JPH0632032A - Apparatus for detecting paper width of printer and method thereof - Google Patents

Abstract

PURPOSE:To avoid mistaking the black part for a paper end even in the paper wherein ruled lines or characters are printed by renewing the other end position of paper whenever optical sensor detecting signals change from white to black. CONSTITUTION:The carriage 5 is moved rightward by one step, and by adding one to the counter and ascertaining whether or not the detecting signals SS of an optical sensor 3 are changed from H to L, a value of the counter denoting the present position of the carriage 5 is stored In the right-hand end register PR within a paper position resister 9. The carriage 5 is checked up whether it reaches the right-hand end B of the movable range, and if not, the detecting operation is still continued. If the carriage 5 reaches the right-hand end B, a detecting control part 8 indicates putting out light to an element driving circuit, in order to put out a luminance element, thereby completing the detection of the paper position. Thereafter, the difference between the right-hand end register PR and the left-hand end resister PL is calculated, so as to decide the width of paper 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer for detecting a paper width using an optical sensor, and a printer paper capable of detecting the paper width even if it is a format paper on which ruled lines and the like have been printed in advance. The present invention relates to a width detection device and the same method.

[0002]

2. Description of the Related Art An optical sensor is mounted on a carriage, and the detection is performed by moving the carriage from left to right, and the output signal of the optical sensor changes from "black" on a platen to "white" on a sheet. By the way, the position of the carriage at that time is the left end position of the paper, and when the output signal of the optical sensor changes from "white" to "black" next time, the position of the carriage at that time is the right end position of the paper and the paper left and right positions are set. Traditionally, the width is calculated.

[0003]

However, according to the conventional method, in the case of printing on a format paper in which ruled lines are already printed or a sheet of paper on which the ruled lines are already printed, the "black lines" such as the ruled lines and the characters already printed are printed. When the optical sensor is applied to the area "", the output signal changes from "white" to "black" and the carriage position at that time becomes the right edge position of the paper, and as a result, the wrong paper width is calculated. There was a drawback that

Therefore, the present invention accurately detects the paper position and calculates the paper width without erroneously detecting the "black" portion of the paper on which the ruled lines or characters are printed as the paper edge. It is an object of the present invention to provide a sheet width detecting device and a method for detecting the sheet width.

[0005]

A paper width detection device for a printer according to the present invention comprises an optical sensor mounted on a carriage, a carriage drive means for driving the carriage, first and second storage means, and The carriage drive means is controlled to cause the optical sensor to perform detection while moving the carriage, and the position of the carriage at that time is stored in the first storage means according to the first "white" detection signal of the optical sensor. Then, each time the detection signal of the optical sensor changes from "white" to "black", the position of the carriage at that time is stored again in the second storage means, and the detection control means, and the first and second storages. And a calculating means for calculating the paper width from the contents of the means.

Further, the paper width detection method for a printer of the present invention is a printer in which an optical sensor is mounted on a carriage and the carriage is moved to detect the position of the paper by the optical sensor. Detection is performed by the optical sensor while moving from the end to the other, and the position of the carriage at that time is stored as a first position in response to the first "white" detection signal of the optical sensor, and then the optical sensor. Each time the detection signal of "changes from" white "to" black ", the position of the carriage at that time is sequentially stored and updated as the second position, and when the carriage reaches the other end of the movable range, it is stored first. The width of the sheet is calculated from the first position and the last stored second position.

Further, in a printer in which an optical sensor is mounted on a carriage and the carriage is moved to detect the position of a sheet by the optical sensor, the optical sensor is moved while moving the carriage from one end of the movable range to the other end. The first "white" of the optical sensor is detected by the sensor.
The position of the carriage at that time is set to the first position according to the detection signal.
The position of the carriage is stored as a position, and each time the detection signal of the optical sensor changes from “white” to “black”, the position of the carriage at that time is sequentially stored and updated as a second position. The difference of one position is sequentially calculated and stored as a sheet width, and the detection is ended when the carriage reaches the other end of the movable range.

[0008]

According to the present invention, one edge position of the paper is stored according to the first "white" detection signal of the optical sensor, and thereafter, each time the detection signal of the optical sensor changes from "white" to "black". The other end position of the sheet is stored again, and the width of the sheet is calculated from the other end position of the sheet stored last and the one end position of the sheet stored first.

