JP2954085B2 - Sensor output adjustment method and mark detection device using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mark detection device for detecting a mark on a recording sheet used in a printer or the like, and more particularly to a method for adjusting the output of a mark sensor.

[0002]

2. Description of the Related Art Heretofore, this type of mark detection device has been used for the purpose of positioning a recording sheet in a printer device or the like.

FIG. 8 is a circuit diagram showing an example of a conventional mark detection device (hereinafter, referred to as a first conventional technology).

A light emitting diode or the like is used as the light source 21b, and emits light to the recording paper 5. The recording paper 5 is marked. The photosensor 21a receives light reflected from the recording paper 5 and changes the current value, and the changed voltage is input to the comparator 22a. The comparator 22a compares the voltage from the photosensor 21a with a fixed reference voltage Vr, and when the voltage from the photosensor 21a is higher than the reference voltage Vr, the level is low (L), and when the voltage is lower, the level is high (H). Is output. The resistance volume RV changes the supply voltage to the light source 21b to change the light emission amount of the light source 21b.

Next, the operation of the above configuration will be described.

When the mark portion of the conveyed recording paper 5 comes to a place where the light emitted and emitted from the light source 21b hits,
Since the reflectance of the mark portion is low, the light receiving voltage of the photo sensor 21a is low, the output of the comparator 22a becomes H, and it is determined that there is a mark. And transport it further,
When a portion without a mark on the recording paper 5 comes to a place where the light emitted and emitted from the light source 21b hits, the reflectance of the portion without the mark is high, so that the light receiving voltage of the photo sensor 21a increases, and the output of the comparator 22a becomes It becomes L and it is determined that there is no mark.

When the influence on the light receiving voltage of the photosensor 21a is considered at the time of production and adjustment, or after the type of recording paper is changed, the supply voltage to the light source 21b is changed by adjusting the resistance volume RV. And the light source 21b
Are changed by changing the light emission amount.

In the first prior art described above, the reference voltage Vr inputted to one input terminal of the comparator 22a and compared with the light receiving voltage of the photo sensor 21a.
Is a fixed value.

On the other hand, as an example in which the reference voltage Vr can be adjusted, there is a mark detecting device disclosed in Japanese Patent Application Laid-Open No. 61-283806 (hereinafter referred to as a second conventional technology).

In the second prior art, at the time of production, output signals of sensors corresponding to states with and without marks are obtained, a set voltage is calculated from both output signals, and the obtained set voltage is obtained. Is input to one input terminal of the comparator instead of the reference voltage Vr in FIG.

[0011]

The first problem in the above-mentioned prior art is that the light receiving voltage of the photosensor is reduced by the change in the type of recording paper during production or after that in the first prior art. When the influence is considered, since the supply voltage to the light source is changed by adjusting the resistance volume, a man-hour for adjustment by a dedicated person is required.

The second problem is that the first conventional technique cannot be used when the environment changes during operation, for example, when dust accumulates in the sensor, or the light emission efficiency of the light source or the efficiency of the photosensor changes. However, it may not be possible to accurately detect the mark because it does not respond to changes in the environment during operation. This is the case. Further, in the second conventional technique, there is a problem that it is not possible to accurately detect a mark because the reference voltage of the comparator is determined only at the time of production and does not correspond to an environmental change during operation.

According to the present invention, there is provided a sensor output adjusting method for automatically adjusting the light source output at the time of production or changing the type of recording paper, and automatically adjusting the light source output to an optimum light source output in response to a change in the environment during operation. An object of the present invention is to provide a mark detection device using the same.

[0014]

[0015]

According to a first aspect of the sensor output adjusting method of the present invention compares the number of steps of detecting that there is the number of steps and the mark corresponding to the width of a mark when the mark detection performed, O and there the mark If the number of steps to be detected is larger, the light source supply voltage is increased by one step. If the number of steps to detect the presence of the mark is smaller, the light source supply voltage is decreased by one step. Is not changed.

According to a second sensor output adjustment method of the present invention, at the time of initial setting, the mark detection operation is repeated by changing the light source supply voltage of the mark sensor, and the light source supply voltage optimal for mark detection is obtained from the collected detection data. And memorize,
At the time of performing mark detection, the number of steps corresponding to the width of a mark and the number of steps for detecting presence of a mark are determined based on the light source supply voltage stored at the time of initial setting or the light source supply voltage updated at the time of previous mark detection execution. In comparison, when the number of steps for detecting the presence of the mark is larger, the light source supply voltage is increased by one step and stored, and when the number of steps for detecting the presence of the mark is smaller, the light source supply voltage is set to 1 It is characterized in that it is stored stepwise, and in the case of the same, the light source supply voltage is not changed.

