JP6957323B2 - Printing machine, printing head - Google Patents

Description

The present invention relates to a printing technique for printing by sliding a squeegee on a mask while applying a printing pressure to the squeegee.

Conventionally, there is known a printing machine that prints the paste supplied to the upper surface of the mask on the printing object by sliding the squeegee on the upper surface of the mask while facing the printing object on the lower surface of the mask. In order to perform such printing well, it is important to apply an appropriate printing pressure to the squeegee. Therefore, the printing machine described in Patent Document 1 includes a strain gauge attached to a squeegee holder that holds the squeegee, and prints while controlling the printing pressure applied to the squeegee based on the output value of the strain gauge.

Japanese Unexamined Patent Publication No. 09-174808

By the way, in order to suppress the impact at the moment when the squeegee comes into contact with the mask, the print head provided with the squeegee as described above may be provided with a load reducing spring for urging the squeegee upward. However, there has been an issue of increasing the size of the print head as the number of parts such as a pressure sensor such as a strain gauge and a load reduction spring increases.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a technique capable of equipping a pressure sensor and a load-reducing spring while suppressing an increase in size of a print head.

The printing machine according to the present invention has a pressure sensor that outputs a detected value according to the applied pressure, a squeegee that is arranged below the pressure sensor and is connected to the pressure sensor, and a squeegee that is connected to the squeegee via the pressure sensor from above. A printing head having a printing pressure applying portion for applying printing pressure and a load reducing portion having a spiral-shaped load reducing spring and urging the squeegee upward by the load reducing spring is opposed to the printing object from above. It is equipped with a mask holding part that holds the mask, and prints on the object to be printed by sliding the squeegee of the print head on the upper surface of the mask. In the print head, at least a part of the pressure sensor is inside the load reduction spring. Is located in.

The print head according to the present invention has a pressure sensor that outputs a detected value according to the applied pressure, a squeegee that is arranged below the pressure sensor and connected to the pressure sensor, and a squeegee that is connected to the squeegee via the pressure sensor from above. It is provided with a printing pressure applying portion that applies printing pressure and a load reducing portion that has a spiral-shaped load reducing spring and urges the squeegee upward by the load reducing spring, and at least a part of the pressure sensor is inside the load reducing spring. Is located in.

In the present invention (printing machine, printing head) configured in this way, the pressure sensor is arranged (in other words, inserted) inside the spiral load reducing spring. In this way, since the pressure sensor is arranged by effectively utilizing the space inside the load reduction spring, it is possible to equip the pressure sensor and the load reduction spring while suppressing the increase in size of the print head. ing.

Further, the load-reducing portion has a flange fixed to the pressure sensor above the load-reducing spring, and the load-reducing spring presses the flange upward to urge the squeegee upward via the pressure sensor. , A printing machine may be configured. In such a configuration, the load reduction by the load reduction spring can be accurately reflected in the pressure sensor.

Further, the printing pressure applying portion has a printing pressure spring arranged above the flange, and the printing machine is configured so as to apply printing pressure to the squeegee by pressing the flange downward by the printing pressure spring. Is also good. In such a configuration, the flange provided for reducing the load of the squeegee by the load reducing spring is shared for applying the printing pressure of the squeegee by the printing pressure spring, which effectively contributes to suppressing the increase in size of the print head.

Further, the printing machine may be configured so that the printing head is provided with a plurality of units including a pressure sensor, a printing pressure applying portion, and a load reducing portion. That is, in the present invention, since the pressure sensor is arranged by effectively utilizing the space inside the load reducing spring, the pressure sensor, the printing pressure applying portion, and the load reducing portion suppress the increase in size of the print head. It is possible to provide a plurality of configured units.

Further, the printing machine may be configured to further include a printing pressure information acquisition unit that acquires information on the printing pressure given to the squeegee based on the detection values of the pressure sensors of each of the plurality of units. In such a configuration, it is possible to accurately acquire information on printing based on the detection values of a plurality of pressure sensors.

Further, the printing pressure information acquisition unit may configure the printing machine so as to acquire the difference between the detection values of the pressure sensors of each of the plurality of units as information indicating the bias of the printing pressure given to the squeegee. In such a configuration, the bias of the printing pressure can be accurately acquired based on the detected values of the plurality of pressure sensors.

