Optotype presentation device and optotype presentation program

Abstract

To provide a target presentation device and a target presentation program which can accurately perform an examination of a subject eye.SOLUTION: A target presentation device for presenting a target to a subject eye comprises: generation means which generates a first target group that is displayed on the same screen of target display means and obtained by randomly arranging a plurality of targets in at least any straight line direction of the row direction and the column direction; and display control means which causes target display means to display the first target group generated by the generation means. The generation means causes the adjacent targets to have different contents when randomly arranging the plurality of targets.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to an optotype presenting device and an optotype presenting program for presenting a test optotype to an eye to be examined. [Background technology]

[0002] There is known an optotype presenting device for presenting an optotype to an eye to be examined. For example, in Patent Document 1, an optotype displayed on a display is switched by an optotype switching signal. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2008-23129 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the optotype presenting device, the arrangement of the optotypes is pre-patterned so that the contents of the optotypes displayed on the display do not overlap. However, in recent years, as the tests have become more diverse, the inventors have considered displaying the contents of the optotypes in a free combination. In this case, the arrangement of the optotypes does not change even when the optotypes are switched, and it was thought that this could affect the test results.

[0005] In view of the above-described conventional techniques, the present disclosure has as its technical object to provide an optotype presenting device and an optotype presenting program capable of performing an examination of a subject's eye with high accuracy. [Means for solving the problem]

[0006] In order to solve the above problems, the present disclosure is characterized by having the following configuration.

[0007] (1) A visual target presenting device according to a first aspect of the present disclosure is a visual target presenting device for presenting visual targets to a subject's eye, the visual target presenting device comprising: a first visual target group displayed on a same screen of a visual target display means, the first visual target group including a plurality of visual targets, No. 1 The targets are randomly arranged in a linear direction, either in the row direction or the column direction. In this case, the adjacent first optotypes are made to have different contents. A generating means for generating a first group of optotypes by a signal acquiring means for acquiring a switching signal for switching the first optotype group of the optotype display means; A display control means for causing the optotype display means to display the first optotype group generated by the generation means, The generating means generates a second group of optotypes to be displayed on the same screen of the optotype display means based on the switching signal from the signal acquiring means, by randomly arranging a plurality of second optotypes in at least one of a row direction and a column direction, so that adjacent second optotypes have different contents, and the display control means switches the screen display of the optotype display means from the first group of optotypes to the second group of optotypes, and the generating means generates the second group of optotypes with different contents from the first optotypes when the row direction and column direction arrangement of the plurality of second optotypes constituting the second group of optotypes is the same as the row direction and column direction arrangement of the plurality of first optotypes constituting the first group of optotypes and the display position of the second optotype in the second group of optotypes overlaps with the display position of the first optotype in the first group of optotypes. It is characterized by: (2) A second aspect of the present disclosure provides an optotype presenting program for use in an optotype presenting device for presenting an optotype to an eye to be examined, the optotype presenting program being executed by a processor of the optotype presenting device to display a first optotype group on the same screen of an optotype display means, the first optotype group being arranged randomly in at least one of a row direction and a column direction. In this case, adjacent visual targets are made to have different contents. A generating step of generating a first optotype group by a signal acquiring step of acquiring a switching signal for switching the first optotype group of the optotype display means; a display control step of causing the optotype display means to display the first optotype group generated in the generating step, the optotype presenting device being caused to execute the display control step, A second group of optotypes is generated on the same screen of the optotype display means based on the switching signal from the signal acquisition step, and when a plurality of second optotypes are randomly arranged in at least one of a row direction and a column direction, adjacent second optotypes are made different in content, and the display control step switches the screen display of the optotype display means from the first group of optotypes to the second group of optotypes, and the generating step makes the second optotypes different in content from the first optotypes when the row direction and column direction arrangement of the plurality of second optotypes constituting the second group of optotypes is the same as the row direction and column direction arrangement of the plurality of first optotypes constituting the first group of optotypes and the display position of the second optotype in the second group of optotypes overlaps with the display position of the first optotype in the first group of optotypes. It is characterized by: [Brief description of the drawings]

[0008] [Figure 1] FIG. 2 is an external view of the optotype presenting device. [Diagram 2] FIG. 2 is a schematic diagram of a control system of the optotype presenting device. [Diagram 3] This is an example of an optotype displayed on an LCD. [Figure 4] 13 is an example of a setting screen. [Diagram 5] FIG. 13 is a diagram for explaining steps of the visual target. [Figure 6] 13 is an example of an examination screen. [Figure 7] This is an example of the current horizontal row target and the next horizontal row target. [Figure 8] This is an example of the transformation of visual targets. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] <Summary> An embodiment of an optotype presenting device according to the present disclosure will be described. The items classified in < > below can be used independently or in association with each other. In this embodiment, a test optotype used for testing a subject's eye is referred to as a "test optotype." The test optotype may be one optotype having a predetermined visual acuity value, or may include multiple optotypes having different visual acuity values.

[0010] The optotype presenting device of the present embodiment is a device for presenting optotypes to the subject's eye. For example, the optotype may be output as an optotype having a direction for the subject to distinguish directions (for example, Landolt ring optotype, tumbling E optotype, etc.), a character optotype for the subject to read characters (for example, hiragana optotype, katakana optotype, alphabet optotype, etc.), a number optotype for the subject to distinguish numbers, etc. In addition, for example, the optotype may be output as an optotype consisting of one optotype (for example, one-letter optotype, etc.), or a group of optotypes consisting of a plurality of optotypes (for example, a horizontal line optotype, a vertical line optotype, a character-crowded optotype, etc.).

[0011] <Format setting means> The optotype presenting device of this embodiment may include a format setting means (e.g., the control unit 20). The format setting means sets the display format of the visual acuity value of the test optotype used in testing the subject's eye based on an operation signal (first operation signal). This allows the examiner to check the visual acuity value of the optotype in a desired display format, improving the convenience of the optotype presenting device.

[0012] The display format of the visual acuity value of the test optotype is a display format expressed based on the visual angle of the optotype, the size of the optotype (size equivalent to the visual acuity value), the test distance, etc. The visual angle of the optotype can be replaced with the size of the optotype. For example, the display format based on the visual angle of the optotype may be a decimal display, and the display format based on the test distance may be a fractional display, etc. Of course, a display format other than the decimal display and the logarithmic display may be used.

[0013] Decimal notation indicates that a certain visual angle of the optotype can be distinguished. For example, if one can distinguish 1 minute of visual angle of the optotype, the visual acuity value is expressed as 1.0. For example, if one can distinguish 0.5 minute of visual angle of the optotype, the visual acuity value is expressed as 2.0. This type of decimal notation is often used in Japan.

[0014] Taking the Landolt ring as an example, when the test distance is 5 m, the slits and lines will span 1 minute of visual angle by making the width of the slits and lines of the Landolt ring approximately 1.45 mm and the outer diameter of the Landolt ring approximately 7.27 mm, resulting in a Landolt ring with a visual acuity value of 1.0. In addition, the slits and lines will span 0.5 minutes of visual angle by making the width of the slits and lines of the Landolt ring approximately 0.73 mm and the outer diameter of the Landolt ring approximately 3.64 mm, resulting in a Landolt ring with a visual acuity value of 2.0.

[0015] Fractional notation indicates that a certain visual angle of the optotype can be identified at a certain test distance. For example, the denominator represents the distance at which an eye that can see 1 minute of visual angle of the optotype (reference eye) can identify the optotype. For example, the numerator represents the test distance of the optotype relative to the test eye. This type of fractional notation is often used overseas.

