing the current test target becomes long, which may cause anxiety and annoyance to the examinee.

In view of the conventional technology described above, the technical problem of the present disclosure is to provide an optotype presenting device and an optotype presenting program capable of reducing the burden on a subject during examination.

In order to solve the above problems, the present disclosure is characterized by having the following configurations.

(1) A optotype presenting device according to a first aspect of the present disclosure is a optotype presenting device for presenting a optotype to an eye to be examined, comprising display control means for causing a display means to display a test optotype; an optotype generating means for starting to generate the second test optotype based on a switching signal for switching the test optotype from the first test optotype to a second test optotype different from the first test optotype; and the display control means continues the display of the first test target for a predetermined time even after the switching signal is acquired, and the generation of the second test target based on the switching signal is completed. It is characterized in that the second test target is displayed at some later timing.
(2) A target presenting program according to a second aspect of the present disclosure is a target presenting program used in a target presenting device for presenting a target to an eye to be examined, and a processor of the target presenting device a display control step for displaying a test target on a display means when executed; and a switching signal for switching the test target from the first test target to a second test target different from the first test target. and causing the optotype presenting device to execute the optotype generating step of starting to generate the second test optotype based on the above, and the display control step is performed even after the switching signal is acquired, even after the first test The display of the optotype is continued for a predetermined time, and the second test optotype is displayed at any timing after the generation of the second test optotype based on the switching signal is completed. do.

1 is an external view of a optotype presenting device; FIG. 3 is a schematic diagram of a control system of the optotype presenting device; FIG. It is an example of an inspection screen. FIG. 10 is a diagram schematically showing the timing of acquisition of a target switching signal for switching the target and switching of the target on the LCD. FIG. 10 is a diagram schematically showing a case where the first test target is erased after the generation of the second test target is completed; FIG. 10 is a diagram schematically showing a case where only a background image is displayed and no disappearing time is provided;

<Overview>
An embodiment of a optotype presenting device according to the present disclosure will be described. The items classified in <> below can be used independently or in conjunction with each other.

The optotype presenting apparatus of this embodiment is an apparatus for presenting an optotype to an eye to be examined. The optotype presenting device may be capable of displaying test optotypes for use in examining an eye to be examined. Further, the optotype presenting device may be capable of displaying a background image used as the background of the test optotype.

The optotype presenting device may be capable of displaying various types of test optotypes. For example, the test target may be an eye test target. Examples include directional optotypes (Landolt circle optotypes, tumbling E optotypes, etc.) for allowing subjects to identify directions, and character optotypes (hiragana optotypes) for allowing subjects to read characters. , katakana optotypes, alphabetical optotypes, etc.), numeric optotypes for allowing the subject to identify numbers, and the like. These visual acuity test optotypes include a one-letter optotype composed of one visual acuity test optotype, a horizontal single-row optotype composed of a plurality of visual acuity test optotypes, a vertical single-rowed optotype, and a blockage It may be a visual target, or the like. Further, for example, the test target may be a test target different from the visual acuity test target. As an example, a red/green optotype, a radiographic optotype, a binocular visual function test optotype, or the like may be used.

The optotype presenting device may be capable of displaying various background images. For example, the background image may be an image with a white background. Of course, an image other than a white background may be used. Also, for example, the background image may be displayed on the entire display area of the display means. Of course, it may be displayed in a part of the display area (for example, a predetermined number of pixels inside from the edge of the display area, etc.).

<Display control means>
The optotype presenting apparatus of the present embodiment includes display control means (for example, control section 20). The display control means causes the display means (for example, the LCD 3) to display the test target. Further, the display control means causes the display means to display the background image. The display control means may display both the test optotype and the background image (that is, superimpose the test optotype on the background image), or display only the background optotype. In addition, the display control means switches and displays the first test target displayed on the display means at the present time and the second test target displayed on the display means next to the first test target. may

The display control means may continue to display the first test target for a predetermined period of time even after obtaining the test target switching signal. In this case, the first test target may be erased from the display means during the generation of the second test target. Also, in this case, the first test target may be erased from the display means at the same time (substantially at the same time) as the generation of the second test target is completed. Also, in this case, the first test target may be erased from the display means after the generation of the second test target is completed.

