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Browse Prior Art Database

Dot Matrix Printhead Module

IP.com Disclosure Number: IPCOM000035858D
Original Publication Date: 1989-Aug-01
Included in the Prior Art Database: 2005-Jan-28
Document File: 2 page(s) / 67K

Publishing Venue

IBM

Related People

Adachi, T: AUTHOR [+5]

Abstract

Disclosed is a compact, thermally efficient, and structurally stiff construction for a dot matrix print head that employs a sparse array of actuators. Head power is efficiently dissipated, increasing reliability.

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Dot Matrix Printhead Module

Disclosed is a compact, thermally efficient, and structurally stiff construction for a dot matrix print head that employs a sparse array of actuators. Head power is efficiently dissipated, increasing reliability.

The printhead * is composed of two interleaved rows of, for example, twelve cantilever beam actuators 10 with dots on their tips 11. Interleaving allows the beam tips to be close together. Pick and hold coils 9 are wound in place on a laminated stator 4 beneath each beam actuator 10. A cross section of the module is shown in the figure.

Improved heat dissipation is obtained by providing aluminum cooling fins 1 and 1A. The fins 1 and 1A are integrally cast with the surrounding frame 12. They stiffen the module and allow the use of lightweight sections. Even though the coils are interleaved, fins 1 and 1A straddle both sides of each coil in their non-overlapped regions, as shown in the figure. This provides a large area for heat transfer.

The small longitudinal gaps between each coil 9 and adjacent fins 1 and 1A are potted with thermally conductive epoxy to enhance heat transfer. To help equalize the temperatures of the coils and to avoid longitudinal hot spots, a partially-slotted-through rectangular copper bar 5 is in contact with the bottom of the stator. Bar 5 is held in position by the coils 9 wound in its slots 7. The heat from the copper bar 5 and fins 1 and 1A is conducted into a heat sink 3 at the bottom of frame 12. Fo...