JPH0872228A - Ink jet printer - Google Patents

Abstract

PURPOSE: To provide a means keeping a printable state as long as possible when the residual amt. of the ink of an ink jet cartridge is reduced to prevent an ink jet recording apparatus such as an exclusive printer or facsimile from getting into a non-printable state in its early stages. CONSTITUTION: Printing density (e.g. ink wt. of one dot) is changed from high to low corresponding to the residual amt. of ink to suppress the consumption amp. of ink.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inkjet printer, for example, a dedicated printer device, a facsimile device, and the like, and a recording device using the inkjet technology.

[0002]

2. Description of the Related Art Today, with the development of information processing systems,
Various information processing devices have been developed. Among these devices, recording devices such as facsimile machines and printers that use this type of inkjet technology are widely used not only for office work but also for general households.

FIG. 12 is an external perspective view of an example of a conventional facsimile machine of this type, and FIG. 13 is a central sectional view of the facsimile machine.

In FIG. 13, a document 5 is displayed in the document reading section.
1 is a document guide portion 52 for guiding the side portion of A1, and the ADF
The ADF portion 53 separates the originals 51 set on the original guide portion 52 one by one, having a roller 53a and a pressing piece 53b pressed by the ADF roller 53a, and separated by the ADF portion 53. A pair of feeding rollers 55a for feeding the original 51 to the perfect contact type image sensor 54,
A pair of feeding rollers 55b and a CS roller 56 for tightly adhering the document 51 fed by the pair of feeding rollers 55 so as not to float up from the reading position 54a of the perfect contact type image sensor 54 are provided. .

In the document reading section, when the document 51 is set on the document guide section 52 and the reading operation is started, the ADF roller 53a, the feeding roller pair 55, and the CS roller 56 start to rotate by a drive motor (not shown). . First, the ADF section 5
3 separates the originals 51 one by one, the separated originals 51 are fed to the perfect contact type image sensor 54 by the feeding roller pair 55, and the reading position 54a is fed by the CS roller 56.
While the sheet is pressed against and conveyed while being brought into close contact with it, the contact type image sensor 54 reads the image information of the original 51, and the read original 51 is discharged from the discharge port 58 to the outside of the apparatus by the discharge roller pair 57.

On the other hand, in the recording unit, a cassette trough 42 for loading the recording paper 41 is mounted at a predetermined position of the apparatus main body, and a pickup roller 43a for separating and conveying the recording paper 41 one by one and a separating piece. A recording / separating unit 43 configured by 43b, a feeding roller pair 45 including a pair of feeding rollers 45a and 45b that conveys the separated recording paper 41a to the recording unit 44, a paper feeding roller 46, and an inkjet for printing. The ink jet cartridge 47 includes a head and an ink tank, and a pair of discharge rollers 48a and 48b for discharging printed recording paper.

The image information read by the document reading unit is printed during copying, and the received image is printed by the recording unit during facsimile reception.

[0008]

However, in the above-mentioned conventional example, the printing (recording) density is printed at a constant high density (recording) even when the ink remaining amount of the ink jet cartridge decreases. Therefore, in some cases, such as when the image information is dense, there is no ink and printing cannot be completed.

The present invention has been made in view of the problems of the conventional example as described above. Even when the ink remaining amount in the ink cartridge is reduced, the printable state is kept as long as possible, and the printable state is quickly set. It aims to provide a means to prevent falling.

[0010]

Therefore, according to the present invention, there is provided an ink jet printer which performs printing by using a print head having a plurality of nozzles, and reduces the amount of ink remaining in the printer. Accordingly, it is intended to achieve the above object by reducing the print density or reducing the dot diameter of each print.

[0011]

According to the above-described structure of the present invention, the ink amount is reduced by checking the ink remaining amount of the ink jet cartridge and decreasing the printing density or the dot diameter of each printing depending on the remaining ink amount. Even in the case of printing, the printable state can be maintained for a long time.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on a plurality of embodiments; (First Embodiment) FIGS. 1 and 2 are explanatory views of the first embodiment of the present invention, and FIG. FIG. 2 is an external view of an example of a facsimile apparatus equipped with a serial type inkjet printer that implements the above, and FIG. 2 is a central sectional view thereof.

First, the overall structure of the apparatus will be described with reference to FIG. Reference numeral 1 denotes a main body of the apparatus, which has an upper surface cover 1a inclined at one end (left side in FIG. 2) so as to be lowered, and is formed compact as a whole. A document reading unit 2 is provided on the one end side of the apparatus main body 1, and a document insertion port 3 is provided in the document reading unit 2 and a document guide capable of sliding in the width direction of the document 4 in the document insertion port 3. 5 are provided.

