JP2558723B2 - Recording device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording device for recording characters, images and the like on recording paper.

2. Description of the Related Art In a recording device such as a digital full-color copying machine or a device for making a color hard copy of a display screen such as a CRT, three colors of yellow, magenta and cyan, or four colors of ink with black added thereto are sequentially applied. Using a color ink sheet, for example, a pixel having a yellow component is formed on the recording paper with a yellow ink, and then a pixel having a magenta component is formed on the screen by using the magenta ink. A recording device that records a cyan image or a fourth color black to obtain a color image is widely used.

A conventional example of this type of recording apparatus will be described below with reference to FIG.

In the figure, reference numeral 1 is a thermal head, which is provided with a platen 2 via an ink sheet 5 and a recording paper 4 wound in a roll shape.
Being pressed against. In the vicinity of the platen 12, two capstan rollers 3a, 3b and pinch rollers 3c, 3d are arranged in pressure contact with each other. The ink sheet 5 is supplied from the supply reel 6 and wound on the take-up reel 7.

In the above-mentioned configuration, at the position (the position shown in FIG. 1) advanced by one screen from the position where the front end 4a of the recording paper 4 faces the platen and the thermal head, together with the ink sheet 5 (for example, yellow) of the first color, thermal Attached by the head and platen. Then, the capstan roller 3a is rotated in the direction of arrow A, and the ink on the ink sheet 5 is heated by the thermal head 1 which is heated according to the input recording signal while the recording paper is conveyed from the abdomen to the tip 4a. Is transferred onto a recording paper to obtain an image. Then, during the recording, even if the leading end 4a of the recording paper is separated from the capstan roller 3b, the recording paper can be continuously conveyed by the capstan roller 3a, so that the recording can be performed up to the end portion 4a of the recording paper 4. . When the recording of one screen sentence is completed in this way and the state shown in FIG. 9 is reached, the thermal head 1 is moved to the platen 12 by the head pressing mechanism (not shown).
The state shown in FIG. And
After that, the capstan rollers 3a and 3b are reversed in the arrow B direction opposite to the arrow A direction. Therefore, the recording paper 4 is conveyed in the direction opposite to the conveying direction at the time of recording, and when the recording start position for the first color reaches the heat generation position of the thermal head 1, that is, the printing position, the rotation of the capstan rollers 3a, 3b is stopped. The conveyance of the recording paper 4 is stopped. During this time, the ink sheet 5 is taken up by the take-up reel 7 and stands by in a state where the head of the second color (for example, magenta) is at the heat generation position of the thermal head 1. After this, the thermal head 1 is pressed again by the platen 12 to the state shown in FIG.
The recording of the second color is performed. In this way, the third color (for example, cyan) is sequentially recorded, and the fourth color (black) is recorded if necessary, and subtractive color mixture of yellow, magenta, and cyan and color hard copy of black are obtained.

Problems to be Solved by the Invention However, in the recording apparatus having the above-described configuration,
The conveyance of the recording paper is disturbed at the moment when the leading end portion 4a of the recording paper leaves the capstan roller 3b. But why,
The recording paper is conveyed by the rotation of the capstan roller 3a during recording, but the recording paper is the capstan roller.
Since the capstan roller 3b and the pinch roller 3d are also sandwiched between the capstan roller 3b and the pinch roller 3d, the load of the capstan roller 3b and the pinch roller 3d causes the recording paper to be pulled in the direction of the arrow X, while the recording paper 4 is capped. This is because the tensile force disappears when the stun roller 3b and the pinch roller 3d are released from the state of being held together. Therefore, the conveyance speed of the recording paper is slightly increased. This phenomenon causes a problem that the quality of the recorded image is deteriorated.

Means for Solving the Problems In the present invention, in order to solve the above-mentioned problems, the transport speed of the recording paper transport unit that transports the recording paper toward the recording position is made higher than the transport speed of the recording paper at the printing position.

Operation Due to the above-mentioned means, the recording sheet is slightly slackened between the platen and the recording sheet conveying section during recording, and the recording sheet conveying section does not exert a tensile force on the recording sheet.

