JPH04128078A - Image forming apparatus - Google Patents

Abstract

PURPOSE:To simply clean a printing head by mounting an image forming part, a printing unit, a printing head and a cleaning part. CONSTITUTION:At first, when a unit 96 is revolved around a support shaft 97, the unit 96 is drawn out of a copier main body 1. Next, when a casing 35 having an ink ribbon cassette 36 received therein is revolved around a support shaft 40, the ink ribbon cassette 36 is moved to a unit replacing position. At the time of the movement of the ink ribbon cassette to the unit replacing position, the casing 35 and a support shaft 56 are revolved around the support shaft 40 and the roller 52a provided to the leading end of a leaf spring 52 gradually moves on a cam 51 upwardly and the support shaft 56 is revolved around the casing 35 in a clockwise direction. As a result, a thermal head 38 is set at a retracted position. The cleaning roller 82 of a cleaning apparatus 80 comes into contact with the head surface 38a of the thermal head 38.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image forming apparatus, and particularly to an image forming apparatus equipped with a printing unit that prints on paper after an image has been formed.

[Conventional technology and its problems]

2. Description of the Related Art Image forming apparatuses are already known that are equipped with a printing device that prints, for example, the date of copying, the name of a company, and other notes on paper after image formation. This printing device mainly includes a printing unit that accommodates, for example, an ink ribbon, and a print head that includes a thermal head or the like.

In such a printing device, if dirt, dust, etc. adhere to the print head, printing performance will deteriorate. Therefore, it is preferable to periodically clean the print head.

However, since the print head is housed inside the image forming apparatus, cleaning the print head is generally not easy.Therefore, it may be possible to remove the print head outside the apparatus and perform cleaning, but this is a complicated process. .

SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus whose print head can be easily cleaned.

[Means to solve the problem]

An image forming apparatus according to the present invention includes an image forming section, a printing unit, a print head, and a cleaning section.

The printing unit is movable between a unit printing position where printing is performed on paper processed by the image forming section and a unit replacement position. The print head can be moved between a head print position and a head retracted position in conjunction with movement of the print unit. The cleaning section cleans the print head by coming into contact with the print head when the print head moves.

[Effect]

In the image forming apparatus according to the present invention, when printing on paper processed by the image forming section, the printing unit is placed at the printing position. Then, the print head and print unit print on the paper.

When cleaning the print head, first, the printing unit is moved between the unit printing position and the unit replacement position. The print head moves in conjunction with this movement of the print unit. At this time, the cleaning section comes into contact with the print head and cleans the print head.

In this way, if the printing unit is moved when replacing the printing unit, the printing head can also be cleaned, so the printing head can be cleaned easily.

〔Example〕

FIG. 1 shows a copying machine according to an embodiment of the present invention.

In FIG. 1, a document table 2 is fixed to the upper surface of a copying machine main body 1, and a document presser 3 is attached to the upper part of the document table 2 so as to be openable and closable. Paper feed cassettes) 4, 5.6 are removably attached to the right side of the copying machine main body 1 in the figure. A paper discharge tray 7 is mounted on the left side of the copying machine main body 1, from which copied sheets are discharged.

Inside the copying machine main body 1, an exposure device 8 for reading a document is provided on the upper side thereof.

This exposure device 8 is composed of a light source, a mirror, and the like. Further, a photosensitive drum 9 on which an electrostatic latent image is formed is arranged in the center of the copying machine main body 1. Photosensitive drum 9
Around the charging device 10, the developing device 11, the transfer device 1
2, a paper separation device 13, and a cleaning device 14 are arranged. A paper feed conveyance path 15 for feeding paper is provided between the paper feed cassettes 4, 5.6 and the image forming section constituted by the photosensitive drum 9 and the like. Further, between the image forming section and the paper ejection tray 7, a paper ejection transport path 16, a fixing device 17, a printing device 18, and a punching device 19 are arranged in order from the image forming section side.

Further, below the fixing device 17, a reversing device 20 for reversing the front and back of the paper is provided.

Next, details of the printing device 18 and its surroundings will be explained.

In FIG. 2, a discharge roller 25 is disposed at the exit portion of the fixing device 17 on the right side of the figure. This discharge roller 2
A detection switch 27 and a conveyance roller 28 are provided in the paper conveyance path 26 at the rear (left side in the figure) of the paper conveyor 5 . *There is a switching pawl 29 in the paper conveyance path 26 behind the feed roller 2B.
is provided. The switching claw 29 moves the paper to the discharge roller 2.
A paper discharge state in which the paper is guided to the 1 side (double-dashed line state) and a paper refeed state in which the paper is guided to the paper refeed path 30 side (solid line 1G) can be taken.

A printing device 18 and a punching device 19 are provided on a path along which the paper is guided from the conveyance roller 28 to the discharge roller 21 .

