JP6839231B2 - Tablet printing device - Google Patents

Description

The present invention relates to a tablet printing device.

In order to print identification information such as characters and marks on tablets, a technique of printing using an inkjet printing head is known. A tablet printing device using this technology transports tablets by a tablet transporting device such as a conveyor, and ink is directed from a nozzle of an inkjet printing head located above the tablet transporting device toward tablets passing under the printing head. And print the identification information on the tablet. Some tablets are provided with a groove (secant line) for facilitating the division of the tablet.

Japanese Unexamined Patent Publication No. 7-081050

At this time, printing on the tablet having this score line may be performed along the score line. In this case, the position and direction of the score line are detected before printing, and printing is performed according to the position and direction.

In some cases, a score line is provided on only one of the front and back surfaces of the tablet. In the case of such tablets, they are generally transported separately on the front and back. Then, in a tablet in which a score line is provided only on one side of the tablet, when printing is performed on the other side on which the score line is not provided according to the direction of the score line, the tablet before printing is performed. Both sides are imaged with a camera, the acquired image is image-processed, and the surface, position, and direction in which the score line is provided are calculated. By performing such image processing, the processing speed of the tablet printing apparatus itself is lowered.

An object to be solved by the present invention is to provide a tablet printing apparatus capable of suppressing a decrease in processing speed.

The present invention is a tablet printing apparatus that prints on a tablet having one side and the other side facing each other and having a score line on any one side.
A transport device that transports tablets and
A print head device that prints on tablets transported by the transfer device, and
A laser displacement meter that measures the height of the tablet transported by the transport device in a direction intersecting the transport direction.
It has a detection device that detects that the tablet to be transported has reached a predetermined reference position.
In response to the detection device detecting the arrival of the tablet at the reference position, the height of the tablet is measured by the laser displacement meter at a predetermined timing from the reference position.
Based on the measured values the measurement, have a control unit that performs printing control of the printing apparatus,
The timing at which the height of the tablet is measured by the laser displacement meter is a position offset from the center position of the tablet along the transport direction of the tablet .

According to the present invention, it is possible to provide a tablet printing apparatus capable of suppressing a decrease in processing speed.

The figure which shows the schematic structure of the tablet printing apparatus which concerns on 1st Embodiment. It is a figure which shows a part of the delivery feeder which concerns on 1st Embodiment, FIG. The schematic diagram of the tablet height measurement by the laser displacement meter which concerns on 1st Embodiment. The schematic diagram of the tablet height measurement by the laser displacement meter which concerns on 1st Embodiment. The schematic diagram of the tablet height measurement by the laser displacement meter which concerns on 2nd Embodiment. The schematic diagram of the tablet height measurement by the laser displacement meter which concerns on 3rd Embodiment. The schematic diagram of the tablet height measurement by the laser displacement meter which concerns on 4th Embodiment. The schematic diagram of the tablet height measurement by the laser displacement meter which concerns on other embodiments.

<First Embodiment>
The first embodiment will be described with reference to FIGS. 1 to 4.

(Basic configuration)
As shown in FIG. 1, the tablet printing device 1 according to the first embodiment includes a supply device 10, a first printing device 20, a second printing device 30, a recovery device 40, and a control device 50. It has. The first printing device 20 and the second printing device 30 have basically the same structure.

The supply device 10 includes a hopper 11, an alignment feeder 12, and a delivery feeder 13 (conveyor device). The supply device 10 is configured to be able to supply the tablet T to be printed to the first printing device 20, and is positioned on one end side of the first printing device 20. The hopper 11 accommodates a large number of tablets T and sequentially supplies the tablets T to the alignment feeder 12. In the present embodiment, the tablet T to be printed is a tablet having a score line on one side, and printing is performed only on the side having no score line. The alignment feeder 12 aligns the supplied tablets T in a row and conveys them toward the delivery feeder 13. The delivery feeder 13 sequentially sucks the tablets T on the alignment feeder 12 and conveys them to the first printing device 20 and supplies them to the first printing device 20. The delivery feeder 13 is provided with a detection device 27 that detects the arrival of the tablet T and outputs a signal, and a laser displacement meter 28 that can measure the height direction of the tablet T. The detection device 27 detects the position of the tablet T (position in the transport direction A1) on the transfer feeder 13 by transmitting and receiving laser light, and functions as a trigger sensor for the laser displacement meter 28 located downstream. As the detection device 27, various laser sensors such as a reflection type laser sensor can be used. The supply device 10 is electrically connected to the control device 50, and its drive is controlled by the control device 50. The signal output by the detection device 27 (detection device) is sent to the control device 50, and functions as a trigger sensor for measurement timing (time, etc.) by the laser displacement meter 28 located on the downstream side thereof. That is, the position where the detection device 27 detects the tablet T is the reference position. As the alignment feeder 12 and the delivery feeder 13, for example, a belt transfer mechanism can be used. The tablet T to be printed has a three-dimensional shape and a thickness.

