JPS5919464A - Information reader - Google Patents

Abstract

PURPOSE:To simplify the shading correction and joint processing, by moving relatively a light source device and an object placing plate to be read. CONSTITUTION:The placing plate 1 for object to be read, plural image pickup elements CCD1, CCD2 arranged in the main scanning direction, a reference optical characteristics section 3 for shading correction, a marker section 4 for the joint processing of the image pickup elements, a main scanning region 2 with a light source device and a means irradiating respectively the reference optical characteristics section 3 and the marker section 4 are provided. Further, the singel optical device 5 and the placing plate 1 for the object to be read are moved relatively to read signals for the shading correction and the joint processing and the object to be read.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an information reading device, and an object of the present invention is to provide a specific configuration for shading correction and connection processing of outputs from a plurality of image sensors.

Regarding conventional technology, in information reading devices used in digital copiers, facsimiles, etc., a bar-shaped light source illuminates a document on which images or characters are displayed, and the light reflected from the document is received by a solid-state image sensor through an imaging lens. , converting the original information into electrical signals.

In this type of device, the light distribution characteristics of the light source are not uniform, the reflective mirror is dirty, and the brightness of the lens approaches the periphery due to the so-called cos' θ characteristic (where θ indicates the half angle of view of the lens). (2) According to (2), it is necessary to correct the shading characteristics caused by variations in sensitivity between bits of the image sensor. As a means to avoid this, it has been proposed to perform shading correction using a signal received from reflected light when a white plate is irradiated, which should be the standard for shading correction.

Furthermore, in the above-mentioned information reading device, it has been proposed to arrange a plurality of image sensors side by side in the scanning direction in order to increase resolution and transfer speed. In this case, it is necessary to prevent optical discontinuity from occurring at the boundary of the area scanned by the pot image sensor, and for this purpose, an area is provided that is scanned overlappingly by a plurality of image sensors.
It has been proposed to arrange a reference marker here, and to connect the outputs of a plurality of image sensors based on the signals read from the reference marker.

Purpose of the Invention The present invention proposes a specific configuration for performing shading correction and connection processing in the above-mentioned type of information reading device (3), which uses a single light source device and an object to be read. An object of the present invention is to provide an apparatus that can reliably read signals for shading correction and splicing processing, and read objects to be read, simply by relatively moving a mounting table.

Structure of the Invention The present invention includes: a light source device; a table for mounting an object to be read (in a specific example described later, the glass plate 1 in FIG. 1); and a plurality of image pickup devices arranged in parallel in the main scanning direction ( Similarly, the solid-state image sensors CCD I and CCD 2): a reference optical characteristic section for shading correction (also reference optical characteristic section 3) disposed outside the main scanning area on the mounting table; and a reference optical characteristic section 3 on the mounting table; a marker unit (also the marker unit 4) for connection processing of the plurality of image sensors arranged outside;
An information reading device comprising: (4) means for relatively moving the light source device and the mounting table to respectively irradiate the main scanning area, the reference optical characteristic section, and the marker section with the light source device; shall be.

Note that the above reference to specific examples shown in the drawings to be described later does not limit the scope of this invention in any way, and this invention can be modified as appropriate within the scope of the claims.

``The information that can be read by the reading device of this invention includes information contained in documents, photographs, maps, or diagrams on which images, characters, symbols, etc. are displayed, as well as information contained in flat objects such as textile fabrics or textile products. It also includes information such as the pattern.

Hereinafter, in this specification, these information carriers will simply be referred to as manuscripts.

An information reading device embodying the present invention will be described below in detail in the order of its first embodiment, second embodiment, shading correction section, and connection processing of outputs of a plurality of image sensors with reference to the drawings. do.

Regarding the first embodiment of the information reading device of the present invention (FIG. 1) FIG. 1(A) is a side view of the first (5) embodiment of the information reading device of the present invention, and FIG. 1(B) shows the plan view.

