JP2003237101A - Image forming device - Google Patents

Abstract

(57) [Problem] To provide a simple and highly reliable inkjet image forming apparatus with a simple configuration capable of accurately detecting the remaining amount of ink and the absence or erroneous insertion of an ink tank. An ink-jet type image forming apparatus having a plurality of ink tanks (2) includes a plurality of ink tanks (2).
Is provided with a pair of electrodes 2b, 2b as an ink amount detecting means, and further provided with an electrode 2c as an ink tank detecting means for detecting the presence or absence of an ink tank. A detection circuit is used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink detecting device for an ink jet printer which is an image forming device.

[0002]

2. Description of the Related Art Conventionally, an ink jet printer is known as an ink jet type image forming apparatus. In this inkjet printer device, in order to suppress deterioration of the device, improve the convenience of maintenance, and form a good image, it is necessary to detect the amount of ink in the ink tank and notify the user of the replacement time and the like. desirable.

Therefore, Japanese Unexamined Patent Publication No. 8-197749 discloses a detection circuit for detecting a change in electrostatic capacitance between two electrodes provided on the outer wall surface of an ink tank to detect the ink amount state in the ink tank. There is disclosed a configuration of an ink jet printer device that can detect ink in a non-contact manner. In this case, specifically, the detection means arranges a plurality of electrodes on the outer wall surface of the ink tank or the ink flow path formed of an insulator, and detects a change in capacitance between these electrodes. Is configured as follows.

[0004]

However, in the prior art described in the above-mentioned publication (Japanese Patent Laid-Open No. 8-197749), one detection device is required for one ink tank, which is a color ink jet system. The image forming apparatus requires at least four color (cyan, magenta, yellow, black) detection devices (four).

Further, in recent years, there has been a demand for higher quality images,
For example, an apparatus provided with 6 color ink tanks requires an apparatus for 2 colors, which is a negative factor in terms of cost. Further, when there are a plurality of ink tanks, it is necessary to prevent erroneous insertion at the time of ink tank replacement in consideration of user convenience, image quality, and the like.

The present invention has been made in view of the above circumstances, and an inkjet image forming apparatus having a simple structure and a highly reliable structure capable of accurately detecting the remaining amount of ink, the non-insertion of an ink tank, the erroneous insertion, etc. is provided at a low cost. The purpose is to provide cheap.

[0007]

The present invention has means for solving the above-mentioned problems as follows.

(1) In an ink jet type image forming apparatus having a plurality of ink tanks, each of the ink tanks has a pair of electrodes as ink amount detecting means, and the electrodes are connected in series. Is characterized by.

In this structure, the ink tanks are connected in series via the electrodes. Therefore, if the amount of ink in any of the ink tanks becomes a certain amount or less, the conduction is lost and the series circuit is not configured. This makes it possible to detect the ink amount, that is, to determine whether or not the ink amount is above a certain level.

Further, when the ink tank is not inserted, the series circuit is not formed, so that it is possible to determine whether the ink tank is not inserted. Therefore, the ink amount can be determined by arranging the series circuit in one detection circuit. Therefore, it is not necessary to separately provide a detection circuit for each ink tank, and when the number of ink tanks increases, it is advantageous in terms of cost.

(2) The electrode is in direct contact with the ink in the ink tank.

In this structure, the electrodes come into direct contact with the ink in the ink tank. Therefore, the series circuit is configured without sandwiching the container portion of the ink tank between the electrode and the ink, and the ink amount can be detected easily and with high accuracy.

(3) The electrode is provided outside the ink tank.

In this structure, the electrodes do not come into direct contact with the ink in the ink tank. Therefore, it is possible to prevent changes in the electrode surface over time, adhesion of deposits to the electrode, oxidation of the electrode, and the like.

Further, since the electrodes do not penetrate the ink tank, there is no problem of ink leakage, which enables more simple and highly accurate detection of the amount of ink.

(4) The position of the electrode is different for each ink tank.

In this structure, since the position of the electrode differs depending on the color of the ink in the ink tank, the contact structure is not formed when the ink tank of the wrong color is inserted,
A series circuit composed of a plurality of ink tanks is not configured, and thus, the incorrect insertion of the ink tank can be detected.

(5) An electrode as an ink tank detecting means for detecting the presence or absence of the ink tank is further provided, and a detection circuit for detecting the ink amount is used for the ink tank detection.

In this structure, when the ink tank is inserted, first, the electrodes as the ink detecting means form contact points,
A series circuit is formed, and thereafter, the contact structure of the electrode as the ink detecting means is released, and the pair of electrodes as the ink amount detecting means is formed as a contact to form the series circuit again.

Therefore, a signal indicating the insertion of the ink tank is sent before the insertion is completed. So after that,
When the wrong ink tank is inserted or the ink tank with empty ink (state below a certain amount) is inserted and the circuit configuration is not performed, it is possible to reliably detect that the ink is erroneously inserted.

(6) An impedance element is inserted between a pair of electrodes which are ink amount detecting means.

In this configuration, the impedance element forms a series circuit even when the ink runs out (a state in which the amount of ink is less than a certain amount). Therefore, by appropriately selecting the impedance element, it is possible to identify which color of the ink tank causes the ink shortage by utilizing the impedance value of the series circuit.

(7) The impedance element is a capacitor or a resistor.

In this structure, the impedance element can be selected according to the impedance characteristic of the ink liquid. Therefore, ink with large impedance,
For example, oil-based ink and ink with low impedance,
For example, with water-based ink or the like, it is possible to specify the ink tank with higher reliability.

(8) The invention is characterized in that the electrodes, which are the ink tank detection means, are electrically connected on the ink tank side.

In this structure, an electrode which is an ink tank detecting means is connected on the ink tank side. Therefore, other components are not required, and it can be easily manufactured.

(9) The electrode which is the ink tank detecting means is composed of a pair of electrodes, and the impedance element is inserted between the pair of electrodes.

In this structure, when the ink tank is inserted, the electrodes serving as the ink detecting means first make contact points,
A series circuit is constructed. Therefore, by appropriately selecting the impedance element, it is possible to determine how many ink tanks are empty, or how many colors are being inserted,
As a result, the color of the ink in the ink tank to be replaced can be designated, and erroneous insertion during the replacement operation can be prevented in advance.

