JPH0234789B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a recording apparatus that records by flying ink droplets or a stream of droplets.

[Prior Art] Non-impact recording methods have recently attracted attention because the noise generated during recording is so small that it can be ignored. Among these, the so-called inkjet recording method, which enables high-speed recording and can record on so-called plain paper without the need for special fixing treatment, is an extremely powerful recording method.
Various methods have been devised so far, some have been improved and commercialized, and others are still being worked on to put them into practical use.

This type of inkjet recording method is a method of recording by causing a stream of droplets of a recording medium called ink to fly and adhere to a recording member, and the method of generating droplets of the recording medium is There are several types of methods depending on the control method used to control the flying direction of the generated recording medium droplets.

The first method is, for example, the one disclosed in USP 3060429 (Tele type method), which generates droplets on the recording medium by electrostatic attraction and converts the generated recording medium droplets into recording signals. The electric field is controlled accordingly,
Recording is performed by selectively depositing recording medium droplets onto a recording member.

More specifically, an electric field is applied between the nozzle and the accelerating electrode to eject uniformly charged recording medium droplets from the nozzle, and the ejected recording medium droplets are subjected to an electric field according to a recording signal. Recording is performed by flying droplets between x and y deflection electrodes that are configured to be controllable, and selectively attaching the droplets to the recording member by changing the intensity of the electric field.

The second method is, for example, USP3596275,
A method (Sweet method) disclosed in USP3298030 etc., in which droplets of a recording medium with a controlled amount of charge are generated by a continuous vibration generation method, and the generated droplets with a controlled amount of charge are generated. By flying between deflection electrodes where a uniform electric field is applied,
It records on a recording member.

Specifically, in front of the orifice of the nozzle, which is a part of the recording head to which the piezo vibrating element is attached, a charging electrode configured to apply a recording signal is placed at a predetermined distance apart. By applying an electric signal of a constant frequency to the piezo vibrating element, the piezo vibrating element is mechanically vibrated, and a small droplet of the recording medium is ejected from the orifice. At this time, the recording medium droplet ejected by the charging electrode is charged with an amount of charge according to the recording signal by electrostatic induction. When a droplet of a recording medium with a controlled amount of charge flies between deflection electrodes to which a constant electric field is uniformly applied, it is deflected according to the amount of charge applied, and the droplet carries the recording signal. only can be deposited on the recording member.

The third method is, for example, the method disclosed in USP3416153 (Hertz method), in which an electric field is applied between a nozzle and a ring-shaped charged electrode, and a continuous vibration generation method is used to generate small droplets of the recording medium into mist. This is a method of converting and recording. That is, in this method, the atomization state of small droplets is controlled by modulating the electric field strength applied between the nozzle and the charging electrode in accordance with the recording signal, and the gradation of the recorded image is produced.

The fourth method is, for example, the method disclosed in USP3747120 (Stemme method), and this method is fundamentally different in principle from the above three methods.

That is, in all three methods, the droplets of the recording medium ejected from the nozzle are electrically controlled while they are in flight, and the droplets carrying the recording signal are selectively attached to the recording member. In contrast, the Stemme method performs recording by ejecting small droplets of the recording medium from an orifice in response to a recording signal.

The Stemme method applies an electrical recording signal to a piezo vibrating element attached to a recording head that has an orifice that ejects the recording medium, and converts this electrical recording signal into mechanical vibration of the piezo vibrating element. According to the mechanical vibration, small droplets of the recording medium are ejected from the orifice and attached to the recording member, thereby performing recording.

Input information is recorded using the control method described above, but even if the ink droplets or ink droplet flow are controlled correctly, the actual recorded record (image) may differ from the input information. be. This is done by controlling the ink while it is in flight.
This is because no control is performed on the recording medium (recording paper).

More specifically, in order to perform recording, a recording device that performs recording control as described above moves either the nozzle that discharges ink or the recording medium to which ink droplets are attached, and moves either or both of them, and the ink is discharged from the ink nozzle. The recording medium is configured so that the position at which the ink droplets adhere to the recording medium is changed to perform recording on the recording medium. Therefore, the air flow around the nozzle or the recording medium changes due to the movement of the nozzle or the recording medium, and the ink droplets ejected from the nozzle are affected by this, causing the ink droplets to reach the desired recording medium. This results in a loss of quality of recorded images. Therefore, there was a drawback that desired image quality could not be obtained.

[Objective] In view of the above-mentioned points, the present invention provides a recording device having a function of detecting its own recorded image, comparing the recorded image with input information, and correcting the difference.

Another object of the present invention is to scan an ink nozzle with a rotating head, read information recorded on a recording medium by an orifice of the ink nozzle based on input information with a sensor, and detect the difference between the recorded information and the input information. The present invention provides a recording apparatus that corrects the ink droplets or the flow of ink droplets from the orifice of an ink nozzle for correction.

[Embodiment] An embodiment of the recording apparatus according to the present invention will be described below with reference to the drawings.

FIG. 1 shows a perspective view of a recording device according to the invention. In the figure, RH is a rotating head which also serves as an ink tank and has orifices N1 and N2 for ink nozzles on its circumference.It rotates clockwise (arrow A in the figure), for example, and releases droplets by centrifugal force due to rotation. generate. The recording head RH is further connected to the orifice N.
A sensor S is provided for reading an image recorded on the recording medium RM by the ink ejected from the recording medium RM based on input information. Such a sensor S is CdS
Photosensors made of materials such as and Si
It has a small light source such as an LED, shines the light from the light source onto the image recorded on the recording medium RM, receives the reflected light with a photo sensor, and reads the image recorded on the recording medium RM. .

