JPH045063A - Sheet conveyance device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention provides a sheet conveying device that can reliably operate a member for preventing a sheet from floating up on a conveying rotor, and a recording device using the sheet conveying device. Regarding.

<Prior art> Today, various recording devices for recording input information have been developed, but these use a sheet conveying device to convey recording sorting,
Predetermined recording is performed on this sheet by a recording means.

In the sheet conveyance structure described above, a pinch roller is pressed against the platen roller, and the sorted material is conveyed by the cooperative action of both rollers. At this time, in order to prevent the sheet from floating up from the platen roller, the sheet is held by the pressure roller. Generally, it is pressed against a platen roller.

The pressing roller is configured to be able to separate from the platen roller when the sheet is sent so that the leading edge of the sheet does not get caught on the pressing roller and jam. As a drive configuration for bringing the pressure roller into contact with and away from the platen roller, for example, as shown in FIG. 8, a worm gear 51 is attached to a motor shaft 50, a transmission gear 52 is meshed with this worm gear 51, and Transmission gear 52
By rotating the link member 53 in one direction and swinging the link member 53, the pressing roller is swinged.

In the above configuration, in order to stop the rotation of the transmission gear 52 when the pressure roller is in contact with the platen roller or when the pressure roller is separated from the platen roller, a cam 54 is attached to the transmission gear 52, and the initial position of the cam 54 is set by a microswitch 55. Detected with
The rotation amount of the transmission gear 52 is controlled based on the initial position to detect the swinging position of the pressing roller. During one rotation of the transmission gear 52, the pressure roller performs a partial operation of contact with the platen roller, separation from the platen roller, and contact with the platen roller, so that the leading edge of the sheet passes through the pressure roller position at the time of separation. .

<Problems to be Solved by the Invention> However, the above configuration not only requires parts such as the cam 54 and the microsinch 55, but also requires accurate control of the motor that drives the transmission gear 52. The contact and separation control of the rollers may vary, and jams may occur when the sheet is centered. That is, when the platen roller rotates and the sheet passes through the pressure roller position, the pressure roller remains in contact with the platen roller, or when the pressure roller that has once separated comes into contact with the platen roller again. The sheet passes through the pressure roller position, resulting in a jam.

An object of the present invention is to solve the above-mentioned conventional problems, and to make it possible to accurately bring into contact with and separate from the conveying rotary body a pressing member for preventing the sheet from lifting from the conveying rotary body that applies conveying force to the sheet. It is an object of the present invention to provide a sheet conveying device and a recording device using the sheet conveying device.

<Means for Solving the Problems> A typical means according to the present invention for solving the above-mentioned problems includes: a conveying rotary body for driving and rotating to apply a conveying force to a sheet; a pressing member for pressing the pressing member, a separating means that swings to separate the pressing member from the conveying rotating body, a driving means for transmitting driving force to a driving gear, and a tooth portion that meshes with the driving gear. a transmission gear configured as a partially toothed gear for transmitting rocking force to the separation means; and urging means for urging an end of a tooth portion of the transmission gear to the drive gear. It is characterized in that the sheet conveyance device is configured by providing the following.

Further, the present invention is characterized in that a recording apparatus is configured that performs recording by conveying a sheet using the sheet conveying device having the above configuration.

<Operation> In the above means, when the drive means is rotated in one direction, the transmission gear is rotated in one direction, and the transmission gear, which is a partially toothed gear, does not rotate any more after being rotated by a predetermined amount. Further, when the driving means is rotated in the other direction, the transmission gear is rotated in the other direction, and in this case as well, the transmission gear stops rotating after a predetermined amount of rotation.

Therefore, depending on the direction of rotation of the driving means, the pressing member is reliably brought into contact with and separated from the conveying rotary body.

<Embodiment> Next, an embodiment of the present invention in which the above means is applied to an electronic typewriter will be described.

FIG. 1 is a schematic cross-sectional view of the sheet conveying device;
The figure is an explanatory diagram of the configuration of a recording apparatus using the sheet conveying device of this embodiment, and FIG. 3 is a perspective explanatory diagram of the entire configuration of an electronic typewriter using this.

(Overall explanation) First, to explain the overall structure of the electronic typewriter, as shown in Fig. 3, when recording information is input by operating the keyboard K, the information is displayed on the display D, and after inputting the information, the recording start key is pressed. When operated, the sorting and conveying means A is driven to center the recording sheet 1, and the recording device B is driven to record input information on the recording sheet 1.

As shown in FIGS. 1 and 2, the sheet a conveying means A includes a conveyance motor 4 consisting of a stepping motor connected to a platen roller 2 serving as a conveyance rotating body via a gear train 3. The configuration is such that rotational force is applied to the platen roller 2 by driving, and conveying force is applied to the recording sheet 1.

Further, the recording sheet 1 is attached so as to be pressed by a sheet pressing member 5 so as not to be lifted off the surface of the platen roller 2, and this sheet pressing member 5 is attached to the contact/separation means 6.
It is configured so that it can come into contact with and separate from the platen roller 2.

Further, as shown in FIG. 2, the recording device B is configured such that a recording means 7 is driven on the recording sheet 1 conveyed by the sheet conveying device A to perform print recording line by line in the width direction of the sheet. .

Next, the configuration of each part will be specifically explained.

(Conveying Rotating Body) The conveying rotating body applies a conveying force to the recording sheet 1, and in this embodiment, it is composed of a platen roller 2 that also serves as a platen that supports the back surface of the recording sheet during recording. The platen roller 2 has a platen shaft 2a supported by bearings 2b of left and right frames 8a and 8b, and a platen gear 9 serving as a rotary gear and a manual knob 12 are attached to one end of the shaft 2a.

A pinch roller 10 is attached to the platen roller 2 so as to be in pressure contact with the platen roller 2 so as to rotate as a result of the rotation of the platen roller 2, and a paper pan 11 is attached along the circumferential surface of the roller 2.

Therefore, when the platen roller 2 is driven to rotate, the recording sort 1 is given a conveying force by the cooperative action of the roller 2 and the pinch roller 10, is guided by the paper pan 11, and is moved along the circumferential surface of the platen roller 2. It is configured to be transported in a U-turn.

(Gear train) The gear train 3 is for transmitting the rotational force of the transport motor 4 to the platen 2, and in this embodiment, as shown in FIGS. The small gear 3a1 of the idler gear 3a meshes with the large gear 3at of the idler gear 3a, and the motor gear 3b meshes with the large gear 3at of the idler gear 3a.
This motor gear 3b is attached to the motor shaft of the transport motor 4.

Regarding the attachment of the gears 3a and 3b, the idler gear 3a is rotatably attached to the bracket 3C, and the transport motor 3b is integrally formed with the flange 3d. The upper portions of the bracket 3C and the flange 3d are provided with elastic members 3e+ and 3, respectively, as will be described later.
It is rotatably attached to the frame 8a via stepped screws 3r, 3fz.

Further, as shown in FIG. 1, at the bottom of the bracket 3C are holding parts 8a, 8, which are formed by bending and raising a part of the frame 8a.
8r restricts the movement of the bracket 3C in the thrust direction.

Note that 8a is an escape hole for the motor shaft when the flange 3d rotates.

Further, as shown in FIG. 1, a hook screw 3g is attached to the lower part of the flange 3d, and a hook portion Ba formed by bending the hook screw 3g and the frame 8a.
A tension spring 3h is attached between z. This spring 3h causes the flange 3d to move as shown by the arrow a in FIG.
As a result, the motor gear 3b and idler gear 3a are urged against the platen gear 9, so that each gear meshes reliably. The tension spring 3h is set to have a tension that does not cause tooth skipping in the gear train.

Further, as shown in FIG. 1, the rotation center 9a of the platen gear 9, the rotation center 3a3 of the idler gear 3a, and the rotation center 3b of the motor gear 3b are arranged so as to be located on a substantially straight line. Thereby, the rotational force from the conveyance motor 4 is efficiently transmitted to the platen roller 2.

Here, the attachment of the bracket 3C and the flange 3d using the stepped screws 3f+ and 3fz will be explained based on the structure. For example, in the bracket 3C, as shown in FIG. 4(a), the threaded portion 3f3 of the stepped screw 3fI is screwed onto the frame 8a via the O-ring 3eI, which is an elastic member, so as to sandwich the bracket 3C, and the bracket 3c is attached to the shaft portion 3f.
, is rotatably attached to. At this time, the dimensions of the shaft portion 3f are rough, and a gap α is created.
Ring 3e+ is attached.

The O-ring 3e is slightly thicker than the gap α, and is configured to be elastically deformed when the screw 3f is tightened. Therefore, the bracket 3C is rotatable relative to the frame 8a, and the gap α
is absorbed by the O-ring 3e+ to prevent rattling in the thrust direction.

The same applies to the flange 3d, and as shown in FIG. 4(b), the threaded portion 3ts of the stepped screw 3f2 is screwed onto the flange 3d via an O-ring 3ez, which is an elastic member, so as to sandwich the frame 8a. A flange 3d is rotatably attached to the frame 8a. As a result, the motor gear 3b is mounted so as not to wobble in the thrust direction.

As mentioned above, even if the stepped screws 3r, 3fz have rough dimensions, it is possible to eliminate backlash in the thrust direction of the idler gear 3a and motor gear 3b, which facilitates parts management and reduces manufacturing costs. This is something that can be lowered.

(Sheet Pressing Member and Separation Means) The sheet pressing member 5 is used to prevent the recording sheet 1 from being lifted off the platen roller 2, and in this embodiment, the pressing roller 5b, which is divided into a roller shaft 5a, is rotated freely. The pressure roller 5b is configured so as to be in pressure contact with the surface of the platen roller 2.

As shown in FIGS. 1 and 2, the pressing configuration of the roller 5b is such that both ends of the roller shaft 5a are connected to a pair of left and right rotating arms 5C.
+, supported at one end of 5C2, this arm 5C, 5cz
The frames 8a and 8 are rotatable about the shaft 5d, respectively.
attached to b.

A torsion coil spring 5e is attached between the frame 8a and the arm 5c1, and a torsion coil spring 5e is attached between the frame 8b and the arm 5c1.
A tension spring 5f is attached between C2.

The arms 5c, 5 are biased by the springs 5e, 5f.
cz is urged in the direction of the arrow in FIG.
is in pressure contact with the platen roller 2.

The pressing roller 5b is configured to be able to come into contact with and separate from the platen roller 2 by a contact/separation means 6. This is to prevent the leading end of the recording sheet 1 from getting caught on the pressing roller 5b and jamming when setting the recording sheet 1.
This is to separate the platen roller 2 from the platen roller 2.

As shown in FIG.
A link member 6a is pivotally attached to the lower end of one arm 5c of the arms 5c2 by a flanged pin 6b.
A long hole 6a is bored in the other end of the a, and a flanged pin 6d is provided in the long hole 6a to protrude from the side surface of the transmission gear 6c.
are connected in a slidable and non-removable manner.

The flanged bottle 6d is attached at a position offset from the center of rotation of the transmission gear 6c, and when the pressing roller 5b is in pressure contact with the platen roller 2 as shown in FIG. Although it is not in contact with the end of the elongated hole 6a, when the transmission gear 6C rotates in the direction of arrow C from this state, the link member 6a is pulled in the direction of arrow d, and the am 5c+ rotates as shown in FIG. The pressure roller 5'b is configured to be separated from the platen roller 2.

Here, to explain the driving force transmission configuration for operating the separation means 6, the transmission gear 6C is configured as a toothless gear in which teeth 6c+ are formed only in a part of the periphery. A worm gear 6e serving as a gear is meshed with the worm gear 6e, and the worm gear 6e is attached to a motor shaft of a DC motor 6f. Therefore, when the DC motor 6f rotates forward and backward, the transmission gear 6C rotates, and the arms 5c+ and 5Cz swing.

Also, the side protrusion 6C2 and the flange 8 of the transmission gear 6C
A tension spring 6g is attached between the bending portion Baa of a and the bent portion Baa. This spring 6g biases the toothed end portions 6cx, 6cm of the toothed portion 6c of the transmission gear 6c so that they come into contact with the worm gear 6e.

To explain this in detail using FIGS. 6(a) to 6(C), when the pressure roller 5b is in pressure contact with the platen roller 2, the worm gear 6e is moved as shown in FIG. 1(a).
The tooth end portion 6c3 of the transmission gear 6c is in contact with the transmission gear 6c. At this time, the transmission gear 6c is urged to rotate in the direction of arrow e by the tension spring 6g, and as a result, the toothed end portions 6 (, 1) are urged to be pressed against the worm gear 6e.

When the DC motor 6f is driven, for example, in the forward direction from the state shown in FIG. 6(a), the transmission gear 6c rotates in the direction of arrow e as the worm gear 6e rotates, as shown in FIG. 6(b). When the DC motor 6f rotates for a certain period of time, the 6th
[As shown in ff1(C), the other tooth end 6c4 of the transmission gear 6C comes off from the gear part of the worm gear 6e, and the transmission gear 6c does not rotate any further even if the DC motor 6f is driven in the forward direction. When the transmission gear 6c rotates to the state shown in FIG. 6(C), the pressing roller 5b is completely separated from the platen roller 2 as shown in FIG. At this time, the tooth end 6
c4 is biased by a tension spring 6g so as to be pressed against the teeth of the worm gear 6e. Therefore,
When the DC motor 6f is driven in reverse, the worm gear 6e reliably meshes with the teeth 6c of the transmission gear 6C.

On the other hand, when the DC motor 6f is reversely rotated from the state shown in FIG. 6(C), the reverse rotation occurs as shown in FIG.
When the transmission gear 6C rotates in the order shown in a) and the tooth end 6C3 comes off the tooth of the worm gear 6e in the state shown in FIG. Transmission gear 6c does not rotate. In this way, the DC motor
When 6f is reversely driven, the rotation arms 5c+ and 5cz are released from tension by the link member 6a, and the arm 5
c++ 5 cz The pressing roller 5b is pressed against the platen roller 2 by rotating in the direction indicated by the arrow for the first time due to the bias of the torsion coil 25e and the tension spring 5f. In the state shown in FIG. 6(C), the tooth end portion 6cs is urged by the tension spring 6g so as to be pressed against the tooth portion of the worm gear 6e.

abutment of the pressure roller 5b against the platen roller 2;
The separation can be managed by setting the forward and reverse rotation driving time of the DC motor 6f to a constant time. Further, there are various ways to control the rotation direction of the DC motor 6f, but for example, the rotation direction may be changed by changing the polarity of the voltage applied to the DC motor 6f. At this time, it is preferable to change the voltage value depending on the direction of rotation. That is, when separating the pressing roller 5b from the platen roller 2 (roller up), the arms 5c+, 5c
z must be twisted and rotated against the urging force of the coil spring 5e and the tension spring 5f.

Therefore, a larger rotational torque is required than when the pressing roller 5b is brought into contact with the platen roller 2 (roller down). Therefore, by increasing the voltage applied to the DC motor 6f when the roller is up compared to when the roller is down, there is no difference in the up-down speed of the pressure roller 5b, and the roller up and down can be performed more smoothly. .

As described above, by swinging the arms 5C1 and 5C2 using partially toothed gears, it is possible to reliably contact the press roller 5b with the platen roller 2 at a distance of 2M, and also to make the arms 5C1 and 5C2 swing. Since there is no need for a sensor to detect the swing position, it is also possible to reduce costs.

(Recording Means) The recording means 7 performs predetermined recording on the recording sort 1 conveyed by the sheet conveying device A having the above configuration, and in this embodiment, recording is performed by rotating a daisy-wheel type element. It is composed of Next, the configuration of the recording means 7 will be explained.

As shown in FIG. 2, a carriage 7b is slidably attached to a guide rail 7a whose ends are fixed to left and right frames 8a and 8b, and this carriage 7b reciprocates along the guide rail 7a and frame end 8C. Possibly installed. Further, a driving pulley 7c+ and a driven pulley 7cz are attached near both ends of the guide rail 7a, and a timing helmet 7d is stretched between both pulleys 7cl and 7c1, and a part of the timing helmet 7d is attached to a carriage. 7b. Therefore, the carriage 7b is configured to reciprocate along the guide rail 7a by driving the carriage and the motor 7e connected to the drive pulley 7c in forward and reverse directions.

Further, a type wheel 7g rotated by a wheel motor 7r is attached to the carriage 7b, and
A hammer 71 driven by a solenoid 7h is attached. Furthermore, a ribbon cassette 7k containing an ink ribbon 7j can be loaded into the carriage 7b, and when the cassette 7k is loaded into the carriage 7b, the winding shaft 7N is connected to the drive transmission roller 7m for winding up the ink ribbon 7j. By driving a ribbon motor 7n connected to the take-up shaft 71, the ink ribbon 7j is unwound from a supply spool (not shown) and wound onto a take-up spool.

In the recording means 7, when the recording start key is operated, the carriage 7b moves to the recording position, and the type wheel 7g moves to the recording position.
rotates to make the desired type face the hammer 71, and the hammer 71 is driven to strike the back surface of the type, whereby the ink on the ink ribbon 7 is transferred to the recording sheet I and printing is performed. . When the minus character is printed in this manner, the carriage 7b moves to the next printing position, and the ink ribbon 7k is wound up by one character to perform the next printing. Then, when the - line printing is completed, the sheet conveying device A
The recording sheet 1 is conveyed by one line, and the next line is printed in the same manner.

In the above-described embodiment, a platen roller that also serves as a platen is exemplified as a conveyance rotating body that applies conveyance force to the recording sheet 1, but this may be a conveyance roller separate from the platen, and is not limited to a roller-shaped conveyance roller. Alternatively, a rotating belt or the like may be used.

Further, in the above embodiment, the motor 4 that drives the platen roller 2 and the motor 6f that drives the worm gear 6e are provided separately, but by configuring as shown in FIG. 7, a single motor can be used. It becomes possible to drive. Its configuration will be explained using FIG. 7. Incidentally, parts having the same functions as those in the above-described embodiment are given the same reference numerals.

In FIG. 7, a planetary gear 13b meshes with a motor gear 13a attached to a motor shaft of a drive motor (not shown), and a platen gear 9 is connected to this planetary gear 13b.
They are constructed so that they mesh with each other.

Therefore, in the state shown in FIG. 7, the platen roller 2 is rotated by the driving of the drive motor, and the recording sheet 1 is conveyed.

The planetary gear 13b is attached to a bracket 4 that is rotatably attached to the rotation axis of the motor gear 13a, and the bracket 14 is rotated by a solenoid 15 while the planetary gear 13b remains engaged with the motor gear 13a. Possibly installed.

Normally, the planetary gear 13b meshes with the platen gear 9, but when the solenoid 15 is turned on, the bracket 14
rotates in the direction of arrow f in FIG. 7, and the planetary gear 13b meshes with the large gear 16a of the two-stage gear 16. This-stage gear 16
An idler gear 17 meshes with the small gear 16b, and an umbrella gear 18a rotating integrally with the idler gear 17 meshes with an umbrella gear 18b attached to the shaft of a worm gear 6e serving as a driving gear. and the worm gear 6e
meshes with the transmission gear 6C, which is the gear with missing teeth described above.

Therefore, when the recording sheet 1 is conveyed by the platen roller 2, the solenoid 15 is turned off and the planetary gear 13b
is engaged with the platen gear 9 to drive the motor. On the other hand, the pressure roller 5b is brought into contact with the platen roller 2,
When separating, turn on the solenoid 15 and turn on the planetary gear 1.
3b is engaged with the two-stage gear 16 to drive the motor.

In this way, it becomes possible to transport the recording sheet 1 and swing the pressing roller 5b using one motor.

Furthermore, in the above-described embodiment, a worm gear was used as an example of the drive gear that meshes with the transmission gear 6c, which is a partially toothed gear, but this need not be limited to a worm gear, and a spur gear or the like may be used instead.

Furthermore, in the above-mentioned embodiments, a typewriter that performs recording by rotating a daisy wheel was used as the recording means, but this recording means may be used in various recording methods such as a thermal transfer recording method, a thermal recording method, a wire tod recording method, etc. You may also use it.

