JPH0312895B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a walking aid for blind people. More specifically, when blind people walk, they use a white cane to avoid dangers such as obstacles and holes in their path, but this method can only detect obstacles up to a few centimeters above the ground. Therefore, the space above this area is unprotected, and the current situation is that people feel uneasy about walking.

According to the device of the present invention, it is possible to obtain a guide device for a blind person that eliminates the above-mentioned concerns and makes walking easier with a small, lightweight, and inexpensive device.

[Conventional technology]

Blind people lack sensory information from a white cane, so
We perceive circumstances in the outside world by perceiving environmental sounds and wind. But this perception is uncertain;
Furthermore, in the case of people who have lost their sight during the course of their lives, which accounts for 90% of blind people, this is almost impossible.

In order to eliminate the above drawbacks, ultrasonic sensors have been manufactured and commercially available. However, this type of equipment has the following drawbacks.

First, although the distance measurement information is accurate, the emitted sound wave spreads widely, and if the wavelength is made smaller in order to make it smaller, the reachable distance becomes small and practicality is lost. Therefore, there is a drawback that the direction of the obstacle cannot be determined.

Second, there is a drawback that the device is large and expensive.

Third, devices that use ultrasonic waves include those that are used as distance measuring devices that change the frequency of sound according to the distance to an obstacle, and those that use the auditory sense of sound source localization, which transmit and receive multiple ultrasound waves. There are devices that use elements to localize obstacles as sound images that correspond to distance and direction. Since the means of transmitting information to the blind person in these devices is auditory, the environmental sounds mentioned above are masked, and as a result, the amount of information from the environmental sound decreases, and the overall amount of information perceived by the blind person does not increase. Devices using this type have the disadvantage of high current consumption, making them unsuitable as walking aid devices. Furthermore, when blind people take the device away from their hands, they are unable to check whether the power switch is open or closed, which a sighted person can easily do, and they tend to forget to turn off the power switch.

Fourth, by the same applicant and same inventor as the present invention, a blind guide device using infrared beams has been disclosed as Japanese Patent Application Laid-Open No. 57-151807. However, there are some practical difficulties.

[Problems to be solved by the present invention]

The first, second, third, and fourth explained in the previous section
The problem that the present invention seeks to solve is to eliminate the disadvantages of the following items.

In order to understand the shortcomings, the current situation will be explained below.

Blind people walk with the help of a cane, but this is not limited to the range at their feet that the cane can reach, but by listening to the echoes of the clicks that are made when the tip of the cane hits the hard ground, they can walk at short distances around the blind person. It is possible to intuitively perceive relatively large objects such as walls. According to experiments, a screen placed in a long hallway can be perceived from 2 meters in front of you. this is,
The principle is the same as echo sounding using ultrasonic waves from bats and dolphins, and the sound source for humans is:
In addition to the sound of the cane mentioned above, there were also the sounds of footsteps and the rustling of clothes.

However, if the object is small or far away, it becomes difficult to accurately know the surrounding conditions, and sonar using a rangefinder is required. Many methods are known for measuring distances to other objects. There are methods that use electromagnetic waves or ultrasonic waves to calculate distance based on wave propagation time, methods that use wave interference, and methods that use the principle of triangulation. Devices using these means are large and expensive, and require high precision mechanisms. Additionally, devices using ultrasonic waves have the disadvantage that because the radiation waves spread widely, the direction cannot be determined and the distance cannot be measured for small objects. Furthermore, as mentioned above, people who have lost their sight during the course of their lives, who make up 90% of the blind, have uncertain perceptions of environmental sounds and are unable to understand the outside world.

As a walking aid for blind people, the signal obtained from the distance measuring device is input to a voltage-controlled oscillator and a voltage-controlled amplifier, and the earphone outputs a sound according to the distance to the object, and the intensity or weakness of the sound is output. By changing the pitch of the sound, or a combination of both,
There is a device that allows blind people to perceive the state of objects in the outside world as a single sound image in their heads.

However, as mentioned above, blind people's hearing is very sensitive, and wearing earphones in one ear, even if it is in one ear, hinders the ability to hear the sounds of the outside world. Furthermore, when the sonar outputs sound from a speaker, it is easy to hear the sound from the speaker in a small space such as indoors, but it is difficult to hear outdoors unless the volume is turned up. Furthermore, the sound coming out outside attracts attention to their blindness, which is good for them, but on the other hand, some people don't like it because it draws too much attention. Blind people can also read Braille with their fingertips, indicating that they have a keen sense of touch.

Therefore, a blind person's sonar is a compact, lightweight, and inexpensive ranging device that can measure the smallest possible area up to a distance of about 10 meters, knows the direction, takes a short distance measurement time, and has no mechanically moving parts. have equipment,
As a medium for allowing blind people to perceive, it is preferable to use a tactile method that does not interfere with hearing the sounds of the outside world, and an auditory method in combination.

[Means for solving problems]

The present invention provides novel configuration means as set forth in the claims in order to eliminate the problems of the conventional technical means described above.

[Effect]

According to the above-mentioned means of the present invention, the following effects can be achieved.

First, by pressing two juxtaposed push buttons,
You can tell the distance and direction to an object by distinguishing between the auditory sense and the tactile sense.

