DE3545689C2 - recording device - Google Patents

Description

The invention relates to a Recording device in which a liquid in the Form of droplets is ejected onto a recording material such as paper or the like applied to record. This is the liquid Eject energy supplied to flying liquid droplets to build.  

In the Japanese publication JP-OS 58-1 87 364 a recording method is proposed, even if no droplet ejection signal is applied, constantly with an electrical signal a level at which no droplets are ejected, is applied to the ejection heater to the recording liquid to preheat in such a way that the Temperature of the recording liquid constantly on one Value kept within a predetermined range is, therefore, with an increase in the viscosity of the recording liquid at low temperatures good ejection of the liquid droplets is achieved.  

In JP-OS 58-2 20 757 is described a recording device with a Liquid discharge recording unit, the an electrothermal transducer device for generating on the liquid acting heat energy for the ejection flying droplets as well as a Heating device for preheating the Has liquid and with a Control device for controlling the converter device and the heater is provided.

In the cited prior art the preheating is done with only each a heating device.

The invention is based on the object a recording device according to the preamble of To further develop claim 1 such that simple Way a quick preheating can be achieved.

The invention will be described below with reference to embodiments explained in more detail with reference to the drawing.

Figs. 1 to 10 are diagrams each showing the overall configuration of the recording apparatus of the invention according to an embodiment.

Fig. 11 is a perspective view showing an example of the configuration of an ink jet printer as a recording apparatus according to the present invention.

Figs. 12A and 12B are respectively enlarged perspective views of a head unit in the recording apparatuses shown in Figs. 1 to 10 and a nozzle unit of the head unit, respectively.

Fig. 13 is a block diagram showing an example of the internal circuitry of the ink jet printer as an embodiment of the recording apparatus of the present invention.

Figs. 14A and 14B are flowcharts showing an example of a printing condition optimization process.

Figs. 15 and 16 are flowcharts each showing an example of a preheating process in the process steps shown in Figs. 14A and 14B, respectively.

Fig. 17 is a waveform diagram for explaining a print output signal supplied to a head unit.

Fig. 18 is a graph of curves showing the relationship between a feed time period and a temperature, using as parameters the frequency of the print output signal supplied to the head unit.

FIGS. 1 to 10 each schematically show the overall design of a recording device according to the invention.

The recording apparatus according to the example shown in FIG. 1 includes a liquid ejection recording unit 100 , a recording unit controller 110 , a heater 120, and a thermal controller 140 . The recording unit 100 includes the ejection energy output device 102 having an electrothermal energy conversion device that can heat the liquid upon application of an electrical signal to form flying liquid droplets. Thereby, the droplets are ejected from the recording unit 100 and are applied to a recording material P, whereby the recording is performed. The controller 110 may set the electric signal for forming the flying droplets according to the input of the recording signal SA and may supply it to the ejection energy output device 102 . A heater 120 is mounted in the recording unit 100 and heats the liquid from the outside. From the heat controller 140 is heated at the switching on of a power supply SW in accordance with the environmental conditions by the heater 120, the liquid and / or set an electric signal within a range of the recording unit controller 110, in which no flying droplets are formed; As a result, the liquid is heated according to the ambient conditions.

The recording apparatus according to the example shown in FIG. 2 includes the liquid ejection recording unit 100 , the recording unit controller 110 , the heater 120 , the thermal control unit 140 , the ejection control unit 150, and a controller 160 . The recording unit 100 includes the ejection energy output device 102 having the electrothermal energy conversion device which, upon supplying an electrical signal, can heat the liquid to form the flying liquid droplets. Thereby, the recording unit 100 discharges the flying droplets and applies them to the recording material P to thereby record. The recording unit controller 110 may set the electric signal to form the flying droplets corresponding to the input of the recording signal SA and supply it to the ejection energy output device 102 . The heater 120 is mounted in the recording unit 100 and heats the liquid from the outside. The liquid is heated by the heat control device 140 to heat the liquid according to the ambient temperatures by the heater 120, and / or to set an electric signal to the recording unit controller 110 within a range where no flying droplets are formed. The ejection controller 150 sets an electric signal to the controller 110 to form the flying droplets, whereby the recording unit 100 can eject the flying droplets. The flow control device 160 sets at the switching on of the power supply SW first the heat control device 140 and then the discharge control 150 in operation.

The recording apparatus according to the example shown in FIG. 3 includes the liquid ejection recording unit 100 , the recording unit controller 110 , the heater 120 , the heat controller 140 , the ejection controller 150, and the process controller 160 . The recording unit 100 includes the ejection energy output device 102 having the electrothermal energy conversion device that can heat the liquid for forming flying liquid droplets upon application of an electrical signal. These droplets are ejected from the recording unit 100 and applied to the recording material P for recording. The recording unit controller 110 may set the electric signal for forming the flying droplets according to a command signal at the beginning of recording upon the input of the recording signal SA and supply it to the ejection energy output device 102 . The heater 120 is mounted in the recording unit 100 and heats the liquid from the outside. The liquid is heated by the heat control device 140 to heat the liquid in accordance with the environmental conditions by means of the heater 120, and / or to set an electric signal on the recording unit controller 110 within a range in which no flying liquid droplets are formed. The ejection controller 150 sets, at the recording unit controller 110, the electric signal for forming the flying droplets, whereby the recording unit 100 can eject the flying droplets. The sequencer 160 , in response to the input of the recording signal SA, operates the thermal controller 140 and the ejection controller 150 , after which it then generates a command signal.

