JP3521625B2 - Ink level detector - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink remaining amount detecting device for optically detecting the ink remaining amount.

[0002]

2. Description of the Related Art Generally, for detecting the remaining amount of ink in an ink remaining amount detecting device, a method is known in which an electrode is provided in an ink tank or an ink flow path to electrically detect. In the case of such a method, it is necessary to provide an electrode in the ink tank or in the ink flow path, and there is a problem that the structure becomes complicated. In addition, there is another problem that the ink is deteriorated by applying a current to the ink and by touching the metal (electrode) with the ink.

Therefore, as a method of non-contact detection with respect to ink, as disclosed in, for example, Japanese Patent Laid-Open No. 7-117238, an ink jet head is provided integrally with an ink cartridge and a porous structure having open cells is formed inside. Ink tank in which a quality member is arranged, a transparent window formed on the side wall of the ink tank, a light irradiating means for irradiating light to at least a predetermined position of the window, and a light reflected from the predetermined position of the window And a light receiving unit that outputs a signal corresponding to the intensity of the reflected light, and detects the remaining amount of ink in the ink tank from the signal of the output signal from the light receiving unit. Detection devices have been proposed.

In such an apparatus, if ink remains in the ink tank and the inner surface of the remaining amount confirmation window of the light irradiating section is wet, the light emitted from the light emitting element, which is the light irradiating means, is applied to the window. The inner surface is almost specularly reflected, and most of it is received by the light receiving element that is the light receiving means, and a relatively large signal output can be obtained from the light receiving element, while the ink in the ink tank is exhausted and the remaining amount of the light irradiation part When the inner surface of the confirmation window is dried, the irradiation light is diffusely reflected and transmitted by the inner surface of the window and hardly reaches the light receiving element, and as a result, a small signal output is obtained from the light receiving element.

[0005]

However, as in the above-mentioned device, the fact that the reflectance in the ink cartridge differs between the ink-impregnated portion and the ink-free portion is used for detection. In the above, the presence or absence of ink is determined by whether or not the signal output exceeds the threshold value for determining the presence or absence of ink. However, in general, the signal output is very small and comparison with the threshold value is made. In addition to being difficult, since the amount of light emitted from the light emitting element, which is the light generating means, and the sensitivity at the light receiving element, which is the light receiving means, both fluctuate depending on the ambient temperature, the output characteristics of the signal change significantly. There was room for improvement in terms of detection accuracy.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide an ink remaining amount detecting device which is capable of optically detecting the presence or absence of an ink remaining amount in a non-contact manner with respect to ink. To aim.

[0007]

According to a first aspect of the present invention, there is provided a cartridge case in which at least a part of a wall surface is made of a light transmissive member having a light transmissive property, and an ink storage member is housed therein. In an ink remaining amount detecting device for detecting the remaining amount of ink in an ink cartridge, a light incident unit for making light incident on at least two detection points of a portion where the light transmitting member is provided, and the light incident unit. In relation to the means, a plurality of light receiving means arranged so as to be able to receive the reflected light of each incident light and a signal from the light receiving means, and the remaining amount of ink according to the difference in the amount of light received by each light receiving means. Ink remaining amount determination means for determining a change is provided.

According to the first aspect of the present invention, the plurality of light receiving means are used, and the ink remaining amount determining means determines the change in the remaining amount of ink according to the difference in the light receiving amount by each light receiving means. The presence or absence of the remaining ink amount can be accurately detected without being affected by the small signal output of the light receiving unit and the change of the output characteristic of the signal due to the change of the environmental temperature.

According to a second aspect of the present invention, in the apparatus of the first aspect, the light receiving means is capable of receiving light that is incident from the light incident means and totally reflected by an inner surface of the light transmissive member that is in contact with ink. It is arranged at each position.

According to the second aspect of the invention, the light which is incident from the light incident means and totally reflected by the inner surface of the light transmissive member which is in contact with the ink is received by the light receiving means without difficulty.

According to a third aspect of the present invention, in the apparatus according to the first or second aspect, the light incident means uses a single light emitting means to inject light of the same light amount at each of the detection points. .

