US3914609A - Signal amplification by illumination of a partially developed latent electrostatic image - Google Patents

Signal amplification by illumination of a partially developed latent electrostatic image Download PDF

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Publication number
US3914609A
US3914609A US448128A US44812874A US3914609A US 3914609 A US3914609 A US 3914609A US 448128 A US448128 A US 448128A US 44812874 A US44812874 A US 44812874A US 3914609 A US3914609 A US 3914609A
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charge
photoconductive surface
developer powder
density
image
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US448128A
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Lothar S Jeromin
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Xerox Corp
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Xerox Corp
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Priority to US448128A priority Critical patent/US3914609A/en
Priority to DE19752506728 priority patent/DE2506728A1/de
Priority to GB7814/75A priority patent/GB1496961A/en
Priority to FR7505771A priority patent/FR2263543B1/fr
Priority to JP50023376A priority patent/JPS50120840A/ja
Priority to NL7502360A priority patent/NL7502360A/xx
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Publication of US3914609A publication Critical patent/US3914609A/en
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    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G15/00—Apparatus for electrographic processes using a charge pattern
    • G03G15/22—Apparatus for electrographic processes using a charge pattern involving the combination of more than one step according to groups G03G13/02 - G03G13/20
    • G03G15/221—Machines other than electrographic copiers, e.g. electrophotographic cameras, electrostatic typewriters
    • G03G15/222—Machines for handling xeroradiographic images, e.g. xeroradiographic processors
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G15/00—Apparatus for electrographic processes using a charge pattern
    • G03G15/06—Apparatus for electrographic processes using a charge pattern for developing
    • G03G15/08—Apparatus for electrographic processes using a charge pattern for developing using a solid developer, e.g. powder developer

Definitions

  • the penetrating radiation utilized is of a substantially lower dosage than normally utilized.
  • the References Cited image is then" partially developed with developing UNITED STATES PATENTS powder and the partially developed image is then ex- 2,711,481 6/1955 Phillips 250/315 A posed to Substantially uniform radiation
  • the exposed 2,756,676 7/1956 Steinhilper,, %/1 image is finally developed by applying additional de- 3,l46,100 8/1964 Kaufman 96/1 veloping powder thereto resulting in an enhanced 3,603,790. 9/1971 Cleare 355/17 image or signal, 3,776,627 12/1973 Ohnishi et al....
  • FIG. 4 38 33 40 W VHIGH CLOUD VOLTAGE GENERATOR SOURCE FIG. 4
  • the latent electrostatic image may be made visible by contacting the latentelectrostatic image on the plate surface with fine powdered particles electrically charged opposite to the latent electrostatic pattern on the plate.
  • the visible image may be viewed, photographed or transferred to another surface where it may be permanently affixed or otherwise utilized. The entire processing is dry, and no dark room is necessary.
  • Xeroradiography in recent years has been utilized to detect breast cancer in women.
  • Xeroradiography or xeromammography provides greater resolving power than the conventional roentgenographic film, and greater image detail is achieved.
  • a wide range of contrast is seen on the xerographic plate as compared to the conventional roentgenographic films so that all structures of the breast from the skin to the chest wall and ribs may be readily visualized.
  • xeromammography detects small structures like tumor calcification and magnifies them more than conventional film, is quicker, less expensive, gives greater detail and requires less radiation than prior nonphotoconductive X-ray techniques.
  • the present invention provides method and appara- 'tus for reducing the X-ray dosage required for xeroradiographic examinations without reducing the relative information capacity of the images produced during the examination.
  • a charged xerographic plate is positioned adjacent the object to be examined and penetrating radiation, such as X-rays, are
  • the penetrating radiation utilized is of a lower dosage than normally utilized.
  • the image is then partially developed with developing powder and the partially developed image is then exposed to substantially uniform radiation.
  • the exposed image is finally developed by applying additional developer powder thereto resulting in an enhanced image or signal.
  • FIG. 1 is a representation of the voltage differences and charge patterns formed on the surface of a photoreceptor in accordance with one embodiment of the present invention
  • FIG. 2 is an exposure curve illustrating the charge retention capabilities of a photoreceptor after exposure to X-rays
  • FIG. 3 is a representation of the voltage differences and charge patterns formed on the surface of a photoreceptor in accordance with another embodiment of the present invention.
