JPS60166464A - Printer - Google Patents

Abstract

PURPOSE:To prevent a dauby feeling from being generated even when printed density is raised, by a method wherein the printing timing in forward movement of a printing head relative to a recording material and the printing timing in backward movement of the head relative to the recording material are made to be different from each other so that the respective printed patterns on the recording material differ substantially from each other. CONSTITUTION:Signals FOR and RV for the forward passage and the backward passages for a carriage and input timing pulses are ANB-gated by AND circuits 113A and 113B. In the case of the forward passage FOR, the signals are inputted directly into an OR circuit 115, while in the case of the backward passage RV, the signals are inputted into the circuit 115 with a predetermined time delay which is set by a delay circuit 114. A timing pulse Tp is taken out from the output of the circuit 115, and the printing head 107 is controlledly driven through a head driver 106.

Description

Detailed Description of the Invention (Technical Field) The present invention involves relatively reciprocating a printing head and a recording medium in a main scanning direction, and moving both in a sub-scanning direction different from the main scanning direction. The present invention relates to a printing device that prints images onto a recording medium using a printing head, and particularly to a printing device that has means for suppressing sticky feeling and printing with a high texture.

(Prior Art) Conventionally, in the above-mentioned type of printing apparatus, in the relative movement of the printing head and the recording medium in the main scanning direction, as shown in FIG. It was printed in the shape of a base grain that developed in a direction perpendicular to this. According to this printing method, if the amount of ink absorbed by the recording medium, such as recording paper, is insufficient in areas where the density is very high, the uniform base grain-like texture will be lost, resulting in a sticky texture. ◇ (Purpose) This invention eliminates the above-mentioned drawbacks of conventional printing devices, has a simple structure, and eliminates the sticky texture even when the printing density is increased. It is an object of the present invention to provide a printing device equipped with a means capable of suppressing the above.

(Explanation based on Examples) Hereinafter, the means taken in this invention to achieve the above object will be exemplified and explained with reference to the illustrated embodiments. In the following, an example in which the present invention is applied to an inkjet printer will be explained in the order of the mechanical section, printing/turning, and control system in an embodiment of the printing apparatus of the present invention.

Note that the present invention is applicable to printing devices other than inkjet printers, and is also applicable to recording either text information or image information.

(Mechanism section in the embodiment of the printing device of the present invention) (First
(Fig. 2) Fig. 1 shows the mechanism of a color inkjet printer to which the present invention is applied, and Fig. 2 shows the internal structure of the inkjet head unit in Fig. 1.
is a 7° latin, and a recording paper, which is an example of a recording medium, is wound around the belt transmission device 2 by a paper feed shimotor 12.
, and feeds the paper in the sub-scanning direction perpendicular to the main-scanning direction.

Note that 3 is a paper transport ship for manual operation. 4 is an inkjet head unit which is an example of a printing unit;
Reference numeral 5 denotes a carriage to which the unit 4 is fixed, and the carriage 5 is moved by a carriage motor 10 along a system screw 6 and a guide 7 in the main scanning direction (in the direction of the arrow).

FIG. 2 shows the internal structure of the inkjet head unit 4, and 41Y, 41M, 41C, and 41BK are inkjet heads that eject yellow (Y), magenta (M), cyan (C), and black (BK) ink, respectively. , 42Y, 42M.

42C and 428 are tanks for storing the above ink, respectively.

Since the structure and operation of the inkjet printer shown in FIGS. 1 and 2 are well known, detailed explanation thereof will be omitted. In the above example, the inkjet head unit 4, which is a printing head unit, moves in the main scanning direction, and the recording paper, which is a recording medium wrapped around a platen, moves in the sub-scanning direction. However, since the mutual movement between the print head and the recording medium is relative, a mechanism that moves either of them may be used. Furthermore, although a color inkjet printer is shown in FIGS. 1 and 2, the present invention is equally applicable to a monochrome printer. In addition, the mechanical section of the printing apparatus to which the present invention is applied can be modified in many ways.

(Print pattern in embodiment of printing device of this invention)
(FIGS. 3 to 5) FIG. 3 shows a printing pattern by a conventional printing device, FIG. 4 shows a printing pattern by an embodiment of the printing device of the present invention, and FIG. The printing head moves in the main scanning direction to perform printing, and the small circle in the figure indicates the printing dot on the recording paper, the arrow pointing to the right indicates the forward main scanning, and the arrow pointing to the left indicates the printing dot on the recording paper. This shows the main scanning along the way.

In the printing pattern shown in Figure 3, if the ink absorption amount of the recording paper is insufficient in the extremely high-density areas as described above, the uniform base texture will be lost, resulting in a sticky print. On the other hand, in the printing pattern shown in Figure 4, by shifting the dots by, for example, half a dot (half a pitch) between the forward and return passes, the relative distance of each dot is averaged, resulting in a high-density print, that is, a large print. It becomes possible to reduce the loss of the regular pattern when printing dots to a high density area as much as possible. In general, sticky expressions in the high-visibility area degrade image quality, and rather, rules and arm turns that have nothing to do with the original drawing (in the case of Figure 4, cross-grained/
It has been experimentally confirmed that the appearance improves when there is an arm turn.

Fig. 5 shows a further improvement of the printing pattern shown in Fig. 4M, in which the pitch in the sub-scanning direction is reduced so that the distance between the centers of all the printing dots formed in alignment with ViFh is almost equal. This is how it was done. This printing pattern is effective in increasing printing density and printing density.

