WO2013146492A1

WO2013146492A1 - Image recording device

Info

Publication number: WO2013146492A1
Application number: PCT/JP2013/057959
Authority: WO
Inventors: 聖竹谷
Original assignee: コニカミノルタ株式会社
Priority date: 2012-03-26
Filing date: 2013-03-21
Publication date: 2013-10-03
Also published as: JP2015110275A

Abstract

The present invention addresses the problem of unerringly handling effects produced by the height of a light-blocking object composed of a portion of a recording medium and the length of the recording medium in the conveyance direction, in an image recording device provided with a light-blocking sensor for detecting bobbing of the recording medium upstream from a recording head in the conveyance direction of the recording medium in order to detect, in advance, contact of the recording medium on the recording head. The detected amount (M) of received light in a photodetector (42) and the threshold (M1, M2) of the amount of received light are compared and assessed. When the detected amount of received light is assessed to be less than the threshold of the amount of received light, the detected light-blocking length (L) obtained by multiplying the conveyance speed produced by a conveyor (20) at that time is calculated. The detected light-blocking length and a threshold (L1) of the light-blocking length are compared and assessed, and the action of the conveyor, the action of the recording head, and the display action to the user are controlled in accordance with factors specified by a combination of the result of comparison and assessment of the threshold of the amount of received light and the result of the comparison and assessment of the threshold of light-blocking length.

Description

Image recording device

The present invention relates to an image recording apparatus.

In an inkjet printer that transports a recording medium and forms an image by ejecting ink droplets from the recording head onto the transported recording medium, the recording medium floats during transportation, and the recording medium comes into contact with the recording head. There are problems such as destruction of the apparatus such as the recording head and carriage, sucking of ink held by the recording head by the recording medium, lack of nozzles and waste of the recording medium.
In a recording medium such as cloth, the float can be crushed and repaired. Therefore, instead of stopping the recording operation and discharging the recording medium, temporarily hold the recording head after the stop with a moisture retaining cap or ink suction. Evacuate to the suction to prevent the nozzle surface of the recording head from drying out and missing nozzles, while the operator corrects the floating of the recording medium and restarts the recording operation to form a good image Is possible.

Conventionally, in order to prevent the recording medium from contacting the recording head, a sensor for detecting the floating of the recording medium has been installed upstream of the recording head.
In consideration of downsizing of sensor configuration, detection of floating of soft materials such as cloth, and detection of fiber fluff of recording medium, an optical sensor (light-shielding sensor) can detect the recording medium without contact. preferable.
In Patent Document 1, in a single-pass image recording apparatus, irradiation light from a light emitting element arranged on the side of a recording medium is transmitted in the width direction of the recording medium, and irradiation light is applied to a light receiving element arranged on the opposite side. Describes a floating detection sensor configured to be turned off while light is incident and turned on when irradiated light is interrupted (FIG. 7 of the same document).
In the image recording apparatus described in the same document, an object of the platen belt is to reliably detect in advance the lifting of a recording medium that is actually harmful to the conveyance from the recording medium conveyance mechanism and to prevent excessive detection. If the sheet (10) that has passed through the first paper guide (19) on the upstream side in the sheet conveying direction of (11 in the same document) has a large float, it is detected by the float detection sensor downstream of the first paper guide. The distance d1 between the first paper guide and the float detection sensor, the distance h1 between the float detection sensor and the platen belt, the second paper guide (18) downstream of the float detection sensor, and the recording head (16). The distance d2 and the distance h2 between the recording head and the platen belt are set as h1 / d1 = h2 / d2 and h1 = h2, and the environment between the first paper guide and the floating detection sensor, the second paper guide, and the recording head. The environment between the same, for detecting the floating of the recording medium immediately below the recording head to reproduce in advance.

JP 2006-341474 A

However, the above prior art has the following problems.
In the invention described in Patent Document 1, not only the light shielding sensor but also the first paper guide and the second paper guide must be installed at a distance in the transport direction in front of the recording head. It is necessary to secure a long conveyance section for detecting the floating of the medium.
Even when the light shielding sensor is ON, the degree of the problem to be dealt with varies depending on the length of the light shielding object formed of a part of the recording medium in the recording medium conveyance direction, and the light shielding sensor is OFF. Even in this case, depending on the length of the light shielding material in the recording medium conveyance direction, there are cases where it is necessary to deal with it, and even if only the ON / OFF signal is obtained from the light shielding sensor, it is not possible to cope with these events accurately.

