JPH11115206A - Ink jet recording apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To certainly and inexpensively detect the residual quantity of ink and to prevent sway of ink in the inside of an ink housing part by a method wherein an optical detecting means wherein a light emitting body and a light receiving body are arranged oppositely with a part of an ink tank interposed in between is provided for detecting deformation of the ink housing part that is flexible. SOLUTION: A transmission photosensor is constructed so that light emitted from a light emitting part 4b thereof is received with a light receiving part 4a thereof and a specified amount of electricity is outputted when intensity of the light received at the light receiving part 4a exceeds a certain level. When an ink tank 100 is in starting of its use, the light emitted from the light emitting part 4b does not reach to the light receiving part 4a because transitivity of light is weakend by ink 50. As consumption of ink 50 inside the ink tank 100 progresses, the light emitted from the light emitting part 4b positioned at a position separating by dx from the end of the container becomes able to reach to the light receiving part 4a because of deformation at the inner wall that arises from consumption of ink.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus having an ink amount detecting mechanism, and more particularly, to an ink jet recording apparatus employing an epoch-making ink tank which forms the ink tank itself by blow molding.

[0002]

2. Description of the Related Art In an ink-jet printer, ink is supplied to a print head from an ink tank connected to a print head, and printing is performed by discharging ink droplets onto a recording medium. When the ink in the ink tank is completely used up, printing becomes impossible, and printing can be performed again by replacing the ink tank or the ink jet cartridge in which the ink tank and the print head are integrated by the user.

On the other hand, conventionally, in order to reduce the number of times of replacing the ink tank itself, it is necessary to increase the ink storage capacity per unit volume occupied by the ink tank, and to increase the use efficiency of the ink stored in the ink tank. There have been proposed ink tanks of various shapes other than those using a porous member as the negative pressure generating member.

For example, a sponge as a negative pressure generating source is stored in an ink tank as a liquid storage container, or a spring is provided in a bag-shaped ink storage section so that the inside of the bag due to ink consumption can be provided. Which form a negative pressure by giving a force against deformation to the surface (Japanese Patent Application Laid-Open No. 56-67269,
No. 226993).

The rubber ink container disclosed in US Pat. No. 4,509,062 has a conical shape in which a conical portion is rounded, and the rounded conical portion has a thickness of a conical peripheral surface. It is of a configuration that makes it thinner. The thin rubber bag structure with the rounded conical portion is a structure for the storage container to be preferentially displaced and deformed in accordance with ink consumption. These have been put to practical use as ink containers for ink jet devices, and are satisfactory at present.

On the other hand, as a means for enabling the user to confirm the ink end and prompting the user to replace the ink tank, for example, a visual method such as making the ink tank transparent, and the conductivity of the ink are used. An electrical detection method, a mechanical detection method using contraction of an ink tank (or a flexible ink storage bag), and the like have been proposed, and an ink detection device that realizes the above-described detection method has been proposed.

[0007]

With the current ink tanks as described above, the demands of the current market are at a satisfactory level. However, when the ideal conditions required for an ink jet ink tank were considered from the perspective of the future, the following problems were found.

The first point is to increase the ink storage capacity of the ink tank by further increasing the ink storage efficiency of the ink tank occupying the same space. (First issue)

Second, the number of components is small, the structure of the components themselves is simple (second problem), and as additional effects, there are advantages such as improvement in product yield and reduction in quality control items. Can be expected.

[0010] It is preferable to deal with environmental problems that have recently become a problem. One of the countermeasures is
The component parts of the ink tank are recyclable. To this end, it is desirable that the components of the ink tank be as small as possible and that the components can be easily separated and collected when collecting the components.

As a method of detecting the ink end or the remaining amount of ink in such a container, it is required that the number of components in the ink tank be small, and that simple and inexpensive but reliable detection can be performed. .

Considering the ink detection method in the conventional ink jet recording apparatus from this viewpoint, an electric detection method using the conductivity of the ink conventionally used, shrinkage of an ink tank (or a flexible ink storage bag), and the like. In the mechanical detection method and the like utilizing the above, the number of parts of the ink tank may increase.

On the other hand, a mere visual method has a problem in terms of certainty and requires the user to constantly check the ink tank.

Therefore, the present inventor has proposed a liquid storage container that can solve the above-mentioned problems, and furthermore, the container has a negative pressure due to the deformation of the wall surface of the liquid storage container as the liquid is used. And the fact that there is a surface that comes into contact with the facing surface with the use of the ink.

