JP2023174095A - Image forming apparatus - Google Patents

Abstract

To provide an image forming apparatus which can suppress deterioration of accuracy of conveyance position of a printing medium.SOLUTION: An image forming apparatus comprises: a printing head; a first roller for conveying a printing medium; a second roller which is disposed above the first roller and sandwiches the printing medium together with the first roller; a roller unit for holding the second roller; and a pressing member which can shift between an action state for pressing the printing medium between the first roller and the printing head in a conveyance path of the printing medium and a release state for releasing the pressing of the printing medium. The roller unit can shift between a closed state in which the second roller is close to the first roller and an open state in which the second roller is separated from the first roller. The pressing member shifts from the action state to the release state in conjunction with shifting of the roller unit from the open state to the closed state.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to an image forming apparatus.

2. Description of the Related Art An image forming apparatus is known that performs printing while conveying a print medium to a print head using a first roller and a second roller that face each other (see Patent Document 1). In this image forming apparatus, the second roller can be moved to a position away from the first roller by the holder.

The user places the print medium on the conveyance path with the second roller separated from the first roller, and then lowers the holder to set the print medium.

JP2014-76544A

In the image forming apparatus described above, when lowering the holder after setting the print medium, there is a risk that the print medium may slip before being nipped by the two rollers. As a result, there is a possibility that the accuracy of the conveyance position will be reduced.

An object of one aspect of the present disclosure is to provide an image forming apparatus that can suppress a decrease in accuracy of the conveyance position of a print medium.

One aspect of the present disclosure includes a print head that prints on a print medium, a first roller that conveys the print medium, a second roller that is disposed above the first roller and that sandwiches the print medium with the first roller, a roller unit that holds two rollers, and a pressing member that is movable between an operating state in which the printing medium is pressed between the first roller and the print head in the conveyance path of the printing medium and a released state in which the pressing of the printing medium is released. An image forming apparatus includes:

The roller unit is movable between a closed state in which the second roller is close to the first roller and an open state in which the second roller is separated from the first roller. The pressing member is displaced from the activated state to the released state in conjunction with the displacement of the roller unit from the open state to the closed state.

According to such a configuration, the slip of the print medium is suppressed by the pressing member until the roller unit is in the closed state (that is, until the print medium is nipped between the first roller and the second roller).

Further, when the roller unit is in the closed state, the pressing member is interlocked and displaced to the released state, so there is no need for the user to perform any additional operations other than operating the roller unit. Therefore, it is possible to suppress a decrease in accuracy of the conveyance position of the print medium without reducing user convenience.

FIG. 1 is a schematic diagram of an image forming apparatus in an embodiment. FIG. 2 is a schematic diagram showing the state around the first roller when the roller unit is in an open state in the image forming apparatus shown in FIG. FIG. 3 is a schematic diagram showing the state around the first roller when the roller unit is in the closed state in the image forming apparatus shown in FIG. 4A is a schematic diagram showing the state around the pressing member in FIG. 3, and FIG. 4B is a schematic diagram of the pressing member in an embodiment different from that in FIG. 4A. FIG. 5 is a schematic perspective view showing the state around the first roller when the roller unit is in a closed state in an image forming apparatus according to an embodiment different from that shown in FIG. FIG. 6 is a schematic perspective view showing the pressing member in an operating state in the image forming apparatus of the embodiment shown in FIG. FIG. 7 is a schematic perspective view showing the pressing member in a released state in the image forming apparatus of the embodiment shown in FIG.

[1. First embodiment]
[1-1. composition]
The image forming apparatus 1 shown in FIG. , a heater 10, a first feeding section 11, a CIS (contact image sensor) 12, a second feeding section 13, a cutter 14, and a roller unit 15.

<Supply section>
The supply unit 3 supplies the print medium 102 to the print head 8 . Specifically, the supply section 3 is a shaft section that is inserted into the shaft tube of the roll 101 around which the sheet-like printing medium 102 is wound. The supply unit 3 sends out the print medium 102 onto the conveyance path by rotating the roll 101 .