[0017]

[0018]

[0019]

The mark detecting apparatus of the present invention, by irradiating the recording sheet from the light source, the reflected amount or one input of the transmission amount is detected by the mark sensor voltage corresponding to the reflection amount or permeation amount comparator A mark detection device that detects the presence or absence of a mark by comparing the voltage with a reference voltage input to the other input terminal of the comparator. The mark detection operation is repeated by changing the above, the optimal light source supply voltage for mark detection is obtained from the collected detection data, and at the time of mark detection execution, the light source supply voltage stored at the time of initial setting or at the time of previous mark detection execution The number of steps corresponding to the width of the mark is compared with the number of steps for detecting the presence of the mark based on the updated light source supply voltage, and the presence of the mark is determined. If the number of steps to be detected is larger, the light source supply voltage is increased by one step and updated.If the number of steps to detect the presence of the mark is smaller, the light source supply voltage is decreased by one step and updated. In the same case, a main control unit that controls not to change the light source supply voltage, and a storage unit that stores the light source supply voltage obtained at the time of initial setting by the main control unit or the light source supply voltage updated at the time of performing mark detection. And a voltage control circuit that controls the light source supply voltage in accordance with an instruction from the main control unit.

[0021]

Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention. A mark detecting device according to the present invention comprises a main control unit 1 for judging input / output of a signal, It comprises a mark detection unit 2 for detecting a mark 51, a sheet conveyance unit 3 for conveying a recording sheet 5, and a storage unit 4 for storing a light source supply voltage set by the main control unit 1.

The main control section 1 outputs a motor drive signal Mo to the sheet conveying section 3 to convey the recording sheet 5 by one step, and determines whether or not there is a mark based on the mark sense output signal Ma from the mark detecting section 2. I do.

The mark detecting section 2 includes a mark sensor 21,
A voltage comparison circuit 22 and a voltage control circuit 23 are provided. The mark sensor 21 may be either a reflection sensor or a transmission sensor. In the present embodiment, the mark sensor 21 will be described as a reflection sensor that measures light by irradiating the recording paper 5 with light.

The paper transport unit 3 includes a motor control circuit 31
The motor includes a motor 32 and a platen 33 for transmitting power. The motor control circuit 31 rotates the motor 32 according to the motor drive signal Mo from the main control unit 1 and
The recording paper 5 is conveyed by rotating the recording paper 5.

The mark 51 is displayed on the recording paper 5 in a predetermined size so that the light reflectance is lower than that of the other portions.

FIG. 2 is a circuit diagram showing the mark detecting section of FIG. 1 in detail. In FIG. 2, a light emitting diode or the like is used as the light source 21b, and irradiates the recording paper 5 with light. A phototransistor or the like is used for the photosensor 21a. The current value changes in response to the light reflected from the recording sheet 5, and the changed voltage is input to the comparator 22a.

The comparator 22a is connected to the photo sensor 21
The voltage from a is compared with the reference voltage Vr. Light source 2
When the mark of the conveyed recording paper 5 comes to a place where the light of 1b is applied, the light receiving voltage of the photosensor 21a becomes lower than the reference voltage Vr because the reflectivity of the mark is low, and the output of the comparator 22a becomes High level (H ), It is determined that there is a mark. And the light source 21b
When a portion of the recording paper 5 where there is no mark comes where light is applied, the light receiving voltage of the photo sensor 21a becomes higher than the reference voltage Vr because the reflectance of the portion without the mark is high, and the output of the comparator 22a becomes low level. When the state becomes (L), it is determined that there is no mark.

The voltage control circuit 23 changes the supply voltage to the light source 21b according to the voltage change signal Ps from the main control unit 1. When the supply voltage of the light source 21b is increased by the voltage control circuit 23, the amount of light emitted from the light source 21b increases, so that the amount of light received by the photo sensor 21a also increases, and the amount of light received by the comparator 22a increases.

Next, the operation of the embodiment of the present invention will be described in detail with reference to FIGS.

FIG. 3 is a schematic diagram showing the positional relationship between the mark sensor and the mark. The recording paper is conveyed, and the mark 51 passes in front of the mark sensor 21. At this time, the position when the mark 51 starts to overlap the mark sensor 21 is represented by S
s, the position when the center of the mark sensor 21 and the center of the mark 51 coincide, Sc, and the mark 51 is the mark sensor 21
And the position at which the overlap has disappeared is Se.

FIG. 4 is a graph showing the relationship between the recording sheet moving position and the photosensor light receiving voltage when the light source supply voltage is changed. The graph shows the change in the received light voltage that enters the comparator 22a from the photo sensor 21a at the time of the mark 51 detection operation. The horizontal axis represents the recording paper moving position, and the vertical axis represents the photo sensor received voltage.

