JPH03169165A - Shading correction device for image reader - Google Patents

Abstract

PURPOSE:To obtain the best picture at all times by facing a white board to a focus of an image reader before reading of a read object and retrogressing the board from the focus at the reading. CONSTITUTION:When an image reader 36 reads a card C, a white board 40 is escaped from a focus and not in the way of feeding of the card C. On the other hand, before the start of reading, the white board 40 faces the focus to correct the white balance. Thus, the best picture is always obtained. Furthermore, the white board 40 is not in contact with the card C and directed downward, then no dust nor dirt is caused.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a shading correction device for an image reader, such as a card image reader that reads written contents of various cards as image data.

[Conventional technology]

In card image readers and the like that read the written contents of an object to be read as image data, it is necessary to adjust the white balance to correct the background color of the card.

Conventionally, this so-called shading correction has been performed during adjustment work after assembly of these devices.

[Problem to be solved by the invention]

As described above, in the past, shading correction was performed before the device was shipped, but correction was rarely performed after the device was shipped. Therefore, the white balance may be out of order due to variations in the plurality of LEDs included in the image reader, changes in characteristics over time, or dirt on the glass surface with which the object to be read comes into direct contact.

In this case, the device should be equipped with a whiteboard so that shading can be corrected from time to time, but if the whiteboard is installed facing the focal position of the image reader, this focal position will be exactly when the object to be read is being transported. If it is located in the route, it becomes impossible to send it. On the other hand, if the whiteboard is provided with a gap that allows for movement, the focal position of the image reader will shift with respect to the whiteboard, resulting in a problem that accurate correction cannot be made.

The present invention enables the feeding of the object to be read without any hindrance.
It is an object of the present invention to provide a shading correction device for an image reader that can accurately correct white balance before a reading operation.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a shading correction device that is used in an image reader that reads the contents of objects to be read that are sequentially introduced into a transport path inside the device, and that adjusts the white balance of the image reader. A whiteboard that serves as a reference for the reading process, and a moving means for moving the whiteboard to a correction position where it faces the focus of the image reader before reading the object to be read, and a retreating position where it retreats from the focus during the reading process of the object to be read. It is characterized by having the following.

[Effect]

Before the reading operation, the whiteboard is moved to the adjustment position by the moving means to enable shading correction, and during the reading operation when the object to be read introduced into the conveyance path faces the image reader, the whiteboard is moved to the retreated position by the moving means. There is no problem in feeding the object to be read.

〔Example〕

A card image reader using a shading correction device according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2.

This card image reader uses a card C as the object to be read.
1. For example, a device that continuously reads business cards, reads the written contents of card C (business card) as image data, and electronically transmits the read data to a host computer (not shown). The card image reader is provided with a translucent transparent lid 2 on the top surface of the device main body 1 formed in a box shape, and a card case 3 that accommodates a large number of business cards in a stacked state inside the transparent lid 2 is opened. is removably stored.

On the external front of the device main body 1, a power switch 4 and an EJEC'T button 5 are provided on the side, and a POWER display 6, an error display 7, a BUSY display 8, and a paper out detection display 9 are provided on the center side. It is being On the other hand, inside the device body 1, there is provided a conveyance path 11 that constitutes a conveyance path for the card C, which starts from the bottom of the card case 3 and extends to the exit 10 at the rear end of the device body 1. Various rollers for conveyance are arranged above and below.

These rollers are arranged in the order of a big up roller 12, a separator roller 13, a first feed roller 14, a second feed roller 15, and a third feed roller 16 from the front side of the conveyance path 11, that is, from the upstream side. The cards C are conveyed in a sequential manner and are dropped into a card tray 17 protruding from the rear of the device body 1 from an exit 10.