The recording apparatus according to the example shown in FIG. 4 includes the liquid ejection recording unit 100 , the recording unit controller 110 , the heater 120 , a capping device 180, and a controller 200 . The recording unit 100 includes the ejection energy output device 102 , which applies ejection energy to the liquid in accordance with the supply of an electrical signal to form flying liquid droplets. As a result, the recording unit 100 discharges these flying droplets, which are recorded on the recording material P. The Aufzeichnungseinheit- control device 110 leads to the input of the recording signal SA toward the discharge energy delivery device 102 to the electric signal for forming the flying droplets. The heater 120 is mounted in the recording unit 100 and heats the liquid from the outside. The capping device 180 may be associated with the recording unit 100 . If the ambient temperatures are inconvenient for a recording operation, a heating operation is commanded by the controller 200 of the heater 120 in connection with a single recording operation by the recording unit 100 . If no next recording signal SA is inputted even after the lapse of a set period of time after the completion of the single recording operation, the control device 200 of the heater 120 commands the cancellation of the heating and simultaneously sets the capping device 180 to operate, thereby covering the capping device 180 with the recording unit 100 is associated.

The recording apparatus according to the example shown in FIG. 5 includes the liquid ejection recording unit 100 , the recording unit controller 110 , the heater 120 , the heat controller 140 , the ejection controller 150, and the process controller 160 . The recording unit 100 includes the ejection energy output device 102 having the electrothermal energy conversion device that can heat the liquid for forming flying liquid droplets upon application of an electrical signal. Thereby, these droplets are radiated and ejected from the recording unit 100 , thereby recording on the recording material P. The recording unit controller 110 may set the electric signal for forming the flying droplets in response to the input of the recording signal SA and supply it to the ejection energy emitting device 102 . The heater 120 is mounted in the recording unit 100 and heats the liquid from the outside. The heat control device 140 operates to heat the liquid according to the ambient conditions, heating the liquid by the heater 120, and / or at the recording unit controller 110, setting an electrical signal within a range in which no flying droplets are formed. The ejection controller 150 sets the electric signal for forming the flying droplets at the recording unit controller 110 , thereby allowing the recording unit 100 to eject the flying droplets. The process controller 160 operates the thermal controller 140 upon turning on the power SW and / or inputting the recording signal SA. After start-up of the thermal control device 140 , the flow control device 160 remains idle for a set period of time, after which it then starts the exhaust control device 150 .

The recording apparatus according to the example shown in FIG. 6 includes the liquid ejection recording unit 100 , the recording unit controller 110, and the thermal controller 140 . The recording unit 100 includes the ejection energy output device 102 having the electrothermal energy conversion device that can heat the liquid for forming flying liquid droplets upon the supply of an electric signal. The recording unit 100 ejects these flying droplets, thereby recording on the recording material P. The recording unit controller 110 may set a pulse width of the electric signal to form the flying droplets and supply the electric signal to the ejection energy output device 102 in response to the input of the recording signal SA. The thermal controller 140 includes a pulse width adjuster 142 for setting a pulse width at the recording unit controller 110 . This heat control means sets an electric signal having a pulse width within a range within which no flying droplets are formed for heating the liquid in accordance with the environmental conditions at the recording unit controller 110 .

The recording apparatus according to the example shown in FIG. 7 includes the liquid ejection recording unit 100 , the recording unit controller 110, and the thermal controller 140 . The recording unit 100 includes the ejection energy output device 102 having the electrothermal energy conversion device that can heat the liquid for forming flying liquid droplets upon the supply of an electric signal. The recording unit 100 ejects these flying droplets, thereby recording on the recording material P. The recording unit controller 110 may set, in response to the input of the recording signal SA, a frequency of the electric signal to form the flying droplets and supply the electrical signal to the ejection energy output device 102 . The thermal controller 140 includes a frequency adjuster 144 for setting a frequency on the recording unit controller 110 . From this heat control device 140 , an electrical signal which is within a range in which no flying droplets are formed is set at the recording unit controller 110 at a frequency higher than the frequency of an electrical signal at the time of recording to thereby adjust the liquid according to the environmental conditions to warm up.

The recording apparatus according to the example shown in FIG. 8 includes the liquid ejection recording unit 100 , the recording unit controller 110, and the thermal controller 140 . The recording unit 100 includes the ejection energy output device 102 having the electrothermal energy conversion device that can heat the liquid for forming flying liquid droplets upon the supply of an electric signal. The recording unit 100 ejects these flying droplets, thereby recording on the recording material P. The recording unit controller 110 may set a voltage of the electric signal to form the flying droplets and supply the electrical signal to the ejection energy output device 102 in response to the input of the recording signal SA. The thermal controller 140 includes a voltage adjuster 146 for adjusting a voltage at the recording unit controller 110 . From this heat controller 140 , an electrical signal having a voltage within a range in which no flying droplets are formed is set on the recording unit controller 110 ; As a result, the liquid is heated according to the ambient conditions.

