JPH07112556A - Recording device - Google Patents

Abstract

PURPOSE:To prevent a recording defect due to the variation of transport pitch caused by the deterioration of a transport capability of a transport roller caused by paper powder or printing powder sticking to the transport roller by detecting the reflective density of the transport roller and inhibiting a recording process, if the reflective density changes higher than a fixed value from an initial value. CONSTITUTION:In a recording device equipped with a transport roller for transporting a recording medium 4, a density detection means 15 is provided for detecting the reflective density of the transport roller 5. If the reflective density of the transport roller 5 changes higher than a certain value from an initial value, a recording action is not activated. In this simple constitution, a recording defect due to the failure to transport a recording medium smoothly can be avoided by detecting the deterioration of a transport capability of the transport roller positively. In addition, the energy can be saved by performing cleaning only if the transport capability of the transport roller deteriorates.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording apparatus having a conveying roller for conveying a recording medium.

[0002]

2. Description of the Related Art Generally, in a recording apparatus having a conveying roller for conveying a recording medium, a paper powder, a recording medium printing powder (when a background image or the like is printed in advance on the recording medium such as a postcard, etc., as recording proceeds. It is used for the purpose of improving the fixing property and the separating property. Examples of the material include corn starch, etc.). For this reason, the friction coefficient of the roller surface is reduced, the transporting force of the recording medium is reduced, and the recording medium may not be transported to the proper position, which may cause defective recording.

Therefore, conventionally, there has been adopted a system in which the carrying roller is regularly cleaned or a cleaning member which constantly cleans the carrying roller is provided. For this reason, the number of recording sheets is large, so that a conveyance failure occurs within the estimated period for cleaning the conveyance roller, or the conveyance roller cleaning member is required, which complicates the configuration of the recording apparatus or consumes extra power. There was a drawback that

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems of the prior art. Generally, if the conveying roller is made of black material such as NBR or CR, paper powder,
When powder or the like is accumulated on the carrying roller, the surface of the carrying roller becomes white. Along with this, it is known that the coefficient of friction of the surface decreases and the carrying force decreases. According to the present invention, by providing the recording apparatus with the reflection type density detecting device for detecting the reflection density of the carrying roller, it is possible to detect the reflection density of the carrying roller for carrying the recording medium. It is possible to estimate the carrying force of the rollers.

With the above structure, it is possible to detect a decrease in the carrying force of the carrying roller with a simple structure. When the decrease in the carrying force is detected, the printing is stopped or the cleaning operation is performed. Thus, it is possible to avoid a recording defect caused by a row pitch unevenness or the like due to a recording medium conveyance defect.

[0006]

【Example】

(Embodiment 1) Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a sectional view of a serial type ink jet recording apparatus according to an embodiment of the present invention.

Here, 1 is a recording head having an ink, an ink ejection port and an electrical connection portion inside. Reference numeral 2 denotes a carrier that mounts a recording head and scans in a direction perpendicular to the paper surface, and is connected to a driving unit (not shown). Reference numeral 3 denotes a guide shaft for guiding the carrier 2, which is inserted into the carrier 2.

Reference numeral 4 is a recording medium such as paper, and 5 is a conveying roller for conveying the recording medium 4 at the time of recording. Reference numeral 6 denotes a paper pan for guiding the recording medium 4 to the front of the recording head 1, and 7A and 7B are arranged in a conveying path of the recording medium 4 to press the recording medium 4 toward the conveying roller 5 and press it. It is a pinch roller for carrying.

Reference numeral 8 denotes a paper discharge roller which is arranged on the downstream side of the recording position in the recording medium conveyance direction and discharges the recording medium toward the discharge port 9. Reference numeral 10 denotes a spur provided corresponding to the paper discharge roller 8, which presses the paper discharge roller 8 through the recording medium 4 and causes the paper discharge roller 8 to convey the recording medium 4. A platen 11 is provided at a position facing the ink ejection port of the recording head 1, and presses the recording medium 4 against the front surface of the paper pan 6 by an elastic member (not shown). The transport roller 5 and the paper discharge roller 8 are
It is connected to a conveyance motor (not shown), and is configured to rotate by its driving force.

