JPH09295440A - Method and device for pressure adjustment of recording head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To adjust the uniformity of a pressure which is applied by a recording head to a recording material being pinched by a method wherein the long-sized recording head and a platen roller being confronted with the recording head, are respectively supported by two sheets of supporting side plates, and at least one of the supporting side plates is moved based on a supporting table, to adjust the parallelism. SOLUTION: The expanded part of a supporting side plate 84b at the lower end, is firmly fixed to a supporting table 102. On the contracy, the lower end part of a supporting side plate 84a, is notched excepting a protruding part 104 at the right lower end, and the left end part turns in the direction shown by arrow (b) with the protruding part 104 as a fulcrum, and the leading end comes into contact with the supporting table 102, and by rotating an adjusting screw 108 which is screwed with a female thread part of an expanded part 106 of the supporting side plate 84a, the left lower end part of the supporting side plate 84a is moved, and the height is changed based on the supporting table 102. As a result, the rotating shaft 61 of a platen roller 60 being rotatably supported by the supporting side plates 84a and 84b with bearings, and a spindle 86 which is the rotating shaft of a thermal head 10, are relatively twisted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording head pressure adjusting method and apparatus for uniformizing a pressure distribution on a recording material by a recording head for recording an image on a recording material, and more specifically to a B4 size and the like. Even for a long recording head that is capable of recording images on recording material with a large thermal sensitivity, the pressure distribution of the recording head applied to the thermal recording material on the platen roller is adjusted to be uniform. The present invention relates to a recording head pressure adjusting method and device.

[0002]

2. Description of the Related Art Image recording using a heat-sensitive recording material such as a heat-sensitive film (hereinafter referred to as a heat-sensitive material or a heat-sensitive film) is used for image recording such as ultrasonic diagnosis. Further, in recent years, image development using a heat-sensitive film (hereinafter, also referred to as heat-sensitive image recording) has advantages such as ultrasonic diagnosis because it does not require wet development processing and is easy to handle. Not only small-sized image recording, but also use for medical diagnosis requiring large-sized images such as MRI diagnosis and X-ray diagnosis is being considered.

As is well known, in thermal image recording, a thermal head is used in which heat-generating elements for image-wise heating a heat-sensitive material to record an image are arranged in one direction, and the thermal head and the heat-sensitive material are connected to each other. Image recording is performed by relatively moving in the direction orthogonal to the arrangement direction. Here, in thermal image recording, energy is supplied to each heating element of the glaze of the thermal head based on an image signal, and each heating element is image-wise heated to heat the heat-sensitive material to perform image recording. To do. Therefore, in thermal image recording, the thermal head, particularly the glaze as the recording portion, is pressed and pressed against the thermal material on the platen.

A pressurizing device for a recording head for printing on thermal paper using such a thermal head and a recording device capable of automatically increasing the relative positional accuracy between the recording head and the platen are disclosed in Japanese Patent Laid-Open No. 7- No. 214864 and No. 7-214867.
In the recording apparatus disclosed in these documents, the opening / closing member 4 is openably / closably connected to the support frame 1, the platen 7 is rotatably supported by the opening / closing member 4, and supports and supports the recording head 10 brought into contact with and separated from the platen 7. A head support plate 9 is provided which is fitted to a support shaft 8 fixed to the frame 1 with a gap and is swingably engaged. And
In these recording devices, when the opening / closing member 4 is in the closed position, the regulating plate 9a which can come into contact with the bearing 6 provided on the opening / closing member 4 to rotatably support the shaft 7a of the platen 7 is provided. Is provided integrally with the head support plate 9, and the recording head 10 is provided with pressurizing means for pressurizing the head support plate 9 so as to elastically contact the platen 7. Thus, the recording apparatus disclosed herein can automatically improve the relative positional accuracy between the recording head and the platen.

[0005]

The recording heads disclosed in these publications are used for printing characters and the like on a small size thermal paper (for example, A6 size) having a width of 108 mm. Since the pressure applied to the platen by the recording head at the time is as high as 2 kgf / 108 mm (platen total length), the pressure is automatically released at the time of non-recording to prevent the platen from being deformed, and the pressure is reduced to 200 gf / 10.
This is for prepressurizing with a light friction so that 8 mm paper can be easily passed.

Therefore, the recording device disclosed herein is
When the opening / closing member 4 is at the closed position, the regulation plate 9a of the head support plate 9 is brought into contact with the bearing 6 of the shaft 7a of the platen 7 by the biasing spring 13, and the recording head 10 is slightly pressed against the platen 7. By urging so as to give a slight friction between the two and 7, only the pre-pressurized state is realized. Therefore, the recording is performed with an accuracy that is acceptable for a small size thermal paper. Head 10 and platen 7
However, when applied to a combination of a long recording head and a long platen roller for image-wise heating a large size thermal film such as A4 size or B4 size, the recording head and the platen roller can be aligned. There has been a problem in that the contact pressure with and is uniformly applied over the entire length of the platen roller, and it cannot always be pressed against the heat-sensitive film on the platen roller at a predetermined uniform pressure during recording. Particularly, a recording head for reproducing a high-quality image and a high-resolution image (for example, 300 dpi), which needs to accurately reproduce a halftone image such as an X-ray diagnostic image, is required to have uniform and appropriate pressure. Therefore, there is a problem in that the parallelism between the recording head and the platen roller, which is necessary, cannot be achieved.

