JPS62211249A - Position detecting method - Google Patents

Abstract

PURPOSE:To surely detect a position, by detecting a light transmittable pattern formed in a band-like light absorbing material at a predetermined position with the use of a light reflecting type photosensor. CONSTITUTION:A light transmittable pattern 100 is formed in a band-like ink ribbon I (light absorbing material) at a predetermined position, and a light- reflecting material 104 (the outer surface of a casing for a thermal head) is located at a position opposing a light reflecting type photosensor 103, the ink ribbon 1 being disposed between the material 104 and the sensor 103. Further, when the light transmittable pattern 100 passes between the sensor 103 and the material 104, the light emitted from a light emitting element in the reflective type photosensor 103 is reflected upon the light reflecting material 103 through the light transmittable pattern 100, and then reaches a light receiving element to detect a predetermined position on the ink ribbon I. As a result it is possible to surely detect a certain position on the ink ribbon.

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Industrial Application Field The present invention relates to a position detection method, and more particularly to a position detection method for detecting a predetermined position on a strip-shaped light-absorbing object using a reflective optical sensor. .

(B) Conventional technology When detecting a predetermined position of a band-shaped light-absorbing object, it is impossible to detect it with an optical sensor in its original state. was performing detection.

For example, a pattern is formed by coating or pasting a light-reflecting material on a predetermined position of a strip-shaped light-absorbing object.
A method of detecting this using a reflective optical sensor has been used.

Especially in the case of ink ribbons for color printers, which are made by coating ink of each color on a transparent substrate such as polyester,
It was necessary to detect the leading edge of each color, and even for a normal single-color ink ribbon, it was necessary to detect its terminal end, but in either case, the conventional detection method described above was employed.

(C) Problems to be Solved by the Invention However, when applying or pasting a light-reflecting substance on a predetermined position of a strip-shaped light-absorbing object, the number of processing steps increases accordingly, and the cost also increases. There is a possibility.

Therefore, an object of the present invention is to provide a position detection method that is inexpensive and can reliably detect a predetermined position of a band-shaped light-absorbing object.

(D) Means for Solving the Problems In the position detection method according to the present invention, a light-transmitting pattern is formed at a predetermined position of a strip-shaped light-absorbing object, and the light-absorbing object is conveyed. A reflective optical sensor consisting of a light-emitting element and a light-receiving element is provided at a position in the width direction that corresponds to the light-transmitting pattern, and the reflective optical sensor is installed with the light-absorbing object in between. A light reflective object is provided at a position facing the optical sensor, and when the light transmitting pattern passes between the reflective optical sensor and the light reflective object, light is emitted from the light emitting element of the reflective optical sensor. The light reflected by the light-reflecting object is reflected by the light-reflecting object through the light-transmitting pattern, and the light reaches a light-receiving element to detect a predetermined position of the light-absorbing object. It is something.

Note that the band-shaped light-absorbing object may be ink on an ink ribbon, and furthermore, the light-reflecting object may be the surface of a thermal head support.

(E) Effect When the light-transmitting pattern formed at a predetermined position on the band-shaped light-absorbing object passes between the reflective optical sensor and the light-reflective object, light is emitted from the light emitting element of the reflective optical sensor. light reaches the light-reflective object through the light-transmissive pattern;
Since the reflected light further reaches the light-receiving element of the reflective photosensor via the light-transmitting pattern, a predetermined position of the light-absorbing object can be detected.

Further, when the band-shaped light-absorbing object is an ink ribbon, by providing a light-transmitting pattern at the leading end of each color or the trailing end of the ink ribbon, these can be easily detected.

Furthermore, when the light reflective object is the surface of the thermal head support, there is no need to newly provide a light reflective object.
The configuration is simple.

(F) Example Next, a case in which the position detection method according to the present invention is applied to a color thermal transfer recording apparatus will be described with reference to the drawings.

FIG. 3 is an external perspective view of the color thermal transfer recording device.