In these figures, 1 is a glass plate that is a document mounting table;
2 is its main scanning area, and 3 is a reference optical characteristic section, which is fixedly or movably arranged with respect to the original platen 1, or placed at a predetermined position thereof. In the statement,
Regarding the reference optical characteristic section 3 and the marker section 4 described later, these means are collectively referred to as arrangement. In this example, the reference optical characteristic section 3 has a white plate at a portion that contacts the mounting table IK. The position of the reference optical characteristic section 3 is the first home position of the light source device 5 (the position when this device is in a resting state)
Corresponds to 21. In the reference optical characteristic section 5, characteristics that affect reflected light, such as color, reflectance, and surface smoothness, serve as standards for shading correction. Reference numeral 4 denotes a marker section, which has the same meaning as the reference optical characteristic section 5 and is similar to the mounting table 1.
In this example, the portion in contact with the mounting table 1 forms a thin black line. The marker unit 4 is a unit whose reflected light provides a signal for connection processing to be described later, and its arrangement (
6) When the position is outside the main scanning area and the light source device 5 illuminates the reference optical characteristic section 5 at the first home position 21, the reflected light from the marker section 4 is picked up by the image sensor. It's in a position like no other. Furthermore, the marker section 4 is provided in a portion that is overlapped and scanned by two adjacent optical systems including lenses 10 and 11, respectively.

Reference numeral 5 denotes a light source device, which includes bar-shaped light sources 6 and 6', and has a reference optical characteristic section 3 at its first home position 21.
When irradiating [7, main scanning direction (dashed line 21 in Fig. 1 (B)
direction), and the marker section 4 is irradiated at the second home position 22. The irradiation of the marker portion 4 needs to be performed not only on the marker portion 4 but also on at least adjacent portions in the main scanning direction, but in a normal embodiment, the irradiation is performed over the entire area in the main scanning direction passing through the marker portion. Furthermore, the light source device 5
moves 17 in the sub-scanning direction (X direction in FIG. 1(A)) and scans the document on the main scanning area 2 (7). Reflecting mirrors 7, 8.9 move as the light source device 5 moves so that the optical path from the point irradiated by the light source device 5 to the lens 10.11't is always equal. Specifically, the reflecting mirror 7 moves together with the light source device 5, and the reflecting mirrors 8 and 9 move together with the light source device 5 so as to satisfy the above-mentioned conditions.
It is possible to move at a predetermined ratio to the amount of movement of .

10 and 11 imaging lenses, the reference optical characteristic section 5
, when the portion including the marker section 4 and the original on the main scanning area 2 are irradiated by the light source device 5, the reflected light is imaged on the light receiving surface of the image sensor via the reflecting mirrors 7 to 9. . CCD
1 and CCD 2 are solid-state image sensors that are image pickup devices, and are composed of charge-coupled devices (MOS) transistors, etc., and electrical scanning is performed in the main scanning direction. In FIG. 1(B), 14 is a reference mark for placing the original, and 15 and 16 are sensors for detecting the first and second home positions 21 and 22 of the light source device 5, respectively. Based on the outputs of these sensors, the position of the light source device 5 is adjusted via a control mechanism (8) not shown.

To explain the operation of the device of FIG. 1, in its resting state, the light source device f5 is located at the home position 21. At the beginning of operation, the light source device 5 illuminates the reference optical characteristic section 3, and the reflected light passes through the reflecting mirrors 7, 8, 9 and the imaging lens 10.11, and is received by the solid-state image sensors CCD i and CCD 2, and the output thereof is A signal showing shading characteristics is obtained. At this time, the characteristics of the light source device 5 and the home positions 21 and 2 are adjusted so that the marker section 4 does not exist on the main scanning line.
2. Determine the distance from 2. The signals exhibiting the above-mentioned shading characteristics are utilized for shading correction as described below in connection with FIG.

Next, the light source device 5 illuminates a portion including the marker section 4 at the home position 22. The reflected light is received by the image sensors CCD1 and CCD2 as described above,
Based on the output, the amount of connection between the document reading signals is calculated. The details will be described later in connection with FIGS. 4 to 6.

