JP3012073B2 - Recording device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording apparatus such as an ink jet printer, and more particularly to a sheet conveying mechanism of the recording apparatus.

[0002]

2. Description of the Related Art An example of a conventional recording apparatus of this type is shown in FIG. In the figure, a conveying roller pair 101 is provided on the upstream side of the platen 103, and a conveying roller pair 10 is provided on the downstream side.
2 are provided, and the sheet material P is indicated by an arrow 105.
It is transported in the direction. On the sheet material P being conveyed, a predetermined image is printed and recorded by a serial scan of a recording unit (not shown) disposed above the platen 103.

As means for detecting the rear end of the sheet material P, a detection end 107a of a paper detection sensor arm 107 is provided near the conveyance roller pair 101, in this example, on the axis of the conveyance roller pair.
The sensor arm 107 pivotally supported by the support shaft 106 is urged clockwise by a tension spring 109. When the trailing end of the sheet material P has exited the conveying roller pair 101, the sensor arm 107
7B, the trailing end of the sheet material P is detected.

According to this, since the presence or absence of the sheet material P in the nip portion of the conveying roller pair 101 can be detected, it is effective when the operation of the apparatus is started by the operation of the sensor arm 107. For example, when used as a manual feed start signal, when the sensor arm 107 is activated by the leading edge of the paper, the leading edge of the paper reaches the nip at the same time.
Paper can be transported smoothly.

[0005]

However, in the above-mentioned conventional example, there is a disadvantage that when the paper edge is to be detected, accurate detection is not possible due to the influence of the curl state of the sheet material P.

That is, when a sheet material P whose paper edge is curled upward passes through a sheet material P having no habit as shown in FIG. 7A, a normal state as shown in FIG. The paper detection sensor arm 107 rises faster than the sheet material P, and conversely, the return of the paper detection sensor arm 107 is slower for paper curled downward. At this time, in an apparatus in which the trailing edge of the sheet is detected and a predetermined trailing margin is provided, the conveyance amount of the sheet material P varies, and the margin becomes large. In the case of a remarkable situation, the margin of the sheet material P is lost and the printing is performed on the platen 103, and a problem occurs in that the back stain is generated in the next printing.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a recording apparatus in which a sheet material is pressed against a platen to reliably detect an edge of the sheet material and to suppress variations in margins.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and is directed to a recording apparatus in which a pair of conveying rollers is disposed upstream of a platen and a pair of discharge rollers are disposed downstream of a platen. During automatic paper feed, the paper discharge rollers rotate forward to discharge the sheet material, while during manual paper feed, the paper discharge rollers rotate reversely to take in the sheet material, and then rotate the paper discharge roller forward. A sheet detecting means provided in the vicinity of the paper discharge roller, and a sheet of paper which can be brought into contact with and separated from the platen and is taken into the apparatus by the reverse rotation of the transport roller. And a sheet pressing member for pressing a sheet material against the platen before the paper detecting means detects that the end comes out of the paper discharge roller pair.

[0009] Further, there is provided recording means for recording an image by serially scanning the sheet material on the platen, and the sheet material pressing member is brought into contact with or separated from the sheet material by moving the recording means. It is characterized by the following.

[0010] Further, the recording apparatus performs a state change including formation of bubbles in a liquid by using thermal energy to form droplets to perform recording on a sheet material.

Further, the paper detecting means has a swingable sensor arm and a sensor operated by the operation of the sensor arm.

[0012]

According to the above construction, a sheet material to be recorded is conveyed on the platen by a pair of conveying rollers arranged on the upstream side of the platen and a pair of discharge rollers arranged on the downstream side of the platen. Before the sheet detecting means detects that the sheet end of the sheet material comes out of the sheet discharge roller pair, a sheet pressing member capable of coming in contact with and separating from the sheet material presses the sheet material against the platen.

[0013] This makes it possible to suppress the variation in the detection position due to the curl state of the sheet material, to suppress the variation in the paper edge detection timing due to the curl of the sheet material, to stabilize the amount of print margin, Problems such as printing on the platen due to a shift in detection timing can also be prevented.

[0014]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view of a recording apparatus according to one embodiment of the present invention, and FIG. 2 is a vertical sectional side view.

A cassette 3 is disposed below the apparatus main body 2 of the recording apparatus 1. The uppermost one of the sheets P stacked in the cassette 3 is separated, fed, and fed to an upper guide. A pickup roller 5 for feeding out between the lower guide 6 and the lower guide 7 is provided. Pickup roller 5 is 1
When it rotates, it stops in the state shown in the figure and loses the conveying force. Before that, the leading end of the sheet material P is sandwiched between the upper conveying roller 9 and the lower conveying roller 10. 10 transported.

The upper conveying roller 9 is pressurized by a spring 13 via a pressing plate 12 having a shaft 11 as a fulcrum, and is driven to rotate following the rotation of the lower conveying roller 10. When it is determined that the sheet material P has been sent by the sensor 22 and the sensor arm 20 urged by the spring 21, the lower conveying roller 10 starts rotating and sends the sheet material P by pulse feeding.

On the downstream side of the platen 15, the upper discharge roller 1
6 and a lower discharge roller 17 are provided.
5 to hold the sheet material P sent thereon. The upper discharge roller 16 is connected to the spring 2 via a pressure plate 25 having a shaft 23 as a fulcrum.
6 and is driven to rotate in accordance with the rotation of the lower discharge roller 17. Further, since the peripheral speed of the discharge lower roller 17 is set to be several percent higher than the peripheral speed of the transport lower roller 10, the sheet material P on the platen 15 is always given an appropriate tension. It has become irresistible.

Above the platen 15, there is provided a carriage 29 movable along a rail 27 provided in a direction intersecting the direction of transport of the sheet material P, and a head 30 as a recording means is mounted on the carriage 29. It is installed. Further, a gear 35 is rotatably provided coaxially with the upper discharge roller 16, and a paper pressing plate 31 that is in contact with the upper surface of the platen 15 is fixed to the gear 35.

A gear lever 36 rotatably provided meshes with the gear 35. A return spring 36 and a solenoid 40 are attached to the gear lever 36 from opposite sides. When the power is not supplied to the solenoid 40, the return spring 36 causes the paper pressing plate 31 to stand by at a position separated from the platen 15 (FIG. 1). When the power is supplied to the solenoid 40, the gear lever 36 rotates to rotate the gear 35, and the paper pressing plate 31 can be pressed against the platen 15.

Next, the operation of the paper holding plate 31 which is a main part of the present invention will be described.

In this apparatus, when performing manual sheet feeding,
When a button (not shown) is pressed, the manual feed tray 43 is lifted up from the tray 41 as shown in FIG. Here, when the sheet material P0 is inserted from the direction of the arrow along the manual feed tray 43, the sensor arm 20 is pushed down at the moment when the leading end of the sheet material P0 enters the nip portion of the pair of paper discharge rollers 16, 17, and the sensor 22 The reverse rotation of the discharge roller pairs 16 and 17 is started by the signal.

By the reverse rotation of the discharge roller pairs 16 and 17,
After the sheet material P0 is drawn into the apparatus by a predetermined amount, the paper holding plate 31 is rotated by the solenoid 40 from the position indicated by the two-dot chain line to the position indicated by the solid line, and while pressing the sheet material P0, the sheet discharge roller pair 16, The reversal of 17 is continued. When the trailing edge of the paper comes out of the nip between the pair of paper discharge rollers 16 and 17, the sensor arm 20 returns to the original position by the force of the spring 21, and the sensor 22 detects this and drives at a predetermined timing. To stop. Here, the carriage 29 scans and prints the first line by the head 30, and thereafter, the transport roller pairs 9, 10 and the discharge roller pairs 16, 17 sequentially perform printing while performing forward step feed. Go.

At this time, the margin at the trailing edge of the paper (the leading edge in printing) changes depending on the detection accuracy of the sensor 22, but in the present embodiment, as shown in FIG. When exiting the nips 16 and 17, the paper holding plate 31
Is holding the sheet material P0 near the nip,
It is possible to stably detect the trailing edge of the paper without being affected by curl or the like. Accordingly, the variation in blank space can be suppressed, and the detection timing can be prevented from being largely shifted to print on the platen 15. <Second Embodiment> Figs. 5 and 6 show a second embodiment of the present invention.
Since only the configuration of the paper presser plate 32 is different from that of the above-described embodiment, the details thereof will be described.

A shaft 16a is provided coaxially with the upper discharge roller 16, and a paper pressing plate 32 is rotatably supported on the shaft 16a. Further, the torsion coil spring 46 is attached to constantly urge the paper holding plate 32, and the stopper portion 32a
Is held where it hits the shaft 23.

On the other hand, the carriage 29 is provided with a roller 47 as means for riding on the upper surface of the paper presser plate 32 and pressing the paper presser plate 32 against the platen 15 when the sheet material P moves on the platen 15. The paper holding plate 32 is rotated by the movement of the carriage 29.

As shown in FIG. 3, in the manual feed mode, when the tip of the sheet material P0 pushes the sensor arm 20, the pair of paper discharge rollers 16 and 17 starts to reverse, and the sheet material P0 is drawn into the apparatus by a predetermined amount. 5, the carriage 29 in FIG. 5 is moved to press the end of the paper pressing plate 32 onto the platen 15 via the roller 47, and the reverse rotation of the paper discharge roller pair 16, 17 continues in this state. Is done.
When the sheet material P0 comes out of the nip of the pair of paper discharge rollers 16, 17 as shown in FIG. 6, the sheet pressing plate 32 presses the sheet material P0 near the nip portion, so that the sheet material P0 curls. Even if there is, the rear end of the sheet material P0 can be detected stably. Further, according to this embodiment, the solenoid 40 and the like are not required as compared with the above-described embodiment, which is advantageous in terms of cost and space.

It should be noted that the paper holding plates 31, 32 of the above-described embodiment are used.
Has a function for stabilizing the detection of the paper edge by the sensor arm 20. The paper holding plate described in Japanese Patent Application No. 2-223268 of the present applicant has a Maintaining distance It is also possible to have a function that also has the function of preventing paper floating at the leading edge printing.

[0029]

As described above, the sheet detection means and the sheet material pressing member which can be brought into and out of contact with the platen are arranged near the pair of conveying rollers so that the sheet material is detected by the sheet detection means. In addition, since the sheet material pressing member presses the sheet material against the platen, it is possible to suppress the variation in the timing of detecting the paper edge due to the curl of the sheet material. As a result, the print margin amount is stabilized, and problems such as printing on the platen due to a shift in detection timing can be prevented.

[Brief description of the drawings]

FIG. 1 is a perspective view of a main part of a recording apparatus according to an embodiment of the present invention.

FIG. 2 is a longitudinal side view showing the entire recording apparatus.

FIG. 3 is a longitudinal side view of the recording apparatus showing a manual insertion state.

FIG. 4 is an operation diagram when the paper edge comes out of the nip.

FIG. 5 is a perspective view of a recording apparatus according to a second embodiment of the present invention.

FIG. 6 is an operation view showing a state in which the paper edge comes out of the nip.

FIG. 7A is a longitudinal sectional side view showing a main part of a conventional recording apparatus, and FIG.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 recording device 2 device main body 9 transport upper roller 10 transport lower roller 15 platen 16 paper discharge upper roller 17 paper discharge lower roller 29 carriage 30 head 31, 32 paper presser plate 20 sensor arm 22 sensor

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁷ identification code FI B65H 5/36 B65H 7/02 7/02 B41J 3/04 101Z (58) Investigated field (Int.Cl. ⁷ , DB name) B41J 11/00-13/32 B41J 2 / 01,29 / 48 B65H 5 / 36,7 / 02

Claims (4)

(57) [Claims] 1. A recording apparatus in which a pair of conveying rollers is disposed upstream of a platen and a pair of discharge rollers is disposed downstream of a platen. In automatic paper feeding, the discharge rollers rotate forward to discharge a sheet material. On the other hand, in the manual feed mode, the paper discharge roller rotates in reverse to take in the sheet material into the apparatus, and then the paper discharge roller is rotated forward, wherein the paper provided near the paper discharge roller is provided. Detecting means, which can be brought into contact with and separated from the platen, and before the paper detecting means detects that the paper end of the sheet material taken into the apparatus by the reverse rotation of the transport roller exits from the paper discharge roller pair. And a sheet pressing member for pressing a sheet material against the platen. 2. A recording device for recording an image by serially scanning a sheet material on the platen, and moving the recording device to move the sheet material pressing member toward and away from the sheet material. 2. The recording apparatus according to claim 1, wherein: 3. The recording apparatus according to claim 1, wherein the recording apparatus uses thermal energy to cause a state change including formation of bubbles in the liquid to form droplets, thereby performing recording on the sheet material.
The recording device according to any one of the preceding claims. 4. The recording apparatus according to claim 1, wherein said paper detecting means includes a swingable sensor arm and a sensor operated by the operation of said sensor arm.