An object of the present invention is to provide an ink jet recording apparatus capable of supplying ink while utilizing a stable negative pressure as one of the constitutional requirements of an ink supply system based on the above-mentioned viewpoint. It is.

[0016]

As a specific means for achieving the above object, the present invention provides a recording head for discharging ink from a discharge port, and a recording head which is detachably mounted on the recording head and supplies the recording head with the recording head. A light emitting body that emits light, and a light receiving body that receives light from the light emitting body and outputs a predetermined electric quantity value according to the intensity of the light. Wherein the light-emitting body and the light-receiving body are provided with optical detection means arranged to face each other with one part of the ink tank interposed therebetween, and the ink tank has a substantially atmospheric communication portion and is substantially polygonal. An outer wall having a columnar shape and having a corner formed by three extended portions of the polygonal column, an outer surface having a shape similar to or similar to the inner surface of the outer wall, and a corner corresponding to the corner of the outer wall; Ink collection containing ink An inner wall that forms a part and is peelable from the outer wall, an ink supply unit that supplies ink from the ink storage unit to the outside, and a pinch-off unit in which a part where the inner wall is integrated is clamped by the outer wall Wherein the partial position is transparent to light emitted from the luminous body.

According to the above configuration, the ink end can be easily and reliably confirmed by detecting the deformation of the wall constituting the liquid storage container accompanying the use of the liquid, and the user can exchange the ink tank. Can be encouraged.

[0018] As for the portion to be detected, if the detection is performed on the largest surface area of the ink tank facing the ink tank, it is possible to easily detect the state where the inner wall surface facing the ink tank is in contact, so that the ink end can be reliably detected. Become. On the other hand, when detection is performed on a pair of opposing surfaces adjacent to the maximum area surface, displacement of the maximum area surface can be easily detected.

Further, as an ink tank used in the above-mentioned ink jet recording apparatus, it is one of more desirable constitutions to provide a member for blocking light transmission other than the detection site.

[0020]

Embodiments of the present invention will be described below in detail with reference to the drawings.

Prior to the detailed description of each embodiment of the present invention, an example of the shape of a container to which the present invention can be applied will be described with reference to FIGS.

FIGS. 1A to 1C are schematic diagrams showing the structure of an ink tank according to an embodiment of the present invention.
(A) is a sectional view, (b) is a side view, and (c) is a perspective view. As can be seen from FIG. 1C, the surface having the maximum area among the surfaces constituting the outer wall of the tank in FIG. 1 is indirectly displayed as in the cross-sectional view in FIG. Face. Further, FIG. 2 is a schematic diagram showing a change when ink is stored in the ink tank of FIG. 1 and ink is derived from an ink supply unit of the ink tank in the order of (a) to (d). 1B is a sectional view taken along the line BB, and the suffix 2 is a sectional view taken along the line AA in FIG. The ink tank of the present invention is manufactured by a method in which the inner and outer walls of the ink tank and the separation layer are simultaneously formed in one step by direct blow molding described later.

In the ink tank 100 shown in FIG. 1, ink is stored in a region (hereinafter referred to as an ink storage portion) surrounded by an inner wall 102 which can be separated from an outer wall 101 forming an outer shell. The outer wall 101 is sufficiently thicker than the inner wall 102, and hardly deforms even if the inner wall 102 deforms due to the outflow of ink. The outer wall is an air intake 105
have. The inner wall has a welded portion (pinch-off portion) 104, and the inner wall is supported by the welded portion so as to engage with the outer wall.

Here, the ink tank of FIG. 1 will be described in detail. The ink tank 100 is composed of eight planes, and a cylindrical ink supply section 103 is added as a curved surface. Of these eight surfaces, the ink supply unit 10
3 has six corners (α1, β1, β1, β1, β1, β2,...) Described later.
1, α1), (α2, β2, β2, β2, β2, α2)
It is divided by.

The thickness of the inner wall surface having the maximum area is thinner at the corners than at the central region of each surface of the substantially polygonal column, and gradually increases from the central region of each surface toward each of the corners. And has a convex shape on the ink storage unit side. This direction is, in other words, the same as the surface deformation direction, and has the effect of promoting the deformation described later.

Here, the corner of the inner wall is formed of three surfaces as described later, and as a result, the strength of the entire corner of the inner wall is relatively higher than the strength of the central region. Further, when viewed from the extension of the surface, the thickness is smaller than that of the central region, so that the movement of the surface described later is permitted. It is desirable that the portions constituting the corners of the inner wall have substantially the same thickness.

