JP2004142221A - Recorder, its platen gap adjusting method and adjusting mechanism, and recording timing control method and controller for writing wire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a recorder in which the platen gap between a recording head and a platen can be corrected upon variation, and to provide a platen gap adjusting method and a mechanism for it, and recording timing control method and controller for a recording wire. <P>SOLUTION: The recorder for recording an image onto a sheet fed between a recording head 18 and a platen 20 by impacting the sheet with a recording wire through an ink ribbon comprises a storage means storing a measurement data table of the distance between the recording head 18 and the surface of the platen 20 measured previously over a plurality of points in the moving range of the recording head 18. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a recording apparatus, a platen gap adjustment method and adjustment mechanism thereof, and a recording wire recording timing control method and control apparatus.
[0002]
[Prior art]
A recording head mounted on a carriage that can travel along the platen records an image on a sheet conveyed between the platen and a dot impact type printer, the platen gap between the recording head and the platen, There is a printer having an automatic platen gap adjustment mechanism for automatically adjusting the thickness of a sheet supplied to a recording apparatus main body (for example, see Patent Document 1).
[0003]
In this type, the recording head is moved toward the platen until the recording head comes into contact with the recording head, the distance between the recording head and the platen surface is detected, and then a sheet is supplied to the recording apparatus main body to perform recording. Generally, the head is moved toward the sheet on the platen until the recording head comes into contact with the recording head, the distance between the recording head and the sheet surface is detected, and the sheet thickness is detected from the difference between these distances.
[0004]
In the conventional configuration, in adjusting the platen gap, it is assumed that the platen gap between the recording head and the platen is always constant at any position on the platen.
[0005]
[Patent Document 1]
JP-A-10-244729
[0006]
[Problems to be solved by the invention]
However, in consideration of a dimensional error in processing the platen, a mounting error of the platen, and the like, if the position on the platen changes, the platen gap between the recording head and the platen changes.
[0007]
Therefore, for example, even if the platen gap between the recording head and the platen is properly adjusted at the first position, if recording is performed by the recording head at a different second position, the second position In such a case, there is a problem that the platen gap is inappropriate, resulting in shading of the recording density, and the recording quality is reduced.
[0008]
Further, when the platen gap between the recording head and the platen changes, there is a problem that an error occurs in the flight time of the recording wire depending on the position on the platen, and accurate recording cannot be performed.
[0009]
Therefore, an object of the present invention is to solve the above-described problems of the conventional technology, and to provide a recording apparatus capable of correcting even if a platen gap between a recording head and a platen changes, and a platen gap adjustment thereof. An object of the present invention is to provide a method and an adjustment mechanism, and a recording wire recording timing control method and control device.
[0010]
[Means for Solving the Problems]
2. The recording apparatus according to claim 1, wherein a recording wire is struck on a sheet supplied between the recording head and a platen via an ink ribbon to record an image on the sheet. And a storage means for storing a measurement data table of the distance between the recording head and the platen surface, which is measured at a plurality of locations in advance.
[0011]
According to a second aspect of the present invention, in the first aspect, the distance between the recording head and the sheet surface is measured, and the measured distance is subtracted from the distance between the recording head and the platen surface obtained from the measurement data table. A platen gap adjusting mechanism that detects the thickness of the sheet and determines the platen gap based on the thickness of the sheet.
[0012]
According to a third aspect of the present invention, in the second aspect, a means for correcting the determined platen gap with an average value of all distances in the measurement data table is provided.
[0013]
According to a fourth aspect of the present invention, in the first aspect, there is provided a means for correcting a recording timing of a recording wire according to a distance between a recording head and a platen surface obtained from a measurement data table. I do.
[0014]
According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the storage means is a memory that can be held even in a power-off state.
[0015]
According to a sixth aspect of the present invention, in the storage medium according to any one of the first to fifth aspects, the recording head and the platen surface measured at a plurality of locations in the beam direction and the circumferential direction of the cylindrical platen in the storage means. Characterized by storing a measurement data table of the distance to the distance.
[0016]
According to a seventh aspect of the present invention, there is provided any one of the first to sixth aspects, further comprising means for storing the measurement data table in the storage means at the time of factory shipment.
[0017]
According to an eighth aspect of the present invention, in any one of the first to sixth aspects, a configuration is provided in which a measurement data table is stored in the storage means when the platen surface measurement mode is selected. And
[0018]
According to a ninth aspect of the present invention, in the platen gap adjusting method of a recording apparatus for recording an image on a sheet supplied between a recording head and a platen by striking a recording wire via an ink ribbon via an ink ribbon, Within the moving range of the recording head, the distance between the recording head and the platen surface is measured in advance at a plurality of locations, stored in a measurement data table, and the distance between the recording head and the sheet surface is measured. The thickness of the sheet is detected by subtracting from the distance between the recording head and the platen surface obtained from the measurement data table, and the platen gap is adjusted based on the thickness of the sheet.
