JPH09239990A - Head holder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure positional accuracy by moving the moving frame of a printing head by small force to enable the pressure contact of an electrical contact with a head reference member and to ensure the high positional accuracy of the printing head and the electrical contact and to facilitate the attachment and detachment of the printing head. SOLUTION: A moving frame 22 is provided above a rotary shaft and, at the same time, an electrical point 19 and a head reference member 20a are provided under the rotary shaft and a printing head is held by a head holder to be formed into a horizontal U-shape and the center point of the length of a head reference hole is allowed to be present on the tangent of a circle drawn centering around the rotary shaft of a base frame 21 by handle operation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a head carriage for an ink jet type image forming apparatus, and more particularly to a head carriage for surely attaching / detaching a print head in the ink jet type image forming apparatus.

[0002]

2. Description of the Related Art Conventionally, in an ink jet type image forming apparatus, a single print head can be mounted at a predetermined position and fixed to a head holder by an operating lever. In the case of color image formation, a method of mounting and fixing a plurality of print heads one by one on a head holder has been adopted.

[0003]

However, in an ink jet type image forming apparatus, particularly a scanning type image forming apparatus, a print head is provided so as not to be affected by vibration during scanning and to satisfy the following conditions. Is required to be firmly fixed to the head holder.

First, since the intervals of nozzles for ejecting ink of an ink jet type print head are formed in micron order, the accuracy of mounting the print head is required to maintain the image accuracy corresponding to the print head. To be done. The mounting accuracy includes mutual positional accuracy of a plurality of heads, distance accuracy with respect to a sheet, inclination accuracy at the time of mounting, and the like. Accurate mounting is required for these conditions.

Second, the print head has electrical contacts necessary for controlling ink ejection. As a matter of course, it is necessary for this contact to surely make contact with the main body and ensure electrical continuity.

Thirdly, there is an operability for mounting / dismounting the print head. Even with a plurality of print heads, it is necessary to attach / fix the action of attaching / detaching the print heads to / from the head holder at once by using a scanning lever having a simple operability as in the case of one print head.

In addition, these mechanisms must be constructed in a small space.

In order to solve the above problems, an object of the present invention is to provide a head carriage in which the print head can be easily attached and detached, the positional accuracy is improved, a reliable electric contact is secured, and the operability is simplified. To provide.

[0009]

In order to achieve the above object, the present invention provides a head holder for mounting a plurality of print heads for forming a color image, wherein each of the print heads is mounted on the head holder. At this time, the head holder is provided with an attachment / detachment device for simultaneously attaching / detaching the print head to / from a predetermined position by lever operation.

According to one embodiment of the present invention, the mounting / demounting device allows the plurality of print heads to be simultaneously rotated and released at respective predetermined positions by a lever operation so as to be detachable.

According to another embodiment of the present invention, the loading / unloading device has a U-shaped member capable of supporting three side surfaces of the print head, the U-shaped member being disposed on the surface facing the print head. Is provided with an elastic member for urging the print head so as to sandwich it from the opposite surface, and at least one U-shaped member also has a function of pressing from above the print head.

According to another embodiment of the present invention, the attachment / detachment device opens the movable member for pressing the upper part of the print head against the elastic member.

Furthermore, according to another embodiment of the present invention,
The attachment / detachment device matches the reference member and the electrical contact of the print head with the reference member and the electrical contact of the head holder by a mounting operation of the print head, and presses the electrical contact of the head holder and the printing. A holding member for preventing fluctuation of the head is provided.

Further, according to another embodiment of the present invention, the loading / unloading device has a rotary fulcrum for mounting the print head such that the rotary tangent for mounting the print head and the reference position of the head holder are horizontal. The reference position of the print head and the reference position of the head holder are matched with each other.

As a result, the print head can be easily attached and detached, the positional accuracy is improved, a reliable electric contact is secured, and the operability is simplified.

[0016]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 4 is an overall perspective view of an ink jet type large format color image forming apparatus embodying the present invention. In the figure, a color plotter (hereinafter referred to as plotter) 1, which is an inkjet large-format color image forming apparatus, is fixed on a stand 2. A sheet is inserted in the A direction from the sheet insertion port 4 by an input and an operation of the operation unit 3, and the inserted sheet is conveyed into the plotter 1, printed as a color image and discharged.

FIG. 5 is a schematic block diagram of the paper conveying section and the printing section, which are the main parts of FIG. In the figure, a path (not shown) for inserting, printing, and ejecting paper is shown, and a large-sized cut paper is aligned on the cover 6 of the roll paper 5 and inserted in the A direction. The large-sized paper is conveyed according to the rotation of the drive roller 8 while being sandwiched between the paper conveyance rollers 9a and 9b which are in contact with the drive roller 8 through the space between the cover 6 and the upper guide 7.

