JPH02238772A - Image reading method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image reading method that can be applied to various image input devices such as image scanners, digital copying machines, and handy copy devices.

[Conventional technology]

In the image input device described above, a sensor head is generally moved at a predetermined pitch in the document scanning direction, an image sensor provided on the sensor head reads an image of the document, and the image data is sequentially stored in a memory. That's what I do. Conventionally, the method for enlarging or reducing a read image in such an image input device is to sequentially convert image data into enlarged or reduced image data using a dedicated additional circuit when capturing image data from a sensor head. There was a way to store it in memory. Alternatively, there is also a method that does not use such an additional circuit and that the image data from the sensor head is once captured in memory, and then the image data is converted to enlarge or reduce the data and then stored in another memory. there were.

[Problems to be Solved by the Invention] However, using a dedicated additional circuit or a separate memory for data conversion not only makes the device expensive, but also makes it difficult to use small image input devices such as hand-held copy devices. In order to mount the above-mentioned additional circuit, mounting problems also arise.

This invention has been made in view of the above points, and it is possible to obtain enlarged or reduced data when capturing image data from a sensor head into memory without using a special additional circuit or memory for enlargement or reduction. The purpose is to make it possible to

[Means to solve the problem]

In order to achieve the above object, the present invention moves a sensor head at a predetermined pitch in the document scanning direction, reads an image of the document with an image sensor provided in the sensor head, and sequentially stores the image data in a memory. In the image reading method, the sensor head reads the image with the image sensor n times (n is an integer of 2 or more) at the same reading position in the document scanning direction, thereby obtaining n-times enlarged image data. I will provide a. Further, the sensor head reads the image once by the image sensor at each reading position n-1 times (n is an integer of 2 or more) by moving in the document scanning direction, and then moves to the next n-th reading position. The present invention also provides an image reading method for obtaining image data reduced by (n-1)/n times without reading an image using an image sensor.

Furthermore, the sensor head is moved in the document scanning direction n-m times (n is an integer of 2 or more, m is an integer of 1 or more, and n
> m) The image is read by the image sensor once at each reading position, and then the image is not read by the image sensor at the m reading positions, resulting in a reduction of (n-m)/n times. An image reading method for obtaining image data is also provided.

[For production]

According to the image reading method according to the present invention, the image data itself output from the sensor head becomes enlarged or reduced image data and is sequentially stored in the memory.
By reading the image data in the memory and sending it to a printing device such as a printer, the enlarged or reduced image can be output on paper. Furthermore, since no special additional circuits or memory for data conversion are used, the image reading device does not increase costs.
It can have enlargement/reduction functions.

[Example] Hereinafter, an example of the present invention will be described in detail based on the accompanying drawings.

First, an outline of the image reading method according to the present invention will be explained with reference to FIG.

(b) is when obtaining twice enlarged image data, (mouth) is 3
/4 times reduced image data is obtained;
The row of 0 marks at the top indicates the reading position of the document image when scanning is performed by moving the sensor head at a predetermined pitch in the direction of the arrow, and the row of 0 marks at the bottom indicates the reading position of the document image when the sensor head is moved at a predetermined pitch in the direction of the arrow. This shows the dot row of the image data.

In order to obtain twice-enlarged image data, the sensor head reads the image twice with the image sensor at the same reading position in the document scanning direction, as shown in Figure 1 (a). Image data can be stored sequentially in memory. Therefore, in order to obtain n-times enlarged image data, the sensor head may read the image with the image sensor n times (n is an integer of 2 or more) at the same reading position in the document scanning direction.

In addition, in order to obtain 3/4 times reduced image data, the first
As shown in the figure, the image sensor reads the image once at each reading position three times (n-1 times; n=4) as the sensor head moves in the original scanning direction, and then the next image is read. At the fourth reading position, the image sensor may not read the image, and the image data read during that time may be sequentially stored in the memory.