  • FIG. 4 shows a diagrammatic cross-section of apparatus which may be utilized to implement the teachings of the present invention
  • FIG. 5 is a schematic view of an automated xerographic processing system which may be utilized to implement the teachings of the present invention.
  • FIGS. 6a and 6b illustrate in schematic form the implementation of the light scanning step in the system described with reference to FIG. 5.
  • representations (a) through (d) illustrate, in schematical form, one embodiment of the present invention and, in particular, a technique for enhancing the signal level of a positively developed xeroradiographic image.
  • the left-hand portion of the representations illustrate the voltage levels, Ve, of the electrostatic charge pattern formed on the surface of a xeroradiographic plate as a function of a distance X along the plate whereas the corresponding right-hand portion of the representations illustrate the charge Q (and developer powder deposition) on the plate surface as a function of distance X along the plate surface.
  • a uniform X-ray beam 10 is generated by a conventional X-ray source 12 and transmitted through an object 14.
  • the X-ray beam is attenuated by the object 14, the subject of the examination procedure, and the transmitted X-rays from the object are modulated in accordance with the density of the object 14 generating a charge pattern of varying surface potentials on the surface of initially positively charged photoreceptor, or xeroradiographic plate, 16.
  • FIG. 2 illustrates a typical exposure curve wherein the surface potential Ve remaining on the surface of the photoreceptor after exposure is plotted with respect to the roentgen dose r of the exposure beam. As can be observed from the graph, the steepest part of the curve is at approximately /2 Ve and 0.05 r and corresponds to the optimal surface potential for optimal signal strength.
  • FIG. 1 describes'the invention wherein positive images are formed on the surface of the photoreceptor.
  • the image when developed, will be a positive of the object being examined.
  • the first step of the technique shownat (a) is to expose a charged xeroradiographic plate to the X-rays transmitted by object 14, the surface of the xeroradiographic plate being initially charged, for example, to 1,600 volts.
  • the resulting representation is a voltage step, corresponding to the X dimension of the object 14, of a magnitude AVe those areas of the photoreceptor surface under the object are not discharged whereas the remaining areas of the plate, corresponding to the width of the X-ray beam, are substantially discharged.
  • the remaining plate areas are discharged to approximately onehalf of the initial surface potential, i.e., 800 volts.
  • various techniques can be utilized to charge the surface of the xeroradiographic plate 16 including the well known use of corona generators..
  • an incident dosage of l Roentgen (l r), corresponding to an X-ray source operation at 120 Kvp and 100 mAs would be required by present xeroradiographic techniques.
  • l r l Roentgen
  • a reduction in the roentgen dose of approximately two to four times can be realized.
  • the incident roentgen dosage is reduced by a factor of two, corresponding to 120 Kvp and 50 mAs.
  • the latent electrostatic charge is then partially developed by applying developer powder to the surface of the photoreceptor.
  • the developer powder, or toner particles, charged negatively in this illustration since the plate was initially charged positive is deposited denser in the areas of higher surface charge (corresponding to object 14) than in the areas of lower surface charge, the potential difference AVe on the surface of the xeroradiographic plate being less than the potential difference at the first step of the process shown in (a), for the reason that more developer powder is deposited on the higher charged area which effectively reduces the surface potential of the chargepattern, i.e., the developer powder (toner) partially neutralizes the surface charge.
  • the surface potential corresponding to the denser areas of the image is reduced to approximately 1,590 volts, corresponding to a potential difference of 790 volts between the areas of higher and lower surface charge.
  • the surface of the photoreceptor, having the partially developed image thereon (which forms an opaque mask on the photoreceptor surface), is exposed uniformly to a light source such as that generated by a standard fluorescent lamp which generates light in the visible spectrum. Since the wavelength of the generated illumination should be compatible with the sensitivity of the photoreceptor, appropriate light filtering is preferably utilized.
  • a blue filter is preferably interposed between the light source and the surface of the photoconductive coating. The light produced by the lamp discharges the lighter developed areas more than the darker developed area due to the ability of the powder particles to absorb light. The pow der particles therefore should have the capability of absorbing light emitted by the aforementioned lamp.
