Means for determining difference in copy sheet transportation states for an electrostatic reproduction machine

• US 4,166,615 A
• Filed: 08/05/1977
• Issued: 09/04/1979
• Est. Priority Date: 12/27/1974
• Status: Expired due to Term

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Noguchi, Hiroshi, Kurokawa, Yasuyoshi
• Primary Examiner(s): Stoner, Jr., Bruce H.
• Application Number:
  US05/822,347
• Time in Patent Office: 760 Days
• Field of Search: 271/259, 271/258, 271/256, 271/265, 340/259, 340/674
• US Class Current: 271/259
• CPC Class Codes: B65H 2553/41 Photoelectric detectors
• CPC Class Codes: B65H 7/06 responsive to presence of faulty articles or incorrect separation or feed B65H7/14 takes precedence
• CPC Class Codes: B65H 7/12 responsive to double feed or separation
• CPC Class Codes: G03G 15/70 Detecting malfunctions relating to paper handling, e.g. jams

Abstract

In an electrostatic reproduction machine there is provided one or more rollers capable of rotating in union with a copy sheet being advanced, in the course of travel of the copy sheet. Sensing switches are provided for sensing nonuniformity in rotation of the rollers which may occur in abnormal copy sheet transportation states and, more particularly, in a jam state. The outputs from the sensing switches are utilized for identifying the abnormal machine states.

Claims

1. A copy sheet transportation state detection arrangement for use in an electrostatic copying machine which comprises:

(a) entering and leaving copy sheet sensing switches each with electrical signal output capability provided for sensing the presence or absence of a copy sheet;

(b) a first copy sheet speed-sensing member with electrical signal output capability provided for monitoring the uniformity or nonuniformity in the speed of copy sheet transportation, said first speed-sensing member being juxtapositioned to said entering sheet-sensing switch;

(c) a second copy sheet speed-sensing member with electrical signal output capability provided for monitoring the uniformity or nonuniformity in the speed of copy sheet transportation, said second speed-sensing member being juxtapositioned to said leaving sheet-sensing switch;

(d) a driving roller positioned opposite said second speed-sensing member such that when the copy sheet is fed through said roller-member combination said copy sheet provides the friction between the driving roller and the second speed-sensing member so as to allow the speed-sensing member to rotate; and

(e) a counter for counting a predetermined number of clock pulses which, if reached, provides an abnormal state detection signal, and,

(f) means for providing a reset signal to said counter to prevent the provision of said abnormal state detection signal when transportation is normal, said reset signal providing means including (1) a first AND gate receiving one actuating signal, via an inverter, from the entering switch denoting the presence of a sheet thereat and another actuating signal from the leaving switch indicating the absence of a sheet thereat, a second AND gate receiving one actuating signal from the first AND gate and another actuating signal from the first speed-sensing member via a first differentiation circuit, whereby, upon simultaneous occurence of all said actuating signals, said second AND gate provides a reset signal to said counter;

(2) a third AND gate for receiving actuating signals from both the entering and leaving switches denoting the absence of sheets at both switches, whereby, upon simultaneous occurence of said actuating signals said third AND gate provides a reset signal to said counter; and

(3) a fourth AND gate for receiving one actuating signal, via an inverter, from the leaving switch denoting the absence of a sheet thereat and another actuating signal, via a second differentiation circuit, from the second speed-sensing member, whereby upon simultaneous occurence of said actuating signals said fourth AND gate provides a reset signal to said counter,

2. The copy-sheet transportation state detection arrangement disclosed in claim 1, wherein said second speed-sensing member comprises a copy sheet contacting roller, a rotary disc disposed in a coaxial relationship with said contacting roller, and a lead switch disposed adjacent to said rotary disc.

3. The copy-sheet transportation detection arrangement disclosed in claim 2, wherein said rotary disc-comprises a magnetic material operatively associated with said contacting roller and said lead switch.

4. The copy-sheet transportation-state detection arrangement of claim 3, wherein said rotary disc has a predetermined number of magnetic sites concentrically and equally disposed thereon.