Ricoh B230 Service Manual

							 
SM 6-43 B230/B237 
Detailed 
Descriptions 
From Image Transfer Belt Unit 
 
The toner collection auger [A] moves the used toner from the image transfer belt and the 
used toner drops into the toner collection duct [B]. The toner collection coil [C] moves the 
used toner to the opening [D] at the rear of the toner collection bottle. The toner transport 
motor [E] drives the toner collection coil. 
Used Toner Distribution Mechanism 
 
The toner collection bottle has two openings (front and rear). The opening at the front is for 
the toner from the PCUs, and the opening at the rear is for the toner from the image 
transfer belt.   
To distribute the toner inside the bottle evenly, the auger [A] moves the toner to the center 
area. The mixing auger has two spirals in different directions. As a result, it is possible to 
gather the toner in the center area of the toner collection bottle even if the mixing auger 
always rotates in the same direction. The toner transport motor [B] drives the mixing auger 
via a timing belt and gears.  
						

							 
B230/B237 6-44  SM 
6.8.2 TONER COLLECTION BOTTLE SET/ NEAR-FULL/ FULL 
DETECTION 
 
The toner collection bottle has a projection at its rear side. When the toner collection bottle 
is set, this projection pushes the waste toner bottle set switch at the rear of the machine. As 
a result, the machine detects that the toner collection bottle is installed. 
The bottle near-full/full detection mechanism is above the bottle. When the used toner 
pushes up the used toner feeler [A], the waste toner sensor [B] turns off   
At this time, the machine detects that the toner collection bottle is almost full, and displays 
a message. 
After this, when 500 sheets of paper have been copied, the machine detects that the toner 
collection bottle is full, and the machine stops.  
						

							 
SM 6-45 B230/B237 
Detailed 
Descriptions 
6.9  IMAGE TRANSFER AND PAPER SEPARATION 
6.9.1 IMAGE TRANSFER 
Overview 
 
 
1. Image transfer belt (ITB) 
2. ID sensor 
3. ITB drive roller 
4. Paper transfer roller 
5. Rotation encoder 6. Lubricant application roller 
7. Toner collection auger 
8. Cleaning blade 
9. Cleaning roller 
10. Image transfer roller 
 
The toner is moved from the four drums to the ITB by the four image transfer rollers. This is 
done with one rotation of the ITB (four toner images are super-imposed onto the belt). The 
arrow above the C and M drums on the diagram shows the direction of ITB rotation. 
The ITB drive roller then moves the four-color toner image from the transfer belt to the 
paper. The paper transfer roller is an idle roller. 
The cleaning unit in the transfer unit cleans the belt surface with the cleaning blade and 
roller. The used toner collected from the belt is transported to the toner collection bottle. 
There are seven ID sensors. Three of them are for the line position adjustment. Four of 
them are for process control.    
						

							 
B230/B237 6-46  SM 
ITB (Image Transfer Belt) Drive 
Drive Motor 
 
The ITB drive motor [A] drives the image transfer belt [B] and the cleaning unit via gears 
and the ITB drive roller [C]. The speed of ITB drive depends on the process line speed (see 
‘Laser Exposure – Optical Path’). 
Transfer belt speed control 
 
This machine uses the rotation encoder to control the transfer belt speed.     
The encoder [A] is on one of the rollers. This encoder checks the rotation speed of the 
image transfer belt. The controller analyzes the signals from the encoder. Then it adjusts 
the rotation speed of the image transfer belt. 
The encoder contains a disk that has 300 notches on its surface [B]. These notches are 
read by the sensor [C]. The controller counts the number of notches that the sensor has 
read in the unit of time. If the sensor has read an unusually large number of notches or an 
unusually small number of notches, the controller ignores such unusual signals. Therefore, 
incorrect reading does not affect the rotation speed.  
						

							 
SM 6-47 B230/B237 
Detailed 
Descriptions 
 
Filter H:   
The number of notches read by the sensor when the rotation speed of the transfer belt is at 
its highest possible value. 
Filter L:   
The number of notches read by the sensor when the rotation speed of the transfer belt is at 
its lowest possible value. 
ITB Current 
 
Each image transfer roller [A] applies current to the image transfer belt to attract the toner 
from each drum [B]. The high voltage supply board supplies current to the image transfer 
rollers and grounds the belt at roller [C]. 
The bias that is applied to the image transfer belt is automatically corrected for paper size, 
temperature (measured by the temperature/humidity sensor at the rear lower right side of 
the machine). 
The other rollers are grounded to neutralize the belt surface.  
						

							 
B230/B237 6-48  SM 
Transfer belt cleaning 
 
The ITB-cleaning unit removes toner (during printing) and the ID sensor patterns (during 
process control or automatic line position adjustment) on the belt. Belt cleaning is 
completed while the image transfer belt makes one rotation. The ITB drive motor drives the 
ITB-cleaning unit. 
The cleaning brush [A] always contacts the image transfer belt [B], and removes used toner 
from the belt. The cleaning blade [C] in the cleaning unit scrapes the toner off the image 
transfer belt. Then the toner collection auger [F] transports the toner towards the toner 
collection duct. 
The lubricant application roller [D] applies lubricant [E] to the image transfer belt to make 
toner removal easy. 
To drive the cleaning unit, the transfer belt rotates gear [G], and gears at the front of the 
transfer unit drive the auger [F] and the rollers [A, D] in the cleaning unit.  
						