Further, a document feeding path of the document reading section 2,
That is, from the document insertion opening 3 to the top cover 1a of the apparatus main body 1.
An ADF roller 7 is provided between the document outlet 6 provided at the left end.
a and a pressing piece 7b that is pressed against the ADF roller 7a to separate the originals 4 sent from the original guide 5 one by one, and the original 4 separated by the ADF 7. A feeding unit 8 including a pair of feeding rollers 8a and 8b for feeding, and a contact type image sensor 9 as a reading unit for reading the image information of the document 4 conveyed from the feeding unit 8.
Then, the CS roller 10 as a contact means for facing the contact image sensor 9 and conveying the document 4 to the reading position 9a of the contact image sensor 9 with a predetermined pressing force, and the document 4 after reading. Is equipped with a discharge unit 11 including a pair of discharge rollers 11a and 11b for discharging the document from the document discharge port 6.

Next, the reading operation of the apparatus will be described; when the document 4 is set on the document guide 5 and a reading start signal is inputted by an operation switch (not shown), a drive motor (not shown) is driven to cause the ADF roller 7a. , Feeding roller 8
a, the discharge roller 11a, and the CS roller 10 rotate, and the ADF unit 7 separates the originals 4 one by one and conveys them to the feeding unit 8.

Next, when the leading edge of the document 4 is detected by a DES sensor (document leading edge detection sensor) (not shown), the drive motor is stopped and the ADF roller 7a, the feeding roller 8a, the discharge roller 11a, and the CS roller are stopped. The rotation of 10 is once stopped.

Next, when a predetermined time has elapsed, the drive motor is driven again, and the ADF roller 7a and the feeding roller 8 are driven.
a, the discharge roller 11a, and the CS roller 10 rotate. After the rotation of each of the rollers 7a, 8a, 11a, 10 and the like, until the leading edge of the document 4 is conveyed to the reading position 9a of the contact image sensor 9, the contact image sensor 9 causes the CS roller 10 to move. The peripheral surface (white as the reference color) is read.

Next, when the leading edge of the original 4 is conveyed to the reading position 9a of the contact image sensor 9, the image information of the original 4 is read. At this time, the original document 4 is pressed by the CS roller 10 from directly above the reading position 9a of the contact image sensor 9, that is, the reading line of the contact image sensor 9 and the bus line of the CS roller 10 coincide with each other. 4 does not rise above the reading position 9a,
Image information can be read with high accuracy.

When the reading of the original 4 is completed as described above, the original 4 is sent to the discharging portion 11 by the CS roller 10 which also serves as a conveying of the original, and the discharging roller 11
It is discharged from the document discharge port 6 to the outside of the apparatus by a and 11b. This completes the work of reading the image information for one sheet of the original 4.

When a read document jams (paper jam) during the reading operation, the upper cover 1a opens around the document discharge portion as the center of rotation, as indicated by the chain double-dashed line in FIG. Then, the pressing piece 7b, the feeding roller backup roller 8b, the CS roller 10, and the discharge roller backup roller 11b, which are held by a member (not shown) attached to the upper surface cover 1a, are shown in FIG. , The paper passing surface is released and the original can be easily removed.

Next, the structure of the recording section 21 will be described; the recording section 21 is provided on the other end side (right side in FIG. 2) of the document reading section 2 of the apparatus main body 1. The cassette tub 23 for loading the recording paper 22 below the center of the apparatus body 1 is the apparatus body 1.
Is held by. Further, since the cassette lid 24 is made of a transparent member, the remaining amount of the recording paper 22 can be visually confirmed without pulling out the cassette tub 23 from the apparatus main body 1.

On the other end side of the recording paper 22, a recording separating section 2 composed of a pickup roller 25a and a separating piece 25b pressed against the same roller by a spring (not shown).
5. Printing is performed on the recording paper 22 conveyed from the feeding unit 26, which is composed of a pair of feeding rollers 26a and 26b for feeding the recording paper 22 separated by the recording separation unit 25. An ink jet cartridge 27 as a recording means for performing, a paper feed roller 28 for conveying the recording paper 22 to a position substantially facing the ink jet cartridge 27, and a pair of ejecting the printed recording paper from a recording paper ejection port 29. A paper discharge unit 30 including paper discharge rollers 30a and 30b is provided.

