Fluid ejection device with nozzle column data groups including drive bubble detect data

A fluid ejection device including a plurality of primitives each having a same set of addresses and including a plurality of fluid chambers, each fluid chamber corresponding to a different address of the set of addresses and including a firing mechanism. Input logic receives a series of fire pulse groups, each fire pulse group corresponding to an address of the set of addresses and including warming data having an enable value or a disable value and a series of firing bits, each firing bit corresponding to a different primitive and having a firing value or a non-firing value. For each firing bit of each fire pulse group, when the warming data has the enable value, activation logic provides a warming pulse to the firing mechanism of the fluid chamber corresponding to the firing bit when the firing bit has the non-firing value.

BACKGROUND

Fluid ejection devices typically include a number of fluid chambers, or firing chambers, having nozzles from which droplets of fluid (such as ink droplets, for example) are selectively ejected via controlled operation of drive bubble formation mechanisms (such as firing resistors, for example). During operation, conditions may arise that adversely affect the ability of ejection chambers and/or nozzles to properly eject fluid. For example, a blockage may occur in the nozzle or ejection chamber, or fluid may become solidified on the drive bubble formation mechanism. To detect such conditions, techniques, such as optical drop detect and drive bubble detect (DBD), for example, have been developed to assess nozzle integrity or health.

DETAILED DESCRIPTION

Fluid ejection devices typically include a number of fluid chambers having nozzles from which droplets of fluid are selectively ejected via controlled activation of drive bubble formation mechanisms. Drive bubble formation mechanisms may include thermal drive bubble formation mechanisms, such as resistors, and other types of drive bubble formation mechanisms, such as piezoelectric mechanisms, for examples. Together, a fluid chamber, nozzle, and drive bubble formation mechanism are sometimes referred to as a drop generator. In one example, a fluid ejection device may be implemented as an inkjet printhead for ejecting ink drops, such as onto a print media form a desired printed image.

Typically, the fluid chambers of a fluid ejecting device are arranged into groups of fluid chambers referred to as primitives, with the primitives further being organized in columns, with each primitive receiving a same set of addresses, and each fluid chamber of a primitive corresponding to a different one of the address of the set of addresses. In one example, print data, or more generally ejection data, to control the operation of the drive bubble formation mechanisms to selectively eject fluid droplets from the nozzle of the fluid chamber to form a desired printed image (such as on print medium, for example) is provided to the fluid ejection device in the form of a series of nozzle column data groups (NCGs), or more generally ejection column groups, with each NCG including a series of fire pulse groups (FPGs). In one example, each FPG corresponds to at least one address of the set of addresses and includes a different set of data bits for each address, and with each data bit of each set of data bits corresponding to a different primitive.

During fluid ejection device operation, conditions may arise that adversely affect the ability of ejection chambers and/or nozzles to properly eject fluid. For example, a blockage may occur in the nozzle or ejection chamber, or fluid, or components of the fluid, may become solidified on the drive bubble formation mechanism. To detect such conditions, techniques, such as optical drop detect and drive bubble detect (DBD), have been developed to assess the integrity or “health” of the nozzle, ejection chamber, and drive bubble formation mechanism. However, such techniques, including DBD, occur between print pages or print jobs which causes delays and reduces printer throughput.

FIG. 1is a block and schematic diagram generally illustrating a fluid ejection device114with nozzle column data groups242including both ejection data264and data for performing DBD operations262for ejection chambers150of fluid ejection device114, according to one example of the present disclosure. In one example, fluid ejection device114includes a plurality of primitives180, illustrated as primitives P1to PM, with each primitive180having a same set of addresses182, illustrated as addresses A1to AN, and each primitive180having a plurality of ejection chambers150. Each ejection chamber150corresponds to a different one of the addresses, A1to AN, of the set of addresses182and includes a drive bubble formation mechanism160and a DBD sensor mechanism164.

Input logic192receives a number or series240of nozzle column data groups (NCGs)242(e.g., from a controller110), with each NCG242including a series of fire pulse groups (FPG)244, with each FPG244including a DBD data262having an enable value or a disable value, and ejection data bits264, each ejection data bit corresponding to a different one of the primitives180(seeFIGS. 6 and 7below, for example).