							
 
SM 6-49 B230/B237 
Detailed 
Descriptions 
ITB (Image Transfer Belt) Contact 
 
Mechanism  
The ITB contact and release mechanism increas es the lifetime of the image transfer belt 
and drums. The drum for black always contacts the belt. But the image transfer belt moves 
away from the other drums during monochro me printing. In the standby mode, the image 
transfer belt contacts only the black drum. It  moves away from the black drum when you 
turn the release lever counterclockwise.   
When the machine prints a color page, the ma chine waits until the previous page has gone 
through the paper transfer unit. Then the ITB  contact motor [A] turns on and a cam [B] 
moves the left side [C] of the image transfer bel t downward, so that it contacts the other 
three drums.   
The machine does not release t he image transfer belt from the color drums during the job, 
even if a monochrome page comes again. This  is because the total printing speed reduces 
if the ITB changes position.  But, if you change SP 2907 003 away from the default setting 
of zero, the image transfer belt will move away  from the color drums if the number of 
consecutive black-and-white pr ints reaches the value of SP 2907 003. The belt moves 
away from the color drums if the job is inte rrupted by any error except a power failure.   
The image transfer belt contact sensor [D] detec ts if the image transfer belt contacts the 
color PCUs. 
 
ƒ   If a power failure occurs when the image transfe r belt is in contact with the drums, the 
belt stays in this position. If you want to  remove the image transfer belt unit while the 
power is still off, you must release the belt.  To do this, swing out the controller box and 
perform the following procedure: 
⇒
Rev. 09/2006 
						

							
 
B230/B237 6-50  SM 
 1.  Remove the Image Transfer Belt Contact Motor [A] (
 sec. 3.10.8). 
2.  Using needle nose pliers, turn  the Transfer Belt Contact Motor Shaft [B] until the flat 
surface of the shaft is facing up          . 
 
3.  Open the front cover of the machine and ens ure the Transfer Belt is away from the 
OPC units before removing. 
4.  To reinstall the Transfer Belt Contact Mo tor, first turn the shaft [B] until the flat 
surface is facing down     . 
5.  Reinstall the Transfer Belt Contact Motor. 
 
Transfer Belt Sensor   
The ITB contact sensor [D] oper ates as the detection sensor during machine initialization, 
and also as the position sensor  during machine operations.   
Before machine initialization, t he left side of the image transfer  belt is in the home position. 
When initialization starts, the IT B contact motor lowers the left side until the actuator has 
passed the sensor. Then ITB contact motor lifts  up the left side to its home position. This 
action actuates t he sensor in a certain pattern. 
The table lists the sens or actuation patterns. 
 
Machine status  Sensor pattern 
Initialization 
On  Off  On  Off  On 
Standby (Default)  On 
B/W printing  On Operation 
Color Printing  Off 
 
On: The actuator is  out of the sensor. 
Off: The actuator is  interrupting the sensor. 
[B] 
[A] 
⇒
Rev. 09/2006 
						

							 
SM 6-51 B230/B237 
Detailed 
Descriptions 
6.9.2  PAPER TRANSFER AND SEPARATION 
Overview 
 
 
1. Paper transfer roller 
2. Discharge plate 
3. ITB drive roller 4. Image transfer roller 
5. Image transfer belt 
6. OPC drum 
 
The paper transfer unit consists of the paper transfer roller and discharge plate. This unit 
completes the toner transfer to the paper.   
PTR (Paper Transfer Roller) Drive 
 
 
ƒ P.P.: Power Pack  
						

							 
B230/B237 6-52  SM 
The toner is moved from the OPC [A] onto the surface of the image transfer belt [B] by a 
positive charge from the image transfer roller (immediately above the drum, not shown 
here). The ITB drive roller [C], which is given a negative charge, pushes the toner to the 
paper [D].   
The paper transfer roller [E] presses the paper against the image transfer belt [B] (with a 
spring that is under tension from the paper transfer roller contact motor), and grounds the 
charge from the ITB drive roller [C]. (The paper transfer roller does not have a drive 
mechanism. This roller is driven by the image transfer belt.)   
 
Finally, the discharge plate [E], which is given an AC charge, discharges the paper. 
The discharge plate receives its charge from a different high voltage power supply board 
than the ITB drive roller. 
PTR (Paper Transfer Roller) Contact and Separation 
 
The paper transfer contact motor [A] keeps the paper transfer roller [B] in contact with the 
image transfer belt [C]. This motor has the paper transfer HP sensor [D] inside. The paper 
transfer HP sensor detects if the paper transfer roller is in contact with the image transfer 
belt. Only when the machine executes the line position adjustment or process control, the