Next, the printing operation of the recording section will be described.
When the document 4 is set on the document guide 5 and a copy start signal is input by an operation switch (not shown) or an image reception signal is input by a telephone line or the like, a drive motor (not shown) is activated to rotate the pickup roller 25a, Cassette tub 2
The recording paper 22 in 3 is conveyed to the separation piece 25b, and the recording paper 22 is separated one by one by the recording separation unit 25 composed of the pickup roller 25a and the separation piece 25b and conveyed to the feeding unit 26. To do.

Before the recording paper 22 reaches the feeding section 26, another driving motor (not shown) is driven to feed the feeding roller 2.
6a, the paper feed roller 28, and the paper discharge roller 30a rotate to convey the recording paper 22. Next, the feeding roller 26
A PE sensor (recording paper leading edge detection sensor) (not shown) detects the leading end portion of the recording paper 22 between a and the paper feed roller 28, and after the PE sensor detects the leading edge, the recording paper 2
After 2 is conveyed for a predetermined length, the inkjet cartridge 27 starts printing.

When the printing on the recording paper 22 is completed, the paper is discharged from the recording discharge port 29 to the outside of the apparatus by the discharge rollers 30a and 30b. This completes the printing operation of the image information for one sheet of the recording paper 22. The recording cover 31 has a structure that can be opened and closed with the other end portion (upper right portion in FIG. 2) of the apparatus main body 1 as the center of rotation, as shown by the chain double-dashed point in FIG. Therefore, the inkjet cartridge 27 can be easily replaced.

In the present apparatus, a sensor (not shown) for measuring the weight of the ink cartridge 27 is attached to the standby position of the ink sheet cartridge, and the weight of the ink sheet cartridge 27 before the start of printing and after the end of printing one page. When the weight is less than a certain weight, the print density is changed from dense (“high”) to sparse (“low”) as shown in the ink remaining amount vs. print density characteristic diagram in FIG. In the print pattern of, the dot pattern is changed from (A) to (B) as shown in FIG.
The printable amount is doubled by keeping the printable amount to 10. Further, for example, in the case of the character "a", the dot pattern is changed from (A) to (B) as shown in FIG. Is increasing.

FIG. 6 shows a flowchart of the above control operation sequence. That is, in step S1, the print density is set to, for example, the "high" (dense) level in FIG. After printing the image of one page in step S2, the weight of the ink is detected by the sensor in step S3, and when the detected remaining ink weight of the ink jet cartridge 27 is less than or equal to a predetermined switching reference value Ws, In step S4, the print density is automatically switched to the "low" (sparse) level state in FIG.

(Second Embodiment) In the first embodiment, the ink remaining amount is measured by measuring the weight of the ink jet cartridge. However, in the case of an ink jet printer, heat is applied to the ink. If the conditions such as the nozzle shape and the nozzle shape are constant, the weight of one dot of ink is almost constant. Therefore, as a second embodiment, by adding the number of printed dots, the weight of the used ink can be known, and thereby the remaining amount of ink can be roughly understood by the following equation.

W = W ₀ -w × Σn where: W: remaining amount of ink (weight) W ₀ : remaining amount of ink in the initial state w: 1-dot ink weight Σn: number of printed dots Facsimile device The reading device and the recording device in are the same as those in the second embodiment. As described above, the ink density is increased (dense) as shown in FIG. 3 according to the remaining amount of ink.
It is possible to reduce the amount of ink used and increase the printable amount by changing the amount from low to sparse. FIG. 7 shows a flowchart of the control operation sequence in this case.

That is, in step S11, the print density is set to the "high" (dense) level in FIG. 3, and the total number of print dots is set to N = 0 in step S12. After printing the image of one page in step S13, a new value N is obtained by adding N (the total number of dots printed in one page) recorded in step S13 to N in step S14. Then, in step S15, it is determined whether or not this N value exceeds a predetermined switching reference value Ns, and if this N exceeds Ns, step S1
At 6, the print density is automatically switched to the "low" (sparse) level.

(Third Embodiment) In the first and second embodiments, an example in which the printing density is changed in two steps from dense to sparse is shown, but of course the invention is not limited to this. , It doesn't matter if you change it further. FIG.
FIG. 3 shows a diagram corresponding to FIG. 3 showing an example in which the print density is changed in three stages.

