Overargument Leads to Prosecution Disclaimer

In Computer Docking Station Corp. v. Dell, Inc. the Federal Circuit affirmed the district court’s holding of no infringement because the patentee disavowed an interpretation of "portable computer" that would encompass a computer with a built-in display or keyboard.

Claim 28 of U.S. Patent No. 5,187,645 [above] was representative of the three asserted independent claims, reciting "A portable computer comprising . . . said single connector for making all connections from the microprocessor to said specific computer peripheral devices."

According to the opinion by Circuit Judge Rader,

During prosecution, in a Response dated June 15, 1992, the applicants sought to
distinguish their invention from Herron [above]. The applicants’ statements clearly and unambiguously disavowed computers with built-in displays and keyboards – that is, laptops. At the outset of those statements, the applicants distinguished
their invention, a portable microprocessing system, from its peripheral devices:

The Applicants’ invention is a portable microprocessing system with a
microcomputer contained within a housing. As is typical of such systems, the microprocessor interfaces with several peripheral devices including a
keyboard, display, modem, serial and parallel port devices, a power source, etc. The Applicants’ system provides all of the interfaces for these devices at a set of interface connectors on the rear bezel of the housing.

Amendment to U.S. application no. 07/711,816, dated June 15, 1992, at 13. The applicants expressly listed a keyboard and display as peripheral devices. They also explained that the interface connectors for the keyboard and display are located on the rear bezel of the housing. If the keyboard and display were built-in or attached to the housing like a laptop, these peripheral connections would not be necessary.

In the same Response, the applicants also contrasted the advantages of their invention with the limitations of the Herron laptop:

The Applicants’ system therefore provides an extremely powerful utility. A full-sized microprocessor with large memory capacity is made completely portable. The processing unit housing or "brick" can be easily removed from one system and transported in a briefcase to another system. Rather, a requirement that would lead one away from the present invention. However, even that requirement can be an advantage over laptop computers in that than requiring a portable display and keyboard, the present invention concentrates on portability of an exceptionally large memory capacity in hard disk drive. . . . For the same sized unit as a conventional lap-top computer, the invention does require
that peripherals be made available at each locationhigher quality peripherals will more likely be used since they need not be transported. Thus, lap-top machines make concessions in memory, display and other areas in favor of portability. The Applicants’ system, on the other hand, is a portable full service microprocessing system which concedes portability of peripherals.

Id. at 14-15. (emphases added). In this statement, the applicants clearly distinguished their invention from computers with a built-in display or keyboard. They told the examiner that the invention concedes portability of peripherals, which they previously defined to include displays and keyboards, in favor of processing power and memory. As a result, they stated that the invention does not require a built-in display and keyboard. In fact, the applicants explained that the invention requires these peripherals at each location of use. In contrast, the applicants emphasized that laptops sacrificed the power of the claimed full-service microprocessing system in favor of built-in peripherals. The applicants also stated that the built-in display and keyboard of a laptop would be inferior in quality to the peripherals stored permanently at each location and used with the claimed invention.
Moreover, the applicants further distinguished their system from the Herron "laptop computer with its own flat panel display and keyboard," arguing that laptops did not have the memory capacity, utilities and functionalities of their system:

The Herron system does not allow a microprocessor having state-of-the-art memory capacity and other capabilities to interface to a full-service processing system as does the Applicants’ system. The Herron system allows a lap-top computer with its own flat panel display and keyboard to interface to other peripheral devices. This lap-top computer does not possess utilities and functionalities comparable to those of the Applicants’ system.

Id. at 17. The applicants also distinguished their invention from laptops based on how the devices connect to the docking station. Because the keyboard and display are not built into the claimed microprocessing system, the applicants described the system as able to fit vertically in the docking station. Because of its built-in keyboard and display, a laptop could not fit vertically. Specifically, the applicants stated: "The Herron reference discloses a docking module which is latched to the rear of a lap-top computer. The computer and docking module rest on a desk top." Id. at 16. "[T]he computer in Herron is not oriented vertically as in the Applicants’ system. It would make no sense to do so with the Herron lap-top with its attached keyboard and display. Therefore, Herron does not have the Applicants’ reduced footprint size." Id. at 17.

This Response to the examiner also referred to laptops. In this statement, the applicants saw that laptops too might find a use for the claimed system:

A single connector to implement all of the interfaces provides for easy
connection and disconnection and may be used to advantage with lap-top computers as well. For example, the lap-top system of Herron, et al. docks to several connectors making it difficult to align the connectors before docking.

This statement, however, does not bring a laptop within the scope of the claims. Instead, the statement suggests that one component of the claimed invention, a single docking connector, could be used with laptops. The single docking connector is one of several limitations recited in the claims, recited separately from the portable computer limitation. Thus this reference to laptops, if anything, just represents another attempt to distinguish the invention from the laptops of Herron.

A careful reading of the prosecution history leaves little doubt that the distinctions between the invention and Herron are more extensive than only the single connector limitation. This court observes that the applicants distinguished their invention from the prior art in multiple ways. Moreover, the examiner’s citation of the single connection limitation in the reasons for allowability does not erase the applicants’ clear disavowal of laptops. . . .

"While the result of Standard Oil and Computer Docking may be fair and equitable, it comes with a price," notes Professor Wegner:

To interpret the scope of claims under Standard Oil and the literally dozens of
following cases including Computer Docking, it is necessary to parse the wording
of an often thick prosecution history.

As technology gets more complex, how is a district court judge without technical background or experience and a political science and history major as his two clerks to fathom whether there is or is not a prosecution disclaimer?It is no wonder that there is such a high reversal rate for claim construction rulings, given the formalistic doctrines that have evolved over the past generation.