EP0730983A1

EP0730983A1 - Erasable marker device

Info

Publication number: EP0730983A1
Application number: EP95303602A
Authority: EP
Inventors: Maurice Miller; Zvi Grinfas
Original assignee: Individual
Current assignee: Individual
Priority date: 1995-03-07
Filing date: 1995-05-26
Publication date: 1996-09-11
Also published as: GB9504489D0; GB2298826A

Abstract

A marker device is disclosed which is of the type in which marks are recorded by creating points or lines of contact between two adjacent layers (1,2,130,140), and erasure is effected by separating said layers by effecting relative movement between a cursor (41,125,126) and said layers. The device comprises a cursor which forms one limb of a frame (4,120); and the central open part of said frame defines the area (45) where marks can be recorded. In one embodiment, the frame is disposed between the working layers and is withdrawn from the body of the device to effect erasure. In a second embodiment, the frame includes a front portion (124) having two bars (125,126) which define between them a slot (127); the upper of the working layers passes through the slot, and erasure is effected by drawing the layers out of the frame so that the upper layer passes over one of the bars and under the other.

Description

This invention relates to an erasable marker device of the type in which marks are recorded by creating points or lines of contact between two adjacent layers, and erasure is effected by separating the layers. Such markers are often termed "magic slate" markers.
Magic slate markers have been devised in a variety of forms aimed at fulfilling various needs. For example, the well-known childrens' toy utilises the magic slate principle, and erasure of recorded marks is effected by moving a cursor between the adjacent layers to separate them, thus destroying the points or lines of contact which give rise to the visible marks or image.
The previously characterised magic slate devices can be grouped into categories in accordance with the technique used for erasing marks previously applied to the device. Thus the first category consists of devices in which a cursor (typically in the form of a bar or a pair of opposed flanges) is moved along the length of the device so as to effect physical separation of the two "working" layers. An externally protruding grip or handle served to enable the cursor to be moved. Examples of this type of device are disclosed in British Patent Specification No. 782,518 (Leswick Ltd.), which was published on 11 September, 1957 and in US Patent Specification No. 2,894,336 (Thorner), published 14 July, 1959.
The second category of previously characterised magic slate devices consists of devices in which the "working" layers are peeled apart, either manually or via some mechanical arrangement such as a hinged pivot. This rather primitive technique may be limiting in terms of the versatility of application of marker devices of this category. Examples of this type of device may be found in US Patent No. 1,881,140 (Settel), published 4 October, 1932; and in US Patent No. 4,589,685 (Lazar), published 20 May, 1986.
The third category of previously characterised magic slate devices consists of devices in which the "working" layers are separated by pulling them out of the body of the device and against a fixed edge located between the layers. Examples of this type are found in British Patent Specification No. 2,055,702 (Squires), published 11 March, 1981; and in International Specification No. WO 92/22901 (UTEC), published 23/12/1992.
One further type of magic slate marker device is disclosed in International Specification No. WO 92/22432 (Bilbie et al), published 23/12/1992; in this device, erasure of marked indicia is effected by rubbing the user's thumb over the written surface - relative movement between the two "working" layers being sufficient to effect erasure. This may be achieved by using an upper layer which is relatively elastic; or by forming the device with a wrinkle in the upper layer, or an air bubble between the two layers; running the thumb along the length of the written area then either moves the wrinkle or the air bubble with it.
Some recent applications of the magic slate principle have been directed towards labelling arrangements. One example of such arrangements is US Patent No. 4,763,929 (published 16 August, 1988) granted to George Weil and subsequently assigned to System RM Ltd. of the Isle of Man. This discloses a video cassette label which is an elongate laminar device having first and second faces on opposite sides of the device, the first face being adapted to be secured to the video cassette and the second face having a window through which indicia marked on the device can be viewed. A transparent paper foil and a wax layer are disposed between these two opposed faces of the device, the wax layer being secured to a basal plate the rear face of which constitutes the first face of the marker device, as just described. The paper foil layer and the wax layer cooperate so that the foil layer can be releasably attached to the wax layer, points of attachment between them being visually distinctive and constituting said indicia. The device further includes means for separating the paper foil layer and the wax layer from one another, thereby erasing any previously marked indicia; the separating means takes the form of an element secured within the device which extends across substantially the full width of the foil and wax layers without interruption and which is slidable along the length of the marker device.
