Abstract: An ink jet printing device supplies first and second signals to cause a pressure generating chamber to jet out ink droplets. A third signal is applied to the pressure generating chamber to effectively attenuate the kinetic energy of the meniscus and to hold the meniscus at a position suitable for jetting out the next ink droplet to provide a stable print output. Also, an ink-jet recording apparatus is provided with a control means for controlling the timing of the start of the second signal and the timing of the start of the third signal according to the environmental temperature. In the ink-jet recording apparatus, the discharge speed of ink drops is made constant by regulating the start time of the second signal so as to make constant the drawing position of a meniscus when the ink drops are discharged.

Abstract: An ink-jet recording head driving method of driving an ink-jet recording head having a pressure generating device corresponding to a pressure generating chamber communicating with a jetting hole includes a driving pulse generating step of generating a driving pulse by taking out part of a driving signal having a time length corresponding to one printing cycle and including a plurality of driving pulse waves, and an ink jetting step of jetting an ink particle through the jetting hole by applying the driving pulse to the pressure generating device to drive the pressure generating device for a predetermined operation. When the driving pulse generating step and the ink jetting step are repeated a plurality of times in one printing cycle to jet a plurality of ink particles, the succeeding ink jetting step is stated a predetermined time interval T after a point when the preceding ink jetting step is ended.

Abstract: A platen gap from a nozzle orifice is detected by a platen gap detecting sensor (16). A control section (46) limits usable recording modes to a high-speed recording mode and a first high-resolution recording mode in case that the detected platen gap is a large gap. At this time, in case that a control command from a host computer is a command for specifying a second high-resolution recording mode, the recording mode to be used is switched to the first high-resolution recording mode.

Abstract: To increase the size of dot printed on a print medium with an on-demand multi-nozzle ink jet head, at least two unit pulses are applied in succession to a piezoelectric element which varies the volume of an ink chamber. The unit pulse has a pulse width substantially equal to a period of Helmholtz natural oscillation determined based on dimensions, materials, and physical properties of an ink channel and the piezoelectric element and other components relating to oscillation. An off duration between adjacent unit pulses applied in succession to the piezoelectric element is preferably set one fifth to one fourth of the unit pulse width.

Abstract: An ink jet head is provided having ink chambers, energy-generating elements provided in the ink chambers, respectively, and ink outlet ports communicating with the ink chambers, respectively. The ink jet head may be left unused for a time longer than a predetermined time, with a meniscus formed in each ink outlet port. In this case, a drive pulse is applied to each energy-generating element several times, thereby forcing the ink outwards from the ink outlet ports and increasing a surface area of the ink from a surface area of the meniscus. Then, a negative pressure is applied in each ink chamber, thereby drawing the ink back toward the ink chambers, thus forming a meniscus again in the ink outlet ports. In this condition, a drive pulse is applied to the energy-generating elements, thus ejecting an ink droplet from the ink outlet ports to record data.

Abstract: A printer and method for shortening printing time is provided for in-line thermal printers using two banks of print elements. Electric currents to the banks are interleaved together. Interleaving provides the advantages of pulse modulation, but with an improved print speed. In the preferred embodiment of the invention, a first set of printing elements is supplied with a first current signal for heating up the first set of printing elements up to the printing temperature. Then, the first set of printing elements is supplied with a series of shorter current signals to retain the temperature of the first set of printing elements until a first bank of dots is printed. Interleaved between the first series of shorter current signals, is a second series of short current signals supplied to the second set of print elements to heat up the second set of printing elements up to the printing temperature.

Abstract: A first supply switch is connected between a piezoelectric vibrator and a drive signal line for supplying a drive signal to the piezoelectric vibrator in order to control a waveform element supplier. A second supply switch is connected between the drive signal line and the piezoelectric vibrator in parallel with the first supply switch. A rectifier connected in serial with the second supply switch such that a current flow direction from the drive signal line to the piezoelectric vibrator is defined as a forward direction.