[0016] As an example, when the test eye can see a target that the reference eye (visual acuity value 20 / 20) can distinguish at 20 feet at a test distance of 20 feet, the visual acuity is expressed as 20 / 20. When the test eye can see a target that the reference eye can distinguish at 10 feet at a test distance of 20 feet, the visual acuity is expressed as 20 / 10. The test distance of 20 feet is a distance that is mainly used in the United States. As another example, when the test eye can see a target that the reference eye (visual acuity value 6 / 6) can distinguish at 6 m at a test distance of 6 m, the visual acuity is expressed as 6 / 6. When the test eye can see a target that the reference eye can distinguish at 3 m at a test distance of 6 m, the visual acuity is expressed as 6 / 3. The test distance of 6 m is a distance that is mainly used in the United Kingdom.

[0017] The visual angle of the optotype (the size of the optotype) and the test distance are equivalent, and decimal notations can be replaced with fractional notations. For example, a visual acuity value of 2.0 corresponds to the test eye being able to distinguish an optotype with a visual angle of 1 minute at a test distance of 5 m at a test distance of 10 m. For this reason, an optotype that the reference eye (visual acuity value of 1.0) can distinguish at 5 m can be considered as being visible to the test eye at a test distance of 10 m, and can be replaced with a visual acuity value of 10 / 5 and a fractional notation. A visual acuity value of 20 / 10 or a visual acuity value of 6 / 3 can be replaced with a visual acuity value of 2.0 and a decimal notation by performing decimal calculations.

[0018] In this embodiment, the operation signal for setting the display format of the visual acuity value of the test optotype may be output by the examiner operating the operation means. For example, the operation means may be capable of directly selecting the display format of the visual acuity value of the test optotype. In this case, the format setting means may set the display format of the visual acuity value of the test optotype based on an operation signal indicating a decimal display, a fraction display, or the like from the operation means. Also, for example, the operation means may be capable of selecting a country or region in order to specify the display format of the visual acuity value of the test optotype. In this case, the country or region may be associated in advance with the decimal display, the fraction display, or the like. The format setting means may set the display format of the visual acuity value of the test optotype based on an operation signal indicating the country or region from the operation means. Note that for the fraction display, the test distance may be set. For example, at least one of 20 feet, 6 m, and the like may be set.

[0019] In the present embodiment, the operation signal for setting the display format of the visual acuity value of the test optotype may be output by using an external storage means (for example, an SD card, a USB memory, a server, a cloud, etc.). In this case, a control means included in the device body or the operation means may read the setting of the display format of the visual acuity value of the test optotype stored in the external storage means and output an operation signal according to this setting. The format setting means may set the display format of the visual acuity value of the test optotype based on such an operation signal.

[0020] <Step setting method> The optotype presenting device of this embodiment may include a step setting means (e.g., the control unit 20). The step setting means sets the visual acuity values ​​of a plurality of optotypes included in the test optotype to a predetermined step based on the display format of the visual acuity value of the test optotype set by the format setting means. This allows a group of visual acuity values ​​that can be presented in the test of the subject's eye to be easily set.

[0021] The predetermined step represents the amount of change between visual acuity values ​​when the visual acuity values ​​of the multiple optotypes are arranged in order (in other words, the amount of change between visual acuity values ​​before and after). The change in visual acuity values ​​of the multiple optotypes can also be represented as a change in visual angle based on the test distance. In this case, the predetermined step may represent the amount of change between visual angles when the visual angles of the multiple optotypes are arranged in order.

[0022] More specifically, the predetermined steps are steps in which the visual acuity values ​​of the multiple optotypes increase with regularity. For example, the predetermined steps may be decimal steps in which at least some of the visual acuity values ​​of the multiple optotypes increase linearly. In this case, the visual acuity values ​​of the multiple optotypes are equally spaced in decimal units. Also, for example, the predetermined steps may be logarithmic steps in which at least some of the visual acuity values ​​of the multiple optotypes increase logarithmically. In this case, the visual acuity values ​​of the multiple optotypes are equally spaced in exponent (or power exponent) units.

[0023] In addition, the visual acuity values ​​of the multiple optotypes may include values ​​that are not in a predetermined step. For example, the decimal step may include values ​​that are not equally spaced, even though they are based on a linear increase in visual acuity values. For this reason, the step setting means may be able to set the decimal step more finely. Similarly, for example, the logarithmic step may include values ​​that are not equally spaced, even though they are based on a logarithmic increase in visual acuity values. For this reason, the step setting means may be able to set the logarithmic step more finely. As an example, it may be possible to set a 20-foot step in which a visual acuity value of 20 / 70 or the like is added based on the logarithmic step, a 6-m step in which a visual acuity value of 6 / 20 or the like is added based on the logarithmic step, and the like.

[0024] In this embodiment, the display format of the visual acuity value of the test optotype may be associated in advance with a predetermined step. As an example, a decimal step may be associated with a decimal display, and a logarithmic step may be associated with a fractional display. Of course, 20-foot steps or 6-m steps may be associated with the test distance in the fractional display. In this case, the step setting means may set the display format of the visual acuity value of the test optotype and the corresponding predetermined step based on an operation signal (first operation signal) indicating the fractional display or the decimal display.

[0025] <Step change method> The optotype presenting device of this embodiment may include a step changing means (e.g., the control unit 20). The step changing means changes the predetermined step set by the step setting means based on the display format of the visual acuity value to a step different from the predetermined step based on an operation signal (second operation signal). In other words, it changes from the initial setting step to a different step. This makes it possible to change the group of visual acuity values ​​based on changes in the visual acuity values ​​of the multiple optotypes as necessary.

[0026] In this embodiment, an operation signal for changing the step of the visual acuity value of the plurality of optotypes included in the test optotype may be output by the examiner operating the operating means. In this case, the step changing means may change the step from the initial setting to a different step based on the operation signal indicating the step change from the operating means. For example, the initial setting decimal step may be changed to a logarithmic step, or the initial setting logarithmic step may be changed to a decimal step. Of course, a change from a decimal step to a 20 foot step, a change from a 20 foot step to a 6 m step, etc. may be included.

[0027] In the present embodiment, the operation signal for changing the step of the visual acuity value of the plurality of optotypes included in the test optotype may be output by utilizing an external storage means. The step changing means may change the visual acuity value of the test optotype to a different step based on the operation signal generated via the external storage means.

[0028] <Step selection method> The optotype presenting device of this embodiment may include a step selection means (for example, the control unit 20). The step selection means sets the change in visual acuity value of a plurality of optotypes, which can be expressed in the display format of the visual acuity value of the test optotype, to an arbitrary step based on an operation signal (third operation signal). For example, even if a predetermined step is not associated with the display format of the visual acuity value of the test optotype, either a decimal step or a logarithmic step can be set. Furthermore, for the logarithmic step, either a 20-foot step, a 6-m step, or the like may be set. This allows a group of visual acuity values ​​based on the change in visual acuity value of a plurality of optotypes to be set according to the purpose and contents of the test.

[0029] In the present embodiment, an operation signal for selecting a step of visual acuity values ​​of a plurality of optotypes included in the test optotype may be output by an examiner operating an operating means. In this case, the step selecting means may set an arbitrary step based on an operation signal specifying the step from the operating means.

[0030] In the present embodiment, the operation signal for selecting the step of the visual acuity value of the plurality of optotypes included in the test optotype may be output by utilizing an external storage means. The step selection means may set the visual acuity value of the test optotype to an arbitrary step based on the operation signal generated via the external storage means.

[0031] <Optotype addition means> The optotype presenting device of this embodiment may include an optotype adding means (e.g., the control unit 20). The optotype adding means adds an optotype having a new visual acuity value expressed in the display format of the visual acuity value of the test optotype based on an operation signal (fourth operation signal). For example, a new visual acuity value group may be constructed by adding visual acuity values ​​from the beginning without setting a predetermined step or an arbitrary step for the visual acuity values ​​of the multiple optotypes. Also, for example, an existing visual acuity value group may be customized by appropriately adding visual acuity values ​​that are not included in the predetermined step or the arbitrary step for the visual acuity values ​​of the multiple optotypes.