<Tensioner>
The tensioner 4 applies tension to the print medium 102 sent out from the supply unit 3, thereby increasing the conveyance accuracy of the print medium 102. Tensioner 4 has an arcuate surface that contacts print medium 102 . The arcuate surface is biased by a spring and swings along the conveyance direction of the print medium 102.

<First roller>
The first roller 5 is arranged downstream of the tensioner 4 in the conveyance path of the print medium 102.

The first roller 5 and the second roller 6 transport the print medium 102 toward the print head 8 . The first roller 5 contacts the lower surface of the print medium 102 (that is, the surface opposite to the printing surface) from below.

The first roller 5 is rotated by the driving force of a motor disposed in the housing 2 . The first roller 5 and the second roller 6 nip the print medium 102 in the vertical direction and push the print medium 102 below the print head 8 .

<Second roller>
The second roller 6 is arranged above the first roller 5 and sandwiches the print medium 102 with the first roller 5.

The second roller 6 contacts the top surface (that is, the printing surface) of the print medium 102 from above. The second roller 6 rotates as the print medium 102 is conveyed. The second roller 6 is held by a roller unit 15.

<Press member>
The pressing member 7 suppresses lifting of the print medium 102. The pressing member 7 is movable between an activated state and a released state.

In the active state, as shown in FIG. 2, the pressing member 7 holds the print medium 102 between the first roller 5 and the print head 8 on the conveyance path of the print medium 102. That is, the pressing member 7 presses the print medium 102 downward toward the base 16 that supports the print medium 102 from below. In the released state, as shown in FIG. 3, the pressing member 7 releases the pressing of the print medium 102.

In a state where the second roller 6 is separated from the first roller 5, that is, in a stopped state in which the image forming apparatus 1 does not convey or print the print medium 102, the pressing member 7 can be displaced to the operating state. On the other hand, in the operating state in which the image forming apparatus 1 is conveying and printing the print medium 102, the pressing member 7 is displaced to the released state.

The holding member 7 has a swing shaft portion 7A, an acting portion 7B, and an actuated portion 7C. The swing shaft portion 7A connects the acting portion 7B and the acted portion 7C to the housing 2 so as to be swingable. The holding member 7 is displaced between an activated state and a released state by swinging. The central axis of the swing shaft portion 7A is parallel to the width direction of the print medium 102 and perpendicular to the conveyance direction T of the print medium 102.

The action portion 7B is a portion that contacts the print medium 102 in the action state. The action portion 7B contacts the portion of the print medium 102 between the first roller 5 and the print head 8 from above.

The acted portion 7C is a portion that comes into contact with the roller unit 15. The acted part 7C is integrated with the acting part 7B. When the actuated portion 7C is pressed downward by the roller unit 15, the acting portion 7B swings upward. That is, the pressing member 7 is displaced from the activated state to the released state in conjunction with the displacement of the roller unit 15.

The pressing member 7 is urged toward the operating state (that is, in the direction in which the operating portion 7B presses the print medium 102) by a biasing force such as a spring. Therefore, when the pressure on the actuated portion 7C by the roller unit 15 is released, the pressing member 7 is displaced from the released state to the activated state by the urging force.

<Print head>
The print head 8 prints on the print medium 102 conveyed by the first roller 5 and the second roller 6.

The print head 8 forms an image by ejecting ink onto the upper surface of the print medium 102 from the nozzle surface 8A (see FIG. 4A). Ink is supplied to print head 8 from cartridge 103 shown in FIG. As the ink, for example, PP (Polymer Particle) ink is used.

PP ink contains resin fine particles. The fine particles adhering to the surface of the print medium 102 are softened by the heater 10 disposed downstream of the print head 8 and are fused together. As a result, a printing film is formed on the printing medium 102. When the print medium 102 passes through the heater 10, the print film is solidified by cooling and fixed to the print medium 102.

<Adsorption mechanism>
The suction mechanism 9 is arranged below the print head 8 so as to face the print head 8. The suction mechanism 9 increases the accuracy of conveyance of the print medium 102 by sucking the print medium 102 downward by airflow and adsorbing the print medium 102 to the conveyance surface 16A (see FIG. 4A).

