JP2009056761A - Printer and mark detection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printer capable of reducing a disposal area formed between images sequentially printed on a recording medium and to provide a mark detection device which reliably carry out positioning when a plurality of inks are overlapped and transferred onto the recording medium. <P>SOLUTION: A first recording unit 11 prints marks M1/M2/M3 having components of particular colors and the image of a first color on the recording medium 2, a recording unit 12 of each color disposed in the downstream side of the first recording unit, and the mark detection devices 31 and 32 disposed for the recording units 11 and 12 of the first and each of the colors, respectively, are provided. A control unit 50 prints the first and second marks M1 and M2 before printing a first-color image 11p of a color recording image of a first sheet in the first recording unit 11, then prints an image 11P while controlling the printing position based on the mark of two images before, and subsequently prints a corresponding mark. The recording unit 12 of each color prints an image 12p while controlling the print position based on the mark of two images before. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a printer that prints a plurality of colored images such as color photographic images, and in particular, a plurality of recording units that print various color inks are provided along the conveyance direction of a recording medium. The present invention relates to a tandem printer and a mark detection device that is disposed in the printer and detects a mark printed on a recording medium.

  Conventionally, a tandem printer having a plurality of color ink ribbons has been used as one means for printing a color image or the like on a recording medium such as recording paper.

  As an example of this tandem printer (hereinafter simply referred to as “printer”) 101, as shown in FIG. 12, a plurality of recording units 111, 112, 113 having ink ribbons 111a, 112a, 113a, 114a are provided. , 114 and transport units 121, 122, 123, 124 for transporting the recording medium 102. The ink ribbons 111a, 112a, 113a, 114a provided in the recording units 111, 112, 113, 114 are, for example, cyan (C), magenta (M), yellow (Y) or Any one color of black (K) is applied on the surface to form a belt shape. The recording units 111, 112, 113, and 114 thermally transfer the ink ribbons 111a, 112a, 113a, and 114a having any one of the colors described above and the inks of the ink ribbons 111a, 112a, 113a, and 114a. Thermal heads 111b, 112b, 113b, 114b are provided. The printer 101 is provided by changing the colors of the ink ribbons 111a, 112a, 113a, and 114a disposed in the recording units 111, 112, 113, and 114, respectively. The plurality of recording units 111, 112, 113, 114 are sequentially arranged along the conveyance direction of the recording medium 102, and are passed through the ink ribbons 111 a, 112 a, 113 a, 114 a mounted inside. It is disposed at a position where it abuts on the recording medium 102. The recording units 111, 112, 113, 114 are referred to as a first recording unit 111, a second recording unit 112, a third recording unit 113, a fourth recording unit 114 from the most upstream side in the conveyance direction of the recording medium 102. To do.

  Each of the recording units 111, 112, 113, 114 is transported to the positions facing the thermal heads 111b, 112b, 113b, 114b via the ink ribbons 111a, 112a, 113a, 114a and the recording medium 102, respectively. Platen rollers 121b, 122b, 123b, and 124b included in the units 121, 122, 123, and 124 are provided. Further, on the downstream side with respect to the conveying direction, cylindrical feed rollers 121a, 122a, 123a, and 124a are arranged to face each other.

  In the printer 101 formed as described above, when the recording start position of the recording medium 102 reaches a position facing the first recording unit 111, the platen roller 121b is pressed against the thermal head 111b provided in the first recording unit 111. Let Specifically, the thermal head 111b provided in the first recording unit 111 is headed down to the first platen roller 121b facing the first recording unit 111, or the first platen roller 121b is moved to the first recording unit 111 side. To up. Then, the first recording unit 111 and the first platen roller 121b are brought into pressure contact with each other via the recording medium 102 and the ink ribbon 111a, so that, for example, Y (yellow) is applied to the recording medium 102 by the first recording unit 111. ) Ink is transferred.

  Subsequently, when the recording start position reaches a position facing the second recording unit 112, the thermal head 112 b provided in the second recording unit 112 is moved down, or the second platen facing the second recording unit 112. The roller 122b is raised. Then, the second recording unit 112 and the second platen roller 122b are brought into pressure contact with each other via the recording medium 102 and the ink ribbon 112a, so that the second recording unit 112 causes M (magenta) from above Y ink. The ink is transferred.

  In this way, the ink is transferred to the recording medium 102 to be printed by sequentially heading down from the upstream recording unit in the conveyance direction of the recording medium 102 or by sequentially raising the upstream platen roller. A desired color image is printed by applying a plurality of inks on the recording medium 102 (see Patent Document 1).

  In order to perform the above-described series of operations accurately, the print start positions of the images of the respective colors to be printed must be the same in any recording unit 111, 112, 113, 114. In order to match the print start positions of images printed by the recording units 111, 112, 113, and 114, generally, the number of steps of the motors disposed in the transport units 121, 122, 123, and 124 is recorded. The control unit 150 controls the medium transport amount. However, in this method, when the conveyance amount of the recording medium 102 is shifted during the conveyance due to the deflection of the recording medium 102, the print start position of the image varies depending on the recording units 111, 112, 113, and 114. was there.

