JP2000141766A - Recording apparatus and recording method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correct a hit position displacement due to thermal expansion by obtaining a displacement amount due to thermal expansion in an arrangement direction of recording elements based on a predetermined amount of print data, shifting and assigning data to be assigned to other recording elements by an amount corresponding to a predetermined displacement amount for every recording element group on the basis of the obtained displacement amount. SOLUTION: Data related to a thermal expansion compression of printing heads 1C, 1M, 1Y and 1X is input to a ROM 52. A control part 5 obtains an amount of print data supplied to the printing heads 1C, 1M, 1Y and 1X at a previous printing operation, applies the amount to a data table stored in the ROM 52, obtains temperature change data and total length change data, and obtains a total length change value of the printing heads 1C, 1M, 1Y and 1X. A boundary position of each discharge opening displaced from an ideal position is obtained on the basis of the total length change value. Print data for each discharge opening is shifted and printed on the basis of the boundary position. A dot displacement can be restricted to not larger than one dot.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording apparatus for performing recording using a print head comprising a plurality of recording elements and a recording method using the print head. Regarding the recording method.

[0002]

2. Description of the Related Art In recent years, with the spread of computers and communication devices, various recording devices have rapidly spread. Examples of these recording apparatuses include those using a system such as an ink jet system, a thermal transfer system, and a thermal system. In such a printing apparatus, a certain amount of heat is generated in principle during the printing operation. And as a result of such a fever,
The print head undergoes thermal expansion, and the position of the ejection port changes with the thermal expansion, and the landing position of the ejected ink droplet on the recording medium may also change.

The print head used in a so-called serial type ink jet recording apparatus which has been widely used in the past is relatively short, and has about several tens to several hundreds of ejection ports. Therefore, even if a change in the position of the discharge port occurs due to thermal expansion, the degree of the change is small and negligible compared to, for example, manufacturing variations of the print head.

[0004]

However, as one configuration for realizing a high-quality image and shortening the recording time, the number of discharge ports of the print head is increased and the arrangement density of the discharge ports is increased. The adopted configuration is adopted. In this configuration, the print head becomes longer, and the ink landing position shift due to the thermal expansion of the print head tends to be larger.

[0005] For example, in a print head in which aluminum is a main material such as a base material and the arrangement density of ejection ports is 600 dpi and the total length is 12 inches, the number of ejection ports is 72.
00.

Here, the linear expansion coefficient of aluminum is represented by a length change ΔL with respect to a temperature change Δt. In the case of aluminum, ΔL / (Δt · L) = 23.1 × 10 ⁻⁶ (deg) ⁻¹ It is.

Therefore, in the case of a print head having a length L, the change in length ΔL when the temperature changes by Δt is ΔL = 23.1 × 10 ⁻⁶ × Δt × L (inch).

Since the length of the recording head of this embodiment is L = 12 (inch), ΔL / Δt = 0.17 (nozzle pitch / deg).

If the operating temperature range of the recording head of this embodiment is from 20 degrees to 50 degrees, it changes in a maximum width of 30 degrees. Therefore, the maximum change in head length is ΔLmax = 4.99 (nozzle pitch). Thus, at the end of the head, there is a shift of about 5 nozzle pitches.

It is desirable that the recording accuracy in the recording apparatus, that is, the landing error of the recording ink, be kept smaller than the regular nozzle pitch from the viewpoint of recording quality. However, as shown in the above example, in a long print head in which ejection ports are arranged at high density, a shift of up to about 5 dots may occur, and the print width is significantly reduced by this shift width. .

In a thermal transfer type or a thermal type recording apparatus, the print head tends to be long in order to improve the image quality and the recording speed, and the same problem as the above-described ink jet type may occur. is there.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a recording apparatus and a recording method having a function of correcting a shift of a landing position due to thermal expansion of a print head during recording. Is to do.

[0013]

According to the present invention, there is provided a recording apparatus for performing recording on a recording medium based on print data allocated to the plurality of recording elements by using a recording head in which a plurality of recording elements are arranged. A displacement calculating means for calculating a displacement amount of the plurality of recording elements due to thermal expansion in the array direction based on a predetermined amount of print data; and a predetermined amount based on the displacement amounts of the plurality of recording elements determined by the displacement calculating means. Allocating means for shifting and allocating data to be allocated to other recording elements by an amount corresponding to the predetermined amount of displacement for each of a plurality of printing element groups distinguished based on the amount of displacement.

According to a recording method of the present invention, in a recording method in which a recording head in which a plurality of recording elements are arranged and recording is performed on a recording medium based on print data allocated to the plurality of recording elements, a predetermined amount of print data is A displacement calculating step of calculating a displacement amount due to thermal expansion in the array direction for the plurality of recording elements, and distinguishing each of the plurality of recording elements based on a predetermined displacement amount based on the displacement amounts of the plurality of recording elements obtained by the displacement calculating step. And a step of allocating data to be allocated to other recording elements by an amount corresponding to the predetermined amount of displacement for each of the plurality of recording element groups.

