US3793508A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Film frame counter
Assignee: Singer Co
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Filing: 1971-12-21
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Granted: 1974-02-19
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Expires: 1991-12-21
Abstract
Abstract A film frame counter in which a first optical scanner is arranged to intersect the top half of one sprocket hole when a second scanner intersects the bottom half of another sprocket hole providing signals at a first level when intersecting a sprocket hole and at a second level when not. Because of this arrangement, a unique series of logic transitions occurs in each direction which is detected and the frame count updated only when all transitions have occurred in proper sequence avoiding false counts due to jitter or hunting.
Inventors
- 👤 C Maggi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 16:46
CPC Classifications
H; H03; H03K; H03K5/00; H03K5/22; H03K5/26
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
351 words
A film frame counter for use with a motion picture projector comprising: a. a first sensor to sense a sprocket hole by sensing an area less than one-half the length of a sprocket hole and arranged in a fixed position where it will intersect only the top half of a first sprocket hole when the film is in a predetermined position; b. a second similar sensor arranged to intersect only the bottom half of a second sprocket hole when said film is in said predetermined position, each of said sensors providing an output at a first level when intersecting a sprocket hole and at a second level when not sensing a sprocket hole; c. means responsive to the outputs of said first and second sensors to provide a forward count pulse only when all of the following sensor output signals occur in the listed order: 1. said first and second sensors provide simultaneous outputs at said first level; 2. said first sensor provides an output at said second level while the output of said second sensor remains at said first level; 3. said first and second sensors provide an output at said second level; 4. said first sensor provides an output at said first level while said second sensor remains at said second level; and 5. said first and second sensors provide an output at said first level; and a reverse count pulse only when the following outputs occur iN the listed order: 1. said first and second sensors provide simultaneous outputs at said first level; 2. said second sensor provides an output at said second level while the output of said first sensor remains at said first level; 3. said first and second sensors provide an output at said second level; 4. said second sensor provides an output at said first level while said first sensor remains at said second level; and 5. said first and second sensors provide an output at said first level; and d. a divide-by-N up-down counter having said count pulses as inputs, N being equal to the number of sprocket holes per frame of film.
Claim 2
Dependent Claim
351 words
A film frame counter for use with a motion picture projector comprising: a. a first sensor to sense a sprocket hole by sensing an area less than one-half the length of a sprocket hole and arranged in a fixed position where it will intersect only the top half of a first sprocket hole when the film is in a predetermined position; b. a second similar sensor arranged to intersect only the bottom half of a second sprocket hole when said film is in said predetermined position, each of said sensors providing an output at a first level when intersecting a sprocket hole and at a second level when not sensing a sprocket hole; c. means responsive to the outputs of said first and second sensors to provide a forward count pulse only when all of the following sensor output signals occur in the listed order: 1. said first and second sensors provide simultaneous outputs at said first level; 2. said first sensor provides an output at said second level while the output of said second sensor remains at said first level; 3. said first and second sensors provide an output at said second level; 4. said first sensor provides an output at said first level while said second sensor remains at said second level; and 5. said first and second sensors provide an output at said first level; and a reverse count pulse only when the following outputs occur iN the listed order: 1. said first and second sensors provide simultaneous outputs at said first level; 2. said second sensor provides an output at said second level while the output of said first sensor remains at said first level; 3. said first and second sensors provide an output at said second level; 4. said second sensor provides an output at said first level while said first sensor remains at said second level; and 5. said first and second sensors provide an output at said first level; and d. a divide-by-N up-down counter having said count pulses as inputs, N being equal to the number of sprocket holes per frame of film.
Claim 3
Dependent Claim
141 words
The invention according to claim 1 wherein said responsive means comprise means to sense a transition of said first sensor from said first to said second level while said second sensor is at said first level and to sense the transition of said second sensor from said second to said first level while said first sensor is at said first level to indicate that the outputs have occurred in the proper order for a forward count and to sense the transition of said second sensor from said first to said second level while said first sensor remains at said first level and to sense the transition of said first sensor from said second to said first level while said second sensor is at said first level to indicate that the outputs have occurred in the proper order for a reverse count.
Claim 4
Dependent Claim
22 words
said first sensor provides an output at said second level while the output of said second sensor remains at said first level;
Claim 5
Dependent Claim
22 words
said first sensor provides an output at said second level while the output of said second sensor remains at said first level;
Claim 6
Dependent Claim
22 words
said second sensor provides an output at said second level while the output of said first sensor remains at said first level;
Claim 7
Dependent Claim
22 words
said second sensor provides an output at said second level while the output of said first sensor remains at said first level;
Claim 8
Dependent Claim
12 words
said first and second sensors provide an output at said second level;
Claim 9
Dependent Claim
12 words
said first and second sensors provide an output at said second level;
Claim 10
Dependent Claim
12 words
said first and second sensors provide an output at said second level;
Claim 11
Dependent Claim
12 words
said first and second sensors provide an output at said second level;
Claim 12
Dependent Claim
302 words
The invention according to claim 2 wherein said responsive means comprise: a. a first inverter having its input connected to the output of said first sensor; b. a second inverter having its input connected to the output of said second sensor; c. a first latch, having a data input and a load input operable such that a transition from said second level to said first level will cause the level on said data input to be provided at the output of said latch, with its data input connected to said first sensor and its load input to the output of said second inverter; d. a second similar latch having its data input connected to said second sensor and its load input to said first sensor; e. a first AND gate having the outputs of said first and second latches connected to its inputs and having its output connected to the down input of said counter; f. a third similar latch having its data input connected to said second sensor and its load input to said first inverter; g. a fourth similar latch having its data input connected to said first sensor and its load input to said second sensor; h. a second AND gate having the outputs of said third and fourth latches as its inputs and having its output connected to the up input of said counter; i. a third AND gate having as its two inputs the outputs of said first and second sensors; and j. delay means having as an input the output of said third AND gate and providing as an output, a predetermined time after an input appears, a short pulse said output being connected to a reset input on said first, second, third, and fourth latches to cause their outputs to go to said second level.
