JP2012190169A - Optical reading device, control method for optical reading device, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively prevent data from being newly written in an area in which data that has not been completely read is written.SOLUTION: A control unit 40 controls movement of a write pointer using a destructive pointer following a read pointer so that the write pointer does not pass the destructive pointer toward a predetermined direction side, and also controls movement of the destructive pointer so that it does not pass, toward the predetermined direction side, the position of a line in which line data containing data that has not been completely read is written regardless of the position of the read pointer.

Description

  The present invention relates to an optical reader that optically reads a medium to be read, a control method for the optical reader, and a program for controlling the optical reader.

2. Description of the Related Art Conventionally, an optical reading apparatus that optically reads a medium to be read and writes reading results in a ring buffer sequentially is known (for example, see Patent Document 1).
In this type of optical reading apparatus, data written in the ring buffer is generally read sequentially.

JP 2004-94735 A

However, in the case where the reading result is written in the ring buffer as in the optical reading device described above, it is necessary to prevent new data from being written to the area where the data that has not yet been read is written. There is.
The present invention has been made in view of the above-described circumstances, and in an optical reading apparatus that writes a reading result in a ring buffer, new data is written in an area where data that has not been read is written. The purpose is to effectively prevent the occurrence of the problem.

In order to achieve the above object, the present invention provides an optical reader, an optical reader that optically reads a medium and includes optical elements arranged in a line, a storage, and a storage of the storage A ring buffer formed in a region, and a control unit that cyclically writes the read data read in line units by the optical reading unit to the ring buffer and reads the read data of a predetermined region in the ring buffer. The control unit writes the read data by a write pointer that indicates the position of the line that writes the read data to the ring buffer, and a read pointer that indicates the position of the line that includes the read data to be read; and Manage the line to be read, and erase in the ring buffer Alternatively, the write pointer is controlled by a discard pointer indicating the position of the overwritable line so that the write pointer does not exceed the position of the discard pointer, and reading is completed regardless of the position of the read pointer. The discard pointer is controlled so as not to exceed the position of the line including the read data that has not been read.
According to this configuration, regardless of the position of the read pointer, the movement of the discard pointer is controlled so as not to exceed the position of the line including the read data that has not been read, and the write pointer is the discard pointer. Since the movement is controlled so as not to exceed the position of the read data, when the read data is overwritten on the line including the read data that has not been read, new data is written or the line Can be effectively prevented from being erased.
Here, in the ring buffer, it is efficient to read only useful read data and handle only a predetermined area containing useful read data. In this case, when there is a predetermined area containing a plurality of useful read data on the same line, the read pointer advances once after reading one area. There is a risk of writing in a predetermined area that has not yet been read. There is such a problem in the management of only the write pointer and the read pointer. Therefore, the position of the erasable or overwritable line is determined by reading all the predetermined areas of the corresponding line so that the position of the line including the predetermined area that has not been read is not exceeded by the discard pointer. Manage as shown. If the line pointer does not exceed the position of the discard pointer, writing to a predetermined area that has not yet been read will not occur. Further, it is understood that the write pointer can be advanced to the position of the discard pointer, and an efficient reading operation is also possible.

Further, in the optical reading apparatus according to the invention described above, the control unit may read the read data in such a manner that when the predetermined area is plural, the read data is read for each area. When one line includes the read data belonging to each of the plurality of predetermined areas, until the reading of the read data belonging to each area is completed, Regardless of the position, the discard pointer does not exceed the position of the one line.
According to this configuration, when reading data belonging to a plurality of areas in the ring buffer is read for each area, even if the read data belonging to each of a plurality of different areas is included in one line, Before the reading of all the included read data is completed, it is possible to effectively prevent new read data from being written to the one line.

Further, in the optical reading device according to the invention described above, the control unit is configured to transfer the ring buffer to each line belonging to one block for each block formed by dividing the ring buffer into a plurality of lines. After writing of the read data is completed, the read data of the line belonging to the block is read while moving the position of the read pointer within the block, and a plurality of predetermined areas are read in one block. The discard pointer does not exceed the position of the line including the read data that has not been read out of the lines belonging to the one block regardless of the position of the read pointer. It is characterized by controlling.
According to this configuration, the reading process is efficiently performed by reading the read data in units of blocks, and the read is not completed even when there are a plurality of predetermined areas in the block. The movement of the discard pointer is controlled so as not to exceed the line including the read data, and it is possible to effectively prevent new read data from being written to the line.

In order to achieve the above object, the present invention includes an optical reading unit that optically reads a medium and includes optical elements arranged in a line, and a ring buffer formed in a storage area of the storage unit. A method for controlling an optical reading apparatus, comprising: a write pointer indicating a position of the line for writing read data read by the optical reading unit to the ring buffer; and a position of the line including the read data to be read. The read data is written and read by the read pointer, and the lines to be read are managed, and the read data read in line units by the optical reading unit is cyclically written in the ring buffer. The read data of a predetermined area in the buffer is read, and the ring buffer is further read. The write pointer is controlled so that the write pointer does not exceed the position of the discard pointer by the discard pointer indicating the position of the erasable or overwritable line in the key, and regardless of the position of the read pointer, The discard pointer is controlled so as not to exceed the position of the line including the read data that has not been read.
According to this control method, regardless of the position of the read pointer, the movement of the discard pointer is controlled so as not to exceed the position of the line including the read data that has not been read, and the write pointer is Since the movement is controlled so as not to exceed the position of the pointer, when the read data is overwritten on the line including the read data that has not been read, new data is written or It is possible to effectively prevent the read data included in the line from being erased.

In order to achieve the above object, the present invention provides an optical reading unit that optically reads a medium and includes optical elements arranged in a line, a ring buffer formed in a storage area of the storage unit, A light pointer indicating the position of the line for writing the read data read by the optical reading unit to the ring buffer; The reading that is read and read in units of lines by the optical reading unit after the lines to be read and written are managed by a read pointer indicating the position of the line including the read data to be read. Data is cyclically written in the ring buffer, and a predetermined area in the ring buffer The read pointer is read, and the write pointer is controlled by a discard pointer indicating the position of the line that can be erased or overwritten in the ring buffer so that the write pointer does not exceed the position of the discard pointer. Regardless of the position of the read pointer, it functions as means for controlling the discard pointer so as not to exceed the position of the line including the read data that has not been read.
When this program is executed, the movement of the discard pointer is controlled so that it does not exceed the position of the line containing the read data that has not been read, regardless of the position of the read pointer, and the write pointer is Since the movement is controlled so as not to exceed the position of the pointer, when the read data is overwritten on the line including the read data that has not been read, new data is written or It is possible to effectively prevent the read data included in the line from being erased.

  According to the present invention, it is possible to effectively prevent new data from being written to an area where data that has not been read is written.

1 is an external perspective view of a dot impact printer according to an embodiment. FIG. 2 is a perspective view showing a printer body. FIG. 3 is a side sectional view of the printer body. It is a block diagram which shows the functional structure of a dot impact printer. It is a figure which shows an image buffer typically. It is a figure which shows an image buffer typically, in order to demonstrate a block. The figure which shows an image buffer typically in order to demonstrate area scanning. The figure which shows an image buffer typically in order to demonstrate a discard pointer. It is a figure which shows typically the image buffer at the time of an area scan. It is a figure which shows typically the image buffer at the time of an area scan.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a front perspective view showing an external appearance of a dot impact printer 10 (optical reading device) according to the present embodiment. FIG. 2 is an external perspective view showing the printer main body 11. FIG. 3 is a side sectional view showing the dot impact printer 10 of FIG.
The dot impact printer 10 shown in FIG. 1 presses a plurality of recording wires provided in the recording head 18 (see FIG. 3) against the recording medium S via an ink ribbon (not shown) fed out from a ribbon cartridge (not shown). By forming dots on the recording surface of the recording medium S, an image including characters is recorded. The dot impact printer 10 includes an optical reading device 110 (see FIG. 3), functions as an optical reading device, and can optically read characters, symbols, images, and the like displayed on the surface of the recording medium S.

