Browse Prior Art Database

Erase Lamp Control

IP.com Disclosure Number: IPCOM000085978D
Original Publication Date: 1976-Jul-01
Included in the Prior Art Database: 2005-Mar-03
Document File: 3 page(s) / 48K

Publishing Venue

IBM

Related People

Underhill, TT: AUTHOR

Abstract

In a xerographic copier the moving photoconductor is uniformly charged, and then selectively discharged in accordance with the light reflectance characteristics of a document to be copied. The photoconductor's working area is defined as the area which will coincide with a sheet of copy paper at the transfer station. The copier's erase lamps must be energized to illuminate, and thus erase, the photoconductor's border area surrounding the working area. When the copier is usable with different size copy paper, a means must be provided to erase a variable size border or nonworking area.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 53% of the total text.

Page 1 of 3

Erase Lamp Control

In a xerographic copier the moving photoconductor is uniformly charged, and then selectively discharged in accordance with the light reflectance characteristics of a document to be copied. The photoconductor's working area is defined as the area which will coincide with a sheet of copy paper at the transfer station. The copier's erase lamps must be energized to illuminate, and thus erase, the photoconductor's border area surrounding the working area. When the copier is usable with different size copy paper, a means must be provided to erase a variable size border or nonworking area.

Fig. 1 shows a portion of such a copier. Paper supply bin 10 is adjustable to hold one of four different sizes of copy paper. The operator indicates the size paper resident within the bin by pushing the proper one of buttons 11. These sizes are arbitrarily designated A, B, C and D for purposes of explanation. In addition, the copier of Fig. 1 may operate in one of two reduction modes, as designated by buttons 16.

Fig. 2 shows drum photoconductor 12 unrolled. The photoconductor has two image areas on its circumference. The direction of photoconductor movement is shown by arrow 13. Broken line 14 designates the separation of the two image areas. Broken line A outlines the photoconductor's working area when the largest paper size A is used. Broken line D outlines the working area when the smallest paper size D is used. All working areas have a common corner 15. The variable size border areas surrounding the working area are erased by operation of Fig. 1's interimage and length erase stations, prior to the photoconductor passing through the developer. The cross-hatched area of Fig. 2 shows the interimage portion of the border area when using size A paper.

The position of drum 12, as it rotates through a 360 Degrees cycle, is indicated by counter 17. This counter is driven by a pulse train generated by m...