The first printing device 20 includes a transport device (tablet transport device) 21, a detection device 22, a laser displacement meter 29, a first image pickup device (imaging device for printing) 23, a print head device 24, and the like. A second imaging device (imaging device for inspection) 25 and a drying device 26 are provided. The laser displacement meter 29 is the same as the laser displacement meter 28.

The transport device 21 includes a transport belt 21a, a pulley body 21b which is a drive pulley, a plurality of driven pulleys 21c (three in the example of FIG. 1), a motor (drive unit) 21d, a position detector 21e, and a suction chamber 21f. doing. The transport belt 21a is formed in an endless shape and is bridged to the pulley body 21b and each of the driven pulleys 21c. The pulley body 21b and each driven pulley 21c are rotatably provided on the main body of the apparatus, and the pulley body 21b is connected to the motor 21d. The motor 21d is electrically connected to the control device 50, and its drive is controlled by the control device 50. The position detector 21e is a device such as an encoder, and is attached to the motor 21d. The position detector 21e is electrically connected to the control device 50 and transmits a detection signal to the control device 50. The control device 50 can obtain information such as the position, the moving speed, and the moving amount of the transport belt 21a based on the detection signal. The transport device 21 rotates the transport belt 21a together with each driven pulley 21c by the rotation of the pulley body 21b by the motor 21d, and the tablet T on the transport belt 21a is directed in the direction of the arrow A1 in FIG. 1 (convey direction A1). Transport. A plurality of circular suction holes 21g are formed on the surface of the transport belt 21a. Each of these suction holes 21g is a through hole for sucking the tablet T, and is arranged along the transport direction A1 so as to form two transport paths. Each suction hole 21g is connected to a suction chamber 21f (see FIG. 1), and the suction chamber 21f makes it possible to obtain a suction force. The suction chamber 21f is a chamber for applying (acting on) a suction force to the tablets T placed in the suction holes 21g of the transport belt 21a. An intake device such as a pump is connected to the suction chamber 21f via a suction pipe (neither is shown), and the inside of the suction chamber 21f is depressurized by the operation of the suction device. The suction pipe is connected to substantially the center of the side surface (plane parallel to the transport direction A1) of the suction chamber 21f. Further, the intake device is electrically connected to the control device 50, and its drive is controlled by the control device 50.

The detection device 22 is provided on the downstream side of the transport direction A1 and above the transport belt 21a with respect to the position where the tablet T is supplied on the transport belt 21a by the supply device 10. The detection device 22 detects the position of the tablet T (position in the transport direction A1) on the transport belt 21a by transmitting and receiving laser light, and functions as a trigger sensor for each device located downstream. As the detection device 22, various laser sensors such as a reflection type laser sensor can be used. The detection device 22 is electrically connected to the control device 50 and transmits a detection signal to the control device 50.

The first imaging device 23 is provided on the downstream side of the transport direction A1 from the position where the detection device 22 is provided, and above the transport belt 21a. Based on the position information of the tablet T detected by the detection device 22, the first image pickup device 23 takes an image at the timing when the tablet T reaches directly under the first image pickup device 23, and an image including the upper surface of the tablet T. (Image for printing) is acquired, and the acquired image is transmitted to the control device 50. As the first image pickup device 23, various cameras having an image pickup device such as a CCD (charge-coupled device) or a CMOS (complementary metal oxide semiconductor) can be used. The first imaging device 23 is electrically connected to the control device 50, and the drive thereof is controlled by the control device 50. Lighting for imaging is also provided as needed.

The print head device 24 is an inkjet head device. The print head device 24 is provided on the downstream side in the transport direction A1 and above the transport belt 21a from the position where the first image pickup device 23 is provided. The print head device 24 includes a plurality of nozzles (not shown), and ink is ejected individually from these nozzles. The print head device 24 is provided so that the alignment direction in which the nozzles are arranged intersects the transport direction A1 in the horizontal plane (for example, so as to be orthogonal to each other). As the print head device 24, it is possible to use various inkjet type print heads having a driving element such as a piezoelectric element, a heat generating element, or a magnetostrictive element. The print head device 24 is electrically connected to the control device 50, and the drive thereof is controlled by the control device 50.

