GB2393558A - Multi-image dislpay with carrier displacing system - Google Patents

Abstract

A unit for displaying a series of images comprising; a transparent screen consisting of one or more lenses (i.e. a lenticular screen), through which an indica carrier may be viewed, and a driving mechanism 14 to move the indica carrier between two positions in an oscillatory motion. The drive mechanism 14 incorporates an automatically reversing gear to allow the drive shaft of the driving means 14 to move in one direction only, whilst moving the indica carrier in two. The line of action of the driving means 14 may be in line with the centre of gravity of the indica carrier. Preferably the driving means is a rack 17 and pinion mechanism. It is claimed that this method of indica carrier oscillation is superior to those in the art that rely on cams, in that it does not subject the indica carrier to mechanical wear.

Description

A DISPLAY UNIT

Field of the Invention

This invention relates to units with one or more lenses for displaying a sequence of images by displacing an indicia carrier in one direction and the opposite direction. 5 Background to the Invention

The prior art proposes a wide variety of approaches for displacing indicia carriers

sequentially in one direction and the opposite direction. Kokai patent application no. HEI 2 (1990) - 211437 teaches that a rack and pinion mechanism is to be used along one of the side edges of the indicia carrier, the rack and pinion mechanism IO being driven by a stepping motor which changes direction according to the instructions received from control means. The system requires complex electronics to achieve the change of direction of the indicia carrier. It will also be inefficient in terms of its consumption, probably requiring connection to an A/C

source or the frequent replacement of batteries. Affixing the rack and pinion mechanism along one of the sides of the indicia carrier will result in poor display quality being particularly variable over time and even possibly subject to premature system failure.

5 EP 1 001 401 Al (Etar-Yona, Itzchak) also shows a prior art system for driving an

indicia carrier sequentially in one direction and the opposite direction. This system uses a conventional cam abutting directly against an indicia carrier edge to achieve its displacement in one direction and the opposite direction. This system requires accurate engagement of the cam to the lower edge of the indicia carrier 10 which is often difficult to achieve. The indicia carrier itself will need to be particularly resistant to friction as the cam rotates against the indicia carrier. Such friction may result in a gradual erosion of the fragile indicia carrier edge. Gradual erosion will in turn cause the optical quality of that kind of display unit to gradually decrease and eventually the display unit may experience difficulties in 15 displaying the series of images it is intended to display. This kind of problem will be accentuated as the size of the display unit is increased. A display unit driven by a cam also requires the cam to carry the indicia carrier. A cam would be, for example, incapable of driving a horizontal carrier displacement.

One of the objectives of the present invention is to provide an indicia carrier 20 which has improved optical properties over the above described prior art systems.

A further aim of the present invention to provide a low consumption driving means employing relatively simple electric components.

It is a further objective of this invention to present a driving means which may be particularly compact and at the same time capable of driving a wide range of 25 indicia carriers. It is envisaged that the teaching of the present invention may be employed to configure indicia carriers with vertical lines of action as well as those in any other direction such as the horizontal line of action.

It will of course also be an objective of the invention to provide a system which is particularly durable without any undue friction between the indicia carrier and its housing or its driving means.

Summary of the Invention

5 In its broadest aspect, the invention presents a unit for displaying a sequence of images and of a kind - generally known in itself- comprising one or more lenses through which an indicia carrier may be viewed and driving means adapted to displace said carrier sequentially in one direction and the opposite direction; characterized in that the driving means incorporates an automatically reversing 10 gear to enable the driving means to operate in one direction only whilst generating the required sequential oppositely directed movements.

Supplying the driving means with an automatically reversing gear is advantageous because it allows the driving means to operate in one direction only which is particularly efficient in terms of its energy consumption. This arrangement 15 requires no complex electric system, for example, the most basic rotor may be used to drive the system. Another advantage that flows from this configuration is that there needn't be a frictional engagement between the indicia carrier and the drive means so that improved optical images may be displayed.

In a subsidiary aspect, the line of action of the driving means is essentially in line 20 with the centre of gravity of the carrier.

In this particular field, the tolerances between the indicia carrier and its housing

will vary from indicia carrier to the next and from one display unit to the next, by placing the line of action of the driving means essentially in line with the centre of gravity of the carrier the optical display quality is improved.

In a further subsidiary aspect, the driving means transmits its drive to the carrier through a carriage which acts to tend to spread the weight of the carrier evenly and/or to move the carrier uniformly.

By driving the carrier through a carriage, the quality of the optics is further 5 improved as the weight of the carrier is spread evenly and the motion of the .. carrier IS umform.

In a further subsidiary aspect, the driving means is a rack and pinion.