The recording apparatus according to the example shown in FIG. 9 includes the liquid ejection recording unit 100 , a driving device 210, and a thermal control device 220 . The recording unit 100 includes the ejection energy delivery device 102 , which, in response to the application of an electrical signal to the liquid, acts on energy to form the flying liquid droplets. These flying droplets are jettisoned by the recording unit 100 , thereby recording on the recording material P. The driving device 210 moves the recording unit 100 in a predetermined direction with respect to the recording material or paper P. When the driving device 210 or the movement caused thereby is stopped, the liquid in the recording unit 100 is heated by the heat control device 220 .

The recording apparatus according to the example shown in FIG. 10 includes the liquid ejection recording unit 100 , the recording unit controller 110 , the thermal control unit 140, and the ejection control unit 150 . The recording unit 100 includes the ejection energy output device 102 having the electrothermal energy conversion device for applying energy to the liquid in accordance with the supply of an electrical signal to form the flying liquid droplets. These flying droplets are ejected from the recording unit 100 , thereby recording on the recording material P. From the recording unit controller 110 , in accordance with the input of the recording signal SA, the electric signal for forming the flying droplets can be set and supplied to the ejection energy output device 102 . From the thermal controller 140 , an electrical signal is set at the recording unit controller 110 for heating the liquid according to the environmental conditions within a range in which no flying droplets are formed. The ejection controller 150 includes a frequency adjuster 154 for setting a frequency of the electrical signal to the recording unit controller 110 . From this ejection control means 150 , the electric signal for forming flying droplets after heating is adjusted at a frequency below a frequency of the electrical signal during recording, thereby causing the ejection of flying droplets from the recording unit 100 .

The recording device according to the invention will now be detailed on the basis of the drawing described.

Fig. 11 shows an example of the structure of recording units in ink-jet printers, which are embodiments of the recording apparatus according to the invention, for the design of which the examples shown in Figs. 1 to 10 are explained. In the ink-jet printer according to the example shown in Fig. 11, a recording unit is mounted on a carriage which is moved in a predetermined direction with respect to a recording surface. FIGS . 12A and 12B are an enlarged view of the head unit of FIG. 11 and an enlarged view of a nozzle unit of the head unit, respectively.

In Figs. 11, 12A and 12B, HU is a liquid ejection recording unit or head unit attached to a carriage C. It is also possible to provide recording units HU in the number of color inks used. By FC is meant a flexible cable consisting of a set of lines for signals for controlling the liquid or ink ejection of the recording unit HU and the like.

The carriage C is attached to a belt or the like, for example, and is moved by means of a motor or the like in the directions shown by the arrows S in FIG. 11. In this case, the carriage C is guided by guide rails R to this movement in the directions S.

With P, the recording material such as paper or the like is referred to, which is transported or advanced in the direction shown by an arrow f in Fig. 11. With PL, a platen roller is designated, which forms a recording surface for the recording material P. That is, the carriage C is moved in the directions S by means of the driving device along the guide rails R, thereby making it possible to record on the recording surface of the recording material P.

With ST an intermediate container is designated, which at the Carriage C is attached; with TB1 is an ink feed tube for connecting a (not shown) Main tank labeled with the intermediate tank ST; with TB2 is an ink feed tube for connecting the Intermediate tank ST with a liquid chamber IR in the recording unit HU called.

Further, a cover or a cover CAP is arranged such that it at a starting position H of the carriage C in the Directions S of the recording unit HU faces. When the carriage C is in the home position H, can by means of an adjusting device such as a motor or the like the cover member CAP to the recording unit  HU moved and pressed against the discharge surface. It is the output surface of the recording unit HU pressed a collecting part SP, which is the ink collects and that for example from a porous material is formed for the absorption of water.

In Fig. 12A, BP denotes a base plate on which the feed tube TB2, a liquid chamber IR, a nozzle unit NZ, the flexible cable and the like are arranged, these components being held by the base plate BP. BSH is an elastic member for supporting the peripheral portion of the nozzle unit NZ; with FP is called a front panel; TS denotes a temperature sensor such as a thermistor or the like for detecting the temperature; HTR is a heater which is formed by, for example, an electrothermal energy converter such as a positive characteristic thermistor or the like and which is attached to the recording unit HU to heat the recording liquid or ink from the outside. TP refers to a heat conducting plate.

In Fig. 12B, OR denotes a nozzle opening serving as an ink ejection port. In this embodiment, in the nozzle unit NZ, nozzle orifices OR are vertically arrayed in a predetermined number. ICH denotes a liquid channel for connecting the respective nozzle opening OR to the liquid chamber IR. ET denotes an ejection heater which serves as an ejection energy ejector which supplies heat energy for ejecting the ink or liquid in the liquid channel ICH.