Second, the two push buttons mentioned above are tactile.
The first and second push button switches can be distinguished by determining the shape of the push button. Also, when you release your hand, it returns to normal and turns off the power, which prevents you from forgetting to turn it off.

Thirdly, there is an effect that the emission angle of the infrared beam can be changed. Therefore, during normal walking, there is no need to move the main body to scan, but when an obstacle is perceived, the infrared beam can be narrowed to determine its direction.

Fourthly, in the infrared region, unlike in the visible region, there is no selective reflection, that is, color recognition, so distance information can be obtained only from the intensity of reflected light. Therefore, when this effect is utilized, a short-range radar device can be obtained, and can be made small, lightweight, and inexpensive.

Fifth, by pasting or painting a retroreflective film on an object in advance, a particular object can be clearly perceived due to its significant reflected light.
Furthermore, by coding the reflective film, it is possible to perceive what the object is.

〔Example〕

Next, the details of the present invention will be explained with reference to the embodiments shown in FIG. 1 and subsequent figures. Since the same symbols indicate the same members, duplicate explanations will be omitted.

FIG. 1 shows a part of the external appearance of the main body of the device of the present invention.

In Fig. 1a, symbols 1a and 1b indicate two outer casings 1c and 1 made by plastic molding.
The part d is a fitting part between them.

Push button switches 2a and 2b indicated by dotted lines are arranged side by side on the upper surface of the outer casing. These details will be explained with reference to FIGS. 1b, c and 3.

On the back of the push button switches 2a and 2b, there is a
Although there are guide grooves 18 shown in the figure, they are omitted and not shown.

FIG. 1b is a view of FIG. 1a viewed from the direction of arrow A.

In FIG. 1b, push button switches 2a and 2b are juxtaposed between protrusions 1e and 1f (also shown with the same symbols in FIG. 1a). As shown in the figure, the surfaces of the push-button switches 2a and 2b are molded with protrusions (thin and long protrusions) that are perpendicular to each other, so a blind person can press the push-button switches 2a by placing his or her finger on them. , 2b.

The height of the protrusions 1e and 1f is the same as that of the push button switch 2.
The height is equal to or higher than that of a and 2b. Therefore, when the main body is stored in a bag or the like, it is possible to prevent the push button switches 2a, 2b from being closed by being pushed by the stored items, thereby inadvertently draining the battery.

The push button switches 2a, 2 shown in Fig. 1c are
The shape of the push button part b is made different to make it easier to distinguish between them. That is, the pressing part of the push-button switch 3a is rectangular, but the pressing part 3c of the push-button switch 3b is circular, and the central part bulges upward.

Therefore, by touching both with your finger, you can identify one of them. push button switch 3
The buttons a and 3b have the same function as the simple button switches 2a and 2b. Details of the push button switches 2a and 2b will be described later with reference to FIG.

FIG. 2 is a view of FIG. 1a viewed from the direction of arrow B, and shows the front side of the main body.

In FIG. 2, red filter plates 4a, 4b
is fitted into a hole of the same shape on the front of the main body. Converging lenses 5a, 5b are indicated by dotted lines on the back surfaces of the filter plates 4a, 4b. Filter 4
a, 4b and lenses 5a, 5b are shown with the same symbols in FIG. 3a.

The filter plates 4a and 4b transmit only wavelengths longer than red, and are used to block visible and ultraviolet light incident from the outside.

Since the lenses 5a and 5b have a short focal length of about 10 mm, it is preferable to use aspherical plastic lenses. FIG. 3a shows the configuration of an infrared light emitting section, that is, an infrared light emitting source and an infrared light receiving section, which are housed in the front part of the main body, and is shown with the outer casing 1a removed.

Although there is a mating groove in the fitting portion of the outer casings 1b and 1a, it is omitted and not shown.

A lens 5a is fitted onto the front surface of the cylinder 6, and a ring-shaped flange 6a is fixed to the lens 5a.

The base of a flat support 7a is fixed to the bottom of the outer casing 1b, and a light emitting diode (which emits a wavelength of 0.8 microns to 1 micron) serving as a photoelectric element is fixed to the recessed portion of the upper edge of the base. Its light emitting surface is located at the focal point of the lens 5a. Support body 7a
The protruding pieces 6b, 6c at the left end of the cylinder 6 are loosely fitted into the holes, and the protruding pieces 6b, 6c are connected to the springs 8a, 6c.
Although it is repelled to the left by support body 7a
The left end of the cylinder 6 contacts and stops.

The base of the support 7 is also fixed to the bottom surface of the outer casing 1b, and its upper edge is semicircular, on which the cylinder 6 is placed.

When the outer casing 1a is fitted to the outer casing 1b from above, a support body having exactly the same structure as the support body 7 is inserted into the outer casing 1.
a is also provided and comes into contact with the upper edge of the support 7,
The cylinder 6 is configured to be able to slide left and right. What is indicated by symbol 9 is a semi-cylindrical support body, and a lens 5b is fitted into the right end of the support body. An infrared photoelectric element (photodiode) 11 is fixed in the hole at the bottom of the left end, and is configured to receive infrared light incident from the right and obtain a corresponding output.

A semi-cylindrical support with the same configuration is also provided on the outer casing 1a to be fitted with the outer casing 1b, and when the outer casings 1a and 1b are fitted, the two supports provided on each are also aligned. , is configured to have a cylindrical shape.

