Patent US3864035A successfully refreshed from Google Patents.
US3864035A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Shutterless camera system
Assignee: Coulter Information Systems Inc
•
Filing: 1973-09-14
•
Granted: 1975-02-04
•
Expires: 1993-09-14
Abstract
Abstract A camera utilizing an electrophotographic film having a photoconductive coating has the coating exposed to the scene to be recorded without an intervening shutter. The camera has a charging circuit for charging the coating by means of a suitable corona producing device; toning means to apply toner to the coating and including means to apply a biasing potential between the toning means and the coating to drive the toner particles to the coating; and means to alter the size of the aperture of the projecting system as an optional feature. Means to fix the toner are also provided. An essential requirement to the use of the camera is that the film be capable of accepting a charge at a rate faster than the light of a scene to be recorded discharges the film. In its simplest form the camera consists of a projector for projecting a scene onto the film, a corona charging system, a toning system, means for measuring the light coming through the projector, means for measuring the surface potential of a dark area of the film while it is being charged and an electronic control circuit which operates the charging system in response to the measured light. The parameters of the circuitry are adjusted to give optimum sensitivity of the film for any particular lighting intensity. The variation of peak surface potential to light intensity is an inverse one. The camera operates as follows: when pointed at an object or scene, the operator energizes the electrical circuitry and the camera mechanism. There is no shutter, the aperture of the projector being open to the desired diameter at all times. The corona power supply is energized and starts to charge up the surface of the electrophotographic film which at the same time sees the scene. When the peak voltage for the particular intensty of light as measured by the light meter has been reached, the corona power supply is disabled and the toning means is operated. There need not be any exposure time period between peak charge and the commencement of the toning operation. Preferably a simple light excluding mask excludes light of any kind from the electrophotographic member while it is being toned. The toner may be fixed after the toning has been completed, either by a mechanism provided inside of the camera or a device on its exterior.
Inventors
- 👤 Manfred R Kuehnle
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 09:02
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/50; G03G15/5033; G03G15/5037; G03G15/22; G03G15/221; G03G15/24; G03G15/26; H; H04; H04N; H04N23/00; H04N23/95; H04N23/958; H04N23/959; G03G15/04; G03G15/043
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
321 words
A shutterless camera for recording a scene on electrophotographic film having a photoconductive coating, said camera comprising: A. a camera housing providing a light-tight enclosure, B. a wall of said camera housing having projecting means for projecting an exterior light pattern through the wall and into said enclosure, C. means for removably mounting an electrophotographic film member having a photoconductive coating within said enclosure in a position such that the light pattern will be projected onto the photoconductive coating, D. a charging device for charging the coating to raise the surface potential thereof rapidly while the coating simultaneously is exposed to said light pattern, E. means within the enclosure for toning the latent image which is adapted to be produced by the projection of said pattern onto said coating, F. means for measuring the surface potential of the coating at an area which achieves the peak voltage first of all areas of the coating and deriving a first electrical signal representative of said potential, G. means for measuring the average intensity of said light pattern and deriving a second electrical signal representative of said intensity, H. means for comparing the first and second signals while the charging device is enabled and deriving a third electrical signal when a predetermined relationship between the first and second signals has been reached which represents a desired peak voltage corresponding to the particular light intensity, I. means for disabling the charging device, J. structure energized by said third signal for operating the last-mentioned disabling means, K. means for enabling the toning means immediately after operation of said last-mentioned disabling means such that the toning of the latent image commences immediately after the peak voltage has been reached, L. means for disabling the toning means after a period of time and M. the camera including means for manually initiating the operation of the charging device when it is desired to commence the recording of a scene.