The second image pickup apparatus 25 is provided downstream of the position where the print head apparatus 24 is provided in the transport direction A1 and above the transport belt 21a. Based on the position information of the tablet T detected by the detection device 22, the second image pickup device 25 takes an image at the timing when the tablet T reaches directly under the second image pickup device 25, and an image including the upper surface of the tablet T. (Image for inspection) is acquired, and the acquired image is transmitted to the control device 50. As the second image pickup device 25, it is possible to use various cameras having an image pickup element such as a CCD or CMOS, as in the case of the first image pickup device 23 described above. The second image pickup device 25 is electrically connected to the control device 50, and the drive thereof is controlled by the control device 50. Lighting for imaging is also provided as needed.

The drying device 26 is positioned downstream of the position where the second image pickup device 25 is provided in the transport direction A1, and is provided, for example, below the transport device 21. The drying device 26 dries the ink applied to each tablet T on the transport belt 21a. As the drying device 26, various drying parts such as a heater that dries the object to be dried by radiant heat or a blower that dries the object to be dried by warm air or hot air can be used. The drying device 26 is electrically connected to the control device 50, and its drive is controlled by the control device 50.

The tablet T that has passed above the drying device 26 is transported along with the movement of the transport belt 21a, and reaches a position near the end of each driven pulley 21c on the transport belt 21a. At this position, the suction action does not work on the tablet T, the tablet T is released from the state of being held by the transport belt 21a, and is transferred from the first printing device 20 to the second printing device 30.

The second printing device 30 includes a transport device 31, a detection device 32, a first imaging device (imaging device for printing) 33, a print head device 34, and a second imaging device (imaging device for inspection). ) 35 and a drying device 36. The transfer device 31 includes a transfer belt 31a, a pulley body 31b which is a drive pulley, a plurality of driven pulleys 31c (three in the example of FIG. 1), a motor (drive unit) 31d, a position detector 31e, and a suction chamber 31f. doing. Since each element constituting the second printing device 30 has basically the same structure as the corresponding component of the first printing device 20 described above, the description thereof will be omitted. The transport direction of the second printing apparatus 30 is the direction of arrow A2 in FIG. 1 (transport direction A2).

The recovery device 40 includes a defective product recovery device 41 and a non-defective product recovery device 42. The collection device 40 is positioned on the downstream side of the transport direction A2 from the position where the drying device 36 of the second printing device 30 is provided, and the defective product collection device 41 collects the defective tablet T. It is collected, and the non-defective tablet T is collected by the non-defective product collection device 42.

The defective product collecting device 41 has an injection nozzle 41a and an accommodating portion 41b. The injection nozzle 41a is provided in the suction chamber 31f of the second printing apparatus 30, and injects gas (for example, air) toward the tablet T (defective tablet T) conveyed by the transfer belt 31a. , The tablet T is dropped from the transport belt 31a. At this time, the gas injected from the injection nozzle 41a passes through the suction hole of the transport belt 31a (similar to the suction hole 21g shown in FIG. 2) and hits the tablet T. The injection nozzle 41a is electrically connected to the control device 50, and its drive is controlled by the control device 50. The storage unit 41b receives and stores the tablet T that has fallen from the transport belt 31a.

The non-defective product recovery device 42 has a gas blowing unit 42a and a storage unit 42b. The non-defective product collecting device 42 is located on the downstream side in the transport direction A2 from the position where the defective product collecting device 41 is provided. The gas blowing portion 42a is provided in the transfer device 31 of the second printing device 30, and is provided at the end of the transfer device 31, that is, at the end of the transfer belt 31a on the side of each driven pulley 31c. For example, during the printing process, the gas blowing unit 42a always blows gas (for example, air) toward the transport belt 31a, and drops the tablet T from the transport belt 31a. At this time, the gas blown out from the gas blowing portion 42a passes through the suction hole of the transport belt 31a (similar to the suction hole 21g shown in FIG. 2) and hits the tablet T. As the gas blowing portion 42a, for example, an air blow having a slit-shaped opening extending in a direction intersecting the transport direction A2 in a horizontal plane (for example, a direction orthogonal to each other) can be used. The gas blowing unit 42a is electrically connected to the control device 50, and its drive is controlled by the control device 50. The storage unit 42b receives and stores the tablet T that has fallen from the transport belt 31a.

Here, the tablet T that has passed through the defective product collecting device 41 is transported along with the movement of the transport belt 31a, and reaches a position near the end of each driven pulley 31c on the transport belt 31a. At this position, the suction action does not work on the tablet T, but by providing the gas blowing portion 42a, the tablet T can be reliably dropped from the transport belt 31a and collected in the accommodating portion 42b.

