JP2004202824A - Recording device and its temperature measurement method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a recording device and its temperature measurement method whereby a temperature can be measured without using a temperature sensor. <P>SOLUTION: The recording device 10 has a platen gap adjustment mechanism 30 for adjusting a platen gap between a recording head 20 and a platen 25. Moreover, the recording device 10 has a table stored in a memory part 118. Each value of the platen gap which changes according to platen temperatures, and the corresponding platen temperatures are described to relate to each other in the table. The temperature is estimated from the platen gap measured by the platen gap adjustment mechanism 30 on the basis of the table. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a recording apparatus and a method for measuring the temperature thereof.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, some recording apparatuses that record an image on a sheet or the like measure the temperature of a platen using a thermistor. For example, some dot impact printers measure the temperature of the platen to know the amount of thermal expansion of the platen in order to prevent the platen gap between the recording head and the platen from changing due to the thermal expansion of the platen. (For example, see Patent Document 1).
[0003]
In addition, in an inkjet printer of a type using a hot melt ink, since the temperature at which the ink is satisfactorily fixed varies depending on the type of the printing medium, the temperature of the platen is measured to control the temperature of the platen to the fixing temperature. (For example, see Patent Document 2).
[0004]
[Patent Document 1]
JP 2001-162891 A
[Patent Document 2]
JP-A-11-020144
[0005]
[Problems to be solved by the invention]
However, when a temperature sensor such as a thermistor is used, the number of components of the recording apparatus increases, which is disadvantageous in cost reduction. Further, the necessity of assembling the temperature sensor complicates the assembly work. is there.
[0006]
In addition, since the platen functions as a sheet placing member, it is preferable that the platen temperature is measured by measuring the temperature of the sheet placement region of the platen. However, it is difficult to arrange the temperature sensor in the sheet arrangement area of the platen due to the close contact of the sheet with the contact type temperature sensor. For example, even if the non-contact type sensor is used, there is no empty space. Can be difficult.
[0007]
The present invention has been made in view of the above circumstances, and has as its object to provide a recording apparatus capable of measuring a temperature without using a temperature sensor and a method of measuring the temperature.
[0008]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, an invention according to claim 1 is a recording apparatus that records an image via a recording head on a sheet disposed between the recording head and a platen. It is characterized by comprising distance measuring means for measuring a distance, and temperature estimating means for estimating a temperature based on a measured value of the distance measured by the distance measuring means.
[0009]
According to a second aspect of the present invention, in the configuration of the first aspect, the temperature estimating means stores information on a temperature change characteristic of a measured value of a distance between the recording head and the platen in the platen gap adjusting means. A storage unit that estimates a temperature from the measured value of the distance based on information stored in the storage unit.
[0010]
According to a third aspect of the present invention, in the configuration according to the second aspect, the information stored in the storage unit includes information on a distance between the recording head and the platen measured by the platen gap adjustment unit at various temperatures. It is a table in which each measured value and the corresponding platen temperature are described in association with each other.
[0011]
According to a fourth aspect of the present invention, in the configuration according to any one of the first to third aspects, the distance measuring means moves the recording head from a reference position to a position in contact with a platen. Is measured as the distance between the recording head and the platen.
[0012]
According to a fifth aspect of the present invention, in the configuration according to the fourth aspect, the distance measuring means includes a pulse signal output means for outputting a pulse signal in accordance with the movement of the recording head; And a counting means for counting the number of pulses of the pulse signal when the pulse signal is moved to a position where the pulse signal comes into contact with the platen.
[0013]
According to a sixth aspect of the present invention, in the configuration according to any one of the first to fifth aspects, the distance measuring means measures a distance between a recording head and a platen at a plurality of positions on the platen, An average value of the measured values is calculated as the distance.
[0014]
According to a seventh aspect of the present invention, in the configuration according to any one of the first to sixth aspects, there is provided a platen gap adjusting mechanism for adjusting a platen gap between the recording head and the platen. The distance measuring means measures a distance between a recording head and a platen.
[0015]
According to an eighth aspect of the present invention, there is provided a temperature measuring method for a recording apparatus for recording an image via a recording head on a sheet disposed between the recording head and a platen, wherein a distance between the recording head and the platen is measured. And a temperature estimating step of estimating a temperature based on the measured value of the measured distance.
