Ricoh B230 Service Manual

							 
SM 6-33 B230/B237 
Detailed 
Descriptions 
Drum Charge and Quenching 
 
This machine uses a non-contact charge roller [A] to reduce ozone. The non-contact 
charge roller gives the drum surface a negative charge. The high voltage supply board – 
C.B, which is located at the rear of the machine, applies a dc and ac voltage (at a constant 
current) to the roller. The ac voltage helps to ensure that the charge given to the drum is as 
uniform as possible. 
The machine automatically controls the charge roller voltage if automatic process control is 
enabled (i.e., if SP3-041-1 is set to CONTROL). However, if process control is switched 
off, (i.e., if SP3-041-1 is set to FIXED), the dc voltage is the value stored in SP2-001-1 to 
-12 (do not adjust in the field unless advised to do so).   
The diameter of the charge roller is 12.5 mm (circumference about 39.3 mm). The gap 
between a drum and the corresponding charge roller is about 50 μm. 
The cleaning roller [B], which always contacts the charge roller, cleans the charge roller. 
Quenching is done by illuminating the whole area of the drum with the laser at the end of 
every job.  
						

							 
B230/B237 6-34  SM 
Drum Cleaning 
 
The cleaning blade [A] scrapes off the used toner that stays on the drum. The toner 
collection auger [B] transports the used toner towards the toner collection duct. Then it 
goes to the toner collection duct. The brush roller [C] put lubricant on the drum to make 
toner removal easy the next time the drum rotates past the cleaning blade.   
If the temperature is above the value of SP 3517, the drum reverses briefly at the end of the 
job to prevent the blade from flipping over. 
The brush roller rubs against the lubricant bar [D] and lubricates the drum surface. 
Lubricant is uniformly applied on the surface of the drum by the lubricant application blade 
[E].  
The toner collection auger [B] in each PCU is driven by gears [F] at the end of the drum. 
This toner then goes to the toner collection bottle (see section Toner Collection Path and 
Drive in this section).    
						

							 
SM 6-35 B230/B237 
Detailed 
Descriptions 
6.6.3 DEVELOPMENT 
Development Operation 
 
This machine uses a dual-component development system and has four development units 
(which are included in the drum units), one for each color. Each contains 225 g of 
developer when it is new. The developer in each unit is supplied to the development roller 
[A] by the two mixing augers [B] and attracted onto the surface of its roller.   
The TD sensor [C] in the development unit and four ID sensors above the ITB control toner 
density. Each development unit has a TD sensor. The TD sensor contains an ID chip in 
which some information about the development unit is stored. 
The diameter of the development roller is 18 mm (circumference about 56.5 mm).  
						

							 
B230/B237 6-36  SM 
Drive 
 
The drum/development drive motor-K [A] drives the development roller for black through 
gears and a clutch. The gear trains are shown in the diagram. 
The development drive motor-CMY [B] drives the development unit for magenta, cyan, and 
yellow through gears.   
Developer Agitation 
 
Two mixing augers [A] circulate the developer forward and backward to agitate the 
developer. 
This happens at the following times: 
ƒ  During process control self check 
ƒ During toner supply  
						

							 
SM 6-37 B230/B237 
Detailed 
Descriptions 
ƒ During development. 
Filters [B] on the top of the developer hopper make sure that the internal pressure does not 
become too high. These ducts are sealed not to let the toner solidify before installing.   
This development unit does not operate well if it placed in a condition of over 50°C during 
transportation. The toner inside the development unit can become solid at temperatures 
higher than this value. A developer initialization error shows if the toner does become solid. 
At this time, you must do the following procedure: 
 
ƒ  You should also do this procedure when you install a new development unit. 
1.  Remove the (old) development unit. 
2.  Keep the (new) development unit level and shake it several times from side to side.   
3.  Install it in the machine. 
Development Bias 
The PSU supplies development bias to the development roller via the receptacle at the rear 
of each development unit. 
There is a dc bias voltage. 
The machine automatically controls the dc bias if the automatic process control is enabled 
(i.e., if SP3-041-001 is set to 1: ON). However, if process control is switched off, (i.e., if 
SP3-041-001 is set to 0: OFF), the dc bias is the value stored in SP3-621-001 to -012 (do 
not adjust in the field unless advised to do so).   
New Unit Detection 
 
The TD sensor [A] in the development unit has an ID chip that contains the new unit 
detection flag. The machine detects that a PCU is new if the flag in the ID chip is activated.  
						

