JPH0259374A - Image recording device - Google Patents

Abstract

PURPOSE:To allow recording sheet to fall below a recording sheet storage section, even if the recording paper almost wound up climbs up the storage section, by arranging a platen roller in an area above the recording sheet storage section. CONSTITUTION:A platen roller 22 is arranged in a position where it does not touch the peripheral surface of a large diameter recording roll paper attached to a storage section 4 and it touches the peripheral surface of a minimum diameter recording roll paper 3 which climbs up the front wall 4a of the storage section 4. In addition, thermosensitive recording paper 3 is wound around a core 3a to become a minimum diameter recording roll paper. The recording roll paper 3 now in contact with the platen roller 2 is separated from the front wall 4a of the recording paper storage section by counter-clockwise rotation of the platen roller 2, and then again is returned to the bottom of the storage section 4. The smooth feeding of the recording paper is ensured by constituting the whole unit or part of the platen roller in an area above the recording paper storage section as described above, if the recording paper becomes small in diameter and unstable in movement. Thus the immobilization of the recording paper due to its stacking in a wedge-like form can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image recording device (for example, a facsimile machine, a copying machine, a printer device, etc.) that records an image on a roll-shaped recording sheet.

[Prior Art and Problems to be Solved by the Invention] Facsimiles, printers, and the like usually use roll-shaped recording paper so that they can handle any length of recording. Although the use of rolled recording paper has these advantages, the roll diameter of the rolled recording paper changes as it is used, so it is necessary to devise a device configuration.
(Hereinafter, the roll of recording paper will be referred to as recording paper.) That is, since new recording paper has a large outer diameter and is heavy, there is little play between the paper and the wall of the paper storage section, and the movement of the paper is stable. This is shown in FIG.

However, as the winding diameter of the recording paper gradually decreases and the end of the winding approaches, a large space is created between the wall of the recording paper storage section 4 and the recording paper 3a having a small winding diameter. Also, recording paper 3
Since the weight of a itself becomes lighter and the curl of the recording paper 3a becomes stronger, the degree of freedom of the recording paper increases and its movement becomes increasingly unstable.

[Problems to be Solved by the Invention] Particularly, as facsimile machines have become smaller in size, there has been a tendency to use recording paper with a 1/2-inch core, which is half the size of conventional facsimile machines. Therefore, as the weight becomes lighter and the curl becomes stronger,
As shown in FIG. 4, the recording paper 3a climbs up the wall 4a of the recording storage section, and the recording paper 3a reaches a position where it touches both the guide member 8 fixed to the recording cover 6 and the wall 4a of the storage section. . At this time, if the winding is near the end, the recording paper will fray at the upper corner of the housing wall 4a, as shown in FIG. The paper gets stuck in a wedge shape, making it impossible to transport the recording paper.

[Means and effects for solving the problem] The present invention has the platen roller disposed in the upper region of the recording sheet storage section, so that even if the recording sheet nearing the end of its roll climbs up the storage section, the platen roller is placed in the area above the recording sheet storage section. The rotational force of the roller is used to drop the recording sheet back to the bottom of the recording sheet storage section.

[Embodiment] Hereinafter, a recording apparatus to which an embodiment of the present invention is applied will be described in detail with reference to the drawings.

FIG. 1 is a side view of a recording apparatus to which an embodiment of the present invention is applied.

In the figure, a thermal head 1 has a plurality of heating elements 1a that selectively generate heat according to seven image information, and records an image on a thermal recording paper 3a.

The thermal head 1 is attached via a support member 6b to a recording cover 6 which is rotatable about a fulcrum 6a and is pivoted about a shaft 6c. When recording an image, the head 1 is pressed so that the thermal head 1 presses the platen roll 2 with a predetermined pressure across the thermal recording paper 3.
A pressing spring 7 is provided on the back surface of the holder. Note that the platen 2 is driven and rotated to convey the thermal recording paper 3a. Furthermore, a guide member 8 is attached to the upstream side of the thermal head 1 on the recording cover 6 (with respect to the conveying direction of the recording paper 3) so that the recording paper does not come into direct contact with the thermal head 1. This guide member 8 extends below the head 1, and by pushing down the recording paper 3 immediately before reaching the pressing point between the head 1 and the platen roller 2, the thermal recording paper 3 is unnecessarily pushed into the head 1. I try not to come into contact with it.

Further, as described above, this recording cover 6 is rotatable around the fulcrum 6a, and when replacing the recording paper 3, the recording cover 6 can be opened clockwise (in the direction of arrow A) around the fulcrum 6a. This allows you to secure the space necessary for replacement.

When the cover 6 is open, the platen roller 2 remains on the main body side, while the thermal head 1 is attached to the recording cover 6.
Since the head 1 is configured above, the head 1 is retracted upward together with the cover 6, and a gap is created between the thermal head 1 and the platen roller 2, which serve as a paper path for the recording paper 3a. Therefore, after loading the rolled recording paper 3 into the storage section 4, the leading edge of the recording paper 3 is pulled out above the platen roller 2, and the cover 6 is opened.
30 recording sheets can be set by locking the recording cover 6 to the main body side using a locking mechanism (not shown).

