CN101261775A

CN101261775A - A Braille point word display

Info

Publication number: CN101261775A
Application number: CNA2008100473067A
Authority: CN
Inventors: 李通; 张玄; 唐秀东; 毛彪
Original assignee: Huazhong University of Science and Technology
Current assignee: Huazhong University of Science and Technology
Priority date: 2008-04-14
Filing date: 2008-04-14
Publication date: 2008-09-10

Abstract

The invention provides a braille display and comprises a contact layer and a circuit layer which are mutually connected; wherein the contact layer consists of a substrate and braille contacts which is composed of two-way memory alloy slice, by controlling the contact temperature through current on-off, the shape switching of the contact layer in high-temperature phase and low-temperature phase is realized and touchable braille display effect is achieved. The braille display has the advantages of simple structure, easy mass manufacture and installation, which is applicable to a plurality of places which the blind need to acquire information from and can be touched in daily life, for example, the surfaces of blind computer displays, various public facilities (e.g. electronic bus stop boards, traffic lights, etc.), the surfaces of various cards, the surfaces of various household electronic appliances, etc.

Description

A kind of Braille point word display

Technical field

The invention belongs to blind person's reading tool technical field, be specifically related to a kind of Braille point word display.

Background technology

Along with the development of computer information technology, microcomputer has become the main tool that contemporary society obtains up-to-date information.The blind person can't observe things with eyes, and mainly the sense of touch by the sense of hearing and finger obtains external information, so designed blind person's special purpose computer, for example number of patent application is 03130824.4 " blind person's computer system ".And the key component of blind person's computing machine is to utilize sense of touch to show " Braille point word display " of braille.

The crucial part of " Braille point word display " is can be in the braille contact of projection and smooth two states intercropping conversion.Marmem SMA (Shape Memory Alloy) is that a kind of atomic arrangement is very regular, volume becomes the martensite phase transformation alloy less than 0.5%.This alloy can produce distortion under external force, when external force is removed, under certain temperature condition, can return to the original form.Memorial alloy is divided into three kinds of one way memorial alloy, round trip memorial alloy and omnidistance memorial alloys, wherein recovers high temperature phase shape during some alloy heating, can recover low temperature phase shape during cooling again, is called double-pass memory effect.Number of patent application is " Braille tactility apparatus " employing memory alloy wire making Braille pixel of 03256935.1, the upper end connecting terminal of memory alloy wire, and the lower end connects on-off circuit, is controlled the combination of protrusions of different contacts by on-off circuit.This technical scheme is mounted with memory alloy wire between braille contact and on-off circuit, be example with the one way memory alloy wire, and this one way memory alloy wire shape after cooling can't change automatically, just deliquescing.So after to certain contact demonstration convex shape, outage makes it the temperature reduction to memory alloy wire, but the memory alloy wire after the cooling still can not change shape, it is protruding that the contact remains, and can not recover open and flat shape naturally.The method of head it off is exactly to utilize the performance of memory alloy wire softness, makes it smooth with the hand push contact, but effect and bad, and reliability is low, and bulky.

Summary of the invention

The object of the present invention is to provide a kind of Braille point word display, projection and smooth switching can be realized automatically according to data to be displayed in the braille contact of this display, the reliability height, and simple in structure, volume is little.

A kind of Braille point word display comprises contact layer and circuit layer, and contact layer comprises braille contact and substrate, and circuit layer is connected with the braille contact, and described braille contact is made of round trip memorial alloy thin slice.

As improvement of the present invention, between described braille contact and circuit layer, be provided with resistance wire, resistance wire is connected with circuit layer, and resistance wire tightly invests the braille contact.

The present invention adopts round trip memorial alloy thin slice directly as the braille contact, temperature by current switching control contact realizes that it is in high temperature phase and the low temperature switching of shape mutually, omit the complicated mechanical mechanism of traditional Braille point word display, reached tangibly braille display effect.The present invention is with respect to traditional Braille point word display, integral body can be accomplished very frivolous, even can curl, be convenient to carry, and simple in structure, cost is low and easy large-scale production manufacturing and installation, need obtain information and tangibly place applicable to blind person in the multiple daily life, as blind person's graphoscope, various communal facility (as electronic public transport stop board, traffic lights etc.) surface, various card faces, various home appliance surfaces etc.