The object of the present invention is to solve the above-mentioned problems of the prior art, and to record even in a recording apparatus using a recording head for recording an image on a recording material such as a large thermal film such as A4 or B4 size. The parallelism between the head and the platen roller can be adjusted with high accuracy, and the uniformity of the pressure applied by the recording head to the recording material sandwiched between the recording head and the platen roller is uniform over the entire length of the recording head. It is an object of the present invention to provide a method and apparatus for adjusting the pressure of a recording head that can be adjusted with high accuracy.

[0008]

In order to achieve the above-mentioned object, the present invention is provided with a long recording head which contacts a recording material at a predetermined pressure to record an image and a recording head which faces the recording head. At least one of the two supporting side plates that respectively support the platen roller that supports and conveys the recording material to be recorded is moved with respect to the support table to which these supporting side plates are attached, and the parallelism between the recording head and the platen roller is increased. And adjusting the uniformity of the pressure applied by the recording head to the recording material sandwiched between the recording head and the platen roller. Is.

Here, the recording head is positioned and fixed from both sides by two head fixing arms, and these head fixing arms are on a straight line connecting the platen roller shaft and the recording position of the recording head. It is preferably fixed to a support shaft pivotally supported by the supporting side plate via a bearing at a remote position. Further, the movement of the at least one supporting side plate is adjusted by an adjusting screw whose tip is in contact with the supporting base and which is screwed into an overhanging portion provided at a substantially right angle below the at least one supporting side plate. It is preferable that one support side plate is fixed to the support base, and the other support side plate is twisted in parallel with the one support side plate.

Further, according to the present invention, a long recording head for contacting a recording material with a predetermined pressure to record an image, a supporting shaft for supporting the recording head, and a recording head provided to face the recording head are provided. Platen roller for supporting and conveying the recording material to be recorded, and two supporting side plates for rotatably supporting the shaft of the platen roller on both sides thereof through bearings and for supporting the shaft on both sides thereof through bearings. And a support base to which these two support side plates are attached,
An adjusting unit that moves at least one of the supporting side plates to adjust the parallelism between the recording head and the platen roller, and the recording material sandwiched between the recording head and the platen roller by the recording head. Pressurizing means for applying the predetermined pressure, by the adjusting means,
At least one of the two supporting side plates is moved with respect to the supporting base to adjust the parallelism between the recording head and the platen roller, and the predetermined pressure applied to the recording material by the pressing unit is adjusted. The present invention provides a pressure adjusting device for a recording head, which is characterized by adjusting the uniformity.

Here, the support shaft is rotatably supported by the support side plate at a position apart from a straight line connecting the platen roller shaft and the recording position of the recording head, and the recording head is configured to perform the recording. It is preferable to provide two head fixing arms that position and fix the head from both sides and are fixed to the support shaft. Further, the adjusting means moves the at least one supporting side plate, and the tip of the adjusting means abuts on the supporting base, and is screwed to an overhanging portion provided at a substantially right angle below the at least one supporting side plate. The adjusting screw is preferably

Further, the pressing means is rotatably supported by the support shaft, and is a head pressing member for pressing the recording head, and the recording member is interposed between the head pressing member and the recording head. A pressure distributing means for uniformly distributing the pressing force to the head, a head pressing arm which is rotatably supported by the support shaft and which engages with the head pressing member to press, and the head pressing arm. And a biasing unit that biases the recording head in a direction to press the platen through the pressing and dispersing unit, a pressing position that presses the head pressing arm by engaging the head pressing member, and the head pressing It is preferable to have a pressure switching cam for switching the engagement of the members to a removable pressure releasing position, and a drive means for driving the pressure switching cam.

Furthermore, it is preferable that the both ends of the recording head have two positioning members that are prepositioned and attached for fixing to the head fixing arm. The head pressing member is supported by the support shaft on both outer sides of the head fixing arm, and has both ends having engaging means for engaging with the head pressing arm provided at a position separated from the supporting point by a predetermined distance. It is preferably a U-shaped member composed of a top plate connecting both ends thereof. Further, the pressing / dispersing means is attached below the top plate of the head pressing member so as to swing about a direction orthogonal to the longitudinal direction of the top plate, and a pressing point for pressing the recording head against the platen is provided. It is preferable that the pressure dispersion member has at least two members.

