JPH0761712B2 - Inkjet recording device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an inkjet recording apparatus capable of accurately fixing a head member in a positioning state with respect to a mounting surface thereof.

[Prior Art] Generally, in an inkjet recording apparatus including a recording head that ejects ink onto recording paper, it is necessary to mount the recording head with high precision in order to realize an accurate recording state. Particularly, in an ink jet recording apparatus having a plurality of recording heads in the width direction of the recording paper, since a recording image is disturbed due to a slight mounting error of each recording head, each recording head is mounted with high accuracy. There is a strong demand.

[Objective] In view of the above point, the present invention is an inkjet recording in which a recording head can be accurately and easily positioned in a direction orthogonal to a recording surface of a recording sheet, a width direction of the recording sheet, and a direction orthogonal to both directions. The purpose is to provide a device.

[Examples] Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an example of the configuration of the main part of an inkjet recording apparatus to which the present invention can be applied. That is, in the present embodiment, the present invention is applied to, for example, a color ink jet printer of four colors, and this ink jet printer has a plurality of print heads in the width direction of the recording paper and prints by the on-demand method. Shall be performed.

In FIG. 1, reference numeral 2 denotes a unit plate made of, for example, aluminum, and seven head elements 4 are alternately provided on both front and back surfaces of the unit plate 2 over the entire width of the recording area of the recording paper. Each head element 4 has 128 ink ejection nozzles facing the recording paper in the width direction. These head elements 4 are appropriately arranged on both sides of the unit plate 2, and the recording area by the nozzles of the head element 4 arranged on the front side of the unit plate 2 and the recording area by the nozzles of the head element 4 arranged on the back side. And 1 do not overlap each other in the width direction of the recording paper, and one line can be recorded. That is, at the time of recording, the head element 4 on the back side is first driven to perform recording, and the head element 4 on the front side is driven when the recorded portion faces the head on the front side as the recording paper moves. By doing 1
Line recording can be performed.

Reference numeral 6 is a distributor, and for example, the distributor disclosed in Japanese Patent Application No. 58-244138 of the present applicant can be used. The distributor 6 has a forward-side distributor 6A that supplies ink to the head element 4 through the supply pipe 8A and a return-side distributor 6B that collects ink from the head element 4 through the supply pipe 8B. Reference numeral 7 denotes a joint portion for connecting the distributor 6 and the supply pipe 8, that is, a DT joint, and for example, one disclosed in Japanese Patent Application No. 58-244132 by the present applicant can be used. Each of these parts is a head unit 10 associated with one predetermined color of ink, and in the present embodiment, four head units 10 are provided corresponding to the number of colors of ink.

Reference numeral 20 is a mother board, and 22 is a guide member for mounting the head unit 10 on the mother board 20 while guiding the unit plate 2.

A first tank 30 stores ink and serves as an ink supply source for the head element 4, and is provided on the side of the mother board 20 opposite to the head unit 10. 40 is a second tank as an ink cartridge tank, which is guided by the guide member 24 provided on the motherboard 20,
Allow it to be attached to motherboard 20. First tank 30
Has a liquid level sensor, and by this liquid level sensor, the first tank
When it is detected that the amount of ink in 30 has become equal to or less than a predetermined amount, the ink is supplied from the second tank 40 to the first tank 30. Reference numerals 32 and 34 denote arm portions of the first tank 30, and opening / closing means 50, 52 such as solenoid valves are attached to the arm portion 32, and opening / closing means 54 such as solenoid valves and a pump 56 are attached to the arm portion 34. As the opening / closing means 50, 52, 54, an opening / closing throttle, a gate valve or the like can be used in addition to the solenoid valve.

The solenoid valve 50 includes a conduit 60 formed in the arm portion 32 to reach the ink storage portion in the first tank 30 and a joint portion to the distributor 6A via the motherboard 20 (hereinafter referred to as D
-V joint 70) is connected to the valve unit 50A, and the valve unit 50A is opened in response to the urging of the solenoid 50B to form an ink flow path. Solenoid valve 52 is the first tank 30
It has a valve section 52A that connects the inside air chamber and the outside air, and opens in response to the urging of the solenoid 52B to open the air chamber inside the first tank 30 to the atmosphere. Note that, for example, the dustproof filter 53 may be provided on the atmosphere side of the valve portion 52A.