Claim 2
Dependent Claim
321 words
A shutterless camera for recording a scene on electrophotographic film having a photoconductive coating, said camera comprising: A. a camera housing providing a light-tight enclosure, B. a wall of said camera housing having projecting means for projecting an exterior light pattern through the wall and into said enclosure, C. means for removably mounting an electrophotographic film member having a photoconductive coating within said enclosure in a position such that the light pattern will be projected onto the photoconductive coating, D. a charging device for charging the coating to raise the surface potential thereof rapidly while the coating simultaneously is exposed to said light pattern, E. means within the enclosure for toning the latent image which is adapted to be produced by the projection of said pattern onto said coating, F. means for measuring the surface potential of the coating at an area which achieves the peak voltage first of all areas of the coating and deriving a first electrical signal representative of said potential, G. means for measuring the average intensity of said light pattern and deriving a second electrical signal representative of said intensity, H. means for comparing the first and second signals while the charging device is enabled and deriving a third electrical signal when a predetermined relationship between the first and second signals has been reached which represents a desired peak voltage corresponding to the particular light intensity, I. means for disabling the charging device, J. structure energized by said third signal for operating the last-mentioned disabling means, K. means for enabling the toning means immediately after operation of said last-mentioned disabling means such that the toning of the latent image commences immediately after the peak voltage has been reached, L. means for disabling the toning means after a period of time and M. the camera including means for manually initiating the operation of the charging device when it is desired to commence the recording of a scene.
Claim 3
Dependent Claim
21 words
The camera as claimed in claim 1 in which the third signal also operates the means for enabling the toning means.
Claim 4
Dependent Claim
43 words
The camera as claimed in claim 1 in which there is a high speed blind and means for operating the blind to cut off the light projected into said enclosure, said blind being arranged to be operated when the charging device is disabled.
Claim 5
Dependent Claim
92 words
The camera as claimed in claim 1 in which there is a high speed blind and means for operating the blind to cut off the light projected into said enclosure, means are provided to move the film member mounting means and the toning means with respect to one another before the enabling of the toning means, and said third signal is arranged and connected also to enable the blind operating means and thereafter to enable said means for moving the film member mounting means and toning means with respect to one another.
Claim 6
Dependent Claim
21 words
The camera as claimed in claim 1 in which means are provided within the camera enclosure to fix the toned image.
Claim 7
Dependent Claim
34 words
The camera as claimed in claim 1 in which means are provided within the camera enclosure to fix the toned image and said last means are enabled when the toning means have been disabled.
Claim 8
Dependent Claim
64 words
The camera as claimed in claim 1 in which the third signal also is connected to operate the means for enabling the toning means, and means are provided for timing the period between enabling and disabling of the toning means in a predetermined relationship to the peak voltage achieved by the surface potential, the time of toning varying generally inversely as the peak voltage.
Claim 9
Dependent Claim
54 words
ThE camera as claimed in claim 1 in which the third signal also operates the means for enabling the toning means and means are provid3ed for timing the period between enabling and disabling the toning means commencing with the initiation of the charging device for a fixed time independently of the peak voltage reached.
Claim 10
Dependent Claim
146 words
The camera as claimed in claim 1 in which said surface potential measuring means comprise a voltage measuring device and the first signal is a varying voltage which rises as the charge increases, said light intensity measuring means and deriving means include a photocell connected to an adjusting circuit whose parameters are adjusted to provide an output voltage having a predetermined characteristic for different values of light intensity, said last-mentioned output voltage being constant for any value of light intensity and comprising the second signal, the comparing means include a differential amplifier arranged in a configuration to produce an output signal only when its two inputs are equal whereby the said predetermined relationship between the first and second signals is equality, the output signal of said differential amplifier comprising said third signal and occurring only when the first signal has risen to equal the second signal.
Claim 11
Dependent Claim
95 words
The camera as claimed in claim 1 in which the means for mounting the film member is arranged so that there is an area of the photoconductive surface thereof which is in darkness notwithstanding the projection of a light pattern onto the major portion of the surface but nevertheless is sufficiently close to the charging device so that it is charged during the operation of the charging device, said surface potential measuring means comprising a voltmeter disposed in position to measure the surface potential of said area of the film member which remains in darkness.
Claim 12
Dependent Claim
43 words
The camera as claimed in claim 1 in which the means for measuring the light intensity comprise photoresponsive means located on the interior of the enclosure and arranged to intercept at least some of the light which is projected onto said film member.
Claim 13
Dependent Claim
50 words
The camera as claimed in claim 1 in which the means for measuring the light intensity comprise transparent photoresponsive means arranged to be interposed so that the majority of the light projected onto the film member will impinge on the photoresponsive means but most of said light will pass through.
Claim 14
Dependent Claim
39 words
The camera as claimed in claim 1 in which the means for measuring the light intensity comprise a transparent photocell, the projecting means include at least one lens and the photocell is coated onto a surface of the lens.