<Heater>
The heater 10 heats the print medium 102 that has passed through the print head 8, thereby turning the ink into a film.

<Feeding section and CIS>
The CIS 12 optically reads a printed image (for example, an identification code such as a bar code) and detects defects in the image (for example, stains, defects, blurring, etc.).

The first feeding section 11 and the second feeding section 13 are roller mechanisms for feeding the print medium 102 to the CIS 12 . The first sending section 11 is arranged upstream of the CIS 12. The second sending section 13 is arranged downstream of the CIS 12.

Among the rollers constituting the first feeding section 11 and the second feeding section 13, the roller that comes into contact with the printing surface of the printing medium 102 is a spur roller provided with a plurality of external teeth along the circumferential direction. By using a spur roller, it is possible to suppress adhesion of a printed film that is not completely solidified to the roller.

<Cutter>
The cutter 14 cuts the print medium 102 on which printing and defect detection have been completed.

<Roller unit>
The roller unit 15 is a part that holds the second roller 6 and is swingable with respect to the housing 2 .

The roller unit 15 can be moved between a closed state and an open state by swinging. As shown in FIG. 3, the closed state is a state in which the second roller 6 approaches the first roller 5 (that is, it nips the print medium 102 together with the first roller 5).

The open state is a state in which the second roller 6 is separated from the first roller 5, as shown in FIG. In the image forming apparatus 1, when the roll 101 of the print medium 102 is replaced and the user places the print medium 102 upstream of the print head 8, the roller unit 15 is moved to the open state by the user.

The roller unit 15 swings around a swing shaft 15A connected to the housing 2. The center axis of the swing shaft portion 15A is parallel to the width direction of the print medium 102. In other words, the pivot axis of the roller unit 15 and the pivot axis of the presser member 7 are parallel.

<Operation of holding member>
As shown in FIG. 2, when the roller unit 15 is in the open state and the pressing member 7 is in the operating state, the user places the print medium 102 between the pressing member 7 and the base 16 that constitutes the conveyance path. By inserting the print medium 102, the print medium 102 is set. The print medium 102 is pressed against the base 16 by the pressing member 7.

After setting the print medium 102, the user displaces the roller unit 15 to the closed state shown in FIG. At this time, the roller unit 15 contacts the operated portion 7C of the pressing member 7 in the operating state from above.

As a result, the actuated portion 7C swings downward and the acting portion 7B swings upward, thereby displacing the pressing member 7 to the released state. That is, the pressing member 7 is displaced from the activated state to the released state by contacting the roller unit 15 that is displaced from the open state to the closed state. Further, the holding member 7 is maintained in the released state by being restricted from swinging by the roller unit 15 in the closed state.

As shown in FIG. 4A, the first distance D1 between the pressing member 7 in the released state and the conveying surface 16A is smaller than the second distance D2 between the nozzle surface 8A and the conveying surface 16A. Here, the first distance D1 is the minimum distance between the pressing member 7 (specifically, the action portion 7B) and the conveyance surface 16A. The second distance D2 is the minimum distance between the nozzle surface 8A and the conveyance surface 16A.

The conveyance surface 16A is a surface of the base 16 against which the printing medium 102 is pressed by the pressing member 7. The conveyance surface 16A extends along the conveyance direction T of the print medium 102 to the print head 8.

The print medium 102 is conveyed to the print head 8 while being guided by the conveyance surface 16A. In this embodiment, the conveyance surface 16A is substantially parallel to the horizontal direction. Therefore, the lowest part of the pressing member 7 in the released state is located below the nozzle surface 8A.

As shown in FIG. 4B, the pressing member 7 may include an auxiliary roller 7D. The auxiliary roller 7D rotates due to contact with the print medium 102 in the released state. The auxiliary roller 7D can guide the print medium 102 while suppressing an increase in friction (that is, conveyance resistance) of the print medium 102.