  Therefore, as shown in FIG. 13, the first recording unit 111 disposed on the surface of the recording medium 102 supplied to the recording units 111, 112, 113, and 114 is disposed on the uppermost stream in the conveyance path of the recording medium 102. A mark M and an image corresponding to the mark M are printed in order, and in each of the recording units 112, 113, and 114 arranged thereafter, mark sensors 132, 133, and 134 are arranged as mark detection devices. A method of printing a desired color image by superimposing images using various inks after a predetermined timing is triggered by the detection of the marks by the mark sensors 132, 133, and 134. (See Patent Document 2).

JP 2000-263864 A JP 2006-188010 A

  When this method is employed, the mark sensors 132, 133, and 134 distinguish between a desired image printed on the recording medium 102 and the mark M so that the mark M can be easily detected. A blank portion (hereinafter, referred to as a non-printing area NP) must be formed in each of the recording units 112, 113, 114, and the non-printing area NP formed between the mark M and the image is at least each of the recording units 112, 113, 114. The distance between the mark sensors 132, 133, and 134 and the thermal heads 112b, 113b, and 114b is required. However, a portion where this mark is printed and a non-printing region NP formed before and after the mark are regions that are eventually cut out and discarded (hereinafter, referred to as a discarding region), and are therefore often included in the recording medium 102. Will be wasted.

  The mark sensors 132, 133, and 134 are complementary colors of colors applied by the first recording unit 11 (for example, when Y (yellow) is printed in the first recording unit 11, the complementary color is blue. ) Emitting light emitting elements 132a, 133a, 134a using LEDs (light emitting diodes) and light receiving elements 132b, 133b, 134b using general-purpose phototransistors. However, if bending or vibration (fluttering) occurs in the recording medium being conveyed, the amount of reflected light at the non-printing portion changes significantly, resulting in variations in the mark detection timing of the mark sensors 132, 133, and 134. As a result, the print start positions of the images printed by the recording units 111, 112, 113, and 114 are not matched, and there is a problem that a good recording result cannot be obtained stably.

  The present invention has been made in view of these points, and a printer capable of reducing the waste area formed between images sequentially printed on a recording medium to improve cost performance, and a plurality of recording media. It is an object of the present invention to provide a mark detection device for reliably performing alignment when transferring the inks in a superimposed manner and obtaining good image printing.

  In order to achieve the above-described object, a printer according to the present invention includes a transport unit that transports a recording medium, and a first color image and a mark having a component of a specific color printed on the transported recording medium. One recording unit, and at least one recording unit disposed downstream of the first recording unit, each color recording unit for printing an image of each color having a color component other than the first color image, A control unit for controlling the printing position of the mark, the printing position of the first color image, and the printing position of each color image, and one each upstream or downstream of the first recording unit and each color recording unit. A light emitting element that emits complementary color light of the mark toward the recording medium, and a light receiving element disposed at a position where the complementary color light reflected by the recording medium is incident And a mark detecting device including a preparative sequentially repeated overlaying images of each color on the image of the first color, printing a plurality of same color recorded image on the recording medium. Here, the recording units of each color mean three recording units excluding the first recording unit when the color of the ink ribbon provided in the printer is four colors of YMCK.

  As a feature of the printer of the present invention, the control unit includes a first mark and a second mark in the first recording unit before printing the first color image of the first color recording image. After that, each image is printed while controlling the printing position based on the two previous marks, and the control is performed so as to print the mark. Control is performed so that printing is performed while controlling the printing position based on the previous mark.

  The mark detection apparatus of the present invention includes a transport unit that transports a recording medium, a first recording unit that prints a mark having a specific color component and an image of a first color on the transported recording medium, At least one downstream from the first recording unit, each color recording unit for printing an image of each color having a color component other than the first color image, and the printing position of the mark; And a control unit that controls a printing position of the first color image and a printing position of each color image.

  Here, the recording units of each color mean three recording units excluding the first recording unit when the color of the ink ribbon provided in the printer is four colors of YMCK. The mark detection apparatus according to the present invention includes a light emitting element that is arranged one by one on the upstream side or the downstream side of the recording unit of each color and emits complementary color light of the mark toward the recording medium, and the recording medium A light receiving element disposed at a position where the complementary color light reflected by the light is incident. As a first feature, the mark detecting device is a plano-convex type between the light emitting element and the recording medium. The cylindrical lens is arranged with the spherical surface facing the light emitting element.

  As a second feature of the printer of the present invention, a slit for selectively passing the complementary color light reflected by the recording medium is formed between the recording medium and the light receiving element. The light receiving element.

  As described above, since the printer of the present invention has the above-described characteristics, the gap size between the mark and the image can be significantly reduced as compared with the conventional method. There is an effect that it is possible to improve the cost performance by reducing the formed waste area.

  In addition, since the mark detection apparatus of the present invention has the first feature, divergent light emitted from a light emitting element serving as a light source can be converted into parallel light by a cylindrical lens. Therefore, it is possible to increase the amount of light when the light emitted from the light emitting element is reflected on the non-printing portion. Accordingly, the level difference from the time when the light emitted from the light emitting element is absorbed by the mark and becomes non-reflecting can be enlarged, and as a result, the detection sensitivity of the mark by the mark detection device can be improved. it can.