The display control means may display the second test target at any timing after the generation of the second test target based on the switching signal of the test target is completed. In this case, the second test target may be displayed on the display means at the same time (substantially at the same time) or immediately after the completion of the generation of the second test target. Also, in this case, the second test target may be displayed on the display means after a certain period of time has passed since the generation of the second test target is completed.

The longer the time from erasing the first test target to displaying the second test target, the more likely the subject will feel anxiety, confusion, annoyance, etc. during the test. By continuing to display the first test optotype even after obtaining the switching signal of the test optotype, and displaying the second test optotype after the generation of the second test optotype is completed, such a subject can can reduce the burden of

The display control means may continue the display of the first test target by setting the generation time required for the generation of the second test target by the target generation means to be a predetermined time. In other words, the display control means may continue the display of the first test target until the generation time of the second test target elapses (that is, until the generation of the second test target is completed). . Therefore, there is no lapse of time from when the display of the first test target is erased to when the display of the second test target is started, and the possible burden on the subject can be reduced. Even if it takes time to generate the second test target, the burden on the subject can be reduced by controlling the display of the test target in this way.

The display control means may display the background image after the generation of the second test target based on the test target switching signal is completed, and display the second test target after the background image. For example, after the first test target has been displayed for a predetermined period of time and the generation of the second test target is completed, the background image may be displayed, and then the second test target may be displayed. . That is, the background image may be displayed between the display of the first test target and the display of the second test target. This allows the subject to easily recognize the switching of the test target.

The display control means causes the background image to be displayed during the generation of the second test target based on the switching signal of the test target, and after the display of the first test target has passed a predetermined time. The second test target may be displayed later. In this case, the background image may be displayed on the display means at the same time (substantially at the same time) or immediately after the elapse of the predetermined time in the first test target. Also, in this case, the background image may be displayed on the display means after a certain period of time has passed since the end of the predetermined period of time for the first test target. In this case, the second test target may be displayed on the display means at the same time (substantially at the same time) or immediately after the completion of the generation of the second test target. Also, in this case, the second test target may be displayed on the display means after a certain period of time has passed since the generation of the second test target is completed. That is, the completion of the display of the background image and the completion of the generation of the second test target may be different timings, or may be coincident (substantially coincident) timings.

As a result, it is possible to reduce the burden on the subject due to prolonged generation of the test optotypes and to easily recognize the switching of the test optotypes. In addition, the display of the background image and the generation of the second test target overlap at least partially in terms of time, so that the test can proceed efficiently.

The display control means may match the timing for ending the display of the background image with the timing for completing the generation of the second test target, and display the second test target after the background image. In this case, the display control means may predict the completion timing of the generation of the second test target. For example, the completion timing may be predicted based on test target information including at least one of the type, visual acuity value, and the like in the test target. For example, based on correspondence information (for example, a correspondence table, an arithmetic expression, etc.) in which the test optotype information and the generation time required for generating the second test optotype are associated based on experiments and simulations, The completion timing of the generation of the second test target may be acquired. Of course, the test optotype information and information different from the test optotype information may be used to predict and acquire the completion timing.

Further, in this case, the display control means sets the erasing timing of erasing the first test target (in other words, the start timing of starting the display of the background image) based on the completion timing of the generation of the second test optotype. You may For example, the predetermined time for the first test target may be the time from when the display of the first test target is started to when it is set as the erasing timing. When the display of the first test target continues for a predetermined time, the first test target is erased and the generation of the second test target is completed, and then the background image and the second test target are displayed in order. may be

For example, by predicting the completion timing of the generation of the second test optotype and setting the erasing timing for erasing the first test optotype, the erasing of the first test optotype and the generation of the second test optotype are completed. Even if it is executed before, the generation of the second test target is completed at the same time that the background image has been displayed for a predetermined period of time. This allows the subject to easily recognize the switching of the test optotype using the background image. In addition, since the first test target can be switched immediately after the generation of the second test target is completed, the time required for presenting the test target can be shortened throughout the entire examination.