Abstract: The invention provides a thermal printer and a recording method of the thermal printer that are capable of reducing the recorded density non-uniformity (jitter) and obtaining a good quality recorded image. The period of the pulse signal generated by an encoder is measured, at least one of the applied voltage and the current flow time of the head pulse is operated based on the difference between the measured value and the theoretical value measured by the encoder, and the head pulse is controlled based on the arithmetic value. Otherwise, the duty ratio of the output time to the non-output time of the pulse signal generated by the encoder is measured, the output correction time of the OFF head pulse is operated based on the duty ratio, and the OFF head pulse is supplied to the heater elements at the time point that delayed by the output correction time from the output ending time of the pulse signal.

Abstract: An apparatus for driving an ink-jet recording head includes a piezoelectric device, a drive waveform generation circuit, a waveform extraction circuit. The drive waveform generation circuit generates a drive waveform in which n basic waveforms are connected in series, each of the n basic waveforms having a single period, where n is an integer equal to or greater than 2. The waveform extraction circuit which extracts m (m is an integer, and 0≦m≦n) of the n basic waveforms as a print drive waveform based on an externally supplied print data, and applies the print drive waveform to the piezoelectric device. Thereby, an ink is discharged from a nozzle based on a distortion of the piezoelectric device.

Abstract: In apparatus and a method of generating waveforms for driving an ink-jet print head, waveform data for the overall head-driving waveforms per given unit are written in waveform buffers BUFFER 0 or BUFFER 1 and then sequentially retrieved at a given timing for analog conversion to obtain an analog head-driving waveform signal. Various head-driving waveforms are thus programmably generated.

Abstract: An ink jet recording apparatus includes an ink jet head having a nozzle, an ink channel, a diaphragm, and an electrode and a part applying first and second driving signals to the ink jet head. The first driving signal generates electrostatic force that deforms the diaphragm so as to eject an ink droplet from the nozzle. The second driving signal for controlling deformation of the diaphragm is applied after a predetermined period of time passes since application of the first driving signal.

Abstract: In order to prevent a viscosity of ink near each nozzle orifice of a recording head from increasing, a time to eject an ink drop therethrough is analyzed based on print data. Dot pattern data is generated by determining the printing period where the fine vibration should be applied to the meniscus of ink in each nozzle in accordance with analysis of the print data. Accordingly, remarkable suppression of the viscosity increase, stabilization of the flying path of the ink drop, and efficient flushing may be achieved without complexity of the whole machine construction.

Abstract: In an on-demand ink jet printer head for discharging minute ink drops by means of meniscus position control and acoustic wave control, the length of each discharge pause period with respect to each orifice of the printer head is determined based on image data, and a pre-discharge waveform is determined for each discharge pause period based on the length of the discharge pause period. The pre-discharge waveform is applied to a piezoelectric element before restart of ink drop discharge by the movement of the piezoelectric element, thereby a large displacement which is designed depending on the length of the discharge pause period is given to ink before the restart of the ink drop discharge so that the ink will be moved and stirred, thereby uniformity and stability of ink drop discharge properties (size, speed, flying direction, etc.) are realized at the restart after the discharge pause period. Continuous meniscus vibration is not employed for maintaining ink viscosity during the discharge period.

Abstract: A drive signal COM1 or COM2 generated by a drive signal generator includes: a drive pulse DP1 or DP3 whose bias level is adjusted to a middle voltage Vm; a drive pulse DP2 whose bias level is adjusted to a ground voltage GND; a ready signal DP0, which includes a first correction element P0 for dropping the voltage from the middle voltage Vm to the ground voltage GND; and a recovery signal DP4, which includes a second correction element P14 for raising the voltage from the ground voltage GND to the middle voltage Vm. The ready signal DP0 precedes the drive pulse DP2, and the recovery signal DP4 follows the drive pulse DP2.

Abstract: Digital ink jet printing apparatus and method. The apparatus receives an input image file having a plurality of pixels, each pixel described by at least one pixel value respectively associated with an optical density. The apparatus comprises a printhead and at least one nozzle integrally attached to the printhead, the nozzle being capable of ejecting an ink droplet therefrom to define an associated one of the optical densities. A waveform generator is connected to the nozzle for generating an electronic waveform to be supplied to the nozzle. In this manner, the nozzle ejects the ink droplet in response to the waveform supplied thereto. The waveform is defined by a plurality of pulses. A look-up table stores a plurality of waveform serial numbers assigned to respective waveforms, each waveform being defined by at least one predetermined parameter, such as number of pulses, pulse amplitude, pulse width and/or time delay between pulses.