Further, the large-sized paper reaches the printing plate 10,
It is temporarily stopped, and color printing is performed during the stop. After color printing, the print amount is conveyed and the printing process is repeated.
A plurality of print heads 13 mounted on a head holder 12 of the head carriage 11 (for example, cyan, magenta,
Yellow and black print heads). The printing process will be described. The reciprocating movement of the head carriage 11 is
The head carriage 11 is fixed to a part of the belt 14 suspended from a drive source (not shown), and the belt 14 reciprocates by the forward and reverse rotation of the drive source, and the head carriage 11 reciprocates. In response to the print signals of the plurality of print heads 13 in the head carriage 11, while scanning a large-sized sheet on the printing plate 10, ink is ejected from each print head 13 to perform a printing process, and a color image is formed. .
After that, the large-sized paper is ejected while being sandwiched between the ejection roller 15 and the spur 6 above it.

As shown in FIGS. 1 and 2, the print head 13
In this arrangement, the left print head 13 is displaced from the other print heads 13 by the nozzle width of the print head 13. Black, C (cyan), M (magenta), and Y (yellow) print heads 13 are mounted in order from the left, and a color image is obtained.

When another black print head is replaced and mounted on the C (cyan) head holder, a black monochrome image can be obtained at almost double the printing speed by color image formation. Of the illustrated head holder 23, the print head 13 is
U-shaped head holders 23 and 28 are provided so as to be sandwiched from the side surface, and are surrounded by a base frame 21 and a moving frame 22 fixed to the head carriage 11.

At the bottom of the head holder 23, there is a rotation hole 24.
And a lower rotary shaft 25 fixed to the base frame 21 are fitted and rotatably attached. Also, the upper rotary shaft 26
Is the moving frame 22 fixed to the upper part of the head holder 23A.
It is fitted into the upper rotation hole 41.

As will be described in detail later, as shown in FIG. 1, when the moving frame 22 moves in the arrow direction E, the head holder 23
Rotates about the lower rotation shaft 25 in the direction of arrow E and tilts. The rotation hole 27 at the left end of the head holder 23 is fitted in the rotation shaft 29 of the U-shaped head holder 28. Spring seats 30 and 31 are provided below the head holders 23 and 28, and a spring 32 is installed between the spring seats 30 and 31. The action of the spring 32 allows the tops of the head holders 23 and 28 to be narrowed. This is for securely pinching the print head 13 with high accuracy when the print head 13 is mounted. On top of the head holder 28, the print head 13
A pressing plate 40 that presses from above is provided. By pressing the print head 13 from above, the print head 13 can be securely fixed to the head carriage 11.

The handle 3 in front of the head holder 28
By rotating 3 in the direction of arrow C, the attached print head 13 can be taken out. Since a presser plate 40 for pressing the print head 13 from above is provided on the upper part of the head holder 23, the print head 13 is released from the press plate 40 and the print head 13 can be removed. In addition, when the print head 13 is mounted, the presser plate 40 can be widened by rotating the print head 13 in the direction opposite to the arrow C, so that the print head 13 can be easily mounted.

A rack 35 is fixed to the right end of the moving frame 22. There is a gear 36 that meshes with the rack 35, and a bevel gear 37 integrally formed with the gear 36 is a rotatably base.
It is attached to the frame 21. A bevel gear 38 that meshes with the bevel gear 37 is connected to a shaft 39, and an operation lever 34 is fixed to the shaft 39. Therefore, when the operation lever 34 is rotated in the rotation direction D, the moving frame 22 moves in the arrow direction E.

As shown in FIG. 3, the head holder 12 rotates to be in an inclined state. The mounted print head 13 also tilts and is opened from the electric contact 19 and the head reference holes 20a and 20b, and the print head 13 can be easily taken out. When the print head 13 is mounted, the head holder 1
In the state in which 2 is tilted, the handle 33 can be rotated and mounted in the direction C.

FIG. 6 shows a perspective view of the print head of the present invention. In the figure, the print head 13 is mainly composed of nozzles (not shown) for ejecting ink and an ink tank. Further, a head electrical contact 17 and head reference holes 18a and 18b are provided as connecting portions. The electric contact 17 and the reference holes 18a and 18b engage with the electric contact 19 of the head holder 13 and the reference shafts 20a and 20b.

FIG. 1 shows a schematic block diagram of an embodiment of the present invention. In the figure, a base 21 is provided with an electric contact 19 and reference shafts 20a and 20b. When the print head 13 is mounted, the electrical contacts 19 provided on the print head 13
And head reference holes 18a and 18b, and head holder 1
Electrical contacts 19 provided on a base frame 21 fixed to
And the reference shafts 20a and 20b are engaged.

When the head electrical contact 17 and the electrical contact 19 are engaged, they are conducted so that a print signal can be transmitted into the attached print head 13, and the print head 1 is driven by a specific signal.
3 receives a print signal and performs a printing operation.

The head reference hole 18 of the print head 13 is also provided.
a, 18b and a reference shaft 20a provided on the base frame 21,
By engaging with 20b, a plurality of color print heads 13
Positional accuracy such as up and down, front and back, and parallelism is guaranteed.

As described above, when the print heads 13 are plural, the rotated print heads interfere with the adjacent head holders by operating the connecting members of the head holders to rotate the head holders at the same time. Never. Therefore, all the print heads can be attached / detached by one action of the operator. Although the number of print heads is four in this embodiment, the number of print heads is not limited to four.

