JPH0464471A - Image recorder - Google Patents

Abstract

PURPOSE:To obtain a small-size structure in which a thermal head can perfectly follow along the peripheral surface of a platen roller by a method wherein pressing springs for pressing the thermal head against the platen roller are provided between a device fixing part and the thermal head. CONSTITUTION:In an action state, a heating surface of a thermal head 24 is positioned on a peripheral surface of a platen roller 4 by the elastic deformation of a leaf spring 22 with a leading end of thermal recording paper X2 clamped between the heating surface and the peripheral surface of the platen roller 4. The heating surface is supported rotatably in the depressing direction of pressing springs 28L, 28R over the full length of the platen roller 4. A depressing force of the heating surface of the thermal head 24 against the peripheral surface of the platen roller 4 is kept longitudinally uniform by the pressing forces of the pressing springs 28L, 28R. If a deviation in parallel relation and an error in machining exist between the platen roller 4 and a head mounting bracket 15, these errors in assembling and machining are absorbed by the deformation of the leaf spring 22.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a thermal image recording apparatus such as a facsimile receiver, and more particularly to an improvement in an image recording apparatus using a contact type thermal head.

1. Prior Art - As is well known, in facsimile receivers and the like, images are recorded on the surface of thermal paper using a so-called line-type thermal head, but this thermal head is separated from the drive roller that feeds the thermal recording paper. It is usually placed in the location recording section. That is, the thermal recording paper is sent to a recording section by the rotational movement of a drive roller that is irregularly driven by a synchronizing signal, and a received image is recorded by a contact type thermal head disposed in this recording section.

Problems to be Solved by the Invention However, in the conventional structure as described above, the drive section for the thermal recording paper, which is composed of a drive roller, etc., and the recording section, in which the thermal head is disposed, are separately provided. This increases the size and complexity of the entire device, which poses an obstacle to downsizing and simplifying the entire device, and is especially an obstacle when making the facsimile receiving section independent from the facsimile transmitting section and making it a desktop type or wall-mounted type. ing.

In addition, in order to solve the problem of device miniaturization,
Conventionally, a method has been proposed in which the drive roller for feeding the thermal recording paper is a platen roller, and the thermal head is brought into direct contact with the circumferential surface of the platen roller to combine the recording paper drive section and the recording section. There is a slight eccentric movement in the rotational movement of the platen roller, and a structure in which a thermal head follows the peripheral surface of the platen roller that performs such eccentric movement has not been realized for a wall-mounted device.

The difficulty in miniaturizing the structure using the platen roller described above also lies in the problem of attaching thermal recording paper when replacing a worn-out thermal recording paper roll. In other words, when replacing a roll of thermal recording paper, the leading edge of the new thermal recording paper must be inserted between the thermal head and the circumferential surface of the platen roller, which are in close contact during operation. This is because it is difficult to request a set operation in such a narrow space.

The first object of the present invention is to miniaturize the thermal head so that it can completely follow the circumferential surface of the platen roller, which performs eccentric movement, in view of the difficulty of the structure in which the thermal head is brought into close contact with the circumferential surface of the platen roller as described above. There is a way to get the structure.

A second object of the present invention is to provide a compact image recording apparatus that has a structure that achieves the first object and allows for easy exchange of thermal recording paper rolls.

A third object of the present invention is to obtain an image recording apparatus that has a structure that can achieve the second object and can alleviate the shock applied to the platen roller.

Means for Solving a Problem - In order to achieve the first object, the present invention uses a rotational movement of a platen roller to feed the heat-sensitive recording paper placed on the peripheral surface in one direction, so that the thermal recording paper is brought into pressure contact with the peripheral surface. In an image recording apparatus that records an image on a thermal recording paper using a thermal head, the central part in the length direction of the thermal head extending along the circumferential surface of the platen roller is fixed to the device fixing part and the base part is fixed to the apparatus fixing part. is fixed to the tip of a leaf spring extending in a direction substantially parallel to the platen roller, and is placed between the device fixing part on both sides of the leaf spring and the thermal head to press the thermal head toward the circumferential surface of the platen roller. This paper proposes an image recording device equipped with springs.

