JPH03173662A - Recorder - Google Patents

Abstract

PURPOSE:To detect and record accurate position of recording medium by detecting the position of the recording medium based on the level of output signal from a sensor for detecting the position of an end of the recording medium. CONSTITUTION:In case of a recording sheet represented by a characteristic curve 601, the recording sheet moves by a distance L upon transition of the output of a sensor 15 from no-sheet state to sheet existing state. Voltage levels VL, VH corresponding, respectively, to no-sheet state and sheet existing state are subjected to A/D conversion and averaged, and a position corresponding to thus averaged voltage level is set as a reference recording sheet position. By such arrangement, position of any type of recording sheet 10 can be detected accurately by detecting the position of the recording sheet 10 at one central point in the inclining part of characteristic curve.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a recording device that records an image on a recording medium.

[Prior Art] FIG. 5 shows the configuration of a recording section of a general thermal transfer printer. In the figure, 13 is a platen roller that holds the recording sheet 10.
It is rolled up and transported. That is, this platen roller 1
3, the recording sheet 10 is conveyed in the forward direction or the reverse direction. Pinch rollers 14a and 14b press the recording sheet 10 against the platen roller 13. An ink sheet 23 is heated by a heating element 29a of a thermal head 29, and the melted (or sublimated) ink is transferred onto the recording sheet 10, thereby recording an image on the recording sheet 10.

Reference numeral 15 denotes a recording sheet position sensor that positions the recording sheet 10.

[Problems to be Solved by the Invention] In the above configuration, conventionally, when the recording sheet position sensor 15 detects the recording sheet 10, that is, when the output of the sensor 15 changes from a state in which there is no recording sheet to a state in which there is a recording sheet, The recording start position is determined based on the position of the recording sheet 10 at that time, and the recording operation is started from there.

However, with such a detection method, variations may occur in the position of the positioned recording sheet 10. In particular, in the case of color thermal transfer recording, each time recording is performed in one color, the recording sheet 10 is returned by a length corresponding to the recording length of one page, and the recording sheet position sensor 15 detects the beginning of the recording sheet 10. positioning. - Therefore, due to the positional deviation of the recording sheet 10, the recording position of the image data of each color is not constant, and each pixel does not overlap accurately, which may deteriorate the quality of the recorded color image.

In addition, if the recording sheet 10 is colored,
Alternatively, in the case of a trans-bearing range film (OHP film), the output of the recording sheet position sensor 15 changes depending on the color, so there is a possibility that the position of the recording sheet 10 cannot be detected accurately.

The present invention has been made in view of the above conventional example, and detects the accurate position of the recording medium by detecting the position of the recording medium based on the output signal level of a sensor that detects the position of the recording medium. The purpose of the present invention is to provide a recording device capable of recording.

[Means for Solving the Problems] In order to achieve the above object, the recording device of the present invention has the following configuration. That is, the recording apparatus records an image on a recording medium, and includes: a conveying means for conveying the recording medium to a recording position; a sensor for outputting a detection signal having a signal level corresponding to the presence or absence of the recording medium; determining means for converting a detection signal into a digital signal and determining a detection level at the edge of the recording medium based on the digital signal when the recording medium is present and when the recording medium is not present; and control means for controlling the conveyance means to convey the recording medium to the recording position until the detection level is reached.

[Operation] In the above configuration, the detection signal from the sensor having a signal level corresponding to the presence or absence of a recording medium is converted into a digital signal, and based on the digital signal when the recording medium is present and when the recording medium is not present, Determine the detection level at the edge of the recording medium. Then, the recording medium is transported to the recording position until the detection signal level reaches the determined detection level.

[Embodiments] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[Description of Thermal Transfer Printer (Fig. 1)] Fig. 1 is a side sectional view of the mechanical part of the thermal transfer printer of the embodiment, and an enlarged view of the recording part by the thermal head 29 of this thermal transfer printer is as follows.
Since the configuration is similar to that shown in FIG. 5, common parts are indicated by the same numbers.

