JP2005074839A - Ink cartridge and inkjet printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the accuracy of detecting an ink end in an ink cartridge storing an ink in a pack. <P>SOLUTION: An ink end detection pipe 40, the other end of which is opened to the atmosphere, is connected to an ink supply opening 36 communicating with the pack 37 storing an ink and a liquid stopper formed of a high viscosity liquid moving in accordance with the consumption of an ink in an ink storage section is enclosed to cover the interface of the ink with a lid. Consequently, when the ink in the pack 37 is almost consumed, a negative pressure large enough to move the liquid stopper against a resistance occurring due to viscous resistance acts on the liquid stopper 39 in the ink end detection pipe 40, permitting an accurate detection of an ink end by detecting the movement of the liquid stopper 39. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an ink cartridge mounted on an ink jet printer or the like, and more particularly to a cartridge and a printer capable of detecting that the remaining amount of ink in the ink cartridge has become a predetermined value or less.

Conventional ink cartridges are known as ink containers that contain ink in a flexible pack. In such an ink container, although the pack is deformed as the ink is consumed, there is also known an ink container provided with a spring that urges the pack in a restoring direction in order to maintain a constant negative pressure. (For example, see Patent Document 1)
In such a pack-type ink cartridge, even when ink is consumed, air does not enter the pack, and therefore, it is not possible to detect the ink end by directly detecting the change in the liquid level in the ink containing portion. Therefore, either a method of detecting that the deformation amount of the pack has exceeded a predetermined value (for example, see Patent Document 2) or a method of detecting the ink end by counting the ink consumption amount on the printer side is taken. It was.

JP-A-7-1743

JP-A-4-347653

  Any of the above methods has lower detection accuracy than the method of directly detecting the liquid level, and it has been desired to detect the ink end of a pack-type ink cartridge with higher accuracy.

  An ink jet cartridge according to the present invention includes an ink container sealed with a flexible material, an ink supply port communicating with the ink container, a spring member that applies a negative pressure to the ink container, and one end supplying ink. An ink end detection tube that communicates with the opening and whose other end is open to the atmosphere, and a liquid stopper that covers the interface of the ink in the ink end detection tube, depending on the amount of ink consumed in the ink container And a high-viscosity liquid that moves.

  In addition, the ink jet printer of the present invention includes an ink container that is sealed with a flexible material, an ink supply port that communicates with the ink container, a spring member that applies negative pressure to the ink container, and one end thereof. An ink end detection tube that communicates with the ink supply port and is open to the atmosphere at the other end, and a liquid stopper that covers the interface of the ink in the ink end detection tube, and reduces the amount of ink consumed in the ink container. Accordingly, an ink supply head of an ink cartridge provided with a moving high-viscosity liquid is connected to an ink jet head that performs printing using ink supplied from an ink storage chamber, and an ink end detection tube And an ink end sensor for detecting the position of the liquid stopper.

  The negative pressure in the container gradually increases as the ink in the ink container is consumed, but the negative pressure increases at a stroke when almost no ink is used. The liquid stopper in the ink end detection tube does not move due to the resistance force generated by the viscous resistance acting between the wall surface of the pipe and the liquid stopper under the negative pressure generated when there is sufficient ink in the container. However, when the ink is almost consumed, the liquid stopper in the ink end detection tube has a negative pressure sufficient to move the liquid stopper against the resistance force caused by the viscous resistance. By detecting that the ink has moved, the ink end can be accurately detected.

  As a preferred embodiment, for example, an incident surface for allowing light from an external light source to enter a part of a wall surface of an ink end detection tube of an ink cartridge, and the incident light to the ink or liquid plug It is also possible to provide a prism having a critical surface that reflects when none of the above is provided, and to use an optical sensor that detects light reflected by the critical surface of the prism as the ink end sensor.

  According to the present invention, even in a pack-type ink cartridge, since the displacement of the liquid level can be directly detected, there is an effect that the ink end can be detected with higher accuracy than the conventional method.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic side view showing the internal structure of the printer. As shown in these drawings, an insertion port 11 for inserting the paper P is formed on the front surface of the printer 10, while a discharge for discharging the paper P after printing is formed on the upper surface of the printer 10. An outlet 12 is formed. A paper path 13 from the insertion port 11 to the discharge port 12 is formed inside the printer 10, and a paper feed roller pair 14 and a print head 15 are disposed on the paper path 13. The paper feed roller pair 14 includes a paper feed roller 16 and a paper presser roller 17 that are opposed to each other with the paper path 13 interposed therebetween, and pinches and conveys the paper P according to the driving rotation of the paper feed roller 16. The print head 15 is mounted on a carriage 18 that reciprocates in the width direction of the paper path 13, and performs dot matrix printing on the paper P whose position is defined by the platen 19. The printing system of the print head 15 is an ink jet system that forms characters and images on the paper P by ejecting ink A from ejection nozzles (not shown). The ink A used for printing is an ink supply unit 20 described later. Supplied from