In the present embodiment, the time for displaying the background image provided between the display of the first test target and the display of the second test target is determined by the subject's first and second test targets. Any length may be used as long as the target can be recognized as being switched (a length that allows the subject to recognize that the test target has indeed disappeared). Normally, the human eye continuously perceives a change of 1/30 second, so a longer time of 0.05 second or more is preferable. On the other hand, if the time for which the background image is displayed is too long, it may give the impression that the time required for switching from the first test target to the second test target is troublesome. For this reason, the background image should be set at a time that takes into consideration ease of recognition by the subject and possible annoyance to the subject. By appropriately displaying the background image, the inspection proceeds smoothly and a certain level of inspection accuracy can be maintained.

<Visual Target Generating Means>
The optotype presenting apparatus of this embodiment includes optotype generating means (for example, the control unit 20). The optotype generating means starts generating the second test optotype based on the switching signal for switching the test optotype from the first test optotype to the second test optotype. For example, the switching signal may be output by the examiner's operation of the operating means (for example, the controller 4). As an example, the switching signal may be output by specifying the visual acuity value of the test optotype. Also, for example, the switching signal may be output according to a program for automatically proceeding with the examination of the subject's eye. In this case, the switching signal may be output by the subject operating the operating means for the subject. Further, in this case, the switching signal may be output after a predetermined period of time has elapsed since the test target was displayed.

The target generating means may generate the second test target based on image processing of the reference image for the test target. For example, such image processing may be performed using at least test target information. Furthermore, in addition to the test target information, pixel information constituting the display means (for example, the number of pixels, pixel density, etc.), display information of the test target on the display means (for example, display position, display color, rotation angle, parameters for conversion processing and correction processing for the test target, etc.). In this case, the optotype generating means may generate the second test optotype by obtaining a magnification for enlarging or reducing the reference image from the test optotype information, the pixel information, the display information, and the like.

Furthermore, the subjective optometry apparatus may include a corrective optical system that changes the optical characteristics of the target light flux from the target presenting device, and is arranged in the optical path of the projection optical system. In this case, the corrective optical system may change the optical characteristics of the target light beam by controlling an optical element arranged between the target presenting device and the optical member of the projection optical system. . That is, the corrective optical system may be a phantom lens refractometer (phantom corrective optical system). Further, the correction optical system may change the optical characteristics of the target light flux by controlling an optical element arranged in front of the subject's eye. That is, the corrective optical system may be an optometry unit (phoropter). For example, the optometry unit has a lens disk in which a plurality of optical elements are arranged on the same circumference, and a drive means (for example, a motor) for rotating the lens disk, and the optical elements are driven by the drive means. It may be configured to be electrically switched.

Note that the present disclosure is not limited to the apparatus described in this embodiment. For example, terminal control software (program) that performs the functions of the following embodiments is supplied to a system or device via a network or various storage media, and a control device (eg, CPU, etc.) of the system or device reads the program. It is also possible to execute

<Example>
An example of the optotype presenting apparatus according to this embodiment will be described.

<Device configuration>
FIG. 1 is an external view of the optotype presenting device 1. As shown in FIG. A liquid crystal display (LCD) 3 for presenting a target is arranged on the front (front) of a housing 2 in the target presenting device 1 . A receiving unit 5 for receiving an operation signal transmitted from the controller 4 is arranged below the front surface of the housing 2 . By operating the controller 4, the target to be displayed on the LCD 3 can be switched. The controller 4 includes a plurality of switch units 40 for operating the main body of the apparatus, a liquid crystal display (LCD) 41 for displaying the operation status of each switch, and a transmission unit 49 for transmitting operation signals based on the operation of each switch. and have Note that the LCD 41 may be a touch panel that also functions as the switch section 40 . Further, the housing 2 and the controller 4 may exist apart from each other, and various operation signals may be transmitted by remote control.

