JPH02235748A - Ink jet recording apparatus - Google Patents

Abstract

PURPOSE:To prevent the clogging of a recording head and to certainly perform irradiation drying by limiting an irradiation position by controlling a laser beam emitting apparatus so that only the recording region of a member to be recorded is irradiated with laser beam corresponding to a recording signal. CONSTITUTION:When a recording head 2 is moved in the direction shown by an arrow F and a laser beam emitting source is present on a recording region 31, laser beam is emitted from the laser beam emitting source 18 and, when the recording head 2 is moved in the direction shown by an arrow R and a laser beam emitting source 19 is present on the recording region 31, laser beam is emitted from the laser beam emitting source 19. By emitting laser beam by this method, the laser beam emitting sources 18, 19 emitting laser beams are positioned in front of a recording direction with respect to each emitting orifice 5 even when the recording head 2 is moved in both directions and, therefore, the recording region 31 is irradiated with laser beam and heated as according scheduled region before recording is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an inkjet recording apparatus that performs recording by discharging a recording liquid (hereinafter referred to as "ink") onto a recording member.

[Prior Art] To form an image, recording droplets discharged from an inkjet recording head adhere to a recording member, a portion of which is absorbed by the recording member, and the remainder remaining on the surface of the recording member.

Conventionally, as a means to solve such problems, a heat generating source is placed at a position facing the recording member and radiant heat is irradiated, or the heat of the heat generating source is used to blow warm air toward the recording member. There were devices that dried and fixed the recorded image on the recording material by blowing air (for example, Japanese Patent Application Laid-Open No. 10773-1983)
Publication No. 5, Utility Model Publication No. 1983-35841, Japanese Patent Application Publication No. 1983
- see Publication No. 101483).

[Problems to be Solved by the Invention] However, in the method of dehumidifying and drying a recording member as described above, the irradiation temperature is It was difficult in practice to irradiate desired areas with radiant heat at an appropriate temperature.

The present invention was proposed in order to solve the problems of the above-mentioned conventional technology, and it is possible to reliably heat only an appropriate range of the recording area without causing temperature unevenness, and to use a laser beam. It is an object of the present invention to provide an inkjet recording apparatus that does not cause a rise in the temperature of a drying and fixing means.

[Means for Solving the Problems] In order to achieve the above object, an inkjet recording apparatus of the present invention includes a recording head that records on a recording member by discharging recording liquid, and a laser emitting device provided on the recording head. The apparatus is characterized by comprising: a laser light emitting source; and a control means for controlling the laser light emitting source so that laser light is irradiated only onto a recording area of the recording member according to a recording signal.

The recording area may be a scheduled recording area before recording is performed, or may be an area after recording is performed. Preferably, the recording head includes an electrothermal transducer that generates thermal energy used to eject droplets of recording liquid.

[Function] The laser light source acts as a drying and fixing means by irradiating a recording area on a recording member with laser light. Therefore, the temperature of the drying and fixing means itself does not increase, and as a result, the temperature of the recording head also does not increase. The laser light emitted from the laser light source irradiates the recording member with a very reliable irradiation position. Since the laser light emitting source is provided on the recording head, it becomes possible to irradiate the laser light to all the locations on the recording member to which ink adheres, which are the locations that require irradiation. Furthermore, since the irradiated laser light corresponds to the recording signal, there is no need for unnecessary heating.

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

The inkjet recording apparatus 1 according to the first embodiment of the present invention shown in FIG. It includes a recording head 2 fixed on a movably provided carriage. The recording head 2 is driven together with the carriage by a carriage motor 8 consisting of a DC motor via a belt 14. FIG. 2 shows the front of the recording head 2. The recording head 2 has
Four ejection ports 5 (one or more may be used) for ejecting ink onto a recording member 15 (shown in FIGS. 4 and 6), which is not shown in FIG. An example is provided. The recording head 2 is also equipped with an electrothermal transducer that generates thermal energy used to form ink droplets. On the extension line of both ends of the drum 1 consisting of each ejection port 5, that is, on the left and right ends of the recording head 2,
A laser light emitting source 18 is provided in the direction of arrow F, and a laser light emitting source 19 is provided in the direction of arrow R, each serving as a light source for heating a portion of the recording member 15 to which ink adheres. Although not shown in FIG. 1, a foot sensor 17 is arranged side by side of the laser light source 18, as shown in FIG. 2.