Abstract: A shape of the drive signal within each one-pixel period of main scan is modified to have N different waveforms corresponding to N different values of the print signal, the N different values of the print signal representing formation of the N different dots. The N different waveforms of the drive signal are changed between the forward pass and the reverse pass. This will align the hitting positions of ink droplets in the main scanning direction during forward and reverse passes.

Abstract: In an ink droplet ejecting method and apparatus, by merely adding one pulse after a driving waveform for a main ejection of ink, without changing the driving voltage, it is possible to obtain an ink droplet of a desired volume and also possible to minimize the decrease of the ink droplet speed. The pulse width Wa of a jet pulse signal A is set equal to time T required for one-way propagation through an ink chamber of a pressure wave which is generated in the ink chamber, while the pulse width Wb of an additional pulse signal B is set at 0.2T to 0.6T, and a time difference between a fall timing of the jet pulse signal A and a rise timing of the additional pulse signal B is set at 0.3T to 0.7T, whereby an ink droplet being ejected is reduced in size and only one drive voltage is sufficient. Thus, the cost can be reduced, and a decrease of the ink droplet speed is prevented.

Abstract: An inkjet recording apparatus includes a moving device which moves an inkjet head relatively to a recording medium. When the head is moved relatively to the recording medium by the moving device, a nozzle of the head ejects ink onto the recording medium, so that recording is carried out. The inkjet head includes (a) pressure chambers containing ink, (b) nozzles communicating through the pressure chambers, (c) piezoelectric elements, (d) piezoelectric actuators deform to increase or decrease the capacities of the pressure chambers due to piezoelectric effect of the piezoelectric elements, and (e) a controller for driving the actuators at a frequency not less than 20 kHz. This structure allows the actuators to operate substantially noiseless, and an image can be recorded at higher speed.

Abstract: An ink jet recording apparatus, in which thermal energy is applied to ink in accordance with a driving signal applied to a heater to produce a bubble, by which ink is ejected onto a recording material, includes a driver for applying a plurality of driving signals to the heater for one ejection of one ink droplet. The driving signals comprise a first driving signal not ejecting the ink and a second driving signal for ejecting the ink, the second driving signal being applied after a rest period after the first driving signal. The apparatus further includes a controller for changing an amount of ink ejected by changing a length of the rest period and changing the first driving signal. The controller effects its changing operation in a first changing region in which the rest period is changed without changing the first driving signal and in a second changing region in which a length of the first drive signal is changed.

Abstract: An ink-jet recording head driving method and an ink-jet recording device wherein the quantity of ink composing an ink droplet can be reduced as much as possible without deteriorating the flying speed of an ink droplet and, consequently, a dot suitable for graphic printing can be formed. A pressure generating chamber is expanded or contracted by driving a piezoelectric layer provided on the pressure generating chamber communicating with a nozzle opening and a reservoir so as to jet an ink droplet from the nozzle opening. A preparatory process is provided for preparing for the jetting of ink by expanding a pressure generating chamber and backing a meniscus from the surface of the nozzle opening before a first contraction process for contracting the pressure generating chamber to jet ink from a nozzle opening.

Abstract: When the printing instruction is issued in S100, it is judged in S110 whether the present mode is the printer mode. When the present mode is not set to the printer mode, it is judged in S120 whether the present mode is set to the facsimile mode. When the present mode is set to the facsimile mode, the driving waveform of the driving signal is set in S130 into a multi-pulse, comprised of two pulses, for every single set of print data. In S140, printing operation is performed with the multi-pulse driving signal. Accordingly, ink droplets are ejected twice from a single nozzle for a single set of data. Thus, the print density of the obtained image is increased.

Abstract: An ink jet printer uses an actuator and an oscillating pressured ink supply. A shutter is located between the ink supply and an ink ejection port, normally blocking the ink ejection port. An actuator is provided for moving the shutter mechanism on demand away from the ink ejection port so as to allow for the ejection of ink on demand from the ink ejection port. The actuator includes a thermal actuator in a coiled form constructed primarily from polytetrafluorethylene. The coil is uncoiled upon heating. The actuator includes a serpentine heater element encased in a material having a high coefficient of thermal expansion. The serpentine heater takes a concertina form upon heating and a thick return trace returns the actuator to its original position upon cooling.