  Furthermore, by having the second feature, the bullet-type light receiving element selectively receives the specularly reflected light that has been irradiated from the light emitting element and reflected by the recording medium and passed through the slit, thereby further providing a mark ( In particular, the detection sensitivity of the edge in the mark conveyance direction FD can be improved.

  As described above, according to the printer of the present invention, by including the mark detection device having the above-described configuration, it is possible to accurately print images of all colors at desired positions, thereby improving print quality. There is an effect that can be.

  Hereinafter, an embodiment of a printer according to the present invention will be described with reference to FIGS. The mark detection apparatus disposed in the printer of this embodiment is an embodiment of the mark detection apparatus of the present invention.

  Here, FIG. 1 is a front view of an embodiment of the printer of the present invention, FIG. 2 is a perspective view of a mark detection device disposed in the printer of this embodiment, and FIG. 3 is a plan view of the mark detection device of FIG. 4 is a sectional view taken along the line IV-IV and a conceptual diagram of the operation of the mark detection apparatus shown in FIG. 3, FIG. 5 is a sectional view taken along the line VV of the mark detection apparatus shown in FIG. FIG. 7 is a circuit diagram of a mark detection device according to the printer of the present invention. FIG. 8 is a mark detection device according to the printer of the present invention, the positional relationship between the mark and the image (a), the input signal (b) of the comparator, and the comparator. FIG. 9 to FIG. 10 are a front view (a) and a plan view (b) showing the printing position adjusting method of the present invention, and FIG. 11 is based on the mark and the mark. This shows the relationship with the print start position of the image whose print position is determined. It is a diagram.

  First, each member provided in the printer of this embodiment will be described.

  For example, as shown in FIG. 1, the printer 1 according to the embodiment of the present invention includes recording units 11, 12, 13, and 14 that print based on each color component included in image data, and a transport unit 21 that transports a recording medium 2. , 22, 23, 24, mark detection devices 31, 32, 33, 34 for detecting the alignment mark M, and a control unit 50 for controlling printing of each recording unit.

  Each recording unit 11, 12, 13, 14 disposed in the printer 1 of the present embodiment records each ink ribbon 11a, 12a, 13a, 14a to which ink of a specific color is applied and the ink. Each of the thermal heads 11b, 12b, 13b, and 14b that thermally transfer to the medium 2 is formed. Each of the recording units 11, 12, 13, and 14 is arranged in order along the conveyance direction FD of the recording medium 2, and each of the four recording units 11, 12, 13, and 14 is Y.multidot. Each ink ribbon coated with a color that is one of M, C, and K (yellow, magenta, cyan, and black) and that is different from the color of the ink of each of the other recording units 11, 12, 13, and 14 11a, 12a, 13a, 14a. In the present embodiment, the ink color of each ink ribbon 11 a, 12 a, 13 a, 14 a disposed in each recording unit 11, 12, 13, 14 is upstream with respect to the conveyance direction FD of the recording medium 2. They are arranged in the order of Y, M, C, K from the left side (left side in FIG. 1). In the following, the names of these recording units 11, 12, 13, and 14 are named in order from the upstream side with respect to the conveyance direction FD of the recording medium 2, in order from the first recording unit 11, the second recording unit 12, and the third recording unit 13. The fourth recording unit 14 is assumed. Also, the image printed by the first recording unit 11 is set as the first color image 11p, and the second color image 12p, the third color image 13p, and the fourth color image are similarly applied after the second recording unit 12. 14p. The order of colors applied to the ink ribbons 11a, 12a, 13a, and 14a disposed in the recording units 11, 12, 13, and 14 is not limited to the order of Y, M, C, and K. Good.

  Each transport unit 21, 22, 23, 24 arranged adjacent to each of the recording units 11, 12, 13, 14 includes at least a platen roller 21b, 22b, 23b, 24b, a feed roller 21a, 22a, 23a, 24a.

  The platen rollers 21b, 22b, 23b, and 24b are disposed below the thermal heads 11b, 12b, 13b, and 14b disposed in the adjacent recording units 11, 12, 13, and 14, respectively. The platen rollers 21b, 22b, 23b, and 24b are formed in a cylindrical shape or a columnar shape.

  A plurality of feed rollers 21a, 22a, 23a, and 24a are arranged on the downstream side of the recording units 11, 12, 13, and 14 with respect to the transport direction FD, and the feed rollers 21a, 22a, 23a, and 24a The shape is formed in a cylindrical shape or a columnar shape. A plurality of these feed rollers 21 a, 22 a, 23 a, 24 a are arranged in the printer 1 of this embodiment, and the plurality of feed rollers 21 a, 22 a, 23 a, 24 a are sandwiched from the front and back of the recording medium 2. Are disposed so as to have a positional relationship that allows them to be conveyed.

  The platen rollers 21b, 22b, 23b, and 24b and the feed rollers 21a, 22a, 23a, and 24a described above have their rotational axes arranged in a direction perpendicular to the conveyance direction FD of the recording medium 2, It is attached so that it can be rotated around the rotation axis. Further, the feed rollers 21a, 22a, 23a, and 24a described above have motors (not shown) for rotating the feed rollers 21a, 22a, 23a, and 24a.

