GB2178874A

GB2178874A - Press-key structure

Info

Publication number: GB2178874A
Application number: GB08520074A
Authority: GB
Inventors: Rock Tong
Original assignee: Individual
Current assignee: Individual
Priority date: 1985-08-09
Filing date: 1985-08-09
Publication date: 1987-02-18
Also published as: GB8520074D0

Abstract

A press-key structure 11, 111, 112 provides the feature of colour change of a liquid crystal element 111 in relation to a change of temperature, caused by a fingertip depressing a press-key on the panel of a calculator. The apparent colour of those press-keys which have not been depressed immediately before remains unchanged. It is believed that this will achieve a beneficial recreational effect for the calculator user. <IMAGE>

Description

SPECIFICATION Press-key structure The invention relates to the press-key structure of an electronic calculator or computer.

Calculators or computers, as a means of calculation or computation in daily life, have been in general use for quite sometime. As a calculator has becomethe primary means of effecting a day's workfor more and more people everywhere, proposals have been made in the past few years to build an audio unit into the computation circuit, the idea being that a melodious tune, however short it may be, is generated each time a key on the keyboard is depressed in the computation process, so as to help while away the working hours more pleasantlyforthose professionalsfor whom use of a calculator is a daily necessity.

Following on from this, and with a view to adding more fantastic features to an ordinarycalculatoror computer, or any similar device which can effect rapid computation, the inventor started to develop, with eventual success, the present invention which provides a filmed press-key structure having the feature of liquid crystal colour change relating to a change of temperature as a part of a calculator or computer.

Accordingly, the invention provides a calculator or computer with a press-key structure having the feature of liquid crystal colour change in relation to a change of temperature as a part thereof; more specifically, it comprises such a structure built into an ordinary calculator in such mannerthat differenttemperature readings will emerge on the press-key as it is depressed by a finger of an operator during computation as a result of the temperature of that part of the body transmitted bythefingertip at work being sensed by the liquid crystal upon contact. It is be lievedthatthiswill achieve a beneficial recreational effectforthe person doing computation with a com puterstructured in such manner.

A filmed press-key structure providing the feature of crystal colour change in relation to a change oftemperature, according to the invention, in substance comprises a liquid crystal element on the base of a press-key topped by a thin cover film on the surface, said film being further protected by a protective layer such as Lager ink orthe like, so that the surface ofthe press-key appears as a blacktransparency, a dielectric member is applied overthe protective layer so that a touch of the press-key will result in the dielectric member coming into contact with a switching source installed on the circuit board associated with the calculator unit, characterised in that transmission ofthe operator's fingertip temperature, which can differ from one moment to another, applied to and as sensed bythe liquid crystal element will bring about a differently hued colour emerging on the press-key being depressed in the computation process. It is believed thatthis will help while away the working hours all the more pleasantlyforthe professional for whom the use of a calculator is a daily necessity.

The invention will now be further described with reference to the accompanying drawings, given by way of example and in which: Figure 1 is an exploded view of the essential components of a preferred embodiment ofthe present invention; Figure 2 is a perspective view of the embodiment; and Figure 3is a cross-sectional view on the lineX-X in Figure 2.

Referring to the drawings it can be seen thatthe pre ss-key portion 11 of a top cover film 1 appears in black transparency exceptforthefigures or symbols thereon; that belowthefilm 1 there is fitted a liquid crystal element 111 enclosed in a protective layer 112, on which protective layer 112 there rests a conductive member. The construction is characterised in that the overall thickness of the liquid crystal element 111, protective layer 112 and conductive member 113 disposed side-by-side is less than the depth of the through hole 21 in the double-sided adhesive paper 2 in which these components are disposed.

To assemble the parts, thefirststep is to fit the liquid crystal element 111 on the base of the press-key 11 relative to the surface film 1, the protective layer 112, and the conductive member 113 which are positioned in the hole 21 on the double-sided adhesive paper 2, the adhesive agent used on the double-sided paper2 being suitableto bondthetop coverfilm 1 to the adhesive paper 2.The adhesive agent on the other or lowerface ofthe double-sided adhesive paper 2 is adhered to the circuit board 31 of the calculator base unit 3, so as to position the hole 21 in the double-sided adhesive paper2 surrounding the circumference of a switching source 311 on the circuit board 31, in a manner such that the assembly comprising the liquid crystal element 11 the protective layer 112 and the conductive member 113 is positioned opposite to the switching source311, and ata suitable clearance with respect thereto.

When the invention incorporated in a calculator is put to use, computation is started in the usual manner, the fingertip touching the press-key 11 moving the assembly ofthe liquid crystal element 11 1,the protective layer 112, and the conductive member 113 downwards until the conductive member 113 contacts the switching source 311 on the circuit board 31, whereupon the switching circuit is activated.As the fingertip laterleavesthe key 11 within a fraction of a second, the elastic recovery of the top cover film 1 forthwith serves to reset the assembly of liquid crystal element 111, protective layer 112 and conductive member 113 back in its original position; in the meantime, the press-key 11 just having been depressed upon bythe fingertip, typically by the index finger on the right hand, will as a result ofthetemperature of the fingertip being sensed by the liquid crystal element 111, present a display of variation of colour bases including but not limited to green, brown and blue. Furthermore, it would be preferable to preset the extent of temperature range in which a change of colour of the liquid crystal element 111 shall occur, preferably in the range of 25"C to 30 C in an ambient temperature of approximately 22 C, as commonly occursfor example in an air-conditioned room; while the nominal temperature reading taken ofthefingertip of a human being is on average 32to, this is not exactly the temperature passed to the surface of the liquid crystal element 111 in the shorttime during which the fingertip remains in contact with the press key, which istypicallyfor milliseconds only and it is, in such case, of the order of 25'C to 30 C only. As has been described hereinbefore, a change ofcolourwill take place in the meantime as seen on the surface of the press-key, the surfaces of the press-keys not having been depressed just a short while ago forthetime being remaining black and all the same.

Claims

1. Afilm press-key structure, having the feature of liquid crystal colour change in relation to a change of temperature,asa partofacalculatororcomputer; wherein a press-key section of the surface film is transparent, the bottom side of the press-key is provided with a liquid crystal element which is enclosed in a protective layer, the protective layer being provided with a conductive member adapted to be brought into contact with a switching source on a circuit board as a result of depression of the presskey, when this happens the switching circuit being activated and the liquid crystal element sensing the temperature of a touch-and-go fingertip shifting about in a computation process, so that eventually and in no time at all the surface of the press-key which has just been depressed yields an accompanying instantaneous change of colourthroughoutthe computation procedure under control ofthefingertip.

2. Afilmed press-key structure substantially as herein particularly described with reference to the accompanying drawings.

3. An electronic calculator or computer em body- ing a filmed press-key structure, substantially as herein particularly described with reference to the accompanying drawings.