Further , the printing pressure information acquisition unit may configure a printing machine so as to warn the operator when the difference between the maximum value and the minimum value of the pressure sensors of each of the plurality of units exceeds the threshold value. .. In such a configuration, when the imbalance of printing pressure is large, it is possible to warn the operator and prompt the necessary work.

Further, the printing pressure information acquisition unit may configure the printing machine so as to measure the printing pressure applied to the squeegee based on the average value of the detection values of the pressure sensors of each of the plurality of units. With such a configuration, the printing pressure can be measured while suppressing the influence of external noise mixed in the detected value of the pressure sensor.

There are various types of sensors that can be used as pressure sensors. Therefore, the pressure sensor may be a magnetostrictive sensor.

According to the present invention, it is possible to equip a pressure sensor and a load reduction spring while suppressing an increase in size of the print head.

FIG. 1 is a front view schematically showing a printing machine to which the present invention is applied. FIG. 3 is a block diagram showing an electrical configuration included in the printing machine of FIG. The perspective view which shows the structure of a print head partially. The front view which shows the structure of a print head partially. The side view which shows the structure of a print head partially. A cross-sectional view taken along the line AA partially showing the configuration of the print head. A cross-sectional view taken along the line AA showing the configuration of the printing pressure sensor included in the print head.

FIG. 1 is a front view schematically showing a printing machine to which the present invention is applied. FIG. 2 is a block diagram showing an electrical configuration included in the printing press of FIG. In FIG. 1 and the following figures, XYZ orthogonal coordinate axes with the Z direction as the vertical direction and the X and Y directions as the horizontal directions are appropriately shown. The printing machine 1 includes a mask holding unit 2 for holding the mask M, a substrate holding unit 4 arranged below the mask M, and a printing head 6 arranged above the mask M. Further, the printing machine 1 includes a main control unit 10 composed of a CPU (Central Processing Unit), a RAM (Random Access Memory), and the like. Then, the main control unit 10 controls the substrate holding unit 4 and the print head 6, so that the substrate holding unit 4 faces the substrate B from below to the mask M, and the tip of the squeegee 61 of the squeegee unit 6 is placed on the upper surface of the mask M. Slide in the X direction. As a result, the paste (solder) supplied to the upper surface of the mask M is printed on the upper surface of the substrate B through the pattern holes penetrating the mask M. Further, the printing machine 1 includes a display unit 11 composed of, for example, a liquid crystal display. Therefore, the operator can confirm the operating status of the printing machine 1 by confirming the display contents of the display unit 11.

The mask holding unit 2 has a clamp member 21, and the mask M is detachably attached to the clamp member 21 via a frame F provided on the peripheral edge thereof. As a result, the mask M having a flat plate shape is horizontally held by the mask holding unit 2. The mask M has a rectangular shape in a plan view, and has through holes (pattern holes) having a shape corresponding to a printing pattern on the substrate B.

The substrate holding unit 4 is arranged below the mask M held by the mask holding unit 2 and has a function of aligning the position of the substrate B with respect to the mask M. The substrate holding unit 4 includes a pair of conveyors 41 that convey the substrate B, a substrate holding portion 42 that holds the substrate B received from the conveyor 41, and a flat plate-shaped movable table 43 that supports the conveyor 41 and the substrate holding portion 42. And have.

The pair of conveyors 41 are arranged in parallel in the Y direction with an interval in the X direction, and both ends of the substrate B in the X direction are supported from below on their respective upper surfaces. Then, each conveyor 41 conveys the substrate B in the Y direction, and carries in or out the substrate B to the printing machine 1.

The substrate holding portion 42 has a flat plate-shaped elevating table 421 and a slide column 422 that can slide in the Z direction with respect to the movable table 43, and the elevating table 421 is supported by the upper end of the slide column 422. Further, on the upper surface of the elevating table 421, a plurality of backup pins 423 erected in the Z direction are arranged at intervals in the X direction and the Y direction. Then, as the slide column 422 moves up and down, the backup pin 423 moves up and down together with the lifting table 421. For example, when the substrate B of the conveyor 41 is carried in, the upper end of each backup pin 423 is located below the upper surface of the conveyor 41. Then, when the conveyor 41 carries the substrate B directly above the backup pin 423, the backup pin 423 rises and the upper end of the backup pin 423 projects upward from the upper surface of the conveyor 41. As a result, the substrate B is delivered from the upper surface of the conveyor 41 to the upper end of each backup pin 423.