By using the recording apparatus and the recording method having the above-described configurations, based on the amount of displacement of each recording element,
For each of the plurality of recording element groups that are distinguished based on the respective predetermined displacement amounts, the data of other recording elements are shifted and assigned by an amount corresponding to the predetermined displacement amount of each recording element group. From the ideal position can be suppressed to a predetermined displacement amount or less. For example, when the predetermined displacement amount is the nozzle pitch, the dot shift can be suppressed to 1 dot or less.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A recording apparatus and a recording method to which the present invention is applied will be described below with reference to the drawings.

FIG. 1 is a configuration diagram of a recording apparatus to which the present invention is applied.

The recording apparatus includes print heads 1C, 1 for ejecting cyan, magenta, yellow, and black inks.
M, 1Y, 1K, head drive circuits 2C, 2M, 2Y, 2K for providing print data to each print head, a paper transport mechanism 3 for transporting a recording medium such as paper to a print position by each print head, and paper A mechanical drive circuit 4 for controlling the driving of each element of the transport mechanism 3 and the print head 1 and a control circuit 5 for comprehensively controlling these circuits are provided.

In each of the print heads 1C, 1M, 1Y, and 1K, a total of 7,200 discharge ports are arranged in a row at a rate of 600 per inch. Further, the print head 1 includes an ink tank (not shown) for supplying ink, and the ink tank communicates with each of the ejection ports via an ink path. Heating heaters are provided in the ink path so as to correspond to the respective ejection ports. At the time of ink ejection, the heater is heated to generate bubbles in the ink, and ink droplets are ejected by the pressure of the bubbles. The method of ejecting ink droplets is not limited to the bubble jet method, but may be another method.

The paper transport mechanism 3 includes a paper feed belt 31, a belt pulley 32, a motor belt 33, a motor 34, and the like. Each part is driven under the control of the mechanical drive circuit 4 to convey a recording medium.

The control circuit 5 includes a central control unit (CPU) 5
1, a ROM 52 for storing a control procedure for each mechanism, a RAM 53 for temporarily storing data, an NVRAM 54 for holding data even when the power is turned off, and a sensor (not shown) for detecting information such as the surrounding environment; An input / output unit 55 for receiving data from a sensor or the like and transmitting control information to the mechanical drive circuit 4 and the like, and an interface circuit (not shown) for an external device or a peripheral electric circuit are provided.

(Embodiment 1) A method of correcting a dot shift, which is a feature of a printing method to which the present invention is applied in a printing apparatus having such a configuration, will be described below.

As a premise of this correction, data relating to the thermal expansion and contraction of the print head is input to the recording apparatus in advance at the time of manufacture. This data is obtained by actually measuring the thermal expansion of the head. The measuring method is such that a current is applied to the print head so as not to eject ink droplets and the print head is heated, and how much the temperature and the length of the print head change due to the heating is measured. The method of heating the print head is not limited to the above-described method, and another method such as providing a heater in the print head and heating the print head may be used. Then, data on the temperature change of the print head with respect to the power supplied to the print head per unit time and data on the total length change of the print head with respect to the power supplied to the print head per unit time are created. Note that the temperature change value is a value changed from the normal temperature, and the total length change value is a change value from the full length of the print head before driving in the normal temperature state. The normal temperature and the total length of the print head at the normal temperature are set as reference values. Further, the number of driving discharge ports per unit time is determined from the data amount assumed to be processed by the print head per unit time, and the amount of power per unit time is determined from the number of driving discharge ports. Then, temperature change data and total length change data for the print data amount are obtained from the power amount. The relationship between the print data amount thus obtained, the temperature change data, and the total length change data is stored in a data table, and this data table is stored in the ROM 52 of the control circuit 5 at the time of manufacture.

Using the temperature change data and the total length change data described above, the dot shift correction process performed by the control circuit 5 will be described below.

The following processing is performed for the print head 1C,
Needless to say, it is performed independently for each of 1M, 1Y, and 1K. Hereinafter, each of these heads is referred to by reference numeral 1.

FIG. 2 is a flow chart showing a process for correcting a dot shift.

This correction process is performed every time printing of one page is completed.

First, the amount of print data supplied to the print head 1 in the previous printing operation is obtained from the printing data (one page) printed in the previous printing operation. Then, the obtained print data amount is applied to a data table stored in the ROM 52 of the control circuit 5 in advance, and temperature change data and total length change data are obtained. Then, a reference value is added to the obtained change value to obtain a head temperature and a head length after expansion (step 1). It is assumed that the length change of the print head 1 is uniform over the entire length of the head.

From the obtained head temperature and head length, a change in the total length of the print head 1 is obtained (step 2).

Then, the displacement from the ideal position is obtained for each of the discharge ports from the following equations 1 and 2 (step 3). In order to distinguish each ejection port, it is assumed that each ejection port is assigned an ejection port number in order from one end of the print head 1 to the other end.