Further, according to the present invention, the second object is to form an opening for inserting and removing the thermal recording paper roll in the recording paper storage case that accommodates the thermal recording paper roll, and to form an opening portion at one end for supporting the platen roller. a head that is rotatably supported on a fulcrum shaft provided in the recording paper storage case with the end plate of the ""-shaped support bracket facing the opening portion, and fixed to the recording paper storage case while facing the platen roller; The base of a leaf spring extending in a direction substantially parallel to the platen roller is fixed to the longitudinal center of the mounting bracket, and the longitudinal center of the thermal head that records an image on thermal recording paper is fixed to the tip of the leaf spring. and press the thermal head toward the circumferential surface of the platen roller by means of a pressure spring interposed between the head mounting bracket and the thermal head while being positioned on both sides of the plate spring, and move the thermal head to the recording position. This is achieved by an image recording apparatus in which the support bracket, which is biased in one direction by a buffer spring that is loaded at a certain time, is locked by a manually operable lock lever.

According to the present invention, the third object is to form an opening through which the thermal recording paper roll can be inserted into and removed from the recording paper storage case that accommodates the thermal recording paper roll, and to support a platen roller at one end. The end plate of the U-shaped support bracket is rotatably supported on a fulcrum shaft provided in the recording paper storage case in a state facing the opening portion, and fixed to the recording paper storage case in a state facing the platen roller. The base of a leaf spring extending in a direction substantially parallel to the platen roller is fixed to the longitudinal center of the head mounting bracket, and the longitudinal center of the thermal head for recording an image on thermal recording paper is fixed to the longitudinal center of the leaf spring. The thermal head is pressed toward the circumferential surface of the platen roller by a pressing spring fixed to the tip and positioned on both sides of the plate spring and interposed between the head mounting bracket and the thermal head, and the recording is performed. One end of the buffer spring is fixed in a cantilever manner to the end wall surface of the paper storage case, and a pair of buffer protrusions are provided that can contact the tips of the buffer spring, respectively, when the support bracket is in the operating position and the open position. This is achieved by an image recording device provided on the support bracket.

Example Embodiments of the invention will now be described in detail with reference to the drawings.

The image recording apparatus according to the illustrated embodiment is a desk facsimile receiver designed as a wall-mountable type, and this desk facsimile receiver is equipped with a recording paper storage case 1 which is open at the top and can accommodate a thermal recording paper roll X. There is. That is, this recording paper storage case 1 is resin-molded in the shape of an elongated box with an open upper part, and its left and right end walls IL and IR are
A "U"-shaped mounting slot 3 is formed in which receives both ends of the center pipe 2 inserted through the paper bobbin x1 of the thermal recording paper roll X. Therefore, the thermal recording paper roll X housed inside the recording paper storage case 1 with its center supported by the central vibrator 2 is in a state where it can freely rotate.

On the outer surfaces of the left and right end walls of the recording paper storage case 1,
A support bracket 5 that supports a platen roller 4, which will be described later.
A first fulcrum shaft 1a serving as a rotation fulcrum is integrally molded, and these first fulcrum shafts 1a include left and right end plates 5L, 5R, and a transverse bracket 5A that connects these left and right end plates 5L, 5R.
A support bracket 5 is rotatably supported. That is, the left and right end plates 5L face the open portion of the recording paper storage case 1.

5R, both end shafts 4a of the platen roller 4 are rotatably supported. As shown in FIG. 2, a driven gear 6 is fixed to the shaft end of the platen roller 4.
The final gear 7a of the reduction gear train 7 is meshed with. Further, as shown in FIG. 2, a drive unit mounting board 8 to which the reduction gear train 7 is assembled is fixed to the outer surface of the right end wall IR of the recording paper storage case 1, and a step motor fixed to the drive unit mounting board 8 is fixed to the outer surface of the right end wall IR of the recording paper storage case 1. The drive pinion 10 of 9 is meshed with the first stage gear 7b of the reduction gear train 7, and the rotational motion of the step motor 9, which has been decelerated by the reduction gear train 7, is transmitted to the platen roller 4. Therefore, the platen roller 4 is driven to rotate in the direction of the arrow in FIG. will be sent irregularly.

