JPH03218849A - inkjet recording device - Google Patents

Abstract

PURPOSE:To improve the extension efficiency of dots to print data by setting a distance so that characters of sizes recorded, then making an ink discharge amount variable so that the dots of a diameter best suited to the recording are obtained and extending dots in accordance with the ink discharge amount. CONSTITUTION:If recorded data is read from an external host computer, the size designated for data is interpreted. Then it is interpreted whether the size falls within a specified range, that is, whether or not a printing head 4 can be adjusted to a distance between a head and a recording medium which is appropriate for the size of a character. If the result of the interpretation is affirmative, a printing head 4 is moved through a distance adjustment mechanism 57 so that an appropriate distance is obtained. Then print data is extended and at the same time, a head driver 4 is set at a place which helps to minimize the distance. Thus the diameter of a discharged dot can be minimized to deal with characters of all different sizes.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an inkjet recording device.

[Conventional technology]

In recent years, office automation has progressed, and many printers have come to be used in offices.

Most of these printers form characters using a dot matrix, such as wire dot method, thermal method,
There are many methods such as an inkjet method, a laser method, and an LCD method.

On the other hand, in order to improve printing quality, the density of fonts for characters such as letters and numbers has been increased, and an increasing number of printers have multiple fonts in order to support desktop publishing functions. However, as dot densities have become higher in order to improve printing quality, the conventional method of storing fonts in a dot matrix format has led to an increase in the capacity of storage devices.

Furthermore, conventional dot matrix format font data requires one type of dot matrix format font data for one type of font. This also caused the capacity of storage devices to increase.

The increased capacity of such storage devices has led to larger printers and higher costs.

Therefore, recently, printers have appeared that have a function of controlling fonts in an outline font format, which requires less storage devices and does not require preparing font data for each font size.

A printer using the outline font format uses a method in which the outline font of a character to be printed is read from a font storage device, data is developed into the shape of the font, and the data is printed.

Regarding the amount of font data, the outline font format requires significantly less storage space than the high-density dot matrix recording method, and a single font can express various character sizes. It has characteristics.

However, since the font data read from the storage device is developed into print data and then output to the print head, there is a problem in that the time required to develop the print data becomes an obstacle to high-speed printing.

An object of the present invention is to shorten the time for developing print data, particularly in an inkjet recording apparatus.

[Means for Solving the Problems] To achieve this, the present invention provides a recording head for performing recording by discharging ink, and a dot diameter adjusting means for controlling the dot diameter by adjusting the amount of ink discharged. a distance adjusting means for adjusting the distance between the recording head and the recording medium; and a storage means for recording an outline font of the character;
A development means for dot development of a character to be recorded using the outline font, an optimum dot diameter is determined from the size of the character to be recorded, and a character having the size is recorded using the dot diameter. , further comprising a control means for controlling the dot diameter adjusting means and the distance adjusting means.

[Function] In the present invention, depending on the size of characters such as letters to be recorded, the distance is set so that a character of that size can be recorded, and a dot diameter suitable for recording the character is obtained. By making the amount of ink ejected variable and performing dot development accordingly, the efficiency of development into print data can be improved.

[Embodiments] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Example 1) FIG. 1 schematically shows an example of an inkjet recording apparatus to which the present invention can be applied.

Here, 1 is a platen roller that conveys a recording medium 3 such as paper and regulates the recording surface, and 2 is its axis. 4
is an inkjet recording head (hereinafter referred to as the print head) for recording (printing) on the recording medium 3, and includes, for example, a group of ejection ports arranged on the surface facing the recording medium 3, and a group of ejection ports (for example, The discharge energy generating element is disposed in the liquid path inside the discharge port. 5 is print head 4
The carriage 6 on which the carriage 5 is mounted and scans the recording medium 3 is a guide rail extending in the scanning direction to support and guide the carriage 5.

The mode of control according to this embodiment will be explained using FIGS. 2 to 4.