In the figure, reference numeral 10 denotes a recording sheet as a recording medium, which is housed in a recording sheet cartridge 11 and detachably attached to the main body of the apparatus. Reference numeral 12 denotes a recording sheet supply roller, which is connected to a recording sheet supply motor 60 (FIG. 2). By rotating the motor 60, the recording sheet 10 is passed from the cartridge 11 through the registration rollers 9. It can be supplied to the platen roller 13. Further, a recording sheet conveying motor 65 (FIG. 2) is connected to the platen roller 13, and as the recording sheet conveying motor 65 rotates, the recording sheet IO is pressed against the platen roller 13 by pinch rollers 14a and 14b. transported in the same condition. In this way, the platen roller 13
By rotating in the forward direction (in the direction of the arrow), the recording sheet 10 is guided to the discharge path 16 and further guided to the discharge roller 17. Reference numeral 15 denotes a recording sheet position sensor for detecting the leading and trailing edges of the recording sheet 10. The recording sheet position sensor 15 irradiates the recording sheet 10 with light, detects the amount of light that has passed through the recording sheet 10 or reflected from the recording sheet 10 using a photosensor on the light receiving side, and performs recording. The presence or absence of the sheet 10 is detected.

A discharge solenoid 18 is connected to the discharge roller 17, and by turning this solenoid 18 on and off, the discharge roller 17 is pressed against the driven discharge roller 19.
Or you can leave. This discharge roller 17
A discharge motor 61 (Fig. 2) is connected to the
By rotating the motor 61 while the discharge roller 17 and the driven discharge roller 19 are in pressure contact,
The recording sheet 10 conveyed through the discharge path 16 is discharged.
] 2 It can be discharged onto the output tray 20.

Further, the recording sheet 10 is placed in the opposite direction of the platen roller 13 (
The switch lever 2 is returned by rotating in the direction opposite to the arrow.
1 to the return passage 22. This operation is performed, for example, when recording a color image, after recording of a certain color is completed, overlapping recording of the next color is performed to record a color image by subtractive color mixture.

The ink sheet 23 has each color of yellow, magenta, cyan, and black applied to it surface-sequentially, and is guided from the ink sheet combining roll 24 to the platen roller 13 and the ink color sensor 25, and then wound onto the take-up roll 26. . An ink sheet transporting motor 4 (FIG. 2) is connected to the rotating shaft of the take-up roll 26, and this motor 64
The take-up roll 26 is rotationally driven by the rotation of the ink sheet 23, and the ink sheet 23 is wound up in the direction of the arrow a.
can be transported. The ink sheet 23, the supply roll 24, and the take-up roll 26 are connected to the ink cartridge 27.
This ink sheet cartridge 2
7 is removably guided and supported by the printer body.

28 is a sensor for determining the type of ink sheet 23, which detects a mark (not shown) provided on the ink cartridge 27 and outputs a corresponding signal. With this configuration, based on the signal from the sensor 28, the cartridge 2
The type of ink sheet 23 stored in 7 can be determined.

Reference numeral 29 denotes a line-type thermal head (having a plurality of line-shaped heating elements 29a), which is fixed to the shift lever 30. This shift lever 30 is connected to a shift shaft 31
The shift cam 32 has a cam roller 34 rotatably supported around the shift cam 32 and engaged with the shift cam 32. As a result, the shift cam 32 rotates counterclockwise and pushes down the cam roller 34, thereby pressing the thermal head 29 against the platen roller 13 (head down). Further, when the shift cam 32 rotates clockwise and the cam roller 34 is no longer pressed down, the thermal head 29 is separated from the platen roller 13 by the force of the spring 35 (head up).

33 is a position sensor for the thermal head 29, which can detect the position of the shift cam 32 based on the signal from this sensor 33, and determines whether the thermal head 29 is up (away from the platen roller 13) or down (away from the platen roller 13). repression). The shift cam 32 is connected to a thermal head moving motor 62 (FIG. 2), and by rotationally driving this motor 62, the thermal head 29 can be moved up or down as explained above. can do.

[Description of the overall configuration (Fig. 2)] Fig. 2 is a block diagram showing the overall configuration of the thermal transfer printer of the embodiment. are indicated by the same number, and their explanation will be omitted.

203 is a CPU such as a microprocessor, which controls the entire apparatus by inputting and outputting various control signals in accordance with the control program stored in the ROM 205 shown in the flowcharts of FIGS. 7 and 8. A host computer 204 performs interface control with the host computer 200, which is an external device, and performs controls such as receiving recorded information from the host computer 200 and transmitting printer status to the host computer 200. This is an interface control unit. Reference numeral 206 is used as a work area for the CPU 203, and also includes a page buffer 207 that stores recorded information in page units, and a position sensor 1 to be described later.
It is provided with a memory area for storing output voltage levels from 5 to 5. Reference numeral 201 denotes an operation panel including an operation section and a display section. The operator sets printer conditions through the operation section, and the status of the printer is displayed on the display section.

