JP4590867B2 - Inkjet recording device - Google Patents

Description

  The present invention relates to an ink jet recording apparatus, and in particular, a temperature difference that occurs between a plurality of recording heads each having a plurality of ink color nozzles and a temperature difference that occurs between a plurality of drive circuits that respectively drive a plurality of ink color nozzles. The present invention relates to an ink jet recording apparatus which is made small.

  As disclosed in Japanese Patent Laid-Open No. 61-104856 (Patent Document 1), an ink jet recording apparatus is known that can perform recording with color ink at the same time without reducing the recording speed with black ink. The recording head of the ink jet recording apparatus is provided with 24 black ink nozzles, 6 cyan ink nozzles, yellow ink nozzles, and magenta ink nozzles, respectively. When performing black and white recording, recording can be performed without reducing the recording speed by using the nozzles for 24 black inks. When performing color recording, the number of nozzles for color ink is small, so the recording speed is slow, but four color inks are ejected from 24 nozzles for black ink and 6 nozzles for color ink respectively. A total of seven colors can be recorded. Therefore, color printing can be performed at the same time while maintaining the recording speed of documents such as characters.

  However, in recent years, it has become possible to form a large number of nozzles within a narrow range due to advances in nozzle processing technology, and simultaneously performing monochrome recording and color recording at high speed without changing the number of nozzles for each ink color. An ink jet recording apparatus capable of performing the above is known. In addition, the number of nozzles has increased further in recent years as the quality of recording on recording media has increased. When a large number of nozzles are formed in a single recording head and the large number of nozzles are operated by a single IC chip (drive circuit), the IC chip generates heat and the recording head itself driven by the IC chip also generates heat. Therefore, an ink jet recording apparatus having a configuration in which the recording head and the IC chip are divided into two parts and heat generation of each IC chip and the recording head is suppressed is known.

  Japanese Patent Application Laid-Open No. 2002-240306 (Patent Document 2) and Japanese Patent Application Laid-Open No. 2003-80793 (Patent Document 3) disclose an ink jet recording apparatus having two recording heads. The two recording heads of the ink jet recording apparatus are laminated with a flexible wiring board electrically connected to each pressure generating means provided in the recording head in order to eject ink from the recording head. On the wiring board, IC chips for outputting drive signals are respectively arranged. The IC chip comes into contact with a part of the heat sink, and the heat generated by the IC chip is radiated to the outside through the heat sink.

In one of the two recording heads, nozzles corresponding to two ink colors of four inks of black ink, cyan ink, yellow ink, and magenta ink are arranged in a line, and the other recording head is used. In the head, nozzles corresponding to two ink colors different from one of the recording heads are arranged in a line.
Japanese Patent Laid-Open No. 61-104856 (FIG. 2 etc.) Japanese Patent Laid-Open No. 2002-240306 (FIGS. 4, 6, etc.) Japanese Patent Laid-Open No. 2003-080793 (FIGS. 6, 9, 14, etc.)

  However, in the above-described ink jet recording apparatus, nozzles corresponding to two of the four colors of ink are arranged on one recording head, and nozzles corresponding to the remaining two colors of ink are arranged on the other recording head. Therefore, when one ink color (for example, black ink) is continuously ejected in large quantities, only one IC chip generates extreme heat, and the heat of the IC chip is also transferred to the recording head. . Further, when the pressure generating means is continuously driven by the drive signal from the IC chip, the pressure generating means also generates heat, so that the temperature of one recording head rises and a temperature difference occurs between the two recording heads. End up. As described above, when a temperature difference occurs between the two IC chips, the rising / falling characteristics of the drive signal change, and a difference occurs in the driving of the pressure generating means. Further, when a temperature difference occurs between the two recording heads, the driving characteristics of the pressure generating means or the viscosity of the ink changes, so the ejection characteristics from the nozzles of the two recording heads change, and the recording medium is changed. There was a problem that the recording quality of the recording medium deteriorated.

  The present invention has been made in order to solve the above-described problems. The temperature difference generated between the recording heads or between the drive circuits is reduced to suppress the change in the ejection characteristics of the ink from the nozzles. An object of the present invention is to provide an ink jet recording apparatus capable of recording.

An ink jet recording apparatus according to claim 1, wherein in order to achieve this purpose, the nozzle array comprised of a plurality of nozzles arranged in a column shape, comprising several double recording heads arrayed a plurality of ink colors a plurality of the nozzle rows jetting frequency of the ink corresponding to the high ink colors, divided plurality of the nozzle rows in the plurality of recording heads ejecting frequency of ink corresponding to the high ink colors provided out of, Among the plurality of ink heads, the plurality of nozzle rows corresponding to at least one ink color that does not have a high ink discharge frequency compared to an ink color that has a high ink discharge frequency among the plurality of ink colors. They are assembled into one of them .
According to a second aspect of the present invention, in the ink jet recording apparatus according to the first aspect, the number of the nozzle rows is set equal among the plurality of recording heads.

