JPH04223182A - Recording medium-positioning device - Google Patents

Abstract

PURPOSE:To enable accurate positioning to be performed by carrying out always accurately positional detection of a recording medium, even though use conditions are different concerning a recording medium-positioning device made to position the recording medium in a recorder by a method wherein the positional detection of the recording medium is performed with a reflection type optical sensor in respective recorders such as a printer, a copying machine, etc. CONSTITUTION:The title recording medium-positioning device is constructed by establishing a reflection type optical sensor 2 which outputs by receiving light reflected on a surface of a recording medium 100 to be carried by a medium carrying means 1 to be converted to an electric signal, a correction data memory means 3 which stores a correction data for correcting fluctuation of an output signal from the reflection type optical sensor 2 to be generated caused by difference of use conditions, and a medium carrying control means 4 which controls operation of the medium carrying means 1 based on the output signal from the reflection type optical sensor 2 and which corrects said operation by the correction data stored in the correction data memory means 3.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] This invention detects the position of a recording medium in various recording devices such as printers and copying machines using a reflective optical sensor to determine the position of the recording medium within the recording device. The present invention relates to a recording medium positioning device.

In printers, copying machines, and the like, in order to correctly record at a desired position on a recording medium, it is necessary to correctly position the recording medium with respect to the recording device.

0003

[Prior Art] In a conventional recording medium positioning device, an optical sensor receives light reflected from the surface of a conveyed recording paper, converts it into an electrical signal and outputs it, and sets the output value to a reference value. The position of the edge of the recording paper was detected by comparing it with the position of the recording medium, and the position of the recording medium was determined based on this.

0004

[Problems to be Solved by the Invention] However, different types of recording paper have different light reflectances on their surfaces. Then,
Even if the edges of the recording paper are in the same position, the intensity of light incident on the optical sensor will differ.

[0005] Therefore, the position of the edge of the recording paper determined from the electric signal value output from the optical sensor causes an error due to the influence of the light reflectance of the surface of the recording paper.

[0006]Furthermore, the response speed of the optical sensor is faster at higher temperatures and slower at lower temperatures. Therefore, errors occur in detecting the edge position of the recording paper due to fluctuations in the environmental temperature.

[0007] As described above, in conventional recording medium positioning devices, errors occur in detecting the edge position of the recording medium (recording paper) due to differences in usage conditions, and the recording medium is not positioned correctly. There was a drawback that recording was not performed correctly at the desired position.

The present invention aims to eliminate such conventional drawbacks and to provide a recording medium positioning device that can always correctly detect the position of the recording medium and perform correct positioning even under different usage conditions. purpose.

[0009]

[Means for Solving the Problems] In order to achieve the above object, the recording medium positioning device of the present invention, as shown in FIG. A reflective optical sensor 2 receives light reflected on the surface of the recording medium 100 conveyed by the conveying means 1, converts it into an electrical signal, and outputs it, and a reflective optical sensor 2 that is generated due to differences in usage conditions. control the operation of the medium transport means 1 based on the output signals from the reflection type optical sensor 2 and the correction data storage means 3 storing correction data for correcting fluctuations in the output signal of the
The present invention is characterized in that a medium transport control means 4 is provided for correcting the operation using correction data stored in the correction data storage means 3.

Note that the correction data storage means 3 may store data for correcting output fluctuations of the reflective optical sensor 2 caused by temperature changes; Data for correcting output fluctuations of the reflective optical sensor 2 caused by differences in reflectance of the recording medium 100 may be stored.

The medium conveyance control means 4 may control the operation of the medium conveyance means 1 so as to stop the recording medium 100 at a predetermined position.

0012

[Operation] In the medium conveyance control means 4, the operation of the medium conveyance means 1 is controlled based on the output signal from the reflective optical sensor 2, and the operation is controlled by the correction data storage means 3.
The correction is controlled by the correction data stored in the .

Therefore, by selecting the correction data to be stored in the correction data storage means 3, it is possible to correct errors caused by temperature changes or errors caused by differences in reflectance on the surface of the recording medium 100.