When recording starts in this state, the platen roller 2 starts rotating counterclockwise (in the direction of arrow B), and the recording paper 3 is guided by the guide member 8 and conveyed to the left side in the figure. A recording sensor 5 using a reflective photosensor is arranged between the platen roller 2 and the end of the recording cover 6. This recording sensor 5 can detect the presence or absence of recording paper. Further, if the recording paper has a black band for an end mark on the back side, it is possible to detect the black band and detect that the remaining amount of the recording paper is small.

In the recording sensor 5, a housing 5A holding the sensor 5 is in contact with the recording paper 3 so that the distance between the sensor 5 and the recording paper 3 is always constant. Specifically, the housing 5A of the recording sensor 5 is positioned on the tangential extension of the point of contact between the platen roller 2 and the thermal head so as to block it. If the recording sensor 5 is placed at this position, the recording paper 3 on which the image has been recorded will come out in the tangential extension direction, so the housing 5A of the recording sensor 5 will always be in contact with the back surface of the recording paper 3. The distance between the light emitting part (not shown) and the light receiving part (not shown) of the recording sensor 5 and the back surface of the recording paper 3 is determined by the housing 5A of the recording sensor 5, and can therefore be set to a constant distance.

Now, until the recording sensor 5 detects that there is no paper, the thermal head 1 and the platen roller 2 work together to gradually convey the recording paper 3 while recording an image, and the winding diameter of the recording paper 3 decreases. As already mentioned, when the diameter of the recording paper 3 becomes smaller, a larger space is created in the storage section 4, the weight of the recording paper itself becomes lighter, and the curl of the recording paper becomes stronger.
The movement becomes unstable and it begins to climb the front wall 4a of the recording paper storage section.

However, in this embodiment, the area (indicated by Ar in the figure) which is the upper area of the recording paper 3 storage part 4 and which always comes into contact with the recording paper 3 with the minimum winding diameter climbing up the front wall 4a. Since all or part of the platen roller 2 is disposed (in FIG. 2, a part of the platen roller 2 is located in the area A).
(Although the example in which the recording paper 3 is located at position r is shown, it does not matter if all of them are located).As shown in FIG. hits the platen roller 2 and is blocked from rising. That is, in this embodiment, the platen roller 2 is located at a position where it does not come into contact with the circumferential surface of the roll-shaped recording paper 3 of the largest diameter loaded in the storage section 4, and is placed at a position where it does not touch the circumferential surface of the roll-shaped recording paper 3 of the largest diameter loaded in the storage section 4, and is located at the position where the platen roller 2 does not come into contact with the circumferential surface of the roll-shaped recording paper 3 of the largest diameter loaded in the storage section 4; It is arranged at a position where it always comes into contact with the circumferential surface of the small-diameter roll-shaped recording paper 3. Note that 3a is a core around which the thermal recording paper 3 is wound, and has the minimum diameter of the rolled recording paper 3. In FIG. 2, the recording paper 3 with the smallest diameter and the platen roller 2 that can come into contact with it are shown by two-dot chain lines.

The rolled recording paper 3 in contact with the platen roller 2 is moved away from the front wall 4a of the recording paper storage section by the counterclockwise rotation of the platen roller 2.
It is returned to the bottom direction.

As explained above, in this embodiment, by configuring all or part of the platen roller in the upper area of the arranged recording paper storage unit, even if the diameter of the recording paper becomes small and the movement becomes unstable, the recording paper It no longer gets stuck in a wedge shape and stops working.

Furthermore, in the conventional example, an extra space was created below the thermal head and the platen roller, which was a disadvantageous layout when aiming at miniaturization of the device, but in this example, the advantage of the conventional example is that the recording paper While maintaining ease of loading and maintenance of the thermal head, it has become possible to eliminate extra space that is disadvantageous to downsizing.

[Effects of the Invention] As described above, according to the present invention, the platen roller is disposed in the upper region of the storage section for rolled recording sheets at a position where it comes into contact with the rolled recording sheet of the smallest diameter. It is possible to provide an image recording apparatus that can prevent the image forming apparatus from entering the wedge-shaped portion and becoming inoperable, thereby eliminating wasted space.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of an image recording apparatus to which an embodiment of the present invention is applied; Fig. 2 is a sectional view of the recording system in which the diameter of the recording paper is small; and Fig. 3 is a sectional view of a conventional recording system. FIG. 4 is a cross-sectional view of the system. FIG. 4 is a cross-sectional view when the recording paper becomes smaller in diameter. FIG. 5 is a cross-sectional view when the recording paper becomes smaller in diameter and enters the guide member in a wedge shape. In the figure, 1 is a thermal head, 2 is a platen roller, 3 is a roll of recording paper, 4 is a recording paper storage section, 4a is a front wall of the recording paper storage section, 5 is a recording sensor, and 5A is a housing.

Claims (2)

[Claims] (1) An image recording apparatus that records an image on a roll-shaped recording sheet, comprising: a platen roller; a recording head for recording an image on the recording sheet, which is provided so as to be able to face the platen roller; and the roller. An image recording apparatus comprising: a storage section for removably storing a shaped recording sheet, wherein all or a part of the platen roller is disposed in an upper area of the storage section. (2) The platen roller is located at a position where it does not come into contact with the circumferential surface of the roll of recording paper of the largest diameter loaded in the storage section, and the platen roller is positioned so as not to contact the circumferential surface of the roll of recording paper of the smallest diameter that climbs up the front wall of the storage section. It is arranged at a position where it always comes into contact with the circumferential surface.