The auxiliary roller 7D is preferably a spur roller provided with a plurality of external teeth along the circumferential direction. By using a spur roller as the auxiliary roller 7D, the conveyance resistance of the print medium 102 can be reduced.

When the roller unit 15 is displaced from the closed state to the open state by the user, the pressing member 7 is displaced from the released state to the activated state due to the biasing force. Note that the pressing member 7 does not necessarily have to be displaced to the operating state by the urging force. For example, the holding member 7 may be moved to the active state by a user's operation.

[1-2. effect]
According to the embodiment detailed above, the following effects can be obtained.
(1a) Until the roller unit 15 is in the closed state (that is, until the printing medium 102 is nipped between the first roller 5 and the second roller 6), the slipping of the printing medium 102 is suppressed by the pressing member 7 .

(1b) When the roller unit 15 is in the closed state, the pressing member 7 is interlocked and displaced to the released state, so there is no need for the user to perform any additional operations other than operating the roller unit 15. Therefore, it is possible to suppress a decrease in accuracy of the transport position of the print medium 102 without reducing user convenience.

(1c) Since the first distance D1 between the pressing member 7 in the released state and the conveying surface 16A is smaller than the second distance D2 between the nozzle surface 8A and the conveying surface 16A, lifting caused by curling of the print medium 102 is prevented. It is suppressed by the pressing member 7. This makes it possible to suppress problems such as a decrease in the accuracy of the conveyance position and jams.

(1d) Since the presser member 7 contacts the roller unit 15 and is displaced, the configuration of the presser member 7 becomes simple and the number of parts of the image forming apparatus 1 is reduced.
(1e) Since the roller unit 15 is displaced by rocking, the user can easily open and close the roller unit 15.

(1f) Since the holding member 7 is displaced by swinging, the configuration of the holding member 7 can be simplified.
(1g) Since the second roller 6 is driven to rotate, the configuration of the roller unit 15 can be simplified.

[2. Second embodiment]
[2-1. composition]
The image forming apparatus of the second embodiment has an intermediate member 17 shown in FIG. 5 added to the image forming apparatus 1 of the first embodiment (see FIG. 1). Therefore, descriptions of the configurations common to the first embodiment will be omitted.

<Intermediate member>
The intermediate member 17 is a lever that displaces the pressing member 7 from the activated state to the released state by being displaced from the first position to the second position in conjunction with the displacement of the roller unit 15 from the open state to the closed state.

The intermediate member 17 is disposed on the outer side in the width direction of the print medium 102 with respect to the conveyance path of the print medium 102. In other words, the intermediate member 17 is arranged at a position that does not overlap the print medium 102 in the thickness direction of the print medium 102.

As shown in FIG. 6, when the intermediate member 17 is in the first position, the holding member 7 is in an active state. As shown in FIG. 7, when the intermediate member 17 is in the second position, the pressing member 7 is in the released state. The intermediate member 17 is connected to the swing shaft portion 7A of the holding member 7, and swings together with the swing shaft portion 7A.

The intermediate member 17 is in the first position when the roller unit 15 is in the open state. The intermediate member 17 in the first position is displaced to the second position by contacting the roller unit 15 as shown in FIG. 5 when the roller unit 15 is displaced to the closed state.

In this way, the intermediate member 17 swings from the first position to the second position by contacting the roller unit 15 that is displaced from the open state to the closed state. The pressing member 7 is displaced from the activated state to the released state by swinging together with the intermediate member 17. That is, in this embodiment, the pressing member 7 is displaced in conjunction with the roller unit 15 via the intermediate member 17.

[2-2. effect]
According to the embodiment detailed above, the following effects can be obtained.
(2a) The intermediate member 17 allows the pressing member 7 to be displaced without bringing the pressing member 7 into contact with the roller unit 15. Therefore, the degree of freedom in designing the holding member 7 is increased.

(2b) Since the intermediate member 17 is a lever that swings in contact with the roller unit 15, the configuration of the intermediate member 17 can be simplified.

[3. Other embodiments]
Although the embodiments of the present disclosure have been described above, it goes without saying that the present disclosure is not limited to the above embodiments and can take various forms.