Fluid ejection device114further includes activation logic190. In one example, for each FPG244of each NCG242of the series of NCGs240, activation logic190identifies the FPG244as a DBD FPG250when the DBD data262has the enable value, where the DBD FPG250corresponds to at least one address of the set of addresses182. When a DBD FPG250is identified, activations logic190activates, in each primitive, the drive bubble formation mechanism160of the ejection chamber150having the same address as the at least one address to which the DBD FPG250corresponds to form a drive bubble and to perform DBD sensing measurement if the corresponding ejection data bit264is set (seeFIG. 3Bbelow, for example).

As will be described in greater detail below, including DBD operations data in the form of FPGs in NCGs, in accordance with the present disclosure, enables DBD operations to be performed during ejection operations without reducing throughput of fluid ejection device114. For example, when fluid ejection device114is implemented as an inkjet printhead114, for instance, including data for performing DBD operations in the form of DBD FPGs250along with ejection data in the form of FPGs244enables DBD operations to be performed on ejection chambers150without reducing a number of pages printed by inkjet printhead114. Furthermore, in an instance where fluid ejection device114is implemented as an inkjet printhead114, even though ink drops will be ejected onto print media as part of performing a DBD operation, a print artifact resulting from such ink drop will be imperceptible to person viewing such image.

FIG. 2is a block and schematic diagram illustrating generally a fluid ejection system100including a fluid ejection device, such as a fluid ejection assembly102, including a number fluid chambers and employing NCGs (more generally, ejection column groups) which, in accordance with the present disclosure, include both ejection data and DBD data for directing DBD measurements of selected fluid chambers of fluid ejecting device102. In addition to fluid ejection assembly102, fluid ejecting system100includes a fluid supply assembly104including an fluid storage reservoir107, a mounting assembly106, a media transport assembly108, an electronic controller110, and at least one power supply112that provides power to the various electrical components of fluid ejecting system100.

Fluid ejecting assembly102includes, in accordance with the present disclosure, activation logic190and input logic192, such as described above, and includes at least one fluid ejection device114that ejects drops of fluid through a plurality of orifices or nozzles116, such as onto print media118. According to one example, as illustrated, fluid ejection device114may be implemented as an inkjet printhead114ejecting drops of ink onto print media118. Fluid ejection device114includes nozzles116, which are typically arranged in one or more columns or arrays, with groups of nozzles being organized to form primitives, and primitives arranged into primitive groups. Properly sequenced ejections of fluid drops from nozzles116result in characters, symbols or other graphics or images being printed on print media118as fluid ejecting assembly102and print media118are moved relative to one another.

Although broadly described herein with regard to a fluid ejection system100employing a fluid ejection device114, fluid ejection system100may be implement as an inkjet printing system100employing an inkjet printhead114, where inkjet printing system100may be implemented as a drop-on-demand thermal inkjet printing system with inkjet printhead114being a thermal inkjet (TIJ) printhead114. Additionally, the inclusion of DBD operations data in PCGs, according to the present disclosure, can be implemented in other printhead types as well, such wide array of TIJ printheads114and piezoelectric type printheads, for example. Furthermore, the inclusion of DBD operations data in PCGs, in accordance with the present disclosure, is not limited to inkjet printing devices, but may be applied to any digital fluid dispensing device, including 2D and 3D printheads, for example.

ReferencingFIG. 2, in operation, fluid typically flows from reservoir107to fluid ejection assembly102, with fluid supply assembly104and fluid ejection assembly102forming either a one-way fluid delivery system or a recirculating fluid delivery system. In a one-way fluid delivery system, all of the supplied to fluid ejection assembly102is consumed during printing. However, in a recirculating fluid delivery system, only a portion of the fluid supplied to fluid ejection assembly102is consumed during printing, with fluid not consumed during printing being returned to supply assembly104. Reservoir107may be removed, replaced, and/or refilled.

In one example, fluid supply assembly104supplies fluid under positive pressure through an fluid conditioning assembly11to fluid ejection assembly102via an interface connection, such as a supply tube. Fluid supply assembly includes, for example, a reservoir, pumps, and pressure regulators. Conditioning in the fluid conditioning assembly may include filtering, pre-heating, pressure surge absorption, and degassing, for example. Fluid is drawn under negative pressure from fluid ejection assembly102to the fluid supply assembly104. The pressure difference between an inlet and an outlet to fluid ejection assembly102is selected to achieve correct backpressure at nozzles116.