  The carriage 18 is supported by a pair of front and rear guide shafts 21 and 22 so as to be movable left and right, and is forcibly moved according to driving of the carriage moving mechanism 23. The carriage moving mechanism 23 includes, for example, a cam shaft 24 provided in parallel below the front guide shaft 21 and a carriage motor (not shown) that drives the cam shaft 24 to rotate. A spiral cam groove is formed on the outer peripheral surface of the cam shaft 24, and a cam follower 25 extending from the carriage 18 is engaged therewith. When the cam shaft 24 rotates in accordance with the drive of the carriage motor, the cam follower 25 and the carriage 18 are fed in the axial direction by the spiral feeding action of the cam groove.

  FIG. 2 is a schematic explanatory view showing an ink supply path and a waste ink recovery path. As shown in this figure, the ink supply unit 20 includes a cartridge holder 26 disposed at the rear of the printer 10, an ink cartridge 27 and a waste ink cartridge that are detachably attached to the cartridge holder 26 from above. 28 is configured. The cartridge holder 26 is a box-like container that is open at the top, and has an ink outlet connection port 29 that communicates with the print head 15 through the ink supply tube 15a and a nozzle through the waste ink collection tube 30a. A waste ink intake connection port 31 communicating with the cleaning mechanism 30 is formed. Further, an ink end sensor 51 for detecting the presence or absence of ink in the ink cartridge 27 (the remaining amount of ink has become a predetermined amount or less) is provided on the side of the cartridge holder 26. As shown in FIG. 5, the ink end sensor 51 of this embodiment includes a phototransistor 51a serving as a light emitting unit (light source) and a photodiode 51b serving as a light receiving unit.

  An ink supply port 32 that can be connected to the ink outlet connection port 29 is formed on the bottom surface of the ink cartridge 27. When the ink cartridge 27 is attached to the cartridge holder 26, the ink A stored in the ink cartridge 27 is guided to the print head 15 via the ink supply port 32, the ink outlet connection port 29, and the ink supply tube 15a. A waste ink intake port 33 that can be connected to the waste ink intake connection port 31 is formed at the bottom of the waste ink cartridge 28. When the waste ink cartridge 28 is attached to the cartridge holder 26, the waste ink B sucked by the nozzle cleaning mechanism 30 passes through the waste ink collection tube 30 a, the waste ink intake connection port 31 and the waste ink intake port 33, and the waste ink. It is guided into the cartridge 28 and accommodated therein. Incidentally, the nozzle cleaning mechanism 30 includes a cap 34 that covers the discharge nozzle portion of the print head 15 when the print head 15 is moved to a predetermined position, and a pump 35 that sucks ink from the discharge nozzle through the cap 34. The ink sucked here is guided as waste ink B into the waste ink cartridge 28.

  FIG. 3 is an internal plan view of the ink cartridge, FIG. 3 shows a state where the ink cartridge is first used, and FIG. 4 shows a state of the ink end.

  As shown in these drawings, the ink cartridge 27 includes a cartridge case 36 having an ink supply port 32 formed on the bottom surface thereof. An aluminum pack 37 is accommodated in the cartridge case 36, and the pack 37 is connected to the ink supply port 32. A spring member 38 that biases the pack 37 in an expanding direction is provided inside the pack 37. A predetermined negative pressure is generated in the pack 37 by the restoring force applied by the spring member 38.

  Further, the ink end detection tube 40 is connected to the ink supply port 32, and the end of the ink end detection tube 40 that is not connected to the ink supply port 32 is open to the atmosphere. A liquid stopper that moves (lowers) in the direction of the ink supply port 32 when the negative pressure in the pack 37 increases while the interface of the ink in the ink end detection tube 40 airtightly covers the interface. 39 is enclosed. The material forming the liquid stopper 39 is a high-viscosity liquid that can follow the interfacial displacement of the ink well while maintaining a state separated from the ink that is a water-based ink. A gel composition to which an agent is added is used. Various gel-like compositions of this type have been proposed for use as ink tube liquid stoppers in water-based ballpoint pens, and these may be used.

  A prism 47 is integrally formed on a part of the transparent wall surface of the ink end detection tube 40. The position of the prism 47 is determined in advance so that the prism 47 faces the ink end sensor 51 when the ink cartridge 27 is attached to the cartridge holder 26. As shown in FIG. 5, the light emitted from the phototransistor 51a of the ink end sensor 51 enters from the incident surface 47a of the prism 47 and reaches the critical surface 47b. When the ink A or the liquid stopper 39 is on the critical surface of the ink end detection tube 40, the light incident on the critical surface 47b is refracted and the light reflected by the critical surface 47b is small. When the amount of ink A becomes less than the predetermined amount and the position of the liquid stopper 39 is lowered, the light incident on the critical surface 47b is totally reflected, reaches the photodiode 51b through the emission surface 47c of the prism 47, and the ink end is detected. Is done. As described above, the ink end sensor according to the present embodiment detects the ink end by using the difference in refractive index between gas and liquid (liquid stopper).

  FIG. 6 is a graph showing the relationship between the remaining amount (consumption amount) of ink in the pack and the pressure in the pack. The state of the pack 37 shown in FIG. 3 corresponds to the point A in FIG. 6, and the state shown in FIG. As shown in the graph, the negative pressure in the pack 37 gradually increases as the ink is consumed (points A to B), but the pack 37 cannot be deformed any more when the ink is almost gone (point C). Negative pressure increases at a stretch. The liquid stopper 39 in the ink end detection tube 40 is a negative pressure generated when there is sufficient ink in the container, that is, at points A to B, a resistance force generated by a viscous resistance acting between the wall surface of the tube and the liquid stopper. Therefore, it hardly moves. However, when the ink is almost consumed (point C), the liquid stopper in the ink end detection tube 40 has a negative pressure sufficient to move the liquid stopper 39 against the resistance generated by the viscous resistance. When the liquid stopper 39 moves and the position of the liquid stopper reaches below the prism 47, the ink end is detected.

  The present invention is not limited to the matters shown in the above-described embodiments, and a range in which a person skilled in the art can make changes and applications based on the claims and the detailed description of the invention and well-known techniques. Is included. For example, the ink end sensor of the above embodiment detects the ink end by utilizing the difference in refractive index between gas and liquid (liquid stopper), but is not limited to this. An ink end sensor that transmits light through the ink end detection tube using the difference may be used.

2 is a schematic side view showing an internal structure of the printer. FIG. It is a schematic explanatory drawing which shows an ink supply path | route and a waste ink collection | recovery path | route. FIG. 3 is an internal plan view of the ink cartridge at an initial time. FIG. 6 is an internal plan view of the ink cartridge at the time of ink end. It is sectional drawing which shows the principal part of the ink detection tube of an ink cartridge. It is a graph which shows the relationship between the residual amount (consumption amount) of the ink in a pack, and the pressure in a pack.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Printer 15 Print head 20 Ink supply part 26 Cartridge holder 27 Ink cartridge 32 Ink supply port 36 Cartridge case 37 Pack 38 Spring member
39 Liquid stopper 40 Ink end detection tube 47 Prism 51 Ink end sensor

Claims (4)

An ink container sealed with a flexible material; an ink supply port communicating with the ink container; a spring member that applies a negative pressure to the ink container; one end communicating with the ink supply port; An ink end detection tube whose end is open to the atmosphere, and a liquid stopper that covers the ink interface in the ink end detection tube, and is a high-viscosity liquid that moves according to the amount of ink consumed in the ink container. An ink cartridge comprising: a formed cartridge. A prism is provided on a part of the wall surface of the ink end detection tube, and an incident surface for entering light from an external light source and light incident on the incident surface are arranged on the prism. The ink cartridge according to claim 1, wherein a critical surface that reflects when neither the ink nor the liquid stopper is present at the position is provided. An ink container sealed with a flexible material; an ink supply port communicating with the ink container; a spring member that applies a negative pressure to the ink container; one end communicating with the ink supply port; An ink end detection tube whose end is open to the atmosphere, and a liquid stopper that covers the interface of the ink in the ink end detection tube, and is a high-viscosity liquid that moves according to the amount of ink consumed in the ink container. An ink jet head that is connected to the ink supply port of an ink cartridge and that performs printing using the ink supplied from the ink storage chamber;
An ink jet printer comprising an ink end sensor for detecting a position of a liquid stopper in the ink end detection tube. The ink cartridge is provided on a part of the wall surface of the ink end detection tube, and there is no incident surface for entering light from an external light source, and neither the ink nor the liquid stopper is used for the incident light. A prism with a critical surface that sometimes reflects,
4. The ink jet printer according to claim 3, wherein the ink end sensor is an optical sensor that detects light reflected by a critical surface of the prism.

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