Abstract: A method and compression unit for compressing a block of image data to satisfy a target level of compression, wherein the block of image data comprises a plurality of image element values, each image element value comprising one or more data values relating to a respective channel. For each of the channels: (i) an origin value for the channel for the block is determined, (ii) difference values are determined representing differences between the data values and the determined origin value for the channel for the block, and (iii) a first number of bits for losslessly representing a maximum difference value of the difference values for the channel for the block is determined.

Abstract: A decompression method determines image element values from compressed data representing a block of image element values relating to a respective one or more channels. For each of the channels, an indication of a first number of bits representing difference values between the data values and an origin value for the channel is read from the compressed data. For each of the channels, a second number of bits is obtained, wherein representations of the difference values for each of the channels are included in the compressed data using the second number of bits for that channel. The obtained second numbers of bits for the respective channels are used to read the representations of the difference values for the image element values being decompressed. Based on the representations of the difference values, a difference value is determined in accordance with the first number of bits for the channel.

Abstract: A method and compression unit for compressing a block of image data to satisfy a target level of compression, wherein the block of image data comprises a plurality of image element values, each image element value comprising one or more data values relating to a respective channel. For each of the channels: (i) an origin value for the channel for the block is determined, (ii) difference values are determined representing differences between the data values and the determined origin value for the channel for the block, and (iii) a first number of bits for losslessly representing a maximum difference value of the difference values for the channel for the block is determined.

Abstract: A decompression method determines image element values from compressed data representing a block of image element values relating to a respective one or more channels. For each of the channels, an indication of a first number of bits representing difference values between the data values and an origin value for the channel is read from the compressed data. For each of the channels, a second number of bits is obtained, wherein representations of the difference values for each of the channels are included in the compressed data using the second number of bits for that channel. The obtained second numbers of bits for the respective channels are used to read the representations of the difference values for the image element values being decompressed. Based on the representations of the difference values, a difference value is determined in accordance with the first number of bits for the channel.

Abstract: A method and compression unit for compressing a block of image data to satisfy a target level of compression, wherein the block of image data comprises a plurality of image element values, each image element value comprising one or more data values relating to a respective channel. For each of the channels: (i) an origin value for the channel for the block is determined, (ii) difference values are determined representing differences between the data values and the determined origin value for the channel for the block, and (iii) a first number of bits for losslessly representing a maximum difference value of the difference values for the channel for the block is determined.

Abstract: A method and compression unit for compressing a block of image data to satisfy a target level of compression, wherein the block of image data comprises a plurality of image element values, each image element value comprising one or more data values relating to a respective channel. For each of the channels: (i) an origin value for the channel for the block is determined, (ii) difference values are determined representing differences between the data values and the determined origin value for the channel for the block, and (iii) a first number of bits for losslessly representing a maximum difference value of the difference values for the channel for the block is determined.

Abstract: A decompression method determines image element values from compressed data representing a block of image element values relating to a respective one or more channels. For each of the channels, an indication of a first number of bits representing difference values between the data values and an origin value for the channel is read from the compressed data. For each of the channels, a second number of bits is obtained, wherein representations of the difference values for each of the channels are included in the compressed data using the second number of bits for that channel. The obtained second numbers of bits for the respective channels are used to read the representations of the difference values for the image element values being decompressed. Based on the representations of the difference values, a difference value is determined in accordance with the first number of bits for the channel.

Abstract: A method and decompression unit for performing decompression to determine image element values from compressed data representing a block of image element values each comprising one or more data values relating to a respective one or more channels. An indication of an origin value for each of the channels is read from the compressed data. For each of the channels, an indication of a first number of bits for representing difference values between the data values and the origin value for the channel is read from the compressed data. For each of the one or more channels, a second number of bits is obtained, wherein representations of the difference values for each of the channels are included in the compressed data using the second number of bits for that channel. The obtained second numbers of bits for the respective channels are used to read the representations of the difference values for the image element values being decompressed from the compressed data.

Abstract: A method and compression unit for compressing a block of image data to satisfy a target level of compression, wherein the block of image data comprises a plurality of image element values, each image element value comprising one or more data values relating to a respective channel. For each of the channels: (i) an origin value for the channel for the block is determined, (ii) difference values are determined representing differences between the data values and the determined origin value for the channel for the block, and (iii) a first number of bits for losslessly representing a maximum difference value of the difference values for the channel for the block is determined.

