JP2012218165A - Liquid container and liquid ejecting apparatus with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress a detection error due to a relief recess when detecting the remaining amount of liquid in a liquid container by using a prism having the relief recess.SOLUTION: The prism with the relief recess is provided on the bottom of a liquid container, and the light irradiated from a light-emitting part to impinge on the prism is made to arrive at a light-receiving part through a predetermined reflection optical path (specified optical path) which reflects the incident light to a part of a first reflective surface exposed from the liquid level and a part of a second reflective surface exposed from the liquid level when the liquid in the liquid container decreases below a predetermined amount. On at least the first or second reflective surface, a part above the intersection with the specific optical path is formed to have a surface shape to scatter the light in the prism. Since the light arriving at the light-receiving part through an unintended optical path while being reflected on the inner surface of the relief recess and on a part above the intersection of the first and second reflective surfaces with the specified optical path is reduced, the detection error of the remaining amount of liquid due to the relief recess can be suppressed.

Description

The present invention relates to a liquid container that is mounted on a liquid ejecting apparatus that ejects liquid and contains the liquid therein.

As represented by so-called ink jet printers, liquid ejecting apparatuses that eject liquid such as ink from an ejecting head are known. The liquid ejected from the ejection head is stored in a dedicated liquid container such as an ink cartridge, and the liquid is supplied from the liquid container to the ejection head. Further, the liquid container is generally configured to be detachable from the liquid ejecting apparatus so that the liquid container is replaced with a new liquid container when the liquid in the interior is exhausted.

In such a liquid ejecting apparatus, if the ejecting operation is performed in a state in which the liquid in the liquid container is exhausted and no liquid is supplied to the ejecting head, so-called idling occurs and the ejection head is damaged. Therefore, a technique for optically detecting the remaining amount of liquid in the liquid container using a right-angle prism provided at the bottom of the liquid container and a light emitting unit and a light receiving unit provided in the main body of the liquid ejecting apparatus has been proposed. (For example, Patent Document 1). If there is enough liquid in the liquid container and the liquid level is above the reference position set at a predetermined height of the prism, the light emitted from the light emitting unit and incident on the prism from the bottom side of the liquid container will be The light passes through the liquid container without being reflected by the slope of the prism. On the other hand, when the liquid in the liquid container is consumed and the liquid level falls below the reference position, the light emitted from the light emitting unit and incident on the prism is exposed from the liquid surface of the two inclined surfaces of the prism (
Reflected at the height of the reference position) and reaches the light receiving unit. Therefore, the remaining amount of liquid in the liquid container (whether the liquid level is above or below the reference position) is detected depending on whether the light receiving part receives light from the light emitting part.

In addition, when such a prism is formed of a plastic material by injection molding, the slope of the prism may be distorted because sinkage is likely to occur due to shrinkage when the plastic is hardened. Therefore, as a measure for suppressing such sink marks, a prism is sometimes provided with a recess called “meat stealing” from the bottom surface of the prism toward the inside (Patent Document 2).

JP 2000-71471 A JP 2000-127432 A

However, when such a stealing is provided on the prism, there is a problem that the light of the light emitting unit reaches the light receiving unit through an unintended optical path, and the remaining amount of liquid in the liquid container may not be detected correctly. there were. In other words, if there is a meat theft on the prism, the liquid level in the liquid container is higher than the reference position by the light path that travels while reflecting on the inner surface of the meat theft and the portion above the reference position of the two slopes of the prism. The light from the light emitting unit may reach the light receiving unit before it falls.
And when light reaches the light receiving part through an extra light path through such a meat theft, the liquid in the liquid container is in spite of the liquid level being above the reference position (the liquid remains). Will be judged to have disappeared.

The present invention has been made to solve the above-described problems of the prior art,
In the case of detecting the remaining amount of liquid in the liquid container using a prism provided with meat theft,
An object of the present invention is to provide a technology capable of suppressing detection errors caused by meat theft.

In order to solve at least a part of the problems described above, the liquid container of the present invention employs the following configuration. That is,
A liquid ejecting apparatus in which a light emitting unit and a light receiving unit are arranged side by side is mounted, the liquid ejected from the liquid ejecting apparatus is accommodated in a liquid storage chamber, and the bottom of the liquid storage chamber is formed by resin molding A liquid container having a prism,
The prism is
A first reflecting surface provided in contact with the liquid in the liquid storage chamber and reflecting light in the prism at a portion exposed from the liquid surface;
A second reflecting surface provided in contact with the liquid in the liquid storage chamber and reflecting light in the prism at a portion exposed from the liquid surface;
A meat stealer that is a recess that reduces deformation of the prism due to resin shrinkage during the resin molding,
The first reflecting surface and the second reflecting surface receive light emitted from the light emitting unit and incident on the prism when the liquid in the liquid storage chamber is reduced below a predetermined amount. A reflecting surface that constitutes a predetermined reflected light path that is reflected by the reflecting surface and guided to the light receiving unit;
At least one of the first reflective surface and the second reflective surface is a portion above the location where the reflected light path intersects the first reflective surface, or above the location where the reflected light path intersects the second reflective surface. This part is formed in a surface shape that scatters light in the prism.