For recording with the above-described recording apparatus  first comes out of the main container via the feed tube TB1 the intermediate container ST ink or recording liquid supplied. Further will be via the feed tube, the liquid chamber IR and the Fluid channel ICH with the recording liquid filled. Next, via the flexible cable FC is off a droplet ejection signal generator explained below to the ejection heater ET an electrical Signal applied, whereby the ejection heater ET in Operation is set. The ejection heater then generates ET thermal energy, that of the recording liquid in the liquid channel ICH near the ejection heater ET is fed, causing in the recording liquid a steam bubble is generated, which from a sudden increase in volume of the recording liquid is accompanied in this area. Thereby that will be in the area downstream of the ejection heater ET located recording liquid such the nozzle opening OR ejected that from the recording liquid the liquid droplet is formed. This droplet will like the recording material P Paper or the like applied, in front of the nozzle unit is transported; that way the Recording performed.

Fig. 13 shows an example of the configuration of a control device for the ink jet printer as an embodiment of the recording device according to the present invention. In this example, it is assumed that the control means obtains print data from a processing computer and stores the print data for one line, and controls the print head by means of a control unit for the recording unit HU, to thereby perform printing.

Referring to Fig. 13, a programmable peripheral interface 1 first receives, in parallel, the print data sent from the processing computer to the printer in this example; thereafter, the interface 1 transmits the print data to a microprocessor (MPU) 2 . The interface 1 also controls an operation panel 6 and effects an input from a home position sensor 7 . The microprocessor 2 controls the respective parts in the printer and executes a processing program explained below. A random access memory (RAM) serves as a line buffer memory 3 for storing the print data received in the amount for one line from the interface 1 . Denoted at 4 is a read-only memory for producing print images of the printed characters, namely, a read-only memory, and at 5 a control read-only memory (ROM) in which processing programs (as shown in Figs. 14 to 16) stored by the Microprocessor 2 are executed. These components 1 to 5 are connected to each other via an address bus AB and a data bus DB.

The control panel 6 includes a keyboard, indicator lamps and the like. The home position sensor 7 is located near the home position of the carriage C. A cover sensor 8 detects the state of the head cover member CAP, namely, whether the cover member CAP is attached to the recording unit HU or not. A paper sensor 9 detects the absence of recording or printing paper.

From a head control unit 10 , the print data and the printout times are buffered and printing commences in accordance with a command from the microprocessor 2 . Namely, in this embodiment, the head control unit 10 is used as a dedicated integrated circuit, thereby achieving a high processing speed. The initially cached print data are output unchanged, unless otherwise desired a change.

Fig. 13 further shows a driver stage 11 for driving the recording unit HU corresponding to the head control unit 10 , a protection circuit 13 for the recording unit HU, a driver stage 14 for driving the outdoor heater HTR mounted in the recording unit HU for heating and keeping the ink warm, a temperature comparator 15 for the ink temperature sensor TS mounted in the recording unit HU, a font switch 16 for commanding the font switching and an input selector 17 which selects the signals from the temperature comparator 15 and the font switch 16 and which is controlled by the microprocessor 2 .

Further, Fig. 13 shows a driver stage 18 for operating a motor M3 for moving the cover member CAP with respect to the recording unit HU, driver stages 22 and 24 for operating a paper feed motor M1 and a carriage M2 moving motor M2, respectively and a solenoid valve 20 and a driver stage 21 therefor, which are used for bleeding the head unit or recording unit HU.

Now, the basic processes in the ink jet printer shown in Figs. 11 to 13 according to this embodiment will be described. In this embodiment, when the power of the printer is turned on and when the printing is initiated, preheating and prefire are performed on the recording unit HU, thereby achieving a good ink discharging state. Further, in connection with these processes, the coverage of the head unit HU is suitably controlled. It is assumed that the preheating process includes an external heating process and / or an internal heating process.

In this case, as externally heating, heating of the ink in the head unit HU from outside is indicated by feeding the outer heater HTR, while as internally heating the ink in the head unit HU by supplying pulses within a range in which the head unit HU no ink is ejected, is designated to the ejection energy-dispensing device. The head control unit 10 is supplied with a print output start signal at each set frequency during internal heating.

Specifically, when the preheating is caused by the internal heating, it is desirable to apply to the head unit a pressure output signal of suitable pulse width, frequency and voltage. However, the use of the head control unit 10 makes it possible to perform satisfactory processes even at the normal processing speed of the microprocessor. That is, according to this embodiment, the parameters of the respective printing output signals can be freely changed and set according to requirements, so that the head unit HU can be optimally heated, the programs can be simplified and a high processing speed can be achieved.

On the other hand, if a prefire is to be effected as well, it is advantageous to supply the head unit HU with a pulse width, frequency and voltage as a parameter equally as in the above case. In this embodiment, these parameters as well as the number of discharges are changed according to the environmental conditions. This case can be accommodated in the embodiment by the program equipment in a simple manner, the optimal preliminary injection can be brought about. Further, in this embodiment, using the head control unit 10, all bits of the print output signals are set to "1" during the prefire. Therefore, it is not necessary to change the print data each time with respect to the print data in this case, so that the program can be simplified and a high processing speed can be achieved.

Below is the pressure state optimization in this Embodiment described.

Figs. 14A and 14B show an example of a print condition optimization program in the recording apparatus of the present invention.

Immediately after the power supply of the printer is turned on, as an initial preparation, the interface 1 and the head control unit 10 are prepared as circuit units, while the program prepares the line buffer memory 3 and checks the operation of the control fixed memory 5 , providing the respective parameters corresponding to the parameters Processing are used (step S1).

