JP2001199083A - Ink jet type image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect automatically that a joint member of an ink supply tube is connected to an ink tank. SOLUTION: The joint member 12 is provided at one end of the ink supply tube 15 supplying ink from an ink bottle to the ink tank in a print head 14. An ink supply pipe 3 of the joint member 12 is inserted into the ink tank in the print head 14. It is detected by an optical sensor comprised of a light- emitting part 5 and a light-receiving part 4 whether or not the joint member 12 is connected to a prescribed position of the print head 14. An operation mode is switched over in accordance with the presence or absence of the ink in the ink bottle detected by a means for detecting this presence or absence and with the presence or absence of the connection of the joint member 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet type image forming apparatus for forming an image on a recording medium by discharging ink, and more particularly to an image forming apparatus for supplying discharged ink to a print head through a tube. .

[0002]

2. Description of the Related Art Conventionally, an image forming apparatus such as an ink jet type printer or a plotter which discharges ink to form an image on a recording medium includes, for example, a print head having a nozzle for discharging ink and a print head having the nozzle. It has a carriage that carries a head and reciprocates in a predetermined direction. In order to reduce the weight of the reciprocating carriage, there is an upper limit on the amount of ink contained in the print head.

Therefore, as shown in FIG. 8, a large-capacity ink bottle 1 is set at a fixed position in the apparatus away from the carriage.
0, and an ink supply device that supplies ink from the ink bottle 10 to the print head 14 via the ink supply tube 15 is used. The ink buffer 8 is disposed between the ink bottle 10 and the ink supply tube 15, and the ink 16 is stored in the ink buffer 8 from the ink bottle 10 via the connection pipe 17. The presence or absence of the ink 16 in the ink buffer 8 is detected by the ink presence / absence detection sensor 9. This makes it possible to indirectly detect that the ink in the ink bottle 10 has run out. One end of the tube 15 is disposed in the ink buffer 8, and the other end is inserted into an ink tank 20 formed in the print head 14 via the joint member 12. As the ink tank 20 of the print head 14, there is known an ink tank which is surrounded by a hard wall or a flexible bag which is spread by a leaf spring. In the example of FIG. 8, a sponge 13 that absorbs ink is disposed in an ink tank 20 surrounded by a hard wall. The nozzle 11 is arranged below the print head 14.

As shown in FIG. 8, the ink supply of the ink supply device is performed by connecting a joint member 12 connecting an ink supply tube 15 and a needle-like ink supply tube 3 to a print head 14.
Of the print head 1 from the large-capacity ink bottle 10 through the ink supply tube 15.
4 is supplied with ink. The ink stored in the ink tank 20 is discharged from the nozzle 11 (FIG. 8).

When ink to be supplied to the ink bottle 10 runs out, the ink presence / absence detection sensor 9 detects this and warns the user of the absence of ink. Thereby, the user is instructed to remove the joint member 12 from the print head 14, and printing is performed until the ink in the ink tank 20 of the print head 14 is used up. When the ink in the ink tank 20 runs out, an instruction is issued to simultaneously replace the ink bottle 10, the print head 14, and the ink tank 20 from the viewpoint of the durability of the print head 14.

[0006]

However, in the conventional example, when the joint member is inserted into the print head,
In some cases, the connection to the print head was incomplete. Therefore, if a slight gap is formed between the print head and the joint member, air enters from the outside and causes the air volume inside the ink tank to fluctuate. As a result, the pressure acting on the ink stored in the ink tank fluctuates, and the amount of ink supplied to the nozzles also fluctuates. When the supply amount of ink fluctuates, the amount of ink ejected from the nozzle also fluctuates, and there is a possibility that the image quality is degraded.

[0007] When the ink in the ink bottle is depleted, as described above, the user is required to remove the joint,
The mode was shifted to a mode in which the ink in the ink tank of the print head was used up. However, if the user forgets to remove the joint when the ink in the ink bottle is depleted, there is no ink in the ink supply tube, and a large amount of air may enter the ink tank in the print head, resulting in deterioration of image quality. there were.