(10) The ink outlet of the ink tank is closed by a seal, and the seal is held when the ink tank is detected by the ink tank detecting means, and the seal is opened when the ink tank is completely attached. It is characterized by being removed.

In this configuration, the color of the ink is detected during the insertion of the ink tank and a warning is issued,
The attachment of the ink outlet seal can be stopped before it is removed, and thus it is possible to reliably prevent color mixture of ink due to erroneous insertion.

(11) In an ink jet type image forming apparatus having a plurality of ink tanks, each of the plurality of ink tanks has a pair of electrodes as ink amount detecting means, and one for each of the plurality of electrode pairs. A detection circuit is connected.

In this structure, the ink tanks are connected in series via the electrodes. Therefore, if the ink amount in any of the ink tanks becomes less than a certain amount, there is no conduction, and the series circuit is not configured. This makes it possible to detect the ink amount, that is, determine whether the ink amount is above a certain level. It will be possible.

Further, when the ink tank is not inserted, the series circuit is not formed, so that it is possible to determine whether the ink tank is not inserted. Therefore, the amount of ink can be determined by arranging the series circuit in one detection circuit. Therefore, it is not necessary to separately provide a detection circuit for each ink tank, which is advantageous in terms of cost.

(12) A detection circuit constituted by a plurality of ink tanks in series is further provided with a connection terminal between adjacent electrodes which are ink amount detection means, and switching means for switching the connection terminal which is a connection destination. It is characterized by switching the connection.

In this structure, the ink amount in each ink tank can be detected by sequentially switching the connection destinations. Further, by selecting the switching order, it is possible to specify an empty ink tank (a state in which the amount of ink is a certain amount or less) with a small number of switching times. Therefore, an empty ink tank can be identified reliably and quickly.

(13) It is characterized in that switching by the switching means is performed by moving the ink carriage.

In this structure, the ink carriage itself moves and the contact structure is sequentially performed. Therefore,
Along with the movement of the ink carriage, the contact surface is slid to be cleaned, thereby improving the reliability of the mechanical contact.

(14) At least two switching positions by the switching means are provided.

In this structure, the stop position of the ink carriage can be set to, for example, the ink replacement position and the ink amount detection position. Therefore, it is possible to detect the ink amount in the side edge area outside the image area that cannot be reached by the user.

Further, the detection processing speed can be improved by setting the image area where the replacement scanning is easy to be performed as the ink replacement position and enabling the detection even at the ink replacement position.

(15) The black ink tank and the color ink tank can be electrically separated.

In this structure, the black ink tank and the color ink tank can form an independent electric circuit. Therefore, by pulling out the intermediate tap from the connection point between the black ink tank and the color ink tank, it is possible to use the black ink tank and the integrated color ink tank.

Further, it is possible to cope with a user whose ink consumption is biased toward black or color. Further, even if there is no black, the black color can be proxy-printed by mixing cyan, magenta, and yellow, and it is possible to prevent printing stop.

(16) A black ink tank is arranged at the end of the ink carriage.

In this structure, the black ink tank is arranged at the end of the ink carriage. Therefore, the color ink tanks can be easily electrically separated from each other, and the ink tanks can be easily replaced and convenient for users who often use black.

(17) The color ink tank is electrically separable into two.

In this structure, the color ink tank composed of a plurality of ink tanks can form two independent electric circuits. Therefore, for example, light magenta (L
By separating the M) and light cyan (LC) inks from the cyan (C), magenta (M), and yellow (Y) inks, the light magenta (LM) or light cyan (LC) ink is empty. Even in this case, it is possible to perform proxy printing with the three colors of cyan (C), magenta (M), and yellow (Y), or four colors in which black (K) is added, and it is possible to prevent printing stop.

(18) It is characterized in that it further comprises means for detecting the number of times of ink ejection from each ink tank.

In this structure, the number of times ink is ejected from each ink tank can be detected. Therefore,
When an empty ink tank is detected (when the amount of ink is less than a certain amount), the cumulative total of the ink consumption estimated by dots and purging is used to determine which ink tank is empty without adding other members. Can be identified.

(19) The ink tank is composed of a main tank and a sub tank, and is provided with a suction device, and the number of times ink is discharged is added to the number of times equal to the consumption amount of ink discharged from a nozzle or the like by suction processing. Is characterized by.

In this configuration, the number of times the ink is ejected and the number of times the ink is expelled at the same time by the air bleeding are added. Therefore, it is possible to identify the empty ink tank more accurately.

(20) The ink tank is composed of a main tank and a sub tank, and is provided with a suction device, and the ink consumption amount discharged from a nozzle or the like by the suction process is added to the discharge ink consumption amount. .

In this structure, the number of times of the ink consumption amount simultaneously discharged by the air bleeding is added to the discharge ink consumption amount. Therefore, the empty ink tank can be specified more accurately.

[0054]

DETAILED DESCRIPTION OF THE INVENTION An image forming apparatus according to an embodiment of the present invention will be described in detail below.

(Embodiment 1) As shown in FIG. 1, the ink jet printer P of this embodiment has a print head 1
And a carriage 4 on which the ink tank 2 is mounted, a shaft 4, a timing belt 5 and the like. The carriage 3 is supported by the shaft 4 and has a timing belt 5
And moves in the main scanning direction.

As shown in FIG. 2, the paper 6 is stacked on the paper feed tray 7 and fed out by the pickup roller 8 to feed the paper feed rollers 9 and 10 and the paper discharge roller 1.
The print heads 1 and 12 convey the print head 1 in the sub-scanning direction and print in the main scan direction.

That is, the print head 1 causes the ink in the ink tank 2 to flow from the nozzles to the paper 6 in response to the print signal.
The main scanning is performed on the paper 6 while ejecting the
Each time the main scanning of the line is completed, sub-scanning (feeding movement) is performed at a predetermined interval, whereby an image is formed on the paper 6, and after the image is formed, the paper 6 is ejected from the paper discharge tray 13.
Is discharged to.

