In wait state, the CPU on the DC controller PCB measures the voltage level of the cartridge detection signal (CRGSNS) a specific number of times to check the

presence/absence of the drum unit when an AC bias is applied to the primary charging roller.

Toner Level Detection Mechanism

While the machine is in wait state, the toner level detection signal (ADDTNR; based on the comparison of the developing bias output and the antenna output inside

the cartridge) occurring when the developing AC bias is detected during normal rotation to monitor the toner level inside the cartridge.

3.1.5 Analog Processor PCB

iR1020J / iR1024J / iR1020 / iR1024 / iR1024A / iR1024N / iR1024F / iR1024i / iR1024iF

Image Processing Control Block

The analog image data read by the contact sensor is converted into digital image data and sent to the ASIC of the image processor PCB.

Drive Control Block

The drive control mechanism acts on the reader motor and the ADF motor by the motor drive IC of the analog processor PCB.

3.1.6 Power Supply PCB

iR1020J / iR1024J / iR1020 / iR1024 / iR1024A / iR1024N / iR1024F / iR1024i / iR1024iF

Switching Regulator

The following is generated using power from the power outlet for loads: +24DC, +5 VDC, +5VRDC, +3.3VDC, +3.3VRDC.

3.1.7 Relay PCB

iR1020J / iR1024J / iR1020 / iR1024 / iR1024A / iR1024N / iR1024F / iR1024i / iR1024iF

The signals from the sensors/solenoids/clutches are sent to the DC controller PCB through the relay PCB.

3.1.8 Control Panel PCB

iR1020J / iR1024J / iR1020 / iR1024 / iR1024A / iR1024N / iR1024F / iR1024i / iR1024iF

Key Detection and LCD/LED Drive

The keys are monitored, and the LCD and LEDs are driven.

LCD Function

The LCD is controlled according to the display signals from the image processor PCB.

Serial Communication Control

The state of the control keys is monitored based on serial communications with the image processor PCB. LCD and LED drive data are received.

3.1.9 NCU PCB (if equipped with fax functions)

iR1020J / iR1024J / iR1020 / iR1024 / iR1024A / iR1024N / iR1024F / iR1024i / iR1024iF

2-Line/4-Line Conversion Circuit

Signals from a 2-line telephone line are converted into 4-line signals (transmission signals and reception signals). Also, the transmission signals from the image

processor PCB are prevented from entering the reception circuit.

Dial Pulse Generation Circuit

The dial pulse generation circuit generates dial pulses by turning on and off the relay inside it according to the control signals from the image processor PCB. It

then sends the dial signals to the telephone line by way of the modular jack PCB.

Off-Hook Detection Circuit

An off-hook state is detected with reference to the direct current flowing into the circuit, occurring when the telephone connected to the telephone terminal of the

modular jack PCB is off the hook.

Line Voltage Conversion Circuit

The primary side of the NCU PCB is controlled using a line voltage of +48 VDC. In light of this, the DC component is cut by the capacitor, and only the audio

signals are converted into voltages suited to the modem level.

3.1.10 Network PCB (if equipped with network functions)

iR1020J / iR1024J / iR1020 / iR1024 / iR1024A / iR1024N / iR1024F / iR1024i / iR1024iF

The communications with the PC are controlled. The image data from the PC is converted into print data for the machine, and is sent to the image processor PCB.

3.1.11 Modular Jack PCB (if equipped with fax functions)

iR1020J / iR1024J / iR1020 / iR1024 / iR1024A / iR1024N / iR1024F / iR1024i / iR1024iF

The signals from the 2 modular jacks (for telephone line and telephone connection) are communicated to the line voltage conversion circuit of the NCU PCB, and

the signals from the fax are communicated to the telephone line.