A.C. Edwards Ltd v Movitex Signs Ltd (formerly Acme Signs & Displays Ltd)

This is an appeal by the defendant from a decision of Aldous J. who held that the plaintiff's patent had been infringed by the defendant

The plaintiff is A.C. Edwards Ltd. It is the proprietor of U.K. Patent 2139391 in respect of an invention called "An Improved Digital Display Apparatus". There are, in fact, two actions. They differ only in the identity of the defendant. The defendant in the second action having taken over the business of the defendant in the other action, the two actions were treated as one at the trial.

The issues before the judge were validity and infringement. As to infringement it was and is accepted that the defendant has manufactured and sold the apparatus alleged to infringe the patent and that the issue is whether the apparatus falls within the monopoly claimed. The judge held that it did and the defendant appeals from that.

The validity of the patent was challenged on two grounds. First, that the invention was obvious; the judge rejected that and there is no appeal on the point. Secondly, that the patent, as granted, discloses matter which extends beyond that disclosed in the application as filed. On this matter also the judge decided in favour of the plaintiff and the defendant now appeals.

The digital display apparatus which is patented is for use particularly in the forecourts of petrol stations to show passing motorists the current prices of petrol and diesel fuel.

The specification states that the selling of commodities such as petrol necessitates the frequent changing of plates bearing numerals which is time-consuming and requires the holding of a large number of plates or, alternatively, the use of an electronic display apparatus which is expensive. As a result there was a need for a digital display apparatus which is of simple mechanical construction and overcomes the disadvantages referred to.

The apparatus is described in the consisting clause as comprising:

"A substantially planar baseboard having one or more seven element displays marked on a front face thereof and a flap or shield for each element of the or each display which is pivotal from a first position in which the associated element is exposed to a second position in which it covers the associated element, selective pivoting movement of the indicated flaps enabling the elements to form and display any required digit with each flap being pivotable manually about one edge from a first position in which one face of the flap is against the front face of the baseboard and a second position in which the other face of the flap is against the front face of the baseboard, and the flaps being attached to the baseboard by mechanisms each comprising: firstly a stud inserted into an aperture in the baseboard, the stud having a transverse aperture therethrough extending substantially parallel to the plane of the baseboard adjacent the front face thereof…"

The seven elements are made up to form the numeral 8. The 8 is not, however, curved but is made up of seven straight lines or elements constituting two rectangles—one above the other thus:

So, for example, by covering, with the flaps, the two elements on the left-hand side, the numeral 3 can be formed.

Claim 1 of the Claims in the Patent relates to a digital display apparatus having the following features:

(i) A planar baseboard having one or more seven-element displays marked on its face.

(ii) A flap for each element of the display which is pivotal to form a first position in which the element is exposed and a second position in which it is covered.

(iii) A pivoting movement of the flaps to enable the elements to form and display any required digit with each flap being pivotable manually about one edge of the baseboard, a first position (with one edge of the flap against the front face of the board) and a second position (in which the other edge of the flap is against the front face of the board).

(iv) The flaps are attached to the baseboard by mechanisms comprising (a) a stud inserted into an aperture in the board, the stud having a transverse aperture extending through it and substantially parallel to the plane of the board adjacent to the front edge thereof, (b) an edge of the flap, being a portion of the material of the flap lying between the edge thereof and a slot formed in the material of the flap adjacent to that edge, (c) means for retaining the stud within the baseboard.

(v) Spring means on the stud retains the associated flap in the first or second position.

Claim 1 thus substantially repeats the consistory clause.

The defendant has marketed two versions of a manual display apparatus, the Mark I and the Mark II. Both are alleged to infringe the patent in suit.

The Mark I is hinged at one place. The important part of that mechanism, for this case, is described by the judge, in language which I adopt, as follows:

"It consists of a body portion which has barbed depending legs which pass through the board. The barbs act to secure the hinge to the board. Attached at each end of the body portion are arms which form with the body portion an H configuration. On the outside ends of those arms are bars which have a tapered surface at one end and a rounded surface at the other. To assemble the Mark I, the edge of the flap is slid between the legs. Thereafter the legs are pushed through a rectangular slot in the baseboard, thereby holding the hinge to the baseboard. The flap can then be moved manually through 180 degrees from a position in which it covers a coloured segment of the display on the baseboard to a position in which it lies flat on the baseboard leaving the coloured segment exposed. Thus by moving the flaps any numeral between 0 and 9 can be displayed.

The purpose of the arms can best be appreciated from the model which is Exhibit P13. If it is desired to expose a coloured segment on the baseboard, the flap which is covering the segment is lifted. This will cause the edges of the slot in the flap to contact the bars on opposing arms. Continued raising of the flap causes the edge of the slot to ride up the bars causing the arms to flex towards each other. After about 45 degrees of rotation, the edge slips off the bars and the flap then is free to rotate about another 90 degrees until the edge of the slot comes into contact with the bars on the other arms. Further rotation causes the arms to flex as the edges of the slots ride up the bars and the tapered surface of the bars will tend to urge the flap towards a flat position parallel to the baseboard."

There is no dispute that the defendant's Mark I has features (i) to (iv) (inclusive) of Claim 1. The defendant contends, however, that Mark I does not have feature (v). The reason for that, it is contended, is that the arms are not "spring means". That is a question of construction of the Claim.

The principle of construction was stated by Lord Diplock in Catnic Components Ltd v. Hill & Smith Ltd [1982] R.P.C. 183 at 243 as follows:

"A patent specification should be given a purposive construction rather than a purely literal one derived from applying to it the kind of meticulous verbal analysis in which lawyers are too often tempted by their training to indulge. The question in each case is: whether persons with practical knowledge and experience of the kind of work in which the invention was intended to be used, would understand that strict compliance with a particular descriptive word or phrase appearing in a claim was intended by the patentee to be an essential requirement of the invention so that any variant would fall outside the monopoly claimed, even though it could have no material effect upon the way [in which] the invention worked."

That is in line with the statutory provisions.Section 125 of the Patents Act 1977 (which corresponds to Article 69 of the European Patent Convention) provides:

"125.-(1) For the purposes of this Act an invention for a patent for which an application has been made or for which a patent has been granted shall, unless the context otherwise requires, be taken to be that specified in a claim of the specification of the application or patent, as the case may be, as interpreted by the description and any drawings contained in that specification, and the extent of the protection conferred by a patent or application for a patent shall be determined accordingly.

(3) The Protocol on the Interpretation of Article 69 of the European Patent Convention (which Article contains a provision corresponding to subsection (1) above shall, as for the time being in force, apply for the purposes of subsection (1) above as it applies for the purposes of that Article."

The protocol referred to provides as follows:

"Article 69 should not be interpreted in the sense that the extent of the protection conferred by a European patent is to be understood as that defined by the strict, literal meaning of the wording used in the claims, the description and drawings being employed only for the purpose of resolving an ambiguity found in the claims. Neither should it be interpreted in the sense that the claims serve only as...