Next, details of the push button switches (hereinafter abbreviated as electric switches) 2a and 2b will be explained.

In FIG. 3a, electric switches 2a, 2b
are provided on the upper surfaces of the outer casings 1a and 1b.

FIG. 3b shows details of the electric switches 2a and 2b. When the upper push button of the electric switch 2a is pressed in the direction of the arrow, the housed electric contact closes, and when the pressing force is removed, it springs back and opens.
Two sets of the electrical contacts described above are housed and open and close at the same time. Symbol 20a is their derivation line.

Long rods 18a, 18b whose bases are fixed to the back surface of the electric switch 2a are adapted to slide left and right through long holes 18, 19 provided in the fitting portions of the outer casings 1a, 1b.

As shown in FIG. 3a, the lower end of the long rod 18a is
Since the electric switch 2a is in contact with the ring 6a from the left side, the electric switch 2a is always biased to the left and stopped.
In order to prevent the electric switch 2a from coming off upward, an E-ring is fitted as shown.

When the push button of the electric switch 2a is pressed, two sets of internal electric contacts are closed, and when it is further pressed and slid to the right, the cylinder 6 in Fig. 3a moves to the right (in the direction of arrow D) together with the ring 6a. . Assuming that the light emitting surface of the light emitting diode 10 is at the focal point before the movement, the infrared beams are emitted in parallel as shown by dotted lines 12a and 12b. However, when the cylinder 6 moves in the direction of arrow D, the infrared beam becomes diffused. The effects of such means will be described later.

The case where the electric switch 2b is pressed from above (in the direction of arrow C) will be described below with reference to the sectional view of FIG. 3c.

An elastic metal disk 21c is fixed to the back surface of the push button 2, its edges are bent, and its outer periphery is fixed to the inside of an outer casing made of a plastic molded body.

Ends of the voice coils 21a and 21b, which are wound into a ring shape and solidified, are fixed to the disk 21c.

Embedded in the bottom surface of the outer casing is the lower surface of a donut-shaped mild steel plate press member 22a whose cross section has the shape shown in the figure.

A ring-shaped ferrite magnet 22 is fixed to the inner ring of the press member 22a.
a becomes a magnetic path, and the inner and outer surfaces are magnetized to N and S poles so that magnetic flux penetrates the voice coils 21a and 21b.

When alternating current is applied to the voice coils 21a and 21b, the disc 21c, that is, the push button 2, vibrates up and down. At this time, the push button 2 is pressed downward, and the electrical contact 2
3 is pressed to close.

The long rods 19a and 19b whose bases are fixed to the bottom surface of the electric switch 2b are attached to the outer casing 1 as shown in figure b.
It is designed to be able to slide left and right through the long holes in the fitting portions a and 1b. The electric switch 2b has the same structure as the electric switch 2a in that the E-ring prevents the electric switch 2b from escaping upward.

The protrusion on the right side of the electric switch 2b is in contact with the electric switch 2a, so the electric switch 2b
When pressed and moved to the right, electric switch 2a
Therefore, as described above, the angle at which the infrared beam is emitted by the light emitting diode 10 becomes wider.

Symbol 20b is an electrical switch 23 and a voice coil lead-out terminal. In this embodiment, a voice coil motor is used as a drive source for vibrating the push button 2, but the same purpose can be achieved by using a well-known piezoelectric element.

Next, referring to FIGS. 6, 7, and 8, a means for obtaining distance measurement information to an object using an infrared light beam will be explained.

There are two methods, but the first principle is to focus the radiated electromagnetic waves onto the object to be measured in the form of a beam and project it.
At this point, the intensity or energy of the reflected electromagnetic wave, that is, the integral value, is received as an amount inversely proportional to the second power of the distance. Therefore, distance information can be obtained.

The second principle is as follows. As mentioned above, it is common knowledge that waves reflected from an object have different reflectances. However, this comes from the concept of colors in the visible range; the concept of colors outside the visible range disappears, and the reflectance remains almost constant. Therefore, by using, for example, a light emitting diode with a wavelength of about 1 micron that emits light in the infrared region, distance measurement can be performed according to the first principle described above. It is also possible to use a laser beam in the infrared region. The above-mentioned distance measurement information is inversely proportional to the second power of the distance to the object, but since this causes significant attenuation in practice, it is better to use distance measurement information that is inversely proportional to the first power of the distance.

Next, the explanation will be given with reference to FIG.

The embodiment shown in FIG. 6 uses the received illuminance of reflected light as distance information, and the output of the oscillation circuit 42 and the output of the monostable circuit 41 are indicated by symbols A-1 and A-1 on the graph of the time chart shown in FIG. It is shown as B-1.

Also, capacitor 41b, transistor 41a
Due to the action of , a sawtooth wave is created and the operational amplifier 3
The output of 7 is shown in graph C-1 of FIG. The output of the operational amplifier 39 is the transistor 39
Since the base voltage of a is provided, the transistor 39
The charging current of the capacitor 38d via the eighth
It will look like graph C-1 in the figure. Therefore, the charging voltage of the capacitor 38d is in the form of integrating the current in graph C-1, and is proportional to the second power of the current.
This is the voltage applied between the base and emitter of a. Therefore, the current flowing to the light emitting diode 10 via the transistor 38a becomes as shown in graph C-2 in FIG. 8 over time. transistor 38c
A base current is obtained through the inverting circuit 40 and conducts, discharging the capacitor 38d.