In FIG. 3, the color thermal transfer recording device 1 has a paper feed cassette 2 for storing transfer paper, a manual feed section 3, and a paper ejection section 4 integrated on the top surface of a body 10 consisting of an upper frame 8 and a lower frame 9. A manual feed and wandering paper tray 5 is provided. In addition, on the front side of the upper surface of the aircraft IO, there is an operating section 6 on the right side in the figure, and a so-called Talamusiel release button on the left side for releasing the upper frame 8 from the lower frame 9 and dividing it into two parts as shown in the third figure. A release lever 7 is provided for this purpose.

FIG. 4 is a sectional view of the color thermal transfer recording device 1, and the fifth
The figure is a sectional view when the shell is released with the ink ribbon conveyance path as its boundary. As is clear from FIG. 5, the upper frame 8 is rotatable about a shaft 42 relative to the lower frame 9, and a portion of the transfer paper conveyance system 11 and the ink ribbon conveyance system 12 are formed in the upper frame 8. , most of the ink ribbon transport system 12 is formed in the lower frame 9.

The transfer paper conveyance system 11 includes, in order along the transfer paper conveyance direction, paper feed cassettes 2 that are attached to a cassette insertion opening 13 provided at the upper rear side of the upper frame 8 and have transfer paper P loaded therein. , a paper feed roller 14 that feeds the transfer paper P one by one from the paper feed cassette 2, and guide plates 15a and 15 that guide the paper fed from the paper feed roller 14.
b, a registration roller 19 for aligning the leading edge of the paper and correcting skew feeding, a guide plate 1G for guiding the transfer paper P sent from the registration roller 19, and a registration roller 19 and a platen roller during paper feeding. 20 (described later), and during reverse feeding, the platen roller 20 and the reverse feeding roller 2
7 (described later), a guide plate 17 that can be switched by a switching means (not shown), a platen roller 20 that forms a transfer section T in combination with a thermal head 23 provided on the lower frame 9, and a platen A pinch roller 22 that contacts the roller 20 and prevents the transfer paper P from shifting; a platen roller 20 and a pinch roller 22;
a guide plate 18 that guides the transfer paper P from the nip point with the paper discharge section 4 directions to be described later; a discharge roller 24 that discharges the transfer paper P to the paper discharge section 4; and a transfer paper sent out by the discharge roller 24. A paper ejection section 4 of a manual feed/ejection tray 5 that receives the paper P is formed to form a substantially U-shaped conveyance path.

The manual feed/ejection tray 5 is provided in front of the paper feed cassette 2 and consists of the paper ejection section 4 and a manual feed section 3 formed behind the paper ejection section 4, and receives the transfer paper P inserted from the core insertion section 3. a manual feed roller 25 that feeds the registration roller 19;
At that time, guide plates 15b and 15C that guide the transfer paper,
It is formed as a manual feed path separate from the normal paper feed path from the paper feed cassette 2, and merges with the registration rollers 19.

Further, a transfer paper reverse feed path 26 is provided between the manual feed section 3 and the paper discharge section 4 of the manual feed/sheet ejection tray 5, and a transfer paper reverse feed path 26 is provided between the platen roller 20 and the transfer paper reverse feed path 26. A reverse feed roller 27 is provided to convey the transfer paper P that has been reversely fed from 20 to a transfer paper reverse path 26.

Next, the ink ribbon transport system 12 will be described.

