JPS62231777A - Tof-of-form adjustment for printer - Google Patents

Abstract

PURPOSE:To provide a TOF adjusting method by which a TOF located between a TOF sensor and a recording head can be corrected easily and accurately, by adjusting the TOF through controlling a reading-starting address in a data memory. CONSTITUTION:When a recording head is deviated from a normal position by a 4-dot amount in a paper-feeding direction, a reading-starting address in a data memory is correctively shifted by a 4-dot amount in the direction of higher writing order of data, and reading positions for color data are shifted under control to positions LA, LB, LC, LD which are shifted from reference positions by a 4-dot amount in the direction of lower reading order, respectively. By thus controlling the reading-starting address in the data memory according to the positional deviation of the recording head, a TOF can be adjusted easily and accurately. The timing for starting reading the addresses in the memory is set at the time when a predetermined number of paper-feeding pulses are counted after detecting a TOF mark.

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a TOF (TOP OF F○) of a printer.
RM) It relates to an adjustment method, and particularly to a method of adjusting a mechanical TOF deviation between a TOF sensor and a recording head.

(Prior art) For example, in a full multi-recording head of a color printer, the first
As shown in the figure, for example, from bottom to top, there are four colors of yellow, magenta, cyan, and black: LA, IB.
, IC, and ID are arranged vertically, and recording is performed by feeding the recording paper 2 in the direction of the arrow with respect to this recording head (head assembly having four hend units).

The recording paper 2 is provided with TOF marks 3 at predetermined intervals, which serve as a reference for setting the recording start position.
Recording is started from a predetermined position on the sheet 2 by detecting the TOF mark 3 at sensor position 4).

In this case, when recording a color image or color graph displayed on a monitor screen such as a CRT, there is a mechanical misalignment between the TOF sensor 4 and the recording head as shown in FIG. If there is a deviation δ in the paper feeding direction (the same applies in the opposite direction), this deviation will cause the TO
F deviation occurs.

This TOF shift causes a shift in the image recording position on the recording paper 2, so it is necessary to reduce it as much as possible.

However, with the conventional technology, it is extremely difficult to adjust such TOF deviation.

Furthermore, since the head assembly (recording head) can be removed and replaced, there is also the problem that TOF deviation cannot be guaranteed during replacement.

〔the purpose〕

The purpose of the present invention is to solve the problems of the prior art,
It is an object of the present invention to provide a T OF Mm adjusting method that can easily and accurately correct the TOF between a TOF sensor and a recording head.

〔overview〕

A feature of the present invention is that the above object is achieved by controlling the reading start address of the data memory of the printer to be read by shifting it by an amount corresponding to the mechanical deviation of the recording head.

〔Example〕

The present invention will be specifically described below with reference to FIGS. 3 to 7.

FIG. 3 is a block diagram of the printer control system.

In FIG. 3, data sent from the host computer IO is divided into yellow, magenta, cyan, and black color data by a switching device (MUX) l1, and each color data memory (RAM) 12A, 12B, 12c
, is switched and transmitted to L2D.

Each memory has a capacity to store data for each color for one page of paper.

The data stored in each data memory 12A to 12D is
The data is sent to the corresponding head units IA to ID, and recording is performed by driving each head unit based on the data.

Reference number 13 indicates a control unit, which controls the operation of the switching device 1), writes to each data memory 12A to 12D, and writes information from each data memory to each head unit IA to I.
Operations such as reading to D are controlled.

One page of each color data to be transmitted is sequentially 12A-12
It has a memory address counter for writing and a read address counter for reading, which control the switching device 1) to store and switch data in D.

FIG. 4 shows the structure of one line of data sent from the host computer IO, with one line in the recording paper. This data includes yellow data 14A and magenta data 14B.
, cyan data 14C1, and black data 14D.

Further, data from the host computer is sent to the blank data 14D first and written into the data memory, contrary to the recording order (reading order from the data memory).

Furthermore, there is a DH (data header) at the front and rear of each color data.
15A, 15B, 15C, 15D and DT (data terminal) 16A, 16B, 16C1)6D are provided.

Therefore, according to the present invention, data memories 12A-12D
Each color data entered in the Hend Unisoto IA of each color
~ When sending IDB, by controlling the data readout start address to be shifted by an amount corresponding to the discrepancy between the TOF sensor number 4 and the recording head (head assembly month),
TOF is adjusted.

Figure 5 shows the relationship between the write position (entrance) W of each color data in the data memory (RAM) of each color and the read reference position (reference address) LA, LB, LC, LD of each color data of yellow, magenta, cyan, and blank. show.

In the case of memory 12B, LB corresponds to it. The write start address is constant regardless of 12A to 12D.

Further, adjustment can be made by ±32 lines, and the adjustment is performed by 1/4 line. This is done by inputting adjustment data α to the control unit 13 to control the read address counter in the vertical direction of the memory. This counter counts signals indicating lines in the memory to proceed with vertical reading, and this is done by determining this initial value.