The solenoid valve 54 is a joint portion formed in the arm portion 34 and connecting a pipe 64 leading to the pump 56 and a pipe 66 leading to the second tank 40.
It has a valve portion 54A that connects the junction portion 72 that penetrates the motherboard 20 to the distributor 6B, that is, the DV joint 74. This valve portion 54A opens in response to the energization of the solenoid 54B, and the pump 56 and the distributor 6B
To form an ink flow path between them. Reference numeral 76 is a joint for connecting the pipe 66 and the second tank 40, that is, a TC joint.

The pump 56 is connected to a pipe 64 leading to the valve portion 54, a pipe 68 leading to the first tank 30, and a second tank via a check valve or other backflow prevention means so as to connect the forward and reverse directions. In response to the operation, ink is supplied from the valve section 54A and the second tank 40 to the first tank 30, and ink is sent to the valve section 54A.

These parts 30, 40, 50, 52, 54, 56, etc. are connected to the head unit 10
In this embodiment, four stages are provided according to the color type of the ink. In FIG. 1, only one stage is shown. This ink supply stage connects these to the head unit 10 via the DV joints 70 and 74, as described above.

Further, in FIG. 1, reference numeral 80 denotes a connector to a control unit (not shown), which is attached to the mother board 20. Reference numeral 82 is an interface board, and 84 is a flexible wiring board for transmitting a print control signal supplied from the control unit via the connector 80 and the interface board 82 to the head element 4 and the like. 300 and 400 are heaters for keeping the temperature of the ink and liquid temperature sensors for detecting the ink liquid temperature, which are provided on the unit plate 2, respectively. In addition, 500
Is a cap portion which is positioned at the illustrated position when performing ejection recovery of the nozzle portion and which caps the nozzle portion. When recording this cap 500,
For example, when it is positioned downward in FIG. 1 and the discharge recovery is performed, it may be positioned as shown in the drawing along the guide rail by, for example, a driving means (not shown).

Next, a mounting member of the head element 4 to the unit plate 2 will be described.

FIG. 2 shows an example of the structure of the head element 4 and its mounting member. Here, 250 is a head portion formed by laminating a hard material such as Si or glass on a portion of the substrate 252 such as SiC facing the recording paper, and a nozzle portion is formed, and 254 is projected from one end surface of the substrate 252. It is the overhanging portion formed in.

Reference numeral 260 denotes a pin that abuts on one side surface (hereinafter, referred to as a head side surface) 250A of the substrate 252 of the head element 4 and an overhanging side surface 254A, which is an embodiment of the second positioning member of the present invention. 260 are press-fitted into predetermined positions on both front and back surfaces of the flat unit plate 2 as an example of the head mounting surface of the present invention. These pins 260 are provided with notches 261 so as to contact only the upper part of the head part side face 250A and the projecting part side face 254A and not the lower part of the head part side face 250A. 262 are pins that are press-fitted in predetermined positions on both front and back surfaces of the unit plate 2.
Serves as an embodiment of the first positioning member of the present invention.

Here, the reason why the notch 261 is provided in the pin 260 is as follows. Since the head portion 250 is formed by cutting the laminated body of the hard material as described above with a cutter, the cutter bends during the cutting process, and the lower portion does not have an accurate dimension, so-called Burrs may occur. On the other hand, there is almost no bending of the cutter at the upper portion, and the cutter is formed to have an accurate size. So pin 260
Comes into contact with the upper part of the head side surface 250A and has a notch 26
This is because the mounting accuracy of the head element 4 can be further improved by making 1 to face each other so as to form an escape from a portion with an incorrect dimension or a flash.

