LAITRAM CORP. v. NEC CORP.

RADER, Circuit Judge.

Laitram Corporation sued NEC Corporation and NEC Information Systems, Inc. for infringement of claims 1 and 2 of reexamined U.S. Patent No. B1 3,952,311 (the '311 patent). A jury found that NEC infringed both literally and under the doctrine of equivalents. The trial court then granted judgment as a matter of law (JMOL) that NEC did not infringe and overturned the jury's verdict. Laitram Corp. v. NEC Corp., No. 89-CV-1571, slip op. at 1, 1994 WL 261966 (E.D.La. June 6, 1994) (Order). Because the trial court erred in granting JMOL, this court reverses and remands for reinstatement of the jury verdict.

BACKGROUND

The '311 patent claims an electro-optical printer that prints letter quality, alpha-numeric characters on a photosensitive recording medium. Apparatus claim 1 and method claim 2 recite:

(Emphasis omitted.)

During printing, photosensitive paper or other recording medium moves at constant speed past an array of light-emitting diodes (LEDs) in a direction perpendicular to the LED array. As the paper moves, the LEDs selectively activate (claim 1) or energize (claim 2) to expose, and thereby darken, stripes of varying lengths on the paper. These stripes form alpha-numeric characters, such as the "S" shown in Figure 1 of the patent.

To create the "S," the LEDs activate for variable periods of time, the activation period determining the length of a stripe.

The '311 specification discloses two ways to print a stripe during an activation period. In one embodiment, an LED corresponding to the desired stripe location turns ON at the beginning of the activation period and remains continuously lit until the end of the period. The stripe thus printed combines with other stripes to form an alpha-numeric character. In a second embodiment, an LED rapidly turns ON and OFF, or strobes, during the activation period. The strobed LED activation method also produces solid stripes which form characters on the paper.

Laitram sued NEC for infringement of claims 1 and 2 of the '311 patent. NEC's accused printer produces letter quality, alpha-numeric characters on a photo-sensitive recording medium. As the recording medium moves past LEDs arranged in an array, the NEC printer selectively strobes the LEDs to print characters. Each strobe is of fixed duration. Oval-shaped marks produced by a strobed LED overlap to create a stripe. The stripe length varies depending on the duration of the strobing. The stripes form characters, such as the "S" shown in the trial exhibit offered by Laitram below.

Before trial, a third party requested reexamination of the '311 patent as originally issued based on newly cited prior art. The trial court stayed the case pending conclusion of the reexamination. During reexamination, Laitram amended and added claims. The reexamination, however, did not change the language of the claim limitations at issue in this case. When the Reexamination Certificate issued, the trial court reopened the case.

The parties introduced extensive evidence over a five-day jury trial. The trial court sent the issues of claim construction, infringement, willfulness, and damages to the jury with proper instructions. The jury rendered its verdict on claim construction and literal infringement in special interrogatory form, as excerpted below:

The jury found that NEC literally and willfully infringed and awarded Laitram a reasonable royalty.

After the jury verdict, NEC filed a JMOL motion challenging the jury's verdict of literal infringement. The trial court held that the jury erred as a matter of law in interpreting the claims and entered JMOL of noninfringement. Laitram Corp., No. 89-CV-1571, slip op. at 1, 1994 WL 261966. Laitram appeals.

DISCUSSION

I.

When a party appeals from a trial court's post-verdict grant of JMOL, this court reviews the trial court's claim construction, a matter of law, de novo. See Markman v. Westview Instruments, Inc., 52 F.3d 967, 979, 34 USPQ2d 1321, 1329 (Fed.Cir. 1995) (en banc). The claim limitations at issue in this case are: (1) "means for selectively activating each of said emitters for predetermined periods of time" in claim 1, (2) "selectively energizing for predetermined periods of time each of the said emitters" in claim 2, and (3) "synchronously generating a first data signal ... and a second data signal which determines the duration of the energization period of said emitters" in claim 2. Both parties agree that the periods of activation (claim 1) or energization (claim 2) — the periods during which the printer prints a stripe — vary with the desired stripe length. The dispute in this case is whether the claim terms "selectively activating" in claim 1 and "selectively energizing" in claim 2 cover printing strobed stripes, or whether those claim terms encompass only printing continuous stripes.

In construing claim language, the court considers the claims at issue, the specification, and the prosecution history. Markman, 52 F.3d at 979 (quoting Unique Concepts, Inc. v. Brown, 939 F.2d 1558, 1561, 19 USPQ2d 1500, 1503 (Fed.Cir.1991)). The specification of the '311 patent discloses strobing the LEDs to print an exposed "region" or stripe:

(Emphasis added.) Thus, the specification contemplates strobing during the variable periods of selective activation (as in claim 1) or selective energization (as in claim 2).