Furthermore, the sensor head moves in the document scanning direction.
The image sensor reads the image once at each reading position m times (n is an integer of 2 or more, m is an integer of 1 or more, n > m), and then the image sensor reads the image at the m reading positions. It is also clear from FIG. 1 (portion) that if reading is not performed, image data reduced by (n-m)/n times can be obtained.

Note that this method can only enlarge or reduce the image in the direction in which the document is scanned one dot (or one line) at a time.

Therefore, when scanning one dot at a time in the horizontal direction, scaling is possible in the horizontal direction, and when scanning one line at a time in the vertical direction, scaling is possible in the vertical direction. Furthermore, when scanning one dot at a time in both the horizontal and vertical directions, it is possible to change the magnification in both the vertical and horizontal directions. Next, a specific example of this invention will be explained. FIG. 2 is a perspective view showing the appearance of a handy copying device as an example of a device to which the image reading method according to the present invention is applied.

This handy copy device 1 is formed into a relatively thin rectangular parallelepiped, and includes a scanner section 10 that reads image information (characters, graphics, etc.) on a document as an input device, and
The main body part 20 can be pulled out and stored by sliding in the direction of arrow A with respect to the main body part 20.

The upper surface of this main body part 20 is equipped with an operation part 21 equipped with various switches to be described later, and inside is used as an output device to print information read by the scanner part 10 and information from external devices (personal computer, word processor, etc.). It houses a printer and a control section that controls the entire handy copying device, and is also removably attached with a battery case 28 that stores a battery (dry cell) for securing power used for this device. 27 is the recording paper output port of the printer. Note that this device can also be powered from a regular household power source by using an AC adapter instead of a battery. As shown in the figure, the scanner unit 10 has a finder 11 (a window for specifying the maximum reading range of the document), and has two sheets of different sizes on the front and back sides (the top and bottom of the finder inner frame). Transparent plate (glass or acrylic plate) 1
2a and 12b are installed. The operation unit 21 includes a lock release button 29 to be described later, a start/stop switch 22 for starting or stopping this device, and a density adjustment switch 23 for adjusting the printing density by the printer, details of which will be described later. 3 modes: scan mode, printer mode and copy mode
a mode changeover switch 24 for specifying one of the two operation modes; a black-and-white inversion switch 25 for inverting the black and white of the image; A magnification change designation switch 26 is provided. Further, on one side of the main body 20, there is provided a connector 40 for an RS-232C interface (I/F) for connecting to various information processing devices such as an office computer, a personal computer, a word processor, a data processor, etc., and a memory. It has a card insertion slot 41, and the other side has a connector for inserting the plug of the AC adapter mentioned above (
(not shown). Here, the three operation modes of the mode changeover switch 24 will be briefly explained.

(1) Scan mode This is a mode used as a scanner, in which the scanner unit 10
The image data read by the computer is sent to various information processing devices such as those mentioned above via the connector 40, and displayed on the screen such as a CRT display, or edited by the information processing device and sent to a printer connected thereto. You can print it out or store it in an external storage device. (II) Printer mode This mode is used as a printer, and receives data from various information processing devices and prints it out using the built-in printer. (III) Copy mode This is a normal mode used for copying, and the image data of the document read by the scanner unit 10 is printed out by the built-in printer.

FIG. 3 is a schematic diagram showing the internal mechanism of the scanner unit 10. Inside the scanner unit 10, a transparent plate 1 of a finder 11 is provided.
Carriage 1 moving in the Y direction on 2b (scanning surface)
3, a carriage drive motor 14 that moves it, and
The sensor head 15 is provided with a sensor head 15 that moves in the direction, and a sensor drive motor 16 that drives the sensor head 15.

The carriage 13 is slidably supported at both ends by two iron rods (not shown) disposed in parallel along the Y direction, and is controlled by the forward and reverse rotation of the carriage drive motor 14 via a wire 17. Moved in the Y direction. The sensor head 15 includes an image sensor 15a, which is slidably supported by a single iron (not shown) disposed in the direction.