  Each of the transport units 21, 22, 23, and 24 in the present embodiment described above is disposed adjacent to the downstream side of each of the recording units 11, 12, 13, and 14, and therefore, in the following, each of the transport units. The names 21, 22, 23, and 24 are named in order from the upstream side in the transport direction FD of the recording medium 2, from the first transport unit 21, the second transport unit 22, the third transport unit 23, and the fourth transport unit 24. And

  In the present embodiment, the mark detection devices 31, 32, 33, and 34 are attached adjacent to the downstream side of the fourth recording units 11, 12, 13, and 14 from the first recording unit, as shown in FIG. It has been. As shown in FIGS. 2 to 6, the mark detection devices 31, 32, 33, and 34 include light emitting elements 31a, 32a, 33a, and 34a and light receiving elements 31b, 32b, 33b, and 34b. Between the light emitting elements 31a, 32a, 33a, 34a and the recording medium 2, so-called plano-convex cylindrical lenses 31c, 32c, 33c, 34c have their spherical surfaces facing the light emitting elements 31a, 32a, 33a, 34a. It is arranged and formed.

  The light emitting elements 31a, 32a, 33a, and 34a are LEDs (light emitting elements) that emit complementary colors of colors applied by the first recording unit 11 (in the present embodiment, blue is the complementary color of Y (yellow)). Diode). Further, bullet-type phototransistors are used as the light receiving elements 31b, 32b, 33b, and 34b.

  Further, between the recording medium 2 and the light receiving elements 31b, 32b, 33b, and 34b, slits 31e of the mark detection devices 31, 32, 33, and 34 that selectively pass the complementary color light reflected by the recording medium 2; 32e, 33e, and 34e are formed. The slits 31e, 32e, 33e, and 34e are narrower in width in the transport direction FD (hereinafter simply referred to as the transport direction FD) of the recording medium 1 than the mark M for printing position printing printed in the first recording unit 11. It is formed in a short size in the width direction of the medium (direction perpendicular to the transport direction).

  The mark detection devices 31, 32, 33, and 34 described above are arranged at positions where the alignment mark M (see FIGS. 9 to 11) is conveyed below the mark detection devices 31, 32, 33, and 34. Has been. The mark detection devices 31, 32, 33, and 34 are arranged from the recording medium 2 to the mark detection devices 31, 32, 33, and 34 according to the detection function of the mark detection devices 31, 32, 33, and 34 to be used. The distance is set.

  The mark detection apparatus according to the present embodiment has at least the characteristics (static characteristics) when detecting a fixed recording medium and the characteristics (dynamic characteristics) when detecting a recording medium being conveyed at least in Table 1. It has been confirmed by the following verification experiment that it is excellent in the specification shown.

  In this verification experiment, ten mark detection devices with provisional specifications shown in Table 2 were prepared and used as samples to grasp the variation in characteristics of each individual, and the optimum OD value of this mark detection device and the effects of LED dimming. The purpose is to bring the numerical value of the specification closer to the optimal one for implementation.

  Tables 3 to 6 to be referred to in Tables 1 and 2 are as follows.

And the measurement conditions in a verification experiment are as follows.
<1: Equipment used>
In-house yellow mark sensor examination jig, digital multi-tester (sanwa), DC stabilized power supply (manufactured by Kikusui), oscilloscope (Agilent Technologies), in-house XY scan driver (for SP motor drive on jig) , N4P TANDEM printer made in-house, block machine for examination, KEYENCE data collection system NR500
<2: Distance d (mm) between recording medium and sensor substrate>
Consider changing to 5.0 mm (contact state), 5.5 mm, 6.0 mm, 7.0 mm, 7.5 mm, and 8.0 mm.
<3: Sensor irradiation angle θ (°) = sensor detection angle>
Consider changing the angle from 0 ° to + 10 °.
<4: Measurement data (static characteristics)>
Measure sensor output voltage of white reflection, yellow reflection (OD value 1.70), yellow reflection (OD value 2.62). However, the recording medium is fixed without being conveyed.
<5: Measurement data (dynamic characteristics)>
A recording medium on which a mark (OD value 2.0) using yellow ink is printed with a width of 2 mm is conveyed at a speed of 2.0 ips, and the rise time tr (msec) of the mark detection pulse is measured with an oscilloscope. The definition of the rise time is the time until the mark detection waveform reaches 0.5V to 1.5V.

Next, an evaluation method and a measurement result will be described.
<1: Sensor-specific variation>
The static characteristics and dynamic characteristics are measured for a total of 10 prototype sensors. At this time, each sensor is in a state of d = 5.5 mm and θ ° = 0 °, and the variable resistance on the phototransistor side is adjusted so that the white reflection is 0.25V. The OD value of the mark is fixed at 2.6.

  Regarding the static characteristics, the white reflection output did not vary from one individual to another. The yellow reflection output had a variation of about 0.7 V at the maximum. However, since the change amount (slope) of the sensor output with respect to changes in θ ° and d is equal, there is no problem to be noted.

  As for the dynamic characteristics, the rise time fluctuation was kept within about 0.5 msec for each sensor even when θ ° was changed by 0 ° to 10 °. In each sensor, even when d varied in the range from 6.0 mm to 7.0 mm, the rise time fluctuation was within about 0.5 msec. In addition, the variation of the rise time absolute value for each individual is about 1.5 msec at the maximum.