[0008] On the other hand, there is a type in which an ink tank and a tube are integrated, and a flexible bag-shaped one whose periphery is spread by a leaf spring as described above is used. In this case, since the air volume in the ink tank is adjusted by the leaf spring, the fluctuation is small, and the amount of ink ejected from the nozzle is relatively stable. Further, there is no gap between the supply tube and the ink tank. However, the use of leaf springs and flexible bags complicates the structure of the ink tank, and if the durability of the ink tank is not semi-permanent, it must be replaced integrally with the tube when replacing it. There is a problem that maintenance becomes essential.

The present invention has been made under such a background, and an object of the present invention is to automatically detect that a joint member of an ink supply tube is connected to an ink tank. An object of the present invention is to provide an inkjet type image forming apparatus.

Another object of the present invention is to provide an ink jet type image forming apparatus capable of setting an appropriate operation mode in accordance with the presence / absence of connection of a joint member and the presence / absence of ink in an ink bottle.

[0011]

According to the present invention, there is provided an ink jet type image forming apparatus having a print head mounted on a carriage which reciprocates in a predetermined direction. An ink bottle provided at a fixed position in the apparatus and storing ink, an ink supply tube for supplying ink from the ink bottle to the ink tank, and an ink supply tube provided at one end of the ink supply tube and inserted into the ink tank A joint member having an ink supply pipe to be
And a detecting means for detecting that the joint member is connected to a predetermined position of the print head.

With this configuration, it is possible to automatically detect whether or not the joint member is connected to the ink tank.

The detecting means has a light emitting part and a light receiving part,
The light emitted from the light emitting unit to the light receiving unit is blocked by the joint member, thereby detecting that the joint member is coupled to a predetermined position of the print head. Alternatively, the detecting means may include a conductive member provided at a portion of the joint member that contacts the print head, a plurality of contact portions provided at a portion of the print head contacting the conductive member, Circuit means for detecting the presence or absence of contact between the plurality of contact portions and the conductive member.

[0014] The inkjet type image forming apparatus includes:
Detecting means for detecting the presence or absence of ink in the ink bottle, and control means for switching an operation mode according to the presence or absence of ink in the ink bottle and the presence or absence of coupling of the joint member detected by the detecting means. It may be further provided. This makes it possible to set an appropriate operation mode according to the presence or absence of the joint of the joint member and the presence or absence of ink in the ink bottle.

In this case, a warning means for generating a warning to a user according to the presence or absence of ink in the ink bottle and the presence or absence of coupling of the joint member may be further provided. The contents of this warning will be described in detail in an embodiment.

[0016]

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

The first embodiment of the present invention is provided with a means for detecting whether or not a joint member connecting a print head and an ink supply tube is at a predetermined position, and a joint detection sequence using the same. It is.

As shown in FIG. 1, a specific configuration of a joint member at a predetermined position above a print head 14 is provided by a light emitting unit 5 and a light receiving unit 4 as separate optical sensors provided on a carriage 6, as shown in FIG. 12 is detected. If the joint member 12 is at a predetermined position on the print head 14, the light from the light emitting unit 5 of the optical sensor is blocked without being received by the light receiving unit 4, and no electric signal is generated from the light receiving unit 4. As a result, the joint member 12 is
It is confirmed that it is bound to. Incidentally, reference numeral 25 in FIG. 1 denotes an ink stopper lever for preventing the flow of ink in the tube 15 when necessary. A rail 7 movably supports the carriage 6, and a cutter 22 cuts the roll paper.

FIG. 2 shows a case where the joint member 12 is detached from the print head 14. In such a case, a storage section 18 for storing the joint member 12 is provided on the carriage 6. If the joint member 12 is not connected to the print head 14, the light from the light emitting unit 5 is received by the light receiving unit 4 and converted into an electric signal. by this,
It is detected that the joint member 12 is not connected to the ink tank 20.

