Fluid ejection dies may eject fluid drops via nozzles thereof. Nozzles may include fluid ejectors that may be actuated to thereby cause ejection of drops of fluid through nozzle orifices of the nozzles. Some example fluid ejection dies may be printheads, where the fluid ejected may correspond to ink.
Throughout the drawings, identical reference numbers designate similar, but not necessarily identical, elements. The figures are not necessarily to scale, and the size of some parts may be exaggerated to more clearly illustrate the example shown. Moreover the drawings provide examples and/or implementations consistent with the description; however, the description is not limited to the examples and/or implementations provided in the drawings.
Examples of fluid ejection dies may comprise a plurality of ejection nozzles that may be arranged in a set, where such plurality of nozzles may be referred to as a set of nozzles. A set of nozzles may be referred to as a “primitive” or a “firing primitive,” where a set of nozzles generally comprises a group of nozzles that have a unique actuation address. For example, a fluid ejection device may have four sets of nozzles, where each set of nozzles may comprise eight nozzles. In this example, each nozzle of the eight nozzle set may have a unique address. Moreover, nozzles may be arranged into sets of a given quantity, where a set may be referred to as a primitive. In some examples, electrical and fluidic constraints of a fluid ejection die may limit a single nozzle of each set of nozzles may be actuated for a given actuation event. For example, if nozzles of a fluid ejection die are arranged in four nozzle sets, for a given actuation event, one nozzle of each four nozzle set may be actuated.
In some examples, each nozzle may comprise a fluid chamber, a nozzle orifice, and a fluid ejector. A fluid ejector may include a piezoelectric membrane based actuator, a thermal resistor based actuator, an electrostatic membrane actuator, a mechanical/impact driven membrane actuator, a magneto-strictive drive actuator, or other such elements that may cause displacement of fluid responsive to electrical actuation. Furthermore, example fluid ejection dies may comprise, for each nozzle of the fluid ejection die, nozzle identification logic disposed proximate to the nozzle, which may be referred to as identification logic herein. Moreover, the identification logic for each respective nozzle may be connected to the respective nozzle and/or the fluid ejector thereof. For a set of nozzles, each respective identification logic for the nozzles of the set may have at least one different component characteristic. For example, if the identification logic comprises a switch (such as a transistor), the component characteristic that may be different for each identification logic may be a channel length, a channel width, a channel depth, etc. If the identification logic comprises a resistor, the component characteristic may be a resistance of each resistor for the identification logic of nozzles of a set.
In such examples, for a set of nozzles, an actuation signal transmitted through a respective nozzle and the connected identification logic may vary from other nozzles and identification logic of the set based on the component characteristic difference of each identification logic. In some examples, the actuation signal may be described as being transmitted through the nozzle, and in other examples the actuation signal may be described as being transmitted through the fluid ejector thereof. Therefore, in such examples, each nozzle (and a fluid ejector thereof) may be connected to a respective identification logic, and the identification logic may be connected to an identification output. When a respective nozzle is actuated, the actuation signal may be transmitted through the connected identification logic, and the actuation signal may be sensed at the identification output. Since each identification logic of the nozzles of a set may have a different component characteristic, it will be appreciated that the sensed actuation signal at the identification output may vary based at least in part on the nozzle and identification logic through which the actuation signal was transmitted.
In some fluid ejection devices and fluid ejection dies thereof, address data may be input to ejection logic, where the address data indicates the nozzle to eject fluid for a given ejection event. Based on the address data, the ejection logic generates ejection signals for nozzles to be ejected (as indicated by the address data). However, if any trace or logic in the address data to ejection signal path includes a defect (such as a shorted trace), a nozzle indicated to be ejected by the address data (e.g., the expected nozzle) may not eject. In some situations, a different nozzle of the set may eject. In addition, in some examples, received address data may not correspond to the fluid ejection die or a fluid ejection device in which the die may be implemented. In such examples, received data may cause incorrect ejection. Therefore, examples disclosed herein may facilitate identification of a respective nozzle that has been actuated. Furthermore, examples may compare the respective nozzle that was actuated (as determined based on sensing the actuation signal output at the Identification output) and the expected nozzle (as indicated in the address data) to determine whether the respective nozzle that was actuated is the expected nozzle.