  • the voltage difference, Ave on the photoreceptor surface after light exposure is greater than AVe and results in a charge and developer powder distribution as shown on the right-hand portion of (0).
  • the surface potential corresponding to the higher initial charge has been reduced to 1,550 volts
  • the surface potential corresponding to the lower initial charge has been reduced to substantially zero volts, a signal of approximately 1,550 volts.
  • the uniform light exposure can be accomplished by moving the photoreceptor past a stationary lamp or by moving the lamp across the photoreceptor surface.
  • the photoreceptor is then subjected to an additional development step whereby the developer powder particles are again applied to the photoreceptor surface, resulting in the representations shown at (d).
  • additional developer powder has been attracted to the positive charge on the photoreceptor surface, reducing the voltage difference, AVe,, to a magnitude less than Ave, but greater than AVe '
  • the surface potential corresponding to the higher initial surface charge has 1,540 reduced to 1540 volts, whereas the surface potential corresponding to the lowerinitial charge remains at substantially zero volts.
  • the voltage difference Ave provides an image which has a relative information capacity (i.e., 1,540 volt signal) which is substantially equivalent to an image which would be developed if the full X-ray dosage was utilized for exposure. In the latter situation, full exposure would reduce those areas of theinitially charged photoreceptor subjected to the penetrating radiation to substantially zero volts, providing an image which has a signal of i -l ,600 volts.
  • a relative information capacity i.e., 1,540 volt signal
  • the photoreceptor substrate is preferably maintained at apositive bias in order to ensure that the negatively charged developer powder particles are attracted to the positive ages.
  • object 14 is initially exposed to penetrating X-rays l0 generated by X-ray source 12 (the same reference numerals are utilized in the figures to identify similar elements), the dosage being lower than normally required, resulting in a charge pattern (and corresponding voltage difference AVe,) on the surface of photoreceptor 16 (photoreceptor 16 comprising a photoconductive insulating layer 18, such as vitreous selenium, and conductive substrate as shown at (a).
  • a photoconductive insulating layer 18 such as vitreous selenium
  • the charge density is greater on those portions of the photoreceptor which receive the least X-ray radiation.
  • the latent electrostatic charge pattern is then subjected to an initial development wherein a negative bias greater than the maximum positive sur face potential (AVe is applied to the photoreceptor substrate.
  • AVe maximum positive sur face potential
  • positively charged developer powder particles are deposited denser in the areas of lower surface charge than in the areas of higher surface charge (background development), resulting in the charge and developer powder distribution as shown at the right hand portion of (b).
  • the corresponding potential difference, AVe is less than AVe due to the greater charge deposition in the areas of lower surface charge.
  • the surface of the photoreceptor 18 is then uniformly exposed to light, resulting in the representations shown at (c).
  • the charge pattern formed on the photoreceptor surface is substantially discharged in the image areas since the thickness of the layer of powder particles is less than the thickness of the layer of powder particles'in the background areas resulting in a pattern wherein only charged background areas are present.
  • the voltage difference, or signal AVe is greater than AVe and greater than the original signal Ave,
  • the remaining background charge pattern is developed with negatively charged developer powder, the bias on the photorecep tor substrate being at ground or slightly positive, which produces a negatively developed image having substantially the same relative information capacity of an image produced by utilizing the full X-ray dosage which normally would have been utilized to develop an image of object 14.
  • the voltage difference at the photoreceptor surface, AVe is approximately 1,160 volts which corresponds favorably to the voltage difference (signal) of 1,600 volts obtained at full exposure.
  • the surface of the photoconductive layer 18 may be slightly AC charged after initial development.
  • the developer powder used for final development may be of a different color than the developer powder utilized during partial development to produce better image contrast.
  • a blue developer powder can be used for the partial development whereas a black developer powder may be utilized for final development.
  • a xerographic plate composed of layer 18 overlying conductive member 20 is placed on supports 22, a source of biasing potential 23 being applied to conductive member 20.