In this embodiment, the optotype A displayed on the LCD 3 consists of a background image a1 and an inspection optotype a2. For example, the background image a1 is an image with a white background and is displayed on the entire LCD3. For example, the test optotype a2 is a Landolt's ring optotype, and is displayed in the center of the LCD 3 in a size corresponding to the visual acuity value. The test optotype a2 is a single-character optotype composed of one Landolt ring optotype. , etc. Moreover, the inspection target a2 does not necessarily have to be placed in the center, and it may be possible to change it as appropriate.

FIG. 2 is a schematic diagram of the control system of the optotype presenting apparatus 1. As shown in FIG. A controller 20 is housed inside the housing 2 . For example, the control unit 20 includes a CPU (processor), RAM, ROM, and the like. The CPU controls driving of each part in the optotype presenting device 1 . Various types of information are temporarily stored in the RAM. The ROM stores various programs executed by the CPU, a decoder circuit for decoding the operation signal from the controller 4, an arithmetic expression for calculating the display size of the test target, and the like. Note that the control unit 20 may be configured by a plurality of control units (that is, a plurality of processors).

LCD 3 , receiver 5 , nonvolatile memory 21 (hereinafter referred to as memory 21 ), etc. are connected to controller 20 . The receiver 5 provided in the housing 2 and the transmitter 49 provided in the controller 4 are connected by wired communication or wireless communication. The memory 21 is a non-transitory storage medium that can retain stored content even when power supply is interrupted. For example, the memory 21 stores reference images (vector images) of test targets and the like. For example, the memory 21 may be a hard disk drive, flash ROM, USB memory, SD card, or the like.

<Control operation>
The control operation of the optotype presenting apparatus 1 will be described by taking a visual acuity test for an eye to be examined as an example.

The examiner operates the switch section 40 of the controller 4 to call up an examination screen for designating an examination optotype to be displayed on the LCD 3 . The control unit 20 causes the LCD 41 to display an inspection screen in response to an operation signal from the switch unit 40 .

FIG. 3 is an example of the inspection screen 9. As shown in FIG. The examiner operates the LCD 41 to select the test target to be presented to the eye (in other words, the type and visual acuity value of the test target a2) from the target designation button 91 for designating the test target to be displayed on the LCD 3. Specify For example, the examiner designates the Landolt ring optotype with a visual acuity value of 1.0 as the test optotype a2.

Based on the operation signal from the LCD 41, the control unit 20 causes the LCD 3 to display the background image a1 and the test target a2. For example, the control unit 20 executes a calculation using the designated visual acuity value, the resolution of the LCD 3, the size of the reference image of the Landolt's ring visual target stored in the memory 21, and the like, so that the test visual target a2 on the LCD 3 Get the display size of the . Further, the control unit 20 enlarges or reduces the reference image of the Landolt ring optotype according to the display size of the test optotype a2. As a result, the background image a1 and the Landolt ring optotype (test target a2) corresponding to the visual acuity value of 1.0 are displayed on the LCD 3. FIG. The LCD 41 may display the same Landolt ring optotype as that designated by the examiner and its visual acuity value.

The examiner asks the examinee about the orientation of the break in the Landolt ring optotype displayed on the LCD 3, and switches at least either the orientation of the cut in the Landolt ring optotype or the visual acuity value according to the examinee's answer.

For example, the examiner may select the direction switching button 92 regardless of whether the answer is correct or not, and switch only the direction of the break without switching the visual acuity value of the Landolt's ring optotype. At this time, the control unit 20 can switch the orientation of the break by rotating the Landolt ring and displaying it on the LCD 3 .

Further, for example, when the answer is correct, the examiner may select the optotype designation button 91 to switch the visual acuity value of the Landolt's ring optotype to a visual acuity value one step higher. That is, the visual acuity value increments of the Landolt's ring optotype may be increased to switch to a larger value than the current value. Further, for example, if the examiner answers incorrectly, the examiner may select the optotype designation button 91 to switch the visual acuity value of the Landolt's ring optotype to one level lower visual acuity value. In other words, the increments of the visual acuity value of the Landolt ring optotype may be reduced and switched to a smaller value than the current value. At this time, since the visual acuity value specified by the examiner changes, the control unit 20 executes the above-described calculation again, and displays the background image a1 and the Landolt ring optotype (test target a2) corresponding to the specified visual acuity value on the LCD 3. You can switch the visual acuity value by displaying .

