JPH05104814A - Printer equipped with i/d mark reader - Google Patents

Abstract

PURPOSE:To prevent paper from being stained due to rubbing the paper with a tip of a carriage when an I/D mark is read with an I/D sensor. CONSTITUTION:A focus point exists behind equipped printing paper 14 under an appropriate printing gap state. A carriage is located at a position wherein the appropriate printing gap is obtained when a mark is printed. When printing of the mark is finished, the carriage 20 is returned to a left end position. Then, the carriage 20 is reacted with a carriage moving device, and the focus of the mark sensor 148 is located on a surface of the printing paper 14. Under this state, the carriage is moved along a platen, and a read is performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer having an I / D mark reading device.

[0002]

2. Description of the Related Art I / D marks are printed on the surface of a print medium and indicate information such as the type of a form. The I / D mark is used for the following purposes, for example. When the printing paper on which the I / D mark is printed is once removed from the printing paper and stored, and it becomes necessary to newly print other information on the printing paper, the printing paper is attached to the printing device again, The I / D mark is read. When the read I / D mark is confirmed by the printing device or the host computer connected to the printing device, the information to be printed on the printing paper is prepared and printing is performed.

As a printing apparatus equipped with a device for reading the above-mentioned I / D mark, the applicant of the present invention has made it possible to use the above-mentioned Japanese Utility Model Laid-Open No. 60-19134
The No. 9 device was developed. This device includes a platen that supports the print medium, a print head that is arranged so as to face the platen, and that is movable toward and away from the platen by moving in the front-back direction, and the position of the surface of the print medium that is supported by the platen. Is detected, and based on the detection result, the print head is moved back and forth to adjust the head gap, which is the gap between the print medium and the print head, and the head gap is fixed so that it cannot move relative to the print head. And read the I / D mark formed on the surface of the print medium.
And a D-mark sensor.

In the apparatus disclosed in Japanese Utility Model Laid-Open No. 60-191349, the I / D mark sensor is located substantially on the same plane as the front end surface of the print head, and is integrated with the print head to the platen. Can be moved closer and further apart. The focus of the I / D mark sensor is
The head gap is positioned on the surface of the print medium with the head gap properly adjusted.

After the print head is moved back and forth according to the thickness of the print medium by the head gap adjusting device and the print head is adjusted to an appropriate position with respect to the print medium, the I / D mark is printed in that state. Done. The carriage moves in synchronization with this printing, and the I / O attached to the carriage
I / I which D mark sensor was just printed at the same time as printing
After passing over the D mark, the I / D mark is read. Then, it is confirmed whether or not the read I / D mark is a desired one, that is, whether or not an I / D mark different from the intended one is read due to faint and unclear printing.

[0006]

However, in the case where the head gap is small, an ink ribbon arranged between the print medium and the front end surface of the print head or a ribbon attached to the front end surface of the print head. Since the mask and the print medium are in close proximity to each other, the ink ribbon or the like comes into contact with the surface of the print medium during the reading of the I / D mark and rubs the I / D mark, so that the print medium is contaminated. / D
There was a problem that the mark might become unclear.

In view of the above problems, the present invention allows an I / D mark to be satisfactorily read without contact of the ink ribbon or ribbon mask with the I / D mark regardless of the size of the head gap. The object of the present invention is to obtain a printing device equipped with a mark reading device.

[0008]

SUMMARY OF THE INVENTION The gist of the present invention is to provide a printer having an I / D mark reading device including the platen, the carriage, the head gap adjusting device and the I / D mark sensor. In the adjusted state, the I / D mark sensor is fixed to the print head while the focus of the I / D mark sensor is positioned behind the print medium, and the print head and the I / D mark sensor are I / D mark sensor. The reading movement control means is provided to move the focus of the D mark sensor to a position located on the surface of the print medium.

[0009]

In the printer constructed as described above,
At the time of reading the I / D mark, the reading movement control means causes the head gap adjusting device to move the print head and the I / D mark sensor in a direction in which the print head and the I / D mark sensor are separated from the platen. Located on the surface of. Therefore, at the time of reading the I / D mark, the distance between the ink ribbon or the ribbon mask and the surface of the print medium becomes larger than the distance after the head gap adjustment, and the ink ribbon or the like comes into contact with the surface of the print medium to cause the I / D.
Rubbing the mark is avoided.

