JPH07172007A - Image input / output device - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To provide an image input / output device capable of reducing the frictional resistance received from the image input / output device of the conveying means and performing a stable sheet conveying operation. In a thermal line printer equipped with a platen roller 1 having a B4 size width and a thermal line head unit 6, when the A4 size roll paper is conveyed, the thermal line head unit 6 is in direct contact with the platen roller 1. Since the friction coefficient of the area B is smaller than that of the area A in which the roll paper is interposed, even if the thermal line head unit 6 is directly contacted with the stepping motor 3, the stepping motor 3 does not step out and is stable. The sheet conveying operation can be maintained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image input / output device such as a facsimile, a printer or a scanner, and more particularly to an image input / output device which conveys an image input / output device while pressing it against a sheet.

[0002]

2. Description of the Related Art In recent years, various kinds of information have been digitized, and information processing of these kinds of information can be performed centrally by a computer. In such an information environment, for example, in a retail store or the like, one computer is used to manage and process product data, and a bar code reader is used as a register,
It is desired to centralize information processing and reduce the cost for investment in information by performing FAX / PC communication or the like.

Image input / output devices such as printers and scanners are necessary for information processing by these computers. Here, the condition required for the image input / output device is that a plurality of types of paper sizes can be used because it must be compatible with various applications. A recording device using a photosensitive drum, such as a laser beam printer or a digital copying machine, can satisfy this condition. In particular, recently, digital copiers have evolved intelligently, and devices with advanced functions have been developed and commercialized, such as models that can print out directly from floppy disks and complex models with laser FAX. . These devices are generally relatively large, require a large footprint, and are very expensive.

Therefore, another image input / output device that can use a plurality of paper sizes is a facsimile device equipped with a thermal line printer. This is for conveying an image input / output device while pressing it against a platen roller via paper in a recording unit.
The platen roller, the image input / output device, the pressing spring, the platen drive motor, the reduction gear, etc. can provide relatively small and inexpensive products. In order to support a plurality of paper sizes, the image input / output device only needs to be adjusted to the largest size, and the structure is simple.

[0005]

However, in the above image input / output device, in the case of a thermal line printer capable of recording on, for example, B4 size paper or small receipt paper, a B4 size thermal head is used for receipt size paper. Must be recorded. At this time, the head and the platen roller are in direct contact with each other in a fairly wide range. The frictional force at the direct contact portion between the head and the platen roller is so large that the motor for driving the platen roller may be stepped out, and the sheet conveying operation may not be normally performed.

An object of the present invention is to solve the above-mentioned problems of the prior art and to provide an image input / output apparatus capable of reducing the frictional resistance received from the image input / output device of the conveying means and performing a stable sheet conveying operation. Especially.

[0007]

A typical means for solving the above-mentioned problems of the prior art and applied to the embodiments described below is to press the image input / output device through the sheet to the conveying means while pressing the sheet. In the image input / output device to convey
When a narrow sheet is conveyed, a means for reducing a frictional force generated by direct contact between the conveying means and the image input / output device in a region other than the sheet width is provided.

[0008]

According to the above means, when a narrow sheet is set and conveyed, the friction force generated by the direct contact between the conveying means and the image input / output device in the area other than the sheet width is reduced and conveyed.

[0009]

【Example】

 [First Embodiment]

An image input / output device using the above means will be described below with reference to the drawings. This embodiment will be described using a thermal line printer as an image input / output device.
FIG. 1 is an explanatory diagram showing an internal configuration of the thermal line printer, FIG. 2 is a sectional explanatory diagram of the thermal line printer, and FIG.
FIG. 3 is a block diagram showing a control system of the device.

First, a schematic configuration of a thermal line printer will be described with reference to FIGS. 1 and 2. In FIG. 1, 1 is a platen roller, and a sheet (roll paper in this embodiment) is a thermal line head unit 6 to be described later.
The paper is conveyed while being pressed. The rotating shaft of the platen roller 1 is rotatably supported by a bearing 2 attached to a main body housing 19 shown in FIG. A stepping motor 3 is fixed to the main body housing 19 and meshes with a platen gear 5 fixed to the shaft end of the platen roller 1 via a gear 4 rotatably attached to the main body housing 19. . The stepping motor 3
When is activated, the platen roller 1 is driven via the platen gear 5 to convey the sheet.