Abstract: Disclosed are an ink jet recording apparatus and method to achieve good balance between the amount of ink supplied and the amount of ink ejected. An ink jet head of the recording apparatus has an ink reservoir chamber having a predetermined capacity for receiving ink from an ink source. The ink reservoir chamber has a nozzle for ejecting ink, and a piezoelectric element. The piezoelectric element is deformable by changing a drive voltage applied thereto, so as to change the capacity of the chamber. A control unit controls the drive voltage applied to the piezoelectric element from the drive voltage generator so that the capacity of the ink reservoir chamber is increased to a first value in a supplying stage, and then reduced to a second value in an ejecting stage, in each ink ejection cycle. Furthermore, the control unit changes the displacement of the piezoelectric element by changing the waveform of the drive voltage.

Abstract: The present invention is a printing system and method having a printhead assembly that controls firing operations of an inkjet printhead. In particular, the system and method control the firing and timing decisions pertaining to ink drop ejection through the use of various types of delays. The printing system includes a controller, a power supply and a printhead assembly. The printhead assembly includes a memory device and distributive processor integrated with an ink driver head.

Abstract: A driving waveform generating device and method comprises the steps of retaining data on absolute coordinate values in a waveform data storage unit 1 as data at a plurality of points in a plurality of driving waveforms a-f at a predetermined temperature, reading the data on the plurality of point in a desired driving waveform a from a waveform data read unit 3A on the basis of gradation data, correcting the difference between the environmental temperature during the printing operation and the aforesaid predetermined temperature in a temperature compensation unit 3B, converting data on the corrected absolute coordinate value to data on the relative coordinate value in waveform data conversion unit 3C, interpolating the point-to-point value by means of a waveform data interpolation unit 5, subjecting the interpolated the data on the driving waveform to analog conversion by means of a D/A conversion unit 7, amplifying the analog signal in a signal amplifier unit 9, and outputting the amplified signal.

Abstract: In the ink jet printer, a pressure generation chamber 11 is expanded in a stepped manner, which enables a high speed discharge of a very small ink droplet. Prior to the ink discharge, the pressure generation chamber is contracted so as to enable a high-accuracy gradation printing with a wide range of ink droplet size. A control unit 20 generates: a first contraction signal for contracting the pressure generation chamber 11 without discharging any ink droplet 17; a first expansion signal for expanding the pressure generation chamber 11 to discharge the ink droplet 17; and a second expansion signal to further expand the pressure generation chamber 11 so as to break off an ink column discharged from a nozzle 12 and pull an unnecessary portion of the ink back into the nozzle 12.

Abstract: A signaling method for a pen driver circuit interface is embodied in a signal interface between a controller circuit and a pen driver circuit for a printer. At least one signal of the interface is omitted; and the pen driver circuit is modified to process a combination of signals including at least one of the signals on the signal interface to provide information pertaining to the at least one omitted signal. According to a preferred method, the combination of signals are processed when data is not being transferred via the signal interface to provide a pen firing control signal for the printer such as a warm enable signal or a fire enable signal.

Abstract: An apparatus and method provide on-demand drop volume modulation by utilizing a single transducer driving waveform to drive an ink jet. The driving waveform includes at least a first portion and a second portion that each excites a different modal resonance of ink in an ink jet orifice to produce ink drops having different volumes. A control signal is applied to the driving waveform to actuate the selected portion of the waveform to eject the desired ink drop volume for a given pixel. The control signal also cancels the non-selected portion(s) of the waveform to avoid extraneous excitation of the transducer.

Abstract: An ink jet recording method includes supplying a driving signal of a phase, wherein the driving signal comprising at least first and second signal periods with a rest period therebetween; and supplying a driving signal of a phase which is different to provide the first or second signal overlaps with the rest period of the driving signal having the first mentioned phase.