[0010]

As described above, according to the present invention, the I / D
The I / D mark can be read without contaminating the mark or the print medium, the reading accuracy is improved, and the print quality is prevented from being degraded. Moreover, since the head gap adjusting device is used when the I / D mark sensor is moved, the object can be achieved at low cost.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. In FIG. 1, reference numeral 12 is a platen of a wire dot printer (hereinafter, simply referred to as a printer). The platen 12 has a prismatic shape, is supported by a frame (not shown), and has a support surface 16 formed on its side surface for supporting the print sheet 14 as a print medium.

A carriage 20 is provided near the platen 12. The carriage 20 is moved in the left-right direction by a carriage driving device (not shown), that is, in the direction parallel to the support surface 16 of the platen 12, but is moved in the front-rear direction by the head gap adjusting device described later, that is, approaches and separates from the support surface 16 of the platen 12. It can also be moved in the direction. A wall portion 22 extending parallel to the platen 12 is formed in the front portion of the carriage 20, and both end portions of the wall surface of the wall portion 22 on the side opposite to the platen 12 have mounting reference surfaces for mounting a print head. 24 are formed. In addition, a pair of female screw holes is formed in the vertical direction at the center of the wall portion 22.

A print head 30 is fixed on the carriage 20. The print head 30 includes a nose portion 34 on an end surface 32 facing the platen 12, and engaging protrusions 35 extend on both sides of the nose portion 34. The engagement protrusion 35 is seatable on the upper surface of the wall portion 22, and is provided with engagement notches 36 at portions corresponding to the female screw holes. Further, a pair of mounting surfaces 38 is formed on the end surface 32, and the mounting surfaces 38 are brought into contact with the mounting reference surface 24 of the wall portion 22 of the carriage 20 and the engaging projections 3 are formed.
5 is brought into contact with the upper surface of the wall portion 22, the print head 30 is positioned on the carriage 20 by inserting the engagement notch 36 and tightening the bolt 39 into each female screw hole. It can be moved together with.

A large number of wires are accommodated in the nose portion 34 of the print head 30, and an appropriate wire is advanced and retracted according to the discharge of the piezoelectric element or the excitation / demagnetization of the solenoid 46 (see FIG. 4). Printing is performed by moving the print head 30 along the platen 12.

The front end of the carriage 20 is formed parallel to the platen 12, and a pair of positioning protrusions 40 are provided on both sides of the print head 30. These positioning protrusions 40 are formed integrally with the carriage 20. The ink ribbon includes the positioning protrusion 40 and the carriage 20.
It is guided between the support surface 16 of the platen 12 and the leading end surface 44 of the print head 30 through a groove 48 formed between the platen 12 and the wall portion 22 of the print head 30.

As shown in the enlarged view of FIG. 2, a contact surface 42 is formed on the platen 12 side of the tip of the positioning projection 40. The contact surface 42 is formed in front of the front end surface 44 of the nose portion 34 of the print head 30 by a predetermined distance L, that is, on the platen 12 side, and the carriage 20
When advancing, the print surface 14 is supported by the support surface 16. In this embodiment, the relative position in the carriage front-rear direction between the mounting reference surface 24 and the contact surface 42 for positioning the print head 30 on the carriage 20 is accurately determined (distance M in FIG. 3). In the state where the print head 30 is fixed to the carriage 20, the distance between the tip end surface 44 of the head 30 and the contact surface 42 of the positioning protrusion 40 is always exactly the distance L.

In FIG. 3, a fitting hole 50 is formed in the lower portion of the carriage 20, and is fitted to a guide shaft 52 arranged parallel to the platen 12 so as to be relatively rotatable and relatively movable in the axial direction. ing. The guide shaft 52 is supported by the frame by eccentric shafts 54 protruding from both ends thereof. Further, the rear end of the carriage 20 is a U-shaped portion 56, and another guide shaft 58 arranged in parallel with the guide shaft 52 is engaged with the carriage 2,
The movement of the carriage 20 in the direction parallel to the platen 12 is guided, and the carriage 20 is allowed to approach and separate from the platen 12.

