JPH07172649A - Residual quality detecting device for roll winding recording medium - Google Patents

Abstract

PURPOSE:To simply, inexpensively and accurately detect a residual quantity of a roll winding recording medium by calculating the residual quantity according to a construction material of the roll winding recording medium by using the fact that a recidual quantity of the roll winding recording medium is in proportion to this diameter or a cross-sectional area and is also in proportion to the prescribed pulse number in a prescribed period. CONSTITUTION:A recording paper roll 1 is held by a paper sheet holder 41, and these are respectively rotated according to a carry of a recording paper. A reflecting plate 42 is stuck to a side surface of the paper sheet holder 41, and a reflection sensor 43 is arranged so as to be opposed to the reflecting plate 42. The paper sheet holder 41 is driven in rotation by a DC motor 44. By the way, a turning angle of the paper sheet holder 41 is detected by the reflection sensor 43 through the reflecting plate 42, and the driving pulse number applied to a recording paper carrying pulse motor is counted in this detecting output generating period. A residual quantity according to a construction material of the recording paper roll 1 is calculated by using the fact that a residual quantity of the recording paper roll 1 is in proportion to this diameter or a cross secional area or an enumerated value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention, for example, uses a long recording medium wound in a roll shape to determine the remaining amount of the recording medium in an image forming apparatus or the like that forms an image on the recording medium. The present invention relates to a remaining amount detecting device for detecting.

[0002]

2. Description of the Related Art A camera, a facsimile, a plotter, or the like uses a roll-shaped recording medium which is a continuous medium. Such an apparatus, especially a camera or a plotter, requires an operation of feeding the recording medium to one side and rewinding it.

For example, in a color electrostatic plotter which is a wet recording device of an electrostatic recording system, a recording head which is a recording portion for an electrostatic latent image, a developing head (developing device) for developing the electrostatic latent image,
It is composed of a developer container containing a developer to be supplied to the developing head and a suction pump for circulating the developer.

Specifically, for example, the developing head has a box-shaped container in which a developing solution can flow, and the upper surface of the substrate is formed in a flat shape, and this flat area serves as a developing action area for a recording sheet. A slit-shaped window is provided, and the plane portion serves as a conveyance path for the recording sheet, and the longitudinal direction of the window is a transverse direction of the recording sheet.

The developing head is connected to a developing solution container by a pipe, and while the recording sheet on which the electrostatic latent image is formed is conveyed through the flat portion of the developing head, the inside of the developing head is sucked by a suction pump. Since the recording sheet covers the slit-shaped window of the developing head, the inside of the developing head has a negative pressure, so that the developing solution is sucked up from the developing solution container and circulated, and the recording sheet has a slit-like shape. In the window portion, a developing solution is applied to the recording sheet to develop the recording sheet.

Usually, there is only one recording head. In the case of multicolor recording (color printing), one recording head for each color is provided on the upstream side of the recording paper conveyance path, and development for each color is provided on the downstream side. The heads are arranged in order, and a long recording paper, which has become a recording paper roll wound in a roll shape on the core of the roll, is fed out from the recording paper roll and is fed to the downstream side for one color by the recording head. Electrostatic latent image is formed on the paper surface, and the electrostatic latent image is developed by using the developing head supplied with the developer used for developing the color corresponding to the electrostatic latent image, and the image of that color is recorded. When the recording of one color is completed, the recording paper is rewound onto the recording paper roll, the recording paper is fed again, and the next color is recorded according to the procedure described above. Rewind to the roll and feed the recording paper again to record the next color Perform, performing the recording by repeatedly overprinting the operation that went with.

Since the print recording paper is reciprocated repeatedly in this manner, the paper for which recording for each color has been completed is wound up by the take-up roller on the downstream side of the recording paper conveyance path, and the next color When recording, the recording paper is rewound to the recording paper roll side.

Therefore, when the remaining amount of recording paper on the recording paper roll becomes small, rewinding cannot be performed for recording the image of the next color even if the image of the first color can be recorded. If the remaining amount of recording paper becomes low, rewinding is performed to take out the paper.

Also, in the case of a roll film, when the remaining amount of the medium reaches a predetermined value, it is rewound on a roll. In a color printing apparatus such as the color plotter described above, in the case of a method of reciprocally moving recording papers to superpose each color, a micro switch is provided in the recording paper conveyance path in order to detect that the recording papers are exhausted. It is detected that the recording paper is exhausted by setting it to be on when there is recording paper and off when there is no recording paper.

However, this method has a problem. In the case of a micro switch, because it is mechanical detection, the position where the detection operation by the switch is possible is determined in relation to the recording paper, and there are also restrictions on the installation space, etc.
Since it cannot be installed near the core of the recording paper roll,
Even if it is provided in the foremost position, it is a conveyance path near the recording head. And, for example,
In the case where the recording paper is used up just before finishing the forward movement (forward conveyance; conveyance in the recording paper feed-out direction), the recording paper is pulled back when the paper is fed out from the recording paper roll. The end of the recording paper roll can be detected only after the trailing end has peeled off from the core, and even if it is desired to control the recording paper to be rewound on the recording paper roll, this is impossible.

When the recording paper has been peeled off from the core of the roll and cannot be rewound, the recording paper on which the first color recording has been completed is taken up by a take-up roller downstream of the recording paper conveyance path. Therefore, the work of taking out and removing it becomes difficult.

Generally, in a large plotter or the like capable of outputting a large drawing, since the paper core, that is, the recording paper roll is large and heavy, the paper core setting position is on the front side so that the paper core can be easily set. The main transport mechanism for transport is in the back, which is difficult to reach. Therefore, if the recording paper runs out during recording, the recording paper during recording remains on the recording paper take-up roller from the main transport mechanism, and if the recording paper end is wound around the recording paper roll core, Although it can be recovered by the reverse rotation operation of 1., if it is completely peeled off and its end is farther from the winding core, it is not easy to pull it back to the winding core, and therefore the recovery work is difficult.

