Appeal No. 1999-0344
Application 08/250,770
are comparable to the pulse width modulation teachings in Hayashi. By selective
application of the pulse signature generator circuit 6 in Figure 6, along with its pulse
signal selection circuitry 7, the chopping means or AND gate array 3 selectively chops
the pixel data presented in shift register 4 before activation by the LED element array 1.
Tomita effectively changes the power levels to the individual light emitting diode
elements in a corresponding manner that Hayashi does so with respect to a laser
emitting element.
To the extent the problems associated with appellant’s admitted prior art exist as
disclosed, Hayashi’s approach appears to teach the solution of these problems for a
similar, corresponding laser-based imaging device. In a corresponding, analogous
manner, Tomita takes a similar approach for light emitting diode-based printing devices.
In contrast to the appellant’s admitted prior art approach in Figure 1 of the user
selecting print density by the use of a selector switch to control the bias voltage to the
developer associated with electrophotographic printing apparatus, both Hayashi and
Tomita take a correspondingly similar approach as to what appellant has done to
effectively control the amount of light illuminating photosensitive drum from the
respective illuminating element, a laser in appellant’s admitted prior art Figure 1 and in
Hayashi and light emitting diodes in Tomita. In either case, the density of the printed
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