Image reading device

An image reading device comprising:

• a reading unit;
• and
• a controller connected to the reading unit through a transmission path,
• wherein the controller includes:
• a first clock generator which generates a first reference clock;
• a second clock generator which generates a second reference clock;
• a line synchronizer which generates a line synchronization signal based on the first reference clock;
• a clock transmitter which transmits the line synchronization signal and a unit clock based on the first reference clock to the reading unit;
• and
• a processor which execute a process based on the second reference clock and which is synchronized with the line synchronization signal, and
• wherein the reading unit includes:
• a reading sensor which reads a document line by line based on the unit clock and the line synchronization signal,
• a data transmitter which transmits, to the controller, reading data obtained by quantizing a read image signal output from the reading sensor based on the unit clock, and
• a timing generator which generates, based on the unit clock, a driving timing signal used for driving the reading sensor and a transmission timing signal used for controlling the transmission timing of the reading data from the data transmitter.