[0032] In the present embodiment, the operation signal for adding the new visual acuity value may be output by the examiner operating the operating means. In this case, the target adding means may add a target having a new visual acuity value based on the operation signal from the operating means.

[0033] In the present embodiment, the operation signal for adding a new visual acuity value may be output by utilizing an external storage means. The target adding means may add a target having a new visual acuity value based on the operation signal output via the external storage means.

[0034] <Type setting method> The optotype presenting device of this embodiment may include a type setting means (e.g., the control unit 20). The type setting means sets the type of test optotype based on an operation signal (fifth operation signal). More specifically, the type of test optotype that can be presented in the examination of the subject's eye is set. For example, the display or non-display of the aforementioned Landolt ring optotype, tumbling E optotype, hiragana optotype, katakana optotype, alphabet optotype, number optotype, etc. may be set.

[0035] In this embodiment, the operation signal for setting the type of the test optotype may be output by the examiner operating the operation means. For example, the operation means may be capable of directly selecting the type of the test optotype. In this case, the type setting means may set the type of the test optotype based on an operation signal indicating display or non-display of each type output from the operation means. A country or region may be associated in advance with the type of the test optotype used in the test, and an operation signal may be obtained from the selection of a country or region to set the type of the test optotype. In addition, the type of the test optotype may be set in conjunction with the setting of a fraction display, a decimal display, or the like based on an operation signal when the format setting means sets the display format of the visual acuity value of the test optotype. That is, the first operation signal may also serve as the fifth operation signal.

[0036] In the present embodiment, the operation signal for setting the type of the test optotype may be output by utilizing an external storage means. The type setting means may set the type of the test optotype based on the operation signal output via the external storage means.

[0037] <Signal acquisition means> The optotype presenting device of this embodiment may include a signal acquiring means (e.g., a control unit 20). The signal acquiring means acquires a switching signal for switching a first optotype group (described later) to be displayed on the optotype presenting means. For example, the signal acquiring means may acquire a switching signal output by an examiner operating an operating means. As an example, the switching signal may be acquired using an operation to switch the type of optotype, an operation to switch the visual acuity value of the optotype, an operation to switch the display of the optotype, or the like as a trigger. When the optotype has directionality, the switching signal may be acquired using an operation to switch the direction of the optotype as a trigger.

[0038] Also, for example, the signal acquiring means may acquire a switching signal based on a self-examination program that automatically advances the examination of the subject's eye. In this case, the signal acquiring means may acquire a switching signal that is output when the subject operates an operating means for the subject. In this case, the signal acquiring means may acquire a switching signal that is automatically output when a predetermined time has elapsed since the presentation of the optotype.

[0039] <Generation means> The optotype presenting device of this embodiment may include a generating means (for example, a control unit 20). The generating means generates a first optotype group by randomly arranging a plurality of optotypes in at least one of the row direction and the column direction, which is a first optotype group displayed on the same screen of the optotype display means. The generating means generates a second optotype group by randomly arranging a plurality of optotypes in at least one of the row direction and the column direction, which is a second optotype group displayed on the same screen of the optotype display means, based on a switching signal from the signal acquiring means. For example, the generating means may generate, as the first optotype group or the second optotype group, any of a horizontal line optotype in which a plurality of optotypes are arranged in the row direction, a vertical line optotype in which a plurality of optotypes are arranged in the column direction, a character-cluttered optotype in which a plurality of optotypes are arranged in the row direction and the column direction, and the like. In the first optotype group and the second optotype group, at least any of the number of a plurality of optotypes constituting them, the distance between the optotypes, the display position, and the like may be arbitrarily determined by the examiner.

[0040] The first group of optotypes may be configured to include a plurality of optotypes having the same first visual acuity value. That is, a vertical row of optotypes and a horizontal row of optotypes may be configured with a plurality of optotypes having the first visual acuity value. The crowded optotype may be configured in at least one row with a plurality of optotypes having the first visual acuity value.

[0041] The second group of optotypes may be configured to include at least one of a plurality of optotypes having the same first visual acuity value and a plurality of optotypes having a second visual acuity value different from the same first visual acuity value. That is, a vertical row of optotypes and a horizontal row of optotypes may be configured with a plurality of optotypes having the first visual acuity value or a plurality of optotypes having the second visual acuity value. The cluttered optotype may be configured with at least one row of a plurality of optotypes having the first visual acuity value, or with at least one row of a plurality of optotypes having the second visual acuity value. Of course, the cluttered optotype may be configured as an optotype that combines a plurality of optotypes having the first visual acuity value and a plurality of optotypes having the second visual acuity value.

[0042] In this embodiment, when the generating means randomly arranges the plurality of optotypes, the adjacent optotypes have different contents. For example, the generating means may configure the first optotype group and the second optotype group so that the adjacent optotypes have different orientations, different letters, different numbers, etc. In other words, the first optotype group and the second optotype group arrange the plurality of optotypes in the row direction and the column direction so that the same orientation, the same letters, the same numbers, etc. are not consecutive. This makes it possible to avoid the appearance of an arrangement of optotypes that is not suitable for the test, even if the arrangement of the optotype group is not stored in advance, and to improve the test accuracy.

[0043] In addition, when the optotypes constituting the first optotype group and the second optotype group have directionality, the generating means may randomly arrange the optotypes so that the orientations of the optotypes do not overlap, at least in the row direction. Of course, when the number of optotypes constituting each optotype group is greater than the number of orientations of the optotypes, they may overlap. In addition, when the optotypes constituting the first optotype group and the second optotype group have directionality, the generating means may randomly arrange the optotypes so that the vertical and horizontal orientations of the optotypes are not biased, at least in the row direction. This allows the examination to proceed while taking into account the astigmatism of the subject's eye.

[0044] In this embodiment, the generating means may change the optotypes to different contents when the order of the optotypes constituting the second optotype group (in other words, the arrangement in the row direction and the column direction) is the same as the order of the optotypes constituting the first optotype group, and the display positions of the optotypes in the second optotype group overlap with the display positions of the optotypes in the first optotype group. Note that the overlap of display positions here does not necessarily require completely identical pixel positions in the optotype display means. For example, in the first optotype group and the second optotype group, there may be a shift in pixel position to the extent that no significant difference occurs in the display positions of the individual optotypes visually recognized by the subject's eye. This makes it difficult for the subject to remember the optotypes, and improves the test accuracy.

[0045] In addition, if the order of the multiple optotypes constituting the second group of optotypes is different from the order of the multiple optotypes constituting the first group of optotypes, when the display positions of the optotypes overlap, the optotypes may be the same or different.

[0046] <Output method> The optotype presenting device of the present embodiment may include an output means. The output means outputs an optotype to be presented to the eye to be examined based on the visual acuity value represented by the display format set by the format setting means. For example, the output means may be an optotype display means (e.g., LCD 3) that displays the optotype. In this case, the output means (optotype display means) may display an optotype of a size corresponding to the visual acuity value. Also, for example, the output means may be a printing means (e.g., a printer) that prints the optotype. In this case, the output means (printing means) may print an optotype of a size corresponding to the visual acuity value. Also, for example, the output means may be a storage means that stores the optotype. The storage means may be a storage means (e.g., a memory, etc.) inside the device, or may be a storage means outside the device. In this case, the output means (storage means) may store an optotype of a size corresponding to the visual acuity value. Of course, the output means may be a means different from these.

[0047] <Display control means> The optotype presenting device of this embodiment may include a display control means (e.g., the control unit 20). The display control means controls the optotype display means to cause the optotype display means to display the optotype. The optotype may be a group of optotypes generated by the generation means, and the optotype display means may display a first group of optotypes, or the optotype display means may display a second group of optotypes. In this case, the screen display of the optotype display means may be switched from the first group of optotypes to the second group of optotypes.