In order to eliminate such a situation and to make it possible to surely detect the absence of the paper immediately after the end of the recording paper is peeled from the winding core, the recording paper is provided in the recording paper conveyance path near the loading position of the recording paper roll. By providing a roller that is driven to rotate in accordance with the conveyance of, and attaching an encoder to the shaft of this roller, a pulse is generated from the encoder in synchronization with the rotation of the roller, and the state of occurrence of this pulse, for example, during conveyance A method has been devised to detect the peeling of the recording paper from the core of the recording paper roll in view of the fact that no pulse is generated even though there is a certain situation.

According to this, even if the recording paper is consumed and the end of the recording paper is peeled off from the winding core of the recording paper roll, it is possible to detect the paper shortage immediately after that, so that the conveyance is stopped at this point. As a result, the recording paper can be stopped in a state where the end of the recording paper is near the winding core. Then, in this case, by pulling the end of the recording paper to the winding core and winding it, the recording paper can be collected by the rewinding operation of the recording paper.

[0015]

In an apparatus that uses roll paper as a recording medium, a micro switch is used to detect the paper shortage of the recording paper, or a roller and an encoder that interlock with the movement of the recording paper are used. Although there is a method of managing the remaining amount of the above, all of them only detect the paper shortage and cannot detect the remaining amount.

In the color electrostatic plotter, in addition to plain paper (electrostatic recording paper) as recording paper, in recent years, various rolled recording media of different materials such as tracing paper, film, or chemically synthesized paper are used. To be done. Then, in order to properly use the medium material according to the purpose, the roll-wound recording medium may be used by removing some used one and replacing it with another recording medium, or the replaced one is not a completely unused one, Since it is a roll that has been used before, the remaining amount is often unknown.

Then, load the one whose remaining amount is unknown,
The technique of measuring the remaining amount while using it has not been established. However, if the remaining amount is not known, it is not even known whether or not the amount of the recording medium will be sufficient for printing the intended product, especially 10
In a color electrostatic plotter capable of printing as long as m, the occurrence of paper shortage in the middle is a waste of recording paper and time.

When the diameter of the winding core is known, the recording medium wound into a roll can be registered to some extent by the outer diameter and the remaining amount. However, the recording medium used for printing has various materials, and if the material of the recording medium is different, the thickness thereof is also different. Therefore, the remaining amount cannot be easily known. Moreover, since the recording medium is loaded into the plotter, it cannot be seen from the outside, and even if the roll diameter of the recording medium is mechanically measured, the numerical value is completely useless as a scale indicating the information of the remaining amount. Don't do it.

Therefore, there is a strong demand for the development of a technique which has a simple and inexpensive structure and is capable of detecting the remaining amount of recording paper with an unknown remaining amount with sufficient accuracy. Therefore, an object of the present invention is to provide a roll which, while having a simple and inexpensive structure, can detect and notify the remaining amount of recording paper of which the remaining amount is unknown, and can detect it with sufficient accuracy. Another object is to provide a wound recording medium remaining amount detecting device.

[0020]

The present invention has taken the following means in order to solve the above problems and achieve the object. That is, to hold a roll-wound recording medium on a holding unit that holds it in a rotatable manner, and to use it in a transporting device that has a transporting unit that is driven by pulse control to feed out and transport this roll-wound recording medium in a predetermined amount unit. As the remaining amount of roll-wound recording medium detecting device, type information giving means for giving type information of the roll-wound recording medium, signal generating means for generating a detection signal each time the roll-wound recording medium rotates by a predetermined amount, and this signal generation Between the counting means for counting the number of pulses in the detection signal generation cycle by the means, the remaining amount of the roll-wound recording medium is proportional to the diameter or cross-sectional area of the roll-wound recording medium, and between the count value. Utilizing the fact that it has a proportional relationship, the calculation means for calculating the remaining amount according to the material of the roll-wound recording medium from the count value, Providing a means for performing a physical.

[0021]

The present invention utilizes that the remaining amount of the roll-wound recording medium is proportional to the diameter or cross-sectional area of the roll-wound recording medium and has a proportional relationship with the count value.
According to the above-mentioned configuration, the signal generating means generates the detection signal every time the roll-wound recording medium rotates by a predetermined amount. Therefore, when the number of pulses in the generation cycle of the detection signal is counted by the counting means, The remaining amount can be calculated from the count value. Then, by adding the given information about the material of the recording paper to this calculation, the remaining amount corresponding to the material, that is, the thickness of the recording medium is obtained. Then, a specific process is performed according to the calculation result. The specific process is, for example, a remaining amount display, an error display, or transportation stop. Further, the present invention utilizes the fact that the remaining amount of the roll-wound recording medium is proportional to the diameter or cross-sectional area of the roll-wound recording medium and has a proportional relationship with the count value. Even for a roll-wound recording medium whose amount is unknown, if the recording medium is a standard product, the remaining amount can be obtained.

As described above, according to the present invention, the roll-wound recording medium remaining, which has a simple and inexpensive structure, can detect and notify the remaining amount of recording paper and can be detected with sufficient accuracy. A quantity detection device can be provided.

[0023]

Embodiments of the present invention will be described below with reference to the drawings. Here, a case where the present invention is applied to a color electrostatic plotter will be described as an example. (First Embodiment) FIG. 1 is a block diagram showing an embodiment of the present invention. In FIG. 1, reference numeral 1 is an electrostatic recording paper roll, in which a long recording paper 2 is wound around the outer circumference of a paper tube which is a winding core. In this electrostatic color plotter device, a guide roller 3 is arranged near the setting position of the recording paper 2, and a recording paper feed roller 11 is arranged downstream of the roller 3. . Further, guides 14 and 23 are arranged downstream of the recording paper feed roller 11, and a take-up roller 31 is arranged downstream of the guide 14.

A recording system and a developing system are installed between the roller 3 and the recording paper feed roller 11, and a recording paper winding system and a cutting system are arranged downstream of the recording paper feed roller 11. Therefore, the end portion of the recording paper 2 is led out to the recording system, the developing system, the recording paper winding system, and the cutting system via the roller 3. An electrostatic recording head 5 constitutes a recording system, which forms an electrostatic latent image on the recording paper 2 which moves in contact with the end surface thereof.

