JP2525803B2 - Inkjet printing equipment - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inkjet printing apparatus, and more specifically, an ink remaining amount for detecting an ink remaining amount of an ink supply source such as an ink storage container arranged in the apparatus. The present invention relates to a detection device.

[Prior Art] For example, as a conventional ink remaining amount detecting device in an inkjet printer, an ink storage container (ink tank) as an ink supply source fixed to the main body of the inkjet printer, or a recording head mounted on a carriage Some of the inkjet printers are provided in a spare ink tank mounted on the carriage.

As such a conventional ink remaining amount detecting device, the remaining amount is detected by utilizing conductivity of ink, providing a pair of electrodes in a tank, and detecting energization / de-energization between the electrodes. was there.

However, in such an ink remaining amount detecting device,
The ink is electrolyzed to energize the ink,
In some cases, the ink composition was changed, and foreign matter generated by electrolysis adhered to the electrodes, resulting in a decrease in conductivity. Further, the compositional change and the foreign matter also bring about a deterioration in recording quality and ejection performance. Furthermore, it was not possible to continuously detect the decrease in the remaining ink amount.

Therefore, an optical means for projecting and receiving visible light is provided at an appropriate part of the tank, and a remaining amount detection device for detecting the presence or absence of the remaining ink amount by the presence or absence of the received light, or the infrared emission In addition to the optical means for receiving light, a float for shutting off infrared rays is provided in the tank, and there is proposed a remaining amount detecting device for detecting the remaining amount of ink depending on whether infrared light is received due to light shielding. There is.

[Problems to be Solved by the Invention] However, with such a configuration, although a problem associated with electrolysis of ink does not occur, it is still difficult to continuously detect a change in the remaining ink amount.

An object of the present invention is to solve the above problems and provide an ink jet printing apparatus including an ink remaining amount detecting device capable of continuously detecting a change in the ink remaining amount.

[Means for Solving the Problems] Therefore, according to the present invention, in an inkjet printing apparatus that prints on a print medium using an inkjet head, an ink storage member that stores ink and an ink in the ink storage member. A float member movable in the vertical direction in accordance with the amount of ink in the ink containing member in a state of being levitated, and a length of a light-transmitting area or a light-shielding area along a predetermined direction different from the vertical direction. A float member having a light blocking member that changes at a predetermined rate according to the vertical position thereof, a light emitting unit and a light receiving unit are provided, and a light blocking state by the light blocking member between the light emitting unit and the light receiving unit is detected. A possible sensor unit, moving means for moving the ink containing member relative to the sensor unit in the predetermined direction, and the moving means. In the relative movement of the ink containing member in the predetermined direction, the ink containing is accommodated in accordance with the length of the light blocking state or the light transmitting state of the light blocking area or the light transmitting area detected by the sensor unit, respectively. And a detection unit that detects the amount of ink in the member.

[Operation] According to the above configuration, the float member moves in the vertical direction in a state of being floated on the ink in the ink containing member, depending on the amount of ink in the ink containing member. The float member has a light-shielding member that changes the length of the light-transmitting region or the light-shielding region along a predetermined direction different from the vertical direction at a predetermined rate according to the position in the vertical direction. On the other hand, when the sensor unit detects the light blocking state by its light emission and light reception, the length of the light transmitting state or the light blocking state along the predetermined direction by the light blocking member differs depending on the vertical displacement of the float member. It will be. Thereby, the ink amount can be detected based on the length of the light transmitting state or the light shielding state.

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

1 and 2 show an embodiment of the present invention. This example is an application example to a serial type ink jet recording apparatus that reciprocally scans a recording head and performs recording in the process, where 1 is an inkjet head unit, 2 is an inkjet nozzle thereof, and 3 is an ink tank. is there.
The ink I in the ink tank 3 is supplied to the head unit 1 side via the ink supply pipe 4. 5 is the ink tank 3
Is a float that is kept floating in the ink quality 3A and can be moved up and down according to the liquid surface of the ink I, and preferably even when the carriage 6 having the head unit 1 and the ink tank 3 is moved. Make sure that 5 does not move with the liquid surface.