Here, the scanning method using this sensor head 15 will be briefly explained with reference to FIG. The sensor head 15 in this embodiment is assumed to perform serial scanning of 81 widths at 8 dots/m using the image sensor 15a shown in FIG.
The length of the effective scan area 12 in the X direction is 88 m, Y
Let the length of the direction be 80 kakus.

Therefore, scanning in the X direction by the sensor head 15 is
10 (80/8) by sequentially shifting the position by 8 m+ in the direction
) times, the effective scan area 1 of the finder 11
It is possible to scan the entire area of 2. In other words, this sensor head 1
The image sensor 15a of No. 5 is 64 (8
It is a contact-type serial image sensor in which X8) light receiving elements, which are reading elements, are arranged in a row, and serially outputs 64 dots of image data in one scan. The carriage 13 shown in FIG. 3 is always at the upper end position of the effective scan area 12, and the sensor head 15 is waiting at its left end position, that is, the position shown in FIG. 4 as its home position.

When the start/stop switch 22 is pressed with scan mode or copy mode specified by the mode changeover switch 24 shown in FIG. 2, the image sensor 15a of the sensor head 15 starts reading images. ．． First, while the carriage 13 is stopped at the first scanning position, the image sensor of the sensor head 15 scans each light receiving element in the direction of arrow a (or in the opposite direction) at the home position shown in the figure to perform one reading. Do it. Next, move one pitch (one dot) in the direction of arrow A,
Similarly, a reading operation by scanning is performed, and thereafter, the first scanning in the X direction is completed by sequentially moving in the direction of arrow A by one pitch 704 (88×8) times and repeating the reading operation.

This makes it possible to read an image in an area of 8 m x 88 mm.

At this time, the sensor head 15 has reached the right end of the effective scan area 12, and then the carriage 13 moves 8 in the Y direction.
The sensor head 15 moves one pitch at a time in the direction of arrow B, and repeats one line scan in the direction of arrow a by the image sensor 704 times until it reaches the left end, reads the image information, and then scans the image information in the second X direction. Finish scanning.

In this way, the carriage 13 moves 8I in the Y direction by 9
The sensor head 15 scans the image sensor 10 times (5 round trips) in the X direction, and completes the reading scan of the entire effective scan area 12. The image data sequentially read in this way is stored in the memory. By performing vertical and horizontal conversion during storage, the image data for the full width of the effective scan area 12 (881Il1) is
It is possible to output each line to a thermal head 31 of a printer 30 (described later) or to the outside.

In addition, as shown in FIG. 5, the number of light receiving elements that can read the entire width of the effective scan area 12 at once (704
Sensor head 1 equipped with a line sensor with bits)
5', the entire effective scan area 12 end the read scan. In this case, there is no need to perform vertical/horizontal conversion of the image data.

The above description of the reading operation is based on the case where the same magnification is specified by the variable magnification switch 26 in FIG. 2, and the reading operation when enlargement or reduction is specified will be described in detail later. do. FIG. 6 is a schematic configuration diagram showing the printer inside the main body section 20. This printer 30 employs a thermal recording method and includes a thermal head 31, a platen roller 32, and a paper feed motor 33.

The platen roller 32 is rotatably supported by a frame (not shown) and rotated by a paper feed motor 33. Then, while the thermal paper 34 fed out from a thermal paper roll (not shown) is wound around the platen roller 32 and automatically fed in the longitudinal direction, the thermal head 31 is pressed by the mechanical part (not shown) on the thermal paper 34, and the thermal head 31 is pressed in the X direction. By selectively generating heat from heating elements arranged in rows of 704 (88 x 8) dots along the paper width direction in accordance with the print data (the above-mentioned one line of image data),
Print each line. Note that this printer can also be used as a thermal transfer type printer, and printing can be performed in the same way by feeding a special sheet-like ink film over plain paper instead of using thermal paper.

By the way, this handy copy device 1 is of a pull-out type when in use, as shown in FIG.