Abstract: A drive regulation method for an ink jet print head, wherein a plurality of ejection signals are prepared for driving an ink jet print head in various states. The ink jet print head is controlled to eject ink based on each of the selected signals. The ejection signal that achieves the most stable ejection aim from each of the nozzles is used as the ejection signal for that ink jet print head. In order to determine which of the ejection signals achieves the best result, dot arrays are printed on a recording medium for each ejection signal and the recorded dot arrays are examined for degree of unevenness. The ejection signal that achieves the most even dot array is selected. The ejection signals selected for each ink jet print head are stored in a memory device.

Abstract: When a dot is formed apart from other dots on a print medium, in response to a discontinuous print command, a first drive waveform is used. The first drive waveform includes an ejection pulse and an ink droplet reducing pulse for retrieving a portion of an ink droplet about to leave the nozzle. When a dot is formed to overlap other dots on a print medium, in response to one of continuous print commands, the second drive waveform is used. The second drive waveform includes an ejection pulse and an ejection stabilizing pulse for suppressing residual vibrations generated by the ejection pulse. By selectively using the first or the second drive waveform , an ink droplet smaller than 20 pl can be ejected stably even at high printing frequencies. As a result, high-quality, high-speed printing can be achieved.

Abstract: The present system counteracts the distorting effect of a bi-directional print head by reducing the visual effect of a satellite drop displacement when the print head is traveling in a direction that increases the satellite displacement from a main drop. The system can also counteract the distorting effect of the bi-directional print head by increasing the visual effect of a satellite drop misplacement when the print head is traveling in a direction that decreases the satellite misplacement from the main drop. The satellite drop displacement can be adjusted by correcting a measured ink temperature, and thereby, an amount of pre-pulsing prior to ejection of the ink.

Abstract: In an ink-jet printer, on the basis of the previous, current, and next drive conditions held in latch circuits 252, 253, and 254, an output control section 255 switches the current drive waveform to be supplied to a pressure generation device. Therefore, the vibrating state of a vibrating state or that of an ink meniscus can be optimized by the time the next expelling of ink is performed. Accordingly, there is no need for consumption of time to wait for the next expelling of ink until the vibration of the vibrating plate or that of meniscus subsides sufficiently, thus resulting in a reduction in time intervals between ink expelling operations and implementing high-speed printing operations.

Abstract: An apparatus and method provide on-demand drop volume modulation by utilizing a single transducer driving waveform to drive an ink jet. The driving waveform includes at least a first portion and a second portion that each excites a different modal resonance of ink in an ink jet orifice to produce ink drops having different volumes. A control signal is applied to the driving waveform to actuate the selected portion of the waveform to eject the desired ink drop volume. The apparatus and method improves resolution in gray scale printing by knowing an input request and placing a combination of small drops and large drops in a conventional blue noise halftone screen represented as a threshold array such that throughput and image quality goals are met while decreasing jetting robustness risk.

Abstract: In order to provide an inkjet recording head in which both high-speed printing and high-quality printing can be attained, a drive signal is generated so as to include a first expanding element and a successive second expanding element. Either a small-dot driving pulse including both of the expanding elements or a large-dot driving pulse including only the second expanding element is generated from the drive signal. The selection of one or the other driving pulse is based on the volume of the ink drop to be ejected.

Abstract: An inkjet printing apparatus having a print head and a control system to control the discharge of variable size ink drops from the print head. The control system for printing half-tone images applies pulse voltages of varying waveforms to the print head to control the volume of ink discharged, thereby controlling the diameter of a printed ink dot on a receiving print medium.

Abstract: A print head ejects ink from ink channels by deformation of piezoelectric material. The number of times ink is ejected by the head is calculated and stored in the memory provided integrally with the print head. When the number of drive times is determined to exceed a predetermined number, then after a print medium is changed, for example, because of a new page, then the pulse width or the pulse height of the waveform of the drive pulse applied to the piezoelectric is changed. Accordingly, reduction in deformation amount caused by degradation of polarization of the piezoelectric can be compensated for, so that speed and volume of ejected ink droplet can be recovered.