Referring to FIG. 4, during the period from S1 to S2, the mark 51 entirely overlaps the mark sensor 21, and the light receiving voltage of the photo sensor 21a becomes the lowest. During the period from Ss to S1, the mark 51 starts to overlap the mark sensor 21 from the position of Ss, and the area occupied by the mark 51 having a low reflectance increases, so that the light receiving voltage of the photo sensor 21a decreases.
During the period from S2 to Se, the mark sensor 21 and the mark 51 start to shift from the position of S2, and the area occupied by the markless portion having high reflectance increases, so that the light receiving voltage of the photosensor 21a increases. The interval between S1 and S2 is the difference between the width of the mark 51 and the width of the mark sensor 21, and the interval between Ss and S1 and the interval between S2 and Se are the width of the mark 51.

The light receiving voltage of the photo sensor 21a is compared with the reference voltage Vr of the comparator 22a. As shown in FIG. 4, when the voltage is higher than the reference voltage Vr, the output of the comparator 22a is Low level (L). And below the reference voltage Vr, the output of the comparator 22a indicates the presence of a High level (H) mark.

Assuming that the moving position of the recording paper 5 at the intersection of the reference voltage Vr and the graph V1 is S3, S4, it is determined that there is a mark between the steps S3 and S4. When the light source supply voltage is increased, the output of the light source 21b is increased, and the light reception voltage of the photosensor 21a is increased. Therefore, if the light source supply voltage is set to V1 <V2 <V3, the graph becomes V1 → V2 → V3. The number of moving steps of the recording paper 5 which moves and determines that there is a mark decreases.

FIG. 5 is a flowchart showing a procedure of a light source supply voltage adjusting method at the time of initial setting, and will be described below step by step.

First, the recording paper 5 with the mark is placed on the mark 51.
Is set in front of the mark sensor 21, and the main controller 1 sets the light source supply voltage to the maximum (step A1).

Then, the number of marked steps of the internal variable is cleared (step A2).

The main controller 1 sends a motor drive signal Mo to the paper transport unit 3 to transport the recording paper 5 by one step (step A3).

Based on the mark sense output signal Ma sent from the comparator 22a, the main controller 1 determines whether or not there is a mark (step A4).

When there is a mark, the number of steps with a mark is incremented by 1 (step A5).

The number of steps by which the mark 51 passes the mark sensor 21 sufficiently is defined as Smax, and steps A3 to A5 are repeated Smax times (step A6).

After repeating Smax times, the main controller 1 compares the number of marked steps with the width of the mark 51 (step A7).

If the number of marked steps is smaller than the width of the mark 51, it is checked whether the light source supply voltage is minimum (step A8).

If the light source supply voltage is not minimum, S
The sheet is conveyed in the reverse direction by max steps (step A9).

Then, the light source supply voltage is reduced by one step,
It repeats from step A2 (step A10).

In step A7, when the number of marked steps is equal to or larger than the width of the mark 51, the main control unit 1 stores the set light source supply voltage in the storage unit 4 (step A11) and ends the adjustment (step A11). Step A12).

In step A8, if the light source supply voltage is at the minimum, an abnormality is notified and the process ends (step A13).

The procedure of the method for adjusting the light source supply voltage at the time of initial setting has been described above with reference to FIG. In the above description, the light source supply voltage is first set to the maximum voltage, and
Although the method of stepping down by steps is adopted, as another embodiment, it is also possible to adopt a method of setting the light source supply voltage to the minimum voltage first and increasing step by step.

FIG. 6 is a graph showing the relationship between the light source supply voltage and the number of marked steps.

The graph shows that while changing the light source supply voltage,
The change in the number of steps determined to have a mark when the mark detection operation is performed is shown. The horizontal axis indicates the light source supply voltage (the right direction is small), and the vertical axis indicates the number of steps with the mark.

Referring to FIG. 6, when the light source supply voltage is the maximum V
When decreasing from the max to the minimum Vmin in the right direction, the number of steps with a mark increases from 0 and exceeds the mark width Sm and becomes the same as the sheet movement amount Smax. In the graph, the number of steps with a mark is the same as the width of the mark, the number of steps Sm
Is Vb.

The adjustment method described with reference to FIG. 5 is a method for obtaining the latest optimum value that satisfies the light source supply voltage Vb.

FIG. 7 is a flowchart showing a method of adjusting the light source supply voltage during operation of the apparatus, which is automatically executed at the time of the mark detection operation.

The operation of the method for readjusting the light source output in the event of a change in the state of operation of the mark detection device, for example, contamination of the mark sensor by dust, a decrease in light source output efficiency, etc., will be described with reference to FIG. A description will be given for each step.

