• 로봇학회논문지
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• 제2권2호
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• pp.137-142
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• 2007

In an information-oriented society, visually impaired persons also should obtain the information with relative ease. They tend to receive the information of letters by tactile sensation through braille display systems. Several types of braille display systems have been suggested so far, but none of them have been widely used yet. The braille display system should provide multiple lines of braille units to improve the level of understanding. In this paper, we propose a cell type braille unit with $3{\times}2$ dots, each of which consists of a piezoelectric linear motor. A braille cell is small and lightweight enough to be portable, and it can be easily assembled in multiple lines. The preliminary tests using the proposed braille display system show that it can provide the information that can be well perceived by visually impaired persons.

• 재활복지공학회논문지
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• 제4권1호
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• pp.63-70
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• 2010

시각장애인을 위한 보조공학(Assistive Technology : AT)의 연구개발은 보행과 정보 접근을 위한 것이 대부분이고, 특히 정보커뮤니케이션을 위한 음성도서용 DAISY플레이어나, 컴퓨터 화면을 읽어 주는 스크린 리더, 저시력자용 독서확대기, 점자 및 점자정보단말기 등이 상품화되어 오늘날 많은 시각장애인들에게 필수적인 보조공학기기로 자리 잡고있다. 시각장애인들이 사용하는 보조공학은 촉각이나 청각을 이용하여 시각 기능을 대행하기 때문에 감각대행기라고도 한다. 촉각을 이용한 감각대행기인 점자디스플레이와 점자정보단말기는 점자 형성을 위한 액츄에이터로 압전 소자로 만든 바이몰프가 사용되며, 점자셀의 점자(핀)는 바이몰프의 상하 운동에 의해 형성된다. 점자 셀은 휴대용 점자정보단말기에 사용되고 있기 때문에, 소형화 및 저가격화가 관건이 되며 현재는 일본의 KGS사가 세계 점자 셀(Cell) 시장의 80% 이상을 점유하고 있다. 본 연구진은 2003년에 저가/소형 원반형 점자디스플레이를 개발하여, 세계 최초로 제품화에도 성공한 바있다. 본고에서는 일본의 점자정보단말기를 비롯한 촉각디스플레이의 연구개발에 대해 검토하고 촉각을 이용한 감각대행 제품의 하나로서, 본 연구진이 개발한 원반형 점자디스플레이에 대해 고찰한다.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제4B권1호
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• pp.12-19
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• 2004

Refreshable Braille displays have already been developed in the past, but they remain quite bulky and expensive. Small displays contain only a single or a few Braille cells, with pins pushing into the fingertips. However, they are not as successful as larger displays because the skin is more sensitive to lateral movement than to orthogonal pressure. This, paper presents the design of linear electromagnetic actuators, which allows a considerable reduction in size and cost for such refreshable Braille displays. Different actuator concepts are compared. A new actuator is proposed and optimised by means of finite element simulations, which are verified with measurements on a prototype.

• 제어로봇시스템학회논문지
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• 제10권11호
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• pp.961-970
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• 2004

Tactile sensation is one of the most important sensory functions along with the auditory sensation for the visually impaired since it replaces the visual one of the persons with sight. In this paper, we present a tactile display device as a dynamic Braille display that is the unique tool f3r exchanging information among them. The tactile cell of the Braille display proposed is based on the dielectric elastomer, which is one of the electroactive polymers. It has advantageous features over the existing ones with respect to intrinsic softness, ease of fabrication, cost effectiveness and miniaturization. We introduce a new idea for actuation as well as additional considerations such as the driving circuit that makes it possible to drive multiple tactile cells in a high speed. Also, we describe the actuating mechanism of the Braille pin in details capable of realizing the enhanced spatial density of the tactile cells. Finally, results of psychophysical experiments are given to evaluate its effectiveness.