Practical Example FIG. 1 is a schematic configuration diagram of a recording apparatus according to an embodiment of the present invention. Reference numeral 21 is a thermal head that has a plurality of heating elements arranged in a line and that generates heat in response to an input recording signal. Ink of three colors of yellow, magenta, and cyan is sequentially applied and wound in a roll shape. Ink sheet 31
(Hereinafter referred to as an ink sheet) and a platen whose outer periphery is covered with an elastic body via a recording paper 41 wound in a roll shape.
Pressed against 42. Further, the thermal head 21 is urged toward the platen 42 by a pressing element 23 and a head pressing spring 24 which are attached to a pressing release plate 22 above the thermal head 21. The pressure release plate 22 is rotatable about the head rotation shaft 20 and is separated from the thermal head 21 when rotated against the biasing force of the head pressing spring 24. A presser release arm 25 for separating the presser 23 from the thermal head 21 and a head release arm 26 for separating the thermal head 21 from the platen 42 are attached to the cam arm shaft 27, and are arranged at the bottom of the platen 42. Has been done. The head release cam 25 and the head release arm 26 are moved from the cam arm shaft 27 as a starting point by a head drive cam 28 in which a cam for moving the pusher release arm 26 is integrated.

The recording paper 41 is conveyed by a capstan roller 43 and a pinch roller 44. Since the conveyance of the recording paper 41 is governed by the metal capstan roller 43, it is effective in preventing color misregistration in the color printer. Reference numeral 45 is a second capstan roller, and 46 is a second pinch roller, which can be rotated forward and backward. Figure 2 shows the capstan roller
FIG. 4 is a diagram showing a recording paper transport system around 43, the platen 42, and the second capstan roller 45. In this figure, the power of the step motor 81 is transmitted to the intermediate timing pulley 82, and the intermediate timing pulley 82 and the capstan roller 82. Pulley 83 and le platen pulley 84 are timing belts
It is connected at 85.

The Capstan Coolie 83 is directly connected to the Capstan 43. The platen pulley 84 has a built-in shell roller type one-way clutch 86, which locks the limiter sleeve 87a when rotating in the direction of the arrow N to drive the limiter sleeve 87a in the N direction (see FIG. 1). . On the contrary, when the platen pulley 84 rotates in the direction of arrow M, the one-way clutch 86 becomes free and idles with respect to the limiter sleeve 87a. The limiter felt 87b attached on the limiter plate 87c is pressed against the limiter sleeve 87a by the limiter spring 87d. Limiter plate 87c
Is attached to the D-cut portion at the end of the axis 42a of the platen 42, so that when the limiter plate 87c rotates, the platen 42 also rotates at the same time. The number of teeth of the platen pulley 84 is set to be smaller than the number of teeth of the pulley of the capstan pulley 83, so that the platen pulley 84 always rotates faster than the capstan pulley 83. On the other hand, since the capstan roller 43 and the platen 42 have the same diameter, the one-way clutch 86 will always be in the idling state when the thermal head 21 is pressed to record the platen 42 itself. Does not occur. On the contrary, when the capstan roller 43 rotates in the direction of arrow J (see FIG. 1), the one-way clutch 86 always locks, so the platen 42
Generates a driving force in the direction of arrow N by the torque capacity of the torque limiter 87. To explain the operation repeatedly, the platen
42 receives power from the capstan roller 43 via the one-way clutch 86 and the torque limiter 87, and when the capstan roller 43 rotates in the direction of arrow I, the platen 42
Is configured so as not to generate power, and when the capstan roller 43 rotates in the direction of arrow J, the one-way clutch 86 locks and the platen 42 rotates in the N direction faster than the capstan roller 43. . The recording paper 41 is held between the capstan roller 43 and the platen 42 while the thermal head 21 is pressed against the platen 42.
When the capstan roller 43 is rotated in the direction of the arrow J while straddling the
Although it tries to rotate faster, the torque limiter 87 rotates at the same peripheral speed as the capstan roller 43, so that tension is stably applied to the recording paper 41. In FIG. 2, 72 and 73 are the platen 42 and the second, respectively.
The bearing of the capstan roller 45 of. 74 and 75 are timing pulleys having the same number of teeth mounted on the platen 42 and the second capstan roller 45, respectively, and the platen 42 and the second capstan roller 45 rotate in synchronization via the timing belt 71. The diameter of the second capstan roller 45 is slightly larger than the diameter of the platen 42. Therefore, the recording paper 41 during recording is slightly faster than the transport speed of the recording paper on the platen 42 than the capstan roller 45. Sent out. Therefore, the recording paper 41 is slightly slack between the second capstan roller 45 and the platen 42. A felt 74a is attached to the end surface of the timing pulley 74, and is pressed against the bearing 72 by the biasing force of a spring (wave washer in this case) 77. The peeling roller 74 provided between the platen 42 and the capstan roller 43 is an ink sheet 31 and a recording paper after recording.
41 is peeled off, and the sheet guide roller 48 provided between the platen 42 and the second capstan roller 45 is
Guide the ink sheet. The peeling roller 47 and the ink sheet guide roller 48 are attached to the thermal head 21 by the roller holder 49, and move up and down with respect to the platen 42 with the head rotating shaft 20 as a fulcrum together with the thermal head 21. The ink sheet 31 is supplied from the supply reel 32 and wound by the take-up reel 33. Third
(A), (b) is a schematic block diagram of the gear and pulley of an ink sheet conveyance part. In the figure, 51 is an ink sheet conveyance motor. 52 is a take-up pulley and 53 is a supply pulley. Both pulleys are timing belts.
The ink sheet conveyance motor 51 is rotated via 54. The take-up pulley 52 has this take-up pulley
A winding pinion gear 55 having a built-in one-way clutch that locks when 52 rotates in the direction of arrow E is coaxially attached. Further, a supply pinion gear 56 having a built-in one-way clutch that locks when the supply pulley 53 rotates in the direction of arrow G is coaxially attached to the supply pulley 53. Reference numeral 57 denotes a reel gear, which is attached to both the winding side and the supply side, and is rotated by the winding pinion gear 55 and the supply pinion gear 56, respectively. 3 (b) is a top view of FIG. 3 (a),
Torque plate 61 with felt 61a attached in this figure
Is pressed against the reel gear 57 by a torque generating spring 63 via a transmission plate 62. The transmission plate 62 is rotated by the frictional force between the reel gear 57 and the torque plate 61, and the leaf shaft 65 is rotated by the pin 64. A winding element 66 is attached to the tip of the reel shaft 65, and the supply element 32 and the winding reel 33 shown in FIG. 1 are rotated by the winding element 66.

 Next, the operation will be described.

FIG. 4 is an enlarged view of the recording portion of FIG. 1. In FIG. 4, the first color ink sheet 31 (eg, yellow) and the recording paper 41 are recorded between the thermal head 21 and the platen 42. When the capstan roller 43 is rotated in the direction of arrow I while being sandwiched by the pressure necessary for the platen 42, the platen 42 is rotated in the direction of arrow M by the frictional force with the recording paper 41. The ink on the ink sheet 31 is transferred by the thermal head 21 which is heated by the recording signal to the recording paper 41 which is being conveyed in this way, and the front end portion 41 from the middle part of the recording paper 41 is transferred.
The image is formed toward a. In this recording state, as described above, the capstan roller 45 and the platen 42 rotate in synchronization with each other and at the same angular velocity by the action of the timing pulleys 74 and 75, but the diameter of the capstan roller 45 is equal to that of the platen 42. Since the recording paper is formed slightly larger than the diameter, the recording paper delivered from the capstan roller 45 to the platen 42 side is slightly deflected between the platen 42 and recording is immediately performed. In this manner, the capstan roller 45 does not pull the recording paper 42 when the recording paper is bent. The transferred recording paper and ink sheet are separated from each other by a peeling roller 47. Then, during this recording, although not shown, the leading end 41a of the recording paper 41 is separated from the sandwiched portion by the capstan roller 45 and the pinch roller 46, and the recording paper 41 is released from the feeding operation by the pinch roller 45. There is. However, since the recording paper 41 is disengaged from the capstan roller 45 in a slightly bent state, there is no change in the feeding of the recording paper at the recording position during the disengagement, and a good recording operation is continued. .

In addition, the recording paper of the recorded part is configured to be conveyed from the platen to the distance roller at a conveyance speed that is substantially the same as the conveyance speed during recording, and the entire screen is peeled under the same peeling conditions and melted during recording. The cooling time of the transferred ink is constant throughout the screen, and a good image is obtained without deterioration in image quality due to the difference in cooling time.

The operation of the ink sheet 31 at this time will be described again with reference to FIG. 3. In FIG. 3, when the ink sheet transport motor 51 rotates in the direction of arrow C, the take-up pulley 52 moves in the direction of arrow E and the supply pulley 53. Rotate in the directions of arrows H, respectively. At this time, the take-up pinion gear 55 enters the locked state as described above and rotates together with the take-up pulley 52 to transmit the rotational force to the reel gear 57 on the take-up side, and the reel gear 57 on the take-up side rotates in the arrow K direction. On the other hand, the supply pinion gear 56 is in the free state as described above, and the rotational force is not transmitted to the reel gear 57. Therefore, the take-up reel 33 shown in FIG. 1 rotates in the direction of arrow K to take up the ink sheet 31. FIG. 5 is a diagram showing a state in which recording for one screen is completed. As shown in FIG. 5, the recording paper 41
When the tip portion 41a of the sheet passes over the peeling roller 47 and the peeling from the ink sheet is completed, as shown in FIG. 6, a pressing element is provided to prevent an excessive load from being applied to the ink sheet conveying motor and the recording sheet conveying motor. The release arm 25 pushes up the press release plate 22, the pusher 23 separates from the thermal head 21, and the load applied to the platen 42 is only the own weight of the thermal head 21 and its holding member. Hereinafter, this state will be referred to as a weak pressure state, and a state in which the thermal head 21 is in pressure contact with the platen 42 will be referred to as a strong pressure state. When this operation, that is, the pressing release operation of the thermal head is completed, the capstan 43 is rotated in the direction of arrow J, the platen 42 is rotated in the direction of arrow N, and the reverse feed capstan roller 45 is rotated in the direction of arrow P, and the recording paper 4 is conveyed in the conveying direction. Transport in the opposite direction. This reverse feeding state is as shown in FIG. The operation of the ink sheet 31 at this time will be described again with reference to FIG. 3. First, when the ink sheet transport motor 51 rotates in the direction of arrow D, the take-up pulley 52 moves in the direction of arrow F and the supply pulley 53 moves in the direction of arrow F. Each rotates in the G direction. At this time, the winding pinion gear 55 is in a free state, and no rotational force is transmitted to the reel gear 57 on the winding side. Also,
The supply pinion gear 56 is in the locked state, and the rotational force is transmitted to the reel gear 57 on the supply side, and the reel gear 57 on the supply side is indicated by the arrow L.
Rotate in the direction. Therefore, the supply reel 32 shown in FIG.
Rotates in the direction of arrow L, and the ink sheet 31 is conveyed in the direction opposite to the conveying direction at the time of recording. Therefore, this ink sheet serves as a guide for conveying the recording paper 41 in the opposite direction. It will be. Then, the recording paper 4 is guided along the ink sheet 31 to the upper part of the platen 42, and when it reaches the contact position between the thermal head 21 and the platen, that is, the recording position, it is sandwiched between the platen and the ink sheet 31 and the second position is reached.
Towards the capstan roller 45 of. When the recording paper 41 is conveyed to the second capstan roller 45, the thermal head 21 and the ink sheet 31 are separated from the platen 42 by the head releasing arm 26 as shown in FIG. The paper 41 is further conveyed to the first
When the recording start position of the color reaches the heat generation position of the thermal head, the rotation of the capstan roller 43 stops and the recording paper 41
Is stopped. When the recording paper 41 is conveyed in the direction opposite to the recording direction, the platen 42 is moved from the capstan roller 43 to the one-way clutch 86 and the torque limiter 87 as described above.
Since the recording paper 41 is directly connected to the recording medium 41, tension is stably applied between the platen 42 and the capstan roller 43, and the recording paper 41 can be conveyed without causing skew or slack. During this time, the ink sheet 31 operates in the same manner as during recording, and the second color of the thermal head 21 is applied to the take-up reel 33.
It is wound up and stopped until it reaches the heat generation position. After that, the thermal head 21 is pressed against the platen 42 again, and the fourth
In the state shown in the figure, the recording of the second color (for example, magenta) is performed. This series of operations is sequentially performed up to the third color (for example, cyan) to obtain a color image / character,
After that, the recording paper is cut into a predetermined length by a cutter 50 and discharged. Note that, in the present invention, the transport speed when the recording paper is transported from the platen to the peeling roller at the time of recording and the transport speed at the time of recording are approximately the same, but even if the transport speed is faster than the transport speed at the time of recording. Good color images, characters, etc. can be obtained, and the recording time can be shortened by increasing the transport speed when the recording paper is transported from the platen to the peeling roller.

 According to the present embodiment, the following effects can be obtained.

That is, the timing pulley 75 connected to the second capstan roller 45 and the timing pulley 74 connected to the platen 42 have the same number of teeth, and the diameter of the second capstan roller 45 is smaller than the diameter of the platen 42. By increasing the speed, the speed of the recording paper passing through the recording position during recording becomes lower than the speed of the recording paper sent from the second capstan roller 45 toward the platen,
For this reason, the recording paper 41 is slightly bent in the recording paper passage between the second capstan roller 45 and the platen 42.
The capstan roller 45 does not exert a tensile force on the recording paper 41. Therefore, at the time of recording, the recording paper may be stuck between the second capstan roller 45 and the second pinch roller 46. Therefore, the recording speed of the recording paper 41 is not affected at all, so that the recording apparatus of the present embodiment can obtain a good recording screen.

EFFECTS OF THE INVENTION As described above, according to the present invention, the transport speed of the recording paper transport unit that sends the recording paper toward the recording position is set to be higher than the transport speed of the recording paper at the printing position. The recording paper is slightly sagged between the recording paper and the recording paper, and the recording paper conveyance unit does not generate a tensile force with respect to the recording paper. Therefore, there is no fluctuation in the conveyance speed of the recording paper at the portion where the platen and the recording head face each other. The recording screen is not deteriorated and the value thereof is great.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a recording apparatus in one embodiment of the present invention, FIG. 2 is a configuration diagram of a recording paper conveying system of the recording apparatus in one embodiment of the present invention, and FIG. 3 is an embodiment of the present invention. FIG. 4 is a schematic configuration diagram of an ink sheet transporting portion of the recording apparatus in FIG. 4, FIG. 4 is a schematic configuration diagram showing a recording state of the recording apparatus in one embodiment of the present invention, and FIG. FIG. 6 is a schematic configuration diagram showing a peeled state, FIG. 6 is a schematic configuration diagram showing a first reverse feeding start state in which the thermal head pressure of the recording apparatus in one embodiment of the present invention is weak pressure, and FIG. FIG. 8 is a schematic configuration diagram showing a second reverse feeding state in which the thermal head and the ink sheet of the recording apparatus in one embodiment are separated from the platen, and FIGS. 8 to 10 are schematic diagrams showing the recording state in the conventional recording apparatus. It is a block diagram. 21 …… Thermal head 31 …… Ink sheet 41 …… Recording paper 42 …… Platen 43 …… Capstan roller 44 …… Pinch roller 45 …… Second capstan roller 46 …… Second pinch roller 47 …… Peeling roller

Claims (1)

(57) [Claims] 1. A recording head having a plurality of printing elements for selectively performing a printing operation according to an input recording signal, a platen sandwiching recording paper between the recording heads, and the recording head. And a first and a second recording paper conveying section disposed on both sides of the printing position in the recording paper conveying path including the printing position by the platen, and recording by the first recording paper conveying section. In a state where printing is performed by the thermal head while pulling the paper, the conveyance speed of the recording paper fed from the second recording paper conveyance unit is set to be higher than the speed of the recording paper passing through the recording position. Characteristic recording device.