Abstract: An ink-jet printer and an apparatus and a method of driving a recording head for an ink-jet printer are provided for faithfully performing various image representations through ink droplet ejection driving signals of different waveforms. Based on a waveform selection signal from a selection controller, a waveform selector selects one of a plurality of drive signals from a drive waveform generator in a time-division manner. The selected signal is supplied to a piezoelectric element of a corresponding nozzle. Control is thereby performed on ink droplet ejection with a drive signal having a temporally varying waveform. The drive signals include a signal having a varying voltage waveform that disables ink droplet ejection in isolation from another waveform. A new composite drive signal waveform is generated by time-divisional selection not only at a point between ejection cycles but also at a point during the ejection cycle.

Abstract: A method of operating an inkjet printhead for printing on a substrate, the printhead having an array of channels; a series of nozzles which communicate respectively with said channels for ejection of droplets therefrom; connection means for connecting the channels with a source of ink; and electrically actuable means associated with each channel and actuable a plurality of times in accordance with print tone data, thereby to eject a corresponding number of droplets to form a printed dot of appropriate tone on the substrate, the method comprising the steps of: applying one or a plurality of electrical signals to the electrically actuable means associated with a channel in accordance with the print tone data, the duration of each signal being chosen such that the velocity of the corresponding ejected droplet is substantially independent of (a) whether or not channels in the vicinity of said selected channel are similarly actuated to effect drop ejection simultaneously with drop ejection from said selected chann

Abstract: A drive method and a drive of an ink-jet recording head which is capable of improving recording speed widely, and which is capable of materializing high quality recording without extending recording time even though the number of gradations increase, are provided. One-printing period T is divided into a plurality of segment T1, T2. The method and device cause plural kinds of drive-voltage-waveform SD1 to SD6 to be generated in accordance with size of an ink-drop in every respective segment T1, T2. The method and device select arbitrary drive-voltage-waveforms from among the plural kinds of drive-voltage-waveforms SD1 to SD6 supplied in every respective segment T1, T2 to supply to a vibration generator in every respective segment T1, T2. Thus it becomes possible to obtain a plurality of gradations during one-printing period T. It is capable of obtaining high quality printing image while improving recording speed widely. Further, printing time is not extended even though the number of gradations increase.

Abstract: An imaging apparatus capable of inhibiting inadvertent ejection of a satellite ink droplet and method of assembling same. The imaging apparatus comprises a print head transducer including a pair of sidewalls defining a chamber therebetween, the channel having the ink body disposed therein. The transducer is in fluid communication with the ink body for inducing a first pressure wave in the ink body in order to eject an ink droplet. A waveform generator is connected to the transducer for supplying voltage waveforms to the transducer, so that the transducer induces pressure waves in the ink body. However, the first pressure wave has a reflected portion formed by the first pressure wave reflecting from the sidewalls. The reflected portion is sufficient to otherwise inadvertently eject unintended satellite ink droplets. Thus, a sensor is in fluid communication with the ink body for sensing the reflected portion and is connected to the transducer for inducing a second pressure wave in the ink body.

Abstract: An ink ejecting apparatus has: a plate member in which an ink channel is formed; an ink supplying source for supplying the ink to the ink channel; a plurality of ink chambers formed in the plate member and each communicating with the ink channel to allow the ink to be moved from the ink channel into the plurality of ink chambers; a plurality of ink ejecting holes formed in the plate member and communicating with the plurality of ink chambers, respectively, to eject the ink from the plurality of ink chambers; a selection device for selecting more than one ink chamber that actually ejects the ink, from among the plurality of ink chambers; a first control device for reducing a volume of each of the selected ink chambers to actually eject the ink from the selected ink chambers; and a second control device for expanding a volume of non-selected ink chambers to absorb a pressure wave which is caused by a change of the volume of each of the selected ink chambers.

Abstract: In a method for driving an ink jet head in which at least a portion of a wall surface of an ink chamber is deformed by a piezoelectric actuator to eject ink, the voltage applied to the piezoelectric actuator is lowered from a voltage value in an initial condition, thereby causing the volume of the ink chamber to increase and thus causing ink to be drawn into the ink chamber, and then the applied voltage is rapidly raised up to a prescribed voltage value higher than the initial condition voltage value, thereby causing the volume of the ink chamber to decrease and thus causing ink to be ejected from the ink chamber. Next, after holding the prescribed voltage value for a prescribed length of time, the applied voltage is caused to drop from the prescribed voltage value down to the initial condition voltage value, thereby causing the volume of the ink chamber to increase.