Further, in order to avoid the interference portion when the print head is pulled out by tilting the print head holder and rotating the print head holder, the attachment / detachment space is not required and the head carriage is made compact. .

As shown in FIG. 7, when the print head 13 is mounted, the head reference hole 18 provided in the print head 13
The position can be secured with high accuracy. Base frame 21
It is a necessary condition that the head reference hole 18 of the print head 13 is smoothly inserted into the reference shaft 20 provided in the. Therefore, the setting of the position of the lower rotary shaft 25 is selected as follows.

When the center of the lower rotary shaft 25 and the print head 13 are mounted, the center of the length of the head reference hole 18 is set to be vertical. That is, the center point of the length of the head reference hole 18 is located on the tangent line of the circle 40 drawn at the center of the lower rotation shaft 25. Under such conditions, the print head 13 can be smoothly attached and detached with a minimum force.

The present invention is not limited to the above embodiment, but can be carried out in other modes by making appropriate design changes, for example, the carriage 1
The rotary shaft 21 fixed to No. 1 is placed at the lowest position, the electric contacts 19 head reference members 20a, 20b, etc. are sequentially provided at the upper position, and the moving frame 31 is further provided in the upper direction.

[0036]

As is apparent from the above description, the head carriage of the present invention has the moving frame above the rotary shaft, and at the same time the electrical contact and the head reference member below the rotary shaft. By the movement of the moving frame with a small force, the electric contact and the head reference member can be crimped, and the positional accuracy is ensured. In addition, the U-shaped head holder that holds the print head ensures high positional accuracy of the print head and electrical contacts, and the print head can be easily attached and detached by operating the handle. Since the center point of the length of the head reference hole exists on the close circle of the circle drawn as the center of the lower rotation axis, the print head can be smoothly attached and detached with the minimum force. This not only improves the position accuracy of the movement, but also simplifies the operability.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a carriage that is an embodiment of the present invention.

FIG. 2 is a diagram showing how the print head is mounted on the head holder shown in FIG.

FIG. 3 is a diagram showing a state in which a print head is attached to and detached from the head holder of FIG.

FIG. 4 is a relationship diagram between the lower rotation shaft and the head reference hole in FIG.

FIG. 5 is an overall view of a color plotter in which the present invention is implemented.

FIG. 6 is a schematic configuration diagram of the paper transport device of FIG.

FIG. 7 is a schematic diagram of a print head of the present invention.

[Explanation of symbols]

 11 Head Carriage 12 Head Holder 13 Print Head 17 Head Electrical Contact 18 Head Reference Hole 20 Reference Axis 21 Base Frame 22 Moving Frame 24 Rotation Hole 25 Lower Rotation Axis 26 Upper Rotation Axis 27 Rotation Axis 32 Spring 34 Clamping Body

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Gonsuke Inomata 6-3-3 Shimorenjaku, Mitaka-shi, Tokyo Within Copier Corporation (72) Inventor Naoki Kiyohara 6-3-3 Shimorenjaku, Mitaka-shi, Tokyo Within Copier Co., Ltd. (72) Inventor Satoru Sago 6-3-3 Shimorenjaku, Mitaka City, Tokyo Copier Co., Ltd. (72) Inventor Ryoma Suzuki 3-3-3 Shimorenjaku, Mitaka City, Tokyo Copier Co., Ltd. Inside (72) Inventor Seiichi Seiichi 6-3-3 Shimorenjaku, Mitaka City, Tokyo Inside Copier Co., Ltd.

Claims (6)

[Claims] 1. A head holder equipped with a plurality of print heads for forming a color image, wherein when the print heads are respectively mounted on the head holders, the print heads are simultaneously mounted at predetermined positions by lever operation. A head holder comprising a mounting / demounting device for desorption. 2. The head holder according to claim 1, wherein the loading / unloading device is capable of being attached and detached by simultaneously rotating and releasing a plurality of print heads at respective predetermined positions by lever operation. 3. The attachment / detachment device according to claim 1, wherein the U-shaped member capable of supporting three side surfaces of the print head is disposed on a surface facing the print head, and the U-shaped member is the above-mentioned member. A head holder, characterized in that an elastic member for urging the print head from the opposite surface is provided, and at least one U-shaped member also has a function of pressing from above the print head. 4. The head holder according to claim 1, wherein the mounting / demounting device opens the movable member that presses the upper part of the print head against the elastic member. 5. The attachment / detachment device according to claim 1, wherein the reference member and the electrical contact of the print head and the reference member and the electrical contact of the head holder are matched with each other by a mounting operation of the print head. At the same time, a head holder is provided, which is provided with a pressing member against an electric contact of the head holder and a pressing member for preventing fluctuation of the print head. 6. The method according to claim 1, 2, or 5,
The attachment / detachment device sets a rotation fulcrum for mounting the print head so that the rotary tangent for mounting the print head and the reference position for the head holder are horizontal, and sets the reference position for the print head and the reference position for the head holder. Head holder characterized by matching.