In this apparatus, an ink jet recording head 1 for recording by ejecting ink is used as the recording head 1. Therefore, the distance between the ink ejection port of the recording head 1 and the recording surface of the recording medium 4 is relatively small, and the interval must be strictly controlled to avoid contact between the recording medium 4 and the ejection port. It is effective to regulate the position of the recording medium 4 on the front surface of the paper pan 6. Lower part of paper pan 6, pinch roller 7
A sensor holder 12 is provided behind A, and a lever 13 is pivotally supported on the sensor holder 12. The lever 13 has its tip protruding from the opening of the paper pan 6, and rotates as the recording medium 4 passes.
Further, PE (paper end) is placed on the sensor holder 12.
A sensor 14 is provided, and by rotating the rear end of the lever 13, it is possible to detect the positions of the front end and the rear end of the recording medium 4. Further, a reflection type density sensor 15 is provided below the paper pan 6 and facing the transport roller 5,
The configuration is such that the reflection density on the surface of the transport roller 5 can be detected. The PE sensor 14 and the reflective density sensor 15 are electrically connected to a recording control unit (not shown).

Next, the recording operation of this embodiment will be described with reference to the flow chart shown in FIG.

In FIG. 2, first, when a print command including print data is received in step S001, step S00 is performed.
At 2, it is determined whether the PE sensor 14 is ON. If the PE sensor 14 is ON at this time, since the recording medium 4 has already been set, the transport motor is reversely rotated in step S003 and the recording medium 4 is run backward. This operation is performed until the PE sensor 14 is turned off in step S004. At this time, the PE sensor 14 is OFF means that the front end of the recording medium 4 is the pinch roller 7A.
It means that the recording medium 4 is not located on the measurement surface of the reflection type density sensor 15, and the reflection type density sensor 15 is measuring the surface of the transport roller 5. Next, in step S005, the reflection density sensor 15 measures the reflection density on the surface of the transport roller 5, and determines whether the value is lower than the set value x. The value of x is set to a value at which the conveyance roller 5 may cause conveyance failure of the recording medium 4. Here, when the reflection density of the transport roller 5 is lower than the set value x, there is a possibility that the transport failure of the recording medium 4 may occur, so the printing operation is stopped in step S006, and then the printing apparatus is run in step S007. The operator is notified of the abnormality. Examples of the notification method include lighting an LED lamp, a buzzer sound, and a message on a display device such as a liquid crystal display.

If it is determined in step S005 that the reflection density of the transport roller 5 is equal to or greater than the set value x, the transport motor is normally rotated in step S008, and the recording medium 4 is transported to the recording position in front of the recording head 2. And then step 009
To print.

In step S002, the PE sensor 14 is turned on.
If not, it is considered that the leading end of the recording medium 4 is stopped at the position of the pinch roller 7A, and thus step S0 is performed.
At 10, the transport motor is rotated in the forward direction. Then, step S0
11 The PE sensor 14 is judged to be ON again by 11 times, and if the PE sensor 14 is ON, it is judged that the recording medium 4 is set, the process proceeds to step S005, and the same operation as described above is performed.

In step S010, the PE sensor 14 is turned on.
The state of the recording medium 4 cannot be detected, that is, the leading edge of the recording medium 4 cannot be detected no matter how many times the transport motor is normally rotated.
Since there may be a case where there is no sheet, or the carrying force of the carrying roller 5 has decreased, after stopping printing in step S006, an abnormality of the recording apparatus is notified in step S007.

When the abnormality is notified, the operator manually conveys the cleaning sheet coated with the adhesive through the inside of the recording apparatus to remove the paper dust, the printing powder, etc. on the conveyance rollers.
The carrying force of the carrying roller can be recovered.

(Embodiment 2) Next, a second embodiment of the present invention will be described with reference to FIG.

In FIG. 4, a PE sensor dedicated to detecting the position of the recording medium 4 is not provided, and the reflection type density sensor 1 is used.
Only 5 is provided under the paper pan. The reflection type density sensor 15 is configured to detect the reflection density of the transport roller 5 and the reflection density of the recording medium 4 transported by the transport roller 5.

The reflection type density sensor 15 is electrically connected to a recording control unit (not shown). In general, the relationship of the recording medium reflection density <the reflection density of the paper powder / powder-carrying roller <the initial reflection density of the carrying roller is satisfied. It is also possible to detect the position of.

Further, the recording control unit (not shown) has a set density of y at the boundary between the reflection density of the recording medium and the reflection density of the paper powder / powder-conveying roller, and the reflection density of the paper powder / powder-conveying roller and the conveyance roller. The set density at the boundary with the initial reflection density of is set as x.