The ink ribbon I is housed in an ink ribbon cartridge 28, is fed out from an ink ribbon supply section 29, and is wound up by an ink ribbon winding section 30. Between the ink ribbon supply section 29 and the ink ribbon take-up section 30, there are provided in order on the upper frame 8 side along the ribbon conveyance direction, and a device for feeding out the ribbon I fed out from the ink ribbon supply section 29 at a constant rate. An idle roller 31 that regulates the position is provided on the lower frame 9 side, and the idle roller 3
1. Back tension roller 32 which is combined with 33 (described later) to give appropriate tension to the ink ribbon ■
．． An idle roller 33 is provided on the upper frame 8 side and keeps the distance between the ribbon sensor 34 and the ribbon 71 constant. A ribbon sensor 34 is provided on the upper frame 8 side and is composed of a reflective photosensor that reads the identification marks of each color marked on the tip of each color of the ink ribbon (3). Thermal head 23 is provided on the lower frame 9 side and melts the ink and transfers it onto the transfer paper P by selectively applying heat to a heating element. A guide/separation member 40 that is provided integrally with the thermal head 23 and separates the transfer paper P and the ink ribbon I after thermal transfer. To remove slack, a ribbon tension roller 50 is pressed against the separated ink ribbon 1. A winding auxiliary roller 35 is also provided for winding up the separated ink ribbon (2) with a constant torque.

36 is a head positioning and pressure release device for positioning the thermal head 23 and the platen roller 20 and releasing pressure on the head 23. The head/throat positioning and pressure release device 36 is comprised of a sliding means 37 in the left-right direction in the plane of the drawing, and a sliding means 38 in a direction perpendicular to the sliding means 37. That is, the slide means 37
b and a sliding member 37a that slides relative to the rail member 37b, and the shell is released.
When transitioning from the state shown in Fig. 5 to the state in which the shell is closed (the state shown in Fig. 4), the head positioning and pressure release device 36
The bearing part 41 is provided at the upper part of the platen roller 20 and has an inlet part slightly wider than the bearing part 41 of the platen roller 20. Further, the slide means 38 that slides in a direction perpendicular to the slide means 37 is composed of a slide member 38a that is slidable relative to a rail member 38b fixed at a predetermined position of the slide member 37a, The sliding member 38
A thermal head 23 is fixed to a. Movement of the slide means 38 is controlled 11 by a solenoid, not shown. That is, when the solenoid is energized, the thermal head 23 comes into pressure contact with the platen roller 20, and when the solenoid is demagnetized, the thermal head 23 is separated from the platen roller 20. Further, the gutter 23 is rotatable left and right about a shaft 39 provided at the center in the width direction at the upper part of the head positioning and pressureless release device 36.
The head 23 is configured to apply uniform pressure to the platen roller 20 in the width direction (direction perpendicular to the plane of the paper).

FIG. 2 is a top view of the ink ribbon I, and the ink ribbon I has a transparent substrate 101 made of polyester or the like (
1), ink 102 of yellow (Y), magenta (M), cyan (C), black (B), etc. is sequentially and repeatedly applied to a predetermined area. At the tip of each color, the part to which ink 102 is not applied forms a certain pattern, and a light-transmissive pattern 10
It constitutes 0. That is, when printing with a color printer, the transfer paper P and the ink ribbon 1 of the first color are conveyed in a stacked manner to print the -th cycle, and then only the transfer paper P is conveyed backwards and its leading edge is Overlap the tip of the color,
The operation of carrying out the second cycle of printing while conveying the transfer paper P and the ink ribbon I again is repeated.
At this time, in order to match the leading edge of the transfer paper P with the leading edge of the ink ribbon (2), it is necessary to detect the leading edge of the ink ribbon (I) in each cycle. In order to form this light-transmissive pattern 100, ink 10 of each color is
When applying 2 to the substrate, it is only necessary to mask that part so that the ink 102 is not applied, so the processing is relatively easy compared to the case where a new white or silver ink is applied for the pattern. Also, the cost is not so high.

FIG. 1 is a schematic diagram showing a method for detecting a light-transmitting pattern on an ink ribbon (2). Reflective optical sensor 10
3 are disposed in the direction perpendicular to the plane of the paper along the transport path of the ink ribbon (3), corresponding to the respective positions of the light-transmitting patterns 100. .

The reflective optical sensor 103 has a light emitting element and a light receiving element arranged side by side, and usually detects the presence or passage of a light reflective object such as paper. However, in this case, the detected object is
Ink 102 as a light-absorbing substance and light-transmitting pattern 10
Since it is an ink ribbon (■) with 0 and 0, it is impossible to detect any of them.