When starting the mark detection, the main control unit 1 sets the light source supply voltage stored in the storage unit 4 in step A11 of FIG. 5 at the time of initialization (step B).
1).

The main controller 1 executes the mark detection while moving the motor 32 one step at a time and counting the number of steps with a mark (step B2).

The main controller 1 compares the number of marked steps counted in step B2 with the width of the mark 51 previously stored in the storage 4 (step B3).

If the marked step variable is smaller than the width of the mark 51, the light source supply voltage is reduced by one step (step B4), and the set light source supply voltage is updated and stored in the storage unit 4 (step B6). .

When the number of marked steps is larger than the width of the mark 51, the light source supply voltage is increased by one step (step B5), and the set light source supply voltage is updated in the storage unit 4.
It is stored (step B6).

When the number of marked steps is equal to the width of the mark 51, the process is terminated without changing the light source supply voltage.

[0062]

As described above, the first effect of the present invention is that, in order to automatically adjust the light source supply voltage to an optimum value, a specialist can use a measuring device to adjust a variable resistance or the like at the time of production or change of paper type. This eliminates the need to adjust the light source supply voltage while changing it.

The second effect is that, since the light source supply voltage is automatically readjusted at the time of detecting a mark, a change in the state of the mark detecting device during operation, for example, contamination of the mark sensor due to dust,
Even if the light source output efficiency is lowered, readjustment of the light source output is not required, and mark detection can be performed reliably.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of the present invention.

FIG. 2 is a circuit diagram showing a mark detection unit of FIG. 1 in detail.

FIG. 3 is a schematic diagram showing a positional relationship between a mark sensor and a mark.

FIG. 4 is a graph showing a relationship between a recording sheet moving position and a photosensor light receiving voltage when a light source supply voltage is changed.

FIG. 5 is a flowchart illustrating a procedure of a light source supply voltage adjustment method at the time of initial setting.

FIG. 6 is a graph showing a relationship between a light source supply voltage and the number of marked steps.

FIG. 7 is a flowchart illustrating a method of adjusting a light source supply voltage during operation of the apparatus.

FIG. 8 is a circuit diagram showing an example of a conventional mark detection device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main control part 2 Mark detection part 21 Mark sensor 21a Photo sensor 21b Light source 22 Voltage comparison circuit 22a Comparator 23 Voltage control circuit 3 Paper conveyance part 31 Motor control circuit 32 Motor 33 Platen 4 Storage part 5 Recording paper 51 Mark

Claims (3)

(57) [Claims] When the number of steps for detecting the presence of a mark is larger than the number of steps for detecting the presence of a mark, the number of steps for detecting the presence of the mark is larger. A sensor output adjusting method, wherein when the number of steps for detecting the presence of a mark is smaller, the light source supply voltage is decreased by one step, and when the number is the same, the light source supply voltage is not changed. 2. Initial setting, the mark detection operation is repeated by changing the light source supply voltage of the mark sensor, the optimum light source supply voltage for mark detection is obtained from the collected detection data, and stored. Comparing the number of steps corresponding to the width of a mark with the number of steps for detecting the presence of a mark based on the light source supply voltage stored at the time of initial setting or the light source supply voltage updated at the time of previous mark detection execution, When the number of steps for detecting the presence of the mark is larger, the light source supply voltage is increased by one step and stored. When the number of steps for detecting the presence of the mark is smaller, the light source supply voltage is decreased by one step. A sensor output adjusting method, wherein the values are stored and, if they are the same, the light source supply voltage is not changed. 3. A recording paper is irradiated from a light source, the amount of reflection or transmission is detected by a mark sensor, and a voltage corresponding to the amount of reflection or transmission is input to one input terminal of a comparator. A mark detection device for detecting the presence or absence of a mark by comparing with a reference voltage input to the other input terminal of the comparator, and performs a mark detection operation by changing a light source supply voltage of a mark sensor at an initial setting. Repeatedly, determine the light source supply voltage optimal for mark detection from the collected detection data, at the time of mark detection, the light source supply voltage stored at the time of initialization or the light source supply voltage updated at the time of the previous mark detection execution Compare the number of steps corresponding to the width of the mark with the number of steps for detecting the presence of the mark based on the number of steps for detecting the presence of the mark. If it is larger, the light source supply voltage is increased by one step and updated. If the number of steps for detecting the presence of the mark is smaller, the light source supply voltage is decreased by one step and updated. A main control unit that controls not to change, a storage unit that stores the light source supply voltage obtained at the time of initial setting in the main control unit or the light source supply voltage that is updated at the time of performing mark detection, and And a voltage control circuit for controlling the light source supply voltage according to the instruction.