JP3186814B2 - Small printer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small printer, and more particularly, to a small printer having a paper feed mechanism.

[0002]

2. Description of the Related Art A printer which is used by arranging it on a desk or the like,
One of the design objectives is to minimize the placement space as much as possible. In particular, this type of small printer is required to reduce the size of the recording paper to the full size.Therefore, the layout of the printer must be such that the transport path of the recording paper is tight and the recording paper is drawn out at a large angle from the loading position. After the recording paper is once sent out to the platen, a large resistance is applied to the paper at the paper feed roller portion, and it is necessary to displace the paper feed roller to the non-paper feed position.

On the other hand, in order to carry out the recording paper without skew, as shown in Japanese Patent Publication No. 58-6637 or Japanese Patent Publication No. 62-39261, the platen is reversed and the leading end of the recording paper is placed on its surface. The recording paper is bent forward of the platen by abutting or pushing back the tip of the recording paper that has been bitten by the reverse rotation of the platen. Therefore, means for correctly positioning the leading end of the recording paper on the platen surface is required.

However, such a complicated mechanism is required for the displacement of the feed roller and the switching of the platen between the forward and reverse rotations. If this mechanism is applied to a small printer, it is impossible to reduce the size of the printer. In addition to this, the cost of the apparatus is increased, and if this type of mechanism is omitted to reduce the size, there arises a problem that smooth paper feeding cannot be expected.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of such a problem.
An object of the present invention is to provide a small-sized printer having a new paper feeding mechanism which is small and can smoothly transport a recording sheet.

[0006]

That SUMMARY OF THE INVENTION The present invention is written
The paper feed roller is driven so that it occupies the paper feed position and the non-paper feed position
The paper feed roller is supported swingably on the gear shaft.
While meshing the gear with the feed roller drive gear,
The paper feed roller drive gear, form capable of binding to a portion of the platen drive gear train through an intermediate transmission gear which is provided on one side of the carriage, only when the carriage is in the standby position, the sheet feeding
The paper feed roller with a driving force of the roller driving gear is obtained so as to impart a rotational force and feed position direction of displacement force in the paper feeding direction.

[0007]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. FIG. 1 is a side view showing the entirety of a small printer according to an embodiment of the present invention.

First, the outline of this printer will be described. In this printer, each unit is formed of a resin material as much as possible, and these units are snap-connected to necessary portions of a case main body, thereby facilitating assembly and disposing at the time of disposal. Are configured so that each unit can be separated and can be reused for each material.

As shown in FIG. 1, the outer shell of the printer main body is roughly divided into a substantially rectangular parallelepiped shape by a lower case 1 and an upper case 3 fitted thereto. , So that it can be placed in a vertical position with the rear surface (the left side surface in the figure) facing down.
The paper guide member 9 has a tractor unit 9
1 so that it can be exchanged with the first paper 1 so that recording and writing can be performed on each of the cut sheet and the fanfold paper.

Next, the configuration of each part will be described. The paper guide member 9 has a mounting portion to the printer in the same shape as the tractor unit 91. The lower surface of the lower case 1 has a manual insertion hole 2 formed on the lower surface of the lower case 1 and a thick paper guide surface 11 for guiding thick papers to the platen 31. A paper guide plate 12 for inserting thick papers is swingably mounted at the lower end corner facing 2 so that it can be stored and pulled out.

Reference numeral 13 denotes a board fixed horizontally on the lower case with a cassette mounting space. A rear half portion 15 of the board 13 forms a mounting portion for a circuit board, and a front edge of the board 13 is a feeder described later. An attachment portion for the paper roller unit 53 and the paper holding unit 59 is provided.

Reference numeral 17 denotes a paper feed cassette which is mounted below the substrate 13 from the front. The paper feed cassette 17 has front edges and both sides of paper feed plates 18, 19 as shown in FIG.
A paper support plate 23 for supporting the rear end of the recording paper S is detachably attached to an insertion guide portion 21 formed as a thin frame surrounded by a circle and provided on the lower surface of the bottom plate 20.