Since the output of the high frequency oscillation circuit 43 is input to the base of the transistor 38b, the current flowing through the light emitting diode 10 is modulated and becomes as shown in the graph F-1 of FIG. Furthermore, graph D-1
is the output of the oscillation circuit 43. Further, symbol 36 is the positive terminal of the DC power supply.

The modulated infrared rays of the light emitting diode 10 are focused by the lens 5a and projected in the direction of the arrow, and the reflected and scattered light from the object passes through the lens 5b.
The light is incident on a photodiode 11 which serves as a light receiving element. This electrical signal proportional to the illuminance is amplified by an operational amplifier 48, the output of which is shown by graph G-1, and the output of filter capacitor 48a is shown by graph H-1. Since the reference voltage is inputted from the reference voltage source 44 to the operational amplifier 49 which serves as an analog comparator, when the illuminance of the photodiode 11 reaches the set value, a detection signal is inputted to the flip-flop circuit 47 to set it. The output is differentiated and input to the analog switch 45. analog switch 4
5. The operational amplifier 46 and the capacitor 46c form a sample hold circuit.

The output of the operational amplifier 49 changes from graph I-1 to J-1 in FIG.
When the input to the terminal disappears, it becomes low level. Therefore, the output of the operational amplifier 49 is as shown in graph J in FIG.
-1. The differential pulse of the above signal becomes the control input of the analog switch 45, resulting in the graph K-1 in FIG.

The output of the operational amplifier 37, that is, the analog switch 4
Since the voltage of the input on the left side of 5 is increasing in proportion to time, it becomes the straight line Z in the graph of FIG. 7b. Therefore, the output voltage of the output terminal 47a of the operational amplifier 46 is as follows after the infrared beam starts to be emitted.
It corresponds to the time until the differential pulse of graph K-1 arrives, and is as shown in graph L-1 in FIG. If there is no change in the distance to the object, it will be a straight line. Graph L-1 shows that the distance has changed by the difference in level.

The output voltage of the terminal 46a provides distance information to the object to be measured, and the details will be explained with reference to the graph of FIG. 7a.

The horizontal axis is the voltage obtained from the above-mentioned terminal 46a, which increases linearly with time as described above in the graph of FIG. 7b, so it can be considered as a time axis. The vertical axis represents the light receiving illuminance L of the photodiode 11 described above. It also increases correspondingly to the current flowing through the light emitting diode 10. The farther the distance to the object is, the smaller the illuminance received by the photodiode 11, that is, the input signal to the operational amplifier 48 in FIG. 6, decreases in inverse proportion to the second power of the distance. Assuming that the distances to the object are r ₁ and r ₂ and the set illuminance of the photodiode 11 is L ₀ , the output of the terminal 46a becomes voltages V ₁ and V ₂ at this illuminance. The curves with symbols X and Y indicate the light receiving illuminance curves of the photodiode 11 when the distances to the object are r ₁ and r ₂ (r ₂ >r ₁ ).

At this time, the illuminance L is, if the distance is r, L=E/r ² (E is the brightness of the object surface) Since the brightness E increases with time T or voltage V in proportion to its second power, E=K ₁ T ² or E=K ₂ V ² . Therefore, the above equation is L ₀ = K ₂ V ² / ₂ / r ² / ₂ = K ₂ V ² / ₁ / r ² / ₁ or L ₀ = K ₁ T ² / ₂ / r ² / ₂ = K ₁ It can be expressed as T ² / ₁ / r ² / ₁ . Therefore, the time to the point where the curve is cut at the set illuminance L ₀ is proportional to the distance to the object. That is, it is proportional to the output voltage of terminal 46a in FIG.

In addition, to find the point where the curves X and Y are cut at the set illuminance L ₀ , the output voltage of the photodiode 11 is
This is equivalent to comparing the voltage of the reference voltage source 44 using the operational amplifier 49.

The frequency of FIG. 8 A-1 is about 100 to 1000 hertz, and the frequency of graph D-1 is about 10 kilohertz to 100 kilohertz. Furthermore, since the above-mentioned modulation is performed, the influence of other infrared rays, such as those contained in the sun, can be removed.

The embodiment shown in FIG. 9 uses the energy of the reflected light wave as distance information.

Now, if we consider the case where the luminous intensity of the light emitting diode 10 increases linearly, the photodiode 1
The received light illuminance of 1 is K ₁ L/r ² where K ₁ is the reflectance of the object and L is the luminous intensity. r is the distance to the object. Since L increases linearly with time,
Letting time be t, the received light illuminance is K ₁ K ₂ t/r ² . K ₂ is a proportionality constant. The output of the light receiving amplification circuit is also proportional to t/r ₂ . If you integrate that signal, it will be proportional to t ² / r ² , and the fact that it has reached the set value indicates that t ² / r ² = 1 constant value. , the time t required to reach the set value is proportional to r. The details will be explained with reference to the embodiment shown in FIG.

In FIG. 9, A-12, A-2, A-
The voltage waveforms of the respective parts indicated by 3, . . . are indicated by the same symbols in the time chart of FIG.