Further, the substrate holding portion 42 has a pair of clamp plates 424 arranged above the pair of conveyors 41 at intervals in the X direction, and at least one of these clamp plates 424 is movable in the X direction. The upper surface of each clamp plate 424 is a plane parallel to the X and Y directions and is located at the same height as each other. Then, when the substrate B on the backup pin 423 rises between the pair of clamp plates 424, the distance between the clamp plates 424 is narrowed, and the substrate B is clamped by these clamp plates 424 from the X direction (horizontal direction).

Further, the substrate holding unit 4 has a table driving mechanism 44 for driving the movable table 43. The table drive mechanism 44 is attached to the X-axis table 441, the Y-axis table 442 attached to the upper surface of the X-axis table 441, the R-axis table 443 attached to the upper surface of the Y-axis table 442, and the R-axis table 443. On the other hand, it has a ball screw 444 that raises and lowers the movable table 43. Therefore, the table drive mechanism 44 drives the conveyor 41 and the substrate holding portion 42 arranged on the movable table 43 in the X, Y, Z, and R directions to position the carried-in substrate B with respect to the mask M. be able to. As a result, the upper surfaces of the clamp plate 424 and the substrate B each come into contact with the lower surface of the mask M.

Further, as shown in FIG. 2, the printing machine 1 has a head drive unit 6D having an X-axis motor Mx for driving the print head 6 in the X direction and a Z-axis motor Mz for driving the print head 6 in the Z direction. Have. Then, the main control unit 10 drives the print head 6 in the X direction by the X-axis motor Mx while pressing the squeegee 61 of the print head 6 against the upper surface of the mask M with a predetermined printing pressure by the Z-axis motor Mz. , The squeegee 61 is trained on the upper surface of the mask M.

Subsequently, the details of the print head 6 will be described with reference to FIGS. 3 to 6. Here, FIG. 3 is a perspective view partially showing the configuration of the print head, FIG. 4 is a front view partially showing the configuration of the print head, and FIG. 5 is a side view partially showing the configuration of the print head. FIG. 6 is a cross-sectional view taken along the line AA partially showing the configuration of the print head, and FIG. 7 is a cross-sectional view taken along the line AA showing the configuration of the printing pressure sensor included in the print head.

The print head 6 has a support bracket 62 that rotatably supports the squeegee 61 about an axis parallel to the Y direction, and a rotation motor Mθ attached to the support bracket 62 (FIG. 1). The rotation motor Mθ is connected to the rotation shaft of the squeegee 61, and by rotating the squeegee 61 by the rotation motor Mθ, the angle (attack angle) at which the squeegee 61 contacts the upper surface of the mask M can be adjusted. can.

Further, the print head 6 has a support frame 63 for supporting the support bracket 62 to which the squeegee 61 is attached above the support bracket 62. That is, the print head 6 has two support rods 64 extending in parallel in the Z direction, and each support rod 64 is provided so as to be slidable in the Z direction with respect to the support frame 63. A rod guide 631 through which the insertion hole 632 penetrates in the Z direction is attached to the support frame 63 corresponding to each support rod 64, and the two support rods 64 are inserted into the insertion hole 632 of the corresponding rod guide 631 from above. Has been done. Each support rod 64 has a flange 641 having a diameter larger than that of the insertion hole 632 at the upper end thereof, and the flange 641 is hooked on the rod guide 631 from above so that the support rod 64 does not come off from the rod guide 631. Has been done. On the other hand, the lower ends of the two support rods 64 are attached to the upper surface of the plate 65 attached to the upper end of the support bracket 62.

Further, the print head 6 has a load reducing portion 7 that urges the squeegee 61 upward. In the present embodiment, two load reducing portions 7 are provided between the two support rods 64, but the configurations of these load reducing portions 7 are the same except for the mechanism related to the printing pressure detection described in detail later. be. Therefore, here, the details of one load-reducing unit 7 will be described, and the configurations common to the two load-reducing units 7 will be designated by corresponding reference numerals and the description thereof will be omitted.

