JP3530719B2 - Printer paper feed mechanism - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper feeding mechanism of a printer, and more particularly to a paper feeding mechanism of a printer which can automatically feed a plurality of sheets and can easily feed the paper manually. Regarding

[0002]

2. Description of the Related Art Generally, a thermal transfer printer is used as an output device for computers, word processors, facsimiles, etc.
Various printers such as page printers are used.

FIG. 15 shows such a conventional printer. This printer 50 uses paper 51 for printer 5
The printer 50 is configured to be conveyed substantially horizontally from the rear to the front of 0 for recording, and the printer 50 has a printer frame 52 disposed inside a printer case (not shown). Below the printer frame 52, a platen 53 having a flat plate shape and extending in the width direction of the printer frame 52 is arranged so that its recording surface is directed upward.

A carriage 54, which is reciprocally movable along a platen 53 by a drive mechanism (not shown), is disposed on one side of the printer frame 52.
At the lower end of the carriage 54, a thermal head (not shown) is disposed so as to come in contact with and separate from the platen 53. Further, a ribbon cassette (not shown) having an ink ribbon of a desired color wound therein is detachably attached to the carriage 54, and the platen 5 is attached.
3 with the paper 51 and the ink ribbon being supplied between the thermal head and the thermal head, the thermal head is moved to the platen 53.
The pressure contact position between the thermal head and the platen 53 in this head-down state is the recording position.

A cassette mounting table 55 is disposed below the printer frame 52 on the upstream side in the sheet conveying direction, and a plurality of sheets 51 are stacked inside the cassette mounting table 55. Paper cassette 56
Is designed to be detachably attached. A separation plate 57 for contacting the leading edge of the paper 51 and separating only the uppermost paper 51 of the stacked paper 51 is inclined at a predetermined angle at the front end of the paper feed cassette 56. It is installed in.

A plurality of paper feed rollers 58 having a substantially D-shaped cross section are arranged above the cassette mounting table 55 so as to have a predetermined interval in the axial direction. The urging member urges the paper feed cassette 56 mounted on the cassette mounting table 55 so as to come into contact with the paper feed cassette 56. Further, a plurality of paper feed rollers 59 are arranged on the upstream side of the platen 53 in the printer frame 52 in the paper transport direction so as to have a predetermined interval, and above each paper feed roller 59, the paper feed rollers 59. An auxiliary roller 60 that is brought into contact with the outer peripheral surface of the sheet and is rotated by the paper feed roller 59 is rotatably provided.

Further, on the downstream side of the platen 53 of the printer frame 52 in the sheet conveying direction, a plurality of sheet discharging rollers 61 for discharging the recorded sheet 51 to the outside are arranged at predetermined intervals.

In such a conventional printer 50, a plurality of sheets of paper 51 are stacked and housed in a paper feed cassette 56, and the paper feed cassette 56 is mounted on a cassette mounting table 55 and the The sheet feeding roller 58 is brought into contact with the sheet feeding roller 58 to rotate the sheet feeding roller 58, so that the sheet 51 stored in the sheet feeding cassette 56 is separated by the separating plate 57 and fed one by one. ing.

Then, the paper 51 fed by the paper feed roller 58 is delivered to the paper feed roller 59 and the auxiliary roller 60 before the recording position, and is sandwiched between the paper feed roller 59 and the auxiliary roller 60. The recording sheet 51 is conveyed to the recording position, and the recording sheet 51 is ejected to the outside of the printer 50 by the ejection roller 61.

Further, FIG. 16 shows another conventional printer.
The printer frame 52 is configured so as to carry out recording by curving upward from the rear of 0, and a platen 53 having a flat plate shape is arranged on the printer frame 52 so that its recording surface is directed forward. ing. Further, on one side of the printer frame 52, a thermal head is mounted and a carriage 54 to which a ribbon cassette is detachably mounted is arranged.

Further, on the upstream side of the printer frame 52 in the sheet conveying direction, a sheet placing table 62 for stacking and placing a plurality of sheets 51 on the upper surface is swingable up and down about the rear end. The separation plate 57 is arranged at the tip of the sheet mounting table 62 so as to be inclined at a predetermined angle.

A plurality of paper feed rollers 58 are arranged above the paper placing table 62 so as to have a predetermined interval in the axial direction, and a plurality of papers are provided below the platen 53 of the printer frame 52. The feed rollers 59 are arranged so as to have a predetermined interval, and an auxiliary roller 60 that is in contact with the outer peripheral surface of the paper feed roller 59 and is driven by the paper feed roller 59 is rotated in front of each paper feed roller 59. It is arranged freely.

Also in such a conventional printer 50, as in the printer 50 shown in FIG. 15, by rotating the sheet feeding roller 58, the sheet mounting table 6 can be obtained.
The paper 51 stored in 2 is separated and fed one by one by a separation plate 57, and is conveyed to a recording position by a paper feed roller 59 and an auxiliary roller 60, and the paper 51 after recording is discharged upward. It is supposed to be done.

[0014]

However, in the above-mentioned conventional printer 50, the separation plate 57 is held so as to have a predetermined angle. For example, a thin sheet 51 such as a cut sheet is inclined. While keeping the angle small, for example, for thick paper 51 such as postcards, by keeping the inclination angle large, each stacked paper 51
However, in any of the printers 50, the structure is such that the inclination angle of the separation plate 57 can be switched by manually operating the lever, so the operation is troublesome. Moreover, the separating plate 5
If the inclination angle of 7 is set incorrectly, there is a problem in that the paper 51 cannot be reliably separated, and proper paper feeding cannot be performed.

The present invention has been made in view of these points, and the inclination angle of the separation plate can be appropriately changed according to the type of paper, and the paper can be reliably separated.
An object of the present invention is to provide a paper feed mechanism of a printer that can perform proper paper feeding.

[0016]

In order to achieve the above object, the paper feeding mechanism of the printer according to the invention of claim 1 is
A sheet placing plate for stacking and storing a plurality of sheets is provided behind the printer, and a separation plate for separating the sheets one by one by contacting the leading edge of the sheet with the sheet placing plate portion. A paper feed roller is provided which is arranged so that its inclination angle can be changed and which can come into contact with the paper stored in the paper placement plate and feeds the paper one by one. An angle changing cam, which has a plurality of stages of cams with different diameters formed on its peripheral surface, is arranged on the drive shaft portion of the device so as to rotate integrally with the paper feed roller and to be movable in the axial direction. A follower cam that follows the outer peripheral surface of the angle changing cam is integrally mounted,
The inclination angle of the separation plate is changed by moving the angle changing cam in the axial direction and selectively causing the driven cam to follow the cams of the respective stages of the angle changing cam. It is a thing.

According to the invention described in claim 1, the angle changing cam is moved in the axial direction according to the type of the sheet, and the driven cam of the separating plate is selectively used as the cam of each stage of the angle changing cam. By making it possible to automatically change the inclination angle of the separation plate by following it, there is no need to manually switch the inclination angle of the separation plate according to the type of paper,
According to the type of paper, the paper can be surely separated and only the uppermost paper can be properly fed.

The invention described in claim 2 is the same as claim 1.
In the above, a paper guide which is movable in the width direction of the paper placing plate is arranged on the paper placing plate, and the movement of the paper guide causes the angle changing cam to move in the axial direction to move the driven cam. The feature is that the cams of the respective stages to follow are selected.

According to the second aspect of the present invention, the cams of the respective stages of the angle changing cam can be selected only by moving the paper guide, and the inclination angle of the separating plate can be easily switched. Is something that can be done.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIGS.

FIGS. 1 to 3 show an embodiment of a printer to which a paper feeding mechanism according to the present invention is applied. The printer 1 of the present embodiment conveys a sheet 2 almost horizontally and records it. The printer 1 is configured to perform
The printer frame 3 is provided inside a printer case (not shown). Below the printer frame 3, a platen 4 having a flat plate shape and extending in the width direction of the printer frame 3 is arranged so that its recording surface is directed upward. Further, on one side of the printer frame 3, a carriage 5 which is reciprocally movable along a platen 4 by a drive mechanism (not shown) is arranged, and a lower end portion of the carriage 5 has a plurality of carriages (not shown). A thermal head (not shown) as a recording head in which heat generating elements are arranged in an array is arranged so as to be able to come in contact with and separate from the platen 4. Further, a ribbon cassette (not shown) having an ink ribbon of a desired color wound therein is detachably attached to the carriage 5, and the ink ribbon is attached to the thermal head of the thermal head. It is configured to be guided between the heating element portion and the platen 4. Then, with the paper 2 and the ink ribbon being supplied between the platen 4 and the thermal head, the thermal head is brought into pressure contact with the platen 4, and the pressure contact position between the thermal head and the platen 4 in this head-down state is recorded. The position is.

Below the printer frame 3, there is formed a paper conveying path 6 which communicates in a substantially straight line in the front-rear direction, and the front portion of the paper conveying path 6 serves as a paper insertion opening 7. There is. Further, a guide plate 8 is arranged above the sheet conveying path 6 so as to have a predetermined gap with respect to the lower surface of the sheet conveying path 6.

Above the guide plate 8, a paper stacking plate 9 is arranged so as to be inclined so that its rear side becomes higher, and is vertically swingable about a rear end thereof. A spring 10 is interposed between the front lower surface of the sheet stacking plate 9 and the guide plate 8, and the sheet stacking plate 9 is always in an upper swing position by the urging force of the spring 10. Held in. Further, the paper loading plate 9 is
A pair of paper guides 11, 11 standing upright at a right angle with respect to and extending in the front-rear direction are movably arranged in the width direction of the paper placing plate 9, respectively.
Insertion guides 12 that properly guide the stacked sheets 2 inserted between the sheet guides 11 to the upper surface of the sheet stacking plate 9 are formed on the surfaces of the sheet 1 facing each other. . Further, a cam receiving concave portion 13 is formed so as to project at a front end portion on one end side (left side in the drawing) of the sheet placing plate 9.

In the vicinity of the leading end of the sheet placing plate 9 of the guide plate 8, the stacked sheets 2 extend along the sheet placing plate 9 and come into contact with the leading edge of the sheet 2. A separating plate 14 for separating only the uppermost sheet 2 among them is provided, and the separating plate 14 is rotatable about a substantially central portion in the front-rear direction, and this rotating operation causes the separating plate 14 to rotate. The tilt angle can be changed.
Further, as shown in FIG. 4, an urging spring 15 is attached to the separating plate 14, and by the urging spring 15,
In FIG. 4, it is always biased in the direction of turning clockwise. Further, a driven cam projection 16 protruding upward is integrally formed on one end side of the separation plate 14.

A paper feed roller drive shaft 17 extending in the width direction of the printer frame 3 and having both ends supported on both sides of the printer frame 3 is disposed above the paper placing plate 9. The feed roller drive shaft 17 has a plurality of D-shaped cross-sections (two in this embodiment).
Paper feed rollers 18, 18 are attached so as to have a predetermined interval in the axial direction.

On one end side of the paper feed roller drive shaft 17,
An angle changing cam 19 is arranged so as to rotate integrally with the paper feeding roller drive shaft 17 and is movable in the axial direction. The end face of the angle changing cam 19 has the paper guide 11 of the paper loading plate 9. When the sheet is moved toward the printer frame 3, a part of the end surface of the sheet guide 11 is brought into contact with the sheet guide 11. Also, the angle changing cam 1
Reference numeral 9 denotes a two-stage cam composed of a large diameter portion 20 and a small diameter portion 21, and a cutout portion 22 is formed in the outer peripheral portion of the angle changing cam 19 by cutting out a part thereof. Further, on the printer frame 3 side of the angle changing cam 19, there is formed a protruding cam 23 which is rotated integrally with the angle changing cam 19 and engages with the cam receiving concave portion 13 of the sheet placing plate 9. The sheet placing plate 9 is swung downward against the biasing force of the spring 10 in a state in which 23 is engaged with the cam receiving recess 13.

The angle changing cam 19 and the projection cam 2 are also provided.
An urging spring 24 is disposed between the printer frame 3 and the angle changing cam 19 in the normal direction, as shown in FIG. 2, by the urging spring 24. 3, the paper guide 11 is moved toward the printer frame 3 so that a part of the end surface of the paper guide 11 is moved to the end surface of the angle changing cam 19 as shown in FIG. By contacting them, the angle changing cam 19 can be moved in the direction approaching the printer frame 3 against the urging force of the urging spring 24.

In the present embodiment, as shown in FIG. 1, the state in which the projection cam 23 is engaged with the cam receiving recess 13 is the reference position. At this reference position, the notch 22 of the angle changing cam 19 is provided. Is a driven cam projection 1 of the separation plate 14.
The angle changing cam 19 is located in the 6th part.
Is movable in the axial direction without contacting the driven cam projection 16. As shown in FIG. 3, when the angle changing cam 19 is held at a position separated from the printer frame 3 by the urging force of the urging spring 24, the driven cam protrusion 16 is larger than the angle changing cam 19. Since it is located on the outer peripheral side of the diameter portion 20, the angle changing cam 19
Is driven to rotate, and the driven cam protrusion 16 moves the angle changing cam 19
Following the large-diameter portion 20 of the driven plate, the driven cam projection 16 is largely pushed downward, whereby the separation plate 14 is pushed by the biasing spring 1.
The separation plate 14 is rotated against the biasing force of the sheet 5 to be held at a large inclination angle, and for example, a relatively thick sheet 2 such as a postcard can be fed. On the other hand, as shown in FIG. 2, a part of the end face of the paper guide 11 is brought into contact with the end face of the angle changing cam 19 so that the angle changing cam 19 resists the urging force of the urging spring 24 to the printer frame 3. The driven cam projection 16 is positioned on the outer peripheral side of the small diameter portion 21 of the angle changing cam 19 while being held in the close position, the angle changing cam 19 is rotationally driven, and the driven cam projection 16 is rotated by the angle. Small diameter part 2 of change cam 19
When the value of 1 is followed, the driven cam projection 16 is slightly pushed downward, whereby the separation plate 14 is rotated against the urging force of the urging spring 15 and the separation plate 14 is held at a small inclination angle. Thus, it is possible to feed a relatively thin sheet 2 such as a normal cut sheet.

In the vicinity of the upstream side of the platen 4 of the printer frame 3 in the sheet conveying direction, the printer frame 3 is provided.
Is provided with a paper feed roller drive shaft 25 extending in the width direction of the printer frame 3 and supported at both ends on both sides of the printer frame 3. The paper feed roller drive shaft 25 has a plurality of paper feed rollers 26, 26 are attached at a predetermined interval.
Further, above the paper feed rollers 26, the paper feed rollers 2 are provided.
An auxiliary roller 27 which is brought into contact with the outer peripheral surface of 6 and is rotated by the paper feed roller 26 is rotatably provided. In addition,
The paper feed roller 18 is arranged such that a gap is formed between the lower portion of the paper feed roller 18 and the lower surface of the paper feed path 6 so that at least one paper 2 can pass therethrough.

Further, on the rear side of the paper transport path 6,
A transport roller drive shaft 28 is provided which extends in the width direction of the printer frame 3 and is supported at both ends on both sides of the printer frame 3. The transport roller drive shaft 28 has a plurality of transport rollers 29. Are attached with a predetermined interval. Further, above each of the transport rollers 29, an auxiliary roller 30 that is brought into contact with the outer peripheral surface of the transport roller 29 and is rotated by the transport roller 29 is rotatably disposed.

Further, the paper feed roller drive shaft 17 has a leading end portion extending rearward of the printer frame 3 located in the vicinity of the carrying roller 29, and the leading end portion formed into an acute angle. A plate 31 is arranged so as to be slightly swingable in the vertical direction.
Usually, it is held at the lower swing position so that its tip portion comes into contact with the lower surface of the sheet conveying path 6 by its own weight.
The paper switching plate 31 may be always biased to a lower swing position by a spring.

Between the front end portion of the guide plate 8 and the paper feed roller 26, the guide plate 8 and the paper feed roller 1 are provided.
A sheet detection lever 32 as a sheet detection member for swinging the sheet 2 when it is conveyed is provided between the sheet conveyance roller 8 and the sheet 8, and the sheet detection lever 32 is also provided near the conveyance roller 29. Further, there is provided a sheet detection lever 33 as a sheet detection member that is rocked when the sheet 2 is conveyed to the conveying roller 29 and detects the sheet 2. Further, in the present embodiment, a detection assisting lever 34 as a detection assisting member having a substantially L-shape is attached to the paper feed roller drive shaft 25 so as to be rotatable around the paper feed roller drive shaft 25. The one end of the detection assisting lever 34 abuts on the tip of the paper detection lever 32, and the other end is positioned at the lower end of the paper feed roller 26 in the paper transport path 6 portion. Then, the paper transport path 6
When the sheet 2 is inserted into the sheet, and the sheet 2 is used to rotate the detection assist lever 34, the detection assist lever 34 is rotated.
The sheet detection lever 32 is swung by the leading end of the sheet, so that the presence or absence of the sheet 2 passing through the sheet conveyance path 6 can be detected.

Further, the platen 4 of the printer frame 3
The printer frame 3 is provided on the downstream side of the paper transport direction.
A discharge roller drive shaft 35 extending in the width direction of the printer and supported by the printer frame 3 is rotatably arranged. The discharge roller drive shaft 35 discharges the recorded paper 2 to the outside. A plurality of paper discharge rollers 36 are attached at predetermined intervals.

A drive motor (not shown) including a stepping motor and the like is disposed on one side of the printer frame 3, and a gear transmission mechanism 37 including a plurality of gears and shafts is used for rotating the drive motor. Via a paper feed roller drive shaft 17, a paper feed roller drive shaft 25, a conveyance roller drive shaft 28, and a paper discharge roller drive shaft 35. Further, in the present embodiment, a clutch lever is provided on one side surface of the printer frame 3, and the swinging operation of the clutch lever 38 causes the rotational force of the drive motor with respect to the paper feed roller drive shaft 17. The gear transmission mechanism 37 can be switched so as not to transmit.

Next, the operation of this embodiment having the above-mentioned structure will be described.

First, the case where paper is fed by the paper feed roller 18 will be described.

In the printer 1 according to the present embodiment, in a normal state, as shown in FIGS. 1 and 7, the protruding cam 23 is held at the reference position in which the cam receiving recess 13 is engaged.

When the paper 2 to be recorded is a normal cut paper 2 or the like, as shown in FIG. 2, the paper guide 11 is moved in the direction of approaching the printer frame 3 so that the paper guide 11 is moved. A part of the end face of the angle changing cam 19 is brought into contact with the end face of the angle changing cam 19 to hold the angle changing cam 19 at a position close to the printer frame 3 against the urging force of the urging spring 24. In this state, the driven cam projection 1
6 is located on the outer peripheral side of the small diameter portion 21 of the angle changing cam 19.

In this state, a plurality of sheets 2 of a desired size are stacked and placed on the upper surface of the sheet placing plate 9 between the sheet guides 11, and the clutch lever 38 is swung to feed. The paper roller drive shaft 17 is switched so as to rotate.

Subsequently, the drive motor is driven to rotationally drive the paper feed roller drive shaft 17 via the gear transmission mechanism 37, so that the paper feed roller 18 is rotationally driven as shown in FIGS. 4 and 8. The angle changing cam 19 is rotated in accordance with the rotation of the sheet feeding roller 18, the engagement between the projection cam 23 and the cam receiving recess 13 is released, and the sheet placing plate 9 is swung upward by the biasing force of the spring. The uppermost sheet 2 is moved and brought into contact with the sheet feeding roller 18. At the same time, angle change cam 1
When the driven cam projection 16 of the separation plate 14 follows the small diameter portion 21 of the angle changing cam 19 by the rotational drive of 9,
The driven cam projection 16 is pushed downward by a small amount, whereby the separation plate 14 is rotated against the urging force of the urging spring 15 and the separation plate 14 is held at a small inclination angle.

By the rotation of the paper feed roller 18, only the uppermost paper 2 is conveyed toward the paper feed roller 26, and the paper 2 is moved by the separation plate 14 held at the small inclination angle. It is possible to apply a load to the leading edge of the sheet and separate only the uppermost sheet 2 for smooth conveyance.

When the sheet 2 is fed in this way, the presence or absence of the sheet 2 is detected by the sheet detection lever 32,
When the presence of the sheet 2 is detected by the sheet detection lever 32, it is determined that the sheet 2 is properly fed, and the sheet feeding operation is continued.

When the leading edge of the paper 2 reaches the contact portion between the paper feed roller 26 and the auxiliary roller 27, in the present embodiment, the paper feed roller 26 makes the paper 2
Since it is rotated in the opposite direction to the transport direction of
The leading edge of the paper 2 hits the paper feed roller 26,
The leading edge of the paper 2 is aligned so as to be parallel to the paper feed roller 26, and the attitude of the paper 2 is controlled.

Next, the drive motor is rotated at the timing when the front end of the paper 2 is abutted against the paper feed roller 26 and the front end of the paper 2 is aligned in parallel with the contact portion between the paper feed roller 26 and the auxiliary roller 27. By switching the direction, the paper feed roller 26 is rotated counterclockwise in FIG. 4, the paper feed roller 18 is rotated in the same direction as it is, and the rotation of the paper feed roller 26 and the paper feed roller 18 causes the paper feed roller 26 to rotate. 2 is conveyed between the platen 4 and the thermal head.

By continuing the rotation of the paper feed roller 18, the angle changing cam 19 is held at the reference position and the projection cam 23 is engaged with the cam receiving recess 13 as shown in FIGS. 5 and 10. And the sheet placing plate 9 is swung downward against the biasing force of the spring, and the uppermost sheet 2 and the sheet feeding roller 1 are
8 is released, and the paper feed roller 18 is held at a position separated from the paper 2. In this state, paper 2
The leading end of the sheet is projected from the platen 4 portion toward the paper discharge roller 36 side.

Thereafter, by driving the drive motor in the reverse direction, the paper feed roller 26 is rotated in the clockwise direction, whereby the paper 2 is transported in the direction opposite to the transport direction, and the paper 2 is indexed. In this case, the paper feed roller 18
Are held as they are at positions separated from the sheet 2.

From this state, the thermal head is brought into pressure contact with the platen 4 via the ink ribbon and the paper 2, and the carriage 5 is moved along the platen 4, while the heating element of the thermal head is driven based on a desired recording signal. The desired recording is performed on the paper 2 by selectively driving it. Then, the paper feed roller 26 is set to the paper 2
By rotating the paper in the feeding direction, the paper feeding is repeated along with the line feed operation required for recording.

When the recording on the paper 2 is completed, the drive motor is driven to rotate in the normal direction to rotate the paper discharge roller 36, whereby the paper 2 is discharged, and the recording operation for one paper 2 is completed. To do.

Then, the above operation is repeated to sequentially form the paper 2
Record.

Next, when recording on a thick paper 2 such as a postcard, the angle changing cam 19 is attached by moving the paper guide 11 in the direction away from the printer frame 3, as shown in FIG. It is held at a position separated from the printer frame 3 by the urging force of the urging spring 24.
In this state, the driven cam protrusion 16 causes the angle changing cam 19 to move.
Is located on the outer peripheral side of the large-diameter portion 20.

In this state, when the paper feed roller 18 is rotationally driven by driving the drive motor to rotationally drive the paper feed roller drive shaft 17 via the gear transmission mechanism 37,
As shown in FIGS. 6 and 9, the angle changing cam 19 is rotated along with the rotation of the paper feed roller 18, and the projection cam 2 is rotated.
3 is disengaged from the cam receiving concave portion 13, the sheet placing plate 9 is swung upward by the biasing force of the spring, and the uppermost sheet 2 is brought into contact with the sheet feeding roller 18. At the same time, the driven cam projections 1 of the separation plate 14 are driven by the rotation of the angle changing cam 19.
6 follows the large-diameter portion 20 of the angle changing cam 19, the driven cam projection 16 is largely pushed downward, whereby the separating plate 14 is rotated against the urging force of the urging spring 15. The separation plate 14 will be held with a large inclination angle.

Then, by rotating the paper feed roller 18, only the uppermost paper 2 is conveyed toward the paper feed roller 26, and the paper 2 is moved by the separation plate 14 held at the large inclination angle. It is possible to apply a load to the leading edge of the sheet and separate only the uppermost sheet 2 for smooth conveyance.

Thereafter, similar to the above-mentioned operation, the paper 2 is conveyed and desired recording is performed by the thermal head.

Next, a case where the paper 2 is manually fed to perform recording will be described.

In this case, first, as shown in FIG.
The sheet 2 is inserted from the sheet insertion port 7 of the printer frame 3 into the sheet conveying path 6 until its leading end abuts between the conveying roller 29 and the auxiliary roller 30, and the clutch lever 38 is swung to feed the sheet feeding roller. The drive shaft 17 is switched so as not to rotate. At this time, the sheet switching plate 31 is slightly swung upward due to the insertion operation of the sheet 2, and the sheet 2 can be inserted between the leading end of the sheet switching plate 31 and the lower surface of the sheet transport path 6 only. Gaps are formed.

When the paper 2 is manually fed in this way, the detection assist lever 34 is rotated to operate the paper detection lever 32, whereby the presence or absence of the paper 2 is detected and the paper is detected. When the presence / absence of the sheet 2 is detected by the detection lever 33 and the presence of the sheet 2 is detected by the sheet detection levers 32 and 33, it is determined that the sheet 2 is properly inserted, and the sheet feeding operation is performed. Is started. As described above, in the present embodiment, by using the detection auxiliary lever 34, one sheet detection lever 32
Accordingly, it is possible to detect the presence or absence of the sheet 2 sent from the sheet placing plate 9 and the sheet 2 sent from the sheet conveying path 6.

Then, the drive motor is driven to rotate the transport roller drive shaft 28 clockwise through the gear transmission mechanism 37 in FIG.
When is rotated, the sheet 2 is conveyed rearward along the sheet conveying path 6, and the conveying roller 29 is stopped when the leading end of the sheet 2 passes the sheet switching plate 31, as shown in FIG. In this state, the sheet switching plate 31 is swung downward by its own weight.

Subsequently, as shown in FIG. 13, the conveying roller 29 is rotated counterclockwise to convey the sheet 2 forward, and the sheet switching plate 31 switches the conveying direction of the sheet 2. , Paper 2 is paper feed roller 2
It is guided to the upper side of the sheet switching plate 31 toward the sheet 6.

The paper 2 is fed by the paper feed roller 26.
And the auxiliary roller 27, the sheet 2 is conveyed between the platen 4 and the thermal head by the rotation of the sheet feeding roller 26 and the conveying roller 29.

After that, as shown in FIG. 14, as in the above-described operation, the sheet 2 is conveyed and desired recording is performed by the thermal head.

Therefore, in the present embodiment, the angle changing cam 19 is moved in the axial direction according to the type of the sheet 2, and the driven cam projection 16 of the separating plate 14 is moved to the angle changing cam 19.
By selectively following the large-diameter portion 20 or the small-diameter portion 21 of the sheet, the inclination angle of the separating plate 14 can be automatically changed. Therefore, the separating plate can be manually changed according to the type of the sheet 2. There is no need to switch the tilt angle of 14,
It is possible to reliably separate the sheets 2 according to the type of the sheets 2 and to reliably feed only the uppermost sheet 2.

A sheet insertion port 7 is provided in the front portion of the printer 1, and the sheet 2 is fed from the sheet insertion port 7 to the sheet conveyance path 6.
Since the paper is manually fed by inserting the sheets, the sheets 2 stacked on the sheet placing plate 9 are stacked.
It is possible to manually feed the sheet 2 without removing the sheet, and since the manually fed sheet 2 can be inserted from the front of the printer 1, the sheet 2 can be easily fed manually. .

The present invention is not limited to the above embodiment, but can be variously modified as necessary.

[0064]

As described above, the paper feeding mechanism of the printer according to the first aspect of the present invention, according to the type of paper,
By moving the angle changing cam in the axial direction and selectively allowing the driven cam of the separating plate to follow the cams of each stage of the angle changing cam, the inclination angle of the separating plate can be changed automatically. Therefore, it is not necessary to manually switch the inclination angle of the separation plate according to the type of paper, and it is possible to reliably separate the paper according to the type of paper and properly feed only the uppermost paper.

Further, according to the second aspect of the present invention, the cam of each stage of the angle changing cam can be selected only by moving the paper guide, and the inclination angle of the separating plate can be easily switched. There is an effect such as being able to.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of a reference state showing an embodiment of a paper feeding mechanism of a printer according to the invention.

FIG. 2 is a partial plan view showing a case of feeding a cut sheet in the sheet feeding mechanism of the present invention.

FIG. 3 is a partial plan view showing a case of feeding postcard paper in the paper feeding mechanism of the present invention.

FIG. 4 is a vertical cross-sectional view showing a paper feeding state by a paper feeding roller when feeding a cut sheet in the paper feeding mechanism of the present invention.

FIG. 5 is a vertical cross-sectional view showing a separated state of a paper feed roller when a cut sheet of paper is fed in the paper feeding mechanism of the present invention.

FIG. 6 is a vertical cross-sectional view showing a paper feeding state by a paper feeding roller when feeding postcard paper in the paper feeding mechanism of the invention.

FIG. 7 is an enlarged view of a paper feed roller portion showing a reference state of the paper feeding mechanism of the present invention.

FIG. 8 is an enlarged view of a sheet feeding roller portion showing a state of feeding a cut sheet in the sheet feeding mechanism of the present invention.

FIG. 9 is an enlarged view of a paper feed roller portion showing a state of feeding postcard paper in the paper feeding mechanism of the present invention.

FIG. 10 is an enlarged view of a paper feed roller portion showing a separated state of the paper feed roller in the paper feeding mechanism of the present invention.

FIG. 11 is a vertical cross-sectional view showing a paper insertion state in a manual paper feeding operation of the paper feeding mechanism of the present invention.

FIG. 12 is a vertical cross-sectional view showing a rearward conveyance state of paper in a manual paper feeding operation of the paper feeding mechanism of the present invention.

FIG. 13 is a vertical cross-sectional view showing a front conveyance state of a sheet in a manual sheet feeding operation of the sheet feeding mechanism of the present invention.

FIG. 14 is a vertical cross-sectional view showing a recording state of paper in a manual paper feeding operation of the paper feeding mechanism of the present invention.

FIG. 15 is a vertical sectional view showing a conventional printer.

FIG. 16 is a vertical sectional view showing another conventional printer.

[Explanation of symbols]

1 printer 2 sheets 3 Printer frame 4 Platen 5 carriage 6 Paper transport path 7 Paper insertion slot 9 Paper loading plate 11 Paper guide 13 Cam receiving recess 14 Separation plate 16 Driven cam protrusion 18 Paper feed roller 19 Angle change cam 20 Large diameter part 21 Small diameter part 23 protruding cam 26 Paper feed roller 29 Conveyor roller 31 Paper switching plate 32, 33 Paper detection lever 34 Detection auxiliary lever 36 Ejection roller

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) B65H 1/24 B41J 13/00

Claims (2)

(57) [Claims] 1. A paper placing plate for stacking and storing a plurality of sheets of paper is provided at the rear of the printer, and the leading edge of the paper comes into contact with the paper placing plate to separate the sheets one by one. A separation plate for changing the inclination angle of the separation plate, and a paper feed roller that can contact the paper stored in the paper placement plate and feeds the paper one by one. In a paper feeding mechanism of a printer, an angle changing cam, in which a plurality of stages of cams having different diameters are formed on a peripheral surface of a drive shaft portion of the paper feeding roller, is rotated together with the paper feeding roller. The driven cam is mounted movably in the axial direction, the driven cam that follows the outer peripheral surface of the angle changing cam is integrally attached to the separating plate, and the angle changing cam is moved in the axial direction to move the driven cam to the angle changing cam. By selectively following the cams of each stage of the A paper feed mechanism for a printer, characterized in that the inclination angle of the is changed. 2. A sheet guide which is movable in the width direction of the sheet placing plate is arranged on the sheet placing plate, and the angle changing cam is moved in the axial direction by the movement of the sheet guide. 2. The paper feeding mechanism of the printer according to claim 1, wherein the driven cam selects a cam of each stage to follow.