<Effects of the Invention> As described above, in the present invention, since the pressing member that comes into contact with and separates from the sheet a feeding rotary body is operated by a partially toothed gear, the contacting and separating operations of the pressing member are controlled. It can be done reliably.

Further, since parts such as a cam and a microsinch for detecting the position of the pressing member are not required, the number of parts can be reduced and costs can be reduced.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional diagram of a sheet conveyance device according to an embodiment of the present invention, FIG. 2 is a configuration diagram of a recording device, and FIG. 3 is an overall electronic typewriter having a sheet conveyance device and a recording device. 4 is an explanatory diagram of the configuration in which the idler bracket is attached with a stepped screw via an elastic member. FIG. 5 is a sectional explanatory diagram of the state in which the pressing roller is separated from the platen roller. (C) is an explanatory diagram of the rotation of the partially toothed gear, No. 7 is an explanatory diagram of another embodiment, and Fig. 8 is an explanatory diagram of the prior art. 1 is a recording sheet, 2 is a platen roller, 2a is a roller shaft, 2b is a bearing, 3 is a gear train, 3a is an idler gear, 3a
+ is the center of rotation, 3b is the motor gear, 3b+ is the center of rotation, 3C is the bracket, 3d is the flange, 3e, 3e
2 is an elastic member, 3ft, 3'r2 is a stepped screw, 3
L+ 3fs is a screw part, 3f is a shaft part, 3g is a free screw, 3h is a tension spring, 4 is a conveyance motor, 5 is a sheet pressing member, 5a is a roller shaft, 5b is a pressing roller,
5+,, 5cz is a rotating arm, 5d is a shaft, 5e is a torsion coil spring, 6 is a separating means, 6a is a link member, 6
a+ is a long hole, 6b is a flanged pin, 6c is a transmission gear, 6c+
is the tooth part, 6C2 is the protrusion part, 6C4, 6cm is the tooth end part, 6
d is a flanged pin, 6e is a worm gear, 6f is a DC motor, 6g is a tension spring, 7 is a recording means, 7a is a guide rail, 7b is a carriage, 7C+, 7cz is a pulley, 7d is a heald, 7e is a carriage motor, 7f is a wheel motor, 7g is a type wheel, 7h is a solenoid, 71 is a hammer, 7J is an ink ribbon, 7 is a ribbon cassette, 71 is a winding shaft, 7m is a drive transmission roller, 7n
is the ribbon motor, 8a is the left frame, 8a+8
a2 is the holding part, 8a3 is the hook, 8aa is the bent part, 8
as is the escape hole, 8b is the right frame, 9 is the platen gear,
9a is the rotation center, 10 is a pinch roller, 11 is a paper pan, 12 is a manual, /f, 13a is a motor gear, 13
b is a planetary gear, 14 is a bracket, 15 is a solenoid,
16 is a two-stage gear, 16a is a large gear, 16b is a small gear, 1
7 is an idler gear, and +8a18b is an umbrella gear.

Claims (4)

[Claims] (1) A conveying rotary body for driving and rotating to apply a conveying force to the sheet, a pressing member for pressing the sheet against the conveying rotary body, and a rocking member for moving the pressing member toward and away from the conveying rotary body. a driving means for transmitting driving force to the driving gear; and a partially toothed gear having a tooth portion that meshes with the driving gear, for transmitting rocking force to the separating means. A sheet conveyance device comprising: a transmission gear; and biasing means for biasing an end of a tooth portion of the transmission gear against the drive gear. (2) The separation means supports the pressing member at the end of the swingable arm member, and includes a biasing means for pressing the pressing member toward the conveyance rotating body, and the transmission gear rotates. The sheet conveying device according to claim 1, further comprising a connecting member that transmits swinging force to the arm member by movement. (3) The driving means is composed of a DC motor, and when the motor is driven and rotated in one direction, the pressing member is separated from the conveying rotary body, and when the motor is driven and rotated in the other direction, the pressing member comes into contact with the conveying rotary body. A sheet conveying device according to claim (1). (4) A recording device comprising: the sheet conveyance device according to claim (1); and a recording means for recording on a sheet conveyed by the sheet conveyance device.