[0019]
According to a tenth aspect of the present invention, in the ninth aspect, the determined platen gap is corrected by an average value of all distances in the measurement data table.
[0020]
According to an eleventh aspect of the present invention, in the ninth or tenth aspect, a measurement data table is stored when the platen surface measurement mode is selected.
[0021]
According to a twelfth aspect of the present invention, in the platen gap adjusting mechanism of a recording apparatus for recording an image on a sheet supplied by striking a recording wire via an ink ribbon to a sheet supplied between a recording head and a platen, Within the moving range of the recording head, the distance between the recording head and the platen surface is measured in advance at a plurality of locations, stored in a measurement data table, and the distance between the recording head and the sheet surface is measured. The thickness of the sheet is detected by subtracting from the distance between the recording head and the platen surface obtained from the measurement data table, and the platen gap is adjusted based on the thickness of the sheet.
[0022]
According to a thirteenth aspect, in the twelfth aspect, the determined platen gap is corrected by an average value of all distances in the measurement data table.
[0023]
According to a fourteenth aspect, in the twelfth or thirteenth aspect, a measurement data table is stored when the platen surface measurement mode is selected.
[0024]
According to a fifteenth aspect of the present invention, there is provided a method for controlling a recording timing of a recording wire in a recording apparatus for recording an image on a sheet supplied by striking a recording wire via an ink ribbon onto a sheet supplied between a recording head and a platen. In the movement range of the recording head, the distance between the recording head and the platen surface is measured in advance at a plurality of locations and stored in a measurement data table, and the distance between the recording head and the platen surface obtained from the measurement data table is measured. The recording timing of the recording wire is corrected according to the distance.
[0025]
According to a sixteenth aspect of the present invention, in accordance with the fifteenth aspect, when the platen surface measurement mode is selected, a measurement data table is stored in the storage means.
[0026]
A recording timing control mechanism for a recording wire in a recording apparatus for recording an image on a sheet supplied by striking a recording wire via an ink ribbon onto a sheet supplied between a recording head and a platen. In the movement range of the recording head, the distance between the recording head and the platen surface is measured in advance at a plurality of locations and stored in a measurement data table, and the distance between the recording head and the platen surface obtained from the measurement data table is measured. The recording timing of the recording wire is corrected according to the distance.
[0027]
The invention according to claim 18 is characterized in that, in the invention according to claim 17, when the platen surface measurement mode is selected, a measurement data table is stored in the storage means.
[0028]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0029]
FIG. 1 is a perspective view showing a dot impact printer to which an embodiment of a recording apparatus according to the present invention is applied. 2 and 3 are perspective views showing the printer main body in the printer of FIG.
[0030]
The printer 10 as a recording apparatus shown in FIGS. 1 and 2 prints an image including characters by hitting a large number of recording wires on a sheet via an ink ribbon (both not shown) and recording dots. It is a dot impact printer.
[0031]
The printer 10 includes a printer main body 11 as a recording apparatus main body, a push tractor unit 12 (FIG. 4) disposed on the rear side of the printer main body 11, and an exterior body that covers the upper and lower sides of the printer main body 11, respectively. An upper case 13A and a lower case 13B, a sheet supply guide 43 installed on the front side of the printer main body 11 to guide the supply of cut sheets, and a rear side of the printer main body 11 installed above the push tractor unit 12; And a cut sheet feeder 44 (FIG. 1) for supplying cut sheets one by one to the recording mechanism of the printer main body 11.
[0032]
The sheet includes the cut sheet cut to a predetermined length and a continuous sheet in which a plurality of sheets are connected. The cut sheet includes, for example, a cut sheet, a cut copy sheet, or a cut film, and the continuous sheet includes a continuous sheet and a continuous copy sheet.
[0033]
As shown in FIGS. 2, 3 and 6, the printer body 11 includes a base frame 14, a rear frame 15, a left side frame 16 and a right side frame 17 as body frames, and a recording head 18 as a recording mechanism. And a carriage 19, and a platen 20, a sheet guide 25, a first transport roller 21, a second transport roller 22, a third transport roller 23, and a fourth transport roller 24 as a sheet transport mechanism. .
