JP2769893B2 - Recording device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a printing apparatus for preventing a printing position shift by performing backlash correction of a carriage drive system.

<Prior Art> Today, printing devices such as electronic typewriters are widely used. These printing devices mount a recording head on a carriage and perform printing while moving the carriage in the space direction. Recording method is used. In these apparatuses, a method of printing when the carriage is moved in one direction is generally used. However, in recent years, in order to shorten the printing time, not only printing is performed when the carriage is moved in the space direction, but also printing is performed. A so-called bidirectional printing method has been developed in which printing is performed even when moving in the back space direction.

In the bidirectional printing method, the printing position of the character printed when the carriage is moved in the space direction and the printing position of the character printed when the carriage is moved in the back space direction may be shifted. It is well known that this often occurs due to backlash when transmitting the driving force of the carriage drive motor to the carriage via gears.

Therefore, conventionally, as shown in FIG. 13, a timing belt 52 is stretched between a motor pulley 51 attached to a carriage motor 50 and a driven pulley (not shown), and a carriage 54 having a recording head 53 mounted thereon is connected to the belt. The carriage 54 is connected to the motor 52 and reciprocated by rotating the motor 50 forward and backward. In this configuration, the pulley 51 is directly attached to the motor 50, and the driving force is directly transmitted to the carriage 54 without passing through a gear train.
Movement errors due to backlash can be eliminated.

As another configuration, as shown in FIG. 14 (a), the driving force of the motor 50 is reduced by meshing a pulley gear 56 with a motor gear 55 attached to the carriage motor 50. As shown in FIG. 2B, the backlash is absorbed by using a so-called two-tooth gear in which the two gears 56a and 56b are biased by a spring so as to be shifted by the backlash. In this configuration, the driving force of the motor 50 is reduced to reduce the carriage 54
, The motor torque can be reduced, and the size of the motor 50 can be reduced.

<Problem to be Solved by the Invention> However, in the above-described configuration, in the former configuration in which the motor pulley 51 is directly mounted on the motor 50, the driving torque of the carriage motor 50 must be increased, and A large motor must be used as the motor 50. Also, the tension of the belt 52 must be increased to about 8 kg, and it is necessary to reduce the friction by using a bearing or the like for the pulley bearing, and it is necessary to use an expensive bearing. There are issues.

In the latter configuration using the two-tooth gear, the carriage motor 50 can be small, but the cost is high because a two-tooth gear having a complicated structure must be used. There is a problem that an expensive bearing must be used because the 52 must be strengthened, which is the same as the former, and the rigidity of the frame needs to be increased.

SUMMARY OF THE INVENTION The present invention is to solve the above-mentioned conventional problems, and an object of the present invention is to provide a recording apparatus which eliminates a carriage movement error due to backlash with a small motor torque without using a two-tooth gear as in the related art. It will not be provided.

<Means for Solving the Problems> A representative means according to the present invention for solving the problems includes a carriage for reciprocating a recording unit in a space direction and a back space direction, and the carriage to a recording apparatus. A pulse motor that can be rotated forward and reverse to move, a driving force transmitting means for transmitting the driving force of the pulse motor to the carriage, and when the moving direction of the carriage is reversed from the space direction to the back space direction. A first correction process for increasing a drive amount of the pulse motor by a predetermined amount from a normal amount to correct a transmission delay amount of a drive transmission unit accompanying the inversion of the carriage, and moving the carriage after the first correction process When the direction is reversed from the back space direction to the space direction, the second correction processing for canceling the correction amount of the first correction processing is performed. After the second correction process, the carriage is moved in the back space direction by the third correction amount equal to or more than the first correction amount, and then the carriage is moved in the space direction by the third correction amount at a slower speed than the normal moving speed. And a control means for performing a third correction process of moving the carriage to determine the position of the carriage, thereby forming a recording apparatus.

Further, as another means, there is provided a detecting means for detecting a reference position of the carriage, and when setting a transmission delay of the drive transmitting means, the pulse motor is driven to output an expected value to the pulse motor. And then move the carriage in the direction opposite to the moving direction until the output value of the detection means is inverted, and set the motor drive amount as the transmission delay amount of the drive transmission means. The feature is.

<Operation> In the above means, the carriage reciprocation is accurately managed by correcting the drive transmission delay amount due to backlash or the like when the carriage reciprocates and moving the carriage. Therefore, even when so-called bidirectional incremental printing is performed when the carriage reciprocates, printing is performed without causing a printing position shift.