Mounting assembly106positions fluid ejection assembly102relative to media transport assembly108, and media transport assembly108positions print media118relative to fluid ejection assembly102, so that a print zone122is defined adjacent to nozzles116in an area between fluid ejection assembly102and print media118. In one example, fluid ejection assembly102is scanning type fluid ejection assembly. According to such example, mounting assembly106includes a carriage for moving fluid ejection assembly102relative to media transport assembly108to scan fluid ejection device114across printer media118. In another example, fluid ejection assembly102is a non-scanning type fluid ejection assembly. According to such example, mounting assembly106maintains fluid ejection assembly102at a fixed position relative to media transport assembly108, with media transport assembly108positioning print media118relative to fluid ejection assembly102.

Electronic controller110includes a processor (CPU)138, a memory140, firmware, software, and other electronics for communicating with and controlling fluid ejection assembly102, mounting assembly106, and media transport assembly108. Memory140can include volatile (e.g. RAM) and nonvolatile (e.g. ROM, hard disk, floppy disk, CD-ROM, etc.) memory components including computer/processor readable media that provide for storage of computer/processor executable coded instructions, data structures, program modules, and other data for fluid ejection system100.

Electronic controller110receives data124from a host system, such as a computer, and temporarily stores data124in a memory. Typically, data124is sent to fluid ejection system100along an electronic, infrared, optical, or other information transfer path. In one example, when fluid ejection system100is implemented as an inkjet printing system100, data124represents a file to be printed, such as a document, for instance, where data124forms a print job for inkjet printing system100and includes one or more print job commands and/or command parameters.

In one implementation, electronic controller110controls fluid ejection assembly102for ejection of fluid drops from nozzles116of fluid ejection device114. Electronic controller110defines a pattern of ejected fluid drops to be ejected from nozzles116and which, together, in the case of being implemented as an inkjet printhead, form characters, symbols, and/or other graphics or images on print media118based on the print job commands and/or command parameters from data124. In one example of the present disclosure, as will be described in greater detail below, electronic controller110provides ejection data in the form NCGs to fluid ejection assembly102which result in nozzles114ejecting the defined pattern of fluid drops. According to one example, as will be described in greater detail below, the NCGs include ejection data in the form of FPGs and DBD operations data in the form of DBD FPGs. In one example, the NCGs may be received by electronic controller110as data124from a host device (e.g., a print driver on a computer).

FIGS. 3A and 3Bare block and schematic diagrams generally showing a cross-sectional view of a portion of fluid ejection device114and illustrating an example of an ejection chamber150. Ejection chamber150is formed in a substrate152of fluid ejection device114and is in liquid communication with a fluid feed slot154via a fluid feed channel156which communicates fluid158from fluid feed slot154to ejection chamber150. A nozzle16extends through substrate152to vaporization chamber150.

According to one example, ejection chamber150includes a drive bubble formation mechanism160disposed there below in substrate152, such as a firing resistor160or other type of fluid ejector, for example. Firing resistor160is electrically coupled to ejection control circuitry162which controls the application of an electrical current to firing resistor162to form drive bubbles within fluid chamber158to eject fluid drops from nozzle16according to a defined drop pattern for forming an image on print media118(seeFIG. 2).

In one example, ejection chamber150includes a metal plate164(e.g. a tantalum (Ta) plate) which is disposed above firing resistor160and in contact with fluid (e.g., ink) within ejection chamber150, and which protects underlying firing resistor160from cavitation forces resulting from the generation and collapse of drive bubbles within ejection chamber150. In one example, metal plate164serves as a DBD sense plate164which is electrically coupled to DBD sense circuitry166, including a ground point165, for detecting the presence of a drive bubble within ejection chamber150, as described in greater detail below.

With reference toFIG. 3B, during printing operations (and more generally during fluid ejection operations), ejection control circuitry162provides a firing current iFto firing resistor160, which evaporates at least one component (e.g., water) of fluid158to form a gaseous drive bubble170in ejection chamber150. As gaseous drive bubble170increases in size, pressure increases in ejection chamber158until a capillary restraining force retaining fluid within ejection chamber158is overcome and a fluid droplet159is ejected from nozzle16. Upon ejection of fluid droplet159, drive bubble170collapses, heating of firing resistor160is ceased, and fluid158flows from slot154to refill ejection chamber158.