In this example, the head element 4 is directed toward the pins 260 and 262 in the W direction (corresponding to the first direction in the present invention) in the drawing.
When the head element 4 is pressed and comes into contact with it, the head element 4 is positioned in the recording paper width direction. Further, when the head element 4 is pressed toward the pin 260 in the F direction (corresponding to the second direction in the present invention) in the drawing, and the side surface 254A of the overhanging portion comes into contact with the pin 260, a planar recording surface is obtained. Positioning should be done in a direction orthogonal to. Furthermore, by pressing the lower surface of the head element 4 against the surface of the unit plate 2 in the V direction,
The head element 4 is positioned vertically.

270 is a fixing member as the first fixing means of the present invention for positioning the head element 4 in the F direction and the V direction,
274 is a small screw for attaching the fixing member 270 to the unit plate 2, and 276 is a pin projecting from the unit plate 2 for positioning and preventing rotation of the fixing member 270. The portion of the fixing member 270 that faces the side surface 254B on the opposite side of the overhang portion side surface 254A is formed on a slope 271 that is inclined with respect to the upper surface of the overhang portion 254 so that the slope 271 and the upper side of the side surface 254B abut. To In addition, a notch is provided between the portion fixed by the machine screw 274 and the inclined surface 271, and the inclined surface 271 elastically presses the overhanging portion 254 by the spring property of the notched portion.

Then, by fixing the fixing member 270 to the unit plate 2 with the machine screw 274, the inclined surface 271 becomes the side surface 254 of the protruding portion.
Since it is pressed to the upper side of B, and as a result, component forces in the F direction and the V direction act on the overhanging portion 254, the overhanging portion 254 is in close contact with the surface of the pin 260 and the unit plate 2 and the head element 4 in those directions. Can be positioned.

Next, 280 is a fixing member as the second fixing means of the present invention for positioning the head element 4 in the W direction and the V direction, 284 is a small screw for attaching the fixing member 280 to the unit plate 2, and 286 is The pins project from the unit plate 2 for positioning the fixing member 280.
Reference numeral 281 denotes an oscillating portion that can oscillate in the W direction due to the springiness of the cutout portion 282. The oscillating portion 281 is provided with a head element pressing cam 290 that is rotatable about a cam rotation shaft 288.

FIG. 3 shows a cam rotating shaft 28 functioning as a rotating member of the present invention.
8 and an example of the head element pressing cam 290 are shown. In this way, the head element pressing cam 290 is formed into a cylindrical shape having a sliding surface 292 on the bottom surface side so as to be inclined with respect to the upper surface of the substrate 252, and further, its central axis 290A is the center of the cam rotating shaft 288. , Ie head element presser cam 2
The configuration is eccentric from the rotating shaft 288A of 90.

When the head element 4 is fixed by such a fixing member 280, first, the head element pressing cam 290 is rotated around the cam rotating shaft 288 so that the sliding surface 292 does not face the substrate 252, and the fixing member 280 is fixed. Is attached to the unit plate 2 with a small screw 284. Then, by rotating the head element pressing cam 290 to bring the sliding surface 292 into contact with the upper side of the head element 252, component force in the W direction and the V direction is applied from the contact portion to the head element 252. To work. As a result, the upper portion of the head side surface 250A and the substrate 252 come into contact with the pins 260 and 262, respectively, and the lower surface of the substrate 252 comes into close contact with the surface of the unit plate 2 to position the head element 4 in the W and V directions. You can

In this way, the pin 262 as the first positioning member for the one head element 4 is provided on the unit plate 2 between the two head elements 4 adjacent to each other on the same front and back surfaces.
Since the pin 260 as the second positioning member, the fixing member 270 as the first fixing member, and the fixing member 280 as the second fixing member for the other head element 4 are arranged, the front and back surfaces are the same. The empty space of the unit plate 2 between two head elements 4 adjacent to each other on the side is effectively used, and the entire head unit 10 can be made compact.

[Effect] According to the inkjet recording apparatus of the present invention, the first positioning member for one head element and the second positioning member are provided on the head mounting surface of the head mounting substrate between the two head elements adjacent to each other on the same front and back surfaces. Since the positioning member, the first fixing member, and the second fixing member for the other head element are arranged, in the direction orthogonal to the recording surface of the recording paper, the width direction of the recording paper, and the direction orthogonal to both directions. The recording head can be positioned accurately and easily, and the mounting accuracy of the recording head can be significantly improved. Further, since it is possible to effectively utilize the empty space on the head mounting surface between two head elements that are adjacent to each other on the same surface side as the front and back surfaces, the entire head unit can be made compact.