<Embodiment> Next, an embodiment of the present invention will be described in which the above means is applied to a daisy-wheel recording type electronic typewriter which performs bidirectional printing when the carriage reciprocates.

(First embodiment)

FIG. 1 is an explanatory diagram of a configuration of a recording apparatus, and FIG. 2 is an explanatory diagram of a configuration of an entire electronic typewriter.

(Overall Description) First, the configuration of the entire apparatus will be described. When the apparatus operates the keyboard K shown in FIG. 2 to input recording information, the information is displayed on the display D. After the information is input, the recording sheet 6 is set and the recording start key is operated, and the recording apparatus P is operated.
Is driven to record the input information on the recording sheet 6.

In the present embodiment, the recording apparatus P uses a daisy-wheel recording method. As shown in FIG. 1, an ink ribbon cassette 1 is removably mounted on a carriage 2, and a recording means 3 is mounted on the carriage 2. Have been. The carriage 2 is configured to be movable by being guided by the guide shaft 4 and one end surface 5a of the main body frame 5, and by moving the carriage 2 to a desired position and driving the recording means 3, printing is performed on the recording sheet 6. The recording sheet 6 on which one line is printed is conveyed in the direction of arrow a by the sheet conveying means 7. In this embodiment, the recording is so-called bidirectional incremental recording that is performed when the carriage 2 moves in any of the space direction F and the backspace direction R.

The carriage 2 is connected to a carriage motor 8 composed of a pulse motor via a driving force transmitting means 9 and reciprocates by forward and reverse rotation of the carriage motor 8, and at that time, driving force is transmitted by a control means described later. The backlash generated by the means 9 is taken into consideration, and the drive is controlled while correcting the backlash.

 Next, the configuration of each section will be specifically described.

(Ink Ribbon Cassette) In the ink ribbon cassette 1, a concave portion 1a is formed in the center of the front of the container, and a long ink ribbon 1b is wound around a supply spool (not shown) provided in the container so that the ink ribbon is once exposed in the concave portion 1a. It is wound around the take-up spool. The take-up spool is connected to a drive transmission roller 1c, and the roller 1c is configured to be fitted with a take-up shaft described later and driven to rotate to take up the ink ribbon 1b. Positioning bosses 1d are provided on both sides of the cassette 1 for positioning when the cassette 1 is loaded on the carriage 2.

(Carriage) The carriage 2 is configured to carry the recording means 3 and to move while loading the ink ribbon cassette 1 thereon. On both sides of the carriage 2, hooks 2b rotatable about a shaft 2a are provided. The hooks 2b are urged by tension springs 2c, and the positioning bosses 1d of the ink ribbon cassette 1 are engaged with the hooks 2b. When the ink ribbon cassette 1 is stopped, the ink ribbon cassette 1 is pressed against and fixed to the upright wall 2d of the carriage 2. At this time, the ink ribbon 1b exposed from the concave portion 1a is replaced with a type wheel 3a and a recording sheet 6 described later.
And is located between them.

A take-up shaft 2e is provided at a predetermined position of the carriage 2, so that when the ink ribbon cassette 1 is loaded on the carriage 2, the drive transmission roller 1c is fitted and locked to the take-up shaft 2e. A ribbon motor 2g is connected to the take-up shaft 2e via a set gear 2f. The drive of the motor 2g winds the ink ribbon 1b around a take-up spool.

The carriage 2 is slidably fitted on a guide shaft 4 mounted on the main body frame 5, and is movably mounted along the guide shaft 4 and the frame end 5a.

(Recording Means) Next, the recording means 3 uses a daisy type element in this embodiment, and a hammer 3c operated by a type wheel 3a and a solenoid 3b is mounted on the carriage 2.

The print wheel 3a has prints radially arranged around a rotation axis, and is configured to rotate when a wheel motor 3d connected to the rotation shaft is driven. Accordingly, the desired type is opposed to the hammer 3c by rotating the type wheel 3a, and the hammer 3c is driven so that the desired type strikes the ink ribbon 1b, so that the back side is on the recording sheet 6 supported by the platen roller 7a. It is to be printed.

(Sheet Conveying Means) As shown in FIG. 1, the sheet conveying means 7 is provided with a platen roller 7a in a movement area of the carriage 2 at a position facing the operation axis of the hammer 3c. Are rotated by a platen motor 7b. A guide 7c is attached around the platen roller 7a, and the roller 7a
Are mounted so that several pinch rollers 7d are pressed against each other.