The ink supply unit 103 is provided with an ink discharge permission member 106 (not shown) having an ink leakage prevention function for preventing ink leakage when a slight vibration or external pressure is applied to the tank. It is connected to an ink outlet tube of the recording means (hereinafter, referred to as an initial state). The ink supply unit 103 has a configuration in which the inner wall and the outer wall are not easily separated by the ink lead-out permission member 106 or the like. Further, γ1 and γ2, which are the intersections between the curved surface and the plane of the cylinder described later, have an inner wall that accompanies the derivation of the ink by the discharge of the ink from the ordinary ink jet recording means because the ink supply unit is substantially cylindrical. It has the property of not being easily collapsed by deformation. In the ink tank of the present embodiment, the ink supply unit is substantially cylindrical, but is not limited to a substantially cylindrical shape. Even with a polygonal prism shape, the size of the ink supply unit is sufficiently small compared to the ink storage unit,
The characteristic that is hard to be crushed by the deformation of the inner wall due to the derivation of the ink does not change. Therefore, even when the consumption of the ink is completely completed, the inner wall and the outer wall of the ink supply unit maintain the initial state without being deformed.

FIGS. 1 and 2 are schematic diagrams schematically showing the outer wall 101 of the ink tank and the inner wall 10 of the ink tank.
The positional relationship with 2 is drawn as if it were separated by space,
Actually, it is sufficient that the inner wall and the outer wall are in a separable state. The inner wall and the outer wall may be in contact with each other or may be configured to be arranged with a small space therebetween. Therefore, in any case, in the initial state, the ink tank is connected to the outer wall 10.
1 at least at the corners α2, β of the inner wall 102 at positions corresponding to the corners α1, β1 of the outer wall 101.
2 (FIG. 2 (a1), (a)
2)).

Here, the corner refers to an intersection of at least three planes, more preferably three planes, or a part corresponding to the intersection of extensions thereof in an ink tank composed of a substantially polyhedron. It is a meaning that includes. The meanings of the signs of the corners indicate that α is a corner formed by the surface having the ink supply port, β is the other corner, and that subscript 1 is an outer wall and subscript 2 is an inner wall. ing. Further, the ink supply portion is formed in a substantially cylindrical shape. Here, when the intersection between the curved surface of the cylinder and the substantial plane is represented by γ, the outer wall and the inner wall are also at corresponding positions at this intersection. And they are respectively referred to as γ1 and γ2 below. The corners may be provided with minute curved surfaces. At this time, the surface is defined as a plane excluding the minute curved surface portion, taking the minute curved surface portion of the polyhedron as a corner.

After the ink is discharged from the ink jet recording head of the ink jet recording means and the ink in the ink container starts to be consumed, the inner wall 102 is positioned at the center of the surface having the largest area in the direction in which the volume of the ink container is reduced. Deformation starts from the part. Here, the outer wall functions to suppress the displacement of the corner of the inner wall. This ink tank has the above-mentioned corner α
2. Since there is almost no positional change in the corners divided by β2, the ink storage unit is acted on by the force of deformation due to ink consumption and the force of returning to the initial state, thereby stabilizing the negative pressure. To work.

At this time, air is introduced from the air intake port 105 between the inner wall 102 and the outer wall 101, and serves to maintain a stable negative pressure during ink use without hindering deformation of the inner wall. . That is, the space between the inner wall and the outer wall communicates with the outside air through the air intake 105. Thereafter, the ink on the inner wall and the meniscus force at the ejection port of the recording head are balanced, so that the ink is held in the ink storage section (FIGS. 2B1 and 2B2).

Further, when a considerable amount of ink in the ink container is led out (FIGS. 2 (c1) and 2 (c2)), the ink container is deformed in the same manner as described above, and the central portion of the ink container becomes inward. A stable crushing way toward is maintained. Further, the welded portion 104 also serves as a deformation regulating portion of the inner wall, and the portion having no pinch-off portion starts to deform first on the surface adjacent to the surface having the maximum area, compared with the region having the pinch-off portion 104. Separated from outer wall.

However, if the inner wall deformation restricting portion alone is used, the inner wall in the vicinity of the ink supply portion is deformed, thereby blocking the ink supply portion, and may not be able to sufficiently use the ink stored in the ink storage portion. There is.