Further, extraction prevention claws 5B protruding into the mounting slot 3 are bent on the surfaces of the left and right end plates 5L, 5R of the bracket. Therefore, when the facsimile receiver is tilted by 90 degrees from the state shown in FIG. Extraction from the server is prevented.

On the other hand, a pair of buffer protrusions 5C and 5D are integrally molded at the lower portions of the left and right end plates 5L5R of the support bracket 5, respectively, and are opposed to the direction of rotation of the support bracket 5 about the first fulcrum shaft 1a. A tip 14a of a buffer spring 14 held by a mounting pin 13 is disposed on the end wall surface of the recording paper storage case 1 facing the protrusions 5C and 5D, and when the support bracket 5 is in the operating position shown in FIG. The spring 14 is biased by the buffer projection 5C. Therefore, the support bracket 5, which is in the operating position in FIG. 3, is biased toward the open position in FIG. 5 by the stored force of the M impulse spring 14. Also, just before the support bracket 5 reaches the open position, the M impact spring 14
The tip 14a of the buffer spring 14 contacts the buffer protrusion 5D.
Since the platen roller 4 and the support bracket 5 are elastically deformed, the shock applied to the platen roller 4 and the support bracket 5 during the opening movement is M-impacted.

Returning to FIG. 1, a head mounting bracket 15 is fixed to the upper part of the recording paper storage case 1 so as to face the platen roller 4. As shown in FIG. That is, the head mounting bracket 15 to which the static elimination brush 16 is fixed has a pair of fixed ends 15L and 15R bent at right angles, and the fixing screw 21 can be inserted into these fixed ends 15L and 15R. A fixing hole 18 and a positioning groove 19 are formed. Therefore, the head mounting bracket 15 is attached to the recording paper storage case 1.
When fixing to the end walls IL and IR of the recording paper storage case 1.
The corresponding positioning grooves 19 are engaged with the positioning pins 20 on the outer surface, and the fixing shafts 1b of the same end walls IL and IR are fixed using the fixing screws 21.
By fixing the corresponding fixed ends 15L and 15R,
The relationship between the recording paper storage case 1 and the head mounting bracket 15 can be stabilized.

Further, a base portion 22a of a plate spring 22 extending in a direction substantially parallel to the platen roller 4 is fixed to a longitudinally central portion of the head mounting bracket 15 using a mounting screw 23;
The tip end 22b of the leaf spring 22 is fixed to the thermal head 24 via a rigid bracket 25 fixed to the back surface of the thermal head 24 in the longitudinal direction. A pair of stopper brackets 26L, 26R or setscrews 27 are fixed to the left and right sides of the back surface of the thermal head 24 to restrict the movable range of the thermal head 24 relative to the head mounting bracket 15.
The bent ears 26a are freely inserted into position regulating grooves 15a formed on the upper surfaces of the fixed ends 15L and 15R of the head mounting bracket 15.

