JP2834503B2 - Inkjet printer - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet printer, and more particularly, to an ink jet printer that forms a visible image by ejecting ink droplets on a recording medium such as recording paper.

[Prior Art] The operation of a normal device of this type is as follows.

When a character code is input from a host or the like, a character pattern corresponding to the character code is generated, and is sequentially developed in a print buffer memory or the like. Line feed code received or 1
When the line is filled with the data to be printed, the bit information of the image data expanded in the buffer is output to the head driver. The head driver controls ON / OFF of driving (discharging of ink) of the corresponding head according to the state of “1, 0” of the input bit information.

[Problems to be Solved by the Invention] By the way, in this type of apparatus, it is desired that characters of different sizes can be printed. Therefore, in recent years, there is a tendency to store character patterns as outline information instead of storing them as dot information. The reason is that a beautiful character pattern of any size can be created based on one data.

In any case, the character pattern generated in this way is
Printing is performed through the process described above, but the following problems have occurred.

. The amount of ink bleeding varies depending on the size of the character, resulting in an uneven character.

. Since the amount of bleeding varies depending on the recording paper, the font and graphics change, resulting in a decrease in print quality.

. In the case of a color ink jet printer, the bleeding is remarkable at the boundary between adjacent colors, and the print quality is reduced.

The present invention has been made in view of such a problem, and the first invention
It is an object of the present invention to provide an ink jet printer which can prevent deterioration of print quality due to ink bleeding due to a difference in character size.

A second object is to provide an ink jet printer capable of always performing high-quality printing regardless of the type of recording medium.

A third object of the present invention is to provide an ink jet printer capable of preventing deterioration of character quality due to bleeding of ink even when characters of mixed colors are printed using a plurality of colors of ink.

[Means for Solving the Problems] and [Operation] The ink jet printer of the present invention for solving the first problem is achieved by providing the following configuration. That is, in an ink jet printer that performs recording by discharging ink droplets onto a recording medium, a control means for controlling the amount of ink discharged at the contour of the dot pattern so as to decrease as the enlargement ratio of the dot pattern increases is provided. It is characterized by.

Further, in order to solve the second problem, the following configuration is provided.

In an inkjet printer that performs recording by discharging ink droplets onto a recording medium, setting means for setting the type of recording medium by the difference in the bleeding rate, and low bleeding rate when a recording medium with a high bleeding rate is set Control means for controlling the amount of ejected ink at the contour of the dot pattern to be smaller than when the recording medium is set.

In order to solve the third problem, the following configuration is provided.

In an ink-jet printer that performs recording by discharging a plurality of types of ink droplets on a recording medium, when an output color of a dot pattern is generated by discharging a plurality of types of ink droplets, the number of types of ink used increases as the number of types of ink used increases. An ink jet printer comprising control means for controlling the total amount of ejected ink at the contour of a dot pattern to be reduced.

Embodiment An embodiment according to the present invention will be described below in detail with reference to the accompanying drawings.

<Description of Configuration (FIG. 1)> FIG. 1 shows a processing circuit located between a print buffer for developing a character pattern and a drive unit of the print head. Since a print buffer and print head for developing a print character pattern are to be those of a known ink jet printer, detailed description thereof will be omitted.

In the figure, reference numeral 1 denotes a delay circuit for delaying print data by one dot unit. A comparison circuit 2 compares the delayed data with the non-delayed data, and outputs a signal indicating whether or not each is equal to each other. A control circuit 3 receives a signal from the comparison circuit 2 and controls data output to the head drive unit. Reference numeral 4 denotes an AND gate, which takes a logical product of a signal from the signal of the control circuit 3 and a signal from a buffer circuit 5 for buffering data. The output of the AND gate 4 is output to the head drive unit, and the
Used for ON / OFF.

<Description of Operation Outline (FIG. 2)> Next, the operation of the above configuration will be described with reference to FIG.