Turning now to the figures, and particularly to
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However, as discussed previously, the ejection logic 60 and/or the connections from the ejection logic to the ejection switches 56a-c, 58a-c, and/or the connections from the ejection switches 56a-c, 58a-c to the nozzles 52a-c, 54a-c may cause actuation of a nozzle 52a-c, 54a-c not indicated in the address data if there is a defect, or if the address data does not correspond to the fluid ejection die.
Therefore, as discussed previously, the fluid ejection die 50 may further comprise identification logic 64a-c, 66a-c connected to each nozzle 52a-c, 54a-c. The identification logic 64a-c, 66a-c for each nozzle of a set 52a-c, 54a-c may have at least one component characteristic that is different from the other identification logic 64a-c, 66a-c. For example, for the first set of nozzles 52a-c, the respective identification logic 64a-c connected to each nozzle 52a-c may have at least one component characteristic difference. Continuing the example, the first set of nozzles 52a-c includes a first nozzle 52a, a second nozzle 52b, and a third nozzle 52c. The first nozzle 52a is connected to a first identification logic 64a; the second nozzle 52b is connected to a second identification logic 64b; and the third nozzle 52c is connected to a third identification logic 64c.
According to some examples, an identification enable input 68 may be electrically actuated (i.e., power may be applied to the identification enable input 68) such that a switch 70 of each identification logic 64a-c, 66a-c may facilitate transmission of a signal from each nozzle 52a-c, 54a-c through each identification logic 64a-64c, 66a-66c to an identification output 72. Therefore, when the identification enable input is electrically actuated, and a respective nozzle 52a-c, 64a-c is actuated, the actuation signal may pass through the respective identification logic 64a-c, 66a-c, to the identification output 72. Based on the signal characteristics of the actuation signal at the identification output, the respective nozzle 52a-c, 54a-c that was actuated may be determined.
To further illustrate by way of example and referring to the above example, the switch 70 of each identification logic 64a-64c connected to the first set of nozzles 52a-c may have a different component characteristic. For example, each switch 70 may be a transistor, and the different component characteristic of each identification logic 64a-c may be a channel length of the transistor. In this example, the first identification logic 64a may have a channel length of a first length; the second identification logic 64b may have a channel length of a second length; and the third identification logic 64c may have a channel length of a third length. As discussed, the first length, second length, and third length are different. Accordingly, an actuation signal transmitted through the first nozzle 52a and first identification logic 64a would be different than an actuation signal transmitted through the second nozzle 52b/second identification logic 64b and the third nozzle 52c/third identification logic 64c. For example, a signal characteristic of the actuation signal that may differ may be a current or a voltage. While at least one component characteristic is different for each respective identification logic for nozzles of a set of nozzles, it may be appreciated that the component characteristics may not be different for identification logic connected to other sets of nozzles. For example, the first identification logic 64a for the first nozzle 52a of the first set 52a-c may have the same component characteristics as a first identification logic 66a for a first nozzle 54a of the second set of nozzles 54a-c. In some examples, that the identification components for a first set of nozzles may be arranged with component characteristics that are similar to identification components for a second set of nozzles.
In this example, A first nozzle 102a of the nozzle set may be connected to a first identification logic 104a including a first transistor 106a having a channel length of ‘x1’, a channel width of ‘y1’, and a channel depth of ‘z1’. A second nozzle 102b of the nozzle set may be connected to a second identification logic 104b including a second transistor 106b having a channel length of ‘x2’, a channel width of ‘y2’, and a channel depth of ‘z2’. A third nozzle 102c of the nozzle set may be connected to a third identification logic 104c including a third transistor 106c having a channel length of ‘x3’, a channel width of ‘y3’, and a channel depth of ‘z3’. A fourth nozzle 102d of the nozzle set may be connected to a fourth identification logic 104d including a fourth transistor 106d having a channel length of ‘x4’, a channel width of ‘y4’, and a channel depth of ‘z4’. In some examples, at least one of the channel length, channel width, and channel depth for each transistor 106a-d is different from the other transistors 106a-d. For example, the second transistor 106b may have a channel length approximately 20% greater than a channel length of the first transistor 106a; the third transistor 106c may have a channel length approximately 20% greater than the channel length of the second transistor 106b; and the fourth transistor 106d may have a channel length that is 20% greater than the channel length of the third transistor 106c. In another example, some combination of channel length, channel width, and channel depth may be different for each transistor 106a-d. Other examples may include various other arrangements.