In addition, the bent portions 2 of the stopper brackets 26L and 26H
6b contacts the bearings 4b inserted in the shafts 4a at both ends of the platen roller 4, the leaf spring 22 is loaded with energy, and the heat generating surface of the thermal head 24 is positioned on the circumferential surface of the platen roller 4. The plate spring 22 is connected between the inner surface of the head mounting bracket 15 and the back surface of the thermal head 24.
A pair of pressure springs 28L and 28R are interposed on both sides of the recording paper storage case 1, and these pressure springs 28L and 28R press the heat generating surface of the thermal head 24 toward the circumferential surface of the platen roller 4. ILIR on the left and right end walls of
A second fulcrum shaft IC serving as a fulcrum for the left lock lever 29 and the right lock lever 30 is integrally molded on the outer surface, and the connecting member 3
The bases of the left lock lever 29 and the right lock lever 30, which are integrated with each other in FIG. 1, are respectively attached to the second fulcrum shaft 1c. That is, the left lock lever 29 and the right lock lever 30
A corresponding end plate 5L of the support bracket 5 is provided at the tip end of the support bracket 5,
Lock grooves 29a and 30a are formed that can be engaged with the lock bin 32 fixed to the surface of 5R. As shown in FIG. 2, the right lock lever 30 includes an arm 30b on which the other end of a return spring 33 whose one end is fixed to the mounting hook 8a of the drive unit mounting board 8 can be hooked, and a recording paper storage case. It has an operating arm 30c that protrudes to the outside of 1,
The operating arm 30c is provided with an opening knob 34 that can be operated with a fingertip in the direction of the arrow in FIG. Therefore, since the force of the return spring 33 urges the support bracket 5 in the counterclockwise direction in FIG. , hold the release knob 34! When you operate lJ,
Due to the stored force of the buffer spring 14, the support bracket 5 is opened toward the open position shown in FIGS. 5 and 6.

Since the facsimile receiver according to the illustrated embodiment has the structure described above, each member in the receiving state is at each position shown in FIGS. 2 to 4. That is, in this operating state,
The buffer spring 14 is biased by contact with the buffer protrusion 5C,
By locking the left lock lever 29 and the right lock lever 30, the support bracket 5 and the platen roller 4 are in the illustrated position. In this operating state, with the leading edge of the thermal recording paper x2 being sandwiched between the peripheral surface of the platen roller 4, the heat generating surface of the thermal head 24 is moved around the platen roller 4 due to the elastic deformation of the leaf spring 22. The pressing spring 28L is positioned on the peripheral surface of the platen roller 4 and extends over the entire length direction of the platen roller 4.

It is rotatably supported in the pressing direction of the thermal head 28R, and the pressing force of the heat generating surface of the thermal head 24 against the circumferential surface of the platen roller 4 is exerted by the pressing spring 28L.

The pressing force of 28R keeps the left and right sides even. Therefore, even if there is an imbalance in the parallel relationship or a machining error between the platen roller 4 and the head mounting bracket 15, the leaf spring 22
These assembly errors and processing errors are absorbed by the deformation.

Therefore, in the reception operation state, the platen roller 4 is rotationally driven by the synchronization signal, the thermal recording paper X2 is sent, and an image is recorded by the thermal head 24. Even if the peripheral surface of the platen roller 4 moves eccentrically due to an error, the thermal head 24 easily follows the eccentric movement due to the elastic deformation of the leaf spring 22. As a result, an image can be reliably recorded by the thermal head 24 without being affected by the eccentric movement of the platen roller 4, so it is possible to provide a compact image recording device with a simple configuration.

When replacing the thermal recording paper roll
When manually operated in the direction of the arrow in Fig. 2, the left lock lever
29 and locks 129a and 3Qa of the right lock lever 30
is removed from the lock bin 32, the support bracket 5 is moved around the first fulcrum shaft 1a by the accumulated force of the buffer spring 14.
is rotated clockwise in FIG. For this reason, as shown in FIG. 6, the open part of the recording paper storage case 1 is exposed to the outside, so the worn out thermal recording paper roll X is taken out and a new thermal recording paper roll X is inserted into the recording paper storage case 1. It is possible to easily restore the receiving state by simply restoring the support bracket 5 in the counterclockwise direction in FIG. In the case of this recovery, the leading end of the thermal recording paper x2 of the thermal recording paper roll By restoring, the thermal recording paper x is placed between the platen roller 4 and the thermal head 24.
Since the leading end of the thermosensitive recording paper x2 can be reliably fed, the user can easily replace the thermal recording paper x2.