FIG. 3 shows an example of a joint detection sequence using such a mechanism. This process is performed periodically, for example, when an instruction to start printing is given or at the end of printing.

In the process of FIG. 3, first, the presence or absence of a joint member mounted on the print head is checked by an optical sensor (S11). Further, the presence or absence of ink in the ink bottle is checked (S12). This may be performed indirectly by checking the presence or absence of ink in the ink buffer (8 in FIG. 8) as described above.

As a result of these checks, if the joint member is connected to the print head and there is ink in the ink bottle, the operation is recognized as the tubing mode (S14). The tubing mode is an operation mode for automatically replenishing a shortage of ink in an ink tank from an ink bottle via a tube.

If there is no ink in the ink bottle and the joint member is mounted on the print head, a warning is issued to the user as an error (S15). The warning in this case is
It instructs the user to remove the joint member and shift to the use-up mode, or prompts the user to replace the ink bottle. The one-time use mode is a mode in which printing is continued without supplying ink to the ink tank in the print head until the current ink in the ink tank runs out. In this use-up mode, since the target is to use up the ink in the print head, it is preferable to detect the presence or absence of the ink in the print head by a sensor. During the single use mode, the ink in the head is detected each time one sheet of paper is printed. When the ink runs out, the user is instructed to replace the head. Any known means for detecting ink in the head can be used.

When no joint member is detected (S1)
(1; No), when there is no ink in the ink bottle (S13, No), the mode shifts to the single use mode (S1).
6). However, although no joint member is detected (S
(11, No), if ink remains in the ink bottle (S13, Yes), it is determined that the joint member is incorrectly mounted, and an error warning is issued (S15). The warning in this case urges the user to confirm the attachment of the joint member, for example.

FIG. 4 shows a main control hardware configuration for realizing the embodiment of the present invention. In this example,
The ink bottle ink presence / absence detection sensor 102, the print head ink presence / absence detection sensor 106, and the joint detection sensor 104 (the light emitting unit 5 and the light receiving unit 4 in FIG.
The MPU 101 operates according to the flowchart shown in FIG. Also, MP
U101 drives the print head 14 via the head drive circuit 103.

Next, a second embodiment of the present invention will be described.

FIG. 5 shows details of the insertion portion of the joint member 12 of the print head 14 according to the second embodiment. In the above embodiment, the joint member 12 is
Although the optical device determines whether or not the joint member 12 is attached to the predetermined position, the present embodiment intends to detect a reliable mounting state of the joint member 12 by another method. is there.

In this embodiment, for this purpose, the terminal plate 1 is provided at the joint member insertion portion of the print head 14, and a GND metal plate (a short-circuiting conductive member) is provided at a corresponding portion of the joint member 12 as shown in FIG. 2 is provided. FIG.
As shown in (b), in this embodiment, four contact portions 1a, 1b, 1c, and 1d are arranged on the terminal plate 1 on the periphery of the insulating substrate 1e at substantially equal intervals. At the center of the substrate 1e, an opening 1f through which the ink supply pipe 3 passes is provided.

When the joint member 12 is securely attached to the joint member insertion portion of the print head 14,
The respective contact portions 1a, 1b, 1c, 1d of the terminal plate 1 are mutually short-circuited by the GND metal plate 2. To assist this operation, a mechanical holding mechanism or a magnet is used between the joint member 12 and the joint member insertion portion of the print head 14, although not shown, by fitting an uneven portion between the two. A holding mechanism may be provided.

The contact portions 1a, 1b, 1c, 1d are connected to a circuit as shown in FIG. In the circuit of FIG. 7, when the contact portions 1a and 1b are pulled up via resistors 114 and 115, respectively, a negative input AND gate (N
(Equivalent to an OR gate) 112. The contact portion 1 c is pulled up via a resistor 116 and connected to an input terminal of the inverter 113. Contact part 1d
Is grounded. The outputs of the negative input AND gate 112 and the inverter 113 are input to the NAND gate 111. N
The output of the AND gate 111 is input to the input port of the MPU 101. With such a circuit configuration, the contact portion 1
a, 1b, 1c are the GND metal plates 2 of the joint member 12
Respectively, the output of the NAND gate 111 changes to the L level via the gate 112 and the inverter 113. By detecting this with the MPU 101, it can be confirmed that the joint member 12 is securely attached to the print head 14. For example, when the joint member 12 is attached to the print head 14 at an angle, the contact portions 1a, 1
b, 1c does not contact the contact portion 1d, and N
The output of the AND gate 111 becomes H level. In such a case, a warning can be issued to urge the user to check the attachment state of the joint member 12.