Although there are variations in the absolute value of the rise time for each individual, if θ ° = 0 ° to 10 ° and d = 6.0 to 7.0 mm are set, the rise time fluctuation for each sensor will be within about 0.5 msec. , Found to be good.
<2: Effect of OD value>
Static characteristics and dynamics of one sensor using OD values as parameters in mark print samples using yellow ink with OD values of 0.8, 1.3, 1.8, 2.5, 2.6 Measure characteristics.

  Regarding the static characteristics, when the OD value changed from 0.8 to 2.6, the output changed by 1.5V. On the other hand, if the OD value decreases to 0.8, the detection range becomes 2.0 V or less when d> 6.0 mm, which is not suitable.

  And in order to ensure a sufficient detection range, it was confirmed that OD value needs 1.3 or more.

  Further, regarding the dynamic characteristics, when the OD value changed from 0.8 to 2.6, the absolute value of the rise time changed from 12 msec to about 8 msec. Moreover, in the range of θ ° = 0 ° to 4 °, the rise time fluctuation was within about 0.5 msec for each OD value.

  In addition, the optimum section of d (the section in which the rise time fluctuation falls within 0.5 msec) when the OD value is 0.8 is 5.0 to 6.0 mm, and the OD value is 1.0 to 2.5. In this case, the optimum interval for d was 5.5 to 6.5 mm, and the optimum interval for d when the OD value was 2.6 was 6.0 to 7.0 mm.

If the OD value is set to about 1.8, θ ° = 0 to 4 °, and d = 5.5 to 6.5 mm, even if the OD value differs by ± 0.5 for each individual, the rise time fluctuation Tends to be within 0.5 msec.
<3: Effects of LED dimming>
The static and dynamic characteristics of the sensor are measured with the LED current varied from 10 to 20 mA and the LED current as a parameter.

  Measurement results: Regarding static characteristics, when the luminous intensity decreased by half, the white reflection output increased by about 1.5 V and the yellow reflection output increased by about 1.0 V. It has been found that when the luminous intensity is 70% or less (If = 14 mA or less), the white reflection output may reach a threshold level or more, which is dangerous.

  As for dynamic characteristics, a decrease to a luminous intensity of 90% (LED current 18 mA) is permissible in order for rise time fluctuations to be within 0.5 msec at θ ° = 0-4 °, d = 5.5-6.5 mm. .

In the measurement of the influence of LED dimming, the rise time was defined as the time until reaching 1.0 to 2.0V. This is because when the LED current is dimmed, the white reflection output increases to 0.5 V or more, so that the rise time cannot be measured.
<4: Consideration of actual installation>
An actual machine equipped with recording units of three colors of yellow, magenta, and cyan, θ ° = 0 °, d = 6.0 mm, mark detection peak voltage 2.5 V, and OD value 1.6 in the mark detection device Prepared.

  In order to see the influence on the disturbance, the mark detection waveform until the first mark was detected at the start of printing was confirmed. In the temporary sensor of the sample, the flutter during conveyance of the recording medium that occurred with the conventional sensor was detected. Thus, it was confirmed that the provisional sensor of the sample was strong against disturbance.

  Further, although the color shift of the printed product was visually confirmed, no color shift occurred in the 30 printed products, and there was no problem.

  Further, as shown in FIG. 7, the electronic circuit formed to connect the mark detection device 31 to the control unit 50 is based on a threshold value TH that is a reference signal preset by the reference voltage rf. It has a comparator 31d that determines the magnitude relationship of the input signal AO obtained from the light receiving element 31b. As shown in FIG. 7, the input terminal formed in the comparator 31d is connected to the light receiving element 32b and the reference voltage rf. The output terminal formed in the comparator 31d is connected to the control unit 50 in order to transmit the output signal DO obtained from the comparator 31d. The electronic circuit is not particularly limited as long as it is a means for determining the magnitude relationship of the input signal AO with respect to the threshold value TH, and may be formed using an A / D converter or the like instead of the comparator 31d. . Further, the electronic circuit from the mark detection device 33 to the control unit 50 and the electronic circuit from the mark detection device 34 to the control unit 50 are formed in the same manner as the electronic circuit shown in FIG. In the following, the names of the mark detection devices 31, 32, 33, and 34 correspond to the names of the recording units 11, 12, 13, and 14, respectively, so that the first mark detection device 31, the second mark detection device 32, the first The three mark detection device 33 and the fourth mark detection device 34 are used.