The control device 50 includes an image processing unit 51, a printing processing unit 52, an inspection processing unit 53, and a storage unit 54. The image processing unit 51 processes the image. The print processing unit 52 performs processing related to printing. The inspection processing unit 53 performs processing related to inspection. The storage unit 54 stores various information such as processing information and various programs. Such a control device 50 controls the supply device 10, the first printing device 20, and the second printing device 30, and is an individual detection device 22 of the first printing device 20 and the second printing device 30. , 32, the position information of the tablet T, the images transmitted from the individual imaging devices 23, 25, 33, 35 of the first printing device 20 and the second printing device 30, and the like are received.
(Laser displacement meter)
FIG. 2 is a diagram showing a part of the delivery feeder 13. The delivery feeder 13 is provided with a suction chamber (not shown) inside, and sucks and conveys the tablet T from the alignment feeder 12. The tablet T transported in the delivery feeder 13 is transported in various directions. Further, since the dividing line is provided on either one surface of the tablet T and the other surface facing the tablet T, the surface facing the laser displacement meter 28 has or does not have the dividing line. .. In FIG. 2, the surface of the tablet T on which the score line is provided is sucked and held by the transfer feeder 13 so as to face the detection device 27. Further, in FIG. 2, the tablet T is an example in which the tablet T is transported in a state where the direction of the score line is tilted by about 45 degrees with respect to the direction orthogonal to the transport direction A1. When the tablet T passes through the detection device 27, the height of the tablet is measured by the laser displacement meter 28 at a predetermined timing. The data obtained by this measurement is sent to the control unit 50 and used for the printing process by the print head devices 24 and 34 (details will be described later).

Next, the calculation of the presence / absence, direction, and angle of the score line by the laser displacement meter 28 will be described.

FIG. 3 is a schematic view when the height of the surface of the tablet T facing the laser displacement meter 28 from the belt surface of the transfer feeder 13 is measured by the laser displacement meter 28. The laser displacement meter 28 measures the height of the tablet T at a position offset from the center of the tablet T in the transport direction A1 of the tablet T. The alternate long and short dash line in FIG. 3 indicates the scanning direction of the laser displacement meter 28. FIG. 3 schematically shows the measurement result. This measurement result shows the height of the tablet T in the direction intersecting the transport direction A1 (in the present embodiment, the direction perpendicular to the direction). Since the height of the portion where the score line is provided is lowered by the depth of the score line, the measured value of the laser displacement meter 28 in the portion corresponding to the score line is displayed low. The angle of the secant can be calculated based on how far the portion where the measured value is low is from the end face of the tablet T (distance indicated by L in FIG. 3).

In FIG. 3A, the secant line is tilted to the right by about 45 degrees with respect to the direction orthogonal to the transport direction A1. In FIG. 3B, the secant line is tilted to the left by about 45 degrees with respect to the direction orthogonal to the transport direction A1. Here, when the measurement position (to be exact, the scanning position) of the laser displacement meter 28 coincides with the center of the tablet T in the transport direction A1 of the tablet T, the place where the dividing line exists is the center of the measured value. Therefore, the distance from the end face of the tablet T becomes the same in FIGS. 3 (A) and 3 (B). Therefore, the direction of the score line (which side is tilted from the direction orthogonal to the transport direction A1) cannot be determined. In the present embodiment, the measurement position of the laser displacement meter 28 is a position offset from the center of the tablet T. This sets the measurement position (scanning timing) based on the signal output that detects the arrival of the tablet T by the detection device 27 described above. As a result, the direction of the secant line can be recognized as described above.

(Printing process)
Next, the printing process and the inspection process performed by the tablet printing apparatus 1 described above will be described.

First, various information such as print data required for printing is stored in the storage unit 54 of the control device 50. Then, when a large number of tablets T to be printed are charged into the hopper 11 of the supply device 10, the tablets T start to be sequentially supplied from the hopper 11 to the alignment feeder 12 and are moved by the alignment feeder 12. The tablet T is sucked up by the delivery feeder 13, and as described above, the presence / absence, direction, and angle (secant line information) of the score line are detected, and this information is sent to the control unit 50. After that, the tablet T is sequentially supplied from the delivery feeder 13 to the transport belt 21a. The transport belt 21a is rotated in the transport direction A1 by the rotation of the pulley body 21b and each driven pulley 21c by the motor 21d. Therefore, the tablets T supplied on the transport belt 21a are lined up on the transport belt 21a and transported at a predetermined moving speed. The transport belt 31a is also rotated in the transport direction A2 by the rotation of the pulley body 31b and each driven pulley 31c by the motor 31d.

In the following, it is assumed that there is a score line on the surface facing the laser displacement meter 28.