FIG. 3 shows a control system of the ink jet printer P. As shown in FIG. 3, a control unit 100 composed of a CPU, a head drive circuit 21 for driving the print head 1,
Carriage drive circuit 2 for driving the carriage motor 22
3. It has a sheet conveying drive circuit 25 for driving the sheet conveying motor 24 and a notification (alarm, warning) means 26. The timing belt 5 is driven by the carriage motor 22, and the paper feed rollers 9, 1 are driven by the paper transport motor.
0 and the discharge rollers 11 and 12 are driven.

The control unit 100 includes the interface unit 101, the image processing unit 27, the drive system control unit 28, and the detection unit 2.
9 and a memory 30, and the interface unit 1
A print command and print data from the outside are received via 01, and a head drive circuit 21 and a carriage drive circuit 23 are received according to the received print command and print data.
And an output signal is sent to the drive circuit 25 for paper transport.

Then, the detection section 29 sends a detection signal from the ink amount detection means or the tank detection means described later (via the detection circuit) via the interface section 101.
The notification means 26 notifies the notification means 26 that there is no ink remaining (empty) or that the ink tank 2 is not installed or erroneously installed (alarm,
Sends an output signal for warning.

The memory 30 is composed of RAM and ROM. The RAM is a memory mainly for temporarily storing print data, and the ROM is a control program for driving the inkjet printer P, various data tables, and detection of ink amount and attachment state of the ink tank 2. It is a memory that stores in advance a program for performing.

The ink tank 2 mounted on the ink jet printer P is inserted on the carriage 3 as shown in FIG. Further, in the present embodiment, the ink tank 2 is composed of six ink tanks 2A to 2F, and each of the ink tanks 2A ... Has light cyan (LC), light magenta (LM), cyan (C), respectively. It is filled with magenta (M), yellow (Y), and black (K) inks.

The ink tank 2 is not limited to the six ink tanks 2A to 2F described above, and although not shown in the drawing, for example, four ink tanks 2A to 2F.
D ink may be used, and eight ink tanks 2A to
It may be configured by 2H.

Each ink tank 2 (2A to 2F) is shown in FIG.
As shown in FIG. 2, the tank main body 2a is provided with an ink detection electrode 2b as an ink amount detection means and a tank detection electrode 2c as an ink tank detection means.
A protrusion 2d for fixing the tank main body 2a to the ink carriage 3 when the tank is inserted is provided at the tip of a.

The ink detecting electrode 2b is the tank body 2
The tank detection electrode 2c is an electrode that detects the amount of ink in a.
~ 2F) is an electrode for detecting whether or not inserted. Further, the tank detection electrode 2c, as shown in FIG.
The electrode width may be widened. The details of each electrode will be described later.

Each of the ink tanks 2 is mounted on the ink carriage 3 as follows. First, FIG.
As shown in (a), the protrusion 2d is fitted into the lateral groove-shaped locking portion 3d of the ink carriage 3 to be locked. As a result, the ink tank 2 becomes the ink carriage 3
It is roughly positioned with respect to.

Next, the ink tank 2 is placed on the bottom plate of the ink carriage 3 so that the sealed outlet 2e provided at the bottom of the ink tank 2 corresponds to (engages with) the ink supply port 3e on the ink carriage 3 side. Seated on
In this state, if the free end of the flexible fixing claw 15 provided on the rear side of the ink carriage 3 is urged against the shoulder portion on the rear side of the ink tank 2, the ink tank 2 The mounting (insertion) work on the ink carriage 3 is completed.

In this mounted state, as shown in FIG. 7B, the seal of the outflow port 2e of the ink tank 2 is broken, and the ink can be supplied, and the fixing claw 15 allows the ink tank 2 to be supplied. The ink tank 2 is stably locked / fixed (positioned) at a predetermined position in a state in which the protruding portion 2d is urged in the direction of being pushed into the locking portion 3d of the ink carriage 3.

As shown in FIG. 8A, each ink tank 2 has a pair of ink detection electrodes 2b, 2b and a single tank detection electrode 2c which is a wide detection electrode penetrating the inside of the ink tank 2. have. The position of the ink detection electrode 2b is set to a different portion (in the longitudinal direction) for each color, as shown in FIG. 8B.

The ink detection electrode 2b may reach (penetrate) inside the ink tank as shown in FIG. 8 (a), or as shown in FIG. May be. When the ink detection electrode 2b is formed only on the surface, there is no problem of ink leakage from the penetrating portion and there is no problem of sealing property, so the ink tank 2 can be manufactured more easily than when penetrating. . Furthermore, it is possible to prevent changes in the electrode surface with time, adhesion of deposits to the electrode, oxidation of the electrode, and the like.

Further, the tank detection electrode 2c is also shown in FIG.
It is not limited to the form shown in FIG.
As shown in (c) and (d), one ink detection electrode 2b
The tank detection electrode 2c and the tank detection electrode 2c may be electrically connected. Alternatively, as shown in FIGS.
The tank detection electrode 2c may be formed outside the ink tank 2.

With the above configuration, when the ink tank 2 is properly inserted, the ink corresponding to the contact leaf 15 provided on the ink carriage 3 is, as shown in FIG. 8B or 8D. When the wrong ink tank 2 is inserted although the detection electrode 2b is in contact with the detection electrode 2b, the ink detection electrode 2b becomes the contact leaf 1 as shown in FIG. 8 (f).
5 does not come into contact (is in a floating state), conduction cannot be achieved, and erroneous insertion is detected.

In such a case, an output signal for sending a warning by a buzzer or a notification (or an alarm, a warning) to the user by blinking a red lamp or the like is sent from the detection section 29 to the notification means 29. As a result, trouble can be prevented from occurring. The notification means 26 may be, for example, a buzzer or a lamp provided on the operation panel of the inkjet printer P or the like as long as it can appeal to the sight and hearing of the user.

In addition to the notification by the notification means 26, the original operation of the ink jet printer P is deactivated (the head drive circuit 21, the carriage drive circuit 23, and the paper transport drive circuit 25 are not activated) to cause a trouble. It may be possible to more reliably prevent the occurrence of.