Therefore, as an example, a case will be explained in which the recording head is shifted by four dots in the paper feeding direction with respect to its normal position.

In this case, the read start address of the data memory is corrected to a position shifted by 4 dots in the earlier direction of the data write order, and as shown in FIG. The positions LA, LB, which are shifted by 4 dots in the direction where the readout order is slower than the
It is controlled to become LC and LD.

In this way, by controlling the read start address of the data memory according to the displacement of the recording head, it was possible to easily and accurately adjust the TOF.

The reading start timing t1 of this address in the memory is when a predetermined number of paper feed pulses have been counted since the detection of the TOF mark.

FIG. 7 is a program for the memory read process of the read address counter in the control unit 13. Since the head assembly misalignment δ is 4 dots (4 lines), m
=4.

Furthermore, if there is a deviation of n lines between each head IA to ID, the read address Y of the memory 12A at a certain time
A is y-4, 7-dress YB of memory 12B is y-n-4
, the address YC of the memory 12G is y-2n-4, and the address YD of the memory 12D is y-3n-4.

Therefore, at the read start timing tl (y=0), the addresses YA-YD are -4, -n-4°-2n-4,
-3n-4, so no data is output. Then, when reading progresses one line at a time in the y direction (paper feeding direction) and advances by 4 lines, that is, when y becomes 4 in step 6, Y
A-YD accesses addresses 0, -n, -2n, and -3n, respectively. If data exists at the address YA=O, the data is output to the yellow hand and printing of yellow is started. Furthermore, reading progresses as the paper feeds, and further n
When the line advances, YB=O (step 3), and if data exists at this address, the data is output to the magenta head and magenta printing is started.

Similarly, YC=O, YD=O, and output of each color data of the same line is sequentially started corresponding to the color head position.

Note that 30+4 (=y) from the read start timing t1
When the paper advances by one line, the addresses YA-YD become 3n, 2n, n, and 0, respectively, so the color line data of each address is output at that time.

Each time one line is read from the memory, the process repeats from step 2 again in synchronization with the paper feed.

When the number of lines ym for one page is reached (step 7),
The count y of the address counter is reset to 0, and it is determined whether or not to print the next second page (step 9). If it is not the last page, steps 2 and subsequent steps are repeated until the last page.

It should be noted that the steps after step knob 2 in FIG. 7 are executed by a program interrupt or the like by the paper feed pulse after tl or line data DH from the memory.

Further, when selecting a desired print position, it is possible to select the desired print position by arbitrarily selecting the wing adjustment amount such as address control.

Furthermore, as another embodiment, T0FM adjustment can also be performed by making the count from TOF detection of pulses synchronized with paper feeding variable, and starting recording from a time point t1 with a different count depending on the misalignment of the recording head. be able to.

The paper feed pulse is composed of a pulse signal for each dot as shown in FIG.

Therefore, for example, if the recording head deviates from its normal position by 4 dots in the paper feeding direction, and if the normal recording start count number N is 4, then the recording start count number will be corrected by 4 dots and the recording will be performed. By controlling the starting count number N = 8, it is possible to obtain the same effect as when controlling the data read start address described above, and the same T
I was able to perform OF II adjustment. In this case, address access is performed with m in FIG. 7 set to 0.

In the above embodiment, four hesod units I-IA to ID
Although the description has been given by exemplifying the case of a full multi-recording head equipped with a recording head, the present invention can be applied regardless of the number of head units. Furthermore, it can be used regardless of recording methods such as inkjet and thermal transfer.

〔effect〕

As is clear from the above explanation, according to the present invention, it is possible to easily and accurately adjust the printer's T OF can be easily dealt with.

[Brief explanation of drawings]

FIG. 1 is a schematic perspective view illustrating a full multi-recording head of a printer, FIG. 2 is a schematic explanatory diagram illustrating the misalignment between the TOF sensor and the recording head in FIG. 1, and FIG. 3 is a diagram illustrating the present invention. FIG. 4 is an explanatory diagram showing an example of the structure of data sent from the host computer in FIG. 3, and FIG. 5 is a block diagram of a control system of a printer suitable for implementing the present invention. An explanatory diagram illustrating the adjustment state of the data read position of the memory, FIG. 6 is an explanatory diagram illustrating the adjustment of the count number of paper feed pulses when implementing the present invention in another embodiment, and FIG. FIG. 2 is a flowchart of memory address control in FIG. IA~ID----Head unit (recording head)
, 12A~12D---Data memory, LA~
LD・～−・Regular data read position, LA-LD・
−・−Data read position after adjustment. Agent Patent Attorney Yasushi Ooto Grain cylinder 3 Figure 4 Figure 5 W Figure 6 Figure 7

Claims (1)

[Claims] (1) In a printer equipped with a full multi-recording head, a method characterized in that TOF is adjusted by controlling a read start address of a data memory.