Soy milk, a lactose-free alternative to cow milk, takes considerable time and effort to prepare. Sensing a business opportunity, several companies have decided to capitalize on this by making appliances that make soy milk without the hassle.

Two companies selling such devices, Ronic Corporation (“Ronic”) and Cadware Sdn Bhd (“Cadware”) found themselves in a legal dispute when Ronic claimed that Cadware infringed upon their patent rights by distributing and marketing a soy milk machine that mirrored theirs. Cadware counter-claimed that Ronic’s patent was invalid and therefore, there was no infringement.

Ronic owns Patent No. MY-134058-A (“‘058 Patent”) for a soy milk making device, which discloses a circuit for sensing presence of water in the device and warning the user when there is an absence of water.

In the case of Ronic Corporation vs. Cadware Sdn Bhd, the Kuala Lumpur High Court ruled in favour of Ronic as the Judge found that Cadware’s product reproduces all the main elements of the ‘058 Patent except for one transistor, that being Transistor Q9. The Judge then concluded that based on balance of probabilities, Cadware’s product had infringed upon Ronic’s patent rights.

The High Court came to this decision by determining the validity of the patent and whether an infringement had taken place. Cadware sought to invalidate the patent by challenging its novelty and inventiveness by citing prior art and alleging that the patented invention was anticipated and obvious based on prior art. It was concluded that the patent was novel and inventive as the inventor was able to hit upon something no other inventor saw previously.

Cadware also alleged that the patent was insufficient as it did not disclose the type of transistor used in its circuitry. An expert witness for Ronic however, stated that it was standard practice that the type of transistor used need not be disclosed. Cadware further alleged that the invention was not workable as a pull-up resistor was needed for it to work, but it was subsequently determined that the invention did not need one as the function of the resistor was provided by I.C. chips that were incorporated into the circuit.

The High Court then sought to establish if infringement had occurred. The circuitries of both devices were examined and found to be similar, save for Transistor Q9 which was not in Cadware’s product. In spite of this, the High Court concluded that it did not affect the functionality of Cadware’s product, which mirrored the functions of Ronic’s product, therefore infringement took place.

Unsatisfied, Cadware appealed against the decision and this time, it won. The Court of Appeal ruled that patent infringement should be established based on the doctrine of purposive construction and not by balance of probabilities. The doctrine of purposive construction states that a patent specification should be purposive in its construction and not a literal description, where the reader ought to understand the meaning of the claims as intended by the patentee. Two landmark cases – Catnic (1982) and Improver (1990) – were key in developing the evaluation test for the doctrine of purposive construction, now known as the “Improver questions”, a three-stage step to establish infringement:

  1. Does the variant have a material effect on the way the invention works? If yes, there is no infringement. If no;
  2. Would the immaterial variant have been obvious at the date of publication of the patent to a reader skilled in the art? If no, there is no infringement. If yes;
  3. Would the reader skilled in the art nevertheless have understood from the language of the claim that the patentee intended that strict compliance with the primary meaning was an essential requirement of the invention? If yes, there is no infringement. If no, infringement will be established.

Applying the first question to this case, it was seen that the absence of Transistor Q9 had material effect on how invention worked. Without said transistor, the circuit would function differently, instead of giving a warning signal when water is absent, the device would give a warning signal when water is present. Therefore the question was answered in the positive and there was no infringement.

Ronic then attempted to establish infringement by citing the Marconi vs. British Radio Telegraph & Telephone (1911) case, in which the decision was based generally on the pith and marrow principle whereby if the accused apparatus is substantially the same as the apparatus said to have been infringed, then infringement is established. However, following the Catnic case, this approach was passed over in favour of the doctrine of purposive construction.

Nevertheless, it was shown that the Cadware’s device was substantially different from Ronic’s as the latter’s device would function differently in the absence of Transistor Q9, and modifications would be required to enable the device to perform its intended function, which confirmed without a doubt that both devices functioned differently and there was no infringement.

In preparing soy milk, adding a little sugar makes it sweet, while a little gypsum powder turns it into bean curd. As seen in this case, the omission of a single transistor, though seemingly negligible, changed how the device functioned entirely. Sometimes, what seems to be insignificant can make all the difference in the world.