The printing device 18 is used to further print predetermined additional information at a predetermined position on the paper onto which the image has been fixed by the fixing device 17. The printing device 18 mainly includes a casing 35, an ink ribbon cassette (printing unit) 36 that is detachably held in the casing 35, and a thermal head 38 that can come into contact with the ink ribbon 37 of the ink ribbon cassette 36.

At both ends of the casing 35 in the left-right direction (direction perpendicular to the plane of the paper in FIG. 2), triangular flange portions 39 that protrude downward are provided, respectively. Further, a pin 40 is inserted through the lower part of the flange portion 39, and the flange portion 39 is rotatable around this pin 40. This results in
The ink ribbon cassette 36 can take a printing position (FIG. 2) where it prints on paper, and a replacement position (solid line position in FIG. 3) where it is moved toward the side wall of the copying machine main body 1.

The ink ribbon cassette 36 includes an ink ribbon 37, a take-up reel 44 around which the ink ribbon 37 is wound, and a feed reel 45. The ink ribbon 37 and each reel 44, 45 are housed within the body 43. Openings 43a and 35a are formed in the center portions of the bottom walls of the body 43 and the casing 35, respectively. The thermal head 38 opens these openings 43a and 35
a, and can abut on the lower platen roller 46.

The driving machine 1150 of the thermal head 38 mainly includes a cam 5.
1, a leaf spring 52 that can come into contact with the cam 51, and a return spring 53 for lifting the thermal head 38 upward. A rotary shaft 55 is eccentrically mounted in a long hole formed in the cam 51 by a coil spring 54 . The rotation shaft 55 is connected to a rotation drive mechanism (not shown). On the other hand, the casing 35 of the printing unit 18 is rotatably provided with a support shaft 56 extending in a direction perpendicular to the plane of the paper in FIG. This support shaft 56 has
The base of the plate 57 to which the thermal head 38 is fixed is fixed. Further, the base of the leaf spring 52 is fixed to the support shaft 56 . With this configuration, when the cam 51 rotates and pushes the leaf spring 52 downward, the thermal head 3
8 is pushed downward. Further, the base of a lower plate spring 58 is fixed to the support shaft 56. The tip of the lower plate spring 58 is pressed against the bottom wall of the casing 35. The thermal head 38 is smoothly moved from below to above by the reaction force caused by the pressure contact of the lower plate spring 58 and the spring force of the return spring 53.

Inside the casing 35, as shown in FIG. 4, a drive mechanism 60 for driving the ink ribbon cassette 36 is provided. This drive mechanism 60 mainly includes a motor 61 and a torque limiter 62 for transmitting the rotational force of the motor 61 to the take-up reel 44 of the ink ribbon cassette 36. In addition, this torque limiter 62
A standing wall portion 35b is provided at the mounting portion. When the ink ribbon cassette 36 is installed in the casing 35, one end of the ink ribbon cassette 36 comes into contact with this standing wall portion 35b. Further, when the ink ribbon cassette 36 is installed, the torque limiter 62 and the take-up reel 44 are connected through a hole (not shown) formed in a part of the vertical wall portion 35b.

The ink ribbon cassette 36 is attached to the other end of the ink ribbon cassette 36 in the casing 35.
A retention mechanism 70 is provided for retention within 5. This holding mechanism 70 is attached to the bottom wall portion 3 of the casing 35.
5c and the bottom wall portion 35c in the left and right direction (in the reel axis direction of the ink ribbon cassette 36).
A slide member 72 is provided so as to be slidable, and is provided between the fixed member 71 and the slide member 72, and both ends thereof are connected to the vertical wall portions 7 of the fixed member 71 and the slide member 72, respectively.
1a and a spring 73 that presses against 72a. The spring force of the spring 73 constantly urges the slide member 72 toward the ink ribbon cassette 36, and the ink ribbon cassette 36 is held between the vertical wall portion 72a of the slide member 72 and the vertical wall portion 35b of the casing 35. Further, although not shown, a plurality of protrusions are formed on the surface of the vertical wall portion 72a facing the ink ribbon cassette. Further, a plurality of recesses that can be engaged with the respective projections are formed on the surface of the ink ribbon cassette 36 facing the vertical wall 72a. Therefore, when the ink ribbon cassette 36 is attached to the casing 35, the protrusion on the slide member 72 side engages with the recess on the ink ribbon cassette 36 side, thereby accurately positioning the ink ribbon cassette 36 with respect to the casing 35. Moreover, it is designed so that it does not come off easily.

A cleaning device 80 (FIG. 4) is provided above the casing 35.

This cleaning device 80 has a rotatable shaft 81 arranged parallel to the support shaft 56 . A cleaning roller 82 is fixed on the shaft 81 at a position where it can face the head surface 38a of the thermal head 3 in the retracted position. A head cleaning member made of felt, for example, is attached to the outer periphery of the cleaning roller 82 . Further, a one-way clutch 83 is attached to one end of the shaft 81. This one-way clutch 83 allows the shaft 81 to rotate only in the direction of the arrow in the figure, and is locked in the opposite direction. Further, an elastic member 84 such as a coil spring is provided at both ends of the shaft 81 (only one side is shown in the figure). This is for pressing 82.