Abstract: In an inkjet printing device, at least two kinds of drive waveforms are selectively fed to each of plezoelectric elements for controlling an injection amount of ink to be jetted toward a print medium via a corresponding nozzle. One of the drive waveforms is in the form of a cardiac waveform which has two voltage changing points in one drive period thereof. At the voltage changing point, a sign of slope of voltage variation is inverted. In the cardiac waveform, a voltage at one of the voltage changing points is set lower than a standby voltage, while a voltage at the other voltage changing point is set higher than the standby voltage.

Abstract: In an ink jet printer provided with a printing head having an ink chamber, a piezoelectric element and a nozzle tip; the printer is further provided with a drive signal generating circuit for generating drive signals corresponding to image information, a temperature sensor for measuring the temperature of the printing head; and a heating signal generating circuit for generating a heating signal on the basis of the temperature of the printing head measured by the temperature sensor. The piezoelectric element vibrates in response to the heating signal and generates heat so that the ink in the ink chamber is heated.

Abstract: Optical encoder system designs and methods for use thereof in printing devices are disclosed which are directed to solving problems caused by contaminant matter accumulating on optical encoder strips as well as scratching of optical encoder strips. An embodiment includes a dispenser and a take-up mechanism. The dispenser includes an encoder strip having first and second lengths. The second length of encoder strip is substantially free of contaminant matter. The first length of the encoder strip is coupled to the take-up mechanism so that the first length of the encoder strip is positioned between the dispenser and take-up mechanism. The take-up mechanism is configured to advance at least a portion of the second length of the encoder strip from the dispenser to a position between the dispenser and take-up mechanism upon actuation of the take-up mechanism.

Abstract: An ink ejector includes an ink jet head. The head has ink channels each defined between a pair of actuator walls. The head also has nozzles each communicating with one of the channels. The ejector can eject ink from each of the channels through the associated nozzle by driving the associated walls to increase the volume of the channel once and decrease it subsequently. The walls can be driven by a first ejection pulse and a second ejection pulse of voltage applied to them. The first pulse precedes the second. The first pulse has a width between 0.5T and 1.5T where T is the one-way propagation time during which a pressure wave is propagated one way in the channel. The interval between the first and second pulses is at least 0.3T. The second pulse has a width which is at least 0.3T. The sum of the interval and the width of the second pulse ranges between 1.3T and 1.7T.

Abstract: An ink jet recording apparatus of the shear mode type includes a recording head having a nozzle and, when a drive pulse signal is supplied thereto, driven to expel, from the nozzle, an ink supplied from an ink supply onto a recording medium so that recording is executed, a driver for supplying the pulse signal to the recording head, a temperature sensor for detecting an ambient temperature, and a control for changing the drive pulse signal corresponding to one record data on the basis of the ambient temperature detected by the temperature sensor.

Abstract: In an ink droplet ejecting method and apparatus, when a continuous dot printing is performed and also when a continuous dot printing is followed by a one-dot rest and again subsequent printing, it is intended to suppress the meniscus oscillation of ink, prevent the decrease in ink droplet ejecting speed of some dots and prevent the ink droplet ejecting direction from becoming unstable. A plurality of driving waveforms are provided in advance, and in accordance with whether there is ink ejection just before and just after one dot, an appropriate driving waveform for the dot is selected, whereby it becomes possible to suppress the meniscus oscillation of ink and a stable ink droplet ejection is ensured in a continuous dot printing and also when a continuous dot printing is followed by a one-dot rest and against subsequent printing.

Abstract: An ink droplet ejecting method and apparatus are provided that are capable of effecting printing at a high resolution and a high quality, and at the same time capable of preventing a drop-out in white and a decrease of print density from occurring, for example, in printing a solid pattern. As a jet pulse signal, a pulse signal is used which, when ejection of ink is performed in a continuous manner, provides a small ink droplet for only a first dot, and large ink droplets for second and subsequent dots and which, when ejection of ink is performed intermittently at intervals of only one dot, provides small ink droplets for all of the ink droplets formed. As a result, a small print portion becomes attractive, and the resolution can be enhanced. Further, in the case of continuous dots, no gap is formed between adjacent dots.