In such a liquid container of the present invention, a prism having a first reflecting surface and a second reflecting surface is provided at the bottom of the liquid storage chamber, and the liquid ejecting apparatus in which the light emitting unit and the light receiving unit are arranged in parallel is provided. When attached, the light emitted from the light emitting unit enters the prism. In this prism, when the liquid in the liquid storage chamber is reduced below a predetermined amount, the incident light is reflected on a portion exposed from the liquid surface of the first reflecting surface and a portion exposed from the liquid surface of the second reflecting surface. Since the light reaches the light receiving part through a predetermined reflected light path (hereinafter referred to as a prescribed light path), the remaining amount of liquid in the liquid storage chamber (decreased from a predetermined amount) is detected based on the light received by the light receiving part. it can. Further, the prism is provided with a meat stealer that is a recess for reducing deformation caused by resin shrinkage during resin molding. In the liquid container of the present invention, at least one of the first reflecting surface and the second reflecting surface of the prism is formed in a surface shape that scatters the light in the prism above the portion that intersects the specified optical path. Yes.

In the prism provided with the meat steal, an unintended optical path that reflects on the inner surface of the meat steal and a portion above the specified optical path of the first reflecting surface and the second reflecting surface is generated, and the inside of the liquid storage chamber The light receiving unit receives light before the liquid is reduced below a predetermined amount (before the part where the first and second reflecting surfaces intersect the specified optical path is exposed from the liquid surface), and the remaining amount of liquid is correctly detected. There are things that cannot be done. Therefore, if at least one of the first reflecting surface and the second reflecting surface is formed in a surface shape that scatters the light in the prism above the portion that intersects the specified light path, the intention is different from the specified light path. The light that travels in the light path that is not scattered is scattered when it hits a portion of the first reflecting surface or the portion that intersects the specified light path of the second reflecting surface, so that the light that reaches the light receiving section in the unintended light path is reduced. Can do. As a result, even when there is a meat theft on the prism, it is possible to suppress an error in detecting the remaining amount of liquid due to the meat theft.

The surface shape that scatters the light in the prism may be any shape that spreads in various directions when light that passes through the prism in one direction hits it. For example, the surface shape of the first reflection surface or the second reflection surface A shape having irregularities on the surface, such as a plurality of thin grooves, a plurality of small protrusions, or a textured finish by embossing or the like can be given.

In the liquid container of the present invention described above, at least a part of the inner surface of the meat stealer may be formed in a shape that scatters the light in the prism.

As described above, the unintended optical path that is different from the prescribed optical path is composed of the inner surface of the stealer and the portion above the location where the prescribed optical path of the first reflecting surface and the second reflecting surface intersect. Therefore, in addition to the portion above the location where the first reflecting surface or the second reflecting surface intersects the specified optical path, the portion constituting the unintended optical path on the inner surface of the meat theft is formed in a shape that scatters the light in the prism. By doing so, it is possible to further reduce the light that reaches the light receiving section in an unintended optical path. As a result, when the remaining amount of liquid in the liquid storage chamber is detected using a prism with meat theft, the detection accuracy of the remaining amount of liquid can be improved.

In addition, the liquid container of the present invention is mounted on the liquid ejecting apparatus and accommodates the liquid ejected from the liquid ejecting apparatus. Therefore, the present invention can be grasped in the form of the liquid ejecting apparatus including the above-described liquid container of the present invention.

In the liquid ejecting apparatus of the present invention grasped in such an aspect, at least one of the first reflecting surface or the second reflecting surface of the prism provided with the stealing is a portion above the portion intersecting with the specified optical path, It is formed in a surface shape that scatters light in the prism. As a result, the light traveling through the prism in an unintended optical path different from the prescribed optical path is scattered by hitting a portion above the location where the first reflecting surface or the second reflecting surface intersects the prescribed optical path. The light reaching the light receiving part can be reduced. As a result, even when the remaining amount of liquid in the liquid storage chamber is detected using a prism with meat theft, the detection error of the remaining amount of liquid due to the meat theft can be suppressed.

