Patent US3905698A successfully refreshed from Google Patents.
US3905698A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Photoprinting apparatus in which developer is replenished in proportion to the treated surface area
Assignee: Hoechst AG
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Filing: 1974-08-22
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Granted: 1975-09-16
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Expires: 1994-08-22
Abstract
Abstract Photoprinting apparatus of the type in which paper is selectively fed from one of at least two widths of paper and developed by material which is replenished in proportion to the treated surface area. The width of the paper is detected by discrete switches to produce an electrical signal which has a magnitude indicating the width and which is multiplied by a further signal indicating the length of paper. This multiplied signal in turn controls a pulse generator which applies its output to a counter which actuates a developer replenishing system upon reaching a predetermined count.
Inventors
- 👤 Herbert Schroter
- 👤 Werner Dennhardt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 11:16
CPC Classifications
G; G03; G03D; G03D13/00; G03D13/007; G03D3/00; G03D3/02; G03D3/06; G03D3/065
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
226 words
Photoprinting apparatus comprising an exposure station, means for selectively feeding one of at least two photoprinting papers of different widths to said exposure station, a developing station for developing the exposed photoprinting paper, means for scanning the photoprinting paper to produce a first electrical signal upon detection of the leading edge and a second electrical signal upon detection of the trailing edge of the photoprinting paper, switching means for detecting the width of the respective photoprinting paper selected and producing an electrical signal indicating that width, and means for replenishing developer material in proportion to the surface area of the paper treated, including an electric pulse generator connected to said scanning means for receiving said first and second signals and producing a number of electric pulses that number being a function of the length of the photoprinting paper, a control circuit connected to said switching elements and to said pulse generator for adjusting the proportionality between the length of the severed photoprinting paper and the number of pulses to a value which is proportional to the width, as a function of the signals produced by said switching elements and counter means for counting the pulses produced by said pulse generator and, as soon as a predetermined value is reached, actuating said developer replenishing system to add a defined quantity of developer and reset said counter means.
Claim 2
Dependent Claim
226 words
Photoprinting apparatus comprising an exposure station, means for selectively feeding one of at least two photoprinting papers of different widths to said exposure station, a developing station for developing the exposed photoprinting paper, means for scanning the photoprinting paper to produce a first electrical signal upon detection of the leading edge and a second electrical signal upon detection of the trailing edge of the photoprinting paper, switching means for detecting the width of the respective photoprinting paper selected and producing an electrical signal indicating that width, and means for replenishing developer material in proportion to the surface area of the paper treated, including an electric pulse generator connected to said scanning means for receiving said first and second signals and producing a number of electric pulses that number being a function of the length of the photoprinting paper, a control circuit connected to said switching elements and to said pulse generator for adjusting the proportionality between the length of the severed photoprinting paper and the number of pulses to a value which is proportional to the width, as a function of the signals produced by said switching elements and counter means for counting the pulses produced by said pulse generator and, as soon as a predetermined value is reached, actuating said developer replenishing system to add a defined quantity of developer and reset said counter means.
Claim 3
Dependent Claim
142 words
Photoprinting apparatus according to claim 1, wherein said pulse generator includes means for generating a voltage proportional to the speed of the photoprinting paper and wherein said control circuit includes a voltage source whose voltage is proportional to the width of the respective photoprinting material and which is switched on by the respective switching elements; means for applying the output of said generating means and said voltage source to the inputs of an electronic multiplier which produces an output voltage whose amplitude is proportional to the product of the numerical values of the input voltages; means for connecting the output of said multiplier to the input of an analogue-to-digital converter which generates, as its output, a number of pulses which is proportional to the input voltage, and means for connecting the output of said analogue-to-digital converter to the input of said counter.