In order to replace the ink tank 2, attach the ink tank 2 to the ink carriage 3 (from top to bottom).
When inserting, first, the tank detection electrode 2c located below
Contacts the contact leaf 15 (see FIG. 8A). After that, by further pushing the ink tank 2 into the ink carriage 3, the contact leaf 15 is
Ink tank 2 is no longer in contact with tank detection electrode 2c.
Is fixed in contact with the ink detection electrode 2b. The ink detection electrodes 2b of the adjacent ink tanks 2 are connected to each other by the contact leaf 15 arranged in the middle.

As described above, when the ink tank 2 is inserted, the tank detection electrode 2c once becomes conductive.
This conduction makes it possible to detect that the insertion work of the ink tank 2 has started. After the insertion, the ink detection electrode 2b and the contact leaf 1 which are arranged differently for each color
Whether or not the wrong ink tank 2 is erroneously inserted is detected by using the presence / absence of the contact structure with the device 5. For example, when the ink tanks 2 having different colors are inserted, as shown in FIG.
As shown in, it is possible to determine that the insertion is incorrect because the contact structure cannot be formed.

When the used empty ink tank 2 of the same color is inserted, since there is no ink as a conductor in the ink tank 2, the two ink detection electrodes 2b and 2b do not collect ink. It is not short-circuited via a closed electric circuit. This makes it possible to determine that the insertion is incorrect. If the ink tank 2 is erroneously inserted and ink is started to be supplied to the ink supply system, a great amount of labor is required for restoration, so erroneous insertion must be avoided at all costs.

Further, regarding the detection of the ink amount, that is, the detection of whether or not the ink amount is above a certain amount level,
If the ink capacity in the ink tank 2 is below a certain amount,
The fact that there is no conduction in the ink tank 2 is used. Specifically, it will be described using an electric circuit A described later.

Here, the electric circuit A for detecting the above-mentioned erroneous insertion and ink amount will be described. The square wave supplied from the power supply side has a resistance R
After passing through s, one of them branches after passing through the capacitor Cs, and then falls to the ground through the ink detection electrode 2b of each ink tank 2, the ink Zk ... In each color ink tank 2, and each contact leaf 15. .

On the other hand, after passing through the diode 16,
A / A path that goes to the ground via the capacitor Cs
It branches to the route to the D converter 17. The A / D converter 17 converts the input analog voltage value into a digital value.

Therefore, when the ink tank of the wrong color is inserted by mistake, the contact structure between the ink detection electrode 2b and the contact leaf 15 having the different arrangement for each color is not formed, so that the ink tanks 2 arranged in series are not connected. The circuit will not be configured. Therefore, a high voltage value is detected on the A / D converter 17 side.

Empty (ink amount is below a certain amount)
When the above ink tank 2 is inserted, the contact structure is formed. However, since the ink is less than a certain amount, the ink does not come into contact with the ink detection electrode 2b, and the circuit structure of the ink tank 2 arranged in series is Not done. Therefore, also in this case, a high voltage value is detected on the A / D converter 17 side.

Regarding the ink amount detection, if the amount of ink in one ink tank 2 is less than a certain amount, the ink tank 2 is not electrically connected, and the supplied square wave is the capacitor Cs and the above-mentioned square wave. A high voltage value is detected on the A / D converter 17 side without flowing through the path through the ink tank 2.

As described above, by using the detected voltage, it is possible to erroneously insert the ink tank 2 and detect the ink amount. The capacitor Cs is for removing a DC component. By the capacitor Cs, it is possible to prevent the substance contained in the ink from being deposited in the ink detection electrode portion, and it is possible to maintain a good electrode state.

In addition, the ink detection electrode 2b is replaced by the one shown in FIG.
As shown in (a) and (b), when it is formed only on the surface, the container itself of the ink tank 2 plays a role of a capacitor, and between the two ink detection electrodes 2b and 2b, the ink itself is not formed. In addition to the impedance, two capacitors are inserted. Even in this case,
By using the configuration of the electric circuit A described above, it is possible to detect the amount of ink by using the detected voltage value.

(Embodiment 2) In the present embodiment, the impedance element 18 is arranged as shown in FIG.
2 of each ink tank 2 outside the ink tank 2.
It is arranged between two ink detection electrodes 2b and 2b. The other configurations are similar to those of the first embodiment, and the description thereof will be omitted.

In addition to the determination of erroneous insertion, the impedance element 18 can determine which ink tank 2 (2A ...) Is out of ink (state in which the amount of ink is below a certain amount), as will be described later. it can. That is, for example, a capacitor is used as the impedance element 18, and the electric circuit A is used to form a circuit.

As a result, for example, as shown in FIG. 12, when the yellow (Y) ink runs out, the circuit is maintained because the impedance element 18 is provided, but the circuit is arranged in series. The impedance value of the entire ink tank will change.

Here, the impedance element 1 for each color
The capacities of 8 are selected so as to be easy to distinguish for each ink tank 2 and different, and the impedance values of the entire ink tanks arranged in series when the ink of each color ink tank 2 runs out do not overlap. To set.

As a result, when the ink runs out, A
It is possible to determine which color of ink has run out by utilizing the difference in voltage magnitude detected by the / D converter 17. It should be noted that the impedance element 18 may be a resistor, and the accuracy of color identification is improved if the impedance element 18 is selectively used depending on the liquid quality of ink having a large impedance, for example, oil-based ink or ink having a small impedance, for example, water-based ink. To do.

(Third Embodiment) In this embodiment, the shape of the ink detection electrode 2b is the same as that of the first embodiment. On the other hand, the tank detection electrode 2c has the same shape as the ink detection electrode 2b, instead of being composed of only one electrode as shown in the first embodiment. That is, in FIG.
As shown in (a) and (b), it is composed of two electrodes.

Further, impedance elements (for example, capacitors Ck, ...) Are arranged between the two tank detection electrodes 2c, 2c of each ink tank 2 outside the tank body 2a, as shown in FIG. 13 (c). . The other configurations are similar to those of the first embodiment, and the description thereof will be omitted.

By selecting the impedance value of the impedance element (Ck, ...) Differently for each ink tank 2, in addition to the effect of the first embodiment, when the ink tank 2 is replaced, the tank detection electrode By 2c,
When it is detected that the tank is inserted, it is possible to determine what color of the ink tank 2 has been inserted.