As described above, conditions may arise that adversely affect the ability of ejection chamber150and nozzle16to properly form and/or eject fluid droplets159. For example, blockages (either partial or complete) may occur in nozzle16and/or ejection chamber158, or fluid make become solidified on surfaces of fluid chamber158. Such conditions may result in an improperly firing nozzle such as a nozzle that fails to fire (i.e., ejects no fluid droplet), fires early, fires late, releases too much fluid, releases too little fluid, or combinations thereof.

DBD is one technique for monitoring the formation and ejection of drive bubbles170within ejection chamber150in order to assess the integrity or health of ejection chamber150, fluid channel156, nozzle16, and other components, such as firing resistor160, for example. According to one example, to perform a DBD operation, ejection control circuitry162provides a firing current iFto firing resistor160which begins heating fluid158within ejection chamber150and begins evaporate at least one component of fluid155(e.g., water) to form a drive bubble.

During generation of the drive bubble, DBD sense circuitry166provides a fixed sense current is to DBD sense plate164, with the current flowing through an impedance path168formed by the liquid fluid158and/or the gaseous material of drive bubble170to ground point165resulting in generation of a chamber voltage VDBDwhich is indicative of the characteristics of drive bubble170which, in-turn, is indicative of the health of ejection chamber150and the associated components. As drive bubble170expands, more of DBD sense plate160comes into contact with drive bubble170and the portions of impedance path168formed by fluid158and drive bubble170changes which results in changes in the impedance of impedance path168and, in-turn, in changes in the level of chamber voltage VDBD.

In one example, chamber voltage VDBDis continuously monitored, such as by controller110(or by logic on fluid ejection device114, or some combination thereof), during formation and collapse of drive bubble170(at ejection of fluid droplet159from nozzle16) and for a time period thereafter, and compared to known voltage profiles of chamber voltages VDBDwhich are indicative of various conditions of nozzle16(e.g., healthy nozzle, partially blocked nozzle, fully blocked nozzle) in order to assess the health of the nozzle. In one example, chamber voltage VDBDis measured at one or more selected points during the formation and collapse of drive bubble170and a time period thereafter, with the one or more selected points being compared to the known voltage profiles of healthy nozzles. If it is determined that a nozzle is misfiring, the controller, such as controller110, may implement servicing procedures or remove the nozzle from service and compensate by adjusting firing patterns of remaining nozzles, for instance.

FIG. 4is a block and schematic diagram generally illustrating a fluid ejection device114, according to one example, and which can be configured for use with NCGs including DBD operations data, in accordance with the present disclosure. Fluid ejection device114includes a number of ejection chambers150, each including a nozzle16, a firing resistor162, and a DBD sense plate164, with the ejection chambers being arranged in nozzle column groups178on each side of an fluid slot154(seeFIG. 3), with ejection chambers150grouped into a number of primitives180.

In the example ofFIG. 4, ejection chambers150are organized into primitives180, with a first group of M primitives, illustrated as primitives P(1) through P(M), arranged to form a nozzle column group178on the left-side of fluid slot154, and a second group of M primitives P(1) through P(M) disposed in a nozzle column group178on the right-side of fluid slot154. In the example ofFIG. 4, each primitive180includes “N” ejection chambers150, where N is an integer value (e.g. N=8). Each primitive180employs a same set of N addresses182, illustrated as addresses (A1) to (AN), with each ejection chamber150, along with its nozzle16, firing resistor162, and DBD sense plate164, corresponding to a different address of the set of addresses182so that, as described below, each ejection chamber150can be separately controlled within a primitive180. While illustrated as being arranged in columns along fluid slots, nozzles16and primitives180may be arranged in other configurations such as in an array where the fluid slot154is replaced with an array of fluid feed holes, for instance.

Although illustrated as each having the same number N ejection chambers150, it is noted that the number of ejection chambers150can vary from primitive to primitive. Additionally, although illustrated as having only a single fluid slot154with nozzle column groups178disposed on each side thereof, it is noted that fluid ejection devices, such as fluid ejection device114, may employ more than one fluid slot and more than two nozzle column groups.