FIG. 4 is an explanatory diagram illustrating a rough configuration of a liquid ejecting apparatus, taking an ink jet printer to which an ink cartridge is mounted as an example. It is explanatory drawing which showed the rough structure of the ink cartridge of a present Example. It is explanatory drawing which showed the shape of the prism provided in the ink cartridge of a present Example. FIG. 6 is an explanatory diagram illustrating a state in which the remaining amount of ink in an ink cartridge is detected using a prism. FIG. 6 is an explanatory diagram showing a state in which a detection error of the remaining amount of ink is caused due to meat theft when a prism on which uneven surfaces are not formed on the first reflecting surface and the second reflecting surface is used. It is explanatory drawing which showed a mode that the detection error of the ink residual amount resulting from a meat theft was suppressed by the prism by which the uneven surface was formed in the 1st reflective surface and the 2nd reflective surface. It is explanatory drawing which showed a mode that the light of a light emission part arrived at the light-receiving part in the optical path reflected on the inner surface of a meat steal, and the part below the reference position of a 1st reflective surface and a 2nd reflective surface. It is sectional drawing which cut | disconnected the prism of the modification by the surface perpendicular | vertical to the 1st reflective surface and the 2nd reflective surface.

Hereinafter, in order to clarify the contents of the present invention described above, examples will be described in the following order.
A. Inkjet printer configuration:
B. Ink cartridge structure:
C. How to detect remaining ink:
D. Variations:

A. Inkjet printer configuration:
FIG. 1 is an explanatory diagram showing a rough configuration of a liquid ejecting apparatus, taking an ink jet printer to which an ink cartridge is mounted as an example. As shown in the drawing, an inkjet printer 10 includes a carriage 20 that forms ink dots on a printing paper 2 as a printing medium while reciprocating in the main scanning direction, a drive mechanism 30 that reciprocates the carriage 20, and printing. A platen roller 40 for feeding the paper 2 and a maintenance mechanism 50 for performing maintenance so that printing can be normally performed. The carriage 20 includes an ink cartridge 100 containing ink, a carriage case 22 in which the ink cartridge 100 is mounted, an ejection head 24 mounted on the bottom side of the carriage case 22 (side facing the printing paper 2), and the like. Is provided. The ejection head 24 is formed with a plurality of ejection nozzles for ejecting ink. The ink in the ink cartridge 100 is supplied to the ejection head 24 and the ink is ejected from the ejection nozzle toward the printing paper 2 by an accurate amount. By jetting, an image or the like is printed.

In the inkjet printer 10 of this embodiment, cyan, magenta, yellow,
It is possible to print a color image using four types of black ink, and correspondingly, the ejection head 24 mounted on the carriage 20 is provided with ejection nozzles for each type of ink. Yes. An ink cartridge 100 is also provided for each type of ink.
Ink is supplied from the ink cartridge 100 of the corresponding color to each ejection nozzle. In addition, the ink cartridge 100 is configured to be attachable to and detachable from the carriage case 22 so that the ink cartridge 100 can be replaced with a new ink cartridge 100 when the ink in the inside is exhausted. The ink cartridge 100 of this embodiment corresponds to the “liquid container” of the present invention.

The drive mechanism 30 for reciprocating the carriage 20 includes a guide rail 38 extending in the main scanning direction, a timing belt 32 having a plurality of teeth formed therein, and a timing belt 32.
The drive pulley 34 meshes with the tooth profile of the above, the step motor 36 for driving the drive pulley 34, and the like. A part of the timing belt 32 is fixed to the carriage case 22, and the carriage case 22 moves along the guide rail 38 by driving the timing belt 32.

A platen roller 40 that feeds the printing paper 2 is driven by a drive motor or a gear mechanism (not shown) to feed the printing paper 2 by a predetermined amount in the sub-scanning direction.

The maintenance mechanism 50 is provided in an area called a home position outside the printing area, and includes a cap 52, a suction pump 54 provided at a position below the cap 52, and the like. The cap 52 can be moved in the vertical direction by an elevating mechanism (not shown), and while the inkjet printer 10 is not printing an image or the like, the carriage 20 is moved to the home position to raise the cap 52. Then, since the closed space is formed so that the cap 52 is pressed against the bottom surface side of the ejection head 24 and covers the ejection nozzle, the ink in the ejection head 24 is prevented from drying. Further, a suction pump 54 is connected to the cap 52 via a suction tube (not shown), and the ejection head 24.
By operating the suction pump 54 in a state where the cap 52 is pressed against the bottom surface of the ink, an operation (so-called cleaning) of sucking out deteriorated ink (such as ink that has been dried and thickened) in the ejection head 24 is performed.

