A printer comprises a print head comprising nozzles to selectively deposit liquid drops to selected portions of a receiving surface, a radiation light source to supply first light to the receiving surface, and a drop detector. The drop detector detects a flying liquid drop ejected by one of the nozzles and comprises a detector light source to emit a light beam of second light and a light detector to detect the light beam of the second light. The second light is distinguishable by the drop detector from the first light.

A directionality detector is configured for use in an inkjet printer to attenuate the effects of ink drying in the nozzles of a printhead during printing operations. The directionality detector includes an optical sensor that generates image data of a test pattern formed on media by the printer, a diffuser that emits humidified air toward the media before the media is printed, and a controller operatively connected to the optical sensor and diffuser. The controller is configured compare the image data of the test pattern to stored image data of the test pattern printed at a previous time and determine whether any difference between the two images is greater than a predetermined threshold. The controller then operates the diffuser to direct humidified air toward the media passing the diffuser using the differences between the stored image data of the test pattern and the image data of the test pattern.

A directionality detector is configured for use in an inkjet printer to attenuate the effects of ink drying in the nozzles of a printhead during printing operations. The directionality detector includes an optical sensor that generates image data of a test pattern formed on media by the printer, a diffuser that emits humidified air toward the media before the media is printed, and a controller operatively connected to the optical sensor and diffuser. The controller is configured compare the image data of the test pattern to stored image data of the test pattern printed at a previous time and determine whether any difference between the two images is greater than a predetermined threshold. The controller then operates the diffuser to direct humidified air toward the media passing the diffuser using the differences between the stored image data of the test pattern and the image data of the test pattern.

Provided are a method for operating a CIJ printer with an optical monitoring means (80) having the steps of generating a bitmap (90,180) of the printed image to be printed, sequential controlling of charge electrodes (25) and/or deflection electrodes (30) of the CIJ printer, in order to generate dots or groups of dots of the bitmap (90,190) by applying ink droplets (12) to a substrate (100) to be printed and thus to sequentially apply a real printed image (195) to the substrate (100), capturing the real printed image (195) applied to the substrate (100) with the optical monitoring means (80), and automated comparing of the bitmap (90,190) of the desired printed image and of the real printed image (195) which has been applied to the substrate (100) and has been captured with the optical monitoring means (80), wherein the bitmap (90,190) of the desired printed image and the real image applied to the substrate (100) are automatically compared either on the basis of rows or columns of the bitmap (90,190) or on the basis of components of rows or columns of the bitmap (90,190), a CIJ printer for carrying out such a method and a method for teaching-in an optical monitoring means (80) of such a CIJ printer.

Provided are a method for operating a CIJ printer with an optical monitoring means (80) having the steps of generating a bitmap (90,180) of the printed image to be printed, sequential controlling of charge electrodes (25) and/or deflection electrodes (30) of the CIJ printer, in order to generate dots or groups of dots of the bitmap (90,190) by applying ink droplets (12) to a substrate (100) to be printed and thus to sequentially apply a real printed image (195) to the substrate (100), capturing the real printed image (195) applied to the substrate (100) with the optical monitoring means (80), and automated comparing of the bitmap (90,190) of the desired printed image and of the real printed image (195) which has been applied to the substrate (100) and has been captured with the optical monitoring means (80), wherein the bitmap (90,190) of the desired printed image and the real image applied to the substrate (100) are automatically compared either on the basis of rows or columns of the bitmap (90,190) or on the basis of components of rows or columns of the bitmap (90,190), a CIJ printer for carrying out such a method and a method for teaching-in an optical monitoring means (80) of such a CIJ printer.

In some examples, a fluid dispensing device includes a plurality of fluidic actuators, activate data storage elements, and sense measurement storage elements. The fluid dispensing device includes a decoder to detect, based on a first activate indicator of the activate indicators, that a first fluidic actuator is to be activated, detect, based on a first sense measurement indicator of the sense measurement indicators that a sense measurement is to be performed on the first fluidic actuator, and in response to detecting that the first fluidic actuator is to be activated and the sense measurement is to be performed on the first fluidic actuator, suppress activation of the first fluidic actuator at a first time, and activate the first fluidic actuator at a second time corresponding to a sense measurement interval to perform the sense measurement of the first fluidic actuator.

In some examples, a fluid dispensing device includes a plurality of fluidic actuators, activate data storage elements, and sense measurement storage elements. The fluid dispensing device includes a decoder to detect, based on a first activate indicator of the activate indicators, that a first fluidic actuator is to be activated, detect, based on a first sense measurement indicator of the sense measurement indicators that a sense measurement is to be performed on the first fluidic actuator, and in response to detecting that the first fluidic actuator is to be activated and the sense measurement is to be performed on the first fluidic actuator, suppress activation of the first fluidic actuator at a first time, and activate the first fluidic actuator at a second time corresponding to a sense measurement interval to perform the sense measurement of the first fluidic actuator.

In some examples, a system includes a device support to receive a fluid dispensing device, and a controller to identify, based on data controlling activation of fluidic actuators, a fluidic actuator that is to be activated in a first activation cycle of a group of activation cycles that correspond to activation intervals of respective fluidic actuators of a group of fluidic actuators of the fluid dispensing device, the identified fluidic actuator being part of the group of fluidic actuators. To perform a sense measurement for the identified fluidic actuator, the controller suppresses activation of the identified fluidic actuator in the first activation cycle, and causes activation of the identified fluidic actuator in a sense measurement cycle different from the first activation cycle, the sense measurement cycle being part of the group of activation cycles.

In some examples, a system includes a device support to receive a fluid dispensing device, and a controller to identify, based on data controlling activation of fluidic actuators, a fluidic actuator that is to be activated in a first activation cycle of a group of activation cycles that correspond to activation intervals of respective fluidic actuators of a group of fluidic actuators of the fluid dispensing device, the identified fluidic actuator being part of the group of fluidic actuators. To perform a sense measurement for the identified fluidic actuator, the controller suppresses activation of the identified fluidic actuator in the first activation cycle, and causes activation of the identified fluidic actuator in a sense measurement cycle different from the first activation cycle, the sense measurement cycle being part of the group of activation cycles.

A cap is positioned to contact a printhead when the printhead is not ejecting liquid ink. The cap and the printhead create a sealed space adjacent printhead nozzles when contacting each other. A flexible blade is positioned to contact the printhead when the printhead is not in contact with the cap. The flexible blade is adapted to fold over to spread a liquid solution on the nozzles in a first direction, and the flexible blade is adapted to remove excess amounts of the liquid solution from the nozzles in a second direction. A humidifier is connected to the cap and adapted to supply a moisture form of the liquid solution to the sealed space. A moisture sensor is connected to the cap. The humidifier is adapted to vary supply of the moisture to the sealed space based on the amount of moisture detected by the moisture sensor.