In the platen roller 1, the width of the roller portion is about 265 mm, and the area A formed in the central portion of FIG. 1 and the area B formed on both sides thereof have different friction coefficients with respect to the thermal line head unit 6. . The area A has a width of about 205 mm around CC ', and the area B is the remaining width portion. As the material of the roller, urethane rubber is used in the area A and silicon rubber is used in the area B. The manufacturing method uses a method of first molding one region and then molding the other region.

A thermal line head unit 6 is fixed to the head holder 7. The thermal line head unit 6 is provided with a heating element in the longitudinal direction. In this embodiment, one dot of 0.125 mm square heating element corresponding to the B4 width is arranged in one row of 2048 dots.
It is arranged to face the platen roller 1. The center line CC 'of this heating element and the center line of the roller width of the platen roller 1 are aligned. When the thermal line head unit 6 contacts the platen roller 1, the head holder fork portion 8 sandwiches the bearing 2 to position the heating element of the thermal line head unit 6 with respect to the platen roller 1.

Reference numeral 9 is a right roll paper guide, 10 is a left roll paper guide, the rack portions of which mesh with the paper guide gears 11, respectively, and the guide rails 12 and 13 extend in the opposite direction by the same distance in the width direction. It is movably attached to the main body housing 19. Therefore, no matter what width the roll paper is set, the center line of the paper width is configured to coincide with CC '.

Next, referring to FIG. 2, the head holder 7 is rotatably supported about a holder mounting shaft 14. The holder mounting shaft 14 is slidably supported in a mounting hole 16 formed in the upper case 15 of the main body. Reference numeral 17 denotes a head pressing spring, the upper and lower ends of which are connected between the upper case 15 of the main body and the head holder 7 so that the thermal line head 6 is brought into close contact with the platen roller 1. As shown in FIG. 1, the platen roller 1 has two parts A and B.
There are two regions, and it is conceivable that a slight step will occur at the boundary of these two regions even if they are made with high precision. The head pressing spring 17 brings the platen roller 1 and the thermal line head unit 6 into close contact with each other with such strength that the influence of the step does not appear in recording.

The upper case 15 of the main body is an upper case opening / closing shaft 18
Can be opened and closed by rotating around. As shown in FIG. 2, when the main body upper case 15 is closed on the main body housing 19, the head pressing spring 17 tries to lift the main body upper case 15 by its restoring force. Since the hook 15a and the hook 19a formed on the main body housing 19 are engaged with each other, the main body upper case 15 is not opened. When the hook 15a is disengaged, the head pressing spring 17 extends, so that the head holder 7 is attached to the holder mounting shaft.
Although it tries to rotate in the direction of arrow D about 14, it hits the hook 7a formed on the upper case 15 of the main body, stops, and is fixed to the upper case 15 of the main body.

There are two types of roll paper used in this embodiment, A4 size and B4 size.
By. This paper width sensor 20 is
It is fixed to the roll paper compartment 21 formed inside 19,
It is provided at one location outside the A4 size paper width. The paper width sensor 20 is a switch, and when the roll paper is set, the paper width sensor 20 is turned on / off depending on whether or not the roll paper is present, and only detects whether or not the paper width is B4. The paper width sensor 20 can discriminate various paper widths by increasing the number of paper width sensors 20, but the basic configuration principle is the same.