According to a third aspect of the present invention, in the ink jet recording apparatus according to the first or second aspect , a drive circuit for driving the recording head so as to eject ink from the nozzles is further provided in the plurality of recording heads. Correspondingly, it was divided into multiple parts.

4. The ink jet recording apparatus according to claim 4 , wherein the ink jet recording apparatus according to claim 3 includes two recording heads, and the driving circuit corresponding to each head extends from each head in the opposite direction. The drive circuits are arranged on the heat sinks connected to the substrate and arranged on both sides in the direction so as to be able to conduct heat.

The ink jet recording apparatus according to claim 5 is the ink jet recording apparatus according to any one of claims 1 to 4 , wherein the recording head includes two recording heads, and one of the recording heads corresponds to an ink color having a high ejection frequency. The two print heads were arranged so that the nozzle rows were symmetric with respect to the nozzle rows corresponding to the ink colors with high ejection frequency of the other print heads.

The ink jet recording apparatus according to claim 6 is the ink jet recording apparatus according to any one of claims 1 to 5 , wherein each of the recording heads includes the nozzle row corresponding to the ink color having a high ejection frequency, and It has nozzle rows corresponding to the plurality of different ink colors.

The ink jet recording apparatus according to claim 7, wherein a nozzle row composed of a plurality of nozzles arranged in a row drives the recording head such that a plurality of the recording heads are arranged and ink is ejected from the nozzles. and a driving circuit, there are a plurality the nozzle rows that discharge frequency of ink among the plurality of ink colors corresponding to the high ink, a plurality of corresponding said drive circuit, a plurality of nozzle arrays for ejecting ink colors of multiple And the plurality of nozzle rows corresponding to the ink colors having a high ejection frequency are provided separately in the driving circuits of the plurality of groups.
An ink jet recording apparatus according to an eighth aspect of the present invention is the ink jet recording apparatus according to the seventh aspect, comprising a plurality of the recording heads and a plurality of the driving circuits corresponding to the plurality of recording heads. It was.

An ink jet recording apparatus according to claim 9, wherein, in the ink jet recording apparatus according to claim 7 or 8, the nozzle array, the nozzle array corresponding to the nozzle row and the another ink color the ejection frequency corresponding to the high ink colors divided into a plurality of groups including the same number preparative respectively, provided with the driving circuit for each group.

The ink jet recording apparatus according to claim 10 is the ink jet recording apparatus according to any one of claims 7 to 9 , wherein the nozzle array corresponds to a nozzle array corresponding to the ink color having a high ejection frequency and another ink color . The two drive circuits corresponding to each group are connected to flexible wiring boards extending in opposite directions from the respective groups, and arranged on both sides of the direction. The drive circuits are arranged on the heat sinks so as to conduct heat.

An ink jet recording apparatus according to an eleventh aspect is the ink jet recording apparatus according to the ninth or tenth aspect , wherein each of the groups has a nozzle row corresponding to the same plurality of ink colors.

12. An ink jet recording apparatus according is an ink jet recording apparatus according to claim 9 or 10, wherein each group, each containing the ejection frequency is high nozzle array corresponding to a different said plurality of ink colors with each other nozzle Has a column .

An ink jet recording apparatus according to a thirteenth aspect of the present invention is the ink jet recording apparatus according to any one of the first to twelfth aspects, wherein the nozzle row having a high discharge frequency is a nozzle row for black ink.

According to the ink jet recording apparatus of claim 1, a plurality of nozzle arrays each including a plurality of nozzles arranged in a line are provided with a plurality of recording heads, and ink ejection is performed among a plurality of ink colors. Since there are a plurality of nozzle rows corresponding to ink colors having a high frequency, and a plurality of nozzle rows corresponding to ink colors having a high ink ejection frequency are provided separately for each of a plurality of recording heads, a plurality of recordings are provided. The temperature difference generated between the heads can be reduced. Therefore, there is an effect that it is possible to suppress the change in the ejection characteristics from the ink nozzles and to perform high-quality recording.
In addition, a plurality of nozzle arrays corresponding to at least one ink color that does not have a high ink discharge frequency compared to an ink color that has a high ink discharge frequency among a plurality of ink colors is selected from any one of the plurality of print heads. As a result, the number of ink tanks can be reduced as compared with the case where the nozzles corresponding to all ink colors are divided into the recording heads, and each ink tank and each nozzle communicate with each nozzle. Since the number can be reduced, the structure can be simplified and the manufacturing cost can be reduced.
According to the ink jet recording apparatus of the second aspect, in addition to the effect produced by the ink jet recording apparatus of the first aspect, the number of the nozzle rows is set equal between the plurality of recording heads, The heat generated by the recording heads is substantially uniform between the recording heads, and the change in the ejection characteristics from the nozzles between the recording heads can be suppressed to a small level, and there is an effect that higher quality recording can be performed.