Current position of discharge port = Ideal position + (Change in total length / Number of discharge ports) × Discharge port number (Equation 1) Displacement of discharge port (nozzle) = Current position of discharge port−Ideal position (Expression 2) Next The minimum discharge port number among the discharge ports having the position displacement obtained at (1) or more than one nozzle pitch is defined as the first boundary position (a1).

Of the discharge ports having a displacement of two nozzle pitches or more, the smallest discharge port number is defined as a second boundary position (a2). Thus, when the positional displacement is 3 nozzle pitches, 4 nozzle pitches,... N nozzle pitches, the boundary position is similarly determined (step 4). The determined boundary position is used as the boundary position of the number of data shifts at the time of the next printing.
3 is stored.

As shown in FIG. 3, for example, the first ejection port is 0.5 nozzle pitch, and the second ejection port is 1 nozzle.
When there is a positional displacement such as the nozzle pitch,..., The ejection port numbers corresponding to the respective boundary positions are: first boundary position (a1) = 2 second boundary position (a2) = 4 third boundary position (a3) ) = 6 ...

That is, it may be considered that the integer part of the nozzle pitch representing the displacement of the discharge port at the k-th boundary position is k.

Next, correction of print data for each ejection port based on the boundary position thus obtained will be described. The following processing is performed for each boundary position (step 5).

The print data of the discharge port at the k-th boundary position is composed of the print data of the discharge port number obtained by adding k to the discharge port number at the k-th boundary position and the print data of the discharge port number obtained by adding (k-1). Logical OR (step 6).

The print data of the ejection port between the k-th boundary position and the next (k + 1) -th boundary position is shifted to the smaller ejection port number by an integer of the displacement (step 7).

The following is a detailed processing procedure based on the above-described correction rule. The print data of the discharge port (0) is B (0).

First, the print data B (0) to B (a1-A1) from the discharge port (0) to immediately before the first boundary position (a1).
1) is used as the print data of the corresponding discharge port without correction.

Next, the print data B (a1) at the first boundary position (a1) is: B (a1) = B (a1) + B (a1 + 1) That is, the ejection port (a1) adjacent to the first boundary position (a1) a1
+1) with the print data B (a1 + 1)
1).

Further, all the print data from the ejection port (a1 + 2) to the second boundary position (a2) are shifted one by one in ascending order of the ejection port number.

B (a1 + 1) = B (a1 + 2) B (a1 + 2) = B (a1 + 3) B (a1 + 3) = B (a1 + 4): B (a2-1) = B (a2) of the second boundary position (a2) The outlet (a2 + 1) immediately after,
The logical sum of the print data of the discharge ports (a2 + 2) adjacent thereto is set as the print data of the second boundary position (a2).

B (a2) = B (a2 + 1) + B (a2 + 2) Further, a third boundary position (a3) from the discharge port (a2 + 3)
All the print data up to the ejection port (a3 + 1) immediately after is shifted by two from the ejection port number in ascending order.

B (a2 + 1) = B (a2 + 3) B (a2 + 2) = B (a2 + 4) B (a2 + 3) = B (a2 + 5): B (a3-1) = B (a3 + 1) Hereinafter, the third boundary position (a3 For the subsequent print data, the print data is shifted according to the correction rule. This process is repeated until the last ejection port (ejection port number n in this example) of the print head or the last raster data to be printed (step 8). The print data thus shifted is printed. This data shift process is performed for each page at the timing when printing for one page is completed.

In the example shown in FIG. 3, when the above-described correction rule is applied to print data, a data shift process indicated by a numeral surrounded by a square in the drawing is performed.

By printing with the print data processed as described above, the displacement of dots can be suppressed to one dot or less.

(Embodiment 2) The method of determining the boundary position is the same as that of Embodiment 1, but in this embodiment, data processing is performed in units of two rasters. That is, a raster number is sequentially assigned to each raster, an even raster number is an even raster number, an odd raster number is an odd raster number, and an even raster number and an odd raster number are set as one set.

A specific description will be given with reference to the flowchart of FIG. This embodiment is the same as the first embodiment up to the step of determining the boundary position in step 4, but performs different processing for even and odd rasters after step 5.

First, in the even-numbered raster, the print data B (a1) from the top ejection port to immediately before the first boundary position (a1) is displayed.
Regarding -1), as in the first embodiment, the print data is not shifted.

The print data B (a) at the first boundary position (a1)
The logical sum of 1) and the next ejection port print data B (a1 + 1) is set as new print data at the first boundary position (a1).

B (a1) = B (a1) + B (a1 + 1) Further, the print data up to the second boundary position (a2) is 1
Each time, the ejection port number is shifted to the smaller one.

B (a1 + 1) = B (a1 + 2) B (a1 + 2) = B (a1 + 3) B (a1 + 3) = B (a1 + 4): B (a2-1) = B (a2) Next, the second boundary position (a2) ) Is the new OR of the print data B (a2 + 1) of the next ejection port (a2 + 1) and the print data B (a2 + 2) of the next ejection port as new print data at the second boundary position (a2).