The eccentric shaft 54 is eccentric to the shaft center of the guide shaft 52, and the fan gear 60 is fixed to one end of the eccentric shaft 54. A circular first gear 62 is meshed with the sector gear 60. The first gear 62 is non-rotatably attached to a shaft 64 arranged in parallel with the eccentric shaft 54, and a second gear 66 is further attached to the shaft 64.
Are mounted so that they can rotate relative to each other. An elongated hole 68 is formed in the second gear 66 along an arc centered on the axis of the shaft 64, and a connecting rod 70 standing upright in parallel with the shaft 64 is inserted into the first gear 62. One arm 74 of the spring 72 wound around the shaft 64 is abutted.

The other arm 76 of the spring 72 is connected to the second gear 6
It is locked by a pin 78 projecting from 6 and urges the connecting rod 70 in a direction to press it against one end of the elongated hole 68. The second gear 66 is also meshed with a drive gear 84 fixed to the output shaft 82 of the step motor 80, and the second gear 66 is
1 is rotated clockwise by the step motor 80 as shown by the arrow in FIG. 1, the connecting rod 70 is biased by the spring 72 and is made to follow the second gear 66 while being in contact with the end face of the slot 68. As a result, the first gear 6
2 rotates in the same direction as the second gear 66 as shown by the arrow, the sector gear 60 is rotated counterclockwise, the eccentric shaft 54 is rotated, and the carriage 20 is advanced toward the platen 12.

As the carriage 20 advances, the contact surface 42 of the positioning projection 40 is moved to the support surface 1 of the platen 12.
6 is brought into contact with the printing paper 14 supported by the carriage 6, and the carriage 20
If the forward movement is stopped, the rotations of the sector gear 60 and the first gear 62 stop. Therefore, the connecting rod 70 does not follow the rotation of the second gear 66, only the second gear 66 rotates, and the rotation of the step motor 80 is not transmitted to the first gear 62, the eccentric shaft 54, and the carriage 20. Slot 68,
The connecting rod 70 and the spring 72 constitute a torque limiter that does not transmit torque exceeding the set amount of the step motor 80. At this time, the spring 72 is elastically deformed in accordance with the rotation of the second gear 66, and a force for pressing the contact surface 42 against the platen 12 via the printing paper 14 is generated.

An encoder 88 is provided on the first gear 62 to detect whether or not the carriage 20 is moving in the front-rear direction. A fan-shaped rotating plate 90 is fixed to an end surface of the first gear 62 opposite to the second gear 66. A plurality of slits 92 are formed in a part of the rotary plate 90 at equal intervals, and a photo interrupter 94 is provided across the rotary plate 90. The photo interrupter 94 includes a slit for generating a reference signal and a slit for generating a direction signal, and two pairs of a light emitting element and a light receiving element with both slits and the rotary plate 90 sandwiched therebetween, and output signals of the two light receiving elements. The amount of movement of the carriage 20 is detected based on the change of. The slits 92 are formed in a sufficient number so that a signal is output when the carriage 20 moves forward and backward.

The step motor 80 is controlled by the control device 100 shown in FIG. The control device 100 is a CP
The main component is a microcomputer including a U 102, a ROM 104, a RAM 106, and a bus 108 connecting them. An input interface 110 is connected to the bus 108, and an encoder processing circuit 112 that processes a signal emitted from the encoder 88 is connected to the bus 108. An output interface 114 is also connected to the bus 108, and a step motor 80 is connected to the output interface 114 via a drive circuit 116. The RAM 106 is provided with a counter for counting the number of drive pulses of the step motor 80 and various memories,
The ROM 104 stores a control program for reading the I / D mark, a table of an appropriate head gap for each thickness of the printing paper 14, and the like. In this table, the thickness of the printing paper 14 and the head gap are represented by the number of drive pulses of the step motor 80. Further, the control device 100 uses the input interface 110 and the output interface 114 to connect the host computer 11
Connected to 5.

As is clear from the above description, the fitting hole 5
0, guide shaft 52, fan gear 60, first gear 62, second gear 66, connecting rod 70, spring 72, step motor 80
And the like constitute a carriage advancing / retreating device 86, and the carriage advancing / retreating device 86 constitutes a head gap adjusting device together with the positioning protrusion 40 and the control device 100.

The output interface 114 of the control device 100 is connected to the print head 30 via a drive circuit 117.
Is connected to the solenoid 46 and the drive circuit 11
A carriage drive motor 119 is connected via the switch 8. By driving the carriage drive motor 119, the carriage 20 can be moved in the left-right direction via the pair of pulleys and the timing belt.