Next, the structure of the control system of the thermal line printer will be described with reference to the block diagram shown in FIG. The thermal line head unit 6 includes a 2048-bit thermal line head 6a composed of 2048 heating elements,
It has a 2048-bit latch register 6b for storing corresponding data during heating with 1 dot = 1 bit, and a 2048-bit shift register 6c for temporarily storing recording data for heating. The thermal line head unit 6 includes a CPU 22 such as an external computer device.
The recording data transmission signal 23 for the shift register 6c, the latch signal 24 for controlling the data transfer from the shift register 6c to the latch register 6b for the latch register 6b, and the heating element by the latch data for the thermal line head 6a. The strobe signal 25 for controlling the execution of heat is transmitted to control the operation. The CPU 22 controls the thermal line head unit 6 in two ways by the sensor signal 26 from the paper width sensor 20 which is different depending on whether the roll paper is A4 or B4. The stepping motor 3 is also controlled by the CPU 22 by the two excitation signals 27 and the hold signal 28.

The sheet conveying operation of the thermal line printer constructed as described above will be described first with reference to FIG.
Open the upper case 15 of the main body shown in, and roll paper guides 9 and 10
After sliding to match the paper width, the roll paper is set in the roll paper storage unit 21. At this time, the external CP shown in FIG.
U22 is 1 if the set roll paper is B4 size
Since the recording data of the line is 2048 bits, the recording data is controlled so as to be sent up to 2048 bits from the beginning of the shift register 6c of the thermal line head unit 6, and if the recording data is A4 size, the recording data of 1 line is 1680 bits. The shift register 6c is controlled to send "0" data up to 184 bits ((2048-1680) / 2) from the beginning of the shift register 6c and then send the recording data for one line. Thus, even if the roll paper size is different, the center line of the paper width can always be aligned with the center line CC ′ of the heating element of the thermal line head unit 6 shown in FIG. 1, and the recording start position can be made to correspond to the paper width. .

Next, the leading end of the roll paper stored in the roll paper storage unit 23 is pulled out and inserted between the thermal line head unit 6 and the platen roller 1, and then the upper case 15 of the main body is closed to prepare to start recording. Is completed. afterwards,
The stepping motor 3 is driven by the control of the CPU 22, the platen roller 1 is rotated, and the paper is fed by the frictional force between the roller 1 and the roll paper.

Here, in order to feed the paper, the frictional force between the paper and the platen roller 1 (denoted by F1), the fixed thermal head and the object (paper or platen roller 1) that moves while rubbing against it The relationship of F1> F2 + F3 (G) is required between the frictional force (denoted by F2) and the force for rotating the roll paper to feed the paper (denoted by F3). The friction coefficient of the platen roller 1 is at least ½ or less in the B region than in the A region, but since it has the characteristics that satisfy the above-described G formula, there is no problem with respect to the paper conveying force. Further, in the above configuration, since the platen roller 1 has a property that the CC 'shown in FIG.
C'left and right are symmetrical and equal, and do not cause skewing.

Next, the frictional state due to the difference in the paper width will be explained. First, when the B4 size roll paper is used, only the roll paper is in direct contact with the platen roller 1, and the above-mentioned G formula is maintained as it is. It is similar to a thermal line printer.

On the other hand, when A4 size roll paper is used, the direct contact with the platen roller 1 is not only with the roll paper but also with the thermal line head unit 6 outside the A4 width area. The contact between the platen roller 1 and the thermal line head unit 6 causes a large frictional force, and the value of F2 in the G formula becomes extremely large. This phenomenon hinders the smooth sheet conveying operation of the printer and sometimes causes the stepping motor 3 to step out. In this embodiment, the thermal line head unit 6 directly contacts the area B of the platen roller 1 and the friction coefficient of this area is smaller than the area A. Therefore, the thermal line head unit 6 directly contacts the area. However, the stepping motor 3 is not out of step, and the stable sheet conveying operation of the printer can be maintained.

[Second Embodiment]

Next, another example of the image input / output device will be described with reference to FIG. Since the schematic configuration of the thermal line printer is the same as that of the first embodiment, the same members are designated by the same reference numerals, and the description will be cited, and the characteristic portions will be mainly described below.