The tablet T on the transport belt 21a is detected by the detection device 22. As a result, the position information of the tablet T (the position in the transport direction A1) is acquired and input to the control device 50. The position information of the tablet T is stored in the storage unit 54 and used in the post-treatment. Next, the tablet T on the transport belt 21a is imaged by the first imaging device 23 at a timing based on the position information of the tablet T described above, and the captured image is transmitted to the control device 50. Based on the individual images transmitted from the first image pickup apparatus 23, the misalignment information of the tablet T (for example, the misalignment of the tablet T in the X direction, the Y direction, and the θ direction) is generated by the image processing unit 51. It is stored in the storage unit 54. Based on the misalignment information of the tablet T, printing conditions (ink ejection position, ejection speed, etc.) for the tablet T are set by the printing processing unit 52 and stored in the storage unit 54.

Next, the individual tablets T on the transport belt 21a are subjected to the print head device based on the above-mentioned printing conditions at the timing based on the position information of the above-mentioned tablets T, that is, the timing when the tablets T reach the lower part of the print head device 24. Printing is executed by 24. In this case, the printing is made on the surface without the score line. In the print head device 24, ink is appropriately ejected from each nozzle, and identification information such as characters (for example, alphabet, single pseudonym, number) and marks (for example, symbols, figures) is printed on the upper surface of the tablet T. At this time, the control unit 50 generates print data based on the score line information (presence / absence, direction, angle of the score line) recognized by the laser displacement meter 28, and the identification information is parallel to the score line on the tablet T based on the print data. Is printed on.

The tablet T on which the identification information is printed is imaged by the second imaging device 25 at a timing based on the position information of the tablet T detected by the detection device 22, and the captured image is transmitted to the control device 50. Based on the individual images transmitted from the second image pickup apparatus 25, print position information indicating the print position of the print pattern for each tablet T is generated by the image processing unit 51 and stored in the storage unit 54. Based on the print position information, the inspection processing unit 53 determines the print quality of the tablet T, and the print quality result information indicating the print quality result for each tablet T is stored in the storage unit 54. For example, it is determined whether or not the print pattern is printed at a predetermined position on the tablet T.

The tablet T after the inspection is transported along with the movement of the transport belt 21a and passes above the drying device 26. At this time, the ink applied to the tablet T is dried by the drying device 26 while the tablet T passes above the drying device 26, and the tablet T to which the ink has been dried is transported as the transport belt 21a moves. It is located near the end of each driven pulley 21c on the transport belt 21a. At this position, the suction action does not work on the tablet T, the tablet T is released from the state of being held by the transport belt 21a, and is passed from the first printing device 20 to the second printing device 30. In this case, the processing by the second printing device 30 is not performed, and the tablet T reaches the defective product collecting device 41. The defective tablet T is dropped from the transport belt 31a by the gas injected from the injection nozzle 41a and collected by the accommodating portion 41b. On the other hand, the non-defective tablet T passes through the defective collection device 41 and reaches the non-defective product recovery device 42. At this position, the non-defective tablet T has no suction action on the tablet T, and is dropped away from the transport belt 31a by the gas blown out from the gas blowing portion 42a and collected by the accommodating portion 42b.

The offset amount from the center of the tablet T in the transport direction A1 of the tablet T described above will be described. Assuming that the width of the secant line is about 1 mm, when the tablet T is circular in a plan view and its diameter is 12 mm, the secant T rotates in the horizontal plane and the direction of the secant line is orthogonal to the transport direction A1. When there is an angle, that is, when the direction of the score line is as shown in FIG. 4 (A), when the scanning position of the laser displacement meter 28 passes through the score line, the tablet is rotated by about 10 degrees. However, it is conceivable that the output value of the laser displacement meter 28 does not change. That is, in the case where the direction of the secant line and the scanning direction of the laser displacement meter match, even if the direction of the secant line rotates by about 10 degrees, the rotation state cannot be recognized. Therefore, even if the identification information is printed in parallel with the score line, it may be displaced in the rotation direction by about 10 degrees.

When the angle that allows such a rotational state is, for example, 1 degree, it corresponds to the end face position of the secant line in order to measure the portion of the secant line with the laser displacement meter 28 when the tablet T changes 1 degree in the rotation direction. If the measurement position is the measurement position and the measurement is performed at a position about 0.1 mm away from that position, which is a distance corresponding to an angle of 1 degree, that is, minus 0.1 mm from the end face position of the secant line, the secant line is oriented at an angle of 1 degree. When it changes, the scored part can be measured. That is, it is desirable that the offset position is on the center side of the end face position of the score line formed on the tablet, and the optimum offset position is slightly inside the end face position of the score line. Then, it is appropriately determined according to the size of the tablet and the required angle in the rotation direction.

By the way, when the laser displacement meter 28 does not obtain the score line information, the laser displacement meter 29 provided in the first printing apparatus 20 obtains the score line information. The laser displacement meter 29 measures the height of the tablet T based on the detection signal output by the detection device 22 in the same manner as the laser displacement meter 28. The print data generated by the score line information obtained by the laser displacement meter 29 is used in the printing process in the print head device 34 of the second printing device 30. In this case, the printing process is not performed in the first printing apparatus 20.