  Examples of the recording medium S (medium) that can be used in the dot impact printer 10 include a cut medium cut to a predetermined length and a continuous sheet in which a plurality of sheets are connected. Examples of the cut medium include cut paper, cut copy paper, and the like, as well as passbooks, postcards, envelopes, etc. The continuous paper includes continuous copy paper and fanfold paper connected by perforations. In this embodiment, a check or bill issued by a financial institution or the like (hereinafter collectively referred to as a check) or a passbook issued by a financial institution or the like is used as the recording medium S. A check is a single-cut sheet in which MICR (Magnetic Ink Character Recognition) information such as a user's account number and a serial number of the check is printed on a partial area MA of the surface by magnetic ink. The passbook is in the form of a booklet in which a plurality of recording papers are bound, and the inner side of the booklet is the recording surface. A magnetic stripe is provided at the rear of the surface corresponding to the back cover of the passbook.

As shown in FIG. 1, the dot impact printer 10 includes an upper cover 12, an upper case 13, and a lower case 14 as exterior bodies, and a recording medium S is inserted and discharged on the front surfaces of the upper case 13 and the lower case 14. A manual feed opening 15 is opened. On the other hand, a discharge port 20 for discharging the recording medium S is opened on the back surface of the upper case 13 and the lower case 14. Whether the recording medium S processed by the dot impact printer 10 is discharged from the manual feed port 15 or the discharge port 20 is set by a command transmitted to the dot impact printer 10 from the host computer 200 described later. it can. The side where the manual feed port 15 is opened, that is, the left side in FIG. 3 is the front (front) side, and the side where the discharge port 20 is opened, ie, the right side in FIG. 3 is the rear (rear) side.
As shown in FIG. 2, the dot impact printer 10 includes a printer main body 11 covered with the above-described exterior body. The printer main body 11 includes a lower main body portion 11A and an upper main body portion (not shown) supported by a shaft 11C at the rear end portion of the lower main body portion 11A. The upper main body can be rotated by operating an open / close lever (not shown) installed on the left side surface of the upper main body. When the upper main body is rotated, the inside of the printer main body 11 is exposed.

As shown in FIGS. 2 and 3, the printer main body 11 includes a base frame 16 and a pair of right side frame 17 </ b> A and left side frame 17 </ b> B fixed to both ends of the base frame 16. Outside the both side frames 17A and 17B, there are both side frames (not shown) of the upper main body, and a carriage guide shaft 31 is bridged between them, and a flat surface shape front is formed between the side frames 17A and 17B. A medium guide 24 and a rear medium guide 25 are fixedly provided. A planar platen 21 is disposed between the front medium guide 24 and the rear medium guide 25, and the recording head 18 is disposed above the platen 21 so as to face the platen 21.
The recording head 18 is mounted on a carriage 19 that is slidably inserted into the carriage guide shaft 31. The carriage 19 is driven via a timing belt (not shown) by a forward or reverse rotation of a carriage drive motor 56 (FIG. 4) that drives the carriage 19, and is guided and reciprocated by a carriage guide shaft 31. The carriage 19 is reciprocally scanned between both side frames of the upper main body in the main scanning direction that coincides with the direction indicated by reference numeral C in FIG. 1, that is, the axial direction of the carriage guide shaft 31 and the longitudinal direction of the platen 21. A direction orthogonal to the main scanning direction C of the carriage 19, that is, a direction indicated by a symbol D in FIG.

  While the recording head 18 mounted on the carriage 19 travels with the carriage 19, the recording wire is projected from a wire projecting portion (not shown) facing the platen 21 at the front end surface of the recording head 18 and hits the ink ribbon. The ink of the ink ribbon is attached to the recording medium S conveyed between the recording head 21 and the recording head 18 to record an image including characters on the recording medium S. The ink ribbon is folded and stored in a ribbon cartridge (not shown) mounted on the main body frame or the carriage 19 and is fed out as the carriage 19 is scanned. Further, as shown in FIG. 3, a medium width sensor 55 is disposed on the rear side of the recording head 18 so as to be positioned above the platen 21. The medium width sensor 55 is mounted on the carriage 19 and scanned on the platen 21 together with the carriage 19, and is used to obtain the position of the side edge of the recording medium S and the width of the recording medium S.

  2 and 3, the platen 21 extends in the traveling direction of the carriage 19 and is formed in a planar shape. The platen 21 is urged toward the recording head 18 by an urging spring 180 and is elastically supported. Yes. The urging spring 180 is a compression coil spring, and the urging force of the urging spring 180 supports the output of the recording wire during the recording operation of the recording head 18. Further, the platen 21 is provided with the biasing spring 180 when the thickness of the recording medium S changes during conveyance of the recording medium S or when the recording medium S having a different thickness is loaded into the printer main body 11. The head is pressed by the tip of the recording head 18 against the force and moves away from the recording head 18. Accordingly, a constant gap is ensured between the tip of the recording head 18 and the recording surface of the recording medium S regardless of the thickness of the recording medium S.

  As shown in FIG. 3, the printer main body 11 has a medium conveying mechanism (conveying unit) 100 that conveys the recording medium S and the leading end of the recording medium S that is conveyed by the medium conveying mechanism 100 abutted against the recording medium An alignment mechanism 28 for aligning S; and a magnetic data reading unit 29 including a magnetic head 34 for reading MICR information provided on a check and reading or writing magnetic information on a magnetic stripe provided on a passbook; The magnetic head 34 of the magnetic data reading unit 29 has a medium pressing unit 30 that presses the recording medium S from above in order to suppress the floating of the recording medium S when performing magnetic information processing including reading of MICR information. is doing.

As shown in FIGS. 2 and 3, the medium transport mechanism 100 includes a platen 21, a first driving roller 22A, a first driven roller 22B, a second driving roller 23A, a second driven roller 23B, a third driving roller 124A, 3 a driven roller 124B, a front medium guide 24, a rear medium guide 25, a medium transport motor 26, and a drive wheel train 27. The medium transport mechanism 100 configures a transport path P that transports the recording medium S via each roller on the front medium guide 24 and the rear medium guide 25, and the upper surfaces of the front medium guide 24 and the rear medium guide 25 are transport paths. This is the P transport surface PA.
In this configuration, the first drive roller 22A and the first driven roller 22B are arranged on the front side of the printer body 11 with respect to the platen 21 and the recording head 18, and the second drive roller 23A, the second driven roller 23B, and the third The driving roller 124 </ b> A and the third driven roller 124 </ b> B are sequentially arranged on the rear side of the printer main body 11 with respect to the platen 21 and the recording head 18.

The first driving roller 22A and the first driven roller 22B are arranged in a vertical direction to make a pair, and the second driving roller 23A and the second driven roller 23B are arranged in a vertical direction to make a pair, a third The driving roller 124A and the third driven roller 124B are arranged in the vertical direction to make a pair.
The first driving roller 22A, the second driving roller 23A, and the third driving roller 124A are driving rollers that are rotationally driven by the medium transport motor 26 and the driving wheel train 27, and are a first driven roller 22B and a second driven roller 23B. And the third driven roller 124B are respectively driven by the springs 42A, 42B, and 42C with a predetermined pressing force toward the first drive roller 22A, the second drive roller 23A, and the third drive roller 124A. It is. Accordingly, the first driving roller 22A and the first driven roller 22B are rotationally driven in opposite directions, the second driving roller 23A and the second driven roller 23B are rotationally driven in opposite directions, and the third driving roller 124A. And the third driven roller 124B are rotationally driven in directions opposite to each other.