The load-reducing portion 7 has a load-reducing spring 71 that has a spiral shape and can expand and contract in the Z direction, and a support ring 72 that supports the load-reducing spring 71. The load-reducing spring 71 is inserted into a through hole 633 that penetrates the support frame 63 in the Z direction from above, and the upper end of the load-reducing spring 71 projects upward from the upper surface of the support frame 63. The support ring 72 faces the through hole 633 from below and is fixed to the lower surface of the support frame 63 by a screw. The support ring 72 supports the load reduction spring 71 from below with respect to the support frame 63.

Further, the load-reducing portion 7 has a rod 73 inserted from below inside the load-reducing spring 71 through the hole of the support ring 72, and a flange 74 arranged above the load-reducing spring 71. The lower end of the rod 73 is fixed to the upper surface of the plate 65, and the rod 73 is erected upward from the plate 65 in parallel in the Z direction. The flange 74 is fixed to the upper end of the rod 73 protruding upward from the load reducing spring 71, and projects laterally (horizontally) from the rod 73. The lower end of the load reduction spring 71 is in contact with the support ring 72, the upper end of the load reduction spring 71 is in contact with the flange 74, and the load reduction spring 71 is sandwiched between the support ring 72 and the flange 74 in the Z direction. It is compressed to. Therefore, the elastic force of the load-reducing spring 71 that presses the flange 74 upward is transmitted to the plate 65 via the rod 73, and urges the squeegee 6 attached to the plate 65 upward.

Further, the print head 6 has a printing pressure applying portion 8 that applies printing pressure to the squeegee 61 by pressing the squeegee 61 downward. In the present embodiment, two printing pressure applying portions 8 are provided, but the configuration of these printing pressure applying portions 8 is the same. Therefore, here, the details of one printing pressure applying unit 8 will be described, and the configuration common to the two printing pressure applying units 8 will be designated by a corresponding reference numeral and the description thereof will be omitted.

The printing pressure applying portion 8 has a printing pressure spring 81 having a spiral shape and being expandable and contractible in the Z direction, and a cover member 82 having a cylindrical shape. The printing pressure spring 81 is arranged above the flange 74 of the load reducing portion 7, and is provided coaxially with the load reducing spring 71. The cover member 82 has a hollow portion 821 that opens downward and has a cylindrical shape, and is externally fitted to the printing pressure spring 81 and the flange 74 from above and fixed to the support frame 63. In this way, the printing pressure spring 81 and the flange 74 are inserted into the hollow portion 821 of the cover member 82 from below. The lower end of the printing pressure spring 81 contacts the flange 74, the upper end of the printing pressure spring 81 contacts the inner wall of the upper end of the cover member 82, and the printing pressure spring 81 is sandwiched between the flange 74 and the cover member 82 in the Z direction. It is compressed to. Therefore, the elastic force of the printing pressure spring 81 that presses the flange 74 downward is transmitted to the plate 65 via the rod 73, and presses the squeegee 61 attached to the plate 65 against the mask M.

The support frame 63 is driven in the Z direction by the Z-axis motor Mz. Therefore, when the support frame 63 is driven downward from the state where the squeegee 61 is in contact with the mask M, the cover member 82 also moves downward along with the support frame 63, and the printing pressure spring 81 is shortened. As a result, the elastic force of the printing pressure spring 81 increases, and the printing pressure generated between the squeegee 61 and the mask M also increases. That is, the printing pressure spring 81 applies a printing pressure to the squeegee 61 according to the height of the support frame 63.

Further, the print head 6 has a mechanism for measuring the printing pressure applied to the squeegee 61. That is, one of the two rods 73 (the rod 73 on the right side of FIGS. 3 and 6) is a sensor rod Sr composed of a magnetostrictive body, and the magnetic permeability changes according to the applied pressure. Has physical characteristics. The sensor rod Sr may be formed by forming the entire sensor rod Sr with a magnetostrictive body, or for example, by forming a thin film of the magnetostrictive body on the entire peripheral surface of a metal axial center by plating. May be done.

A coil Sc is wound around the outer circumference of the sensor rod Sr. As shown in detail in FIG. 7, the printing pressure sensor S has a resin bobbin Sb fitted to the outside of the sensor rod Sr, and a coil Sc is wound around a recess provided on the outer periphery of the bobbin Sb. .. Further, the printing pressure sensor S has a metal shield Ss fitted to the outside of the bobbin Sb, and the noise from the outside is shielded by the shield Ss. In the Z direction, the sensor rod Sr (in other words, the arrangement range of the magnetostrictive body) is longer than the coil Sc, and both ends of the sensor rod Sr project from both ends of the coil Sc.