A recording sheet supply control unit 210 controls the rotation of the recording sheet supply motor 60 that rotationally drives the recording sheet supply roller 12 and registration rollers 9 under the control of the CPU 203 . 211 is a recording sheet discharge control unit;
The ejection motor 61 that drives the rotation of the ejection roller 17 and the ejection solenoid 18 are driven by instructions from the PU 203 . 212 is a thermal head position control unit, which is a CPU
The thermal head moving mokuro 2 is rotationally driven in accordance with an instruction 203 to move the thermal head 29 up or down. 213 is a thermal heat control unit that detects the temperature of the thermal head 29 using a thermistor 39 and controls the temperature of the thermal head 29 according to instructions from the CPU 203.
Performs heat control.

214 is a recording data transfer control unit which transfers one line of recording data stored in the page memory 207 of the RAM 206 to the thermal head 29 under the control of the CPU 203.
Transfer to. 215 is an ink sheet conveyance control unit which inputs signals from the ink sheet type sensor 28 and ink color detection sensor 25 and outputs them to the CPU 203;
The ink sheet conveyance motor 6 is controlled by the CPU 203.
4 to convey the ink sheet 23.

Reference numeral 202 denotes a recording sheet conveyance control unit, which rotates the recording sheet conveyance motor 65 under the control of the CPU 203 to rotate the platen roller 13 to move the recording sheet 10 in the forward direction (
(discharge direction) or the opposite direction. 2
16 is an A/D converter which inputs the output signal of the recording sheet position sensor 15, converts it into, for example, an 8-bit digital signal, and outputs it to the CPU 203.

[Description of Ink Sheet (FIG. 3)] FIG. 3 is a diagram showing an example of a color ink sheet used in the thermal transfer printer of the embodiment.

The color ink sheet 23a is a uniform ink sheet, in which yellow, magenta, cyan, and black heat-melting inks are sequentially applied onto a base film. 230 is a mark provided for each four colors, 23
Each of 1 to 234 is a mark (color code) provided corresponding to an ink color. These marks 230-23
4 by the ink color detection sensor 25, the color of the ink on the ink sheet 23a to be recorded can be detected and identified.

On the other hand, if the ink sheet 23 is a monochrome ink sheet, for example, a black ink sheet, the ink (black) will be applied over almost the entire surface of the ink sheet without any gaps, instead of being painted unevenly like the color ink sheet 23a. It is a coated ink sheet.

[Description of Thermal Head (FIG. 4)] 90 FIG. 4 is a block diagram showing the configuration of the thermal head 29 of the embodiment.

In the figure, the clock (CL) is input from the data input terminal 297.
K) One line of recording data input serially in synchronization with the signal is stored in the shift register 294. In this way, one line of recording data is transferred to the shift register 29.
When set to 4, it is latched into the latch circuit 293 by the latch signal 296. Next, the strobe signal (ST
When B) is input, the output of the AND circuit 292 whose corresponding recording data is at a high level "°1" becomes high level while the strobe signal is at a high level.

As a result, the corresponding transistor 291 is turned on for that time, and the common electrode 29 is connected to the corresponding heating element 29a.
A current from 0 is applied to generate heat.

[Operation Description (FIGS. 1 to 8)] FIG. 7 is a flowchart showing the recording operation in the thermal transfer printer of the embodiment, and a control program for executing this process is stored in the ROM 205.

This recording process receives data from the host computer 200 and stores page buffer 207b: at least 1
Record data for one page is stored, and the recording starts when a recording start instruction is manually given from the host 200.

First, in step S1, the ink sheet conveyance motor 64 is rotationally driven, the ink color detection sensor 25 detects the color portion of the ink sheet 23 to be printed first, and the desired color portion of the ink sheet 23 is placed at the recording position. set. Next, the recording sheet supply motor 60 is rotated to take out one recording sheet 10 from the paper feed cassette 11, or when the recording sheet 10 is manually inserted, the paper feed The roller 12 is driven to rotate. Then, based on the amount of rotational drive of the registration rollers 9, the recording sheet 10 is conveyed to a position where it is held between the platen roller 13 and the pinch roller 14a, and the leading edge of the recording sheet 10 is detected by the recording sheet position sensor 15. The recording sheet 10 is conveyed until. This process will be described in detail later with reference to FIG.