After completion of the initial preparation, the head cover CAD motor M3 is operated to open the head cover CAD, while the cover sensor 8 is monitored by the microprocessor 2 (step S2). Under supervision of the home position sensor 7 , the carriage motor M2 is driven so that the carriage C is returned to the home position H (step S3). Thereafter, under supervision of the cover sensor 8, the motor M3 for closing the head cover CAD of the head unit HU is driven (step S4). Further, the motor M1 for conveying the recording paper P is driven by a distance of, for example, 1 line (step S5). After these operations, the head unit HU is prepared.

In the initial preparation program, first the Preheating the head unit HU started (step SH).

Fig. 15 shows an example of the preheating process for external and internal heating. According to the foregoing, for internal heating from the head control unit 10 to the head unit HU, an output signal having a pulse width, a voltage and / or a high frequency is applied within respective areas where no ink is ejected; As a result, heat is generated in the head unit HU. For external heating, the heater HTR attached to the head unit HU is used as the heating element, and the driver 14 is turned on by the microprocessor 2 , thereby heating the head unit HU. The external heating is started at step SH1, whereafter at step SH2 control unit in the head 10, the operating mode "external heating" into sets is. At a next step SH3, all the dots or bits of the print signal are set to "1". At a step SH4, the internal heating is started.

For the interte heating, the pulse width, the span tion and the frequency of the pressure output signal or Pressure signal adjusted in a suitable manner, according to is explained below.

After starting the preheating of the head unit in this manner, the temperature of the head unit HU is checked to determine whether or not the temperature of the head unit HU exceeds a constant upper temperature (step SH5). If the answer is "YES", the preheat is ended. If the answer is "NO", a step SH6 follows, wherein the preheating continues to proceed, and it is determined whether a predetermined time has elapsed after the start of external or internal heating (step SH6). If the answer is "YES" at step SH6, namely, even after the lapse of the predetermined time, the temperature has not exceeded the constant upper temperature, a step SH7 follows. At the step SH7, in order to prevent thermal destruction of the head unit to the head control unit 10, a command to cancel the internal heating is sent, whereby the internal heating is terminated. In a next step SH8, the driver stage 14 is turned off to stop the exter ne heating. Thus, the preheat is ended, after which the program returns to a step S6 of FIG. 14A. The constant temperature for comparison with the temperature is the upper operating limit temperature of the head unit HU (for example, 42 ° C). It can be seen that the switching on and off of the external and the internal heating between these can be reversed in the process.

Referring to Fig. 14A, after the completion of preheating, the apparatus assumes a rest condition for a predetermined time, with the temperature uniformly distributed in the local heating unit HU (step S6). After the lapse of the predetermined rest time, a prefire process is executed (step SJ). If preheating was suddenly or rapidly heated after the power was turned on, a relatively long sleep time can be selected. In this case, for example, a rest time of 500 ms can be set.

Fig. 16 shows an example of the prefire process. First, at a step SJ1 in the head control unit 10, the ejection conditions are set. Then, in step SJ2, all the dots or bits of the print signal are set to "1". At a next step SJ3, the printing signal is applied to the head unit HU to eject the ink. This ejection is repeated under test in a step SJ4 in a predetermined number. Thereafter, the program returns to a step S10 of Fig. 14A at which a printing ready state of the apparatus starts. In this way, namely, the initial preparation of the head unit HU is completed. The program then changes to the print ready state for the processing computer. The determined number of discharges as well as the parameters of the discharge conditions may be suitably selected according to the environmental conditions, which will be explained below.

When a print signal or print start signal is supplied to the print standby state from the processing computer (step S10), the following print data is latched in the interface 1 and transferred to the line buffer memory 3 . From the same temperature Ver 15 a signal from the mounted on the head unit HU temperature sensor TS is detected and it is averaged, whether the temperature is higher than a lower konstan te temperature, namely higher than 20 ° C or not (step S11). If the answer is "YES", the head cover motor M3 is driven to close the cover (step S12). Thereafter, the head control unit 10 is switched to the normal printing mode to execute the prefire (step SJ of Fig. 16). In contrast, when the answer is "NO" at step S11, namely, it is determined that the temperature is lower than the lower constant temperature, the cover is closed (step S13) and then the preheating process is executed (steps SH of FIG . 15). After an idle state for a predetermined period of time (step S15), the ejection conditions and the ejection number are set in the head controller 10 again, after which the prefire is effected (steps SJ of Fig. 16).

In this case, the standby or rest period shorter than the rest period mentioned above be chosen, if not the fast heating as at the commissioning of the recording unit brought about becomes. The lower constant temperature is the lower one Operating limit temperature of the head unit HU.

Next, the driver stage 14 is turned off to terminate the external heating (step S16), whereafter the printing state of the recording apparatus starts. That is, during the printing operation in the drive of the carriage motor M2, no heating operation is performed.

In addition, the heating process can also without increasing the Electricity consumption in connection with the Printing process in step S20 are executed. Ie., if during movement of the carriage C the movement  direction at the two ends of the range of movement of the Carriage C changes, is at these reversal points of the Carriage C first stopped; therefore, to this Timing of the heating process to be carried out.