B (a2) = B (a2 + 1) + B (a2 + 2) Further, the print data up to the third boundary position (a3) is shifted by two each to the smaller ejection port number.

B (a2 + 1) = B (a2 + 3) B (a2 + 2) = B (a2 + 4) B (a2 + 3) = B (a2 + 5): B (a3-1) = B (a3 + 1) Hereinafter, the third boundary position (a3 ) For the subsequent print data, the print data is shifted similarly to the embodiment value 1. This process is repeated until the last ejection port (ejection number n in this example) of the print head or the end of raster data to be printed.

When there is a positional displacement shown in FIG.
The discharge port numbers corresponding to the respective boundary positions are: first boundary position (a1) = 2, second boundary position (a2) = 4, third boundary position (a3) = 6,.

The shifted print data has the ejection port number indicated by the numeral enclosed in a square in the figure.

On the other hand, in the odd raster, the following data shift processing is performed.

First, the first boundary position (a
As for the print data B (a1-2) up to two positions before 1), the print data is not shifted as in the case of the even raster.

Next, the print data of the discharge port (a1-1) is replaced with the logical sum of the print data of the first boundary position (a1).

B (a1-1) = B (a1-1) + B (a1) Further, print data from the ejection port (a1 + 1) to the ejection port (a2-1) immediately before the second boundary position (a2). Are shifted one by one to the smaller ejection port number.

B (a1) = B (a1 + 1) B (a1 + 1) = B (a1 + 2) B (a1 + 2) = B (a1 + 3): B (a2-2) = B (a2-1) Next, the second boundary The logical sum of the print data of the position (a2) and the print data of the next discharge port (a2 + 1) is calculated by using the discharge port (a2
-1) is the print data.

B (a2-1) = B (a2) + B (a2 + 1) Further, from the discharge port (a2 + 2), the third boundary position (a
All the print data up to 3) are shifted by two to the smaller ejection port number.

B (a2) = B (a2 + 2) B (a2 + 1) = B (a2 + 3) B (a2 + 2) = B (a2 + 4): B (a3-2) = B (a3) Hereinafter, the third boundary position (a3) The print data is similarly shifted for the subsequent print data. This process is repeated until the last ejection port (ejection number n in this example) of the print head or the end of raster data to be printed.

When there is a displacement as shown in FIG. 4B, the ejection port numbers corresponding to the respective boundary positions are: first boundary position (a1) = 2 second boundary position (a2) = 4 third The boundary position (a3) = 6...
The print data of 3, 5, and 7 is the logical sum of two adjacent print data.

That is, in the even-numbered raster, the logical sum of the print data of the adjacent discharge ports is used as the print data at the boundary position, whereas in the odd-numbered raster, the logical sum of the print data of the adjacent discharge ports is not the boundary position but the boundary position. The ejection port number is the print data of the ejection port one before the position.

By the way, there are two types of printing data for each ejection port, ie, printing or not printing. Therefore, when the print data is shifted by an integer of the position displacement, the probability that the ejection port corresponding to the print data prints is ２. On the other hand, the probability of printing by the ejection port corresponding to the logical sum of the print data of the adjacent ejection ports is 3/4. Therefore, when the logical sum of the print data is always printed at the boundary position as in the first embodiment, the printing load of the discharge port at the boundary position becomes larger than that of the other discharge ports. Therefore, in the present embodiment, the discharge port for printing the logical sum of the print data is changed by shifting the print data that takes the logical sum between the even raster line and the odd raster line, so that the printing load on the discharge port at the boundary position is reduced. be able to.

(Embodiment 3) Next, as a form developed from Embodiment 2, a method of performing data processing in units of n rasters will be described below.

First, as in the first and second embodiments, FIG.
According to the flow up to step 4 of the flowchart shown in
Determine the boundary position.

Next, it is assumed that the serial raster number from the start of printing is N (N = 0, 1, 2, 3,...), And the remainder obtained by dividing N by the processing raster unit number n is m.

In the raster where m = 0, the print data from the top ejection port to immediately before the first boundary position (a1) is not shifted.

Next, the logical sum of the print data at the first boundary position (a1) and the print data at the discharge port (a1 + 1) adjacent thereto is defined as the print data at the first boundary position (a1).

B (a1) = B (a1) + B (a1 + 1) Further, the print data up to the second boundary position (a2) is shifted one by one to the smaller ejection port number.

B (a1 + 1) = B (a1 + 2) B (a1 + 2) = B (a1 + 3) B (a1 + 3) = B (a1 + 4): B (a2-1) = B (a2) at the second boundary position (a2) The logical sum of the next ejection port (a2 + 1) and the ejection port (a2 + 2) is used as the print data at the second boundary position (a2).

B (a2) = B (a2 + 1) + B (a2 + 2) Further, the discharge port (a3 +) next to the third boundary position (a3)
All of the print data up to 1) is shifted by two to the smaller ejection port number.