Therefore, the reflective optical sensor 103 is inserted between the ink ribbon ■.
By providing a light-reflecting object 104 at a position facing the light-transmitting pattern 100 and reflecting the light that has passed through the light-transmitting pattern 100 and guiding it to the light-receiving element, it is possible to detect the tip of each color of the ink ribbon I. It is said that In addition, ink 102
Even though it is said that it is a light-absorbing substance, for example, yellow (Y
) etc., the light passes through the part where the ink 102 is applied and is reflected by the light-reflecting object 104 and the light-transmitting pattern 100 passes through the light-reflecting object 104. It is necessary to set the detection level of the reflective optical sensor 103 in advance in order to distinguish the reflected light from the reflected light.

Furthermore, the light-transmitting pattern 100 can also be detected by a transmission-type optical sensor, but a transmission-type optical sensor must be installed above and below the object to be detected, which tends to cause errors in installation, and wiring. It is preferable to install the ribbon near the transfer section because the processing becomes complicated, and when it is applied to a color thermal transfer printer, there will be no wastage of the ribbon. Reflective optical sensors are preferable because there is not enough space to install an optical sensor.

Next, the operating status of the color thermal transfer recording apparatus 1 will be explained with reference to FIGS. 6(a) to 6(g). In FIG. 6(a), the transfer paper p fed by the paper feed roller 14 is once aligned at the leading edge by the registration roller 19, and then transferred to the transfer portion T.
sent to. The transfer paper P is guided by the guide portion 40 a of the guide/separation means 40 and conveyed along the circumferential surface of the platen roller 20 . When the transfer paper P is nipped at the nip point between the pinch roller 22 and the platen roller 20, the conveyance of the transfer paper P is temporarily stopped. On the other hand, at the same time as the registration roller 19 starts to rotate, the ink ribbon I is fed out so that its tip will send the detected first color, that is, yellow (Y), to the transfer section T. Note that at this time, the heating element of the thermal head 23 is not energized.

In FIG. 6(b), the head positioning prepressure release device 2
Since the solenoid No. 3 (not shown) is demagnetized and the sliding member 38a slides downward with respect to the rail member 38b, the thermal head 23 is separated from the platen roller 20. At this time, with the clutch means (not shown) provided on the registration roller 19 disconnected, that is, with the registration roller 19 free, the main motor is driven to rotate in the normal direction and the platen roller 20 rotates. Due to the resistance when the registration rollers 19 follow, the slack in the transfer paper P is corrected and tightened at the nip point between the platen roller 20 and the pinch roller 22 and between the pair of registration rollers 19.

In FIG. 6(c), the head positioning prepressure release device 3
When the solenoid 6 is energized, the thermal head 23 is pressed against the platen roller 20. Then, the heating element of the head 23 is energized and printing is performed. At this time, the transfer paper P and the ink ribbon I, which have passed through the transfer section T, are separated at the corner 40b of the guide/separation means 40. The ink ribbon (2) separated by the guide/separating means 40 is then removed by ribbon tension rollers 50 to remove the slack formed from the boundary between the image forming area and the non-image forming area to the inside. This prevents transfer defects caused by the spread to the T direction. Furthermore, in order to remove slack from the ink ribbon I during printing, the driving speed of the back tension roller 32 is set to the platen roller 2.
It is preferable to set the drive speed to be slightly slower than the zero drive speed, and to use a material with a high coefficient of friction, such as sponge or rubber, as the material for the back tension roller 32. The circumferential speed difference with the platen roller 20 is corrected by slipping the ribbon between the back tension roller 32 and the ribbon. Therefore, regardless of the diameter of the ink ribbon I, a constant bank tension is always applied so that the ink ribbon I is fed evenly without slack. Further, the driving peripheral speed of the winding auxiliary roller 35 is set to be slightly faster than the driving peripheral speed of the platen roller 20, and
The upper roller 5 is made of a material with a high friction coefficient such as rubber, and the lower roller is made of iron or the like. That is, the ink ribbon I is wound up at the ink ribbon winding section 3o, but since the winding force at the ink ribbon winding section 30 changes depending on the diameter of the ink ribbon I, the ink ribbon winding section By interposing the take-up auxiliary roller 35 between the platen roller 20 and the platen roller 20, the ink ribbon is kept under constant tension!
While pulling the winding auxiliary roller 35, the excess rotational force
By using a structure in which the material slips, that is, only the lower roller is driven, and the upper roller only rests on the lower roller due to its own weight, the material escapes and stable winding is performed.

