JP2000141816A - Support mechanism of printing head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve the miniaturization/compactification and cost reduction of the whole by realizing the reduction of part cost and the simplification of a peripheral structure. SOLUTION: The support mechanism 1 of a printing head supports a printing head 3 at the position on this side of a recording paper feed direction with respect to a platen roller 4 in a revolvable manner by a pair of support shafts 6p, 6q, and is equipped with positioning parts 9p, 9q having a pair of the regulation parts 7p, 7q provided to the platen roller 4 and a pair of the parts 8p, 8q to be regulated provided to the printing head 3 and regulating the displacement of the parts 8p, 8q to be regulated in a recording paper feed direction by the regulation part 7p, 7q. At this time, one support shaft 6p is supported by the support hole 10p releasing the shift of the displacement of the printing head 3 moving to a release position X and the degree of pallalelization of the printing head 3 to the platen roller 4, and the other support shaft 6q is supported by the support hole 10q releasing the displacement of the printing head 3 moved to the release position X.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a print head supporting mechanism suitable for use in a copying machine having a printing mechanism for printing on a recording sheet between a print head and a platen roller.

[0002]

2. Description of the Related Art In general, a printing mechanism prints a recording paper between a printing head (thermal head) and a platen roller which is urged by an urging member by a printing head, and conveys the recording paper by rotation of the platen roller. Copiers and facsimile machines equipped with a printing unit are known. Usually, in this type of printing mechanism, it is necessary to accurately position the print head with respect to the platen roller, and to secure the proper printing position and printing quality. The print head is supported by a support mechanism having a positioning function with respect to the platen roller.

[0003] Conventionally, such a print head support mechanism is known from Japanese Utility Model Publication No. 5-12046. The support mechanism disclosed in this publication provides a pair of U-shaped guide members on both sides of a print head, and engages (fits) the U-grooves of the guide members with shaft portions provided on both sides of a platen roller. Accordingly, the print head is positioned with respect to the platen roller in the recording paper conveyance direction.

[0004]

However, the above-described conventional print head support mechanism has the following problems.

[0005] First, since a U-shaped guide member is required to be accurately fitted to the shaft portion of the platen roller,
The dimensional accuracy of the guide member is required, which leads to an increase in the cost of the guide member.

Second, since a U-shaped guide member is attached to the print head, if a release mechanism for separating the print head from the platen roller is configured, it is necessary to move the print head along the U groove of the guide member. As a result, the degree of freedom of design of the release mechanism is limited, and as a result, the surrounding structure becomes complicated and large.

The present invention has been made to solve the problems existing in the prior art, and realizes a printing which realizes reduction of parts cost and simplification of a peripheral structure, thereby achieving miniaturization and cost reduction of the whole. An object of the present invention is to provide a head support mechanism.

[0008]

According to the present invention, printing is performed by the print head 3 on the recording paper Pr between the print head 3 and the platen roller 4 urged by the urging member 2, and the recording is performed. When configuring the print head support mechanism 1 in the print mechanism unit 5 that conveys the paper Pr by the rotation of the platen roller 4, a pair of both sides of the print head 3 are located at a position in front of the platen roller 4 in the recording paper conveyance direction. The print head 3 is configured to be displaceable to the release position X by being rotatably supported by the support shafts 6p and 6q, and the pair of regulating portions 7p and 7q provided on both sides of the platen roller 4 and the print head 3 By having a pair of regulated portions 8p and 8q provided on both sides, the positioning of the regulated portions 8p and 8q in the recording paper conveyance direction is regulated by the regulating portions 7p and 7q. Parts 9p and 9q, and one support shaft 6p is supported by a support hole 10p for relieving displacement of the print head 3 moving to the release position X and deviation of the parallelism of the print head 3 with the platen roller 4, and The other support shaft 6q is supported by a support hole 10q for releasing the displacement of the print head 3 moving to the release position X.

