JP2006262063A - Image reader - Google Patents

Abstract

By automatically setting a white reference for each scan, it is possible to reliably set a white reference and obtain a stable image density. In addition, the burden on the operator is reduced.
A reflection mirror mechanism including a reflection mirror, a lens mechanism, and a reflection mechanism for guiding reflected light from a CCD sensor and an image reading surface of an article to the CCD sensor, and reflection of the reflection mirror mechanism. A movable first carriage 9 incorporating a mirror 8 and a carriage controller that drives and controls the first carriage for movement; the first carriage is moved from a predetermined position P1 to a position P2, At the position P2, the image reading surface is read and scanned. Then, while the first carriage is moved to the position P2, a white reference plate 14 in which white paint is applied to the ground glass is disposed. Thus, before reading an image from the image reading surface, the white reference plate is scanned to set a white reference value and perform image density correction.
[Selection] Figure 1

Description

  The present invention relates to an image reading apparatus that reads an image by scanning an image reading surface.

Conventionally, for example, a form creation device is known as a device including an image reading device. This form creation device reflects on the image reading surface of the distribution object by reflecting light from the distribution object such as mail as the subject with a reflection mirror and entering the image sensor such as a CCD sensor through the imaging lens. A bar code, an ID number, and the like are imaged (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 4-177595

  However, the conventional apparatus has no white reference plate for shading correction and cannot adjust the white reference. For this reason, it is conceivable that the operator sets a white reference by putting a blank sheet for adjusting the white reference on the image reading surface when the power is turned on, but this is large when the power is turned on and when the image is actually read. If there is a time difference, the environment inside the device will change, and the white reference set at power-on will be used even though the illuminance on the image reading surface has changed, so the read image density will change. Problem occurs. In addition, the burden on the operator is large, and there is a problem that the white reference is forgotten to be set.

  Therefore, the present invention can automatically set the white reference for each scan, thereby making it possible to reliably set the white reference, obtain a stable image density, and An image reading apparatus capable of reducing the burden is provided.

  The present invention incorporates an imaging device, a reflecting mirror mechanism and a lens mechanism for guiding reflected light from an image reading surface to the imaging device, and at least a part of the reflecting mirror mechanism into a movable carriage, and the carriage is located at a predetermined position. And a white reference plate for image density correction, and before the carriage scans and scans the image reading surface, the white reference plate is scanned to scan the white reference plate. The purpose is to perform image density correction by setting a value.

  According to the present invention, it is possible to automatically set the white reference for each scan, thereby making it possible to reliably set the white reference, obtain a stable image density, and An image reading apparatus capable of reducing the burden can be provided.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram showing a configuration of a main part of an image reading apparatus. A casing 2 having a shape in which an L-shape is inverted and tilted 90 degrees counterclockwise is erected on one end side of a base 1. The space formed between the other end of the base 1 and the housing 2 forms an image reading unit, and an article to be image-read on the base 1 of the image reading unit. 3 is placed. The upper surface of the article 3 forms an image reading surface 3a, and characters, bar codes, etc. are displayed on the image reading surface 3a by printing or the like.

  A control board 4 in which various control circuit components are arranged inside a portion of the housing 2 that faces the base 1, and a CCD that is an image sensor electrically connected to the control board 4 via a cord 5. The sensor 6 is accommodated. A lens mechanism 7 including an imaging lens is disposed in front of the CCD sensor 6. Further, a first carriage 9 having a reflection mirror 8 and a second carriage 12 having reflection mirrors 10 and 11 are disposed inside a portion of the housing 2 facing the base 1. Each of the reflection mirrors 8, 10, and 11 constitutes a reflection mirror mechanism.

  Each of the carriages 9 and 12 is disposed in the vicinity of the upper portion of the translucent glass 13 disposed at the bottom of the portion of the housing 2 facing the base 1. The first carriage 9 is movably disposed along the translucent glass 13, and is usually at a predetermined position P1, and starts scanning from the position P1 when reading an image. At the position P2, the reflection mirror 8 is just an image. It is located on the reading surface 3a. The second carriage 12 can move within a predetermined range, but once the position is fixed, the position is fixed until at least one scan is completed, and is used for optical path adjustment.