The sawtooth wave oscillation circuit including the oscillation circuit 42, the monostable circuit 41, the transistor 41a, the capacitor 41b, and the operational amplifier 37 has the same function and effect as the case shown in FIG.
The output of graph A-3 in FIG. 10 is a sawtooth wave.

Further, the transistor 38a and the operational amplifier 38 are connected to the sixth
The same effect as in the case shown in the figure is performed, and since the input to the + terminal of the operational amplifier 38 is performed by the output of the operational amplifier 37, the light emitting diode 10
A sawtooth wave current is applied.

At the same time, the output of the high frequency oscillation circuit 43 (graph A
-4) controls the transistor 38b in the saturation region, the current flowing through the light emitting diode 10 and the light emission curve proportional to this are
It is modulated as shown in graph A-5 in Figure 0.

Upon light reception by the photodiode 11, the output proportional to the received light illuminance is amplified by the operational amplifier 48, and this waveform becomes graph A-6 in FIG. 10, and the output waveform of the filter capacitor 48a is as follows.
It will look like graph A-7. Synchronous detection circuit 53
corresponds to an analog switch, and the detection output is as shown in graph A-8. Therefore, it has the effect of being isolated from external noise and obtaining only the required signal output.

The output of the synchronous detection circuit 53 is an operational amplifier 51,
It is integrated over time by a capacitor 50a. The analog switch 50 is closed by the output of the monostable circuit 41, and the capacitor 50a is closed by the output of the monostable circuit 41.
It is discharged only during the positive pulse width of Figure A-2.

The output of the operational amplifier 51 is proportional to the received light intensity (which can be considered as the received light energy), and is shown in graph A-9 in FIG. 10.

The rising edge of the sawtooth wave in graph A-8 is proportional to t/r ² , and the integral value is proportional to t ² /r ² . This becomes the rising curve of graph A-9.

The operational amplifier 52 obtains a detection signal by setting a comparison level for this rising curve from the reference voltage of the reference voltage source 44. Therefore, graph A-
The straight line 44a of 9 indicates the above-mentioned comparison level. Therefore, from the position corresponding to the intersection,
The output of the operational amplifier 52 is obtained, and this output is converted into a hold pulse (shown in graph A-10) through the differentiating circuit and inverting circuit 45b, this hold pulse closes the analog switch 45, and this output is , operational amplifier 46, capacitor 4
It is held through a sample hold circuit consisting of 6c.

The output of the analog switch 45 is the operational amplifier 3.
7, that is, the peak value of the rising straight portion of the sawtooth wave. This peak value becomes a voltage proportional to the time from the start of light emission until the integrated output of the operational amplifier 51 reaches a predetermined value. In other words, since it indicates the time t until the aforementioned t ² /r ² becomes a constant value, the terminal 46
The output of a is a voltage proportional to the distance to the object to be measured, and the output shown in graph A-11 is obtained.

Next, a method will be described in which a blind person is made to perceive the distance to an object using the two methods described above, that is, a distance measuring device that calculates the distance to an object from the received light illuminance and the received light amount.

Next, a method for making a blind person perceive distance information based on distance information to an object, that is, the output voltage of the terminal 46a in FIGS. 6 and 9 will be explained.

In FIG. 11a, the terminal 46a of FIGS. 6 and 9
The output is input to the terminal 53a, and in response to this input, electric vibration is generated by the F-V conversion circuit.

Assuming that the distance to the object responds up to 6 meters, the change between 6 meters and 0.1 meters is 100
About 1000 cycles is best.

The circuit for converting input voltage into electrical vibrations may be any known circuit. The output of the F-V conversion circuit 53 is sent to the amplifier circuit 55 via the changeover switch 54.
a, 55b, and then emitted as a sound wave from the speaker 56 or the voice coil 21.
(shown as symbols 21a and 21b in FIG. 3c), which causes the push button 2 to vibrate.

If the input frequency of the voice coil 21 is lower than the sound wave of the speaker 56, the tactile sensation of human fingertips will be perceived more clearly, so a circuit is installed before the amplification circuit 55b to reduce the frequency to 1/2 to 1/3. 55c may be added.

FIG. 11b shows an example of the V-F conversion circuit 53. The inputs of the terminal 53a are the 6th and 9th
This is the output of the terminal 46a in the figure.

The input at terminal 53a is amplified by transistor 59a and charges capacitor 57.

When a predetermined charging voltage is reached, the SCR or trigger diode 58 discharges and the base input of the transistor 59b is obtained, so that the voice coil 21 or the excitation coil 56a of the speaker 56 is energized via the changeover switch 54.

The smaller the input voltage of the terminal 53a, that is, the smaller the distance to the object, the larger the base current of the transistor 59a, and therefore the higher the frequency at which the transistor 59b conducts. Therefore, the speaker 56
The sound waves are high-pitched. Or press button 2 in Figure 3 c.
The frequency of vibration increases.

It is more effective to use a circuit that increases the amplitude by adding to the frequency change.

Although not shown, the circuits shown in FIGS. 6, 9, and 11 are housed together with a battery serving as a power source in the main body consisting of the outer casings 1a and 1b shown in FIG.