[0034]
At approximately both ends of the base frame 14 and the rear frame 15, a left side frame 16 and a right side frame 17 are fixed upright. A carriage guide shaft 26 is bridged between the left side frame 16 and the right side frame 17 to be pivotally supported. Further, a platen 20 is bridged between the left side frame 16 and the right side frame 17 so as to be rotatable, and a seat guide 25 is further fixedly provided.
[0035]
As shown in FIGS. 3 and 6, the sheet transport mechanism including the platen 20 includes a first transport roller 21 and a second transport roller 22 with respect to the platen 20, and a third transport roller 21. 23 and a fourth transport roller 24 are arranged on the rear side of the printer main body 11, respectively. The first transport roller 21 and the second transport roller 22 are arranged vertically in contact with each other to form a pair, and constitute a front-side sheet transport roller 27. Further, the third transport roller 23 and the fourth transport roller 24 are arranged vertically in contact with each other to form a pair, and constitute a rear-side sheet transport roller 37.
[0036]
Among them, the first transport roller 21 and the fourth transport roller 24 are driving rollers as described later, and the second transport roller 22 and the third transport roller 23 are driven rollers. Further, the first transport roller 21 and the third transport roller 23 are disposed below the sheet guide 25 together with the platen 20, and the second transport roller 22 and the fourth transport roller 24 are disposed above the sheet guide 25. The upper portions of the platen 20, the first transport roller 21, and the third transport roller 23 project above the sheet guide 25.
[0037]
The platen 20, the first transport roller 21, and the fourth transport roller 24 are driven to rotate in the forward or reverse direction by a drive train wheel unit 34 shown in FIG. The drive wheel train 34 is installed on one of the left side frame 16 and the right side frame 17, for example, on the left side frame 16.
[0038]
The drive train wheel portion 34 includes a motor pinion 36 that is fixed to the drive shaft of a sheet conveyance motor 35 that can rotate forward or reverse, and is integrally rotated. The driving force from the motor pinion 36 is transmitted to the platen 20 via the plurality of reduction gears 48, 49 and 50, and further transmitted from the reduction gear 50 to the first transport roller 21 via the reduction gears 51 and 52. Further, it is transmitted from the reduction gear 49 to the fourth transport roller 24 via the reduction gears 53 and 54.
[0039]
As a result, the platen 20 and the first transport roller 21 rotate in the same direction and the fourth transport roller 24 rotates in the opposite direction, and the cut sheet or the continuous sheet is moved from the front to the rear of the printer main body 11 by an arrow A (FIG. 6). In the direction of arrow B (FIG. 6) from the rear of the printer body 11 to the front. Therefore, the cut sheet and the continuous sheet are conveyed in the sub-scanning direction orthogonal to the main scanning direction of the carriage 19 described later.
[0040]
The push tractor unit 12 shown in FIGS. 4 and 6 supplies a continuous sheet (for example, continuous paper) to the sheet transport mechanism provided with the platen 20, and has a pair of left and right tractors 28. The tractor 28 includes a tractor driving pulley (not shown) rotatably supported on a tractor driving shaft 29 and being slidable in the axial direction, and a tractor driving shaft 29 rotatably supported on a tractor guide shaft 30 and slidably in the axial direction. A tractor belt 31 is wound around the tractor driven pulley (not shown) and a sheet holding lid 32 is provided.
[0041]
The distance between the pair of tractors 28 can be adjusted according to the width of a continuous sheet (continuous paper) to be conveyed. Also, a plurality of pins 33 protruding from the entire outer periphery of the tractor belt 31 can be engaged with holes (not shown) formed on both sides in the width direction of the continuous sheet. The tractor belt 31 is also driven by the driving wheel train 34 (FIG. 3).
[0042]
That is, the driving force from the motor pinion 36 of the driving wheel train 34 is pushed from the transmission gear 55 provided on the roller shaft of the fourth transport roller 24 via the intermediate gears 56 and 57, as shown in FIG. The power is transmitted to a tractor drive gear (not shown) fixed to the tractor drive shaft 29 of the tractor unit 12, whereby the tractor belt 31 of the push tractor unit 12 can be driven.
[0043]
The push tractor unit 12 includes a platen 20, a front-side sheet conveying roller 27 (the first conveying roller 21 and the second conveying roller 22), and a rear-side sheet conveying roller 37 (the third conveying roller 23 and the fourth conveying roller 24). A continuous sheet such as continuous paper can be conveyed mainly in the direction of arrow B (FIG. 6) from the back of the printer main body 11 to the front, or can be conveyed in the direction of arrow A from the front of the printer main body 11 to the back.
