JP2945194B2 - Printer device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer apparatus for printing a high-density image by reciprocating a print head, which is disposed opposite a recording medium moving in the sub-scanning direction, in the main scanning direction.

[0002]

2. Description of the Related Art At present, an ink jet printer which discharges ink droplets from an orifice and fixes it on a printing paper has been put into practical use as a printer device capable of quiet high-density printing.

For example, in a line type ink jet printer, a print head having a number of orifices connected in the main scanning direction is provided, and the printing is performed on an image forming section made of a recording medium which is held in position by a platen or the like and moves in the sub scanning direction. It has a structure in which the ink ejection surfaces of the head are fixedly opposed to each other, and prints an image on a recording medium by ejecting ink droplets from the orifice of the print head with driving power corresponding to the print image. .

In order to print a high-density image in the same manner as in the line type while reducing the number of orifices in the print head, a shuttle type ink jet printer in which a print head having sporadically formed orifices reciprocates in the main scanning direction. Are disclosed in JP-B-63-54552, JP-B-2-31543, JP-A-55-121067 and the like. This means that orifices are formed in the print head at intervals of an integral multiple of the print density in the main scanning direction, and the print head is displaceably supported in the main scanning direction by a main scanning mechanism such as a linear motor so as to be reciprocally driven, It has a structure in which a recording medium, such as printing paper, arranged by a sub-scanning mechanism such as a platen roller at a position facing the recording medium is delivered in the sub-scanning direction. In such a structure, the orifice of the print head that reciprocates in the main scanning direction ejects ink droplets to the recording medium at a predetermined timing, so that the print density can be set to an integral multiple of the arrangement interval of the orifices of the print head. it can.

The apparatus disclosed in Japanese Patent Laid-Open No. 55-121067 will be described as a conventional example of a shuttle type ink jet printer with reference to FIGS.
First, in the inkjet printer 1, as illustrated in FIG. 3, long grooves 4 are formed at both ends of a print head 3 in which a large number of orifices 2 are formed at intervals of an integral multiple of the print density in the main scanning direction. , Support pins 5
A head support mechanism 6 that supports the print head 3 so as to be displaceable in the main scanning direction by engaging with the head is formed. At a position facing the orifice 2 of the print head 3 supported by such a head support mechanism 6, a peripheral surface of a platen roller 8 rotatable via a conveyance path of a printing paper 7 as a recording medium is positioned. A sub-scanning mechanism 11 is provided by connecting a drive motor (not shown), an encoder 9 and a cylindrical cam 10 to the platen roller 8 via a gear train. Therefore, the cylindrical cam 1 of the sub-scanning mechanism 11
The main scanning mechanism 13 for reciprocatingly driving the print head 3 within the interval of the orifice 2 is formed by connecting the tip end of the swing arm 12 engaged with the print head 3 to one end of the print head 3. . The print head 3 has a pressure chamber 14 communicating with the orifice 2 as illustrated in FIG.
Is formed on a diaphragm 15 and an electrostrictive element 16 is adhered on the diaphragm 15 in an on-demand type.

In such an arrangement, in the ink jet printer 1, the printing head which is mechanically reciprocated with respect to the printing paper 7 conveyed in the sub-scanning direction by the rotating platen roller 8 in synchronization with the conveying speed. 3 discharges ink droplets from a predetermined orifice 2 so that a high-density image is printed.

[0007]

In the above-described ink jet printer 1, a high-density image several times the arrangement density of the orifices 2 is printed by reciprocating the print head 3 in the main scanning direction. .

Here, when the above-described ink jet printer 1 is actually used, for example, trial printing is repeated in order to trial and error the appearance on paper, and when the appearance is determined, actual printing is performed. However, in such a case, in test printing, printing speed is more important than printing quality, and in actual printing, printing quality is more important than printing speed.

An object of the present invention is to provide an ink jet printer capable of selectively performing high-speed printing and high-density printing.