Hold the main body in your hand so that the surfaces of the lenses 5a and 5b in Figs. 1 and 3 face the object, and press the push button electric switch 2a with the tip of your thumb.The power switch turns on the power, and at the same time The changeover switch 54 shown in FIG. 11 is switched, and the speaker 5
6 (housed in the main body) emits sound waves corresponding to the distance to the object. A blind person can tell the distance to an object by hearing it.
Therefore, it is possible to walk while avoiding obstacles.

If the object is a pedestrian, training can also be used to learn whether the object is approaching towards you or moving away from you.

By holding the device in your hand and pointing it up, down, left, or right, you can perceive the distance to objects in the outside world, making it easier to walk.

When there is a lot of noise, such as on the road, or when it is necessary to judge external sounds based on the sounds that enter your ears, or when the generated sound waves cause a nuisance to others, press the push button switch 2b shown in Fig. 3. . In this case, the power switch is only turned on, but since the selector switch 54 shown in FIG. 11b is spring-backed to the position shown in the figure, vibrations are generated from the fingertip touching the push button 2 shown in FIG. 3c. perceived.

Therefore, the higher the frequency, the closer the object is, which can provide an effective means for walking.

It is also possible to use one power switch in common, so that when either push button switch 2a or 2b is pressed, the actuator of the power switch is pressed and the power is turned on.

juxtaposed push button switches 2a, 2b or 3
Since they have different shapes, they can be identified by the tactile sensation of the fingertips, and the vibrating body of the fingertips and distance measuring means using sound waves can be easily selected as needed, so they are effective for use by blind people.

Since the device of the present invention uses the infrared region, there is no selective reflection, and therefore there is no reflectance difference of more than 10 to 20% for white, black, red, and blue colors.
It has the feature of being able to obtain useful ranging information. However, in the case of a transparent glass plate, if the object surface is significantly tilted or the object is small, the amount of reflected light will be small, and the object will be perceived as being farther away than the actual distance.

If the object is close to the blind person (approximately 0.1 to 0.2 meters), the above-mentioned false signal may cause a collision.

Even when there is a decrease in reflectance and reflected light,
Next, a method for making the user perceive that the distance is 0.1 to 0.2 meters will be explained. In FIG. 3a, the beam emitted from the infrared light emitting section is located between the dotted lines 12a and 12b in parallel;
It diffuses between a and 13b. The shaded area is the diffusion area. In order to know the distance of objects as far away as possible and to know small objects, it is preferable that the beams are emitted as parallel as possible.

If the infrared light receiving section is sensitive only to parallel beams, it will not be able to receive the scattered light of the infrared beam projected onto the object. Therefore, the ideal condition is to remove the lens 5b so that the light receiving angle spreads out to 180 degrees. However, such means causes a decrease in the illuminance of the light received by the photodiode 11, making it impossible to distinguish distant objects. Therefore, the sensitivity is increased through convergence by the lens 5b, and the spread of the light receiving angle is indicated by the dotted line 1.
4a and 14b. For this reason, the light-receiving surface of the photodiode 11 is placed slightly offset from the focal point of the lens 5b.

Also, due to the reflection on the inner surface of the cylinder 9, the dotted lines 15a, 1
The acceptance angle extends to between 5b and 5b. Of course, dotted lines 14a and 15a and dotted lines 14b and 1
5b, the sensitivity decreases.

The ideal condition is that if the direction of the optical axis of the lens 5b is the dotted line 17a, the optical axis is tilted from this by the amount indicated by the arrow 17 to be in the direction of the dotted line 17b, and the dotted line 1
The point of intersection of lens 7b and the optical axis of lens 5a is the distance of the farthest point for object detection (generally about 6 meters).

Dotted line 1 passing through the intersection of dotted line 15a and dotted line 13b
Objects to the left of 6a cannot receive reflected light and therefore cannot be detected. Also, dotted line 14a and dotted line 12a
Objects on the right side of the dotted line 16b at the intersection with the dotted line 16b can be completely detected.

When there is an object between the intersection of dotted lines 14a and 12a and dotted line 16a, the closer the object is to the infrared receiver, the smaller the output of the photodiode 11 becomes. As we go, we reach the intersection of dotted lines 14a and 12a, that is, dotted line 1.
6b (the distance to the object is preset at about 0.1 to 0.2 meters), the frequency of the sound emitted from the speaker decreases, or the frequency of the push button 2 begins to decrease. The position of the above-mentioned intersection has no relation to the reflectance of the object, so it is effective because it allows accurate information on the distance to the object.

Even when directly facing a transparent glass plate, it is possible to know when the distance is 0.1 to 0.2 meters by the above-mentioned means. Therefore, there is an effect that the risk of collision can be avoided.

As mentioned above, the dotted lines 12a and 12b in FIG.
In other words, if the infrared beam is made as thin as possible, distance information about small objects can be obtained.

However, blind people have to hold the device in their hands and rotate it vertically and horizontally to change its orientation. If the infrared beam is spread out, this is not necessary. The ideal spread is a rectangle with a distance of 2 meters, a height of 1.5 meters, and a width of about 0.5 meters.

This shape is shown in Figure 5a with dotted lines 32a and 32b having lengths of 0.5 meters and 1.5 meters, respectively. The blind pedestrian is the position of the light emitting diode 10.

However, the illuminance of the infrared beam emitted with the above-mentioned spread on the object surface is small, making it impractical.

