WO2000036839A1

WO2000036839A1 - Aid for visually handicapped people

Info

Publication number: WO2000036839A1
Application number: PCT/SE1999/002386
Authority: WO
Inventors: Bernt Mannesson
Original assignee: Lvi Low Vision International Ab
Priority date: 1998-12-17
Filing date: 1999-12-16
Publication date: 2000-06-22
Also published as: AU3091700A; SE9804373D0; SE520259C2; SE9804373L

Abstract

An aid for visually handicapped people, which comprises a stand (6) that carries a video camera unit (10) for scanning an object (5) that holds a defined position in front of the camera unit (10), and a display (2) connected to the camera unit (10) for showing an enlarged image of at least part of the scanned object (5). The camera unit (10) is mounted on the stand (6) with the aid of a universal joint and, for scanning the object (5), the camera is pivotable about the universal joint by an operating device.

Description

AID FOR VISUALLY HANDICAPPED PEOPLE

The present invention relates to an aid for visually handicapped people, which comprises a stand that carries a video camera for scanning an object that holds a defined position m front of the camera, and a display con- nected to the camera for showing an enlarged image of at least part of the scanned object

Aids intended for visually handicapped people and comprising a video system for optical enlargement are previously Known and are getting more and more popular concurrently with the technical αevelopment, especially of tne electronic components included

An aid comprising a reading desk is the most common, on which the object to be scanned by the camera is placed. This reading desk is either manually displaceable forwards and backwards as well as to the right and the left m relation to the user, or, controlled by e.g. a joystick, displaceable by servomotors m the corresponding directions and, thus, this makes it possible to show on the display selected parts of the object m an en- larged form. Advantages of the aids comprising displaceable reading desks are the facts that they are relatively easy to use and that they can scan both entire pages and selected parts thereof. Disadvantages of the aids are the facts that the displaceability of the reading desk re- quires much space and that the manual variant furthermore has to be placed in front of the user for optimum manageability. All in all, this means that it is difficult to combine aids comprising a displaceable reading desk with computer workstations, where the space m front of the user is occupied by a keyboard and the adjoining space on that side of the keyboard which is preferred by the user is occupied by a mouse.

As an alternative to the prior-art aids comprising a reading desk there are also hand-held cameras, which more or less are formed as a mouse and which when scanning an object are moved across selected parts thereof. The advantage of this solution is that it requires extremely little space and, thus, is suitable for a workstation, especially if the display included m the workstation is used as a display. The greatest disadvantage of this solution is that it can only be used for scanning flat objects, i.e. it cannot be used as an aid when writing by hand or when doing handicraft, such as knitting. Another disadvantage is the fact that such cameras do not allow simultaneous reading of an entire or at least great parts of a large object and, thus, they cannot be used to give the user an overall view of the object on the display. A further disadvantage is the fact that when the scanned object, for instance, is a book, such cameras have to be removed to allow changing of pages and that, because of the small distance between camera and object, they reproduce the joints of the pages of open books with a relatively great distortion. In these circumstances the object of the invention is to provide an aid of the type stated by way of introduction, which should be combmable with a computer workstation, but still involve the advantages of an aid comprising a displaceable reading desk over an aid compr s- ing a hand-held camera.

According to the invention, this is achieved by an aid of the type stated by way of introduction by the camera being mounted on the stand with the aid of a universal joint and, for scanning the object, being pivotable about the universal joint by an operating device.

By making the camera movable according to the invention, the object no longer has to be displaced to be scanned. This means that the aid according to the invention requires less space. It can thus be installed next to a computer workstation and still be at a convenient distance for the user. Moreover, the arrangement of the camera spaced from and preferably above the scanned ob- ject makes it possible to carry out various manual operations below the camera as well as reproduce overall views of a scanned object on the screen, surprisingly enough, without much image distortion as a result of turning the camera.