That is, when not in use, the main body section 20 is connected to the scanner section 10.
The main body part 20 can be stored inside the scanner part 10 to make it compact and convenient to carry, and by pressing the lock release button 29, the main body part 20 can be pulled out from the scanner part 10 and used.

A switch (not shown), such as a microswitch, is provided to turn on and off the power circuit in conjunction with the insertion and removal of the main body 20, and the power can be turned off by storing the main body 20 in the scanner unit 10. When the main body section 20 is pulled out from the scanner section 10, the power is automatically turned on. FIG. 7 is a block diagram showing the configuration of the control section of this handy copy device. This control unit 50 includes an RS-232C interface 51 for connecting to the various information processing devices described above as an external interface, a memory card interface 52 for connecting to a memory card, and a CPU, ROM, and RAM.
It consists of an 8-bit microcomputer (hereinafter referred to as rCPUJ) 53 consisting of an I/O port, etc., a random access memory (hereinafter referred to as rRAM'J) 54 that stores a large amount of information, and a large number of logic circuits. It includes a gate array 55 and a driver circuit 56 consisting of a plurality of transistors and the like. The CPU 53 is in charge of controlling the entire device.
Various processes are executed according to program data stored in the ROM in the 53 or program data loaded from a memory card.

The RAM 54 is used as a memory for storing incoming information from the sensor head 15, a system memory used by the CPU 53, and the like. The gate array 55 converts input information from the sensor head 15 or input information from the memory card into information that can be input to the CPU 53. The CPU reads the data and stores it in the RAM 54, but when using the sensor head 15 explained with reference to FIGS. 3 and 4, the data is converted vertically and horizontally at that time. This vertical/horizontal conversion of data is detailed in Utility Application No. 165238/1983, which was previously filed by the present author, but since it is not directly related to this invention, the explanation will be omitted here. When outputting the image data stored in the RAM 54 to the thermal head 31 of the printer 30, the gate array 55
Performs data conversion to convert parallel data to serial data within the

The driver circuit 56 amplifies the pulse signal from the CPU 53 and outputs it to the carriage drive motor 14 and sensor drive motor 16 of the scanner section 10 and the paper feed motor 33 of the printer 30, respectively.

As described above, the sensor head 15 is provided with a serial scan type image sensor 15a having a resolution of, for example, 8 dots/m and having a width of 8 mn+, which is composed of a light emitting element and a light receiving element.

The thermal head 31 has, for example, 8 dots/
It is a line thermal head with an effective length of 88 mm and a resolution of m, and 704 heating elements are arranged in a dot pattern. Each of the motors 14, 1B, and 33 is, for example, a four-phase stepping motor having four sets of internal coils, and is parked using a two-phase excitation method. Each motor rotates by a rotation angle proportional to the number of pulses applied from the CPU, rotates at a rotation speed proportional to the frequency of the pulses, and furthermore, the direction of rotation changes depending on the order of the pulses applied to each coil. In this embodiment, the amount of movement of the sensor head 15 in the X direction in FIG.
1/8 m. Next, an explanation will be given of the image reading operation when changing the magnification according to this embodiment. When enlargement or reduction (the magnification can also be selected) is specified by the magnification change designation switch 26 of the operation section 21 shown in FIG. 2, the control section 50 of FIG. The sensor head 15, carriage drive motor 14, sensor parking motor 16, etc. are controlled to execute the reading method. FIG. 8 is a flowchart showing the control operation when the control unit 50 (mainly the CPU 5) is instructed to perform n-fold enlarged reading, and FIG. 9 similarly shows (n-1)/n-fold reduced reading. FIG. 2 is a flow diagram showing control operations when an instruction is given. Furthermore, FIGS. 10 and 11 are timing charts showing the relationships among image reading pulses, sensor head movement pulses, and read data during 2x enlarged reading and 3/4x reduced reading, respectively. First, the n-fold enlarged reading operation will be explained with reference to FIG. When the sensor head 15 is at the home position shown in FIG.
The counter in S''5 is set to ``1'', and the first image data is read by the image sensor 15a at that position.

