FI113493B - Device to facilitate the movement of the visually impaired - Google Patents

Description

1,113,497

The present invention relates to a device for the visually impaired, and more particularly to a device which enables the visually impaired to readily follow, for example, the white border of a road.

Visually impaired people usually move outside, usually using a traditional white cane and possibly a guide dog. Although, in theory, 10 very different aids have been developed for the visually impaired, based on the use of senses other than vision, only a few devices have actually been used in the daily movement of the visually impaired.

One device in use is the ultrasonic radar, which can be used to warn 15 visually impaired people about the risk of a collision. However, the features of the device do not include precise orientation to the obstacle because the ultrasonic beam transmitted by the device is approximately 10 degrees wide. Also, the beam cannot be narrowed because narrow-band radar gives too soft an echo of soft material.

Numerous other applications are also known, of which only a few have gone beyond trial use. One proposed device modifies the video signal of a CCD camera: '· to provide electrical stimuli to the optic nerves of the fundus: or to a separate sensor plate. The device is too obscure and therefore unusable.

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Other known devices proposed for use by the visually impaired, such as those described in U.S. Patent Nos. 5307137, 3654477 and 5487669, are used primarily on the radar principle, whereby they measure distance. The equipment is both expensive. that complex structure. Expression of continuous distance measurement! : · 30 frequency-changing audio signals, as occurs in the latter publication, cause an infernal signal cacophony as the device changes ;,; frequency all the time even as a result of small unintentional movements of the hand. For this reason, instead of accurately estimating the distance, the device causes an unacceptable frequency noise.

A disadvantage of all the known solutions described above is, in addition to the drawbacks listed above, that no one can detect contrast differences.

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Accordingly, it is an object of the present invention to provide a device which enables a visually impaired person to easily and safely follow, for example, a road edge or various colored lines marked on a hospital corridor to guide patients to desired locations.

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A further object is to provide a device for obtaining the desired information as an audio signal.

The foregoing and other advantages and advantages of the present invention are provided as set forth in the appended claims.

The invention will now be described in more detail with reference to the accompanying drawing, which shows, in principle, the basic features of a device developed for carrying out the method of the invention.

20: Thus, the figure shows the basic configuration of a device developed to perform the method according to the invention. The basic component is an oscillator 7, the frequency of which can be adjusted within certain limits by a suitable controller 12.

The oscillator 7 controls the amplifier 3 which supplies voltage to the laser 1. The light emitted by the laser 1 • 25 is controlled by suitable optics. Optic 2 in turn controls light transistors 4-6. The light transistor 6 controls the listening channel amplifier 10 which supplies the audio frequency to the headphones 13. The volume of the audio can be adjusted by a suitable control 11 in a conventional manner.

The light transistor 4 controls the amplifier 8. As the obstacle approaches the device, the light point of the laser 1 moves to the transistor 5, whereupon the amplifier 8 controls the oscillator ';'; 7 changing the frequency from, for example, the original 400 Hz to 500 Hz. Can •: · 1 use multi-frequency changes of frequency as the object continues to approach, Ί1? / c 7 3 I \ J 'i j v with a dedicated light transistor 4 and amplifier 9. For this purpose, the frequencies are optional and are examples only.

The device of the present invention differs substantially in function from previously known devices. The device has no deflection of the laser beam or field of vision, but the light beam of the laser 1 is modulated at a specific frequency, which frequency is directly heard through the photosensitive element, in particular the light transistor 6 and the amplifier 10. Thus, in addition to the actual listening channel, there is also at least another channel 4, 9 or 5, 8 which serves to change the laser modulation frequency at a certain distance 10 from the device. The principle is that a change in luminance in an object that is in the path of a laser beam causes a change in the volume level of the sound, which makes it easier to track a lighter and thus more reflective object.

In practice, the device can be made into a very small device, such as a flashlight 15, in which the transmitting optics and the receiving optics 2 are located at the front of the housing of the device and other operating switches and other appropriate means disposed.

The above structure is particularly simple and inexpensive to build. It is also very reliable due to the small number of parts. It has the particular advantage of being able to read contrast variations that no previously known device can. As a result of this, as mentioned above, the user can follow: for example, the edge of a road or other objects by simply moving the laser beam in the transverse direction, giving the lighter spot of accurate information. · 25 directions.

The invention can be modified in many ways without departing from the spirit and scope of the appended claims. The housing of the device according to the invention is small and its shape can be chosen as desired. 1 30 ·

Claims (3)

Apparatus for facilitating visual impairment of movement and reading of information, comprising a purposeful cut with a laser light source (1) and an apparatus (13) for listening to an amplified (10) audio signal, characterized in that the device further comprises an oscillator (7) for modulating the laser at a certain frequency and a light sensitive element, in particular a light transistor (6), for measuring the reflected light at said frequency and for generating an audio signal which is proportional to the reflected 10 amount of light. Device according to claim 1, characterized in that the device further comprises at least one other light-sensitive receiver, in particular a light transistor (4, 5), for gradually changing the modulation frequency of the laser according to the distance to the object of measurement. Device according to claim 1, characterized in that the device comprises headphones (13) for listening to the audio signal. • t>