In this way, in step S2, the leading edge of the recording sheet 10 is detected by the recording sheet position sensor 15, and the leading edge of the recording sheet 10 is detected by the recording sheet position sensor 15.
When the positioning of
is pressed against the platen roller 13 (head down). Then, the conveyance of the recording sheet 10 and the ink sheet 23 is started, and the recording data is read from the page buffer 207.
One line of image data is sequentially transferred to the thermal head 29, which is driven to generate heat using a strobe (STB) signal.
Record the line image. These operations are repeated a number of times corresponding to the number of lines on one page to record an image for one page.

When the image recording for one page is completed in this way, step S
Proceed to step 4 and raise the thermal head 29. and,
In step S5, it is checked whether image recording in four colors has been completed,
If it has not finished, proceed to step S6, and step S
In the same manner as in step 1, a desired color portion of the ink sheet 23 to be printed next is selected. Then, in step S7, the recording sheet 10 is returned, and in step S8, the recording sheet position sensor 1
5 to check whether the leading edge of the recording sheet 10 has been detected. As will be described later with reference to FIG.
The determination is made based on whether the output level ①8 of 5 has become equal to the voltage level V. When the head of the recording sheet 10 is detected in this way, the process returns to step S3 and image recording is performed as described above.

In this way, when the image recording for the four colors is completed in step S5, the process proceeds to step S9, where the recorded recording sheet 10 is discharged to the paper discharge tray 20, and the process is completed.

FIG. 8 shows the recording sheet 1 shown in step S2 of FIG.
12 is a flowchart showing edge detection processing for 0;

Before explaining this process, the principle of this embodiment will be explained with reference to FIG.

In FIG. 6, ■ indicates the output signal level of the sensor when the recording sheet 10 has not reached the position of the recording sheet position sensor 15. In FIG. 601,602 each indicate the signal level of the sensor 15 when recording sheets of different colors are used, and Vu and ■. ° is the sensor 15 when the corresponding recording sheet is at the sensor position.
shows the output signal level.

Now, considering the case where the recording sheet represented by the characteristic curve 601 is used, in order for the output of the sensor 15 to change from the state where there is no recording sheet to the state where there is a recording sheet, the recording sheet must be moved at a distance equivalent to the length. move only. Therefore, if the recording sheet position is detected simply by the on/off output of the recording sheet position sensor 15, an error corresponding to the maximum length L may occur. Therefore,
In this example, the voltage level when there is no recording sheet is
, and the voltage level vH in the state where the recording sheet is present are inputted with A/D converted values. Then, find the average value of those values (corresponding to the voltage value ■),
Alignment is performed using the recording sheet position when the voltage value is reached as a reference position. Similarly, in the case of a recording sheet having the characteristics indicated by 602, its reference voltage level is 1
°.

As a result, the position of the recording sheet 10 can be adjusted depending on the type of recording sheet (, 1 of the slope part of the characteristic curve in FIG.
Since the position of the recording sheet 10 can be detected accurately at all times, the position of the recording sheet 10 can be detected accurately.

Based on the above premise, the flowchart shown in FIG. 8 will be explained below.

In FIG. 8, in step Sll, the digital value of the output signal level ``■8'' of the sensor 15 is input, and the value becomes the voltage ``■''.

(Threshold value in FIG. 6, V, )>VL) is checked. Here, since the recording sheet 10 has not reached the position of the sensor 15, ■8>■. If so, position sensor 15
Alternatively, it is assumed that the A/D converter 216 or the like is abnormal, and the process proceeds to step SL2 for error processing.

At step Sll, vl+〉■. If not, step 31
Proceed to step 3 and record the current voltage level without a recording sheet.
, is stored in VL of the RAM 206. Next, the process proceeds to step S14, where the recording sheet conveying motor 65 rotates the platen roller 13 in the forward direction (in the direction of the arrow in FIG. 1) to convey the recording sheet 10 in the forward direction. Then, in step S15, the output signal level ■3 of the sensor 15 becomes ■. In other words, it is checked whether the recording sheet 10 has been detected.

When the recording sheet 10 is detected, the process advances to step S16, and the platen roller 13 is further rotated in the forward direction by a predetermined amount to convey the recording sheet 10 by a predetermined amount in the forward direction, thereby ensuring that the recording sheet 10 is positioned at the recording sheet position sensor 15. Make sure it's in position. Then, in step S17, it is assumed that the recording sheet 10 is present, and the signal level (■) of the sensor 15 at this time is determined. is stored in the VH of the RAM 206. Next, in step 318, the average value of these VL and VH is calculated, and the value is stored as ■1 in ■1. This becomes the positioning signal level of the recording sheet 10 shown in FIG.

When the signal level (Vl) is determined in this way, step S19
Then, the recording sheet conveyance motor 65 is driven to rotate in the opposite direction, and the recording sheet 10 is returned. At this time, step S20
Then, the recording sheet 10 is returned until the signal level ■9 of the recording sheet position sensor 15 becomes equal to or less than the signal level ■1 determined in step 318. In this way, when the conditions of step S20 are satisfied, it is assumed that the recording sheet 10 has been accurately positioned, and the process proceeds to step S21, where the rotation of the platen roller 13 is stopped and the edge detection process is completed.

By determining the positioning level of the recording sheet 10 in this way, even if the color of the recording sheet changes and the output level of the recording sheet position sensor 15 changes, as shown in FIG. The seat can be positioned.

[Description of Other Embodiments (FIGS. 9 to 11)] FIG. 19 is a flowchart showing the recording process of another embodiment.

In the above-mentioned embodiment, as shown in FIG. 10, for example, when the recording sheet 10 is conveyed, the recording sheet 10 fluttering in the vertical direction causes the output signal level of the sensor 15 to momentarily drop to ■ or lower. It is possible that In such a case, the positioning of the recording sheet 10 ends assuming that the leading edge of the recording sheet 10 is detected at that position, resulting in incorrect positioning.

Therefore, in this embodiment, the recording sheet 10 is
Once the recording sheet 10 is returned to the position where the signal level becomes smaller than the signal level that may fluctuate, the recording sheet 10 is conveyed in the forward direction again, and the output signal level 3 of the sensor 15 becomes the voltage mentioned above. Is level ■ equal to 1?
Convey the recording sheet 10 until it becomes larger than that,
The recording sheet 10 is positioned.

Steps 331 to S36 in FIG. 9 are steps 8 in FIG.
Since they are the same as steps 1 to S6, their explanation will be omitted.

Then, in step S7, sensor 1 is removed without recording sheet 10.
The recording sheet 10 is conveyed in the opposite direction and returned until the output signal level of 5 becomes 2), which is smaller than 1. This process will be described in detail later with reference to FIG.

Next, in step 838, the recording sheet 10 is conveyed in the forward direction again, and in step S39, it is checked whether the output signal level ``8'' of the recording sheet position sensor 15 becomes larger than the signal level ``1'' described above. In this way, when the output signal level vg of the sensor 15 becomes equal to or larger than Vl, it is assumed that the positioning of the recording sheet 10 has been completed, and step 3
Returning to step 33, image recording is performed in the next color.

In FIG. 11, in step S51, the counter in the RAM 206 is set to O"°, and the recording sheet 10 is conveyed back in the opposite direction 1 2 . Then, in step S53, the output signal level ■8 of the sensor 15 is set to be less than ■2. If it is not less than 0°, the process proceeds to step S54 and the counter is set to 0°
Set to .

In step S53, the output signal level ■8 of the sensor 15 is V.
When the number is 2 or less, the process advances to step S55, and the recording sheet 10 is
Stop transporting. Next, in step S56, the counter is
1, and in step S57 it is checked whether the value of the counter has become larger than a predetermined value N. When the value of the counter is less than or equal to N, the process returns to step 353 and the above-described process is executed again.

This is to eliminate the detection of instantaneous signal level fluctuations as shown in FIG. It is checked whether this signal level can be detected continuously until the value reaches a predetermined value N. This results in
Erroneous detection due to instantaneous voltage fluctuations as shown at 700 in FIG. 10 is prevented.

In addition, although the above-mentioned embodiment was explained in the case of a color thermal transfer printer, the present invention is not limited to this.
Of course, the present invention can also be applied to laser beam printers, thermal printers, inkjet printers, wire dot printers, etc., which transport a recording medium such as a recording sheet to a recording position and perform recording.

Furthermore, in this embodiment, it has been explained that the average value of the detection signal level indicating the presence of the recording sheet and the detection signal level indicating the absence of the recording sheet is set as the detection level, but the present invention is not limited to this. It does not have to be a value, but it may be a value close to this average value.

3 4 As explained above, according to this embodiment, the leading edge of the recording sheet can be detected with high accuracy and the recording sheet can be positioned.

This is particularly effective for printers such as color thermal transfer printers that return the recording sheet to the recording position and perform overlapping recording multiple times.

[Effects of the Invention] As explained above, according to the present invention, the position of the recording medium is detected based on the output signal level of the sensor that detects the position of the edge of the recording medium, so that the accurate position of the recording medium can be determined. It has the effect of detecting and recording.

[Brief explanation of the drawing]

FIG. 1 is a side cross-sectional view showing the structure of the mechanical section of the thermal transfer printer of the embodiment, FIG. 2 is a block diagram showing the structure of the electric circuit section and the mechanical section of the thermal transfer printer of the embodiment, and FIG. 3 is the implementation example. FIG. 4 is a block diagram showing the configuration of the thermal head; FIG. 5 is a diagram showing the configuration of the recording section of a general thermal transfer printer; FIG. The figure shows the output signal level of the recording sheet position sensor, Figure 7 is a flowchart showing the recording process in the thermal transfer printer of this embodiment, and Figure 8 shows the edge detection process of the recording sheet in step S2 in Figure 7. FIG. 9 is a flowchart showing recording processing in a thermal transfer printer of another embodiment, FIG. 10 is a diagram showing an example of the output signal of the recording sheet position sensor, and FIG. 11 is a flowchart of another embodiment. 7 is a flowchart showing recording sheet detection processing. In the figure, 9... registration roller, 10... recording sheet, 12... recording sheet supply roller, 13... platen, 15... recording sheet position sensor, 17... discharge roller, 18... Solenoid, 19... Driven roller for discharge, 20... Tray, 23... Ink sheet, 24... Ink sheet supply roll, 25... Ink color detection sensor, 26... - Ink sheet take-up roller, 27... Cartridge, 28... Ink sheet quip sensor, 29... Thermal head, 30...
・Shift lever 132...Shift cam, 33...Thermal head position sensor, 200...Host computer, 203...CPU, 205...ROM, 20
6...RAM, 207...Page memory, 216.
...A/D converter, 60...Recording sheet supply motor, 61...Recording sheet 1-discharging-11-1, 62
. . . thermal head driving motor, 64 . . . ink sheet conveyance motor, 65 . . . recording sheet conveyance motor. 7 8 Japanese Unexamined Patent Publication No. 3 173662 (15)

Claims (4)

[Claims] (1) A recording device that records an image on a recording medium, comprising: a conveyor that conveys the recording medium to a recording position; a sensor that outputs a detection signal having a signal level corresponding to the presence or absence of the recording medium; determining means for converting the detection signal into a digital signal and determining a detection level at the edge of the recording medium based on the digital signal when the recording medium is present and when the recording medium is not present; A recording apparatus comprising: control means for controlling the conveyance means to convey the recording medium to a recording position until the detection level is reached. (2) A recording device that records an image on a recording medium, comprising: a conveyor that conveys the recording medium to a recording position; a sensor that outputs a detection signal having a signal level corresponding to the presence or absence of the recording medium; determining means for converting the detection signal into a digital signal and determining a detection level of the edge of the recording medium based on the digital signal when the recording medium is present and when the recording medium is not present; After image recording is completed, when the recording medium is returned to the recording position by the conveyance means, the control means controls the conveyance means to return the recording medium until the detection signal level reaches the detection level. A recording device characterized by: (3) A recording device that records an image on a recording medium, comprising: a conveyor that conveys the recording medium to a recording position; a sensor that outputs a detection signal having a signal level corresponding to the presence or absence of the recording medium; determining means for converting the detection signal into a digital signal and determining a detection level of the edge of the recording medium based on the digital signal when the recording medium is present and when the recording medium is not present; After the image recording is completed, when the recording medium is returned to the recording position by the conveyance means, the recording medium is returned until the detection signal level becomes equal to or lower than the detection level;
Thereafter, a control means controls the conveyance means to convey the recording medium in a forward direction until the detection signal level reaches the detection level. (4) A recording device that records an image on a recording medium, comprising: a conveyance means that conveys the recording medium to a recording position; and a sensor that outputs a detection signal having a signal level corresponding to the presence or absence of the recording medium; a first step of converting the detection signal into a digital signal and determining a detection level of the edge of the recording medium based on the digital signal when the recording medium is present and when the recording medium is not present;
and a second determining means for determining the detection level of the presence or absence of the recording medium; and when the recording medium is returned to the recording position by the conveying means after the recording of the image on the recording medium is completed, the detection signal level is determined. The recording medium is returned until the detection signal level becomes equal to or lower than the detection level of the edge of the recording medium, and then the recording medium is moved forward by the conveyance means until the detection signal level reaches the detection level of the edge of the recording medium. a control means for controlling the recording medium to be conveyed to the sensor position when the detection signal level becomes equal to or lower than the detection level of the presence or absence of the recording medium when the recording medium is conveyed by the conveyance means; A recording device comprising: a determining means for determining that there is no such thing.