In the optotype presenting apparatus 1 , the controller 20 thus acquires the operation signal (the optotype switching signal) from the LCD 41 to generate the next test optotype a 2 and display it on the LCD 3 . Here, the LCD 3 is limited in the test target a2 that can be represented according to the number of pixels that constitute the LCD 3 . For example, the larger the number of pixels of the LCD 3, the higher the resolution, and the finer and smoother the inspection target a2 can be expressed. However, when the test target a2 is represented by a large number of pixels (that is, the larger the number of pixels used as the test target a2 in the LCD 3), the time required to generate the next test target a2 may become longer. . In particular, complicated test targets a2, such as a vertical single-row target, a horizontal single-line target, a clogging target, and the like, which are composed of a plurality of Landolt's ring targets, tend to take a long time to generate.

Therefore, even if the display of the current test target a2 is turned off based on the optotype switching signal from the LCD 41, if the next test target a2 cannot be generated yet, the next test target a2 is generated. is completed, only the background image a1 is displayed on the LCD 3. Although there are individual differences for each subject, if the display of only the background image a1 exceeds a certain period of time, the subject may feel uneasy and annoyed. In other words, the more time it takes to generate the next test target a2, the more the subject may be burdened.

In this embodiment, the load on the subject can be reduced by controlling the timing of switching between the current test target a2 and the next test target a2. Hereinafter, the current test target a2 will be referred to as a first test target a21, and the next test target a2 will be referred to as a second test target a22, and will be described in detail.

FIG. 4 is a diagram schematically showing the timing of acquisition of a target switching signal for switching the target (inspection target) and switching of the target on the LCD 3 . The widths of the background image a1, the first test target a21, and the second test target a22 represent the length of time displayed on the LCD3. The respective arrows indicate timing T1 at which the control unit 20 acquires the target switching signal, timing T2 at which the display of the first test target a21 is erased, timing T3 at which generation of the second test target a22 is completed, and a timing T4 for starting the display of the second test target a22.

Both the background image a1 and the first test target a21 are displayed on the LCD3. Even if the control unit 20 acquires the optotype switching signal at a certain timing T1 during the examination, the control unit 20 continues to display the first examination optotype a21. In addition, the control unit 20 starts generating the second test target a22 with the acquisition of the target switching signal as a trigger. For example, a predetermined generation time G is required until the generation of the second test target a22 is completed.

While generating the second test target a22, the control unit 20 predicts the timing T3 at which the generation of the second test target a22 is completed. For example, the control unit 20 may predict the timing T3 using a correspondence table that associates the type of test target and the visual acuity value with the generation time G corresponding thereto. Such a correspondence table may be created in advance based on the results of experiments and simulations and stored in the memory 21 .

Subsequently, the control unit 20 causes the LCD 3 to display only the background image a1 during the disappearance time D for allowing the subject to recognize the switching from the first test target a21 to the second test target a22. Considering the disappearance time D (for example, 0.2 seconds), the timing T2 for erasing the first test target a21 is set. For example, the timing T2 is the time that is the disappearance time D before the timing T3.

When the subject's visual acuity is not sufficiently high with respect to the first test target a21 and the second test target a22 (in other words, when the readability of each test target is close to the limit), the subject is unable to test the test target. It is difficult to recognize the change of target. For example, if the examinee cannot clearly recognize the switching of the test optotypes, he/she may be confused by the responses of the cuts of the Landolt ring optotypes, and the examination may not proceed smoothly. In addition, for example, depending on the examinee, when the direction of the break in the Landolt ring optotype is changed, a white break suddenly appears between the black line widths, making it possible to predict the direction of the break, leading to a decrease in inspection accuracy. Sometimes. Therefore, in this embodiment, only the background image a1 is displayed on the LCD 3 in switching the test target. By providing the disappearance time D, even if the test target has a large visual acuity value (that is, the test target has a small size), the switching can be easily recognized.