The claims 3 An ink jet recording apparatus according, in addition to the effects of the ink jet recording apparatus according to claim 1 or 2, the drive circuit is provided for driving the recording head for ejecting ink from the nozzle, the driving circuit Since the recording head is divided into a plurality of parts corresponding to a plurality of recording heads, the heat generation of the drive circuit and the heat generation of the recording head can be substantially equalized, and the ejection characteristics of ink from the nozzles change. There is an effect that the recording can be performed with higher quality.

In addition to the effects of the ink jet recording apparatus according to claim 3 , the ink jet recording apparatus according to claim 4 is provided with two recording heads, and a drive circuit corresponding to each recording head is provided from each recording head. It is connected to a flexible wiring board extending in the opposite direction. Furthermore, each drive circuit is arrange | positioned so that heat conduction is possible by each heat sink arrange | positioned at the opposite direction both sides. Therefore, since the heat generated by the drive circuit is thermally conducted to the heat sink and dissipated, it is possible to reduce the temperature of the drive circuit and to reduce the heat conduction of the drive circuit to the recording head. There is.

In addition to the effect of the ink jet recording apparatus according to any one of claims 1 to 4 , the ink jet recording apparatus according to claim 5 has a nozzle array corresponding to an ink color with a high discharge frequency of one recording head for the other recording. Since the two recording heads are arranged so as to be symmetric with respect to the nozzle row corresponding to the ink color with high ejection frequency of the head, the heat generating portion in each recording head is symmetric, and the heat generation state of each recording head Can be made substantially uniform. Therefore, since the change in the ejection characteristics from the nozzles between the two recording heads can be suppressed small, there is an effect that high quality recording can be performed.

In addition to the effect produced by the ink jet recording apparatus according to any one of claims 1 to 5 , each recording head includes a nozzle row corresponding to an ink color having a high ejection frequency. It has nozzle rows corresponding to a plurality of different ink colors. When all the nozzles corresponding to a plurality of ink colors are arranged in each recording head, the arrangement positions of the nozzles of each ink color are separated from each other, so that the structure until ink is supplied to the nozzles becomes complicated. . However, according to the present invention, nozzle arrays corresponding to a plurality of different ink colors are arranged in each recording head, and the nozzle arrangement positions of all the ink colors cannot be separated from each other, so that the ink supply structure to each nozzle is simplified. There is an effect that can be.

According to the ink jet recording apparatus of the seventh aspect , the nozzle row composed of a plurality of nozzles arranged in a row includes a plurality of recording heads arranged, and is driven by a drive circuit to receive ink from the plurality of nozzles. Discharged. Also, there are a plurality of nozzle rows corresponding to the ink ejection frequency is high ink among the plurality of ink colors, the driving circuit is divided into a plurality of groups corresponding to a plurality of nozzle arrays for ejecting ink colors of multiple In addition, a plurality of nozzle groups corresponding to ink colors having a high discharge frequency are divided into a plurality of groups of drive circuits. Accordingly, since the plurality of nozzle groups corresponding to ink colors having a high ejection frequency are driven by different drive circuits, it is possible to prevent only one drive circuit from generating heat extremely. Accordingly, the output characteristics of the drive signal from the drive circuit, that is, the rise and fall characteristics of the drive pulse change for each drive circuit, and as a result, the ejection characteristics from the nozzles in the nozzle group corresponding to each drive circuit change. Therefore, it is possible to perform high-quality recording.
In addition to the effects achieved by the ink jet recording apparatus according to claim 7, the ink jet recording apparatus according to claim 8 includes a plurality of recording heads, and the drive circuit is divided into a plurality corresponding to the plurality of recording heads. As a result, the heat generation of the drive circuit and the heat generation of the recording head can be substantially equalized, and it is possible to suppress the change in the ink ejection characteristics from the nozzles and to perform higher quality recording. .

An ink jet recording apparatus according to claim 9, in addition to the effects of the ink jet recording apparatus according to claim 7 or 8, nozzle, nozzle arrays discharge frequency corresponding to the high ink colors and the nozzle array of other ink colors the divided into a plurality of groups of the same number each including, since the drive circuit is provided for each group, the heat generation of the drive circuit can be made substantially equal, the ejection characteristics of the nozzles in each group are changed Is suppressed, and it is possible to perform higher quality recording.