Further, at the home position, a sensor 200 for optically detecting the remaining amount of ink in the ink cartridge 100 is provided adjacent to the print region side of the cap 52. As will be described in detail later, a light emitting unit and a light receiving unit are arranged in parallel inside the sensor 200, and light is emitted from the light emitting unit when the ink cartridge 100 passes above the sensor 200 as the carriage 20 moves. The remaining amount of ink in the ink cartridge 100 is detected based on whether the light receiving unit receives the light.

Furthermore, a control unit 60 that controls the entire operation of the inkjet printer 10 is mounted on the back side of the inkjet printer 10. The operation of reciprocating the carriage 20, the operation of feeding the printing paper 2, the operation of ejecting ink from the ejection nozzle, the operation of driving the maintenance mechanism 50, and the remaining amount of ink in the ink cartridge 100 are detected. The operation and the like are all controlled by the control unit 60.

B. Ink cartridge structure:
FIG. 2 is a perspective view showing a rough structure of the ink cartridge 100 of the present embodiment.
As shown in the drawing, the ink cartridge 100 is a box formed of a hard resin material in a rectangular parallelepiped shape, and the inside of the box is a liquid storage chamber for storing ink.

An ink supply port 102 for supplying ink to the ejection head 24 is provided on the bottom surface of the ink cartridge 100. The carriage case 22 to which the ink cartridge 100 is mounted is provided with a recess (not shown) for mounting the ink cartridge 100 from above, and an ink intake needle (not shown) faces upward from the bottom surface of the recess. It is erected. When the ink cartridge 100 is mounted in the recess of the carriage case 22, the ink take-in needle is inserted into the ink supply port 102, so that the ink in the ink cartridge 100 is taken into the ink take-in needle and supplied to the ejection head 24. . Ink cartridge 10
An air release hole (not shown) is provided on the upper surface of 0, and air is introduced from the air release hole as the ink in the ink cartridge 100 is consumed. Absent.

In addition, a prism 104 made of a light-transmitting plastic material is provided at the bottom in the ink cartridge 100 (liquid storage chamber), and the bottom surface of the prism 104 forms a part of the bottom surface of the ink cartridge 100. ing. A through hole (not shown) is provided at a position corresponding to the prism 104 on the bottom surface of the carriage case 22 to which the ink cartridge 100 is mounted, and the ink cartridge 100 is attached to the sensor 2 as the carriage 20 moves.
When passing above 00, the light emitted from the light emitting portion of the sensor 200 enters the prism 104 from the bottom surface side.

FIG. 3 is an explanatory diagram showing the shape of the prism 104 provided in the ink cartridge 100 of this embodiment. First, FIG. 3A is a perspective view showing the shape of the prism 104.
The prism 104 of this embodiment is a so-called right-angle prism, and has a first reflecting surface 106 and a second reflecting surface 108 that are orthogonal to each other. The prism 104 has the first reflecting surface 106.
The second reflective surface 108 is placed at the bottom of the ink cartridge 100 with the surface facing the intersecting line 104r between the first reflective surface 106 and the second reflective surface 108 as the bottom surface 110 so that the ink is in contact with the ink in the ink cartridge 100. Yes. In addition, at each upper position of the first reflecting surface 106 and the second reflecting surface 108, an uneven surface 106u having a plurality of fine grooves carved on the surface,
108u is formed. Furthermore, a rectangular recess 112 called “meat stealing” is provided in the center of the bottom surface 110 of the prism 104. Note that the surface of the prism 104 is formed transparent (smooth) except for the uneven surfaces 106u and 108u.

FIG. 3B shows the prism 10 on a surface orthogonal to the first reflecting surface 106 and the second reflecting surface 108.
It is sectional drawing which cut | disconnected 4. FIG. As shown in the figure, the prism 104 has a cross-sectional shape of a right isosceles triangle in which the first reflecting surface 106 and the second reflecting surface 108 are provided at an angle of 45 degrees with respect to the bottom surface 110. And the bottom face 1 constituting the hypotenuse of a right isosceles triangle
A concave meat stealer 112 is provided vertically upward from the center position of 10. This meat stealing 112 is provided for the following reason. As described above, the prism 104 is made of a plastic material. When the prism 104 is formed by injection molding using a mold, sinking due to contraction when the plastic is hardened is likely to occur. It may be distorted. Therefore, as a countermeasure for reducing such sink marks, the meat 104 is provided on the prism 104 from the bottom surface 110 to the inside.

In the prism 104 of this embodiment, a reference position (reference position) for detecting the remaining amount of ink in the ink cartridge 100 is set to a predetermined height from the bottom surface 110. The height of the reference position of the prism 104 is set to the height of the ink surface (ink surface) when the remaining amount of ink in the ink cartridge 100 reaches a predetermined amount. The first reflecting surface 106 and the second reflecting surface 108 have a concave and convex surface 10 at a portion above the reference position.
6u and 108u. The role of the uneven surfaces 106u and 108u formed on the first reflecting surface 106 and the second reflecting surface 108 will be described in detail later.