B (a2 + 1) = B (a2 + 3) B (a2 + 2) = B (a2 + 4) B (a2 + 3) = B (a2 + 5): B (a3-1) = B (a3 + 1) Data shift processing is performed in the same manner. Is repeated until the last ejection port of the print head and the last print data of the raster.

In the raster where m = 1, the ejection port (a1−2) immediately before the first ejection port (a1) from the first ejection port (a1).
The print data up to 2) is not shifted.

The logical sum of the print data B (a1-1) and B (a1) is defined as a new B (a1-1).

B (a1-1) = B (a1-1) + B (a1) Further, (a2-) immediately before the second boundary position (a2)
The print data up to 1) is shifted one by one toward the smaller ejection port number.

B (a1) = B (a1 + 1) B (a1 + 1) = B (a1 + 2) B (a1 + 2) = B (a1 + 3): B (a2-2) = B (a2-1) Second boundary position (a2) ) Is the new OR of the print data B (a2) and the print data B (a2 + 1) of the next ejection port (a2 + 1) as new print data B (a2-1).

B (a2-1) = B (a2) + B (a2 + 1) Further, all the print data up to the third boundary position (a3) are shifted by two in the direction of the smaller ejection port number.

B (a2) = B (a2 + 2) B (a2 + 1) = B (a2 + 3) B (a2 + 2) = B (a2 + 4): B (a3-2) = B (a3) Data shift processing is performed in the same manner. Is repeated until the last ejection port of the print head and the last print data of the raster.

The above processing is repeated.

In the raster in which m = n−1, the print data from the leading ejection port (0) to the ejection port (a1-n) that is n pieces before the first boundary position (a1) does not move.

The print data of the discharge port (a1-n + 1) n-1 before the first boundary position (a1) is B (a1-n + 1) = B (a1-n + 1) + B (a1-
(n + 2) Further, all the print data from the next ejection port (a1-n + 3) to n-th (a2-n) before the second boundary position (a2) is shifted one bit at a time in the direction of smaller position value.

B (a1-n + 2) = B (a1-n + 3) B (a1-n + 3) = B (a1-n + 4) B (a1-n + 4) = B (a1-n + 5): B (a2-n-1) ) = B (a2-n) print data B (n-1) before the second boundary position (a2)
Print data B of the next ejection port adjacent to (a2-n + 1)
The logical sum of (a2-n + 2) is added to the new print data B (a
2-n + 1).

B (a2-n + 1) = B (a2-n + 1)
+ B (a2-n + 2) Further, all the print data from the next ejection port (a2-n + 3) to the third boundary position (a3) is shifted by two in the direction of the smaller ejection port number.

B (a2) = B (a2 + 2) B (a2 + 1) = B (a2 + 3) B (a2 + 2) = B (a2 + 4): B (a3−2) = B (a3) Data shift processing is performed in the same manner. Is repeated until the last ejection port of the head or the last print data of the raster.

As described above, by shifting the discharge port for printing the logical sum of adjacent print data for each raster, it is possible to reduce the bias of the printing load to a constant discharge port.

(Embodiment 4) This embodiment is characterized in that the data is passed through an address shift circuit 6 before data transfer to a print head as shown in FIG.

As shown in FIG. 6, the address shift circuit 6
Consists of a bit adder 61, a bit selector 62 and a data selector 63. As shown in FIG. 7, the bit adder 61 is an arithmetic unit that calculates the logical sum of a single bit and an adjacent next bit from the eight bit signals. As shown in FIG. 8, the bit selector 62
This is a selection means for selecting a single bit from the book bit signals. As shown in FIG.
Is data selection means for selecting one of a bit selector output and a bit adder output.

It is assumed that the input multi-bit signal has three bits before and after the reference position. These electric circuits are prepared for all the discharge ports.

Next, the control method will be described.

The determination of the boundary position and the data shift method are the same as those in the first embodiment.
However, in the first, second, and third embodiments, the data shift processing is performed by the control unit 5, but in the present embodiment, the data shift processing is performed by operating the address of the data by the address shift circuit 6. The operation method is as follows.

Since the bit is not moved from the leading outlet to the outlet immediately before the first boundary position (a1), the bit adder 61 is not operated. The bit selector 62 selects a bit at the reference position, and the data selector 63
Selects the bit selector side.

For the first boundary position (a1), the bit adder 61 calculates the logical sum of the bit data of the next ejection port and the bit position of the bit at the reference position, that is, the bit of the first boundary position (a1). Select OR with bit. The bit selector 62 is not operated. The data selector 63 selects the bit adder side.

The discharge port (a1) next to the first boundary position (a1)
Since the bit data is shifted one by one toward the smaller outlet number for the outlets from +1) to immediately before the second boundary position (a2), the bit adder 61 is not operated. The bit selector 62 selects a bit obtained by adding +1 to the reference position. The data selector 63 selects the bit selector side.

