JPS60241416A - Visual field measuring apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] The present invention relates to a visual field measurement device that presents an optotype to a subject and measures whether or not there is an abnormality in the visual field of the subject. It is.

BACKGROUND ART Conventionally, visual field measurement devices have been known that present an optotype to a subject and measure whether or not there is an abnormality in the subject's visual field. This visual field measurement device has a face receiving hole, and the inner part of the face receiving hole is a dome having a substantially hemispherical shape.
Light-emitting elements as visual targets are arranged on the inner surface of the 1-mimu based on a predetermined pattern. To measure the visual field, the subject inserts his or her face into the face receiving hole, keeps the line of sight constant, looks at the inner surface of the dome as the observation surface, observes the lighting of each light emitting element, and observes the lighting of each light emitting element. By operating a recognition switch, whether or not the lighting of a light emitting element existing in any direction of the line of sight is confirmed is counted as a take.

By the way, from the viewpoint of accurate measurements, it is required for visual field measuring devices to maintain the brightness of the observation surface at a predetermined level in order to keep the visibility of the subject constant. , the brightness of the observation surface is detected and the illumination light source that illuminates the observation surface is controlled so that the brightness of the observation surface becomes a predetermined brightness.However, the brightness of the observation surface becomes the predetermined brightness. Even though the illumination light source is controlled in this way, the observation surface may not have a predetermined brightness.

For example, if the illumination light source is about to burn out and its light emission amount decreases, and even though the illumination light source is controlled to increase the brightness, the brightness of the observation surface does not increase to the specified brightness. , the amount of external light entering the dome from the face receiving hole is too large, and even though the illumination light source is controlled to reduce the brightness, the brightness of the observation surface decreases to the predetermined brightness. There are cases where it doesn't.

The present invention has been made in consideration of the above-mentioned circumstances, and its purpose is to detect abnormal brightness of the observation surface when the brightness of the observation surface does not reach a predetermined brightness. It is an object of the present invention to provide a visual field measurement device which issues a warning as a result.

The features of the present invention include a determination circuit that determines whether or not the brightness of the observation surface is within a predetermined brightness range based on the brightness detection of the observation surface; A brightness abnormality warning circuit is provided which warns of abnormal brightness when the brightness of the observation surface is abnormal.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the visual field measuring device according to the present invention will be described below with reference to the drawings.

In FIG. 1, l is a visual field measuring device, and this visual field measuring device 1 is composed of a pedestal 2 and a visual field measuring device book #F.
It is roughly composed of three parts. The pedestal 2 is roughly composed of a pedestal section 4 and a support section 5, and includes a main body 3 of the visual field measuring device.
are attached to the two ends of the support column 5. The visual field measuring device main body 3 is configured such that the height of the support column 5 can be adjusted to change the height. The visual field measuring device main body 3 has a housing 6 . This housing 6 has a built-in dome 7 having a substantially hemispherical shape. A large number of light emitting elements 8 are arranged on the inner surface of the dome 7 based on a predetermined pattern.
is installed. This light emitting element 7 is here
It is composed of D elements and functions as an optotype. The housing 6 is provided with a panel 9 on the front thereof. A face receiving hole 10 is formed in this panel 9, and the person to be measured inserts his or her face into this face receiving hole 10 to respond to the measurement. In the face receiving hole 10,
A face rest for fixing the face is provided with a member 11, and the face rest is composed of a forehead rest part 12 and a chin rest part 13.

The visual field measuring device body 3 has an operation display device 1 on its side.
Four handles 15 and 16 are provided.

The handle 15 has the function of driving the face rest member 1 to adjust the height of the face, and the handle 16 has the function of driving the face rest member 11 to adjust the horizontal position of the face. This function allows the center of the line of sight to be aligned with the light emitting element as a fixed visual target placed at the center of the -C dome. Operation display device! 14 has an operation screen 17, a visual monitoring screen 18, a control switch 19, a light switch 19, and a monitor 20. Information including a plurality of operation commands is displayed on the operation screen 17, and an operation command can be selected by operating the control switch 19 and the light bezel 20. The fixation monitoring screen 18 displays the anterior segment of the subject's eye, allowing the measurer to monitor whether the subject is gazing at the fixed visual target. 711, at the bottom of the operation display device 14,
A printing mechanism 21 is provided so that the measurement takes are totaled and printed.

The light-emitting elements 8 are individually lit, and the person to be measured inserts his/her face into the face receiving hole lO, looks at the light-emitting elements with the line of sight fixed, and looks at the light-emitting elements that are individually lit. The main body 3 of the visual field measuring device is used to observe the light emitting elements 8 that are individually lit, and the main body 3 of the visual field measuring device is provided with a switch 22 for recognizing the lighting of the light emitting elements 8. .