In the ink cartridge 100 of this embodiment in which such a prism 104 is provided at the bottom, the remaining amount of ink inside is detected as follows.

C. How to detect remaining ink:
FIG. 4 is an explanatory diagram showing how the remaining amount of ink in the ink cartridge 100 is detected using the prism 104. First, as described above, the ink cartridge 100 is mounted on the carriage 20 that reciprocates in the main scanning direction. In the mounted state, the prism 104 in the ink cartridge 100 has a first reflecting surface 106 and a second reflecting surface 1 as shown in FIG.
08 are arranged in the main scanning direction (intersection line 1 between the first reflecting surface 106 and the second reflecting surface 108).
04r is orthogonal to the main scanning direction). In addition, a sensor 200 is provided at a lower position in the middle of the path along which the carriage 20 moves in the main scanning direction. Inside the sensor 200, a light emitting unit 202 formed of an infrared light emitting diode, and a photo A light receiving unit 204 formed of transistors is provided side by side in the main scanning direction. Since the light emitting unit 202 and the light receiving unit 204 face vertically upward and the light emitting unit 202 and the light receiving unit 204 are partitioned by a member that does not transmit light, the light from the light emitting unit 202 is directly received by the light receiving unit. 204 never reaches.
When the ink cartridge 100 passes above the sensor 200 as the carriage 20 moves, the light emitted from the light emitting unit 202 enters the bottom surface 110 of the prism 104 perpendicularly.

FIG. 4 shows the prism 10 in the ink cartridge 100 as the carriage 20 moves.
4 shows a state in which the apex 4 (intersection line 104r between the first reflecting surface 106 and the second reflecting surface 108) is positioned vertically above the center of the sensor 200 (intermediate between the light emitting unit 202 and the light receiving unit). Hereinafter, the position of the prism 104 is referred to as “origin”. When the prism 104 is at the origin position, light (incident light) that is irradiated vertically upward from the light emitting unit 202 and enters the prism 104 is incident on the portion corresponding to the height of the reference position set in the prism 104. 1 hits the reflecting surface 106.

At this time, as shown in FIG.
If the ink surface is immersed in the ink in 0 and the ink surface is above the reference position, the first reflecting surface 10
A portion where the incident light 6 hits (a portion corresponding to the height of the reference position) is in contact with the ink. Then, as shown by a thick broken line arrow in FIG. 4A, incident light does not reflect even when it hits the first reflecting surface 106, and is refracted and transmits ink in the ink cartridge 100. Therefore, the light from the light emitting unit 202 does not reach the light receiving unit 204.

On the other hand, the ink in the ink cartridge 100 is consumed and decreases below a predetermined amount.
As shown in b), when the ink surface falls below the reference position, the portion of the first reflecting surface 106 where the incident light strikes is exposed from the ink. The portion exposed from the ink is in contact with air, and when incident light hits it, it is reflected toward the horizontal direction as shown by the thick dashed arrow in FIG. 4B. The reflected light strikes the second reflecting surface 108 at a portion corresponding to the height of the reference position. In a state where the ink surface is lower than the reference position, the second reflective surface 108 is exposed to the air from the portion where the light reflected by the first reflective surface 106 is exposed, and is in contact with the air. When the reflected light hits, it reflects downward in the vertical direction. The light reflected by the second reflecting surface 108 thus reaches the light receiving unit 204 arranged in parallel with the light emitting unit 202 at a predetermined interval. The interval between the light emitting unit 202 and the light receiving unit 204 is such that the light irradiated from the light emitting unit 202 is reflected by the first reflecting surface 106 and the second reflecting surface 108 with the prism 104 being at the origin position. It is set to an interval to reach 204. Further, in this specification, an optical path in which light emitted from the light emitting unit 202 is reflected by the first reflecting surface 106 and the second reflecting surface 108 and reaches the light receiving unit 204 may be referred to as a “specified optical path”. And

Thus, when the ink surface in the ink cartridge 100 is above the reference position of the prism 104 (the ink in the ink cartridge 100 is a predetermined amount or more), the light emitting unit 20.
2 does not reach the light receiving unit 204, but when the ink surface falls below the reference position (the ink in the ink cartridge 100 decreases below a predetermined amount), the light from the light emitting unit 202 is received by the light receiving unit along the specified optical path. 204 is reached.

