JP2946836B2 - Media mark reading method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for reading a medium mark, and more particularly to a method for reading a medium mark suitable for preventing a reading rate of the medium mark from being lowered.

[0002]

2. Description of the Related Art In recent years, a technique of attaching a mark such as a barcode to a medium and reading the mark with a device to obtain various information has been widely used. This kind of mark is an optical type, for example, in order to recognize the type, price, etc. of a product in a supermarket with a register device, and to recognize account information, page information, etc. of a passbook used in a financial institution such as a bank with a bookkeeping device. It is used for various purposes, such as for recognizing ID information or the like of a form with a character reading device, or for recognizing format information of a print medium with a serial printer or the like.

As a medium mark reading apparatus for reading a mark such as a bar code attached to such a medium, there is, for example, JP-A-63-10290. This example is shown in FIG. In this medium mark reading device, a medium mark is read as follows.

First, the initial setting of the gain of the programmable amplifier 52 and the reference voltage set by the reference voltage generator 55 is performed according to a command from the CPU 56. The initial setting is such that the detector 51 sets the level (white level) of the mark-unprinted portion of the medium.
Is detected so that the output of the comparator 54 changes. When the output of the comparator 54 changes due to the detection of the level of the mark-unprinted portion, the reference voltage generator 55 outputs the reference voltage (1) to the comparator 54 according to a command from the CPU 56, while the output of the programmable amplifier 52 outputs 1) The gain of the amplifier 52 is set so as to be above.

Next, the reference voltage generator 55 sets a reference voltage (2) higher than the reference voltage (1) in accordance with a command from the CPU 56, and the output of the programmable amplifier 52 outputs the reference voltage (1) and the reference voltage (2). The amplifier 52
Is set. Thereby, the detector 51 and the code detector 53 operate in a state where the output level of the programmable amplifier for the mark-unprinted portion is fixed,
Mark reading is performed.

As described above, the medium mark reading apparatus performs gain control (gain control) in advance to determine the white level of the medium and reads the medium mark.

[0007]

However, in the apparatus having the above-described configuration, it is necessary to set a position where the gain should be set in advance, so that the medium is inserted by moving the medium insertion guide, for example. In the extreme case, there is a problem that the gain is set outside the medium or the gain is set on the medium mark, and the medium mark reading rate is reduced.

An object of the present invention is to solve such a conventional problem and to provide a stable medium mark reading method in which the gain is set stably and the medium mark reading rate does not decrease. .

[0009]

According to the present invention, a medium mark reading method for reading a mark-free portion of a medium, setting a gain for determining an output level of an amplifier, and reading a mark of the medium is performed. To the reading position of
The carriage on which the medium mark sensor is mounted is moved in one direction, and when the state of the medium mark sensor changes from having a medium to having no medium, the carriage is moved in a direction opposite to the one direction and a predetermined distance in the opposite direction. A medium mark reading method for setting a gain when the movement is completed is provided.

The medium is conveyed to a predetermined reading position, and the carriage on which the medium mark sensor is mounted is moved in one direction. When the state of the medium mark sensor changes from medium-present to medium-less, the carriage is moved in one direction. Since the gain is set when the movement is completed in the opposite direction and a predetermined distance has been completed in the opposite direction, the gain can be set stably regardless of the change in the insertion position of the medium guide, and the mark reading rate is reduced. Is also gone.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 2 is a configuration diagram of a horizontal dot printer to which the present invention is applied. This means that in a dot printer that prints a mark such as a barcode on a medium in accordance with a command from a higher-level device, the mark is read by a mark sensor after the mark is printed, and the reflectance is determined. The possible configurations are shown.

In FIG. 2, reference numeral 2 denotes a medium guide for determining a position where a medium is to be inserted. The medium guide is movable in the same direction as the space direction B, and can be set at any position by an operator. Reference numeral 3 denotes a medium on which a medium mark has been printed, 4 denotes a medium transport path for guiding the medium 3 to the reading unit, and 5 denotes a medium transport path
The medium 3 is driven by driving means (not shown) provided above.
Is a roller for transporting the medium. Reference numeral 6 denotes a dot impact type print head, and 7 denotes a carriage on which the print head 6 is mounted. The carriage 7 is fitted on a carriage shaft 8 and moves in the space direction B. Reference numeral 11 denotes a mark sensor for reading a medium mark mounted on the carriage 7, and in the medium conveyance direction A with the movement of the carriage 7.
Moves in the direction perpendicular to the space direction, that is, the space direction B, and reads a medium mark printed on the medium 3.

