Electrophotographic printing device

• US 5,276,461 A
• Filed: 04/13/1990
• Issued: 01/04/1994
• Est. Priority Date: 04/18/1989
• Status: Expired due to Fees

• Current Assignee: Tokyo Electric Co., Ltd.
• Original Assignee: Tokyo Electric Co.
• Inventors: Saito, Akihiro
• Primary Examiner(s): Miller, Jr., George H.
• Assistant Examiner(s): YOCKEY, DAVID F
• Application Number:
  US07/509,597
• Time in Patent Office: 1,362 Days
• Field of Search: 346/107 R, 355/208, 355/209, 355/202, 355/206, 355/211, 439/152, 439/153, 439/155, 439/157, 439/159, 439/160
• US Class Current: 347/129
• CPC Class Codes: G03G 15/5079 for maintenance
• CPC Class Codes: G03G 15/55 Self-diagnostics; Malfunction or lifetime display
• CPC Class Codes: G03G 15/553 Monitoring or warning means for exhaustion or lifetime end of consumables, e.g. indication of insufficient copy sheet quantity for a job
• CPC Class Codes: G03G 21/1889 for auto-setting of process parameters, lifetime, usage
• CPC Class Codes: G03G 2215/00092 the support being an IC card
• CPC Class Codes: G03G 2215/00109 Remote control of apparatus, e.g. by a host
• CPC Class Codes: G03G 2221/1606 for the photosensitive element
• CPC Class Codes: G03G 2221/1636 for the exposure unit
• CPC Class Codes: G03G 2221/1654 Locks and means for positioning or alignment
• CPC Class Codes: G03G 2221/1663 having lifetime indicators
• CPC Class Codes: G03G 2221/1823 Cartridges having electronically readable memory
• CPC Class Codes: G03G 2221/183 Process cartridge

Abstract

A laser printer comprises a cartridge of a photosensitive unit, a printing mechanism for effecting a printing operation by electrifying a photosensitive member of the photosensitive unit, applying a light beam to the electrified photosensitive member to form an electrostatic latent image thereon, developing the electrostatic latent image to create a visible image and then transferring the image to printing paper, and a nonvolatile memory for storing data indicating the printing history of the photosensitive unit. The printing device further comprises a microprocessor for updating the data stored in the nonvolatile memory each time the printing operation is effected, checking whether the data stored in the nonvolatile memory has reached a value corresponding to a service life of the photosensitive unit, and generating a replacement requiring signal when it is detected that the data stored in the nonvolatile memory has reached the value.

Claims

1. An electrophotographic printing device comprising:

a cartridge of a photosensitive unit;

a printing mechanism for effecting a printing operation by electrifying a photosensitive member of said photosensitive unit, applying a light beam to the electrified photosensitive member to form an electrostatic latent image thereon, developing the electrostatic latent image to create a visible image and then transferring the visible image to printing paper;

a nonvolatile memory means for storing data indicating a printing history of the photosensitive unit;

processing means for updating the data stored in said nonvolatile memory means each time the printing operation is effected, said processing means including means for checking whether the data stored in said nonvolatile memory means has reached a value corresponding to a service life of said photosensitive unit, and means for generating a replacement requiring signal when said checking means detects that the data stored in said nonvolatile memory means has reached said value,

wherein said nonvolatile memory means is a nonvolatile memory card, and said processing means includes a connecting section to which said nonvolatile memory card is removably attached; and

stopper means for preventing removal of said nonvolatile memory card when the photosensitive unit has been set in the printing device.