							 
B230/B237 6-38  SM 
The machine automatically does the following adjustments when detecting the new unit 
detection flag. 
ƒ  PM counter clear for items related to the PCU 
ƒ Developer initialization 
ƒ  Charge roller voltage control 
ƒ Process control 
ƒ  Line position adjustment 
If the PM counter clear fails, clear the following SPs manually. 
ƒ  SP3-902-1 to -4   
ƒ  SP3-902-5 to -8 
ƒ  SP3-902-9 to -12 
6.7 TONER SUPPLY 
6.7.1 OVERVIEW 
 
 
1. Toner bottle (each color) 
2. Memory chip (each color) 
3. Toner end sensor (each color) 4. Toner attraction pump (each color) 
5. Development unit (each color) 
6. TD sensor (each color) 
 
This machine uses four toner bottles. Each bottle has a spiral groove in it and its groove 
moves toner to the toner attraction pump. And the toner attraction pump transports the  
						

							 
SM 6-39 B230/B237 
Detailed 
Descriptions 
toner to the development unit. 
The toner end sensor is attached to the toner supply tube. The toner end sensor and the 
output from the process control define when the machine detects toner end. 
6.7.2  TONER SUPPLY MECHANISM 
Toner supply from toner bottle to toner attraction pump 
 
The toner transport motor [A] rotates the toner bottle-Bk via gears and a clutch. It also 
rotates the toner bottle-Y, -C, -M via gears, clutches and timing belts.   
Each bottle has a spiral groove, and this groove moves toner to the mouth [B] of the bottle. 
Here, toner spills into a hopper [C]. The opening [D] of the toner hopper is normally closed 
if the toner bottle is not installed in the machine. When the toner bottle is installed in the 
machine, the transport tube [E] pushes the toner hopper shutter [F] and then the opening of 
the toner hopper is open.   
The toner passes part of the way along the transport tube towards the toner attraction 
pump. The toner goes through the toner end sensor [G].   
Toner Near End Detection 
The toner end sensors [G] detect toner near end conditions (  Toner Near End/Toner 
End Detection in this section).  
						

							 
B230/B237 6-40  SM 
Toner supply from toner attraction pump to development unit 
 
Each toner attraction pump [A] is driven by the toner transport motor [B]. Each toner 
attraction pump has the same mechanism. The pump (toner attraction pump) has the 
following components:   
ƒ  Toner supply clutch [C] 
ƒ Rubber tube  
ƒ Rotor [D] 
The above components attract the toner in the toner transport tube [E] toward the 
development unit. 
The toner supply clutch controls the rotor, which draws the toner in from the cartridge and 
passes it to the development unit. When supplying toner, the clutch turns on and off as 
many times as necessary to supply the necessary amount of toner. The amount of toner 
depends on the results of toner supply control. 
Shutter Mechanism 
The development unit and toner attraction pump each have a shutter mechanism. The 
shutter [F] on the pump opens when the development unit is placed in the machine. At the 
same time, the pump opens the shutter [G] in the development unit. When both shutters 
are open, toner can enter the development unit from the toner attraction pump. 
The shutter springs pull and close the shutter when the development unit is removed.  
						

							 
SM 6-41 B230/B237 
Detailed 
Descriptions 
6.7.3 TONER CARTRIDGE 
RFID (Radio Frequency ID) 
 
Each toner cartridge of this machine has a RFID chip [A]. This stores the total “on” time of 
the toner supply clutch. This is used to calculate the amount of toner remaining in the toner 
cartridge. The chip is also used to detect whether the cartridge is installed (if the cartridge 
is not installed, the machine does not detect a signal from the memory chip). 
The RFID transmits its data to the RFID antenna board [B] without any contact.    
						

							 
B230/B237 6-42  SM 
6.8  WASTE TONER COLLECTION 
6.8.1 TONER COLLECTION PATH AND DRIVE 
From PCU 
 
The used toner from the collection augers in the four PCUs drops into the toner collection 
duct from the four openings [A][B][C][D] at the front of the PCUs. The toner collection auger 
[E] in the duct transports this used toner towards the toner collection bottle [F]. The coil [E] 
is driven by the toner transport motor [G]. The openings and PCUs correspond as follows:   
Yellow 
 [A], Cyan  [B], Magenta  [C], Black  [D].