The circumferential speed of the drive applied to the ink ribbon winding section 3o via the friction plate is set higher than the circumferential speed of the drive applied to the winding auxiliary roller, and the rolled ink ribbon itself in the ink ribbon winding section 30 is The difference between the circumferential speed of the drive and the circumferential speed of the drive is caused to slip at the friction plate.

In FIG. 6(d), when printing of the negative color is completed, the main motor stops and the head positioning prepressure release device 36
The solenoid is demagnetized, and the thermal head 23 is separated from the platen roller 20. Then, the guide plate 17 is switched from the position indicated by the solid line to the position indicated by the two-dot chain line, and the paper conveyance path is switched from the registration roller 19 side to the reverse feed roller 27 side. At this time, the rear end of the transfer paper P is placed on the guide plate 17.
When the guide plate 17 is switched, the reversing roller 2
Turn to the 7th side.

In FIG. 6(f3), the main motor rotates in reverse, and the transfer paper P is fed backward. At this time, since the driving speed of the reverse feed roller 27 is set to be slightly higher than the drive speed of the platen roller 20, the transfer paper P is reversely fed without causing any slack. The surplus rotational force that exceeds the rotational force necessary to pull the transfer paper P with a constant tension is eliminated by configuring the reverse feed roller 27 to be slipped. That is, the upper roller of the reverse feed roller 27 is made of a material such as sponge so that a certain amount of frictional force is applied thereto and it can slip. In addition, since the guide/separation member 40 is also lowered together with the thermal head 23, the transfer paper P and the ink ribbon 1 are completely separated, and when the transfer paper P is being fed backwards, the ink ribbon I is also fed out at the same time. then move the tip of the next color to the ribbon sensor 34.
It can be detected by Discrimination of each color of ink is performed by reading the color identification mark constituted by the light-transmitting pattern 100 provided at the tip of each color as described above. At this time, as the ribbon sensor 34, several reflective photosensors are arranged in the width direction of the machine body, and the light emitted from the light emitting part is absorbed in the part where the ink 102 of each color is applied. The light transmitted through the light-transmitting pattern 100 is transmitted through the portion where the light-transmitting pattern 100 is formed, but the light that has passed through the light-transmitting pattern 100 passes through the thermal head 23 formed of a light-reflecting material such as aluminum.
is reflected on the casing surface of the ribbon sensor 34.
incident on the light receiving section. Therefore, it is possible to create several types of identification marks depending on where the light-transmitting pattern 100 is provided in the width direction of the ribbon I.

In FIG. 6(f), when the platen roller 20 is reversed by the same amount as the transfer paper P is fed for image formation, the main motor is stopped.

At this time, the leading edge of the transfer paper P is in a state of being nipped by the platen roller 20 and the pinch roller 22, so that positional deviation will not occur during the next printing. On the other hand, after the ribbon sensor 34 detects the leading edge of the next color, the ribbon 1 is further fed by a predetermined number of pulses, and the leading edge of the ribbon 1 is sent to the head 23.
When the winding motor (not shown) is located at the heating element, the winding motor (not shown) is stopped.

In FIG. 6(g), the solenoid of the head positioning and pressure release device 36 is energized again, and the thermal head 23 is pressed against the platen roller 20.