The present embodiment differs from the first embodiment only in the structure of the platen roller. In FIG. 4, the platen roller 29 is divided into three rollers 29a, 29b, 29c (areas H, I, J) having the same physical properties as the roller portion. The roller portion has a symmetrical shape with EE 'as the center line, and the entire width is about 265 mm as in the first embodiment, the central roller 29b (I region) is 215 mm, and the rollers 29a, 29c (H and H J area) is the remaining width.
Of the above roller portions, the roller 29b (I region) is fixed to the rotary shaft 30, but the rollers 29a and 29c (H and J regions) are combined with the rotary shaft 30 by a torque limiter structure to form the rotary shaft 30. It is configured to allow different rotations.

The center slip washer 31 disposed between the platen rollers 29 is a roller 29b.
The side slip washer 32 is
It is configured to interlock with the rotation of 29a and 29c. The gap formed between the rollers by the center slip washer 31 and the side slip washer 32 is
It is about 0.1 mm. These washers 31,
When the torque limiter operates and the roller 29b fixed to the rotary shaft 30 and the rollers 29a and 29c rotate differently, the reference numeral 32 smoothly slips so as not to interfere with each other's movements. .

Next, the frictional state due to the difference in the paper width when the platen roller 29 having the above-mentioned structure is used will be explained. When an A4 size roll paper having a paper width of 210 mm is used, the platen roller 29 and the thermal line are used. The head unit 6 is pressed against the roller 29b (region I) of the platen roller 29 with the paper covering a portion of the platen roller 29, and the rollers 29a and 29c (regions H and J) directly contact the thermal line head unit 6. .

Here, the frictional force between the paper and the platen roller 29 is F21, the frictional force between the fixed thermal head and the platen roller 29 is F22, the frictional force between the thermal head and the paper is F23, and the rotary shaft 30. Let F24 be the frictional force at which the torque limiter with the roller 29b (region I) starts to idle, and F25 be the driving force applied to the rotary shaft 30 of the platen roller 29.
It is configured such that the relationship of F22, F25,>F24>F21> F23 ... (K) is established between them. Therefore,
The rollers 29a and 29c (H and J areas) stop by hitting the thermal line head unit 6, but the rotary shaft 30 idles with respect to the rollers 29a and 29c, which hinders the smooth conveyance operation of the roll paper or causes stepping. The motor 3 does not step out. The roller 29b rotates with the rotary shaft 30 to convey the roll paper, and the thermal line head unit 6 performs the recording operation.

When B4 size roll paper is used,
Only the roll paper is in direct contact with the platen roller 29, and the above-mentioned K formula is maintained as it is, similar to a normal thermal line printer. Roller 29b and rollers 29a, 29
As for the gap formed between c and the rollers, the rollers are crushed by the pressure contact with the thermal line head unit 6 to further narrow the gap, and the tension of the roll paper causes sufficient contact between the paper and the thermal line head unit 6. Since it can be ensured, the image quality can be maintained in good condition.

[Third Embodiment]

Next, another example of the image input / output device will be described with reference to FIGS. Since the schematic configuration of the thermal line printer is the same as that of the first embodiment, the same members are designated by the same reference numerals, and the description is incorporated by reference.
The characteristic part will be mainly described below.

This embodiment is different from the first embodiment in the structure around the head holder. In FIG. 5, reference numeral 33 denotes a spring releasing arm, one end of which is attached rotatably around an arm fulcrum 34 provided on the upper case 15 of the main body, and the other end of which is attached by a head pressing spring 17 connected to the upper part. Both ends of the head holder 7 are pressed from above by a spherical portion formed under pressure. Reference numeral 35 denotes a spring releasing cam, which is attached to the shaft portion of the platen roller 1 by a one-way clutch structure. Therefore, the rotation of the shaft is indicated by the arrow M.
In the case of the direction, it is interlocked with the shaft part, and in the case of reverse rotation, the friction force between the spring release cam 35 and the shaft part is such that the spring release cam 35 does not idle under its own weight but rotates with the shaft part, so the spring release When a load larger than its own weight is applied to the cam 35, the shaft portion idles with respect to the spring release cam 35.

