Case Study: Correcting a Problematic Main Claim

An independent claim generally defines the broadest scope of protection for an invention. Drafting them can be an intricate process, and even experienced patent attorneys can encounter challenges. In this case study, we examine the process of identifying and correcting a mistake in a patent claim.

Consider the following example claim.

1. An electrical device comprising:
    a substrate on which a plurality of guiding blocks are arranged, neighbouring guiding blocks being spaced apart by an inter-block spacing,
    at least two neighbouring guiding blocks being spaced apart by an inter-section spacing, with the inter-section spacing being greater than the inter-block spacing and arranged to affect an electrical characteristic of the substrate.

At first glance, this claim may seem reasonable. However, a closer look would reveal that it is rendered unclear due to the phrase "at least two neighbouring guiding blocks", which may have two alternative interpretations.

Interpretation 1

In the first interpretation, "at least two neighbouring guiding blocks" may be assumed to refer to the already introduced blocks, such that the phrase may be construed to mean:

1. An electrical device comprising:
    a substrate on which a plurality of guiding blocks are arranged, neighbouring guiding blocks being spaced apart by an inter-block spacing,
    at least two neighbouring ones of the guiding blocks being spaced apart by an inter-section spacing, with the inter-section spacing being greater than the inter-block spacing and arranged to affect an electrical characteristic of the substrate.

The problem with this construction is that it is logically impossible. See the following diagram, showing the substrate in red and the blocks in blue.

It is apparent that "the inter-section spacing being greater than the inter-block spacing" cannot be true. Thus, the first interpretation is ruled out.

Interpretation 2

In the second interpretation, "at least two neighbouring guiding blocks" may be assumed to introduce new blocks, such that the phrase may be construed to mean:

1. An electrical device comprising:
    a substrate on which a plurality of guiding blocks are arranged, neighbouring guiding blocks being spaced apart by an inter-block spacing, and
    at least two neighbouring further guiding blocks being spaced apart by an inter-section spacing, with the inter-section spacing being greater than the inter-block spacing and arranged to affect an electrical characteristic of the substrate.

The problem with this construction is that the further guiding blocks may represent additional guiding blocks of the electrical device that are not arranged on or otherwise associated with the substrate, which is uncontemplated and unreasonable. See the following diagram.

With such a construction, claim 1 would not be supported by the description, nor would the description enable such a claim. Thus, the second interpretation is also ruled out.

Correction

The claim may be corrected to read:

1. An electrical device comprising a substrate on which a plurality of guiding blocks are arranged,
    each neighbouring pair of the blocks in each of neighbouring first and second sections being substantially spaced apart from each other by an inter-block spacing, and
    the first and second sections being spaced apart from each other by an inter-section spacing, with the inter-section spacing being greater than the inter-block spacing and being arranged to affect an electrical characteristic of the substrate.

See the following diagram, further showing the sections in green.

Main claim 1 holds the most weight, defining the broadest protection and framing the entire disclosure. This example demonstrates why it may be a good idea to spend more time to ensure that the main claim is logically sound. 

Note:  The corrected claim effectively demonstrates the preceding points on claim clarity.  It clarifies the arrangement of the guiding blocks and the spacing between them.  However, to fully capture the functional relation between the spacing and the electrical characteristic, additional details might be needed.