[0048] The display control means may acquire a display size for displaying the optotype on the optotype display means based on the visual acuity value designated from the visual acuity value setting screen corresponding to the display format of the visual acuity value of the test optotype. In this case, the display size of the optotype on the optotype presenting means may be acquired by using correspondence information (for example, at least one of a correspondence table, an arithmetic expression, etc.) that associates the visual acuity value with the display size.

[0049] The visual acuity value setting screen corresponding to the display format of the visual acuity value of the test optotype may be a screen for setting the visual acuity value, and may be a screen that is switched and displayed for each display format. As an example, when a decimal display is set, a visual acuity value setting screen may be displayed that reflects the decimal step associated with the decimal display and includes a visual acuity value group based on the decimal step. As an example, when a logarithmic display is set, a visual acuity value setting screen may be displayed that reflects the decimal step associated with the logarithmic display and includes a visual acuity value group based on the logarithmic step. Of course, the visual acuity value setting screen may be a screen different from these. For example, by switching the visual acuity value setting screen for each display format of the visual acuity value of the test optotype in this way, various settings can be easily performed or changed.

[0050] <Operation means> The optotype presenting device of this embodiment may include an operation means (for example, a controller 4). The operation means may be configured to allow the examiner to input an operation signal, and at least one of user interfaces such as a mouse, a keyboard, a touch panel, a controller, etc. When the operation means is a touch panel, the operation means also serves as the display means.

[0051] For example, the operation means can input an operation signal for operating the display of the optotype display means (e.g., LCD 3). As an example, an operation signal for changing at least one of the type of test optotype, the visual acuity value of the test optotype, the display of the test optotype, etc. can be input. Also, for example, the operation means can input an operation signal for operating the display of the display means (e.g., LCD 41). As an example, an operation signal for changing at least one of the display format of the visual acuity value of the test optotype, various setting screens, etc. can be input.

[0052] Of course, the operation means may be capable of inputting an operation signal for operating a means other than the optotype display means and the display means. For example, the operation means may be capable of inputting an operation signal for operating an optical element in a correction optical system (correction means) described later.

[0053] The optotype presenting device of the present embodiment may be used as a part of a visual acuity testing device for measuring visual acuity and the like by having a subject look into a presentation window. In other words, the optotype presenting device may be used as an optotype presenting means in the visual acuity testing device.

[0054] The optotype presenting device of this embodiment may be used as a part of a subjective optometry device for subjectively measuring the optical characteristics of the subject's eye. In other words, the optotype presenting device may be used as an optotype presenting means in a subjective optometry device. In this case, the optotype light beam from the optotype presenting device may be directly projected toward the subject's eye. In addition, in this case, the optotype light beam may be projected via a light projection optical system having at least one optical member (e.g., a lens, a mirror, etc.) through which the optotype light beam from the optotype presenting device passes.

[0055] Furthermore, the subjective eye examination device may include a correction optical system that changes the optical characteristics of the visual target light beam from the visual target presenting device and is arranged in the optical path of the light projection optical system. In this case, the correction optical system may change the optical characteristics of the visual target light beam by controlling an optical element arranged between the visual target presenting device and an optical member of the light projection optical system. That is, the correction optical system may be a phantom lens refractometer (phantom correction optical system). The correction optical system may also change the optical characteristics of the visual target light beam by controlling an optical element arranged in front of the eye to be examined. That is, the correction optical system may be an eye examination unit (phoropter). For example, the eye examination unit may have a lens disk on which a plurality of optical elements are arranged on the same circumference, and a driving means (e.g., a motor) for rotating the lens disk, and the optical elements may be electrically switched by driving the driving means.

[0056] The present disclosure is not limited to the devices described in the present embodiment. For example, terminal control software (programs) that perform the functions of the following embodiments may be supplied to a system or device via a network or various storage media, and a control device (e.g., a CPU) of the system or device may read and execute the program.

[0057] <Example> An example of the visual target presenting device according to this embodiment will be described.

[0058] <Device configuration> FIG. 1 is an external view of an optotype presenting device 1. A liquid crystal display (LCD) 3 for presenting optotypes is disposed on the front (front face) of a housing 2 in the optotype presenting device 1. The LCD 3 has a display screen large enough to display optotypes with visual acuity values ​​of at least 0.1 to 2.0 (or a size equivalent to this visual acuity value) even when placed at a distant test distance (for example, 5 m, etc.). A receiver 5 for receiving an operation signal transmitted from a controller 4 is disposed below the front face of the housing 2. The optotypes displayed on the LCD 3 can be switched by operating the controller 4. The controller 4 has a plurality of switches 40 for operating the device body, a liquid crystal display (LCD) 41 for displaying the status of operation by each switch, and a transmitter 49 for transmitting an operation signal based on the operation of each switch. The LCD 41 may be a touch panel that also functions as the switch 40. The housing 2 and the controller 4 may be located separately, and various operation signals may be transmitted by remote operation.

[0059] 2 is a schematic diagram of a control system of the optotype presenting device 1. A control unit 20 is stored inside the housing 2. For example, the control unit 20 includes a CPU (processor), RAM, ROM, etc. The CPU controls the driving of each unit in the optotype presenting device 1. Various information is temporarily stored in the RAM. Various programs executed by the CPU, a decoder circuit that decodes operation signals from the controller 4, reference images (vector images) of each optotype, etc. are stored in the ROM. The control unit 20 may be composed of multiple control units (i.e., multiple processors).

[0060] The control unit 20 is connected to the LCD 3, the receiving unit 5, a non-volatile memory 21 (hereinafter, memory 21), etc. The receiving unit 5 provided in the housing 2 and the transmitting unit 4 provided in the controller 4 are connected by wireless communication. The memory 21 is a non-transient storage medium that can retain stored contents even if the power supply is cut off. For example, the memory 21 can be a hard disk drive, a flash ROM, a USB memory, etc. <Types of optotypes and visual acuity value formats> There are various types of optotypes presented to the subject's eyes, such as directional optotypes (e.g., Landolt ring optotypes, tumbling E optotypes, etc.) for enabling the subject to distinguish directions, character optotypes (e.g., hiragana optotypes, katakana optotypes, alphabet optotypes, etc.) for enabling the subject to read characters, and number optotypes for enabling the subject to distinguish numbers.

[0061] The visual acuity value of such a target can be expressed in various ways. In this embodiment, the display format of the visual acuity value of the target can be arbitrarily set, so that the visual acuity value can be displayed in a display format desired by the examiner, and therefore the test can be carried out efficiently. The setting of the display format will be described in detail later.

[0062] <Display of optotype> Fig. 3 shows an example of a target displayed on the LCD 3. Fig. 3(a) shows a single letter target, Fig. 3(b) shows a horizontal line target, and Fig. 3(c) shows a crowded target. Note that in this embodiment, the Landolt ring target is used as an example, but the same applies to other types of targets.

[0063] The one-letter optotype in Fig. 3(a) is an optotype consisting of one Landolt ring. For example, in the one-letter optotype, the Landolt ring is displayed in the middle position of the LCD 3. Of course, the Landolt ring may be displayed in a position other than the middle of the LCD 3.

[0064] The horizontal row target in FIG. 3(b) is a target group consisting of multiple Landolt ring targets. In the horizontal row target, the Landolt ring targets are arranged in a horizontal row. Here, five Landolt ring targets are arranged in a horizontal row (in other words, a row of five columns and one row). For example, in the horizontal row target, the row of the Landolt ring targets is displayed in the middle position of the LCD3. Of course, the row of the Landolt ring targets may be displayed in a position other than the middle of the LCD3.

[0065] The crowded optotype in FIG. 3(c) is a group of optotypes consisting of a plurality of Landolt rings. In the crowded optotype, the Landolt rings are arranged in a plurality of rows and a plurality of columns. Here, 15 Landolt rings are arranged in a 3-row, 5-column arrangement. The visual acuity values ​​of the optotypes in each row may be the same or different. That is, the visual acuity values ​​of the optotypes in all three rows may be the same, or the visual acuity values ​​of the optotypes in at least two of the first, second, and third rows may be different. For example, in the crowded optotype, each row of the Landolt rings is displayed at the upper, middle, and lower positions of the LCD 3. Of course, each row of the Landolt rings may be arranged at a position different from that in FIG. 3(c).