In this case, according to a preferred embodiment, the biasing member 2 uses a leaf spring member 2s for pressing the center of the print head 3 toward the platen roller 4. Also, the print head 3
Has a support bracket 11 having a pair of support shafts 6p and 6q on both sides, and a print head body 12 fixed to the support bracket 11. Such a print head support mechanism 1 is particularly suitable for being applied to a portable copying machine M.

As a result, the print head 3 is positioned at a position short of the platen roller 4 in the recording paper conveyance direction, and
Since the platen roller 4 is rotatably supported by p and 6q, for example, if the platen roller 4 is rotated by pre-feed or the like,
The print head 3 pressed against the platen roller 4 (recording paper Pr) is displaced in the recording paper transport direction,
A pair of regulated parts 8p, 8q provided on both sides of the print head 3
Are a pair of regulating portions 7 provided on both sides of the platen roller 4.
The print head 3 is positioned in the recording paper transport direction because the print head 3 is regulated by abutting on p and 7q. On the other hand, if the print head 3 is rotated about the support shafts 6p and 6q and moved to the release position X separated from the platen roller 4,
At the same time, it is displaced rearward in the recording paper conveyance direction in accordance with the engagement position between the regulated parts 8p, 8q and the regulation parts 7p, 7q, but this displacement is absorbed by the support holes 10p and 10q. Further, the deviation of the parallelism of the print head 3 with respect to the platen roller 4 is absorbed by the one support hole 10p.

[0011]

Next, preferred embodiments according to the present invention will be described in detail with reference to the drawings.

First, an external configuration of a portable copying machine M including a print head support mechanism 1 according to the present embodiment will be described with reference to FIG.
This will be described with reference to FIGS.

The portable copier M is, for example, small and compact enough to be held by one hand, and has a casing 50 formed in a flat rectangular parallelepiped shape at the outer shell. The upper surface of the casing 50 is an operation panel 51, and includes a start key 52s, a stop key 5
2e, various operation keys 52n... And a display unit are arranged. A horizontally long leg 53 is provided on the lower surface of the casing 50.
Is attached. The legs 53 extend in the longitudinal direction of the casing 50.
Can be displaced to a storage position to be attached to the storage position or a use position rotated 90 degrees from the storage position. Thereby, in the use position, the longitudinal direction of the leg 53 is perpendicular to the casing 50, and the portable copier M can be erected as shown in FIG. On the other hand, a paper feed unit 54 is provided at the front of the casing 50. The paper feeding section 54 has a document supply port 55 provided at an upper portion and a recording paper supply port 56 provided below the document supply port 55. Reference numeral 57 denotes an opening / closing cover, and 58 denotes an operation lever of a release mechanism. In addition, it has a battery doorway and a roll paper doorway (not shown).

Next, the internal configuration of the portable copying machine M including the support mechanism 1 according to the present embodiment will be described with reference to FIGS.

In FIG. 4, reference numeral 21 denotes a chassis disposed inside a casing 50. The chassis 21 has a base plate portion 21o and a pair of opposed side plate portions 21p and 21q bent at right angles from both sides thereof. . The reading mechanism 22 is located at the top of the chassis 21.
And a printing mechanism 5 is provided at an intermediate portion of the chassis 21 located below the reading mechanism 22. The lower portion of the chassis 21 located below the printing mechanism 5 serves as a housing for a circuit board, a battery, and the like. The lower part of the casing 50 below the chassis 21 is a roll paper P
rr (recording paper Pr), and an outer surface of the base plate 21b serves as a guide surface 21g for guiding the roll paper Prr to the printing mechanism 5.

