Incremental printing of symbolic information – Electric marking apparatus or processes – Electrostatic
Reexamination Certificate
2002-12-12
2004-08-17
Hirshfeld, Andrew H. (Department: 2854)
Incremental printing of symbolic information
Electric marking apparatus or processes
Electrostatic
C399S075000, C399S090000
Reexamination Certificate
active
06778197
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an image forming apparatus such as a laser printer or a copying machine that forms an image by an electrophotographic process and, in particular, to an apparatus having various electric substrates.
2. Related Background Art
An example of a configuration of functional components in a conventional laser printer is shown in FIG.
5
.
FIG. 5
is a sectional view of a conventional image recording apparatus. As shown in
FIG. 5
, the image recording apparatus has an engine control substrate
11
for controlling a printer engine, an image controller substrate
12
for generating bit map data to modulate ON/OFF a semiconductor laser based on image data sent from a host computer (not shown), a scanner unit
13
constituted by a semiconductor laser, a laser driving circuit, a horizontal synchronizing signal generation circuit, a polygon motor, a lens, a turnback mirror or the like, a process cartridge
14
constituted by a photosensitive drum, a charging roller, a developing device, a cleaner container or the like, a conveying path
15
for feeding and conveying a recording sheet, and a motor
16
functioning as a driving source for driving means for driving the conveying path
15
.
In the image recording apparatus having the structure shown in
FIG. 5
, the engine control board
11
is arranged in a planar state below the conveying path
15
, the image controller board
12
is arranged further below the engine control board
11
, the scanner unit
13
is arranged above the conveying path
15
, and the process cartridge
14
is arranged between the conveying path
15
and the scanner unit
13
.
FIG. 6
is a functional block diagram of each circuit board. As shown in
FIG. 6
, the engine control board
11
is constituted by a switching power supply circuit part
11
a
, a motor driver circuit part
11
b
for performing sheet conveyance driving or the like, a high voltage power supply circuit part
11
c
necessary for an electrophotographic process, and an engine control circuit part
11
d
including a processor for controlling each driving circuit.
In addition, the image controller board
12
is constituted by a processor for generating bit map data to modulate ON/OFF the semiconductor laser based on image data from the host computer and communicating with an engine control circuit, a control ROM, an RAM
12
a
for temporarily storing the bit map data or the like.
The scanner unit
13
is constituted by a semiconductor laser driving circuit part
13
a
for driving the semiconductor laser based on the ON/OFF data from the image controller board
12
, a polygon scanner
13
b
for horizontally scanning laser beams from the semiconductor laser on the photosensitive drum, a not-shown BD sensor for generating a horizontal synchronizing signal, and the like. The above is an example of the structure of the conventional image recording apparatus such as a laser printer.
However, in the above-mentioned conventional image recording apparatus, the engine control board
11
and the image controller board
12
are arranged in a planar state below the conveying path
15
, and the scanner unit
13
is arranged above the conveying path
15
. Thus, the engine control board
11
or the image controller board
12
and the scanner unit
13
are connected by a bundled line (cable or jumper)
17
, FFC, or the like. Since the engine control substrate
11
or the image controller substrate
12
and the scanner unit
13
are arranged far from each other, wiring for them is long. In particular, since high resolution of a laser printer has been advanced in recent years, a frequency of a laser ON/OFF signal (VDO) has also become high. As a result, radiation field noises (RFI) have increased, and it tends to be difficult to cope with the radiation field noises.
In order to cope with the radiation field noises, a ferrite core is used in a bundled line or a shield electric wire is used, which leads to significant increase in costs.
Moreover, in the conventional image recording apparatus shown in
FIGS. 5 and 6
, the switching power supply circuit part
11
a
with a large heat value is arranged horizontally on a bottom surface of a main body of the image recording apparatus. Thus, heat radiation efficiency is low, and harmful effects such as deterioration of components and decrease in quality of an image due to increase in temperature in the apparatus are likely to occur. In addition, using air cooling means such as a fan in order to avoid the harmful effects leads to increase in costs.
SUMMARY OF THE INVENTION
An object of the present invention is to provide an image forming apparatus in which a high-frequency wiring part can be shortened to realize reduction of radiation field noises and costs for coping with the noises, and at the same time, heat radiation efficiency can be increased to prevent deterioration of components, degradation of an image quality, and the like due to increase in temperature in the apparatus.
Another object of the present invention is to provide an image forming apparatus including a driving circuit substrate for driving an apparatus main body, a control circuit substrate for controlling the apparatus main body, and an image controller substrate for controlling image data, in which the driving circuit substrate is connected to the control circuit substrate, and the control circuit substrate is connected to the image controller substrate, and in which the driving circuit substrate and the image controller substrate are provided substantially vertically, and the control circuit substrate is provided substantially horizontally.
Further objects of the present invention will be apparent in the following description.
REFERENCES:
patent: 5510827 (1996-04-01), Kubota et al.
patent: 6084622 (2000-07-01), Sugiura et al.
patent: 6151057 (2000-11-01), Yamazaki et al.
patent: 6477345 (2002-11-01), Kimura et al.
Fitzpatrick ,Cella, Harper & Scinto
Hinze Leo T.
Hirshfeld Andrew H.
LandOfFree
Image forming apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Image forming apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Image forming apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3356690