[0044]
The sheet supply guide 43 shown in FIG. 1 is detachably mounted on the upper case 13A on the front side of the printer main body 11. The sheet supply guide 43 guides the cut sheets such as cut sheets or cut copy sheets when the cut sheets are supplied one by one from the front to the rear of the printer main body 11 by hand. The cut sheet guided by the sheet supply guide 43 is transported by a sheet transport mechanism such as the platen 20, the front sheet transport roller 27, and the rear sheet transport roller 37.
[0045]
The cut sheet feeder 44, also shown in FIG. The automatic supply is performed one by one.
[0046]
In other words, although not shown, the cut sheet feeder 44 picks up and supplies the uppermost cut sheet from a hopper that holds a plurality of cut sheets in a stacked state by the rotation of a supply roller. This is to separate the cut sheets which are fed together with the upper cut sheet by a separation mechanism. One or more rotations of the supply roller supply one cut sheet to the printer body 11.
[0047]
The supply roller of the cut sheet feeder 44 is also driven by the driving wheel train 34 (FIG. 3). That is, as shown in FIG. 4, the driving force from the motor pinion 36 of the drive train wheel portion 34 is transmitted from the transmission gear 55 provided on the roller shaft of the fourth transport roller 24 to the cut sheet via the intermediate gears 56 and 57. The power is transmitted to the supply roller driving gear of the feeder 44, whereby the supply roller of the cut sheet feeder 44 is driven.
[0048]
The intermediate gear 57 can be selectively meshed with the supply roller drive gear of the cut sheet feeder 44 and the tractor drive gear of the push tractor unit 12, and the contact pressure of the rear sheet transport roller 37 can be changed. The release mechanism 58 is a release mechanism. The release mechanism 58 switches the sheet use mode of the printer 10 according to the type of sheet (cut sheet, continuous sheet) supplied to the printer 10.
[0049]
The carriage 19 shown in FIGS. 2 and 3 is slidably inserted through the carriage guide shaft 26, is slidably contacted with the upper end of the rear frame 15, and further has the recording head 18 mounted thereon. Since the carriage guide shaft 26 is arranged in parallel with the platen 20, the carriage 19 is provided so as to be able to travel (scan) in the main scanning direction coinciding with the axial direction of the platen 20 and the carriage guide shaft 26.
[0050]
The carriage 19 is coupled to a timing belt 39 (FIG. 6) that is reciprocated by forward or reverse rotation of a carriage drive motor 38. Accordingly, the carriage 19 is guided by the carriage guide shaft 26 via the timing belt 39 by the forward or reverse rotation of the carriage drive motor 38, and is scanned leftward or rightward in FIGS. 2 and 3 in the main scanning direction. Here, the carriage drive motor 38 is configured by, for example, a stepping motor together with the sheet conveyance motor 35 and a platen gap adjustment motor 66 described later.
[0051]
As shown in FIG. 5, the carriage 19 is provided with a ribbon cassette mounting portion 40, and a ribbon cassette 40A containing an ink ribbon is mounted on the ribbon cassette mounting portion 40. Further, the carriage 19 is provided with a ribbon mask holder 41 for protecting the ink ribbon of the ribbon cassette from a sheet (cut sheet or continuous sheet) conveyed in contact with the platen 20.
[0052]
The ink ribbon in the ribbon cassette 40A is provided so as to be movable in front of the recording wire of the recording head 18 by a ribbon drive shaft (not shown) installed in the ribbon cassette mounting section 40.
[0053]
The recording head 18 has a large number of recording wires (not shown), and the ink ribbon is located in front of the recording wires in the projecting direction as described above. While traveling in the main scanning direction together with the carriage 19, the recording head 18 projects a recording wire and strikes the ink ribbon, and the ink on the ink ribbon is transported between the platen 20 and the recording head 18. The sheet is attached to a sheet (cut sheet or continuous sheet), and an image including characters is recorded on the sheet.
[0054]
The recording operation by the recording head 18 is such that one line of recording is performed by the recording wire of the recording head 18 while the carriage 19 is traveling leftward or rightward in the main scanning direction in FIGS. 2 and 3. Each time the sheet is a cut sheet, the sheet conveying mechanism (the platen 20, the first conveying roller 21, the second conveying roller 22, the third conveying roller 23, and the fourth conveying roller 24) is used for the sheet. Is a continuous sheet, the sheet transport mechanism unit and the push tractor unit 12 transport the sheet by a predetermined length (normal line spacing), respectively, and these operations are repeated.
[0055]
Here, the control of the sheet transport motor 35 for driving the platen 20, the first transport roller 21, the fourth transport roller 24, the push tractor unit 12, and the cut sheet feeder 44 shown in FIG. 38, control of a recording operation by a recording wire of the recording head 18, control of a release drive motor (not shown) for operating a release mechanism 58 shown in FIG. 4, and an automatic platen gap adjustment mechanism described later shown in FIG. The control of the platen gap adjusting motor 66 in 65 is performed by a control board unit 75 (FIG. 6) as a control device.