[0014] Using the correction data, it is possible to control the recording medium 100 to stop at a predetermined position.

[0015]

[Embodiment] An embodiment will be described with reference to the drawings.

FIG. 2 shows a printer device to which the present invention is applied. In the figure, reference numeral 11 denotes a platen roller, and a paper conveyance path 12 for conveying the recording paper 100 is formed about half a circumference along the outer circumference of the platen roller.

The paper conveyance path 12 includes a platen roller 11.
A paper conveyance roller 1 is provided that rotates and conveys the recording paper 100 while sandwiching the recording paper 100 therebetween. 14 is a drive motor for rotationally driving the paper conveyance roller 1. 15 is a drive circuit for the drive motor 14.

The recording paper 1 is placed on the exit side of the paper conveyance path 12.
A print head 18 for printing 00 is arranged facing the platen roller 11.

In addition, the paper conveyance roller 1 and the print head 18
A reflective optical sensor 2 is located in the middle of the paper conveyance path 12 between the
is provided. The reflective optical sensor 2 includes a light emitting element that irradiates light onto the surface of the recording paper 100 passing in front of it, and an electrical signal that is received by the light reflected from the surface of the recording paper 100 and corresponds to the brightness of the light. (voltage) and a light-receiving element that converts it into voltage and outputs it.

The output signal from the reflective optical sensor 2 is converted into a digital signal by an analog-to-digital converter 21, and is input to an input terminal of a control unit 4 that includes a central processing unit (CPU) and the like.

A drive motor 1 is connected to the output end of the control section 4.
4 drive circuits 15 are connected, and the rotation and stop of the drive motor 14 is controlled by output signals from the control section 4, thereby controlling the position of the recording paper 100.

Incidentally, the output voltage of the reflective optical sensor 2 is affected by temperature changes even if the brightness of the light incident on the light receiving element is the same. This is because the dark current of the light receiving element increases at high temperatures.

Furthermore, the brightness of light entering the light receiving element of the reflective optical sensor 2 is influenced by the light reflectance of the surface of the recording paper 100 even if the brightness of the light emitting element is the same. and,
The result appears as a change in the output voltage of the reflective optical sensor 2.

Therefore, correction data for correcting the effects of temperature and reflectance is stored in a read-only memory (
The data is stored in the ROM (ROM) 3 as a temperature change correction table 3a and a reflectance change correction table 3b, and each data is read out by the control unit 4.

The temperature change correction table 3a includes, for example, as shown in FIG. 3, the output value from the reflective optical sensor 2 when there is no recording paper 100, and the output value at a reference temperature (for example, 20° C.). A paper offset amount M corresponding to eliminating the difference is stored.

The paper offset amount M in this case is the amount of correction of the reference position necessary for determining the position of the recording paper 100, and specifically, the amount is as follows.

That is, when the leading edge of the recording paper 100 is in front of the reflective photosensor 2, if the position of the leading edge changes, the amount of light reflected by the recording paper 100 changes and the output voltage changes. . Therefore, the amount of movement of the leading edge of the recording paper 100, which corresponds to eliminating the difference in the output values caused by the dark current, is stored as the reference position correction amount (paper offset amount M).

The reflectance change correction table 3b includes, for example, as shown in FIG. The output value from the optical sensor 2 is compared with that when recording paper 100 having a reference reflectance is used, and a paper offset amount N corresponding to eliminating the difference is stored.

Next, the operation of the above embodiment will be explained with reference to FIGS. 5 and 6, which are control processing flowcharts in the control section 4. S indicates a step.

This process is started with the start of automatic paper feeding of the recording paper 100, and first, before sucking the recording paper 100 into the paper transport path 12, the output X from the reflective optical sensor 2 is
is read (S1). Then, the difference D between the output value A from the reflective optical sensor 2 and the reference temperature is calculated (S2).
.

Next, from the temperature change correction table 3a,
The paper offset amount corresponding to D is read (S3), and the drive motor 14 rotates the paper transport roller 1 to start paper feeding (S4).