Figure 2 (a) shows the dot diameter when the ink lands at ゜゛07.
The model when recording (printing) as ゜゜, the same <
(b) and (C) are models when printing is performed using dots having dot diameters of "1" and "1.2", respectively, compared to the dot diameter of (a). Figure 3 (a)
-(c) are font data of various sizes to be printed.

In an outline font, one font data is expanded to express characters such as letters of various sizes as shown in FIG.

With normal printers, it is extremely difficult to change the dot diameter, and when printing large fonts, small dots must be collected in a dot matrix.

The time required for the printer to develop the font data and output it to the print head is too long to ignore.

On the other hand, in the inkjet recording apparatus according to this example, as shown in FIG. 2, the same font data is printed by changing the ink dot diameter, and the font data is developed to change the character size. To make it possible to omit processing time to be changed. Further, in this example, by changing the distance between the recording medium 3 and the print head 4,
Make it correspond to the font size.

FIGS. 4(a) to 4(c) are diagrams showing the relationship between the distance between the recording medium 3 and the print head 4 and the dot diameter, respectively. Here, (a) in the figure. (b) and (C) are the same as (a) in FIG. 3, respectively. The distance (d,
d', d"). In this example, L is the array range of the discharge ports arranged along the arc. In other words, in this example, the above distances are set as d, d', d". By adjusting it, it is possible to appropriately correspond to the size of characters such as letters.

In this way, by appropriately setting the distance between the recording medium 3 and the print head 4 and changing the diameter of the formed dots according to the font size, it is no longer necessary to collect small dots to form large characters. This shortens the time to develop font data, making it possible to support high-speed printing.

FIG. 5 shows the distance change 4j between the head and the recording medium according to this example.
This mechanism can be mounted on the carriage 5 shown in FIG. 1.

Here, 5 is a rack coupled to the print head 4, which can be linearly displaced as shown by the arrow to adjust the distance d.

Reference numeral 6 denotes a pinion that meshes with the rack 5 and is attached to the shaft of the motor 7. That is, in such a mechanism,
The drive of the motor 7 may be controlled so that the pinion 6 rotates clockwise in the figure when the distance d is decreased, and conversely so that the pinion 6 rotates counterclockwise when the distance d is increased.

FIG. 6 shows an example of the configuration of the control system of the recording apparatus according to this example.

Here, 50 is a main control unit, for example, a CPU. It consists of a ROM that stores fixed data such as programs and outline fonts corresponding to the processing procedure, and a RAM that has an area for developing recorded data and a work area.

5l is a sub-scanning means, which includes a platen roller l for conveying the recording medium 3, a motor connected to its shaft 2, and the like. 55 is a main scanning means, which includes a motor for operating the carriage 5 and the like.

Further, 57 is a distance changing mechanism including the motor 7 and gears shown in FIG. 5, and 56 is a driver for the motor 7.

Reference numeral 54 denotes a driver for the print head 4, which drives the ink ejection energy generating element in a set manner (eg, set pulse width, applied voltage, etc.) to vary the amount of ink ejection.

FIG. 7 shows an example of the printing processing procedure according to this example.

First, when recording data (print data) is read from an external host device or the like (step s1), the specified size of the data is determined (step S3). Then, it is determined whether the size is within the specified range, that is, whether the print head 4 can be adjusted to a distance between the head and the recording medium that exactly corresponds to the size of the character (step S5).
).

If the determination is affirmative here, the print head 4 is moved via the distance adjustment mechanism 57 so as to obtain an appropriate distance (step S7), the print data is developed, and the head is moved so that an appropriate ejection dot diameter is obtained. Configure the driver 54. On the other hand, if the determination is negative, the print head 4 is set at the position where the distance is the minimum (step Sll), and the ejected dot diameter is minimized (step S13), so that it can correspond to characters of all sizes. Make it. After the above-described processing, the character is printed (step S15).
). In this embodiment, the distance between the print head 4 and the recording medium 3 can be varied by the motor 7, and the ink ejection dot diameter can also be varied, so the size of the character can be determined when printing data is developed. By controlling the distance changing mechanism based on the font size, it becomes possible to reduce the time required to develop print data, and high-speed printing becomes possible without a significant increase in price.