A reading section 18 is interposed between the first feed roller 14 and the second feed roller 15, and the reading section 18 reads the contents written on the card C as image data. In addition, first and second
An optical sensor 19 and a second optical sensor 20 are provided,
Both optical sensors 19 and 20 include light emitting elements 19a and 20a on the upper side and one light receiving element b and 20 on the lower side with the transport path 11 in between.
When the card C approaches this part of the transport path 11, the light from the light emitting elements 19a and 20a is blocked, which is used to detect the presence or absence of the card C, and sends a signal to the control system for jam detection, etc. It is ready to send.

The pickup roller 12, the first feed roller 14, the second feed roller 15, and the third feed roller 16 are
All of them are designed to rotate in the transport direction of card C.
These roller pulleys 21a. 21a, 21a, 21a
An endless timing belt 22 is stretched across the two intermediate booms 21b and 2lb so as to interlock with each other. The drive source is a drive motor 23 provided between the second feed roller 15 and the third feed roller 16. 2 feed roller 15
The input signal is inputted from the input gear 25.

The card case 3 can be taken out from the device main body 1, and stores cards C to be read in a stack (100 business cards in this embodiment).

Further, the card C accommodated in the device main body 1 can be visually recognized through the window 2a of the transparent lid 2 of the device main body 1, so that the remaining amount can be checked at all times. The bottom half of the card case C near the back is opened to form an inlet 26 for the cards C which is connected to the transport path 1l, and the pickup roller 12 faces this. On the other hand, a card presser 27 having a roller at the tip is attached to the transparent lid 2, and by closing the transparent lid 2, the cards C in the card case 3 can be pressed toward the pickup roller 12 side.

The upstream side of the conveyance path 11 extends parallel to the bottom plate 3a of the card case 3 with a small gap to the front of the device body 1, and has a slit-shaped opening in the front surface of the device body 1. It is connected to the card insertion slot 28 of. This card insertion slot 28 is used to insert another card C in addition to the card C in the card case 3. When a card C is inserted through this card insertion slot 28, the tip of the card C is directly inserted into the big up roller. 12, and this card C is read by an interrupt.

The big-up roller 12 faces the carry-in port 26 at the bottom of the card case 3, and continuously introduces the stacked cards C into the conveyance path 11 one by one starting from the bottom. Further, an electromagnetic clutch 31 (one-way clutch) consisting of a ratchet mechanism 29 and an electromagnetic solenoid 30 is connected to the big up roller 12, and this electromagnetic clutch 31 is connected to a first
It is turned on and off by an optical sensor 19.

That is, when the first optical sensor 19 detects the rear end of the preceding card C and the card C can be sent out, the electromagnetic clutch 3
1 is ONL, and the pickup roller 12 is rotationally driven to feed the card C toward the separator roller 13. When the leading edge of the card C passes the first feed roller 14 and reaches the first optical sensor 19, the electromagnetic clutch 31 turns OFF. The pickup roller 12 stops. Therefore, the pickup roller 12 picks up the card C from the first feed roller 1.
If a jam or the like occurs on the first feed roller 14 side and card feeding is interrupted, the electromagnetic clutch 31 is not turned on and the pickup roller 12 is stopped and the card feeding is stopped. do. thus,
If a problem occurs in card feeding, it can be quickly dealt with and damage to the card C and equipment can be prevented.

The separator roller 13 is composed of an upper braking roller 32 and a lower freely rotating roller 33 with the conveyance path 11 in between.
Regarding the cards C sent in a stacked state from the pickup roller 12, the upper card C is stopped by the friction of the braking roller 32, and the lower card C is transferred to the first feed roller 14 side via the free rotation roller 33. It is now possible to reliably send one card C. The brake roller 32 is configured to be rotatable up to an angle of 75 degrees in the direction of rotation of the card C, and is biased in a direction opposite to the direction of rotation of the card C by a coil spring (not shown). Therefore, the braking roller 32 rotates somewhat due to the friction generated by the feeding of the card C, thereby preventing the progress of wear in some parts. In addition, it is possible to exert a braking force corresponding to the frictional force at that time.