The reading mechanism section 22 includes a reading head 23 for reading a document Pa supplied from a document supply port 55, and a reading-side platen roller 24 disposed below the reading head 23.
Is provided. The reading head 23 is provided with a support bracket 25. If the document conveying direction is forward, the reading head body 23a using a contact image sensor is fixed to the front of the support bracket 25, and the support bracket 2
The rear end of 5 is rotatably mounted via a support shaft 26 between side plate portions 21p and 21q located near the rear end of the upper end of the chassis 21. Also, the reading-side platen roller 24
Are connected to the side plate portions 21p and 2p via the shaft 27.
Rotatably mount between 1q. As a result, the reading-side platen roller 24 comes into contact with the head surface of the reading head 23,
Further, it is rotationally driven by a driving mechanism section 40 described later. Further, the support bracket 25 and the side plate portion 2
A spring 28 is provided between 1p and 21q, and the reading head 23 is pressed against the reading-side platen roller 24.

On the other hand, the printing mechanism 5 includes a recording paper supply port 56.
A print head 3 for printing on cut paper Prc (recording paper Pr) supplied from the printer or a roll paper Prr (recording paper Pr) supplied from the lower part of the casing 50, and a printing platen disposed below the print head 3. The roller 4 is provided.

The printing-side platen roller 4 is disposed below the reading-side platen roller 24. The printing-side platen roller 4 has a shaft 29 protruding on both sides.
Are rotatably supported by bearings 30p, 30q attached to the side plate portions 21p, 21q, respectively. The print-side platen roller 4 comes into contact with the head surface of the print head 3 and is driven to rotate by a drive mechanism 40 described later.

The print head 3 is provided with a support bracket 11.
And a print head body 12 using a thermal head is fixed to a front portion of the support bracket 11. That is, as shown in FIG. 3, the support bracket 11 has a base portion 11o along the printing-side platen roller 4, and side portions 11p, 1 bent at right angles from both sides of the base portion 11o.
1q, the print head main body 12 is fixed to the lower surface of the base portion 11o, and support shafts 6p, 6q projecting outward are fixed to intermediate portions of the outer surfaces of the side portions 11p, 11q, respectively. The support bracket 11 is mounted on the chassis 2.
1 support holes 1 provided in side plate portions 21p and 21q
The support shafts 6p and 6q are inserted from 0p and 10q from the inside and attached. Accordingly, the print head 3 is rotatably supported between the side plate portions 21p and 21q with the support shafts 6p and 6q as fulcrums, and can be displaced to a release position X separated from the print side platen roller 4.

The support holes 10p and 10q are formed as follows according to the present invention. First, each support hole 10p, 10q
Is formed at a position before the printing-side platen roller 4 in the recording paper conveyance direction. As shown in FIG. 1, one support hole 10p is formed in a non-circular shape having a predetermined play with respect to the support shaft 6p. That is, the support hole 10p is formed in such a shape that the displacement of the print head 3 moving to the release position X can be released, and at the same time, the deviation of the parallelism of the print head 3 with respect to the print side platen roller 4 can be released. On the other hand, the other support hole 10q is, as shown in FIG.
It is formed in a long hole so that the displacement of the print head 3 that moves to the release position X can be released. Therefore, the support holes 10p and 10q have different shapes.

The side portion 11 of the support bracket 11
At the front end sides of p and 11q, regulated portions 8p and 8q that are substantially perpendicular to the recording paper conveyance direction are formed. On the other hand, bearings 30p, 3 provided on both sides of the printing side platen roller 4
The outer peripheral surface of 0q is used as restricting portions 7p and 7q. As a result, the displacement of the print head 3 in the recording paper conveyance direction is controlled by the regulated portions 8p and 8q by the regulated portions 7p and 7q, as shown in FIG.
It is regulated by abutting on q. This regulated part 8
The p and 8q and the regulating parts 7p and 7q constitute positioning parts 9p and 9q.

Further, the side plate portions 21p and 21q
A frame 31 is provided between the frames, and the upper surface of the print head 3 is pressed toward the print-side platen roller 4 by a leaf spring member 2s (biasing member 2) attached to the lower surface of the center position of the frame 31. As a result, the print head 3 is pressed against the print-side platen roller 4.