[0066] In the horizontal line and the crowded optotypes of this embodiment, at least one of the number of rows and the number of columns of the Landolt ring may be configured to be different from the above. Also, when there are four or more Landolt rings in a row, all of the slit directions, such as upward, downward, leftward, and rightward, may be configured to appear. Similarly, when there are four or more Landolt rings in a column, all of the slit directions may be configured to appear. Furthermore, the slits of the Landolt rings in a row may be oriented in different directions at least between adjacent optotypes. Similarly, the slits of the Landolt rings in a column may be oriented in different directions at least between adjacent optotypes. That is, the slits of the Landolt rings may be configured not to be continuous in the row direction and the column direction.

[0067] In this embodiment, in the optotype presenting device 1, the direction of the gap of the Landolt ring optotype is randomly determined according to the display of each optotype every time the display screen of the LCD 3 is switched. A horizontal line optotype or a crowded optotype is generated by randomly arranging a plurality of Landolt ring optotypes in at least one of the linear directions of the row direction and the column direction. The generation of the optotype will be described in detail later.

[0068] <Control action> The control operation of the optotype presenting device 1 will be described taking as an example a visual acuity test for a subject's eye using the optotype presenting device 1.

[0069] <Setting the test target> First, the examiner sets in advance the type of test optotype to be presented to the subject's eye, the display format of the visual acuity value of the test optotype, etc., for the test optotypes to be used in the examination of the subject's eye. The examiner operates the switch unit 40 of the controller 4 to call up a setting screen for setting the test optotype. The control unit 20 causes the LCD 41 to display the setting screen in response to an operation signal from the switch unit 40.

[0070] FIG. 4 shows an example of a setting screen. FIG. 4(a) shows a type setting screen 6 for setting the type of test optotype. FIG. 4(b) shows a visual acuity value display setting screen 7 for setting the display format of the visual acuity value of the test optotype. For example, the type setting screen 6 and the visual acuity value setting screen 7 can be switched by a tab 8. Of course, for example, the type setting screen 6 and the visual acuity value setting screen 7 may be displayed as a single integrated screen.

[0071] First, the examiner operates the type setting screen 6. The type setting screen 6 has a display change button 61 for changing between display and non-display on the LCD 3 for each type of test optotype. For example, a display change button 61a for the Landolt ring optotype, a display change button 61b for the Tumbling E optotype, a display change button 61c for the Hiragana optotype, a display change button 61d for the alphabet optotype, a display change button 61e for the number optotype, and the like are provided.

[0072] The examiner operates the LCD 41 to select each display change button and switch between display and non-display for each test optotype. For example, in this embodiment, the Landolt ring optotype and the Hiragana optotype are changed to display, and the other optotypes are changed to non-display. An operation signal indicating display or non-display based on the operation of the LCD 41 is transmitted from the transmitting unit 49 to the receiving unit 5.

[0073] For hiragana, katakana, and alphabetic optotypes that may produce many combinations of characters, and for numeric optotypes that may produce many combinations of numbers, fixed patterns in which a plurality of letters or numbers are grouped and associated in advance may be provided. When the examiner switches these test optotypes to display, a selection button 62 for selecting a fixed pattern appears. When the examiner selects an arbitrary fixed pattern from the selection button 62, an operation signal for designating the arbitrary fixed pattern is transmitted from the transmission unit 49. Of course, for hiragana, katakana, alphabetic, and numeric optotypes, it may be possible to switch between display and non-display for each character.

[0074] The receiving unit 5 receives the operation signal transmitted from the transmitting unit 49 and inputs it to the control unit 20. The control unit 20 sets the test optotypes that can be displayed on the LCD 3 based on at least one of the operation signal that specifies whether to display or not display the type of test optotype and the operation signal that specifies a fixed pattern of the test optotypes.

[0075] Next, the examiner operates the visual acuity value display setting screen 7. The visual acuity value display setting screen 7 has a format change button 71 for setting the display format of the visual acuity value of the test optotype. For example, a decimal button 71a for expressing the visual acuity value in decimal, a logarithm button 71b for expressing the visual acuity value in fraction, etc. are provided.

[0076] The examiner operates the LCD 41 to select either the decimal button 71a or the fraction button 71b to switch the visual acuity value to a decimal or fraction display. The control unit 20 changes the display of the visual acuity value on the setting screen displayed on the LCD 41 and on the test screen 9 (described later) to a decimal or fraction display based on the operation signal from the LCD 41. For example, in this embodiment, the selection of the decimal button 71a causes the display format of the visual acuity value to be reflected in a decimal display.

[0077] When the fraction button 71b is selected, a details button may appear to set a more detailed display format. As an example, a 20 feet button 72a representing the visual acuity value at a test distance of 20 feet, a 6 m button 72b representing the visual acuity value at a test distance of 6 m, etc. may appear. Of course, buttons for display formats different from these may also appear. When the examiner selects an arbitrary display format from the details button, the control unit 20 changes the display of the visual acuity value to 20 feet display or 6 m display.

[0078] Here, the test optotype used in testing the subject's eye includes a plurality of optotypes, each having a different visual acuity value. In other words, the test optotype has a visual acuity value group composed of different visual acuity values. For example, in the test optotype, the visual acuity values ​​of the plurality of optotypes change in either decimal steps or logarithmic steps.

[0079] FIG. 5 is a diagram for explaining the steps of the optotype. FIG. 5 shows an example in which the visual acuity value of the optotype is displayed as a decimal. The decimal step D1 is a step in which the change in the visual acuity value of the optotype is at equal intervals in decimal units. In other words, it is a step in which the decimal visual acuity value is at equal intervals. For example, the decimal step may be a step in which at least a part of the visual acuity value of the optotype increases by 0.1. Note that the decimal step may be one in which the visual acuity value increases linearly, and the interval is not limited to 0.1.

[0080] On the other hand, for example, the logarithmic step L1 is a step in which the change in the visual acuity value of the optotype is at equal intervals in units of exponent (power exponent). In other words, it is a step in which the logarithmic visual acuity value is at equal intervals. The logarithmic step can also be considered as a step in which the visual acuity value expressed as a decimal calculated as the reciprocal of the visual angle of the optotype is converted to a logarithm with a base of 10, and the logarithm is changed at equal intervals. For example, the logarithmic step may be a step in which at least a part of the visual acuity value of the optotype increases by 0.1 Log (common logarithm). Note that the logarithmic step may be any step in which the visual acuity value increases logarithmically, and the interval is not limited to 0.1.

[0081] In this embodiment, the steps that can be expressed in the display format of the visual acuity value in the test optotype are associated in advance. Therefore, the step of the visual acuity value is automatically selected based on the display format of the visual acuity value selected by the examiner. For example, when the examiner selects the decimal button 71a that expresses the visual acuity value in decimal, the control unit 20 automatically sets the change in the visual acuity value to the decimal step D1. In addition, based on the setting of the visual acuity value step, the control unit 20 displays the visual acuity value group 75 represented by that step on the visual acuity value display setting screen 7 of the LCD 41 (see FIG. 4(b)). For example, in the examination of the subject's eye, the optotype is displayed on the LCD 3 in a size equivalent to the visual acuity value specified from the visual acuity value group.

[0082] In this embodiment, the step of the visual acuity value may be selected regardless of the display format of the visual acuity value in the test optotype. For example, in this case, the visual acuity value display setting screen 7 may be provided with a step change button 73 for switching between the decimal step D1 and the logarithmic step L1 of the visual acuity value. For example, when the examiner operates the LCD 41 to select the step change button 73 and switch the visual acuity value from the decimal step D1 to the logarithmic step L1, the control unit 20 causes the visual acuity value display setting screen 7 to display a group of visual acuity values ​​represented by the logarithmic step L1.