Assume that the number of delay dots of the delay circuit 1 is m, and that the n-th dot information has been input. Then, the comparison circuit 2
Are compared with the nth dot information and the nmth dot information. Therefore, this delay dot number m is set to "1".
As a result, in the comparison circuit 2, the adjacent dots are compared with each other.

Now, assume that images as shown in FIG. 2 (a) are sequentially input in the direction of the arrow. At this time, the comparison circuit 2 sets "0" when the adjacent dots are equal, and sets "1" when the adjacent dots are different.
Is output from the AND gate 4 to one of FIGS. 2 (b) and 2 (c).

In the case of FIG. 2B, the logic of the comparison circuit 2 is "1" when the input adjacent dots are equal and "0" when the adjacent dots are different, and FIG. In this case, a logic comparison circuit is used.

The width of the contour can be changed in the horizontal direction (main scanning direction) by setting the delay dot number "m" of the delay circuit 1.

Although the description has been made only in the main scanning direction, the contour can be processed only in the sub-scanning direction with the same configuration.

In any case, in the present embodiment, as shown in FIG. 2 (c), a case will be described where the thickness of the line segment of the character pattern is reduced.

FIG. 3A shows a print result of a character "A" having a normal size, and FIG. 3B shows an example in which this character is enlarged and printed. Each is an example of printing according to a character pattern generated from one outline font.
As shown in the figure, when the image is enlarged and printed (FIG. 3B),
As the amount of ink increases, bleeding becomes severe, and the line width becomes relatively thicker than the line width of normal characters.

Therefore, in the embodiment, when the enlargement ratio becomes a certain level or more, a character pattern of a corresponding magnification is generated from the outline font data as in the related art. Then, instead of printing immediately with the generated character pattern, the circuit of FIG. 1 is operated once to convert the character pattern into a thinner character pattern as shown in FIG. 3 (c). By printing in accordance with this character pattern, it is possible to print balanced characters as shown in FIG. 3 (d).

By making it possible to change the number of dots to be reduced stepwise, it is possible to deal with characters having a plurality of levels of enlargement.

<Explanation of the Second Embodiment (FIGS. 4 and 5)> The above description is intended to prevent thickening of character line segments caused by excessive ink during printing of enlarged characters.

However, even if the characters have the same magnification, the degree of bleeding may be different. This is due to the difference in the characteristics of the printing paper as the printing medium.

 FIG. 4 shows an example of the processing circuit in this case.

In the figure, reference numeral 6 denotes a switch input circuit for selecting the type of printing paper, in other words, whether or not it is easily bleeding (or how much it is easy to bleed), which is directly selected by the operator.

The contents selected by the switch input circuit 6 are taken into the control circuit 3 'to determine the delay dot number "m" of the delay circuit 1. However, when using paper with little bleeding, “m” may be set to “0”. Conversely, when using paper that easily bleeds, “m” may be set to a larger numerical value.

For example, as shown in FIG. 5 (a), in an ordinary print pattern, it is assumed that an area of 5 to 19 dots in the first to nth dots is a print portion. When printing on designated paper, it does not spread, so printing is performed in the set area of 5 to 19 dots. However, when the recording paper is different, printing becomes wider than the set area. Therefore, in this embodiment, a switch input circuit 6 is added, and the type of paper is distinguished by specifying the switch. Then, in order to make the printing appropriate with the amount of bleeding corresponding to the paper, a control is performed so as not to print, for example, the 5th dot and the 19th dot as shown in FIG. 5B. The result printed on the recording paper is as shown in FIG. 5 (c), and the original purpose can be achieved.

If the amount of paper bleeding is larger than this, a corresponding control method without printing the fifth and sixth dots and the 18,19th dot is also possible, and control in the sub-scanning direction should be performed in the same manner. Thus, a more balanced character can be reproduced.

Although the switch input circuit 6 is described as being manually switched by the operator, the switch may be replaced with a sensor that can identify the type of recording paper as long as the type can be identified. According to this, it is possible to automatically perform balanced printing in the best printing state.