Effects of the Invention - As is clear from the above description, according to the present invention, the longitudinal center portion of the thermal head for recording an image is fixed to the tip of the plate whose base is fixed to the device fixing portion. Therefore, even if the platen roller that feeds the thermal recording paper moves eccentrically, the thermal head reliably presses against the entire lengthwise circumferential surface of the platen roller. An image recording device can be obtained.

Further, according to the present invention, since the support bracket for supporting the platen roller is rotatably attached to the recording paper storage case that accommodates the thermal recording paper roll, the thermal recording paper roll can be replaced. However, it is possible to achieve a structure that allows the thermal recording paper to be easily replaced.

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view of essential parts of a facsimile receiver according to the present invention, FIG. 2 is a right side view of the same facsimile receiver, and FIG.
The figure is a left side view of the same facsimile receiver, Figure 4 is a sectional view of the same facsimile receiver in an operating state, Figure 5 is a left side view of the same facsimile receiver when the thermal recording paper X20 is replaced, and Figure 6 is a left side view of the same facsimile receiver. The figure is a sectional view corresponding to FIG. 4 of the same facsimile receiver when the thermal recording paper X20 is replaced. X... Heat-sensitive recording paper roll, 1... Recording paper storage case, 4... Platen roller, 5... Support bracket, 15... Head mounting bracket, 22... Leaf spring, 24...・Thermal head, 26L, 26R...stopper bracket, 29.30
...Lock lever Fig. 6/Patent applicant Iwasaki Tsushinki Co., Ltd. r)

Claims (1)

[Claims] 1) An image recording device that sends thermal recording paper placed on the circumferential surface in one direction by the rotational movement of a platen roller, and records an image on the thermal recording paper using a thermal head that is pressed against the same circumferential surface. A longitudinal center portion of the thermal head extending along the circumferential surface of the platen roller is fixed to a tip portion of a leaf spring whose base portion is fixed to a device fixing portion and extends in a direction substantially parallel to the platen roller. An image recording apparatus characterized in that a pressing spring for pressing the thermal head toward the circumferential surface of the platen roller is disposed between the device fixing part and the thermal head on both sides of the leaf spring. 2) Form an opening in the recording paper storage case that accommodates the thermal recording paper roll, through which the thermal recording paper roll can be inserted and removed, and attach the end plate of the "U"-shaped support bracket that supports the platen roller at one end to the opening. A head mounting bracket is rotatably supported on a fulcrum shaft provided in the recording paper storage case in a facing state, and is fixed to the recording paper storage case in a state facing the platen roller. The base of a leaf spring extending in a substantially parallel direction is fixed, the longitudinal center portion of a thermal head for recording an image on thermal recording paper is fixed to the tip of the leaf spring, and the thermal head is located on both sides of the leaf spring. In this state, a pressure spring interposed between the head mounting bracket and the thermal head presses the thermal head toward the circumferential surface of the platen roller, and a buffer spring that is biased when in the recording position presses the thermal head in one direction. An image recording apparatus characterized in that the supported bracket that is pushed is locked by a manually operable lock lever. 3) Form an opening in the recording paper storage case that accommodates the thermal recording paper roll, through which the thermal recording paper roll can be inserted and removed, and attach the end plate of the "U"-shaped support bracket that supports the platen roller at one end to the opening. A head mounting bracket is rotatably supported on a fulcrum shaft provided in the recording paper storage case in a facing state, and is fixed to the recording paper storage case in a state facing the platen roller. The base of a leaf spring extending in a substantially parallel direction is fixed, the longitudinal center portion of a thermal head for recording an image on thermal recording paper is fixed to the tip of the leaf spring, and the thermal head is located on both sides of the leaf spring. In this state, a pressure spring interposed between the head mounting bracket and the thermal head presses the thermal head toward the circumferential surface of the platen roller, and one end of the buffer spring is pressed against the surface of the end wall of the recording paper storage case. An image recording apparatus, characterized in that the support bracket is provided with a pair of buffer protrusions that can be fixed in a cantilever manner and can contact the tips of the buffer springs when the support bracket is in an operating position and an open position.