On the other hand, the reading mechanism 22 and the printing mechanism 5 are provided with a release mechanism 32. First, the reading mechanism unit 22
A part of the support bracket 25 located in front of and below the support shaft 26 on the side is bent to form a reading-side engaging portion 33 integrally. Further, a part of the side part 11p of the support bracket 11 located behind and above the support shaft 6p on the side of the printing mechanism 5 is bent to form the printing side engaging part 34 integrally.

As a result, the reading side engaging portion 33 and the printing side engaging portion 34 face each other at a predetermined distance. A shaft 35 is rotatably mounted on one side plate 21p between the reading-side engaging portion 33 and the printing-side engaging portion 34. The outer end of the shaft 35 is exposed to the outside of the casing 50, and the operation lever 58 described above is attached to the outer end of the shaft 35, and the release cam 3 is attached to the inner end of the shaft 35.
Install 6. The release cam 36 is located between the reading side engaging portion 33 and the printing side engaging portion 34.

The release mechanism 32 functions as follows. It is assumed that a part of the document Pa, for example, only a part of a newspaper article is copied. In this case, if the start key 52s is pressed, the required amount of the document Pa is fed, and then the stop key 52e is pressed, the document Pa and the recording paper Pr are stopped halfway. Then, when the operation lever 58 is rotated counterclockwise from the non-release position shown in FIG. 4 by 90 °, the release cam 36 that is integrally rotated and displaced (interlocked) is engaged only with the reading side engagement portion 33. Then, the reading side engaging portion 33 is pushed up. Thereby, the support bracket 25 is attached to the support shaft 2.
The reading head 23 is separated from the reading-side platen roller 24 because the reading head 23 is rotated upward about the fulcrum 6. Accordingly, since the document conveying path of the reading mechanism unit 22 is opened, the document Pa can be taken out. By repeating the same operation, it is possible to sequentially copy only the necessary portions of the plurality of originals Pa on the recording paper Pr.

On the other hand, during copying, the original Pa or the recording paper Pr
When the paper jam occurs or when the roll paper Prr ends during copying, it is basically necessary to start copying again from the beginning. Therefore, in this case, if the stop key 52e is pressed during copying and the operation lever 58 is turned clockwise from the non-release position shown in FIG. 36 is engaged with the reading-side engaging portion 33 to push the reading-side engaging portion 33 upward, and at the same time, to engage with the printing-side engaging portion 34 to push down the printing-side engaging portion 34. As a result, the reading head 23 is separated from the reading-side platen roller 24, and at the same time, the support bracket 11 is pivotally displaced counterclockwise about the support shafts 6p..., So that the printing head 3 is separated from the printing-side platen roller 4. It is displaced to the release position X (FIGS. 1 and 2). Therefore, since the document conveyance path of the reading mechanism unit 22 and the recording paper conveyance path of the printing mechanism unit 5 are opened at the same time, the jam processing for removing the document Pa and the recording paper Pr can be performed.

By the way, when the print head 3 is in the release position X
When the print head 3 moves to the position, the print head 3 is displaced rearward in the recording paper conveyance direction in accordance with the engagement position of the regulated portions 8p, 8q and the regulation portions 7p, 7q, but this displacement is absorbed by the support holes 10p and 10q. You. Therefore, the problem that the structure for releasing the print head 3 is limited as in the conventional art is eliminated, and the simple structure associated with the high degree of freedom in the design of the release mechanism 32 allows the peripheral structure of the support mechanism 1 to be simplified. And compactness can be realized. The operation lever 58 of the release mechanism 32 is basically
Also, since the number of components is reduced, the structure of the entire copying machine M is simplified, and the size and size of the copying machine M can be reduced and the cost can be reduced. Further, since one or both of the reading mechanism unit 22 and the printing mechanism unit 5 can be selectively released by the single operation lever 58, not only the easiness of the operation but also the ease of operation, such as being able to use differently according to various situations, Usability and convenience can be dramatically improved.