For the second boundary position (a2), the bit adder 61 selects the logical sum of the bit at the reference position +1 and the next bit. The bit selector 62 is not operated. The data selector 63 selects the bit adder side.

In the same manner, the operation of selecting the output data of the discharge port is repeated until the last discharge port of the print head or the last print data of the raster.

As described above, by performing the data shift processing by using the address shift circuit 6 without performing the control section 5, the data shift processing can be performed by the address operation instead of the data operation, so that the time required for the processing can be reduced. can do.

Although the first, second, third, and fourth embodiments have been described by taking the ink jet system as an example, it is needless to say that the present invention may be applied to a recording apparatus of another system.

Further, each of the above embodiments can be applied not only to a single head single-color recording apparatus but also to a multi-color recording apparatus having a plurality of heads. At this time, if the print heads used are manufactured similarly, it may be considered that their thermal expansion and contraction characteristics are equivalent. In this case, the measurement of the thermal expansion / shrinkage characteristics in the preparation stage may be performed not for each print head but for all similarly manufactured print heads. Then, the measurement result may be applied to each print head. as a result,
The displacement of each print head nozzle from the ideal position can be suppressed to one dot or less. And
The displacement between the print heads can be suppressed to 2 dots or less.

As described in each of the above embodiments, it is most preferable to perform the displacement detection processing for each bit from the viewpoint of accuracy. However, in order to simplify the calculation processing, for example, for example, The process of detecting the displacement may be performed for each of a plurality of bits, such as for each even number of bits.

(Others) The present invention includes a means (for example, an electrothermal converter or a laser beam) for generating thermal energy as energy used for discharging ink, particularly in an ink jet recording system. An excellent effect is obtained in a recording head and a recording apparatus of a type in which the state of ink is changed by the thermal energy. This is because according to such a method, it is possible to achieve higher density and higher definition of recording.

The typical configuration and principle are described in, for example, US Pat. Nos. 4,723,129 and 4,740.
It is preferable to use the basic principle disclosed in the specification of Japanese Patent No. 796. This method is a so-called on-demand type,
Although it can be applied to any type of continuous type, in particular, in the case of the on-demand type, it can be applied to a sheet holding liquid (ink) or an electrothermal converter arranged corresponding to the liquid path. By applying at least one drive signal corresponding to the recorded information and giving a rapid temperature rise exceeding the nucleate boiling, heat energy is generated in the electrothermal transducer, and film boiling occurs on the heat acting surface of the recording head. Liquid (ink) corresponding to this drive signal on a one-to-one basis.
This is effective because air bubbles inside can be formed. The liquid (ink) is ejected through the ejection opening by the growth and contraction of the bubble to form at least one droplet. When the drive signal is formed into a pulse shape, the growth and shrinkage of the bubble are performed immediately and appropriately, so that the ejection of a liquid (ink) having particularly excellent responsiveness can be achieved, which is more preferable. As the pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. Further, if the conditions described in US Pat. No. 4,313,124 relating to the temperature rise rate of the heat acting surface are adopted, more excellent recording can be performed.

As the configuration of the recording head, in addition to the combination of the discharge port, the liquid path, and the electrothermal converter (linear liquid flow path or right-angled liquid flow path) as disclosed in the above-mentioned respective specifications, U.S. Pat. No. 4,558,333 and U.S. Pat.
A configuration using the specification of Japanese Patent No. 59600 is also included in the present invention.

Further, the present invention can be effectively applied to a full-line type recording head having a length corresponding to the maximum width of a recording medium on which a recording apparatus can record. Such a recording head may have a configuration that satisfies the length by a combination of a plurality of recording heads, or a configuration as one integrally formed recording head.

In addition, even in the case of the serial type as described above, the recording head fixed to the apparatus main body or the electric connection with the apparatus main body and the ink from the apparatus main body by being attached to the apparatus main body. The present invention is also effective when a replaceable chip-type recording head that can be supplied or a cartridge-type recording head in which an ink tank is provided integrally with the recording head itself is used.

Further, it is preferable to add ejection recovery means for the recording head, preliminary auxiliary means, and the like as the configuration of the recording apparatus of the present invention since the effects of the present invention can be further stabilized. If these are specifically mentioned, the recording head is heated using capping means, cleaning means, pressurizing or suction means, an electrothermal transducer, another heating element or a combination thereof. Pre-heating means for performing the pre-heating and pre-discharging means for performing the discharging other than the recording can be used.

The type and number of recording heads to be mounted are, for example, not only one provided for single color inks, but also a plurality of inks having different recording colors and densities. A plurality may be provided. That is, for example, the printing mode of the printing apparatus is not limited to a printing mode of only a mainstream color such as black, but may be any of integrally forming a printing head or a combination of a plurality of printing heads. The present invention is also very effective for an apparatus provided with at least one of the recording modes of full color by color mixture.