Therefore, the present invention provides an image recording apparatus in which a light-blocking sensor that detects floating of a recording medium is installed upstream of the recording head in the recording medium conveyance direction in order to detect contact of the recording medium with the recording head. It is an object of the present invention to accurately cope with the influence of the height of a partially configured light shield and the length in the recording medium conveyance direction.

The invention according to claim 1 for solving the above-described problems is
A transporter for transporting a recording medium;
A recording head for forming an image on the recording medium;
An image having a light projector and a light receiver, an optical axis disposed in a direction intersecting with the transport direction upstream of the recording head in the transport direction of the recording medium, and a light-blocking sensor for detecting floating of the recording medium In the recording device,
Compare and determine the received light amount detected by the light receiver and the received light amount threshold value,
Calculating a detected light shielding length obtained by multiplying the time when the detected light reception amount is lower than the light reception amount threshold by the conveyance speed by the conveyance device at the time;
Comparing and determining the detected light shielding length and a light shielding length threshold;
Control for controlling the operation of the transport device and the operation of the recording head according to an event specified by a combination of the result of the comparison determination with the light reception amount threshold and the result of the comparison determination with the light shielding length threshold An image recording apparatus including the apparatus.

The invention according to claim 2 is the image recording apparatus according to claim 1, wherein the control device controls a display operation to a user in accordance with the event.

The invention according to claim 3 is provided with two high and low received light intensity threshold values,
During the recording operation, the control device
In the event that it is determined that the detected received light amount is lower than the lower received light amount threshold value, and the detected light shielding length is longer than the light shielding length threshold value, the recording operation is stopped,
In the event that it is determined that the detected light reception amount is lower than the lower light reception amount threshold value and the detected light shielding length is shorter than the light shielding length threshold value, the recording operation is stopped according to a preset setting or a warning display to the user Output
In the event that it is determined that the detected light reception amount is lower than the higher light reception amount threshold value and higher than the lower light reception amount threshold value, and the detection light shielding length is determined to be longer than the light shielding length threshold value, a warning display to the user is displayed. Output,
The recording operation is permitted in an event where it is determined that the detected light reception amount is lower than the higher light reception amount threshold value and higher than the lower light reception amount threshold value, and the detected light shielding length is determined to be shorter than the light shielding length threshold value. The image recording apparatus according to claim 2.

According to the present invention, the detected light-receiving amount of the light-shielding sensor that detects the floating of the recording medium is compared and determined, and the detected light-shielding length is calculated by multiplying the light-shielded time by the conveyance speed, thereby detecting the light-shielding. Since the length and the light-shielding length threshold value are compared and determined, it is possible to appropriately cope with an event that is influenced by the height of the light-shielding object constituted by a part of the recording medium and the length in the recording medium conveyance direction.

1 is a schematic plan view showing a basic configuration of an image recording apparatus according to an embodiment of the present invention. 1 is a schematic side view showing a main part of an image recording apparatus according to an embodiment of the present invention. In the image recording device which concerns on one Embodiment of this invention, it is a side view schematic diagram which shows the mode of detection by a light-shielding sensor. FIG. 3B is a schematic side view showing a state of detection by the light-shielding sensor in the image recording apparatus according to the embodiment of the present invention, and shows a scene where the conveyance proceeds from FIG. 3A. FIG. 3 is a schematic side view showing the optical axis of the light shielding sensor and the type of floating of the recording medium in the image recording apparatus according to the embodiment of the present invention. 5 is a graph showing a recording medium conveyance speed and a detection waveform by a light shielding sensor in the image recording apparatus according to the embodiment of the present invention. It is a plane view schematic diagram which shows the basic composition of the image recording apparatus which concerns on other one Embodiment of this invention.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The following is one embodiment of the present invention and does not limit the present invention.

In the single-pass image recording apparatus, the recording medium moves relative to the recording head by being conveyed. In a scanning image recording apparatus, a recording head is mounted on a carriage and reciprocates in the main scanning direction, and the recording medium is conveyed in the sub-scanning direction.
The image recording apparatus according to the present embodiment is a scan type, but may be a single pass type.
In order to clearly indicate the directions, the main scanning direction X and the recording medium conveyance direction Y are shown in the drawing.
As shown in FIGS. 1 and 2, the image recording apparatus according to the present embodiment includes a control device 2, a display device 3, a transporter 20 that transports a recording medium 10, a recording head 30, and a recording head 30. A carriage 31 and a light shielding sensor 40 are provided, and a control system is configured with the control device 2 at the center.

