JP2007152736A - Inkjet recording apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To detect a condition in which ink is sufficiently fixed without costing so that the inside of a paper path is not stained when a face already printed by printing on both sides or the like passes through the inside of the paper path in an inkjet printer. <P>SOLUTION: By using a temperature-detecting means near a head which is approximately normally carried on an inkjet printer for controlling ink delivering, the detected temperature by this temperature detecting means is recognized as an environmental temperature under a specified condition, and the waiting time after a first printing face is printed is changed in accordance with this environmental temperature to ensure a necessary and sufficient ink fixing time, and thereafter, printing on a second printing face is started. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an ink jet recording apparatus, and more particularly to an ink jet recording apparatus capable of duplex printing.

  In recent years, ink jet printers that record images by ejecting ink onto a recording sheet have been widely used in various fields because of their simple structure, small size, high quietness, and low cost. This ink jet printer has a principle of forming an image by ejecting fine ink droplets onto the surface of a recording sheet by applying mechanical vibration or heat to the ink in the ejection nozzle of the ink jet head. It has become.

  The ejected ink is very small particles (several picoliters to several tens of picoliters), and its ejection mechanism is very precise, so the ink ejection amount is easily influenced by conditions near the ejection nozzle, particularly temperature. In addition, since vibration and heat are frequently applied to the ejected ink / ejection nozzle, the temperature change in the vicinity of the ejection nozzle inevitably increases. Therefore, in order to realize stable ink discharge, it is proposed to provide a temperature detection means near the discharge nozzle and vary the amount of vibration and heat applied according to the detected temperature to control the ink discharge amount. (See Patent Document 1).

  Ink jet printers have also evolved in speeding up image formation and recording sheet conveyance. The problem here is the fixability and dryness of the recorded image. As the printer speed increases, the phenomenon that the formed image is not sufficiently fixed to the recording sheet or the recording sheet is conveyed before it is dried cannot be ignored. In particular, when image formation is performed on both front and back sides of a recording sheet (see Patent Document 2), if the recording sheet is pulled into the front and back reversing path of the recording sheet immediately after surface printing, fixing and drying are still insufficient. There is a possibility that the ink on the front surface adheres to the front and back reversing paths of the recording sheet, and the recording sheet is soiled when performing double-sided printing in the same manner from the next time.

Therefore, in order to ensure the fixing and drying of the ink immediately after printing, the recording sheet is stopped and waited for a certain period of time immediately after the front surface printing to advance the fixing and drying of the ink, and then drawn into the front / back reversing path. Measures can be considered. In addition, proposals have been made to forcibly fix and dry by blowing warm air or the like during surface printing or immediately after printing (see Patent Document 3).
Japanese Laid-Open Patent Publication No. 10-16226 JP-A-5-138965 Japanese Unexamined Patent Publication No. 2001-63019

  However, when a standby time immediately after printing is ensured, the standby time required within the range of the environmental temperature in which the printer apparatus is installed and used is not constant. Depending on the recording sheet and ink used, for example, 30 It may be 5 seconds at 10 ° C. and 10 seconds at 10 ° C. For this reason, if the waiting time is made constant in accordance with either environment, the waiting time becomes redundant on the one hand, and fixing and drying are insufficient on the other hand. However, if a separate environmental temperature detection means is provided in order to optimize in response to the temperature change, it also causes a cost increase.

  Further, the drying system as described in Patent Document 3 described above leads to an increase in size and complexity of the apparatus, and of course a significant cost increase.

In order to solve the above-described problems, in the present invention, an inkjet recording apparatus that sequentially records on a first recording surface and a second recording surface of a sheet-like recording medium by a recording unit that ejects ink according to recording data. In
A temperature detecting means for measuring the temperature in the vicinity of the ink discharge port of the recording unit, and the temperature detecting means at the moment when the main power supply of the ink jet recording apparatus is turned on or after a lapse of a fixed time A from the main power supply turning on or when the final image formation ends After the recording on the first recording surface is completed according to the temperature detected at least after the state where no new image formation is continued for a certain time B or the type of the recording medium, the first Standby time setting means for setting a standby time until an operation relating to recording on the second recording surface is started, and relating to recording on the first recording surface according to the standby time set by the standby time setting means It is characterized by comprising control means for starting an operation relating to recording on the second recording surface after the operation is completed.

