Opinion ID: 750685
Heading Depth: 3
Heading Rank: 2

Heading: Construction of Claim 1 of the '463 Patent

Text: 25 Claim construction is a question of law, and therefore we review the district court's claim interpretation de novo. See Markman v. Westview Instruments, Inc., 52 F.3d 967, 979, 34 USPQ2d 1321, 1329 (Fed.Cir.1995) (in banc), aff'd, 517 U.S. 370, 116 S.Ct. 1384, 134 L.Ed.2d 577, 38 USPQ2d 1461 (1996). Proper construction requires an examination of claim language, the written description, and, if introduced, the prosecution history. See Vitronics Corp. v. Conceptronic, Inc., 90 F.3d 1576, 1582, 39 USPQ2d 1573, 1576 (Fed.Cir.1996). The appropriate starting point, however, is always with the language of the asserted claim itself. See id.; Bell Communications Research, Inc. v. Vitalink Communications Corp., 55 F.3d 615, 620, 34 USPQ2d 1816, 1819 (Fed.Cir.1995). 26
27 The crucial clause of claim 1 requires a call cost register means, including a digital display, for providing a substantially instantaneous display of cumulative call cost in dollars and cents. Because we can dispose of this appeal by construing only the call cost register means, we need not and do not construe other, unrelated clauses except to the extent they can help us establish the requirements attributed to a call cost register means by the '463 patent. We therefore focus our attention on reviewing the construction of this clause, and this clause only. 28 According to claim 1, the call cost register means provides a substantially instantaneous display of cumulative call cost in dollars and cents. Thus, it appears that a call cost register means functions to display current, accurate information about the cost of a call. It is not immediately clear, however, what the limitation substantially instantaneously requires. NTI and United suggest that it requires displayed information about the cost of the call at the same instant that charges accrue. Phonometrics argues, however, that it simply requires the display of accurate cost information immediately upon termination of the call. Fortunately, we need not rely solely on the words used in this means clause to determine the requirements of this limitation, for there are other clauses in claim 1 that inform our construction of the call cost register means and further define the functions attributed to it by the patentee. Specifically, the final three clauses of claim 1 provide such information. 29 The first of these three clauses requires an initial cost transfer means ... for applying the complete initial fixed charge data from said charge selector means to said call cost register means substantially instantaneously upon resetting of said call timing means and said call cost register (emphasis added). Thus, when the device is reset, the initial fixed charge data is transferred substantially instantaneously from the charge selector means to the call cost register means and displayed there via the digital display. 30 Claim 1 further requires (emphasis added) an incremental cost transfer means for applying the complete incremental charge data from said charge selector means to said call cost register means substantially instantaneously upon completion of timing out the initial call interval ... and for again applying the complete incremental charge data from said charge selector means to said call cost register means substantially instantaneously upon completion of timing out of each incremental call interval following said initial call interval. 31 According to this clause, if the call is still in progress when the initial call interval has expired, the incremental charge data is transferred to the call cost register means and displayed there substantially instantaneously. Additional incremental charges are transferred to the call cost register means substantially instantaneously upon the passage of additional call intervals. This process of transferring successive interval costs continues throughout the duration of the call. 32 The limitations in these clauses are revealing. The repeated use of the limitation substantially instantaneously to convey the immediacy by which the call interval cost information is transferred to the call cost register means supports our interpretation that the register displays cumulated costs as they accrue, in real time, and not only once the call has ended. A word or phrase used consistently throughout a claim should be interpreted consistently. Thus, as each cost increment is accrued, it is transferred to and displayed substantially instantaneously by the call cost register means. The phrase substantially instantaneously clarifies that the display in the register is current throughout the duration of the call; the call cost register does not merely display the cost after the call has ended. 33 Furthermore, the final clause addresses what occurs upon call termination; the claimed device includes a termination means for interrupting operation of said computer apparatus, with the cumulative call cost held in and displayed by said call cost register means, upon operation of said switch by replacement of the calling telephone. It is especially significant that, at the point at which the call is terminated, the apparatus does not perform a calculation to determine the total cost of the call. Thus, the cost displayed in the register must be accurate at all times during the call, so that regardless of the point at which the call is terminated, the cumulative cost displayed in the register will be accurate without further calculation. Phonometrics's description of its claimed device as a calculator is therefore misleading; rather, the claimed device is simply a continuous counting device, for no provision is made for any calculation upon completion of a call. 34 When the claim itself is considered in its entirety, it becomes clear that the call cost register means has two separate and equally important functions: (1) it provides the caller with real time, accurate information about the cost of the call via digital display as the long distance charges accrue during the call; and (2) it reflects the total cost of the call via the same digital display after the call has been terminated. Phonometrics argues that only the second function is claimed, or that only this second function is important for determining infringement. We disagree. Both functions are claimed explicitly in the '463 patent, and both are significant for construction. 35