Note that the disappearance time D is set to a length that allows the examinee to recognize the disappearance of the test optotype and does not make him/her feel confused or annoyed. For example, the decay time D may be 0.05-1.0 seconds, preferably 0.1-0.5 seconds.

The control unit 20 displays the background image a1 and the first test target a21 and generates the second test target a22 in parallel, and erases the first test target a21 when the set timing T2 is reached. to continue to display only the background image a1. The timing (timing T2) for erasing the display of the first test target a21 is set based on the timing (timing T3) for completing the generation of the second test target a22. The completion of generation of the second test target a22 coincides (substantially coincides) at timing T3. When the generation of the second test target a22 is completed, a completion signal indicating that the generation of the second test target a22 is completed is issued, and the second test target a22 is stored in the RAM. Note that the second test target a22 may be stored in another storage unit (for example, the memory 21 or the like).

When the control unit 20 acquires the completion signal indicating that the generation of the second test target a22 is completed, the control unit 20 causes the LCD 3 to display the second test target a22. For example, in this embodiment, the display of the second test target a22 is started immediately after the generation of the second test target a22 is completed. In this case, the timing T3 at which the generation of the second test target a22 is completed matches (substantially matches) the timing T4 at which the display of the second test target a22 is started.

The same can be applied to the case where the second test target a22 is switched to the third test target (not shown) and displayed on the LCD 3 based on the target switching signal from the LCD 41. FIG.

In the above description, it has been illustrated that the time tends to be long especially when generating horizontal single-row optotypes, vertical single-row optotypes, and clogging optotypes, etc., which are composed of a plurality of Landolt's ring optotypes. However, for example, it is also time-consuming to generate a horizontal single-row optotype, a vertical single-row optotype, and a character-stuffed optotype composed of a plurality of hiragana optotypes or a plurality of numeric optotypes. . This is because, depending on the combination of hiragana optotypes and numeric optotypes, it is necessary to perform operations for enlarging or reducing a plurality of reference images. Even in such a case, the load on the subject can be reduced by controlling the timing of switching between the current test target a2 and the next test target a2.

As described above, for example, the optotype presenting apparatus of the present embodiment continues to display the current first test optotype even after acquiring the switching signal for switching from the first test optotype to the second test optotype. After the generation of the next second test target based on the switching signal is completed, the second test target is displayed. Therefore, for example, the non-display time during which neither the first test target nor the second test target is displayed on the LCD is shortened, and the possibility of giving the subject anxiety, confusion, annoyance, etc. is reduced. be.

Further, for example, the optotype presenting apparatus of the present embodiment causes the background image to be displayed after the display of the first test optotype has passed a predetermined time while the second test optotype is being generated based on the switching signal. , to display the second test target after the background image. For example, this makes it possible to easily recognize the switching of the test target while reducing the load that may be imposed on the subject due to the prolonged generation of the test target. In addition, the generation of the second inspection target and the display of the background image overlap at least a part of time, so that the inspection can proceed efficiently.

Further, for example, the optotype presenting apparatus of the present embodiment causes the background image to be displayed after the display of the first test optotype has passed a predetermined time while the second test optotype is being generated based on the switching signal. , the timing of completing the generation of the second test target and the timing of ending the display of the background image are matched, and the second test target is displayed after the background image. As a result, the subject can easily recognize the switching of the test optotype using the background image, and the first test optotype can be used for the second test immediately after the completion of the generation of the second test optotype. You can switch to target. Therefore, there is no time during which the LCD is not displayed, and there is no need to separately provide time for displaying only the background image, so that the examination can proceed more efficiently.

<transformation example>
In this embodiment, the examiner operates the LCD 41 of the controller 4 to output a target switching signal for switching the test target. However, the present invention is not limited to this. In the present embodiment, the configuration may be such that the optotype switching signal is output based on the operation of the switch section 40 in the controller 4 . Of course, both the LCD 41 and the switch section 40 may be configured to output a visual target switching signal based on the operation thereof.