According to one aspect of the present invention, there is provided a marker device of the type in which marks are recorded by creating points or lines of contact between two adjacent layers, and erasure is effected by separating said layers by effecting relative movement between a cursor and said layers, characterised in that: (a) the device comprises a cursor which forms one limb of a frame; and (b) the central open part of said frame defines the area where marks can be recorded.
In a marker device as defined above, the frame may be generally rectangular, but is not limited to this geometry.
The two working layers preferably consist of a first, basal layer which carries a wax film and a second, opalescent layer above said wax film.
It is preferred to incorporate a third, transparent layer overlying said second, opalescent layer. This can conveniently be formed of a plastics material.
The first, basal layer may be formed of paper or a plastics material; and the second, opalescent layer may, inter alia, be formed of a plastics material.
The plastics material used to fabricate layers used in the device of this invention is preferably a thin film or foil; suitable materials for this purpose include polyesters, e.g. polyethylene terephthalate (PET) and polyvinylchloride (PVC), which are available in clear and opalescent (or milky) forms.
In one embodiment of the invention, the relative movement between the cursor and the "working layers" which function to display indicia is effected by withdrawing the frame from the body of the device. In this embodiment, a second limb of the frame preferably provides a grip whereby the whole frame may be moved relative to the working layers in order to effect erasure of recorded marks. Also, the frame in this embodiment is disposed between the working layers.
In this first embodiment, the two adjacent layers - i.e. the working layers - are preferably secured together along a line positioned within said central open area of the frame relatively remote from the cursor when the frame is in its rest position (i.e. the position for recording marks). This not only assists in maintaining the integrity of the overall structure, it also performs a valuable function in providing a stop member (i.e. the line where the two layers are joined together) which prevents the frame from being fully separated from the body of the device.
A preferred marker device of this first embodiment is generally rectangular and the layers of the device other than said frame are secured together along a first edge of the device which is that edge adjacent to the cursor, and along the two edges adjoining said first edge.
The preferred construction of a marker device of this first embodiment is such that the frame, when in its rest position, is located substantially wholly within the device. This gives a neat appearance to the device, as well as facilitating its use, for example with data storage disks. With such a form of construction, the grip portion of the frame is advantageously made accessible, when the frame is in its rest position, by providing a cut away region formed in the or each layer of the device which lies above the frame. This can resemble a "thumb notch" through which a part of the edge of the frame remote from the cursor can be held by a user, who will then pull the frame out of the body of the device, thereby effecting erasure of any marks in the writing area.
In a second embodiment of this invention, the frame is formed, at one end thereof, with two bars extending across the width of the frame and defining between them a narrow slot. In this second embodiment, the frame is stationary and relative movement between the cursor and the working layers is effected by drawing the upper of the two working layers through the slot so that one of the bars functions as the cursor. Preferably, the inner of the two bars is arranged to function as the cursor, i.e. the upper of the two working layers passes over this bar and then down through the slot to pass under the outer bar.
According to a second aspect of this invention, there is provided a marker device of the type in which marks are recorded by creating points or lines of contact between two adjacent layers, and erasure is effected by separating said layers by causing relative movement between the layers and a cursor located between them, characterised in that: (a) the device comprises a frame having side portions, a rear portion and a front portion; (b) the front portion of said frame comprises two bars separated by a narrow slot; (c) the central open part of said frame between the side portions thereof is dimensioned so as to receive said layers; and (d) the device is assembled so that one of said layers passes through said slot in the front portion of said frame whereby relative movement between said layers and one of said two bars effects erasure of marks previously recorded, so that said one of the two bars constitutes said cursor.
In this second embodiment, erasure is effected by drawing the layers out of the frame so that the upper layer passes over one of the bars at the front of the frame and under the other.
A marker device in accordance with this invention is preferably constructed as a laminated structure. Because of the mode of operation of the device, it can be fabricated as an extremely thin lamination (especially in its second embodiment as defined above). Typically, the laminated structure has a thickness not exceeding 2mm, and preferably its thickness does not exceed 1mm.
One especially useful application of a marker device in accordance with this invention is to function as a label for a data storage disk. For this purpose, the base of the device may be adhesively attached to, for example, a computer diskette. Accordingly, in another aspect, the present invention provides a data storage disk to which there is secured a marker device as hereinbefore defined.
For a better understanding of the invention, and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which:

Figure 1 shows an exploded view of a laminar marker device in accordance with the first embodiment of this invention;
Figures 2a, 2b, 2c and 2d illustrate separately the components of the device of Fig. 1;
Figure 3 shows a schematic view of the device of Figs. 1 and 2 in operation during the erasure of recorded information;
Figure 4 shows an exploded view of the components of a laminar marker device in accordance with the second embodiment of this invention; and
Figure 5 shows a dimensionally exaggerated and schematic perspective view of part of the marker device of Figure 4.

Referring now to Figures 1-3 of the drawings, the device comprises layers 1, 2 and 3 which are co-extensive and are laminated together; and frame member 4 which is positioned between layers 1 and 2 as shown in Fig. 1. Layers 1, 2 and 3 are dimensioned so as to enable the device to be secured to the top face of a standard 3½ inch data storage disk ("floppy disk"). Suitable dimensions for this purpose are 53mm by 70mm. The total thickness of the laminate 1, 4, 2, 3 is approximately 0.5mm.
The device is not capable of opening out in the way depicted in Fig. 1; the figure is depicted with the parts separated from one another solely for reasons of clarity.
The layers 1 and 2 constitute the "working layers", i.e. the layers which, when brought together (e.g. by a blunt tip or stylus) in point or line contact, maintain contact, thereby generating a visible image corresponding to the points of application of the blunt tip or stylus.
The basal layer 1 (shown in Fig. 2a) consists of a thin sheet 10 of paper or a plastics material, e.g. PET or PVC film (which may be clear or coloured), to the upper surface of which an area 11 of wax has been applied. Edges 12, 13 and 14 (but not edge 15) carry (on the upper surface of film 1) an adhesive 16, e.g. glue. A further line 17 of adhesive (e.g. glue) is carried by the film 1 on its upper surface. This line 17 abuts the area 11 of wax on that side thereof remote from edge 16. The adhesive used may be any suitable adhesive, e.g. a contact adhesive or one which is activated by heat. Alternatively, the adhesive may be dispensed with where the layers of the marker device are formed of suitable plastics material(s) such that they can be heat-bonded to one another without the need for an intermediate adhesive layer.
As shown in Figs. 1 and 2b, the frame 4 is dimensioned so as to fit freely between the layers 1 and 2 without contacting the lines of adhesive 16 and 17. When in this condition, with frame 4 wholly within the bounds of layers 2 and 3, the frame is in its normal or rest condition and marks such as information may be made on the device.
The frame 4 comprises an upper limb 41, side limbs 42 and 43, and a bottom limb 44. The frame defines a central opening 45 whose dimensions correspond with those of waxed area 11. Lower limb 44 functions as a grip and, to assist its operation, a slot 46 is provided.
Inner edge 47 of limb 41 of frame 4 constitutes the means for effecting erasure of marks recorded by creating contact between layers 1 and 2. The frame is moved with respect to the other components of the device - downwardly as seen in Fig. 2b, or to the lower left as seen in the perspective view of Fig. 1. It can thus be termed a cursor.
The second layer 2 consists of a thin film 20 of opalescent PVC. Edges 22, 23 and 24 (but not 25) carry a strip of adhesive 26 which corresponds to the strip 16 on layer 1. Similarly, a further linear strip 27 of adhesive is provided on layer 2, this again corresponding exactly with the position of line 17 on layer 1. The adhesive may be applied to the upper surface alone, or if desired to both upper and lower surfaces in order to assist proper lamination of layers 1, 2 and 3. The adhesive used may be any suitable adhesive, e.g. a contact adhesive or one which is activated by heat. Alternatively, the adhesive may be dispensed with where the layers of the marker device are formed of suitable plastics material(s) such that they can be heat-bonded to one another without the need for an intermediate adhesive layer. Bottom edge 25 of layer 2 is formed with a cut out portion 28 - this resembling a thumb notch. The purpose of notch 28 is to permit access to the grip portion 44 of frame 4 in the vicinity of slot 46.