For example, if one line is printed after the start of printing and the carriage motor M2 stops (step S20), it is then checked whether the temperature of the head unit HU is higher than the lower constant temperature or not (step S21). If the answer is "YES", a step S23 follows. If the answer is "NO", the driver stage 14 is driven to effect the external heating (step S22), followed by step S23. That is, it is determined whether or not the temperature of the head unit HU is higher than the upper constant temperature (step S23). If the answer is "YES", the external heating is immediately canceled (step S25). If the answer is "NO", a standby state is established for a predetermined time (for example, 200 ms) (step S24), after which the external heating is stopped (step S25).

Next, as shown in Fig. 14B, the paper feed motor M1 is driven to convey the paper P (step S30), then steps S21 and S22 are performed similarly to steps S31 and S32, followed by a step S40. That is, an internal timer is turned on by the microprocessor 2 , and it is determined whether or not print data has been stored in the interface 1 within a predetermined time (5s, for example) (steps S40 and S41). Here, if the answer is "YES", step S16 follows FIG. 14A. If the answer is "NO", the driver stage 14 is turned off to terminate the external heating (step S42). Thereafter, the carriage motor M2 is driven to return the carriage C to the home position H (step S43). Then, the cover motor M3 is driven to close the cover (step S44), after which the program returns to step S10 of Fig. 14A.

In this way, according to this embodiment to carry out the preheating process the preliminary to the Ejecting the not used for the recording or usable liquid droplets brought about. To this Way can be at a very long interruption of the up drawing and also at a considerable increase the viscosity of the recording liquid due to Evaporation of the solvent component of the ejection optimized for printing. Ie, first by preheating the high viscosity part of the up heated drawing liquid and its temperature lifted so that the viscosity of the recording liquid is reduced to a value at which the liquid droplets can be ejected. By the following This preliminary part of this condition will become part of the Recording liquid from the liquid channel ICH drained so that the area near the ejection heater Direction ET the recording liquid with in one viscosity suitable for ejection is fed and thereby the for a good output bring about suitable state of the recording liquid leads. To establish the consistency of this Ejection state, the following experiments were carried out:

Experiment using the embodiment

The ink-jet printer according to this embodiment was used with the recording head unit shown in Fig. 12B, in which 24 nozzle orifices (having respective dimensions of 50 x 40 μm) were arranged vertically in a line at uniform intervals of 0.141 mm. This recording apparatus was supplied with a recording liquid having components as shown below. Upon resumption of recording after the lapse of a recording interruption period of 12 hours, a signal having a voltage of 23.5 V, a pulse width of 5 μs and a frequency of 10 kHz was recorded at 25 ° C and 30% RH of preheating applied to the ejection heater ET. Thereafter, 100 pulses of a signal having a voltage 23.5 V, a pulse width of 10 microseconds and a frequency of 2 kHz were applied to the Ausstoßheizvor direction ET, whereby the liquid droplets not used for the recording were ejected. Regarding a defective ejection after the recording interruption, the recording apparatus was evaluated by detecting the number of liquid droplets which were not ejected to the recording signal up to the ejection of the recording liquid liquid droplets of the recording liquid from all 24 nozzle orifices were. The results are shown in Table 1 below.

The components of the used for the recording Recording liquid were as follows:

C.I. direct black 19 2 parts by weight diethylene glycol 30 parts by weight water 70 parts by weight

Experiment using a comparator

A recording apparatus used in the Structure of the recording apparatus according to the Ausfüh same example, but against the output heater for recording only one electric Signal for the output of the used for the recording Liquid droplets was created. This comparison Recording device was the above Supplied recording liquid. At the resumption me the record after the expiration of the interruption 12 hours at 25 ° C and 30% relative humidity Only the electric power was supplied to the ejection heater signal with the voltage of 23.5 V, the pulse width of 10 μs and the frequency of 2 kHz for the droplet created and made the record. After Break was the recording device in Hin look at the defective output in a similar way as rated in the experiment with the embodiment. The results are shown in Table 1.  

Table 1

From Table 1 it can be seen that even with the Resume the recording after the expiration of a such a particularly long interruption or standstill always a good and steady ejecting the Liquid droplets can be achieved.

Next is the choice of parameters for the impulse width, frequency, voltage and the like of the Pressure signal in the preheat and the preliminary blow erläu tert.

The extent of the deviation of the viscosity in the Liquid channel ICH and in particular near the Düsenöff OR recording liquid located on the suitable area due to the recording interruption differs depending on the own of the device used, the physical  Properties of the recording liquid, the environment conditions such as temperature, humidity and humidity The like at the installation and deployment of Vor direction, etc. Therefore, the parameters of the pressure signal in the preheating and especially in the internal Hei in a suitable way according to the individual requirements directions and their conditions of use.

On the other hand, this will be in the preliminary of the Ejector ET supplied signal among such Conditions that the recording liquid, whose viscosity is outside of the output of the Droplet for recording suitable area lies out the liquid channel ICH ejected and removed.

Further, the number of discharges in the prefire according to the existing at that time Umge conditions are changed, which makes this process can be carried out in an effective manner.

