Abstract: The door can be safely and exactly opened and shut even when the door opening and shutting stroke value is not memorized in the non-volatile memory. The door opening and shutting stroke value measured in the setting time of the automatic door is memorized in the non-volatile memory 14. Then, the memorized door opening and shutting stroke value is read in the plant memory 15 for the door stroke value of the micro-computor 12. In the automatic door for opening and shutting the door 5 according to the door opening and shutting stroke value, when the door opening and shutting stroke value is not memorized in the non-volatile memory 14 after the power supply, the door 5 is opened and shut at the low speed to measure the door stroke value. And the door stroke value is memorized in the plant memory 15 for the door stroke value of the micro-computor 12 as the door opening and shutting stroke value, and the door 5 is opened and shut in accordance with the memorized value.

Abstract: An opening/closing mechanism for use in a circular-arc shaped sliding door including a transverse frame having a circular-arc horizontal sectional shape and mounted on the upper parts of a pair of left and right door bodies; a drive pulley and a driven pulley mounted on the circumferentially one end of the transverse frame and on the other end thereof, respectively; and an endless belt wound between and around the drive pulley and a driven pulley, the pair of door bodies being connected in place to the endless belt so that they may be slidably moved in opposite directions to each other along a pair of left and right guide rails, respectively, each of which is bent in a circular-arc shape concentric with the center of the circular-arc of the transverse door frame.

Abstract: A method for controlling a torque of a door opening and closing motor for an automatic door is improved in that the door opening and closing motor is such motor that a rotary torque therein is generated on the basis of control pulses applied to that motor from a control unit, the rotary torque is regulated by changing a total pulse width of the control pulses rising in one repetition cycle, and thereby an acceleration of the motor can be controlled. In one preferred mode of embodiment of the invention, each of the control pulse has a fixed pulse width, and th total pulse width is changed by varying the number of the control pulse rising in one repetition cycle.

Abstract: For the purpose of knowing an angular position and a rotational speed of a rotary body, according to an encoding pattern on an encoder mounted to and synchronously rotated with the rotary body, rotational angular position signals consisting of n-phase rectangular waves and sensing pulses occurring at a predetermined rotational angle interval are generated. In response to the issue of each sensing pulse, levels of the respective rotational angular position signals are detected, a variation pattern of a combination of the detected n levels is compared with a reference variation pattern, and it is determined whether an abnormal condition has arisen or not, and if the condition is normal, whether the variation pattern is a forward traveling pattern or a backward traveling pattern. In the case of the forward traveling pattern, (+1) is added to a rotational angle counter, while in the case of the backward traveling pattern, (-1) is added to the rotational angle counter.

Abstract: According to a method for controlling an automatic door of the present invention, even when an accidental condition occurs due to some obstacle clogging a traveling lane of the door, the door can move at a high speed to its deceleration point so as to immediately enable a man to go through the door opening, while the door is prevented from colliding at a high speed against the obstacle repeatedly to make it possible to increase both the durability and safety of the door.

Abstract: In a method for controlling an automatic door system, after a power-supply switch of the system is turned on, a door of the system initially conducts its low-speed opening/closing operation when a first human-body detection signal is inputted to the system; and then, when the door travels a distance more than a predetermined minimum door stroke, the door conducts its normal-speed opening/closing operation after completion of its traveling the predetermined minimum door stroke to enable the door to conduct its normal-speed operation within a short time after the power-supply switch is turned on.