FIGS. 5-8below are block and schematic diagrams generally illustrating portions of primitive drive and logic circuitry190of fluid ejection device114, and nozzle column data groups242with embedded DBD Fire Pulse Groups250which enable printing system100and fluid ejection device114to perform DBD operations during printing and servicing operations, according to examples of the present disclosure. As described below, primitive drive and logic circuitry190serves as activation logic for activating drive bubble formation mechanism160(e.g., firing resistors160) and drive bubble sensor mechanism164(e.g., DBD plate164) to perform a DBD operation in accordance with DBD FPG250.

With reference toFIG. 5, primitive drive and logic circuitry190is described with respect to a single nozzle column group, in this case, nozzle column group178on the left-hand side of fluid slot154having primitives P2to PM, with each primitive having N ejection chambers150, as generally illustrated above byFIG. 4. According to the example ofFIG. 5, primitive drive and logic circuit190includes input logic192, including a data buffer194and an address encoder196, a fire pulse generator198, and a DBD controller200including DBD sense circuitry202.

Data buffer194is coupled to a set of M data lines204, illustrated as data lines D1to DM, with one data line corresponding to each primitive180, and address encoder196is coupled to an address bus206. Fire pulse generator198generates a fire pulse on a fire pulse line208. DBD controller200is in communication with a DBD enable line210, and DBD sense circuitry202is coupled to a set of M DBD sense lines212, illustrated as DBD sense lines S1to SM, with one sense line corresponding to teach primitive180. Primitive drive and logic circuitry190further includes a primitive power line214and a ground line216.

Each ejection chamber150of each primitive180includes a firing resistor160(illustrated as firing resistors160-1to160-N) and a DBD sense plate164(illustrated as DBD sense plates164-1to164-N). Each firing resistor160is coupled between primitive power line214and ground line216via an activation device, such as a controllable switch220(e.g., a field effect transistor (FET)), illustrated as FETs220-1to220-N for each primitive180. Each DBD sense plate is coupled to ground line216via fluid in the corresponding ejection chamber (illustrated as a dashed line), and is coupled to the DDB sense line212corresponding to the particular primitive180via a controllable switch224, illustrated as FETs224-1to224-N for each primitive180.

Each ejection chamber150of a primitive180has a corresponding address decoder230(illustrated as address decoders230-1to230-N) coupled to address bus206to decode the address corresponding to the ejection chamber (i.e. one of the addresses A1to AN in this example). For each ejection chamber150of each primitive180, an AND-gate232(illustrated as AND-gates232-1to232-N) has inputs coupled to the output of the corresponding address decoder230, to the corresponding data line204, and to fire pulse line208, and an output coupled to the control gate of the corresponding switch220for controlling the associated firing resistor160. Also for each ejection chamber150of each primitive180, an AND-gate234(illustrated as AND-gates234-1to234-N) has inputs coupled to the output of the corresponding address decoder230, to the corresponding data line204, and to DBD enable line210, and an output coupled to the control gate of the corresponding switch224for controlling the DBD sense plate164.

In operation, fluid ejection device114receives nozzle ejection data in the form of a series of nozzle column data groups (NCGs), such as from electronic controller110(seeFIG. 2, for example).FIG. 6illustrates generally a series240of NCGs242, in accordance with one example of the present disclosure, with each NCG242including a series of nozzle fire pulse groups (FPGs)244, or simply FPGs244. In one example, as described in greater detail below, one or more FPGs244of one or more NCGs242of the series242may be a DBD FPG250.

FIG. 7is a block diagram generally illustrating an example of an FPG244in accordance with the present disclosure. As illustrated, FPG244includes a header portion252, a footer portion254, and an ejection data portion256. According to one example, header portion252includes address data258indicative of the ejection chamber address to which FPG244corresponds. In one example, in accordance with the present disclosure, header portion252includes DBD operations data260, including one or more DBD enable bits262having an enable value or a disable value. According to one example, when DBD enable bits262have a disable value, the FPG244is not a DBD FPG250. Conversely, when DBD enable bits262have an enable value, the FPG is a DBD FPG250. In one example, in addition to DBD enable bits262, DBD operations data260includes DBD parameters such as measurement delay settings (e.g., when during formation of drive bubble170are voltage measurement(s) taken), threshold settings for comparators, and sense current and/or voltage levels, for example.

In addition to address bits258and DBD operations data260, header portion252includes other information such a start and sync information, for example. Header portion254includes stop bits, among other data.