Here, as a sequence procedure, first perform the shape-in (9) correction and then calculate the joint amount.If the accurate shading value is not calculated, it will be difficult to read the marker part 4 (thin black line). This is because misreading may occur and cause errors. Next, the light source device 5 moves to the main scanning area 2 (12), advances in the sub-scanning direction (X direction) as shown in FIG. Signals from reading the original are sent by solid-state image sensors CCD I and COD.
2 is output and processed by the circuits shown in FIGS. 3 and 5, which will be described later. When the document scanning is completed, the light source device 5 returns to its first home position 21.

Regarding the second embodiment of the information reading device of the present invention, FIGS. 2(M) and 2(B) respectively show a side view and a plan view of the second embodiment of the information reading device of the present invention. The embodiment shown in FIG. 2 differs from the first embodiment in that the reference optical characteristic section 3' is provided on the side opposite to the marker section 4 with respect to the main scanning area 2. Note that 25 and 24 in the figure are the first and second home positions of the light source device 5, respectively;
', (10) and 16' are sensors for detecting the first and second home positions, respectively, and these parts have the same functions as those in the first embodiment. The parts indicated by the same reference numerals basically have the same structure and function as those in FIG.

In the apparatus shown in FIG. 2, in its resting state, the light source device 5
is located at its first home position 23. At the beginning of the operation, the light source device 5 illuminates the reference optical characteristic section 3', and a signal indicating the shading characteristic is transmitted to the solid-state image sensor CCD.
1 and CCD2. Next, the light source device 5
(The light source device 5 moves in the direction opposite to the direction of direction, scans the document, and returns to the first home position 23 when this is completed.

In the second embodiment described above, since the reference optical characteristic section 3' is arranged on the opposite side to the marker section 4, the position control of the light source device 5 is performed by W.
Example of Jl) is also easy.

(11) For example, in the first embodiment, when the reference optical characteristic section 3 is irradiated at the home position 21, the light reflected by the marker section 4 is prevented from being received by the solid-state image sensors CCD1 and CCD2, and the light source device 5 is set at the home position/ 22
Since the reflections @7 to 9 are also moved by a short distance, precise positional control is required. , the accuracy requirements regarding the optical characteristics of the light source device 5 and the position control of the light source device 5 and the reflecting mirrors 7 to 9 are relaxed.

As described above, the apparatuses shown in FIGS. 1 and 2 can reliably perform shading correction, connection processing of the outputs of a plurality of image pickup elements, and reading of a document simply by moving the light source device.

Regarding the shading correction unit in this invention (fifth
FIG. 5 shows an example of a shading correction section, and only shows a device that processes the output of one image sensor CCD I. In FIG. 3, when starting the shape (12) ink correction, the selector SEL is switched to the A side. A bit-serial image signal from the image sensor CCD 1 is amplified by an amplifier 31 and converted into a digital signal by a RAM D converter 32, and this digital signal is sent to a random access memory (hereinafter referred to as RAM) 6.
It is written in 3. Address control of this RAM 55 is performed by the clock generator 34 for the image sensor CCD1.
This is done via the sear address counter 33' using a clock signal that is in synchronization with the clock signal of . Next, in scanning the portion including the marker section 4 and scanning the document, the selector SEL is switched to the B side. Then, the portion including the marker section 4 and the image data obtained by reading the document are input to one of the multiplication read-only memory (hereinafter referred to as read 4, memory is referred to as ROM) 38. The other input of the multiplication ROM 5B is given a signal from the RAM 35 containing the shading values obtained in the above-mentioned shading sequence. The address control L1 clock generator 34 clock signal of the multiplication ROM 3B and the clock signal in synchronization with (13) the seat address counter 5.
8'. Multiplication ROM 58 is RAM
55, when the input is n and the image data is m, m/
It is built in to output a code n, and the shading is corrected by this logic. Multiplication ROM 58
The output of dither ROM 39 which is a threshold determining circuit
The comparator circuit 40 compares the output of the image data with the output of the image data, and obtains binarized image data, which is input to the shift memory 1 (41). Main scan counter 4 for dither ROM 59
2 is inputted with a signal that is in a synchronous relationship with the clock signal of the clock generator 34, and a count pulse is inputted into the sub-scanning counter 43 at every fixed count of the main-scanning counter 42, which is in a synchronous relationship with the sub-scanning of the light source device 5. keep it.