1--A fluorescent lamp 23 is provided in the dome 7 as an illumination light source for illuminating the inner surface of the dome as an observation surface. This fluorescent light 23 is connected to a fluorescent light lighting circuit 24 as shown in FIG.
The light is turned on and off by the fluorescent light circuit 24.
has a switching transistor 25, and the fluorescent lamp 23 is turned on and off by this switching transistor 25.
It is something that will be destroyed. A light receiving element 26 is provided on the inner surface of the dome. This light receiving element 26 constitutes a part of a brightness detection circuit 27 that detects the brightness of the observation surface and outputs a brightness detection signal. This brightness detection circuit 27 has operation amblifiers 28 and 29, and the anode of the light receiving element 26 is connected to the non-inverting input terminal 10 of the operation amblifier 28, and the anode of the light receiving element 26 is connected to the ground. has been done. The output terminal of the operation amblifier 28 is a variable resistor 30
It is connected to the inverting input terminal of the operational amplifier 9, 4, 30 and the cathode of the light receiving element 26 through the resistor 31, and to the inverting input terminal of the operational amplifier 29 through the resistor 31. A non-inverting input terminal + of the operation amblifier 29 is grounded via a resistor 32. The output terminal of the operation amblifier 29 is connected to the illumination light source control circuit 3.
3 and is also connected to the inverting input terminal of the operation amblifier 29 via a resistor 34. The operation amblifier 28 outputs an output signal corresponding to a change in the amount of light received by the light receiving element 26, and the operation amblifier 29 has a function of amplifying the output of the operation amblifier 28 and outputting a brightness detection signal. ing. The output value of this brightness detection signal is shown using the symbol ■1.

The illumination light source control circuit 33 has a microprocessor 35, and the microprocessor 35 controls the reference voltage ■1.
The output value ■1 of the brightness detection signal is compared with the output value ■1 of the brightness detection signal, and the fluorescent lamp lighting circuit 24 is controlled so that the output value ■1 of the brightness detection signal approaches the reference voltage ■1. Here, this microprocessor 35 includes μ manufactured by NEC Corporation.
PC494 is used, and this μPC49/I is
It has a function of outputting a pulse with a predetermined period, and the switching transistor 25 turns on/off based on the pulse.
It is something that is turned off. The fluorescent light 23 blinks and blinks each time the switching transistor 25 is turned on and off, and its blinking cycle is set to a period that does not cause flickering, and the output value ■1 of the brightness detection signal is the standard. voltage v1
When the output value v1 of the luminance detection signal is higher than the reference voltage v1, the pulse width output from the μPC 494 is controlled so that the lighting time of the fluorescent light 23 becomes longer for each pulse. The pulse width output from the μPC 494 is controlled so that the lighting time of the fluorescent light 23 is short (S) for each pulse.

The brightness detection signal is input to a discrimination circuit 36, and the discrimination circuit 36 has a function of determining whether or not the brightness of the i-measured surface is within a predetermined brightness range that includes a predetermined brightness based on the brightness detection signal. are doing. This discrimination circuit 36 includes a comparison circuit 37, a NOR circuit 38, and a reference level setting circuit 39. The comparison circuit 37 includes a comparator 40 and a comparator 41, and the reference level setting circuit 39 is a parallel circuit including a resistor 42 and a resistor 43. Comparator 4
0 has a reference voltage level v3 applied to its positive terminal through a resistor 42, and a reference voltage level v2 is applied to its negative terminal to the comparator 41 through a resistor 43. The output value v1 of the luminance detection signal is connected to the negative terminal and the positive terminal of the comparator 41 via a resistor 44.
is to be given. Here, the reference voltage level VB is base II! Voltage level v,! The comparator 40 outputs H1 when the output value of the brightness detection signal ■1 is lower than the reference voltage level ■3, and output H1 when the output value of the brightness detection signal ■1 is higher than the reference voltage v3. The comparator 41 has a reference voltage level v
When the output value Vi of the brightness detection signal is lower than the reference voltage level v2, the output value Vi of the brightness detection signal is lower than the reference voltage level v2.
When 1 is high, the output is 1]. Comparison circuit 3
7 is the output value of the brightness detection signal ■1 is the reference voltage level ■2
The output of the comparator 40 is connected to the NOR circuit 38 via the resistor 45. The output of the comparator 41 is input to the other input terminal 48 of the NOR circuit 38 via the resistor 46.

