JP3514405B2 - Serial printer bidirectional printing position adjustment device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bidirectional printing position adjusting device for a serial printer. 2. Description of the Related Art In general, a serial printer performs printing in the process of moving a carrier in both directions, right and left, in order to speed up printing. In this case, the printing position differs depending on the moving direction of the carrier due to the influence of the elongation of the belt for driving the carrier. This difference is caused by subtle variations in assembly, even for the same type of printer. For this reason,
Adjustment (alignment adjustment) of the printing position caused by the moving direction of the carrier is performed for each printer. That is, bidirectional printing positions are equalized by correcting the drive timing of the print head according to the difference in the printing position depending on the moving direction of the carrier. On the other hand, in order to speed up printing, it is necessary to increase the driving cycle of the print head, but there is a limit. Therefore, even if the dot density changes depending on the selected character font and pitch, the carrier speed is changed without changing the print head driving cycle. When the carrier speed is different, the elongation of the belt for driving the carrier is affected, and the printing position is also affected. However, since there are about 30 types of carrier speeds depending on the print head mounted on the carrier, it is very difficult to perform the alignment adjustment for each carrier speed. Going at speed. [0004] Conventionally, alignment adjustment is performed at a standard one carrier speed.
When printing is performed at a carrier speed having a large speed difference from the standard carrier speed, a printing position error due to a difference in the moving direction of the carrier is large. According to the present invention, there is provided a carrier driving section for reciprocatingly driving a carrier on which a print head is mounted along a platen, and a printing position depending on a difference in a moving direction of the carrier for each carrier speed. deriving an operating unit for inputting an alignment adjustment value for adjusting the difference, and a storage unit for storing the alignment adjustment value input by the operation unit, by two of the alignment adjustment value corresponding to each of the two kinds of carrier velocity Calculating means for calculating an alignment adjustment value corresponding to a desired carrier speed based on a linear function to be performed; and a head for correcting the timing of driving the print head based on the alignment adjustment value corresponding to a desired carrier speed Output timing correction means. Accordingly, when an alignment adjustment value for adjusting the difference in the printing position due to the difference in the moving direction of the carrier for each carrier speed is input from the operation unit, a desired carrier is determined based on the two alignment adjustment values corresponding to each of the two carrier speeds. Calculating means calculates an alignment adjustment value corresponding to the speed, and the timing of the drive timing of the print head is corrected based on the calculated alignment adjustment value. An embodiment of the present invention will be described with reference to the drawings. In FIG. 1, a ROM 1 in which fixed data such as a program is stored, a CPU 2 showing a function as a calculating means and a head output timing correcting means to be described later and controlling the operation of other parts, and an NVRAM 3 as a storage part. Is connected. To the CPU 2, a carrier driver 4, a head driver 5, a transport driver 6, a panel key 7, and the like as a carrier driving unit are connected. The carrier driver 4 is connected to a forward / reverse rotatable carrier motor 8 for reciprocatingly driving a carrier (not shown) along a platen (not shown). A print head (a wire dot printer head in this example) 9 mounted on a carrier is connected to the head driver 5. The transport driver 6 is connected to a paper feed motor 10 that drives a transport mechanism (not shown) that transports printing paper. That is, the carrier moves in an arbitrary direction by driving the carrier motor 8 by the carrier driver 4, and in this process, printing is performed by driving the print head 9 by the head driver 5. When the paper feed motor 10 is driven by the transport driver 6, the transport mechanism is driven, and the recording paper is transported. In a serial printer, when performing bidirectional printing, a difference occurs in a printing position depending on a moving direction of a carrier. Therefore, alignment adjustment is performed at the time of shipment from a maker or at the time of maintenance performed over a user. The panel key 7 also has a function as an operation unit for inputting an alignment adjustment value for adjusting a difference in printing position due to a difference in the moving direction of the carrier for each carrier speed. Hereinafter, the alignment adjustment will be described with reference to the flowchart shown in FIG. First, when an alignment adjustment mode is set by a key operation (not shown), bidirectional printing in which the carrier moving speed is set to a specific carrier speed A is executed. In this case, there may be a difference between a printing position printed when the carrier is moved from the left side to the right side and a printing position printed when the carrier is moved from the right side to the left side. This difference can be visually confirmed by actually printing out. If it is necessary to adjust the difference, an alignment adjustment value (α value) corresponding to the confirmation result is increased in the panel key 7.・ Input by operating the down key. The quality of the alignment adjustment value can be visually checked by reprinting or the like. When the confirmation key of the panel key 7 is turned on after the input of the alignment adjustment value, bidirectional printing in which the moving speed of the carrier is set to the specific carrier speed B is executed. Also in this case, similarly to the case of the carrier speed A, if the alignment adjustment value (β value) is input by using the up / down keys of the panel key 7 and the confirmation key of the panel key 7 is turned on, the input is made. Two alignment adjustment values (α value, β value) are NVRA
This is stored in M3, at which point the alignment adjustment processing ends. In this case, the initial α value is temporarily held in another storage area or the like, and is then determined as a value fixed together with the β value.