In addition, in the embodiments of the present invention described above, the ink is described as a liquid. However, an ink which solidifies at room temperature or lower and which softens or liquefies at room temperature may be used. In general, the ink jet method generally controls the temperature of the ink itself within a range of 30 ° C. or more and 70 ° C. or less to control the temperature so that the viscosity of the ink is in a stable ejection range. Sometimes, the ink may be in a liquid state. In addition, in order to positively prevent temperature rise due to thermal energy by using it as energy for changing the state of the ink from a solid state to a liquid state, or to prevent evaporation of the ink, the ink is solidified in a standing state and heated. May be used. In any case, the application of heat energy causes the ink to be liquefied by the application of the heat energy according to the recording signal and the liquid ink to be ejected, or to start solidifying when it reaches the recording medium. The present invention is also applicable to a case where an ink having a property of liquefying for the first time is used. In the present invention, the most effective one for each of the above-mentioned inks is to execute the above-mentioned film boiling method.

In addition, the recording apparatus of the present invention may be used not only as an image output terminal of an information processing apparatus such as a computer, but also as a copying apparatus combined with a reader or the like, or a facsimile apparatus having a transmission / reception function. It may take a form.

[0112]

By using the recording apparatus of the present invention,
Since the data is shifted and printed in accordance with the expansion of the print head, the printing position deviation can be suppressed to a predetermined nozzle pitch or less (for example, one nozzle pitch).

Since this data shift process is performed only by software and an electric circuit and is performed without using a machine for data shift, an image improving effect can be obtained without increasing a mechanical cost burden.

Further, if the data shift processing is performed by an address operation instead of a data operation, the time required for the processing can be shortened.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a recording apparatus of the present invention.

FIG. 2 is a flowchart illustrating a shift process.

FIG. 3 is a diagram illustrating a displacement width of an ejection port according to the first embodiment.

FIG. 4A is a diagram illustrating a displacement width of an ejection port at the time of an even raster according to the second embodiment, and FIG. 4B is a diagram illustrating a displacement width of the ejection port at the time of an odd raster in the second embodiment; is there.

FIG. 5 is a schematic configuration diagram of another example of the recording apparatus of the present invention.

FIG. 6 is a block diagram of an address shift circuit.

FIG. 7 is a configuration diagram of a bit adder.

FIG. 8 is a configuration diagram of a bit selector.

FIG. 9 is a configuration diagram of a data selector.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Print head 2 Head drive mechanism 3 Paper transport mechanism 4 Mechanical drive circuit 5 Control circuit 51 Central control device 52 ROM 53 RAM 54 NVRAM 55 Input / output unit 6 Address shift circuit 61 Bit adder 62 Bit selector 63 Data selector

Claims (12)