Reference numeral 4 is an optical mark reading head, and this mark reading head 4 is arranged in the vicinity of the guide roller 3 and on the downstream side. The mark reading head 4 reads a recording position control marker, which will be described later, recorded on the recording paper 2 and also reads an edge of the recording paper 2.
A CCD (charge coupled device) linear image sensor (solid-state line image sensor) is used. This image sensor has a one-dimensional position resolution, and therefore, it is possible to identify the position and the width of the mark on the recording paper from the output signal of the image sensor.

In this system, the mark reading head 4
Is sent to a processor (not shown) which is the center of control of the present system, and is used for detection of the absence of recording paper and recording control by the recording system. Therefore, when the recording paper 2 is used in the present system, the recording paper 2 is in the vicinity of one edge (side edge) on the recording surface, in an area outside the recording area, along the edge of the recording paper 2 at predetermined intervals, for example, a rectangular shape having a predetermined size. The recording position control marker filled in is recorded together with the image of the first color when recording the first color, and is read each time when recording the image of the second color and thereafter, and is used for position correction and scale correction.

Reference numerals 6a to 6d denote developing heads constituting a developing system, and these developing heads 6a to 6d are arranged along the downstream side of the recording paper conveyance path in order. The developing heads 6a to 6d are for black (K), cyan (C), magenta (M), and yellow (Y) in order, and all of them can be moved up and down with respect to the recording paper conveyance path. It is controlled that only the print developing head of the color for which the print recording is to be performed is placed in the ascending position where the upper surface is in contact with the recording paper transporting path, and the others are in the descending position away from the recording paper transporting path. The ascending position is the developing position, and the descending position is the standby position.

These developing heads 6a to 6d are long prisms, and are arranged along the axial direction in the direction traversing the recording paper conveyance path. Developing heads 6a to 6d
Has a developing solution acting portion on its upper surface side, where the developing solution is applied to the recording paper to develop the latent image on the recording paper.

For example, long prism-shaped developing heads 6a to 6
d is formed by arranging a plurality of long slits extending in the longitudinal direction in order on the upper surface side in the lateral direction, and each slit is sucked from a suction port provided near one end on the bottom side thereof. The inside is sucked by the pump. Then, due to this suction, the inside of the slit becomes negative pressure, and when the recording paper covers the upper surface of the slit and the internal negative pressure becomes large, the developer flows into the slit due to this negative pressure and adheres to the recording paper surface to perform development. It is a mechanism.

10 is a downstream side of the developing device 6, and
A developer sucking roller installed on the upstream side of the recording paper feed roller 11 is for sucking and removing the excess developer adhering to the recording paper 2 during development by the developing heads 6a to 6d. Most of the excess developer is removed by the suction groove during development, and the developer suction roller 1
0 has the effect of wiping away moisture.

A pinch roller 12, which is a pressing roller, is arranged in pressure contact with the peripheral surface of the recording paper feed roller 11, and the recording paper feed roller 11 cooperates with the pinch roller 12 to form the recording paper 2. The recording paper feed roller 11
The recording paper 2 can be fed by rotating the. The recording paper feed roller 11 is provided with a guide plate 13 curved in an arc shape. By feeding the leading end of the recording paper 2 between the recording paper feed roller 11 and the guide plate 13, a pinch roller is provided. The recording paper 2 can be held between the recording paper feed roller 12 and the recording paper feed roller 11.

The guide 14 is provided with a guide 23 paired with the guide 14. A sensor 34 for detecting the front end of the recording paper 2 is arranged on the guide 14 located on the exit side of the recording paper feed roller 11, and further downstream thereof, the sensor 34 is fed out from the recording paper feed roller 11 and guided. A branch guide 26 is provided for switching the lead-out direction of the recording paper 2 guided and sent between 14 and 23.

Reference numeral 15 is a Y cutter for cutting the recording paper in a direction orthogonal to the recording paper feeding direction, and 16 is an X cutter for cutting the recording paper in a direction parallel to the recording paper feeding direction. The branch guide 26 for switching the recording paper path is rotatably supported by a pin 27 at its base end side. The branch guide 26 switches the leading end of the recording paper 2 guided and fed by the guides 14 and 23 toward the automatic sheet winding device 30 or the Y cutter 15 and the X cutter 16. It is for.

When the recording paper 2 is guided to the Y cutter 15 and the X cutter 16 by the branch guide 26, the guided recording paper 2 is guided to the Y cutter 15 and the X cutter 16,
Guide rollers 19 and 20 and a guide plate 24 are arranged, and further, a guide plate 25 and a pair of guide rollers 21 and 22 are arranged to send the recording paper 2 cut by the Y cutter 15 and the X cutter 16 to the outside. ing.

The automatic recording paper take-up device 30 takes up the recording paper 2 guided and guided by the take-up roller 31, the pressure contact roller 33 having a peripheral surface in contact with the take-up roller 31, and the peripheral surface of the take-up roller 31. Guide along the pressure roller 3
3 and a guide plate 32 which is guided between the guide plates 32 and 3. The recording paper 2 guided and guided by the branch guide 26 is automatically wound around the winding roller 31.

Winding roller 31, recording paper feed roller 11
Rotates the recording paper 2 forward when sending it out for recording, etc.
At this time, the electrostatic recording paper roll 1 is slowly rotated forward with an appropriate force in order to apply tension to the recording paper 2.
Gives the moment of reverse rotation. In the case of rewinding, the electrostatic recording paper roll 1 is rotated in the reverse direction so that the winding roller 31,
In order to apply tension to the recording paper 2, the recording paper feed roller 11 slowly rotates in the reverse direction with an appropriate force or applies a forward rotation moment.