Another object of the present invention is to provide an ink jet printer which can select high-speed printing or high-density printing and has good print quality.

[0011]

According to the first aspect of the present invention,
A print head in which a large number of active elements individually forming print pixels are formed at predetermined intervals in the main scan direction is provided, and a main scan mechanism that reciprocates and supports the print head so as to be displaceable in the main scan direction is provided. A high-density printing method is provided in which a sub-scanning mechanism that conveys a recording medium in the sub-scanning direction with the recording head opposed to the print head supported by the main scanning mechanism is driven, and the sub-scanning mechanism is driven at a low speed to drive the main scanning mechanism. There is provided a mode setting means for switchingably setting a mode and a high-speed printing mode in which the sub-scanning mechanism is driven at a high speed and the driving of the main scanning mechanism is stopped.

According to a second aspect of the present invention, there is provided a print head in which a plurality of orifices for ejecting ink droplets are formed at predetermined intervals in a main scanning direction as active elements for individually forming print pixels. A pixel diameter changing mechanism is provided to set the ejection amount of ink droplets to be switchable between a small amount and a large amount,
A sub-scanning mechanism for displacing the print head in the main scanning direction and reciprocatingly driving the recording medium; and sub-scanning the recording medium facing the print head supported by the main scanning mechanism and transporting the recording medium in the sub-scanning direction. A high-density printing mode in which a sub-scanning mechanism is driven at a low speed to drive the main scanning mechanism and the pixel diameter changing mechanism to set the ejection amount of ink droplets of the print head to a small amount; And a mode setting means for switching between a high-speed printing mode and a high-speed printing mode for setting a large amount of ink droplets discharged from the print head by the pixel diameter variable mechanism by driving the main scanning mechanism at a high speed. Was.

[0013]

According to the first aspect of the present invention, high-speed printing of low-density images and low-speed printing of high-density images can be freely selected by switching operation of the mode setting means. A selectable inkjet printer can be obtained.

According to a second aspect of the present invention, high-speed printing of a low-density image and low-speed printing of a high-density image can be freely selected by switching operation of the mode setting means. High-volume, large-diameter pixels reduce gaps between pixels in low-density images, reducing print quality degradation. You can get a printer.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. First, in this inkjet printer 17,
As illustrated in FIG. 1, a drive circuit (not shown) is connected to a print head 19 in which a number of orifices 18 are formed in the main scanning direction at intervals of an integral multiple of the print density.
With a changeover switch that switches the output voltage of this drive circuit,
A pixel diameter changing mechanism (not shown) is provided for setting the ejection amount of the ink droplets of the print head 19 to be small and large.

The ink jet printer 17
Then, the slide shaft 2 is provided on the bottom surface of the print head 19.
0 is fixed, and the slide shaft 20 is slidably inserted into the bearing 22 of the main body frame 21. And in this inkjet printer 17,
A coil spring 23 disposed coaxially with the slide shaft 20 is press-fitted between the inner surface of the main body frame 21 and both ends of the print head 19, and the coil spring 23 mainly includes the print head 19. It is designed to be pressed from both directions of the scanning direction and to be urged toward the center of amplitude. Further, in the ink jet printer 17, the electromagnetic solenoid 2 having the slide shaft 20 as a plunger is provided on the outer surface of the one main body frame 21.
4 is fixed, and a drive circuit (not shown) for generating a drive pulse synchronized with the natural frequency of the print head 19 is connected to the electromagnetic solenoid 24. By doing so, in the ink jet printer 17, the print head 19 is movably supported in the main scanning direction by the slide shaft 20, the coil spring 23, the electromagnetic solenoid 24, and the like, and is driven to reciprocate at a substantially resonance frequency. A main scanning mechanism 25 is formed. In the ink jet printer 17, a slit 26 is formed at one end of the slide shaft 20.
The lock arm 27 which is detachably engaged with the solenoid is a solenoid.
(Not shown) and attached to the main body frame 21.

Further, in the ink jet printer 17, the platen roller 28 is located at a position facing the print head 19 which is movably supported in the main scanning direction as described above.
Are rotatably supported, and the platen roller 28
A driving motor (not shown) is connected to the sub-scanning mechanism 30 for arranging the printing paper 29 as a recording medium facing the print head 19 and conveying the printing paper 29 in the sub-scanning direction.

The ink jet printer 17
A mode setting means (not shown) for controlling the driving states of the main scanning mechanism 25, the sub-scanning mechanism 30, and the pixel diameter changing mechanism to switch between a high-density printing mode and a high-speed printing mode. Is CPU (Central Processing)
Unit).

In such a configuration, the ink jet printer 17 switches between a high-speed printing mode for printing the low-density image 31 at high speed and a high-density printing mode for printing the high-density image 32 at low speed by switching the mode setting means. You can choose. That is, in the inkjet printer 17, when the high-speed printing mode is selected, the sub-scanning mechanism 30 is driven at a high speed, the printing paper 29 is conveyed at a high speed in the sub-scanning direction, the driving of the main scanning mechanism 25 is stopped, and the lock arm 27 is stopped. Is the slit 26 of the slide shaft 20
, The print head 19 is fixedly supported,
Since the ejection amount of ink droplets from the print head 19 is set to a large amount by the pixel diameter variable mechanism, as shown in FIG. 2A, a low-density image 3 composed of large-diameter pixels 33 is printed on the printing paper 29.
1 will be printed at high speed. When the high-density printing mode is selected, the sub-scanning mechanism 30 is driven at a low speed, and the printing paper 29 is conveyed at a low speed in the sub-scanning direction.
5 is driven, the print head 19 reciprocates in the main scanning direction, and the ejection amount of the ink droplets of the print head 19 is set to a small amount by the pixel diameter variable mechanism. As illustrated in FIG. A high-density image 32 composed of small-diameter pixels 34 is printed on the printing paper 29 at a low speed.

By doing so, the ink jet printer 17 can freely switch between a high-speed print mode for printing a low-density image 31 at a high speed and a high-density print mode for printing a high-density image 32 at a low speed, as desired by the user. You can choose. Therefore, in the ink jet printer 17, for example, in a case where the test printing is repeated and then the actual printing is performed in order to improve the appearance on the paper surface, the low density image 31 is printed at a high speed in the test printing and the high density is printed in the actual printing. The low-density image 32 can be printed at a low speed, which can contribute to improving the efficiency of various printing operations.

In addition, the ink jet printer 17
Then, when printing the low-density image 31 in the high-speed printing mode, the gap between these pixels 33 is reduced by increasing the ejection amount of the ink droplets of the print head 19 and increasing the diameter of the pixels 33. It is designed to reduce the deterioration of print quality.

In the ink jet printer 17, the main scanning mechanism 25 reciprocates the print head 19 resiliently held by the coil spring 23 at a substantially resonant frequency in the high-density printing mode. The driving force is very small and power saving is realized.

In this embodiment, the electromagnetic solenoid 24 is exemplified as the main scanning mechanism for driving the print head 19 back and forth. However, the present invention is not limited to the above-described type, and has no element for regulating the vibration amplitude. A voice coil type linear motor or the like can also be used.

Further, in the present embodiment, the ink jet printer 17 is exemplified as the printer device. However, the present invention is not limited to the above-described type, and an LED (Light Emitting Diode) or an edge emitting EL is used as an active element of the print head. An electrophotographic printer using an (Electro Luminescence) element can also be implemented. A printer using such an edge-emitting EL element is disclosed in detail in Japanese Patent Application Laid-Open No. 2-245569 filed by the present applicant.

[0025]

According to the first aspect of the present invention, there is provided a print head in which a large number of active elements for individually forming print pixels are formed at predetermined intervals in the main scanning direction, and this print head is displaceable in the main scanning direction. A main scanning mechanism that supports and reciprocates the recording medium, and a sub-scanning mechanism that conveys the recording medium in the sub-scanning direction with the recording medium opposed to the print head supported by the main scanning mechanism. A mode setting means for switchingably setting a high-density printing mode in which the main scanning mechanism is driven by driving and a high-speed printing mode in which the sub-scanning mechanism is driven at a high speed and the driving of the main scanning mechanism is stopped. The user can freely select between high-speed printing of a low-density image and low-speed printing of a high-density image by switching the mode setting means. Those having an effect such as can be obtained.

According to a second aspect of the present invention, there is provided a print head in which a large number of orifices for ejecting ink droplets are formed at predetermined intervals in the main scanning direction as active elements for individually forming print pixels. A pixel diameter changing mechanism is provided to set the ejection amount of ink droplets to be switchable between a small amount and a large amount,
A sub-scanning mechanism for displacing the print head in the main scanning direction and reciprocatingly driving the recording medium; and sub-scanning the recording medium facing the print head supported by the main scanning mechanism and transporting the recording medium in the sub-scanning direction. A high-density printing mode in which a sub-scanning mechanism is driven at a low speed to drive the main scanning mechanism and the pixel diameter changing mechanism to set the ejection amount of ink droplets of the print head to a small amount; And a mode setting means for switching between a high-speed printing mode and a high-speed printing mode for setting a large amount of ink droplets discharged from the print head by the pixel diameter variable mechanism by driving the main scanning mechanism at a high speed. As a result, high-speed printing of a low-density image and low-speed printing of a high-density image can be freely selected by the switching operation of the mode setting means. Because of the large number of pixels and the large diameter, it is possible to reduce the gap between the pixels of the low-density image and reduce the decrease in print quality. It has effects such as being able to be obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention.

FIG. 2 is a front view of a print image.

FIG. 3 is a perspective view showing a conventional example.

FIG. 4 is a vertical sectional side view of a print head.

[Explanation of symbols]

 Reference Signs List 17 inkjet printer 18 orifice 19 print head 25 main scanning mechanism 29 recording medium 30 sub-scanning mechanism

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B41J 2/51 B41J 2/01 B41J 2/07 B41J 2/485 B41J 29/46

Claims (2)

(57) [Claims] A print head having a plurality of active elements for individually forming print pixels formed at predetermined intervals in a main scanning direction;
A main scanning mechanism that reciprocates the print head while supporting the print head in a displaceable manner in the main scanning direction, and a sub-scanning mechanism that conveys the recording medium in the sub-scanning direction with the recording medium facing the print head supported by the main scanning mechanism A high-density printing mode in which the sub-scanning mechanism is driven at a low speed to drive the main scanning mechanism, and a high-speed printing mode in which the sub-scanning mechanism is driven at a high speed to stop driving the main scanning mechanism. A printer device comprising: 2. A print head in which a large number of orifices each discharging ink droplets are formed at predetermined intervals in the main scanning direction as active elements for individually forming print pixels, and a discharge amount of ink droplets of this print head is small. A pixel diameter changing mechanism that is set to be switchable between a large amount and a large amount; a main scanning mechanism that reciprocates while supporting the print head so that it can be displaced in the main scanning direction; and records on the print head that is supported by the main scanning mechanism. A sub-scanning mechanism that conveys the medium in the sub-scanning direction by opposing the medium; and driving the main scanning mechanism by driving the sub-scanning mechanism at low speed, and controlling the ejection amount of the ink droplets of the print head by the pixel diameter changing mechanism. A high-density printing mode in which a small amount is set, the sub-scanning mechanism is driven at a high speed to stop the driving of the main scanning mechanism, and the ejection amount of ink droplets of the print head is set to a large amount by the variable pixel diameter mechanism. A printer device comprising: a mode setting means for setting a high-speed print mode so as to be switchable.