While rack and pinion mechanisms are well known in themselves, applying such a mechanism to drive in line with the centre of gravity of the carrier has 10 unforeseeable advantages. It achieves a particularly stable motion of the carrier guaranteeing advanced quality of optics and enhanced durability and versatility of the system.

Brief Description of the Drawings

Figure 1 shows a side elevation of a display unit with one half of its support 1 S structure removed and a portion of its driving mechanism also removed.

Figure 2 shows a side elevation of the display unit as in Figure I with one half of its support structure removed but with the driving mechanism placed therein.

Figure 3 presents a schematic perspective view of a section of the driving means.

Figure 4 shows two stretched elevations of the driving means.

20 Figure 5 presents a side elevation of the driving means.

s Detailed Description of the Drawings

Figure 1 presents a display unit I with a window 2 incorporating an array of lenses. These lenses form a horizontally extending linear array. While this particular type of array is the one illustrated, the invention envisages other 5 configurations of arrays including honeycomb and spherical. The display unit I comprises two overlapping windows (only window 2 being visible in the drawing). The display unit's windows are held together at their upper corners by releasable means 3 which can be selected from a range of known alternatives.

The windows are sufficiently spaced from one another to allow an indicia carrier 10 to be inserted between them. A lid 4 is adapted to engage with releasable attachment means 3 in order to facilitate its straight forward removal to enable the operator to change the indicia carrier when required.

The group comprised of the indicia carrier, the windows and the lid are held by two mating halves such as the one presented in Figure 1 at 5. These halves are 15 sufficiently spaced apart to accommodate the unit's driving means. Only part of such driving means has been illustrated in the figure: a battery compartment 6 and a carriage 7. The halves are constructed in such a way as to mount a stand 8 which allows pivoting about axis 9.

Carriage 7 has the particularity of running along tracks 10 and I I which form part 20 of half 5. These tracks are preferably parallel to and symmetrical about the centre of gravity of the carrier. A projection 12 extends from the carriage 7 and comprises a group (not illustrated in the drawing) destined to receive a protruding extremity of the indicia carrier. A second projection 13 extends out of the plane of carriage 7 and is sufficient in dimensions to be pushed by the drive means.

25 Figure 2 shows a portion of the same display unit as described in the context of Figure 1. Identical components have retained identical numerical references. In this illustration however, the driving means 14 are present. A socket 15 for

receiving the current from an AC/DC transformer and switch 16 for on/off and AC/DC or battery operation selection have been illustrated.

Driving means 14 shows a protruding rack 17 abutting against carriage projection 13 so that when the rack displaces in the upwards direction or the downwards 5 direction the indicia carrier correspondingly displaces. Rack 17 operates up and down along the centre of gravity of the carrier and by so doing improves the quality of the display and the durability of the unit.

The following section will describe in detail how the movement of the rack is achieved according to this invention. In its broadest sense, the driving means 10 employs a rotor which generates motion and transmits motion through gears to a rack and pinion mechanism. The driving means operates in one direction only while generating the required sequential oppositely directed movements of the indicia carrier.

Figure 3 shows a schematic perspective of how this sequential oppositely directed 15 movement of the indicia carrier is achieved. The motion from the rotor is transmitted through a series of gears to cog 21 which rotates in one direction only during its operation. Similarly, motion is transmitted to a wheel 22 which also rotates in one direction. The motion of cog 21 is transmitted to cog 23 which transmits its motion to a pinion 24. Pinion 24 engages a rack 25.

20 In the mode of operation illustrated, cog 23 directly engages pinion 24 and by so doing drives the displacement of the rack in one direction. Cog 21 is rotated about a shaft 26. On to this same shaft is mounted a pivoting arm 27 which itself has a shaft 28 about which cog 23 rotates. Arm 27 is adapted to pivot along with shaft 28 and cog 23 about shaft 26 which is fixed to the gear box casing (not 25 illustrated in the drawing). Arm 27 incorporates a cut-out 29 into which is inserted an extremity 30 of a sliding arm referenced 31.

The opposite extremity of arm 31 incorporates a projection 32 extending perpendicular to arm 31 and engaging with wheel 22. Wheel 22 has the particularity of comprising a channel 33 which extends around the wheel's axis and has at least two radii values. In this particular embodiment, there are two 5 main radii portion 34 and 35. As the wheel is rotated about its fixed axis 36, arm 31 oscillates about axis 36 and displaces as indicated by the arrows 37 when projection 32 passes from one radius of the channel to another.