The length in the direction of the dotted line 32b is slightly reduced to the solid line 31.
The infrared beam has a rectangular spread as shown by arrow F.
By rotating the main body held in your hand up and down, you can scan the required area (the space that a person passes through).

At this time, when a detection signal indicating that there is an obstructing object is output, the infrared beam is narrowed down to the spread shown by symbol 31a by the means described later, and by rotating the main body vertically and horizontally, Since information about direction and distance can be obtained, it is effective to avoid this while walking.

In the case shown in FIG. 5b, the spread of the infrared beam is circular as shown by symbol 33, and by rotating in the direction of arrow G, an obstacle in the space shown by dotted line 34 can be detected. By narrowing down the infrared beam to a small size as shown by symbol 33a, exactly the same effect as in the case of figure a can be obtained.

Next, referring to FIG. 3, a means for narrowing down the infrared beam will be explained.

In the state shown in FIG. 3a, there is no light emitting diode 10 at the focal point of the lens 5a, so the infrared beam is spread out as shown by symbols 31 and 33 in either FIG. 5a or b. There is.

In this state, the blind person presses the push button switch 2a in Figure 3.
When walking while pressing one of 2b,
The presence of an obstacle ahead is perceived by sound waves or vibrations to the finger. At this time, it is only known that the object is within the range of symbols 31 and 33 in FIG.

At this time, press the push button switches 2a and 2b as shown in Figure 3a.
When the ring 6a is pressed and slid in the direction of arrow D, the long rod 18a presses and moves the ring 6a in the same direction, and the light emitting diode 10 becomes the focal point of the lens 5a. Therefore, the infrared beam becomes parallel light and falls between the dotted lines 13a and 13b. By rotating the main body up, down, left and right, it is possible to know the distance and direction to obstacles, so you can avoid them while walking.

When you release your hand from the push button switch, it springs back and the power is cut off, and the cylinder 6 and lens 5a also spring back. Push button switch 2a, 2b
The same purpose can be achieved even if the infrared beam is narrowed between dotted lines 13a and 13b when pressed in the direction of arrow C, and expanded when pressed in the direction of arrow D.

The same purpose can also be achieved by controlling the expansion and aperture of the infrared beam by sliding the push button switches 2a and 2b with fingers in the direction opposite to arrow D.

As mentioned above, by using a cane and the device of the present invention, it is possible to perceive the ground and objects above it, but blind people may also be troubled by the following problems.

First, when you return to your home, you can tell that you have arrived in front of the house, but you cannot find the front door knob.

On both sides of the door knob 24 in Fig. 4a, a fourth
As shown in FIG. The detection current is
It will be about 200 times more. Therefore, by scanning left and right, 2
Since two detection signals are obtained from a distance, the user can easily find the knob by walking in that direction.

The retroreflective film is made as follows. Glass bulbs are made into a fine powder and then diffused into transparent plastic to form a film, which has the ability to reflect light in the direction of the projected light without scattering. Since there is no scattering, it is not very useful as distance information, but it has the feature of being able to reliably know the direction.

Even if you stick Scotch tape on the door knobs of public buildings and the door knobs of the toilets, it will not work for blind people.
This is effective because the locations of these objects can be seen from a distance. In this case, it is effective to code the number of Scotch lights 25a and 25b to be different in order to identify whether the knob is for the entrance door, an internal room, or a toilet door. be.
It can also be used for the same purpose at home.

When staying at a hotel, it is nearly impossible for a blind person to walk down the hallway and find the doorknob to his or her room. In this case, when leaving the club room, as shown in FIG.
If you hang the string 25d at the top of the Scotchilight 25c, you can easily find it using the infrared beam when you return home. In this case, Scotchilite 25
Since it is not possible to attach the C.c., it is better to use one that has retroreflective films on both sides.

Several methods of assisting blind people walking on roads have already been implemented. The most common ones are
This is a method that allows you to reach your destination by creating an uneven surface on the road and stepping on it while walking.

Although such measures are effective, they are expensive to implement and have only been implemented on some roads. Also, this is not a good thing for ordinary pedestrians.

The currently implemented white road signs include:
Microscopic glass bulbs are mixed in to increase reflected light. Therefore, when using the device of the present invention, the sign can be identified by its strong reflected light.

When a large number of vitreous bulbs are mixed in, the identification becomes easier. The white paint is prepared and applied along the road 26 as shown in FIG. 4b.
Apply b. The coating means can be easily applied in the same manner as the coating of road signs that is already practiced. This is an effective means for blind people because they can walk and reach their destination while searching for the signs 27a and 27b with the infrared beam pointing downward.

FIG. 4c is an example for informing a blind person of a crosswalk on a road 28.

White line 29 with the same code as the well-known crosswalk sign
a, 29b, ... with white paint for a retroreflective film, and then 1 with the same paint at right angles to them.
Paint the white line 30 on the book.

When a blind person crosses from the direction of arrow E, he first sees the white lines 29a, 29b, . . . juxtaposed by the infrared beam.
, and then cross along the white line 30.

Therefore, it is possible to cross the road without feeling anxious.

〔Effect of the invention〕

According to the device of the present invention, the following effects can be achieved.

First, by using it in conjunction with a cane, it is possible to perceive obstacles in space above the ground.