Dependent claims 4 and 27 confirm that "selectively activating" in claim 1 and "selectively energizing" in claim 2 cover strobing. Although each claim is an independent invention, dependent claims can aid in interpreting the scope of claims from which they depend. Claim 4 which depends from claim 3, in turn depending from claim 1, recites:

Claim 4 covers an embodiment of the invention recited in claim 1 where the printer flashes, or strobes, LEDs during the activation period to print "linear regions" or stripes. Claim 27, which depends from claim 2, recites:

The prosecution history does not suggest a different result, moreover. During prosecution of the reexamination application, Laitram distinguished claim 2 from two prior art references. The first reference, United States Patent No. 3,085,132 to Innes (the Innes patent), discloses a dot matrix printer that forms alpha-numeric characters by marking distinct dots on a recording medium. For example, an "E" produced by the Innes printer appears below:

Laitram distinguished the Innes patent on the basis of the "fixed timing of the Innes dot matrix" and the Innes' "fixed-time-duration pulses":

(Emphasis in original.) Unlike the claimed printer, the Innes printer does not print stripes of varying length. Rather, the Innes printer produces distinct dots of fixed length by fixed duration pulses. Thus, this passage from the prosecution history does not define the relevant claim language of the '311 patent to mean something other than strobing during the activation period.

Laitram also distinguished United States Patent No. 1,201,624 to Baylis (the Baylis patent) from claim 2 of the '311 patent. The Baylis patent discloses an electro-optical printer that uses LEDs to record an image on a recording surface. Laitram explained a difference between the claimed printer and that disclosed in the Baylis patent:

(Emphasis in original.) Again, this passage does not define the relevant claim language to exclude strobed striping. Laitram noted that the Baylis printer builds characters from rows of distinct spots. Laitram then pointed out that the Baylis patent does not teach synchronization of a plurality of emitters with the movement of a recording medium to form vertical line images or stripes. At no time during prosecution did Laitram represent that the relevant claim language could not embrace painting stripes by fixed-time strobing during variable periods of activation.

In sum, claims 1 and 2, as properly construed, cover both printing continuous and strobed stripes.

II.

The trial court sent the issue of claim construction to the jury in the form of special interrogatories. Because claim construction is a legal issue within the sole province of the court, this court will treat the jury's claim construction as an advisory determination. In granting JMOL to NEC, however, the trial court ultimately construed claims 1 and 2 of the '311 patent, exercising its power and obligation to decide the meaning of the claims as a matter of law. See Markman, 52 F.3d at 979. This court now must determine whether the trial court's claim construction survives our de novo review.

The trial court began correctly by recognizing that the '311 patent claims a method and apparatus for activating LEDs for variable periods of time, depending on the desired stripe length. The trial court also correctly found that the claims "may allow flashing or strobing during the [activation] period." The trial court thus correctly construed the claims to cover variable activation periods and strobing during those variable activation periods.

Yet, the trial court inexplicably concluded that NEC's accused printers could not literally infringe the claims. The trial court held:

The trial court thus construed claims 1 and 2 not to cover strobed printing. This erroneous conclusion contradicts the trial court's own prior determination that claims 1 and 2 embrace strobing.

Claims 1 and 2, as properly construed in view of the specification, other claims, and prosecution history, cover LEDs which are strobed — each strobe of fixed duration — during variable periods of activation. To the extent the trial court found differently in granting JMOL, it erred.

Although claim construction is properly a matter of law for the trial court, this court notes that the jury applied the correct construction of the claims in reaching its infringement verdict. The jury found that claims 1 and 2 cover "LED printers in which the LEDs are turned ON on different occasions but on each occasion for a fixed period of time." The jury presumably read "ON" to refer to rapid ON-and-OFF strobing and properly construed the claims to cover LED printers which print with fixed pulse LED strobes during variable periods of activation. In other words, the jury could have read the special interrogatory to ask whether claims 1 and 2 cover "LED printers in which the LEDs are turned ON [i.e., strobed or flashed] on different occasions but on each occasion for a fixed period [i.e., strobe or flash period] of time." The jury's affirmative response to this special interrogatory on claim construction is consistent with its infringement finding. See Atlantic & Gulf Stevedores, Inc. v. Ellerman Lines, Ltd., 369 U.S. 355, 364, 82 S.Ct. 780, 786, 7 L.Ed.2d 798 (1962).

III.

It remains only to determine whether substantial evidence supports the jury's fact finding that NEC infringes claims 1 and 2 as properly construed. See Read Corp. v. Portec, Inc., 970 F.2d 816, 821, 23 USPQ2d 1426, 1431 (Fed.Cir.1992). Laitram presented substantial evidence from which the jury could reasonably find that NEC's accused printers infringed. Using a mechanical model to represent the electronics of an electro-optical printer, Laitram's expert, Mr. Prohofsky, demonstrated to the jury how such a printer prints stripes by strobing. Mr. Prohofsky also testified in detail about the operation of NEC's printer and compared the claims to circuit diagrams of NEC's printer and to its operation. Thus, substantial evidence supports the jury's finding of literal infringement. Because this court resolves the issues on appeal on literal infringement grounds, this court need not reach the issue of infringement under the doctrine of equivalents.

CONCLUSION

The trial court erred in granting NEC JMOL and overturning the jury's infringement verdict. Therefore, this court reverses and remands with instructions to reinstate the jury's verdict.

COSTS

Each party shall bear its own costs.

REVERSED AND REMANDED.