Further, the offset position may be outside the end face position of the score line formed on the tablet. However, since it is necessary to be at least a position where the height of the tablet T can be measured, it is essential that the offset amount is equal to or less than the inscribed circle radius of the outer shape of the tablet T. The larger the offset amount, the larger the distance from the end face of the tablet T (distance indicated by L in FIG. 3) of the portion corresponding to the score line of the measured value of the laser displacement meter 28 according to the angle change in the rotation direction of the score line. Since it changes, the calculation accuracy of this angle is improved. However, in this case, for example, as shown in FIG. 4 (B), the score line is detected because the score line does not exist in the scanning region of the laser displacement meter 28 even though the surface is formed with the score line. May become impossible. In such a case, neither the laser displacement meter 28 nor the laser displacement meter 29 can detect the score line.

As described above, when the score line cannot be detected by both the laser displacement meters 28 and 29, as an error, the first printing device 20 and the second printing device 30 are prevented from printing on the tablet T. To control. After that, the tablet T in which the error occurs is collected by the defective product collecting device 41.

As described above, according to the present embodiment, by obtaining the score line information by the laser displacement meter 28, printing can be performed according to the position and direction of the score line.

In particular, when there is a score line on only one side of the tablet T, the height of the tablet T is measured by measuring the presence (presence or absence) of the score line on either side of the tablet T and the angle in that direction prior to printing. It can be calculated only by the value. Therefore, it is possible to suppress a decrease in the processing speed of the printing apparatus.

Further, the tablet T to be printed may be a colored tablet or a tablet having a glossy surface. When such a tablet is recognized by a camera, the reflected light of the illumination provided by the camera may be reflected in the captured image, and it may be difficult to accurately recognize the split line by image processing. However, according to the present embodiment, since the laser displacement meter 28 obtains the score line information, the presence / absence, direction, and angle of the score line can be calculated even for a colored tablet or a tablet made of a material having a glossy surface. Yes, you can print.

<Second embodiment>
Next, the second embodiment will be described with reference to FIG.

By the way, in the first embodiment, when the score line is aligned with the measurement direction of the laser displacement meter 28, the score line may not be measured even though the score line is present. As shown in FIG. 5, when the measurement is performed only at the measurement position S2, the output is the same as when the score line is not formed even though the score line is formed on the surface of the tablet T. In such a case, neither the laser displacement meter 28 nor the laser displacement meter 29 can obtain the score line information, and the defective product collection device 41 collects the information as a detection error.

In the second embodiment, even if the tablet T is transported so that the score line is located in such a direction, the score line information can be reliably detected. As shown in FIG. 5, the laser displacement meter 28 in the second embodiment scans two places (S1, S2) with respect to the transport direction A1 of the tablet T, and measures the height of each of the tablets (twice). Measure). That is, in the height measurement of the tablet T at two places, the height of the center position S2 of the tablet T is measured in addition to S1 which is a position offset from the center position of the tablet of the first embodiment. ..

In FIG. 5, the measured value by the laser displacement meter 28 is shown on the right side of FIG. The right side shows the measured value at the position S1 offset from the center of the tablet, and the left side shows the measured value at the center position S2 of the tablet. When the score line is in the direction orthogonal to the transport direction A1, the height orthogonal to the transport direction A1 at the center position (S2) of the tablet T is measured lower by the score line as shown in FIG. It will be the same height as the width. Further, the measured value at the position offset from the center position of the tablet T (S1) is the height of the tablet T in the portion without the score line. From the measured values of the laser displacement meters 28 at these two locations, it can be seen that a score line exists on the measured surface. If there is no score line, the height data of the tablet without score line is used in both places.

In the above embodiment, the measurement at two points is performed by measuring twice with the laser displacement meter 28, but a plurality of laser displacement meters 28 may be provided to perform the measurement at two points.

<Third embodiment>
Next, the third embodiment will be described with reference to FIG.

In the third embodiment, different from the second embodiment, even if the tablet T is conveyed so that the score line is aligned with the measurement direction of the laser displacement meter 28, the score line information can be reliably detected. Disclose the method.

In the present embodiment, in addition to the laser displacement meter 28 that measures the height in the direction orthogonal to the transport direction A1, the height of the tablet T in the transport direction A1 is also measured. The detection device 27 is used to measure the height in the transport direction A1.