(Embodiment 2) FIGS. 8(A) and FB) show a configuration example of a distance changing mechanism of a recording device according to a second embodiment of the present invention. In this example, the movement of the print head 4 is controlled by a gear moving mechanism. 1 (rack and binion), but instead uses a pantograph-type link mechanism.

In the figure, 17 is a shaft for fixing the print head 4, 18 is a connection part with a lead screw for moving the print head 4, 19 is a pantograph provided with these, and 20 is a shaft of the drive motor 15, which is a lead screw. is formed.

In this embodiment, the same control system and control procedure are adopted to drive the motor 15, and the vantagraph 19 is transformed as shown in FIGS. 8(A) and (B). Effects can be obtained. However, in Embodiment 1, the means for moving the print head was constructed with a gear, so it may be difficult to achieve accuracy due to gear back rush, whereas in this embodiment, a pantograph is used as the means for moving the print head. By increasing the rotation speed of the motor, it is possible to eliminate the decrease in accuracy caused by gear pack lash.

(Embodiment 3) FIG. 9 (A1 to CB) shows a configuration example of a distance changing mechanism of a recording apparatus according to a third embodiment of the present invention. Here, 24 is a motor, and 25 is a print head support shaft fixed to the shaft of the motor 24. The surrounding area (A) shows the state where the head-recording medium distance is minimum, the same figure (B) shows the state where the distance is increased by driving the motor 24, and the same figure (C) shows the state where this distance is further increased. It shows.

In other words, the same effect can be obtained in this example by adopting the same control system and control procedure as in (Example 1), and the problem of decreased accuracy due to pack rush can be solved as in (Example 2). .

(Others) Note that the present invention is not limited to the above embodiments,
Of course, appropriate modifications are possible.

For example, in each embodiment, the print head 4 is moved to adjust the distance between the head and the recording medium, but the platen 1 may be made movable to displace the recording medium side.

Further, by providing a mechanism for detecting the distance described above, it becomes possible to control the font size more accurately.

Further, the present invention brings about excellent effects particularly in a bubble jet type recording head and recording apparatus among inkjet recording types.

As for typical configurations and principles thereof, it is preferable to use the basic principles disclosed in, for example, US Pat. No. 4,723,129 and US Pat. No. 4,740,796. This method can be applied to both the so-called on-demand type and continuous type, but especially in the case of the on-demand type, it is necessary to arrange the liquid (ink) in accordance with the sheet and liquid path that hold it. The electrothermal converter that is
Generating thermal energy in the electrothermal transducer and producing film boiling on the thermally active surface of the recording head by applying at least one drive signal that corresponds to recorded information and provides a rapid temperature rise above nucleate boiling. As a result, bubbles in the liquid (ink) can be formed in a one-to-one correspondence with this drive signal, which is effective. The growth and contraction of the bubble causes liquid (ink) to be ejected through the ejection opening to form at least one droplet. If this drive signal is in the form of a pulse, bubble growth and contraction will occur immediately and appropriately.
Particularly responsive liquid (ink) ejection can be achieved,
More preferred. This pulse-shaped drive signal is described in U.S. Pat. No. 4,463,359 and U.S. Pat.
Those described in the specification are suitable. Furthermore, if the conditions described in US Pat. No. 4,313,124 concerning the invention regarding the temperature increase rate of the heat acting surface are adopted, even more excellent recording can be performed.