  • the plate is sensitized or charged by passing across the surface of layer 18 corona discharge electrode 30 preferably comprising one or several fine conductive strands supplied with a corona-generating voltage from high voltage source 31.
  • Door 32 in a side of chamber 34 is adapted to open to allow corona discharge electrode 30 to enter chamber 34.
  • Electrode 30 is driven by conventional drive means while supported and positioned by guide means and when operated will pass in front of and across the surface of plate layer 18 to place thereon a uniform electrostatic charge while conductive member 20, is at a positive potential.
  • a sliding member 33 is positioned within one side of chamber 34 and formed to completely enclose powder cloud storing area 35 and separate it from chamber 34 when conventional means are utilized for pulling the sliding member across the lower portion of chamber 34. When the system is operative, sliding member 33 is released to allow it to rewind upon itself due to a spring controlled recoil action creating one open area composed of powder cloud storing area- 35 and chamber 34.
  • a vacuum cleaner 36 is positioned to allow vacuum cleaner nozzle 36 to extend through a side in chamber 34.
  • Cloud spray nozzle 40 extends into cloud storing area 35 from a cloud generator with powder particles mixed in pressurized air.
  • Nozzle 40 has an internal opening through which the particles supplied in pressurized air are supplied to the cloud storing area 35.
  • developconventional drive means such as a motor driven lead screw, in a scanning mode in front of and across the surface of photoconductive layer 18.
  • an object to be examined may be placed on conductive member 20, conductive member 20 acting as a support for the object 60 to be examined.
  • Door 32 opens to the position shown and corona electrode 30 is caused to traverse across the surface of layer 18 supplying charge thereto.
  • An exposure is then made by causing penetrating radiation generated by X-ray source 62 to be directed to and through object 60, source 62 being energized by high voltage supply 64.
  • sliding member 33 remains in a closed position while a cloud of charged developer particles are supplied to storage area 35. Following exposure, sliding member 33 is released making storage area 35 and chamber 33 one enclosure.
  • the cloud of developer particles in air which is already generated and which is continuously being generated during development is supplied to the plate following exposure by allowing the powder cloud to flow upward into the area of influence of the electrostatic latent image on the surface of layer 18.
  • sliding member 33 returns to its closed position and vacuum cleaner 30 may be operated to purge the remaining cloud of particles in air from chamber 34.
  • An air intake valve may also be opened to prevent the creation of a negative pressure within chamber 34.
  • sliding member 33 is again released and the cloud of developer particles is supplied again to the plate surface, thereby finally developing the image.
  • Sliding member 33 returns to its closed position and the purge cycle is repeated. At this point the plate is ready for viewing and/or further processing to obtain a permanent record of the image and the object is removed to give access to the plate. This cycle of operation which has just been described may then be repeated.
  • the plate used in connection with this invention may be a conventional plate used in the art of xeroradiography as set forth hereinabove and includes plates generally used in xerographic apparatus.
  • Backing member 12 may be any conductive material, a preferred plate, however, having a backing member composed of aluminum or aluminum having a radiation absorbant coating thereon such as a coating of lead. Other metals or conductors operate very well in this invention when used as backing members in properly formed xeroradiographic plates.
  • Layer 16 should be composed of a manal exposure station.
  • the aforementioned processing system may be adapted to incorporate the novel techniques of the present invention with a simple modification thereto as will be described hereinafter. In order to place the present invention in proper perspective relative to the aforementioned automated processing system, theoperation thereof will be briefly described.
  • Storage box 80 is inserted into charging unit 90 through port 92.
  • A- xerographic plate 94 with the photoconductor layer on the top side, is withdrawn there from and passed to conditioning means 96 where it is maintained at the appropriate temperature for a predeterial which becomes conductive when exposed to penetrating radiation and which in the absence of penetrating radiation is a good insulator.
  • conditioning means 96 where it is maintained at the appropriate temperature for a predeterial which becomes conductive when exposed to penetrating radiation and which in the absence of penetrating radiation is a good insulator.