  As shown in FIG. 2, the drive wheel train 27 is disposed outside the right side frame 17A. The drive wheel train 27 includes a motor pinion 51 that is rotatably and integrally fixed to a drive shaft of a medium transport motor 26 that can rotate forward or reverse. The driving force from the motor pinion 51 is transmitted to the second driving gear 53B attached to the second roller shaft 33 of the second driving roller 23A via the reduction gear 52, and further from the second driving gear 53B to the middle. It is transmitted to the first drive gear 53A attached to the first roller shaft 32 of the first drive roller 22A via the gear 54. Further, the rotational force of the second roller shaft 33 of the second drive roller 23A is transmitted to the third roller shaft 134 of the third drive roller 124A by, for example, a drive belt (not shown). Accordingly, the first drive roller 22A, the second drive roller 23A, and the third drive roller 124A shown in FIG. 3 rotate in the same direction, and the recording medium S can be conveyed into the printer main body 11. That is, the first driving roller 22A, the second driving roller 23A, and the third driving roller 124A illustrated in FIG. 3 are denoted by F in the drawing along the sub-scanning direction when the medium transport motor 26 is rotating forward. When the recording medium S is transported into the printer main body 11 and the medium transport motor 26 is reversely rotated, the recording medium S is transported in the direction of ejection from the printer main body 11 as indicated by reference numeral R in the figure. To do.

  The alignment mechanism 28 aligns the recording medium S before recording on the recording medium S by the recording head 18 or reading the surface of the recording medium S by the optical reading device 110. The alignment mechanism 28 is provided between the first driving roller 22A and the first driven roller 22B, the recording head 18 and the platen 21 in the main scanning direction, and a plurality of alignment plates 38 protruding into the conveyance path P. An alignment motor 58 (FIG. 4) for driving the alignment plate 38 is provided, and the recording medium S can be aligned and aligned by abutting the leading end portion of the recording medium S against the alignment plate 38.

As shown in FIG. 2, the printer main body 11 includes a plurality of alignment sensors 39 that detect the presence or absence of the recording medium S abutted against the alignment plates 38 in the vicinity of the upstream side of the alignment plates 38 in the conveyance path P. The alignment sensor 39 is a light transmission type sensor that includes a light emitting unit (such as an LED) and a light receiving unit (such as a phototransistor) that face each other across the transport path P, and is aligned in the main scanning direction. Based on the number and arrangement of the sensors that detect the leading edge of the recording medium S among the plurality of alignment sensors 39, it is possible to determine whether the inclination of the recording medium S after the alignment by the alignment mechanism 28 with respect to the transport direction is within an allowable range.
Further, the dot impact printer 10 includes the drive control of the medium transport motor 26, the traveling control of the carriage 19, the control of the recording operation by the recording wire of the recording head 18, the control of the reading operation of the optical reader 110, etc. As a control unit for controlling the whole, for example, a control board unit (not shown) is provided below the rear side of the printer body 11.

  In the printer main body 11, a plurality of medium edge sensors 47 that detect insertion of the recording medium S into the conveyance path P are arranged in parallel on the front side of the first drive roller 22 </ b> A. These medium edge sensors 47 are light reflecting sensors each having a light emitting unit that emits light toward the conveyance path P and a light receiving unit that detects the reflected light, and the recording medium S inserted from the manual feed port 15. Is detected. The medium edge sensor 47 may be a light transmission type sensor in which a light emitting unit and a light receiving unit are arranged so as to face each other with the conveyance path P interposed therebetween. In this configuration, the recording medium S is inserted into the conveyance path P when the light receiving portions of all the medium edge sensors 47 are blocked by any one of the medium edge sensors 47 from the received light state. To be judged.

Further, as shown in FIG. 3, the printer main body 11 includes an optical reading device 110 (optical reading unit) that reads characters, symbols, images, or the like displayed on the surface of the recording medium S. The optical reading device 110 is disposed opposite to the first scanner 111 (reading unit) that reads information displayed on the upper surface side of the recording medium S by printing or the like, and the lower surface of the recording medium S. And a second scanner 112 (reading unit) that reads information displayed by printing or the like on the side. Usually, the recording medium S is inserted from the manual feed slot 15 so that the surface on which the MICR information is printed is the lower surface.
The first scanner 111 and the second scanner 112 are optical image sensors that are arranged between the second drive roller 23A and the third drive roller 124A, and continuously read information on the recording medium S being conveyed on the conveyance path P. is there.

The first scanner 111 and the second scanner 112 are, for example, CIS (Contact Image Sensor) type image reading sensors, and hold flat cover glasses 140 and 150 that are in close contact with the recording medium S, and these cover glasses 140 and 150. Main body cases 141 and 151 respectively. Inside the main body cases 141 and 151, an irradiation unit (not shown) for irradiating light output from a light source such as an LED to a reading area of the recording medium S and a main scanning direction (C direction) in a line. A plurality of light receiving sensors (not shown) arranged and an output part (not shown) for outputting a signal from the light receiving sensor to the control board part are accommodated. The first scanner 111 and the second scanner 112 are not limited to those having a CIS, but may be those having a CCD (Charge Coupled Device).
As shown in FIG. 2, the second scanner 112 includes a main body case 151 and a cover glass 150 that extend in the width direction of the dot impact printer 10 substantially in parallel with the platen 21 and have a longitudinal shape. 151 is arranged such that the upper surface (glass surface) of the cover glass 150 is exposed to the transport path P through an opening formed in the rear medium guide 25. As shown in FIG. 3, the first scanner 111 is provided above the second scanner 112 so that the lower surface (glass surface) of the cover glass 140 faces the upper surface of the cover glass 150. The two scanners 112 are formed in a longitudinal shape substantially the same length.

  A biasing member 113 is provided above the first scanner 111, and the first scanner 111 is biased by the biasing member 113 so as to be close to the recording medium S of the rear medium guide 25. Further, the urging member 113 presses the first scanner 111 against the second scanner 112 side with a substantially uniform force in the width direction. Here, as the urging member 113, a coil spring, a leaf spring, an elastomer cushion member, or the like can be used. Between the glass surfaces of the cover glasses 140 and 150, an interval is provided so that a recording medium having a predetermined thickness can enter. When the recording medium S is read, the first scanner 111 is read by the conveyed recording medium S. Is pushed upward and the biasing member 113 is contracted, so that the recording medium S can pass between the cover glasses 140 and 150. That is, in the optical reading device 110, the recording medium S and the glass surfaces of the cover glasses 140 and 150 are pressed by pressing the recording medium S against the second scanner 112 side by the first scanner 111 urged by the urging member 113. It is firmly attached to improve reading quality.

The light receiving sensors (not shown) of the first scanner 111 and the second scanner 112 are arranged in a line in the main scanning direction of the dot impact printer 10 and read in a line extending in the main scanning direction. That is, the first scanner 111 and the second scanner 112 which are optical reading units have optical elements arranged in a line. The light receiving sensors of the first scanner 111 and the second scanner 112 are arranged in a wider range than the printable range of the recording head 18 in the main scanning direction, and are larger than all the recording media that the dot impact printer 10 can print. Reading is possible with a wide width. That is, the optical reading device 110 can read the entire surface of all the recording media S used in the dot impact printer 10.
As shown in FIG. 3, the first scanner 111 and the second scanner 112 are arranged to face each other with the conveyance path P interposed therebetween. However, the linear light receiving sensor provided in the first scanner 111 and the second scanner are provided. The line-shaped light receiving sensor included in 112 is offset by about 5 mm in the conveyance direction of the recording medium S. With this configuration, it is possible to eliminate the influence of light from each other's light source on the other light receiving sensor, and higher reading quality can be obtained.

  The first scanner 111 and the second scanner 112 include R, G, and B light sources, respectively, and can read monochrome (binary, 16 gradations, 256 gradations) and full color. In addition, the reading resolution of the first scanner 111 and the second scanner 112 can be set in, for example, three stages of 200 dpi (dots / inch), 300 dpi, and 600 dpi. The number of reading lines in the conveyance direction (sub-scanning direction) of the recording medium S is set according to the reading resolution in the main scanning direction, and the conveyance speed of the recording medium S at the time of reading is the processing of the reading resolution and the detection value of the light receiving sensor. It is adjusted according to specifications such as speed.