In the pressure adjusting device for the recording head described above, lock pins that engage with openings at both end portions of the head pressing member are fixed to one end, and an intermediate portion is rotatable at an upper portion of the both end portions. The pressing member has a lock lever having the other end projecting from both ends of the top plate of the pressing member connected to each other by a connecting member, and the head pressing arm is provided on each of the support shafts outside the both ends of the pressing member. The arm comprises two fixed arms, and has a notch hole at the tip thereof to which a lock pin fixed to the lock lever engages, and the biasing means biases at least one of these head pressing arms, The recording head is pressed against the platen via the lock pin, the head pressing member, and the pressing dispersion member, and the pressing position of the head pressing arm by the pressing switching cam. Pressing release position and are preferably positioned a removable position and the locking pin to press the locking pin respectively engaging said notch hole from the cut hole. Here, it is preferable that both ends of the head pressing member further include biasing means for biasing the lock pin in the support shaft direction. Further, it is preferable that the notch hole at the tip of the head pressing arm has a recess in a direction facing the platen for locking the lock pin.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The method and apparatus for adjusting the pressure of a recording head according to the present invention will be described below in detail with reference to the preferred examples shown in the accompanying drawings.

FIG. 1 is a schematic sectional view of an embodiment of a thermal image recording apparatus using a pressure adjusting device for a recording head according to the present invention for carrying out a pressure adjusting method for a recording head (hereinafter referred to as a thermal head) according to the present invention. Is. The thermal image recording device 12 (hereinafter referred to as the recording device 12) shown in FIG. 1 uses a thermal recording material (hereinafter referred to as a thermal film) having a predetermined size, such as B4, a so-called cut sheet thermal film A, Thermal image recording is performed on the thermal film A by the thermal head 10. The thermal head 10 is supported by the loading unit 14, the feeding and conveying unit 16, the recording and conveying unit 18, and the pressure adjusting device of the recording head of the present invention. Further, it has a recording unit 20 and a discharge unit 22 using a pressure supporting device 11 that uniformly pressurizes with an appropriate pressure.

In this recording device 12, a large number of heat-sensitive films A are stacked and housed in a magazine 24 with the heat-sensitive recording layer as the lower surface. The magazine 24 has a lid 26
It is loaded in the loading unit 14 of the recording device 12 in a housing having the. The loading unit 14 includes an insertion opening 30, a guide plate 32, and a guide roll 3 formed in the housing 28 of the recording device 12.
4, 34 and a stop member 36, and the magazine 24
The recording device 12 from the insertion opening 30 with the lid 26 side first.
The recording device 12 is loaded in a predetermined position by being inserted into the recording device 12 and being guided by the guide plate 32 and the guide roll 34, and pushed into a position where it abuts against the stop member 36.

The feeding / conveying means 16 has a sheet feeding mechanism using a suction cup 40, a conveying means 42 and a conveying guide 44, and takes out the thermosensitive film A from the magazine 24 and conveys it to the recording / conveying section 18 downstream in the conveying direction. To do. The conveying means 42 includes a conveying roller 46, a pulley 47a coaxial with the conveying roller 46, a pulley 47b and a tension pulley 47c connected to a rotary drive source, an endless belt 48 stretched around these three pulleys, and a conveying roller. And a nip roller 50 that is pressed against the suction roller 46.
The leading edge of the heat-sensitive film A separated by 0 is nipped by the conveying roller 46 and the nip roller 50, and the heat-sensitive film A is conveyed downstream.

In the recording device 12, when a recording start instruction is issued, the magazine 2 is opened by an opening / closing mechanism (not shown).
The lid 26 of No. 4 is opened, and the sheet-fed mechanism using the suction cup 40 moves the leading end of the heat-sensitive film A in the magazine 24 to the conveying means 42.
It supplies to (conveying roller 46 and nip roller 50). The supplied heat-sensitive film A is transported to the recording transport section 18 by the transport means 42 while being guided by the transport guide 44. When the heat sensitive film A is nipped by the transport roller 46 and the nip roller 50, the suction by the suction cup 40 is released, and when the heat sensitive film A for recording is completely discharged from the magazine 24, The lid 26 is closed by the opening / closing means.

The recording / conveying section 18 has a regulating roller pair 52, a conveying roller pair 56 and a guide 58.
The thermal film A first reaches the regulation roller pair 52 at its tip. Therefore, the distance defined by the transport guide 44 from the transport means 42 to the regulation roller pair 52 is set to be slightly shorter than the length of the heat-sensitive film A in the transport direction. The regulation roller pair 52 is initially stopped, and when the leading end of the heat-sensitive film A reaches the regulation roller pair 52, the thermal head 10
When the temperature of the thermal head 10 is confirmed and the temperature of the thermal head 10 is a predetermined temperature, the transport of the heat-sensitive film A by the regulation roller pair 52 is started (this point will be described later in detail),
It is conveyed to the recording unit 20 while being guided by the guide 58.

The recording unit 20 supports the thermal head 10, the thermal head 10, and the platen roller 60.
Pressurizing support device (hereinafter, simply referred to as a pressurizing device) 11 for the thermal head that presses the guide 11, the guide 62, and the cooling fan 7.
6. The thermal head 10 is supported by a head fixing arm 82 that is rotatable with respect to a support shaft 86 of the pressure device 11. Before the thermal film A is transported,
The head fixing arm 82 rotates the thermal head 10 to a position not in contact with the platen roller 60.
When the leading edge of the thermal film A is transported to the recording start position (the position corresponding to the glaze 70 of the thermal head 10 (see FIGS. 2 and 4)) by the recording transport unit 18, the thermal head 10 and the head fixing arm 82 rotate. The thermal film A is sandwiched between the thermal head 10 and the platen roller 60, and the thermal head 10 is pressed by the pressure device 11 over its entire length.
The heat-sensitive film A above 0 is uniformly pressed with a predetermined pressure.
In this way, the thermal film A is held at a predetermined position by the platen roller 60 and transported downstream, while the thermal image is recorded by the thermal head 10. The thermal head 10 and the pressure device 11 will be described later.