  • Typical materials which may be employed in accordance with the present would be iden tical to the negative, or background, mode of development, with the modification of having an initial negative bias on the conductive member 20 greater than the initial positive surface potential and changing the bias to ground or slightly positive at the final development step (see discussion set forth hereinabove). Further, in order to reduce granularity of the negative image, the surface of layer 18 may be slightly AC
  • FIG. 5 there is shown a schematic illustration of the operative elements of the automated, flatplate xerographic processing system described in U.S. Pat. No. 3,650,620 showing the relationship of two automated processing units to each other and to an exter' termined period of time whereby the residual image normally associated with the exposure of xerographic plates to high energy penetrating radiation, such as X- rays, is eliminated.
  • the xerographic plate is withdrawn from the conditioning means 96 and passed to storage magazine 100 where i t is cooled to the proper xerographic pro.
  • xerographic plate 94 is withdrawn from storage magazine 100, passed beneath vacuum cleaning means 110 and uniform electrostatic charging means 42 and into cassette 104, which is automatically released and closed whereby the uniformly charged xerographic plate is held in a lighttight environment.
  • the cassette with the latent electrostatic image-bearing xerographic plate therein, is inverted and inserted into printing unit 200 through port 204.
  • the cassette is automatically opened and the xerographic plate, held in proper alignment with the xerographic plate processing path by the internal structure of the cassette, is withdrawn and transported to powder cloud development. means 210.
  • a single support sheet is withdrawn from support sheet supply means 212.
  • This sheet is transported by transport means 214 to a point adjacent the path of xerographic plate travel during its advancement from the development chamber, where the sheet is stopped.
  • the development chamber is lowered in a manner described in the aforementioned'patent and scanning means 216, comprising lamp 218 and housing 220 having an aperture slit therein, is caused to pass across and adjacent to the surface of the plate 10. It should be noted at this point that appropriate bias levels for posi-. tive and negative. images are controlled by biasing agrid interposed between the plate surface and a baffle in lieu of applying a bias directly to the plate substrate.
  • the xerographic plate After the final development step, the xerographic plate, with the powder image thereon, is transported out of the development means, over pretransfer corotron 224 which uniformly charges the photoconductive surface and the powder image to a first polarity. As the leading edge of the xerographic plate comes into registration with the stationary support sheet, they are caused to move in synchronization over transfer corotron 226 which charges the back side of the support-sheet to a polarity opposite the charging polarity utilized by pre-transfer corotron 224, whereby the powder image is transferred to the support sheet.
  • the plate After the support sheet has been stripped from its position adjacent the xerographic plate, the plate passes over pre-clean corotron 236 and into contact with brush cleaner 238 which removes residual toner from the photoconductive surface. The movement of the plate is continued into inverted storage box 240. To I complete the cycle, it is only necessary to withdraw storage box 240 from printing unit 300 through port 242. Invert the storage box such that slot 244 is in the lower left-hand corner, and insert the storage'box into charging unit 90 through port 92. In this manner, the xerographic plates can be reused for subsequent xerographic processing.
  • the apparatus described in reference to FIG. can be utilized to implement the negative development mode by appropriate control of the bias applied to the grid (or plate substrate if the development chamber described in the aforementioned copending application is utilized). Further, in order to reduce granularity of the negative image, the surface of the photoreceptor may be slightly. LAC charged after initial development.
  • FIGS; 6d and6b illustrate in schema'ticalform the light scanning step of the present invention utilizing the automated flat-plate processing system described with reference to FIG. 5.
  • the development chamber is raised into contact with plate 10 by inflatable means 250 (FIG. 6a) and the image is partially developed by applying approximately seven bursts of toner to the chamber.
  • chamber2l'0 is'-lowered 65 tion of arrow 264, the light generated from lamp 218 being emitted from aperture slit 221.
  • the scanning means returns in the direction of arrow 266 to its initial, or home, position.
  • scan- 5 ning means 216 reaches its initial position, the development chamber is raised (position shown in FIG. 6a) and finally development occurs by applying approximately ten bursts of toner.
  • the chamber is lowered and the normal process continues.
  • FIGS. 6a and 6b The development chamber shown in FIGS. 6a and 6b is described in detail in U.S. Pat. No. 3,640,246. It is to be recalled that the development chamber described in the aforementioned copending application may be utilized with appropriate modification since the plate is raised or lowered onto the development chamber.