[Brief description of drawings]

1 is a perspective view showing an example of the configuration of an inkjet recording apparatus according to the present invention, and FIG. 2 is a perspective view showing an example of the configuration of a head element and its mounting member in the inkjet recording apparatus shown in FIG. FIG. 3 is a front view showing an example of a mounting part used for this mounting member. In addition, reference numerals 2 ... Unit plate, 4 ... Head element, 6,6A, 6B ... Distributor, 7 ... Joint (DT joint), 8, 8A, 8B ... Supply pipe, 10 …… Head unit, 20 …… Motherboard, 22,24 …… Guide member, 30 …… First tank, 32,34 …… First tank arm part, 40 …… Second tank, 50,52,54… … Opening / closing means (solenoid valve), 50A, 52A, 54A …… valve part, 50B, 52B, 54B …… solenoid, 53 …… dust filter, 56 …… pump, 60,64,66,68 …… pipe line, 70 …… Joined part (D-V joint), 72 …… Joined part, 74 …… Joined part (D-V joint), 76 …… Joined part (TC joint), 80 …… Connector, 82 …… Interface board, 84 ... Flexible wiring board, 250 ... Head section, 250A ... One side of the board (side of the head section), 252 ... Board, 254 … Overhang part, 254A …… Overhang part side, 254B …… Overhang part side and opposite side, 260,262 …… Pin, 261 …… Notch, 270,280 …… Fixing member, 271 …… Slope, 274,284 …… Small Screw, 276,286 …… Pin, 280 …… Fixing member, 281 …… Rotating part, 288 …… Cam rotating shaft, 288A …… Rotating shaft, 290 …… Head element pressing cam, 290A …… Center shaft, 292… … Sliding surface, 300 …… Heater, 400 …… Liquid temperature sensor, 500 …… Cap section.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Taku Nakamura 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Shunichi Uzawa 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Incorporated (72) Inventor Shigeru Yoshimura 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (56) Reference JP-A-58-194542 (JP, A) JP-A-50-118250 (JP) , A) Actual development Sho 58-116266 (JP, U) Actual development Sho 58-144652 (JP, U) Actual public Sho 52-43128 (JP, Y1)

Claims (2)

[Claims] 1. A head mounting substrate having head mounting surfaces formed on both front and back surfaces thereof, and an ink jet head having a plurality of ink ejection openings facing a recording medium, respectively. A plurality of heads arranged alternately on the front side head mounting surface and the back side head mounting surface of the head mounting substrate along the width direction of the recording medium so as to be arranged over the entire width of the recording area of the recording medium. An inkjet recording apparatus including an element, wherein the head element is formed with an overhanging portion projecting from one end surface of the head element, and between the two head elements that are adjacent to each other on the same front and back surfaces. The one side end surface of one of the head elements is in contact with the head mounting surface of the head element, and the one head element is moved in the first direction along the head mounting surface. The first positioning member for positioning the element, the one end surface of the one head element and the projecting portion of the head element, respectively, come into contact with each other, and the head attachment intersects the first direction and the first direction. A second positioning member for positioning the one head element in a second direction along the surface, and an inclined surface that abuts the overhanging portion of the one head element from obliquely above are formed. A first fixing member for pressing and fixing the head element to the second positioning member and the head mounting surface is provided, and the other side end surface of the other head element is obliquely from above. An abutting slope is formed so that the other head element is adjacent to the other head element and another head element adjacent to the other head element. And a second fixing member for pressing and fixing the first positioning member and the second positioning member on the head mounting surface between the head mounting surface and the head mounting surface. Characteristic inkjet recording device. 2. The first fixing member and the second fixing member are arranged on each head mounting surface between two head elements that are adjacent to each other on the same surface side as the front and back sides. The inkjet recording apparatus according to claim 1, wherein the inkjet recording apparatuses are arranged in a direction intersecting with each other.