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AN 'INSTANT ON' APPROACH TO HEAT MANAGEMENT OF THERMAL INK JET PRINTHEADS

IP.com Disclosure Number: IPCOM000026229D
Original Publication Date: 1990-Dec-31
Included in the Prior Art Database: 2004-Apr-05
Document File: 4 page(s) / 168K

Publishing Venue

Xerox Disclosure Journal

Abstract

Generally, methods of heat management of thermal ink jet printheads require that the entire printhead structure be heated and then maintained at the "print-ready" temperature of, for example, 45°C. If the printhead is not maintained at the desired temperature, then a certain waiting period is necessary every time the printer is called on to print. With the method below, it is not necessary to wait until the entire system is warmed up, and power can be completely cut off when no printing is carried out.

This text was extracted from a PDF file.
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This is the abbreviated version, containing approximately 56% of the total text.

Page 1 of 4

XEROX DISCLOSURE JOURNAL

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AN 'INSTANT ON' APPROACH TO HEAT MANAGEMENT OF U.S. C1.346/140R THERMAL INK JET PRINTHEADS
Narayan V. Deshpande

Proposed Classification

Int. C1. Gold 15/18

T

THEAD TEMPERATURE

----__

K TEMPERATURE

TOTAL POWER

P
0

  w E 0 40 80 120 160 200 240 R
(SEC.) TIME (WATTS)

FIG. I

XEROX DISCLOSURE JOURNAL - Vol15 No 6 NovembedDecember 1990 419

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Page 2 of 4

AN 'INSTANT ON' APPROACH TO HEAT MANAGEMENT OF THERMAL INK JET PRINTHEADS(Cont'd)

I

T

E M

P

E

R

A

T

U R

E

(DEG C) 20 -

OR

0

W 0

6o 1

40 I---------- ---_- -1-5-A*-

30 f'cxSINK TEMPERATURE

TOTAL POWER

PRINTING -\/

POWER

RINTHEAD TEMPE TURE

I f

FIG. 2

420 XEROX DISCLOSURE JOURNAL - Vol15 No 6 NovernbedDecember 1990

[This page contains 1 picture or other non-text object]

Page 3 of 4

AN 'INSTANT ON' APPROACH TO HEAT MANAGEMENT OF THERMAL INK JET PRINTHEADS(Cont'd)

Generally, methods of heat management of thermal ink jet printheads require that the entire printhead structure be heated and then maintained at the "print-ready" temperature of, for example, 45°C. If the printhead is not maintained at the desired temperature, then a certain waiting period is necessary every time the printer is called on to print. With the method below, it is not necessary to wait until the entire system is warmed up, and power can be completely cut off when no printing is carried out.

For a two component printhead (not shown) of the type disclosed in U.S. Patent Re. 32,572 to Hawkins et al, comprising mated channel plate and heating element chip, the temperature of the chip, the temperature of the portion of a heat sink member (not shown) nearest the chip, and the ambient temperature must be monitored (or their temperature differences) to meter the power going into the chip. An algorithm can be developed to control the temperature of the chip, and the success of this approach will depend upon how accurately this procedure can be implemented in the machine. Because of the small mass of the chip, its temperature is very sensitive to the power put into it.

Theoretical modeling has shown that the best way to manage the temperature control of the printhead is to place a large capacity heater directly on the printhead chip. The idea of placing a heater on the chip is not new, but the idea appeared to be impractical because of the objectionably high warm-up time required to bring the printhead assembly to "print-ready" states for any given set of ambient temperature conditions. Controlling the temperature not only eliminates this problem but also eliminates the need to add power to the printhead structure constantly to maintain it at the "print-ready" temperature. This is possible because of the very short time needed to bring the printhead at the desir...