In addition, each respective identification logic 106a-d may include an additional component 108a-d, such as a resistor, capacitor, memristor, EPROM storage element, EEPROM storage element, etc. In examples in which identification logic 104a-d includes an additional component, it may be appreciated that a component characteristic of the additional component may be different for each identification logic 104a-d connected to a nozzle 102a-d of a set of nozzles. For example, if the additional component 108a-d of each respective identification logic 104a-d is a resistor, the different component characteristic for each respective identification logic may be a resistance value for each resistor.
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The connected device may determine whether the expected nozzle corresponds to the respective nozzle (block 312). In other words, the device may determine whether the nozzle indicated in the address data corresponds to the nozzle that was determined to have been actuated. In response to determining that the expected nozzle does not correspond to the respective nozzle (“N” branch of block 312), the device may determine that the fluid ejection die includes a defect (block 314). For example, if the device is a testing device, and the expected nozzle does not correspond to the respective actuated nozzle, the testing device may determine that the fluid ejection die includes a defect. As discussed above, a defect may occur in ejection logic, connective traces between elements on a fluid ejection die, etc.
In other examples, in response to determining that the expected nozzle does not correspond to the respective nozzle (“N” branch of block 312), the device may determine that the fluid ejection die is incorrect for the device (block 316). For example, if the device is a fluid ejection system, such as a printer, if the actuated respective nozzle does not correspond to the expected nozzle, the fluid ejection die may not be correctly arranged to accurately eject fluid for address data received from the fluid ejection system.
In response to determining that the expected nozzle corresponds to the actuated respective nozzle (“Y” branch of block 312), the device may determine if additional nozzles remain to be identified/evaluated (block 318). If additional nozzles remain to be evaluated (“Y” branch of block 318), the device may proceed with evaluating the next nozzle (block 320) by repeating at least some of the operations described in blocks 304-316 with regard to the next nozzle.
If the device is a testing device, a some or all nozzles of the fluid ejection die may be actuated and the results may be analyzed to determine that the fluid ejection die does not include a defect, i.e., that the fluid ejection die or fluid ejection device upon which the fluid ejection die is implemented is determined to operate as expected. In such examples, a fluid ejection die and/or fluid ejection device in which the die is implemented that includes nozzles in which address data causes actuation of the expected nozzle, the die/device may be determined to be ‘OK’ (block 322). If the device is a fluid ejection system (such as a printer), and the address data causes actuation of the expected nozzle, the device may determine that the fluid ejection die/device is correct for the device (block 324).
Accordingly, examples provided herein may provide a fluid ejection die including nozzle identification logic connected to each nozzle. When enabled, the nozzle identification logic may transmit an actuation signal from the connected nozzle therethrough to an identification output. Since the nozzle identification logic for each nozzle of a set of nozzles has a different component characteristic, the actuation signal output at the identification output may vary in a manner corresponding to the component characteristic difference. Therefore, for a given set of nozzle, a respective nozzle of the set that was actuated may be identified. In some examples, comparison of the respective nozzle that was actuated and the nozzle that was expected to be actuated based on address data may facilitate a determination of whether the ejection logic and electrical connections of the set of nozzles is correct. In other examples, the comparison may facilitate determining whether the fluid ejection die is correctly arranged for a given device in which the die is implemented.
The preceding description has been presented to illustrate and describe examples of the principles described. This description is not intended to be exhaustive or to limit these principles to any precise form disclosed. Many modifications and variations are possible in light of the description. In addition, while various examples are described herein, elements and/or combinations of elements may be combined and/or removed for various examples contemplated hereby. For example, the example operations provided herein in the flowcharts of
Filing Document | Filing Date | Country | Kind |
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PCT/US2017/015820 | 1/31/2017 | WO | 00 |