Claim 15
Dependent Claim
42 words
The camera as claimed in claim 2 in which there is a high speed blind and means for operating the blind to cut off the light projected into said enclosure, said blind arranged to be operated when the charging device is disabled.
Claim 16
Dependent Claim
92 words
The camera as claimed in claim 2 in which there is a high speed blind and means for operating the blind to cut off the light projected into said enclosure, means are provided to move the film member mounting means and the toning means with respect to one another before the enabling of the toning means, and said third signal is arranged and connected also to enable the blind operating means and thereafter to enable said means for moving the film member mounting means and toning means with respect to one another.
Claim 17
Dependent Claim
25 words
A camera as claimed in claim 3 in which the blind and means for operating the same are located on the interior of said enclosure.
Claim 18
Dependent Claim
25 words
A camera as claimed in claim 4 in which the blind and means for operating the same are located on the interior of said enclosure.
Claim 19
Dependent Claim
16 words
The camera as claimed in claim 9 in which said adjusting circuit includes a non-linear circuit.
Claim 20
Dependent Claim
123 words
The camera as claimed in claim 9 in which the means for disabling the charging device includes an AND gate having two input terminals and a single output terminal adapted to have an energizing signal produced thereat to effect disAbling of said charging device, one AND gate input terminal being connected to said light measuring means and deriving means to receive a continuous fixed gating signal therefrom during said charging period and the other AND gate input terminal being connected to said differential amplifier to receive the third signal from the output of said differential amplifier, whereby, said AND gate will have no energizing signal output until the third signal appears after the first signal has risen sufficiently to equal the second signal.
Claim 21
Dependent Claim
188 words
A shutterless camera for recording a light pattern on electrophotographic film having a photoconductive coating, said camera comprising; A. a camera housing providing a light tight enclosure and having means for holding an electrophotographic film member removably therein, said film member having a photoconductive coating, B. means for exposing said coating of said film member to a light pattern from the exterior of said housing, C. means for charging the coating simultaneous with exposing the same, D. means for sensing the absolute potential of the charge on the coating at a location thereon that remains in darkness and simultaneously sensing the flux of said light pattern which is impinging on said coating and deriving respective signals from the potential and flux, E. a triggering circuit operated by said signals and having a predetermined characteristic which provides an output signal for any level of light flux when the charge potential sensed reaches a chosen value corresponding to any particular flux level and built into said characteristic and F. means driven by the output signal of said triggering circuit sequentially to disable the charging means and to tone the coating.
Claim 22
Dependent Claim
188 words
A shutterless camera for recording a light pattern on electrophotographic film having a photoconductive coating, said camera comprising; A. a camera housing providing a light tight enclosure and having means for holding an electrophotographic film member removably therein, said film member having a photoconductive coating, B. means for exposing said coating of said film member to a light pattern from the exterior of said housing, C. means for charging the coating simultaneous with exposing the same, D. means for sensing the absolute potential of the charge on the coating at a location thereon that remains in darkness and simultaneously sensing the flux of said light pattern which is impinging on said coating and deriving respective signals from the potential and flux, E. a triggering circuit operated by said signals and having a predetermined characteristic which provides an output signal for any level of light flux when the charge potential sensed reaches a chosen value corresponding to any particular flux level and built into said characteristic and F. means driven by the output signal of said triggering circuit sequentially to disable the charging means and to tone the coating.
Claim 23
Dependent Claim
21 words
The camera as claimed in claim 21 in which means are provided for adjusting the amount of flux entering the enclosure.
Claim 24
Dependent Claim
18 words
The camera as claimed in claim 22 in which means are provided for adjusting the time of toning.
Claim 25
Dependent Claim
31 words
The camera as claimed in claim 22 in which means are provided to adjust the toner bias in response to the charge potential sensed at the end of the charging period.
References Cited (Backward Citations)
US2831409A
Cited
US3028799A
Cited
US3057275A
Cited
US3528355A
Cited
US3542465A
Cited
US3680955A
Cited
US3773416A
Cited
US3788739A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-02-03 | 1978-08-05 | 1979-02-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-03 | 1982-08-05 | 1983-02-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-03 | 1986-08-05 | 1987-02-04 | $7700.00 | Window Closed / Lapsed |