Ejection data portion256includes a series of data bits264, each data bit corresponding the address defined by address bits258and to a different one of the primitives180of a group of primitives forming a nozzle column group, such as nozzle column group178on the left-hand side of fluid slot154inFIG. 4. As will be described below, when DBD enable bits262have a disable value, the FGP is not a DBD FPG such that data bits264represent print data bits which are combined with the address and fire pulse to control firing of the corresponding firing resistor160. When DBD enable bits262have an enable value, the FPG is a DBD FPG250such that the data bits264represent DBD ejection data and are combined with the address, fire pulse, and DBD enable data to control firing resistor160and activation of the corresponding DBD sense plate164.

Returning toFIG. 6, according to one example, as illustrated, each NCG242includes a series of N FGPs244, with one FPG corresponding to each of the N addresses in a primitive (e.g., seeFIG. 5), and the one or more DBD FPGs250, in this case a single DBD FPG250, representing FPGs in addition to the N FPGs244.

In one example, each FPG244has a duration, with FPGs244each having a duration t1and DBD FPG250having a duration t2, where the durations t1of each FPG244and the duration t2of DBD FPG250together represent a duration tNCGof NCG242, where each NCG242of the series242has a same duration. In one example, the duration t1and duration t2are equal. In one example, duration t1and duration t2are different. For example, as illustrated, duration t2may be longer than duration t1.

FIGS. 8A and 8Bare block diagrams generally illustrate other examples of NCGs242.FIG. 8Aillustrates an example where, in addition to including a DBD FPG250, NCG252further includes an idle time251having a duration t3. In one example, idle time251is included in NCG252to maintain timing synchronization with the operation of other components of printing system100(e.g., registration of media118by media transport assembly, seeFIG. 3) which may vary depending on particular implements or configurations.FIG. 8Billustrates an example where NCG242does not include a DBD FPG250, but includes idle time251. In one example, regardless of whether NCG242includes a DBD FPG250, duration tNCGof each NCG242of the series240is the same.

In one example, with reference toFIGS. 6 and 7, for example, when a DBD operation is to be performed on one or more selected ejection chambers150of fluid ejection device114, electronic controller110(or other controller) inserts a DBD FPG250in a suitable NCG242, wherein DBD FPG250instructs primitive drive and logic circuitry190to perform DBD operations on identified nozzles as part of ongoing fluid ejection operations in accordance with the series of NPGs240. By including DBD FPGs250in a series of NPGs240, in accordance with the present disclosure, where each DBD FPG initiates performance of DBD measurements in one or more ejection chambers150, the integrity of all ejection chambers150can be assessed over several NCGs during a print job, thereby greatly lessening or eliminating reductions in throughput of fluid ejection device114and printing system100otherwise caused by conventional DBD operations.

Returning toFIG. 5, in operation, input logic192of fluid ejection device114receives nozzle ejection data256in the form of a series of nozzle column data groups (NCGs)240, such as from electronic controller110(seeFIG. 2, for example). For each FPG244, input logic192checks header252for the value of DBD enable bits262. In a first example scenario, when DBD enable bits262have a disable value, input logic192deems FPG244to not be a DBD FPG250and, as a result, does not pass DBD operations data260, including DBD enable bits262, to DBD controller200.

In such case, address data258is provided to address encoder196, which encodes the corresponding address onto address bus206, and data buffer194receives and places each of the data bits264from data portion256of FPG244onto its corresponding data line204, where, in the case of fluid ejection device114being an inkjet printhead, the print data on data lines204represents characters, symbols, and/or other graphics or images to be printed, such as onto a print media, for example.

The encoded address on address bus206is provided to each address encoder230-1to230-N of each primitive P1to PM, with each of the address decoders corresponding to the address encoded on address bus206providing an active output to corresponding AND-gates232and234. For example, if the encoded address from FPG244placed on address bus206represents address A1, address decoders230-1of each primitive P1to PM will provide an active output to corresponding AND-gates232-1and234-1.