FIG. 4 is a block diagram showing the configuration of the control system of the dot impact printer 10.
Each unit shown in FIG. 4 is realized by cooperation of hardware and software mounted on a control board (not shown).
The dot impact printer 10 includes a CPU and other peripheral circuits. The control unit 40 controls the entire dot impact printer 10 based on a control program, and the control program and data read from the EEPROM 42 by the control unit 40. When transmitting / receiving information to / from the RAM 41 (storage unit) that temporarily stores, the EEPROM 42 that stores control programs executed by the control unit 40, data to be processed, and the host computer 200 that controls the dot impact printer 10 Interface (I / F) 43 for converting the data format, gate array (G / A) 45 connected to various sensors, motor driver 46 for driving various motors, and head driver 48 for driving the heads These parts are bus 4 It is connected via a.
In the RAM 41, an image buffer 60 in which read image data read by the optical reading device 110 is written is formed. Although details will be described later, the image buffer 60 is a ring buffer in which data is cyclically written in accordance with a predetermined procedure, and the control unit 40 reads the read image data written in the image buffer 60. To the host computer 200.

An alignment sensor 39, a medium edge sensor 47, a medium width sensor 55, a first scanner 111, and a second scanner 112 are connected to the gate array 45. The gate array 45 quantizes the analog voltage input from the alignment sensor 39, the medium edge sensor 47, and the medium width sensor 55 to generate digital data, and outputs the digital data to the control unit 40.
The first scanner 111 and the second scanner 112 optically read the surface of the recording medium S by CIS, and supply the detection voltage of CIS to the gate array 45 for each pixel of the CIS. The analog voltage supplied from the second scanner 112 is quantized and output to the control unit 40 as digital data. The control unit 40 develops the read image data in the image buffer 60 based on the acquired digital data in accordance with a predetermined procedure described later.
The motor driver 46 is connected to the medium transport motor 26, the carriage drive motor 56, the magnetic head drive motor 57, and the alignment motor 58, and supplies these motors with drive currents and drive pulses to operate these motors. The motor driver 46 may be connected to an alignment motor 58 (FIG. 4) for operating the alignment plate 38 (FIG. 3).
The medium edge sensor 47 is connected to the recording head 18 and the magnetic head 34 and supplies a driving current to the recording head 18 to cause the recording wire to protrude, while the magnetic head 34 drives for reading / writing. When outputting current and reading magnetic data, the detection voltage (analog voltage) of the magnetic head 34 is detected and output to the control unit 40 as digital data.

  Based on a control program stored in the EEPROM 42, the control unit 40 acquires detection states of various sensors via the gate array 45, the motor driver 46, and the head driver 48, and drives each motor to record the recording medium S. The recording is performed on the recording medium S by conveying and driving each head.

  Next, the operation when the read image data is written in the image buffer 60 and the written read image data is sequentially read will be described in detail.

FIG. 5 is a diagram schematically showing the state of the image buffer 60 formed in the RAM 41 when reading the recording medium S, which is a cut sheet of a predetermined size, with a predetermined reading resolution (for example, 600 dpi). FIG. 5A shows a first image buffer 60a that is an image buffer 60 into which read image data is written based on a read result of the first scanner 111, and FIG. 5B shows a read result of the second scanner 112. 2 shows a second image buffer 60b, which is an image buffer 60 into which read image data is written.
As shown in FIG. 5, in the present embodiment, two buffers are formed in the RAM 41, and the read image data is written into the first image buffer 60a, which is one of the buffers, based on the read result of the first scanner 111. In addition, the read image data is written to the second image buffer 60b, which is the other buffer, based on the reading result of the second scanner 112.
In the following description, the configuration of the image buffer 60 and the mode of use of the image buffer 60 will be described using the first image buffer 60a. The second image buffer 60b is similar to the first image buffer 60a. The configuration is the same and the mode of use is the same.

The first image buffer 60a is a buffer in which the read image data is developed.
The read image data is bitmap format data. For each pixel arranged in a dot matrix at a pitch according to the read resolution on the data, RGB color components are converted into tone values (for example, RGB) for each pixel. Each color component of the system is held as a gradation value expressed in 0-256 levels, or a monochrome color component is expressed as a binary value). Hereinafter, for convenience of explanation, information held for each pixel may be simply expressed as “pixel”.
In the example of FIG. 5A, the first image buffer 60a can develop 8400 dots in a predetermined direction (arrow Y1) and 5100 dots in a line direction (arrow Y2) that is orthogonal to the predetermined direction. It has a configuration. The first image buffer 60a is formed by arranging a plurality (8400 lines) (line L1 to line L8400) extending in the line direction side by side in a predetermined direction. As shown in FIG. 5A, the predetermined direction is specifically a direction from the line L1 toward the line L8400.

In each line of the first image buffer 60a, line data (read data) is sequentially written in a predetermined direction for each line according to the reading result of the first scanner 111.
More specifically, as described above, the first scanner 111 includes a plurality of light receiving sensors arranged in a line in the main scanning direction (C direction in FIG. 1), and reads the upper surface of the recording medium S. As the recording medium S is transported, the upper surface of the recording medium S is intermittently read in the scanning direction (the direction opposite to the transport direction) by a row of light receiving sensors. At that time, for each reading of the light receiving sensor in one row, based on the output value of the light receiving sensor in one row, from a pixel of 5100 dots extending in the direction corresponding to the main scanning direction (C direction) (information on the color for each pixel). Are sequentially generated.
In the first image buffer 60a, the line direction (arrow Y2) is a direction corresponding to the main scanning direction (C direction), and the predetermined direction (arrow Y1) is a direction corresponding to the scanning direction. The line data generated as described above is sequentially written in a predetermined direction for each line. More specifically, the line data generated based on the first reading result of the light receiving sensor in one row is written to the line L1, and the line data generated based on the reading result of the light receiving sensor in the next row is The line data is sequentially written in a predetermined direction for each line.
Here, the first image buffer 60a is a ring buffer, and writing of line data is performed cyclically in a predetermined direction. More specifically, when line data is written to the line L8400, next, line data is written to the line L1. In this case, line data is already written in the line L1, but is overwritten by new line data.

In the present embodiment, the control unit 40 manages lines to be written and read with line data by using the write pointer PW and the read pointer PR.
More specifically, the write pointer PW is a pointer indicating a line in which line data is written. The pointer may be information holding a value indicating a specific line. For example, the pointer may be a variable defined on a program for managing the pointer, and can be rewritten to a predetermined area of the RAM 41. May be stored in the data. The same applies to the read pointer PR and the discard pointer PH described later.
When writing the generated line data to the line of the first image buffer 60a, the control unit 40 writes the line data to the line indicated by the write pointer PW, and after the writing of the line data is completed, the write pointer PW The indicated line is moved to the predetermined direction side by one.

In the following description, moving the line indicated by the pointer to the predetermined direction side may be simply expressed as “moving the pointer in the predetermined direction”.
In the following description, the “pointer position” is a line indicated by the pointer.

The read pointer PR is a pointer indicating a line from which line data is read.
When reading the line data written in the first image buffer 60a, the control unit 40 reads the line data written in the line indicated by the read pointer PR, and after the reading of the line data is finished, the read pointer is read out. One line indicated by PR is moved to the predetermined direction side. The control unit 40 transfers the read line data to the host computer 200 via the interface 43 according to a predetermined procedure described later.
The read pointer PR basically moves following the movement of the write pointer PW. As a result, the line data written in the first image buffer 60 a is read in the order of writing and transferred to the host computer 200.

  In the present embodiment, line data is read and transferred in units of blocks.