FIG. 3 is a diagram showing the relationship between the carriage position and the medium position when the medium 3 has been fed to the predetermined position for reading the medium mark by the medium transport roller 5. Here, A, B, and C indicate that the medium guide 2 is left, center,
This indicates the medium position when set to the right, but may be set to an intermediate position between these depending on the case.

FIG. 4 is a diagram showing the printing position of the medium mark printed on the medium 3. As shown in FIG. As shown in FIG. 4, the medium mark is printed in a direction perpendicular to the medium transport direction A, that is, in the same direction as the space direction B. Further, since the medium mark has a variable length, it is necessary to set the gain before reading the medium mark at a position a which is α from the medium edge on the medium 3. However, as shown in FIG. 3, the gain setting position A depends on the set position of the medium guide 2.
The carriage positions of a, Ba, and Ca (in FIG. 3) are different.
In this case, the position of α from the medium edge is the gain setting position.

FIG. 1 is a diagram for explaining a medium mark reading method according to an embodiment of the present invention. This is shown in FIG.
Horizontal dot printer and CP as upper device
The block structure which connected U is shown.

In FIG. 1, 7 is a carriage, 11 is a medium mark sensor, and 13 is a carriage 7 characteristic of the present invention.
, A carriage drive circuit for controlling the drive of the carriage 7, a medium transport roller drive circuit for controlling the drive of the media transport roller 5, and 18 for controlling these circuits as a whole. This is a CPU serving as a higher-level device. 19 is a medium mark reading circuit.

Next, the operation of this embodiment will be described. First,
The CPU 18 issues a command to the medium transport roller drive circuit 17 to transport the medium to a predetermined position. Next, the CPU 18
Sends a command to the carriage drive circuit 16, moves the carriage 7 in the direction in which the carriage position decreases, monitors the state of the medium mark sensor 11, and changes the state of the medium mark sensor 11 from medium-present to medium-less. The carriage position CP at this time is read by the carriage position detection circuit 13. That is, the medium edge is detected. Next, C
The PU 18 issues a command to the carriage drive circuit 16 to move the carriage 7 from the carriage position CP to the position of CP + α. After completing the movement of the carriage 7 to the carriage position CP + α, the CPU 18 issues a gain control command to the medium mark reading circuit 19. Thereafter, the CPU 18 issues a command to the carriage drive circuit 16 to move in the direction in which the carriage position increases, and at the same time, issues a command to the medium mark reading circuit 19 to read a medium mark.

As described above, in the present embodiment, the position at the time of reading the medium edge is detected by the carriage position detecting circuit, and the gain setting position is determined based on the position. Even if it is set, gain control (gain control) can be performed at a position α from the medium edge.

[0019]

As described above, according to the present invention, a medium is transported to a predetermined reading position, and a carriage on which a medium mark sensor is mounted is moved in one direction. The carriage is moved in the direction opposite to the one direction when the change is made to nothing, and the gain is set when the carriage is moved by the predetermined distance in the opposite direction. As described above, in the present invention, after the medium is conveyed to the predetermined reading position, the edge of the medium is detected only by moving the carriage on which the medium mark sensor is mounted, and the gain is set only by moving the carriage in the reverse direction. Since the position is established, it is possible to reliably detect the medium edge position and move to the gain setting position without any fluctuation in the transport speed due to slipping of the medium. As a result, the gain setting can be performed stably, and the medium mark reading can be performed stably. Further, since only one medium mark sensor mounted on the carriage is required for sensors for detecting the medium edge position and reading the medium mark, the mechanical configuration is further simplified, and the manufacturing cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining a medium mark reading method according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a horizontal dot printer to which the present invention is applied.

FIG. 3 is a diagram illustrating a relationship between a carriage position and a medium position after medium conveyance.

FIG. 4 is a diagram illustrating a print position of a medium mark printed on a medium.

FIG. 5 is a configuration diagram of a conventional medium mark reading device. 2 Medium Guide 3 Medium 4 Medium Transport Path 5 Medium Transport Roller 6 Print Head 7 Carriage 8 Carriage Shaft 11 Medium Mark Sensor 13 Carriage Position Detection Circuit 16 Carriage Drive Circuit 17 Medium Transport Roller Drive Circuit 18 CPU 19 Medium Mark Read Circuit

Claims (1)

(57) [Claims] In a medium mark reading method for reading a mark-free portion of a medium to determine an output level of an amplifier and reading a mark on the medium, the medium is conveyed to a predetermined reading position. Is moved in one direction, and when the state of the medium mark sensor changes from medium presence to medium absence, the carriage is moved in the opposite direction to the one direction, and the movement is completed by the predetermined distance in the opposite direction. A medium mark reading method, wherein a gain setting is performed when the medium mark is read.