This recording means is as shown in FIG.
(A) Print start position of the first mark M1,
(B) the printing start position of the second mark M2,
(C) Print start position of the first color image 11p in the first color recording image (D) Until printing of the mark M after the third mark M3 is started in succession to the first color image 11p Transport amount,
(E2) In printing the first color recording image, the transport amount from when the second mark detection device 32 detects the mark M1 to when the second recording unit 12 starts printing the second color image 12p. ,
(E3) In printing the first color recording image, conveyance from when the third mark detection device 33 detects the mark M1 to when the third recording unit 13 starts printing the third color image 13p. amount,
(E4) In printing the first color recording image, transport from when the fourth mark detection device 34 detects the mark M1 to when the fourth recording unit 14 starts printing the fourth color image 14p. amount,
(F1) In printing a color recording image after the second sheet, the first recording unit 11 corresponds to the mark M after the first mark detection device 31 detects the mark M after the second mark M2. A carry amount until printing of the first color image 11p is started,
(F2) In printing the color recording images after the second sheet, the second recording unit 12 corresponds to the mark M after the second mark detection device 32 detects the mark M after the second mark M2. A carry amount until printing of the second color image 12p is started,
(F3) In printing color recording images after the second sheet, the third recording unit 13 corresponds to the mark M after the third mark detection device 33 detects the mark M after the second mark M2. The fourth mark detection device 34 detects the mark M after the second mark M2 in the transport amount until the printing of the third color image 13p and (F4) the printing of the color recording image after the second sheet. Then, the print information relating to the transport amount from when the fourth recording unit 14 starts to print the fourth color image 14p corresponding to the mark M is recorded in advance.

In addition, this recording means can record the detection start position of the (') mark M detected by each mark detection device 31, 32, 33, 34.

  The transport amounts E2, E3, E4, F1, F2, F3, and F4 of the image 11p for which the print position is determined based on the mark M are expressed as (each image from the detection start position of the corresponding mark M). 11p, 12p, 13p, 14p to the print start position) − (distance from each mark detection device 31, 32, 33, 34 to each recording unit 11, 12, 13, 14), At least the distance between the mark sensors 31, 32, 33, and 34 of the recording units 11, 12, 13, and 14 and the thermal heads 11b, 12b, 13b, and 14b is set.

  The reason for individually setting the transport amounts E2, E3, E4, F1, F2, F3, and F4 is that an error in the arrangement positions of the mark detection devices 31, 32, 33, and 34 is taken into consideration. Further, the length in the transport direction FD of each mark M for alignment printed by the first recording unit 11 and the length in the transport direction FD of the non-printing area NP formed before and after each mark M are as follows. The detection functions of the mark detection devices 31, 32, 33, and 34 are such that the detection devices 31, 32, 33, and 34 have a length that allows the print start position and the print end position of the mark M to be reliably recognized. These are set in advance in accordance with the length of the image conveyance direction FD, and these settings are recorded in the recording means.

  Then, in the first recording unit 11, the control unit prints the first mark M1 and the second mark M2 before printing the first color image 11p of the first color recording image, and thereafter Controls printing of each image 11p while controlling the printing position based on the previous mark M, and then printing the mark M. In each color recording unit, each image 12p, 13p, 14p is controlled to be printed based on the previous mark M while controlling the printing position.

  Specifically, in the first recording unit 11, for the first color recording image, the second mark from the print start position B that has been transported by a preset transport amount from the print start position A of the first mark M1. Control is performed so that M2 is printed and the image 11p is printed from the print start position C which is also transported by a preset transport amount from the print start position A of the first mark M1. The distance from the detection start position A ′ of the mark M1 to the print start position C of the image 11 based on the mark M1 is at least the mark sensors 31, 32, 33, and 34 of the recording units 11, 12, 13, and 14. And the distance between the thermal heads 11b, 12b, 13b, and 14b. Further, the distance from the printing end position of the mark M after the mark M2 to the printing start position C of the image 11p to be subsequently printed is the length in the transport direction FD of the non-printing area NP formed after each mark M. .

  In the first recording unit 11, for the second and subsequent color recording images 11p, only the carry amount F1 obtained in advance from the detection start position B ′ of the mark M after the second mark M2 is used. The position of the conveyed recording medium is formed as a printing start position.

  Similarly, in the second to fourth recording units 12, 13, and 14, the images 12p, 13p, and 14p of the first color recording image are obtained in advance from the detection start position of the first mark M1. The position of the recording medium that has transported the transport amounts E2, E3, and E4 is formed as the print start position, and the second color recording image images 12p, 13p, and 14p also follow the second mark M. From the detection start position of the mark M, the position of the recording medium transported with the transport amounts F2, F3, and F4 determined in advance is formed as the print start position.

  Next, the operation of the present embodiment will be specifically described with reference to FIGS. 1, 9, 10, 11, and 12.

  In the printer 1 of the present embodiment, the transport unit 21, 22, 23, 24 causes the recording medium 2 such as recording paper to be transported in the transport direction FD (in FIGS. 1, 9, and 10) from the upstream side to the downstream side. Is transported from the left to the right).

  The first recording unit 11 that has received a command related to printing from the control unit 50 first uses the first mark M1 for printing alignment as the recording means at the printing start position of the first mark M1 recorded in the recording means. Printing is performed by thermally transferring Y (yellow), which is a color applied to the ink ribbon 11a, with a predetermined recorded length. The mark M printed by the first recording unit 11 is formed to have a length in the transport direction FD that can be detected by each mark detection device 32, 33, 34.

  Subsequently, as shown in FIG. 9, the second mark M2 is applied to the ink ribbon 11a at a printing start position of the second mark M2 recorded on the recording means with a predetermined length recorded on the recording means. Printing is performed by thermally transferring Y (yellow), which is the color that has been performed.