(3a) In the image forming apparatus of the above embodiment, if the pressing member can press the print medium in the activated state, the distance between the pressing member in the released state and the conveying surface is not necessarily longer than the distance between the nozzle surface and the conveying surface. It doesn't have to be small either.

(3b) In the image forming apparatus of the above embodiment, the pressing member does not necessarily have to be displaced by rocking. For example, the holding member may be displaced by translation or a combination of rocking and translation.

(3c) In the image forming apparatus of the above embodiment, the roller unit does not necessarily have to be displaced by rocking. For example, the roller unit may be displaced by translation or a combination of rocking and translation.

(3d) In the image forming apparatus of the above embodiment, the second roller may be rotated by driving force, or both the first roller and the second roller may be rotated by driving force. Further, the first roller may be driven to rotate.

(3e) The function of one component in the above embodiment may be distributed as multiple components, or the functions of multiple components may be integrated into one component. Further, a part of the configuration of the above embodiment may be omitted. Further, at least a part of the configuration of the above embodiment may be added to, replaced with, etc. in the configuration of other embodiments. Note that all aspects included in the technical idea specified from the words described in the claims are embodiments of the present disclosure.

DESCRIPTION OF SYMBOLS 1... Image forming apparatus, 2... Housing, 3... Supply part, 4... Tensioner, 5... First roller,
6... Second roller, 7... Holding member, 7A... Swinging shaft portion, 7B... Acting part, 7C... Acted part,
7D... Auxiliary roller, 8... Print head, 8A... Nozzle surface, 9... Adsorption mechanism, 10... Heater,
11...First feeding section, 12...CIS, 13...Second feeding section, 14...Cutter,
15...roller unit, 15A...swing shaft section, 16...base, 16A...conveyance surface,
17... Intermediate member, 101... Roll, 102... Print medium, 103... Cartridge.

Claims (10)

a print head that prints on a print medium;
a first roller that conveys the print medium;
a second roller disposed above the first roller and sandwiching the print medium together with the first roller;
a roller unit that holds the second roller;
a pressing member that is movable between an operating state in which the printing medium is pressed between the first roller and the print head in the conveyance path of the printing medium and a released state in which the pressing of the printing medium is released;
Equipped with
The roller unit is movable between a closed state where the second roller is close to the first roller and an open state where the second roller is separated from the first roller,
In the image forming apparatus, the pressing member is displaced from the activated state to the released state in conjunction with the displacement of the roller unit from the open state to the closed state. further comprising a conveyance surface against which the print medium is pressed by the pressing member and which extends to the print head;
The print head has a nozzle surface that ejects ink onto the print medium,
The image forming apparatus according to claim 1, wherein a distance between the pressing member in the released state and the conveying surface is smaller than a distance between the nozzle surface and the conveying surface. The image forming apparatus according to claim 1, wherein the pressing member includes an auxiliary roller that rotates by contacting the print medium in the released state. The image forming apparatus according to claim 3, wherein the auxiliary roller is a spur roller provided with a plurality of external teeth along the circumferential direction. The pressing member according to any one of claims 1 to 4 is displaced from the operating state to the released state by contacting the roller unit that is displaced from the open state to the closed state. Image forming device. The intermediate member further includes an intermediate member that displaces the pressing member from the activated state to the released state by being displaced from a first position to a second position in conjunction with the displacement of the roller unit from the open state to the closed state. , The image forming apparatus according to any one of claims 1 to 4. The intermediate member is a lever that swings from the first position to the second position by contacting the roller unit that is displaced from the open state to the closed state,
The image forming apparatus according to claim 6, wherein the pressing member is displaced from the activated state to the released state by swinging together with the intermediate member. The image forming apparatus according to any one of claims 1 to 4, wherein the roller unit is displaced between the open state and the closed state by rocking. The image forming apparatus according to any one of claims 1 to 4, wherein the pressing member is displaced between the activated state and the released state by rocking. The first roller rotates by a driving force,
The image forming apparatus according to any one of claims 1 to 4, wherein the second roller is driven to rotate as the print medium is conveyed.