As described above, the entire operation of the ink jet printer 10 is controlled by the control unit 60, and when the ink cartridge 100 passes above the sensor 200 as the carriage 20 moves, the light emitting unit 202 of the sensor 200. Irradiate with light. Sensor 2
When the 00 light receiving unit 204 receives light, a signal indicating that is sent from the sensor 200 to the control unit 60.
Therefore, if the light receiving unit 204 does not receive light in a state where the prism 104 in the ink cartridge 100 is at the origin position, a predetermined amount or more of ink remains in the ink cartridge 100. Judge that On the other hand, when the light receiving unit 204 receives light, the ink remaining amount in the ink cartridge 100 is equal to or less than a predetermined amount (hereinafter, this state is referred to as “
“Ink end” is determined, and a display prompting replacement with a new ink cartridge 100 is performed on a liquid crystal panel (not shown). As described above, in the ink jet printer 10 of this embodiment, the ink cartridges 100 for each ink type (cyan, magenta, yellow, black) are mounted in the carriage case 22 side by side in the main scanning direction. (See FIG. 1) While moving the carriage 20, the ink remaining amount is detected at the origin position of the prism 104 for each color ink cartridge 100.

Here, as described above, the prism 104 is provided with the meat stealing 112 which is a concave portion formed from the bottom surface 110 toward the inside as a measure for suppressing sink marks during manufacture. On the other hand, if there is a meat theft 112 on the prism 104, the light of the light emitting unit 202 is transmitted to the light receiving unit 204 through an unintended optical path that is reflected by the inner surface of the meat theft 112 and the first reflecting surface 106 and the second reflecting surface 108. The remaining amount of ink in the ink cartridge 100 may not be detected correctly. Therefore, in the prism 104 mounted on the ink cartridge 100 of this embodiment,
The uneven surface 106u is formed in a portion above the reference position of the first reflecting surface 106 and the second reflecting surface 108.
, 108 u are formed to suppress detection errors caused by the meat theft 112.
In the following, this point will be described in detail. As a preparation for this, first, a detection error caused by the stealing 112 of the prism 104 will be briefly described.

FIG. 5 is an explanatory diagram showing a state in which an ink remaining amount detection error occurs due to the meat theft 112 when the prism 104 on which the uneven surfaces 106u and 108u are not formed is used. FIG. 5 shows a state where the ink surface in the ink cartridge 100 is below the apex of the prism 104 but above the reference position. In this state, the portions corresponding to the heights of the reference positions of the first reflecting surface 106 and the second reflecting surface 108 are in contact with the ink, so that the light from the light emitting unit 202 is transmitted in the prescribed optical path shown in FIG. It does not reach the light receiving unit 204. However, the light from the light emitting unit 202 may reach the light receiving unit 204 through an optical path different from the prescribed optical path. That is, in the ink jet printer 10, a light emitting unit 202 having a wide directivity angle may be used. In this case, light from the light emitting unit 202 is emitted from the bottom surface 110 of the prism 104.
Incident at various angles. Among these incident lights, as shown by the dashed arrows in FIG.
Some hit the inner wall surface of the meat steal 112. Since the inner wall surface of the meat stealer 112 is in contact with air, it reflects when incident light hits it. In the example shown in FIG. 5, the light reflected on the inner wall surface of the meat stealer 112 is reflected by the portion exposed from the ink of the first reflecting surface 106 (the portion above the reference position), and further the second The light is reflected by the portion of the reflective surface 108 exposed from the ink, and the light receiving unit 2
04 is reached.

In this way, if the prism 104 has the meat stealing 112, an unintended optical path that travels while reflecting on the inner surface of the meat stealing 112 and the portion above the reference position of the first reflecting surface 106 and the second reflecting surface 108 is generated. As a result, the light from the light emitting unit 202 may reach the light receiving unit 204 before the ink surface in the ink cartridge 100 falls below the reference position. When the light from the light emitting section 202 reaches the light receiving section 204 through an extra optical path different from the specified optical path, the ink surface is above the reference position (a predetermined amount or more of ink remains in the ink cartridge 100). However, it is determined that the ink end is reached (the remaining amount of ink in the ink cartridge 100 has decreased below a predetermined amount). Therefore, in the prism 104 mounted on the ink cartridge 100 of this embodiment, as a measure for suppressing the detection error of the remaining amount of ink due to such a meat theft 112, the first reflecting surface 106 and the second reflecting surface 108 are provided. Concave and convex surfaces 106u and 108u are formed in a portion above the reference position.