Claim 4
Dependent Claim
153 words
Photoprinting apparatus according to claim 2, wherein said switching means includes, connected between said generating means and one of the inputs of said multiplier: a first control switch switched on by the leading edge and off by the trailing edge of said paper and wherein said control circuit includes an integrator and a second control switch means switched on for a constant period of time by the trailing edge of said paper, means connected between said voltage source and the other input of said mUltiplier, switched on by the trailing edge of the copying material for the same period of time for producing voltage proportional to the width of the material and applying that voltage to second input of said multiplier; an analogue-to-digital converter connected to said multiplier for producing a pulse train whose frequency is proportional to its input voltage; and means connecting output of said analogue-to-digital converter to said counter means.
Claim 5
Dependent Claim
115 words
Photoprinting apparatus according to claim 2, wherein the signal at the output of said generating means is connected to one of the inputs of said multiplier by way of a first control switch which is switched on by the leading edge of the copying material and switched off by its trailing edge; that voltage of the control circuit is connected by way of a control switch wired in the same way as control switch with the other input of the multiplier, the output voltage of said multiplier being proportional to the product of the numerical values of the input voltages; and the output of the multiplier is connected with the input of said pulse generator.
Claim 6
Dependent Claim
50 words
Photoprinting apparatus according to claim 2, wherein said control circuit includes a single control switch arranged between the output of said pulse generator and the input of said counter, said control switch being switched on by the leading edge of the copying material and switched off by its trailing edge.
Claim 7
Dependent Claim
190 words
Photoprinting apparatus according to claim 1, wherein the pulse generator comprises a generator which generates a voltage which is proportional to the speed of the photoprinting paper; a first control switch actuated by the leading edge of the copying material for applying the speed-related signal of the generator to an electrical integrator unit which thus yields at its output a voltage which is proportional to the time integral of the time slope of the voltage at the input; a voltage generator whose voltage is inversely proportional to the width of the copying material being processed and which is switched on by a switching element relating to the respective width; means for connecting the output voltage of the integrator and the adjusted voltage at the output of the control circuit to the inputs of a comparator which releases a pulse at its output when the two voltages are identical; and means for connecting the output of the comparator with the input of said counter, and, at the same time, with the reset input of the integrator unit in a manner such that the pulse released by the comparator resets the integrator.
Claim 8
Dependent Claim
150 words
Photoprinting apparatus according to claim 1, wherein said pulse generator includes a speed-related generator connected, by way of a switch which is actuated, by the leading edge of the copying material with the input of an integrator; the output signal of the integrator being connected to one of the inputs of a multiplier whose other inputs are connected, by way of a control unit with a width-related voltage; the signal at the output of the multiplier being operated by a further control circuit responsive to one of the inputs of a comparator whose second input is connected with the output of a sawtooth; said further control circuit being actuated by the trailing edge of the paper to start a pulse generator which passes pulses of a constant frequency to said counter means; and that, when the input voltages are identical, the comparator releases a pulse which stops the pulse generator.
Claim 9
Dependent Claim
117 words
Photoprinting apparatus according to claim 1, wherein a speed-related generator is connected, by way of a switch actuated through control circuit by the leading edge of the material, with an integrator the output of which is connected with the input of an amplifier; the amplifying ratio of the amplifier is adjusted in proportion to the width of the material by a control circuit actuated by the leading edge of the paper; the output voltage of the amplifier which is proportional to the surface area of the material is converted by means of an analogue-to-digital conveRter into a number of pulses which is proportional to the input voltage, and that these pulses are connected to the counter means.
Claim 10
Dependent Claim
111 words
Photoprinting apparatus according to claim 1, wherein the drive of the feeding system for the copying material is provided with elements which revolve with it and which produce, with each revolution, a number of electrical pulses in the connections associated with them the ratios between the numbers of pulses being the same as the ratios between the different widths of copying material; switches actuated by the leading edge of the copying material connect the one of the connections which relates to the copying material of the selected width, to the input of a pulse counter; and the counter actuates the replenishing system as soon as a predetermined number has been reached.
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) | 1978-09-15 | 1979-03-17 | 1979-09-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-15 | 1983-03-17 | 1983-09-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-15 | 1987-03-17 | 1987-09-16 | $7700.00 | Window Closed / Lapsed |