The image information read by the sensor S is compared with input information by a control circuit to be described later, and when there is a difference between the two, the difference is corrected by ink droplets ejected from the orifice N2.

FIG. 2 shows a control circuit of the embodiment shown in FIG. 1, which controls the above-mentioned orifices N1 and N2 sensors S as follows.

Input information signal control device ICU information recording signal 3rd
The recording droplet discharge control device RDC is controlled by the signal a in the figure.
causes the orifice N1 to eject droplets based on the information recording signal, and the droplets are recorded on the recording medium RM.

The above information recording signal is passed through the delay circuit DL1.
T With a delay of ₁ hour, the signal b in Figure 3 becomes the comparator.
Applied to COM. The delay time _T1 of the delay circuit DL1 is determined by the rotational speed of the rotating head and the distance between the orifice and the sensor S. That is, when the sensor S reads the recorded image at the position where the ink droplet ejected from the orifice N1 is recorded on the recording medium, the ink droplet is applied to one input terminal of the comparator COM.

The recorded image read out by the sensor S passes through the readout control circuit RC and becomes the signal C in Figure 3, which is sent to the comparator.
It is applied to the other input terminal of COM and compared with the information recording signal delayed by the delay circuit DL1.

The above-mentioned comparison circuit COM detects whether the image density is low or recording is not being performed.
Once found at COM, this result (signal d in Figure 3) is applied to the delay circuit DL2 and the orifice N
When 2 faces the correction part of the recording medium RM,
The signal e obtained from the delay circuit DL2 is applied to the correction control circuit AC, and the correction control circuit AC causes a correction amount of ink droplets to be ejected from the orifice N2, thereby performing recording correction. The delay time of delay circuit DL2 is also determined in the same manner as DL1 described above.

The above embodiment includes orifice N1, sensor S,
Although the orifice N2 was arranged in a straight line, the orifice N1, sensor S, and orifice N2 may be arranged from top to bottom with the rotating head parallel to the rotation axis as shown in FIG.

Further, as shown in FIG. 5, the orifice N1, the sensor S, and the orifice N2 may be provided obliquely with respect to the rotation axis.

FIG. 6 is a perspective view showing another embodiment according to the present invention. In the figure, RH1 is the recording head section,
It consists of the following components.

The RD is a disc made of an aluminum plate with a diameter of 120 mm and a thickness of 5 mm, with an axis AX at its center.

IN1 and IN2 are ink nozzles, which are fixed to the axis AX at an interval of 240° from each other, and their orifices are
It is 70 μm. The ink nozzle IN1 is used for information recording, and the ink nozzle IN2 is used for correction. S1 is a sensor, which is placed between the ink nozzles IN1 and IN2, and is fixed to the axis AX. The sensor S1 has a light emitting section and a light receiving section, each of which is composed of an LED, a phototransistor, and the like. Recording ink nozzle IN1, sensor S1, correction ink nozzle IN
2 are each provided at an interval of 120°.

The above-mentioned ink nozzles IN1 and IN2 eject ink droplets and droplet streams using pressure waves generated by piezos. SP is an ink supply pipe, which is rotatably provided on the axis AX, and has a viscosity of 27CP and a surface tension of 46.2dyn/
cm, and the ink with a density of 1.08 g/ ^cm2 is supplied to the ink nozzle through a tube (not shown) provided in the axis AX.
Supply to IN1 and IN2. CON is the connector, shaft
Rotatably installed on AX, sensor inside axis AX
Connected to the lead wire that connects S1 and connector CON.

The recording head section RH1 constructed as described above is rotated by a motor M in the direction of the arrow shown in the figure via the axis AX.

RM2 is a recording paper placed opposite the recording head RH1, and is fed in the direction of the arrow by means not shown.

The embodiment with the above configuration can be controlled by a control circuit as shown in FIG.
If the delay time of DL1 and DL2 is set according to this embodiment, the recorded information can be corrected in the same manner as described above.
For example, when the disk RD is rotated at 2000 rpm and recording is performed during such rotation, if a problem is artificially caused with the droplets ejected from the ink nozzle and the reading-correction function is investigated,
It was confirmed that the correction was performed appropriately.

In the above embodiment, a case was explained in which recording is performed with one ink nozzle and recording correction is performed with one ink nozzle. You can also do it.

[Effects] As detailed above, according to the present invention, the first recording means, the sensor, and the second recording means can be associated with the same pixel point during one scan, and recording correction can be performed at high speed. It has become possible to record extremely high quality data.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an embodiment of a recording apparatus according to the present invention, FIG. 2 is a control circuit of the embodiment shown in FIG. 1, and FIGS. 3 a, b, c, d, and e are signal waveform diagrams. FIG. 4 is a perspective view showing another embodiment according to the present invention. FIG. 5 is a perspective view showing another embodiment according to the present invention. FIG. 6 is a perspective view showing another embodiment according to the present invention. N1, N2... Orifice, IN1, IN2...
Ink nozzle, DL1, DL2...Delay circuit.

Claims (1)

[Scope of Claims] 1. A first recording means for recording information on recording paper based on input information, and a first recording means for recording information on the recording paper based on the input information, and the same scan at the same recording position as the information recorded by the first recording means. a recording means having a second recording means that can be correlated therein; a monitoring means for monitoring the information recorded by the first recording means during the same scan; input information and information from the monitoring means; a comparing means for comparing, a recording operation by the first recording means, a monitoring operation by the monitoring means, and a recording operation of the second recording means for the same recording position based on information from the comparing means, sequentially controlled during the same scan; 1. A recording device comprising a control means for controlling.