A paper pressing plate 25 urged upward by a coil spring 24 is attached to the paper feed cassette 17 such that its rear end is locked in a locking hole 22 of a bottom plate 20 as in the conventional case. The paper cassette 17
A paper separating claw 26 having a triangular shape is integrally formed on both sides of the front paper backing plate 18. Reference numeral 27 denotes a non-slip material such as a cork material attached to the upper surface of the paper pressing plate 25.

On the other hand, members mounted in the printer main body are roughly classified into a platen 31 horizontally supported at the rear of the lower case 1 and a carriage guide shaft 33 along the platen 31 in the main scanning direction. Reciprocating carriage 3
5, a paper feed roller unit 53 swingably mounted at the center of the front portion of the substrate 13 so that the cut paper in the paper feed cassette 17 can be fed out without a load, and Paper press roller unit 5 mounted on substrate 15 to guide cut sheets to platen 31
9 and a paper discharge roller unit 69 that is swingably attached to the upper case 3 immediately before the paper discharge slit 4.

Next, these details will be described in order.
Based on a preset program, the carriage 35 first waits at the standby position, that is, at the opposite side of the home position, during the reverse rotation operation of the platen 31, and then the platen 31 shifts to the normal rotation by the print start signal,
The vehicle travels to the center of the printing area, and waits for the input of a printing signal, and performs a required reciprocating operation. In FIG. 1, reference numeral 38 denotes a print head mounted on the carriage 35.

FIG. 4 shows a drive unit 39 disposed between the side plates on the standby side of the upper case 3. The drive unit 39 includes a reduction gear 42 meshing with a pinion 41 of a drive motor 40, Platen gear 45 and feed roller transmission gear 47 meshing with pinion 43 integral with reduction gear 42
And a tractor transmission gear 49 meshing with the platen gear 45. The platen gear 45 drives the platen 31 integrated therewith, and the tractor of the tractor unit 91 mounted on the printer via the transmission gear 49. 105 is driven.

An idler 3 provided on one side of the carriage 35 is located at a position where the idler 3 is engaged with the feed roller transmission gear 47.
A feed roller driving gear 51 meshing with the transmission gear 47 is disposed with its position shifted in the axial direction. In the drawing, reference numeral 42a denotes a knurl for manual operation formed on the circumference of the reduction gear 42 so that the knurl can be operated from outside the printer main body.

FIGS. 2 and 3 show the feed roller driving gear 5.
1 shows a paper feed roller unit 53 driven and operated by the apparatus 1. The paper feed roller unit 53 swings a paper feed roller holder 56 which supports a paper feed roller 54 between a paper feed position and a non-paper feed position. By displacing the paper, the paper leading end and the subsequent paper feeding load are reduced.

The upper end of the paper supply roller holder 56 is movably attached to the end of a long drive shaft 52 extending from the paper supply roller drive gear 51 to the center of the substrate 13. by axially supporting the rear end of 13, the paper feed roller holder 56 is held swingably to a rear end center of the substrate 13, further, small-diameter sun gear 58 fixed to an end portion of the drive shaft 52 When the platen 31 is rotated in the reverse direction by meshing the sheet feed roller 54 with the gear 55 integral with the sheet feed roller 54, the sheet feed roller 54 is turned counterclockwise in FIG. When the platen 31 is pressed forward and the platen 31 is rotated forward, the paper feed roller 54 is rotated clockwise in FIG. 1 to displace the paper feed roller 54 away from the cut sheet . Reference numeral 57 in the drawing denotes a stopper for abutting a part of the frame to determine the sheet feeding roller unit 53 at the sheet feeding position.

On the other hand, the paper holding roller units 59 disposed on the left and right of the rear end of the substrate 13 so as to sandwich the paper supply roller unit 53 are snap-fit to the rear edge of the substrate 13 as shown in FIG. Roller holder 60,
It is composed of a horizontal lever 62 and a vertical lever 63 assembled in a T-shape via a pin 61 on a roller holder 60.

The upper end of the horizontal lever 62 is supported by a paper press roller 65 which rolls by pressing against the surface of the platen 31, and the lower end is supported by a paper press auxiliary roller 66 facing the paper guide surface 10. These rollers 65 and 66 are arranged so as to guide cut sheets from the paper feed cassette 17 onto the platen 31 while being urged by a coil spring 64 interposed in the roller holder 60 via a vertical lever 63. ing.