As shown in FIG. 1, a mounting plate 120 is fixed to the front end of the carriage 20. Mounting plate 120
Has a flat plate shape as shown in FIG. 5 and FIG.
A notch 1 that allows the nose portion 34 of the print head 30 and the positioning member 40 to project toward the platen 12 in the central portion.
22 is provided. Also, on both sides of the notch 122,
A pair of tongue pieces 124 are horizontally formed on the upper end portion of the mounting plate 120, and a pair of tongue pieces 126 are horizontally formed on the lower end portion thereof. Further, each tongue piece 124 is formed with a female screw hole 128, and each tongue piece 126 is formed with a through hole 130.

As shown in FIG. 10, female threaded holes 132 (only one of which is shown) are formed at the left and right ends of the front end of the carriage 20, and each tongue piece 126 is attached to the carriage 2.
When the bolt 134 is brought into contact with the upper surface of 0, the bolt 134 is tightened into the female screw hole 132 through the through hole 130, whereby the mounting plate 120 is fixed in a state of vertically rising from the carriage 20.

On the other hand, the sensor holder 136 shown in FIGS. 7 to 9 is attached to the tongue piece 124 of the attachment plate 120. The upper end of the sensor holder 136 has a mounting portion 138 that extends horizontally.
As shown in FIG. 10, with the mounting portion 138 and the tongue piece 124 in close contact with each other, the female screw hole 128 of the tongue piece 124 is passed through the U-shaped notch 140 formed in the mounting portion 138.
The sensor holder 136 is fixed in a state of being hung from the tongue piece 124 of the mounting plate 120 by tightening the bolt 142 to the. In FIG. 1, the bolts 134, 1
42 is omitted.

A cylindrical sensor holding portion 146 is formed at the center of the sensor holder 136, and an I / D is provided there.
An I / D mark sensor 148 as a mark reading device is fitted. The I / D mark sensor 148 is the sensor holder 1
After being fitted to 46, it is soldered and made immovable in the axial direction, that is, in the front-back direction of the carriage 20. In this embodiment, the I / D mark sensor 148 is mounted on the carriage 20 via the sensor holder 136 and the mounting plate 120.
By being fixed to the print head 30, the print head 30 cannot be moved relative to the print head 30. I / D mark sensor 148
The detection-side end surface of the print head 30 is located substantially on the same plane as the front end surface 44 of the print head 30, and the carriage advancing / retracting device 86 retracts the carriage 20 to cause the print head 30 to move.
And be retreated together.

Further, the sensor holder 136 is formed with an engaging projection 150 and an engaging hole 152 in the vertical direction with the sensor holding portion 146 interposed therebetween, and the cover 154 shown in FIG.
Are attached (omitted in FIGS. 1 and 10). The cover 154 has a U-shaped cross section, and the engaging projection 150 is engaged with the through hole 156 of the cover 154, and the claw portion 158 is elastically engaged with the edge of the engaging hole 152 so that the sensor holder is held. Fixed at 136, I /
The D mark sensor 148 is covered.

As shown in FIG. 10, a relay board 162 is placed on the carriage 20, and a cable 164 extending from the rear end of the I / D mark sensor 148 is connected to the relay board 162 and an amplifier (not shown). It is connected to the input interface 110 of the control device 100 via. The I / D mark sensor 148 is of an optical reflection type, and its focus is located behind the print sheet 14 when the head gap between the print head 30 and the print sheet 14 is proper, and the I / D mark sensor 148 is 148 is located on the surface of the printing paper 14 at a position separated from the printing paper 14 by retracting a certain amount.

In this embodiment, since the platen 12, the print head 30, the head gap adjusting device, the carriage drive motor 119, the I / D mark sensor 148, the control device 100 and the like constitute an I / D mark reading device. is there.

In the printer 10 constructed as described above, the I / D mark 168 shown in FIG.
Is printed, and the printed I / D mark 168 is I / D
The case of reading by the mark sensor 148 will be described. First, the head gap is adjusted before printing the I / D mark 168. Support surface 1 of platen 12
After the printing paper 14 is set in 6, the carriage 20 in the initial position is advanced toward the platen 12,
The contact surface 42 of the positioning protrusion 40 of the carriage 20 is brought into contact with the printing paper 14 supported by the platen 12.
If the contact surface 42 comes into contact with the surface of the print paper 14 and the forward movement of the carriage 20 is stopped, the output signal of the encoder 88 does not change. Therefore, a step motor stop command signal is issued from the control device 100, and the step motor is stopped. 80
Is stopped.