In this way, the printing pressure sensor S is composed of the sensor rod Sr, the coil Sc, and the like, and the upper end portion of the printing pressure sensor S is inserted inside the load reducing spring 71. In such a printing pressure sensor S, impedance corresponding to the pressure applied to the sensor rod Sr is generated in the coil Sc.

Further, the print head 6 has a circuit board C and a wiring W for electrically connecting the circuit board C and the printing pressure sensor S, and the circuit board C passes through the wiring W to the coil Sc of the printing pressure sensor S. When a current is supplied to the coil Sc, the printing pressure sensor S outputs a voltage corresponding to the impedance of the coil Sc. Then, the circuit board C transmits the voltage output from the printing pressure sensor S to the main control unit 10 as a detection value of the printing pressure sensor S. Therefore, the main control unit 10 can measure the printing pressure applied to the squeegee 61 based on the detection value of the printing pressure sensor S received from the circuit board C. The circuit board C is attached to one of the two support rods 64, which is closer to the printing pressure sensor S.

In the present embodiment configured as described above, the printing pressure sensor S is arranged (in other words, inserted) inside the spiral load reducing spring 71. In this way, since the printing pressure sensor S is arranged by effectively utilizing the space inside the load reducing spring 71, the printing pressure sensor S and the load reducing spring 71 can be mounted while suppressing the increase in size of the print head 6. It is possible to equip it.

Further, the load reducing unit 7 has a flange 74 fixed to the sensor rod Sr of the printing pressure sensor S above the load reducing spring 71, and the load reducing spring 71 presses the flange 74 upward to cause the printing pressure sensor. The squeegee 61 is urged upward via the sensor rod Sr of S. In such a configuration, the load reduction by the load reduction spring 71 can be accurately reflected in the printing pressure sensor S.

Further, the printing pressure applying portion 8 has a printing pressure spring 81 arranged above the flange 74, and presses the flange 74 downward by the printing pressure spring 81 to apply printing pressure to the squeegee 61. In such a configuration, the flange 74 provided for reducing the load of the squeegee 61 by the load reducing spring 71 is shared for applying the printing pressure of the squeegee 61 by the printing pressure spring 81, thereby suppressing the increase in size of the print head 6. Effectively contribute.

As described above, in the present embodiment, the printing machine 1 corresponds to an example of the "printing machine" of the present invention, the printing head 6 corresponds to an example of the "printing head" of the present invention, and the printing pressure sensor S corresponds to the present invention. The squeegee 61 corresponds to an example of the "squeegee" of the present invention, and the printing pressure applying portion 8 corresponds to an example of the "printing pressure applying portion" of the present invention. The load reduction unit 7 corresponds to an example of the "load reduction unit" of the present invention, the load reduction spring 71 corresponds to an example of the "load reduction spring" of the present invention, and the mask holding unit 2 corresponds to the "mask holding" of the present invention. The flange 74 corresponds to an example of the "flange" of the present invention, the printing pressure spring 81 corresponds to an example of the "printing pressure spring" of the present invention, and the printing pressure sensor S and the printing pressure are applied. The sensor unit U (FIG. 6) including the unit 8 and the load reduction unit 7 corresponds to an example of the “unit” of the present invention.

The present invention is not limited to the above embodiment, and various modifications can be made to the above as long as it does not deviate from the gist thereof. For example, the number of sensor units U is not limited to the above one, and a plurality of sensor units U can be provided on the print head 6. That is, in the present invention, since the printing pressure sensor S is arranged by effectively utilizing the space inside the load reducing spring 71, it is possible to provide a plurality of sensor units U while suppressing the increase in size of the print head 6. It is possible.

Further, when a plurality of sensor units U are provided on the print head 6 in this way, the main control unit 10 (printing pressure information acquisition unit) squeezes based on the detection values of the printing pressure sensors S of each of the plurality of sensor units U. Information on the printing pressure given to 61 can be obtained. That is, the information can be accurately acquired based on the detected values of the plurality of printing pressure sensors S. Specifically, the main control unit 10 can execute the controls shown in the following control examples.