An ink jet recording apparatus according to claim 10, wherein, in addition to the effects of the ink jet recording apparatus according to any one of claims 7 to 9, the nozzle rows, nozzle row ejecting frequency corresponds to a high ink color and other ink colors divided into two groups each including a nozzle row corresponding to the two drive circuits corresponding to each group, and connected to a flexible wiring board extending in opposite directions from their respective groups, located on both sides of the opposite direction Each drive circuit is arranged on each heat sink so as to be able to conduct heat. Therefore, the heat generated by the drive circuit is thermally conducted to the heat sink and dissipated, so that it is possible to reduce the drive circuit from reaching a high temperature and to reduce the heat conduction of the drive circuit to each group. effective.

According inkjet recording apparatus of claim 11, wherein, in addition to the effects of the ink jet recording apparatus according to claim 9 or 10, since each group has a nozzle row corresponding to the same plurality of ink colors, respectively, each The heat generation for each bluepe can be substantially equalized. Therefore, it is possible to prevent only one drive circuit from generating heat excessively, so that it is possible to suppress changes in the ink ejection characteristics from the nozzles in the corresponding recording head, and to ensure high quality recording on the recording medium. There is an effect that can be performed.

An ink jet recording apparatus according to claim 12, wherein, in addition to the effects of the ink jet recording apparatus according to claim 9 or 10, each group includes a respective discharge frequently nozzle arrays, corresponding to different ink colors with each other It has a nozzle row . When all the nozzles corresponding to a plurality of ink colors are arranged in each group, the arrangement positions of the nozzles of the respective ink colors are separated from each other, and the structure until ink is supplied to the nozzles becomes complicated. However, in the present invention, since the nozzle rows corresponding to a plurality of different ink colors are arranged in each group, the nozzle arrangement positions of all the ink colors cannot be separated from each other, so that the ink supply structure to each nozzle is simplified. There is an effect that can be.

In addition to the effects of the ink jet recording apparatus according to any one of claims 1 to 12 , the ink jet recording apparatus according to the thirteenth aspect has a high ejection frequency because the nozzle array is a black ink nozzle array. This is advantageous in that it can be used in an inkjet recording apparatus that records a large number of documents.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a schematic view showing an ink jet recording apparatus 1 and an ink cartridge 2 attached to the ink jet recording apparatus 1 in the first embodiment of the present invention.

  The ink jet recording apparatus 1 includes a mounting unit 3 that detachably mounts an ink cartridge 2, an ink tank 5 that stores ink supplied from the ink cartridge 2 via an ink supply tube 4, and the ink tank 5 that stores the ink. A recording head 7 that ejects the ink toward the recording medium 6, a recording head unit 8 including the ink tank 5 and the recording head 7, and a carriage 9 that reciprocates in a linear direction, and the carriage 9 reciprocates. A carriage shaft 10 serving as a guide, a transport mechanism 11 for transporting the recording medium 6, and a purge device 12 are provided.

  The ink cartridge 2 is provided for each of a plurality of color inks such as cyan, magenta, yellow, and black, and is mounted on the ink jet recording apparatus 1 so that color printing is possible.

  The mounting portion 3 includes a base portion 3a and guide portions 3b standing from both sides of the base portion 3a. From the base portion 3a sandwiched between the guide portions 3b, the ink stored in the ink cartridge 2 is received. A hollow ink extraction tube 13 for extraction and a hollow outside air introduction tube 14 for introducing outside air into the ink cartridge 2 are disposed so as to protrude.

  An ink supply tube 4 is connected to one end side of the ink extraction tube 13, and the ink extraction tube 13 communicates with the ink tank 5 through the ink supply tube 4. An outside air introduction tube 15 is connected to one end side of the outside air introduction tube 14, and the outside air introduction tube 14 communicates with outside air via the outside air introduction tube 15.

  The purge device 12 is disposed so as to face the recording head 7 outside the recording range, and communicates with the purge cap 12a covering the nozzle 16 (see FIG. 3) formation surface of the recording head 7 and the purge cap 12a. A waste ink tube 12b and a pump 12c for sucking ink from the nozzles 16 through the waste ink tube 12b are provided.

  Next, the structure of the recording head unit 8 will be described with reference to FIGS. 2 is a sectional view, FIG. 3 is a bottom view, FIG. 4 is an exploded perspective view of the recording head 7a and the flexible wiring board 27a, and FIG. 5 is a sectional view taken along the line III-III in FIG. .

  The recording head unit 8 includes the ink tank 5 and the recording head 7 as described above. The ink tank 5 is disposed on the inner side, and the head holder 20 that supports the recording head 7, and an upper portion of the head holder 20. And a printed circuit board 21 which is connected to a control circuit which is positioned and placed on the main body side of the inkjet recording apparatus 1 via a flexible cable.