The first feed roller 14 to the third feed roller 16 are the upper push roller 1 with the conveyance path 11 in between.
4a, 15a, 16a and lower drive rollers 14b, 15
b, 16b. Each push roller 14a. 15
a, 15a are biased toward each drive roller 14b, 15b, 16b, and each drive roller 14b, 15b, 16b
is driven by the timing belt 22, and the card C
is transported at a constant speed and sent out to the outlet 10 at the rear end of the device main body 1.

In addition, the brake roller 32 of the separator roller 13 and each feed roller 14, which are disposed at the upper part of the conveyance path l1,
15.16. Push rollers 14a, 15a, 16a
is supported by an upper chassis 34 provided so as to cover the transport path 11, and the upper chassis 34 is configured to stand upward with its rotation shaft 35 as a fulcrum. Therefore, when the upper chassis 34 is erected and the card case 3 is removed from the device body 1, the entire conveyance path 11 is exposed, which facilitates jam recovery work and maintenance work.

The reading unit 18 includes an image reader 36 that reads the written contents of the card C as image data, and an image reader 3.
When the power is turned on, an electromagnetic solenoid 38, which is a means of moving the shading correction device 37, automatically moves the whiteboard 40 to the image reader 36 via a board support arm 39. the focal point of the camera.

Next, the mechanical drive section 41 and the electronic control section 42 that drives it will be explained based on FIG.

The mechanical drive unit 41 includes a power source 43, an image reader 6 that reads the written contents of the card C as image data, and first and second optical sensors 1 that detect the leading and trailing ends of the card C.
9 and 20, an electromagnetic solenoid 38 that moves the whiteboard 40 of the shading correction device 37, an electromagnetic solenoid 30 that turns on and off the electromagnetic clutch 31 of the pickup roller 12, and a drive motor 23 that drives the timing belt 22. It's hollowed out. The image reader 36 includes an LED array 44 as a light emitting section, a CCD sensor 45 as a light receiving section, an output driver 46 and an amplification amplifier 47 for driving the CCD sensor 45.

The electronic control unit 42 includes a control circuit 48 that controls each of these drive devices, and the rPOWERJ, "error", and l"BU
An LED display section 49 for displaying SYJ and "paper out detection", an alarm buzzer '50 for warning of jam etc., a DIP switch 51 for connecting/disconnecting with the host computer, and an interface 52 for connecting to the host computer are incorporated. . This allows the card image reader to be driven by instructions from the host computer.

Next, the reading section 18 will be described in detail with reference to FIGS. 4 and 5.

This reading section 18 is provided with a shading correction device 37 at the top and an image reader 36 at the bottom, sandwiching the conveyance path 11, and this portion of the conveyance path 11 is cut out to form a reading gap 11a.

The image reader 36 has an LED array 4 at the bottom of the main body 53.
4 is a lens 5 that focuses the light of the LED array 44 in the middle.
4, a CCD sensor 45 is installed diagonally at the top, and a transparent glass 55 is installed at the top to form a unit.
The focus is on the surface of the transparent glass 55, that is, the surface of the conveyance path 11 that is in contact with the back surface of the card C.

On the other hand, the shading correction device 37
A substantially U-shaped board support arm 39 rotatably supported by a board support arm 39, a whiteboard 40 attached to the tip of this support arm 39, an electromagnetic solenoid 38 that rotates the three board support arms, and an electromagnetic solenoid 38 that rotates the three board support arms. Drive shaft 38a of solenoid 38
The drive shaft 38 of the electromagnetic solenoid 38
The board support arm 39 is rotated by the forward and backward movement of a, and the whiteboard 40 is moved to a correction position facing the focal point and a retreating position away from the focal point.

This movement is performed on the whiteboard 4 before reading the card C.
0 toward the focus position of the image reader 36, and a retreat position where it retreats from the focus during the reading operation of the card C. In this embodiment, by turning on the power source 43, the whiteboard 40 is moved to the correction position. The white balance can be adjusted before each reading sequence. After the correction, it is returned to the retracted position and reading begins.