Therefore, when projection 32 runs along one portion of the channel, cog 23 directly engages pinion 24 and when it passes to the second radius, cog 23 is 10 displaced to a position where it can transmit motion from cog 21 to cog 38. In that position, cog 38 will drive cog 39 and cog 40 in series so that the motion of cog 21 is transmitted to pinion 24 at cog 40. Cog 40 engages pinion 24 at all times whether cog 23 directly engages pinion 24 or engages cog 38. Cog 23 transfers motion to pinion 24 in one direction while cog 40 when being driven 15 transmits motion to pinion 24 in the opposite direction. By so doing, rack 25 sequentially displaces in one direction and the opposite direction in order to achieve the displacement of the indicia carrier.

The entire gear box generally referenced at 41 will now be described in detail with references to both Figures 4A and B. The same reference numerals are used 20 for the same components in Figures 3, 4A and 4B. Rotor 42 drives an output cog 43 which rotates cog 44. Cog 44 rotates about a shaft 45 which is fixed relative to the gear box housing 46. Cog 44 presents a first array of teeth 50 placed about a first diameter of the cog about its largest diameter and a second array of teeth 47 placed about a smaller diameter of the cog, inwardly located with reference to the 25 largest diameter so that this arrangement essentially constitutes a reduction gear.

The second array of teeth 47 engages a first array of teeth 51 of cog 48 which also presents a second array of teeth 52 destined to further reduce the rotation. This latest second array of teeth engages a further reduction gear 53 placed about a

third shaft 54. The rotation of reduction cog 53 is transmitted to a further reduction cog 55 rotating about a fourth shaft 56. Instead of this time transmitting motion to the fifth shaft of the system, this reduction cog 55 transmits motion to a further reduction cog 57 arranged below cog 53 on shaft 54. This configuration is 5 particularly advantageous as it permits the gear box to be compact.

The rotation of cog 57 is transferred back onto shaft 56 but this time onto cog 58 which is arranged below cog 55 but allowed to rotate separately from said cog.

Array 59 of teeth are arranged about the greater diameter of cog 58 so and engage wheel 22 about teeth array 60 (this engagement cannot be seen on the drawing).

10 Cog 58 transmits about its smaller diameter 61, the motion to cog 21 which goes on to transmit motion to cog 23 and to the rack and pinion mechanism constituted of pinion 24 and rack 25.

Figure 4B shows gear box 41 in a stretched elevation (i.e. along the shafts about which the cogs are rotated). In this configuration cog 23 is engaged with a series 15 of reversing cogs 38, 39 and 40 which transmit motion to the pinion 24 in the opposite direction than that achieved in the engagement described in Figure 4A.

As a consequence of the pinion 24 being rotated in the opposite direction, the rack 25 will also be displaced in the opposite direction to that achieved in the context of Figure 4A.

20 Figure 5A displays a side elevation of the driving means. The different components of the driving means have been given the same numerical references as used in Figures 3, 4A and 4B. It would be superfluous at this stage to reiterate the description of this system as detailed with reference to the previous figures,

the figure is therefore simply referenced for added clarity. We will focus in the 25 following section in those elements which were not fully visible in Figure 4A and 4B.

Arm 31 can be seen extending over wheel 22 while its projection 32 engages channel 43. Projection 32 is depicted as engaging the larger radius portion of the channel. As the wheel 22 is rotated, projection 32 will pass into the smaller radius portion. This passage from one radius portion to another corresponds to the 5 displacement of cog 23 from its engagement with the pinion 24 to its engagement with cog 38. Arm 31 is constrained between four rails 62, 63, 64 and 65 which project from the housing and constrain arm 31 to displace essentially linearly.

The extremity 30 of arm 31 locks into cut-out 29 of pivoting arm 27.

Alongside cog 23 a member 68 projects on either side of the cog. Protruding 10 from the inner wall of the housing are two stops 66 and 67. Member 68 abutts against stop 66 when engaging pinion 24 and against stop 67 when engaging cog 38. From member 68, a hook 69 extends so as to overlap a portion of the pinion.

Claims (5)

1. A unit for displaying a sequence of images and of a kind - generally known in itself- comprising one or more lenses through which an indicia carrier may be viewed and driving means adapted to displace said carrier sequentially in one 5 direction and the opposite direction; characterized in that the driving means incorporates an automatically reversing gear to enable the driving means to operate in one direction only whilst generating the required sequential oppositely directed movements.

2. A unit according to any preceding claim, wherein the line of action of the 10 driving means is essentially in line with the centre of gravity of the carrier.

3. A unit according to claim 2, wherein the driving means transmits its drive to the carrier through a carriage which acts to tend to spread the weight of the carrier evenly and/or to move the carrier uniformly.

4. A unit according to claim 2 or 3, wherein the driving means is a rack and 1 5 pinion.

5. A unit substantially as described with referenced to and as illustrated in any appropriate combination of the accompanying text and drawings.