The operation of this embodiment will be described below with reference to the flow chart shown in FIG.

In FIG. 4, first, when a print command including print data is received in step S101, step S10 is performed.
In step 2, the reflection density sensor 15 determines the reflection density. At this time, if the reflection density is less than or equal to the set value y, it can be recognized that the recording medium 4 is set, and then step S
At 103, the conveyance motor is rotated in the reverse direction to cause the recording medium 4 to run in the reverse direction. This operation is performed until the reflection density becomes larger than the set value y in step S104. At this time, the fact that the reflection density is larger than the set value y means that the recording medium 4
Of the recording medium 4 is not located on the measurement surface of the reflection type density sensor 15, and the reflection type density sensor 15 is measuring the surface of the conveyance roller 5. I mean. Next, in step S105, the reflection density sensor 15 measures the reflection density on the surface of the transport roller 5, and determines whether the value is lower than the set value x. The value of x is set to a value at which the conveyance roller 5 may cause conveyance failure of the recording medium 4. Here, when the reflection density of the transport roller 5 is lower than the set value x, there is a possibility that the transport failure of the recording medium 4 may occur, so step S1
The recording operation is stopped at 06, and then at step S107, the operator is notified of the abnormality of the recording apparatus. Examples of the notification method include lighting an LED lamp, a buzzer sound, and a message on a display device such as a liquid crystal display.

If it is determined in step S105 that the reflection density of the transport roller 5 is equal to or greater than the set value x, the transport motor is normally rotated in step S108 to transport the recording medium 4 to the recording position in front of the recording head 1. And then step S10
Print at 9.

If the reflection density is larger than the set value y in step S102, the measurement surface of the reflection type density sensor 15 is
Since the recording medium 4 is not located, the reflection density of the transport roller 5 is measured in step S110. At this time, when the reflection density is smaller than the set value x, the conveyance roller 5 is paper dust,
Since it is considered that the printing power is dirty and the carrying force is reduced, the printing operation is stopped in step S106, and the device abnormality is notified in step S107.

If the reflection density is greater than the set value x in step S110, it is determined that the conveyance force of the conveyance roller 5 is normal, and in step S111 the conveyance motor is rotated in the normal direction to convey the recording medium 4 by a predetermined amount. Next, in step S112, the reflection density of the recording medium 4 is measured. If the reflection density does not become smaller than the set value y here, the recording medium 4 is not conveyed, so printing is stopped in step S106.

If the reflection density is larger than the set value y in step S112, the recording medium 4 is normally conveyed, so that the conveying motor is normally rotated in step S108, and printing is performed in step S109.

(Embodiment 3) The structure of this embodiment is shown in FIG. The configuration of the present recording apparatus is almost the same as the configuration of FIG. 1, but as shown in FIG. 5, only the reflection-type density sensor 15 is different in position, and the sensor is located above the transport roller 5. Therefore, the reflection density of the transport roller 5 can be measured during the printing operation and when the recording medium is running.

The details of this embodiment will be described below with reference to the flow chart shown in FIG. Step S0 here
09 is step S00 of the flowchart shown in FIG.
9. Therefore, this embodiment defines the operation of the first and subsequent embodiments. When the printing operation is started in step S009, first, in step S202, the recording head 1 prints one line while the carrier 2 is driven by driving a carrier scanning motor (not shown).

Next, in step S203, it is determined whether or not the recording data to be printed remains. If the recording data remains, the process proceeds to step S204, and the reflection density of the transport roller 5 is measured. At this time, if the reflection density is smaller than the set value x, there is an abnormality in the conveyance force of the conveyance roller 5, so that printing is stopped in step S205 and the apparatus abnormality is notified in step S206, as in the first embodiment.

If the reflection density of the carrying roller 5 is larger than the set value x in step S204, there is no abnormality in the carrying force of the carrying roller 5, so the printing operation is continued, and step S201 is performed.
Return to. After the recording medium 4 is conveyed again by a predetermined amount, printing for one line is performed. This operation is repeated until it is determined in step S203 that there is no print data, and when it is determined in step S203 that there is no print data, the transport motor is rotated in the normal direction to eject the print medium 4,
The printing operation ends in step S208.

In the above description, the reflection density of the conveying roller 5 is measured during the recording operation, but before the recording operation or after the page printing is completed, the conveying roller 5 is rotated to cover the entire area in the circumferential direction. The method of measuring the reflection density is also effective.