Thermal film A for which thermal image recording has been completed
While being guided by the guide 62, is transported to the platen roller 60 and the transport roller pair 63 and discharged to the tray 72 of the discharge unit 22. The tray 72 is projected to the outside of the recording device 12 through a discharge port 74 formed in the housing 28, and the thermal film A on which an image is recorded is discharged to the outside through the discharge port 74 and taken out.

As shown in FIG. 2, this thermal head 1
Reference numeral 0 denotes a long recording head capable of recording a heat-sensitive image having a recording (pixel) density of about 300 dpi capable of recording an image of a maximum B4 size. The glaze 7
A thermal head body 64 which is a ceramic substrate on which 0 is formed, a heat sink 66 directly fixed to the thermal head body 64, and a planar heater which is attached to a base portion 66a of the heat sink 66 and which preheats the thermal head body 64 to a predetermined temperature. 68 and a thermistor (not shown) for temperature control and a fin 66 of the heat sink 66
The thermal head 69 has a thermal protector 69 for detecting abnormal heating of the thermal head body 64. In the present invention, the configuration of the thermal head 10 and the structure and shape of the heat sink 66 are not limited to the illustrated examples, and for example, the thermal head body 64 is fixed to a metal base such as aluminum, and the heat sink is attached to the metal base. 66 may be fixed, or the fins 6 of the heat sink 66
The structure, shape and arrangement of 6a may be appropriately selected according to the thermal head main body 64 and the glaze 70.

The cooling fan 76 provided near the heat sink 66 of the thermal head 10 constitutes a cooling means together with the heat sink 66. Cooling fan 76
Are arranged in the extending direction of the glaze 70, and the cooling air sucked from the intake port 78 (see FIG. 1) formed in the housing 28 is mainly applied to the fins 66a to cool the fins 66a. The thermal head body 64, and thus the glaze 70, is cooled. It is preferable that the cooling fan 76 is disposed in the fan box 77 communicating with the intake port 78 and selectively takes in cool air outside the apparatus to obtain excellent cooling efficiency.

FIG. 3 shows a thermal film A supporting such a thermal head 10 and on the platen roller 60.
It is a front schematic diagram of the pressurization support device 11 for pressing on above with a predetermined appropriate pressure. As shown in the figure, the pressure supporting device 11 constitutes a platen roller 60 provided to face the thermal head 10, a positioning member 80 of the thermal head 10, a head fixing arm 82, and a supporting frame of the device. A support shaft 86 pivotally supported by the support side plates 84a and 84b via a bearing 85, a head pressing member 88,
The pressure distribution member 90, the lock lever 92, the head pressing arm 94, the tension spring 96, the pressure switching cam 98 (see FIG. 5), and the driving means (not shown) for the pressure switching cam 98.
And a support section 102 for supporting the pressurizing and supporting device 11, and an adjusting section 100 which constitutes the pressure adjusting device which is the most characteristic of the present invention.

The positioning member 80 is the thermal head 10.
Is for accurately adjusting the position of the glaze 70 of the thermal head 10 to the platen roller 60. As shown in FIG.
4 is positioned with respect to the glaze 70, and in the illustrated example, the end face thereof is mounted so as to be separated from the position of the glaze 70 by a distance x. The respective end faces of the two positioning members 80 are provided with positioning pins 81 of the head fixing arm 82.
Alternatively, fix it by hitting it against a protrusion (protrusion). Thus, the accurate and proper position of the glaze 70 of the thermal head main body 64 with respect to the platen roller 60 can be automatically determined. Therefore, in the present invention, the positioning adjustment of the thermal head 10 becomes unnecessary. The head fixing arm 82 is for supporting the thermal head 10, is L-shaped, and has the positioning member 8 at the tip (one end).
0 is fixed using positioning pins 81 and the like, and the top (the other end) thereof is fixed to the support shaft 86 at a position different from the axial center of the platen roller 60. Thus
The thermal head 10 is fixed to a rotatable support shaft 86,
It is rotatably supported.

The head pressing member 88 is for pressing the thermal head 10 against the platen roller 60. As shown in FIGS. 3 and 5, the head pressing member 88 is a U-shaped band plate member, and both end portions (one end thereof) Part 88a has an L-shape that is rotatably supported on the support shaft 86 on both outer sides of the head fixing arm 82, and a top plate 88 that connects the top parts of both end parts 88a.
b. The both end portions 88a are fixed to the lower end portions (open end portions) of both side plates 92a of the lock lever 92 at their (L-shaped) base portions, that is, at positions separated from the supporting point of the head pressing member 88 by the support shaft 86 by a predetermined distance. An opening (oblong hole) 88c with which each of the lock pins 93 is engaged is provided. Openings 88d through which the side plates 92a of the lock lever 92 penetrate are provided in the vicinity of both ends of the top plate 88b (connection portions with the both ends 88a).

