The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 11, 1978
Filed:
Mar. 25, 1977
Herbert Schroter, Taunusstein, DE;
Eckehard Stein, Frankfurt, DE;
Hoechst Aktiengesellschaft, , DE;
Abstract
This invention relates to an improvement in a copying apparatus, particularly a photoprinting apparatus, comprising an exposure station, a developing chamber, and an evaporator associated with the developing chamber, in which a developer composed of an ammonia/water mixture is virtually completely evaporated and over-heated at a temperature about 100.degree. C, preferably about 105.degree. C, and at a predetermined pressure, preferably atmospheric pressure, the apparatus further including, for dosage of the ammonia/water mixture, a feed pipe connected with the evaporator, a valve connected with the feed pipe, and a control unit connected with the valve, whereby the rate of feed of the ammonia/water mixture may be adapted to different operating conditions, the improvement comprising first switch means, actuatable by an original, positioned at an entrance for the original upstream of an exposure station in the feed direction of the apparatus. Second switch means, actuatable by a copying material, positioned at a delivery point of said copying material downstream of said developing chamber, control unit means electrically connected with said first and second switch means, said control unit being so constructed that after said first switch means has been switched to a first position by the original, the valve is first opened for a relatively long period of time, and the valve is then alternately opened and closed, in accordance with pulses, as long as the first or second switch means is maintained in its first switching position by one or more originals or one or more sheets of copying material, respectively, and said pulse-wise opening and closing of the valve is terminated only when neither the first nor the second switch means is maintained in its first switching position by an original or a sheet of copying material, respectively.