Second, it is smaller, lighter, and less expensive than known means that utilize ultrasound. In addition, it is possible to know the direction of an object.

Thirdly, it is possible to selectively use methods that utilize the sense of hearing or the sense of touch of the fingers.

Fourthly, since it is possible to freely choose to widen or narrow down the spread of the emitted infrared beam, it is possible to easily perceive obstacles and to reliably obtain direction and ranging information.

Fifth, the push button switch that controls the emission of the infrared beam is configured to be easy for blind people to operate.

Sixth, by painting a retroreflective film on the road surface or coded and pasting it on door knobs, etc., and scanning and identifying it with an infrared beam, it can be used as a road guide and to identify objects. I can sense what is there.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the external appearance of the device of the present invention, Fig. 2 is a front view thereof, Fig. 3 is an explanatory diagram of the push button switch and the infrared light emitting and receiving device, and Fig. 4 is an illustration of the road. An explanatory diagram when the device of the present invention is used for guidance and object perception. Figure 5 is an explanatory diagram of an example of use when the infrared beam is expanded and condensed. Figure 6 is an illustration of the electric power of the device of the present invention. Circuit diagram, FIG. 7 is a graph showing the principle of distance measurement, FIG. 8 is a time chart of electrical signals of each part of the electric circuit of FIG. 6, and FIG. 9 is another implementation of the electric circuit of the device of the present invention. For example, Figure 10 shows
FIG. 9 shows a time chart of electrical signals of various parts of the electrical circuit of the embodiment, and FIG. 11 shows an electrical vibration generating circuit diagram of the device of the present invention. 1a, 1b...outer casing, 2, 2a, 2b, 3a, 3
b...Push button switch, 1e, 1f...Protrusion, 4a,
4b...Red filter, 5a, 5b...Lens, 6,
9... Cylinder, 6a... Ring, 8a, 8b... Spring, 7, 7a... Support body, 10... Light emitting diode,
11...Photodiode, 6b, 6c...Protruding piece,
18a, 18b, 19a, 19b...long rod, 18,
19...Long hole, 20a, 20b...Leading wire, 23...Electric switch, 21, 21a, 21b...Voice coil, 22...Magnet, 21c...Elastic disc, 2
2a... Mild steel press member, 24... Door knob, 25
a, 25b, 25c... retroreflective film, 26, 28
...Road, 27a, 27b, 29a, 29b,...,
30... Retroreflective film white paint, 25d... String, 3
1a, 33a, 31, 33... spread of infrared beam, 41... monostable circuit, 42, 43... oscillation circuit,
36...DC power supply positive electrode, 38a, 38b, 38c,
41a, 59a, 59b...transistor, 40,
45b...inversion circuit, 37, 38, 39, 46, 4
9, 48, 51, 52... operational amplifier, 44... reference voltage source, 45, 50... analog switch, 47...
Flip-flop circuit, X, Y...light receiving illuminance curve,
A-1, B-1,..., L-1... Time chart of voltages at various parts of the electric circuit in Figure 6, 53... Synchronous detection circuit, A-2, A-3,..., A-12... Figure 9 44a...Reference voltage, 53...Electric vibration generation circuit corresponding to the voltage, 55a, 55b, 45a...Amplifying circuit, 56a
...excitation coil of the speaker 56.

Claims (1)

[Scope of Claims] 1. An infrared light emitting section provided on the front surface of the main body, which includes an infrared light emitting source and a converging lens that emits infrared light forward in the form of a beam with a predetermined emission angle, and an infrared light emitting source. Contains a photoelectric element that converges and receives reflected light from an object illuminated by a converging lens,
It is placed in parallel with the above-mentioned infrared light emitting part at a predetermined distance on the front of the main body, and the distance to the object is 0.1 to 0.2.
An infrared light receiving section whose amount of received light gradually decreases when approaching the object more than a meter, an electric circuit that obtains distance information to the object through the received light intensity or received light energy of the photoelectric element, and the distance obtained from the electric circuit. an oscillation circuit that generates electrical vibrations at an audible frequency having a frequency and amplitude corresponding to information, and an oscillation circuit that opens and closes power supply from a power source to the above-mentioned electric circuit and oscillation circuit, and which are arranged adjacent to each other on the outside of the main body. 1. A second electric switch, and a first electric switch.
By closing a second electric switch, the output of the oscillation circuit drives a speaker housed in the main body to generate sound waves, and by closing a second electric switch, the output of the oscillation circuit drives the main body. A device that drives a vibrator housed in the body to allow distance information to be perceived by the tactile sensation of the hand gripping the main body, and a code that is pasted or painted on a specific object to be detected and is irradiated with an emitted infrared beam. A guide device for a blind person comprising a retroreflective film. 2. A guide device for blind people according to claim 1, characterized in that it is constituted by a retroreflective film applied in a narrow strip along the road edge. 3. A guide device for a blind person according to claim 1, characterized in that it is constituted by an elongated retroreflective film attached in parallel to both sides of a door knob. 4. A guide device for a blind person according to claim 1, characterized in that it is constituted by an elongated retroreflective film that can be attached to and removed from a door knob using a hanging string. 5. A blind person according to the claim set forth in item 1, characterized in that a retroreflective film is applied to one road crosswalk in the walking direction and in parallel to the crosswalk in the vertical direction. guide device.