Claims
- 1. In an electrophotographic copying apparatus for producing images on copy sheets capable of being used in the apparatus, having a treatment zone including a charging means for charging a copy sheet, a light-exposing means having an optical system for projecting an image of an original to be copied on a charged copy sheet to form an electrostatic image on the copy sheet, a developing means for developing the exposed copy sheet thereby converting the electrostatic image to a visible image, a drying or fixing means for drying or fixing the image formed on the copy sheet, a forwarding mechanism for moving a copy sheet along a running path through the treatment zone from an initial nip to a discharge end, a copy sheet feeding mechanism for delivering single copy sheets to the initial nip of the forwarding mechanism, an original support for reciprocating the original laterally from a central position in synchronism with movement of the copy sheet and returning the original to the central position and a source of electricity, said copying apparatus comprising:
- an activating means for controlling the copy sheet feeding mechanism;
- first switch means having both a normally closed contact connecting said actuating means with a source of electricity and a normally open contact;
- detecting means for detecting a copy sheet in the running path at least at one detecting point and controlling said first switch means to open said normally closed contact and close said normally open contact when a copy sheet is detected at said detecting point, said detecting point being positioned in the running path according to the following conditions:
- l.sub.1 < L
- l.sub.2 < L
- where L is the minimum length of the copy sheets capable of being used in the apparatus, l.sub.1 is the distance between the initial nip of the forwarding mechanism and said detecting point forwarding mechanism, and l.sub.2 is the distance between said detecting point forwarding mechanism and the discharge end of the forwarding mechanism;
- a second switch means closed only when the original support is stationary at the central position; and
- alarm means connected with the source of electricity through said second switch means and said normally open contact of said first switch means, said alarm means being energized to signal occurrence of jamming of the copy sheet if the copy sheet is jammed in the running path and detected at said detecting point and closes said normally open contact of said first switch means when the original support returns to the central position and closes said second switch means.
- 2. The improvement as recited in claim 1 wherein said detecting means comprises a normally open switch closed by contact with a copy sheet and a relay coil connected in series with said normally open switch, and said normally closed contact of said first switch means comprises a normally closed relay contact controlled by said relay coil whereby said normally closed relay contact is opened to deenergize said actuating means in response to energizing of said relay coil by closing said normally open switch.
- 3. The improvement as recited in claim 1 wherein said detecting means includes a source of light, photoelectric means disposed to receive light from said source and disposed so that light to the photoelectric means is blocked when a copy sheet has a portion thereof at said detecting point, and control means responsive to said photoelectric means to open said normally closed contact and to close said normally open contact of said first switch means when a portion of a copy sheet is positioned at said detecting point.
- 4. In an electrophotographic copying apparatus for producing images on copy sheets capable of being used in the apparatus, having a treatment zone including of a charging means for charging the copy sheet, a light-exposing means having an optical system for projecting an image of an original to be copied on the charged copy sheet thereby forming an electrostatic image on the copy sheet, a developing means for developing the exposed copy sheet thereby converting the electrostatic image into a visible image, a drying or fixing means for drying or fixing the image formed on the copy sheet, a forwarding mechanism for moving a copy sheet along a running path through the treatment zone from an initial nip to a discharge end, a copy sheet feeding mechanism for delivering single copy sheets to the initial nip of the forwarding mechanism, an original support for reciprocating the original laterally from a central position in synchronism with movement of the copy sheet and returning the original to the central position and a source of electricity, the improvement comprising:
- actuating means controlling the copy sheet feeding mechanism;
- first switch means having normally closed contact connecting said actuating means with a source of electricity and normally open contact;
- a plurality of detecting means spaced along the running path such that the distance between successive detecting means along the running path is less than the minimum length of the copy sheets capable of being used in the apparatus, the distance between the initial nip of the forwarding mechanism and one of said detecting means along the running is less than the minimum length of a copy sheet and the distance between the discharge end of the forwarding mechanism and one of said detecting means is less than the minimum length of a copy sheet, each of said detecting means controlling said first switch means to open said normally closed contact when a copy sheet is detected thereby preventing energizing of said actuating means for the copy sheet feeding mechanism when a copy sheet is in the running path;
- second switch means closed only when the original support is stationary at the central position; and
- alarm means connected with the source of electricity through said second switch means and said normally open contact of said first switch means, said alarm means being energized to signal occurrence of jamming of the copy sheet if the copy sheet is jammed in the running path and detected at said detecting point and closes said normally open contact of said first switch means when the original support returns to the central position and closes said second switch means.
- 5. The improvement as recited in claim 4 wherein each of said detecting means includes a lever movable upon contact with a copy sheet, further including a normally open switch operable to be closed by each of said levers and a relay coil connected in series with said normally open switch, said normally closed contact of said first switch means comprising a normally closed relay contact controlled by said relay coil whereby said normally closed relay contact is opened to deenergize said actuating means in response to energizing of said coil by closing said normally open switch.
- 6. The improvement as recited in claim 4 wherein each of said detecting means includes a source of light, photoelectric means disposed to receive light from said source and to have the light from said source blocked by a copy sheet in the running path, and further comprising control means responsive to each of said photoelectric means to open said normally closed contact of said first switch means when a copy sheet is in the running path.
- 7. The improvement as recited in claim 4 wherein each of said detecting means includes a normally open switch, said normally open switches being connected in parallel, and further comprising a relay coil connected in series with said normally open switches, and said normally closed contact of said first switch means comprises normally closed relay contact controlled by said relay coil whereby said normally closed relay contact is opened to deenergize said actuating means in response to energizing of said relay coil by closing of any of said normally open switches.
Priority Claims (1)
Number |
Date |
Country |
Kind |
45-63211 |
Jul 1970 |
JA |
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Parent Case Info
This application is a continuation of copending patent application Ser. No. 164,779 filed July 21, 1971, now abandoned.
US Referenced Citations (6)
Continuations (1)
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Number |
Date |
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Parent |
164779 |
Jul 1971 |
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