Signal amplification by illumination of a partially developed latent electrostatic image

Claim 1

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. providing 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, b. initially depositing a developer powder which is charged to a second polarity on said photoconductive surface whereby said developer powder is deposited denser in the areas of higher surface charge density than in the areas of lower surface charge density, thereby providing a developed charge pattern, c. uniformly exposing the developed charge pattern of 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 d. thereafter applying additional developer powder charged to said second polarity to said developed charge pattern whereby the potential difference between adjacent developed charge patterns of differing density is at least equal to the potential difference between said adjacent initial charge patterns.

Claim 2

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. providing 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, b. initially depositing a developer powder which is charged to a second polarity on said photoconductive surface whereby said developer powder is deposited denser in the areas of higher surface charge density than in the areas of lower surface charge density, thereby providing a developed charge pattern, c. uniformly exposing the developed charge pattern of 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 d. thereafter applying additional developer powder charged to said second polarity to said developed charge pattern whereby the potential difference between adjacent developed charge patterns of differing density is at least equal to the potential difference between said adjacent initial charge patterns.

Claim 3

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. providing 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, b. initially depositing a developer powder which is charged to said first polarity on said photoconductive surface whereby said developer powder is deposited denser in the areas of lower surface charge density than in the areas of higher surface charge density, thereby providing a developed charge pattern, c. uniformly 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 d. thereafter applying additional developer powder charged to a second polarity to said developed charge pattern whereby the potential difference between adjacent developed charge patterns of differing density is at least equal to the potential difference between said adjacent initial charge patterns.

Claim 4

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. providing 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, b. initially depositing a developer powder which is charged to said first polarity on said photoconductive surface whereby said developer powder is deposited denser in the areas of lower surface charge density than in the areas of higher surface charge density, thereby providing a developed charge pattern, c. uniformly 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 d. thereafter applying additional developer powder charged to a second polarity to said developed charge pattern whereby the potential difference between adjacent developed charge patterns of differing density is at least equal to the potential difference between said adjacent initial charge patterns.

Claim 5

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 adjacent said photoconductive surface and exposing said object to penetrating radiation comprising the steps of: a. providing a charged photoconductive surface adjacent an object to be imaged, said photoconductive surface being sensitive to light of a first wavelength, b. passing penetrating radiation through said object and onto said charged photoconductive surface whereby an electrostatic image of said object is formed on said surface whereby at least two adjacent initial charge patterns of differing charge density is formed on said photoconductive surface, said charge patterns being of a first polarity, c. initially depositing a developer powder which is charged to a second polarity on said photoconductive surface whereby said developer powder is deposited denser in the areas of higher surface charge density than in the areas of lower surface charge density, thereby providing a developed image, d. 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. thereafter applying additional developer powder charged to said second polarity to said developed image whereby the potential difference between adjacent developed charge patterns of differing density is at least equal to the potential difference between said adjacent initial charge patterns.

Claim 6

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 adjacent said photoconductive surface and exposing said object to penetrating radiation comprising the steps of: a. providing a charged photoconductive surface adjacent an object to be imaged, said photoconductive surface being sensitive to light of a first wavelength, b. passing penetrating radiation through said object and onto said charged photoconductive surface whereby an electrostatic image of said object is formed on said surface whereby at least two adjacent initial charge patterns of differing charge density is formed on said photoconductive surface, said charge patterns being of a first polarity, c. initially depositing a developer powder which is charged to a second polarity on said photoconductive surface whereby said developer powder is deposited denser in the areas of higher surface charge density than in the areas of lower surface charge density, thereby providing a developed image, d. 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. thereafter applying additional developer powder charged to said second polarity to said developed image whereby the potential difference between adjacent developed charge patterns of differing density is at least equal to the potential difference between said adjacent initial charge patterns.

Claim 7

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 adjacent said photoconductive surface and exposing said object to penetrating radiation comprising the steps of: a. providing a charged photoconductive surface adjacent an object to be imageD, said photoconductive surface being sensitive to light of a predetermined wavelength, b. passing penetrating radiation through said object and onto said charged photoconductive surface whereby an electrostatic image of said object is formed on said surface whereby at least two adjacent initial charge patterns of differing charge density is formed on said photoconductive surface, said charge patterns being of a first polarity, c. initially depositing a developer powder which is charged to said first polarity on said photoconductive surface whereby said developer powder is deposited in the areas of lower surface charge density than in the areas of higher surface charge density, thereby providing a developed image, d. 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. thereafter applying additional developer powder charged to a second polarity to said developed image whereby the potential difference between adjacent charge patterns of differing density is at least equal to the potential difference between said adjacent initial charge patterns.