[0016]
According to a ninth aspect of the present invention, in the configuration according to the eighth aspect, in the temperature estimating step, the measured value of the distance between the recording head and the platen in the platen gap adjusting unit is stored in the storage unit. The platen temperature is estimated from a measured value of the distance between the recording head and the platen based on information on the temperature change characteristic.
[0017]
According to a tenth aspect of the present invention, in the configuration according to the ninth aspect, the information stored in the storage unit includes information on a distance between the recording head and the platen measured by the platen gap adjustment unit at various temperatures. It is a table in which each measured value and the corresponding platen temperature are described in association with each other.
[0018]
According to an eleventh aspect of the present invention, in the configuration according to any one of the eighth to tenth aspects, in the distance measuring step, the recording head is moved from a reference position to a position in contact with a platen. The distance is measured as a distance between a recording head and a platen.
[0019]
According to a twelfth aspect of the present invention, in the configuration according to the eleventh aspect, in the distance measuring step, when the recording head is moved from a reference position to a position in contact with a platen, the recording head is moved. And counting the number of pulses of the pulse signal output by the control unit.
[0020]
According to a thirteenth aspect of the present invention, in the configuration according to any one of the eighth to twelfth aspects, in the distance measuring step, a distance between a recording head and a platen is measured at a plurality of positions on the platen; The average value of each measured value is calculated as the distance.
[0021]
According to a fourteenth aspect of the present invention, in the configuration according to any one of the eighth to thirteenth aspects, the recording apparatus has a platen gap adjusting mechanism for adjusting a platen gap between a recording head and a platen, In the distance measuring step, the platen gap adjusting mechanism measures a distance between the recording head and the platen.
[0022]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing an outline configuration of a dot impact printer 10 according to the present embodiment, and FIG. 2 is a side sectional view thereof. The dot impact printer 10 records an image including characters by pressing a recording wire included in the recording head 20 onto a sheet via an ink ribbon to form dots on the sheet. Here, the sheet includes a cut sheet cut to a predetermined length and a continuous sheet in which a plurality of sheets are connected. The cut sheet includes, for example, passbooks, postcards, envelopes, and the like, in addition to plain paper such as cut sheets and cut copy paper, and the continuous sheets include continuous paper and continuous copy paper.
[0023]
The dot impact printer 10 is roughly divided into a printer main body 11, a push tractor unit 12, a sheet supply guide 13, a paper feeding device (CSF: cut sheet feeder) 14, and an upper part and a lower part of the printer main body 11. An upper case 15 and a lower case 16 that cover each are provided.
[0024]
The printer main body 11 is schematically composed of a recording mechanism section including a recording head 20 and a carriage 21, and a sheet transport mechanism section including a sheet guide 24, a platen 25, and first to fourth transport rollers 26 to 29.
[0025]
In the printer main body 11, a left side frame 42 and a right side frame (not shown) are fixed to substantially both ends of a base frame 40 and a rear frame 41 as main body frames, respectively. A carriage guide shaft 43 and a platen 25 are rotatably supported between the left side frame 42 and the right side frame, and a sheet guide 24 for guiding a sheet is supported.
[0026]
The carriage 21 on which the recording head 20 is mounted is supported by the carriage guide shaft 43 so as to be movable in the axial direction.
[0027]
The carriage 21 is driven by a carriage driving motor (not shown) in the axial direction of the carriage guide shaft 43 via a timing belt. Thus, the recording head 20 is driven in the main scanning direction that matches the axial direction of the carriage guide shaft 43. An ink ribbon cassette 44 is detachably mounted on the carriage 21. The ink ribbon of the ink ribbon cassette 44 is drawn between the recording head 20 and the platen 25.
[0028]
The recording head 20 includes a large number of recording wires (not shown), and the ink ribbon is located in front of the recording wires in the protruding direction. While traveling in the main scanning direction together with the carriage 21, the recording head 20 projects the recording wire and strikes the ink ribbon, and the ink on the ink ribbon is transported between the platen 25 and the recording head 20. An image including characters is recorded on the sheet (cut sheet or continuous sheet).