On the other hand, a drive mechanism section 40 is provided on the other side plate section 21q. As shown in FIG. 6, the drive mechanism unit 40 includes a single drive motor 41. The rotation of the pinion 42 attached to the rotation shaft of the drive motor 41 rotates the first transmission gear 43, the second transmission gear 44, and the The driving mechanism 46 is transmitted to the driven gear 46 attached to the shaft 29 on the printing mechanism unit 5 side via the three transmission gears 45, and the rotation of the driven gear 46 is transmitted via the fourth transmission gear 47 to the reading mechanism unit. The power is transmitted to a driven gear 48 attached to the shaft 27 on the 22 side. Thus, the reading mechanism unit 22 and the printing mechanism unit 5 are driven by the single drive motor 41, and the reading-side platen roller 24 and the printing-side platen roller 4 rotate at the same rotation speed in synchronization.

Next, the basic operation and usage of the portable copying machine M including the function of the support mechanism 1 according to this embodiment will be described.
The description will be made with reference to the drawings.

First, as shown in FIG. 6, the portable copying machine M can be used upright by setting the leg 53 to the use position. The operation lever 58 switches to the non-release position shown in FIG. As a result, the release cam 36 does not engage with either the reading-side engaging portion 33 or the printing-side engaging portion 34, and the reading head 23 and the print head 3 are located at the nip position.

On the other hand, the original Pa and the recording paper Pr are set. The document Pa is inserted from the document supply port 55 into the inside. Thus, a document sensor (not shown) detects the document, slightly rotates the reading-side platen roller 24, and pre-feeds the document Pa between the reading head 23 and the reading-side platen roller 24.

Further, of the recording paper Pr, the roll paper Prr
, The opening / closing cover 57 is opened, and the leading end of the roll paper Prr set at the lower portion of the casing 50 is guided to the print head 3 along the guide surfaces 21g. Insert between. As a result, a recording paper sensor (not shown) detects the recording paper Pr (roll paper Prr), and the print side platen roller 4 slightly rotates to feed the roll paper Prr between the print head 3 and the print side platen roller 4. I do.

At this time, the print head 3 is rotatably supported by a pair of support shafts 6p and 6q at a position in front of the print side platen roller 4 in the recording paper conveying direction.
Since the positioning unit 9p, 9q is provided, if the printing-side platen roller 4 is slightly rotated by pre-feed, the printing head 3 pressed against the printing-side platen roller 4 (recording paper Pr) is displaced in the recording paper transport direction, A pair of regulated portions 8p and 8q provided on both sides of the print head 3 are regulated by contacting a pair of regulated portions 7p and 7q provided on both sides of the print-side platen roller 4, respectively. 3 is performed. Since the print head 3 is positioned in this manner, it is re-positioned each time the print-side platen roller 4 rotates even during printing. Therefore, according to the print head support mechanism 1 according to the present embodiment,
Since the regulated portions 8p and 8q are positioned by being regulated by the regulating portions 7p and 7q, a member requiring dimensional accuracy such as a conventional U-shaped guide member becomes unnecessary, and the cost of parts can be reduced.

On the other hand, the print head 3 is pressed toward the printing platen roller 4 by the leaf spring member 2s (biasing member 2) and comes into pressure contact with the recording paper Pr on the printing platen roller 4. At this time, the deviation of the parallelism of the print head 3 with respect to the print side platen roller 4 is caused by one of the support holes 10p having play.
Is absorbed by

On the other hand, of the recording paper Pr, the cut paper Prc
Is used, the cut sheet Prc is supplied to the recording paper supply port 5.
Insert from 6 into the interior. As a result, a recording paper sensor (not shown) detects the recording paper Pr (cut paper Prc) and slightly rotates the print side platen roller 4 to move the cut paper Prc between the print head 3 and the print side platen roller 4. Pre-feed.