Reference numeral 36 is a rotation position plate, which is provided integrally with the spring releasing cam 35 on the peripheral surface 180 degrees opposite to the maximum eccentric portion. This rotational position plate 36 is a spring release cam
When the maximum eccentric part of 35 reaches the highest position, it enters the recess of the photo interrupter 37, and the rotational position of the spring release cam 35 is detected.

FIG. 6 is a block diagram showing the arrangement of the control system of the thermal line printer in this embodiment. When the main body upper case 15 is opened, the CPU 22 drives the stepping motor 3 so that the platen roller 1 rotates in the direction of arrow M in response to a signal from the main body upper case opening / closing sensor 38.
In this rotation direction, the spring release cam 35 moves the platen roller 1
Works with the shaft of. Next, by the combination of the signals from the paper width sensor 20 and the photo interrupter 37, the CPU 22
If the roll paper is A4 size, the stepping motor 3 is driven and stopped until the maximum eccentric part of the spring release cam 35 reaches the highest position, and if it is B4 size, the stepping motor 3 is driven until it reaches a position rotated 180 degrees from that position. . In this state, when the upper case 15 of the main body is closed, the CPU 22 causes the platen roller 1 to move in the direction of the arrow M by fitting from the upper case open / close sensor 38.
The stepping motor 3 is rotated in the direction opposite to the direction and makes the stepping motor 3 stand by so that paper can be conveyed.

FIG. 7 assumes the case where A4 size roll paper is set. Since the maximum eccentric part of the spring releasing cam 35 is at the highest position, the spring releasing arm 33 is pushed up and the arm fulcrum 34 is centered. To rotate in the direction of the arrow L to compress the head pressing spring 17 and separate it from both ends of the head holder 7. Since the head holder 7 and the thermal line head unit 6 are elastic bodies that are slightly convex with respect to the platen roller 1 when there is no load, the spring release arm
When 33 is separated from both ends of the head holder 7 and the pressing of the head pressing spring 17 is released, the pressing of the thermal line head unit 6 on both sides of the A4 width with respect to the platen roller 1 decreases. By this action, the frictional resistance of the direct contact portion between the thermal line head unit 6 and the platen roller 1 is reduced, and smooth paper conveyance is ensured.

When recording is started, by closing the upper case 15 of the main body, the spring releasing cam 35 is fixed to the spring releasing arm 33 as it is, the platen roller 1 idles with respect to the spring releasing cam 35, and recording is performed. Paper is conveyed. Further, when B4 size roll paper is used, the spring release arm 33 transmits the pressure of the head pressing spring 17 and contacts both ends of the head holder 7, so that the thermal line head unit 6 uses the roll paper and the platen. The roller 1 comes into close contact with the roller 1 in the width direction, and normal recording and paper conveyance are performed.

[Fourth Embodiment]

Next, another example of the image input / output device will be described with reference to FIG. The first to third embodiments have shown the embodiments using the thermal line printer, but the thermal line head unit as the image input / output device is replaced with the line sensor unit for image reading and applied to the scanner apparatus. It becomes possible to do. FIG. 8 shows the basic configuration of the scanner device. It should be noted that any of the above-described embodiments can be applied to a portion, such as a driving method of the platen roller, which is not different from that of the thermal line printer and a means for reducing the frictional resistance received by the platen roller from the reading sensor unit, and the description thereof is omitted. To do. The same members as those in the first to third embodiments are designated by the same reference numerals and the description thereof is incorporated.

FIG. 8 shows the construction of the scanner device. Reference numeral 39 denotes an image reading line sensor unit, which presses the platen roller 1 to read the image of the original 40 and conveys the original 40 together with the platen roller 1. To do.
The contact angle between the image reading line sensor unit 39 and the platen roller 1 is set so as to easily bite when the document 40 is inserted, as shown in FIG. Reference numeral 41 denotes a phototransistor, which detects that the leading edge of the original 40 has entered the apparatus main body along the original table 42 and has approached the image reading line sensor unit 39.

