Appeal No. 1998-1231 Page 8
Application No. 08/729,835
this arrangement was that occasional slip between the motor
and the driven belt caused an error between the sensed door
position and the actual door position, resulting in either
premature stopping of the door or a collision between the door
and the wall. Yoshida’s invention (Figures 1 and 6; and
col. 1, line 63 through col. 2, line 2) includes driving means
(belt) 4 coupled to the motor M, motion sensing means 10
generating pulses having a pulse repetition rate in proportion
to the velocity of the belt, door position detecting means 23
for counting the pulses to obtain the current door position,
and “control means responsive to the obtained current door
position for controlling the operation of said motor”
(underlining added). Operation of the main control of Yoshida
(col. 6, lines 12-66) is as follows. When sensor A detects
the approach of a person to the door, a signal R is
1
generated. State sequencer 24 then generates signal R to
4
door position counter 23 and generates door opening signal R2
to speed controller 9. This generates high speed command
signal H to speed control 9 so that the motor M will operate
at a high speed. Upon movement of drive belt 4, photo
transistors generate first and second trains of pulses. Speed
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