FIG. 6 is a diagram for explaining blocks, and is a diagram schematically showing a state of the first image buffer 60a divided for each block.
As shown in FIG. 6, in this embodiment, the first image buffer 60a is divided into a plurality of lines to form n blocks (blocks B1 to Bn). The number of lines constituting one block is specified to a value suitable for the transfer of line data in consideration of the communication speed between the dot impact printer 10 and the host computer 200 within a range not exceeding 500. The
In the present embodiment, line data is transferred in units of blocks formed as described above.
More specifically, referring to FIG. 6, when the first scanner 111 reads an image on the upper surface of the recording medium S, line data is sequentially written line by line from the line L1 in a predetermined direction. Is done. In this case, the reading of the line data is not executed until the writing of the line data to the K1 lines constituting the block B1 to which the line L1 belongs, and therefore the read pointer PR indicates the line L1. State is maintained.
When the writing of the line data proceeds and the writing of the line data to all K1 lines constituting the block B1 is completed, the control unit 40 reads the line data for each of the lines constituting the block B1. Are sequentially executed in a predetermined direction. Then, after the reading of the line data of all the lines constituting the block B1 is completed, the control unit 40 transfers all of the read line data to the host computer 200 in accordance with a predetermined protocol. Note that when the reading of the line data of all the lines constituting the block B1 is completed, the read pointer PR is in a state indicating the head line of the block B2.
After the transfer of the line data of the lines constituting the block B1 is completed, the control unit 40 similarly transfers the line data for the block B2. That is, until the writing of line data to all the lines constituting the block B2 is completed, reading of the line data written to the lines constituting the block B2 is stopped, and the lines to all the lines constituting the block B2 are stopped. After the data writing is completed, reading of the line data is started, and the read line data is comprehensively transferred to the host computer 200.
In this way, the control unit 40 executes line data transfer in units of blocks, whereby the line data has already been written and the size (number of lines) is defined in consideration of the transfer. Processing related to reading and transfer can be executed collectively on a group of areas (blocks) that have been read, and processing related to reading and transfer is made more efficient.

  Further, the dot impact printer 10 according to the present embodiment can execute an area scan in which only line data belonging to a predetermined area in the first image buffer 60a is read and transferred.

FIG. 7 is a diagram schematically showing the first image buffer 60a for explaining the area scan.
In FIG. 7, it is assumed that the first image buffer 60a is developed in a predetermined coordinate system, and pixels constituting the first image buffer 60a (= pixels constituting read image data developed in the first image buffer 60a). Among them, the pixel located at the top leftmost in the figure is set as the origin, and (0, 0) is given to the pixel as coordinates, and the direction from the origin toward the right in the figure is defined as the x-axis + direction. In addition, the direction from the origin to the lower direction in the figure is defined as the y-axis + direction, and (5100, 0) is assigned as a coordinate to the pixel arranged at the uppermost right in the figure, and the leftmost in the figure (0, 8400) is assigned as the coordinate to the pixel arranged at the bottom of (5100), and (5100, 8400) is assigned as the coordinate to the pixel arranged at the bottom right of the drawing. All the pixels constituting the first image buffer 60a are uniquely specified by coordinates indicating a relative position from the origin.
In the example of FIG. 7, in the area scan, for example, an area A1 defined by four points of P1 (1000, 4000), P2 (4000, 4000), P3 (1000, 8000), and P4 (4000, 8000). It is possible to read and transfer only line data included in (belongs to). In this case, of the images on the recording medium S, only the image data of the images belonging to the area A1 is finally transferred to the host computer 200.
In executing the area scan, the user designates a rectangular area on the upper surface of the recording medium S where the image is to be transferred using a predetermined user interface provided by the host computer 200. Based on this designation, the host computer 200 calculates the coordinates of the four points in the area corresponding to the designated area in the first image buffer 60a, and outputs the calculated coordinates to the control unit 40 of the dot impact printer 10. .

The operation during the area scan for the area A1 will be described in detail with reference to FIG. Note that, as illustrated in FIG. 7, the region A1 is a region straddling three blocks of the block B (i−1), the block Bi, and the block B (i + 1).
In the area scan, line data is written sequentially in a predetermined direction for each line, as in the case where the area scan is not performed. As the first scanner 111 reads the upper surface of the recording medium S, writing of the line data in a predetermined direction proceeds, and the block B (i−), which is a block immediately before the block B (i−1). It is assumed that the writing of line data to all lines constituting 2) is completed. In this case, the write pointer PW is in a state indicating the line La that is the first line of the block B (i−1).
On the other hand, the controller 40 does not move the read pointer PR because the line data to be read does not exist when the writing of the block B (i-2) is completed, and the read pointer PR indicates the line L1. Maintain the state.
After the writing of the line data to the block B (i-2) is completed, the writing of the line data in a predetermined direction further proceeds, and the writing to all the line data constituting the block B (i-1) is completed. And The area A1 extends in the block B (i-1). However, as described above, since the reading and transfer of line data are performed in units of blocks, the control unit 40 performs the block B (i The read pointer PR is not moved until the writing of the line data to all the line data constituting -1) is completed, and the state in which the read pointer PR indicates the line L1 is maintained.

When writing to all the line data constituting the block B (i-1) is completed, the control unit 40 moves the read pointer PR in a predetermined direction until reaching the line La. During this movement, line data is not read. Next, the control unit 40 includes a line in which line data to which the area A1 does not belong, specifically, a line interposed between the line La and the line Lb (including the line La and not including the line Lb). ), The line indicated by the read pointer PR is sequentially moved in a predetermined direction without reading the line data, and the line indicated by the read pointer PR is defined as a line Lb. The line Lb is line data including data belonging to the area A1, and is a line in which line data located closest to the predetermined direction in the block B (i-1) is written.
Next, the control unit 40 reads out the data belonging to the area A1 (the data in the area represented by the oblique lines in FIG. 7) among the line data written to the line Lb. Next, the control unit 40 moves the read pointer PR by one in a predetermined direction, and reads data belonging to the area A1 among the line data written in the line indicated by the read pointer PR. In this way, the control unit 40 sequentially reads out data belonging to the area A1 in a predetermined direction for each line for the block B (i-1).
In this way, in the block B (i−1), the movement of the read pointer PR in the predetermined direction and the reading of the data belonging to the area A1 are sequentially executed, and the line indicated by the read pointer PR is the head of the block Bi. When the line Lc is reached, the control unit 40 transfers the read data (= data belonging to the area A1 in the block B (i−1)) to the host computer 200.
For the block Bi and the block B (i + 1), the control unit 40 reads the data belonging to the area A1 and transfers the data in units of blocks in the same manner as the block B (i-1). . As a result, all data belonging to the area A1 is transferred to the host computer 200.
As described above, since the data belonging to the area A1 is read and transferred collectively in units of blocks, it is possible to realize the efficiency of processing related to the read and transfer.

As described above, the first image buffer 60a is a ring buffer, and the write pointer PW and the read pointer PR that follows the write pointer PW are the end lines of the first image buffer 60a (FIG. 5A). In this example, the line is moved to the head line (line L1 in the example of FIG. 5A) next to the line L8400).
In this case, there is a possibility that a situation occurs in which the movement of the write pointer PW in a predetermined direction advances and the read pointer PR exceeds the predetermined direction. In this case, line data is newly written to a line from which line data has not been read out, so it is necessary to prevent the above situation from occurring.
In order to prevent this, in this embodiment, in addition to the write pointer PW and the read pointer PR, a discard pointer PH is provided, and the control unit 40 uses the discard pointer PH to cause the write pointer PW to set the read pointer PR to a predetermined value. The position of the light pointer PW is managed so as not to exceed the direction side.