Concerning the process of connecting the outputs of the plurality of image sensors according to the present invention (FIGS. 4 to 6) Next, means for automatically connecting the output signals of the solid-state image sensors CCD1 and CCD2 will be described.

In the same way as the output of the solid-state image sensor CCD1 is stored in the shift memory 1 in FIG. 5, the output of the solid-state image sensor CCD 2 is stored in the shift memory 2 (FIG. 5).

Figure 4 shows the principle of connection processing, where a is the CCD1
The scanning area b indicates the scanning area of the CCD 2, and the scanning direction is indicated by Y in the figure. This direction corresponds to the scanning direction Y in FIG. 1(B) and FIG. 2(B). Light source device 5
is at the home position 22 or 24, and the marker section 4
Figure 4C shows the last 128 bits of the bit serial signal from CCD 1 when the part containing the CCD is irradiated.
The first 128 bits of the bit-serial signal from 2 are shown in d of the same figure. Here, 128 bits is 16, pips) 7
When the resolution is m, this corresponds to 8 widths on the document surface.

Then extract each of these 128 bits and RA
Expand to M. This state is shown in θ and f in the same figure, but if the ranges scanned by the two optical systems are set to overlap as described above, the 128 bits developed in the RAM will always include white bits before and after. , and the black bit corresponding to the aforementioned marker section (1 of 4) is interposed.

Therefore, the number of lower white bits (L, W
, ) and the number of upper white bits in the output of COD 2 (U, W
, ) and the number of black bits (B) are thinned out and connected when reading from the shift memory, and C
The outputs of CD j and CCD 2 are extracted as continuous signals.

Next, FIG. 5 shows a connection processing section that executes the above operation. According to FIG.
The manner in which 28 bits are extracted will be explained. The basics of this extraction and deletion processing are to insert data 16 times each in 8-bit units from both sides, and to develop this into the RAM. The device operates on write clock signal φ2 and read clock signal φ. First, the central processing unit (CPTJ)
That's what it means. ) sets write address counter 1 and read address counter 2 to down count mode. Note that the read address counter 1 is always reset to up count mode (16). and 259 in I10 register 1
Set address 2 (A20H in hexa code) and press 10
Set address 8 (same <8■) in register 3. In this circuit, when the CPU activates the test terminal T of the register 4, the reading circuit (not shown) generates a video enable signal (Fil in FIG. 6) indicating one main scanning period, and along with this, the CCD 1 and It is designed to send bit-serial signals from CCD 2.

The video enable signal KN is input to each set terminal S of flip-flops 1 and 2 in FIG. 5, and the video signal from CCD 1 is input to shift memory 1 (same as shift memory 41 in FIG. In register 1, CC
The video signal from D2 is input to a shift memory 2 and an 8-bit shift register 2. Both 8-bit shift registers 1 and 2 start shifting operations upon activation of the video enable signal, and are moved in response to the count completion signal RPC1 from write address counter 1 and read address counter 2, respectively (17). Finish the work. Note that this operation is performed via flip-flops 1 and 2, respectively.

Therefore, when cpv activates the aforementioned test terminal T,
At the point in time when the video enable signal ends, the last 8 bits of the signal from CCD 1 remain in 8-bit shift register 1, and the last 8 bits of the signal from CCD 1 remain in 8-bit shift register 2.
The first 8 bits of the signal from 2 will remain. Next, the CPU reads the contents of these shift registers and expands them onto the RAM. To process the next 8 bits, set address (2592-8) to step 1 register 1.
Set (address 8+8) in 0 register 3 and process in the same way as above. These processes are repeated 16 times to extract 128 bits.

