SHARP SP1903 Technical Report

Date: Jul. 19, 1995

COPIER : Z-20

1. PREVENTION OF JAM DISPLAYS DUE TO STATIC ELECTRICITY DISCHARGE.

2. CHANGE IN SPRINGS AND DISCONTINUANCE OF WASHERS IN THE DRIVE
UNIT TO IMPROVE PRODUCTIVITY.

3. DISCONTINUANCE OF WASHERS IN THE FAN TO IMPROVE PRODUCTIVITY.

No. : SP-1903

1. Prevention of JAM displays due to static electricity discharge.

1.Model name: Z-20/25/27

2.General: Static electricity discharge in the main motor section occasionally causes the jam

display even though no feeding jam has occurred. To alleviate this problem, the
following measures were taken.

3.Description: (1)<Temporary measure>
A copper plate has been added and static electricity on the motor shaft has been
grounded in motors made in China to alleviate the problem described above.

Copper plate

This preventive measure was implemented from 1994 mid-August production to 1994
mid-November production. The problem described above has not occurred in
machines produced before this period because the motors were made in Japan. The
permanent measure described below was implemented directly to the motors in
machines produced after 1994 mid-November, and the copper ground plate was
discontinued.

SHARP CORPORATION Reprography Division

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Green

C

(2)<Permanent measure>

An conductor washer has been added between the shaft and the electrode brush in the
motor section. The static electricity on the shaft is discharged to the brush electrode,
preventing static electricity buildup on the shaft.

Conductor washer

Brush electrode

<Note>

The inscription label attached to the main motor (shown in the
figure to the right) has a blue line printed for units with the temporary
measure implemented. Labels attached to units with the permanent
measure implemented are entirely blue.

The main motors offered as service parts are made in Japan, and no changes in parts
codes have been carried out. Furthermore, the temporary measures described above
are not necessary.

4.Action: From 1994 mid-November production.

Magnet

Rotor

Magnet

Shaft

HOSIDEN
R3614

Blue line

2. Change in springs and discon tinuance of washer s in the drive un it to improve produ ctivity.

1.Model name: Z-20/25/27

2.General: The washers have been discontinued in the drive unit ad the springs have been

changed to improve productivity. In accordance with these changes the parts codes of
the drive unit have also been changed.

3.Description:

(Old) (New)

PS Brake SP

(Shaft length: 13 mm)

2 Washers
PS Brake SP

PS Brake SP-N

(Shaft length: 19.6 mm)

PS Brake SP-N

4.Action: From the start of 1994 December production.

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