36 The language used throughout the specification preceding the claims supports this construction of dual functions of the call cost register means. For example, the written description explains that the call cost register means operates so that [t]he cumulative cost of a single call is displayed in the single call cost register ... to continuously remind the caller as to the cost of the call as the call progresses and to indicate the total cost of the call at the completion. Col. 3, II. 27-31 (emphasis added). This description of the operation of the call cost register means in a preferred embodiment supports our construction of the claim language: the call cost register means clearly provides information about the cost of the call while the call progresses. Although claims are not necessarily restricted in scope to what is shown in a preferred embodiment, neither are the specifics of the preferred embodiment irrelevant to the correct meaning of claim limitations. See Markman, 52 F.3d at 979, 34 USPQ2d at 1329. Phonometrics of course argues that additional limitations cannot be imported into a claim from the written description. We may, however, construe a specifically claimed limitation in light of the specification, which is all we do here. 37 Similarly, the written description carefully explains the importance of the initial and incremental cost transfer means for the real time operation of the device: 38 When the party called is reached, the 90-volt pulse derived from the telephone line upon the lifting of the receiver of the called party substantially simultaneously clears the elapsed time indicator and starts the indicator counting time. Further, substantially instantaneously the single call cost register is cleared and loaded with the 3-minute charge indicated on the set charge selector.... Should the call exceed three minutes, the elapsed time indicator causes the per-minute overtime charge to be added to [the] cost register[ ], and this is repeated at further 1-minute intervals during the call. At the conclusion of the call, all counting stops and the displays in the cost register[ ] and elapsed time indicator are retained. 39 Col. 3, II. 3-19 (emphasis added, internal figure references omitted). Thus, the specification further clarifies the way in which the claimed device operates, adding each incremental charge to the call cost register means as each interval elapses, to provide real time long distance charge information while the long distance call is in progress. 40 Phonometrics, however, objects to the district court's construction of the call cost register means--that it displays the mounting cost of a call in progress--observing that the phrase in progress appears nowhere within the language of claim 1. While Phonometrics is correct that this phrase does not appear in the claim itself, that fact does not render erroneous the construction given the claim by the district court. In fact, when the claim is considered properly as a whole, we think it clear that the '463 patent is limited to a device which displays the cumulative cost of a long distance call both as charges accrue during the call and after the call has been terminated. 41
42 Finally, the prosecution history supports our understanding that the call cost register means performs two distinct functions by displaying cumulated costs both during the call and upon its termination. During prosecution of the '463 patent, the applicants specifically emphasized the functions of the cost transfer means in distinguishing over the prior art: 43 In addition, and as clearly set forth in Claim 10 [now claim 1 of the '463 patent], the apparatus of the present invention instantaneously transfers the three minute charge information to the cost register when the call is completed by the receiving party lifting the called telephone, and the incremental one minute charges are applied to the cost registers substantially instantaneously upon the timing out of each one minute interval. In the Fletcher device, and other similar prior art apparatus, the call charge information requires considerable time for entry and may well result in an erroneous charge recording if the calling telephone is hung up after only a minor increment of a charge interval is completed. This operational error is entirely obviated by the cost computer apparatus of the present invention. Accordingly, it is submitted that Claim 10 affords distinctive and patentable differences, in comparison with the prior art of record, and should be allowed. 44 Amendments to Application No. 229,711, April 4, 1973, p. 12 (emphasis added). Thus, the in-progress transfer of accrued costs to the call cost register means increased the inherent accuracy of the device compared to the prior art Fletcher device. By the applicants' own statement, the in-progress and instantaneous transfer of incremental costs was an important function for patentability. The function is clearly set forth by the claim language as viewed in light of the written description and the prosecution history, and cannot be ignored by us here. 45 Our independent review of the claim language thus reveals that the district judge's construction of claim 1 of the '463 patent with respect to the functions of the call cost register means was supported by the language of the claim itself, the rest of the specification, and the prosecution history. We hold that claim 1 of the '463 patent requires a call cost register means which functions both to provide accurate cost information while the call progresses as well as total cost information once the call has ended. 46