  Two recording heads 7 are supported on the bottom of the head holder 20 that faces the recording medium 6. A plurality of groups of nozzles 16 corresponding to a plurality of ink colors are arranged in a row on the lower surfaces (see FIG. 3) of the recording heads 7a and 7b. The recording heads 7a and 7b are supported side by side in a second direction substantially orthogonal to the direction of the nozzle rows (hereinafter referred to as the first direction) so that the rows of nozzles 16 are substantially parallel to each other.

  In this embodiment, for each of the recording heads 7a and 7b, yellow ink nozzles 16y1 and 16y2, cyan ink nozzles 16c1 and 16c2, magenta ink nozzles 16m1 and 16m2, and black ink nozzles 16k1 and 16k2 are provided. Although one row (one group) is arranged, the number of columns can be varied according to the ink color, or the columns can be divided into a plurality of groups in the column direction. The nozzles of the same color of the two recording heads 7a and 7b may be arranged on the same line in the scanning direction of the carriage 9, but may be arranged with a half pitch shift in the nozzle row direction.

In general , since there are many opportunities to record a large number of documents such as characters using black ink, the nozzles 16k1 and 16k2 are nozzle groups corresponding to ink colors with high ink ejection frequency. That is, the recording heads 7a and 7b are divided into nozzle groups 16k1 and 16k2, which are nozzle groups for black ink having a high discharge frequency, and have nozzle groups corresponding to the same plurality of ink colors. The arrangement state of each nozzle group is symmetrical with respect to a line passing through the center between the two recording heads 7a and 7b.

  The ink tank 5 includes two ink tanks 5c1 and 5c2 for cyan ink, two ink tanks 5y1 and 5y2 for yellow ink, two ink tanks 5m1 and 5m2 for magenta ink, and black according to the color of each ink. It comprises an ink tank 5k for ink. Each ink tank is connected to ink supply ports 30y1, 30c1, 30m1, 30k2, 30y2, 30c2, 30m2, and 30k2, which will be described later, of the recording heads 7a and 7b by pipes 31y1, 31c1, 31m1, 31k1, 31y2, 31c2, 31m2, and 31k2. Is done. The ink tank 5k has a larger capacity than other ink tanks because the ink discharge frequency is high.

Head holder 20 is formed more substantially box shape with the pair of side walls 20b and a pair of side walls 20c that rises vertically, inside thereof, a recording head 7a, the space 22 and the ink tank 5 7b are arranged is disposed A bottom wall 20 a that partitions the space 23 is provided.

  On the lower surface of the head holder 20 that is opened, a closing member 24 that closes the space 22 and is formed with an exposure port that exposes each nozzle 16 to the outside is fixed. The recording heads 7a and 7b are fixed to the lower surface of the bottom wall 20a with an adhesive (not shown).

  Each of the recording heads 7a and 7b includes cavity plates 25a and 25b formed by laminating a plurality of plates, and plate-type piezoelectric actuator plates 26a and 26b. The cavity plates 25a and 25b have ink supply ports 30y1, 30c1, 30m1, 30k1, 30y2, 30c2, 30m2, and 30k2 (only the recording head 7a is shown in FIG. 4) on the upper surface. In the same manner as described and known, ink is distributed to a plurality of pressure chambers via manifold channels extending from the respective ink supply ports, and corresponding nozzles 16y1, 16c1, 16m1, 16k1, 16y2 are provided from the pressure chambers. , 16c2, 16m2, and 16k2. The piezoelectric actuator plates 26a, 26b have a plurality of pressure generating means corresponding to the pressure chambers, that is, piezoelectric deformation portions, and electrodes 41y, 41c, 41m, 41k (recording heads) connected to the piezoelectric deformation portions on the upper surface thereof. 7a only).

  IC chips that have flexible wiring boards 27a and 27b having flexibility are stacked on the upper surfaces of the piezoelectric actuator plates 26a and 26b, and drive circuits mounted on the flexible wiring boards 27a and 27b are mounted on the electrodes. Wiring patterns (not shown) extending from 33a and 33b are connected. When drive pulses are supplied from the IC chips 33a and 33b to the piezoelectric deformation portions of the piezoelectric actuator plates 26a and 26b, pressure is applied to the ink in the pressure chamber, and the ink can be ejected downward from the nozzles.

  As shown in FIG. 4, the flexible wiring boards 27a and 27b have a width in the row direction of the electrodes 41y, 41c, 41m, and 41k, that is, the nozzle row direction, and are opposite to each other from the two recording heads 7a and 7b. And it extends in the second direction. The flexible wiring boards 27a and 27b enter the upper space 23 through the communication paths 28a and 28b formed in the bottom wall 20a, and are substantially parallel to the side walls 20b on both sides in the arrangement direction of the two recording heads 7a and 7b. The holder 20 extends upward. And the terminal part 43a of the front-end | tip of flexible wiring board 27a, 27b is connected to the printed circuit board 21 arrange | positioned at the upper part of the head holder 20, respectively by connector 32a, 32b.