Claim 8

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 adjacent said photoconductive surface and exposing said object to penetrating radiation comprising the steps of: a. providing a charged photoconductive surface adjacent an object to be imageD, said photoconductive surface being sensitive to light of a predetermined wavelength, b. passing penetrating radiation through said object and onto said charged photoconductive surface whereby an electrostatic image of said object is formed on said surface whereby at least two adjacent initial charge patterns of differing charge density is formed on said photoconductive surface, said charge patterns being of a first polarity, c. initially depositing a developer powder which is charged to said first polarity on said photoconductive surface whereby said developer powder is deposited in the areas of lower surface charge density than in the areas of higher surface charge density, thereby providing a developed image, d. 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. thereafter applying additional developer powder charged to a second polarity to said developed image whereby the potential difference between adjacent charge patterns of differing density is at least equal to the potential difference between said adjacent initial charge patterns.

Claim 18

A method of forming a xeroradiographic image of an object by exposing the object to a first dosage of penetrating radiation, the formed xeroradiographic image having a relative information content which is equivalent to that of a xeroradiographic image formed by exposing the object to penetrating radiation of second dosage, said first dosage being lower than said second dosage, comprising the steps of: a. providing a photoconductive surface having a substantially uniform cHarge pattern thereon, said photoconductive surface being sensitive to light of a predetermined wavelength, b. positioning an object to be imaged adjacent said photoconductive surface, c. passing penetrating radiation of said first dosage through said object and onto said charged photoconductive surface whereby an electrostatic image of said object is formed on said surface whereby at least two adjacent charge patterns of differing charge density is formed on said photoconductive surface, said charge patterns being of a first polarity, d. initially depositing a developer powder which is charged to a second polarity on said photoconductive surface whereby said developer powder is deposited denser in the areas of higher surface charge density than in the areas of lower surface charge density, thereby providing a developed image, e. 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 f. thereafter applying additional developer powder charged to said 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.

Claim 19

A method of forming a xeroradiographic image of an object by exposing the object to a first dosage of penetrating radiation, the formed xeroradiographic image having a relative information content which is equivalent to that of a xeroradiographic image formed by exposing the object to penetrating radiation of second dosage, said first dosage being lower than said second dosage, comprising the steps of: a. providing a photoconductive surface having a substantially uniform cHarge pattern thereon, said photoconductive surface being sensitive to light of a predetermined wavelength, b. positioning an object to be imaged adjacent said photoconductive surface, c. passing penetrating radiation of said first dosage through said object and onto said charged photoconductive surface whereby an electrostatic image of said object is formed on said surface whereby at least two adjacent charge patterns of differing charge density is formed on said photoconductive surface, said charge patterns being of a first polarity, d. initially depositing a developer powder which is charged to a second polarity on said photoconductive surface whereby said developer powder is deposited denser in the areas of higher surface charge density than in the areas of lower surface charge density, thereby providing a developed image, e. 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 f. thereafter applying additional developer powder charged to said 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.

Claim 20

A method of forming a xeroradiographic image of an object by exposing the object to a first dosage of penetrating radiation, the formed xeroradiographic image having a relative information content which is equivalent to that of a xeroradiographic image formed by exposing the object to penetrating radiation of second dosage, said first dosage being less than said first dosage, comprising the steps of: a. providing a photoconductive surface having a substantially uniform charge pattern thereon, said photoconductive surface being sensitive to light of a predetermined wavelength, b. positioning an object to be imaged adjacent said photoconductive surface, c. passing penetrating radiation through said object and onto said charged photoconductive surface whereby an electrostatic image of said object is formed on said surface whereby at least two adjacent charge patterns of differing charge density is formed on said photoconductive surface, said charge patterns being of a first polarity, d. initially depositing a developer powder which is charged to said first polarity on said photoconductive surface whereby said developer powder is deposited denser in the areas of lower surface charge density than in the areas of higher surface charge density, thereby providing a developed image, e. 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 f. thereafter 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.

Claim 21

A method of forming a xeroradiographic image of an object by exposing the object to a first dosage of penetrating radiation, the formed xeroradiographic image having a relative information content which is equivalent to that of a xeroradiographic image formed by exposing the object to penetrating radiation of second dosage, said first dosage being less than said first dosage, comprising the steps of: a. providing a photoconductive surface having a substantially uniform charge pattern thereon, said photoconductive surface being sensitive to light of a predetermined wavelength, b. positioning an object to be imaged adjacent said photoconductive surface, c. passing penetrating radiation through said object and onto said charged photoconductive surface whereby an electrostatic image of said object is formed on said surface whereby at least two adjacent charge patterns of differing charge density is formed on said photoconductive surface, said charge patterns being of a first polarity, d. initially depositing a developer powder which is charged to said first polarity on said photoconductive surface whereby said developer powder is deposited denser in the areas of lower surface charge density than in the areas of higher surface charge density, thereby providing a developed image, e. 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 f. thereafter 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.