According to the third aspect of the invention, a single light emitting means causes the light of the same light quantity to be incident on each of the detection points.

According to a fourth aspect of the present invention, in the apparatus according to any one of the first to third aspects, the ink remaining amount detecting device ejects ink onto the recording medium onto a carriage that moves along the recording medium. Is to detect the remaining amount of ink in an ink cartridge mounted together with a print head for printing, and the light incident means and the light receiving means are arranged on the carriage.

According to the fourth aspect of the invention, ink is ejected onto the recording medium onto the carriage that moves along the recording medium, using the light incident means and the light receiving means provided on the carriage. The remaining amount of ink in the ink cartridge mounted together with the print head for printing is detected.

According to a fifth aspect of the present invention, in the apparatus according to any one of the first to third aspects, the ink remaining amount detecting device ejects ink onto the recording medium onto a carriage that moves along the recording medium. For detecting the remaining amount of ink for each color of an ink cartridge mounted together with a color print head for performing multi-color printing, and the light incident means and the light receiving means are provided at predetermined positions along the moving path of the carriage. The ink remaining amount determination means is fixed and receives a signal from the light receiving means at each timing when each light transmissive member corresponding to each color reaches the predetermined position in synchronization with the movement of the carriage. The change in the remaining ink amount is determined for each color.

According to the fifth aspect of the present invention, the ink remaining amount determining means causes the light receiving means to detect the light transmitting member corresponding to each color at each timing in synchronization with the movement of the carriage. Is received, the change in the remaining ink amount is judged for each color.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a state in which a print head and an ink cartridge are mounted on a carriage of a printing apparatus using an ink remaining amount detecting apparatus according to the present invention. Figure 1
In the above, the ink cartridge 1 is removably mounted on the head unit 2, and the head unit 2 is mounted on a carriage 4 which is guided by a guide shaft 3 and is movable along a recording medium (not shown). Has been done.

The ink cartridge 1 has a cartridge case 5 made of a light-transmissive member having a light-transmitting property, and the ink storage member 6 is provided inside the cartridge case 5.
Is housed. The head unit 2 has a print head 8 attached to the head holder portion 7, and a packing 9 is interposed between the head unit 2 and the ink cartridge 1.

A light emitting diode 12 (LED) as a light incident means is provided on a vertical wall member 11 erected on the carriage 4 so as to face the rear surface of the cartridge case 5, and the upper and lower portions thereof are associated with the light emitting diode 12. First and second phototransistors 13 and 14 as light receiving means are provided in the. As shown in FIG. 2, the light emitting diode 12 causes light to be incident on at least two detection points P1 and P2 on the rear surface of the cartridge case 5, and
The phototransistors 13 and 14 are arranged so as to be able to receive the reflected light of each incident light.

More specifically, the light emitting diode 1
A single light source 2 is configured to be incident on the detection points P1 and P2 with substantially the same amount of light, including the incident angle and the like. The phototransistors 13, 1
Reference numerals 4 are respectively arranged at positions where the light incident from the light emitting diode 12 and totally reflected by the inner surface of the rear surface (light transmitting member) of the cartridge case 5 in contact with the ink can be received. Each phototransistor 13, 14
Is configured such that when the ink level is exhausted, the amount of light totally reflected as described above decreases, so that the amount of light received decreases and the signal output increases.

In FIG. 1, a base member 21 provided with predetermined electrical wiring is provided on the lower surface of the head unit 2, and the print head 8 and the light emitting diode 1 are provided on the base member 21.
The second, first and second phototransistors 13 and 14 are electrically linked via the flexible printed boards 22 and 23 (FPC). Reference numeral 24 is a flexible printed circuit board (FPC) with dimples, 25 is a wiring pattern printed on the base material 21, 26 is a backup rubber, and 27 is a backup rubber.
Is a carriage retainer. Further, in FIGS. 1 and 2, 5a and 5b are an atmosphere communication hole and an ink supply port formed in the cartridge case 5, respectively, and S1, S
Reference numerals 2 respectively indicate a portion not impregnated with ink and a portion impregnated with ink.