Fig. 17 shows an electrical signal applied to the ejection heater ET. In this illustration, v _o denotes the voltage, while mti w _i denotes the pulse width. In the case of supplying the signal to the ejection heater ET when preheating by the heating bubble, it may be the case that the subsequent droplet ejection becomes uneven or, in the worst case, no droplets are ejected. Therefore, the electric signal applied to the ejection heater ET in the preheat must be within a range within which no bubbles are generated at the ejection heater ET.

On the other hand, since these preheating operations are performed upon turning on the power of the printer and at the start of printing, the preheating is done fairly frequently. Therefore, deterioration of the durability of the discharge heater ET caused by these preheating operations must be avoided. The durability of the exhaust heater ET was examined under the conditions that in the preheating operation with the ejection heater ET, the ejection device ET supplied electric power (W) was kept constant and the pulse width w _i and the applied voltage v _{o were} changed. It was found that the durability of the ejection heater ET was better when the pulse width w _i and the applied voltage v _{o were} chosen small.

On the other hand, for heating the head unit HU through the time required to the desired temperature the electric heater supplied to the ejection heater ET Power (W) determined. In the actual use of the Recording device is but to strive that the time required to start printing, viz the waiting time is as short as possible.

Nevertheless, it is in view of the above Durability of the ejection heater ET not favorable, safely the chip applied to the heater to increase the quality of Furthermore, the generation of a bubble at the ejection heater ET in the preheating subsequently incorrect printing or failure of the It is also difficult to eject the impulse width to enlarge.

Therefore, to raise the temperature of the heating unit  the desired temperature in a short time and within of such a range that the preheating operations not the durability of the ejection heater ET be harmonize and produced at this no bubbles be an increase in the frequency of the ejection heater Device ET supplied electrical signal purpose relevant.

Fig. 18 shows an example of the relationships between the time (in minutes) and the head unit Tempe temperature (° C), wherein the frequency of the applied to the Ausstoßheizvor direction ET preheat signal is used as a parameter. In this example, the applied voltage v _{o was set} to 24 V, the pulse width w _i to 5 μs and the frequency to 10 kHz, 5 kHz and 2 kHz, respectively. The head unit temperature was measured with the temperature sensor TS.

Under change of the voltage, the pulse width and the Frequency over the above values carried out two attempts.

Trial 1

The ink jet printer according to the embodiment was used with the nozzle unit NZ shown in Fig. 12B in which 24 nozzle openings (each having dimensions of 50 × 40 μm) were vertically aligned in a line at regular intervals of 0.141 mm. This recording apparatus was supplied with the recording liquid having the above components. The ejection heater ET was supplied with the electric signal under the conditions shown in Table 2, and thus the preheating operation was performed.

The presence or absence of bubbles was due to Observe the heater with an optical Microscope detected. The results are in Table 2 cited.  

Table 2

experiment 2

It became the same inkjet printer as the Experiment 1 uses and the recording device the Recording liquid with the aforementioned Supplied components. The signal was sent to the output heater ET among those listed in Table 3 created conditions. The preheating operations were repeatedly to the durability of the ejection heater ET to investigate. The results are in Table 3 cited.

Table 3

From Table 3 it can be seen that the pulse width  in the preheating of the ejection heater ET supplied led electrical signal preferably less than that of the electrical signal for recording is selected. As a result of further detailed It has been determined that it is desirable to aim for Pulse width in a range of 1 to 1/20 of the pulse width for the record to choose.

Furthermore, it will be apparent that it is preferable that the applied voltage of preheating the ejection heater device ET supplied electrical signal same or lower than the applied voltage for the Record to choose.

Moreover, by adjusting the frequency of the electrical signal for preheating to a frequency, which is higher than the one for the recording that is for the heating time required to be shortened.

These parameters, as well as the number of pulses or off bumps can be very easily adjusted by means of the head control unit 10 according to the above.

It will now be the ejection conditions in the preliminary round explained.

If the recording is interrupted for a long time was due to the evaporation of water and water volatile organic solvent and the like Viscosity of the in and near the nozzle openings OR lag Add ink so that the ink is less well ejected can be. Although the viscosity of the remaining ink reduced by the preheating described above it is higher than the one for recording  suitable ink, so that the sizes, speeds and the like of the droplets are different and these remaining ink is unsuitable for recording. Therefore, in this embodiment, after the Vor warm the advance blow brought about.

In the preliminary blow, the ink is not always through the first impulse of the ejection heater at this time Device ET applied signal emitted. Therefore, can by increasing the energy of the signal for the prefire versus the energy of the signal for printing as well by changing the ejection duration according to the environment conditions the time required for the preliminary shortened and brought about a very effective ejection become.

The increase of the energy of the signal for the preliminary blow can be practically brought about by the Voltage and / or the pulse width over those be enlarged for recording. That is, if the Voltage and the pulse width of the ejection heater direction ET for printing applied signal respectively 24 V or 10 μs, the voltage and / or the Pulse width of the signal for the predischarge chosen so that they are larger than these values. In experiments were achieved good results when the voltage on the 1 to 5 times and preferably 1 to 2 times those was set for printing and alike the pulse width to 1 to 5 times and preferably 1 to 2 times that set for printing has been.