  The IC chips 33a and 33b are disposed on both sides in opposite directions from the recording heads 7a and 7b and at a position approximately in the middle between the recording heads 7a and 7b and the printed circuit board 21, and are emitted from the IC chips 33a and 33b. The transmission of heat to the recording heads 7a and 7b is reduced. The substantially middle position is a substantially middle position of the side wall 20b rising from the bottom wall 20a. The IC chips 33a and 33b may be disposed at any position between the recording heads 7a and 7b and the printed circuit board 21 as long as the heat transfer to the recording heads 7a and 7b can be reduced. It is good also as what is arrange | positioned from the position to the printed circuit board 21 side.

  In the recording head unit 8, heat sinks 35a and 35b arranged so as to be able to conduct heat with the IC chips 33a and 33b and dissipating heat generated by the IC chips 33a and 33b are arranged on opposite sides of the recording heads 7a and 7b. Has been.

  As shown in FIG. 2, the heat sinks 35a and 35b are arranged on the inner sides of the side walls 20b and 20b on both sides in the arrangement direction of the two recording heads 7a and 7b, and are disposed in parallel with the side walls 20b and 20b. Portions 37a and 37b, and exposed portions 38a and 38b that extend the upper ends of the side wall portions 37a and 37b so as to cross the upper portions of the side walls 20b and 20b in an inverted U shape and are exposed to the outside of the head holder 20. .

  As shown in FIG. 5, a through-hole 39a is formed in the curved portion of the exposed portion 38a of the heat sinks 35a and 35b to pass the flexible wiring board 27a from the recording head 7a side to the printed board 21 (see FIG. 2) side. Yes. The heat sinks 35 a and 35 b are fixed by two mounting bosses 34 projecting from the bottom wall 20 a and are mounted in the head holder 20.

  The flexible wiring boards 27a, 27b are disposed between the heat sinks 35a, 35b and the side walls 20b, 20b, and the IC chips 33a, 33b are rubber-like elastic members 36a, 36b fixed to the side walls 20b, 20b. The heat sink 35a and 35b are pressed so as to contact the heat sink 35a and 35b.

  As described above, according to the inkjet recording apparatus 1, the nozzles 16k1 and 16k2 with high ejection frequency are divided into the recording heads 7a and 7b, respectively, and a plurality of nozzle groups corresponding to each ink color are recorded in two. The heads 7a and 7b are arranged in substantially the same number. In the same color nozzle row of the two print heads 7a and 7b, the print data from the control circuit on the main body side is intentionally placed in one row in the same manner as the print head having two rows of nozzles for one normal color. Assigned without bias. Therefore, even when black ink is frequently ejected from the nozzles 16k1 and 16k2, and even when another ink is continuously ejected, the temperature difference generated between the recording heads 7a and 7b can be reduced. Furthermore, since the IC chips 33a and 33b individually output drive signals to the recording heads 7a and 7b, the temperature difference between the IC chips 33a and 33b is also reduced. Therefore, the output characteristics of the drive signal from each IC chip, that is, the rising / falling characteristics of the drive pulse change between the IC chips 33a and 33b, or a temperature difference occurs between the recording heads 7a and 7b. It is possible to prevent the viscosity of the ink from changing and the discharge characteristics from the nozzle from changing, so that high quality recording can be performed.

  Next, the recording head unit 8 of the second embodiment will be described with reference to FIGS. 6 is a cross-sectional view, and FIG. 7 is a bottom view. In addition, the same code | symbol is attached | subjected to the part same as 1st Example, and the description is abbreviate | omitted.

  The arrangement of the plurality of nozzle groups formed on the lower surface of the recording heads 7a and 7b of the second embodiment is that nozzles arranged in a staggered pattern in two rows for magenta ink on the recording head 7a from the right side of FIG. 116m, nozzles 116c1 for cyan ink and nozzles 116k1 for black ink are arranged in a row, and nozzles 116y arranged in a staggered pattern in two rows for yellow ink on the recording head 7b from the left side of FIG. The cyan ink nozzles 116c2 and the black ink nozzles 116k2 are arranged in a line. That is, each of the recording heads 7a and 7b includes nozzles 116k1 and 116k2 that serve as nozzle groups of black ink that are frequently ejected, and includes nozzles 116m and 116y that serve as nozzle groups corresponding to different magenta ink and yellow ink. It is configured.