[0083] In addition, in this embodiment, a configuration may be adopted in which a visual acuity value that is not included in the visual acuity value group based on the step of the visual acuity value of the test optotype can be added. For example, in this case, the visual acuity value display setting screen 7 may be provided with an input button 74 for the examiner to input an arbitrary visual acuity value. For example, when the examiner operates the LCD 41 to select the input button 74 and input an arbitrary visual acuity value, the control unit 20 adds the arbitrary visual acuity value to the visual acuity value group. As an example, a visual acuity value such as 1.8 that is not included in the visual acuity value group of the decimal step D1 can be newly added to the visual acuity value group.

[0084] <Start of vision test> When the examiner has completed the various settings of the test optotypes on the setting screens (type setting screen 6 and visual acuity value setting screen 7) of the LCD 41, the examiner starts the visual acuity test on the subject's eye. The examiner operates the switch unit 40 of the controller 4 to call up a test screen for designating the optotype to be presented to the subject's eye and to be displayed on the display screen of the LCD 3. The control unit 20 causes the LCD 41 to display the test screen in response to the operation signal from the switch unit 40.

[0085] FIG. 6 is an example of the test screen 9. The test screen 9 has an optotype designation button 91 for designating an optotype to be displayed on the LCD 3. For example, the control unit 20 changes the configuration of the optotype designation button 91 on the LCD 41 based on the setting of display or non-display of the test optotype from the type display change button 61, the setting of the display format of the visual acuity value from the format change button 71, and the setting of the step of the visual acuity value, and displays it. In this embodiment, the visual acuity value that increases in decimal steps for the Landolt ring optotype and the Hiragana optotype is set to be displayed in decimal. For this reason, for example, the designation button 91a for the Landolt ring optotype is expressed by a visual acuity value displayed in decimal set from a group of visual acuity values ​​in decimal steps. Similarly, for example, the designation button 91b for the Hiragana optotype is also expressed by a visual acuity value displayed in decimal set from a group of visual acuity values ​​in decimal steps.

[0086] The examiner operates the LCD 41 to specify the type of optotype and visual acuity value to be presented to the subject's eye from among the specification buttons 91a and 91b. The control unit 20 acquires the display size for displaying the corresponding optotype on the LCD 3 based on the operation signal from the LCD 41. For example, the control unit 20 may acquire the display size of the corresponding optotype by using a correspondence table that associates the visual acuity value of the test optotype with the display size.

[0087] For example, in this embodiment, the examiner selects a horizontal row of optotypes with a visual acuity value of 0.9 from the selection button 91a. The control unit 20 acquires the display size of the visual acuity value of 0.9 based on the correspondence table, and displays a horizontal row of optotypes with a display size corresponding to a visual acuity value of 0.9 on the LCD 3 by enlarging or reducing the reference image of the Landolt ring optotype stored in the memory 21 and randomly arranging them. The LCD 41 may display the same optotypes and their visual acuity values ​​as those selected by the examiner.

[0088] The examiner asks the subject about the direction of the slits of the Landolt ring displayed on the LCD 3, and switches at least one of the direction of the slits of the Landolt ring or the visual acuity value according to the subject's answer. For example, the examiner may select the direction switching button 92 to switch only the direction of the slits without switching the visual acuity value of the Landolt ring, regardless of whether the answer is correct or incorrect. Also, for example, if the answer is correct, the examiner may select the designation button 91a to switch the visual acuity value of the Landolt ring in the horizontal line of the target to a visual acuity value one step higher. That is, the visual acuity value of the Landolt ring may be increased in increments and switched to a value larger than the current value. As an example, the visual acuity value of the Landolt ring may be switched from 0.9 to 1.0. Also, for example, if the answer is incorrect, the examiner may select the designation button 91a to switch the visual acuity value of the Landolt ring in the horizontal line of the target to a visual acuity value one step lower. That is, the visual acuity value of the Landolt ring may be reduced in increments and switched to a value smaller than the current value. As an example, the visual acuity value of the Landolt ring may be switched from 0.9 to 0.8.

[0089] <Random generation of visual targets> The control unit 20 generates a horizontal line of targets and displays it on the LCD 3 every time it receives an operation signal from the designation button 91a or the direction switching button 92. That is, the control unit 20 displays a horizontal line of targets in which Landolt ring targets are randomly arranged on the LCD 3 every time it receives an operation signal. In this embodiment, the control unit 20 generates a horizontal line of targets so that the breaks in the Landolt ring targets are oriented in different directions when the order (i.e., the order of rows and columns) of the Landolt ring targets is the same in the current horizontal line of targets and the display positions of the Landolt ring targets overlap.

[0090] FIG. 7 shows an example of the current horizontal row optotype and the next horizontal row optotype. FIG. 7(a) shows the current horizontal row optotype. The horizontal row optotype in FIG. 7(a) is an example in which Landolt rings having the same visual acuity value are arranged in one row and five columns at the middle position P2 among the upper position P1, the middle position P2, and the lower position P3 on the LCD 3. For example, the first row R1a to the fifth row R1e of the Landolt rings are arranged at equal intervals, and are arranged so that the centers of the Landolt rings are located at display positions Q1 to Q5 on the screen. For example, the display position Q3 of the third row R1c of the Landolt rings is the center on the screen. FIG. 7(b) and FIG. 7(c) show the next horizontal row optotype. In FIG. 7(b), the order and display positions of the Landolt rings are the same. In FIG. 7(c), the order and some display positions of the Landolt rings are different.

[0091] First, a case where the horizontal line of the visual target in FIG. 7(a) is switched to the horizontal line of the visual target in FIG. 7(b) will be described. Here, an example will be given in which the control unit 20 receives an operation signal from the direction switching button 92 and changes the direction of the slits of the Landolt ring visual target. In the horizontal line of the visual target, the Landolt ring visual target is spaced apart so as to secure a standardized predetermined distance. When switching the direction of the slits of the Landolt ring visual target from the current horizontal line of the visual target, the visual acuity value of the Landolt ring visual target does not change and the display size does not change, so that the same number of Landolt ring visual targets are placed at the same display positions in the next visual target. That is, in the next horizontal line of the visual target shown in FIG. 7(b), the first row R2a to the fifth row R2e of the Landolt ring visual target are placed at the display positions Q1 to Q5.

[0092] The control unit 20 determines the orientation of the slits of the Landolt rings for each row so that the orientations of the slits do not overlap, since the display positions of each row of the Landolt rings in the current horizontal row and the next horizontal row are the same. More specifically, since the first row R1a of the Landolt rings of the current horizontal row is downward, the Landolt rings of the next horizontal row are set in an orientation different from the first row R2a, which is downward (i.e., upward, leftward, or rightward). Similarly, orientations not used in the Landolt rings of the current horizontal row are set for the second to fifth rows.

[0093] Next, a case where the horizontal row of targets in FIG. 7(a) is switched to the horizontal row of targets in FIG. 7(c) will be described. For example, when switching the visual acuity value of the Landolt ring targets from the current horizontal row of targets, if the display size of the Landolt ring targets is increased and a standardized predetermined distance can be secured, the same number of Landolt ring targets are placed at the same display position in the next target. However, for example, if the display size of the Landolt ring targets is increased and it becomes impossible to secure a predetermined distance, the number of Landolt ring targets is reduced in the next target, and at least some of the Landolt ring targets are placed at different display positions. Here, a case where the control unit 20 receives an operation signal from the designation button 91a, changes the visual acuity value of the Landolt ring targets, and the number of Landolt ring targets is reduced to three is taken as an example.