[0056]
The control board section 75 is disposed, for example, below the sheet guide 25 in front of the printer main body 11. Further, detection signals from a rotary encoder 67 and sheet detectors 45 and 46 to be described later are input to the control board unit 75.
[0057]
By the way, in the printer 10, as shown in FIG. 5, the carriage guide shaft 26 is rotated according to the sheet thickness of the supplied sheet, and the platen gap between the recording head 18 and the platen 20 is adjusted. An automatic platen gap adjustment mechanism 65 is provided.
[0058]
The automatic platen gap adjustment mechanism 65 includes a platen gap adjustment motor 66, a rotary encoder 67, an output gear 68, reduction gears 69, 70 and 71, and a control board unit 75. One of the eccentric shafts 72 (FIG. 6) at both ends of the carriage guide shaft 26 is fixed coaxially with the eccentric shaft 72. An eccentric amount L by which the eccentric shaft 72 is eccentric with respect to the carriage guide shaft 26 is, for example, about 1 mm. The carriage guide shaft 26 is rotatably supported by the side frames 16 and 17 via both eccentric shafts 72.
[0059]
The output gear 68 is fixed to an output shaft of a motor 66 for adjusting a platen gap, and a reduction gear 69 meshes with the output gear 68 as shown in FIG. The reduction gear 70 is formed integrally with the reduction gear 69 so as to rotate, and meshes with the reduction gear 71. As a result, the driving force of the motor 66 for adjusting the platen gap is transmitted to the eccentric shaft 72 via the output gear 68 and the reduction gears 69, 70 and 71, and the carriage guide shaft 26 is rotated. Then, the carriage guide shaft 26 moves up and down in the vertical direction by an amount corresponding to the amount of eccentricity L with the eccentric shaft 72 (for example, 2 mm in the case of L = 1 mm), and the recording head 18 20.
[0060]
The rotary encoder 67 includes a slit plate 73 provided integrally with the output shaft of a motor 66 for adjusting the platen gap, and a light emitting and receiving device including, for example, a light emitting diode and a photodiode arranged opposite to the slit plate 73. 74, and is operatively connected to a motor 66 for adjusting the platen gap. The light emitted from the light emitting diode of the light emitting and receiving device 74 and passing through the slit of the slit plate 73 is received by the photodiode of the light emitting and receiving device 74 and converted into a pulse wave. The rotation angle of the adjustment motor 66 is detected.
[0061]
FIG. 7 is a diagram schematically showing the arrangement of the recording head 18 and the platen 20.
[0062]
In the above configuration, the platen 20 is a cylindrical platen. The cylindrical platen 20 does not become a true cylinder due to processing errors, but is distorted in both the circumferential direction and the girder direction. As a result, the platen gaps G1 and G2 between the recording head 18 and the platen 20 change. For example, even if the platen gap G1 between the recording head 18 and the platen 20 is properly adjusted at the position A, if recording is performed by the recording head 18 at the position B, the platen gap G2 is Is improper, and consequently the recording density varies, and the recording quality is degraded.
[0063]
In this embodiment, at the time of shipment from the factory, the platen gap G between the recording head 18 and the platen 20 is measured in advance in a plurality of locations in the circumferential direction and the girder direction of the platen 20, and a platen surface data table is prepared. Is created.
[0064]
FIG. 8 shows a control flow at the time of this creation. When the creation sequence of the platen surface data table is started, first, the initial position of the rotation angle of the platen 20 is recognized according to a predetermined rotation angle initial position recognition sequence (S1). In the recognition sequence in this case, as shown in FIG. 9, the carriage 19 is moved to the initial position recognition position located at the end of the carriage movement area (S11), and the platen rotation angle flag is set by the rotary encoder 67 at that position. Is detected (S12), and the rotation angle counter at that position is reset (S13). Thereafter, in this control flow, the rotation angle counter is reset for each pulse corresponding to one rotation of the platen, so that the rotation angle of the platen 20 can be detected.
[0065]
Next, in FIG. 8, the initial position of the platen 20 in the digit direction is recognized according to a predetermined digit initial position recognition sequence (S2). In the recognition sequence in this case, as shown in FIG. 10, the carriage 19 is moved in the direction of the carriage digit initial position detector located at the end of the carriage movement area (S21), and the position is detected (S22). ), The digit position counter at that position is reset (S23). The detection by the digit initial position detector is performed, for example, by a sheet edge detection sensor (not shown) mounted on the carriage 19 detecting an object to be detected provided at an initial position of the platen 20 in the digit direction.