When the stitch amount calculation is completed, the document is scanned, but before this, the CPU writes 2504 to I10 register 2.
Set the address (2592 one link amount) in the register 6 of the machine 10. This situation is shown in Figure 4 g and h, where g shows the output of CCD 1, which is 88 y
θB), 2376 bits corresponding to the amount of information for 148.5 gm, 128 bits for connection processing, and a total of 2592 bits. On the other hand, the same figure shows the output of CCD 2,
This is also a total of 2592 bits, but the first C
ON indicates the amount of connection. Note that the video output is taken out via the OR circuit on the output side of the shift memories 1 and 2.

Figure 6 shows the video enable signal (F!N), CCD
1 shows the time relationship between the output signal from CCD 1 (CCD 1), the output signal from CCD 2 (CCD 2) and the write clock (φ2). In addition, the register 4 of the middle work 10 in Fig. 5 is as follows.
The above-mentioned counter is used to switch the modes of the write address counter 1 and read address counter 2 and to select the address selectors 1 and 2. C in Figure 5
The PU also controls the shading correction section shown in FIG.
The RAM and ROM shown in FIG. 5 can also be used as those shown in FIG.

Although an example in which the present invention is applied to a device with a fixed original and a moving light source has been described above, the present invention can be similarly applied to a device with a fixed light source and a moving original (19). Transmitted light can also be used instead. Further, the number of image sensors is not limited to 62, but may be three or more.

Effects of the Invention Based on the above-described configuration and operation, the present invention provides an information reading device including a plurality of image sensors, which performs shading correction, connection processing of the outputs of the image sensors, and information reading from an object to be read. Scanning of the nozzle can be reliably performed simply by relative movement of the light source device and the object to be read table, thereby improving the operability of this type of device.

[Brief explanation of drawings]

FIG. 1(A) is a side view of a first embodiment of the information reading device of the present invention, FIG. 1(B) is a plan view thereof, and FIG. 2(A)
is a side view of a second embodiment of the information reading device of the present invention;
FIG. 2(B) is a plan view thereof, FIG. 3 is a block diagram of a shading correction unit in the present invention, and FIG. ) FIG. 5 is a block diagram of a connection processing section for the outputs of a plurality of image pickup devices according to the present invention, and FIG. 6 is an explanatory diagram of the operation of the connection processing section of FIG. 5. In the figure, 1 is a glass plate that is a document placement table, 2 is a main scanning area,
3 is a reference optical characteristic section, 4 is a marker section, 5 is a light source device, C
CD1 and CCD2 indicate solid-state image sensors that are imaging devices. (21) No. 3 3R Middle 2 Writ of amendment to the old procedure (voluntary) October 1983 IF Commissioner of the Patent Office Kazuo Wakasugi 1, Indication of the case 1980 Patent Application No. 128073 2, Invention Name information reading device 3, relationship with the person making the amendment Patent applicant name (100) Canon Co., Ltd. 4, agent address: 105 (telephone: 434-2859)
1-4-4 Shiba Daimon, Minato-ku, Tokyo Voluntary amendment 6, No change in the number of inventions due to amendment 8, Contents of amendment Drawings Figure 1 (A), Figure 1 03), Figure 2 (A) and Figure 2 φ) is corrected as shown in the attached sheet. 9. List of attached documents (1) 1 document describing drawings Figure 1 (&) and Figure 1 (B) (2) Column describing drawings Figure 2 (A) and Figure 2) 1 letter

Claims (4)

[Claims] (1) A light source device, a mounting table for an object to be read, a plurality of image sensors arranged side by side in the main scanning direction, and a reference optical characteristic section for shading correction arranged on the mounting table outside the main scanning area. , a marker section for connecting the outputs of the plurality of image sensors arranged outside the main scanning area on the mounting table; and a marker section for relatively moving the light source device and the mounting table, An information reading device comprising: means for respectively irradiating the main scanning area, the reference optical characteristic section, and the marker section. (2) The information reading device according to claim (1), wherein the image sensor is a solid-state image sensor. (3) The information reading device according to any one of the above claims, wherein the marker section is arranged on the same side as the reference optical characteristic section (1) with respect to the main scanning area. (4) The information reading device according to claim (2), wherein the marker portion is disposed on the opposite side of the reference optical characteristic portion with respect to the main scanning area.