With regard to the ejection duration, it is favorable to set the number of ejections, namely, the number of pulses corresponding to the environmental conditions. In experiments, in the pre-discharge (steps SJ after step S6 of Fig. 14A) before the start of printing after the power was turned on, when 100 to 150 pulses were applied to the discharge heater ET, then a good print quality was obtained. After the onset of printing, the viscosity of the ink is high at low temperatures and, compared to high temperatures, uniform ejection is more difficult to achieve; Therefore, it is advantageous to set the number of Tin tenausstöße accordingly suitable. In experiments, in the preliminary blow at a temperature above the lower constant temperature (of, for example, 20 ° C) ("YES" at step S11 in Fig. 14A), it was determined that the uniform discharge was achieved when the ejection heater ET 20 to 50 pulses were created. In contrast, in the pre-discharge at a temperature lower than the lower limit temperature ("NO" in step S11), the uniform discharge was achieved when 50 to 100 pulses were applied to the discharge heater ET.

The ejection conditions in these preliminary ejection operations can also be easily adjusted by means of the head control unit 10 . The processes can be carried out in a suitable manner at high speed, without the load of the microprocessor 2 is increased.

If, on the other hand, the region where the printer is in accordance with This embodiment is used, limited and Precisely know in advance, the number of ejections also be changed according to the respective region, For example, in a high temperature region and low humidity the temperature is always high, so that the ink dries considerably. Therefore, the  Precipitation amount at the higher temperature compared that at the lower temperature increased to thereby stabilizing the ink ejection. Furthermore, can by changing the numerical values for the number of outputs or discharge number of uniform ink discharge reached become.

Although, as this embodiment, an ink jet printer has been described, exists for the erfindungsge The recording device is not limited thereto; rather, the same design is obvious also with an inkjet printer in the so-called full time len multi-nozzle design applicable, in which a lot number of head units in the width direction of the up paper is arranged.

Furthermore, in the embodiment, the respec gen parameters in the preheating operations and the respective parameters and the number of outputs in the Vor ejection operations according to the temperature conditions set. In the recording invention vorvor However, there is no restriction on this Method; Rather, for example, a procedural be used, in which these parameters and the Number of discharges according to environmental conditions such as Humidity, the air pressure or the like become.

As described above, in the inventions  Recording device according to the invention before the beginning of the Printing after turning on the power in the Head control unit the appropriate ejection conditions after which the pre-discharge operations were brought about become. Therefore, it is possible to have a liquid ejection Recording device to create their program tion can be simplified and in which the Druckzu stood fast and easy to be optimized.

Furthermore, in the inventive recording device the discharge conditions in a simple manner be changed.

Claims (7)

1. Recording device with
a liquid discharge recording unit ( 100 ), the
an electrothermal transducer means ( 102 ) for generating ejection heat energy applied to the liquid for ejecting flying droplets and
a heating device ( 120 ) for preheating the liquid has, and with
a control device ( 2; 140, 150, 160, 200, 220 ) for controlling the converter device ( 102 ) and the heating device ( 120 ),
characterized
in that the control device ( 2; 140, 150, 160, 200, 220 ) is formed by a microprocessor device ( 2 ),
receives the recording signals and processes them to control the liquid ejection recording unit ( 100 ), and
which, after a predetermined time (S41) was not carried out the recording with the liquid discharge recording unit (100) for performing a pre-heating in dependence on the instantaneous temperature of the flues sigkeitsausstoß recording unit (100) which Heizeinrich device (120) is activated and also the transducer means ( 102 ) for delivering a preheat heat energy to the liquid at which no flying droplets are ejected. 2. Recording device according to claim 1, characterized in that the control device ( 2; 140, 150, 160, 200, 220 ) when the power supply, the heater ( 120 ) is activated and also the transducer means ( 102 ) for delivering the preheating heat energy controls. 3. Recording device according to one of claims 1 or 2, characterized in that the control device ( 2; 140, 150, 160, 200, 220 ) causes a preparatory ejection before the start of a recording and that the preheating is performed before the preparatory ejection. 4. Recording device according to one of claims 1 to 3, characterized in that the control device ( 2; 140, 150, 160, 200, 220 ), the heating of the liquid depending on the ambient state or the temperature of the liquid ejection recording unit ( 100 ) by determining the pulse voltage or frequency of the drive signal applied to the transducer means ( 102 ) for outputting the preheat thermal energy. 5. Recording device according to one of claims 3 or 4, characterized in that the control device ( 2; 140, 150, 160, 200, 220 ) a capping means (CAP) for covering the Flüssigkeitsaus shock-recording unit ( 100 ) controls such that this is closed before the preliminary discharge. 6. Recording device according to one of claims 1 to 5, characterized in that the control device ( 2; 140, 150, 160, 200, 220 ) during re-recording before the expiration of the predetermined period (S41) for preheating only the Heizein direction ( 120 ) is activated. 7. Recording device according to claim 6, characterized in that the heating device ( 120 ) during a recording on only a reversal of the direction of movement (S) of the liquid keitsausstoß recording unit ( 100 ) carrying carriage (C) is activated.