[0066]
In the case of a cylindrical platen, the initial position of the rotation angle and the initial position in the girder direction are recognized, and two-dimensional data is created.
[0067]
Next, the distance from the recording head 18 to the platen surface of the platen 20 is measured in advance in a plurality of locations in a circumferential direction and a digit direction in the recording area of the platen 20 according to a predetermined measurement sequence (S3). In this measurement sequence, as shown in FIG. 11, first, the recording head 18 is moved to the first measurement point among a plurality of measurement points on the platen 20 set in advance (S31). The distance to the surface is measured (S32), the measurement data is stored (S33), it is determined whether or not the measurement point is completed (S34), and S31 to S33 are repeated until the measurement point is completed. In S31 to S33, for example, the rotation angle of the platen 20 is adjusted to a predetermined rotation angle, and the recording head 18 is moved from the recording head 18 at a plurality of measurement points in the digit direction corresponding to the rotation angle while moving the carriage 19. The distance to the surface of the platen 20 is measured, and then the platen 20 is rotated by a predetermined angle, and the carriage 19 is moved at the rotation angle, and recording is performed at a plurality of measurement points in the girder direction corresponding to the rotation angle. The distance from the head 18 to the platen surface of the platen 20 is measured, and this measurement is repeated at appropriate intervals in the circumferential direction to measure over 360 °.
[0068]
In S32, for example, the recording head 18 at the measurement reference position is moved to the platen 20 side until the recording head 18 contacts the platen 20, and the fact that the recording head 18 has contacted the platen 20 is indicated by the rotary encoder 67. The distance from the recording head 18 to the surface of the platen 20 (the platen surface measurement) is detected by detecting the change in the pulse waveform detected in step (1) and detecting the distance between the contact position and the measurement reference position by the number of pulses. Value).
[0069]
Next, in FIG. 8, in S4, a platen surface average value is obtained from all platen surface measurement values (S4), and this platen surface average value and all platen surface measurement values are not shown in the control board unit 75. The data is stored in a non-volatile memory (such as an EEPROM or a flash memory) (S5).
[0070]
In the above configuration, an example in which the platen surface data table is created at the time of shipment from the factory is shown. However, the present invention is not limited to this, and a platen surface measurement mode is provided. Alternatively, the sequence may be such that the platen surface data table is updated and stored.
[0071]
This is because it is important to update the platen surface data every time the recording head is replaced or the alignment is corrected, in order to improve the recording accuracy in consideration of the aging of the recording apparatus.
[0072]
FIG. 12 is a flowchart showing an example in which the platen surface data table is used for platen gap adjustment. Here, the recognition of the initial position of the rotation angle of the platen 20 and the recognition of the initial position in the digit direction are performed at the time of starting the printer, after returning from the energy saving mode, or before measuring the platen gap, and then the subsequent processing is started. Normally, the platen gap adjustment measures the distance (platen surface measurement) from the recording head 18 to the surface of the platen 20 in a procedure similar to S32 in FIG. 11 and then feeds the sheet onto the platen 20 11, the distance from the recording head 18 to the sheet surface on the platen 20 (sheet surface measurement) is measured, and the sheet thickness is detected from the difference between the measured values. The recording is performed by separating the recording head 18 from the platen 20 according to the thickness.
[0073]
In the present embodiment, first, the platen surface data table is read from the memory (S41). This data is used for platen gap adjustment in the following steps. According to this, in the platen gap adjustment, it is not necessary to perform the platen surface measurement each time, and only the sheet surface measurement is required, so that the throughput of the platen gap adjustment is improved.
[0074]
Next, after the sheet is supplied onto the platen 20, a distance (sheet surface measurement) from the recording head 18 to the sheet surface on the platen 20 is measured by a procedure similar to S32 in FIG. 11 (S42). From the difference between the distance to the actual sheet surface and the distance to the platen surface according to the platen surface data table corresponding to the position, the sheet thickness of the sheet to be supplied is determined. Thus, the platen gap is determined (S43). In this case, the determined platen gap is not always an appropriate value at any position on the platen 20. As shown in FIG. 7, the cylindrical platen 20 is not a true cylinder due to an error in processing, and is distorted in both the circumferential direction and the spar direction. is there. Therefore, in S43, the determined platen gap is corrected using the platen surface average value obtained in S4 of FIG. For example, in FIG. 7, the average value of the platen surface in the digit direction is substantially the platen gap G <b> 3 at the position C. In S43, when the sheet surface measurement is performed at the position A and the platen gap G1 between the recording head 18 and the platen 20 is determined at the position A, the platen gap G1 is compared with the average value, Should be decided a little smaller. On the other hand, when the sheet surface measurement is performed at the position B and the platen gap G2 between the recording head 18 and the platen 20 is determined at the position B, the platen gap G2 is determined to be slightly larger than the average value. It should be. Therefore, in order to obtain a truly proper gap, the determined platen gap is corrected in S43.