Then, when the start key 52s is pressed, the drive motor 41 operates, and the reading-side platen roller 24 and the printing-side platen roller 4 rotate synchronously and at the same speed. Thus, high-quality copying without expansion and contraction can be performed. Due to the rotation of the reading-side platen roller 24 and the printing-side platen roller 4, the document Pa and the recording paper Pr are sent forward, and are discharged from the rear surface of the casing 50 as shown in FIG. At this time, the content of the original Pa is read by the reading head 23, and the read content of the original Pa is printed (thermal recording) on the recording paper Pr by the print head 3.

The embodiment has been described in detail above.
The present invention is not limited to such an embodiment,
It is possible to arbitrarily change, add, or delete the details, configuration, shape, quantity, etc., without departing from the gist of the present invention. For example,
Although the portable copier M has been exemplified as a preferred embodiment, the present invention can be similarly applied to various electronic communication devices having a print head.

[0038]

As described above, the print head support mechanism according to the present invention rotatably supports both sides of the print head by the pair of support shafts at a position in front of the platen roller in the recording paper conveyance direction. The print head is configured to be displaceable to the release position, and has a pair of regulating portions provided on both sides of the platen roller and a pair of regulated portions provided on both sides of the print head. It has a positioning part that regulates the displacement of the restriction part by the restriction part,
One of the support shafts is supported by a support hole for releasing a displacement of the print head moving to the release position and the parallelism of the print head to the platen roller, and a displacement of the print head moving the other support shaft to the release position. Is supported by the support holes that allow the air to escape, and the following remarkable effects are achieved.

A member requiring dimensional accuracy, such as a conventional U-shaped guide member, becomes unnecessary, and the cost of parts can be reduced.

The degree of freedom in designing the release mechanism is increased, and a simpler release mechanism can be employed, so that the peripheral structure can be simplified and downsized, and thus the overall size and size can be reduced and the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a right side view showing a main part of a support mechanism according to a preferred embodiment of the present invention;

FIG. 2 is a left side view showing a main part of the support mechanism,

FIG. 3 is a rear view showing a main part of the support mechanism,

FIG. 4 is an internal configuration diagram of a portable copying machine including the support mechanism.

FIG. 5 is a right side view showing the appearance of the portable copying machine.

FIG. 6 is a left side view showing the appearance of the portable copying machine;

FIG. 7 is a front view showing the appearance of the portable copying machine;

[Description of Signs] 1 support mechanism 2 biasing member 2s leaf spring member 3 print head 4 platen roller 5 printing mechanism 6p ... support shaft 7p ... regulating part 8p ... regulated part 9p ... positioning part 10p support hole 10q support hole 11 Support bracket 12 Print head body Pr Recording paper X Release position M Portable copier

Claims (4)

[Claims] 1. A printing mechanism for printing on a recording sheet between a print head and a platen roller, which is urged by an urging member, by the print head, and conveying the recording sheet by rotation of the platen roller. In the head support mechanism, both sides of the print head are rotatably supported by a pair of support shafts at a position in front of the platen roller in the recording paper transport direction, and the print head is displaceable to a release position. And a pair of regulating portions provided on both sides of the platen roller and a pair of regulated portions provided on both sides of the print head, whereby the displacement of the regulated portion in the recording paper conveyance direction is regulated. A positioning portion for regulating the position of the print head, and moving the one of the support shafts to the release position and displacing the platen roller. And a support hole for releasing displacement of the print head moving to the release position, and supporting the other support shaft by a support hole for releasing displacement of the print head moving to the release position. Print head support mechanism. 2. The print head support mechanism according to claim 1, wherein said urging member is a leaf spring member for pressing a center of said print head toward said platen roller. 3. The print head support mechanism according to claim 1, wherein the print head includes a support bracket having a pair of the support shafts on both sides, and a print head main body fixed to the support bracket. 4. The print head support mechanism according to claim 1, wherein the print head support mechanism is applied to a portable copying machine.