Topmost layer 3 consists of a thin film of clear PVC. As with layers 1 and 2, edges 32, 33 and 34 (but not 35) carry an adhesive 36. Similarly, a further linear strip 37 of adhesive is provided on layer 3, this again corresponding exactly with the position of line 17 on layer 1 and the line 27 on layer 2. In the case of layer 3, the adhesive is provided only on the lower surface of the film. The adhesive used may be any suitable adhesive, e.g. a contact adhesive or one which is activated by heat. Alternatively, the adhesive may be dispensed with where the layers of the marker device are formed of suitable plastics material(s) such that they can be heat-bonded to one another without the need for an intermediate adhesive layer. Bottom edge 35 of film 3 is formed with a cut out portion 38 - this notch corresponding to notch 28 of layer 2 and serving the same purpose.
The device is fabricated by bringing together the four components so that layers 1, 2 and 3 are contiguous, and frame 4 fits freely between layers 1 and 2. The adhesive strips 16, 17, 26, 27, 36 and 37 are then effective to bind the device together as a laminate. If necessary, pressure and/or heat may be applied to effect the necessary bonding, with or without the use of an adhesive between adjacent parts of the device. In this condition, frame 4 is contained wholly within the overall dimensions of the layers 1, 2 and 3. It is held in place through frictional contact, but is free to move downwardly (as seen in Fig. 2b) when a user takes hold of grip portion 44 in the vicinity of slot 46. The extent of downward movement is determined by the edge 47 of the frame reaching the bond formed between adhesive strips 17 and 27; this bond acts as a stop member which holds the frame 4 captive, preventing it from becoming separated from the rest of the device.
Referring now to Fig. 3, the laminar device 1 is shown in a perspective view during an erasing operation. Indicia 52 are shown as visible within the central area of the device. Such indicia are formed by writing on the device (through layers 3 and 2) by applying a blunt point or stylus thereto. As depicted, the wax area (11 of Fig. 2a) is divided into a first zone 50 which has been erased of markings; and a second zone 51, which still carries markings in the form of information 52. Partially erased indicia 53 are also visible in Fig. 3. Leading edge 47 of limb 41 of frame 4 acts as a cursor which separates the wax 11 (see Fig. 2a) from its overlying opalescent film 2, thus destroying the visible points or lines previously formed.
Frame 4 is extracted from the body of device 1 by inserting a finger nail into slot 46, made accessible because of notches 28 and 38, and drawing the frame out. Once lower limb 44 of frame 4 has become free of layers 1, 2 and 3, part 45' of the central open area 45 is revealed. By continuing to pull frame 4 out of the body of device 1, the remaining indicia 52 ("Authors' Catalogue A - F") is erased.
As the frame 4 continues to be extracted from device 1, the leading edge 47 eventually reaches the area 54 of bonding between layers 1 and 2 (bond 54 being formed by cooperation of adhesive strips 17 and 27). This bond 54 provides a barrier which serves to retain the frame captive within the device.
After erasing all the indicia from the device, the frame 4 is returned to its rest position by pushing it back into the body of the device.
Referring now to Figures 4 and 5, an example of the second embodiment of the invention is illustrated. As shown in Figure 4, the marker consists of five layers which are interconnected and laminated together as will be described shortly. The base layer 110 is advantageously formed of paper or of a plastics material and may be clear or coloured. Edge regions 111, 112 and 113 are intended to be bonded to the corresponding areas of frame member 120 above, and to a substrate (not shown) below; the substrate may be a standard 3½ inch data storage diskette. Base layer 150 is preferably relatively rigid to act as a support for the remainder of the device and to assist in bonding between the device and the substrate. Where paper is used to fabricate the base layer, edge regions 111, 112 and 113 will be coated with an adhesive to permit bonding either by contact or under application of heat and/or pressure. Where a plastics material (e.g. PET) is used to fabricate base layer 110, an adhesive may be used as just described; or bonding may be effected by welding the plastics material to frame member 120 above and to the substrate below.