In this apparatus, the electrostatic recording paper roll 1 has a long recording paper wound around a winding core such as a paper tube. This is the recording paper loading position in the main body of the color electrostatic plotter. It is held by a paper holder 41 provided in the. The paper holder 41 is as shown in FIG. 2 and has, for example, a bobbin shape having a pair of flange portions facing each other, and holds the electrostatic recording paper roll 1 between the flange portions. Then, as the recording paper is conveyed, the electrostatic recording paper roll 1 and the paper holder 41
Rotate integrally.

A reflection plate 42 is provided on the surface of the flange portion of the paper holder 41, and a reflection sensor fixedly provided at a fixed position in the main body of the color electrostatic plotter so as to face the reflection plate 42. 43 is configured to detect the presence or absence of the reflector 42 and output a signal. Then, the feeding amount of the recording paper can be counted by this.

The reflection sensor 43 is composed of a photoelectric detecting element, and the reflection plate 42 attaches, embeds, or coats a small rectangular or circular chip that reflects light to emit light. The position can be notified by reflecting the light. The light is projected from the light projecting device and the reflected light is photoelectrically detected by the reflection sensor 43.

Of course, the structure is not limited to this, and the slit disk and the light emitting device and the light receiving device are opposed to each other with the slit disk sandwiched therebetween, and the slit disk is attached to the paper holder 41 or rotation is interlocked. The same detection can be performed with the configuration.

The paper holder 41 is driven by a DC motor 44 for driving the paper holder 41 so as to rotate in the reverse direction with respect to the forward conveying direction of the recording paper. However, the DC motor 44 is used for the recording paper 2
Is conveyed in the positive direction (conveying direction of the recording paper), it is driven so as to rotate in the negative direction with a weak force (reverse rotation drive), and when the recording paper 2 is rewound on the recording paper roll 1,
The motor 44 is rotated in the negative direction by a strong force (reverse rotation), and the recording paper feed roller 11 is also in the negative direction (reverse direction).
Drive.

Reference numeral 35 is a control unit, and 36 is a control panel. Of these, the control unit 35 plays a central role in controlling the entire system, and includes the rotation drive control of the DC motor 44 and the pulse motor of the recording paper feed roller 11.
Implement the necessary various controls. Further, when data for printing and various commands are received from the outside, conveyance control is started, and in response to these data and various commands, the recording head 5 is driven and the developing position of the developing head used for development is moved to the developing position. It has a function of executing a series of sequences required for print recording, such as movement and supply of a developing solution.

The control panel 36 has a display section 36a for displaying the remaining amount and a sheet conveyance amount, and a sheet selection key 36c which can be operated by an operator, so that the user can select the type of recording sheet. Then, by pressing the paper selection key 36c, one of "plain paper", "trepe" (tracing paper), "film", and "synthetic paper" can be sequentially selected. The selected paper type is an LED (light emitting element) 36 which is a display lamp provided corresponding to the type.
b is turned on and displayed.

The operation input from the control panel 36 is given to the control unit 35, and the display output is also given from the control unit 35. The control unit 35 calculates the remaining amount of recording paper according to the type of paper from the detection output from the reflection sensor 43 and the number of drive pulses for the motor for driving the recording paper feed roller 11, and obtains the remaining amount. At the same time, the control of displaying the result on the display unit 36a is also performed.

Reference numeral 17 is a paper-out detection sensor, which is provided between the recording head 5 and the installation position of the roller 3 and operates to output a paper-out signal when the recording paper runs out. . This no-paper signal is given to the control unit 35, and when receiving the signal, the control unit 35 stops the forward conveyance of the recording paper and displays an error of paper shortage to notify the user.

In the electrostatic color plotter device having the above-mentioned structure, first, the recording paper 2 is pulled out from the recording paper roll 1 prior to the start of recording, and the leading end of the recording paper 2 exceeds the detection positions of the feed roller 11, the pressure contact roller 12 and the sensor 34. The guide 24 is set so as to come to the position of the guide 24, and a standby state is set. In the standby state, not only the setting of the recording paper but also the stage after the print portion is cut and discharged from the recording paper is transferred. Therefore, in this standby state, the leading end of the recording paper is not the winding roller 31 side but the cutter side. I am being led to the passage.

When the printing operation is started, the recording paper roll 1 and the recording paper feed roller 11 are reversely rotated, the leading end of the recording paper is moved, and the sensor 34 is stopped at a position where the sensor 34 is turned off (OFF; detection of no paper state). After that, the branch guide 26 rotates about the shaft 27 so that the guide direction is the winding roller 31.
Switch to the side.

Next, the developing head 6a for the first color (for example, a black image) is moved to the developing position (the position facing the conveying path of the recording paper) to enable the development of the color for the first color. In this state, when the suction pump of the developing system of the developing head 6a is driven, the inside of the slit of the developing head 6a becomes negative pressure, and the negative pressure causes the recording paper 2 to be attracted to the upper surface of the developing head 6a, The negative pressure of becomes large to form a closed flow path of the developing solution. As a result, the developing solution is sucked up from the developing solution tank, circulates to the suction pump through the slit (developing groove) of the developing head 6a, and circulates in the route of returning to the developing solution tank to transfer the developing solution to the recording paper 2. It becomes possible to act on the paper surface.

Next, the forward transportation of the recording paper 2, that is, the transportation toward the recording paper feed roller 11 is started. At this time, by the branch guide 26 for switching the recording paper path,
Since the front end of the recording paper 2 is guided in the direction of the take-up roller 31, when the recording paper 2 is fed in the forward direction for forming the marker for recording position control and forming the color image of the first color, the recording paper 2 is forwarded. The leading end of the wire 2 is guided toward the take-up roller 31 and taken up by the take-up roller 31. Then, after being conveyed by a certain amount, the electrostatic recording head 5 forms an electrostatic latent image of the first color image on the recording paper 2 for the formation of the first color image, and controls the recording position. The electrostatic latent image for forming the marker is formed on one side of the recording paper 2.

Then, the developing head 6 for the corresponding color of the first color
By developing these electrostatic latent images in a, a toner image is obtained, and the image of the first color and the recording position control marker are recorded on the recording paper 2. The solvent of the liquid developer is highly volatile, and the toner attached to the electrostatic latent image has a property of firmly fixing when the solvent volatilizes. This allows printing with the color of the developer.