(Control system in embodiment of printing apparatus of this invention) (Sixth
FIG. 6 is a block diagram showing the control system of an embodiment of the printing apparatus of the present invention, and this example is an example applied to a video printer. In FIG. 6, reference numeral 101 denotes an A/D converter to which image color signals R, G, and BL, which are analog quantities, are input, and are controlled by a synchronization control circuit 102 based on a synchronization signal to convert signals R1G and BL into digital signals, respectively. Signal R'l
G', B L'. This R', G',
BL' multiplied signal Ink color signals Y, M, and C in the image processing circuit 103.

The image is converted to BK and input to the image memo IJ 104.

The output of the image memory 104 is converted into an analog signal by the D/A converter 105, and is sent to the printing head 1oz (heads 41Y to 4 in FIG. 2) at a predetermined timing via the head driver 06 under the control of the timing pulse Tp. 'lBK
shows one example).

On the other hand, a system controller 08 composed of a microprocessor, etc. controls the above-mentioned crystal circuit, and also controls the gear ridge motor 10 via a carriage motor and drive circuit 109, and the paper feed shimo motor via a paper feed shimo motor drive circuit 111. 112 at a predetermined timing, and these operations form an image on the recording paper. Note that S is a timing pulse generated by the system controller 10B, and indicates a plurality of shift registers (not shown) provided in the image memo I) 104 (the capacitance difference between them is, for example, the head 41Y in FIG. 2). 41BK (corresponding to the spacing of 41BK), and to set the printing timing taking into account the spacing of the heads (for details regarding this, see, for example, Japanese Patent Application No. 1983-1999 filed by the applicant).
130026).

In the above configuration, the timing pulse T for controlling the operation of the head 107 is made different between the outgoing path and outgoing path of the carriage to which the printing head is fixed, so that the printing/guiding turn shown in FIG. to control. FIG. 7 shows an example of a control circuit for this purpose. In the figure, FOR and RVU are shown signals indicating that the carriage is in the forward and outward directions, respectively, and the input timing pulse shown in the figure and these signals are ANDed, respectively. Circuits 113A and 113B
fL is input to the OR circuit 115 after being AND-gated directly in the case of the forward path and delayed for a predetermined time by the delay circuit 114 in the case of the backward path.

Timing pulses T and 9 are output from the output.

FIG. 8 shows the timing pulses output from the circuit of FIG. 7, where T (FOR) is for the outward path and T, (RV) is for the invasion, in which case there is a half-pinch deviation between the two. It shows that there is.

Note that in order to obtain the printing turn shown in FIG. 5, the paper feed speed in the sub-scanning direction by the paper feed shimoter 12 is adjusted to be adjacent to the paper feed speed in the main scanning direction as shown in the figure. The distance between the centers of the dots can be maintained.

(Effects) As described above, according to the present invention, the printing timing when the printing head and the recording medium move relative to each other in the forward direction is the same as the printing timing when the printing head and the recording medium move relative to each other in the backward direction. Since the patterns printed on the recording medium by both types are different so that there is a substantial deviation, even if the printing density is increased, the sticky feeling in some shadows can be suppressed, making it possible to express high texture. Become.

[Brief explanation of the drawing]

FIG. 1 is an external view of a mechanism in an embodiment of the printing device of the present invention, FIG. 2 is a perspective view showing the internal structure of the inkjet head unit in FIG. 1, and FIG. FIG. 4 is an explanatory diagram of a printed pattern according to an embodiment of the printing device of the present invention, and FIG. 5 is an explanatory diagram of a printed pattern according to a further improved embodiment of the printing device of the present invention. 6 is a block diagram of a control system in an embodiment of the printing apparatus of the present invention, FIG. 7 is a block diagram of a circuit forming the timing and pulse T in the control source of FIG. 6, and FIG. FIG. 7 is an explanatory diagram of the timing 4) Lux T formed by the circuit of FIG. 7; Explanation of symbols 1: f Latin, 4: inkjet head unit which is an example of a printing unit, 5: carriage, 10: carriage motor, 12: introduction transfer motor, 1oz: ni/D converter, 103: image processing circuit, 104: ii! j+image memory, 105: D/converter, 106-head driver, 107: printing head, 108 system controller, 114 knee: M extension circuit, T: timing signal.

Claims (3)

[Claims] (1) means for relatively reciprocating the printing head and the recording object in the main scanning direction; and means for relatively moving the printing head and the recording object in a sub-scanning direction different from the main scanning direction. means for causing the printing head to make an impression on the recording medium; and means for making an impression when the printing head and the recording medium move relative to each other in the forward direction. A printing apparatus comprising: a control means for making a printing timing different from a printing timing during relative movement in the backward direction so as to cause a substantial shift in the printing pattern on the recording medium by both. (2) The control means causes a deviation of approximately half a pitch between the printed pattern on the recording medium due to the forward movement and the printed pattern on the recording medium due to the backward movement. A printing device according to claim (1), configured as follows. (3) The means for relatively moving the printing head and the recording medium in the sub-scanning direction is such that the movement pitch thereof is the same as that of the printing heads formed side by side on the recording medium. The printing device according to claim (1), wherein the printing device is adjusted so that the distances between the centers of both of the printing devices are approximately equal.