According to a first embodiment of the invention, the operating device is a rod which is connected to the camera and directed towards the object and has a length substantially corresponding to the distance between the camera and the object. This embodiment is both very simple and easy to use and, moreover, very inexpensive to manufacture .

In this embodiment, the rod is preferably arranged outside the recording area of the camera so as not to m- terfere with the image shown on the display and, furthermore, conveniently telescopically adjustable, on the one hand to be removable when changing the viewing object and, on the other hand, to always allow a comfortable working position. In the first embodiment, the rod preferably has a turnable handle part which is adapted to control the setting of the obtained degree of image enlargement. This also contributes to creating a comfortable working position and, furthermore, makes the operating extremely sim- pie and intelligible. As a further sophistication of this solution, it is also conceivable that the setting of the degree of image enlargement can be performed at least at two different speeds which are selected by turning the handle part to a smaller or greater extent . According to a second embodiment of the invention, the operating device is an electromechanic, electromagnetic or optoelectronic input unit which is adapted to be manually actuated m different directions and to pivot the camera by means of motors m the direction indicated by the input unit. This embodiment gives an even greater freedom as to the arrangement of the camera and the object scanned since an operating device in the form of such an input unit does not have any direct spatial connection to them.

In this embodiment, the input unit preferably has keys or knobs to adjust the achieved degree of image en- largement, so that a comfortable setting of the degree of image enlargement corresponding to the first embodiment is rendered possible.

Practical experiments have shown that the universal joint advantageously can be a cardan joint whose two pivot pins which are perpendicular to one another are substantially parallel with two preferred directions for scanning the object. Such a solution makes it significantly easier, for example, to follow the lines in a book provided that the object is aligned with the pivot pins, and can in the solution according to the above-mentioned second embodiment relatively easily be combined with a function of automatic scanning of a line and of automatic changing of lines at the end of this line. Moreover, precisely to make it easier to follow the lines it may be advantageous if the inertia of the pivoting of the camera about the two pivot pins of the cardan joint is adjustable .

In the following, the invention will be described in more detail with reference to the accompanying drawings, in which

Fig. 1 is a perspective general view of the first embodiment of the invention,

Fig. 2 is an enlarged view of parts of the first embodiment , and Fig. 3 is an enlarged view, corresponding to that of

Fig. 2, of a part of a second embodiment of the invention.

Fig. 1 shows a computer workstation which comprises a desk 1 on which a display 2, a keyboard 3, a mouse 4 and an object 5, here in the form of a sheet of paper, are placed. A stand 6 is attached to the desk 1, the stand having a vertical column part which stands on the desk 1 and a horizontal column part which extends parallel across the desk 1. Both the vertical and the horizontal column part are telescopically adjustable, turnable and lockable m the required position by means of one knob each 7 and 8, respectively. Moreover, at the outer end of the horizontal part, the stand 6 has a vertically directed joint 9 about which a camera unit 10 carried by the stand 6 is pivotable, if required, for parallel displacement when turning the stand 6 about the vertical column part.

In the following, the camera unit 10 shown m Fig. 1 will be described m more detail with reference to Figs 1 and 2. The camera unit 10 comprises a CCD camera 11 which is of the autofocus type and is directed downwards to the object 5 placed on the desk 1. The camera is rigidly connected to a rod 12, which extends from the camera 11 downwards to the desk 1 and is telescopically adjustable, so that a handle part 13 arranged at its end can have a desired distance m relation to the desk 1. The camera unit 10 also includes a universal joint generally designated 14, which comprises an outer U- shaped fork 15, a ring 16 which is arranged inside the fork and which is pivotable m relation to the fork about a first, substantially horizontal pivot pin 17, and a camera holder 18 which is arranged inside the ring 16 and is pivotable m relation to the ring 16 by means of a second pivot pm 19, which is perpendicular to the first pivot pin 17. The thus-constructed universal joint 14 makes it possible to pivot the camera 11 m the desired directions about the two pivot pins 17 and 19 by means of the rod 12 for scanning the object 5 on the desk 1, the end positions of the pivoting motion conveniently being limited by a stopping means, such as the pm which is designated 20 m Fig. 2. In the shown embodiment, the camera unit 10 which is constructed as described above is connected to the display 2, on which an image of the object 5 taken by the camera 11 can be shown. The shown image can then be reproduced with different degrees of enlargement, the degree of enlargement conveniently being adjusted by means of the handle part 13 of the rod 12, the handle part being, for this purpose, turnable clockwise and counter-clockwise to, for instance, enlarge or reduce the image .