  In the ink jet recording apparatus, it provides appropriate fixing and drying conditions according to the installation environment temperature and the type of the recording medium without adding new means or incurring a large cost increase. This has the effect of preventing the printed product from being stained.

  Next, details of the present invention will be described in accordance with the description of the embodiments.

  Embodiment 1 of a printer apparatus according to the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic configuration diagram showing an example of an ink jet recording apparatus applicable to the present invention. The ink jet recording apparatus shown here is a double-sided recording medium that allows recording on both sides of a recording medium by inverting the recording medium. It has a recording mechanism.

  In FIG. 1, 1 is a paper feed tray (paper feed section), 2 is a recording section (recording means), 3 is a paper discharge tray (paper discharge section), 4 is a reversing mechanism, 5 is a switching member, 6 is a platen, 7 Is a conveying path, 8 is an upstream conveying roller pair, and 9 is a downstream conveying roller pair.

  Recording media are stacked on the paper feed tray 1, and the recording media are fed one by one to the conveyance path 7 from here. The fed recording medium is sandwiched between upstream conveying roller pairs (pinch roller pairs) 8 and conveyed in the direction of arrow X1 while being supported by the platen 8 by the forward rotation operation of the roller pairs. As a result, an image is recorded in the tip region of the first recording surface (front surface). Thereafter, the recording medium is sandwiched between the upstream conveying roller pair 8 and the downstream conveying roller pair 9, and an image is recorded in the normal area of the first recording surface (front surface) in this state. Finally, the rear end of the recording medium is disengaged from the pinch roller pair 8, and the recording medium is sandwiched only by the downstream conveying roller pair 9. In this state, the rear end area of the first recording surface (front surface) is reached. An image is recorded. Thus, the surface recording is completed. In the case of single-sided recording, the recording medium is discharged as it is to the paper discharge tray 3 by the rotation of the conveyance roller pair 9 on the downstream side that holds the recording medium.

  When performing double-sided recording, after the surface recording is completed as described above, the recording medium is not discharged to the discharge tray 3, and the downstream conveying roller pair 9 is reversed to move the recording medium in the arrow X2 direction. To the reversing mechanism 4. At this time, if it is necessary to dry the recording medium, the recording medium is put on standby on the platen 6 before being fed to the reversing mechanism 4. In this embodiment, the length of this waiting time (from the end of recording on the surface of the recording medium to the start of reverse feeding of the recording medium) is sufficient for the ink applied to the surface of the recording medium to be sufficiently fixed and dried. It takes time to complete. This time is determined in consideration of the environmental temperature in which the present apparatus is installed, and the operation relating to the back side recording is started after the determined time has elapsed.

  When the recording medium is made to stand by for a predetermined time, reverse feeding of the recording medium is started. At this time, the rear end of the recording medium (the front end during reverse feeding) is guided by the switching member 5 indicated by a solid line and is conveyed in the direction of the arrow K along the loop-shaped reversing path 4 a in the reversing mechanism 4. The switching member 5 is urged in the direction of the arrow L around the rotation center 5a and is stopped at the position indicated by the solid line. However, when the rear end of the recording medium conveyed in the direction of the arrow K along the reverse path 4a is hit. The recording medium rotates to the position indicated by the broken line by the pushing force due to the rigidity of the recording medium. The recording medium is supplied to the recording unit 2 again with the front and back sides and the front and rear sides reversed. That is, the recording medium after passing through the reversing path 4a has the back surface facing the recording unit 2 and the front end in the transport direction during single-sided recording passes the reversing path 4a before the front end in the transport direction. Will be located. The recording medium reversed in this way is recorded on the back surface by the recording unit 2 and then discharged to the paper discharge tray 3.

  FIG. 2 is a perspective view showing an example of the peripheral configuration of the recording unit 2 shown in FIG.