First Control Example In the first control example, the main control unit 10 acquires the difference between the detected values of the plurality of printing pressure sensors S as information indicating the bias of the printing pressure given to the squeegee 61, in other words, the biased load. do. Specifically, the main control unit 10 determines whether or not the difference between the maximum value and the minimum value of the detected values of the plurality of printing pressure sensors S is equal to or greater than the threshold value. Then, when this difference becomes equal to or greater than the threshold value, the main control unit 10 displays a warning that the eccentric load is excessive on the display unit 11 toward the operator. In such a control example, when the imbalance of the printing pressure is large, a warning can be given to the operator to prompt the necessary work.

Second Control Example In the second control example, the main control unit 10 calculates the average value of the detected values of the plurality of printing pressure sensors S as the printing pressure applied to the squeegee 61. In such a configuration, the printing pressure can be calculated (measured) while suppressing the influence of external noise mixed in the detected value of the printing pressure sensor S.

In addition, it is of course possible to add a modification different from the control example given here to the above embodiment. For example, based on the result of acquiring information indicating the bias of the printing pressure given to the squeegee 61, feedback control may be executed for the printing pressure applied to the squeegee 61 so as to eliminate the bias.

Further, the type of sensor that can be used as the printing pressure sensor S is not limited to the magnetostrictive sensor. That is, the sensor rod Sr made of a material whose physical properties change with respect to the applied pressure (for example, a piezoelectric body) and the detection element (coil Sc in the above example) for detecting the change in the physical properties of the sensor rod Sr. The printing pressure sensor S can be configured.

1 ... Printing machine 2 ... Mask holding unit (mask holding part)
6 ... Print head 61 ... Squeegee 7 ... Load reduction part 71 ... Load reduction spring 74 ... Flange 8 ... Printing pressure application part 81 ... Printing pressure spring S ... Printing pressure sensor (pressure sensor, magnetic strain sensor)
U ... Sensor unit (unit)

Claims (10)

A pressure sensor that outputs a detected value according to the applied pressure, a squeegee that is arranged below the pressure sensor and connected to the pressure sensor, and a squeegee that applies printing pressure to the squeegee from above via the pressure sensor. A printing head having a printing pressure applying portion and a load reducing portion having a spiral-shaped load reducing spring and urging the squeegee upward by the load reducing spring.
It is provided with a mask holding unit that holds the mask facing the print object from above.
By sliding the squeegee of the print head on the upper surface of the mask, printing is executed on the print object.
In the printing head, a printing machine in which at least a part of the pressure sensor is arranged inside the load reducing spring. The load-reducing portion has a flange fixed to the pressure sensor above the load-reducing spring, and the load-reducing spring pushes the flange upward to push the squeegee upward via the pressure sensor. The printing machine according to claim 1, which is urged to. The second aspect of the present invention, wherein the printing pressure applying portion has a printing pressure spring arranged above the flange, and the printing pressure is applied to the squeegee by pressing the flange downward by the printing pressure spring. Printer. The printing machine according to any one of claims 1 to 3, wherein a plurality of units including the pressure sensor, the printing pressure applying portion, and the load reducing portion are provided on the printing head. The printing machine according to claim 4, further comprising a printing pressure information acquisition unit that acquires information on the printing pressure given to the squeegee based on the detection value of the pressure sensor of each of the plurality of units. The printing machine according to claim 5, wherein the printing pressure information acquisition unit acquires the difference between the detected values of the pressure sensors of each of the plurality of units as information indicating the bias of the printing pressure given to the squeegee. The printing according to claim 6, wherein the printing pressure information acquisition unit determines to warn the operator when the difference between the maximum value and the minimum value of the detection values of the pressure sensors of each of the plurality of units becomes equal to or more than a threshold value. Machine. The printing according to any one of claims 5 to 7, wherein the printing pressure information acquisition unit measures the printing pressure applied to the squeegee based on the average value of the detection values of the pressure sensors of the plurality of units. Machine. The printing machine according to any one of claims 1 to 8, wherein the pressure sensor is a magnetostrictive sensor. A pressure sensor that outputs a detected value according to the applied pressure,
A squeegee located below the pressure sensor and connected to the pressure sensor,
A printing pressure applying portion that applies printing pressure to the squeegee from above via the pressure sensor,
It is provided with a load-reducing portion having a spiral-shaped load-reducing spring and urging the squeegee upward by the load-reducing spring.
A print head in which at least a portion of the pressure sensor is located inside the load-reducing spring.

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