<Explanation of Third Embodiment (FIGS. 6 and 7)> In the first and second embodiments described above, printing with a single-color ink has been described as an example. In the third embodiment, an example of printing by combining a plurality of color inks will be described.

FIG. 6 shows an example of a processing circuit according to the third embodiment.

 In the figure, reference numeral 7 denotes a thinning circuit for specifying a thinning rate.

As shown in FIG. 7 (a), the printing is performed in a certain area in the normal single color printing (having a printing rate of 100%) on the designated paper.

However, in a color printer that expresses a color by combining single colors, two-color solid printing must be performed. Then, the driving rate becomes 200%, and the blur at the boundary increases conspicuously. Therefore, in the third embodiment, when printing is performed by mixing two colors, the boundary of the printed portion is thinned out and printed as shown in FIG. 7B. As a result, as shown in FIG. 4C, the bleeding becomes as good as possible, and the printing quality can be maintained in two-color solid as well as in single-color solid. Also, the outline width thinning method can be adjusted by a combination of the driving rate colors and the like.

In the first to third embodiments described above, the dots located at the contours of the character pattern are all limited by hardware, but these may be realized by software. is there.

[Effects of the Invention] As described above, according to the present invention, it is possible to perform printing with little deterioration by controlling the amount of ink ejected to the outline of a character based on the difference in the size of the character. .

In addition, since the amount of ink ejected to the outline of the character is controlled in accordance with the type of recording paper, high-quality printing can always be performed.

Furthermore, even when printing a mixed color character using a plurality of colors of ink, the amount of ink ejected to the outline of the character is controlled according to the number of inks when the mixed color is generated.
It is possible to perform printing with little deterioration regardless of the type of printing color.

[Brief description of the drawings]

FIG. 1 is a block diagram of a processing circuit in the first embodiment, FIGS. 2 (a) to 2 (c) are diagrams for explaining an outline of processing of a contour dot of a character pattern, and FIG. 3 (a). Fig. 3 (b) shows a conventional example of enlarged character printing, and Figs. 3 (c) and 3 (d) show the character dot pattern in the first embodiment. FIG. 4 is a block diagram of the processing circuit of the second embodiment, and FIGS. 5 (a) to 5 (c) are diagrams for explaining an outline of printing in the second embodiment. FIG. 6 is a block diagram of a processing circuit according to the third embodiment. FIGS. 7A to 7C are diagrams for explaining an outline of printing in the third embodiment. In the drawing, 1... Delay circuit, 2... Comparison circuit, 3, 3 ′ and 3 ″... Control circuit, 4.
... A buffer circuit, 6 a switch input circuit, and 7 a thinning circuit.

Claims (4)

(57) [Claims] 1. An ink-jet printer which performs recording by ejecting ink droplets onto a recording medium, wherein the control means controls the amount of ejected ink at the contour of the dot pattern to be reduced as the enlargement ratio of the dot pattern increases. An ink jet printer comprising: 2. An ink jet printer which discharges ink droplets onto a recording medium to perform recording, wherein a setting means for setting a type of recording medium by a difference in a bleeding rate, and when a recording medium having a high bleeding rate is set. An ink-jet printer comprising: control means for controlling the amount of ejected ink at the contour of a dot pattern to be smaller than when a recording medium having a low bleed rate is set. 3. An ink jet printer which performs recording by discharging a plurality of types of ink droplets onto a recording medium, wherein when the output color of the dot pattern is generated by discharging a plurality of types of ink droplets, the number of types of ink used is limited. An ink jet printer, comprising: a control unit for controlling the total amount of ejected ink in the outline of the dot pattern to be smaller as the number of the ink droplets increases. 4. The apparatus according to claim 1, wherein said control means controls the amount of ink to be ejected at the contour of the dot pattern by reducing the number of dots at the contour of the dot pattern. The inkjet printer according to any one of the above.