FIG. 8 is a diagram schematically showing the first image buffer 60a in order to explain the basic movement of the discard pointer PH.
In FIG. 8, the write pointer PW, the read pointer PR, and the discard pointer PH are schematically shown, and the line indicated by the tip of each pointer graphic is a line indicated by each pointer.
In the following description, for clarity of explanation, it is assumed that not all of the above-described area scan but all read image data developed in the first image buffer 60a is transferred, and that blocks are not considered. To do.
As shown in FIG. 8A, the discard pointer PH basically moves following the read pointer PR with the exception described later. In the present embodiment, the discard pointer PH basically maintains a state indicating a line located in a direction opposite to a predetermined direction (hereinafter simply referred to as “reverse direction”) for 10 lines from the line indicated by the read pointer PR. The read pointer PR is followed.
Further, the position of the write pointer PW is controlled so as not to exceed the discard pointer PH in the predetermined direction. As a result, the write pointer PW is prevented from exceeding the read pointer PR, and new line data is prevented from being written to a line in which line data that has not been read is written.
More specifically, it is assumed that the positional relationship among the write pointer PW, the read pointer PR, and the discard pointer PH is as shown in FIG. 8A. In FIG. 8A, the line data written in a line (a line included in the hatched area) interposed between the write pointer PW and the read pointer PR is read out even though the writing has been completed. This is line data that is not performed.
Then, it is assumed that the state moves from the state shown in FIG. 8 (A) to the state shown in FIG. 8 (B) as the movement of the light pointer PW proceeds in a predetermined direction. In this case, since the position of the write pointer PW is controlled so that it does not exceed the discard pointer PH toward the predetermined direction, the write pointer PW is a line that has been written but has not been read. It is possible to reliably prevent the area where the line in which the data is written exists (the area indicated by hatching in FIG. 8B).

  In the area scan described above, it is possible to read and transfer only data belonging to a plurality of different areas in the first image buffer 60a. In some cases, overlapping portions in the line direction exist for each of a plurality of different regions. In such a case, reading of data belonging to a plurality of different areas is executed as follows.

FIG. 9 is a diagram schematically showing the first image buffer 60a in order to explain processing when reading data belonging to each of the areas where the overlapping portions in the line direction exist.
In the example of FIG. 9, it is assumed that the area scan is performed for the area A2 and the area A3. In other words, it is assumed that only data belonging to the areas A2 and A3 is read and transferred. As shown in FIG. 9, the area A2 and the area A3 each have a portion overlapping in the line direction in the range Q1.
In such a case, the reading is executed individually for the area a2 that belongs to the block Bi in the area A2 and the area a3 that belongs to the block Bi among the areas A3.
In the following description, the control unit 40 determines the state (range) of the area a2 and the area a3 in the block Bi, the information about the block Bi, the area A2 input from the host computer 200, and the area A3. Detection is performed in advance based on the coordinates of each vertex and the movement of the read pointer PR is managed based on the detection result.
In detail, assuming that the writing of line data to all the lines constituting the block Bi has been completed, the control unit 40 first determines the data belonging to the area a2 for each line by the method described above. Read sequentially in the direction. In this case, the read pointer PR moves as indicated by the arrow Y4 and finally reaches the position T1. When reading of the data belonging to the area a <b> 2 is completed, the control unit 40 transfers the read data to the host computer 200. As described above, in this embodiment, when there are a plurality of different areas in the same block, the data is read and transferred for each area. Thus, data reading and transfer are performed for each area in a lump, thereby simplifying the processing related to reading and transfer and improving the processing efficiency associated therewith.
When the reading of the data belonging to the area a2 is completed, the control unit 40 moves the read pointer PR to the head position T2 of the area a3. Next, the control unit 40 sequentially reads data belonging to the region a3 in a predetermined direction for each line. In this case, the read pointer PR moves as indicated by an arrow Y5. Next, the control unit 40 outputs the data belonging to the read area a3 to the host computer 200.
As described above, the control unit 40 individually reads and transfers the data belonging to the area a2 and the data belonging to the area a3 to the host computer 200.

Here, when the discard pointer PH described above is moved in any case so as to maintain a state indicating a line located in the opposite direction by 10 lines from the line indicated by the read pointer PR, When area scan is executed for a plurality of areas where overlapping portions exist in the line direction as in the example 9 described above, the following problems may occur.
That is, when the reading of the data belonging to the area a2 is completed and the read pointer PR reaches the position T1, the discard pointer PH is accordingly moved to the position T3 which is a position on the reverse direction side by 10 lines. Suppose you move.
In this case, regarding the line belonging to the range Q2 between the position T2 and the position T3, data to be read and data that has not been read (data belonging to the region a3) remains. . Therefore, for the line belonging to the range Q2, new line data should not be written until the reading of the data belonging to the region a3 is completed. However, since the discard pointer PH is located at the position T3, the light pointer PW whose movement is controlled so as not to exceed the discard pointer PH in the predetermined direction reaches the position of the discard pointer PH. Along with this, there is a possibility that a new line data is written in the line belonging to the range Q2 when the reading is not completed.
Based on the above, in the above case, the control unit 40 controls the position of the discard pointer PH as follows.

That is, when the control unit 40 moves the discard pointer PH by one line in a predetermined direction, first, the line data written in the line to be moved is data to be read and the reading is not completed. Determine whether data is included. When the data is not included, the control unit 40 moves the discard pointer PH for one line, and when the data is included, stops the movement of the discard pointer PH. Then, the control unit 40 monitors whether or not all of the data that should be read out of the line data written in the line after the movement and that has not been read out has been read out. When all of the data has been read and the distance between the discard pointer PH and the read pointer PR in the predetermined direction exceeds 10 lines, the discard pointer PH moves in one direction in the predetermined direction. Execute.
For example, referring to FIG. 9, it is assumed that the discard pointer PH is located at a position T4 on the reverse direction side by one line from the position T2. Further, it is assumed that the data belonging to the area a2 has been read, but no data belonging to the area a3 has been read. Under such circumstances, it is assumed that the control unit 40 is about to move the discard pointer PH from the position T4 to the position T2 as the read pointer PR moves in a predetermined direction.
In this case, before the movement of the discard pointer PH to the position T2, the control unit 40 is data to be read out in the line data written in the line corresponding to the position T2, and the reading is not completed. Determine whether data is included. This determination may be performed based on the information indicating the data reading status, and for each line, the line data is the data to be read and the reading is completed. Whether or not data that is not included is included may be managed by a flag, and may be performed based on the state of the flag.
Since the line data written in the line corresponding to the position T2 includes data to be read and data that has not been read (data related to the region a3), the control unit 40 Stops moving the discard pointer PH to the position T2.
Next, the control unit 40 monitors whether or not the reading of data belonging to the region a3 included in the line data written in the line corresponding to the position T2 has been completed, in other words, the line corresponding to the position T2. In the written line data, it is monitored whether or not all of the data to be read and the data that has not been read has been read, and the reading of the data belonging to the area a3 is completed. If the distance in the predetermined direction between the discard pointer PH and the read pointer PR exceeds 10 lines, the discard pointer PH is moved from position T4 to position T3.

As described above, in the present embodiment, the control unit 40 performs control when the line data written to a certain line includes data to be read and data that has not been read. The unit 40 controls the movement of the discard pointer PH so that the discard pointer PH does not move beyond the one line in a predetermined direction regardless of the position of the read pointer PR.
This suitably prevents new line data from being written to a line that contains data to be read and data that has not been read.
Further, if the movement of the discard pointer PH is controlled as described above, when there are a plurality of different areas in the block, a range in which these areas do not overlap in the line direction (for example, a range Q3 in FIG. 9). For, the discard pointer PH is appropriately moved in a predetermined direction according to the reading status of the data to be read included in the line data. Unnecessarily, the movement of the discard pointer PH in the predetermined direction is restricted, Accordingly, it is possible to prevent an area where new line data can be written from being unnecessarily narrowed. More specifically, with reference to FIG. 9, in the range Q3, when the reading of the data related to the region a2 is completed, the reading of the data to be read out of the line data written in the line belonging to the range Q3 is completed. Therefore, the discard pointer PH may be moved in a predetermined direction. However, by controlling the movement of the discard pointer PH as described above, the range Q3 is read according to the reading of the data related to the area a2. Appropriately, the pointer PH moves in a predetermined direction.

  In the area scan described above, it is possible to read data belonging to an area that is spaced apart in a predetermined direction.