A shaft 66a of the paper holding assist roller 66 is formed at the center of the paper holding assist roller, and when a tractor unit 91 described later is loaded in the printer body, it is rotated by a release lever 88 described later. The operated release cam 101 is connected to the paper pressing assist roller shaft 66a.
To the paper guide surface 1 against the coil spring 64.
When the paper holding roller 65 is pulled toward the
It is configured to be separated from the surface.

On the other hand, the paper discharge roller unit 69 shown in FIGS. 2, 6, and 7 is composed of a paper discharge transmission roller 72, a paper discharge roller 73, and a roller holder 70 that supports them. The upper case 3 is attached below the paper discharge slit 4.

That is, on the upper part of the inner surface of the upper case 3, that is, on the inner surface facing the discharge slit 4, the discharge roller unit 6 is provided.
9, a roller holder 70 is provided with a fulcrum pin 6 protruding from the inner surface thereof.
6 is pivotally supported.

The roller holder 70 is provided with an elongated hole 71 for supporting the shaft of the paper discharge transmission roller 72, and the paper discharge transmission roller 72 which rolls in contact with the platen 31 surface.
Is loosely displaced in the elongated hole 71, meshes with the pinion 74 at the shaft end of the discharge roller 73 when the platen 31 rotates forward, and rotates the pinion 74 when the platen 31 rotates reversely. As shown in (1), it is configured to be displaced away from the paper discharge roller 73 and to cut off the transmission of the driving force to the paper discharge roller 73.

Reference numeral 7 in the figure denotes a torsion coil spring having one end in contact with the upper case 3 and the other in contact with the roller holder. The torsion coil spring always applies a force in such a direction as to rotate the roller holder clockwise in FIG. The paper transmission roller is urged against the platen 31.

On the other hand, the printer body includes a cut sheet fed from the paper feed cassette 17 to the platen 31, a single paper detection unit 77 for detecting fanfold paper fed from the tractor unit to the platen, and a platen gap. And a single PG / HP detection unit 81 for detecting the home position of the carriage.

FIG. 8 shows a paper detecting unit 77. The paper detecting unit 77 is mounted on the substrate 13 so as to face a paper transporting path from the paper feed cassette 17 to the platen 31. The paper detection lever 79 protruding inward is detected by being displaced by being pushed by the cut sheet S. When the tractor unit 91 is mounted, the paper detection auxiliary lever 104 on the tractor unit 91 side is detected.
Is pressed from the outside, and is protruded into the transport path of the fanfold paper, and is configured to detect displacement of the lever 104 by touching the paper.

FIG. 9 shows the PG / HP detection unit 81 described above.
3 is provided on the home position side.

The detecting unit 81 detects a platen gap detecting lever 82 for detecting two rotational positions of the platen gap lever 34, and rotates integrally with the lever 82 to determine a swing range of the carriage detecting lever 86. It comprises a displacement transmission lever 83 that is displaced as much as possible, a carriage detection lever 86 that is displaced by contacting a part of the carriage 35 that has returned to the home position, and a detector 87 that detects the displacement of this lever 86.

The platen gap detecting lever 82 moves the platen gap lever 34 to a one-step position (FIG. 9).
9A, the platen gap lever 34 is moved to move the axis of the carriage guide shaft 33 from the position corresponding to plain paper to the position corresponding to thick letters. When the rotating operation is performed, the arm 34a comes into contact with the arm 34a on the platen gap lever 34, and rotates to displace the displacement transmitting lever 82 projecting from the other side away from the carriage detecting lever 86. The displacement transmission lever 83 is provided with a carriage detection lever 86.
Is normally urged by a spring 84 and abuts against a stopper 85 so as to stop at a contact OFF position A. When the platen gap detection lever 82 is pressed and rotated clockwise in FIG. 86 can be further swung counterclockwise in the figure.

The carriage detection lever 86 includes a detector 87
When the platen gap lever 34 is at the first position, that is, when the platen gap lever 34 is at the position corresponding to plain paper, it is shown in FIG. 9A. When the carriage 37 moves from the position A urged by the displacement transmission lever 83 to the position C, and the platen gap lever 34 is at the two-stage position, that is, at the position corresponding to the thick letter, the neutral position The detector 87 is displaced from the position B to the left transition position C, and the detector 87 outputs signals of L, H, and L according to the positions A, B, and C of the carriage detection lever 86, and sends the detection signals to a CPU (not shown). The carriage 37 is returned to the home position, and it is determined whether the platen gap is at the position corresponding to the plain paper or the position corresponding to the thick letter. It has been.

On the other hand, FIGS. 4 and 13 show an optional tractor unit 91 which can be attached to the mounting position of the paper guide member.
The printer is mounted and used with the printer body in the horizontal position.

Reference numeral 92 denotes a frame of the tractor unit 91. The front of the frame 92, that is, the platen 31
The side facing the side has the same shape as the paper guide member 9 and forms a paper guide surface 93 for cut paper.

A release gear 96 for connecting the tractor transmission gear 49 on the printer main body side and the tractor gear 95 on the frame 92 is slidably mounted on the frame 92 in the axial direction. A release lever 88 is rotatably supported on the pivotal attachment portion 97 of the first gear, and the release lever 88 facing the release gear 96 is provided with a cam surface 99 for displacing the release gear 96 in the axial direction. By rotating the release lever 88 clockwise in FIG. 4, that is, the solid line position in the figure, the release gear 96 and the tractor gear 95 mesh with each other, and further, counterclockwise, that is, in the broken line position in the figure. By doing so, the gears 95 and 96 are disengaged from each other.

As shown in FIG. 5, release cams 101, 101 which are engaged with and disengaged from the paper pressing assist roller shaft 66a are rotatably mounted on the release shaft 93 inserted through the frame 92. The pinion 102 on 103 is engaged with the sector 100 which rotates integrally with the release lever 88, and when the release lever 88 is rotated counterclockwise in FIG. When the release cam 101 is rotated so as to be transmitted, the release cam 101 is moved via the sector 100 in FIG.
In the counterclockwise direction to project it into the paper transport path of the cut sheet, and engage the leading end thereof with the paper holding auxiliary roller shaft 66a, and push this toward the cut sheet guide surface 93 side. Pull the paper holding roller 65 away from the platen 31,
When the release lever 88 is rotated clockwise, the release cam 101 is rotated so as to be pulled in from the front surface of the frame, so that the cut sheet can be transported.

In the drawing, reference numeral 105 denotes a push tractor, 106 denotes a drive shaft of the tractor 105, and in FIG. 1, reference numeral 107 denotes a printer in which the front and back sides are changed depending on the horizontal and vertical postures of the printer. Paper slit 4
The paper ejection tray fixed to the vicinity is shown.

Next, the operation of the printer configured as described above will be described. When the main switch is pressed, the carriage 35 moves from the home position to the standby side,
An idler 37 attached to the side of the feed roller transmission gear 4 is inserted into a hole (not shown) provided in a side plate of the upper case 3.
7 is engaged with the feed roller drive gear 51 to enter a standby state.

In this state, when the drive motor 40 first starts to rotate in the reverse direction in response to the print start signal, the platen gear 45 meshing with the deceleration pinion 43 reverses the platen 31 integral therewith, and feeds the paper. The transmission gear 47 transmits this rotation to the feed roller driving gear 51 via the idler 37 on the carriage 35.

For this reason, the sun gear 58 integral with the drive gear 51 transmits the rotation in the paper feed direction to the paper feed roller gear 55, and at the same time, the drive shaft 5
1 is rotated to the position indicated by the solid line in FIG. 1 so that the paper feed roller 54 is pressed against the uppermost cut-sheet paper housed in the paper feed cassette 17, and the rotation is used to cut the cut-sheet paper. To the platen 31.

On the other hand, at the time of recording and writing using ordinary cut-sheet paper, a paper guide member 9 is attached to the rear end opening 2 of the lower case 1, and in this state, a paper pressing roller unit 59 is provided.
As shown in FIG. 5, the vertical lever 63 is pressed by the coil spring 64 in the roller holder 64, and the paper pressing roller 65 at the upper end of the horizontal lever 62 is pressed against the platen 31 via the lever 63.

For this reason, the cut sheet sent out to the sheet conveying path by the sheet feeding roller 54 firstly receives the sheet detecting lever 79.
Is discharged from the paper transport path, the paper detection unit 77 detects passage of the cut sheet, and then the platen 31 that is rotating in the reverse direction.
, And the paper press roller 6 pressed against the surface and rotated in reverse.
Stops in contact with 5.

When the leading edge of the cut sheet is bent by the subsequent paper feeding operation, the stiffness of the sheet caused by this causes the leading end of the cut sheet to be correctly positioned between the platen 31 and the paper pressing roller 65. The drive motor 40 is switched to the normal rotation by a preset program, and the platen 31 and the paper pressing roller 65 are rotated forward so that the cut sheet is recorded on the recording head 3.
Send it to 8.

On the other hand, at the same time as the normal rotation of the drive motor 40, the carriage drive motor (not shown) moves the carriage 35 to the center of the printing area via a timing belt so that the carriage 35 functions as a paper bail.

As a result, the paper feed roller driving gear 51 is cut off from the transmission of the driving force from the paper feed roller transmission gear 47 to be in a flow state.
The paper feed roller 54, which has been coupled with the paper feed roller gear 55, is rotated by the cut sheet in the counterclockwise direction in FIG. 1 to reduce the paper feeding load applied to the platen 31 as much as possible. Reduced and accurate recording and writing operations are performed.

On the other hand, the paper discharge roller unit 69 disposed in the paper discharge part is displaced in the direction in which the paper discharge transmission roller 72 is separated from the paper discharge roller 73 while the platen 31 is rotating in the reverse direction. In addition, when the platen 31 is switched to the normal rotation, the platen 31 is coupled to the paper discharge roller 73 to transmit the rotational driving force in the paper discharge direction to the roller. For this reason, cut sheets that have undergone the required printing
The sheet is taken over from the platen 31 to the sheet discharge roller 73 and discharged onto the sheet discharge tray 107.

By the way, the recording and writing on the cut sheet is performed as follows.
This is performed in a state where the platen gap lever 34 is rotated to the first position. In this state, the carriage guide shaft 33 mounted eccentrically has its axis centered on the platen 31.
And the platen gap detection lever 8
2, the displacement detection lever 83 is rotated to the normal position as shown in FIG. 9A, and the carriage detection lever 86 is turned OFF, ON, and OFF between the position A and the position C. Each time the carriage 37 returns to the home position, the H and L signals output from the detector 87 detect the return of the carriage 37 in a state corresponding to plain paper.

On the other hand, when printing on thick paper such as a postcard, the printer body is first held in a vertical position with the rear face down, and the platen gap lever 34 is rotated to a two-stage position corresponding to thick letters. In addition, a thick letter is inserted from the manual insertion hole 2 using the paper guide plate 12 as a guide.

As a result, the platen gap detection lever 82 rotates clockwise in the figure as shown in FIG. 9B, and separates the displacement detection lever 83 from the carriage detection lever 86. At position B
, And can be further displaced to three positions of the left rotation position C.

In this state, when the carriage returns to a position other than the home position, the CPU outputs a H signal.
Receives this signal, determines that the platen gap is in a state suitable for printing on the thick letter, and continues the subsequent printing operation to perform the required recording and writing on the thick paper.

When recording and writing on fanfold paper or the like, the printer body is first set to the horizontal position, and the optional tractor unit 91 is mounted on the front end opening of the lower case 1. Thereby, the frame 9
2. A paper inspection auxiliary lever 1 pivotally supported near the cut sheet paper guide surface 93.
As shown in FIG. 8, the printer 04 is positioned in the conveyance path of the fanfold paper by contacting the paper detection lever 79, and in this state, the release lever 88 is rotated to the position indicated by the solid line in FIG. When the release gear 96 meshing with the tractor transmission gear 49 on the side is displaced in the axial direction by the cam surface 99 on the lever 88 and meshes with the tractor gear 95, the release gear 96 is interlocked with the movement of the release lever 88 via the sector 100. As shown in FIG. 5, the release cam 101 also engages with the paper press assist roller shaft 66a, pulls it toward the cut sheet guide surface 93, and pushes the paper press roller 65 to the platen 31.
Away from

For this reason, the fanfold paper sent out from the tractor 105 is first fed to the paper detection assist lever 10.
4 is removed from the paper transport path, the paper is detected by the paper detection unit 77, and the paper itself reaches the platen 31 surface without receiving the resistance of the paper pressing roller 65, and the paper transport by the platen 31 is performed. The required recording / writing process is performed while receiving the action.

When recording and writing on cut sheets with the tractor unit 91 mounted, the release lever 91 is turned to the position indicated by the broken line in FIG.
6, the transmission of the driving force to the tractor gear 95 is cut off, and the engagement between the release cam 101 and the paper holding auxiliary roller shaft 66a is released, so that the paper holding roller 65 is pressed against the surface of the platen 31, and the normal cut sheet printing mode is performed. Then, the recording and writing operation on the cut sheet may be performed.

[0054]

As described above, according to the present invention, paper feeding
The roller is swingably supported by the feed roller drive gear shaft,
Gear with the paper feed roller meshes with the paper feed roller drive gear
Align, further, return the paper feed roller drive gear, since the Do couplable to a portion of the platen drive gear train through an intermediate transmission gear which is provided on one side of the carriage, to the standby position at the time of non-printing
Of the paper feed roller drive gear using the carriage
The paper feed roller is pulled strongly onto the recording paper by force
Not only can make reliably feed the, in the printer, such as a platen by forward and reverse rotation to the skew correction of the recording sheet, is <br/> Rukoto configure the paper feed mechanism significantly simplified it can.

In addition, during the printing operation, the driving force to the sheet feeding roller can be cut off and the sheet feeding roller can be displaced to the non-sheet feeding position. Good recording and writing can be performed by minimizing the load as much as possible.

[Brief description of the drawings]

FIG. 1 is a side view of a small printer showing one embodiment of the present invention.

FIG. 2 is a diagram showing details of a sheet feeding unit and a sheet discharging unit in the above device.

FIG. 3 is an exploded perspective view of a sheet feeding unit.

FIG. 4 is a side view showing a drive unit and a tractor unit.

FIG. 5 is a side view showing the relationship between the paper holding unit and the tractor unit.

FIG. 6 is a perspective view of a paper discharge unit.

FIGS. 7A and 7B are diagrams showing respective states of a paper discharge unit.

FIG. 8 is a diagram illustrating a relationship between a paper detection unit and a tractor unit.

FIG. 9 is a perspective view showing a PG / HP detection unit;
(A), (b) is a figure which shows the state switched to each corresponding position of a plain paper and a thick letter.

FIG. 10 is a plan view of the same unit.

FIG. 11 is a diagram showing a detection output at each switching position.

FIG. 12 is a perspective view showing a paper guide member.

FIG. 13 is an exploded perspective view showing a transmission system for transmitting the driving force of the tractor unit.

FIG. 14 is an exploded perspective view showing a sheet feeding cassette.

[Explanation of symbols]

 Reference Signs List 1 lower case 3 upper case 9 paper guide member 17 paper feed cassette 39 drive unit 42 reduction gear 47 paper feed roller transmission gear 51 paper feed roller drive gear 53 paper feed roller unit 54 paper feed roller 56 paper feed roller holder 59 paper press roller Unit 69 Discharge roller unit 77 Paper detection unit 81 PG / HP detection unit 91 Tractor unit

──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Toshikazu Odaka 3-5-5 Yamato, Suwa-shi, Nagano Seiko Epson Corporation (56) References JP-A-63-139765 (JP, A) JP-A Sho 61-188340 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B41J 13/00-13/32

Claims (1)

(57) [Claims] 1. A paper feeder occupying a paper feed position and a non-paper feed position.
When the roller is supported swingably on the feed roller drive gear shaft,
In both cases, the gears integral with the paper feed roller
While meshing the car, the feed roller driving gear, form capable of binding to a portion of the platen drive gear train through an intermediate transmission gear which is provided on one side of the carriage, when the carriage is in the standby position Only the drive of the feed roller drive gear
Small printer, characterized in that with the power and so as to impart a rotational force and feed position direction of displacement force in the paper feeding direction to the feed roller.