While the preferred embodiment of the present invention has been described above, various modifications and changes can be made within the scope of the invention described in the claims.

[0032]

According to the present invention, by detecting the presence or absence of the connection of the joint member of the ink supply tube to the print head, the connection state can be recognized without the user's visual observation. Poor connection between the print head and the joint can be prevented. Further, the operation mode can be automatically switched according to the detection result.

[Brief description of the drawings]

FIG. 1 is a side view showing a configuration of a carriage on which a print head according to a first embodiment of the present invention is mounted (a state in which a joint member is removed from the print head).

FIG. 2 is a side view illustrating a configuration of a carriage on which a print head is mounted (a state in which a joint member is mounted on the print head) according to the first embodiment of the image forming apparatus according to the present invention.

FIG. 3 is a flowchart showing an example of a joint detection sequence of the present invention related to FIGS. 1 and 2;

FIG. 4 is a block diagram showing a main control hardware configuration for realizing an embodiment of the present invention.

FIG. 5 is a side view of a print head according to a second embodiment of the present invention, showing a joint member insertion portion of the print head, with a portion of the print head cut away.

6A is a diagram illustrating a state in which a joint member is attached to the print head in FIG. 5; FIG. 6B is a diagram illustrating a plan view of a terminal plate;

FIG. 7 is a circuit diagram of a circuit used in a second embodiment of the present invention for detecting a reliable mounting state of a joint member.

FIG. 8 is an explanatory diagram of a conventional technique.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 terminal plate 2 GND metal plate 3 ink supply tube 4 light receiving unit 5 light emitting unit 6 carriage 7 rail 8 ink buffer 9 ink presence / absence detection sensor 10 ink bottle 11 nozzle 12 joint member 13 sponge 14 print head 15 ink supply tube 16 ink 17 connection Tube 18 Storage section 25 Ink stopper lever

Claims (5)

[Claims] An ink jet type image forming apparatus having a print head mounted on a carriage which reciprocates in a predetermined direction, an ink tank provided in the print head, and an ink tank provided in a fixed position in the apparatus to store ink. An ink bottle; an ink supply tube for supplying ink from the ink bottle to the ink tank; a joint member provided at one end of the ink supply tube and having an ink supply tube inserted into the ink tank; And a detecting means for detecting that the print head is coupled to a predetermined position of the print head. 2. The apparatus according to claim 1, wherein said detecting means has a light emitting unit and a light receiving unit.
The ink jet type image forming apparatus according to claim 1, wherein the light emitted from the light emitting unit to the light receiving unit is blocked by the joint member to detect that the joint member is coupled to a predetermined position of the print head. apparatus. 3. The printing apparatus according to claim 2, wherein said detecting means includes a conductive member provided at a portion of said joint member contacting said print head, and a plurality of contact portions provided at portions of said print head contacting said conductive member. 2. The ink jet type image forming apparatus according to claim 1, further comprising: a circuit for detecting whether or not the plurality of contact portions are in contact with the conductive member. Detecting means for detecting the presence or absence of ink in the ink bottle; and detecting presence / absence of ink in the ink bottle detected by the detection means and presence / absence of connection of the joint member.
4. A control means for switching an operation mode, further comprising:
The inkjet type image forming apparatus as described in the above. 5. The apparatus according to claim 4, further comprising warning means for generating a warning to a user in accordance with the presence / absence of ink in said ink bottle and the presence / absence of connection of said joint member. Ink jet type image forming apparatus.