The control device 2 receives an input of a signal indicating a conveyance speed from an encoder attached to the conveyance device 20 and an input of a signal from the light shielding sensor 40, and also displays the display device 3, the conveyance device 20, the recording head 30, and the carriage 31. To control the operation.
As shown in FIG. 2, the transport machine 20 holds the recording medium 10 on the transport belt 21 and transports and passes the recording medium 10 under the recording head 30. The transport belt 21 presses the recording medium 10. A roller 22 that rolls in contact with the roller. In addition, the machine configuration of the conveyor 20 in the present embodiment is an example and is not particularly limited.
The recording head 30 is mounted on the carriage 31 and reciprocates in the main scanning direction X to form an image on the recording medium 10. The conveyance direction Y of the recording medium is the sub-scanning direction. In the case of the single pass type, as indicated by a broken line 32, the recording head is provided long over the recording width.

The light shielding sensor 40 includes a projector 41 and a light receiver 42. The light receiving portion of the light receiver 42 is disposed on the optical axis 43 of the projector 41, and a light shielding object is interposed on the optical axis 43, whereby the detected light reception amount of the light receiver 42 changes. The optical axis 43 is arranged in a direction parallel to the main scanning direction X and perpendicular to the conveyance direction Y, and is arranged upstream of the recording head 30 in the conveyance direction Y. The optical axis 43 is arranged at a predetermined height from the surface on which the recording medium 10 is held in the conveyance path that passes under the recording head 30, that is, the surface of the conveyance belt 21. The floating of the recording medium 10 that can come into contact is detected. Note that the light shielding sensor may be replaced with a reflective light shielding sensor using a reflector.
The optical axis 43 is arranged downstream in the transport direction Y from the roller 22 immediately before the recording head 30. This is to detect the floating of the recording medium 10 after the roller 22 has acted.
A distance Y1 in the transport direction Y between the optical axis 43 and the recording head 30 is set to be equal to or longer than one transport distance of the recording medium 10 during the recording operation in the case of the scan type, and in the case of the single pass type, the transport machine. The braking distance from when the stop signal is input to 20 to when the conveyance actually stops is greater than or equal to the braking distance. When the floating of the recording medium 10 to which the recording operation is to be stopped is detected, the floating of the recording medium 10 does not enter the main scanning movement range of the recording head 30 or the single-pass recording head arrangement range (broken line 32). This is because the conveyance operation is stopped and the recording operation is stopped without bringing the recording medium 10 into contact with the recording head 30.

As shown in FIG. 3B, if the recording medium 10 that has passed through the roller 22 has a float 11 having a certain height or more from the conveyance belt 21 as shown in FIG. 3A, the conveyance of the recording medium 10 proceeds, as shown in FIG. 3B. The float 11 overlaps with the optical axis 43, so that the amount of light received by the light receiver 42 is reduced.
The control device 2 detects the float 11 by comparing and determining the detected light reception amount of the light receiver 42 and the light reception amount threshold value. The higher the float 11 is, the more light is blocked, and the amount of light received by the light receiver 42 is further reduced. Two threshold values are provided for the received light amount. Here, it is assumed that the detected light reception amount is M, the higher light reception amount threshold value is M1, and the lower light reception amount threshold value is M2 (M1> M2).
In the present embodiment, an example in which the shape of the optical axis 43 is circular is shown, but the shape of the optical axis 43 is not limited to the example illustrated here. For example, the shape of the optical axis 43 may be a vertically long rectangle in the height direction.

As shown in FIG. 4, the floating of the recording medium 10 includes

fluffs

11c and 11d in addition to the

overall floats

11a and 11b, and the height and width thereof vary. In particular, when the recording medium 10 is a cloth, overall floating and fluff are likely to occur.
Since the continuous length in the transport direction differs depending on the type of the float, the time for passing through the optical axis 43, that is, the light shielding time differs. However, the situation is different when the conveyance speed of the recording medium 10 changes.
For example, as shown in a graph G1 in FIG. 5, consider a case where the conveyance speed of the recording medium 10 by the conveyance device 20 changes through an acceleration region, a constant velocity region, and a deceleration region. At this time, even if a light shield having a constant length in the transport direction Y passes through the optical axis 43, as shown in the graphs G2 to G4 in FIG. Shading time is shortened. In order to convert this into the length of the light shielding object in the conveyance direction Y, the control device 2 determines that the detected light reception amount M is lower than the light reception amount thresholds M1 and M2, and the conveyance speed of the conveyance device 20 at that time. The detected light shielding length multiplied by is calculated. By this conversion, the detection waveforms shown in the graphs G2 to G4 in FIG. 5 are converted to the same detection length as shown in the graphs G5 to G7 in FIG.
Further, the control device 2 compares and determines the calculated detected light shielding length and the light shielding length threshold. Here, the detected light shielding length is L, and the light shielding length threshold L1 is set.

Here, a control setting when a cloth is applied as the recording medium 10 will be described.
As shown in Tables 1 to 3, the recording medium floating phenomenon is divided into four events according to the detected light reception amount M and the detected light shielding length L. Table 1 shows the control settings for each event during a recording operation when a thick cloth is applied, and Table 2 shows the control settings for each event during a recording operation when a thin cloth is applied. Indicates the control settings for each event during the stop of the recording operation and the conveyance of the recording medium.
The control device 2 compares and determines the detected light reception amount M and the light reception amount threshold values M1 and M2, and compares and determines the converted detected light shielding length L and the light shielding length threshold value L1 to determine whether the four events 1 to 4 are different. To do.
The event 1 is an event for which it is determined that the detected light shielding length L converted in the time when it is determined that M2> M is longer than the light shielding length threshold L1 (that is, L1 <L).
The event 2 is an event for which it is determined that the detected light shielding length L converted in the time when it is determined that M2> M is shorter than the light shielding length threshold L1 (that is, L <L1).
Event 3 is an event for which it is determined that the detected light-shielding length L converted at the time when it is determined that M1>M> M2 is longer than the light-shielding length threshold L1 (that is, L1 <L).
The event 4 is an event for which it is determined that the detected light shielding length L converted in the time when it is determined that M1>M> M2 is shorter than the light shielding length threshold L1 (that is, L <L1).

The control device 2 executes the following control when it is determined whether the events 1 to 4 are different.
Event 1 is mainly when the overall float is high or when the fluff is high and high, and the recording operation is stopped for both thick and thin cloths. This is to prevent contact with the recording head 30. Stopping the recording operation includes stopping the recording operation of the recording head 30 and stopping the feeding operation in the sub-scanning direction by the transporter 20. In addition, when the carriage 31 is controlled to retreat the recording head 30 to the moisture retaining cap or the ink suction suction, the recording medium 10 is fed back by a certain distance, and in the case of the single pass type, the recording head can be lifted to move away. The evacuation movement control is arbitrarily performed.
In event 2 in which the detected light shielding length is shorter than event 1, the recording operation is similarly stopped for a thick cloth, and a warning display to the user is output to the display device 3 for a thin cloth. In the case of a thick cloth, when the recording head 30 is touched, the amount of ink sucked is large and trouble is likely to occur. Therefore, in order to prevent this, the recording operation is stopped. In the case of a thin cloth, the possibility is low. Since this is a preliminary situation to shift to 1, a warning is given. Note that if there is an operation input from the user, the control device 2 stops the recording operation accordingly.
In event 3, when the overall float is low, the fluff is low and there are many fluffs. Since this is a preliminary situation to move to event 1, warning display to the user is output to the display device 3 for both thick and thin cloths. To do.
In event 4 in which the detected light-shielding length is shorter than event 3, the possibility of immediately shifting to event 1 is lower than in

events

2 and 3, and therefore “None”, that is, handling of floating of the recording medium. Special control is not performed (common to Table 1-3). In event 4, the recording operation can be continued and started, and the recording operation is allowed. Regarding the fact that no special control for dealing with the floating of the recording medium intervenes, the control in event 4 is the same as the control in the case of determining that M> M1 (common in Tables 1-3).
As shown in Table 3, when the recording operation is stopped and the recording medium is being conveyed, a warning display to the user is output to the display device 3 in

Events

1, 2, and 3. This is for informing the user of the possibility of trouble in conveyance and the possibility of trouble in the recording operation when the recording operation is started. For example, the user can correct the floating of the recording medium 10. The warning in event 1 may be displayed as a higher warning level than the warning in

events

2 and 3.
Note that when the conveyance of the recording medium 10 by the conveyance device 20 is stopped, the above floating detection process is not performed.

As shown in FIG. 6, the image recording apparatus 4 to which two sets of light shielding sensors are applied can be implemented. In FIG. 6, the same elements as those in FIG.
In the image recording apparatus 4 shown in FIG. 6, a light shielding sensor 50 is added to the image recording apparatus 1 shown in FIG. 51 is a projector, 52 is a light receiver, and 53 is an optical axis. The light shielding sensor 50 complies with the arrangement conditions of the light shielding sensor 40 described above. However, the light projector 41 of the light shielding sensor 40 and the light projector 51 of the light shielding sensor 50 are opposite to each other through the conveyance path of the recording medium 10. Therefore, the light receiver 42 of the light shielding sensor 40 and the light receiver 52 of the light shielding sensor 50 are opposite to each other through the conveyance path of the recording medium 10. The optical axis 43 and the optical axis 53 are separated in the transport direction Y.
A laser sensor or the like is used as the light shielding sensor, but the optical axis is diffused at a long distance from the light receiver, and the detection accuracy may be different at a distance and near. Therefore, as shown in FIG. 6, a projector and a light receiver are provided on both sides and two sets of

light shielding sensors

40 and 50 are provided, and determination based on detection by the light shielding sensor 40 and determination based on detection by the light shielding sensor 50 are: By making the determination valid when both are established, the detection accuracy can be improved.

In the above-described embodiment, the two received light amount threshold values are provided, but the received light amount threshold value may be one or three or more. In one case, only

events

1 and 2 are specified in Table 1-3. While the threshold value of the amount of received light is set appropriately, event 1 is as shown in Table 1-3, and event 2 is executed as “warning” or “none”. In the case of 3 or more, a new event is added as a warning between

events

1 and 2 and events 3 and 4 in Table 1-3. The operator may be urged to correct the floating of the recording medium.
By combining not only the determination based on the received light amount threshold value but also the determination based on the received light amount threshold value with the determination based on the light shielding length threshold, it is possible to identify an event that should be truly dealt with, and excessively stop the recording operation to make it inefficient. It is prevented.

The present invention can be used for image recording on a recording medium.

DESCRIPTION OF SYMBOLS 1 Image recording apparatus 2 Control apparatus 3 Display apparatus 4 Image recording apparatus 10 Recording medium 20 Conveyor 21 Conveyor belt 22 Roller 30 Recording head 31 Carriage 40 Light shielding sensor 41 Light projector 42 Light receiver 43 Optical axis 50 Light shield sensor 51 Light projector 52 Light receiver 53 Optical axis X Main scanning direction Y Transport direction

Claims

A transporter for transporting a recording medium;
A recording head for forming an image on the recording medium;
An image having a light projector and a light receiver, an optical axis disposed in a direction intersecting with the transport direction upstream of the recording head in the transport direction of the recording medium, and a light-blocking sensor for detecting floating of the recording medium In the recording device,
Compare and determine the received light amount detected by the light receiver and the received light amount threshold value,
Calculating a detected light shielding length obtained by multiplying the time when the detected light reception amount is lower than the light reception amount threshold by the conveyance speed by the conveyance device at the time;
Comparing and determining the detected light shielding length and a light shielding length threshold;
Control for controlling the operation of the transport device and the operation of the recording head according to an event specified by a combination of the result of the comparison determination with the light reception amount threshold and the result of the comparison determination with the light shielding length threshold An image recording apparatus comprising the apparatus.
The image recording apparatus according to claim 1, wherein the control device controls a display operation to a user in accordance with the event.
Two thresholds are provided for the amount of received light,
During the recording operation, the control device
In the event that it is determined that the detected received light amount is lower than the lower received light amount threshold value, and the detected light shielding length is longer than the light shielding length threshold value, the recording operation is stopped,
In the event that it is determined that the detected light reception amount is lower than the lower light reception amount threshold value and the detected light shielding length is shorter than the light shielding length threshold value, the recording operation is stopped according to a preset setting or a warning display to the user Output
In the event that it is determined that the detected light reception amount is lower than the higher light reception amount threshold value and higher than the lower light reception amount threshold value, and the detection light shielding length is determined to be longer than the light shielding length threshold value, a warning display to the user is displayed. Output,
The recording operation is permitted in an event where it is determined that the detected light reception amount is lower than the higher light reception amount threshold value and higher than the lower light reception amount threshold value, and the detected light shielding length is determined to be shorter than the light shielding length threshold value. The image recording apparatus according to claim 2.