[0075]
In step S43, the sheet surface measurement value is corrected by the platen surface average value, and the sheet thickness is calculated based on the difference between the corrected sheet surface measurement value and the distance to the platen surface according to the platen surface data table corresponding to the position. And the platen gap may be determined in consideration of the sheet thickness.
[0076]
When the platen gap is determined in S43, the automatic platen gap adjusting mechanism 65 shown in FIG. 5 is driven, and the platen gap is adjusted so as to match the platen gap setting value (S44). Next, desirably, platen gap delay control is performed (S45), and thereafter, recording such as printing is performed according to a predetermined recording timing (S46).
[0077]
The above configuration has been described on the assumption that the sheet surface measurement is performed at an arbitrary position.However, assuming that the sheet surface measurement is performed at a predetermined position, the storage unit stores the platen surface data table. However, only the platen surface data at a predetermined position need be stored. In this case, in order to adjust the platen gap at the same position, the carriage 19 is moved to that position, and the platen 20 is rotated at a predetermined rotation angle.
[0078]
FIG. 14 shows the principle of platen gap delay control. The recording head 18 has a recording wire. Here, the moving speed Vcr of the carriage 19, the flight speed Vw of the recording wire, the distances L and L 'from the recording head 18 to the sheet surface, the flight times T and T' of the recording wire, from the recording wire launch position to the sheet surface arrival. Where Δk and Δk ′ are
T = L / Vw
Δk = Vcr × T = Vcr × L / Vw
And the recording deviation amount Δ is
Δ = Δk−Δk ′ = (L−L ′) × Vcr / Vw (1)
It becomes. According to the equation (1), the shift amount Δ increases in proportion to the error LL ′ of the platen surface and the moving speed Vcr of the carriage 19, and the higher the moving speed Vcr, the greater the error L−L ′ of the platen surface. Under the influence of L ', there is a possibility that the recording deviation amount [Delta] increases and the recording quality deteriorates.
[0079]
In the present embodiment, the platen gap delay control in S45 in FIG. 12 is performed according to the flowchart in FIG.
[0080]
That is, the platen surface data table is read from the memory (S51), platen surfaces corresponding to a plurality of positions on the platen 20 are obtained, and all deviation amounts at the positions are determined with reference to Expression (1). The delay amount Δ is calculated, and a delay amount table is calculated (S52). Then, in response to the recording command, a delay amount corresponding to the recording position is read, and according to the delay amount, the recording timing of the recording wire in recording at the position is corrected, and recording is performed at the corrected timing ( S53). For example, when recording is performed at a position where the distance to the platen surface is large, recording is performed earlier than the average timing, and when recording is performed at a position where the distance to the platen surface is small, the recording is performed later than the average timing. Recording is performed at the timing of
[0081]
As described above, the present invention has been described based on the embodiment, but the present invention is not limited to this. Although the cylindrical platen has been described, the present invention is not limited to this, and can be applied to, for example, a flat platen. In this case, the initial position is provided in, for example, the girder direction and a direction orthogonal thereto.
[0082]
【The invention's effect】
According to the present invention, it is possible to correct an error in the distance between the recording head and the platen caused by a dimensional error in processing the platen, an error in mounting the platen, and the like.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a dot impact printer to which an embodiment of a recording apparatus according to the present invention is applied.
FIG. 2 is a perspective view of the printer main body with an upper case removed.
FIG. 3 is a perspective view illustrating a printer main body.
FIG. 4 is a perspective view illustrating a sheet conveying mechanism of the printer body.
FIG. 5 is an enlarged perspective view showing a printer main body.
FIG. 6 is a sectional view taken along the line VI-VI in FIG. 3;
FIG. 7 is a schematic diagram illustrating positions of a recording head and a platen.
FIG. 8 is a flowchart illustrating a platen surface data table creation sequence.
FIG. 9 is a flowchart showing a rotation angle initial position recognition sequence.
FIG. 10 is a flowchart showing a digit initial position recognition sequence.
FIG. 11 is a flowchart illustrating a platen surface reference data measurement sequence.
FIG. 12 is a flowchart showing a sequence from sheet thickness measurement to recording.