  • a second toner dispenser may be added.
  • a single toner dispenser with two separate compartments, each having a separate aspirator tube, can be utilized.
  • the system described hereinabove may be arranged wherein the scanning means is maintained outside the development chamber in a fixed position and the plate transported across the scanning means aperture slit after initial development, the plate thereafter being returned to the chamber for final development.
  • a photoconductive surface having at least two adjacent initial charge patterns of differing charge density thereon, said charge patterns being of a first polarity, said photoconductive surface being sensitive to light of a predetermined wavelength
  • a method of increasing the potential difference between two adjacent developed charge patterns of differing charge density formed on a photoconductive surface comprising the steps of:
  • a photoconductive surface having at least two adjacent initial charge patterns of differing charge density thereon, said charge patterns being of a first polarity, said photoconductive surface being sensitive to light of a predetermined wavelength, Y
  • a method of increasing the potential difference between two adjacent developed latent electrostatic charge patterns of differing charge density formed on a photoconductive surface, said latent electrostatic charge patterns being produced by positioning an object to be imaged adjacentsaid photoconductive surface and exposing said object to penetrating radiation comprising the steps of:
  • a method of increasing'the potential difference between two adjacent developed latent electrostatic charge patterns of differingcharge density formed on a photoconductive surface, said latent electrostatic charge patterns being produced by positioning an object to be imaged adjacent said photoconductive surface and exposing said object to penetrating radiation comprising the steps of:
  • Apparatus for increasing the potential difference between two adjacent developed charge patterns of differing charge density formed on a photoconductive surface comprising:
  • a photoconductive surface having at least two adjacent initial charge patterns of differing charge density thereon, said charge patterns being of a first polarity, said photoconductive surface being sensitive to light of a predetermined wavelength
  • Apparatus for increasing the potential difference between two adjacent developed charge patterns of differing charge density formed on a photoconductive surface comprising:
  • a photoconductive surface having at least two adjacent initial charge patterns of differing charge density thereon, said charge patterns being of a first polarity, said photoconductive surface being sensitive to light of a predetermined wavelength
  • c means uniformly for exposing the developed charge pattern to light of said predetermined wavelength, the initially deposited developer powder forming a mask which absorbs light in proportion to the density of the deposited developer powder, and
  • Apparatus for increasing the potential difference between two adjacent developed latent electrostatic charge patterns of differing charge density formed on a photoconductive surface said latent electrostatic charge patterns being produced by positioning an object to be imaged adjacent said photoconductive surface and exposing said object to penetrating radiation comprising:
  • a charged photoconductive surface adjacent an object to be imaged said photoconductive surface being sensitive to light of a predetermined wavelength
  • d. means for uniformly exposing the developed image to light of said predetermined wavelength, the initially deposited developer powder forming a mask which absorbs light in proportion to the density of the deposited developer powder, and
  • Apparatus for increasing the potential difference between two adjacent latent electrostatic charge patterns of differing charge density formed on a photoconductive surface comprising:
  • a charged photoconductive surface adjacent an object to be imaged said photoconductive surface being sensitive to light of a predetermined wavelength
  • a photoconductive surface having a substantially uniform charge pattern thereon, said photoconductive surface being sensitive to light of a predetermined wavelength
  • the initially deposited developer powder forming a mask which absorbs light in proportion to the density of the deposited developer powder
  • a photoconductive surface having a substantially uniform charge pattern thereon, said photoconductive surface being sensitive to light of a predetermined wavelength
  • the initially deposited developer powder forming a mask which absorbs light in proportion to the density of the deposited developer powder