[0029]
The printer main body 11 also includes a first conveyance roller 26 and a second conveyance roller 27 that convey a sheet on the sheet guide 24 in a pair up and down, and a third conveyance roller 28 and a fourth conveyance roller 29. Have been. Of these, the first transport roller 26 below the sheet guide 24 and the fourth transport roller 29 above the sheet guide 24 are drive rollers, and the second transport roller 27 and the third transport roller 28 are driven rollers. It has become. That is, gears are provided at the shaft ends of the first transport roller 26 and the fourth transport roller 29, and a gear train (not shown) including the gears is disposed on, for example, the left side frame 42. A motor pinion of a sheet conveying motor (not shown) meshes with one gear of the gear train. Thus, by rotating the sheet conveying motor forward or backward, the sheet is conveyed from the front of the printer main body 11 to the rear or from the rear of the printer main body 11 to the front.
[0030]
The push tractor unit 12 supplies a continuous sheet to the sheet guide 24, and has a pair of left and right tractors 46. The tractor 46 includes a tractor drive pulley 45, a tractor driven pulley 47, and a tractor belt 48 laid over these pulleys 45, 47. The shaft of the tractor drive pulley 45 meshes with a gear train that meshes with the motor pinion of the sheet transport motor, so that when the sheet transport motor rotates, the tractor drive pulley 45 rotates, and the tractor belt 48 causes the continuous sheet to rotate. It is supplied to the guide 24.
[0031]
The sheet supply guide 13 is detachably attached to the upper case 15 at the front side of the printer main body 11, and guides the sheet. The sheet supply guide 13 functions as a manual feed tray for manually feeding cut sheets from the front of the printer main body 11, and as a discharge tray for sheets (cut sheets and continuous sheets) fed from the rear of the printer main body 11. Also works.
[0032]
The paper feeding device 14 is detachably mounted on the rear side of the printer main body 11 and feeds cut sheets one by one. Next, the configuration will be described in detail. FIG. 3 is a perspective view of the sheet feeding device 14. As shown in this figure, the sheet feeding device 14 is supported so as to be movable in the axial direction of a slider shaft 60, and a slider 61 that regulates the sheet width, and a hopper 63 that is supported so as to be movable in the axial direction of a hopper shaft 62. And a sheet feeding roller 65 supported movably in the axial direction of the sheet feeding roller shaft 64 and covered with a sheet feeding roller cover 69, one set each on the left and right.
[0033]
The hopper shaft 62 is disposed between the slider shaft 60 and the paper feed roller shaft 64, and is configured to be able to move in parallel between the slider shaft 60 and the paper feed roller 65 by a drive mechanism (not shown). The hopper 63 is urged toward the paper feed roller 65 by a spring (not shown), and a bundle of cut sheets set between the hopper 63 and the paper feed roller 65 is brought into contact with the paper feed roller 65. It is a configuration to make it. The paper feed roller shaft 64 is rotated by a sheet transport motor of the printer main body 11, and the paper feed roller 65 is rotated, whereby the cut sheet is transported substantially obliquely downward in the figure and guided to the printer main body 11.
[0034]
Under the above configuration, the recording operation by the recording head 20 is such that one line of recording is performed by the recording wire of the recording head 20 while the carriage 21 is traveling in the main scanning direction, and each time one line of recording is performed. If the sheet is a cut sheet, the sheet transport mechanism (platen 25, first transport roller 26, second transport roller 27, third transport roller 28, and fourth transport roller 29) is used. In this case, the operation is performed by the sheet transport mechanism and the push tractor unit 12 transporting the sheet by a predetermined length (normal line spacing), respectively, and these operations are repeated.
[0035]
The control of the recording head 20, the carriage driving motor, the sheet conveying motor, and the platen gap adjusting motor 53 described later is performed by the control board unit 100. The control board unit 100 is housed in, for example, the lower case 16.
[0036]
Further, in the printer 10, the platen gap between the recording head 20 and the platen 25 is adjusted by rotating the carriage guide shaft 43 according to the sheet thickness of the supplied sheet (cut sheet, continuous sheet). A platen gap adjustment mechanism 30 is provided. Here, FIG. 4 is a diagram showing the configuration of the platen gap adjustment mechanism 30 together with the peripheral configuration. The platen gap adjustment mechanism 30 includes a platen gap adjustment motor 53, a rotary encoder 50, a control board unit 100, and the like.