Reference numerals 7A and 7B denote an infrared light emitting element and an infrared light receiving element, respectively, and an ink chamber 3A accommodating the float 5 enters between them at a predetermined position outside the recording range, for example, the home position of the carriage 6, by a holding member 8. It is kept as far away as possible. By providing the infrared light emitting element 7A and the light receiving element 7B, the infrared light transmitted from the light emitting element 7A transmits ink regardless of its color unless light is shielded by the float portion described later. And is received by the light receiving element 7B.

It should be noted that the opposing wall of the ink chamber 3A of the ink tank 3, at least the portion located in the optical path of infrared rays, must be formed of a material that easily transmits infrared rays. Considering ink resistance, for example, a transparent acrylic plate, etc. Is preferably used.

FIG. 3 shows an example of the structure of the float 5 in FIGS. 1 and 2. Here, 9 is a light-shielding plate formed of, for example, a metal for blocking the optical path of the infrared rays L, 10 is a light-shielding plate 9 which holds the light-shielding plate 9 and imparts an appropriate buoyancy to the float 5 to shield the light when the liquid surface changes It is a float main body for displacing the plate 9, and is made of a material that transmits infrared rays L.

FIG. 4 shows a configuration example of the light shield plate 9. In this example, the light shielding plate 9 is provided with a slit 9A that transmits infrared rays obliquely in a plane intersecting the optical axis of the infrared rays L.

FIG. 5 and FIG. 6 are explanatory views for explaining the infrared transmission state due to the movement of the carriage 6 to the vicinity of the home position.

In FIG. 5, when the carriage 6 moves in the S direction toward the elements 7A, 7B arranged near the home position, the infrared rays emitted from the light emitting element 7A are initially emitted by the light shielding plate 9 in the float 5. L is blocked by the light shielding plate 9 and is not received by the light receiving element 7B. When the carriage 6 is moved further in the S direction from the position shown in FIG. 5 and reaches the position where the slit 9A of the light shielding plate 9 in the float 6 intersects the optical axis of the infrared rays L, the light emitting element 7A emits light at this point. Infrared L
Is incident on the light receiving element 7B.

That is, in FIG. 2, the carriage 6 is replaced by the elements 7A and 7B.
When it is moved toward, the infrared ray L emitted from the light emitting element 7A initially enters the light receiving element 7B as it is because there is no object that blocks its progress. When the carriage 6 is further moved, the light ray L emitted from the light emitting element 7A is blocked by the light shielding plate 9 in the float 5 as shown in FIG. 5, and the light ray L enters the light receiving element 7B. It will not shine. When the carriage 6 is further moved, the light beam L passes through the slit 9A provided in the light shielding plate 9 as shown in FIG.
Will be incident on. Here, assuming that the light ray L is incident on the light receiving element 7B is "1" and the light ray is not incident on the light receiving element 7B is "0", the above process can be represented in FIG.

In FIG. 7, the vertical axis represents the state of the light receiving element 7B, and the horizontal axis represents the movement distance of the carriage 6.

The moving distance of the carriage 6 from the time when the infrared ray L is blocked by the light blocking plate 9 to the time when it passes through the slit 9A (the light receiving element 7B is "0").
During a period of time) changes as the liquid surface of the ink I changes. This situation will be described with reference to FIGS. 8 and 9.

8 and 9 are front views of the main part of the configuration shown in FIG. 1, showing the case where the water surface of the ink I is high and the case where it is low. In these figures, LA is the optical axis of the infrared ray L projected from the light emitting element 7A to the light receiving element 7B, and a is the distance between the optical axis LA and the end surface 9B of the light shielding plate 9. b
And b ′ are end faces 9B of the light shielding plate 9 at the height H of the optical axis LA.
And the distance between the slit 9A and the end of the slit 9A.

That is, the period in which the light receiving element 7B is "0" is short corresponding to the distance b when the water level of the ink I is high as shown in FIG. 8, and the distance b'when the water level is low as shown in FIG. Corresponding to become longer. Therefore, the ink level can be detected by measuring the period of “0” or the distances b and b ′.

FIG. 10 shows a configuration example of a control system of the ink remaining amount detecting device according to the present example. Here, 50 is a microprocessor type CPU that controls each part according to the processing procedure shown in FIG. 11, and in this example, the head unit 1, the motor 57 for driving the carriage 6, the recording medium conveying system 59, etc., during recording processing and the like. It is also used as a main control unit for controlling each unit of.