The data is transferred to the VRAM 3, but may be stored in the NVRAM 3 immediately when the α value is input. Next, the printing start process will be described with reference to the flowchart shown in FIG. At the time of printing, a desired carrier speed corresponding to the selected character font, pitch, and the like is determined. Thereafter, the CPU 2 calculates an alignment adjustment value corresponding to the determined carrier speed based on the determined carrier speed and the alignment adjustment value recorded in the NVRAM 3, and reflects the alignment adjustment value on the launch position. Start printing. Here, the formula for calculating the alignment adjustment value will be described. The setting values recorded in the NVRAM 3 are α for the carrier speed A and β for the carrier speed B. As shown in FIG. 4, the change of the alignment adjustment value with respect to the change of the carrier speed includes two types of carrier speeds A,
B, two alignment adjustment values α corresponding to each of
Assuming that it is on a linear function created based on β,
The alignment adjustment value γ corresponding to the carrier speed C determined at the time of actual printing can be calculated by γ = {(α−β)} (AB)} × (CB) + β. Here, the change in the printing position before and after the alignment adjustment will be described with reference to FIG. Taking the case of printing the character "H" as an example, the print position printed when the carrier is moved from left to right (upper row in FIG. 5)
And a print position (the middle part in FIG. 5) where printing is performed when the carrier is moved from the right side to the left side. Reflecting in the launch position of the print head 9 based on the result of the alignment adjustment means that the starting point R or L is set shortly before the start of the launch and the distance from the starting point R or L to the start of the launch is a. To b. R is the starting point of rightward printing, and L is the starting point of leftward printing. By adjusting the distance b, the print position in both directions is determined equally (lower part in FIG. 5). Adjusting the distance a until the CPU 2 starts the launch from the starting point R or L means that the timing of the drive timing of the print head 9 is corrected based on the alignment adjustment value corresponding to the determined carrier speed. It is equivalent to doing. That is, the CPU 2 also has a function as the above-described head output timing correction means. Incidentally, even when a thermal printer head or an ink jet printer head is used as the print head 9, printing may be performed while changing the carrier speed, so that the present invention can be applied. As described in the present embodiment, when a wire dot printer head is used as the print head 9, the number of changes in the carrier speed may be as large as more than 30. Therefore, the alignment adjustment of the two carrier speeds is performed. The fact that the alignment adjustment for an arbitrary carrier speed can be obtained only by the value can greatly contribute to facilitating the adjustment operation. In addition, it is possible to accurately adjust the shift of the printing position in the bidirectional printing to improve the printing quality. According to the present invention, two alignment adjustment values corresponding to each of the two carrier speeds are stored in the storage unit, and are derived from the two alignment adjustment values.
Based on the linear function , an alignment adjustment value corresponding to a desired carrier speed is obtained by a computing unit, and a timing of a print head drive timing is corrected by a head output timing correction unit based on an alignment adjustment value corresponding to a desired carrier speed. Therefore, the alignment adjustment work can be extremely facilitated, and the printing quality can be improved by accurately adjusting the printing position shift in bidirectional printing.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of an electronic circuit according to an embodiment of the present invention. FIG. 2 is a flowchart illustrating alignment adjustment processing. FIG. 3 is a flowchart illustrating a print start process. FIG. 4 is a graph showing a change in an alignment adjustment value with respect to a change in a carrier speed. FIG. 5 is an explanatory diagram showing a state of a printing position before and after alignment adjustment. [Description of Signs] 2 Calculation means, head output timing correction means 3 Storage unit 4 Carrier drive unit 7 Operation unit 9 Print head

Claims (1)

(57) [Claim 1] A carrier driving section for reciprocatingly driving a carrier on which a print head is mounted along a platen, and a printing position difference due to a difference in a moving direction of the carrier for each carrier speed. An operation unit for inputting an alignment adjustment value to be adjusted; a storage unit for storing the alignment adjustment value input by the operation unit; and a storage unit for deriving the alignment adjustment value corresponding to each of two carrier speeds.
Calculating means for calculating an alignment adjustment value corresponding to a desired carrier speed based on a linear function to be obtained, and a head output for correcting the timing of driving the print head based on the alignment adjustment value corresponding to a desired carrier speed A bidirectional printing position adjusting device for a serial printer, comprising: timing correction means.