That is, a circuit is constructed using the electric circuit A using a capacitor having a certain capacitance as the impedance element (Ck, ...). This allows
As shown in FIG. 13C, for example, while the yellow (Y) ink is being inserted, since the impedance element (Ck, ...) Is provided, the tank detection electrode 2c of the ink tank 2 to be inserted, Adjacent ink tank 2
And the ink detection electrode 2b of 2 are short-circuited. As a result, the series circuit of the entire ink tanks arranged in series is configured.

Since the impedance elements (Ck, ...) Of the ink tanks 2 have different capacities, a specific impedance value can be obtained in the series circuit. Therefore, it is possible to determine which color ink has been inserted by utilizing the difference in the magnitude of the voltage detected by the A / D converter 17.

(Fourth Embodiment) In this embodiment, the electric circuit A shown in the first embodiment is improved, and as shown in FIG. 14, the ink detection electrodes 2b, Contact leaf 1 that shorts 2b
Terminals T1 ... Are drawn from 5, and intermediate taps (switching means) 19 are used to sequentially switch the short-circuited portion with the capacitor Cs. The other configurations are similar to those of the first embodiment, and the description thereof will be omitted.

By sequentially changing the connection destinations of the movable connection terminals of the intermediate tap 19, it is possible to specify the color without using the impedance element 18 as shown in the second embodiment. That is, when the movable connection terminal is connected to a fixed terminal, a circuit in which a maximum of six ink tanks 2 are arranged is formed between the capacitor Cs and the ground.

Suppose that each ink tank 2 has light magenta (LM) and light cyan (L) sequentially from the ground side.
C), yellow (Y), magenta (M), cyan (C), and black (K) inks are contained.
Note that the order of insertion is not limited to the above.

For example, as shown in FIG. 14, when the terminal T2 is connected and the impedance on the ink tank 2 side becomes high and the A / D converter 17 detects a high voltage, the light magenta ( Of the LM ink tank 2 and the light cyan (LC) ink tank 2,
It indicates that any one of the inks is empty (a certain amount or less).

In this case, it is possible to determine which tank is empty by connecting the terminal Tl. That is, if a high voltage is detected on the A / D converter 17 side, the light magenta (LM) ink tank 2 is empty, and if a low voltage is detected, the light cyan (LC) ink tank 2 is. It can be determined that it is empty.

More specifically, as shown in FIG. 15, first, in S1, the movable connection terminal of the intermediate tap 19 is connected to one of the fixed connection terminals T of the black (K) ink tank 2.
Connect with 6. Then, the process proceeds to S2, and if there is conduction between T6 and the ground, the process further proceeds to S3, and since there is ink in all the ink tanks 2, the process ends.

On the other hand, if there is no conduction between T6 and the ground, the process proceeds to S4, and the movable connection terminal of the intermediate tap 19 is connected to the connection fixed terminal T4. Then, the process proceeds to S5, further proceeds to S6 if there is conduction between T4 and the ground, and proceeds to S7 if there is no conduction. After proceeding to S6 and connecting the movable connecting terminal to the fixed connection terminal T5, proceeding to S8, the T
Check if there is continuity between 5 and ground.

Here, if there is continuity, the process proceeds to S9, it is determined that the black (K) ink is empty, the warning (notification, warning) process is performed in S10, and then the process ends. On the other hand, if there is no continuity between T5 and the ground, the process proceeds to S11, it is determined that the cyan (C) ink is empty, the warning process is performed in S10, and the post-process is terminated.

In S7, the movable connection terminal of the intermediate tap 19 is connected to the connection fixed terminal T2. afterwards,
Proceed to S12 to check if there is continuity between T2 and ground. If there is continuity, the process proceeds to S13, and the movable connection terminal is connected to the connection fixed terminal T3. On the other hand, if there is no conduction between T2 and the ground, the process proceeds to S14.

After S13, the process proceeds to S15 to check whether there is continuity between T3 and the ground. If there is continuity, the process proceeds to S16, it is determined that the magenta ink is empty, and the warning process is performed in S10, and then the process ends. On the other hand, if there is no continuity between T3 and the ground,
After proceeding to S17, it is determined that the yellow (Y) ink is empty, a warning process is performed at S10, and then the process is terminated.

Further, in S14, the intermediate tap 1
The movable connection terminal 9 is connected to the connection fixed terminal Tl. After that, the process proceeds to S18, and it is checked whether or not there is continuity between T1 and the ground. If there is continuity, the process proceeds to S19, it is determined that the light cyan (LC) ink is empty, and the warning process is performed in S10, and then the process ends. On the other hand, if there is no continuity between Tl and the ground, the process proceeds to S20, it is determined that the ink of the light magenta (LM) is empty, and the warning process is performed in S10, and then the process ends.

As described above, by adopting the intermediate tap method of the present embodiment, when the ink tank 2 of 6 colors is used, the switching operation of the connection destination terminal is performed up to 3 times. Similarly, when the ink tank 2 of four colors is used, the switching operation is performed twice, and when the ink tank 2 of eight colors is used, the switching operation is performed three times.

Further, when the ink tank 2 of 16 colors is used, the empty ink tank 2 can be determined by the switching operation four times. Therefore, as described above, it is possible to quickly identify the empty ink tank 2.

Further, the switching of the intermediate tap 19 is performed as shown in FIG.
As shown in FIG. 6, it may be performed by a movable carriage 20. In this case, the connection terminals can be switched without adding an electric circuit, and the contact surface slides as the carriage 20 moves, thereby improving the reliability of the mechanical contacts. .

As shown in the third embodiment, the tank detection electrode 2c is composed of two electrodes, and the electrodes 2c,
A capacitor, for example, may be arranged as an impedance element between 2c. In this case, a terminal is drawn out between the impedance elements, and the terminal is also brought into contact with the movable terminal at the same time.

As a result, as described in the third embodiment, when it is detected by the tank detection electrode that the tank is inserted when the ink tank 2 is replaced,
It is possible to determine how many colors of ink tank 2 will be inserted.

When the switching of the intermediate tap 19 is performed by moving the carriage 20, the carriage 20 moves at the time of detection. Therefore, when the user tries to touch the ink tank for ink replacement or the like when the printing is not performed, the user comes into contact with the moving carriage 20, which is not preferable. Therefore, it is preferable that the position for detecting the ink amount or the like is the position of the side end portion outside the image area that cannot be reached by the user.