The lock lever 92 is for locking and unlocking the pressing of the thermal head 10 against the platen roller 60 by the head pressing member 88, and includes two side plates 92a and these two side plates 92a. And a connecting member 92b for connecting. This side plate 9
A lock pin 93 that engages with the opening 88c of the end 88a of the head pressing member 88 is fixed to one end (open end) of 2a. One end of the tension spring 91 is attached to the lock pin 93, and the other end of the tension spring 91 is attached to the head pressing member 88.
Attached to the end 88a, and the lock pin 93 is opened 88c.
Further, it is preferable to urge the head pressing arm 94 to the pressing position at the inner side of the cutout hole 94a, that is, the lock position. The middle portion of the side plate 92a is rotatably supported at a fulcrum 92c above the end portion 88a. The other end (connection end) of the side plate 92a projects from the opening 88d of the top plate 88b of the head pressing member 88. Therefore, this pressing member 8
The opening 88d of No. 8 is configured to rotate the side plate 92b of the lock bar 92 so that the lock pin 93 can be swung between the locked position and the unlocked position in the elongated hole 88c. Although the lock pin 93 may be directly provided on the head pressing member 88 and the lock lever 92 may be omitted, the lock lever 92 is preferably provided from the viewpoint of easy locking and unlocking by the lock pin 93.

The pressure dispersing member 90 is for making the pressing force of the head pressing member 88 on the platen roller 60 of the thermal head 10 uniform over its entire length.
A swing shaft 90a mounted below the top plate 88b of the head pressing member 88 in a direction orthogonal to the longitudinal direction of the top plate 88b (direction perpendicular to the paper surface in FIG. 3), and a swing shaft below the top plate 88b. A swing plate 90b mounted so as to swing in the direction of arrow a in FIG. 3 around 90a, and pressing pins 90c fixed on both sides of the swing shaft 90a on the lower surface of the swing plate 90b. Swing plate 90b to top plate 88b
And a support pin 90d that swingably supports. Although the two pressing pins 90c directly press the cooling fins 66a of the heat sink 66 of the thermal head 10 at two symmetrical points, the number of the pressing pins 90c, that is, the thermal head 10c.
There are two or more pressing points for pressing the platen roller 60 against the platen roller 60, and the number is not limited as long as the pressing can be performed uniformly.
In the pressure supporting device 11 of the illustrated example, for example, in the case of a heat sensitive film having a base thickness of 175 μm, the pressing force of the thermal head 10, that is, the pressing force to the platen roller 60 is about 7 kg / 257 mm.

The head pressing arm 94 is for applying the pressing force of the thermal head 10 to the head pressing member 88, and the hook-shaped base of the head pressing arm 94 presses the supporting member 86 against the support shaft 86.
Lock pin 93 fixed to the lock lever 92 at the tip of the hook shape of the lock pin 93.
Is a member that has a notch hole 94a that engages with and has an extended portion (handle portion) 94b at the other end of the hook shape that extends for a long time. At least one of these two head pressing arms, in the illustrated example, one end of a tension spring 96 is attached near the tips of both extension portions 94b, and the other end of the tension spring 96 is at the other end.
a and 84b. Thus, the tension spring 96 locks the lock pin 93 of the lock bar 92, which engages with the notch hole 94a of the head pressing arm 94, and the fulcrum 92c.
The thermal head 10 is urged by the pressing pin 90 through the head pressing member 88 rotatably supported by the head pressing member 88 and the pressing dispersion member 90 attached thereto. That is, the pressure applied to the thermal head 10 is applied to the tension spring 96 that constitutes the biasing means.
Notch hole 94a of the head pressing arm 94 by the urging force of
Lock pin 93 fixed to the lock lever 92 by
Fulcrum 92c that pushes down to support the lock lever 92
By pushing down both end portions 88a of the head pressing member 88 by means of the pressure dispersing member 90. Here, the head pressing member 88 and the pressure dispersing member 9
0, the lock lever 92, the head pressing arm 94, the tension spring 96, the pressing switching cam 98, and the driving means of the pressing switching cam 98 constitute the pressing means of the recording head pressure adjusting device of the present invention.

Here, the notch hole 94a opposes the platen roller 60 at the pressing position, that is, the locking position so that the pin lock of the thermal head 10 by the lock pin 93 at the pressing position, that is, the locking position does not come off when pressing. Direction, in FIG. 5, the shape becomes deeper by one step,
That is, it is preferable to have a depression. Even in this case, if the head pressing arm 94 is at the pressing release position shown by the dotted line in FIG. 5, the head pressing member 88 and / or the lock pin 92 or both of them are slightly pushed down to easily move the lock pin 92. The head pressing member 88 and the thermal head 1 are removed from the notch hole 94a.
Since 0 can be rotated and the part of the glaze 70 can be opened upward, it can be easily cleaned.