Claim 13
Dependent Claim
65 words
The invention according to claim 3 wherein said delay means comprise; a. a first one-shot multivibrator having its input connected to said third AND gate and providing an output a predetermined time after an input appears; and b. a second one-shot multivibrator having its input connected to the output of said first multivibrator to provide, on occurrence of an input, a pulse of predetermined length.
Claim 14
Dependent Claim
20 words
said first sensor provides an output at said first level while said second sensor remains at said second level; and
Claim 15
Dependent Claim
20 words
said first sensor provides an output at said first level while said second sensor remains at said second level; and
Claim 16
Dependent Claim
20 words
said second sensor provides an output at said first level while said first sensor remains at said second level; and
Claim 17
Dependent Claim
20 words
said second sensor provides an output at said first level while said first sensor remains at said second level; and
Claim 18
Dependent Claim
37 words
said first and second sensors provide an output at said first level; and d. a divide-by-N up-down counter having said count pulses as inputs, N being equal to the number of sprocket holes per frame of film.
Claim 19
Dependent Claim
37 words
said first and second sensors provide an output at said first level; and d. a divide-by-N up-down counter having said count pulses as inputs, N being equal to the number of sprocket holes per frame of film.
Claim 20
Dependent Claim
27 words
said first and second sensors provide an output at said first level; and a reverse count pulse only when the following outputs occur iN the listed order:
Claim 21
Dependent Claim
27 words
said first and second sensors provide an output at said first level; and a reverse count pulse only when the following outputs occur iN the listed order:
Claim 22
Dependent Claim
57 words
The invention according to claim 1 wherein said first and second sensors comprise: a. means to illuminate the sprocket hole area of said film on a first side; b. light absorbing means placed on the other side of said film; and c. light sensing means having an input field of view less than one-half sprocket hole length.
Claim 23
Dependent Claim
72 words
The invention according to claim 5 wherein said sensing means and illuminating means comprIse a micro-character detector having a bundle of light transmitting fibers to provide illumination arranged around a light receiving fiber aligned with said sprocket holes and amplifying means to amplify the sensed signal and provide outputs at said first level when a low light level is received and at said second level when a high light level is received.
Claim 24
Independent Claim
192 words
A method of counting film frames comprising: a. establishing a reference film frame position; b. aligning first and second sensing means which detect an area less than one half sprocket hole so that when the film is in said reference position said first means will be aligned with the top half of one sprocket hole and said second means with the bottom half of a second sprocket hole whereby if presence of a sprocket hole is designated a logic ''''1'''' and absence of a sprocket hole and logic ''''0'''' displacement of the film in one direction by the distance equal to the sprocket hole spacing causes the first and second sensing means to have outputs following a first order 1, 1;0,1;0,0;1,0; and 1,1 and in the other direction following a second order 1,1;1,0;0, 0;0, 1; and 1,1; c. sensing the order and occurrence of said logic states and providing, to an up-down counter, a count in one direction only when said first order occurs and in another direction only when said second order occurs; and d. dividing the count in said counter by the number of sprocket holes per frame of film.
Claim 25
Independent Claim
192 words
A method of counting film frames comprising: a. establishing a reference film frame position; b. aligning first and second sensing means which detect an area less than one half sprocket hole so that when the film is in said reference position said first means will be aligned with the top half of one sprocket hole and said second means with the bottom half of a second sprocket hole whereby if presence of a sprocket hole is designated a logic ''''1'''' and absence of a sprocket hole and logic ''''0'''' displacement of the film in one direction by the distance equal to the sprocket hole spacing causes the first and second sensing means to have outputs following a first order 1, 1;0,1;0,0;1,0; and 1,1 and in the other direction following a second order 1,1;1,0;0, 0;0, 1; and 1,1; c. sensing the order and occurrence of said logic states and providing, to an up-down counter, a count in one direction only when said first order occurs and in another direction only when said second order occurs; and d. dividing the count in said counter by the number of sprocket holes per frame of film.
Claim 26
Dependent Claim
108 words
The invention according to claim 7 wherein sensing said orders is accomplished by sensing only the first and last transitions in said first and second orders whereby a transition of said first sensor from 1 to 0 while the second remains at 1 and of said second sensor from 0 to 1 while said first sensor is 1 will result in a count in said one direction and a transition of said second sensor from 1 to 0 while said first sensor is 1 and of said first sensor from 0 to 1 while said second sensor is 1 will result in a count in said other direction.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-02-18 | 1977-08-20 | 1978-02-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-18 | 1981-08-20 | 1982-02-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-18 | 1985-08-20 | 1986-02-19 | $7700.00 | Window Closed / Lapsed |