Description of drawings

Fig. 1 is the structural representation of embodiment Braille point word display;

Fig. 2 is the high temperature phase and low temperature shape synoptic diagram mutually of round trip memorial alloy sheet;

Fig. 3 is a braille display unit effect synoptic diagram.

Embodiment

Describe the present invention in detail below in conjunction with drawings and Examples.

The Braille point word display of present embodiment comprises film 1, contact layer 2, circuit layer 3 and shell 4 as shown in Figure 1.Film 1 and shell 4 are used for encapsulation, play the protective effect to display.

Contact layer 2 comprises substrate and braille contact, and the braille contact is produced on the substrate.A contact is made of a slice round trip memorial alloy thin slice, and per six braille contacts are a side, and the number of side is according to display model difference and the quantity difference is an example with the four lines display, and every row has 28 sides, and totally 4 is capable.The size in braille hole is arranged standard with reference to State Standard of the People's Republic of China GB/T15720-1995 Chinese braille standard.

Circuit layer 3 comprise microprocessor, with the interface circuit and the SMA power driving circuit of computing machine communication.Circuit layer can adopt flexible printed circuit board, reaches the effect of circuit layer flexible.Realize that the mode that round trip shape memorial alloy heats up mainly is divided into snead process and indirect heating method dual mode, snead process, promptly Control current directly by round trip shape memorial alloy thin slice, makes its heat temperature raising; The indirect heating method, at the tight additional heat resistance wire in round trip shape memorial alloy thin slice lower end, the indirect heating round trip shape memorial alloy thin slice thereby the resistance wire energising heats up.Microprocessor from the external world or reservoir read and want content displayed, point for the needs projection, the microprocessor control Driver Circuit give this contact round trip memorial alloy sheet or with the tight attached resistive heater heating power of memorial alloy sheet, its temperature is risen, reach round trip memorial alloy sheet high temperature phase deformation temperature, round trip memorial alloy sheet produces deformation and remains on the high temperature phase morphology; For the open and flat point of needs, the microprocessor control Driver Circuit stops to switch on to the round trip memorial alloy sheet of this point or with the tight attached resistive heater of round trip memorial alloy sheet, the reduction of round trip memorial alloy sheet temperature reaches low temperature phase deformation temperature, produces deformation and shows open and flat form and remain on this low temperature phase morphology always.

Microprocessor in the circuit layer can adopt the MCS-51 series microprocessor of Intel company, adopt usb circuit with the interface of computing machine communication, the SMA power driving circuit is divided into some switch drive unit, each round trip memorial alloy thin slice is connected with a switch element circuit by two leads, microprocessor is according to the data-signal that receives, gating or closed different switch element, make it corresponding energising of round trip memorial alloy thin slice or outage, thereby different deformation takes place in the round trip memorial alloy thin slice of diverse location, shows different Brailles.

Fig. 2 be round trip memorial alloy sheet high temperature mutually and low temperature shape synoptic diagram mutually, 5 is round trip memorial alloy sheet, is in low temperature phase (left side) and the high temperature shape on (right side) mutually respectively.

Fig. 3 is a braille display unit effect synoptic diagram, and wherein the round trip memorial alloy thin slice of protruding point keeps the high temperature phase shape of projection, and open and flat memorial alloy keeps open and flat low temperature phase shape, and whole side's display result is braille letters W.

Claims

1, a kind of Braille point word display comprises contact layer and circuit layer, and contact layer comprises braille contact and substrate, and circuit layer is connected with the braille contact, it is characterized in that, described braille contact is made of round trip memorial alloy thin slice.

2, a kind of Braille point word display is characterized in that, is provided with resistance wire between described braille contact and circuit layer, and resistance wire is connected with circuit layer, and resistance wire tightly invests the braille contact.