FIG. 10 is a diagram schematically showing the first image buffer 60a in order to explain reading of data belonging to an area that is spaced apart in a predetermined direction.
First, referring to FIG. 10 (A), a conventional process related to reading before the present invention is applied will be described.
In the example of FIG. 10A, an area scan is executed for the area A4 and the area A5 that is spaced apart from the area A4 in a predetermined direction.
As shown in FIG. 10A, the area A4 belongs to the first block B1 among the plurality of blocks formed in the first image buffer 60a, and the area A5 is the first image buffer 60a. Belong to block Bn which is the last block.
Conventionally, when the area A4 and the area A5 are defined as described above, line data for all the lines constituting the block B1 in accordance with the reading of the upper surface of the recording medium S of the first scanner 111. When the writing is completed, the control unit 40 reads and transfers data belonging to the area A4 as described above. At the time when reading and transfer of data belonging to the area A4 included in the block B1 is completed, the read pointer PR is located at a position T6 that is a position corresponding to the first line of the block B2.
Even after the writing of the line data to all the lines constituting the block B1 is completed, the writing of the line data is continuously executed, and the lines to all the lines constituting the block B2 to the block B (n-1) are performed. Assume that data writing is complete. In this case, since there is no data to be read out in the block B2 to the block B (n−1), the control unit 40 reads and transfers the data belonging to the area A4 included in the block B1 for the read pointer PR. Is maintained, that is, the state located at the position T6 corresponding to the first line of the block B2.

Furthermore, it is assumed that the writing of line data in a predetermined direction has progressed and the writing of line data to all the lines constituting the block Bn has been completed. With the completion of writing line data to the block Bn, that is, the block including the region A5 as a trigger, the control unit 40 starts moving the read pointer PR in a predetermined direction. In this case, since there is no data to be read for the lines constituting the blocks B2 to B (n-1), the read pointer PR is moved in a predetermined direction without actually reading the data. I do.
Then, after moving the read pointer PR to the first line of the block Bn, the control unit 40 performs data reading and transfer for the data belonging to the area A5 in the block Bn.

When the area scan is performed for different regions separated in a predetermined direction by such a conventional method, the following problems may occur.
That is, in the above case, since the completion of the writing of the line data to the block Bn is used as a trigger, the movement of the read pointer PR located at the position T6 in a predetermined direction is started. The distance between the pointer PH and the write pointer PW in the predetermined direction (the distance indicated by the arrow with the symbol D1 in FIG. 10A) appears close, and this causes the write by the discard pointer PH. Although the movement of the pointer PW is limited and line data to be newly written is generated, there is a possibility that the generated line data cannot be written to the first image buffer 60a.
Based on this, in the present embodiment, the control unit 40 controls the position of the read pointer PR as follows.

That is, the control unit 40 always monitors the number of lines between the write pointer PW and the read pointer PR.
When the number of lines between the write pointer PW and the read pointer PR exceeds a predetermined number of lines as a threshold value, reading is performed in the area defined by the write pointer PW and the read pointer PR. It is determined whether or not data to be present exists. When there is no data to be read, the control unit 40 sets the read pointer PR to a predetermined value without reading the line data for the line belonging to the area sandwiched between the write pointer PW and the read pointer PR. Execute dummy read processing to move in the direction.
Specifically, referring to FIG. 10B, in the state where the reading and transfer of the area A4 belonging to the block B1 is completed and the read pointer PR is located at the position T6, the control unit 40 performs the write operation. The number of lines between the pointer PW and the read pointer PR is monitored. Then, as shown in FIG. 10B, when the number of lines between the write pointer PW and the read pointer PR exceeds “1000” defined as the threshold value, the control unit 40 makes these write pointers PW. And the read pointer PR, it is determined whether or not there is data to be read in the range Q4. When there is no data to be read in the range Q4, the control unit 40 moves the read pointer PR in a predetermined direction for the lines belonging to the range Q4, while executing the dummy read process that does not read the line data. Execute.
As described above, the dummy read process is executed for the range Q4, so that the read pointer PR moves to the position T7 before the writing of the line data to all the lines constituting the block Bn is completed. Following the movement of the pointer PR, the discard pointer PH moves in a predetermined direction. Even after the read pointer PR is moved to the position T7, the number of lines between the write pointer PW and the read pointer PR exceeds the threshold value, and there is no data to be read in the range interposed between these pointers. In this case, a dummy read process is executed as appropriate, and the read pointer PR and the discard pointer PH are moved in a predetermined direction.

As described above, in the present embodiment, when the number of lines between the write pointer PW and the read pointer PR exceeds the threshold value and there is no data to be read out in the range interposed between these pointers, Dummy read processing is executed, and movement of the read pointer PR and the discard pointer PH in a predetermined direction is executed. Here, since the discard pointer PH is a pointer having a function as a stopper for restricting the movement of the write pointer PW, in the first image buffer 60a, the discard pointer PH moves in a predetermined direction accompanying the dummy read process. The area in which new line data can be written is expanded as compared with the conventional case, and the risk that the generated line data cannot be written to the first image buffer 60a can be reduced. In addition, even when area scanning is performed on different areas separated in a predetermined direction, it is difficult for the distance between the write pointer PW and the discard pointer PH to be close, and line data to be newly written is generated. However, it is possible to prevent as much as possible the situation that the generated line data cannot be written to the first image buffer 60a.
In the present embodiment, “1000” is set as the threshold value for the number of lines between the write pointer PW and the read pointer PR. This threshold value is set from the following viewpoints.
That is, as described above, in the present embodiment, the number of lines constituting one block does not exceed 500. The threshold value is a value (1000 lines) for two blocks having the maximum number of lines (500 lines). This is because the write pointer PW and the read pointer PR are related to the number of lines in a predetermined direction (8400 lines) in the entire first image buffer 60a when two blocks having the maximum number of lines (500 lines) are separated. This is because it can be said that the write pointer PW and the read pointer PR are separated from each other by a relatively large distance.

As described above, in the present embodiment, the control unit 40 exceeds the position of the line where the line data including the data that has not been read out is written to the predetermined direction side regardless of the position of the read pointer PR. The movement of the discard pointer PH is controlled so as not to occur.
According to this, regardless of the position of the read pointer PR, the discard pointer PH is moved so as not to exceed the position of the line where the line data including the data that has not been read out is written. Since the movement of the write pointer PW is controlled so as not to exceed the discard pointer PH in the predetermined direction, the write pointer PW is controlled with respect to a line in which line data including data that has not been read is written. Thus, new line data can be effectively prevented from being written.

In the present embodiment, the control unit 40 can read data in such a manner that data belonging to a plurality of different areas in the first image buffer 60a serving as a ring buffer is read for each area in the area scan. . When the data belonging to each of a plurality of different areas is included in one line data, the control unit 40 determines the position of the read pointer PR until the reading of the data belonging to each area is completed. Regardless, the discard pointer PH does not exceed the position of the line in which the one line data is written in the predetermined direction.
According to this, at the time of area scanning, when data belonging to a plurality of different areas in the first image buffer 60a as a ring buffer is read for each area, one line data includes data belonging to each of the plurality of different areas. Even when the data is written, it is possible to effectively prevent new line data from being written to the line in which the one line data is written before the reading of all the included data is completed. .

In this embodiment, the control unit 40 writes line data to each line belonging to one block for each block formed by dividing the first image buffer 60a serving as a ring buffer into a plurality of lines. After completion, when the read pointer PR is moved in the predetermined direction in the one block, the line data of the line belonging to the block is read in the predetermined direction, and different areas belong to the one block Regardless of the position of the read pointer PR, the line is discarded so that it does not exceed the position of the line in which line data including data that has not been read out is written in the predetermined direction. Controls the movement of the pointer PH.
According to this, when line data including data that has not been read is present in a block while realizing efficiency of read processing by executing line data read in block units, The movement of the discard pointer PH is controlled so as not to exceed the line in which the data is written in the predetermined direction, and it is possible to effectively prevent new line data from being written to the line.