Reference numeral 51 denotes a ROM that stores a program executed by the CPU 50 corresponding to the procedure shown in FIG. 11 and the like, as well as a table for recognizing the remaining ink amount. Also, 53 is a RAM, which is a light receiving element
It has a working area such as a counter for measuring the period of "0" of 7B or the corresponding movement distance of the carriage 6 or the rotation amount of the motor 57.

FIG. 11 shows an example of the ink remaining amount detecting means according to this example. The timing of starting this procedure is, for example, a) at power-on, b) after printing a predetermined amount, for example, after printing 1000 lines.

c) When printing is completed and the printer enters the standby state.

And so on.

When this procedure is started, first, in step P1, the motor 57 is driven to detect that the carriage 6 has reached the reference position, for example, the home position. Then, in step P2, the light emitting element 7A is driven to emit the infrared ray L.

Next, in step P3, the motor 57 is further driven to move the carriage 6 in the S direction in FIGS. 5 and 6,
In step P4, it is detected that the light receiving element 7B becomes "0".
In response to the detection, the motor 57 is further driven in step P5, the rotation amount of the motor 57 is recorded in step P6, and it is detected in step P7 that the light receiving element 7B becomes "1".

The procedure of steps P5 to P7 is, for example, resetting the counter area of the RAM 53 after the positive determination in step P4, and when the pulse motor is used as the motor 57 until the positive determination is made in step P7, the drive pulse Whenever a DC motor is used, it can be performed by stepping through the counter area in response to the detection of the pulse output of the encoder combined with the DC motor. In addition, using a software or hardware timer,
You may make it count the period of "0" of 7B.

If an affirmative determination is made in step P7, the table in the ROM 51 in which the amount of ink remaining is associated with the amount of rotation is accessed in step P8, and the amount of ink remaining corresponding to the measured value is obtained.

The information about the remaining ink amount thus obtained is displayed by an appropriate display means or the like to allow the operator to recognize it,
Further, when the remaining amount of ink becomes extremely small, the operator can be notified by a notification means such as a buzzer or a display.

Although detection of the home position in step P1 in the procedure shown in FIG. 11 can be performed by an appropriate sensor,
Since the float 5 floats in the ink chamber 3A, the home position may be displaced relative to the float 5 and the light emission timing in step P2 may not be appropriate with respect to the above procedure.

Therefore, in another embodiment of the float according to the present invention,
As shown in FIG. 12, if a light blocking member 18 capable of blocking the infrared ray L from the light emitting element 7A is appropriately arranged on the float 5 and the home position is detected by the light blocking, after the home position is detected. The light emission timing of can be made appropriate. Further, it is not necessary to provide a special sensor for detecting the home position.

On the other hand, since the float 5 has to follow the change of the ink level, it is preferable to float it in the ink chamber 3A with an appropriate play. Therefore, even if the structure shown in FIG. There is a possibility that the detection of the "0" period of 7B may shift.

Therefore, as shown in FIG. 13, a light shielding portion 90 having a slit 90A is further provided.

FIG. 14 shows a state of the light receiving element 7B at the time of detecting the remaining ink amount according to the configurations shown in FIGS. 12 and 13. Time point c is the position where the light beam 14 is first blocked by the light blocking member 18 shown in FIG. 12, and this is used for detecting the home position. Time point d is a position where the light beam is re-entered into the light receiving element 7B by the right side portion of the slit 90A of the light shielding plate 90 shown in FIG. 13 in the figure. Further, the time point e is a position where the light beam is blocked by the light shielding plate 90, and at the time point f, the light beam enters the light receiving element 7B by taking the left side portion of the slit 90A in the figure again. In this case, the period from time point e to f corresponds to the remaining amount of ink,
The change in this period depends only on the displacement of the float 5 in the vertical direction due to the drop of the ink level, and does not depend on the floating position of the float 5 in the horizontal direction, so that the ink remaining amount can be accurately detected.

The ink tank 3 of the inkjet printer to which the present invention is applied is attached to and detached from the head unit 1,
Alternatively, the head unit 1 may be integrally attached to and detached from the printer, that is, the head unit 1 itself may form the most upstream ink supply source, or the ink tank may contain ink from another main tank. Even in the case of the relay tank that receives the supply, the liquid level of the relay ink tank cannot fall below a predetermined level unless the ink in the main tank runs out. It is possible to detect the presence or absence of ink via the.