  Further, the first color image 11p is printed from the print start position of the first color image 11p of the first color recording image recorded in the recording means, and then the mark M is printed from the print start position. To do.

  When the first recording unit 11 prints the first color image 11p in this manner, as shown in FIG. 10, the print start position of the first color image 11p from the print end position of the mark M printed just before. A non-printing area NP that does not print Y over a certain interval is formed in the area up to C. The non-printing area NP is a length in the transport direction FD necessary for each mark detection device 31, 32, 33, 34 to clearly distinguish the printing end position of the mark M from the printing start position of the first color image 11p. It is provided with a thickness. The length of the non-printing area NP in the transport direction FD is equal to the length of the printed mark M in the transport direction FD in order to prevent the mark detection devices 31, 32, 33, and 34 from erroneously detecting them. Alternatively, the transport amount D is set in advance so as to be longer than that.

  The first recording unit 11 controls the printing position of the image 11p of the second color recording image based on the detection of the second mark M2.

  That is, when the second mark M <b> 2 printed on the recording medium 2 is conveyed below the first mark detection device 31 on the downstream side of the first recording unit 11, the light emitting element 31 a of the first mark detection device 31. Is emitted by the Y (yellow) mark M printed on the recording medium 2. When the complementary color light L is absorbed, the complementary color light is not reflected by the recording medium 2, and thus the light receiving element 31b does not receive the complementary color light L.

  If the complementary color light L is not received from the light receiving element 31b, the input signal AO measured from the light receiving element 31b falls below the threshold value TH as shown in FIG. . That is, the position where the light receiving element 31b does not receive the complementary color light L is detected as a position (detection position) where the mark M2 printed on the recording medium 2 is conveyed below the first mark detection device 31. The principle of detection of the mark M by the mark detection device 31 is the same in the second to fourth mark detection output devices 32, 33, and 34. The detection position of the mark M includes various standards such as the detection start position of the mark M, the detection end position of the mark M, the detection start position of the mark M, and the detection intermediate position of the mark M obtained from the detection end position of the mark M. In this embodiment, the reference position of the detection position of the mark M is set as the detection start position of the mark M.

  At this time, the first to fourth mark detection devices 31, 32, 33, and 34 in the present embodiment convert the diverging light emitted from the light emitting elements 31a, 32a, 33a, and 34a serving as the light sources into the cylindrical lenses 31c, 32c, and 33c. , 34c are converted into parallel light. Therefore, it is possible to increase the amount of light when the light emitted from the light emitting elements 31a, 32a, 33a, and 34a is reflected on the non-printing portion NP. Therefore, the level difference from the time when the light irradiated from the light emitting elements 31a, 32a, 33a, and 34a is absorbed by the mark M and becomes non-reflecting can be enlarged, and as a result, the mark detection devices 31, 32, The detection sensitivity of the mark M by 33 and 34 can be improved.

  Further, the light receiving elements 31b, 32b, 33b, 34b in the form of bullets are reflected from the light emitting elements 31a, 32a, 33a, 34a, reflected by the recording medium 2, and passed through the slits 31e, 32e, 33e, 34e. By selectively receiving the reflected light, the detection sensitivity of the mark M (in particular, the edge portion of the mark M) can be further improved.

  After the mark M is detected by the first mark detection device 31, when the recording medium 2 is transported by the transport unit 21, 22, 23, 24 by the transport amount F 1 obtained in advance, the first recording unit 11 is below the first recording unit 11. The print start position of the first color image 11p in the second color recording image arrives. Therefore, as shown in FIGS. 10A and 10B, the first recording unit 11 has the first color image 11p formed by Y (yellow) from the printing start position of the first color image 11p. Start printing.

  Thereafter, in the first recording unit 11, the corresponding image 11p is printed from the printing start position based on the mark M detected by the first mark detection device 31, and then the mark M is conveyed at a set conveyance amount. Is repeatedly printed as the print start position.

  In the second to fourth recording units 12, 13, and 14, the printing start position is controlled based on the detection of the mark M from the printing of the first color recording image.

  For example, in the second recording unit 12, after the mark M is detected by the second mark detection device 32 on the downstream side, the recording medium 2 is made to correspond to the mark M by the transport units 21, 22, 23, and 24. The sheet is conveyed downstream by a preset conveyance amount. In the present embodiment, the carry amount differs between the carry amount E2 when the first mark M1 is detected and the carry amount F2 when the second mark M2 and subsequent marks are detected.

  When the recording medium 2 is transported by a predetermined transport amount after the mark M is detected, the print start position of the second color image 12p arrives below the second recording unit 12. Then, as shown in FIGS. 10A and 10B, the second recording unit 12 has the second color image 12p formed by M (magenta) from the printing start position of the second color image 12p. Start printing.

  That is, after the mark M is detected by the complementary color light L, and the printing of the second color image 12p is started based on the detection result, the printing start position of the second color image 12p is the first color image. It always matches the print start position C of 11p.

  The third color image 13p and the fourth color image 14p are also printed in the same manner as the second color image 12p described above, so that there is no deviation from the print area of the first color image 11p. Printing can be performed in accordance with the first color image 11p.