Frame member 120 is a generally rectangular frame comprising side portions 121 and 123, rear portion 122 and front portion 124 which delimit central open area 128. The dimensions of portions 121, 122 and 123 match those of edge regions 111, 112 and 113 of base layer 110. The front portion 124 of frame 120 takes the form of two bars 125 and 126 separated by a slot 127. The forward edge of bar 126 is cut away slightly as shown in the form of an arc.
Layers 130 and 140 are the working layers of the marker device; they are secured to each other at their front ends by strip 160 and at their rear ends by strip 170. The lower layer 130 consists of a support, e.g. of paper or a plastics material, which carries a wax layer (not identified separately in the drawings). Upper layer 140 is in the form of an opalescent layer, which may conveniently be a plastics material, e.g. milky PVC or PET. When the marker device is used, it is contact between layers 130 and 140 in the form of points or lines which generates visible markings, just as described above with reference to Figures 1-3. In the case of this embodiment, layers 130 and 140 are dimensioned so as to fit snugly within the internal space defined between side portions 121 and 123 of frame member 120. When the marker is assembled, the leading edge 144 of layer 140 is passed over bar 125 and down through slot 127 so as to pass under bar 126. Layer 130 passes beneath both bars 125 and 126. This configuration is illustrated schematically in Figure 5, where the relative dimensions of the various components depicted are altered for illustrative purposes only. The thickness of frame 120 and of layer 130 is also exaggerated in Figure 5.
An alternative assembly arrangement (not shown) is essentially the reverse of that depicted in Figure 5 so far as the relationship between opalescent layer 140 and the bars 125 and 126 is concerned. Thus in this alternative, layer 140 passes beneath the first bar 125 and is threaded upwardly through slot 127, after which it passes over bar 126.
It will be appreciated that one or other of the bars 125 and 126, each of which constitutes a limb of the frame member 120, acts as a cursor in that relative movement between the bar and the working layers causes erasure of any marks previously recorded on the marker device by effecting separation of the wax covered layer 130 from the opalescent layer 140.
The topmost layer 150 of the marker device comprises a transparent central area 155 and a peripheral masking area 156. One suitable mode of fabricating layer 150 is to use a clear plastics foil to which a pigment, e.g. white paint, is applied in peripheral region 156. The lower surface of side portions 151 and 153 and of rear portion 152 are secured to the upper surfaces of the corresponding portions 121, 123 and 122 respectively of frame member 120. The leading edge 154 of layer 150 is cut away in the shape of an arc which corresponds to that of the leading edge of bar 126.
Notches 138, 148 and 168 are formed, respectively, in parts 130, 140 and 160; they are located at the middle of the forward edges of the components, as shown (for the sake of simplicity, these notches are omitted from Figure 5). In use, they cooperate to permit a user to draw the layers 130 and 140 out of frame member 120 in the direction of arrow 139 of Figure 5. This motion causes layers 130 and 140 to become separated as they reach bar 125; this results in erasure of any indicia marked on the device. To re-use, the layers 130 and 140 are pushed back into the body of the marker device. Because frame member can be constructed from a very thin material, bars 125 and 126 present no significant impedance to the return of layer 140 into the gap defined by side portions 121 and 123.
With the structure shown in Figure 4 it is possible to fabricate an extremely thin marker device (of the order of 0.5mm thick) which can be secured to a standard computer diskette without interfering with the action of inserting and removing the diskette from a disk drive. Such a marker could also be used if desired for direct attachment to the surface of a video cassette. Other uses will become apparent to users of the marker device.
Although depicted as a generally rectangular device, it will be appreciated that the device may be fabricated in other shapes as desired, provided that the principles of form defined herein are satisfied. Similarly, although depicted as a very thin device, the marker may if desired be constructed in a more robust manner if its intended usage does not require it to be extremely thin.