Accordingly, when the platen roller 7a is driven and rotated, the recording sheet 6 is guided by the guide plate 7c in cooperation with the pinch roller 7d, and the platen roller 7a and the ink ribbon 1b are driven.
Are transported in the direction of arrow a in FIG.

(Driving force transmitting means) The driving force transmitting means 9 is for transmitting the driving force of the carriage motor 8 to the carriage 2, and as shown in Fig. 1, a driving pulley 9a and a driven pulley are provided at both ends of the carriage moving range. A timing belt 9c is loosely stretched between the pulleys 9a and 9b with a tension of about 0.7 kg, and the belt 9c is connected to the carriage 2. Further, the drive pulley 9a has a pulley gear 9d composed of a single gear.
The gear 9d is meshed with a motor gear 9e attached to the drive shaft of the carriage motor 8.

Thus, when the carriage motor 8 rotates forward and backward, the driving force is reduced by the gears 9d and 9e and transmitted to the carriage 2, and the carriage 2 reciprocates along the guide shaft 4.

(Backlash of Driving Force Transmission Means) Here, the backlash generated when the driving force of the carriage motor 8 is transmitted to the carriage 2 will be described.

In the driving force transmitting means 9, the pulley gear 9d and the motor gear 9e are meshed with some backlash.

For example in order to move the carriage 2 to the space direction F, when rotating the motor gear 9e to C _f direction shown in FIG. 3 (a) is left right side of the teeth of the motor gear 9e is tooth pulley gear 9d The driving force is transmitted in contact with the surface. Gap G _f is generated on the left side surface of the teeth of the right side and the motor gear 9e of teeth in this case the pulley gear 9d.

In order to move the carriage 2 to the backspace direction R, to rotate the motor gear 9e to C _r direction shown in FIG. 3 (b), right side left side of the teeth of the pulley gear 9d of the teeth of the motor gear 9e And the driving force is transmitted. Gap G _r is generated on the right side surface of the teeth of the left side surface of the teeth of this time the pulley gear 9d and motor gear 9e.

Therefore, when the carriage 2 is reversed from the space direction F to the back space direction R, both gears 9d and 9e
The state changes from the state shown in FIG. 3A to the state shown in FIG. However, the driving force is not transmitted between the motor gear 9e is rotated amount of the gap G _f be rotated a carriage motor 8 to C _r direction upon reversal.

On the other hand, when the carriage 2 is reversed from the back space direction R to the space direction F, the two gears 9d and 9e change from the state shown in FIG. 3B to the state shown in FIG. . However, the driving force is not transmitted between the motor gear 9e is rotated amount of the gap G _f be rotated a carriage motor 8 to C _f direction during this case inverted.

As described above, when the carriage 2 reciprocates, a back crash exists between the pulley gear 9d and the motor gear 9e.

In the driving force transmitting means 9, the belt 9c may be bent when the carriage 2 moves. For example, as shown in FIG.
The when rotating the C _f direction to move the carriage 2 to the space direction F may be lower in deflection amount D _f of the belt 9c occurs. Also that deflection amount D _r is generated in the upper part of the belt. 9c when the carriage motor 8 as shown in FIG. 4 (b) to reverse rotate the C _r direction to move the carriage 2 to the backspace direction R is there.

Therefore, when the belt 9c is bent as described above, when the carriage 2 is reversed from the space direction F to the back space direction R, the state shown in FIG. The state changes to the carriage motor 8
Is rotated in the _Cr direction, the driving force of the motor 8 is not transmitted to the carriage 2 until the deflection amount _Dr is removed.

Therefore, if the belt 9c bends when the carriage 2 moves, backlash also exists between the belt 9c and the pulley gear 9d.

The gap G _f, G _r or deflection of D _f, backlash by D _r a transmission delay amount of the driving force.

(Control Unit) Next, the control unit will be described. The control unit controls the driving of the carriage motor 8 so as to correct the influence of the backlash or the like generated in the driving force transmitting unit 9.

The configuration is as shown in the block diagram of FIG.

In FIG. 5, a CPU 10 is a central processing unit composed of a microcomputer or the like, which reads out a program or various data from a ROM 11 or the like to be described later, performs necessary calculations and determinations, and performs various controls.

The ROM 11 is a read-only memory, and stores various programs (for example, the program shown in FIG. 6) and various data for operating the CPU 10.