In this embodiment, the first test target a21 is erased during the generation of the second test target a22. , is described as an example, but the present invention is not limited to this. The first test target a21 may be deleted after the generation of the second test target a22 is completed. Also, the disappearance time D may not necessarily be provided.

FIGS. 5 and 6 are diagrams schematically showing changes in the timing of acquisition of the optotype switching signal and switching of the test optotype. FIG. 5 shows the case where the first test target a21 is erased after the second test target a22 has been generated. FIG. 6 shows the case where the disappearance time D for displaying only the background image a1 is not provided.

First, FIG. 5 will be described. When the control unit 20 acquires the optotype switching signal at a certain timing T1 during the examination, it continues to display the first test optotype a21 and starts generating the second test optotype a22. When the generation of the second test target a22 is completed after the generation time G has passed (timing T3), the display of the first test target a21 is erased (timing T2), and only the background image a1 is displayed on the LCD3. When the display of the background image a1 passes the disappearance time D, the display of the second test target a22 is started (timing T4). In such a configuration, timing T2 and timing T3 match (substantially match).

For example, in the optotype presenting apparatus of the present embodiment, the display of the first test optotype a21 is continued for the generation time G required for generating the second test optotype a22, and the optotype switching signal for switching the test optotype is The background image a1 is displayed after the generation of the second test target a22 is completed, and the second test target a22 is displayed after the disappearance time D of the display of the background image a1 has elapsed. As a result, even if it takes time to generate the test target, there is no time during which the LCD 3 is not displayed during the generation of the test target, and the possible load on the subject can be reduced. In addition, by displaying only the background image a1 for the optimum disappearance time D after the generation of the second test target a22 is completed, the subject can easily recognize the switching of the test target. In addition, the prediction of the timing T3 when the second test target a22 is completed and the setting of the timing T2 for erasing the display of the first test target a21 are not required. suppressed. Note that the configuration described above with reference to FIG. 3 is complicated in control, but can shorten the examination time particularly when there are many switching displays of examination optotypes for the eye to be examined.

Next, FIG. 6 will be described. When the control unit 20 acquires the optotype switching signal at a certain timing T1 during the examination, it continues to display the first test optotype a21 and starts generating the second test optotype a22. When the generation of the second test target a22 is completed after the generation time G has passed (timing T3), the display of the first test target a21 is erased (timing T2), and the display of the second test target a22 is started instantaneously. (timing T4). In such a configuration, timing T2, timing T3, and timing T4 match (substantially match).

For example, when both the first test target a21 and the second test target a22 are Landolt ring targets, it is difficult for the examinee to recognize the switching of the test target. However, for example, when either the first test target a21 or the second test target a22 is not the Landolt ring target (for example, red/green target, radiographic target, binocular function test target, etc.) ), and since the shape and size are significantly different before and after the switching of the test target, the subject can easily recognize the switching of the test target.

Therefore, in the case of a combination in which the subject can easily recognize the switching of the test target, the second test target a22 is immediately released without setting the disappearance time D (in other words, for a time shorter than the disappearance time D). d) may be displayed on the LCD 3. Of course, the disappearance time D may be set even for such a combination that is easy to recognize, and the second test target a22 may be immediately displayed on the LCD 3 even for a combination that is difficult to recognize. For example, whether or not to provide the disappearance time D may be arbitrarily selected by the examiner. Alternatively, it may be determined in advance for each test target.

In this embodiment, the memory 21 built in the optotype presenting apparatus 1 stores the reference image of the test optotype, the arithmetic expression for calculating the display size of the test optotype, and the like. However, it is not limited to this. For example, an external memory connectable to the optotype presentation device 1 (for example, an SD card detachable from the device, a cloud capable of communicating with the device, etc.) is used to read the reference image and the arithmetic expression. may In this case, the control unit 20 reads these data from the external memory, executes calculations based on the specified visual acuity value, the resolution of the LCD 3, the size of the reference image, etc., and generates the test target a2. good too. Further, the control unit 20 may develop the test target a2 in the RAM or the memory 21 and display it on the LCD3.