Next, while feeding the paper, the output value X of the reflective optical sensor 2 is read (S5).

When the leading edge of the recording paper 100 approaches the front of the reflective optical sensor 2, the sensor light begins to be reflected on the surface of the recording paper 100, and as the recording paper moves, the output value from the reflective optical sensor 2 changes. becomes larger. Then, when the leading edge of the recording paper 100 passes through the front position of the reflective optical sensor 2, the output value from the reflective optical sensor 2 becomes constant at the maximum value.

[0034] Also, under the reference temperature, the recording paper 10
The output value (reference value) B from the reflective optical sensor 2 when the leading edge of the sheet of paper passes near the center of the front of the reflective optical sensor 2 is set to mean "detection of the leading edge of the paper". There is.

Therefore, the output value X from the reflective optical sensor 2
The position obtained by adding the paper offset amount M to the position of the leading edge at the moment when B reaches the reference value B is set as the reference position of the leading edge position of the recording paper 100 (S6, S7).

Then, the paper is fed by a predetermined amount from the reference position, and the leading edge of the recording paper 100 is sent out beyond the front position of the print head, and then the paper feeding is stopped.

However, at the reference position determined in S7,
Although errors due to temperature effects are not included, recording paper 1
Errors due to the influence of the reflectance of the 00 surface are included.

Therefore, in this state, the output value X from the reflective optical sensor 2 is read (S9), and the difference E from the output value C when the recording paper 100 having the reference reflectance is used is determined.
is calculated (S10).

Then, the paper offset amount N corresponding to E is read from the reflectance change correction table 3b (S11
), advance (or return) the paper by N, and record paper 10.
0 Corrects the effect of surface reflectance.

In the above embodiment, paper feeding is once stopped in S8, and errors due to the influence of reflectance on the surface of the recording paper 100 are corrected in that state. However, correction calculations may be performed while feeding the paper. You may also do so.

Furthermore, the present invention is applicable not only to printers but also to various recording devices such as copying machines and typewriters.

[0042]

According to the recording medium positioning device of the present invention, it is possible to correct position detection errors of the recording medium caused by temperature changes, differences in reflectance of the recording medium, etc., and perform correct positioning. This has an excellent effect of allowing recording to be performed correctly at a desired position on a recording medium.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the principle of the present invention.

FIG. 2 is a configuration diagram of an embodiment.

FIG. 3 is a table content diagram of the embodiment.

FIG. 4 is a table content diagram of the embodiment.

FIG. 5 is a processing flow diagram of the embodiment.

FIG. 6 is a processing flow diagram of the embodiment.

[Explanation of symbols]

1 Media conveyance means 2 Reflective optical sensor 3 Correction data storage means 4 Media transport control means 100 Recording medium

Claims (4)

[Claims] 1. A medium conveying means (1) for conveying a recording medium (100); and a medium conveying means (1) for receiving light reflected on the surface of the recording medium (100) conveyed by the medium conveying means (1); A reflective optical sensor (2) that converts the signal into an electrical signal and outputs it, and correction data that stores correction data for correcting fluctuations in the output signal from the reflective optical sensor (2) that occur due to differences in usage conditions. The operation of the medium transport means (1) is controlled based on the output signals from the storage means (3) and the reflective optical sensor (2), and the operation is stored in the correction data storage means (3). 1. A recording medium positioning device comprising: a medium conveyance control means (4) that performs correction based on correction data. 2. The recording medium positioning device according to claim 1, wherein the correction data storage means (3) stores data for correcting output fluctuations of the reflective optical sensor (2) caused by temperature changes. . 3. The correction data storage means (3) stores data for correcting output fluctuations of the reflective optical sensor (2) caused by differences in reflectance of the recording medium (100). A recording medium positioning device according to claim 1 or 2. 4. The medium transport control means (4) controls the operation of the medium transport means (1) so as to stop the recording medium (100) at a predetermined position.
The recording medium positioning device described.