RAM 12 is random access memory and CPU 10
Is composed of a working area for temporarily storing data in a command and an operation result, a buffer area for storing various data input from the keyboard A or the like, a text area for storing a document, and the like. The RAM 12 has a first register 12a for storing the moving direction of the carriage 2 in advance.
And a second register 12 for storing a correction amount for correcting the aforementioned backlash when the carriage 2 reverses.
Area b is reserved.

In this embodiment Yes to set it in the register 12a is a space direction F, the register 12b sum of either or both of the gap G _f and the amount of deflection D _f described above, that is, the drive force transmission delay The number of motor steps corresponding to the amount is set.

The ROM 11, the RAM 12, the keyboard K and the recording device P described above are connected to the CPU 10 via the CPU bus 13.

The CPU 10 is activated by a reset operation such as turning on the power of the apparatus.
The program stored in the ROM 11 is read out via the PU bus 13, and the program is executed in accordance with the program. When an input instruction is inputted from the keyboard K, the instruction is analyzed and the recording device P is driven if necessary. Control is performed to record desired characters, store an input document in the RAM 12, read the input document from the RAM 12, edit the document, and print and record the document.

Next, the carriage drive control means by the control means will be described with reference to the flowchart of FIG.

First, in step S1, the designated moving direction is compared with the previous moving direction stored in the first register 12a in order to detect the reversal of the moving direction of the carriage 2, and if the same direction, the process proceeds to step S2. In step S2, the contents of the instructed moving direction are updated to the first register 12a, and the flow advances to step S3 to drive and control the carriage motor 8 to move the carriage 2 in the instructed moving amount and direction in printing.

At the end of this movement, the recording means 3
Is driven to perform predetermined printing on the recording sheet 6. Then, in step S5, it is determined whether or not the recording is completed, and if there is the next print, the process returns to step S1.

Next, when the printing in the space direction F is completed and the carriage 2 is reversed from the space direction F to the back space direction R, the process proceeds from step S1 to step S6, and the reverse direction is from the space direction F to the back space direction R. It is determined whether or not there is a space direction F to a back space direction R.
If the instruction is a reversal instruction, the process proceeds to step S7 to perform a first correction process.

This first correction process is a process of adding the number of steps set in the second register 12b, that is, the number of steps corresponding to the driving force transmission delay amount.
Next, proceeding to step S2, the fact that the carriage movement direction is the backspace direction R is stored in the register 12a, and the carriage 2 is moved according to the carriage movement amount specified in step S3 and stopped, and then printing is executed. I do. The carriage motor 8 at this time will be driven by an amount adding the transmission delay amount to the amount of movement to the C _r direction.

As a result, the amount of backlash when reversing from the space direction F to the backspace direction R in the first correction process is corrected, and the printing position while moving in the backspace direction R is changed while printing in the space direction F. No displacement occurs with respect to the position.

Since the moving direction of the carriage 2 is stored in step S2, even if the moving direction instruction in the next printing is the same backspace direction R, the process proceeds to step S2 by the discrimination in step S1. And the correction operation is not performed excessively. As described above, even when the carriage 2 moves in the back space direction R, printing is performed without any positional deviation.

Next, when printing while moving in the back space direction R is completed, and when the carriage 2 is reversed from the back space direction R to the space direction F for recording, the process proceeds from step S1 to step S6, and the reverse direction is the back space direction. When it is determined that the direction is the space direction F from the direction R, the process proceeds to step S8 to perform the second correction process.

The second correction process is a process for canceling the correction amount of the first correction process. The movement of the carriage 2 in the back space direction R is determined by the first correction processing performed in step S7. Therefore, the movement position of the carriage 2 that drives the carriage motor 8 according to the correction value and the movement of the carriage motor 8 A phase shift has occurred between the phase position.

So when the second correction processing to invert the carriage 2 from the back space directions R to space direction F, the amount of setting the carriage motor 8 in the second register 12b, i.e. the first correction amount and the same amount by C _f direction ( (The direction opposite to the first correction process). As a result, the positional shift is canceled, and the physical transfer position of the carriage 2 and the phase position of the carriage motor 8 match.

Although there is theoretically no problem with this second correction processing, in this embodiment, after the second processing is further completed, step S9
Then, the third correction process is performed. This is a process for ensuring that the driving force of the carriage motor 8 is transmitted to the carriage 2, and is a process of positioning the carriage 2. That is, if there is a relatively large backlash in the drive transmission means 9, there is a possibility that the motor gear 9e and the pulley gear 9d do not actually come into contact with the state shown in FIG. In addition, the amount of deflection of the belt 9c may not change to the state shown in FIG. Therefore, in the present embodiment, the above-mentioned fear is completely eliminated by performing the third correction processing, and the drive transmission means 9 is shifted to the state shown in FIGS. 3 (a) and 4 (a) at the inversion reference position. The driving force of the carriage motor 8 in the C _f direction
It is surely transmitted to.

The third correction process is a third correction amount (gap of FIG. 3A) corresponding to the number of steps equal to or more than the correction amount performed in the first correction process.
The G _f and the fourth diagram the number of steps than the sum of the deflection D _f (a)) the carriage motor 8 is driven to C _r direction, more usually gentler than this step as many partial carriage motor 8 to C _f direction The carriage 2 is driven at an appropriate speed to position the carriage 2. As a result, the driving force transmitting means 9 is reliably brought into the state shown in FIGS. 3 (a) and 4 (a) at the reversal reference position, and the driving force is reliably transmitted. Also, there is no deviation between the transfer position of the carriage 2 and the phase position of the carriage motor 8 at the inversion reference position.

When the third correction process is completed as described above, the step
Proceeding to S2 and thereafter, recording in the space direction F is performed. At this time, since the moving direction of the carriage 2 is stored in step S2, when the moving direction instruction in the next printing is the same space direction F, the correction operation is not performed excessively.

By controlling the driving of the carriage motor 8 as described above, even if a backlash or the like exists, characters recorded by the bidirectional recording by the recording means 3 are recorded without relative displacement.

Incidentally, the correction amount in the first correction processing is the pulley gear 9d.
Backlash of motor gear 9e and belt 9c
The deflection amount and the like can be easily obtained by testing the relationship between the gears 9d and 9e and the tension of the belt 9c, etc., and may be appropriately set according to each case.

Second Embodiment In the above-described first embodiment, an example in which the driving of the carriage motor 8 is controlled by using the CPU 10 has been described. However, the carriage driving control means may be configured without using this.

FIG. 7 shows an example. In the figure, CMD is a carriage transfer instruction means, and the carriage control direction of the printing apparatus P instructs the carriage transfer direction. For example, the carriage 2 is transported after printing of characters input from the keyboard K, or the input text is stored in advance, and the desired text of the carriage 2 is stored for each printing operation such as recording and printing the desired text. The direction and the direction of the transfer are designated. The control means operates according to this instruction.

Reference numeral 14 denotes a transfer direction reversal detecting means for detecting the reversal of the carriage transfer direction, and compares the previously specified transfer direction with the carriage transfer direction specified this time, and if the same direction, the control line L ₃ Thus, the amount and direction of transfer of the carriage 2 are instructed to the carriage drive control means 15. The carriage drive control means 15 controls the number of drive steps and the motor phase switching direction to drive the carriage motor 8 by a predetermined amount according to the commanded transfer amount and transfer direction so that the carriage 2 is moved by a predetermined amount according to the command. Then, voltage conversion or voltage-current conversion is performed by the motor drive circuit 16 through the control line CNT, and the carriage motor 8 is step-driven by the control line DRV.

Here, a case where the carriage transfer instruction is different from the transfer direction previously instructed, that is, a case where the carriage 2 is reversed will be described.

In the case of reversal from the space direction F to the backspace direction R, the transfer direction reversal detection means 14 determines that the previous transfer direction is the space direction F and the transfer direction designated this time is the backspace direction R, L command to to perform the first correction means 17 through _one of the first correction process.

This first correction process, as described in the first embodiment,
The correction value is added to the carriage transfer amount instructed by the carriage transportation request CMD, either deflection of D _f of the belt 9c of the gap G _f or the fourth view of FIG. 3 (a) (a), or cancel both the transfer amount and the moving direction through a control line L ₂ to be commanded to the carriage driving unit 15. The carriage driving means 15 receiving this command drives and controls the carriage motor 8 via the motor driving circuit 16. This corrects the backlash when the carriage 2 is reversed and moved from the space direction F to the back space direction R, and the space direction F
The position of the character printed in the backspace direction R with the character printed in the position is prevented.

Inversion from backspace direction R to space direction F Next, when the transfer direction inversion detection means 14 determines that the previous carriage transfer direction is the backspace direction R and the transfer direction designated this time is the space direction F, , Control line
L ₄ commands the second correction process to the second correction means 18 via a.