  That is, the printer 1 of the present embodiment completely matches the print start positions C or C ′ of the first color image 11p, the second color image 12p, the third color image 13p, and the fourth color image 13p. Therefore, it is possible to print a high-quality image with no printing position shift.

  Then, as in the printer 1 of the present embodiment, each image 11p, 12p, 13p, 14p is printed while controlling the printing position based on the previous mark M, so that the mark and the mark shown in FIG. The gap size between the mark M and the image 11 can be significantly reduced as compared with the conventional method so as to show the relationship with the print start position of the image on which the print position is determined. Therefore, it is possible to reduce the discard area including the mark M and the non-printing area NP formed between the color recording images sequentially printed on the recording medium 2 and improve the cost performance.

  In addition, this invention is not limited to embodiment mentioned above etc., A various change is possible as needed. For example, in the present embodiment, the arrangement positions of the mark detection devices 31, 32, 33, and 34 are changed from the downstream side to the upstream side of the corresponding first recording unit 11 and each recording unit 12, 13, and 14, and printing is performed. It is also possible to control the conveyance of the recording medium so as to align the positions. Further, the mark M does not need to be formed over the entire width of the recording medium 2, and the relationship with the slits 31e, 32e, 33e, 34e formed in the mark detection devices 31, 32, 33, 34. In this case, it is only necessary to be formed so as to be detectable with an appropriate length.

Front view showing the printer of this embodiment The perspective view of the mark detection apparatus used for the printer of this embodiment FIG. 2 is a plan view of the mark detection apparatus of FIG. IV-IV sectional view and operation conceptual diagram of the mark detection apparatus of FIG. VV sectional view of the mark detection apparatus of FIG. VI-VI sectional view of the mark detection device of FIG. Electronic circuit diagram of mark detection device used in printer of this embodiment FIG. 2 is a conceptual diagram illustrating a relationship between a mark detection apparatus, a mark and image positional relationship (a), a comparator input signal (b), and a comparator output signal (c) according to the printer of the present embodiment. First front view (a) and plan view (b) showing a printing position adjustment method in the printer of this embodiment. Second front view (a) and plan view (b) showing a printing position adjustment method in the printer of this embodiment. Explanatory drawing of the relationship between the mark of the printing position adjustment method in the printer of this embodiment, and the printing start position of the image in which a printing position is defined based on the mark Front view showing an example of an embodiment of a conventional printer Explanatory drawing of the relationship between the mark of the printing position adjustment method in the conventional printer, and the printing start position of the image in which a printing position is determined based on the mark

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Printer 2 Recording medium 11, 12, 13, 14 Recording unit
11a, 12a, 13a, 14a Ink ribbon
11b, 12b, 13b, 14b Thermal head
M (for alignment) mark 11p, 12p, 13p, 14p Each color image 21, 22, 23, 24 Transport unit 21a, 22a, 23a, 24a Feed roller 21b, 22b, 23b, 24b Platen roller 31, 32, 33, 34 Mark detection device 31a, 32a, 33a, 34a Light emitting element 31b, 32b, 33b, 34b Light receiving element 31c, 32c, 33c, 34c Cylindrical lens 31e, 32e, 33e, 34e Slit member 50 Control unit FD Transport direction L Complementary color light

Claims (3)

A transport unit for transporting the recording medium;
A first recording unit for printing a mark having a component of a specific color and an image of a first color on the conveyed recording medium;
At least one recording unit arranged downstream of the first recording unit, and a recording unit for each color for printing an image of each color having a color component other than the first color image;
A control unit for controlling the printing position of the mark, the printing position of the image of the first color, and the printing position of the image of each color;
One light emitting element that is arranged upstream or downstream of the first recording unit and each color recording unit and emits complementary color light of the mark toward the recording medium, and the complementary color reflected by the recording medium A mark detection device having a light receiving element disposed at a position where light is incident,
A printer that sequentially repeats superimposing each color image on a first color image using the mark, and prints a plurality of color recording images on the recording medium,
The control unit is
In the first recording unit, the first mark and the second mark are printed before printing the first color image of the first color recording image, and thereafter, based on the two previous marks. While printing each image while controlling the printing position, and controlling to print the mark continuously,
In the recording unit for each color, the printer controls each image to be printed while controlling the printing position based on the previous two marks. A transport unit for transporting the recording medium;
A first recording unit for printing a mark having a component of a specific color and an image of a first color on the conveyed recording medium;
At least one recording unit arranged downstream of the first recording unit, and a recording unit for each color for printing an image of each color having a color component other than the first color image;
A control unit for controlling the printing position of the mark, the printing position of the image of the first color, and the printing position of the image of each color;
Arranged in a printer comprising:
A light emitting element that is arranged one by one upstream or downstream of the recording unit of each color and emits complementary color light of the mark toward the recording medium, and the complementary color light reflected by the recording medium is incident. A mark detection device having a light receiving element disposed at a position,
A mark detecting apparatus, wherein a plano-convex cylindrical lens is disposed between the light emitting element and the recording medium with a spherical surface facing the light emitting element.   The slit for selectively passing the complementary color light reflected by the recording medium is formed between the recording medium and the light receiving element, and the light receiving element is a shell type light receiving element. The mark detection apparatus described.

Images