FIG. 13 is a diagram illustrating the principle of platen gap delay control.
FIG. 14 is a flowchart illustrating platen gap delay control.
[Explanation of symbols]
10 Printer (recording device)
11 Printer body
18 Recording head
19 Carriage
20 Platen
65 Automatic platen gap adjustment mechanism
66 Platen gap adjustment motor
67 Rotary encoder
75 Control board
76 Seat surface

Claims (18)

A recording apparatus that records an image on a sheet supplied by striking a recording wire via an ink ribbon to a sheet supplied between a recording head and a platen,
A recording apparatus comprising: a storage unit that stores a measurement data table of the distance between the recording head and the platen surface, which is measured in advance at a plurality of locations within the moving range of the recording head. The distance between the recording head and the sheet surface is measured, and the measured distance is subtracted from the distance between the recording head and the platen surface obtained from the measurement data table to detect the thickness of the sheet. 2. The recording apparatus according to claim 1, further comprising a platen gap adjusting mechanism for determining a platen gap. 3. The recording apparatus according to claim 2, further comprising means for correcting the determined platen gap with an average value of all distances in the measurement data table. 2. The recording apparatus according to claim 1, further comprising means for correcting recording timing of the recording wire according to a distance between the recording head and the platen surface obtained from the measurement data table. 5. The recording apparatus according to claim 1, wherein the storage unit is a memory that can be held even in a power-off state. 6. The storage means according to claim 1, wherein a measured data table of the distance between the recording head and the platen surface measured at a plurality of positions in the beam direction and the circumferential direction of the cylindrical platen is stored. A recording device according to claim 1. 7. The recording apparatus according to claim 1, further comprising means for storing the measurement data table in the storage means at the time of factory shipment. 7. The recording apparatus according to claim 1, further comprising: a storage unit configured to store a measurement data table when the platen surface measurement mode is selected. In a platen gap adjusting method of a recording apparatus that records an image on a sheet by hitting a recording wire via an ink ribbon on a sheet supplied between a recording head and a platen,
Within the moving range of the recording head, the distance between the recording head and the platen surface is measured in advance at a plurality of locations and stored in a measurement data table, and the distance between the recording head and the sheet surface is measured. Is subtracted from the distance between the recording head and the platen surface obtained from the measurement data table to detect the thickness of the sheet, and the platen gap is adjusted based on the thickness of the sheet. Adjustment method. The platen gap adjusting method according to claim 9, wherein the determined platen gap is corrected by an average value of all distances in the measurement data table. 11. The platen gap adjusting method according to claim 9, wherein a measurement data table is stored when the platen surface measurement mode is selected. In a platen gap adjustment mechanism of a recording apparatus that records an image on the sheet by hitting a recording wire via an ink ribbon to a sheet supplied between a recording head and a platen,
Within the moving range of the recording head, the distance between the recording head and the platen surface is measured in advance at a plurality of locations and stored in a measurement data table, and the distance between the recording head and the sheet surface is measured. Is subtracted from the distance between the recording head and the platen surface obtained from the measurement data table to detect the thickness of the sheet, and the platen gap is adjusted based on the thickness of the sheet. Adjustment mechanism. The platen gap adjusting mechanism according to claim 12, wherein the determined platen gap is corrected with an average value of all distances in the measurement data table. 14. The platen gap adjusting mechanism according to claim 12, wherein a measurement data table is stored when a platen surface measurement mode is selected. In a recording wire recording timing control method in a recording apparatus for recording an image on the sheet by hitting a recording wire via an ink ribbon to a sheet supplied between a recording head and a platen,
Within the movement range of the recording head, the distance between the recording head and the platen surface is measured at a plurality of locations in advance and stored in the measurement data table, and the distance between the recording head and the platen surface obtained from the measurement data table is calculated. A recording timing control method for a recording wire, wherein the recording timing of the recording wire is corrected accordingly. 16. The recording wire recording timing control method according to claim 15, wherein a measurement data table is stored in the storage unit when the platen surface measurement mode is selected. In a recording timing control mechanism of a recording wire in a recording apparatus for recording an image on a sheet by hitting a recording wire via an ink ribbon on a sheet supplied between a recording head and a platen,
Within the movement range of the recording head, the distance between the recording head and the platen surface is measured at a plurality of locations in advance and stored in the measurement data table, and the distance between the recording head and the platen surface obtained from the measurement data table is calculated. A recording timing control mechanism for a recording wire, wherein the recording timing of the recording wire is corrected accordingly. 18. The recording timing control mechanism for a recording wire according to claim 17, wherein a measurement data table is stored in the storage unit when the platen surface measurement mode is selected.

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