As described in the first embodiment, the second correction processing is for equalizing the position of the carriage motor 8 when the sheet is transferred in the space direction F according to the correction amount corrected in the first correction processing. a process, instructs the carriage drive control unit 15 via the control line L ₅ from the second correction means 18 is to correct the phase position of the carriage motor 8.

Then the second correcting unit 18, a third correction process instructs the third correction means 19 via a control line L _6, control line L ₇ this directive
Carriage drive control means 15 received via the controller controls the carriage motor 8 to drive. In the third correction processing, the carriage motor 8 is driven in the C _r direction by an amount slightly larger than the correction amount in the first correction processing, and then the carriage motor 8 is driven more slowly in the C _f direction by the same amount. I do. Thus, the position of the carriage 2 is determined.

When the third correction process is completed, printing is performed while the carriage 2 is moved at a normal speed in accordance with the carriage transfer amount instructed by the carriage transfer instructing means CMD.

Even in the above-described control configuration, it is possible to eliminate a backlash or the like generated by the driving force transmitting means 9 to the carriage 2 and eliminate a printing position shift in bidirectional printing.

(Third embodiment)

In the above-described first and second embodiments, the drive control is performed with the backlash amount of the drive transmission means 9 being constant. However, in the third embodiment, the backlash amount is detected in consideration of the change in the backlash amount. An example in which the carriage is driven and controlled will be described.

If high precision is required for the tension and the like of the belt 9c in the drive transmission means 9, it will increase the cost. If these devices are used, the belt 9c may be elongated due to aging, the motor gear 9e, the pulley gear 9d may be worn, or the pulley gear 9d may be worn. It is considered that the bearing portion wears and the backlash amount changes.

8 (a) and 8 (b) show an example of a configuration for detecting the backlash amount. FIG. 8 (a) is a front left enlarged view of the carriage drive system, and FIG. 8 (b) Is a top view.

As shown in the figure, a boss 20 is attached to the lower part of the carriage 2 and a detector 21 is attached to the frame 5 at the left end of the movement of the carriage 2. This detector 21 uses a photo interrupter in the present embodiment, and when the carriage 2 reaches the left reference position, the boss 20 blocks the light irradiation part of the detector 21, and at this time, the detector 21 is turned on. It is configured to detect.

As shown in FIG. 9, the detector 21 detects the amount of backlash by connecting the detector 21 to the control means shown in the first embodiment via the CPU bus 13 and changing the state of the detector 21. It is configured so that it can be detected by the CPU 10.

The ROM 11 of the control means stores a program shown in the flowchart of FIG. 10 for detecting a backlash amount based on a signal from the detector 21. This backlash amount detection processing is executed when the recording mechanism is initialized during a reset operation such as when the apparatus is turned on.

The backlash amount detection processing procedure will be described with reference to the flowchart of FIG. 10.First, in step S10, it is determined whether or not the detector 21 has already detected the boss 20. the carriage motor 8 at to S11 and driven by a predetermined amount to the C _f direction carriage 2 eighth
It is moved by a predetermined amount in the space direction F shown in the figure. The amount of movement is such that the boss 20 is reliably separated from the detector 21 and the detector 21
Is the amount of movement that turns off. Next, after the boss 20 is separated from the detector 21 as described above, or in step S10.
Already boss 20 is driven each time an amount corresponding to the minimum resolution of the carriage motor 8 to C _r direction proceeds to step S12 when spaced apart from the detector 21 (e.g., one step In the pulse motor) In Then, the carriage 2 is moved in the backspace direction R. This is continued until the detector 21 detects the boss 20 in step S13. This step
S12 and S13 are operations for detecting the left reference position of the carriage 2.

Next, when the detector 21 detects the boss 20 in step S13,
Proceeding to step S14, an initial value is set in the second register 12b for storing the backlash correction value. Next, with the amount driven corresponding carriage motor 8 to the minimum resolution to C _f direction proceeds to step S15 to move the carriage 2 to the space direction F. Then, in step S16, the contents of the second register 12b are updated so as to store the number of driving steps as a correction value. Next, in step S17, it is determined whether or not the detector 21 has detected the boss 20, that is, whether or not the carriage 2 has started moving. If the detector 21 has detected the boss 20 (carriage 2 Step S15)
Then, the carriage motor 8 continues to be minutely driven, and the integrated amount is updated to the second register 12b as the backlash amount. When the detector 21 stops detecting the boss 20 in step S17, that is, when the carriage 2 starts to move downward in the space direction, the backlash amount detection processing ends.