In FIG. 2, the punching device 19 has a punch 90 that is supported so as to be movable up and down. A cam 91 for driving the punch 90 up and down is arranged above the punch 90. A rotation shaft 92 of the cam 91 is connected to a rotation drive mechanism (not shown).

A guide plate 93 for guiding the paper is arranged below the punch 90. The guide plate 93 is the punch 90
It has a die hole 94 at a position opposite to. Die hole 94
A collection bottle 95 is arranged below the punch 90 and die hole 94 to collect the scraps extracted from the paper. Further, the punching device 19, the collection bottle 95, and the discharge roller 21 constitute one unit 96.

The unit 96 is rotatable around a shaft 97 provided at its lower part.

Next, the operation will be explained. The copying operation of the above-mentioned copying machine is common, so the explanation will be omitted here, and the following will be explained below.
The cleaning operation of the thermal head 38 when the ink ribbon cassette 36 is crossed will be described.

First, when the unit 96 is rotated around the support shaft 97,
As shown in FIG. 3, the unit 96 is pulled out of the copying machine main body 1. Note that at this time, the work of discharging paper scraps from the collection bottle 95 is performed as necessary.

Next, when the casing 35 containing the ink ribbon cassette 36 is rotated around the spindle 40, the ink ribbon cassette 36 is moved to the unit exchange position (the solid line position in FIG. 3).
Move to. When the ink ribbon cassette 36 is rotated to the unit replacement position, the casing 35 and the support shaft 5 are
6 rotates around the bin 40, and the roller 52a at the tip of the leaf spring 52 gradually moves upward on the cam 51. This causes the support shaft 56 to rotate clockwise in FIG. 3 around the casing 35. As a result, at the unit replacement position of the ink ribbon cassette 36, the thermal head 38 is placed in the retracted position shown by the solid line in FIG.

At this retracted position of the thermal head 38, a cleaning device 8 is provided on the head surface 38a of the thermal head 38.
0 (FIG. 4) comes into contact with the cleaning roller 82. Here, the cleaning roller 82 is pressed into contact with the head surface 38a of the thermal head 38 by the elastic member 84. During this contact, the thermal head 38 comes into contact with the cleaning roller 82 while moving from below to above.
As described above, the one-way clutch 84 (FIG. 4) allows the cleaning roller 82 to freely rotate in the direction of the arrow in FIG.

In this state, work such as replacing the ink ribbon cassette 36 is performed. After the replacement work is completed, the casing 35 is rotated around the bin 40 from the state shown by the solid line in FIG. 3, and the casing 35 and the ink ribbon cassette 36 are moved inward of the copying machine main body l. During this movement, the support shaft 56 rotates about the bin 40 together with the casing 35 .

As a result, the thermal head 38 gradually moves downward. Here, a cleaning roller 82 of a cleaning device 80 is in pressure contact with the head surface 38a of the thermal head 38, and the cleaning roller 82 is kept in a locked state against downward movement of the thermal head 38. Therefore, the head surface 38a of the thermal head 38 slides on the cleaning roller 82, and the head surface 38a is cleaned. Thus, in this case,
The thermal head 3B can be easily replaced by simply moving the ink ribbon cassette 36 from the unit replacement position to the printing position.
Head cleaning is performed.

When the casing 35 is further rotated, the thermal head 38 separates from the cleaning roller 82. Then, the printing position of the ink ribbon cassette 36 (solid line position in Figure 2)
At this time, the thermal head 3B is placed in a printing position in which it contacts the ink ribbon 37.

〔Effect of the invention〕

According to the image forming apparatus according to the present invention, since the print head is cleaned when the print unit moves, the print head can be cleaned easily.

[Brief explanation of the drawing]

FIG. 1 is a schematic longitudinal cross-sectional view of a copying machine according to an embodiment of the present invention, FIG. 2 is an enlarged partial view of its printing device, and FIG. 3 is a diagram illustrating the cleaning operation of the print head. The corresponding figure, FIG. 4, is a schematic perspective view of the cleaning device. 18... Printing device, 36... Ink ribbon cassette, 38... Thermal head, 80... Cleaning device, 82... Cleaning roller. Patent applicant Yukio Ono, agent of Mita Kogyo Co., Ltd., patent attorney

Claims (1)

[Claims] (1) an image forming section; a printing unit that can move between a unit printing position for printing on paper processed by the image forming section and a unit replacement position; interlocking with the movement of the printing unit; An image forming apparatus comprising: a print head that can move between a head print position and a head retracted position; and a cleaning section that comes into contact with the print head and cleans the print head when the print head moves.