In addition, in order to recover from defective ink droplet ejection from each ejection port 5 of the recording head 2, an ink absorbing cap 3 that is moved by the drive of a cap motor 6 is provided.
The operating position of the cap 3 is detected by a cap sensor 10. The platen 4 has a black surface and is rotationally driven by a line feed motor consisting of a stepping motor to feed the recording member 15. The presence or absence of this recording member is detected by a mechanical paper sensor 9.

The home position sensor 11 is used to detect a home position that is a reference position when detecting the position of the recording head 2, and the linear encoder 12 and encoder sensor 13 are used to detect the position when the recording head 2 moves. Each is provided for the purpose of

FIG. 3 shows the control system of the inkjet recording apparatus 1 shown in FIG. The following control operations are performed accordingly. That is, referring to inputs from the encoder sensor 13 and the home position sensor 11, the carriage motor 8 is driven via the DC servo forward/reverse rotation φ22 to control the moving direction and moving speed of the recording head 2. Further, the line feed motor is driven and controlled via the stepping motor drive circuit 23.

Further, the head driver 2 uses recording data 26 transferred from an external control device such as a computer as a recording signal.
4, and the ink droplets are sent from the recording head 2 to the recording member 1.
The liquid is ejected toward the recording surface No. 5. This control is a drop-on-demand method in which whether or not to eject an ink droplet is controlled for each droplet. Further, other mechanisms (not shown) are controlled in response to inputs from other sensor groups 25.

In addition to the above, the CPU 20 performs control as described below.

First, when data recording data 26 regarding the size of the recording member 15 is given, the recording area 31 is determined from the recording data 26, and the home position sensor 11
, the detection results of the position of the recording head 2 by the linear encoder l2 and the encoder sensor 13 are input. Then, when it is detected that the laser light source 18.19 is located on the recording area 31 based on the input detection result, the laser light source 18.19 is caused to irradiate laser light.

Further, the CPU 20 connects the laser light emitting source 18.
It also serves as a control means for controlling the laser beam irradiation by 19.

Further, the CPU 20 includes a reflected light sensing circuit 29 shown in FIG.
The detection signal from Vx. Enter Vy. The reflected light sensing circuit 29 is provided in the photosensor 17 and converts the output voltage from the phototransistor 16, which is pulled up to the power supply voltage Vcc via the resistor R1, into comparators IC, IC2.
The detection signals Vx and Vy are then compared with the respective reference voltages V th2 and V th+ to obtain detection signals Vx and Vy, respectively.

When the recording member 15 is not set on the platen 4, since the surface of the platen 4 is black, almost no laser light from the laser light source 18 is reflected, and the internal resistance of the phototransistor 16 becomes high. . Phototransistor at this time! As shown in the graph on the left side of FIG. 5 ("none"), the output voltage Va of
takes a value close to . On the other hand, when plain white paper is set on the platen 4 as the recording member 15, the laser light from the laser light source 18 is strongly reflected, and the internal resistance of the phototransistor 16 becomes low. At this time, the output voltage Vc of the phototransistor 16 takes a value close to Ov, which is the ground voltage, as shown in the graph on the right side of FIG. 5 (paper r). When a transparent film is set on the platen 4 as the recording member 15, the recording member 15 is in a state between the two and somewhat close to ``no''. At this time, the output voltage vb of the phototransistor 16 takes a value somewhat close to the output voltage Va, which is between the output voltage Va and the output voltage VC, as shown in the center graph of FIG.