[Claims] 1. A printing apparatus for performing printing on a printing medium based on print data assigned to a plurality of printing elements using a printing head having a plurality of printing elements arranged therein, the printing apparatus comprising: Displacement calculating means for calculating a displacement amount of the recording element due to thermal expansion in the array direction; and a plurality of recordings each distinguished based on a predetermined displacement amount based on the displacement amounts of the plurality of recording elements obtained by the displacement calculating means. And a allocator for shifting and allocating data to be allocated to another recording element by an amount corresponding to the predetermined displacement amount for each element group. 2. The recording head, wherein the recording elements are arranged at a fixed arrangement interval, and the allocating means calculates a displacement amount of the plurality of recording elements obtained by the displacement calculating means. Divided by the interval, those having the same quotient are regarded as the same recording element group, and among the same recording element group, the recording element having the smallest remainder is defined as the boundary position, and the data allocated to the boundary position is divided into two consecutive recording elements. 2. The printing apparatus according to claim 1, wherein the data of the following printing elements are shifted and assigned to each of the other printing elements of the same printing element group by the quotient. 3. A printing element number is assigned to each printing element in order from one end of the printing head to the other end, and the allocating means assigns the one having the quotient of k to the k-th boundary among the boundary positions. When the recording element number of the recording element at the k-th boundary position is s, the data assigned to the k-th boundary position is the recording element number (s + k) obtained by adding k to the recording element number s at the k-th boundary position.
And the data of the recording element of the recording element number (s + k-1) obtained by adding (k-1) to the data of the recording element of the recording element number (s + 1).
3. The printing apparatus according to claim 1, wherein the data assigned to the print element immediately before the boundary position is data of a print element number obtained by adding k to its own print element number. 4. The recording head performs recording on a recording medium in units of columns of the recording elements, divides data to be recorded in units of columns of recording elements in a recording order, forms one row as a raster, When assigning a raster number to a raster, if the raster number is an even number,
The data to be allocated to the boundary position is the printing element number (s + k) obtained by adding k to the printing element number s at the k-th boundary position, and the printing element number (s +
The data to be assigned from the printing element of the printing element number (s + 1) to the printing element immediately before the (k + 1) th boundary position is set as a logical sum with the data of the printing element of (k-1). If the raster number is odd, the data to be assigned to the print element immediately before the k-th boundary position is assigned to the print element number s at the k-th boundary position (k -1) The added recording element number (s + k-
The logical sum of the data of the print element of 1) and the data of the print element of the print element number (s + k−2) obtained by adding (k−2), which is two positions before the (k + 1) th boundary position from the kth boundary position 4. The printing apparatus according to claim 1, wherein the data assigned to the printing elements up to the first printing element is data of a printing element number obtained by adding k to its own printing element number. 5. When the number of rasters that can be continuously processed is defined as a raster unit number n, and a remainder obtained by dividing a raster number by the raster unit number n is defined as m, the assigning unit determines that the remainder is m In the case of the raster number, the data to be assigned to the k-th boundary position is added to the recording element number s at the k-th boundary position by (km), and the data of the recording element of the recording element number (s + km) and (( k-1)-
m) The logical sum of the added data of the recording element of the recording element number (s + k−1−m) and the recording element of the recording element number (s + 1) to the recording element immediately before the (k + 1) th boundary position. 5. The recording apparatus according to claim 1, wherein each of the data assigned to the recording elements is data of a recording element number obtained by adding k to its own recording element number. 6. The allocating means according to a displacement amount of the plurality of printing elements obtained by the displacement calculating means, for each of a plurality of printing element groups distinguished on the basis of a predetermined displacement amount. 6. The method according to claim 1, wherein the processing of shifting data to be assigned to another printing element by a corresponding amount is performed using an address shift circuit that shifts a data storage address of each printing element. The recording device according to claim 1. 7. The recording element according to claim 1, wherein the recording element uses heat energy to generate bubbles in the ink near the recording element, and discharges the ink by the pressure of the generated bubbles. 7. The recording device according to any one of 6. 8. A recording method for performing recording on a recording medium based on print data allocated to a plurality of recording elements using a recording head having a plurality of recording elements arranged therein, the method comprising: A displacement calculating step of calculating a displacement amount of the recording element due to thermal expansion in the array direction; and a plurality of recordings each of which is distinguished based on a predetermined displacement amount based on the displacement amount of the plurality of recording elements obtained by the displacement calculating step. An assignment step of shifting and assigning data to be assigned to another printing element by an amount corresponding to the predetermined displacement amount for each element group. 9. The print head, wherein the print elements are arranged at a fixed array interval, the allocating step includes calculating a displacement amount of the plurality of print elements obtained by the displacement calculation step. Dividing by the array interval, those having the same quotient are regarded as the same recording element group, and among the same recording element group, the recording element with the smallest remainder is defined as a boundary position, and data assigned to the boundary position is recorded in two consecutive recordings. 9. The recording method according to claim 8, wherein a logical sum of element data is obtained, and data of a succeeding recording element is shifted and assigned to each of the other recording elements of the same recording element group by the quotient. 10. A printing element number is sequentially assigned to each printing element from one end to the other end of the printing head, and the assigning step includes, among the boundary positions, the one having the quotient of k as a k-th boundary. When the recording element number of the recording element at the k-th boundary position is s, the data assigned to the k-th boundary position is the recording element number (s + k) obtained by adding k to the recording element number s at the k-th boundary position.
And the data of the recording element of the recording element number (s + k-1) obtained by adding (k-1) to the data of the recording element of the recording element number (s + 1).
10. The recording method according to claim 8, wherein the data assigned to the recording element immediately before the boundary position is data of the recording element number obtained by adding k to the own recording element number. 11. The recording head performs recording on a recording medium in units of columns of the recording elements, divides data to be recorded in units of columns of recording elements in a recording order, forms one row as a raster, and records each in the recording order. When assigning a raster number to a raster, the assigning step includes the step of:
The data to be allocated to the k-th boundary position is added to the recording element number s at the k-th boundary position by k, and the recording element data of the recording element number (s + k) is added to the recording element number (s + k-1). And the data to be allocated from the printing element of the printing element number (s + 1) to the printing element immediately before the (k + 1) th boundary position is added to the own printing element number by k. If the raster number is an odd number, the data assigned to the recording element immediately before the k-th boundary position is added to the recording element number s at the k-th boundary position by (k-1). Recording element number (s + k-
The logical sum of the data of the print element of 1) and the data of the print element of the print element number (s + k−2) obtained by adding (k−2), which is two positions before the (k + 1) th boundary position from the kth boundary position 11. The recording method according to claim 8, wherein the data assigned to the recording elements up to the recording element number is data of a recording element number obtained by adding k to its own recording element number. 12. When the number of rasters that can be continuously processed is defined as the number of raster units n, and the remainder obtained by dividing the raster number by the number of raster units n is defined as m, the assigning step includes: In the case of the raster number, the data to be assigned to the k-th boundary position is added to the recording element number s at the k-th boundary position by (km), and the data of the recording element of the recording element number (s + km) and (( k-1)
−m) The logical sum of the added print element number (s + k−1−m) and the data of the print element, and the print element number (s + 1)
The data to be allocated from the print element of (1) to the print element immediately before the (k + 1) th boundary position is data of a print element number obtained by adding k to its own print element number. 12. The recording method according to any one of 11.