  • a charged photoconductive surface positioned adjacent an object to be imaged, said photoconductive surface being sensitive to light of a predeter mined wavelength
  • d. means for uniformly exposing the developed image to light of said predetermined wavelength, the initially deposited developer powder forming a mask which absorbs light in proportion to the density of the deposited developer powder, and
  • a charged photoconductive surface positioned adjacent an object to be imaged, said photoconductive surface being sensitive to light of a predetermined wavelength
  • d. means for uniformly exposing the developed image to light of said predetermined wavelength, the initially deposited developer powder forming a mask which absorbs light in proportion to the density of the deposited developer powder, and e.- means for applying additional developer powder charged to a second polarity to said developed image whereby the relative information content of the additionally developed image is equivalent to that of an image formed by exposing the object to penetrating radiation of said second dosage.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Combination Of More Than One Step In Electrophotography (AREA)
  • Exposure Or Original Feeding In Electrophotography (AREA)
  • Control Or Security For Electrophotography (AREA)
  • Apparatus For Radiation Diagnosis (AREA)
  • Photoreceptors In Electrophotography (AREA)
US448128A 1974-03-04 1974-03-04 Signal amplification by illumination of a partially developed latent electrostatic image Expired - Lifetime US3914609A (en)

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Application Number Priority Date Filing Date Title
US448128A US3914609A (en) 1974-03-04 1974-03-04 Signal amplification by illumination of a partially developed latent electrostatic image
DE19752506728 DE2506728A1 (de) 1974-03-04 1975-02-18 Verfahren und vorrichtung zur bildverstaerkung bei der xeroradiographie
GB7814/75A GB1496961A (en) 1974-03-04 1975-02-25 Signal amplification by illumination of a partially developed electrostatic latent image
FR7505771A FR2263543B1 (enrdf_load_html_response) 1974-03-04 1975-02-25
JP50023376A JPS50120840A (enrdf_load_html_response) 1974-03-04 1975-02-25
NL7502360A NL7502360A (nl) 1974-03-04 1975-02-27 Signaalversterking door verlichting van een gedeeltelijk ontwikkeld, latent, elektrostatisch beeld.

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Cited By (9)

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Publication number Priority date Publication date Assignee Title
US4002906A (en) * 1974-07-31 1977-01-11 Siemens Aktiengesellschaft Apparatus and method for the recording and reproduction of X-ray pictures
US4038943A (en) * 1974-06-05 1977-08-02 Xerox Corporation Signal amplification by charging and illuminating a partially developed latent electrostatic image
US4071648A (en) * 1974-07-19 1978-01-31 Xonics, Inc. Electron radiograph receptor
US4119849A (en) * 1975-03-19 1978-10-10 Agfa-Gevaert N.V. Radiography
FR2426930A1 (fr) * 1978-05-22 1979-12-21 Savin Corp Procede et appareil de formation d'images par un procede electrophotographique
DE2944735A1 (de) * 1978-11-09 1980-05-22 Savin Corp Verfahren und vorrichtung zum herstellen von xeroradiographien
EP0179418A1 (en) * 1984-10-20 1986-04-30 Fuji Photo Film Co., Ltd. Radiation image read-out apparatus
US5023661A (en) * 1989-04-10 1991-06-11 Xerox Corporation Precharging of the X-ray photoreceptor to eliminate the fatigue artifact
CN108968995A (zh) * 2018-08-20 2018-12-11 创辉医疗器械江苏有限公司 一种骨骼定位胶片及骨骼定位方法

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4233381A (en) * 1978-11-09 1980-11-11 Savin Corporation Method and apparatus for increasing the apparent resolution of developed electrophotographically reproduced images
JPS63260424A (ja) * 1987-04-17 1988-10-27 Mazda Motor Corp 多層中空成形容器の製造方法

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US4038943A (en) * 1974-06-05 1977-08-02 Xerox Corporation Signal amplification by charging and illuminating a partially developed latent electrostatic image
US4071648A (en) * 1974-07-19 1978-01-31 Xonics, Inc. Electron radiograph receptor
US4002906A (en) * 1974-07-31 1977-01-11 Siemens Aktiengesellschaft Apparatus and method for the recording and reproduction of X-ray pictures
US4119849A (en) * 1975-03-19 1978-10-10 Agfa-Gevaert N.V. Radiography
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DE2944735A1 (de) * 1978-11-09 1980-05-22 Savin Corp Verfahren und vorrichtung zum herstellen von xeroradiographien
FR2441199A1 (fr) * 1978-11-09 1980-06-06 Savin Corp Procede et appareil de radiographie electrostatique
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FR2263543A1 (enrdf_load_html_response) 1975-10-03
GB1496961A (en) 1978-01-05

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