In the above example, the ink tank is mounted on the carriage of the serial type printer, and the ink remaining amount is detected by moving the carriage with respect to the remaining amount detecting sensor including the fixed light emitting element and light receiving element. However, the above detection may be performed by moving the remaining amount detection sensor after setting the carriage at a predetermined position, for example.

Furthermore, the present invention is ready to be applied to an appropriate ink tank used in a serial type or line printer type ink jet printer, so that relative movement is performed between the ink tank and the ink remaining amount detection sensor. Good.

In addition, the light-shielding plate is not limited to the one provided with the slits as in the above example, and the same effect as described above can be obtained even if the shape of the light-shielding plate itself is appropriately determined, for example, by making it a trapezoid.

[Effects of the Invention] As described above, according to the present invention, the float member moves in the vertical direction in a state of being floated on the ink in the ink containing member according to the amount of ink in the ink containing member. The float member has a light-shielding member that changes the length of the light-transmitting region or the light-shielding region along a predetermined direction different from the vertical direction at a predetermined rate according to the position in the vertical direction. On the other hand, when the sensor unit detects a light blocking state by its light emission and light reception, the length of the light transmitting state or the light blocking state along the predetermined direction by the light blocking member differs depending on the vertical displacement of the float member. It will be. Thereby, the ink amount can be detected based on the length of the light transmitting state or the light shielding state.

As a result, it becomes possible to continuously know the change in the ink amount in the ink storage member such as the ink tank.

[Brief description of drawings]

1 and 2 are a perspective view and a top view, respectively, showing a structural example of an ink remaining amount detecting apparatus according to an embodiment of the present invention, and FIG. 3 shows a structural example of the float. FIG. 4 is a perspective view, FIG. 4 is a schematic view showing an example of the configuration of a light shielding plate arranged on the float, and FIGS. 5 and 6 are top views for explaining the operation of the present embodiment in detecting the remaining ink amount. FIG. 7 is a waveform diagram showing the state of the light receiving element, and FIGS. 8 and 9 are front views for explaining the change in the detection amount according to this embodiment with the change in ink level. Is a block diagram showing a configuration example of a control system of the ink remaining amount detecting device according to the present embodiment, FIG. 11 is a flowchart showing an example of the ink remaining amount detecting means, and FIG. 12 is a float applicable to the present invention. FIG. 13 is a schematic diagram showing another configuration example of FIG. FIG. 14 is a schematic diagram showing a configuration example of a light-shielding plate that can be arranged, and FIG. 14 is a waveform diagram showing a state of a light-receiving element for explaining the operation for detecting the ink remaining amount with the configurations shown in FIGS. 12 and 13. . 1 ... Head unit, 2 ... Ink nozzle, 3 ... Ink tank, 3A ... Ink chamber, 4 ... Supply pipe, 5 ... Float, 6 ...
Carriage, 7A ... Light emitting element, 7B ... Light receiving element, 8 ... Holding member, 9,90 ... Light blocking plate, 9A, 90A ... Slit, L ... Infrared ray, LA
… Optical axis, I… Ink.

Claims (1)

(57) [Claims] 1. In an inkjet printing apparatus for printing on a print medium using an inkjet head, an ink containing member for containing ink, and an ink in the ink containing member in a state of being floated on the ink in the ink containing member. A float member movable in the vertical direction according to the amount, the length of the light-transmitting region or the light-shielding region along a predetermined direction different from the vertical direction at a predetermined ratio according to the position in the vertical direction. A float unit having a light-shielding member to be changed, a light-emitting unit and a light-receiving unit, and a sensor unit capable of detecting a light-shielding state by the light-shielding member between the light-emitting unit and the light-receiving unit; Moving means for relatively moving the ink storage member in the predetermined direction, and the predetermined direction of the ink storage member by the moving means. The relative movement of, in accordance with the length of the light shielding state or the light transmitting state of the light shielding area or the light transmitting area detected by the sensor unit, respectively, a detection means for detecting the ink amount in the ink containing member, An inkjet printing device characterized by comprising: