JPH10193637A - Small-sized printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To hold a movable range of a head large and to always hold a distance and angle between the head and a recording medium constant by tiltably supporting a recording means to a body of a printer, and connecting an ink storage means to the recording means by an ink supply tube having flexibility. SOLUTION: A head unit 14 integrally constituted by a recording head 12 and a roller 13 is provided at a lower part of a body, and a body housing 1a is oscillatorily connected to the unit 14 by a linkage. The unit 14 holds a predetermined attitude to a recording medium even in the state that the housing 1a is inclined, thereby suitably printing. A tube 14 for connecting an ink tank to the head is synthesized with flexible resin. Thus, a movable range of the unit 14 for holding the distance and angle between the head 12 and the medium is lengthened to increase an angle for holding the attitude constant.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small-sized printing device for a user to hold a device by hand and to print a predetermined pattern on a recording medium such as paper, and more particularly to supply ink to a recording means. The present invention relates to an ink tank.

[0002]

2. Description of the Related Art Heretofore, small-sized printing apparatuses have been proposed as apparatuses for printing on various recording media at desired locations. In this printing apparatus, printing is performed by a user manually scanning the printing apparatus at an arbitrary speed on a recording medium and ejecting ink to the recording medium from a recording head according to the amount of movement. In a small-sized printing apparatus of this type, an ink tank for supplying ink to an inkjet head is fixed to the head, and the head and the ink tank have an integral structure. In addition, regardless of the posture of the housing held by the user's hand, the distance and angle between the inkjet head and the recording medium are always kept constant, and a stable printing operation can be performed. The applicant has previously proposed.

[0003]

However, in a small-sized printing apparatus in which the angle of the ink-jet head section can be freely changed as described above, the head is configured to be tiltable with respect to the apparatus main body (housing). In the case of the integrated structure in which the ink jet head and the ink tank are directly fixed and connected as described above, the movable range of the head is limited because the unit including the head and the ink tank is large.
For this reason, it may be difficult to keep the distance and angle between the head and the recording medium constant at all times.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and provides a flexible space between an ink tank and an ink jet head when the head is configured to be tiltable with respect to the apparatus main body. By connecting with a certain tube, the movable range of the head can be widened, the distance and angle between the head and the recording medium can be always kept constant, and small printing that can perform stable printing operation It is intended to provide a device.

[0005]

According to a first aspect of the present invention, there is provided a small-sized printing apparatus which scans a recording medium manually, automatically, or semi-automatically (runs). In a small printing apparatus including a recording unit that performs printing by discharging ink thereon and an ink storage unit that stores ink supplied to the recording unit, the recording unit tilts with respect to a main body of the device. Freely supported,
The ink storage means and the recording means are connected by a flexible ink supply pipe.

In the above arrangement, the recording means and the ink storage means are connected by a flexible ink supply pipe, so that the recording means and the ink storage means can be installed separately. The unit provided with the recording means can be reduced in size. Thus, when the recording unit is configured to be tiltable with respect to the main body in order to keep the distance and angle between the recording unit and the recording medium constant, the conventional ink storage unit and the recording unit are configured as one unit. Since the movable range of the recording means can be made larger than that which is performed, a stable printing operation can be performed.

According to a second aspect of the present invention, there is provided a small-sized printing apparatus according to the first aspect, wherein the ink storage means and the ink supply pipe are integrally formed.

In the above configuration, since the ink storage means and the ink supply pipe are integrally formed, air bubbles are less likely to be formed in the ink supply pipe, so that the number of purges required when replacing the ink storage means can be reduced. . In addition, the ink storage means can be easily replaced.

According to a third aspect of the present invention, there is provided a small-sized printing apparatus according to the first or second aspect, wherein a spring member is provided around the ink supply pipe. .

In the above configuration, since the spring member is provided around the ink supply tube, the ink supply tube can be protected by the spring member, and the strength can be improved.

According to a fourth aspect of the present invention, there is provided a small-sized printing apparatus according to the first or second aspect, wherein the ink supply pipe is a flexible member incorporating a metal wire. It is formed.

In the above configuration, the strength of the ink supply tube can be improved by incorporating a metal wire into the ink supply tube.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A small printing apparatus according to an embodiment of the present invention will be described below with reference to the drawings. FIG.
FIG. 3 is a perspective view showing a state of printing by the printing apparatus according to the present invention. The printing device 1 is an inkjet printing device that performs printing by scanning on a recording medium P such as paper.
At the lower part of the main body housing 1a (main body), a recording head 12 for performing printing by ejecting ink, and rollers 13 for running the printing apparatus 1 on the recording medium P
Unit (recording means) 1 integrally configured with
4 are provided. The main body housing 1a is swingably connected to the head unit 14 in a scanning direction and a direction orthogonal to the scanning direction by a link mechanism 21 and a link mechanism 24 (FIG. 2 and thereafter) described later. Thus, even when the main body housing 1a is in a tilted state, the head unit 14 is configured to maintain a constant posture with respect to the recording medium P and perform appropriate printing. Details of this configuration will be described later. Further, a cap 35 is provided on the main body housing 1a to protect the head unit 14 during non-printing. When printing is performed by the printing apparatus 1, the printing apparatus 1 is placed at a desired printing start position on the recording medium P as shown in the drawing, and
The printing device 1 is scanned in the direction of the arrow. In accordance with the movement of the printing device 1 by this scanning, ink is ejected from the recording head 12 and printing is performed on the recording medium P. The small printing apparatus 1 is configured so that it can be divided into two parts, a control part and a head part, in the vicinity of the central part.
It is divided when the ink cartridge is mounted on the head. Details of the method of mounting the ink cartridge will be described later.

Main body housing 1a and head unit 14
The configuration of the connection portion with the will be described with reference to FIG.
FIG. 2A is a perspective view illustrating a configuration of the head unit 14,
(B) is a perspective view schematically showing a connection mechanism between the main body housing 1a and the head unit 14, and (c) is a side view of (b). The head unit 14 includes a head holder 14 a that supports the recording head 12, and an encoder unit 14 b that supports the roller 13 and includes an encoder for detecting the amount of rotation of the roller 13 therein. The recording head 12 is configured such that a fixed gap is maintained between the recording head P and the recording medium P by the lower portion of the head holder 14a and the rollers 13.

A tube portion (ink supply pipe) 15 for guiding ink from an ink tank (storage means) (not shown) to the recording head 12 is connected to a connection portion 12a provided on the upper portion of the recording head 12, and a manifold is provided. Ink is supplied to the recording head 12 via 12b. Details of the configurations of the ink tank and the tube section 15 will be described later. Further, the recording head 12 is connected to an FPC (flexible printing circuit) 16 for inputting a control signal from a control unit (not shown) for controlling the operation of the entire printing apparatus 1. The encoder in the encoder unit 14b is also connected to the control unit by the FPC 17. The head holder 14a is provided with shafts 23a and 23b for attaching a link mechanism described later.

The head unit 14 includes the head unit 1
4 is connected to the main body housing 1a via a holder 19 provided above. Main body housing 1a and holder 19
Are connected by a link mechanism 21 configured by crossing arms. This link mechanism 2
Reference numeral 1 designates three arms, namely, a pair of arms 21b rotatably provided on shafts 18b and 20b on both sides of the main body housing 1a and the holder 19 facing each other, and a main body housing 1a and a central portion of the upper surface of the holder 19. Axis 18a. 20a.

The holder 19 and the head unit 14 are
A four-node link mechanism where nodes intersect, that is, a link mechanism 24 formed by crossing two arms, is provided with shafts 22a, 22b, 23a, and 23b provided on opposite side surfaces.
Are rotatably provided as a pair. The arms 21b and 21b of the link mechanism 21 for connecting the main body housing 1a and the holder 19 are arranged on the surface in the scanning direction, respectively.
Link mechanism 2 between holder 19 and head unit 14
The two pairs of the four arms 24a and 24b are disposed on the surface at right angles to the scanning direction. With the above configuration,
The main body housing 1a can swing in the Y direction in the figure with respect to the recording medium P by the connection by the link mechanism 21, and can swing in the X direction (printing direction) in the figure by the connection by the link mechanism 24. .

Next, the swing of the head unit 14 with respect to the holder 19 by the link mechanism 24 will be described with reference to FIGS.
This will be described with reference to FIG. FIG. 3 is a sectional view showing a state in which the head unit 14 is not swinging, and FIG.
4 is a sectional view showing a state where the head unit 14 swings in the printing direction, and FIG. 5 is a sectional view showing a state where the head unit 14 swings in the direction opposite to the printing direction. As described above, the link mechanism 24
Is composed of two crossed arms 24a and 24b. In a normal state, that is, in a state in which no force is applied to the main body housing 1a in the printing direction or in the opposite direction, the arms 24a and 24b move the head unit 14 to the main body housing 1a as shown in FIG. It is set to be parallel to In this state, when a force is applied to the main body housing 1a in the printing direction, the arm 24a is accordingly moved around the shaft 22a.
b rotates counterclockwise in the figure around the shaft 22b. As a result, as shown in FIG.
4 swings in the printing direction with respect to the holder 19, and the main body housing 1a
While maintaining the same posture as in the normal case, tilt in the printing direction.

When a force is applied to the main body housing 1a in a direction opposite to the printing direction from the normal state, the arm 24a is centered on the shaft 22a and the arm 24b is centered on the shaft 22b. Rotate clockwise. As a result, as shown in FIG.
Reference numeral 4 swings in the direction opposite to the printing direction with respect to the holder 19, and the main body housing 1a tilts in the direction opposite to the printing direction while maintaining the attitude of the head unit 14 with respect to the recording medium P in the same manner as in normal times. . At this time, a force is applied to the link mechanism 21 connecting the holder 19 and the main body housing 1a in a direction perpendicular to the plane on which the arms 21a and 21b rotate, so that the head unit 14 swings by the link mechanism 21. Absent.

Next, the swing of the holder 19 and the head unit 14 with respect to the main body housing 1a by the link mechanism 21 will be described with reference to FIGS. FIG. 6 is a sectional view showing a state where the holder 19 and the head unit 14 are not swinging, and FIG.
FIG. 4 is a cross-sectional view showing a state in which the reference numeral 4 swings forward when viewed from the user. As described above, the link mechanism 21 is composed of three arms set to cross each other, that is, a pair of arms 21 b attached to the side surface of the holder 19 and an arm 21 a attached to the upper surface of the holder 19. In a normal state where no force is applied to the main body housing 1a on the front side or the opposite side when viewed from the user,
The arms 21a and 21b are, as shown in FIG.
The head unit 14 is set so as to be parallel to the main body housing 1a. From this state, when a force is applied to the main body housing 1a in a direction toward the user as viewed from the user, that is, in the right direction in the figure, the arm 21a
The arm 21b rotates counterclockwise in the figure around the shaft 18a and around the shaft 18b. As a result, FIG.
As shown in the figure, the holder 19 and the head unit 14 swing rightward, that is, toward the front side as viewed from the user, and the main body housing 1a changes the posture of the head unit 14 with respect to the recording medium P in the same manner as in the normal state. While keeping it, tilt it toward you as viewed from the user. At this time, the link 2 connecting the holder 19 and the head unit 14 has the arm 2
Since a force is applied in a direction perpendicular to the plane on which the 4a and 24b rotate, the head unit 14
There is no swing.

Although not particularly shown, when a force is applied to the main body housing 1a from the normal state in a direction opposite to the front side as viewed from the user, that is, in the left direction in the figure, the arm 21a is accordingly actuated. The arm 21b rotates clockwise about the axis 18a about the axis 18a. As a result, the holder 19 and the head unit 14 swing with respect to the main body housing 1a in a direction opposite to the front side as viewed from the user, and the main body housing 1a sets the posture of the head unit 14 with respect to the recording medium P as normal. In the same way, the user leans away from the user. Again,
There is no swing of the head unit 14 by the link mechanism 24. In FIG. 6, a detection switch 3 for detecting the presence or absence of the recording medium P is provided on the left side of the head unit 14a.
0 is provided.

Next, the movement of the head unit 14 between the printing area and the non-printing area will be described with reference to FIGS.
This will be described with reference to FIG. FIG. 8A is a cross-sectional view showing the printing apparatus 1 in a state where the head unit 14 is in a printing area, FIG. 8B is a cross-sectional view showing the printing apparatus 1 in a state where the head unit 14 is in a non-printing area, and FIG. a) to (g)
Are the link mechanism 21 and the rotating arms 32a, 3a when the head unit 14 moves between the print area and the non-print area.
It is the side view which showed operation | movement of 2b part sequentially. The shafts 31a, 3d connected by gears 31c, 31d meshed with each other are provided on the upper portions of the shafts 18a, 18b of the link mechanism 21.
1b is provided. The shafts 31a and 31b are connected to the shafts 18a and 18b of the link mechanism 21 by rotating arms 32a and 32b, respectively. In this configuration,
When the shaft 31b is rotated counterclockwise, the shaft 31a rotates clockwise due to the engagement of the gear 31c and the gear 31d. As the shafts 31a and 31b rotate, the rotating arms 32a and 32b also rotate clockwise or counterclockwise, respectively.

When the rotating arms 32a and 32b rotate as described above, the rotating arms 32a and 32b
Arms 21a and 21 respectively connected to the tip of 2b
b moves sequentially as shown in FIGS. 9 (a) to 9 (g). By the movement of the arms 21a and 21b, the holder 19 and the head unit 14 connected to the arms 21a and 21b are moved from the print area position shown in FIG.
It is moved upward to the non-printing area position shown in FIG. Each of the rotation arms 32a and 32b has a rotation angle of 90 degrees.
The arm 21a, 21b is set to be at the uppermost position when the arm 21a is moved 90 degrees (FIG. 9 (g)).

Next, a gear mechanism 33 for rotating the shaft 31b will be described with reference to FIGS. FIG. 10 is a sectional view showing the printing apparatus 1 and the gear mechanism 33 in a state where the head unit 14 is in the non-printing area. A cap (cap member) 35 for protecting the head unit 14 is provided on the outer periphery of the main body housing 1a.
Is provided. The cap 35 is configured to be slidable with respect to the main body housing 1a,
A rack 35a that meshes with the gear 33a is formed. The gear mechanism 33 includes a gear 33a that converts a linear motion of the rack 35a into a rotary motion, and a shaft 31b of the rotary arm 32b.
A gear 33b having a large diameter that is coaxial with the shaft 31b and that rotates, and a gear 33c that transmits the rotation of the gear 33a to the gear 33b.

In the rack 35a and the gear mechanism 33 configured as described above, when the cap 35 is moved downward when the head unit 14 is in the printing area (see FIG. 6), the rack 35a moves downward. With gear 3
3a rotates counterclockwise in FIG. The gear 33c meshing with the gear 33a rotates clockwise, and the gear 33b meshing with the gear 33c rotates counterclockwise. This gear 33
Due to the counterclockwise rotation of b, the shaft 31b and the rotating arm 32b also rotate in the counterclockwise direction. Shaft 31b and Shaft 31
Since a is meshed with the gears 31c and 31d, the shaft 31a and the rotating arm 32a rotate clockwise symmetrically with the shaft 31b and the rotating arm 32b. By this rotation, the rotation arms 32a and 32b move the arms 21a and 21b of the link mechanism 21 as shown in FIGS. 9A to 9G, so that the holder 19 and the head unit 14 move upward. And moves to the non-printing area shown in FIG. When moving the head unit 14 from the non-printing area to the printing area, the cap 35 is moved upward, and the gears of the gear mechanism 33 and the rotating arms 32a, 3a are moved.
2b and the shafts 31a, 31b are rotated in the opposite direction.

As described above, according to the printing apparatus 1 of the present embodiment, when the cap 35 is moved, the linear movement of the cap 35 is converted into the rotational movement by the rack 35a and the gear mechanism 33, and the rotation is performed on the shafts 31b and 31a. Since the rotation is transmitted and the rotation arms 32a and 32b rotate symmetrically, the arms 21a and 21b of the link mechanism 21 rotate symmetrically to move the head unit 14 upward and housed in the main body housing 1a. I do. Thereby, the head unit 14
Can be freely inserted into and removed from the main body housing 1a, so that the possibility that the head unit 14 is exposed from the main body housing 1a due to an erroneous operation when the head unit 14 is stored can be reduced. In addition, the printing device 1 during non-printing can be made compact.

Next, a configuration of the ink cartridge of the small printing apparatus 1 according to the present embodiment and a method of mounting the ink cartridge to the apparatus 1 will be described with reference to FIGS. FIG. 11A is a front view of the ink cartridge, and FIG. 11B is a sectional view of the ink cartridge.
The cartridge 40 includes a tank part 41 storing ink, a tube part 15 connecting the tank part 41 and the recording head 12, and a tank cover 42 covering the tank part 41 and the tube part 15. . Guide windows 43 are provided at the lower ends of both side surfaces of the tank cover 42, and guide rods 44 protrude from the guide windows 43. The tube 15 is made of a flexible resin, and one end of the tube 15 is connected to the tank 41 in advance. The other end of the tube portion 15 has a valve 45 and is supported by a guide rod 44.

FIG. 12 is a cross-sectional view of the printing apparatus 1 viewed from the printing direction for explaining a method of mounting the ink cartridge 40 to the small printing apparatus 1. FIG.
Printer 1 as viewed from the printing direction showing the state after mounting 0
FIG. 14 is a cross-sectional view of the printing apparatus 1 viewed from a direction perpendicular to the printing direction, showing a state after the cartridge 40 is mounted. In FIG. 14, the tank cover 42 of the cartridge 40 is omitted. The upper end of the connection portion 12a (FIG. 12) of the print head 12 has a shape obtained by diagonally cutting off a hollow cylinder, and the cut end has a blade shape.
A flange 46 is provided in the middle of the connection portion 12a. A guide groove 47 for moving the guide rod 44 of the ink cartridge 40 along the inside of the main body housing 1a is provided. The guide groove 47 is bifurcated at the lower end (see FIG. 14), and when the head unit 14 swings in the printing direction, the guide rod 44
Are configured not to hinder the movement of the head unit 14. To mount the ink cartridge 40 on the device 1, the user loosens the screw portion 50 (FIG. 12) and divides the device 1 into two parts, a control unit (not shown) and a head unit 51.
The guide rod 44 of the cartridge 40 is inserted into the guide groove 47 of the main body housing 1a of the head portion 51. Next, the cartridge 40 is inserted into the head portion 51 along the guide groove 47, and a force is applied to the cartridge 40 from above in a state where the valve 45 of the tube portion 15 of the cartridge 40 is in contact with the upper end portion of the connection portion 12a. . When the upper end of the connection portion 12a breaks the valve 45 of the tube portion 15, the tube portion 15 is connected to the connection portion 12a, and the mounting of the ink cartridge 40 ends.

As described above, in the small printing apparatus 1 of the present embodiment, since the tank 41 and the recording head 12 are connected via the tube 15, the conventional tank 41 and the recording head 12 are integrated. The size of the head unit 14 can be reduced as compared with the structure. Accordingly, in order to keep the distance and angle between the recording head 12 and the recording medium P constant, the head unit 14 is connected to the main housing 1.
When the main unit 1a is tilted during the printing travel, the posture of the head unit 14 with respect to the recording medium P can be increased. The angle that can be kept constant increases, and a stable printing operation can be performed. Further, since the tube portion 15 is flexible, the link mechanism 21 or 24 causes the head unit 14 to be inclined with respect to the main body housing 1a, or the rotating arms 32a and 32b cause a printing area to a non-printing area. Even when the head unit 14 moves between
The movement of the head unit 14 is not hindered. In addition, since the tank portion 41 and the tube portion 15 are integrally formed in the ink cartridge 40, the tube portion 1 is formed.
5, it is difficult to form air bubbles in the ink cartridge 40.
Since the number of purges required when replacing the ink cartridge can be reduced, waste of ink can be reduced.

The present invention is not limited to the configuration of the above embodiment, and various modifications are possible. For example, in the above-described embodiment, the tube portion 15 is made of a flexible resin. However, the tube portion 15 may be provided with a spring member around the tube portion 15. In this configuration, since the tube portion 15 is protected by the spring member, the tube portion 15 is less likely to be damaged. In addition, the tube part 15
Is less likely to bend and the flow of ink is stagnated.

The tube portion 15 may be formed of a flexible member incorporating a metal wire. In this configuration, the strength of the tube portion 15 is increased, so that the tube portion 15 is hardly deteriorated.