(Fourth Embodiment) Further, the same effect can be obtained by controlling the method of applying heat to the ink to change the particle diameter of one dot and the diameter of the ink adhering to the recording paper. . FIG. 9 shows a control operation sequence flowchart of this embodiment. FIG. 10 shows solid black when the ink dot diameter is controlled such that γ _a when the ink remaining amount is large and the dot diameter γ _b when the ink remaining amount is small is γ _b = 0.63γ _a. The pattern is shown as an example of printing. Also,
FIG. 11 shows the dot pattern difference (corresponding to FIG. 5) depending on the ink dot diameter when the character “a” is printed, for example.

FIG. 9 shows a control operation sequence flowchart of this embodiment. That is, in step S21, the ink particle diameter (ink dot diameter) is set to "large". After printing the image of one page in step S22, the remaining amount of ink is detected by the sensor in step S23, and when the detected ink residual weight of the ink jet cartridge 27 is less than or equal to the predetermined switching reference value Ws. In step S24, the ink particle diameter (dot diameter) is automatically switched to the "small" level.

[0034]

As described above, according to the present invention,
By reducing the print density or reducing the dot diameter of each print depending on the remaining ink amount of the inkjet printer, even if the remaining ink amount decreases, it becomes possible to print without falling into the unprintable state at an early stage. Now it can last longer.

By changing the print density or the dot diameter between pages of the image, it is possible to prevent the uneven density caused by the change of the print density or the dot diameter in the middle of one page. .

Furthermore, according to the present invention, since it is possible to perform printing control according to the amount of information stored in the memory, it is possible to prevent printing from becoming impossible during printing of information.

[Brief description of drawings]

FIG. 1 is an external perspective view of an embodiment of a facsimile device.

FIG. 2 is a central sectional view of the apparatus shown in FIG.

FIG. 3 is an ink remaining amount-printing density characteristic diagram of the first and second embodiments.

FIG. 4 is an example of a solid black dot pattern.

[Fig. 5] Example of character dot pattern

FIG. 6 is a control operation sequence flowchart of the first embodiment.

FIG. 7 is a control operation sequence flowchart of the second embodiment.

FIG. 8 is an ink remaining amount-printing density characteristic diagram of the third embodiment.

FIG. 9 is a control operation sequence flowchart of the fourth embodiment.

FIG. 10 shows an example of a solid black pattern of the fourth embodiment.

FIG. 11 is an example of a character dot pattern of the fourth embodiment.

FIG. 12 is an external perspective view of an example of a conventional facsimile apparatus.

FIG. 13 is a central sectional view of the apparatus shown in FIG.

[Explanation of symbols]

 1 Device Main Body 1a Top Cover 2 Original Reading Section 3 Original Insertion Port 4 Original 6 Original Ejection Port 7 ADF Section 8 Feeding Roller Pair 9 Contact Image Sensor 10 CS Roller 11 Ejection Roller 21 Recording Section 22 Recording Paper 23 Cassette Tab 25 Recording separation unit 26 Feed roller pair 27 Inkjet cartridge 28 Paper feeding roller 29 Recording paper ejection port 30 Paper ejection unit 31 Recording cover

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location B41J 2/12 B41J 3/04 103 B 104 F

Claims (7)

[Claims] 1. An ink jet printer for performing printing using a print head having a plurality of nozzles, wherein the print density is reduced in accordance with a decrease in the amount of ink remaining in the printer. Inkjet printer characterized by. 2. The ink jet printer according to claim 1, wherein the remaining amount of the ink is detected after printing one page, and the print density is reduced according to the detected remaining amount of the ink. 3. The ink jet printer according to claim 1, wherein the decrease in the printing density is due to a decrease in the number of dots per unit length of printing. 4. The ink jet printer comprises a carriage having a print head having a plurality of nozzles arranged at right angles or obliquely with respect to a scanning direction of the carriage, the carriage being moved with respect to a recording medium. The inkjet printer according to claim 1, wherein printing is performed. 5. An inkjet printer for performing printing using a print head having a plurality of nozzles, wherein each dot diameter of printing is reduced in accordance with a decrease in the amount of ink remaining in the printer. An inkjet printer having the above structure. 6. The ink jet printer according to claim 5, wherein the remaining amount of ink is detected after printing one page, and each dot diameter of printing is reduced according to the detected remaining amount of ink. . 7. The inkjet printer comprises a print head having a plurality of nozzles arranged in parallel at right angles or obliquely with respect to a scanning direction of the carriage, mounted on the carriage, and moving the carriage with respect to a recording medium. The inkjet printer according to claim 5, wherein printing is performed.