  The ink tank includes an ink tank 105k for black ink, two ink tanks 105c1 and 105c2 for cyan ink, an ink tank 105y for yellow ink, and an ink tank 105m for magenta ink according to the color of each ink. Each ink tank is connected to the ink supply ports 130y, 131m, 130c1, 130c2, 130k1, 130k2 of the recording heads 7a, 7b by tubes 131y, 131m, 131c1, 131c2, 131k1, 131k2.

  As described above, in the ink jet recording apparatus 1 of the second embodiment, the nozzle arrangement is divided into the recording heads 7a and 7b because the nozzles 116k1 and 116k2 corresponding to the black ink having a high ejection frequency are divided into the first embodiment. Similarly to the example, the temperature difference generated between the IC chips 33a and 33b and between the recording heads 7a and 7b can be reduced. Therefore, since the change in the ink ejection characteristics from the nozzles between the recording heads 7a and 7b can be suppressed, high-quality recording can be performed.

  Further, the number of ink tanks can be reduced as compared with the case where the nozzles corresponding to all the ink colors are divided into the recording heads 7a and 7b, respectively, and the number of each tube that communicates each ink tank with each nozzle. Therefore, the structure can be simplified and the manufacturing cost can be reduced.

  Next, the recording head unit 8 of the third embodiment will be described with reference to FIGS. 8 is a cross-sectional view, and FIG. 9 is a bottom view. The ink jet recording apparatus 1 of the third embodiment is configured by integrally forming the recording heads 7a and 7b of the first embodiment, and the same parts as those of the first embodiment are denoted by the same reference numerals. The description is omitted.

  In the ink jet recording apparatus 1 of the third embodiment, one recording head 207 is supported by the head holder 20. On the lower surface of the recording head 207, a group A composed of a plurality of nozzle groups of a nozzle 16y1 for yellow ink, a nozzle 16c1 for cyan ink, a nozzle 16m1 for magenta ink, and a nozzle 16k1 for black ink, and yellow A group B composed of a plurality of nozzle groups of an ink nozzle 16y2, a cyan ink nozzle 16c2, a magenta ink nozzle 16m2, and a black ink nozzle 16k2 is formed.

  That is, each of the groups A and B is divided so that the nozzles 16k1 and 16k2 having a high discharge frequency and the other nozzles 16y1, 16y2, 16c1, 16c2, 16m1, and 16m2 have the same number, and the same plurality of inks. It has a nozzle group corresponding to the color.

  The recording head 207 includes a single cavity plate 225, a piezoelectric actuator plate 26a that ejects ink from each nozzle of group A, and a piezoelectric actuator plate 26b that ejects ink from each nozzle of group B. IC chips 33a and 33b are connected to the plates 26a and 26b, respectively.

  Therefore, the recording head 207 of the inkjet recording apparatus 1 of the third embodiment is divided so that the nozzles 16k1 and 16k2 having a high ejection frequency are divided into groups, and the nozzle groups corresponding to a plurality of ink colors are the same. Therefore, there is no difference in ejection frequency for each group. Therefore, only one of the IC chips 33a and 33b can be reduced in temperature rise, and the ink ejection characteristics from the nozzles in the recording head 207 can be prevented from differing depending on the location, so that high quality recording is performed. be able to.

  In the third embodiment, the cavity plate 225 is integrally manufactured and the two piezoelectric actuator plates 26a and 26b are arranged side by side. However, the piezoelectric actuator plates 26a and 26b are integrally formed, and electrodes on the upper surface thereof are formed. Can be divided into two groups in a direction orthogonal to the nozzle rows, and the flexible wiring boards 27a and 27b can be connected to each group.

  The recording heads 7a and 7b of the second embodiment may be integrated. In this case, on the lower surface of the integrally formed recording head, groups A and B each including nozzles for black ink as nozzle groups with high ejection frequency and nozzles corresponding to different magenta ink and yellow ink are configured. The

  The present invention has been described above based on the embodiments. However, the present invention is not limited to the above embodiments, and various improvements and modifications can be made without departing from the spirit of the present invention. It can be easily guessed.

  For example, in the first or second embodiment, the recording head is composed of the two recording heads 7a and 7b. However, the recording head may be composed of a plurality of recording heads. In this case, a nozzle group for black ink is divided for each recording head, and a flexible wiring board and an IC chip are provided for each recording head.

  In the third embodiment, the recording head 207 includes the two groups A and B. However, the recording head 207 may include a plurality of groups. In this case, a nozzle group for black ink is divided for each group, and a flexible wiring board and an IC chip are provided for each group.