Then, it is determined whether one scan is completed, and if not, it is then determined whether the count value is n.

Since n is an integer greater than or equal to 2, the count value is not n at first, so add 1 to the count value (initially, change ``1'' to ``2'').
”), then read the image data again at the same reading position.

In this way, the image sensor 15a performs data (image) reading operations n times at the same reading position without moving the sensor head 15 until the count reaches n.

When the count value reaches n, the sensor head 15 is moved one pitch in the main scanning direction (in this example, one pitch in the X direction in FIG.
/8III1) After moving, set the internal counter to “1”.
” and repeat the above operation.

Then, when one scan in the direction of arrow A in FIG. 4 is completed,
It is determined whether or not all scanning has been completed, and if not, the carriage 13 is moved by one pitch in the sub-scanning direction (in this example, 8 am in the Y direction in FIG. 4), and then the above-mentioned operation is repeated.

However, during the even-numbered main scan, the direction of movement of the sensor head 15 is set in the direction of arrow B in FIG.

In this way, when all scanning of the effective scan area is completed. The carriage 13 is returned to the home position and the process is completed. At this time, if the entire scan is completed by an even-numbered main scan, the sensor head 15 will return to its home position. Here, if n=2, when the sensor head 15 is at the home position, the image sensor 1
5a is read twice, then the sensor head 15 is moved one pitch in the main scanning direction, and data is read twice by the image sensor 15a at that reading position as well. Thereafter, while moving the sensor head 15 one pitch at a time, data is read by the image sensor 15a twice at the same reading position.

Therefore, as shown in FIG. 10, two image reading pulses are sent out during one cycle of the sensor head movement pulse, and data (image) is read twice by the image sensor 15a.
The read operation is performed and the read data is sent to RA.
Store in M54.

Note that at the first position of each main scan, two image reading pulses are sent out before sending out the sensor head movement pulse.

In this way, twice enlarged image data can be obtained when reading the image without using special circuitry. n
Double image data can also be obtained during reading in the same way. Next, a reduction reading operation of (n-1)/n times will be explained with reference to FIG. When the sensor head 15 is at the home position shown in FIG. 4, when reading with a reduction of (n-1)/n is started, the counter in the CPU 53 is set to "2" and the image sensor 15a is at that position. Image data is read once.

Then, it is determined whether one scan is completed, and if not, the sensor head 15 is moved one pitch in the main scanning direction, and then it is determined whether the count value is n.

Here, taking the case of n=4 as an example, the count value is "2" at first, so it is not equal to n, so after increasing the count value by 1 to "3", the image data is read. Do this.

Since one scan has not yet been completed, the sensor head 15 is moved one pitch in the main scanning direction again, and since the count value has not yet reached n, it is increased by +1 again to "4", and then
It also reads image data. Then, the sensor head 15 is moved one pitch in the main scanning direction again to judge the count value, but this time the count value is "4", which is equal to n, so the count value is set to "1". Then, return to the judgment of whether one scan is completed or not. If it is not completed, move the sensor head 15 in the main scanning direction by 1.
Move the pitch, judge the count value again, and
Since it is not, add 1 to make it "2", then return to reading the image data and repeat the above operation.

In other words, four consecutive images in the main scanning direction of the sensor head 15
The image sensor 15a is detected at three of the reading positions.
When data is read by , the sensor head 15 is moved by only one pitch without reading data at the next location. In this way, when one scan in the direction of arrow A in FIG.
Repeat the above operation. However, during the even-numbered main scan, the direction of movement of the sensor head 15 is set in the direction of arrow B in FIG.

When all scanning of the effective scan area is completed, the carriage 13 is returned to the home position and the process is completed. Therefore, in the case of n=4, as shown in FIG.
The image reading pulse and the sensor head movement pulse are output alternately up to three times, but the fourth time, the image reading pulse is not output and only the sensor head movement pulse is output. Accordingly, after the sensor head 15 outputs read data by the image sensor 15a at three consecutive reading positions, it does not output read data at the next reading position.