Further, it is desirable to be able to detect even at the ink exchange position where the exchange operation is easy in the image area which is the central portion of the apparatus, from the viewpoints of preventing erroneous insertion and improving the detection processing speed. When a tap switching operation at the exchange position is required, the operator may reduce the feed speed to be safe and perform the switching operation. Thus, if there are a plurality of connection locations, convenience is improved.

(Fifth Embodiment) In this embodiment, the dot count stored by counting the number of times each color ink is ejected in (the memory 30 of) the ink jet printer P shown in the first to fourth embodiments. A dot count memory is provided as a means. This dot count memory is set so that when the new ink tank 2 is attached, the memory is erased and becomes zero.

Thus, for example, in the first embodiment, when the ink in a certain ink tank 2 is exhausted, it is possible to determine how many colors of ink tank 2 are exhausted by referring to the dot count. The same applies to the third embodiment. Further, in the second or fourth embodiment, by using this dot count memory together, it is possible to specify the color more accurately.

Next, a specific method of determining the empty ink tank 2 will be described. As shown in FIG. 17, first, S
At 30, it is detected whether or not the ink tank 2 is inserted. If the ink tank 2 is not inserted, that is, the first
If it can be detected that the mounting operation state of the step (see FIG. 7A) is not detected, the process proceeds to step S31.
Proceed to.

In S31, it is judged whether or not there is an ink amount, and if it is not empty (state below a certain amount), the mounting operation state of the second step or the third step or the mounting completion state (see FIG. 7B). Then, the process returns to S30 again.

On the other hand, if it is empty, it means the mounting operation state of the first step, and therefore the process proceeds to S33. In S33, the process of inserting and mounting the new ink tank 2, that is, the suction of the ink by the pump (suction means) pp by capping,
A series of operations such as purging, spitz, and wiping are performed, and thereafter, in step S34, the dot count (DC
The value of the memory of (NT) is set to zero. Then, proceed to S35,
Perform printing.

In S32, which is not the mounting operation state in the first step, the presence or absence of the ink amount is determined. If the ink is not empty, the ink tank 2 is in a normal state, so the process proceeds to S36 and continues to be used. If it is empty, the ink tank 2 is installed, and since the ink is empty or the ink tank is not installed, the process returns to S30.

After S36, the process proceeds to S37, the dot count is read from the dot count memory, and then the process proceeds to S35. In S35, after executing printing, the process proceeds to S38, and the dot count at the time of printing is added.

Next, in S39, the added count is stored in the dot count memory. Then, in S40,
If the stored dot count value is less than the fixed upper limit value, the process proceeds to S41, and if it is equal to or higher than the upper limit value, the process proceeds to S42. It should be noted that in S41, it is determined whether or not the printing of all the data is completed, and if completed, the process is ended.

On the other hand, if not completed, the process returns to S35 again. Further, in S42, the tanks that are out of ink (state below a certain amount) are displayed. Then, proceed to S43,
Move to the step of ink shortage processing.

Next, a method of determining the empty ink tank 2 using only the level detecting electrodes will be specifically described.
In this case, as shown in FIG. 18, first, in S50, the tank memory in which the history of ink amount change is recorded and stored is read out. After that, the process proceeds to S51, the tank memory is empty,
That is, if the amount of ink is equal to or less than the predetermined amount, the process proceeds to S52, and if the tank memory is not empty, the process proceeds to S53. In S52, it is confirmed that the ink is empty even in the previous use, and then the process proceeds to S54.

In S54, it is judged whether or not the state where the ink is empty has been released.
Returning to 53, if released, the process proceeds to S55. In S55, the mounting process, that is, a series of operations such as ink suction by the pump (suction means) pp by capping, purging, spitz, and wipe are performed, the value of the dot counter (DCNT) is set to zero, and the tank memory is stored. Erased. After that, printing is executed in S56.

After S53, the value of the dot counter is read from the dot count memory in S57, and then the process proceeds to S56. After S56, the process proceeds to S58, and the dot count for printing is added.

Then, in S59, the dot count value is stored. Then, in S60, if the stored dot count value is less than the fixed upper limit value, the process proceeds to S61, and if it is equal to or more than the upper limit value, the process proceeds to S62. In S61,
It is determined whether or not all the data has been printed, and if so, the processing ends.

On the other hand, if not completed, the process returns to S51 again. In addition, in S62, the ink depletion tank is displayed. Then, in step S63, information indicating that the space is empty is written in the advance tank memory. After that, the process proceeds to S64, and proceeds to the step of ink shortage processing.

Further, in the present embodiment, the ink tank 2 of the ink jet printer P may be composed of a main tank 2M and a sub tank 2S as shown in FIG. In this case, as shown in FIG. 20, air may accumulate in the tube t connecting the main tank 2M and the sub tank 2S, and uniform image quality may not be maintained.

Therefore, at the start of printing, it is necessary to evacuate the air by the pump (suction means) pp. At this time, the ink is also sucked into the waste ink tank 2.

Therefore, in order to more accurately grasp the ink consumption amount, it is necessary to add the dot count corresponding to the ink amount consumed by the air bleeding to the dot count memory. This makes it possible to replace the ink tank 2 more accurately.

As described above, in the present embodiment, by providing the tank memory, the total value of the estimated ink consumption can be known, and the color can be specified without the need for an additional member.

(Sixth Embodiment) In this embodiment, in addition to the first to fifth embodiments, the black (K) ink tank 2 can be electrically separated from the other ink tanks 2. According to this, by pulling out the intermediate tap 19 from the connection point between the black (K) ink tank 2 and the color ink tank 2, the black (K) ink tank 2 and the integrated color ink tank 2 are formed. It can be used in the form of.

Further, by being electrically separable, it is possible to cope with a user whose ink consumption is biased to black (K) or color. Further, even if there is no black (K), the color of black (K) can be proxy-printed by the mixed color of cyan (C), magenta (M), and yellow (Y), and the printing stop can be prevented.

Here, the black (K) ink tank 2
Is located at the end of the series of ink tanks 2,
It is preferable in consideration of electrical separation.

