A drive circuit which drives a capacitive load on the basis of a drive signal output from a node includes a first wire; a second wire; an amplification unit; a capacitor and a resistance element; a determination unit which determines whether or not a voltage of a differentiated drive signal is within a predetermined range in case where a magnitude of a voltage change of the signal is less than or equal to a threshold; and a voltage output unit which amplifies the a voltage of the signal by a predetermined multiple, for example, one time, and outputs the amplified signal toward the node in a case where it is determined that the voltage of the differentiated drive signal is within the predetermined range.

An image forming apparatus includes a controller configured to, each time an unpaired first pattern element formed on a recording medium is conveyed over a particular distance in a conveyance direction in response to a conveyor rotating by a first amount, control an image former to form a second pattern element to be paired with the unpaired first pattern element thereby forming a first test pattern, and each time an unpaired third pattern element formed on the recording medium is conveyed over a specific distance in the conveyance direction in response to the conveyor rotating by a second amount, control the image former to form a fourth pattern element to be paired with the unpaired third pattern element thereby forming a second test pattern. At least one of the first and second amounts is a non-integer multiple of a rotation amount of the conveyor that makes a single rotation.

In a capacitive load drive circuit, a first driving signal generator generates a first driving signal from a first control signal according to a characteristic of a first capacitive load, and a second driving signal generator generates a second driving signal from a second control signal according to a characteristic of a second capacitive load. A control signal supply portion supplies a common control signal to the first driving signal generator and the second driving signal generator. The first driving signal generator corrects the common control signal to generate the first control signal, and the second driving signal generator corrects the common control signal to generate the second control signal.

The uniformity of performance of inkjet nozzles within a print head containing a plurality of said nozzles is optimized by characterizing one or more performance attributes of the nozzles within said print head. A waveform set is generated that comprises a plurality of waveforms to compensate for variations of the one or more performance attributes among the nozzles. One of the waveforms within the waveform set is assigned to each nozzle to optimize the one or more performance attributes of each nozzle relative to each other nozzle in the print head. Based upon the waveform assigned to each nozzle, each nozzle in the print head responds substantially uniformly relative to each other nozzle in the print head.

According to an embodiment the present invention, a printing apparatus detects a distance between a printhead and a print medium using a sensor while using a print medium for sensor calibration and changing a height from a print position to a carriage, stores first distance information indicating a relationship between the height and a signal representing a result of detecting the distance for each of heights in a memory, obtains second distance information indicating a relationship between the height and the signal representing the result of detecting the distance for each of the heights while using a predetermined print medium and changing the height, compares the first and second distance information, and corrects the first distance information stored in the memory, based on a result of the comparison.

A printing system includes a storage unit, a print unit and a control unit. The storage unit includes a print media catalog including a list of print media, each print medium in the list having a plurality of media attribute values characterizing the print medium, and each print medium categorized in at least one group based on at least one media attribute value. The print unit includes a print head for ejecting marking material on a print medium of the list. The control unit is configured to control the printing on a print medium of the list according to a plurality of optimization parameters, an optimization parameter being related to the at least one media attribute value used for categorization in a group of the at least one group. Upon receipt of a value of a particular optimization parameter for a print medium categorized in a particular group of the at least one group, the received value is automatically propagated to other print media categorized in the same particular group. A method is suitable for application in the printing system.

An inkjet head includes a plurality of head units including a first head unit and a second head unit. Each head unit has a plurality of nozzles and a plurality of drive elements. The second head unit has an ejection performance of nozzles lower than an ejection performance of nozzles of the first head unit. The second head unit is farther from a center portion of the inkjet head than the first head unit is. A drive unit is configured to apply a drive voltage for generating energy to each of the plurality of drive elements included in each of the plurality of head units. The drive voltage applied to each of the plurality of drive elements included in the first head unit is lower than the drive voltage applied to each of the plurality of drive elements included in the second head unit.

In a capacitive load drive circuit, a first driving signal generator generates a first driving signal from a first control signal according to a characteristic of a first capacitive load, and a second driving signal generator generates a second driving signal from a second control signal according to a characteristic of a second capacitive load. A control signal supply portion supplies a common control signal to the first driving signal generator and the second driving signal generator. The first driving signal generator corrects the common control signal to generate the first control signal, and the second driving signal generator corrects the common control signal to generate the second control signal.

A printing system includes a storage unit, a print unit and a control unit. The storage unit includes a print media catalog including a list of print media, each print medium in the list having a plurality of media attribute values characterizing the print medium, and each print medium categorized in at least one group based on at least one media attribute value. The print unit includes a print head for ejecting marking material on a print medium of the list. The control unit is configured to control the printing on a print medium of the list according to a plurality of optimization parameters, an optimization parameter being related to the at least one media attribute value used for categorization in a group of the at least one group. Upon receipt of a value of a particular optimization parameter for a print medium categorized in a particular group of the at least one group, the received value is automatically propagated to other print media categorized in the same particular group. A method is suitable for application in the printing system.

A liquid discharge apparatus includes an actuator element configured and arranged to receive a drive signal to discharge a liquid, the liquid being an ink including 0.1 wt % to 10 wt % of a polar solvent. The waveform of the drive signal supplied to the actuator element includes a non-rectangular shaped pulse with a ripple being formed in a falling portion of the non-rectangular shaped pulse.