[0037]
As shown in FIG. 4, a stepping motor is used as the platen gap adjustment motor 53, and transmits a rotational force to the carriage guide shaft 43 via a speed reduction mechanism 55. An eccentric shaft is fixed to the carriage guide shaft 43, and the carriage 21 is disposed therebetween. Thereby, the eccentric shaft is rotated by the rotation of the motor 53 for adjusting the platen gap, and the carriage 21 is moved in the α direction in FIG. 4 by an amount corresponding to the eccentric amount L of the eccentric shaft (for example, 2 mm when L = 1 mm). The recording head 20 moves back and forth with respect to the platen 25. As a result, the distance (platen gap) between the recording head 20 and the platen 25 is changed. Here, the moving range of the recording head 20 is from a position where the recording head 20 contacts the platen 25 to a position where the carriage 21 contacts the carriage auxiliary shaft 43a and the movement thereof is regulated (reference position). A micro switch 58 is arranged on the rear side of the carriage 21, and whether the recording head 20 is located at the reference position is detected based on whether the micro switch 58 is turned on.
[0038]
The rotation amount of the motor 53 for adjusting the platen gap is detected by the rotary encoder 50. The rotary encoder 50 includes a slit plate 56 provided integrally with the shaft 53a of the motor 53 for adjusting the platen gap, and a light emitting and receiving device including, for example, a light emitting diode, a photodiode, and the like, disposed opposite to the slit plate 56. 57. The light emitted from the light emitting diode of the light emitting and receiving device 57 and passing through the slit of the slit plate 56 is received by the photodiode of the light emitting and receiving device 57 and converted into a pulse signal, and this pulse signal is output to the control board unit 100. You.
[0039]
In the control board unit 100 shown in FIG. 4, a control unit 102 centrally controls each unit of the dot impact printer 10, and includes a CPU. The storage unit 118 stores various programs such as a control program executed by the control unit 102 and a platen temperature identification table 120 described later. The control unit 102 performs various controls, such as print control based on print data, platen gap adjustment control, and a platen temperature calculation process described below, according to a program stored in the storage unit 118.
[0040]
The interface (I / F) 104 transmits and receives various data such as print data to and from a computer (PC) connected via a communication cable (not shown) under the control of the control unit 102.
[0041]
Under the control of the control unit 102, the motor drive unit 106 supplies drive pulses to various motors such as the platen gap adjustment motor 53, the carriage drive motor, and the sheet conveyance motor, and drives each motor to rotate.
[0042]
The recording head driving unit 108 drives the recording head 20 under the control of the control unit 102 to selectively strike a recording wire.
[0043]
The time difference detection unit 110 detects a time difference between the cycle of the pulse signal from the rotary encoder 50 and the cycle of the drive pulse of the motor 53 for adjusting the platen gap, and outputs the difference to the time difference integration unit 112. The time difference integration section 112 obtains the integrated value of the input time difference and outputs it to the contact determination section 114. The contact determination unit 114 determines that the input integral value matches a preset value, for example, 以下 or less (specifically, 1.5 milliseconds) or less of the cycle of the drive pulse of the motor 53 for adjusting the platen gap. Then, it is determined that the recording head 20 has contacted the platen 25 or the sheet, and the fact is notified to the distance calculation unit 116.
[0044]
The distance calculation unit 116 starts counting the pulse signals from the rotary encoder 50 starting from the reception of the signal from the microswitch 58, and calculates a count value at the time when the contact is notified from the contact determination unit 114. Accordingly, when there is no sheet on the platen 25, the distance calculation unit 116 determines a pulse corresponding to a platen gap between the recording head 20 at the reference position and the platen 25 (hereinafter, referred to as a reference platen gap). On the other hand, when the sheet is present on the platen 25, the pulse count value corresponding to the distance between the recording head 20 at the reference position and the sheet is calculated.
[0045]
The control unit 102 obtains the distance of the reference platen gap and the distance between the recording head 20 and the sheet from the distance calculation unit 116, calculates the sheet thickness from the difference between these distances, and uses this sheet thickness as a reference. Adjust the platen gap.
[0046]
Each of the components such as the distance calculation unit 116 described above may be configured as a separate circuit from the control unit 102, as shown in FIG. May be realized by software. Further, the case where distance calculating section 116 measures the distance by counting the pulse signals from rotary encoder 50 has been described, but the distance may be measured by counting the driving pulses of motor 53 for adjusting the platen gap.
[0047]
The value of the platen gap (reference platen gap) between the recording head 20 and the platen 25 changes due to thermal expansion of the platen 25, the recording head 20, and the like. Therefore, the pulse count value counted by the distance calculation unit 116 has a different value according to the temperature environment of the printer 10. Here, FIG. 5 is a diagram showing pulse count values when the reference platen gap is measured when the temperature of the platen 25 is low, normal, or high. More specifically, FIG. 5 shows that when the platen temperature is 0 ° C. to 10 ° C. (low temperature), the pulse count value is 330 to 337 pulses, and when the platen temperature is 10 ° C. to 20 ° C. (normal temperature). The pulse count value is 338 to 345 pulses, and the pulse count value is 346 to 353 when the platen temperature is 20 ° C. to 30 ° C. (high temperature).
[0048]
In the present embodiment, attention is paid to the fact that the reference platen gap is correlated with the platen temperature, and information on the correlation is described in the platen temperature specification table 120, and based on this table 120, the distance calculation unit 116 A process for estimating the platen temperature from the calculated pulse count value at the time of measuring the reference platen gap is performed.
[0049]
Here, FIG. 6 is a diagram showing the contents of the platen temperature identification table 120 in the case of FIG. As shown in the figure, the platen temperature specification table 120 stores the platen temperature and the pulse count value at the time of measuring the reference platen gap in association with each other. Hereinafter, the platen temperature estimation processing will be described.
[0050]
FIG. 7 is a flowchart showing the platen temperature estimation process. As shown in this figure, the control unit 102 first measures a platen gap (reference platen gap) between the recording head 20 at the reference position and the platen 25 (step S1). Specifically, the control unit 102 controls the motor driving unit 106 to move the carriage 21 to a position where the microswitch 58 is turned on, and then moves the carriage 21 to a position where the recording head 20 contacts the platen 25. Let it. As a result, the number of pulse signals corresponding to the movement of the carriage 21 is output from the rotary encoder 50, and the distance calculation unit 116 calculates the pulse count value when the contact determination unit 114 determines that the recording head 20 is in contact. Output to the control unit 102.
[0051]
Upon receiving the pulse count value from the distance calculation unit 116, the control unit 102 stores the pulse count value in the storage unit 118 (step S2). The pulse count value may be stored in a RAM (not shown) inside the control unit 102 instead of the storage unit 118. Next, the control unit 102 refers to the platen temperature specification table 120 stored in the storage unit 118, and specifies the platen temperature corresponding to the pulse count value received from the distance calculation unit 116 (Step S3). For example, when the pulse count value is 340, the control unit 102 determines that the platen temperature is 10 ° C. to 20 ° C. (normal temperature) (see FIG. 6). Thus, the control unit 102 can estimate whether the platen temperature is low, normal, or high. In the present embodiment, the case where the platen temperature is detected in a unit of 10 ° C. has been described, but the temperature may be specified more finely or more roughly. Also, the case where the platen temperature is specified based on the pulse count value has been described, but the platen temperature and the distance of the corresponding reference platen gap are described in association with each other in the platen temperature specification table 120, and the pulse count value is specified. The platen temperature may be specified based on the distance of the reference platen gap calculated from.
[0052]
The platen temperature obtained in this manner may be displayed on a display panel (not shown) provided in the printer 10 or may be transmitted to a computer to simply notify the user. May be used. For example, when characteristics such as the surface hardness of the platen 25 change according to the platen temperature, and it is necessary to adjust the platen gap in consideration of the change in the characteristics, the platen gap may be adjusted as follows. Hereinafter, an example of the processing flow in this case will be described.
[0053]
FIG. 8 is a flowchart of the platen gap adjustment processing in this case. As shown in this figure, the control unit 102 first performs the above-described platen temperature estimation processing (step S10), acquires the distance of the reference platen gap from the distance calculation unit 116, estimates the platen temperature, and The value is stored in the storage unit 118 or the RAM.