In this case as well, at the first position of each main scan, the image reading pulse is sent out before the sensor head movement pulse is sent out. In this way, 374 times reduced image data can be obtained when reading an image without using any special circuit. (n-1)/n times reduced image data can also be obtained during reading in the same way. Furthermore, the sensor head 15
out of n consecutive reading positions (man
), if reading operation is not performed, (n-m)/
It is possible to obtain n-times reduced image data.

By the way, in this embodiment, the sensor head 15 can only be enlarged or reduced in the main scanning direction, but if you wish to enlarge or reduce it in the direction perpendicular to this direction,
For enlargement, the software writes multiple lines to memory or outputs the same line of image data n times (when enlarging it by n times), and for reduction, thins out the output lines, etc. It can be easily achieved.

For example, when input image data is taken in one bit at a time, it can be enlarged twice by reading it twice during 1-bit processing, and it can be enlarged by n times by reading it n times during 1-bit processing. can.

Also, when importing input image data bit by bit,
By skipping m times during n-bit processing, (n-m
)/n times. [Effects of the Invention] As explained above, according to the image reading method of the present invention, image data can be captured from the sensor head into the memory without using a special additional circuit or memory for enlarging/reducing the image. In this case, enlarged or reduced data can be obtained.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the image reading method according to the present invention, FIG. 2 is a perspective view showing the external appearance of a handy copying device as an example to which the image reading method according to the present invention is applied, and FIG. 3 is the scanner section 10 in FIG. 4 is an explanatory diagram of the scanning method according to this embodiment, FIG. 5 is an explanatory diagram showing another example of the scanning method, and FIG. 6 is a diagram showing the main body 20 in FIG. 2. FIG. 7 is a block diagram of the control unit of this handy copying device; FIG. 8 is a flowchart showing the control operation during n-fold enlargement reading according to this embodiment; FIG. 9 is a schematic diagram of the built-in printer; Flowchart showing the control operation when reading the same <(n-1)/n times the reduction. FIG. 10 is a timing chart for explaining the operation when reading the enlarged twice as much as this embodiment. 11th is the same. 3
3 is a timing chart for explaining the operation when reading a /4 times reduced size. 1... Handy copy device 10... Scanner section 11... Finder 13... Carriage 12... Effective scan area 14... Carriage drive motor 15.15'... Sensor head 15a... Image sensor 16... Sensor parking motor 20... Main body part 26
...Magnification specification switch 30...Printer 50.
...Control unit 53...Microcomputer (CPU) 54...Random access memory (RAM) 55...Gate array 56...Driver circuit

Claims (1)

[Claims] 1. Image reading in which a sensor head is moved at a predetermined pitch in the document scanning direction, an image sensor provided on the sensor head reads an image of the document, and the image data is sequentially stored in a memory. The method is characterized in that the sensor head obtains n-fold enlarged image data by reading the image with the image sensor n times (n is an integer of 2 or more) at the same reading position in the document scanning direction. Image reading method. 2. An image reading method in which a sensor head is moved at a predetermined pitch in the document scanning direction, an image sensor provided on the sensor head reads an image of the document, and the image data is sequentially stored in a memory, wherein the sensor head is n- due to the movement in the document scanning direction.
At each reading position (n is an integer of 2 or more), the image sensor reads the image once, and at the next n-th reading position, the image sensor does not read the image (n -1) An image reading method characterized by obtaining image data reduced by a factor of /n. 3. An image reading method in which a sensor head is moved at a predetermined pitch in the document scanning direction, an image sensor provided on the sensor head reads an image of the document, and the image data is sequentially stored in a memory, wherein the sensor head is n- due to the movement in the document scanning direction.
The image sensor reads the image once at each reading position m times (n is an integer of 2 or more, m is an integer of 1 or more, n>m), and then the image sensor reads the image at the m reading positions. An image reading method characterized in that image data reduced by (n-m)/n is obtained by not performing reading.