As shown in FIG. 3, the signals from the phototransistors 13 and 14 are input to a detection circuit 31 as a remaining ink amount determination means, and the phototransistors 1 are detected.
It is configured to determine the change in the remaining amount of ink according to the difference in the amount of light received by the light sources 3 and 14. That is, the signal output from each of the phototransistors 13 and 14 corresponds to the amount of received light and is input to the comparator 32 to compare the sizes thereof, and the signal of the first phototransistor 13 located on the upper side. When the output becomes larger than the signal output of the second phototransistor 14 located on the lower side, the comparator 32 determines that there is no ink remaining near the detection point P1 and the comparator 32 is "H".
When the signal outputs of the first and second phototransistors 13 and 14 are substantially equal to each other while the level signal is output, the comparator 32 determines that there is ink remaining above the detection point P1 and the comparator 32 outputs the "L" level signal. Is output. In this way, the presence / absence of the remaining ink amount is determined according to the signal output from the comparator 32. Incidentally, in FIG. 3, 33 and 34 are resistors.

In this way, it is possible to detect the remaining amount of ink in the ink cartridge 1 mounted together with the print head 8 that prints by ejecting ink onto the recording medium on the carriage 4 that moves along the recording medium. An ink remaining amount detecting device for performing the operation is configured. In particular, since the two phototransistors 13 and 14 are used, it is possible to detect a slight change in reflectance even if ink remains on the wall surface of the cartridge case 5 that comes into contact with the ink, because the ink decreases. False detection is prevented. Further, it is possible to detect the presence or absence of the remaining ink amount (the remaining amount of the remaining ink is small) with high accuracy without causing a decrease in accuracy due to a disturbance such as a change in environmental temperature.

Then, the signal from the detection circuit 31 (comparator 32) is, as shown in FIG.
It is inputted to the control means 44 having Nos. 2 and 43, and, for example, on the operation panel 45, a display indicating that there is no ink remaining, an alarm or the like is issued. Further, the control means 44 drives and controls the paper feed motor 48 and the carriage drive motor 49 via the drivers 46 and 47. In addition, the control means 4
4 receives signals from an origin sensor 50 that detects that the carriage 4 is at the origin position and a paper sensor 51 that detects the presence or absence of paper as a recording medium, and also an input / output interface 52, an operation panel 45, and a RAM 53.
Signals are exchanged with the ROM 54 and the ROM 54. The RAM 53 and the ROM 54 are also linked to the control circuit 55, and the control circuit 55
However, the drive circuit 56 drives and controls the head unit 2, that is, the print head 8.

In the above-described embodiment, the entire cartridge case 5 of the ink cartridge 1 is formed of the light transmissive member having light transmissivity, but it is not always necessary to form the entire cartridge case 5 of the light transmissive member. If at least the wall surface of the cartridge case 5 corresponding to the light emitting means and the light receiving means is formed of a light transmissive member, the remaining amount of ink in the ink cartridge can be detected.

Further, in the above embodiment, only two phototransistors are provided, but the number of phototransistors can be further increased to detect the remaining amount of ink stepwise. .

Further, in the above-described embodiment, the remaining ink of the single-color ink cartridge mounted on the carriage moving along the recording medium together with the print head for ejecting the ink to the recording medium for printing. As described above, the present invention uses two phototransistors and compares their signal outputs (corresponding to the amount of received light) to detect the remaining amount of ink. Therefore, even if the ink is different, the remaining ink amount can be detected with high accuracy without being influenced by the spectral characteristics of each ink, and thus the ink is ejected onto the recording medium on the carriage that moves along the recording medium. The present invention can be similarly applied to the case of detecting the remaining amount of ink for each color of an ink cartridge mounted together with a color print head for performing multicolor printing. In this case, the light incident means and the light receiving means are fixed at predetermined positions along the movement path of the carriage,
The ink remaining amount determination means synchronizes with the movement of the carriage,
It is necessary to receive a signal from the light receiving means at each timing when each light transmissive member corresponding to each color arrives at the predetermined position, and determine the change in the remaining amount of ink for each color.

[0029]

According to the first aspect of the invention, as described above, the change in the remaining amount of ink is judged according to the difference in the amount of light received by each light receiving means, so that the accuracy is not deteriorated by the disturbance. It is possible to detect the presence or absence of the remaining ink amount.