As shown in FIG. 5, the above output voltage Va and output voltage v
The voltage intermediate between the output voltage vb and the output voltage Vc is the reference voltage Vth2, and the voltage intermediate between the output voltage vb and the output voltage Vc is the reference voltage vth.
Then, as shown in Table 1, when there is no recording member 15 on the platen 4 (J without r), when a film is set on the platen 4 ("film"), when plain paper is set on the platen 4, It is possible to determine from the logic levels of the detection signals Vx and Vy, respectively, whether there is a paper (“paper”).

Table 1 In place of the laser oscillation circuit and laser source 18, a light emitting source that emits normal light, such as a light emitting diode, with almost no heating capacity is provided, and the reflected light emitted by the light source is detected by the reflected light. It is also possible to have the circuit 29 sense it.

Next, the operation of this embodiment will be explained.

The recording operation is started by operating the switch group 21, and when the paper sensor 9 detects that the recording material 15 is on the paper feeding side of the platen 4, the line feed motor 7 operates in steps to feed the platen. 4 rotates, and the recording member 15 is set at the recording start position. Subsequently, the carriage motor 8 moves the recording head 2 back and forth while controlling its speed. At this time, from the laser light source 18 to the recording member 1
5 is irradiated with laser light. The reflected light of the laser beam is detected by the photosensor 17, and from the logic levels of the detection signals Vx and Vy shown in Table 1 above, it is determined that the recording member 15 has been fed to the normal position on the platen 4. At the same time, it is determined whether the recording member 15 is a film or white plain paper.

If the recording material 15 is plain paper, irradiation with strong laser light may cause it to change in quality, so the irradiation is stopped, and the line feed motor 7 synchronizes with the carriage motor 8 to feed the recording material 15 one line at a time. send. During this time, a signal according to the print data 26 is applied from the head driver 24 to the print head 2 which is moving back and forth left and right, and ink droplets are ejected from each ejection port 5 of the print head 2 to record characters and images. Ru.

When the recording member 15 is a film, recording is performed in the same manner as in the case of plain paper, and laser light irradiation is performed as described below.

Timings A and B shown in FIG. 6 correspond to the timings A and B shown in FIG.
The position of the center line 32 between the lines 19 and 19 corresponds to the irradiation of the laser emission sources 18 and 19, respectively. Timing A
, B, when the level is "H", irradiation is performed, and when the level is "off", irradiation is not performed.

For example, if the recording head 2 is moving in the direction of arrow F,
When the laser emission source 18 is above the recording area 31, the laser emission source 18 emits light, and when the recording head 2 is moving in the direction of arrow R and the laser emission source 19 is above the recording area 31. irradiates from the laser light source 19. If irradiation is performed in this manner, no matter which direction the recording head 2 is moving, the laser emission sources 18 and 19 for irradiation will be located in front of each ejection port 5 in the recording direction, so recording will be performed. The recording area 31 is irradiated and heated as the previous recording area.

A laser light source 18 that irradiates the recording head 2 in the moving direction.
Alternatively, if the relationship with 19 is reversed as described above, the laser light emitting sources 18 and 19 for irradiation are located at the rear of each ejection port 5 in the recording direction, so that the recording area 31 is the area after recording. is irradiated and heated.

Regardless of whether the recording head 2 is moving in the direction of the arrow F or the direction of the arrow R, the laser emission sources 18 and 19 are in the recording area 3.
If the laser emitting sources 18 and 19 for irradiation are positioned before and after each ejection port 5 in the recording direction, the recording area 31 will be illuminated before and after recording.
is irradiated and heated.

Preferably, the heating before recording, after recording, or before and after recording can be selected by instructing the CPU 20 by operating the switch group 21 or the like.

A transparent OHP film was used as the recording member 15, and when only the recording area 31 of the film was irradiated with laser light before and after ink was applied, the water contained in the film was removed by the irradiation before recording. By removing the ink and promoting drying by post-recording irradiation, it was possible to obtain good recording results without ink bleeding, running, etc.

In the above embodiment, when the recording member 15 is plain paper, no irradiation is performed, and only when the recording member 15 is film, as shown in FIG.
As shown in 1), laser light of a constant intensity is continuously irradiated onto the recording area 31. However, even in the case of plain paper, by irradiating a small amount of laser light, the recording member 15 can be dried without fear of deterioration.

In order to irradiate a small amount of laser light, the intensity of the laser light may be adjusted, but irradiation may be performed intermittently as described below.

In synchronization with the timing shown in FIG. 7(2), in which the ink droplets are ejected one by one, the 60 ink droplets are ejected one by one as shown in FIG.
When plain paper was irradiated with a laser beam of the same intensity as that for the film mentioned above at a duty ratio of The results were obtained.

Furthermore, during recording, a laser beam can be irradiated onto the recording area at the same time as the ink droplets are attached.

The laser light emitting source 19A of the inkjet recording apparatus according to the second embodiment of the present invention shown in FIG. It is arranged to face the part to which ink droplets are attached. The laser light source 19A irradiates the ink droplet ejected from the recording head 2A with a laser beam onto the recording member 15 at the same time as the ink droplet is deposited on the recording member 15.

Note that even if the recording head has a plurality of ejection ports, by providing a plurality of laser light emitting sources 19A as in the above embodiment, laser light can be irradiated to the plurality of parts at the same time as the ink droplets are attached. be able to.

[Effects of the Invention] Since the present invention is configured as described above, it produces the effects described below.

Since the light irradiated onto the recording material is laser light, there is no temperature rise of the laser light source itself, which acts as a dry fixing means, or of the recording head, thus preventing clogging of the recording head. Moreover, the irradiation position can be limited to ensure reliable irradiation drying.

Further, by providing a laser emission source on the recording head, it is possible to reliably irradiate all necessary locations with low energy. Therefore, unevenness in irradiation temperature is less likely to occur, and a desired region can be irradiated with laser light at an appropriate temperature.

Furthermore, since the laser light is irradiated according to the recording signal,
There is no unnecessary heating.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing the main parts of the mechanical system of a first embodiment of the inkjet recording apparatus of the present invention, FIG. 2 is an enlarged front view of the recording head 2 shown in FIG. 1, and FIG. A block diagram showing the control system of the inkjet recording apparatus 1, FIG. 4 is a circuit diagram showing the reflected light sensing circuit 29 including the photosensor 17 shown in FIG. 2, and FIG. 5 shows the photosensor 1 according to the type of recording material.
FIG. 6 is a schematic diagram for explaining the operation of the inkjet recording apparatus 1, FIG. 7 is a timing chart showing an example of changing the amount of laser light irradiation, and FIG. FIG. 2 is a schematic diagram showing main parts of a second embodiment of the inkjet recording apparatus of the present invention. 1--Inkjet recording device, 2.2A--Recording head, 3--Cap, 4-Platen, 5.5--One discharge port, 6-Cap motor, 7--Line feed motor, 8-- Carriage motor, 9. Paper sensor, 1 0. Cap sensor, 11. Home position sensor, 12. Linear encoder, 1 3. Encoder sensor, 14. Belt, 15. Recorded object. Members, 16--phototransistor, 17--photosensor, 18, 19, 19A--laser light source, 20-ICPU
, 2 1--Switch group, 22-DC servo forward/reverse inversion circuit, 2 3--Stepping motor drive circuit, 24--head driver, 25--sensor group, 2 6--recorded data, 29- 1 reflected light sensing circuit, 31. 1 recording area, 32. center line.

Claims (1)

[Claims] 1. A recording head (2, 2A) that discharges a recording liquid to record on a recording member (15), and a laser light source (2, 2A) provided on the recording head (2, 2A).
18, 19, 19A), and a recording area (15) of the recording member (15) according to the recording signal.
control means (20
); An inkjet recording device comprising: 2. The inkjet recording apparatus according to claim 1, wherein the recording area (31) is a scheduled recording area before recording is performed. 3. The inkjet recording apparatus according to claim 1, wherein the recording area (31) is an area after recording has been performed. 4. The inkjet recording apparatus according to claim 1, 2 or 3, wherein the recording head (2, 2A) has an electrothermal transducer that generates thermal energy used for ejecting droplets of recording liquid. .