AND-gates232-1to232-N of each primitive P1to PM receive outputs from corresponding address decoders230-1to230-N, from the corresponding one of the data lines D1to DM, and from fire pulse line208. If the corresponding address decoder is providing an active output, if print data is present on the corresponding data line (e.g. a “1”), and the fire pulse on fire pulse line208is active, the output of the AND-gate will activate its output and close the corresponding switch220, thereby energizing the firing resistor160to vaporize fluid in ejection chamber150and eject fluid from the associated nozzle16. Continuing with the above illustrative example, with address A1encoded on address bus206, the outputs of address decoders230-1of each primitive P1to PM will be activated so that if print data is present on the corresponding data line206, AND-gates232-1of each primitive P1to PM will close the corresponding switch220-1when the fire pulse is active, thereby causing energizing the corresponding firing resistor160-1to eject fluid from the nozzle16of the corresponding fluid chamber150.

In the first example scenario, since FPG244is not a DBD FPG256, even though output of address decoders230-1is active, and even though print data might be present on the corresponding data line204, the output of AND-gate234-1of each primitive P1to PM will not be active because the DBD enable line is not active. As a result, FET224-1controlling DBD sense plate164-1of ejection chamber150corresponding to firing resistor160-1will not be closed so that a DBD sense operation will not be performed for the fluid chamber.

In a second example scenario, where DBD enable bits262of a received FPG244have an enable value, upon checking the value of DBD enable bits262in header252, input logic192deems the FPG244to be a DBD FPG250, and passes DBD operations data260to DBD controller200. Again, address data250is provided to address encoder196, which encodes the corresponding address onto address bus206, and data buffer194receives and places each of the data bits264from data portion256of DBD FPG250onto its corresponding data line204. Each address encoder230-1to230-N of each primitive P1to PM receives the encoded address, with each of the address encoders corresponding to the address encoded on address bus206providing an active output to corresponding AND-gates232and234. For example, if the encoded address from DBD FPG250placed on address bus206represents address A1, address decoders2301-1of each primitive P1to PM provide an active output to corresponding AND-gates232-1and234-1.

Continuing with the above example, with the outputs of address decoders230-1of each primitive P1to PM being activated, if DBD ejection data264is present on the corresponding data line204and fire pulse208is active, the outputs of AND-gates232-1of each primitive P1to PM will be active, thereby closing the corresponding switch220-1and energizing the corresponding firing resistor160-1to vaporize fluid in ejection chamber150and form a drive bubble170to eject an fluid drop159from the associated nozzle16.

In this second example scenario, with the FPG having been deemed to be a DBD FPG250, DBD controller200, based on delay information included in DBD operations data260, activates DBD enable line210at a predetermined time after activation of the firing resistors160-1(e.g.; at a point after drive bubble170is expected to have been formed or to have already have collapsed, for instance). With the outputs of address decoders230-1of each primitive P1to PM being activated, and with the DBD enable line210being activated, outputs of AND-gates234-1of each primitive P1to PM will be activated if DBD ejection data264is present on the corresponding data line204(e.g., has a value of “1”), thereby closing DBD switch224-1and coupling DBD sense plates164-1to the DBD sense line212corresponding to the particular primitive.

In view of the above, for each primitive P1to PM for which the DBD ejection data bit264on the corresponding data line D1to DM is set (e.g., has a value of “1”), the firing resistor160-1will have been energized to generate drive bubble170within the corresponding fluid chamber150to eject an fluid droplet159from the nozzle16thereof. At some point during the formation or collapse of the drive bubble170, as based on the delay information included in DBD operations data260, DBD sensor202of DBD controller200injects a sense current, is, into the corresponding DBD sense212. DBD sensor202measures a resulting voltage level, VDBD, on each of the active sense lines212, and provides such voltage measurements to a controller, such as electronic controller110, such as via a communication link236. In one example, DBD controller200places analog voltage measurements on terminal or contacts sensed by an external controller, such as electronic controller110. In one example, DBD controller200provides such voltage measurements in digital format. In one example, electronic controller110(or other controller) compares such voltage measurements to expected voltage measurements of known healthy nozzles to determine an operating condition of the fluid chamber150(e.g., healthy, blocked, partially blocked).

As a specific example, if address data258of DBD FPG250corresponds to address A1, and DBD ejection data bit264corresponding to primitive P1is set (e.g., has a value of “1”), AND-gates232-1of primitive P1will first close switch220-1to energize firing resistor160-1to form a drive bubble170, and at a later time, DBD controller200will activate DBD enable line210such that AND-gate234-1of primitive P1will close switch224-1, thereby connecting DBD sense plate164-1to DBD sense line S1. DBD sensor202will impress a fixed sense current, is, on DBD sense line S1which will flow through impedance path168-1in ejection chamber150-1to generate a resulting voltage, VDBD, on DBD sense line S1(seeFIG. 3B).