The pressing switching cam 98 is a head pressing arm 9
4 to a pressing position shown by a solid line in FIG. 5 for pressing the lock pin 93 engaged with the cutout hole 94a and a pressing release position shown by a dotted line in FIG. 5 where the lock pin 93 can be removed from the cutout hole 94a. It is switched, and is driven by a driving means (not shown). The pressure switching cam 98 and its driving means are not particularly limited, and a known cam and its driving means can be applied. Here, the drive means may be a drive source such as a motor that automatically switches and rotates the pressure switching cam 98, or may be a switching lever that performs manual switching.

The most characteristic pressure adjusting device 10 of the present invention
As shown in FIGS. 3, 6 and 7, 0 supports a support shaft 86 for fixing the thermal head 10 via a head fixing arm 82 so as to be rotatable via a bearing 85, and
Support side plates 84a and 84b that rotatably support the rotary shaft 61 of the platen roller 60 via a bearing 85, and a protrusion 104 provided at the lower end of one side end (right end in FIG. 7) of the support side plate 84a. 7, a protruding portion 106 provided vertically below the support side plate 84a, in the bottom portion in FIG. 7, and an adjusting screw 1 that is screwed into a female screw portion provided on the protruding portion 106.
08, brackets 110a and 110b for fixing the support side plate 84a to the support base 102, and the brackets 110a and 110b and the support side plate 84b for the support base 10.
2 and a fixing screw 112 for fixing the brackets 110a and 110b to the supporting side plate 84a. In order to maintain the parallelism between the supporting side plates 84a and 84b, the supporting side plates 84a and 84b are connected to each other by at least one stay (not shown).

Here, the supporting side plate 84b is fixed to the supporting base 102 with the protruding portion at the lower end thereof fixed to the supporting base 102 by a fixing screw 112. On the other hand, the support side plate 84
7A, the lower end portion is cut out except for the protruding portion 104 at the lower right end in FIG. 7, and the left end portion in FIG. 7 is configured to rotate in the arrow b direction with the protruding portion 104 as a fulcrum. Arrow b at the left end of the support side plate 84a with the protrusion 104 as a fulcrum
In the rotation in the direction, the tip end contacts the support base 102, and the adjustment screw 1 is screwed into the female screw portion of the projecting portion 106 of the support side plate 84a.
By rotating 08, the lower left end of the support side plate 84a is moved, and its height is changed with respect to the support base 102. Even if the projecting portion 104 does not project, it can be used as a fulcrum for the rotation of the support side plate 84a by sandwiching a cylindrical spacer and allowing it to rotate freely as a free end.

In this way, the support side plate 84a becomes the support side plate 8
It will be twisted parallel to 4b. At this time,
The stay itself that connects the support side plates 84a and 84b is also made of sheet metal, and has a structure capable of absorbing distortion caused by twisting. As a result, the supporting side plate 84a
The rotary shaft 61 of the platen roller 60, which is rotatably supported by bearings 85 and 84b, and the support shaft 86, which is the rotary shaft of the thermal head 10, are relatively twisted. In this way, the rotary shaft 61 of the platen roller 60 and the thermal head 10 due to processing errors, assembly errors, and mounting errors of the support side plates 84a and 84b, the rotary shaft 61 of the platen roller 60, the support shaft 86 of the thermal head 10, and the like. The deviation of the parallelism with the support shaft 86 can be corrected, and the parallelism of both axes can be adjusted with high accuracy. As a result, the thermal head 10, particularly the glaze 70 thereof, comes into uniform contact with the platen roller 60 in a parallel and straight line, and the pressure applied to the thermal head 10 by the pressurizing means is spread over the entire length of the glaze 70 of the thermal head 10. Can be made even. The adjusting screw 108 functions as a parallelism adjusting means by relative movement (at least one movement) of the supporting side plate of the present invention.

The brackets 110a and 110b are L-shaped members (angles) for fixing the supporting side plate 84a in which the parallelism between the thermal head 10 and the platen roller 60 is adjusted with high accuracy to the supporting base 102, After adjusting the parallelism, the support side plate 84a is fixed by the plurality of fixing screws 112.
Both the support and the support base 102 are respectively fixed, and both are firmly fixed. The brackets 110a and 110b are provided with long holes corresponding to the maximum movement amount so as to be applicable to the movement of the support side plate 84a, and the support side plate 84a and the support base 102 are screw holes into which the fixing screws 112 are screwed. Is provided.

The pressure adjusting device for a recording head according to the present invention is basically constructed as described above. The pressure adjusting method for a recording head according to the present invention will be described in detail below.
When the pressure supporting device 11 of the recording head shown in FIGS. 2 to 5 is assembled, the supporting side plate 84b is firmly fixed to the supporting base 102 with the fixing screw 112. In contrast,
The support side plate 84a is temporarily fixed to the support side plate 84a and the support base 102 using the fixing screws 112 via the brackets 110a and 110b.

