Musicians who have trouble reading notes may soon be able to find help with a Toledo music instructor's invention that can magnify sheet music to more than 100 times the notes' original size.

After four years of creating and refining his Music Magni-Viewer, Richard Friedmar says the final hurdle is to obtain national distribution."It's been an incredible feat, testing my nerves, patience, and finances," Friedmar said of the development process that saw 29 protypes. "I'm glad I'm single and can live broke."

The viewer uses the principles of a slide projector to display notes on a self-contained 18-inch screen, advancing each measure to a set tempo.

"It's intended for someone who is legally blind," he said.

Dr. Norman Johnson, chairman of the department of ophthalmology at the Medical College of Ohio in Toledo, said the viewer will be of particular help to the elderly, whose lack of sight has restricted their ability to pursue hobbies and leisure activities.

Friedmar said he spent more than $300,000 on the viewer, which he developed while working on a master's degree at the University of Toledo and which will be produced by Innovative Controls Corp. of Toledo.

The device came about as a result of piano lessons Friedmar gives at his suburban Toledo music conservatory to visually impaired people. He sells the rear-projection Magni-Viewer for $1,500.

The viewer uses standard 35 millimeter slides and can be set to operate automatically, or the musician can advance each measure by using a foot pedal. The slide carousel holds up to 140 slides or six pages of music.

"I've gone way beyond a slide projector in a wooden box," Friedmar said, taking issue with critics who have called it a glorified slide projector.

"I didn't spend four years of my life to drop a slide projector into a wooden box," he said.

"The transport mechanism is the only thing left of a slide projector. I've gutted the entire thing," he said.

Lorrain H. Marchi, executive director of the National Association for Visually Handicapped, said the device is "a step forward" toward making life easier for her members.

"It's another tool that makes their life more full, and to do what they want, to feel more fruitful," said Marchi in a telephone interview from her New York office.

The viewer has been placed on display in the association's visual aids room to allow partially sighted visitors and their families to try it, she said.

"It makes available to people who are legally blind an opportunity to learn to play the piano," she said.

But the device may not be practical for concert pianists who must play complicated scores, she said. Music is projected from slides and a concert pianist would find the screen too small to adequately carry all of the information, Marchi said.