According to this embodiment, since the carrying force of the carrying roller 5 is detected even during the printing operation, even if there is a part where the carrying force is low in a part of the carrying roller 5 in the circumferential direction, this is detected. Therefore, it is possible to avoid the defective recording due to the defective conveyance of the recording medium 4.

(Embodiment 4) The configuration of this embodiment is shown in FIG. The configuration of the present embodiment is almost the same as that of FIG. 1, but as shown in FIG. 7, only the reflection-type density sensor 15 is different in position, and the sensor is located on the carrier.
Therefore, the reflection-type density sensor 15 is configured to measure the reflection density of the transport roller 5 along the guide shaft 3 over the entire area of the transport roller 5 in the axial direction.

According to this structure, before the printing operation or after the printing is completed, the carrier scanning motor (not shown) is driven, and at the same time, the reflection density sensor 15 measures the reflection density in the entire axial direction of the transport roller 5. It is possible to

By performing the above operation while driving the carry motor, the reflection density can be measured over the entire outer peripheral surface of the carry roller 5.

As is clear from the above description, according to the present embodiment, it becomes possible to estimate the carrying force in the entire area of the outer peripheral surface of the carrying roller 5.

(Embodiment 5) The configuration of this embodiment is shown in FIG. In the present embodiment, in addition to the configuration of FIG. 1, a cleaning roller 16 is provided above the carrying roller. The cleaning roller 16 is driven by a driving unit (not shown) to rotate the rotary shaft 1.
It is provided so as to be rotatable around 7, and can be pressed against or separated from the conveying roller according to a control signal from the recording device control section. In addition, the cleaning roller 16
The surface of (1) has an adhesive property, and when it is pressed against the transport roller 5, it is possible to remove the paper dust and powder on the transport roller 5.

In the recording operation, the reflection type density sensor 15
Detects a change in the reflection density of the carrying roller 5, and when it is determined that the carrying force has decreased, the recording operation is temporarily stopped and the cleaning roller 16 is brought into pressure contact with the carrying roller 5.
After that, by driving the carry motor, the carry roller 5
After removing the above paper dust and powder, the recording operation is restarted.

[0040]

As described above, according to the present invention,
With a simple configuration, it is possible to reliably detect that the transport force of the transport roller has decreased, and avoid recording defects due to poor transport of the recording medium, or clean only when the transport force of the transport roller has decreased. Since the operation is performed, it is possible to save energy.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a recording apparatus of the present invention.

FIG. 2 is a flowchart showing a control procedure of the recording apparatus in the configuration of FIG.

FIG. 3 is a cross-sectional view showing another embodiment.

FIG. 4 is a flowchart showing a control procedure of the recording apparatus in FIG.

FIG. 5 is a sectional view showing another embodiment.

6 is a flowchart showing a control procedure of the recording apparatus in FIG.

FIG. 7 is a cross-sectional view showing another embodiment.

FIG. 8 is a sectional view showing another embodiment.

[Explanation of symbols]

 1 Recording Head 2 Carrier 3 Guide Shaft 4 Recording Medium 5 Conveying Roller 6 Paper Pan 7A, 7B Pinch Roller 8 Paper Ejection Roller 9 Ejection Port 10 Spur 11 Platen 12 Sensor Holder 13 Lever 14 PE Sensor 15 Reflective Density Sensor 16 Cleaning Roller 17 Axis of rotation

Claims (6)

[Claims] 1. A recording apparatus having a conveying roller for conveying a recording medium, comprising density detecting means for detecting the reflection density of the conveying roller, wherein the reflection density of the conveying roller has changed from an initial value pair by a certain value or more. In this case, the recording device is characterized by not performing a recording operation. 2. When the reflection density of the carrying roller changes by a certain amount or more with respect to an initial value by the density detecting means,
The recording device according to claim 1, wherein the recording device abnormality is notified. 3. The recording apparatus according to claim 1, wherein the density detecting unit has a recording medium position detecting function. 4. The recording apparatus according to claim 1, wherein the density detecting unit measures the reflection density over the entire circumference of the conveying roller. 5. The recording apparatus according to claim 1, wherein the density detecting unit measures the reflection density over the entire area of the conveying roller in the axial direction. 6. When the reflection density of the carrying roller changes by a certain amount or more with respect to an initial value by the density detecting means,
The recording apparatus according to any one of claims 1 to 5, wherein the recording operation is temporarily interrupted, the conveyance roller cleaning operation is performed, and then the recording operation is restarted.