FIG. 6 is a schematic view when measuring the height of the transfer feeder 13 on the surface of the tablet T facing the laser displacement meter 28 from the belt surface using the laser displacement meter 28. A two-point chain line offset from the center of the tablet T in the transport direction A1 and orthogonal to the transport direction A1 indicates a position measured by the laser displacement meter 28 (to be exact, a scanning position by the laser displacement meter 28). There is. A two-dot chain line passing through the center of the tablet T along the transport direction A1 indicates a measurement point of the tablet height by the detection device 27.

That is, in the second embodiment, the heights of the tablets T at two locations in the transport direction A1 were measured, whereas in the present embodiment, the heights at the two locations intersecting the transport direction A1 and the transport direction A1. Measure the height. Then, the measurement of the height of the tablet T in the direction intersecting the transport direction A1 (orthogonal in FIG. 6) is offset from the center position of the tablet as in the first embodiment.

As shown in FIG. 6A, even when the dividing line is formed in the direction orthogonal to the transport direction A1, the tablet T is obtained from the data of the heights of the two orthogonal tablet Ts. Even if the split line is not detected in the direction orthogonal to the transport direction A1, the height data of the tablet along the transport direction A1 measures the low height data due to the split line, so that it can be seen that the split line exists. .. Further, from these two height measurement values, it can be seen that the score line is formed in the direction orthogonal to the transport direction A1.

Further, as shown in FIG. 6B, a case where a dividing line is formed in a direction parallel to the transport direction A1 is shown. In this case, the measured height of the tablet along the transport direction A1 indicates the height of the score line and does not change from end to end of the tablet T. The height data orthogonal to the transport direction A1 of the tablet T shows the measured value corresponding to the secant line in the center. Even in this case, the score line information can be obtained based on the two height measurement values. Further, since only the height corresponding to the score line is measured in the measured value along the transport direction A1, it can be seen that the score line is in the direction parallel to the transport direction A1.

In the third embodiment, the detection device 27 is used for measuring the height of the tablet T in the transport direction A1, but another laser displacement meter may be used.

Further, in the second embodiment, as a method of measuring the height of the tablet T, the height in the direction intersecting the transport direction A1 is measured at two places, but the height is not limited to this, and there are three or four places. It doesn't matter where you are.

Further, in the third embodiment, the height measurement positions of the tablet T are set to two positions, one in the transport direction A1 and the other in the direction orthogonal to the transport direction A1, but two or three positions are set only in the transport direction A1. Is also good.

Further, in each of the above embodiments, the tablets T are transported in a single row, but the present invention is not limited to this, and tablets T may be transported in a plurality of rows. When the tablets T are transported in a plurality of rows and the tablets are transported at different intervals for each row, the detection device 27, the laser displacement meter 28, the detection device 22, the laser displacement meter 29, the first imaging device 23, The print head device 24, the second image pickup device 25, the detection device 32, the first image pickup device 33, the print head device 34, and the second image pickup device 35 are provided in each row. When all the tablets T in multiple rows are transported at the same interval (that is, when the tablets in each row are transported so as to be aligned at the same position in the direction orthogonal to the transport direction), the tablets transported in multiple rows are collectively transported. The lengths of the above-mentioned sensors, image pickup devices, and print head devices may be set so that they can be detected or printed.
<Fourth Embodiment>
Next, the fourth embodiment will be described with reference to FIG. 7.

In the present embodiment, another detection device 27 is added to the third embodiment, and the height measurement in the transport direction A1 is performed at two locations (S3, S4). In addition, the laser displacement meter 28 measures (scans twice) the heights at two locations (S1, S2) in the direction orthogonal to the transport direction A1 of the tablet T, as in the second embodiment. Similar to the second embodiment, S2 detects the height of the center position of the tablet, and S1 detects the height of the position deviated from the center position of the tablet T. S3 detects the height of the center position in the tablet transport direction A1, and S4 detects the height of the position deviated from the center position in the tablet transport direction A1.

By measuring the height in this way, height data at a total of four locations as shown in FIGS. 7A and 7B may be obtained. By combining the data at these four locations, the presence / absence, direction, and angle of the score line can be detected. For example, the signals of S1, S2, S3, and S4 are set and stored for 180 degrees in each rotation direction of the tablet T (for example, once), and the result obtained by scanning the actual laser displacement meter 28 is obtained. You can get the score line information by matching.
<Other Embodiments>
Next, other embodiments will be described with reference to FIG. FIG. 8 shows a plurality of examples in which height measurements are performed at two locations along the transport direction A1 and two locations in the direction intersecting the transport direction A1, for a total of four locations, as in the fourth embodiment. .. In FIG. 8, the display of the score line of the tablet T is omitted.

In FIG. 8A, the height of the tablet T is measured at two points along the transport direction A1 by the detection device 27 (using two), and the direction (orthogonal direction) intersecting the transport direction A1 by the laser displacement meter 28. This is an example of performing height measurement at two locations. As described above, the location where the height is measured does not have to be in the direction orthogonal to the transport direction A1.