At the time when the left reference position of the carriage 2 is detected in steps S12 and S13 as described above, FIG.
When the carriage 2 starts moving in the space direction F in steps S14 to S17 as shown in FIG.
The state shown in FIG. 4A and the state shown in FIG. The amount of backlash can be detected by detecting the number of drive steps of the carriage motor 8 required for this. Therefore, by storing the detected backlash amount in the second register 12b and performing the drive control of the above-described first embodiment with this amount as a correction amount, even if the backlash amount changes due to aging or the like, An appropriate correction process can always be performed.

In the third embodiment, an example is shown in which a photo interrupter is used as the detector 21. However, the detector 21 may be anything as long as it can detect the movement of the carriage 2, for example, using a mechanical contact. May be.

In the third embodiment, the left reference of the carriage 2 is detected. However, the detector 21 is provided on the right side of the frame 5 and the backlash amount is detected by detecting the right reference position of the carriage 2. You may do it. In this case, the driving direction of the carriage motor 8 in steps S11, S12, and S15 may be set to be reversed.

Further, the boss 20 and the detector 21 are opposite to the boss in the third embodiment.
It goes without saying that the detector 20 may be mounted on the carriage 2 while the detector 20 is mounted on the frame 5.

The detector 21 can use a home position sensor or the like for detecting the home position of the carriage 2 attached to most of the recording devices. If this sensor is used, a special detector can be used. No need to provide.

Further, the above-described detection operation may be performed a plurality of times, and the second register 12b may be set so as to take an average thereof.

[FIG. 4 Embodiment] Next, the detector 21 of the third embodiment described above as the fourth embodiment.
An example is shown in which, when has a hysteresis characteristic, the backlash amount is detected by correcting this.

In general, many detectors 21 have a hysteresis characteristic when changing from ON to OFF or from OFF to ON. If the detector 21 has the hysteresis characteristic, the relationship between the detector 21 and the moving position of the carriage 2 described in the third embodiment is as shown in FIG. In this figure, the horizontal axis is the carriage 2
The vertical axis represents the ON / OFF state of the detector 21.

In FIG. 11, the solid line shows the detection state of the detector 21 when there is no hysteresis. That is, when the left reference position of the carriage 2 as described in the third embodiment is assumed to be D _1, the detector 21 and the carriage 2 from the position D ₁ moves space direction F is switched from ON to OFF, ON carriage 2 Detect movement.

However, if the detector 21 has a hysteresis characteristic,
Even if is separated from the detector 21, the detector 21 is not immediately turned off, and after a certain time elapses as shown by a broken line in FIG.
It turns off. At this time the carriage 2 is in the position of D ₂ already moved h amount. Therefore, in the detection procedure shown in FIG. 10, in addition to the actual backlash amount, the amount by which the carriage 2 is moved by the h amount is stored in the second register 12b as the backlash amount. Become.
Therefore, if the correction amount is set based on the amount stored in the second register 12, there is a possibility that a displacement of the h amount will occur during bidirectional printing.

In order to solve this problem, in the fourth embodiment, the backlash amount is detected by correcting the detection error due to the hysteresis characteristic.

The procedure for detecting the backlash amount for that purpose is shown in the flowchart of FIG.

12, steps S10 to S17 are the detection of the left reference position of the carriage 2 and the detection of the backlash amount described in the third embodiment.

In the processing up to step S17, the amount including the error due to the hysteresis characteristic is stored in the second register 12b as the backlash amount. Therefore, in step S18, the hysteresis error amount h is corrected from the second register 12b storing the above amount, that is, a correction process of subtracting the error amount h from the content of the second register 12b is performed. To the second register 12b.

The detection error amount h due to the hysteresis characteristic is determined by the detector 21.
The amount h may be stored in advance in the ROM 11 and the RAM 12 because it is easily obtained by a test.

If the amount of backlash is detected as described above, it is possible to accurately detect the amount of backlash even if the detector 21 has a hysteresis characteristic, thereby preventing misalignment during bidirectional printing. I can do it.

With the configuration as in the first to fourth embodiments, even when there is a backlash or the like, it is possible to perform recording without causing a positional shift in bidirectional printing by motor drive control. In the above-described first to fourth embodiments, the daisy-wheel recording method has been described as an example of the recording means. However, the recording means does not need to be limited to this. It is natural that you can do it.