Next, the flow of this shading correction will be specifically explained based on FIG. 6. First, by turning on the power supply 43, a reset is performed (601 in FIG. 6), and the CPU is initialized (602 in the same figure).

Next, the LED array 44 is turned on (603 in the same figure), and then the power to the electromagnetic solenoid 38 is turned on to operate it (604 in the same figure). That is, the whiteboard 40
to the correction position.

This travel time is determined to be 0.5 seconds (605 in the figure).

The above operations complete the preparation for shading correction.

From this state, the CCD sensor 45 is activated by the output driver 46, and the image signal obtained by the CCD sensor 45 is amplified by the amplifier 47 and transferred to the electronic control unit 42 (606 in the figure). This activation time is determined at 300 mS (607 in the same figure), and then the LED array 44 is turned off and the power to the electromagnetic solenoid 38 is turned off (
608). When the power is turned off, the electromagnetic solenoid 38 is returned to its normal position by the coil spring. That is, the whiteboard 40 is moved to the backward α position. In this manner, a series of shading correction operations are performed.

Further, this shading correction can also be performed using the first optical sensor 19 and the second optical sensor 20. That is, the image reader 360 is disposed before and after the image reader 360, and the transport path 1
This uses a first sensor 19 and a second sensor 20 that face the central through-hole 1lb, 1'1b.For example, the first sensor 19 detects the tip of the card C being conveyed, and the second sensor 20 detects the rear end of the card C, and when the second sensor 20 detects the rear end of the preceding card C, the whiteboard 40 is rotated to the correction position as shown in FIG. When the first sensor 19 detects the leading edge of the next card C, the whiteboard 40 is rotated to the retreat position as shown in FIG. 5(b). In this way, it is also possible to perform correction using the whiteboard 40 for each card C.

As described above, when the image reader 36 reads the card C, the whiteboard 40 is away from the focal position and does not interfere with the feeding of the card C. On the other hand, before reading starts, the whiteboard 40 faces the focal position, making it possible to correct the white balance and always obtain the best image.

Further, since the whiteboard 40 does not come into contact with the card C and faces downward, it is not contaminated by dirt or dust.

In this embodiment, the three board support arms are rotated so that the whiteboard faces the focal position, but they may be directly connected to the electromagnetic solenoid 38 and moved up and down to face the whiteboard.

Further, this drive is not limited to the electronic solenoid 38, but may also be a motor or the like.

Furthermore, in this embodiment, the adjustment timing is linked to the ON of the power source 43, but the cards C may be counted and the correction performed every predetermined number of cards.

〔Effect of the invention〕

As described above, according to the present invention, the whiteboard can be brought to the focal position before the reading operation, and the whiteboard can be moved back from the focal position during the reading operation, so that there is no problem with card feeding. This has the effect of making it possible to accurately correct the white balance and always obtain the best image.

[Brief explanation of the drawing]

FIG. 1 is a cutaway side view of an embodiment of a card image reader incorporating the shading correction device of the present invention, FIG. 2 is an external view thereof, and FIG. 3 is a related diagram of a mechanical drive section and an electronic control section. FIG. 4 is an exploded perspective view of the reading section, FIG. 5 is a side view showing the operation around the reading section, and FIG. 6 is a flowchart showing the flow of shading correction when the power is turned on. DESCRIPTION OF SYMBOLS 1... Equipment main body, 11... Transport path, 18... Reading section, 36... Image reader, 37... Seeding device, 38... Electromagnetic solenoid, 3... Board support Arm, 40... Whiteboard, 56...
Connection bar C. ．． card. Figure 5. Flow of the JIH Figure 6

Claims (1)

[Scope of Claims] A shading correction device for use in an image reader that reads the contents of objects to be read that are sequentially introduced into a transport path inside the device, and that adjusts the white balance of the image reader, the device comprising: a whiteboard, and a moving means for moving the whiteboard back and forth between a correction position where it faces the focal point of the image reader before reading an object to be read, and a retreating position where it retreats from the focal point during the reading operation of the object to be read. A shading correction device for an image reader, comprising: