JPH02265836A - Recorder device - Google Patents

Abstract

PURPOSE:To prevent deterioration of conveying accuracy, when a recording sheet escapes from the first conveying means, so as to improve the conveying accuracy by providing a press contact variable means for weakening press contact force of the sheet by the first conveying means before the rear end of the sheet to be conveyed escapes from the first conveying means. CONSTITUTION:The first conveying means 2 conveys a recording sheet 1 to a recording means 3 and the second conveying means 4. Before this sheet 1 in its rear end escapes from the first conveying means 2, sheets press contact force of the first conveying means 2 is weakened by a press contact variable means 5. Thus, deterioration of conveying accuracy is eliminated when the recording sheet 1 escapes from the first conveying means 2.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a recording device for recording input information such as a facsimile machine, a word processor, or an electronic typewriter. Use a recording device that can record without deterioration.

<Prior Art> Today, office automation equipment such as facsimile machines and word processors are widely used, and information processing is made faster and simpler. Various improvements have been made to these OA devices, one of which is improving the quality of recorded images.

In order to improve the image quality, it is necessary to improve the feeding accuracy of the recording sheet. Therefore, in the past, two or more pinch rollers were press-contacted on the circumference of one sheet conveyance roller to increase the conveyance force of the recording sheet, or as shown in FIG. 51a, and pinch rollers 50b and 51b that are in pressure contact with the pinch rollers 50b and 51b to rotate as a result of the recording head 52a and the platen 52b.
The recording means 52 is provided before and after the recording means 52 consisting of
The structure is such that the recording sheet 53 passing through is conveyed accurately.

<Problems to be Solved by the Invention> However, in the configuration shown in FIG. Since the pressing force between the two rollers changes rapidly depending on the thickness of the recording sheet 53, etc., sheet conveyance accuracy may sometimes deteriorate.

In particular, in the configuration shown in FIG. 6, while recording is being performed on the recording sheet 53, the recording sheet 53 is
The rear end escapes, but at this time both rollers 50a and 50b
A phenomenon occurs in which the recording sheet 53 pops out due to the pressing force. Since this pop-out phenomenon occurs during recording, a decrease in sheet feeding accuracy at this time greatly affects the decrease in image quality. This was more noticeable when a plurality of pinch rollers 50b were in pressure contact with the conveyance roller 50a.

The present invention solves the above-mentioned conventional problems, and its purpose is to provide a sheet conveying device that eliminates changes in sheet pressing force of a conveying means during recording and does not reduce sheet conveyance accuracy. It's about doing.

Means for Solving the Problem> A typical means according to the present invention for solving the above problem includes a recording means for recording an image on a recording sheet according to both signals, and a recording means for recording an image on a recording sheet in accordance with both signals. a first conveyance means disposed upstream in the sheet conveyance direction for conveying the recording sheet in pressure contact with the recording sheet;
The present invention is characterized in that it is provided with a second conveyance means disposed on the downstream side in the conveyance direction for conveying the recording sheet, and a pressure contact force variable means for changing the sheet pressure contact force of the first conveyance means.

Further, the pressure contact force variable means is configured to release the sheet pressure contact by the first transport means when the recording sheet is transported by the second transport means.

<Operation> In the above means, the recording sheet is conveyed by the first conveying means to the recording means and the second conveying means, and before the trailing edge of the sheet escapes from the first conveying means, the sheet of the first conveying means is conveyed. Weaken the pressure force. This eliminates a decrease in conveyance accuracy when the recording sheet escapes from the first conveyance means.

<Embodiment> Next, an embodiment in which the above means is applied to a serial type thermal transfer recording device will be described.

FIG. 1 is a perspective explanatory view of a thermal transfer recording apparatus according to a first embodiment.

First, to explain the general structure of this recording apparatus as a whole, a recording sheet 1 is conveyed to a recording means 3 by a first conveyance means 2 in which a conveyance roller 2a and a pinch roller 2b are in pressure contact with each other, and a recording sheet on which a predetermined recording is performed by the recording means 3. ] is configured to be discharged in the direction of arrow A in FIG. 1 by a second conveying means 4 in which a conveying roller 4a and a pinch roller 4b are pressed against each other in the same way as the first conveying means.

Further, the first conveyance means 2 is provided with a pressure contact force variable means 5 for releasing the pressure contact between the conveyance roller 2a and the pinch roller 2b, and when the recording sheet 1 is conveyed by the second conveyance means 4, the conveyance The roller 2a and the pinch roller 2b are configured to be separated from each other.

Next, the configuration of each part of the recording apparatus will be explained in detail.

(First Conveyance Means) First, as described above, the first conveyance means 2 is configured such that the pinch roller 2b is pressed against the conveyance roller 2a. The conveying roller 2a is fixed to a roller shaft 2ai which is rotatably mounted on both side plates 6, and one end of this roller shaft 2a+ is connected to a reduction gear train 2c, 20x+2c3.
It is connected to a transport motor (stepping motor) 7 via r and a motor gear 7a. Therefore, when the motor gear 7a rotates in the direction of arrow B in FIG.
The conveyance roller 2a is configured to be driven and rotated in the direction of arrow C to convey the recording sheet 1.

The pinch roller 2b is also fixed to a roller shaft 2b+, and both ends of the roller shaft 2b+ are connected to long holes formed in both side plates 6.
a, is attached so as to be movable up and down within the elongated hole 6a, and is pressed downward by a pressing means (not shown). Therefore, the pinch roller 2b is in pressure contact with the conveyance roller 2a, and when the conveyance roller 2a is rotated by the drive of the conveyance motor 7, the pinch roller 2b is configured to rotate as a result of this rotation. Further, when the roller shaft 2b moves upward along the elongated hole 6a, the pinch roller 2b is separated from the conveyance roller 2a.

(Recording Means) Next, the recording means 3 will be explained. This recording means 3 is arranged downstream of the first conveyance means 2 in the conveyance direction of the recording sheet 1.

Its structure is such that a carriage 3b into which an ink ribbon cassette 3a can be loaded is guided by a guide shaft 3c and can reciprocate in the direction of the arrow in FIG.

That is, a belt (not shown) is connected to the carriage 3b, and this belt is passed around a pulley, and a driving force is transmitted from the carriage motor 3d to the eight pulleys, and the carriage 3b is moved along the guide shaft 3c by the drive of the motor 3d. It is designed to travel back and forth along the

The ink ribbon cassette 3a loaded in the carriage 3b is an ink ribbon 3 coated with thermal transfer ink.
The ink ribbon 3a+ is wound around a supply core 3at and a take-up core 3a, and when the carriage 3b travels in the direction of the arrow in FIG. Tori core 3as
It is structured so that it can be played out.

Further, a recording head 3e is mounted on the carriage 3b. This recording head 3e is an arrangement of a plurality of heating elements that generate heat in response to both signals.
is configured such that it can be moved down in the direction of arrow E in FIG. 1 by a known means (not shown), and is configured to press the ink ribbon 3a against the recording sheet 1 when the head is moved down.

Further, a platen 3f is provided at a position facing the recording head 3e over the traveling range of the carriage 3b, and is configured to support the back surface of the recording sheet l which is in pressure contact with the ink ribbon 3a+ when the head is down.

Therefore, when the recording head 3e is made to generate heat in accordance with the image signal while the carriage 3b is traveling in the direction of the arrow, the ink on the ink ribbon 3a+ is transferred and recorded on the recording sheet 1.

(Second Conveyance Means) Next, the second conveyance means 4 is disposed downstream of the recording means 3 in the sheet conveyance direction, and similarly to the first conveyance means 2 described above, the conveyance roller 4a is pinched by a pressing means (not shown). The roller 4b is configured to press against the roller 4b. The conveyance roller 4a is fixed to a roller shaft 4a+ rotatably attached to both side plates 6, and one end of this roller shaft 4aI is connected to the conveyance roller 4a through a reduction gear train 4c+, 4cz, 4cs and a motor gear 7a. Connected to motor 7. Therefore, when the motor gear 7a rotates in the direction of arrow B in FIG. 1, the conveyance roller 4a rotates in the direction of arrow F, and the recording sheet 1 is conveyed.

Note that the rotational peripheral speed of the conveyance roller 4a is the same as that of the first conveyance means 2.
The reduction ratio is set to match the rotational peripheral speed of the conveyance roller 2a.

(Variable pressure contact means) Next, the variable pressure contact means 5 will be explained. As shown in FIGS. 2b+
is rotatably supported, and the lever 5a has a boss 5a.
1 is provided in a protruding manner and is fitted into a long hole (not shown) formed in the side plate 6 and elongated in the vertical direction.

Therefore, the lever 5a can be moved up and down along the elongated hole, and the pinch roller shaft 2b is configured to move up and down as the lever 5a moves.

Further, a gear 5b and a sun gear 5c are sequentially meshed with the rack portion 5 of the lever 5a, and a planetary gear 5d is meshed with the sun gear 5C. This planetary gear 5d is configured to be movable in the directions of arrows F and C in FIGS. 2(A) and 2(B) by a solenoid (not shown), and when the solenoid is turned on, the driving force transmission system of the first conveying means 2 When the reduction gear 2c is turned off, the reduction gear 2c is engaged with the reduction gear 2c.
It is configured to be separated from cz.

Therefore, as shown in FIG. 2(B), the planetary gear 5d
When the motor gear 7a rotates in the direction of arrow B while meshing with the reduction gear 2cs, the lever with rack 5a moves in the direction of the arrow (upward), the pinch roller 2b separates from the conveyance roller 2a, and conversely the motor When the gear 7a rotates in the opposite direction, the lever 5a moves downward and the pinch roller 2b comes into pressure contact with the conveying roller 2a. That is, the pressure contact force of the pinch roller 2b with respect to the conveyance roller 2a is configured to be variable.

Incidentally, as shown in FIG. 3, the separation amount of the pinch roller 2b is determined by the separation amount of the recording sheet 1 conveyed by the sheet detection sensor 8 disposed between the recording means 3 and the second conveyance means 4.
The configuration is such that the tip of the solenoid is detected, the number of pulses of the transport motor 7 is counted based on this, and the solenoid is controlled on and off based on the number of pulses.

(Control Means) Next, a control means for varying the pressing force of the pinch roller 2b of the first conveyance means 2 will be explained.

As shown in the block diagram of FIG. 4, this control means is, for example, a CPU 9a such as a microprocessor.

ROM 9b stores control programs and various data for the CPU 9a, and R is used as a work area for the CPU 9a and temporarily stores various data.
AM9c, lil Operation panel 1 for inputting recording density, etc. via an interface 10 to a control unit 9 equipped with a counter 9d for counting the number of rotational pulses of the feed motor 7, etc.
1. A motor driver 12 for driving each motor (carriage motor 3d, transport motor 7, etc.) and a head driver 1 for driving the recording head 3e.
3. A seat detection sensor 8 and a solenoid driver 15 for driving a solenoid 14 for moving the planetary gear 5d are connected.

The control unit 9 receives signals from an external device 16 that outputs image signals, an operation panel 11, and a sheet detection sensor 8,
It outputs signals to the motor driver 12, head driver 13, and solenoid driver 15 according to the program.

Here, the procedure for conveying the recording sheet 1 by the control means will be explained according to the flowchart shown in FIG. In addition, in FIG. 3, the distance from the nip portion of the first conveyance means 2 to the sheet detection sensor 8 is IIs, and the distance from the sheet detection sensor 8 to the nip portion of the second conveyance means 4 is Ilz.
It will be explained as follows. Also, the recording sheet 1 is conveyed by the recording means 3.
The paper is conveyed in synchronization with the recording operation by the printer.

First, in step S1, when recording starts, the transport motor 7 is driven to rotate forward (motor gear 7a rotates in the direction of arrow B in FIG. 1), and the recording sheet 1 is transported by the first transport means 2 in the direction of arrow A. do.

Next, in step S2, when the leading edge of the recording sheet 1 is detected by the sheet detection sensor 8 (sheet detection sensor ON), the process proceeds to step S3, where the conveyance motor 7
The recording sheet 1 is further conveyed a distance of 12 minutes by driving in normal rotation. As a result, the leading edge of the recording sheet 1 is transported by the transport roller 4a of the second transport means 4 to the nip portion of the pinch roller 4b.

Next, when the leading edge of the recording sheet 1 reaches the second conveyance means 4 as described above, the solenoid 14 is turned on in step S4, and the planetary gear 5d in FIG. 2 is engaged with the reduction gear 2c. Therefore, when the transport motor 7 continues to rotate forward in this state, the lever with rack 5a moves upward in FIG.
Along with this, the pinch roller 2b also moves upward.

Next, in steps S5 to S7, the number of rotation pulses of the transport motor 7 is counted, and the count number is a predetermined number M.
(The number of pulses necessary for the pinch roller 2b to completely separate from the conveyance port-ra 2a)
Turn off. As a result, the planetary gear 5d and the reduction gear 2
The meshing state with Cs is released, and the pinch roller 2b is kept separated from the conveyance roller 2a.

Next, in step S8, the conveyance motor 7 is further rotated in the forward direction to convey the recording sheet 1. At this time, since the conveying roller 2a and the pinch roller 2b of the first conveying means 2 are separated from each other as described above, the recording sheet 1 is transferred to the second conveying means 2.
transported only by Therefore, when the trailing edge of the recording sheet 1 passes through the first conveying means 2, the phenomenon of popping out unlike in the prior art does not occur.

Next, in step S9, when the sheet detection sensor 8 detects the trailing edge of the recording sheet 1 (sheet detection sensor 8 is OFF)
, proceed to step 310 and record sheet 1 by distance 12+α
(α is the distance by which the rear end of the recording sheet l completely escapes the nip portion of the second conveying means 4). As a result, the rear end of the recording sheet 1 is separated from the second conveying means 4, and thereafter is ejected by a known ejecting means.

In addition, detection of the conveyance amount of recording sheet 1 (distance! or!,
÷α, etc.) is performed by detecting the number of pulses of the transport motor 7.

Next, in step 311, the solenoid 14 is turned on again to engage the planetary gear 5d with the reduction gear 2Cs, and in step 312, the transport motor 7 is driven in reverse (the motor gear 7a is rotated in the opposite direction to arrow B in FIG. 2), thereby moving the ranked lever 5a downward in FIG.

Then, in steps S13 to S15, the solenoid 14 is turned off when the number of pulses exceeds M.

As a result, the pinch roller 2b comes into pressure contact with the conveyance roller 2a again, returning to the initial state.

When a plurality of recording sheets 1 are continuously transported and recorded using an automatic paper feeder or the like, the above-mentioned transport procedure is repeated.

By conveying the recording sheet 1 as described above, 1.
This prevents the sheet from flying out due to the first conveyance means 2, and improves conveyance accuracy.

In the above-described embodiments, a Sorial type thermal transfer recording system was used as the recording means, but the present invention need not be limited to this, and can also be applied to, for example, a thermal recording system that does not use an ink ribbon. Furthermore, instead of the serial type, a so-called line type recording method in which the recording head is stationary may be adopted.

Furthermore, although this embodiment uses a so-called thermal head as the recording head, it is also possible to use a recording method using infrared rays, laser beams, etc.
Furthermore, instead of the thermal recording method, an impact type recording method such as a wire tod may be used.

Further, in the above-described embodiment, a configuration in which a pinch roller is pressed against a conveyance roller as a sheet conveyance means was illustrated, but the present invention does not need to be limited to a roller-shaped sheet conveyance member, and a rotating belt may be used instead of a conveyance roller. Alternatively, a member such as a plate may be used in place of the pinch roller, and the sheet may be conveyed by pressing the two together.

<Effects of the Invention> As described above, in the present invention, the first conveying means and the second conveying means are arranged before and after the recording means, and the first conveying means is arranged before the rear end of the sheet being conveyed escapes from the first conveying means. Since the sheet pressing force of the means is weakened, it is possible to prevent a decrease in conveyance accuracy when the recording sheet escapes from the first conveyance means, and it is possible to improve conveyance accuracy and record a clear image.

[Brief explanation of drawings]

FIG. 1 is a perspective explanatory view of a recording apparatus according to an embodiment of the present invention, FIGS. Figure 3 is No.-
FIG. 4 is a block diagram of the control means, FIG. 5 is a flowchart showing the sheet conveyance procedure, and FIG. 6 is an explanatory diagram of the prior art. . (2) is a recording sheet, 2 is a first conveyance means, 2a is a conveyance roller, 2a+ is a roller shaft, 2b is a pinch roller, 2b is a roller shaft, 2cI to 2c are gears, 3 is a recording means, 3a is an ink ribbon cassette, 3a+ is ink ribbon, 3az
is a supply core, 3as is a take-up core, 3b is a carriage, 3
c is a guide shaft, 3d is a carriage motor, 3e is a recording head, 3f is a platen, 4 is a second conveyance means, 4a is a conveyance roller, 4a+ is a roller shaft, 4b is a pinch roller, 4
c+~4cs are gears, 5 is a variable pressure contact means, 5a is a lever with a rank, 5al is a boss, 5a is a rack part, 5b is a gear, 5C is a sun gear, 5d is a planetary gear, 6 is a side plate, 7
is a transport motor, 7a is a motor gear, 8 is a sheet detection sensor, 9 is a control unit, 9a is a CPU, 9b is a ROM,
9c is a RAM, 9d is a counter, 10 is an interface, 11 is an operation panel, 12 is a motor driver, 1
3 is a head driver, 14 is a solenoid, 15 is a solenoid driver, and 16 is an external device.

Claims (3)

[Claims] (1) a recording means for recording an image on a recording sheet according to an image signal; and a first conveyor disposed on the upstream side of the recording sheet in the recording sheet conveying direction than the recording means, for conveying the recording sheet while being pressed against it. means, a second conveyance means disposed downstream of the recording means in the recording sheet conveyance direction and for conveying the recording sheet, and a pressing force variable means for changing the sheet pressing force of the first conveyance means. A recording device having: (2) The recording apparatus according to claim 1, wherein the pressure contact force variable means is configured to release the sheet pressure contact by the first transport means when the recording sheet is transported by the second transport means. (3) The recording apparatus according to claim (1), wherein the first conveyance means includes a conveyance member and a pinch member pressed against the conveyance member, and the pinch member is configured to be able to be separated from the conveyance member.