In the above-described embodiment, a manual scanning type printing apparatus is described as a small printing apparatus. However, the present invention is not limited to this, and a printing method in which the printing head scans automatically or semi-automatically (runs). The same applies to devices.

[0033]

As described above, according to the first aspect of the present invention, the ink storage means and the recording means are connected by a flexible ink supply pipe. Therefore, the recording means and the ink storage means can be installed separately. Accordingly, in a small-sized printing apparatus configured such that the recording unit is tiltable with respect to the main body, the distance and the angle between the recording unit and the recording medium can be kept constant. Since the range can be made large, the range in which the attitude of the recording unit with respect to the recording medium when the main body is tilted can be kept constant, and a stable printing operation can be performed.

According to a second aspect of the present invention, there is provided a small-sized printing apparatus according to the first aspect, wherein the ink storage means and the ink supply pipe are integrally formed. In addition, air bubbles are less likely to be generated in the ink supply pipe, and the number of purges required when replacing the ink storage means can be reduced. Further, the replacement work of the ink storage means is facilitated.

According to a third aspect of the present invention, there is provided the small-sized printing apparatus according to the first or second aspect, wherein a spring member is provided around the ink supply pipe. Therefore, the ink supply pipe is protected by the spring member, and the ink supply pipe is hardly damaged. In addition, it is less likely that the ink supply pipe is bent and the flow of ink is interrupted.

According to a fourth aspect of the present invention, there is provided the small-sized printing apparatus according to the first or second aspect, wherein the ink supply pipe is provided with a flexible metal wire. Since it is formed of a member, the strength of the ink supply tube is improved, and the ink supply tube is hardly deteriorated.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a printing state by a small printing apparatus according to an embodiment of the present invention.

FIG. 2A is a perspective view showing a configuration of a head unit.
(B) is a perspective view schematically showing a connection mechanism portion between the main body housing and the head unit, and (c) is a side view of (b).

FIG. 3 is a cross-sectional view illustrating a state where the head unit is not swinging.

FIG. 4 is a cross-sectional view illustrating a state in which the head unit swings in the printing direction.

FIG. 5 is a cross-sectional view showing a state where the head unit swings in a direction opposite to a printing direction.

FIG. 6 is a sectional view showing a state where the holder and the head unit are not swinging.

FIG. 7 is a cross-sectional view showing a state in which the holder and the head unit swing toward the user as viewed from the user.

FIG. 8A is a cross-sectional view showing a small printing apparatus in a state where the head unit is in a printing area, and FIG. 8B is a cross-sectional view showing the small printing apparatus in a state where the head unit is in a non-printing area.

FIGS. 9A to 9G are side views sequentially showing the operations of the link mechanism and the rotating arm when the head unit moves between the print area and the non-print area.

FIG. 10 is a cross-sectional view illustrating the small printing apparatus and the gear mechanism in a state where the head unit is in a non-printing area.

FIG. 11A is a front view of an ink cartridge mounted on the small printing apparatus according to the present invention, and FIG. 11B is a cross-sectional view showing an internal configuration of the ink cartridge.

FIG. 12 is a cross-sectional view of the small printing apparatus for explaining a method of mounting the ink cartridge.

FIG. 13 is a cross-sectional view illustrating the small printing apparatus in a state where the ink cartridge is mounted as viewed from the printing direction side.

FIG. 14 is a cross-sectional view showing the small printing apparatus in a state where the ink cartridge is mounted, as viewed from a side orthogonal to the printing direction.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Small printing apparatus 1a Main body housing (main body) 15 Tube part (ink supply pipe) 14 Head unit (recording means) 41 Ink tank part (ink storage means) P Recording medium

Claims (4)

[Claims] A recording means for ejecting ink onto the recording medium to perform printing by being scanned on the recording medium; and an ink storing means for storing ink supplied to the recording means. In the small printing apparatus, the recording unit is supported so as to be tiltable with respect to a main body of the device, and the ink storage unit and the recording unit are connected by a flexible ink supply pipe. Small printing device. 2. The small printing apparatus according to claim 1, wherein said ink storage means and said ink supply pipe are integrally formed. 3. The small printing apparatus according to claim 1, wherein a spring member is provided around the ink supply pipe. 4. The small printing apparatus according to claim 1, wherein the ink supply pipe is formed of a flexible member incorporating a metal wire.