In the present invention, the corner α2 of the inner wall shown in FIG. 1 (c) is formed along the corner α1 of the outer wall in the initial state. The corner portion α2 of the inner wall is less likely to be deformed as compared with the above, and the deformation of the inner wall can be restricted. The inner wall of this ink tank is
The angle formed by the plurality of corners α2 is expressed as 90 degrees.

Here, the angle of the corner portion α2 of the inner wall is defined as the angle formed by two of at least three of the substantially planar surfaces forming the corner portion α1 of the outer wall, that is, the intersection of the extension of the two surfaces. Defined as the angle of the part. The angle of the corner of the inner wall is defined by the angle of the corner of the outer wall in order to manufacture the outer wall as a reference in a manufacturing process described later, and as described above, the inner wall and the outer wall are substantially similar in the initial state. This is because

As described above, in FIGS. 2 (c1) and (c2), the corner α2 of the inner wall shown in FIG. 1 (c) is positioned so as to be separable from the corresponding corner α1 of the outer wall. on the other hand,
The corner β2 of the inner wall other than the corner formed by the surface having the ink supply port is slightly away from the corresponding corner β1 of the outer wall as compared with α2. However, in the embodiments shown in FIG. 1 and FIG. 2, in many cases, β at the opposing position is formed by an angle of 90 degrees or less. Therefore, the positional relationship with the corresponding outer wall can be maintained at a position closer to the initial state as compared with the region of the other inner wall forming the ink containing portion, and thus the auxiliary support of the inner wall is realized.

Further, in FIGS. 2 (c1) and 2 (c2), the opposing surfaces having the largest surface area, which will be described later, are deformed almost simultaneously, so that the center portions of the ink containing portions come into contact with each other. 2 (c1), (d)
The hatched portion (1)) is further expanded by further deriving the ink. That is, the ink tank of the present invention
Before deriving the ink, before the edge formed by the surface having the maximum area and the surface adjacent to the surface having the maximum area is bent, the surface having the maximum area comes into contact with the opposing surface.

Eventually, almost all of the ink stored in the ink storage section is used (hereinafter, referred to as a final state).
However, the state at this time is shown in FIGS. 2 (d1) and (d2).

In this state, the contact portion of the ink containing portion covers almost the entire area of the ink containing portion and the corner portion β of the inner wall.
In some cases, some of them are completely separated from the corresponding corners β1 of the outer wall. On the other hand, the corner α2 of the inner wall is
Even in the final state, it is positioned so as to be separable at the corresponding corner portion α1 of the outer wall, and serves as a deformation regulating portion of the inner wall to the end.

Further, in this state, the welded portion 104 may separate from the outer wall depending on the thickness of the inner wall. In this case, since the welded portion 104 has a length component, the deformation direction is Limited. Therefore, even when the welded portion comes off the outer wall, the deformation is not irregular, and the deformation is performed while maintaining the balance.

The change when the ink is stored in the ink storage section of the ink tank of the present invention and the ink is drawn out from the ink supply section is as described above. Before the edge formed by the adjacent surface is bent, the surface having the largest area comes into contact with the opposite surface, and the corners other than the corner formed by the surface having the ink supply unit move, thereby causing deformation of the ink tank. In this case, the configuration has a priority of the deformation.

Here, at least one of the substantially planar surfaces of the outer wall of the ink tank constituted by the substantially polygonal prism, which is one of the stable negative pressure generating mechanisms, has a maximum area. The fact that it is not fixed to the inner wall will be described in more detail.

In the above configuration, when the ink in the ink storage portion is reduced by the discharge of the ink from the ink jet recording head, the inner wall of the ink tank is most likely to be deformed under the condition of the above-described structure for restricting the deformation. Attempt to begin deformation. Here, in the present embodiment, at least one of the surfaces having the largest surface area among the substantially planar surfaces of the ink tank outer wall formed by the polyhedron is not fixed to the inner wall,
Deformation starts from the substantially central portion of the inner wall surface corresponding to this surface.

Since this surface has a substantially planar shape, the surface is uniformly and continuously deformed in the direction in contact with the opposing surface in accordance with the amount of ink reduction in the ink container. Therefore,
There is no discontinuous large deformation of the ink storage section during ejection and non-ejection, making it possible to maintain a more stable negative pressure and stabilize the negative pressure at the time of ink ejection, which is optimal for an ink tank used in an ink jet recording apparatus. It is possible to realize.

Furthermore, as in the present embodiment, the pair of opposing surfaces both have the largest surface area, do not have a joint between the inner wall and the outer wall, and can be easily peeled off. Since the deformation is performed, it is possible to further maintain the negative pressure and stabilize the negative pressure between the ink and the source.

The volume of the ink-jet ink tank to which the present invention is applied, up to 500 cm ^3, a commonly range used is about 5 to 100 cm ^3.

The maximum surface area of the ink tank,
In the case of an ink tank having the above capacity, a desirable range of the size ratio with respect to the other surface can be determined as follows. That is, considering a rectangular parallelepiped of the smallest size that can include the ink tank of the present invention inside, if the sides of the rectangular parallelepiped are set to l1, l2, and l3 (l1 ≧ l2> l3), the lengths of l1 and l3 are determined. The ratio is about 10: 1 to about 2: 1.
Is desirable. This length ratio can determine the area of the surface having the largest surface area with respect to the total surface area, particularly when the ink tank is a substantially rectangular parallelepiped. In the ink tank of the present invention, the surface having the largest area is larger than the total area of the surfaces adjacent to the surface.

It is also found that a preferable thickness condition is such that a thickness near the center of the inner wall surface is 100 to 250 μm and a thickness near the corner is 20 to 80 μm can generate a particularly stable negative pressure. Was.

FIG. 3 shows the relationship between the amount of ink used in the ink container and the negative pressure of the ink tank in the ink tank of the present invention. In FIG. 3, the abscissa represents the amount of ink discharged to the outside, and the ordinate represents the negative pressure. In FIG. 3, the negative static pressure is indicated by □. Further, + represents the total negative pressure obtained by adding the dynamic negative pressure generated when the internal ink is led to the outside to the static negative pressure.

Here, the following three points are required for the negative pressure in the ink storage section.

The first point is that when the ink tank is shipped from the product, the ink tank is about +2 to −60 mmAq.
More preferably, it has an initial static negative pressure of about -2 to -30 mmAq. When the internal pressure indicates a positive value at the time of product shipment, the negative pressure can be kept in a more desirable range by performing an initial recovery operation in the recording apparatus main body, for example. Here, the state at the time of product shipment is not limited to the initial state, that is, the state shown in FIGS. 2A1 and 2A2. If the condition of the negative pressure with respect to the atmospheric pressure is satisfied, the state shown in FIG. As shown in (b2), a state in which a slightly smaller amount of ink is injected than the maximum amount of ink that can be stored in the ink storage unit may be used.

The second point is that the pressure change in the ink tank when printing is performed and when printing is not performed is small, that is, the difference between the static negative pressure and the total negative pressure is small. It is solved by making it smaller. here,
In the ink tank of the present invention, the dynamic negative pressure of the ink container itself as seen when a porous body is used for the ink container can be ignored, and as a result, the dynamic negative pressure can be easily reduced. It is a configuration that can be realized.

The third point is that, from the initial state to the final state, the change in the static negative pressure caused by the change in the amount of ink existing inside the ink container is caused in the ink stored in the ink container of the ink tank. It is less. In the case where the ink is simply filled in the ink container, the static negative pressure changes linearly or non-linearly with respect to the amount of ink present in the ink container, and the rate of the change becomes large. As shown in FIG. 3, the ink tank according to the present invention has a small rate of change from the initial state to immediately before the final state, realizes a substantially stable static negative pressure, and exhibits excellent characteristics.

The above-mentioned ink tank employs a double-wall structure made of a molding resin material, and has a strong outer wall to provide strength, while a softer inner wall is used and further thinned to accommodate the inside. It is possible to follow the fluctuation in the volume of the liquid that has been discharged. As a material used for each wall, it is preferable that the inner wall has liquid resistance and the outer wall has impact resistance and the like.

Next, a method for manufacturing the above-described ink tank will be described. In the present invention, blow molding using blowing air is employed as a method of manufacturing the above-described ink tank. This is because the wall forming the ink tank is formed of a resin that is not substantially stretched, and thereby the inner wall of the ink tank forming the liquid container can withstand a substantially uniform load in any direction. Like that. Therefore, even if the liquid stored in the ink tank inner wall oscillates in any direction while the liquid is consumed to some extent, the ink tank inner wall can surely hold the liquid, and the overall ink tank durability is improved. Have improved.

As the blow molding method, there are a method using injection blow, a method using direct blow, a method using double wall blow, and the like. A method using direct blow will be briefly described.

First, an injection nozzle is used as a multi-layer nozzle, and an inner resin and an outer resin are simultaneously injected into a mold to prepare an integrated first and second parison.
In this case, the surface where the inner resin and the outer resin are in contact with each other should be made of a material that does not cause the resin to weld to each other. Or the outer material may be multi-layered and the resin may be supplied so that different materials are located on the contact surface.

Next, with respect to the integrated parison, a mold arranged so as to sandwich the parison moves to sandwich the parison, air is injected from an air nozzle, and the parison is blow-molded into a shape suitable for the mold. You. At this time, the inner wall and the outer wall are in close contact with no gap. Further, since the parison is processed in a viscous state, neither the inner wall resin nor the outer wall resin has orientation. The use of blow molding as a method of manufacturing the ink tank not only reduces the number of steps during manufacturing and improves the yield by reducing the number of parts, but also improves the ink tank as shown in FIG. According to the shape of the outer wall 101, the outer wall 1
The shape of the inner wall 102 can be made so that the corner of the inner wall 102 comes to a position corresponding to the corner of 01, and an outer wall having an inner surface equivalent to the outer surface of the inner wall can be made. Then, by pressing the cylindrical parison against a mold having a polygonal cross section and performing blow molding, the thickness distribution of the inner wall described with reference to FIG. 1 can be realized. Is formed, and the thickness distribution gradually becomes thinner toward the peripheral portion.

Next, the inner and outer walls other than the liquid supply section are peeled off. As a method of separating the inner wall and the outer wall other than performing the evacuation, there is a method of using materials having different thermal expansion rates (shrinkage rates) for the molding resin forming the inner wall and the outer wall. In this case, after the blow molding, the temperature of the molded product decreases, so that the molded product can be automatically peeled, and the number of steps can be reduced. Similarly, during blow molding, an external force is applied to the part sandwiching the parison between the molds after molding to separate the inner wall and the outer wall, and the gap is communicated with air, which can be used as an atmosphere communication port. Is more preferable because the number of steps can be reduced. In this way, after preparing an ink tank in which the part excluding the ink supply port is integrally formed,
The ink is injected, and finally the ink lead-out permission member is attached to complete the ink tank.

Next, each embodiment of the ink jet recording apparatus according to the present invention, in which the ink tank having the above-described configuration is mounted, will be described in detail.

(First Embodiment) FIG. 4 is a schematic perspective view of a first embodiment of the ink jet recording apparatus of the present invention. FIG.
As shown in FIG. 1, the ink jet recording apparatus of the present embodiment is a so-called serial type
Is a timing belt which is slidably fitted to the guide shaft 8 in the direction of the arrow (substantially horizontal direction), and is wound around a pulley 10 fixed to the output shaft of the carriage motor 9 and a pulley 11 rotatably supported by the shaft. Twelve sites. By driving the carriage motor 9, the timing belt 12 rotates forward and backward, and the carriage 3
Is reciprocated in the direction of the arrow. The carriage 3 includes a head unit 1 including four recording heads.
Are mounted side by side in the direction of movement of the carriage 3 (the direction of the arrow in the figure), and four ink tanks 100, 110, and 12 for supplying ink to each recording head.
Numerals 0 and 130 are provided detachably, and a light-emitting portion 4b of a transmission type photosensor as an optical detecting means, which will be described later, is provided on a portion of the bottom wall of the carriage 3 where each ink tank 2 is mounted. A light receiving section 4a is formed.

Further, as shown in FIG.
Is transported by a paper feed roller (not shown) guided by a paper pan 16 and pressed against a pinch roller. This conveyance is performed using the paper feed motor 18 as a drive source. The transported recording paper 13 is tensioned by a paper discharge roller 15 and a spur 14,
The paper is conveyed while being pressed against the paper pressing plate 19 formed of an elastic member.

Each of the ink tanks shown in FIG. 4 is an ink tank having the above-described configuration, and has a property of transmitting light from a transmission type photosensor. Inside each ink tank, yellow, magenta, cyan, and black inks are stored, respectively. From each ink tank, ink is supplied to a corresponding recording head,
By discharging ink from each recording head 1 based on a discharge signal, full-color image recording is possible.

An ink end detection operation of the ink jet recording apparatus according to the present invention based on the above-described configuration will be described with reference to FIG.

The transmission type photo sensor used in the present embodiment receives light emitted from the light emitting section 4b at the light receiving section 4a,
When the intensity of the light received by the light receiving section 4a exceeds a certain level, a predetermined amount of electricity is output.

Therefore, as shown in FIG. 5A, when the ink tank 100 is started to be used, the amount of light transmitted by the ink 50 is small, so that the light emitted from the light emitting unit does not reach the light receiving unit.

On the other hand, as the consumption of the ink inside the ink tank progresses, as shown in FIG. 5B, the light emitted from the light emitting portion at a distance of dx from the end of the container becomes the light receiving portion. Will be able to reach. This is because the inner wall was deformed with the consumption of ink.

Therefore, assuming that the width of the container is t, the distance from one end of the container (the left end in FIG. 5B) to t / 2 is:
The amount of ink can be detected by measuring where the light from the light emitting unit can be received for the first time. Assuming that this distance is dx, ideally dx = t / 2
At this point, the ink in the ink tank has been completely consumed.

However, in practice, in consideration of the negative pressure condition required by the recording head to be used and the individual difference of the ink tank itself, the ink end is set within an appropriate range of t / 2 or less. May prompt the user to exchange.

The ink tank mounted on the ink jet recording apparatus of the present invention has a flexible ink container therein, and faces the ink container when the ink container is deformed as the ink is consumed. Until the surface of the maximum area comes into contact, the corners of the inner wall constituting the ink storage portion hardly change the positional relationship with the corresponding corners of the outer wall, so that the carriage is moving in the reciprocating direction such as during a recording operation. Also, there is almost no fluctuation of the ink inside the ink container,
The ink storage unit is not affected by the deformation due to the reciprocating movement of the carriage. Therefore, there is an advantage that the ink end can be reliably detected even during the operation of the carriage.

(Second Embodiment) FIGS. 6A and 6B show a second embodiment of the ink jet recording apparatus of the present invention.

This embodiment differs from the first embodiment in the mounting position of the transmission type photosensor and the method of detecting the ink end.

In the present embodiment, a head holder 2 in which a recording head, a transmission type photosensor (both not shown), and a partition wall 2a of an ink tank are integrated on a carriage 3
Is provided. Other configurations are the same as those of the first embodiment, and a description thereof will be omitted.

In this embodiment, as shown in FIG. 6B, the portion of the ink tank detected by the transmission type photo sensor is covered by the head holder. The transmissive photosensor includes a light emitting unit 4c and a light receiving unit 4d.

Here, the light emitting section of the transmission type sensor according to the present embodiment irradiates light only to the portion where it is desired to check whether or not the opposing surfaces of the inner walls constituting the ink containing section are in contact with each other. . In this embodiment, it is possible to check whether or not the opposing inner walls are in contact with each other in a region near the ink supply port in the maximum area of the ink tank.

That is, when the ink tank is in use, the ink from the light emitting section 4c hardly reaches the light receiving section 4d because the ink is filled in the ink containing section. However, when the ink container is deformed with the consumption of ink and the inner wall surfaces 102 facing each other come into contact with each other at the measurement location, light from the light emitting unit passes through the ink container and reaches the light receiving unit. , The ink end can be detected.

The measurement location is arbitrary as long as the opposing inner wall surfaces are in contact with each other, but it is needless to say that it is desirable to measure the portion near the ink supply port from the viewpoint of ink use efficiency.

Also in this embodiment, the ink tank mounted on the ink jet recording apparatus has a flexible ink container therein, and when the ink container is deformed as the ink is consumed. Until the opposing maximum area surface comes into contact, the positional relationship between the corners of the inner wall constituting the ink container and the corresponding corners of the outer wall hardly changes, so that the carriage moves in the reciprocating direction, such as during a recording operation. Even in this case, the ink inside the ink storage unit does not substantially oscillate, and the ink storage unit is not affected by the reciprocating movement of the carriage. Therefore, there is an advantage that the ink end can be reliably detected even during the operation of the carriage.

(Other Embodiments) Each of the embodiments described above is suitable for an ink container containing a liquid having a particularly high density such as black, but the sensitivity of the sensor can be increased for ink having a low density by increasing the sensitivity of the sensor. Can correspond.

The ink tank of each of the above embodiments is
Although the inner wall and the outer wall are made of a material having transparency to light from the transmissive photosensor, in order to further improve the accuracy of the sensor, the transmissive photosensor of the outer wall is used. A cover member made of a material that is opaque and hardly reflects light from the sensor may be provided in a portion that is not related to the light transmission path. By configuring the cover member with a highly rigid material such as a metal, the strength of the ink tank at the time of transportation or the like can be further increased.