FIG. 2 is a schematic diagram illustrating an ink jet recording apparatus according to an embodiment of the present invention and an ink cartridge attached to the ink jet recording apparatus. FIG. 3 is a cross-sectional view illustrating a structure of a recording head unit. It is a bottom view of the recording head unit. It is a disassembled perspective view of a recording head and a flexible wiring board. FIG. 3 is a sectional view taken along the line III-III in FIG. 2. It is sectional drawing which showed the structure of the recording head unit of 2nd Example. It is a bottom view of the recording head unit of the second embodiment. It is sectional drawing which showed the structure of the recording head unit of 3rd Example. FIG. 10 is a bottom view of a recording head unit according to a third embodiment.

7a, 7b, 207 Recording head 9 Carriage 16y1, 16y2 Nozzle 16c1, 16c2 Nozzle 16m1, 16m2 Nozzle 16k1, 16k2 Nozzle 20 Head holder 21 Printed circuit board 27a, 27b Flexible wiring board 33a, 33b IC chip (drive circuit)
35a, 35b Heat sink 116y Nozzle 116c1, 116c2 Nozzle 116m Nozzle 116k1, 116k2 Nozzle A, B group

Claims (13)

Nozzle array comprised of a plurality of nozzles arranged in a column shape, comprising several double recording heads arrayed, the nozzle array ejecting frequency of ink corresponding to the high ink color among the plurality of ink colors A plurality of nozzle rows corresponding to ink colors having a plurality of ink discharge frequencies and provided separately for each of the plurality of recording heads;
Among the plurality of ink heads, the plurality of nozzle rows corresponding to at least one ink color that does not have a high ink discharge frequency compared to an ink color that has a high ink discharge frequency among the plurality of ink colors. An ink jet recording apparatus that is assembled into any one of the above . 2. The ink jet recording apparatus according to claim 1, wherein the number of the nozzle rows is set equal between the plurality of recording heads. A drive circuit for driving the recording head to discharge ink from the previous SL nozzles, corresponding to said plurality of recording heads placing serial to claim 1 or 2, characterized in that provided divided into a plurality Inkjet recording apparatus. Two recording heads are provided, and the drive circuits corresponding to the heads are connected to flexible wiring boards extending in opposite directions from the heads, and the drive circuits are heated by heat sinks disposed on both sides of the direction. The ink jet recording apparatus according to claim 3 , wherein the ink jet recording apparatus is arranged to be conductive. A nozzle array corresponding to an ink color having a high ejection frequency of one of the recording heads is symmetric with respect to a nozzle array corresponding to an ink color having a high ejection frequency of another recording head. an ink jet recording apparatus according to claim 1, wherein the fourth in that an array of two recording heads as. The respective recording heads each comprise a nozzle row in which the discharge frequency corresponding to the high ink color, claims 1-5, characterized in that it has a nozzle row corresponding to a different said plurality of ink colors with each other Any one of the inkjet recording apparatuses. A recording head in which a plurality of nozzle arrays composed of a plurality of nozzles arranged in a row are arranged , and
A drive circuit that drives the recording head to eject ink from the nozzles,
There are a plurality of the nozzle rows corresponding to ink having a high ink discharge frequency among a plurality of ink colors,
The driving circuit, as well as configured to be divided into a plurality of groups corresponding to a plurality of nozzle arrays for ejecting ink colors of multiple, said plurality of groups of the plurality of nozzle rows in which the discharge frequency corresponding to the high ink colors An ink jet recording apparatus characterized by being provided separately for each of the drive circuits. 8. The ink jet recording apparatus according to claim 7, wherein a plurality of the recording heads are provided, and the driving circuit is provided in a plurality corresponding to the plurality of recording heads. In that the nozzle array, the divided nozzle array discharging frequency corresponding to high ink colors and a nozzle row corresponding to the other ink colors into a plurality of groups equal comprising respectively, provided the drive circuit for each group The inkjet recording apparatus according to claim 7 or 8 , characterized in that The nozzle row is divided into two groups each including a nozzle row corresponding to the ink color having a high ejection frequency and a nozzle row corresponding to another ink color , and the two drive circuits corresponding to each group are arranged. , connected to a flexible wiring board extending in opposite directions from their respective group, one of claims 7 9 in which each of said driving circuits in the heat sinks arranged on both sides of the direction, characterized in that arranged so as to be thermally conductive serial mounting of the ink jet recording apparatus or. Wherein each group, ink jet recording apparatus according to claim 9 or 10, characterized in that it has a nozzle row corresponding to the same said plurality of ink colors, respectively. Wherein each group, each containing the ejection frequency is high nozzle array, ink-jet recording apparatus according to claim 9 or 10, characterized in that it has a nozzle row corresponding to a different said plurality of ink colors with each other. The discharge frequency is high nozzle array, ink-jet recording apparatus according to any one of claims 1 to 12, characterized in that a nozzle row for black ink.

Images