[0054]
When the distance of the reference platen gap and the platen temperature are acquired in this way, the control unit 102 measures the distance between the recording head 20 and the sheet (Step S11). Specifically, the control unit 102 controls the motor driving unit 106 to convey the sheet between the recording head 20 and the platen 25, and then moves the carriage 21 from the reference position where the microswitch 58 is turned on to the recording head. 20 is moved to a position where the sheet 20 comes into contact with the sheet on the platen 25, thereby acquiring a pulse count value corresponding to the distance from the distance calculation unit 116.
[0055]
Next, the control unit 102 calculates the sheet thickness by calculating the difference between the pulse count values of the two measured distances (step S12). Here, the moving distance of the recording head 20 when the carriage guide shaft 43 is rotated by a fixed angle changes according to the rotation angle of the carriage guide shaft 43. Therefore, a table or an approximate expression describing the relationship between the count value of the pulse signal from the rotary encoder 50 and the moving distance is stored in the storage unit 118 or the like, and the control unit 102 calculates the difference based on the information. Calculate the sheet thickness from the number of pulses.
[0056]
Then, the control unit 102 determines a platen gap that sets the distance between the recording head 20 and the sheet to a predetermined value based on the sheet thickness (step S13). As described above, the platen gap determined here needs to be corrected according to a temperature change in characteristics such as the surface hardness of the platen 25. Therefore, a table or an approximate expression that describes the relationship between the platen temperature and the correction amount of the platen gap is stored in the storage unit 118 or the like, and the control unit 102 acquires the platen acquired in step S10 based on the information. The correction amount is specified from the temperature, and the determined platen gap is corrected (step S14). Then, the control unit 102 controls the motor driving unit 106 to drive the motor 53 for adjusting the platen gap to adjust the platen gap to adjust the platen gap (Step S15). Thereby, the platen gap can be adjusted to an appropriate value in consideration of the temperature change of the characteristics of the platen 25, and as a result, good recording quality can be maintained over a wide temperature range.
[0057]
As described above, according to the present embodiment, the temperature of the platen 25 can be estimated without using a temperature sensor. As a result, the printer 10 according to the present embodiment can reduce the number of components and facilitate assembly as compared with a conventional printer using a temperature sensor. Further, since the recording head 20 is brought into contact with the sheet arrangement area of the platen 25 to measure the distance, the thermal expansion or the like in that area can be accurately detected. Therefore, the printer 10 of the present embodiment can accurately measure the temperature of the area related to the recording quality.
[0058]
As described above, the present invention has been described based on the above embodiment, but the present invention is not limited to this. In the present embodiment, the case where the platen temperature is specified based on the platen temperature specification table 120 has been described. However, the platen temperature is specified based on an approximate relational expression indicating a platen gap measurement value (such as a pulse count value) and the platen temperature. You may make it.
[0059]
In the present embodiment, the case where the measurement of the platen gap (reference platen gap) is performed only once has been described. However, the platen gap is measured at a plurality of locations in the circumferential direction and the girder direction of the platen. An average value may be calculated. By doing so, it is possible to reduce the influence of an error in processing the platen 25 on the platen gap measurement value.
[0060]
Further, in the present embodiment, the case where the recording head 20 is moved from the reference position to the position in contact with the platen 25 to measure the distance therebetween has been described, but the platen 25 is configured to be movable, and the platen 25 is moved to the reference position. The distance may be measured by moving from the position (fixed in the above embodiment) to a position where the recording head 20 abuts.
[0061]
Further, the present invention is not limited to measuring the temperature of the platen, but can also measure the internal temperature of the printer 10. In this case, for example, information (such as a table) in which the internal temperature of the printer 10 is associated with a platen gap measurement value (such as a pulse count value) is stored, and the internal temperature is specified based on this information. do it.
[0062]
In the above embodiment, the cylindrical platen has been described. However, the present invention is not limited to this, and is applicable to, for example, a flat platen. Further, the case where the present invention is applied to a dot impact printer has been described. However, the present invention can be widely applied to a recording apparatus such as a hot-melt ink type ink-jet printer which requires temperature control of a platen.
[0063]
【The invention's effect】
As described above, according to the present invention, the temperature can be measured without using a temperature sensor.
[Brief description of the drawings]
FIG. 1 is a perspective view illustrating a configuration of a dot impact printer according to an embodiment of the present invention.