In the example ofFIG. 5, DBD controller200includes one sense line212for each primitive180, illustrated as sense lines S1to SM corresponding to primitives P1to PM. Such implementation enables DBD operations to be concurrently performed on one ejection chamber150in each primitive180. As such, inFIG. 5, DBD operations may be concurrently performed on M ejection chambers150(i.e., one in each of the M primitives150) of column178of primitives P1to PM. By successively cycling through primitive addresses A1to AN (not necessarily in numerical order), DBD operations can ultimately be performed on all ejection chambers150of fluid ejection device114in groups of M ejection chambers at a time.

While illustrated inFIG. 5as employing one sense line212per primitive180, it is noted that more or fewer sense lines212can be employed. For instance, in one example, a single sense line212may be shared by all primitives P1to PM. In such instance, a DBD operation may be performed on only one ejection chamber150at a time in column178of primitives P1to PM. Additionally, in other examples, switches224may be implement in configurations other than a FET, such as an enable-able amplifier, for instance, the output of each being connected to a single sense line, wherein bases on primitive data, only the amplifier of one primitive would be driving the single sense line at a time. In another example, two sense lines212may be employed, with one sense line212being connected to even-numbered primitives180and the other sense line being connected to odd-numbered primitives180, for instance.

With reference toFIGS. 7 and 8, according to the illustrated example, DBD FPG250includes address data258for a single address and ejection data264for each ejection chamber150at the identified address in each primitive P1to PM. In one example, DBD FPG250may include address data258and ejection data264for performing DBD operations for more than one address (e.g. two addresses). In such case, DBD operations may be sequentially performed for each of the different addresses.

By adding an ejection address to a NCG in the form of a DBD FGP, in accordance with the present disclosure, DBD operations can be performed on a fluid chamber without affecting fluid ejection by the fluid chamber or servicing (e.g., recirculation pumping). As a result, adverse effects on throughput of the fluid ejection device otherwise resulting from performance of DBD operations is greatly reduced or eliminated relative to conventional processes where DBD operations are performed between ejection jobs.

FIG. 9is a flow diagram generally illustrating a method300of operating a fluid ejecting system, such as fluid ejection system100including a fluid ejection device, such as fluid ejection device114ofFIGS. 4 and 5, according to one example of the present disclosure. At302method300includes arranging a plurality of ejection chambers into a plurality of primitives with each primitive receiving a same set of addresses, such as ejection chambers150being organized into primitives180and having a same set of addresses182as shown inFIGS. 4, 5, and 9. Each ejection chamber of a primitive includes a drive bubble formation mechanism and a drive bubble sensor mechanism, with each ejection chamber corresponding to a different address of the set of addresses, such as ejection chambers150each including a drive bubble formation mechanism160and a drive bubble sensor mechanism164as illustrated byFIGS. 4, 5, and 9.

At304, method300includes arranging ejection data into a series of nozzle column data groups, with each nozzle column data group including a plurality of fire pulse groups, such as controller110arranging ejection data into a series of nozzle column data groups240, with each nozzle column data group242including a plurality of fire pulse groups, as illustrated byFIG. 6.

At306, method300includes adding a DBD FPG in a nozzle column data group, the DBD FPG corresponding to at least one address of the set of addresses and including a series of ejection data bits, each ejection data bit corresponding to a different one of the primitives, such as controller110including DBD FPG250in NCG242of the series of NCGs240, with DBD FGP250including a series of ejection data bits264corresponding to a different one of the primitives P1to PM, as illustrated byFIGS. 6 and 7.

At308, method300includes activating in each primitive, in response to the drive bubble detect fire pulse group, the drive bubble formation mechanism and the drive bubble sensor mechanism of the ejection chamber having the same address as the at least one address to which drive bubble detect fire pulse group corresponds to form a drive bubble and to perform a drive bubble sensing measurement when the corresponding ejection data bit is set, such as primitive drive and control logic190of fluid ejection device114ofFIG. 5activating drive bubble formation mechanisms160and drive bubble sensor mechanisms164of each primitive180having an address (e.g., addresses A1to AN) corresponding to the at least one address of the drive bubble detect fire pulse group received at240(e.g., received from printing system controller110).