The configuration of the recording head includes, in addition to the combination configuration of ejection ports, liquid paths, and electrothermal converters (straight liquid flow path or right-angled liquid flow path) as disclosed in the above-mentioned specifications, a heat acting section. The present invention also includes configurations using US Pat. No. 4,558,333 and US Pat. No. 4,459,600, which disclose configurations in which the wafer is placed in a bending region. In addition, Japanese Patent Application Laid-Open No. 1989-5 discloses a configuration in which a common slit is used as a discharge part of a plurality of electrothermal converters.
No. 9-123670 and Japanese Patent Application Laid-Open No. 59/1989 which discloses a configuration in which a discharge portion is made to correspond to an opening that absorbs pressure waves of thermal energy.
- The effects of the present invention are also effective even with a configuration based on Publication No. 138461. In other words, regardless of the form of the recording head, recording can be performed reliably and efficiently.

Furthermore, the print head can be a replaceable chip-type print head that is attached to the main body of the device to enable electrical connection with the main body of the device or supply of ink from the main body of the device, or the print head itself. The present invention is also effective when using a cartridge type recording head that is integrally provided with the recording head.

Further, it is preferable to add recovery means for the recording head, preliminary auxiliary means, etc., which are provided as a configuration of the recording apparatus, to the present invention because the effects of the present invention can be further stabilized. Specifically, these include capping means for the recording head, cleaning means, pressure or suction means, preheating means using an electrothermal transducer or another heating element, or a combination thereof; It is also effective to perform a preliminary ejection mode in which ejection is performed separately from printing in order to perform stable printing.

In addition, regarding the type and number of recording heads installed, for example, in addition to only one recording head for single-color ink, there are also multiple recording heads for recording multiple inks with different recording colors and densities. It may be provided.

In addition, in addition to being used as an image output terminal for information processing equipment such as a computer, the inkjet recording apparatus of the present invention may also take the form of a copying machine combined with a league, etc., or a facsimile machine having a transmission/reception function. It may be something.

[Effects of the Invention] As explained above, according to the present invention, it is possible to change the distance between the print head and the recording medium, and also to change the ink ejection dot diameter, so that the size of the character can be changed when printing data is developed. By determining the size of the font and controlling the above changes or adjustments based on the font size, the print data development processing time is reduced and high-speed printing becomes possible.

[Brief explanation of drawings]

FIG. 1 is a schematic perspective view showing an example of an inkjet recording device to which the present invention can be applied. FIG. 2 is an explanatory diagram illustrating the state of printing with various dot diameters. FIG. 4 is an explanatory diagram of the distance between the print head and the recording medium and the corresponding size of the characters formed. FIG. 5 is an explanatory diagram of an embodiment of the present invention. FIG. 6 is a block diagram showing a configuration example of a recording device control system according to an embodiment of the present invention; FIG. 7 is a flowchart showing an example of its control procedure; FIG. A). (Bl and FIGS. 9(A) to 9(C) are schematic diagrams showing two examples of distance changing mechanisms according to other embodiments of the present invention. 1... Platen roller, 3... ...Recording medium, 4...Print head, 5...Carriage, 7, 15. 24...Motor, 5,6...Gear, 19... Pantograph, 57... Distance changing mechanism. Figure 3 Figure 7 Figure 19 Figure 8 (B)

Claims (1)

[Scope of Claims] 1) A recording head for performing recording by discharging ink, a dot diameter adjusting means for controlling the dot diameter by adjusting the amount of ink discharged, and the recording head and a recording medium. a storage means for recording an outline font of the character; a development means for developing dots of the recorded character using the outline font; and an optimum dot diameter based on the size of the character to be recorded. An inkjet recording apparatus comprising: a control means for controlling the developing means, the dot diameter adjusting means, and the distance adjusting means so as to determine the dot diameter and to record a character having the corresponding size with the dot diameter. 2) In the inkjet recording apparatus, the element used in the recording head to generate energy for ejecting ink has the form of an electrothermal transducer that acts on the ink with thermal energy used as the energy.