, the NOR circuit 38 becomes L when the outputs input to its two input terminals 47 and 48 are both H,
In any other state, it becomes H, and the NOR circuit 38
The output is input to a brightness abnormality warning circuit 50 via a resistor 49. The brightness abnormality warning circuit 50 is the 1 discrimination circuit 36
Based on the determination result, when the brightness of the observation surface is not within a predetermined brightness range, the brightness of the observation surface is determined to be abnormal and has a function of warning of brightness abnormality. This brightness abnormality warning circuit 50 has a light emitting diode 52 for warning display such as switching I/Runsista 51, etc. When Switching 1 to Runsista 51 are turned on, the light emitting diode 52 is energized in six directions of arrows and turns on. The switching transistor 51 is turned on when the output of the NOR circuit 38 is set to 1, and the NOR circuit 38 is connected to the output of the comparator 40 and the When the output of comparator 41 is H, and when the output of comparator 40 is H and the output of comparator 4X is L, the output is 11, and the output of comparator 40 is The fact that the output of the comparator 41 is 14 is based on the output value Vi of the luminance detection signal P1
This corresponds to the case where the voltage level is higher than v3, and the fact that the output of the comparator 40 is 14 and the output of the comparator 41 is L means that the output value νl of the luminance detection signal is lower than the reference voltage v2. Correspondingly, the output of the comparator 40 is H and the output of the comparator 41 is ! (This corresponds to the case where the output value ■1 of the luminance detection signal is higher than the reference voltage level v2 and lower than the reference voltage level v3.

As explained above, the present invention includes a discrimination circuit that discriminates whether or not the luminance of the observation surface is within a predetermined luminance range based on the luminance detection of the wt measurement surface, and based on the discrimination result. When the brightness of the observation surface is not within the predetermined brightness range, a warning is issued indicating that the brightness of the 11th side is abnormal. Even though the illumination light source is controlled so that the side surface has a predetermined brightness, it can be confirmed that the observation surface is not at the predetermined brightness. This leads to the effect that the measurement accuracy is improved by preventing the measurement at the bottom.

[Brief explanation of drawings]

FIG. 1 is a perspective view illustrating a schematic configuration of a visual field measuring device according to the first aspect of the present invention, and FIG. 2 is a circuit diagram of the visual field measuring device according to the present invention. l.. Visual field measurement device, 23.. Fluorescent lamp, 26.. Light receiving element, 27. Brightness detection circuit, 28, 29.. Operation amblifier, 33. Light source control circuit for illumination, 36.. Discrimination circuit, 37.・・Comparison circuit, 38・Nor circuit, 39・Reference level setting circuit, 50・Brightness abnormality warning circuit, 52・・Light emitting diode. Figure 1 Procedural amendment (voluntary) August 6, 1980 Commissioner of the Japan Patent Office 1. Indication of the case 1982 Patent Application No. 94713 2. Name of the invention Visual field measurement device 3. Person making the amendment Related Patent Applicant Address: 75-1 Hasunuma-cho, Itabashi-ku, Tokyo Name: Tokyo Kogaku Kikai Co., Ltd. 4, Agent: 103 Phone: 669-4421 Address: 1, Nihonbashi Kakigara-cho, Chuo-ku, Tokyo. -13-126, Contents of the amendment: (1) In the first line of page 2 of the specification, after ``presentation,'' ``in response thereto'' is inserted. (2) On page 3, line 20, the phrase "does not reach brightness" is corrected to "[:does not fall within brightness range"]. (3) Correct the phrase “It is centered.” in lines 1 to 3 of page 6 to read “9 where the limit to be measured is placed at the center.” 9 (4) Line 11 of page 6 [Correct the fixation target J to [fixation shelf placed in the center of the dome]. (5) Lines 16 to 20 of the same page: ``The visual field measuring device body 3 uses the light-emitting elements 8 that are individually presented as optotypes while keeping the visual line direction constant.'' This is to judge whether or not it is possible to recognize the visual field measurement device main body 3. (6) On page 8, lines 15, 16, and 20, the words "microprocessor" are corrected to read "pulse width control circuit." (7) On page 9, line 13, the phrase "for each piece" is corrected to read "for each piece."that's all

Claims (1)

[Scope of Claims] An illumination light source that illuminates an observation surface on which an optotype is presented, a brightness detection circuit that detects the brightness of the observation surface and outputs a brightness detection signal, and a brightness detection signal output from the brightness detection circuit. A visual field measuring device comprising: an illumination light source control circuit that controls the illumination light source so that the brightness of the observation surface becomes a predetermined brightness based on a brightness detection signal, the predetermined brightness range including the predetermined brightness. a discriminating circuit for discriminating whether or not there is a luminance of the observation surface on the basis of the luminance detection signal; A visual field measurement device equipped with a brightness abnormality warning circuit that warns of abnormal brightness when the brightness of an observation surface is abnormal.