The recording paper 2 which has been developed and sent out is taken up by the take-up roller 31 until the predetermined image formation is completed. When the development is completed, the developing head 6a is lowered to the standby position, the negative pressure is released to the atmospheric pressure, and the supply of the developing solution is stopped. During this period, a drying process is performed, and when the excess developer on the surface of the recording paper is dried, the recording paper feed roller 11 is reversed to rewind the recording paper 2 and rewind the recording paper 2 to the print start position. (Reverse operation of recording paper).

The same drive control as described above is performed for the second and subsequent colors. Then, the above operation is repeated for each color while sequentially switching the developing heads by the number of colors required for forming the latent image and the image for which development is desired to be recorded, thereby obtaining a color image.

The toner contained in the liquid developer is colored black such as black for the liquid developer for black, magenta for the liquid developer for magenta, and cyan for the liquid developer for cyan. By repeating the above operation for each color, the images of the respective colors are superimposed on the same paper surface of the recording paper 2 with the marker for recording position control as a reference to form a color image.

At the start of printing the final color, the branch guide 2
6 is switched to the discharge side, and the recording paper 2 is guided to the Y cutter 15 and X cutter 16 sides. While printing the final color, the leading edge of the recording paper is guided along the guide 24 on the paper ejection side, the margin of the leading edge is removed by the Y cutter 15 and the X cutter 16, and then ejected to the outside to complete the printing. After the printed recording paper 2 is discharged, the recording paper feed roller 11 is rotated in the reverse direction to rewind the recording paper 2 on the recording paper roll 1 by a certain amount, and the margin of the leading end of the recording paper comes to the position of the developing head 6a. Stop the transportation with.

In this way, the color electrostatic plotter performs predetermined processing on the vector data and image data given from the external computer in accordance with the command (command) given from the external computer while controlling the conveyance of the recording paper. The recording operation is performed on the recording paper for each color, but the forward transport operation and the reverse operation are repeated four times in order to form a color image by superimposing four colors.

In the apparatus to which the present invention is applied, even when the electrostatic recording paper roll 1 whose remaining amount is unknown is loaded and started to be used, the remaining amount of recording paper can be measured and displayed. Yes, you can let the user know the remaining amount,
It is characterized in that it prevents the occurrence of paper breaks during printing. This point will be described in detail below.

The electrostatic recording paper roll 1 is formed by winding a long recording paper around a winding core such as a paper tube. The winding start end of the roll paper, that is, the recording paper end is an adhesive tape around the winding core. It is attached weakly.

The electrostatic recording paper roll 1 is held by the paper holder 41 provided at the recording paper loading position in the main body of the color electrostatic plotter, and the electrostatic recording paper roll 1 and the paper are conveyed as the recording paper is conveyed. The holder 41 rotates.

The paper holder 41 has a reflector 42 on its side surface.
Is attached, and the presence / absence of the reflector 42 is detected by a reflection sensor 43 fixedly provided at a fixed position in the main body of the color electrostatic plotter so as to face the reflector 42, and a signal is output. . That is, the reflection sensor 43 is composed of a photoelectric detection element, and the reflection plate 42 reflects light by attaching, embedding, or applying a small rectangular or circular chip that reflects light. By doing so, the position can be notified, and light is projected from the light projecting device and the reflected light is photoelectrically detected by the reflection sensor 43.

The DC motor 44 that rotationally drives the paper holder 41 conveys the recording paper 2 in the forward direction (conveyance of the recording paper in the forward direction).
When doing, the drive is controlled to rotate in the negative direction with a weak force (reverse rotation drive). However, since the force of the pulse motor that drives the recording paper feed roller 11 is stronger and overcomes the force of the DC motor 44, the recording paper is fed in the forward direction. In this way, by applying a force to the DC motor 44 in the negative direction, tension is applied and the recording paper 2 is tensioned.

When the recording paper 2 is rewound on the recording paper roll 1, the DC motor 44 is rotated in the negative direction by a strong force (reverse rotation), and the recording paper feed roller 11 is also driven in the negative direction (reverse direction). To do. At this time, the recording paper is conveyed in the negative direction. In any of the states, the conveyance speed of the recording paper is determined by the rotation speed of the pulse motor that drives the recording paper feed roller 11.

By rotating the paper holder 41 forward and backward in this way, the rotation angle of the paper holder 41 associated therewith can be counted by detecting the reflector 42 by the reflection sensor 43. In the embodiment, the two reflectors 42 are provided on the paper holder 41 with their positions shifted by 180 °. Therefore, a detection output is obtained from the reflection sensor 43 every time the paper holder 41 rotates by 180 °, and the detection output is given to the control unit 35 to count the rotation amount of the paper holder 41 as follows. Ask.

That is, assuming that the recording paper conveyance is stopped, in this state, the control section 35 gives a drive pulse to a pulse motor (not shown) to cause the recording paper feed roller 11 to move.
Is started to control the conveyance of the recording paper 2, and the detection output from the reflection sensor 43 is obtained to detect the rotation of the recording paper roll 1.

The two reflection plates 42 are connected to the reflection sensor 4
While 3 is finished detecting, the number of drive pulses applied to the pulse motor for driving the recording paper feed roller 11 is counted. The counted number of drive pulses is N. Then, the control unit 35 calculates the remaining amount of recording paper from the value of the counted driving pulse number N as follows.

