Claims
- 1. In a method for the visualization of electrostatic charge images, including deriving an electrical signal by electro-optical means from said images for control of a developing process for said images, said control being over the deposition of colored pigment, the improvement comprising: absorbing light at least at a portion of the surface of the charge image during the deposition of the pigment in the developing area, measuring the absorption of light at the charge image by generating with the use of the electro-optical means the electrical signal from non-absorbed light, feeding the generated electrical signal to control means for a pigment supply, and terminating the subsequent pigment supply to the developing image in response to the electrical signal reaching a predetermined value.
- 2. A method as claimed in claim 1, said charge image being disposed on a light-transparent carrier, said electrical signal determining the light-transmissiveness of said carrier and the pigment deposited thereon.
- 3. In an apparatus for the visualization of electrostatic charge images including an electro-optical converter for deriving an electrical signal from said images for control of a developing process for said images, said apparatus including a developing area, means for depositing colored pigment in said developing area to form an image; said electro-optical converter being responsive to non-absorbed light for measuring the absorption of light on at least a portion of the surface of said image during the deposition of said pigment in the developing area; and means for controlling the subsequent supply of said pigment responsive to said electrical signal, the improvement comprising: a developing arrangement including a chamber within which said pigment is deposited on said charge image; a light source for projecting a light beam on the surface adapted to be coated with pigment; and the electro-optical converter being located in the path of said light after impingement on said surface and being operatively responsive thereto to generate said electrical signal, said control means for the supply of said pigment having adjustable threshold forming means for supplying a cut-off signal thereto, said threshold forming means being operatively connected to said electro-optical converter and operable to supply the cut-off signal to said control means when the electrical signal from the converter reaches a selected value, said control means being responsive to said cut-off signal for terminating the supply of said pigment.
- 4. An apparatus as claimed in claim 3, comprising a light-transmissive carrier, said light source being located on one side of said carrier and a light probe of said converter on the other side thereof.
Priority Claims (1)
Number |
Date |
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Kind |
2410188 |
Mar 1974 |
DEX |
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Parent Case Info
This is a continuation of application Ser. No. 553,545, filed Feb. 27, 1975 now abandoned.
US Referenced Citations (4)
Continuations (1)
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Number |
Date |
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Parent |
553545 |
Feb 1975 |
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