The number of drive pulses of the step motor 80 required for the carriage 20 to move until the positioning protrusion 40 comes into contact with the printing paper 14 is counted and stored by the counter in the RAM 106. The difference between the number of drive pulses and the number of drive pulses of the step motor 80, which is stored in advance and corresponds to the distance from the carriage initial position of the positioning protrusion 40 to the support surface 16 of the platen 12, is the thickness of the printing paper 14 ( It is represented by the number of pulses). Therefore, a head gap (gap G between the front end surface 44 of the print head 30 shown in FIG. 2 and the print sheet 14 shown in FIG. 2) suitable for the thickness of the print sheet 14 is read from the table stored in the ROM 104. A value obtained by subtracting the distance L between the contact surface 42 and the front end surface 44 from the head gap G is calculated as the retreat amount of the carriage 20. If the step motor 80 is rotated in the reverse direction by the number of drive pulses corresponding to this backward movement amount and the second gear 66 is rotated in the counterclockwise direction, the connecting rod 70 is rotated.
Is pushed by the end of the slot 68, the first gear 62 is rotated counterclockwise, the print head 30 is retracted, and the head gap is adjusted to an appropriate size.

After the head gap is adjusted, the carriage drive motor 119 is driven, the carriage 20 is moved from the left end position to the right, and the solenoid 46 of the print head 30 is excited to print the I / D mark on the print paper 14. 168 is printed.

When the printing of the I / D mark 168 is completed, the carriage 20 is returned to the left end position. Next, the ROM 10
In accordance with the I / D mark reading program stored in 4, the carriage advancing / retreating device 86 moves the carriage 20 backward, and the focus of the I / D mark sensor 148 is positioned on the surface of the printing paper 14. At this time, since the thickness of the printing paper 14 has already been recognized, it is not necessary to newly measure it. When the head gap between the print head 30 and the print paper 14 is proper, the I / D mark sensor 148
The number of drive pulses of the step motor 80 required for the carriage 20 to move until the focus of is placed on the surface of the printing paper 14 is stored in the RAM 106 in advance, and the number of steps corresponding to the stored number of drive pulses is used. The motor 80 is driven and the carriage 20 is retracted.

When the backward movement of the carriage 20 is completed, the I / D
When the focal point of the mark sensor 148 is positioned on the printing paper 14, the carriage 20 is moved to the right according to the I / D mark reading program as in the printing, and the I / D is read.
The mark 168 is read. At this time, the distance between the ink ribbon and the print paper 14 becomes larger than the distance after the head gap adjustment, and the ink ribbon is prevented from coming into contact with the surface of the print paper 14 and rubbing the I / D mark 168.

The signal read by the I / D mark sensor 148 is input to the CPU 102 from the input interface 162 of the control device 100 via the relay board 162,
Printed I based on I / D mark reading program
It is determined whether or not the / D mark 168 is proper.

As a result of the judgment, when the I / D mark 168 is proper, the carriage 20 is returned to the left end position and the reading is completed, and the carriage advancing / retreating device 86 causes the step motor 80 by the number of drive pulses. Is driven,
The carriage 20 is advanced. As a result, the head gap is set to an appropriate value again, and printing is performed on the printing paper 14.

On the other hand, if the result of determination is that the I / D mark 168 is incorrect, a warning buzzer, warning lamp, or the like (not shown) is activated to notify the operator of that fact. If an appropriate read value of the I / D mark 168 cannot be obtained, the I / D mark 168 may be printed again at the same position.

Next, a case will be described in which the print paper 14 on which the I / D mark 168 has already been printed is newly fed from the outside of the apparatus and read. When the printing paper 14 with the I / D mark 168 is fed, the I / D mark 16
Feeding is performed with the carriage 20 in the retracted position so that 8 is not soiled. After the paper is fed, the contact surface 42 of the positioning protrusion 40 is brought into contact with the printing paper 14 by the same process as the head gap adjustment described above, and the printing paper 14 is
Of the I / D mark 16 is measured while the carriage 20 is retracted by a distance corresponding to the focal length and the carriage is moved in parallel with the platen 12.
8 readings are taken. After the reading is completed, the head gap is adjusted to an appropriate value, but since the thickness of the print paper 14 has already been measured, the step motor 80 is driven by the number of drive pulses stored in the RAM 106, Only the carriage 20 needs to be moved forward by a predetermined amount.

When the I / D mark 168 is read, the I / D mark 168 is converted into an electric signal and sent to the host computer 115. Host computer 11
In 5, the print position information corresponding to the I / D mark 168, the character information to be printed, and the like are prepared, and the information is sent to the control device 100 to perform printing and the like. At this time, in addition to the already printed I / D mark 168, a new I
The / D mark may be printed on the printing paper 14 to indicate that the target information is printed. In this way, when different information needs to be printed on the same printing paper several times over several days, it is possible to inform the host computer 115 side which information has already been written.

In this embodiment, the I / O of the ROM 104 is
CPU storing D mark reading program and CPU
102 and the portion of the RAM 106 that executes the I / D mark reading program form the reading movement control means.

Further, in this embodiment, after the I / D mark 168 is printed, the carriage 20 is moved again (they need not be in the same direction) to read the I / D mark 168 for confirmation. However, it is not limited to this. That is, at the time of printing the I / D mark, the reading operation can be performed while the focal lengths are inconsistent and the reading operation is performed. In this case, the reading conditions become very bad at the stage of performing the confirmation operation, but if the reading is possible in such a state, after a certain period of time (the reading conditions are deteriorated due to dirt on the printing paper during that time). Do)
It is considered that the I / D mark can be almost certainly read even if the reading is performed. Even in this case,
It goes without saying that the carriage can be moved to an appropriate position according to the focal length as described above.

Further, in this embodiment, after the I / D mark 168 is printed by the print head 30, the I / D mark 168 is read.
The present invention can also be applied to the case of reading the I / D mark on the printing paper on which the I / D mark is printed in advance.

Further, in the present embodiment, when the head gap is adjusted, the corresponding proper head gap is read from the ROM 104 after the thickness of the printing paper 14 is measured, but when the number of data is large. May store a function (mathematical expression) for obtaining an appropriate head gap in the ROM 104 and calculate for each measurement. Also,
It is also possible to set the proper head gap by retracting the carriage for a certain distance after the contact surface of the positioning protrusion contacts the print sheet.

Although the I / D mark sensor 148 is fixed to the carriage 20 in this embodiment, it may be directly attached to the print head.

In addition, the present invention can be implemented in various modified and improved forms based on the knowledge of those skilled in the art, such as applying the present invention to another type of printing device such as an ink jet printer.

[Brief description of drawings]

FIG. 1 is a plan view showing a main part of a printing device including an I / D mark reading device according to an embodiment of the present invention.

FIG. 2 is an enlarged front view showing the vicinity of a positioning member of the apparatus.

FIG. 3 is a perspective view schematically showing the device.

FIG. 4 is a block diagram showing a control device of the device.

FIG. 5 is a front view showing an I / D mark sensor mounting plate of the apparatus.

FIG. 6 is a plan view of the I / D mark sensor mounting plate.

FIG. 7 is a plan view showing an I / D mark sensor holder of the above apparatus.

FIG. 8 is a front view of the I / D mark sensor holder.

9 is a sectional view taken along line IX-IX in FIG.

FIG. 10 is a side sectional view of the printing apparatus of FIG.

FIG. 11 is a front view showing an example of a print medium on which an I / D mark is printed.

[Explanation of symbols]

 12 platen 14 printing paper 16 support surface 20 carriage 30 print head 80 step motor 86 carriage advance / retreat device 88 encoder 100 controller 120 mounting plate 136 sensor holder 148 I / D mark sensor 168 I / D mark

Claims (1)

[Claims] 1. A platen for supporting a print medium, a print head which is disposed so as to face the platen and can be moved toward and away from the platen by moving in a front-back direction, and a position of a surface of the print medium supported by the platen. A head gap adjusting device that adjusts a head gap that is a gap between the print medium and the print medium by advancing and retracting the print head based on the detection result, and immovable relative to the print head. I / D that is fixed and reads the I / D mark formed on the surface of the print medium
In a printing device provided with an I / D mark reading device including a mark sensor, the I / D mark reading device is provided with the I / D mark reading device when the head gap is adjusted.
The I / D mark sensor is fixed to the print head in a state where the focus of the / D mark sensor is located behind the print medium, and the print head and the I / D mark sensor are attached to the head gap adjusting device. A printing apparatus comprising a reading movement control means for moving the focus of the mark sensor to a position located on the surface of the print medium.