After assembly, the pressure supporting device 11 is driven to supply pressure-sensitive pressure-sensitive paper, for example, prescale (manufactured by Fuji Photo Film Co., Ltd.), between the thermal head 10 and the platen roller 60 and allow it to pass. . The degree and uniformity of the coloring (red coloring on the prescale) of the pressure-sensitive paper after passing are visually judged. Here, the force applied between the thermal head 10 and the platen roller 60 is B4 size (2
5 to 15 kg in total (60 mm width), preferably 7 to 9 kg
It is. If the contact pressure between the thermal head 10 and the platen roller 60 varies as a result of the visual determination, for example, if there is left-right variation, the parallelism between the thermal head 10 and the platen roller 60 is poor.

As described above, when the parallelism between the two is poor and the contact pressures between the two vary from side to side, the bracket 1
10a, 110b to support side plate 84a and support base 102
Loosen the fixing screw 112 temporarily fixed to the support side plate 84a.
Is movable with respect to the support base 102. Here, according to the visual judgment of the coloring of the pressure-sensitive paper after passing, the adjustment screw 108 is used to adjust the parallelism between the thermal head 10 and the platen roller 60 by a predetermined amount in the lower left end portion of the support side plate 84a ( 7) is rotated with the protrusion 104 as a fulcrum. Here, the size of the support side plate 84a is about 40 as a rectangle.
When the distance between the axis of the shaft 61 of the platen roller 60 and the fulcrum (protrusion 104) is about 300 mm, and the movement amount of the lower left end of the support side plate 84a is 1 mm, the thermal head 10 The relative movement between the platen roller 60 and the platen roller 60 was 0.1 mm.

After the adjustment with the adjusting screw 108, the brackets 110a and 110b are temporarily fixed to the supporting side plate 84a and the supporting base 102 with the fixing screw 112. After that, the pressure-sensitive pressure-sensitive paper is again passed between the thermal head 10 and the platen roller 60, and the coloring of the pressure-sensitive paper that has passed is visually judged. If there is a color discoloration, repeat the above procedure. As a result, when there is no variation in coloring of the pressure paper passing through or when the pressure is below the allowable limit, the brackets 110a and 110b, the support side plate 84a, and the support base 1 are provided.
The fixing screw 112 that has been temporarily fixed to 02 is tightened with a predetermined torque to firmly fix it. In this way, the supporting side plate 8
By twisting 4a in parallel with the support side plate 84b, the support shaft 86 of the thermal head 10 rotatably supported by these support side plates 84a and 84b via the bearing 85.
The parallelism between the platen roller 60 and the rotary shaft 61 of the platen roller 60 can be adjusted with high accuracy, and the contact pressure between the thermal head 10 and the platen roller 60 can be made uniform over the entire length of the thermal head 10.

In the pressure adjusting method described above, the contact pressure between the thermal head 10 and the platen roller 60 is tested by using a pressure adjusting pressure sensitive paper such as a prescale, but the present invention is not limited to this. Alternatively, the surface pressure of the contact surface between the thermal head 10 and the platen roller 60 may be measured by a sensor such as a gauge, or the support shaft 86 may be used.
The parallelism between the rotary shaft 61 and the rotary shaft 61 may be verified by using a conventionally known measuring method, such as optically measuring the force applied to both ends of both shafts and verifying the contact pressure. . In the illustrated example, the adjusting screw 108 rotates the supporting side plate 84a with the projecting portion 104 as a fulcrum to adjust the parallelism between the thermal head 10 and the platen roller 60, but the present invention is not limited to this. However, as long as the parallelism between the thermal head 10 and the platen roller 60 can be adjusted, the supporting side plate 84b may be rotated, or both the supporting side plates 84a and 84b may be moved to move the relative position between them. It may cause movement. Further, although the brackets 110a and 110b are fixed to the support side plate 84a and the support base 102 by the fixing screws 112, the present invention is not limited to this, and a conventionally known fixing tool or fixing metal fitting that can be firmly fixed may be used. The fixing method is not particularly limited, and a conventionally known method may be used.

Although the method and apparatus for adjusting the pressure of the recording head of the present invention have been described in detail above, the present invention is not limited to these, and various improvements and designs can be made without departing from the scope of the present invention. Of course, you may make changes.

[0043]

As described in detail above, according to the recording head pressure adjusting method and apparatus of the present invention, image recording is performed by using a recording head compatible with large image recording of A4 or B4 size or more. Even in such a case, it is possible to easily adjust the parallelism between the recording head and the platen roller with high accuracy with a simple device configuration. As a result, according to the present invention, the contact pressure between the recording head and the platen roller can be equalized not only on the left and right sides of the recording head but also over the entire length thereof, and the predetermined pressure can be made uniform over the entire length of the recording head. You can call

Further, according to the present invention, since the rotation fulcrum and the adjusting means are provided at a position apart from the position supporting the shaft of the recording head and the platen roller, a large amount of adjustment by the adjusting means can be taken. Therefore, it is possible to easily and accurately adjust the minute deviation and parallelism deviation between the recording head and the platen roller. Therefore, according to the present invention, even if the processing accuracy of the recording head and the platen roller and the supporting side plate that supports them varies, the support base that supports the supporting side plate, or the parallelism of the floor or frame serving as the support base. Even if the flatness of the flat surface is poor, it can be absorbed by using the adjusting means and the adjusting mechanism of the present invention. Therefore, the parallelism between the recording head and the platen roller can be adjusted with high accuracy, and the contact pressure can be maintained over the entire length. The pressure applied during recording to the heat-sensitive recording material can be made uniform. As a result, according to the image recording apparatus to which the present invention is applied, it is possible to always record a high-quality and high-resolution image without density variations.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of an embodiment of a thermal image recording apparatus to which a pressure adjusting device for a recording head according to the present invention is applied.