FIG. 6 shows a detection error of the remaining amount of ink caused by the meat theft 112 by the prism 104 having the concave and convex surfaces 106u and 108u formed above the reference position of the first reflecting surface 106 and the second reflecting surface 108. It is explanatory drawing which showed a mode that it was suppressed. In FIG. 6, as in FIG.
Although the ink surface in the ink cartridge 100 is lower than the apex of the prism 104, it shows a state above the reference position. In this state, the portions of the first reflecting surface 106 and the second reflecting surface 108 exposed from the ink are the uneven surfaces 106u and 108u. As described above, the uneven surfaces 106u and 108u of the present embodiment are formed by cutting a plurality of thin grooves on the surfaces of the first reflecting surface 106 and the second reflecting surface 108. When the reflected incident light hits a portion of the first reflecting surface 106 exposed from the ink, the uneven surface 10
Diffuse reflection is caused by the unevenness of 6u. Among the scattered light, there is light that travels toward the exposed portion of the second reflecting surface 108 from the ink, but the light before being irregularly reflected by the uneven surface 106u (light reflected by the inner wall surface of the meat steal 112). Of course, the strength is reduced.

In addition, a part of the light irregularly reflected by the uneven surface 106 u of the first reflecting surface 106 is reflected by the second reflecting surface 108.
When it hits a portion exposed from the ink, the light is further irregularly reflected by the unevenness of the uneven surface 108u. As a result, the intensity of the light that finally reaches the light receiving unit 204 is significantly reduced compared to the light that is first reflected by the inner wall surface of the meat stealer 112.

As described above, in the prism 104 mounted on the ink cartridge 100 of the present embodiment, the concave and convex surface 106 is formed at a portion above the reference position of the first reflective surface 106 and the second reflective surface 108.
u and 108u are formed, and the light in the prism 104 is transmitted through the first reflection surface 106 or the second reflection surface 106.
When it hits a portion above the reference position of the reflecting surface 108, the light is scattered. As a result, light directed toward the light receiving unit 204 is reduced in an unintended optical path that travels while reflecting on the inner surface of the meat theft 112 and a portion above the reference position of the first reflecting surface 106 and the second reflecting surface 108. It is possible to suppress the light receiving unit 204 from receiving the light from the light emitting unit 202 before the ink surface in the ink cartridge 100 falls below the reference position of the prism 104. As a result, even when there is a meat theft 112 in the prism 104, the detection accuracy of the remaining amount of ink can be improved.

Here, the uneven surfaces 106u and 108u formed on the first reflecting surface 106 and the second reflecting surface 108 of the prism 104 only need to have a surface shape that scatters when the light in the prism 104 strikes, and the mode thereof is as follows. It is not limited to a plurality of narrow grooves. For example, the first reflecting surface 106
In addition, a plurality of small protrusions may be provided on the surface of the second reflecting surface 108, or may be formed into a satin finish by applying a texture process or the like. When the prism 104 is formed by injection molding, the concave and convex surfaces 106u and 108u are formed simultaneously with the injection molding of the prism 104 by engraving a shape corresponding to the shape of the concave and convex surfaces 106u and 108u in the mold. can do.

Further, in the prism 104 mounted on the ink cartridge 100 of the present embodiment, not only the portion corresponding to the height of the reference position of the first reflecting surface 106 and the second reflecting surface 108 (the portion where the prescribed optical path intersects), but also Since the lower part is also transparent (smooth), when the ink surface in the ink cartridge 100 falls below the reference position, the light receiving unit 204
The intensity of reflected light received by can be increased. That is, the light that is emitted from the light emitting unit 202 having a wide directivity angle and enters the prism 104 includes, as shown in FIG.
After being reflected by the portion exposed from the ink below the reference position, the light is reflected by the upper surface of the meat stealing 112 (the bottom surface of the concave portion), and further, the portion exposed from the ink below the reference position of the second reflecting surface 108 In some cases, the light reaches the light receiving unit 204 after being reflected. In the optical path that travels while reflecting on the inner surface of the meat theft 112 and the portion below the reference position of the first reflecting surface 106 and the second reflecting surface 108, the ink surface in the ink cartridge 100 is more than the reference position. Since the light from the light emitting unit 202 does not reach the light receiving unit 204 while it is above, this optical path does not cause a detection error of the remaining amount of ink. On the other hand, when the ink surface falls below the reference position, an optical path for the light from the light emitting unit 202 to reach the light receiving unit 204 is generated in addition to the prescribed optical path, so that the intensity of reflected light received by the light receiving unit 204 can be increased. it can.

D. Modified example:
In the prism 104 of the embodiment described above, the first reflecting surface 106 and the second reflecting surface 10 are used.
The concave and convex surfaces 106 u and 108 u are formed in a portion above the reference position 8, and the other portions of the surface of the prism 104 are formed transparent (smooth). However, since the unintended optical path different from the regular optical path is constituted by the inner surface of the meat stealing 112 and the portion above the reference position of the first reflecting surface 106 and the second reflecting surface 108, An uneven surface may also be formed on the inner surface. Hereinafter, the first reflecting surface 106 and the second reflecting surface 1 are used.
A modified example in which an uneven surface is formed not only on 08 but also on the inner surface of the meat steal 112 will be described. In the description of the modification, the same components as those of the above-described embodiment are denoted by the same reference numerals as those of the above-described embodiment, and the detailed description thereof is omitted.