<Effect of the Invention> As described above, according to the present invention, the backlash and the like generated in the driving force transmitting means for transmitting the driving force of the motor to the carriage are corrected by the motor driving, so that the occurrence of the recording position shift in the bidirectional recording is generated. Can be prevented.

In addition, since the driving force of the motor can be transmitted to the carriage via gears and the like, the driving force of the motor can be reduced, so that a motor having a small driving torque can be used. Can be achieved.

Furthermore, since there is no need to strongly stretch the belt as in the conventional case and it is not necessary to use a two-tooth gear, the mechanical durability is improved, and an inexpensive recording mechanism can be adopted, thereby reducing the cost of the apparatus. I can plan.

Further, if the backlash amount or the like is detected at any time and the correction control is performed based on the detected backlash amount or the like, it is possible to more reliably prevent the recording position deviation in bidirectional recording.

[Brief description of the drawings]

FIG. 1 is an explanatory perspective view of a recording apparatus according to an embodiment of the present invention, FIG. 2 is an external perspective view of an electronic typewriter using the recording apparatus, and FIGS. 3 (a) and 3 (b) are motors. 4 (a) and 4 (b) are explanatory diagrams of a backlash between a pulley gear and a belt, FIG. 5 is a block diagram showing a configuration of a carriage drive control means, and FIG. FIG. 7 is a flowchart showing a carriage drive control procedure, FIG. 7 is a block diagram showing a carriage drive control unit according to the second embodiment, and FIGS. 8 (a) and (b).
Is an explanatory view of a third embodiment in which a detector and a boss for detecting the left reference of the carriage are provided, FIG. 9 is a block diagram showing a carriage drive control configuration according to the third embodiment, and FIG. FIG. 11 is a graph showing a hysteresis characteristic in the fourth embodiment, FIG. 12 is a flowchart showing a procedure for correcting the hysteresis characteristic and detecting a backlash amount, and FIGS. 13 and 14 ( (a), (b) is explanatory drawing concerning a prior art. K is a keyboard, D is a display, P is a recording device, 1
Is an ink ribbon cassette, 1a is a concave portion, 1b is an ink ribbon, 1c is a transmission roller, 1d is a positioning boss, 2 is a carriage, 2a is a shaft, 2b is a hook, 2c is a tension spring, 2d
Is an upright wall, 2e is a take-up shaft, 2f is a set gear, 2g is a ribbon motor, 3 is a recording means, 3a is a type wheel, 3b is a solenoid, 3c is a hammer, 3d is a wheel motor, 4 is a guide shaft, and 5 is a guide shaft. Body frame, 5a is end face, 6 is recording sheet, 7
Is a sheet conveying means, 7a is a platen roller, 7b is a platen motor, 7c is a guide plate, 7d is a pinch roller, 8 is a carriage motor, 9 is a driving force transmitting means, 9a is a driving pulley, 9b is a driven pulley, and 9c is a timing. Belt, 9d is pulley gear, 9e is motor gear, 10 is CPU, 11 is ROM, 12 is RA
M, 12a and 12b are registers, 13 is a CPU bus, 14 is a transfer direction inversion detecting means, 15 is a carriage drive control means, 16 is a motor drive circuit, 17 is a first correction means, 18 is a second correction means, 19
Is a third correction means, 20 is a boss, and 21 is a detector.

Claims (2)

(57) [Claims] A carriage for reciprocating a recording means in a space direction and a back space direction; a pulse motor capable of rotating forward and reverse to move the carriage to a recording apparatus; and a driving force of the pulse motor. A driving force transmitting means for transmitting to the carriage, when the moving direction of the carriage is reversed from the space direction to the back space direction, the driving amount of the pulse motor is increased by a predetermined amount from a normal amount, and the carriage is reversed. A first correction process for correcting the transmission delay amount of the accompanying drive transmission means, and a correction of the first correction process when the moving direction of the carriage reverses from the back space direction to the space direction after the first correction process. A second correction process for canceling the amount, and after the second correction process, move the carriage in the backspace direction to the first position. A third correction amount that is equal to or more than the positive amount, and then is moved in the space direction by the third correction amount at a speed slower than the normal movement speed to perform a third correction process of positioning the carriage. A recording device comprising: a control unit. A detecting means for detecting a reference position of the carriage; driving the pulse motor to move the carriage until an output of the detecting means reaches an expected value; The recording apparatus according to claim 1, wherein the carriage is moved in a direction opposite to the moving direction until the output value of the carriage is inverted, and a motor drive amount thereof is set as a transmission delay amount of the drive transmission unit.