[0009]

EXAMPLE FIG. 2 is a block diagram showing the structure of this example, in which 1 is a platen whose surface is made of rubber and which has a blackish color,
A sheet 2 to be printed is attached to the platen 1, and the ruled lines 2a, 2b and 2c have been printed. Reference numeral 3 is an optical sensor capable of discriminating between "black" of the platen 1 and "white" of the paper 2, and 4 is a print head mounted on the carriage 5 together with the optical sensor 3. Reference numeral 6 denotes a CR motor that is driven by a motor drive circuit 7 to reciprocate the carriage 5 left and right along the platen 1, and more specifically, the CR motor 6
Is constituted by a stepping motor and causes the carriage 5 to perform a step operation. Reference numeral 8 is a detection control unit for detecting the position of the paper 2 and calculating the paper width in accordance with a paper width detection command sent from the host device through the interface unit 12, and 9 is a paper position for storing the detected position of the paper 2. register,
Reference numeral 10 is a print position register for storing the print position on the paper sent from the host device, and 11 is a print buffer for storing print data sent from the host device. The detection control unit 8 also includes the contents of the paper position register 9 and the print position register 1.
The absolute print position is calculated from the contents of 0 and the contents of the print buffer 11 are sent to the print head 4 to control printing.

The optical sensor 3 will be described in more detail. As shown in FIG. 3, it comprises a light emitting element 30 as a light emitting source, an element driving circuit 31 for driving the light emitting element 30, and a light receiving circuit 32. The light emitted from the optical path R shown by the dotted line
The platen 1 or the paper 2 is reflected and the reflected light enters the light receiving circuit 32. This reflected light is weak from the platen 1 of black color and is sufficiently strong from the paper 2 of white color, so that the light receiving circuit 32 discriminates both and detects the detection signals of L and H corresponding to each. This is a configuration for outputting SS.

The operation of this embodiment will be described below with reference to the flow chart of FIG.

When the paper width detection command is received from the host device, the detection control unit 8 instructs the motor drive circuit 7 to control the CR motor 6 and move the carriage 5 to the reference position A at the left end. Next, the left end register PL and the right end register PR in the paper position register 9 and the counter CN that counts the number of drive steps of the CR motor 6 are initialized to 0, and the element drive circuit 31 is instructed to turn on the light emitting element 30. , Start detecting the paper position.

The sheet position is detected by reading the detection signal of the optical sensor 3, that is, the detection signal SS of the light receiving circuit 32 while moving the carriage 5 from the left end to the right.

The detection control unit 8 instructs the motor drive circuit 7 to drive the CR motor 6 one step, move the carriage 5 right one step, and increment the counter CN by one. The counter CN represents the absolute position of the carriage 5 from the reference position A. And next, the optical sensor 3
Of the detection signal SS is H, and if it is H, it means that the detection light of the optical sensor 3 is reflected on the paper 2. Therefore, the value of the counter CN representing the current position of the carriage 5 is stored in the paper position register 9. To the left end register PL. If the detection signal SS of the optical sensor 3 is L, the carriage 5 is further moved to the right to continue the detection operation in step S104.
Return to.

When the left end position of the paper 2 is detected, the process proceeds to the detection of the right end position of the paper 2 after step S109.

Similarly to the above, the carriage 5 is moved one step to the right, the counter CN is incremented by 1, and this time, it is confirmed whether the detection signal SS of the optical sensor 3 has changed from H to L. Value of the counter CN indicating the position of the carriage 5 of
Remember. Then, the carriage 5 moves to the right end B of the movable range.
Has been reached, and if the right edge B has not been reached, the process returns to step S109 to continue the detection operation. In other words, until the carriage 5 reaches the right end B, the detection signal SS of the optical sensor 3 is monitored to change from H to L at each step movement, and the value of the counter CN is stored in the right end register PR each time it changes. To do.

When the carriage 5 reaches the right end B, the detection control section 8 instructs the element drive circuit 31 to turn off the light emitting element 30, and ends the detection of the sheet position. After that, the difference between the right end register PR and the left end register PL is calculated to determine the width of the paper 2.

In the initial detection of the left end position, while the detection signal SS is L, the step movement of the carriage 5 to the right continues, so that the detection signal SS is L when the paper 2 is not loaded. Since the carriage 5 reaches the right end B as it is, in step S108, the carriage 5
When it reaches the right end B, the detection operation is stopped.

When the right edge position of the sheet 2 is detected after step S109 in FIG. 1, the value of the counter CN is stored in the right edge register PR every time the detection signal SS of the optical sensor 3 changes from H to L. Is a ruled line 2a printed on the paper 2.
Even when the detection light of the optical sensor 3 is applied to the
This is because S changes from H to L.