According to the second aspect of the invention, since the light receiving means is arranged at a position capable of receiving the light which is incident from the light incident means and totally reflected by the inner surface of the light transmitting member which is in contact with the ink, the light receiving means is disposed. Light can be reliably received by the means. That is, it is possible to detect the remaining amount of ink that is resistant to disturbance.

According to the third aspect of the invention, the light incident means uses a single light emitting means so that light of the same light quantity is made incident on each of the detection points. Therefore, erroneous detection due to variations in the light quantity is caused. Therefore, the detection accuracy of the remaining ink amount determining means is improved. In addition, since the structure can be simplified, it can be formed in a small size and can be arranged at any place. At the same time, the cost can be reduced.

According to a fourth aspect of the present invention, a light-injecting means and a light-receiving means are arranged on a carriage, and a print head for performing printing by ejecting ink onto the recording medium on the carriage moving along the recording medium. Since the amount of ink remaining in the attached ink cartridge is detected, the remaining amount of ink can be constantly determined with a simple structure.

According to a fifth aspect of the invention, in synchronization with the movement of the carriage, a signal from the light receiving means is received at each timing when each light transmissive member corresponding to each color reaches a predetermined position.
Since the change in the remaining ink amount is determined for each color, the ink amount can be determined for each ink cartridge that supplies ink to the color print head with a simple configuration without providing a remaining amount detection device for each cartridge. The remaining amount can be determined.

[Brief description of drawings]

FIG. 1 is a diagram showing a state in which a print head and an ink cartridge are mounted on a carriage of a printing apparatus using an ink remaining amount detecting apparatus according to the present invention.

FIG. 2 is an explanatory diagram of detection points.

FIG. 3 is an explanatory diagram of an ink remaining amount determination means of the present invention.

FIG. 4 is an explanatory diagram of a control system.

[Explanation of symbols]

1 ink cartridge 4 carriage 5 cartridge case 6 Ink storage member 12 Light emitting diode (light incident means) 13 First phototransistor (light receiving means) 14 Second phototransistor (light receiving means) 31 detection circuit (ink remaining amount determination means)

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) B41J 2/175 B41J 2/125 G01F 23/28

Claims (5)

(57) [Claims] 1. A remaining amount of ink in an ink cartridge in which at least a part of a wall surface has a cartridge case made of a light-transmitting member having a light-transmitting property, and an ink storage member is housed in the cartridge case is detected. In the remaining ink amount detecting device, at least two of the parts where the light transmitting member is provided.
Light incident means for making light incident on one detection point, a plurality of light receiving means arranged in relation to the light incident means so as to be able to receive reflected light of each incident light, and a signal from the light receiving means. And an ink remaining amount determination unit that determines a change in the remaining amount of ink according to the difference in the amount of light received by each light receiving unit. 2. The light receiving means is arranged at a position capable of receiving light which is incident from the light incident means and totally reflected by an inner surface of the light transmissive member which is in contact with ink. Item 1. The remaining ink amount detection device according to item 1. 3. The ink remaining amount detecting device according to claim 1, wherein the light incident unit uses a single light emitting unit to inject light of the same light amount to each of the detection points. 4. The remaining amount of ink in an ink cartridge mounted on a carriage that moves along a recording medium, together with a print head that ejects ink onto the recording medium to perform printing. The remaining ink amount detection device according to any one of claims 1 to 3, which performs detection, and in which the light incident unit and the light receiving unit are disposed on the carriage. 5. The ink remaining amount detection device is provided on a carriage that moves along a recording medium, and each color of an ink cartridge mounted together with a color print head that ejects ink onto the recording medium to perform multicolor printing. The light incident unit and the light receiving unit are fixed at predetermined positions along the moving path of the carriage, and the ink remaining amount determination unit is 2. The change in the remaining amount of ink is determined for each color by receiving a signal from the light receiving means at each timing when each light transmissive member corresponding to each color reaches the predetermined position in synchronization with the movement. The remaining ink amount detection device according to any one of 3 to 3.