Then, the main motor rotates forward and printing of the second color is started. At this time, since the reverse feed roller 27 is connected to the drive means via a one-way clutch, the drive is not actively transmitted and is only driven as the transfer paper P moves by the drive of the platen roller 20. be. As mentioned above, the upper roller of the reverse feed roller 27 is made of a material such as sponge, and since the reverse feed roller 27 is driven to rotate by the conveying force of the transfer paper P, the circumferential speed of the reverse feed roller 27 itself is The peripheral speed is the same as or slightly slower than the peripheral speed of the platen roller 20 itself, and as a result, the transfer paper P is conveyed under tension.

After printing the second color, when it is desired to print the third color, the operations shown in FIGS. 6(d) to 6(g) are repeated.

Note that various other methods can be considered as a method for forming the light-transmissive pattern 100.

For example, a region to be coated with black (B) may be provided between each color, and that portion may be coated with black (B) except for the light-transmissive pattern (100).

In that case, the light from the reflective optical sensor 103 is black (
B) Since it is reliably absorbed when it hits the light-reflecting object 1, it passes through the light-transmitting pattern 100 as described above.
In order to distinguish between the light reflected by the light reflecting object 104 and the light that is transmitted through the yellow (Y) portion and reflected by the light reflective object 104, for example, there is no need to perform operations such as setting a comparison level. It's okay.

It is also possible to form holes by punching holes in the ink ribbon I. In that case, it can be applied to detecting the position of any light-absorbing object. That is, even if the ink 102 or the like is not applied to the transparent substrate 101, a light-transmitting pattern can be easily formed.

Further, in the above embodiment, the casing of the thermal head 23 is made of a material with a high reflection coefficient to reflect the light that has passed through the light transmitting pattern 100. A sexual object may also be provided.

(G) Effects of the Invention The position detection method according to the present invention forms a light-transmitting pattern at a predetermined position on a strip-shaped light-absorbing object, and connects the light-transmitting pattern to a reflective optical sensor and a light-reflecting object. Since the detection is performed using the following, the following specific practical effects are achieved.

That is, a light-transmitting pattern for detecting a predetermined position of a strip-shaped light-absorbing object is formed by providing a portion where no light-absorbing material is applied, or by punching holes in the light-absorbing object. Regardless of the method used, the processing for forming a light-transmitting pattern on the light-absorbing object is relatively easy and can be easily formed, and the cost is not so high. To detect a specific position of a sexual object, we did not use a transmission type optical sensor, but instead used a reflective type optical sensor and a light reflective object. There is no need to perform wiring processing, and wiring processing is relatively easy.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram showing a state in which the position of a light-transmitting pattern formed on a light-absorbing object is detected, Fig. 2 is a plan view of an ink ribbon, which is an example of a light-transmitting object, and Fig. 3 is a A perspective view of the external appearance of a thermal transfer recording device to which the position detection method according to the present invention is applied, FIG. 4 is a longitudinal sectional view thereof, FIG. 5 is a longitudinal sectional view when the shell is released, and FIGS. ) is an operational diagram of the thermal transfer recording device. 23...Thermal head. 34... Ribbon sensor. 100...Light transmittance pattern. 103... Reflective optical sensor. 104...Light reflective object. ■...Ink ribbon (light-absorbing object).

Claims (3)

[Claims] (1) A light-transmitting pattern is formed at a predetermined position on a strip-shaped light-absorbing object, and the position in the width direction of the light-absorbing object corresponds to the light-transmitting pattern while the light-absorbing object is being conveyed. a reflective optical sensor consisting of a light-emitting element and a light-receiving element is provided at a position, and a light-reflective object is provided at a position facing the reflective optical sensor with the light-absorbing object in between, and the light-transmitting pattern passes between the reflective optical sensor and the light-reflective object, the light emitted from the light-emitting element of the reflective optical sensor is reflected on the light-reflective object via the light-transmitting pattern. A position detection method characterized in that the light reaches a light receiving element to detect a predetermined position of the light absorbing object. (2) The position detection method according to claim 1, wherein the band-shaped light-absorbing object is ink on an ink ribbon. (3) The position detection method according to claim 2, wherein the light reflective object is a casing surface of a thermal head.