(Embodiment 7) In this embodiment, in addition to Embodiment 6, light magenta (LM) is used.
And light cyan (LC) are electrically separable from cyan (C), magenta (M), and yellow (Y).

As a result, in addition to the effect of the fifth embodiment, even if the light magenta (LM) ink or the light cyan (LC) ink is empty, cyan (C), magenta (M), and yellow (Y) are used. ), Or four colors in which black (K) is added to it, proxy printing is possible, and printing stop can be prevented.

Although the respective embodiments have been described above,
It goes without saying that the present invention is not limited to this, and improvements and design changes can be freely made as needed without departing from the spirit of the present invention.

[0138]

As is apparent from the above description, the present invention has the following effects.

(1) Since the electrodes of each ink tank are connected in series, if the ink amount in any one of the ink tanks becomes a certain amount or less, there is no continuity and the series circuit is not formed. It is possible to detect, that is, determine whether or not the ink amount is above a certain level.

Further, even when the ink tank is not inserted, since the series circuit is not formed, it can be determined that the ink tank is not inserted. Therefore, the ink amount can be determined by arranging the series circuit in one detection circuit. Therefore, it is not necessary to separately provide a detection circuit for each ink tank, and when the number of ink tanks increases, it is advantageous in terms of cost.

(2) Since the electrodes come into direct contact with the ink in the ink tank, the series circuit is constructed without sandwiching the container part of the ink tank between the electrodes and the ink, and the ink is simple and highly accurate. The amount can be detected.

(3) Since the electrodes are provided outside the ink tank, the electrodes do not come into direct contact with the ink in the ink tank, and the changes over time of the electrode surface, the deposition of deposits on the electrodes, and the electrode It is possible to prevent oxidation and the like. Further, since the electrodes do not penetrate the ink tank, there is no problem of ink leakage, and it is possible to detect the amount of ink more easily and with high accuracy.

(4) Since the positions of the electrodes are made different depending on the color of the ink in the ink tank, when the ink tank of the wrong color is inserted, the contact structure is not formed and a series circuit of a plurality of ink tanks is used. Is not configured, it is possible to detect the incorrect insertion of the ink tank.

(5) When the ink tank is inserted, first the electrodes as the ink detecting means form contact points to form a series circuit, and then the electrode as the ink detecting means is released from the contact point arrangement, and the ink amount detecting means is released. Since the pair of electrodes as the contact point are configured as contacts and the series circuit is configured again, the signal notifying the insertion of the ink tank is sent before the insertion is completed. Therefore, after that, when a wrong ink tank is inserted or an ink tank in which ink is empty (state below a certain amount) is inserted and the circuit configuration is not performed, it is possible to reliably detect that the ink is wrongly inserted.

(6) The impedance element inserted between the pair of electrodes, which is the ink amount detecting means, configures the series circuit even when the ink runs out (a state in which the amount of ink is less than a certain amount). Therefore, by appropriately selecting the impedance element, it is possible to identify which color of the ink tank causes the ink shortage by utilizing the impedance value of the series circuit.

(7) Since the impedance element is a capacitor or a resistor, the impedance element can be selected according to the impedance characteristic of the ink liquid. Therefore, it is possible to specify the ink tank with higher reliability using the ink having a large impedance, for example, the oil ink, and the ink having a small impedance, for example, the water-based ink.

(8) Since the electrode which is the ink tank detecting means is connected on the ink tank side, other components are not required and the manufacture can be simplified.

(9) Since the impedance element is inserted between the pair of electrodes as the ink tank detecting means,
When the ink tank is inserted, first, the electrodes as the ink detecting means form contact points to form a series circuit. Therefore,
By properly selecting the impedance element, it is possible to determine what color of the ink tank is empty, how many colors are being inserted, and the like. Therefore, the color of the ink in the ink tank to be replaced can be designated, and erroneous insertion during the replacement operation can be prevented in advance.

(10) The ink outlet of the ink tank is closed with a seal, and the seal is held when the ink tank is detected by the ink tank detecting means, and the seal is opened when the installation of the ink tank is completed. Since it is removed, by detecting the color of the ink during the insertion of the ink tank and issuing a warning, it is possible to stop the installation of the ink outlet seal before removing it. Color mixture can be reliably prevented.

(11) Since one detection circuit is connected to a plurality of electrode pairs, each ink tank is connected in series via the electrodes, so that the ink amount in any one of the ink tanks is constant. In the following cases, conduction is lost and the series circuit is not configured. This makes it possible to detect the ink amount, that is, to determine whether or not the ink amount is above a certain level.

Further, when the ink tank is not inserted, the series circuit is not formed, so that it is possible to determine whether the ink tank is not inserted. Therefore, the amount of ink can be determined by arranging the series circuit in one detection circuit. Therefore, it is not necessary to separately provide a detection circuit for each ink tank, which is advantageous in terms of cost.

(12) It is possible to detect the ink amount in each ink tank by sequentially switching the connection destinations by the switching connection means. Further, by selecting the switching order, it is possible to specify an empty ink tank (a state in which the amount of ink is equal to or less than a certain amount) with a small number of times of switching, and it is possible to reliably and quickly specify an empty ink tank.

(13) The ink carriage itself moves,
Since the contact structure is sequentially performed, the contact surface is slid and cleaned as the ink carriage moves, and the reliability of the mechanical contact is improved.

(14) Since at least two switching positions by the switching means are provided, the stop position of the ink carriage is
For example, the ink replacement position and the ink amount detection position can be set. Therefore, it is possible to detect the ink amount in the side edge area outside the image area that cannot be reached by the user. In addition, the image area that is easy to scan for replacement is the ink replacement position,
By making it possible to detect even at the ink replacement position,
The detection processing speed can be improved.

(15) Since the black ink tank and the color ink tank can be electrically separated from each other, the black ink tank and the color ink tank can form an independent electric circuit. Therefore, by pulling out the intermediate tap from the connection point between the black ink tank and the color ink tank, it is possible to use the black ink tank and the integrated color ink tank.

Further, it is possible to cope with a user whose ink consumption is biased toward black or color. Further, even if there is no black, the black color can be proxy-printed by mixing cyan, magenta, and yellow, and it is possible to prevent printing stop.

(16) Since the black ink tank is arranged at the outermost end of the ink carriage, it is easy to electrically separate from the color ink tank, and the ink is used even for a user who frequently uses black. The tank can be easily replaced and the convenience is improved.

(17) Since the color ink tank can be electrically separated into two, the color ink tank composed of a plurality of ink tanks can form two independent electric circuits. Therefore, for example, light magenta (LM)
By separating the light cyan (LC) ink and the cyan (C), magenta (M), and yellow (Y) inks, the light magenta (LM) or light cyan (LC) ink is empty. However, it is possible to perform proxy printing with three colors of cyan (C), magenta (M), and yellow (Y), or four colors of which black (K) is added, and it is possible to prevent printing stop.

(18) Since the means for detecting the number of times ink is discharged from each ink tank is further provided, the number of times ink is discharged from each ink tank can be detected.
Therefore, when an empty ink tank (a state in which the amount of ink is less than a certain amount) is detected, by using the cumulative total of the estimated values of ink consumption by dots and purging, which ink tank is added without adding other members. Can be identified as empty.

(19) Since the number of times ink is expelled and the number of times ink is expelled at the same time due to air bleeding are added, it is possible to specify an empty ink tank more accurately.

(20) Since the number of times the ink is expelled at the same time as the amount of ink expelled by adding air is added to the amount of ink expelled, the empty ink tank can be specified more accurately.

[Brief description of drawings]

FIG. 1 is a perspective view of an inkjet printer according to an embodiment of the present invention.

FIG. 2 is a sectional view of the same.

FIG. 3 is a control system diagram of the same.

FIG. 4 is a perspective view showing an arrangement state of the ink tanks.

FIG. 5 is a perspective view of the ink tank.

FIG. 6 is a perspective view of another ink tank of the same.

FIG. 7 is an explanatory diagram of a procedure for mounting the ink tank.

FIG. 8 is an explanatory diagram of a conductive state of the ink tank.

FIG. 9 is a cross-sectional view of the same different ink tank.

FIG. 10 is an electric circuit diagram in the first embodiment.

FIG. 11 is a sectional view of the ink tank according to the second embodiment.

FIG. 12 is a same electric circuit diagram.

FIG. 13 is a diagram showing a configuration and an electric circuit of an ink tank according to the third embodiment.

FIG. 14 is an electric circuit diagram in the fourth embodiment.

FIG. 15 is a flowchart of the same.

FIG. 16 is another electric circuit diagram of the same.

FIG. 17 is a flowchart in the fifth embodiment.

FIG. 18 is another flowchart of the same.

FIG. 19 is an explanatory diagram of an ink tank including the two tanks.

FIG. 20 is an explanatory diagram showing a state where an ink tank including the two tanks is incorporated in an inkjet printer.

[Explanation of symbols]

2-ink tank 2b-ink amount detection means 2c-ink tank detection means 2e-ink outlet 2M-Main tank 2S-sub tank 3-ink carriage 18-impedance element 19-Switching means A-Detection circuit Cs-capacitor Rs-resistance pp-suction means

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kazuya Masuda             22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka             Inside the company F-term (reference) 2C056 EA26 EA29 EB20 EB44 EB45                       EB51 EB56 KC06

Claims (20)

[Claims] 1. An inkjet type image forming apparatus having a plurality of ink tanks, wherein each of the ink tanks has a pair of electrodes as an ink amount detecting means, and both electrodes are connected in series. An image forming apparatus characterized by. 2. The image forming apparatus according to claim 1, wherein the electrode directly contacts the ink in the ink tank. 3. The image forming apparatus according to claim 1, wherein the electrode is provided outside the ink tank. 4. The image forming apparatus according to claim 1, wherein the positions of the electrodes are different for each ink tank. 5. An electrode as an ink tank detecting means for detecting the presence / absence of an ink tank is further provided, and a detection circuit for detecting an ink amount is used for the ink tank detection. The image forming apparatus according to any one of claims. 6. The image forming apparatus according to claim 1, wherein an impedance element is inserted between a pair of electrodes which are ink amount detecting means. 7. The image forming apparatus according to claim 6, wherein the impedance element is a capacitor or a resistor. 8. The image forming apparatus according to claim 5, wherein the electrode, which is the ink tank detecting means, is electrically connected on the ink tank side. 9. The image according to claim 5, wherein the electrode which is the ink tank detecting means is composed of a pair of electrodes, and an impedance element is inserted between the pair of electrodes. Forming equipment. 10. The ink outlet of the ink tank is closed with a seal, and the seal is retained when the ink tank is detected by the ink tank detecting means, and the seal is removed when the mounting of the ink tank is completed. The image forming apparatus according to claim 9, wherein the image forming apparatus is formed. 11. An inkjet type image forming apparatus having a plurality of ink tanks, wherein each of the plurality of ink tanks includes a pair of electrodes as an ink amount detecting means, and one detection is performed for the plurality of electrode pairs. An image forming apparatus having a circuit connected thereto. 12. A connection of a detection circuit configured in series with a plurality of ink tanks, further comprising a connection terminal between adjacent electrodes which are ink amount detection means, and switching means for switching the connection terminal which is a connection destination. The image forming apparatus according to claim 11, wherein the image forming apparatus is switched over. 13. The image forming apparatus according to claim 12, wherein the switching by the switching means is performed by moving the ink carriage. 14. The image forming apparatus according to claim 13, wherein at least two switching positions of the switching unit are provided. 15. The image forming apparatus according to claim 11, wherein the black ink tank and the color ink tank are electrically separable from each other. 16. The black ink tank is located at the end of the ink carriage.
The image forming apparatus according to item 1. 17. A color ink tank is electrically 2
The image forming apparatus according to claim 15, wherein the image forming apparatus is separable into two parts. 18. The image forming apparatus according to claim 11, further comprising means for detecting the number of times ink is ejected from each ink tank. 19. The ink tank comprises a main tank and a sub tank, and is provided with a suction device, wherein the number of times ink is discharged is added to the number of times equal to the consumption amount of ink discharged by the suction process. The image forming apparatus according to claim 18. 20. The ink tank comprises a main tank and a sub tank, and is provided with a suction device, and the ink consumption amount discharged by the suction process is added to the discharge ink consumption amount. The image forming apparatus described.