FIG. 4 shows the relationship between the platen 1 and the sheet 2 and the detection signal SS when the carriage 5 is moved from the reference position A to the right end B and the detection by the optical sensor 3 is performed. When the carriage 5, that is, the optical sensor 3 is moved from the reference position A to the right end B, the reflected light from the platen 1 first enters the light receiving circuit 32, and therefore the detection signal SS is L. When the optical sensor 3 is applied to the left end C of the sheet 2 in time, the detection signal SS becomes H, and the value of the counter CN at this time is stored in the left end register PL. When the optical sensor 3 is applied to the ruled line 2a further, the ruled line 2a becomes "black".
In response to the detection signal SS becomes L, the counter CN
The value of is stored in the right end register PR. Immediately after this, the optical sensor 3 deviates from the ruled line 2a, and the detection signal SS becomes H in response to "white" of the paper 2 again.
In the detection of the right end position after 9, the detection signal SS is changed from H to L.
Since only the change to H is monitored, the change to H of this detection signal is ignored.

Returning to FIG. 4, the ruled line 2b and then the ruled line 2c
Even when the optical sensor 3 passes through, the detection signal SS changes from H to L and immediately from L to H as shown in the figure.
As described above, each time the detection signal SS changes from H to L,
The value of the counter CN is stored in the right end register PR. Even when the optical sensor 3 deviates from the right end D of the sheet 2 and hangs on the platen 1, the detection signal SS changes from H to L, and similarly, the value of the counter CN is stored in the right end register PR.

After that, since the optical sensor 3 moves on the platen 1, the detection signal SS remains L, and therefore the right edge register PR does not change while memorizing the position of the right edge D of the paper 2. Finally, when the carriage 5 reaches the right end B, the paper position detection operation is completed, and the PR and P of the paper position register 9 are
The width of the paper 2 is determined by calculating the difference of L.

By the way, in the present embodiment, each time the detection signal SS changes from H to L, the value of the counter CN is stored in the right end register PR, and finally it is confirmed that the carriage 5 has reached the right end B, Although the difference between the registers PR and PL is calculated, in step S112 of FIG. 1, after the value of the counter CN is stored in the right end register PR, the difference between the registers PR and PL is calculated and prepared separately. It may be stored in the paper width register PW. In this case, step S115 is omitted, but the same effect as that of the above embodiment is obtained.

The same effect can be obtained even if the paper width register PW is also used as the right end register PR and the above operation is performed in step S112.

[0025]

As described above, according to the present invention, even if the paper has ruled lines or characters printed thereon, the position of the paper can be accurately detected and the width of the paper can be accurately detected without erroneously detecting the "black" portion as the paper edge. Can be calculated.

[Brief description of drawings]

FIG. 1 is a flowchart showing processing contents in an embodiment.

FIG. 2 is a block diagram showing a configuration of an example.

FIG. 3 is a block diagram showing a configuration of an optical sensor of an example.

FIG. 4 is a diagram showing a relationship between a printed sheet and a platen and a detection signal.

[Explanation of symbols]

 1 Platen 2 Paper 3 Optical Sensor 5 Carriage 6 CR Motor 8 Detection Control Section 9 Paper Position Register

Claims (3)

[Claims] 1. An optical sensor mounted on a carriage, a carriage driving unit for driving the carriage, first and second storage units, and the optical unit while controlling the carriage driving unit to move the carriage. The detection by the sensor is performed, and the position of the carriage at that time is stored in the first storage means in response to the first "white" detection signal of the optical sensor, and the detection signal of the optical sensor changes from "white" to "black". Detection control means for re-storing the position of the carriage at that time in the second storage means, and calculation means for calculating the paper width from the contents of the first and second storage means. A paper width detection device for a printer, characterized in that 2. A printer in which an optical sensor is mounted on a carriage, and the carriage is moved to detect the position of a sheet by the optical sensor, while the carriage is moved from one end of the movable range to the other end of the optical range. The detection by the sensor is performed, and the position of the carriage at that time is stored as the first position in response to the first "white" detection signal of the optical sensor, and then the detection signal of the optical sensor is "white".
Every time it changes from “black” to “black”, the position of the carriage at that time is sequentially stored and updated as the second position, and when the carriage reaches the other end of the movable range, the first position stored first and the last position stored A paper width detection method for a printer, characterized in that the width of the paper is calculated from the second position. 3. A printer in which an optical sensor is mounted on a carriage, and the carriage is moved to detect the position of a sheet by the optical sensor, while the carriage is moved from one end of a movable range to the other end of the optical range. The detection by the sensor is performed, and the position of the carriage at that time is stored as the first position in response to the first "white" detection signal of the optical sensor, and then the detection signal of the optical sensor is "white".
Each time from "black" to "black", the position of the carriage at that time is sequentially stored and updated as the second position.
A paper width detecting method for a printer, wherein a difference between a position and the first position is sequentially calculated and stored as a paper width, and detection is terminated when the carriage reaches the other end of the movable range. .