That is, the number of drive pulses generated during the detection of two reflectors is N, the remaining amount (unit%) of the recording paper on the recording paper roll 1 is k, and the remaining roll is k (%). The radius of the paper is R (k), and the radius of the roll when the remaining amount of the recording paper of the recording paper roll 1 becomes zero (the roll paper is wound around a tube of radius R0) as R (0 ), When the radius of the recording paper roll when the recording paper roll is wound in the maximum amount (here, the maximum is 150 m tentatively) is R (150), the remaining amount k of the recording paper is “the recording paper roll 1 is disconnected. Area R (k) ² "
-Proportional to the cross-sectional area R (0) ² of the winding core of the recording paper roll 1. Therefore, k = ((R (k) ² −R (0) ² ) / (R (150) ²
−R (0) ² ) × 100 (%) (1)

Further, N is the number of drive pulses given while the reflection sensor 43 finishes detecting the two reflection plates 42, and corresponds to the carry amount of the recording paper. It has a proportional relationship with the cross-sectional area of the recording paper roll 1.
Therefore, the remaining amount k can be obtained based on N from these relationships.

When the calculated remaining amount k is actually displayed, the value of the calculated remaining amount k is rounded up or rounded down in units of 10%, for example, or arranged according to the application and displayed stepwise. To do.

Since the thickness of the recording paper differs depending on the type of the recording paper, it can be seen from the equation (1) that the remaining amount is different even with the same radius. Therefore, it is necessary to specify the type of recording paper to be used. The apparatus has a paper selection key 36c that can be operated by an operator and a control panel 36 having a display section 36a for displaying the remaining amount and the amount of conveyed paper, so that the user can select the type of recording paper. Therefore, when the operator sets the recording paper roll 1, the operator operates the paper selection key 36c to specify the type of recording paper to be used. By pressing the paper selection key 36c, the control unit 35 selects one of "plain paper", "trepe" (tracing paper), "film", and "synthetic paper" in this order.
The type of the selected sheet is displayed by controlling the lighting of an LED (light emitting element) 36b which is a display lamp provided corresponding to the type.

In this apparatus, R in the equation (1) is
(K) is calculated as follows. Recording paper feed roller 1
If 2 pulses are given to the pulse motor for 1 drive, 1/40
It is assumed that 0 [inch] recording paper advances. However, 1 [inch]
Is 25.4 [mm].

Since the reflecting plate 42 is installed at two points on a diagonal line about the axis of the recording paper roll 1, N pulses are applied to the pulse motor for driving the recording paper feeding roller 11 while detecting the two reflecting plates 42. Is given, the remaining amount k (%)
The radius R (k) of the roll paper at the time of has the relationship of the following equation (2).

R (k) = (25.4 × N) / (400 ×
π × 2) [mm] (2) Number of pulses N until two reflectors 42 are detected
When we obtain, by computing using the above relational expression,
The remaining amount k can be calculated.

The remaining amount is displayed in units of 10% in this device. The reason is that the user only needs to know the rest of the recording paper. Then, by roughly knowing the remaining amount, "Is it better to prepare a new recording paper?", "Is there enough recording paper when printing a large amount at a time?", "Night time unattended printing" Can you use it when making a judgment such as "Is there enough recording paper?"

Here, the remaining amount k is simply k = (R (k) -R (0)) / (R (150) -R
(0)) × 100 [%] ... (3) may be obtained. In this case, the remaining amount is 0%
Although it is inaccurate except when 100%, it is possible to know the approximate remaining amount with a simple calculation formula.

Further, by calculating from the above formula in units of 10%, for example, a table as shown in FIG. 4 is prepared,
It is also possible to adopt a format in which the control unit 35 adopts a calculation method for obtaining the remaining amount by referring to this table according to the recording paper type.

Here, in FIG. 4, plain paper, trepe,
The numerical values shown for the synthetic paper and the film are within the range of the number of clocks for the recording paper transport motor (driving pulses applied to the driving motor for the recording paper feed roller 11) while the paper holder 41 rotates by a predetermined amount. And the remaining amount k of the recording paper for each recording paper type
(%) Is shown.

The data of the remaining amount k obtained by the control unit 35 based on the above pulse number and corresponding to the recording paper type set by the control panel 36 is the control unit 35.
Given to the control panel 36 by the display unit 3
6a to notify the user. The display unit 36a is composed of a liquid crystal panel, an LED display, etc., and is displayed as a numerical value.

Next, the detection timing of the remaining amount of recording paper will be described. In this apparatus, the paper wrinkle is removed by reciprocating the recording paper several times under the control of the control unit 35 after the power is turned on or after the recording paper is set. At this time, the remaining amount is detected by utilizing the fact that the recording paper is conveyed, that is, the detection output from the reflection sensor 43 obtained during this conveyance and the number of drive pulses for the motor for driving the recording paper feed roller 11. From the above, the remaining amount of recording paper is calculated according to the type of paper, the remaining amount is obtained, and the remaining amount is displayed on the display unit 36a at the end of the initial, thereby displaying the remaining amount to the user.

The remaining amount is detected as described above even when the recording sheet is conveyed in the forward direction during the printing operation or the operation of manually feeding the recording sheet, and the result is displayed on the display section 36a. .

When performing color printing with this apparatus,
Since the recording paper is reciprocated several times to print each color and overlap the colors, the operation of rewinding the recording paper is entered, but the detection output from the reflection sensor 43 is generated regardless of the conveying direction of the recording paper. Therefore, even if the recording paper is rewound in the reverse direction, if the remaining amount detection is performed as described above,
When the recording paper is rewound, the remaining amount may be displayed as if the remaining amount of the recording paper has increased.
Therefore, in the case of the reflector mounting structure as shown in FIG. 2 used in the first embodiment, the remaining amount is detected only during the forward conveyance.

Since the control unit 35 also controls the recording paper conveyance direction, it is possible to ensure the accuracy of the remaining amount by performing this correction in the remaining amount detection calculation during the backward conveyance. However, in this case, an error occurs in the remaining amount due to variations in the reading of the reflection sensor, and if forward and reverse conveyance is repeated, the cumulative error may increase and there may be a problem in the reliability of the remaining display amount. Further, when the printing is finished at the place where the level of the remaining amount is changed (boundary of the step of the remaining amount), there is a possibility that the next printing may return to the original one level due to the variation in reading of the reflection sensor. Since the recording paper is basically decreasing, such an operation is a useless operation that only confuses the user.