[0081]

As described above, according to the present invention,
A light-emitting body that emits light, and a light-receiving body that receives light from the light-emitting body and outputs a predetermined electric quantity value according to the intensity of the light, wherein the light-emitting body and the light-receiving body are the ink tank. By having optical detection means arranged to face each other across one part, and by detecting the deformation of the flexible ink container,
Inexpensive and reliable detection of the remaining amount of ink can be performed.

In particular, when the ink storage portion of the ink tank is deformed, the corners of the inner wall constituting the ink storage portion have a positional relationship with the corresponding corners of the outer wall until the opposing maximum area surface comes into contact. Since there is almost no change, even when the carriage is moving in the reciprocating direction, such as during a recording operation, there is almost no swinging of the ink inside the ink container,
Even during the operation of the carriage, the ink end can be reliably detected.

[Brief description of the drawings]

FIG. 1 is a schematic schematic cross-sectional view of an ink tank according to a first embodiment of the present invention, (a) is a cross-sectional view, (b) is a side view, and (c) is a perspective view.

FIG. 2 is a schematic diagram showing a deformation of the ink tank of FIG.

FIG. 3 is a schematic diagram illustrating negative pressure characteristics of the ink tank of FIG. 1;

FIG. 4 is a schematic perspective view of a first embodiment of the ink jet recording apparatus of the present invention.

FIGS. 5A and 5B are explanatory diagrams illustrating an ink end detection operation according to the first embodiment of the present invention.

FIGS. 6A and 6B are explanatory views of a second embodiment of the present invention, in which FIG. 6A is a schematic perspective view showing the vicinity of a carriage, and FIG. 6B is an explanatory view showing an ink end detection operation of the second embodiment of the present invention. .

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Recording head 3 Carriage 4a, 4d Light receiver 4b, 4c Light emitter 8 Guide shaft 9 Carriage motor 10, 11 Pulley 12 Timing belt 13 Recording paper 14 Spur 15 Discharge roller 18 Paper feed motor 19 Paper press plate 100 Ink tank 101 Outer wall 102 inner wall 103 ink supply section (ink supply port) 104 pinch-off section

Claims (7)

[Claims] 1. An ink-jet recording apparatus comprising: a recording head for discharging ink from a discharge port; and an ink tank detachably mounted on the recording head and containing ink to be supplied to the recording head. And a photoreceptor that receives light from the luminous body and outputs a predetermined electric quantity value in accordance with the intensity of the light, wherein the luminous body and the photoreceptor form one part of the ink tank. An outer wall having optical detection means disposed to face each other with the optical tank being disposed therebetween, the ink tank having a substantially atmospheric communication portion, having a substantially polygonal column shape, and having a corner formed by an extension of three surfaces of the polygonal column; And an inner wall having an outer surface having a shape similar to or similar to the inner surface of the outer wall and a corner corresponding to a corner of the outer wall, forming an ink storage portion for storing ink therein, and being peelable from the outer wall. And the ink An ink supply unit that supplies ink from the container to the outside, and a pinch-off unit in which a part where the inner wall is integrated is sandwiched by the outer wall, and the part position is for light emitted from the luminous body. An ink jet recording apparatus characterized by having transparency. 2. The ink jet recording apparatus according to claim 1, wherein one part of the ink tank is near the ink supply unit. 3. A part of the ink tank having a maximum area which is provided as a set and is opposed to a surface of the ink tank excluding a surface provided with an ink supply portion and a surface having a pinch-off portion. The ink jet recording apparatus according to claim 1, wherein: 4. A part of the ink tank which has a maximum area provided opposite to a surface of the ink tank excluding a surface provided with an ink supply portion and a surface having a pinch-off portion. 3. The ink jet recording apparatus according to claim 1, wherein the ink jet recording apparatus is a pair of adjacent surfaces. 5. The ink jet recording apparatus according to claim 1, wherein a shielding member for shielding light other than the partial position is provided outside an outer wall of the ink tank. 6. The ink jet recording apparatus according to claim 1, wherein a plurality of the ink tanks are provided, and each of the plurality of ink tanks is provided with a light source and a light receiving unit. 7. The apparatus according to claim 1, further comprising a carriage on which the ink tank is removably mounted and which is capable of scanning, wherein the light source and the light receiving unit are provided on the carriage.
The inkjet recording apparatus according to claim 1.