Next, the reading operation of the scanner device will be described. When the original 40 is inserted along the original table 42 and the leading end is detected by the phototransistor 41, the CPU of the control system (not shown) causes the phototransistor 41 to operate. Approximately 1 second after the document 40 passes by the detection signal, the platen roller 1
Start driving. Therefore, the platen roller 1 starts to rotate after the leading edge of the document 40 hits the image reading line sensor unit 39 or the platen roller 1.

When the original 40 is read about 0.5 seconds after the platen roller 1 starts to rotate, the original 40 is bitten between the image reading line sensor unit 39 and the platen roller 1, and the original 40 is read. The timing when the conveyance starts and the timing when the document reading starts can be substantially matched. With the above-described configuration, it is possible to apply the present invention to a scanner device that conveys a document only by the platen roller 1.

In the first to fourth embodiments, a thermal line printer or a scanner device is used as the image input / output device, but the image input / output device is not limited to this, and another device such as a facsimile device is used. It is also possible to use it by incorporating it into the like.

[0044]

As described above, according to the present invention, in an image input / output apparatus which conveys a sheet while pressing the image input / output device to the conveying means via the sheet, when a narrow sheet is set and conveyed, Since the frictional force generated by the direct contact between the conveying means and the image input / output device in the area other than the sheet width is reduced and the sheet is conveyed, the motor for driving the conveying means does not step out, and stable sheet conveying is possible. Can maintain operation.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an internal configuration of a thermal line printer according to a first embodiment.

FIG. 2 is a cross-sectional explanatory diagram of a thermal line printer.

FIG. 3 is a block diagram showing a control system of the apparatus.

FIG. 4 is an explanatory diagram showing a configuration of a platen roller according to a second embodiment.

FIG. 5 is an explanatory diagram showing a configuration around a platen roller according to a third embodiment.

FIG. 6 is a block diagram showing a control system of the apparatus.

FIG. 7 is an explanatory diagram showing a pressed state of the thermal line head unit when transporting A4 size roll paper.

FIG. 8 is an explanatory diagram of a configuration of a scanner device according to a fourth embodiment.

[Explanation of symbols]

 1, 29 ... Platen roller 2 ... Bearing 3 ... Stepping motor 4 ... Gear 5 ... Platen gear 6 ... Thermal line head unit 6a ... Thermal line head 6b ... Latch register 6c ... Shift register 7 ... Head holder 7a, 15a, 19a ... Hook 8 … Head holder fork part 9… Right roll paper guide 10… Left roll paper guide 11… Paper guide gears 12, 13… Guide rail 14… Holder mounting shaft 15… Main case 16… Mounting hole 17… Head pressing spring 18… Top case Open / close shaft 19 ... Main body housing 20 ... Paper width sensor 21 ... Roll paper storage 22 ... CPU 23 ... Record data transmission signal 24 ... Latch signal 25 ... Strobe signal 26 ... Sensor signal 27 ... Excitation signal 28 ... Hold signal 29a, 29b, 29c … Roller 30… Rotary shaft 31… Center slip washer 32… Side slip washer 33… Bar Release arm 34 ... arm fulcrum 35 ... spring release cam 36 ... rotational position plate 37 ... photointerrupter 38 ... main body upper case closing sensor 39 ... image reading line sensor unit 40 ... document 41 ... phototransistor 42 ... platen

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location B41J 25/312 25/316 H04N 1/00 108 Q

Claims (4)

[Claims] 1. An image input / output apparatus that conveys a sheet while pressing an image input / output device against the conveying means via the sheet, and in the case of conveying a narrow sheet, the conveying means in a region other than the sheet width. An image input / output device equipped with means for reducing a frictional force generated by direct contact with the image input / output device. 2. The image input / output apparatus according to claim 1, wherein a specific area on the surface of the conveying means has a smaller friction coefficient with respect to the image input / output device than other areas. 3. The image input / output device according to claim 1, wherein the conveying means is equipped with a roller fixed to a rotary shaft and a roller combined by a torque limiter. 4. The image input / output apparatus according to claim 1, wherein the pressure contact force between the conveying means and the image input / output device is reduced at a specific portion.