In the case of a color electrostatic plotter, the maximum length is 10 m
Up to the long length color printing is possible, and the length of the recording paper roll is 150 m in the case of plain paper, which is about 6.7% of the length of the entire unused recording paper roll. Therefore,
When the method of displaying in 10% units is adopted, the amount of increase in the remaining amount is one stage (10%) at the maximum.

Therefore, as described above, in the present apparatus, firstly, the remaining amount is detected only when the recording paper is conveyed in the forward direction (discharging direction). The control unit 35 is always adapted to take in the output of the reflection sensor 43, whereby the state of the reflection plate 42 is constantly detected, and the number N of drive pulses until the two reflection plates 42 are detected is counted. However, the count value is used in the above calculation for detecting the remaining amount only when the recording paper is conveyed in the forward direction.

Further, in order to prevent the user from being confused, when the calculation result that the remaining amount k returns by one step is obtained, the control unit 35
Is set to ignore this. By taking these measures, the above inconvenience can be avoided.

Next, this apparatus is provided with a large number of means for detecting an abnormality in each part, and one of them is to consider the case where the remaining amount detection value is abnormal. FIG. 5 is an arrangement of the table of FIG. 4 in consideration of this. However, for the sake of space, here, only plain paper is shown without a frame.

As shown in FIG. 5, first, 0% and 10
A value of 0% was set with a margin in consideration of the sensor and other variations. Then, if the value outside that range is X
Out of the range, X1 indicates a case outside the range when the value exceeds 0%, and X2 indicates a case outside the range when the value exceeds 100%.

Here, as a case where the state of X1 out of the range may occur, there is a failure of the control circuit, a failure of the motor, an abnormality of the paper transport system, etc. when the recording paper is used up and the recording paper is used up. When the state of the out-of-range X1 is detected, the control section 35 controls the apparatus to immediately stop the machine and cut off the power supply to the drive section.

When the recording paper is used up, the end of the recording paper peels off from the recording paper roll core, and the recording paper roll core rotates in the reverse direction, and its rotation speed is faster than the rotation speed when the recording paper is slightly left. It is set.

Further, the possibility of the out-of-range X2 state may occur because the recording paper roll 1 is disengaged from the paper holder 41, the recording paper runs out, the recording paper is torn, or the motor is driven at a high speed due to an abnormality in the control system. For example, when the rotation starts. When the state of X2 out of range is detected, X out of range is detected.
As with case 1, the machine immediately shuts down the machine,
The control unit 35 controls to cut off the power supply to the drive unit.

In the embodiment described above, the number of drive pulses given to the drive motor (pulse motor) of the recording paper feed roller 11 is generated while the paper holder 41 is rotated by a predetermined amount. The remaining amount of the recording paper is detected by performing detection and calculation based on this, and the remaining amount k of the recording paper is "cross-sectional area R (k) ^{2 of} recording paper roll 1"-
It is proportional to “the cross-sectional area R (0) ² of the winding core of the recording paper roll 1”, and the rotation angle per drive pulse of the pulse motor is fixed, and therefore the recording paper conveyance amount per drive pulse is determined. Is determined, and the number N of drive pulses during the rotation of the paper holder 41 by a predetermined amount is proportional to the cross-sectional area of the recording paper roll, it is possible to obtain k from the value of N, which affects the thickness. If the correction according to the given paper quality is taken into consideration, the remaining amount k of the recording paper can be grasped from the value of N, and the remaining amount k of the recording paper can be grasped. Therefore, the remaining amount of the recording paper is always displayed. Printing can be performed by knowing the remaining amount of recording paper, and by knowing in advance the remaining amount of recording paper, you can change the recording paper roll, etc. in a good operability state. In the middle of the transport route Are the deficiencies of the prior art, such as time-consuming recovery of the recording sheet had can be solved. Further, in this apparatus, the number N of drive pulses during the rotation of the paper holder 41 by a predetermined amount.
Since the remaining amount is calculated more, it is possible to obtain an advantage that the remaining amount can be obtained even when a recording paper roll that has been used halfway is newly set and used.

(Second Embodiment) In the embodiment described above, the recording paper feed roller 1 is rotated while the paper holder 41 is rotated by a predetermined amount.
This is a system in which the number of drive pulses given to one drive motor is detected and the calculation is performed based on this to know the remaining amount of recording paper.

Since the motor for driving the recording paper feed roller 11 uses the pulse motor, contrary to the above embodiment,
It is obvious that the same effect can be obtained by checking how many times the paper holder 41 has rotated before a predetermined number of drive pulses of the motor for driving the recording paper feed roller 11 are generated. Therefore, the present invention can be realized even with a configuration using this method.

(Third Embodiment) In the first embodiment, the types of recording paper to be used, such as "plain paper", "trepe", "film", and "synthetic paper", are manually operated by operating the control panel 36. It was a composition to give. It is also possible to adopt a configuration in which this can be given automatically rather than manually.

An example thereof will be described with reference to FIG. As a means for automatically detecting the paper type, a mechanism for indicating the paper type on a recording paper core (paper core) is provided, and various configurations in which the apparatus detects it and automatically sets the paper type are shown in FIG. .

FIG. 6A is a front view showing a state where the recording paper roll 1 is attached to the paper holder 41.
Reference numeral 1a is a pipe-shaped recording paper core, and 41a and 41b are disc-shaped receiving portions constituting the paper holder 41. Receiver 4
1a and 41b are arranged to face each other, and convex portions 41c and 41d that engage with the recording paper core 1a and press the recording paper core 1a from both ends are provided in the central portions of the opposing surfaces.

Chips 1b and 1c made of permanent magnets are embedded in the side surface of one end of the recording paper core 1a. The embedding position and number are determined according to the type of recording paper wound around the recording paper core 1a.

