Printer including printhead capping mechanism

• US 20020051030A1
• Filed: 08/31/2001
• Published: 05/02/2002
• Est. Priority Date: 11/09/1998
• Status: Active Grant

• Current Assignee: Memjet Technology Ltd. (Memjet Limited)
• Original Assignee: Silverbrook Research Pty Limited
• Inventors: Silverbrook, Kia
• Granted Patent: US 6,547,368 B2
• Time in Patent Office: Days
• US Class Current: 347/32
• CPC Class Codes: B41J 2/16511 Constructions for cap positioning B41J2/16547 takes precedence
• CPC Class Codes: G06F 3/1296 Printer job scheduling or printer resource handling
• CPC Class Codes: G06K 15/02 using printers
• CPC Class Codes: G06K 15/1815 Receiving print data in mixed format
• CPC Class Codes: G06K 15/1852 involving combining data of different types
• CPC Class Codes: G06K 15/1856 characterized by its workflow

Abstract

This invention concerns a printhead capping mechanism for preventing evaporation of ink from a printhead when it is not in use. The invention has utility, for instance, in a color printer which uses a drop-on-demand inkjet printhead. The mechanism includes a cap fitted with an elastomeric seal to seal against the face of the printhead, and a sponge to catch drops ejected from the printhead during the nozzle cleaning cycle. The mechanism also includes an actuating structure operable to selectively move the cap between an engaged position to press against the printhead and a disengaged position spaced away from the printhead.

Claims

1. A printer comprising:

a circular drive wheel rotated in first and second opposite directions,

a printhead,

a capping mechanism for preventing evaporation of ink from said printhead, the capping mechanism comprising;

a printhead cap,

an actuating structure attached to said cap to selectively move said cap between a printhead engaging position and a disengaged position spaced away from said printhead, said actuating structure including a slip member having a fixed axis about which said actuating structure pivots, said slip member engaging with a surface of said drive wheel and gripping against said surface during at least a part of a revolution of said drive wheel in either of said first and second directions so as to effect pivotal movement of said cap about said axis between said printhead engaging position and said disengaged position, wherein further rotation of said drive wheel results in slipping of said slip member against said surface.

2. A printer according to claim 1, wherein said cap includes a capping plate which holds an elastomeric seal and a sponge.

3. A printer according to claim 2, wherein said elastomeric seal is shaped and sized to seal against said printhead when said cap is in said engaged position.

4. A printer according to claim 2, wherein said sponge is sized and positioned to catch any drops of ink emerging from said printhead when said cap is in said engaged position.

5. A printer according to claim 1, wherein the disengaged position of said cap is out of the paper path of the printer.

6. A printer according to claim 1 wherein said cap is spaced laterally away from said axis so that pivoting of said slip member about said axis causes movement of said cap between said engaged and disengaged positions.

7. A printer according to claim 1 wherein said drive wheel is coupled to a paper transport motor of the printer such that when printing is occurring said slip member is driven to cause said cap to move to said disengaged position.

8. A printer according to claim 7 wherein said drive wheel is coupled to the paper transport motor of the printer such that when printing stops said slip member is driven to cause said cap to move to said engaged position.

9. A printer according to claim 7, wherein a resilient member is used to assist in holding said cap in said engaged position.

10. A printer according to claim 9 including a rod to which said slip member is affixed, wherein said resilient member is included in a connection between the cap and the rod.

11. A printer according to claim 10, wherein said slip member is positioned at an end of said rod.

12. A printer according to claim 10, wherein said connection is a series of flexible arms.