FIG. 2 is a side view illustrating the configuration of the printer.
FIG. 3 is a perspective view illustrating an appearance of a sheet feeding device of the printer.
FIG. 4 is a diagram showing a functional configuration of the printer together with peripheral components.
FIG. 5 is a diagram illustrating pulse count values when a platen gap is measured when the platen of the printer is at low, normal, and high temperatures.
FIG. 6 is a diagram showing a platen temperature specification table.
FIG. 7 is a flowchart illustrating a platen temperature estimation process.
FIG. 8 is a flowchart of a platen gap adjustment process.
[Explanation of symbols]
10 dot impact printer (recording device)
20 Recording head
21 carriage
25 Platen
30 Platen gap adjustment mechanism
50 Rotary encoder
53 Platen gap adjustment motor
100 control board
102 control unit
116 Distance calculator
118 Memory
120 Platen temperature specification table

Claims (14)

In a recording apparatus that records an image via a recording head on a sheet disposed between a recording head and a platen,
Distance measuring means for measuring the distance between the recording head and the platen,
And a temperature estimating means for estimating a temperature based on a measured value of the distance measured by the distance measuring means. The temperature estimating means includes:
A storage unit in which information on a temperature change characteristic of a distance measurement value between the recording head and the platen in the platen gap adjustment unit is stored,
2. The recording apparatus according to claim 1, wherein a temperature is estimated from a measured value of the distance based on information stored in the storage unit. The information stored in the storage means is a table in which each measured value of the distance between the recording head and the platen measured by the platen gap adjustment means at various temperatures and the corresponding platen temperature are described in association with each other. 3. The recording apparatus according to claim 2, wherein: The apparatus according to claim 1, wherein the distance measuring unit moves the recording head from a reference position to a position in contact with a platen, and measures a moving distance at this time as a distance between the recording head and the platen. 5. 3. The recording device according to any one of 3. The distance measuring means,
Pulse signal output means for outputting a pulse signal in accordance with the movement of the recording head,
5. The recording apparatus according to claim 4, further comprising a counting unit that counts the number of pulses of the pulse signal when the recording head moves from a reference position to a position where the recording head comes into contact with the platen. 6. The apparatus according to claim 1, wherein the distance measuring unit measures a distance between the recording head and the platen at a plurality of positions on the platen, and calculates an average value of the measured values as the distance. The recording device according to any one of the above. Having a platen gap adjustment mechanism to adjust the platen gap between the recording head and the platen,
7. The recording apparatus according to claim 1, wherein the platen gap adjusting mechanism measures a distance between a recording head and a platen as the distance measuring unit. In a temperature measurement method of a recording apparatus that records an image via a recording head on a sheet disposed between a recording head and a platen,
A distance measuring step of measuring a distance between the recording head and the platen;
A temperature estimating step of estimating a temperature based on a measured value of the measured distance. In the temperature estimating step, the distance between the recording head and the platen is determined based on the information on the temperature change characteristic of the measured distance between the recording head and the platen in the platen gap adjusting unit, which is stored in the storage unit. 9. The temperature measuring method according to claim 8, wherein the platen temperature is estimated from the measured value. The information stored in the storage means is a table in which each measured value of the distance between the recording head and the platen measured by the platen gap adjustment means at various temperatures and the corresponding platen temperature are described in association with each other. The temperature measuring method according to claim 9, wherein 9. The method according to claim 8, wherein in the distance measuring step, the recording head is moved from a reference position to a position where the recording head comes into contact with the platen, and a moving distance at this time is measured as a distance between the recording head and the platen. 11. The temperature measuring method according to any one of claims 10 to 10. In the distance measuring step, the number of pulses of a pulse signal output in accordance with the movement of the recording head when the recording head is moved from a reference position to a position in contact with a platen is counted. The temperature measuring method according to claim 11, wherein: 13. The distance measuring step, wherein a distance between the recording head and the platen is measured at a plurality of positions on the platen, and an average value of the measured values is calculated as the distance. The temperature measurement method according to any one of the above. The recording apparatus has a platen gap adjustment mechanism for adjusting a platen gap between the recording head and the platen,
14. The temperature measuring method according to claim 8, wherein in the distance measuring step, the platen gap adjusting mechanism measures a distance between the recording head and the platen.

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