Switches SWA and SWB are provided on the surface of the receiving portion 41a that engages with the recording paper core 1a. These switches SWA and SWB are magnet chips 1b and 1c attached to the winding core 1a of the recording paper roll 1.
It is a reed switch that detects the presence or absence of

Therefore, on the winding core 1a of the recording paper roll 1,
Whether to attach or not attach the magnet tip is determined according to the type of recording paper, and the type is discriminated by the control unit 35 of the machine based on the detection output of the switches SWA and SWB. Since the detection output of the switches SWA and SWB constitutes a 2-bit signal, it is possible to discriminate four kinds of recording papers by the 2-bit signal.

The state of mounting the chips 1b and 1c and the switches SWA and SWB by magnets will be described in detail. FIG. 6B shows the winding core 1 a of the recording paper roll 1,
It has a pipe shape and is generally called a paper tube. Winding core 1a
A groove 1d is engraved on one end of the groove.

FIG. 6C shows a state in which the recording paper 2 is wound around the winding core 1a. It is engaged with the convex portion 41c of the paper holder 41 shown in FIG. 6 (d). The protrusion 41c of the sheet holder 41 has a protrusion 41e at one location on the peripheral surface, and the groove 1d engraved on the winding core 1a fits snugly on the protrusion 41e.

FIG. 6E shows the magnet chips 1b and 1c embedded in the end surface of the winding core 1a. FIG. 6F shows a switch SW by a reed switch on the paper holder 41.
A and SWB are attached. The outputs of the switches SWA and SWB are given to the control unit 35.

With such a structure, the recording paper roll 1
Is set on the paper holder 41, the winding core 1a of the recording paper roll 1 is engaged with the paper holder 41 without fail to keep its own positional relationship, and the switches SWA, SWB and the magnet chips 1b, 1c face each other. To do. Since the presence or absence of the magnetic chips 1b and 1c is determined according to the type of recording paper,
The output from the operation of the switches SWA and SWB can be used as a 2-bit signal indicating the recording paper type.

Therefore, the recording paper type can be automatically set, and can be used when the control unit 35 is made to recognize the recording paper type to perform the remaining amount calculation and the print control. that's all,
Although various embodiments have been described, the present invention is such that the remaining amount of recording paper is obtained from the cross-sectional area or winding diameter of the recording paper roll and the remaining amount is displayed. Is related to the drive amount of the recording paper transport system during the rotation of a predetermined amount, the drive amount of the recording paper transport system is used, and the recording paper remaining amount is obtained by adding the recording paper material to this. Even if the recording paper roll has an unknown remaining amount, the paper quality information of the recording paper can be given and the remaining amount can be detected and notified by carrying the recording paper. Moreover, this is the paper holder that holds the recording paper roll. It is possible to realize by simply providing a photoelectric detection mechanism for detecting the rotation amount, etc., and it is possible to detect and notify the remaining amount of recording paper while having a simple and inexpensive configuration, and it is possible to detect with sufficient accuracy. Roll recording done It is possible to provide a Karadazanryou detection device.

It is needless to say that the present invention is not limited to the above-mentioned embodiments, and can be carried out by appropriately modifying it within a range not changing the gist thereof. Further, in the embodiment of the present invention, the example applied to the color electrostatic plotter has been described, but the present invention can be applied to all apparatuses using a roll-wound recording medium, including a camera using a film. It is possible. Further, the remaining amount display and the error display are not limited to the character display, and various forms such as a sound display, blinking of a lamp, lighting of a lamp corresponding to the remaining amount, and the like can be used.

[0104]

As described in detail above, according to the present invention, it is possible to detect and notify the remaining amount with sufficient accuracy even with a recording paper roll whose remaining amount is unknown, while having a simple and inexpensive structure. It is possible to provide a roll-wound recording medium remaining amount detecting device which is made possible.

[Brief description of drawings]

FIG. 1 is a diagram for explaining an embodiment of the present invention,
The schematic block diagram which shows the example in case this invention is applied to a color electrostatic plotter.

FIG. 2 is a diagram for explaining an embodiment of the present invention,
The figure for demonstrating the principal part structure of this invention.

FIG. 3 is a diagram for explaining an embodiment of the present invention,
The figure which shows the structural example of the control panel of this invention apparatus.

FIG. 4 is a diagram for explaining an embodiment of the present invention,
The figure which shows the example of the remaining amount conversion table used by this invention.

FIG. 5 is a diagram for explaining an embodiment of the present invention,
The figure which shows the example of another remaining amount conversion table used by this invention.

FIG. 6 is a diagram for explaining an embodiment of the present invention,
FIG. 6 is a diagram for explaining a structure for automatically detecting a recording paper material which is another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Electrostatic recording paper roll 1a ... Core (paper tube) 1b, 1c ... Magnet chip 2 ... Recording paper 6a-6d ... Development head 11 ... Recording paper feed roller 35 ... Control part 36 ... Control panel 36a ... Display part 36c ... switch (paper selection key) 41 ... paper holder 42 ... reflector 43 ... reflection sensor 44 ... DC motor SWA, SWB ... switch

Claims (4)

[Claims] 1. A transport device having a transport means for holding a roll-wound recording medium rotatably by a holding means, and driven by pulse control to feed and roll the roll-wound recording medium in units of a predetermined amount. As a roll-wound recording medium remaining amount detecting device for use, type information giving means for giving type information of the roll-wound recording medium, signal generating means for generating a detection signal each time the roll-wound recording medium rotates by a predetermined amount, Counting means for counting the number of pulses in the detection signal generation period by the signal generating means, the remaining amount of the roll-wound recording medium is proportional to the diameter or cross-sectional area of the roll-wound recording medium, and the count value And a calculation means for calculating the remaining amount according to the material of the roll-wound recording medium from the count value by utilizing the proportional relationship between Rolled recording medium residual amount detection device, characterized in that constructed by providing means for performing constant-processing, the. 2. A roll-wound recording medium remaining amount detecting apparatus according to claim 1, wherein display means is provided and the specific processing is display of the calculation result on the display means. 3. The roll-wound recording medium remaining amount detecting apparatus according to claim 1, wherein the specific processing is to stop the conveyance. 4. A roll-wound recording medium remaining amount detecting device according to claim 1, wherein an error display means is provided and an error display is given to the error display means as the specific processing.