FIG. 8 is a cross-sectional view of the modified prism 104 cut along a plane perpendicular to the first reflecting surface 106 and the second reflecting surface 108. As shown in the drawing, in the prism 104 of the modification, the first
Similar to the portion above the reference position of the reflecting surface 106 and the second reflecting surface 108, the meat theft 11
An uneven surface 112u is also formed on the inner wall surface of No. 2. The uneven surface 112u may have a surface shape that scatters the light in the prism 104. For example, a plurality of thin grooves or a plurality of small protrusions are formed on the surface of the inner wall surface of the meat steal 112. It can be formed by, for example, providing or applying a textured finish.

In the prism 104 of such a modified example, as described above with reference to FIG.
Is incident on the inner wall surface of the meat stealer 112, it is irregularly reflected by the unevenness of the uneven surface 112u. Thereby, the intensity of the light traveling toward the portion above the reference position of the first reflecting surface 106 is reduced compared to the light before hitting the inner wall surface of the meat burglar 112, and thus an unintended optical path different from the prescribed optical path ( The light reaching the light receiving unit 204 is further reduced on the inner surface of the meat theft 112 and the light path that travels while being reflected by a portion above the reference position of the first reflecting surface 106 and the second reflecting surface 108. Thereby, it is possible to further suppress the light receiving unit 204 from receiving the light of the light emitting unit 202 before the ink surface in the ink cartridge 100 falls below the reference position of the prism 104. As a result, the remaining amount of ink in the ink cartridge 100 can be reduced. Detection accuracy can be improved.

Although various embodiments have been described above, the present invention is not limited to all the above embodiments, and can be implemented in various modes without departing from the scope of the invention.

For example, in the above-described embodiment, the first reflecting surface 106 and the second reflecting surface 1 of the prism 104 are used.
Concave and convex surfaces 106u and 108u were formed on each of 08. However, the uneven surface (106
u, 108u) need only be formed on at least one of the first reflecting surface 106 and the second reflecting surface 108, and need not be formed on both. As described above, the unintended optical path different from the prescribed optical path is constituted by the inner surface of the meat theft 112 and the portion above the reference position of the first reflecting surface 106 and the second reflecting surface 108. 1 reflective surface 10
If the concave / convex surface (106u, 108u) is formed on either the sixth reflective surface 108 or the second reflective surface 108, the light in the prism 104 is scattered by the concave / convex surface, and the light reaching the light receiving unit 204 through an unintended optical path Can be reduced.

10 ... inkjet printer, 20 ... carriage,
22 ... Carriage case, 24 ... Ejection head, 30 ... Drive mechanism,
40 ... Platen roller, 50 ... Maintenance mechanism, 60 ... Control part,
100: Ink cartridge 104: Prism 106: First reflecting surface
106u: Uneven surface, 108 ... Second reflecting surface, 108u ... Uneven surface,
112 ... Stealing meat, 200 ... Sensor, 202 ... Light emitting part,
204. Light receiving part

Claims (3)

A liquid ejecting apparatus in which a light emitting unit and a light receiving unit are arranged side by side is mounted, the liquid ejected from the liquid ejecting apparatus is accommodated in a liquid storage chamber, and the bottom of the liquid storage chamber is formed by resin molding A liquid container having a prism,
The prism is
A first reflecting surface provided in contact with the liquid in the liquid storage chamber and reflecting light in the prism at a portion exposed from the liquid surface;
A second reflecting surface provided in contact with the liquid in the liquid storage chamber and reflecting light in the prism at a portion exposed from the liquid surface;
Meat stealing that is a recess that reduces deformation of the prism due to resin shrinkage during the resin molding,
With
The first reflecting surface and the second reflecting surface receive light emitted from the light emitting unit and incident on the prism when the liquid in the liquid storage chamber is reduced below a predetermined amount. A reflecting surface that constitutes a predetermined reflected light path that is reflected by the reflecting surface and guided to the light receiving unit;
At least one of the first reflective surface and the second reflective surface is a portion above the location where the reflected light path intersects the first reflective surface, or above the location where the reflected light path intersects the second reflective surface. The liquid container is formed in a surface shape that scatters the light in the prism. The liquid container according to claim 1,
A liquid container in which at least a part of an inner surface of the meat theft is formed in a shape that scatters light in the prism.   A liquid ejecting apparatus comprising the liquid container according to claim 1.

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