In this embodiment, the control unit 40 writes line data to each line belonging to one block for each block formed by dividing the first image buffer 60a serving as a ring buffer into a plurality of lines. After completion, the read pointer PR is moved to a position indicating a line to be read in the one block, and the read pointer PR is moved in a predetermined direction in the one block, while the line data of the lines belonging to the block Is read in a predetermined direction, and a line that is interposed between the write pointer PW and the read pointer PR and in which line data that does not need to be read is written is written to the line. Without reading data, move the read pointer PR in the specified direction. Executing a dummy read process of moved.
According to this, for the line that is interposed between the write pointer PW and the read pointer PR and has line data that does not need to be read, the line data written to the line is read. Since the dummy read process for moving the read pointer PR in the predetermined direction is executed without the read pointer PR moving in the predetermined direction before the writing of the line data to all the lines belonging to the block is completed. Accordingly, reading is completed in the first image buffer 60a, and it is possible to secure a large area where new line data can be written.

Further, in the present embodiment, the control unit 40 is a case where the write pointer PW and the read pointer PR are spaced apart from each other by a threshold value in a predetermined direction, and the lines written in each of the lines interposed between these pointers. When the data is data that does not need to be read, dummy read processing is executed for the lines interposed between these pointers.
According to this, the write pointer PW and the read pointer PR are separated from each other by a threshold in a predetermined direction, and the line data written in each of the lines interposed between the pointers does not need to be read. In this case, since the dummy read process is executed for the line interposed between these pointers, the dummy read process is appropriately executed when necessary.

In the present embodiment, the control unit 40 can read line data in such a manner that line data belonging to a plurality of different areas in the first image buffer 60a is read for each area. One area in 60a and another area are separated in a predetermined direction, and reading is necessary between one block to which the one area belongs and another block to which the other area belongs. When there are intervening lines in which line data is written, dummy read processing is executed for these lines.
According to this, when there is no data that needs to be read for a line existing between one block to which one area belongs and another block to which another area belongs, dummy read processing is executed. Thus, the read pointer PR can be moved in a predetermined direction before the writing of line data to all the lines constituting the block to which the other area belongs is completed. In the first image buffer 60a, it is possible to secure a region where reading has been completed, in other words, a region where new line data can be written.

In the present embodiment, the control unit 40 controls the movement of the write pointer PW by the discard pointer PH that follows the read pointer PR so that the write pointer PW does not exceed the discard pointer PH in the predetermined direction.
According to this, as the read pointer PR moves in a predetermined direction by the dummy read process, the discard pointer PH that follows the read pointer PR also moves in the predetermined direction, and accordingly, a new line is newly generated. It is possible to secure a large area where data can be written.

Although one embodiment of the present invention has been described above, the present invention is not limited to this.
In the above embodiment, the control unit 40 mounted on a control board (not shown) mounted on the dot impact printer 10 is configured to manage each pointer. For example, the control unit 40 is externally connected to the dot impact printer 10. The apparatus may be configured to manage these pointers. In other words, each functional block shown in FIG. 4 is realized by the cooperation of hardware and software, and the specific hardware implementation form, software specifications, etc. are arbitrary. The details of the configuration can be arbitrarily changed.
In the above embodiment, the case where the present invention is applied to a flat bed type apparatus that horizontally conveys the recording medium S has been described as an example. However, the present invention is not limited to this, and forms such as checks. Of course, the present invention can be applied to an apparatus having a conveyance path for conveying the recording medium S in a standing state. In the above-described embodiment, the dot impact printer 10 including the optical reading device 110 has been described as an example. However, the present invention is not limited to this, and for example, an ink jet printer, a thermal printer, A laser printer or the like may be provided with an optical reading unit corresponding to the optical reading device 110. In addition to an apparatus used as an independent printer, an optical reading unit corresponding to the optical reading apparatus 110 is included in an apparatus incorporated in another apparatus (ATM (Automated Teller Machine), CD (Cash Dispenser, etc.)). It may be provided.
Furthermore, the present invention is not limited to a configuration in which the optical reading device 110 is provided integrally with a device that records characters and images on a recording medium such as paper, and the present invention is applicable to various devices including, for example, an independent scanner device and a copying machine. Is possible.
That is, the present invention can be widely applied to an optical reading apparatus capable of optically reading a medium.

  DESCRIPTION OF SYMBOLS 10 ... Dot impact printer (optical reader), 40 ... Control part, 41 ... RAM (memory | storage part), 60 ... Image buffer (ring buffer), 60a ... 1st image buffer (ring buffer), 60b ... 2nd image buffer (Ring buffer), 111 ... first scanner (reading unit), 112 ... second scanner (reading unit), 200 ... host computer, PH ... discard pointer, PR ... read pointer, PW ... write pointer, S ... recording medium ( Medium).

Claims (5)

An optical reading unit having optical elements arranged in a line so as to optically read a medium;
A storage unit;
A ring buffer formed in a storage area of the storage unit;
A controller that cyclically writes the read data read in line units by the optical reading unit to the ring buffer, and reads the read data of a predetermined area in the ring buffer, and
The controller is
The read data is written and read by the write pointer indicating the position of the line for writing the read data to the ring buffer and the read pointer indicating the position of the line including the read data to be read. Manage the line,
Further, the write pointer is controlled by the discard pointer indicating the position of the line that can be erased or overwritten in the ring buffer so that the write pointer does not exceed the position of the discard pointer, and the position of the read pointer is set. Regardless, the discard pointer is controlled so as not to exceed the position of the line including the read data that has not been read. The controller is
When there are a plurality of the predetermined areas, it is possible to read the read data in such a manner that each area is read.
When one line includes the read data belonging to each of the plurality of predetermined areas, the read data belonging to each area is not related to the position of the read pointer until the reading of the read data belonging to each area is completed. The optical reading apparatus according to claim 1, wherein the discard pointer does not exceed the position of the one line. The controller is
For each block formed by dividing the ring buffer into a plurality of lines, after the writing of the read data to each line belonging to one block is completed, the read pointer of Reading the read data of the line belonging to the block while moving the position,
When a plurality of predetermined areas belong to one block, regardless of the position of the read pointer, out of the lines belonging to the one block, the line including the read data that has not been read out. The optical reading apparatus according to claim 2, wherein the discard pointer is controlled so as not to exceed a position. A method for controlling an optical reading device comprising: an optical reading unit that optically reads a medium and having optical elements arranged in a line; and a ring buffer formed in a storage area of the storage unit,
Write of the read data by a write pointer indicating the position of the line for writing the read data read by the optical reading unit to the ring buffer, and a read pointer indicating the position of the line including the read data to be read; and The line to be read is managed, the read data read in line units by the optical reading unit is cyclically written in the ring buffer, and the read data in a predetermined area in the ring buffer is read. ,
Further, the write pointer is controlled by the discard pointer indicating the position of the line that can be erased or overwritten in the ring buffer so that the write pointer does not exceed the position of the discard pointer, and the position of the read pointer is set. Regardless of this, the discard pointer is controlled so as not to exceed the position of the line including the read data that has not been read out. An optical reading unit that optically reads a medium and includes optical elements arranged in a line, and a ring buffer formed in a storage area of the storage unit is executed by a control unit that controls the optical reading device. A program,
The control unit
Write of the read data by a write pointer indicating the position of the line for writing the read data read by the optical reading unit to the ring buffer, and a read pointer indicating the position of the line including the read data to be read; and The line to be read is managed, the read data read in line units by the optical reading unit is cyclically written in the ring buffer, and the read data in a predetermined area in the ring buffer is read. ,
Further, the write pointer is controlled by the discard pointer indicating the position of the line that can be erased or overwritten in the ring buffer so that the write pointer does not exceed the position of the discard pointer, and the position of the read pointer is set. Regardless, a program that functions as means for controlling the discard pointer so as not to exceed the position of the line including the read data that has not been read.

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