Photographic film web cutter and method

• US 4,436,008 A
• Filed: 04/05/1982
• Issued: 03/13/1984
• Est. Priority Date: 04/05/1982
• Status: Expired due to Fees

• Current Assignee: Pako Corporation
• Original Assignee: Pako Corporation
• Inventors: Strunc, Gerald R.
• Primary Examiner(s): Meister, James M.
• Application Number:
  US06/365,284
• Time in Patent Office: 708 Days
• Field of Search: 83/42, 83/208-212, 83/364, 83/371
• US Class Current: 83/42
• CPC Class Codes: B26D 5/32 with the record carrier formed by the work itself
• CPC Class Codes: G03D 15/046 Automatic cutting
• CPC Class Codes: Y10T 83/0538 Repetitive transverse severing from leading edge of work
• CPC Class Codes: Y10T 83/446 With means to initiate tool feed by same control impulse
• CPC Class Codes: Y10T 83/531 With plural work-sensing means
• CPC Class Codes: Y10T 83/543 Sensing means responsive to work indicium or irregularity

Abstract

A photographic film cutter for cutting film segments from a web of photographic film includes a knife located along a web advancement path, a splice sensor located upstream from the knife, and a notch sensor located between the knife and the splice sensor. A stepper motor moves the web along the path in fixed length steps. A step counter counts the steps to determine the length that the web has advanced since the web was cut by the knife. When a splice is detected by the splice sensor, a maximum feed switch determines, based upon the count of the step counter, whether the distance from a leading cut edge to the splice sensor is greater than or equal to a predetermined maximum distance. If the length is less than the maximum, the web is advanced until a portion of the web adjacent the splice is positioned at the knife, and the web is cut. If the length from the cut edge to the splice is greater than the predetermined maximum length, an additional cut is made. A minimum feed switch determines if the distance from the leading cut edge to the knife is greater than a predetermined minimum. A notch distance verifier determines whether notches marking the film are normally spaced, and if so, the web is cut between frames. If a normal notch is not found, the web is advanced by an additional step count before cutting to assure that no frame is bisected by the knife.

Claims

1. A photographic film cutter for cutting segments from a web of spliced lengths of photographic film, the web containing notches for indicating location of variable spaced frames, the photographic film cutter comprising:

an intermittently activable knife means stationed along a feed path of longitudinal advancement of the web for cutting a segment extending past the knife means from the web;

web advance means for advancing the web along the feed path between successive actuations of the knife means;

splice sensing means positioned prior to the knife means along the feed path for sensing a splice in the web and for generating a splice signal indicative of the sensing of the splice;

length sensing means responsive to web advance means for providing a first length signal indicative of a first length of the web from its leading end to the sensed splice and a second length signal indicative of a second length of the web from its leading edge to the knife means;

notch sensing means positioned prior to the knife means along the feed path for sensing notches in the web and providing a notch signal indicative of sensing of a notch; and

control means for controlling the web advance means based upon the first length signal, the splice signal, and the notch signal so that each segment cut has a length less than or equal to a predetermined maximum length and greater than a predetermined minimum length, the control means causing the web advance means to advance the web to a position with a portion of the web adjacent the splice in alignment with the knife means if, based upon the first length signal, the first length is less than the maximum length, and the control means causing the web advance means to advance the web a total feed length determined by the notch signal and the second length signal if the first length is greater than the maximum length.

2. The photographic film cutter of claim 1 wherein the web advance means advances the web in fixed-length steps, and wherein the length sensing means includes a step counter for generating a count signal indicative of the number of steps the web has been advanced.

3. The photographic film cutter of claim 2 wherein the web advance means includes:

a stepper motor for advancing the web in fixed-length steps;

a stepper motor pulse generator for generating a step pulse signal for each step that the stepper motor is to advance the web; and

a stepper motor driver for activating the stepper motor to advance the web one step for each pulse signal.

4. The photographic film cutter of claim 2 wherein the length sensing means further includes:

maximum feed switch, responsive to the count signal from the step counter, for comparing the count signal to a predetermined stored maximum count and for generating a feed signal having a first state indicating that the count signal has reached the maximum predetermined count and a second state indicating that the count signal has not reached the predetermined maximum count.

5. The photgraphic film cutter of claim 2 wherein the control means includes:

a splice feed length counter, responsive to the web advance means and a splice sensing means, for providing a second count signal indicative of a third length of the web advanced since the splice was sensed; and

splice length switch means, responsive to the count signal for generating a splice feed signal indicating that the web has advanced a length equal to the distance between the knife means and the splice sensing means.

6. The photographic film cutter of claim 2 wherein the control means includes:

notch distance verifier means, responsive to the notch sensing means and step counter, for determining a notch distance between successive notches in the web and for generating a notch distance signal indicative of whether the notch distance is equal to a predetermined notch distance.

7. The photographic film cutter of claim 6 wherein the control means further includes:

interframe cut logic, responsive to the notch distance signal, for comparing the notch distance signal to a stored predetermined notch distance and for activating the web advance means to advance the web an additional fourth distance if the notch distance signal is not equal to the predetermined notch distance.

8. The photographic film cutter of claim 2 wherein the control means further includes:

a minimum feed switch, responsive to the step counter and the splice sensing means, for storing a predetermined minimum feed value and for generating a minimum feed signal if the length the web has advanced is equal to or greater than the predetermined minimum feed value.

9. A method of cutting a photographic film web made of spliced lengths of notched film with variable frame spacing into sections with a knife located at a fixed knife position along a feed path, the method comprising:

(a) advancing the web along a feed path so that a leading end of the web extends past the fixed knife position;

(b) sensing a splice in the web at a splice sensing position upstream from the fixed knife position;

P1 (c) determining a first length of web from a cut end to to the splice;

(d) if the first length to the splice is less than a predetermined maximum length, advancing the web until a portion of the web adjacent the splice is aligned with the fixed knife position and activating the knife to cut a segment extending past the fixed knife position from the web; and

(e) if the first length of the splice is greater than the predetermined maximum length, advancing the web a second length so that a portion of the web greater than a predetermined minimum length from the cut end is aligned with the fixed knife position, and cutting the web.

10. The method of claim 9 wherein step (e) comprises:

activating a notch sensor located at a notch sensing position between the splice sensing position and the fixed knife position to sense a location of a frame;

if a frame location is sensed by the notch sensor, advancing the web a length so that the portion of the web aligned with the fixed knife position is between frames, and is greater than a predetermined minimum length from the cut end, and cutting the web; and

if no frame is located, advancing the web a fourth length so that the portion of the web, which is aligned with the fixed knife position is greater than the predetermined minimum length from the cut end and cutting the web.

11. The method of claim 9 wherein:

advancing the web includes stepping the web in fixed steps; and

determining a first length includes counting steps by counting step pulses indicating steps that the web has advanced.

12. The method of claim 9 wherein step (e) includes:

determining a fifth length of web from the cut end to the fixed knife position.