In this embodiment, the configuration for generating the test target to be presented to the subject's eye by enlarging or reducing the reference image of the test target has been described as an example, but the present invention is not limited to this. In this embodiment, the configuration may be such that the test target a2 is generated by performing conversion processing and correction processing on the test target. For example, the conversion processing may be adjustment of the contrast of the test target, black-and-white reversal of the background image a1 and the test target a2, and the like. For example, the correction processing may be processing that considers distortion and aberration that may occur when light passes through an optical element, especially in a configuration in which an optical element is arranged between the subject's eye and the LCD 3 . Data such as correspondence tables and arithmetic expressions necessary for conversion processing and correction processing may be read out from the built-in memory 21 or an external memory, and each processing may be executed. The generation of the test optotype in the control unit 20 takes longer due to the additional execution of the conversion process and the correction process, but even in such a case, the application of the present technology can reduce the burden on the subject.

In this embodiment, the optotype presenting apparatus 1 includes the housing 2 and the controller 4. However, the present invention is not limited to this. The optotype presenting apparatus 1 may be used as part of a subjective optometry apparatus. In other words, the optotype presenting apparatus 1 may be used as an optotype presenting unit in a subjective optometric apparatus. For example, the subjective optometric apparatus may include a corrective optical system for correcting the subject's eye, and may subjectively measure the optical characteristics of the subject's eye.

In the present embodiment, the configuration in which the optotype switching signal for switching the test optotype is generated based on the operation of the controller 4 by the examiner has been described as an example, but the present invention is not limited to this. For example, a visual acuity test program that automatically measures the visual acuity of the subject's eye, a self-optometry program that automatically measures the optical characteristics of the subject's eye (for example, spherical power, cylindrical power, astigmatism axis angle, etc.), etc. Alternatively, the target switching signal may be generated as appropriate. In this case, the control unit 20 generates the test target a2 based on each target switching signal, and causes the LCD 3 to display the test target a2 at the timing when the target switching signal is acquired (that is, the test target a2). By appropriately controlling the timing of switching to the visual target a2, the burden on the subject can be reduced.

1 optotype presentation device 2 housing 3 LCD
4 controller 9 inspection screen 20 control unit a1 background image a21 first inspection target a22 second inspection target

Claims (6)

A target presenting device for presenting a target to an eye to be examined,
a display control means for displaying an inspection target on a display means;
a target generating means for starting to generate the second test target based on a switching signal for switching the test target from the first test target to a second test target different from the first test target; ,
with
The display control means continues the display of the first test target for a predetermined period of time even after the switching signal is obtained, and the display control means continues to display the first test target for a predetermined period of time after the switching signal is acquired, and any time after the generation of the second test target based on the switching signal is completed. A target presenting device characterized by displaying the second test target at this timing. In the optotype presentation device of claim 1,
wherein the display control means continues the display of the first test target with the generation time required for the generation of the second test target by the target generation means as the predetermined time. presentation device. In the optotype presentation device of claim 2,
The display control means displays a background image after the generation of the second test target based on the switching signal is completed, and displays the second test target after the background image. presentation device. In the optotype presentation device of claim 1,
The display control means causes the background image to be displayed after the predetermined time has elapsed during the generation of the second test target based on the switching signal, and displays the second test target after the background image. An optotype presentation device characterized by displaying the In the optotype presentation device of claim 4,
The display control means is characterized in that the timing of ending the display of the background image coincides with the timing of completion of generation of the second test target, and the second test target is displayed after the background image. optotype presentation device. A target presenting program for use in a target presenting device for presenting a target to an eye to be examined,
By being executed by the processor of the optotype presenting device,
a display control step of displaying the test optotype on the display means;
a target generating step of starting to generate the second test target based on a switching signal for switching the test target from the first test target to a second test target different from the first test target; ,
causes the optotype presentation device to execute
The display control step continues the display of the first test target for a predetermined time even after the switching signal is obtained, and any time after the generation of the second test target based on the switching signal is completed. A target presenting program characterized by displaying the second test target at the timing.

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