FIG. 2 is a schematic perspective view of an embodiment of a recording head used in the present invention.

FIG. 3 is a schematic front view of an embodiment of a pressure supporting device for a recording head used in the present invention.

FIG. 4 is a schematic bottom view of an embodiment of a recording head to which a positioning member used in the present invention is attached.

5 is a schematic side view of a pressure supporting device of the recording head shown in FIG.

FIG. 6 is a schematic perspective view of an embodiment of a pressure adjusting device for a recording head according to the present invention.

7 is a schematic front view of the pressure adjusting device for the recording head shown in FIG.

[Explanation of symbols]

 10 Thermal Head 11 Pressure Supporting Device 12 Thermal Image Recording Device 60 Platen Roller 61 Rotating Shaft 80 Positioning Member 82 Head Fixing Arm 84a, 84b Support Side Plate 86 Spindle 88 Head Pressing Member 90 Press Dispersing Member 92 Lock Bar 94 Head Pressing Arm 96 Tensile spring 98 Pressure switching cam 100 Pressure adjusting device 102 Support base 104 Projection portion 106 Overhanging portion 108 Adjustment screw 110a, 110b Bracket 112 Fixing screw

Claims (8)

[Claims] 1. A long recording head which contacts a recording material with a predetermined pressure to record an image and a platen roller which is provided so as to face the recording head and supports and conveys the recording material to be recorded. At least one of the two support side plates is moved with respect to the support base to which these support side plates are attached, the parallelism between the recording head and the platen roller is adjusted, and the recording head and the platen roller are sandwiched. A method of adjusting the pressure of a recording head, comprising adjusting the uniformity of the pressure applied to the recording material by the recording head. 2. The recording head is positioned and fixed from both sides by two head fixing arms, and these head fixing arms are separated from a straight line connecting the platen roller shaft and the recording position of the recording head. The pressure adjusting method for a recording head according to claim 1, wherein the recording head is fixed at a fixed position to a support shaft pivotally supported by the supporting side plate through a bearing. 3. The movement of the at least one support side plate is
The pressure of the recording head according to claim 1 or 2, wherein an end of the recording head is in contact with the support base and is adjusted by an adjusting screw that is screwed into an overhanging portion provided at a substantially right angle below the at least one support side plate. Adjustment method. 4. The movement of the at least one support side plate is
4. The pressure adjusting method for a recording head according to claim 1, wherein one supporting side plate is fixed to the support base, and the other supporting side plate is twisted in parallel with the one supporting side plate. 5. A long recording head for contacting a recording material with a predetermined pressure to record an image, a support shaft for supporting the recording head, and a recording material for recording which is provided so as to face the recording head. A platen roller for supporting and transporting the platen roller, two support side plates for rotatably supporting the shaft of the platen roller on both sides thereof via bearings, and for supporting the support shaft on both sides thereof via bearings, A support base to which the one support side plate is attached; an adjusting unit that moves at least one of the two support side plates with respect to the support base to adjust the parallelism between the recording head and the platen roller; A pressurizing means for applying the predetermined pressure to the recording material sandwiched between the recording material and a platen roller by the recording head, and the adjusting means controls at least one of the two supporting side plates. One of them is moved with respect to the support base to adjust the parallelism between the recording head and the platen roller, and to adjust the uniformity of the predetermined pressure applied to the recording material by the pressing means. A pressure adjusting device for the recording head. 6. The support shaft is rotatably supported by the support side plate at a position away from a straight line connecting the platen roller shaft and a recording position of the recording head, and the recording head is the recording head. The pressure adjusting device for a recording head according to claim 5, further comprising: two head fixing arms that position and fix the head from both sides and are fixed to the support shaft. 7. An overhanging portion provided at a substantially right angle below the at least one supporting side plate by the adjusting means for moving the at least one supporting side plate so that the tip of the adjusting means abuts on the supporting base. 7. The pressure adjusting device for a recording head according to claim 5, wherein the pressure adjusting device is an adjusting screw that is screwed into. 8. The recording means is rotatably supported by the support shaft and presses the recording head, and the pressing means is interposed between the head pressing member and the recording head. A pressure distributing means for uniformly distributing the pressing force to the head, a head pressing arm which is rotatably supported by the support shaft and engages with the head pressing member to press the head pressing arm, and the head pressing arm includes the head pressing member. And a biasing unit that biases the recording head in a direction to press the platen via the pressing and dispersing unit, a pressing position that engages and presses the head pressing arm with the head pressing member, and the head pressing unit. 8. A pressure switching cam for switching the engagement of the members to a removable pressure releasing position, and a drive means for driving the pressure switching cam. The pressure regulating device of the recording head according to.