  A recording head 11 having an ejection port array for ejecting ink is installed on a carriage 13. A recording medium such as plain paper or an OHP sheet is sandwiched between a pair of transport rollers 9 via an upstream transport roller 8 (not shown here), and is sent in the direction of the arrow as the transport motor (not shown) is driven. The carriage 13 is guided and supported by a guide shaft 12 and an encoder (not shown). The carriage 13 reciprocates in the Y direction in the figure along the guide shaft 12 by driving the carriage motor 15 via the drive belt 14.

  The recording head 11 is an ink jet recording head that ejects ink, and a heating element (electric / thermal energy converter) that generates thermal energy for ink ejection is provided in the inside (liquid path) (this configuration). Will be described in detail later in conjunction with FIG. 3 and FIG. 4). This heating element is driven based on a recording signal in accordance with a reading timing of an encoder (not shown), and forms an image by flying and adhering ink droplets onto the recording medium.

  A recovery unit having a cap portion 16 is disposed at the home position (HP) outside the maximum width area (recording area) where the recording operation is performed by the recording head 11. When recording is not performed, the carriage 13 is moved to the home position (HP), and the ink discharge port forming surface of the recording head 11 is sealed by the cap unit 16 to fix the ink due to evaporation of the ink solvent, dust, paper dust, or the like. Prevent clogging due to adhesion of foreign substances such as.

  Further, the capping function of the cap unit 16 allows the ink to be supplied to the cap unit 16 away from the ink ejection port in order to eliminate ejection failure and clogging due to ink thickening and sticking of the ink ejection port with low recording frequency. A suction operation mode for recovering the ink discharge port that caused the discharge failure by using a pump (not shown) as a place for executing the preliminary discharge mode for discharging the ink, or operating a pump (not shown) to suck ink from the ink discharge port It is used as a place to execute. In addition, by disposing a blade adjacent to the cap portion 16, it is possible to clean the ink discharge port forming surface of the ink jet recording head.

  FIG. 3 is a perspective view schematically showing an ink discharge port array of the ink discharge portion of the recording head 11 as viewed from the recording medium side, and FIG. 4 is a portion schematically showing the internal structure of the ink discharge portion. It is a perspective view. This ink discharge portion has an ink discharge port surface 22 having a plurality of ink discharge ports 23, and each liquid path portion 31 communicating with each ink discharge port 23 has energy necessary for discharging ink. The generated discharge energy generating elements 32 are respectively arranged. Note that the arrow Y in FIG. 3 indicates the scanning direction of the carriage 13.

  4 is a temperature sensor for detecting the temperature of the recording head 11. In this embodiment, the thermistors are provided at both ends of the ejection port array as temperature sensors. However, the means for detecting the temperature is not particularly limited to this, and a sensor of any principle may be used as long as it can detect the temperature in the vicinity of the ink discharge port 23.

  As shown in FIG. 4, in the embodiment of the present invention, a recording system that ejects ink using thermal energy is used. However, the present embodiment is not limited to this recording system. In the case of the demand type, a pressure control system that ejects ink droplets from an orifice (ejection port) by mechanical oscillation of a piezoelectric vibration element, and in the case of a continuous type, a charge control type, a divergence control type, etc. can be applied. .

  FIG. 5 is a block diagram showing a schematic configuration of a control system of the ink jet recording apparatus according to the embodiment of the present invention.

  In FIG. 5, reference numeral 130 denotes a CPU that controls driving of each unit of the ink jet recording apparatus, and has a function as means for executing processing such as calculation, determination, and control described later. Reference numeral 131 denotes a ROM that stores a control program executed by the CPU 130, and 132 denotes a RAM 132 that stores processing data executed by the CPU 130, input data, and the like.

  The CPU 130, ROM 131, and RAM 132 include a recording head movement driving unit 133, a recording medium conveyance driving unit 134, a recording head recording driving unit 135, a data receiving unit 136, a standby time timer unit 137, an interface unit 138, and the like. They are connected via a bus 141. A host computer 140 is connected to the interface unit 138. A printer driver 139 is stored in the host computer 140.

  The recording information transmitted from the host computer 140 via the printer driver 139 is received by the data receiving unit 136 on the ink jet recording apparatus side via the interface 138. The data receiving unit 136 exchanges data according to the state of the ink jet recording apparatus, and the received data is stored in the RAM 132. In accordance with a recording command from the host computer 140, the CPU 130 controls the recording head movement driving unit 133, the recording medium transport driving unit 134, and the recording head recording driving unit 135, respectively.

  Further, FIG. 5 will be described in detail. The CPU 130 reads programs and various data from the ROM 131, the RAM 132, and the like, performs necessary calculations and determinations, outputs various control signals according to the control program, and controls the drive of the entire apparatus. The ROM 131 is a program memory, and stores various programs and various data for the CPU 130 to operate. A RAM 132 is a buffer memory, and is composed of a working area for temporarily storing the data being processed by the CPU 130 and operation results, a text area for storing various data, and the like. A standby time timer unit 137 is connected to the CPU 130 via the data bus 141 for measuring time based on an instruction signal from the CPU 130 and outputting time information.

  The CPU 130 is electrically connected to the host computer 140 via the interface unit 138, and controls a recording operation based on image data (recording data) from the host computer 140 stored in the ROM 131 or the RAM 132. Here, the host computer 140 is provided with a printer driver 139 for receiving recording information created or edited on the computer and passing it to the inkjet recording apparatus 144 side via the interface unit 138. The printer driver 139 can set and select various information related to recording by the recording device 144, and these settings and selected information are also transmitted to the recording device 144 side. Yes.

  Examples of various information relating to recording include setting of the type of recording medium such as a sheet to be recorded, selection of whether to execute the single-sided recording mode or the double-sided recording mode, and the like. The CPU 130 controls the recording head movement driving unit 133 and the recording medium transport driving unit 134, and also records the recording unit 2 (recording head 11) via the recording head recording driving unit 135 based on the recording information stored in the RAM 132. To control. An operation panel for setting recording information such as a recording mode and a sheet sensor (not shown) for detecting the leading edge and the trailing edge of the recording sheet are connected to the CPU 130 via a data bus.

  The RAM 132 as the buffer memory has a function as a line buffer for storing print data for one scan or a plurality of scans. This line buffer is a buffer for storing information on which position in the recording area is to be recorded by the orifice of the recording head in one main scanning of the recording head. 6 and 7 show an example of how recording data is stored in a buffer provided in the RAM 132. FIG.

  The buffer is composed of M columns necessary for expressing the maximum recording width of the recording sheet usable in the inkjet recording apparatus 144 at a predetermined dot pitch, and rows corresponding to the number of orifices of the recording head. ing. The recording data sent from the host computer 140 and developed is recorded from the dot (dotted black) information in the first row and first row of the buffer as shown in FIG. 6 when recording on the surface of the recording medium. When data is stored and recorded on the back side, as shown in FIG. 7, the information is stored from dot (black dots) information in the H-th row and M-th column of the buffer. This is because, when performing double-sided recording, the recording medium is sent to the recording head 11 in a state where the recording medium is switched. However, the recording data storage order on the back surface is the same as the recording data storage order on the front surface as shown in FIG. 6, and the recording data transmission order is transmitted from the printer driver 139 to the ink jet recording apparatus 144. May be reversed. Each dot shown in FIGS. 6 and 7 schematically represents a dot developed and recorded on a recording sheet, and one dot is not necessarily handled as one recording data.

  Next, the operation in the double-sided recording mode executed by the ink jet recording apparatus configured as described above will be described. Here, the recording data stored in the line buffer (RAM 132) of the inkjet recording apparatus is data after a predetermined process for double-sided recording is performed in the printer driver 139 of the host computer 140.

  FIG. 8 is a flowchart showing the operation procedure of the recording operation in the duplex recording mode.

  First, in step S1, it is determined whether or not a recording start command is received from the host computer 140. If a recording start command is received, a recording sent from the printer driver 139 of the host computer 140 is subsequently received. Data is received and stored in the buffer of the RAM 132. Next, in step S3, based on the stored recording data, an operation related to recording on the back surface (second recording surface) after the recording on the front surface (first recording surface) of the recording medium is completed (for example, on the recording medium). It calculates and sets (determines) the length of time (waiting time) until the start of (reverse feed).

  In this embodiment, the waiting time is determined according to the environmental temperature in which the printer device is installed, and the environmental temperature is detected by the temperature sensor 33 that detects the temperature in the vicinity of the ejection nozzle 23 of the head 11. It is to detect. However, since the above-described device for ejecting ink is provided in this portion, even if the temperature is carelessly detected due to vibration or heat generation, the temperature becomes considerably higher than the environmental temperature. Therefore, in the present invention, it is determined that the temperature detected by the temperature sensor 33 in the following operating state is the environmental temperature where the device is installed.

(1) Immediately after the main power is turned on (2) After a certain time has elapsed since the end of the final printing (1) The state immediately after the main power is turned on has a very high probability that the device was not used before the main power was turned on. It can be estimated that not only the vicinity of the temperature sensor 33 but also the entire apparatus is almost equal to the environmental temperature. In the case of (2), even if the temperature sensor 33 is in the vicinity of the discharge nozzle 23, the temperature of the ink discharge device that is detected is not a large portion in terms of heat capacity. Alternatively, it can be estimated that the temperature is equal to the temperature near the platen (that is, the ambient temperature near the standby position of the recording medium). For example, when the detected environmental temperature (M) is the first temperature m1, the first standby time (T) is set to t1, and when the detected environmental temperature (M) is the second temperature m2, the second standby time t2 is set. The At this time, in the case of m1 <m2, t1> t2, and the standby time is shorter as the environmental temperature is higher. As described in (2), the environmental temperature (T) can be updated whenever a fixed time elapses from the end of the final printing.

  The description will be continued with reference to FIG. When the standby time is set as described above, in step S4, the recording medium is fed from the sheet feeding tray 2 and recording is performed on the surface of the recording medium. Next, in step S5, the standby time set in step S3 is set in the timer. Thereafter, in step S6, it is determined whether or not the set standby time has elapsed from the time when the front surface recording is completed (step S6), and the operation relating to the back surface recording is stopped until the standby time has elapsed. When the standby time has elapsed, the recording medium conveyance operation (reverse feeding) for back side recording is started (step S7). Thereafter, when the recording unit 2 reaches the recording unit 2 through the inversion path R10, the recording unit 2 performs recording on the back surface of the recording medium (step S8). When the recording on the back surface is completed, the recording medium is discharged to the discharge tray (discharge section) 3 by the continuous rotation operation of the discharge roller 9, and the double-sided recording is completed (step S9). During the standby time, the rear end of the recording medium, that is, the end on the recording unit 2 side is held in the platen 6 in a standby state, and after the standby time has elapsed, the discharge roller 9 The conveyance operation for the back side recording is started immediately by the reverse rotation.

  In the above-described embodiment, the case where the CPU 130 executes the stepless calculation process in which the standby time becomes longer as the environmental temperature is lower has been described as an example. However, the standby time (T) and the environmental temperature (M ) Is stored in advance in a standby time determination table, and the standby time in a finite stage may be determined by reading from the table. For example, as shown in FIG. 9, the ambient temperature (M) ranges M <m1, m1 ≦ M <m2, m2 ≦ M <m3, m3 ≦ M (m1 <m2 <m3) and the length of time (T ) A table in which T = t1, T = t2, T = t3, T = t4 (t1> t2> t3> t4) is prepared, and the waiting time may be obtained by referring to the table. That is, if the environmental temperature (M) is in the range of M <m1, the length of time (T) is set to t1, and if the environmental temperature (M) is in the range of m1 ≦ M <m2, the length of time is set. (T) is set to t2, and if the environmental temperature (M) is in the range of m2 ≦ M <m3, the time length (T) is set to t3, and the environmental temperature (M) is m3 ≦ M. If it is within the range, the time length (T) may be set to t4.

  In the form of the first embodiment, the standby time (T) is determined based only on the environmental temperature (M), but the present invention is not limited to this. For example, as a factor for determining the standby time (T), the type of the recording medium may be considered in addition to the environmental temperature. In this case, the relationship between the standby time (T), the environmental temperature (M), and the type of the recording medium is stored in advance as a standby time determination table, and the standby time (T) is determined by calling from the table. You may make it do.

  An example of this table is shown in FIG. By using such a table, it is possible to consider the ink fixing / drying characteristics according to the type of the recording medium, and it is possible to set a standby time (T) more suitable for the characteristics of each recording medium. .

  In the second embodiment, it is assumed that the recording medium type setting is performed when setting the recording medium to be used on the printer driver. Of course, the printer device itself has means for detecting the recording medium type. You may have it. For example, when the recording medium is set in the printer device, it is easy to manually set the type of the recording medium with a dial switch. Also, light receiving and emitting that automatically determines the type of the recording medium by irradiating the recording medium with specific light and the difference in the intensity of the reflected light in the range before passing through the recording medium and before image formation is performed. It is also possible to provide a sensor or the like and determine the type of recording medium by the printer device itself.

  Needless to say, the present invention includes all other recording medium type discriminating means.

1 is a schematic configuration diagram showing an example of an ink jet recording apparatus applicable to the present invention. FIG. 2 is a perspective view illustrating an example of a peripheral configuration of a recording unit illustrated in FIG. 1. FIG. 3 is a schematic perspective view illustrating a state where an ink ejection port array of an ink ejection unit of a recording head is viewed from a recording medium side. FIG. 3 is a partial perspective view schematically illustrating an internal structure of an ink discharge unit of a recording head. 1 is a block diagram illustrating a schematic configuration of a control system of an ink jet recording apparatus according to an embodiment of the present invention. Explanatory drawing for demonstrating the state which stores the recording data for surface recording in the buffer memory in embodiment of this invention. Explanatory drawing for demonstrating the state which stores the recording data for back surface recording in buffer memory in embodiment of this invention. 6 is a flowchart showing a recording operation procedure in a double-sided recording mode. The table showing the relationship between the range of environmental temperature (M) used in this invention Example 1, and the length (T) of waiting time. The table showing the relationship between the kind of recording medium, the range of environmental temperature (M), and the length of waiting time (T) used in Example 2 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Paper feed tray 2 Recording part 3 Paper discharge tray 4 Inversion mechanism 4a Inversion path 5 Switching part 6 Platen 7 Conveyance path 8 Conveyance roller 9 Paper discharge roller 11 Recording head 12 Guide shaft 13 Carriage 14 Drive belt 15 Carriage motor 16 Cap part 22 Ink discharge surface 23 Ink discharge port 31 Liquid passage portion 32 Discharge energy generating element 33 Temperature sensor 130 CPU
131 ROM
132 RAM
133 Recording Head Movement Driving Unit 134 Recording Head Medium Conveying Unit 135 Recording Head Recording Driving Unit 136 Data Receiving Unit 137 Standby Time Timer Unit 138 Interface Unit 139 Printer Driver 140 Host Computer 144 Inkjet Recording Device

Claims (4)

In an inkjet recording apparatus that sequentially records on a first recording surface and a second recording surface of a sheet-like recording medium by a recording unit that ejects ink according to recording data,
A temperature detecting means for measuring the temperature in the vicinity of the ink discharge port of the recording unit, and the temperature detecting means at the moment when the main power supply of the ink jet recording apparatus is turned on or after a lapse of a fixed time A from the main power supply turning on or when the final image formation ends After the recording on the first recording surface is completed according to the temperature detected at least after the state where no new image formation is continued for a certain time B, the recording on the second recording surface is performed. A standby time setting means for setting a standby time until the operation related to the start of the operation, and the first after the operation related to the recording on the first recording surface according to the standby time set by the standby time setting means 2. An ink jet recording apparatus comprising: a control unit that starts an operation related to recording on a recording surface.   After the arbitrary image formation, the standby time setting means waits for the waiting time setting means according to the temperature detected by the temperature detection means after the state where no new image formation is continued for the predetermined time B. The ink jet recording apparatus according to claim 1, wherein is updated as needed.   The inkjet recording apparatus according to claim 1, wherein the standby time setting unit sets the standby time according to a type of the recording medium and the detected temperature. .   4. The recording medium type determination is performed manually or automatically by a recording medium determination unit provided inside the ink jet recording apparatus or a printer driver that controls the ink jet recording apparatus from the outside. The ink jet recording apparatus described.

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