Liquid discharge apparatus, image forming apparatus, liquid discharge head, and operation method

A liquid discharge head comprising:

• multiple nozzles to discharge a liquid during a printing period;
• multiple pressure chambers respectively communicating with the multiple nozzles;
• a memory that stores a manufacturing history including a discharge history of each of the multiple nozzles at a time of manufacturing the multiple nozzles;
• and
• circuitry configured to:
• measure a residual vibration generated in each of the multiple pressure chambers during a printing period;
• and
• store, in the memory:
• a measurement frequency for each of the multiple nozzles set based on:
• the manufacturing history stored in the memory;
• and
• the residual vibration measured;
• and
• a target nozzle, to be measured during the printing period, selected from the multiple nozzles based on the measurement frequency.

An operation method comprising:

• storing, in a memory, a manufacturing history including a discharge history of each of multiple nozzles of a liquid discharge head to discharge a liquid during a printing period, at a time of manufacturing the multiple nozzles;
• and
• measuring a residual vibration generated in each of multiple pressure chambers of the liquid discharge head, during a non-printing period;
• setting a measurement frequency for each of the multiple nozzles based on:
• the manufacturing history stored in the memory;
• and
• the residual vibration measured;
• and
• selecting a target nozzle, to be measured during the printing period, from the multiple nozzles based on the measurement frequency.