Claims

A marker device of the type in which marks are recorded by creating points or lines of contact between two adjacent layers (1,2; 130, 140), and erasure is effected by separating said layers by effecting relative movement between a cursor (41; 125/126) and said layers, characterised in that: (a) the device comprises a cursor (41; 125/126) which forms one limb of a frame (4; 120); and (b) the central open part (45; 128) of said frame defines the area where marks can be recorded.
A marker device as claimed in claim 1, characterised in that a second limb (44) of said frame (4) provides a grip whereby the whole frame may be moved relative to the working layers (1, 2) in order to effect erasure of recorded marks.
A marker device of the type in which marks are recorded by creating points or lines of contact between two adjacent layers, and erasure is effected by separating said layers by moving a cursor between them, characterised in that: (a) the device comprises a cursor (41) which forms one limb of a frame (4); (b) the central open part (45) of said frame (4) defines the area where marks can be recorded; and (c) a second limb (44) of said frame (4) provides a grip whereby the whole frame may be moved relative to said adjacent layers (1, 2) in order to effect erasure of recorded marks.
A marker device as claimed in claim 1, 2 or 3, characterised in that said frame (4; 120) is generally rectangular.
A marker device as claimed in claim 3, wherein said two adjacent layers (1, 2) are secured together along a line (17, 27) positioned within said central open area (45) of the frame (4) relatively remote from the cursor (41) when the frame is in its rest position (i.e. the position for recording marks).
A marker device as claimed in any preceding claim, characterised in that said two adjacent layers consist of a first layer (1; 130) which carries a wax film and a second, opalescent layer (2; 140) above said wax film.
A marker device as claimed in claim 6, characterised in that the frame (4) is disposed between said first and second layers (1, 2).
A marker device as claimed in claim 6, characterised in that the device further comprises a third, transparent layer (3; 150) overlying said second, opalescent layer (2; 140).
A marker device as claimed in claim 6, characterised in that said first layer (1; 130) is formed of paper or a plastics material.
A marker device as claimed in claim 6, characterised in that said second, opalescent layer (2; 140) is formed of a plastics material.
A marker device as claimed in claim 8, characterised in that said third layer (3; 150) is formed of a plastics material e.g. a thin film of polyethylene terephthalate (PET) or of polyvinylchloride (PVC).
A marker device as claimed in any preceding claim, characterised in that the device is constructed as a laminated structure.
A marker device as claimed in claim 12, characterised in that said laminated structure has a thickness not exceeding 2mm.
A marker device as claimed in claim 13, characterised in that said laminated structure has a thickness not exceeding 1mm.
A marker device as claimed in claim 12, characterised in that: (a) the device is generally rectangular, and (b) the layers (1,2,3) of the device other than said frame (4) are secured together along a first edge (12/22/32) of the device which is that edge adjacent to the cursor (41), and along the two edges (13/23/33; 14/24/34) adjoining said first edge.
A marker device as claimed in claim 3, characterised in that said frame (4), when in its rest position, is located substantially wholly within the device.
A marker device as claimed in claim 16, characterised in that the grip portion (44) of said frame (4) is accessible, when the frame is in its rest position, through a cut away region (28/38) formed in the or each layer of the device which lies above the frame.
A marker device of the type in which marks are recorded by creating points or lines of contact between two adjacent layers (130, 140), and erasure is effected by separating said layers by causing relative movement between the layers and a cursor (125; 126) located between them, characterised in that: (a) the device comprises a frame (120) having side portions (121, 123), a rear portion (122) and a front portion (124); (b) the front portion (124) of said frame comprises two bars (125, 126) separated by a narrow slot (127); (c) the central open part (128) of said frame (120) between the side portions (121, 123) thereof is dimensioned so as to receive said layers; and (d) the device is assembled so that one of said layers (140) passes through said slot (127) in the front portion (124) of said frame (120) whereby relative movement between said layers (130, 140) and one of said two bars (125, 126) effects erasure of marks previously recorded, so that said one of the two bars (125, 126) constitutes said cursor.
A device as claimed in claim 18, characterised in that said layers (130, 140) are secured together at their forward edges (134, 144) and are provided with a grip (138, 148) whereby the layers may be moved relative to said frame (120) in order to effect erasure of recorded marks.
A data storage disk to which there is secured a marker device as claimed in any preceding claim.