The second embodiment of the invention which is shown more closely in Fig. 3 differs from the embodiment shown in Figs 1 and 2 by the camera unit 10' being motorised. Since there are no differences in the camera 11' and the cardan joint 14', they will not be described in more detail, and in the following only the differences that are relevant in the context will be mentioned. A first motor 21, such as a stepping motor, is arranged on the fork 15' for the pivoting motion about the first pivot pin 17' of the cardan joint. By means of a roller 22, the motor 21 pulls a band 23 in the desired directions, the band being connected to the ring 16'. For the pivoting motion about the second pivot pin 19', a motor 24, such as a stepping motor, is arranged on the ring 16' and pulls a band 25 in the desired directions by means of a rotateable roller 26, the band being connected to the camera holder 18' . The embodiment of the invention which is shown in Fig. 3 is conveniently connected to an input unit, such as the keyboard 3 or the mouse 4, to initiate the pivoting motions, the input unit suitably having knobs 27 for adjusting the desired degree of enlargement.

Claims

1. An aid for visually handicapped people, which comprises a stand (6) that carries a video camera (11; 11') for scanning an object (5) that holds a defined position in front of the camera (11; 11'), and a display (2) connected to the camera (11; 11') for showing an enlarged image of at least part of the scanned object (5), c h a r a c t e r i s e d in that the camera (11; 11') is mounted on the stand (6) with the aid of a universal joint (14; 14') and that, for scanning the object (5), the camera is pivotable about the universal joint (14; 14') by an operating device (12; 3, 4) .

2. An aid as claimed in claim 1, c h a r a c t e r i s e d in that the operating device is a rod (12) which is connected to the camera (11) and directed towards the object (5) and has a length substantially corresponding to the distance between the camera (11) and the object (5) .

3. An aid as claimed in claim 2, c h a r a c t e r i s e d in that the rod (12) is arranged outside the recording area of the camera (11) .

4. An aid as claimed in claim 2 or 3, c h a r a c - t e r i s e d in that the rod (12) is telescopically adjustable .

5. An aid as claimed in any one of claims 2-4, c h a r a c t e r i s e d in that the rod (12) has a turn- able handle part (13) which is adapted to control the setting of the obtained degree of image enlargement.

6. An aid as claimed in claim 5, c h a r a c t e r i s e d in that the setting of the degree of image enlargement can be performed at least at two different speeds which are selected by turning the handle part (13) to a smaller or greater extent.

7. An aid as claimed in claim 1, c h a r a c t e r i s e d in that the operating device is an electrome- chanic, electromagnetic or optoelectronic input unit (3, 4) which is adapted to be manually actuated in different directions and to pivot the camera (11') by means of motors (21, 24) in the direction indicated by the input unit (3, 4) .

8. An aid as claimed in claim 7, c h a r a c t e r i s e d in that the input unit (3, 4) has keys (27) or knobs to adjust the obtained degree of image enlargement.

9. An aid as claimed in any one of the preceding claims, c h a r a c t e r i s e d in that the universal joint is a cardan joint (14; 14') whose two pivot pins (17, 19; 17', 19') which are perpendicular to one another are substantially parallel with two preferred directions for scanning the object (5) .

10. An aid as claimed in claim 9, c h a r a c t e r i s e d in that the inertia of the pivoting of the camera (11; 11') about the two pivot pins (17, 19; 17', 19') of the cardan joint (14; 14') is adjustable.