[0094] For example, in the next horizontal row target shown in Fig. 7(c) for the current horizontal row target shown in Fig. 7(a), the first row R3a and the third row R3c of the Landolt ring targets are arranged at different display positions, and the second row R3b is arranged at the same display position Q3. At this time, since the order (arrangement of rows and columns) of the Landolt ring targets in the current horizontal row target and the next horizontal row target are different, the control unit 20 sets the orientation of each of the first row R3a to the third row R3c to be upward, downward, leftward, or rightward. In other words, the control unit 20 sets the orientation of the Landolt ring targets in the next horizontal row target regardless of the orientation of the Landolt ring targets in the current horizontal row target. For example, the third row R1c of the Landolt ring in the current horizontal row and the second row R3b of the Landolt ring in the next horizontal row are displayed at the same display position Q3, but the directions of the gaps in the Landolt ring may overlap. Of course, the gaps may be oriented in different directions, taking into account that they are displayed at the same position.

[0095] As described above, when there are four or more Landolt ring targets in one row, the control unit 20 may randomly generate the horizontal row of targets so that all slit orientations, such as upward, downward, leftward, and rightward, appear. Also, the horizontal row of targets may be randomly generated so that at least adjacent Landolt ring targets have slits with different orientations.

[0096] For example, when the examiner switches the direction of the slits or the visual acuity value of the Landolt ring target presented to the subject's eye, the control unit 20 generates a horizontal row of targets in this manner and controls the display of the LCD 3 to display them.

[0097] As described above, for example, the display format of the visual acuity value of the test optotype used in the test of the subject's eye is set based on an operation signal, and the optotype to be presented to the subject's eye is output based on the visual acuity value represented by the set display format. For example, in the past, it was difficult to freely select the display format of the visual acuity value of the test optotype, so that the visual acuity value was not displayed in the display format desired by the examiner, which was inconvenient. However, such a configuration of the device improves convenience, and the examiner can easily check the visual acuity value and proceed with the test. In addition, for example, the examiner can change the display format of the visual acuity value of the optotype according to the nationality of the examinee, and can respond to various situations.

[0098] In addition, for example, in the optotype presenting device of this embodiment, the test optotypes used for testing the subject's eye include a plurality of optotypes having different visual acuity values, and the change in visual acuity value of the plurality of optotypes is set to a predetermined step based on the display format of the set visual acuity value. For example, when the display format of the visual acuity value of the test optotype changes, the step represented by the display format may also change. By previously associating the display format of the visual acuity value with the step, it is possible to easily determine the visual acuity value group of the optotype that can be presented to the subject's eye.

[0099] Also, for example, the optotype presenting device of this embodiment changes a predetermined step corresponding to the display format of the visual acuity value of the test optotype to a different step based on an operation signal. For example, the display format of the visual acuity value of the test optotype may have a plurality of steps (for example, a decimal step and a logarithmic step) represented in the display format. By being able to change the step initially set according to the display format of the visual acuity value to another step, it is possible to change the visual acuity value group of the optotype that can be presented to the subject's eye as necessary.

[0100] Also, for example, the optotype presenting device of this embodiment adds an optotype having a new visual acuity value represented in the display format of the visual acuity value of the test optotype based on an operation signal. For example, this allows the examiner to add a visual acuity value required by the examiner to a visual acuity value group based on the change (step) in the visual acuity value of a plurality of optotypes. Also, a new visual acuity value group consisting of only the visual acuity values ​​required by the examiner can be created. The examiner can efficiently proceed with the test by using such a visual acuity value group.

[0101] In addition, for example, the optotype presenting device of the present embodiment sets the type of the test optotype based on an operation signal. For example, by being able to change the optotype of the test optotype, it is possible to proceed with the test using the type of optotype familiar to the country or region.

[0102] Also, for example, the optotype presenting device of this embodiment acquires the display size of the optotype based on the visual acuity value specified from the visual acuity value setting screen corresponding to the display format of the visual acuity value of the test optotype, and displays the optotype in that display size on the LCD 3. For example, the visual acuity value setting screen is switched for each display format of the visual acuity value of the test optotype, so that the examiner can easily execute or change various settings.

[0103] In addition, for example, the optotype presenting device of this embodiment generates the first optotype group by randomly arranging a plurality of optotypes in at least one of the linear directions of the row direction and the column direction, which is the first optotype group displayed on the same screen of the LCD 3, and makes adjacent optotypes different in content. This makes it possible to avoid the appearance of an optotype arrangement that is not suitable for testing, such as the Landolt ring optotype having the same slit direction, even if the arrangement of the optotype group is not determined in advance, and improves the accuracy of the test. In addition, in a configuration in which the examiner can add any visual acuity value, such a configuration is particularly effective because the arrangement of the optotype group cannot be determined in advance for each visual acuity value.

[0104] In addition, for example, when the optotype presenting device of this embodiment switches the first optotype group of the LCD3 to generate a second optotype group displayed on the same screen of the LCD3 by randomly arranging a plurality of optotypes in at least one of the linear directions of the row direction and the column direction, if the order of the plurality of optotypes constituting the second optotype group is the same as the order of the plurality of optotypes constituting the first optotype group and the display positions of the optotypes in the second optotype group overlap with the display positions of the optotypes in the first optotype group, the optotypes are made to have different contents. That is, for example, when the current first optotype group is switched to the next second optotype group, if the display positions of the optotypes on the LCD3 overlap, the next optotype is made to have different contents. Therefore, it is difficult for the subject to remember the optotype, and the test accuracy can be improved.

[0105] Also, for example, in the optotype presenting device of this embodiment, the optotype has a direction, and when switching from the current first optotype group to the next second optotype group, if the display positions of the optotypes on the LCD 3 overlap, the next optotype is made to have a different direction. This makes it difficult for the subject to remember the direction of the optotype, and the test accuracy can be improved. Also, by making the optotype have a different direction, the test can be carried out while taking into account astigmatism, as described later.

[0106] In addition, for example, in the optotype presenting device of this embodiment, when the optotypes are letter optotypes or number optotypes and the current first optotype group is switched to the next second optotype group, if the display positions of the optotypes overlap on the LCD 3, the next optotype is made to be a different letter or number. This makes it difficult for the subject to remember the letters or numbers of the optotypes, and improves the test accuracy.

[0107] <Example of transformation> In this embodiment, a configuration in which a predetermined step is associated with the display format of the visual acuity value of the test optotype as an initial setting is described as an example, but this is not limited thereto. In this embodiment, the display format of the visual acuity value of the test optotype is not associated with the step, and the examiner may select any step. In other words, regardless of the display format of the visual acuity value of the test optotype, any step that can be displayed in a predetermined display format may be selected. This allows the examiner to freely set the visual acuity value group of the optotype that can be presented to the subject's eye each time according to the purpose and content of the test.

[0108] In this embodiment, the configuration is described by taking as an example a configuration in which either the decimal step D1 or the logarithmic step L1 is selected for the visual acuity values ​​of multiple optotypes, but this is not limiting. In this embodiment, the configuration may be such that the logarithmic step can be selected more finely. For example, the logarithmic step L1 is often used for the visual acuity values ​​of multiple optotypes overseas, but there are cases in which the intervals are not equal because visual acuity values ​​specific to a country or region are included. For this reason, the logarithmic step D1 may be subdivided into steps based on the logarithmic step and specific visual acuity values ​​are added.

[0109] In this embodiment, the configuration has been described in which all Landolt rings of the visual acuity value group based on a predetermined step of the visual acuity value of the test optotype are displayed on the LCD 3, but the present invention is not limited to this. In this embodiment, it may be possible to switch whether or not the Landolt rings having each visual acuity value constituting such a visual acuity value group are displayed on the LCD 3. For example, in this case, the visual acuity value display setting screen 7 may be provided with a button (e.g., a check box or the like) for switching between displaying and not displaying each visual acuity value. The control unit 20 may display only the Landolt rings having the visual acuity values ​​set to be displayed among the individual visual acuity values ​​on the LCD 3.

[0110] In this embodiment, the configuration in which a fixed pattern is provided for the letter and number optotypes has been described as an example, but the present invention is not limited to this. For example, these optotypes may be able to switch between display and non-display for each character. However, in this case, when the horizontal line optotype is generated, the character line may be an arrangement of characters that is not suitable for the test. For this reason, the control unit 20 may generate the horizontal line optotype so as to avoid the arrangement of characters stored in the memory 21 in advance. Of course, the examiner may be able to set the arrangement of characters to be avoided from the controller 4.

[0111] In the present embodiment, the examiner operates the controller 4 to manually set at least one of the display format of the visual acuity value of the test optotype, the step and display target of the visual acuity value, the addition of visual acuity value, the type of the test optotype, the sequence of the letter optotype and the number optotype, etc., but the present invention is not limited to this. For example, the present invention may be configured to read various settings and automatically set them using an SD card detachable from the device, a cloud capable of communicating with the device, etc.

[0112] In this embodiment, the display size of the Landolt ring on the LCD 3 is obtained by using a correspondence table that associates the visual acuity value of the test optotype with the display size, but the present invention is not limited to this. For example, the display size of the Landolt ring may be obtained by using an arithmetic expression that calculates the display size based on the visual acuity value of the test optotype. Of course, these correspondence tables and arithmetic expressions may be used in combination. In particular, when the examiner can add a new visual acuity value, it is difficult to prepare the visual acuity value that can be added and the display size as a correspondence table in advance. Therefore, for the visual acuity value group based on a predetermined step of the visual acuity value, the display size may be obtained from the correspondence table, and for the newly added visual acuity value, the display size may be obtained from the arithmetic expression, etc.

[0113] In this embodiment, the case where a horizontal row of targets is switched in a visual acuity test has been described as an example, but the present invention is not limited to this. For example, a vertical row of targets consisting of a plurality of Landolt ring targets, in which five Landolt ring targets are arranged in a vertical row (in other words, a 5-row, 1-column arrangement), or a crowded target can be considered in the same way.

[0114] In the present embodiment, the number of optotypes is reduced when the standardized predetermined distance cannot be ensured, but the present invention is not limited to this. For example, the display positions of the optotypes may be changed so that the predetermined distance can be ensured without reducing the number of optotypes.

[0115] Fig. 8 shows an example of transformation of the optotype. For example, when the visual acuity value of the Landolt rings is changed from the horizontal line optotype shown in Fig. 7(a) to a smaller one (i.e., the display size is increased) and it becomes impossible to secure a predetermined distance between the Landolt rings in a single horizontal line, the control unit 20 may display the Landolt rings in two rows on the LCD 3 as shown in Fig. 8. For example, the Landolt rings may be arranged in one row and three columns at the upper row position P1, and the Landolt rings may be arranged in one row and two columns at the lower row position P3.

[0116] Even in such a case, the control unit 20 may set the slits of adjacent Landolt ring targets to be oriented in different directions. Furthermore, when switching from the target in FIG. 8 to the next target, if the display positions of the Landolt interval targets overlap, the control unit 20 may set the slits of the Landolt ring targets to be oriented in different directions.

[0117] In this embodiment, the Landolt ring targets are arranged randomly so that all the slits in one row of the horizontal row of targets appear according to the number of targets, and at least adjacent targets have different orientations, but the present invention is not limited to this. In this embodiment, the Landolt ring targets may be arranged randomly in consideration of the possibility that the subject eye is an astigmatic eye. In this case, when arranging an even number of Landolt ring targets in one row, the control unit 20 may set the number of vertical orientations (upward and downward) of the slits to be the same as the number of horizontal orientations (leftward and rightward). When arranging an odd number of Landolt ring targets in one row, one of the vertical orientations and the horizontal orientations of the slits may be n, and the other may be n+1. When switching the horizontal row of targets, the ratio of the number of vertical orientations and the number of horizontal orientations of the slits of the Landolt ring target may be reversed. For example, by taking into consideration the orientation of the slits in the Landolt ring in this manner, the vertical and horizontal orientations of the slits can be presented without bias, thereby improving the accuracy of the test.

[0118] In the present embodiment, the optotype presenting device 1 includes the housing 2 and the controller 4, but the present invention is not limited thereto. The optotype presenting device 1 may be used as a part of a subjective optometry device. That is, the optotype presenting device 1 may be used as an optotype presenting unit in a subjective optometry device. For example, the subjective optometry device may include a correction optical system for correcting the subject's eye, and may subjectively measure the optical characteristics of the subject's eye. In this case, the control unit 20 may switch the horizontal row of optotypes and randomly arrange the Landolt ring optotypes when it receives an operation signal for changing the direction of the slits of the Landolt ring optotypes and an operation signal for changing the visual acuity value of the Landolt ring optotype from the controller 4, as well as an operation signal for changing the correction power for correcting the subject's eye. Of course, the horizontal row of optotypes and the like may be switched according to the progress of a self-eye examination program, and the Landolt ring optotypes may be randomly arranged. [Explanation of symbols]

[0119] 1. Visual target presentation device 2. Chassis 3 LCD 4. Controller 6 types setting screen 7. Vision setting screen 9. Inspection screen 20 Control section

Claims

1. An optotype presenting device for presenting an optotype to an eye to be examined, comprising: A generating means for generating a first optotype group displayed on the same screen of the optotype display means, the first optotype group being generated by randomly arranging a plurality of first optotypes in at least one of a row direction and a column direction, so that adjacent first optotypes have different contents; a signal acquiring means for acquiring a switching signal for switching the first group of optotypes of the optotype display means; A display control means for causing the optotype display means to display the first optotype group generated by the generation means; Equipped with The generating means generates a second optotype group to be displayed on the same screen of the optotype display means based on the switching signal from the signal acquiring means, and generates the second optotype group by randomly arranging a plurality of second optotypes in at least one of a row direction and a column direction, so that adjacent second optotypes have different contents; The display control means switches the screen display of the optotype display means from the first optotype group to the second optotype group, The generation means is configured to make the second optotype different from the first optotype when the row and column arrangement of the second optotypes constituting the second group of optotypes is the same as the row and column arrangement of the first optotypes constituting the first group of optotypes, and when the display position of the second optotype in the second group of optotypes overlaps with the display position of the first optotype in the first group of optotypes.

2. 2. The optotype presenting device according to claim 1, A visual target presenting device, characterized in that the multiple first visual targets in the first visual target group include the same first visual acuity value.

3. In the visual target presenting device of claim 2, The optotype presenting device, characterized in that the second optotype group is a second optotype including at least one of the same first visual acuity value and a second visual acuity value different from the same first visual acuity value.

4. A target presenting program for use in a target presenting device for presenting a target to a subject's eye, When executed by a processor of the visual target presenting device, a generating step of generating a first optotype group displayed on the same screen of the optotype display means, in which a plurality of first optotypes are randomly arranged in at least one linear direction of a row direction and a column direction, by making adjacent optotypes have different contents; a signal acquiring step of acquiring a switching signal for switching the first optotype group of the optotype display means; a display control step of displaying the first optotype group generated in the generating step on the optotype display means; and causing the visual target presenting device to execute the above. The generating step generates a second optotype group to be displayed on the same screen of the optotype display means based on the switching signal from the signal acquiring step, and generates the second optotype group by randomly arranging a plurality of second optotypes in at least one of a row direction and a column direction, so that adjacent second optotypes have different contents; The display control step includes switching a screen display of the optotype display means from the first optotype group to the second optotype group, The generation step is characterized in that, when the row and column arrangement of the second optotypes constituting the second group of optotypes is the same as the row and column arrangement of the first optotypes constituting the first group of optotypes, and when the display position of the second optotype in the second group of optotypes overlaps with the display position of the first optotype in the first group of optotypes, the second optotype is made different from the first optotype.

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