How does the VideoTIM work?

VideoTIM consists of the base unit with a tactile interaction monitor (“TIM”) and a small hand-held video camera. With one hand, the image sent by the video camera is read on the TIM. The video camera is guided with the second hand. The reading hand can rest with the heel of the hand on the large surface of the VideoTIM5, which allows for a relaxed feel.

The VideoTIM5 handheld video camera has a built-in template illumination. With this handheld camera, the user moves over the lines of text. The image is simultaneously transmitted (in near real time) to the TIM’s touchpad, where it is tactilely recognized (with the sense of touch) by the reading hand. The hand holding the camera moves in a straight line over the lines of text. The camera is moved as quickly as the other hand can read at the same time.

The tactile quality of the characters displayed on the VideoTIM monitor is very good. Every image point (pixel) can be felt exactly. The dot spacing is 2.5 mm. The TIM area is 4 x 4 cm and has a total of 256 tactile points.

The user can switch between active and passive tactile perception. During active tactile perception, the touching hand moves and explores the details of the shape, e.g. of a letter, with the fingertips. Passive tactile perception works in such a way that a tactile ticker is written from below on the fingers lying still on the TIM. The groping fingers completely cover the VideoTIM5 monitor. We call this reading method TPS – Tactile Projection System. Learning TPS takes about one to two days of practice. Once learned, this reading method enables much faster reading than is possible with the actively groping method.

Using music notes as an example, reading with VideoTIM5 will be explained here. The sheet music is placed on a non-slip surface next to the base device. The hand-held video camera then moves over the sheet music and first looks for the heading, here “Spring” by Antonio Vivaldi. Then the first staff underneath is viewed tactilely, the clef, the time signatures and the individual notes and symbols. It is important to understand that VideoTIM5 has different zoom levels that the user can select according to their needs. With one zoom level, all five staff lines can be viewed at the same time. However, the individual notes become very small. By zooming, the user can now enlarge any note to the entire touch field and thus view all the details.

The tactile monitor of the VideoTIM5 has three buttons on the right and left of the monitor. Two buttons on the right allow the displayed image to be enlarged (top button) or reduced (bottom button) as required. A third button on the right, the middle one, is used to reset to zoom level 5, which is also set when the device starts. Double-clicking this button reverses the image (white becomes black, black becomes white).
The middle button on the left of the TIM is used to switch the five contrast levels (“modes”), and double-clicking this button resets the brightness to the starting value. The brightness (technically: the threshold value) can be individually adjusted using the buttons at the top and bottom left.

The image recorded by the mini hand-held video camera is transmitted to the TIM touch monitor in real time at up to 30 frames per second.
The VideoTIM5 shown here has a number of technical developments compared to its predecessor models, which primarily serve to optimize image display.

Gunnar Matschulat

ABTIM Devices for the Blind / ABTIM Blindenhilfsmittel

Ferdinand-Schrey-Str. 84
42119 Wuppertal
Germany

Tel. +491781568866

(Phone within Germany: 01781568866)
info@abtim.com