FIG. 8B shows that the laser displacement meter 28 measures the height at two points in the direction orthogonal to the transport direction A1 of the tablet T, and the detection device 27 (using two) measures the height in a direction intersecting the transport direction A1. This is an example of performing height measurement at two locations.

In FIG. 8C, the heights of the tablet T are measured at two locations in the direction intersecting the transport direction A1 with the laser displacement meter 28, and the direction intersecting the transport direction A1 with the detection device 27 (using two). This is an example of measuring the height of two places. The position scanned by the laser displacement meter 28 and the position detected by the detection device 27 intersect.

In FIG. 8D, the heights of the tablet T are measured at two locations in the direction intersecting the transport direction A1 of the tablet T by the laser displacement meter 28, and the height is set to the transport direction A1 by one of the two detection devices 27 provided. The height in the direction along the line is measured, and the height in the direction intersecting the transport direction A1 is measured by the other detection device 27. The position scanned by the laser displacement meter 28 and the position detected by the detection device 27 intersect.

In the above-mentioned plurality of embodiments, an example of printing only on a surface without a score line is shown, but the present invention is not limited to this. The secant information should be detected by either the laser displacement meter 28 or the laser displacement meter 29. If printing is performed using both the printing device 20 and the printing device 30 using this score line information, printing can be performed on both sides of the tablet T in parallel with the score line.

Further, in the above-mentioned plurality of embodiments, an example in which printing is performed on a tablet in which a score line is formed only on one side is shown, but the present invention is not limited to this. Each embodiment can also be applied to tablets in which secant lines are formed on both sides. When printing a tablet having a score line formed on both sides, an error occurs if the score line is not detected by the laser displacement meter 28, and the tablet is collected by a defective product recovery device without printing. be able to.

Further, in the above-mentioned plurality of embodiments, an example in which the tablet T before printing is imaged by the first imaging devices 23 and 33 is shown, but the present invention is not limited to this. Since the presence / absence, position, and direction of the score line of the tablet T can be detected by the laser displacement meter 28 and the laser displacement meter 29, the first imaging devices 23 and 33 can be omitted. In this case, the processing speed of the tablet printing device 1 can be increased because the time for image processing the image pickup results by the first image pickup devices 23 and 33 can be saved.

In the above-mentioned plurality of embodiments, printing on a tablet T having a substantially perfect circular shape has been illustrated, but the present invention is not limited to this. Even if it is a deformed tablet (for example, an elliptical tablet or a triangular tablet), it is possible to detect a score line and print accordingly. When detecting the score line formed on these deformed tablets, the measurement is performed with a laser displacement meter at a position offset from the center, but the offset position may be inside the end face of the score line formed on the tablet. preferable.

In addition, in FIGS. 3 to 7, it was shown that the offset position of the height measurement position of the tablet T by the laser displacement meter 28 in the above-mentioned plurality of embodiments is on the downstream side along the tablet transport direction A1 as an example. However, it goes without saying that it may be on the upstream side.

Although some embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other embodiments, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are also included in the scope of the invention described in the claims and the equivalent scope thereof.

T Tablet 1 Tablet Printing Device 13 Delivery Feeder 24 Printing Head Device 28, 29 Laser Displacement Meter 22, 27 Detection Device 50 Control Unit

Claims (5)

In a tablet printing apparatus that prints on a tablet having one side and the other side facing each other and having a score line on at least one side.
A transport device that transports tablets and
A print head device that prints on tablets transported by the transfer device, and
A laser displacement meter that measures the height of the tablet transported by the transport device in a direction intersecting the transport direction.
It has a detection device that detects that the tablet to be transported has reached a predetermined reference position.
In response to the detection device detecting the arrival of the tablet at the reference position, the height of the tablet is measured by the laser displacement meter at a predetermined timing from the time when the tablet arrives at the reference position.
Based on the measured values the measurement, have a control unit that performs printing control of the printing head unit,
A tablet printing apparatus characterized in that the timing at which the height of the tablet is measured by the laser displacement meter is a position offset from the center position of the tablet along the transport direction of the tablet. The height of the tablet is measured by the laser displacement meter at two timings, a center position of the tablet and a position offset from the center position of the tablet in the transport direction. The tablet printing apparatus according to claim 1. The tablet printing apparatus according to claim 1 or 2, wherein the offset position is a position on the center side of the tablet from the end face of the score line formed on the tablet. The tablet printing apparatus according to any one of claims 1 to 3 , further comprising a second laser displacement meter that measures the height of the tablet along the transport direction of the tablet. The tablet printing device according to claim 4, wherein the second laser displacement meter is the detection device.

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