Abstract: A method and decompression unit for performing decompression to determine image element values from compressed data representing a block of image element values each comprising one or more data values relating to a respective one or more channels. An indication of an origin value for each of the channels is read from the compressed data. For each of the channels, an indication of a first number of bits for representing difference values between the data values and the origin value for the channel is read from the compressed data. For each of the one or more channels, a second number of bits is obtained, wherein representations of the difference values for each of the channels are included in the compressed data using the second number of bits for that channel. The obtained second numbers of bits for the respective channels are used to read the representations of the difference values for the image element values being decompressed from the compressed data.

Abstract: An inkjet printhead that has a support member, and a plurality of printhead IC's mounted adjacent each other on the support member. Each of the printhead IC's has an array of nozzles for ejecting drops of printing fluid onto a media substrate, and drive circuitry for driving the array of nozzles. A print engine controller (PEC) sends print data to each of the printhead IC's and the drive circuitry extracts a clock signal from the data transmission from the PEC.

Abstract: A printhead having at least first and second rows of print nozzle cells. Each each nozzle cell has an ink chamber, control circuitry and drive circuitry. Each nozzle cell in the first row has a corresponding nozzle cell in the second row. The drive circuitry of each nozzle cell of the first row is arranged adjacent the drive circuitry of the corresponding nozzle cell in the second row and distant the control circuitry of the corresponding nozzle cell in the first row.

Abstract: A printhead integrated circuit including a MEMS layer having a plurality of nozzle assemblies and a CMOS layer having control circuitry. Each nozzle assembly includes a heater element for ejecting ink and sensing a temperature of the nozzle assembly. The control circuitry modifies operation of the heater elements in response to a sensed temperature exceeding a predetermined threshold.

Abstract: A printhead IC is provided having an array of ejection nozzles, sensing circuitry for sensing temperatures of regions of the nozzle array, and drive circuitry for providing drive pulses to the nozzles to cause ejection. The drive circuitry is configured to set a different profile of the drive pulses for each region of the nozzle array in accordance with the sensed temperatures.

Abstract: A print engine controller for a pagewidth inkjet printhead having a plurality of abutting printhead modules mounted on a carrier. The print engine controller is configured to: (a) receive data identifying a rotational yaw displacement of an erroneously displaced printhead module; (b) determine a correction factor that compensates for ink dot displacement by nozzles in the erroneously displaced printhead module; (c) use the correction factor to determine an accumulative Y-offset for each printhead module in the printhead; and (d) alter the output of the ink dots from nozzles in each printhead module having a non-zero accumulative Y-offset to compensate for the rotational yaw displacement of the erroneously displaced printhead module.

Abstract: A printhead having at least first and second rows of print nozzle cells. Each each nozzle cell has an ink chamber, control circuitry and drive circuitry. Each nozzle cell in the first row has a corresponding nozzle cell in the second row. The drive circuitry of each nozzle cell of the first row is arranged adjacent the drive circuitry of the corresponding nozzle cell in the second row and distant the control circuitry of the corresponding nozzle cell in the first row.

Abstract: An inkjet printhead that has a support member, and a plurality of printhead IC's mounted adjacent each other on the support member. Each of the printhead IC's has an array of nozzles for ejecting drops of printing fluid onto a media substrate, and drive circuitry for driving the array of nozzles. A print engine controller (PEC) sends print data to each of the printhead IC's and the drive circuitry extracts a clock signal from the data transmission from the PEC.

Abstract: A printhead is provided having a plurality of rows of nozzles, with the nozzles in each row being grouped into fire groups, and a controller configured to fire the nozzles of each fire group by outputting firing pulses to the nozzles. The controller sets the number of fire groups in each row based on the width of the firing pulses and a predetermined length of time for firing all of the nozzles of that row.

Abstract: A printhead having at least first and second rows of print nozzles. Each nozzle has first circuitry of a first type arranged asymmetrically to second circuitry of a second type. The respective positions of the first and second circuitry of each nozzle of the first row are arranged mirrored with respect to the first and second circuitry of each nozzle of the second row.

Abstract: An inkjet printer that has a printhead IC an array of nozzles for ejecting drops of printing fluid onto a media substrate and drive circuitry for driving the array of nozzles and, a print engine controller (PEC) for sending print data to the printhead IC. The drive circuitry is configured to extract a clock signal from the data transmission from the PEC.