  The arrangement of the reflecting mirrors 8, 10, 11 of the carriages 9, 12 is such that light from the image reading surface 3 a passes through the transmission glass 13 and enters the reflecting mirror 8, and is reflected by the reflecting mirror 8. Is incident on the reflecting mirror 10, and the light reflected by the reflecting mirror 10 is reflected by the reflecting mirror 11 and then passes through the lens mechanism 7 to form an optical path that enters the CCD sensor 6.

  The end portion of the translucent glass 13 on the side on which the first carriage 9 moves is formed in a ground glass shape, and a white reference plate 14 is formed by applying a white coating on that portion. The white reference plate 14 is positioned exactly at the position P3 where the first carriage 9 that starts moving from the position P1 accelerates. A shading correction lamp 15 is disposed near the lower part of the white reference plate 14. Further, an illumination lamp 16 for illuminating the image reading surface 3a is disposed in the vicinity of the lower portion of the end portion of the transmission glass 13 on the side where the second carriage 12 is disposed.

  A reflector 17 is disposed at the end of the housing 2 in the vicinity of the illumination lamp 16 so that the light from the illumination lamp 16 is directly irradiated onto the image reading surface 3a and reflected by the reflector 17. It comes to irradiate. In addition, a reflector 18 is disposed on the wall surface of the casing 2 in the vicinity of the shading correction lamp 15, and the light from the shading correction lamp 15 is also reflected by the reflector 18 to illuminate the image reading surface 3a. Also comes to be used effectively.

  FIG. 2 is a block diagram showing the configuration of the control unit. A CPU (Central Processing Unit) 21 constituting the control unit main body, and a ROM (Read Only Memory) 22 storing program data for the CPU 21 to control each unit. A RAM (random access memory) 23 provided with various memories such as a memory for temporarily storing data when the CPU 21 processes data, a memory used for calculation, and a memory for temporarily storing data is provided.

Further, the sensor controller 24 for controlling the CCD sensor 6, the carriage controller 25 for moving and controlling the first carriage 9, the carriage controller 26 for moving and controlling the second carriage 12, and the illumination lamp 16 are driven to light. A lamp inverter 27 and a lamp inverter 28 for driving the shading correction lamp 15 are provided.
The CPU 21, ROM 22, RAM 23, controllers 24, 25, 26 and lamp inverters 27, 28 are connected to each other by a bus line 29.

  When reading an image displayed on the image reading surface 3 a of the article 3 in such a configuration, the operator places the article 3 at a predetermined position on the base 1 with the image reading surface 3 a facing up. When a start key (not shown) is operated, the first carriage 9 starts moving from a predetermined position P1. And it passes on the white reference | standard board 14 in the position which accelerates on the way.

  At this time, the light from the white reference plate 14 is incident on the CCD sensor 6 through the reflecting mirror 8 → the reflecting mirror 10 → the reflecting mirror 11 → the lens mechanism 7 in order. The detection signal from the CCD sensor 6 at this time is input to the sensor controller 24, and white reference data is supplied from the sensor controller 24 to the CPU 21. Thereby, the CPU 21 sets a white reference value for image reading to be performed from now on, and corrects the image density.

  When the first carriage 9 reaches the position P2, reading of the image displayed on the image reading surface 3a of the article 3 is started via the transmission glass 13. The light from the image reading surface 3 a is incident on the CCD sensor 6 through the reflecting mirror 8 → the reflecting mirror 10 → the reflecting mirror 11 → the lens mechanism 7 in order. Thus, the CCD sensor 6 reads the image displayed on the image reading surface 3a, and the sensor controller 24 supplies the read image data to the CPU 21. The CPU 21 processes the image data read using the memory of the RAM 23. At this time, since the image density is corrected using the white reference value set under the same ambient temperature, a stable image density can be obtained.

  As described above, when the image reading scan is performed once, the white reference plate 14 is read to set the white reference, and then the actual image reading is performed. Therefore, the white reference setting can be automatically performed for each scan. it can. As a result, the white reference can be reliably set and the read image density can be made constant. In addition, the operator only needs to operate the start key by placing the article 3 on the base 1, and the burden can be reduced.

  In addition, the white reference plate 14 is not configured as a separate member, but is configured by applying white coating to a part of the conventionally used translucent glass 13, so that the configuration is simple and inexpensive. Can be configured. Further, since the white reference plate 14 is disposed at an acceleration position in the middle of the movement of the first carriage 9 from the predetermined position P1 to the position P2 for reading an image, the first carriage 9 reads the white reference plate 14. There is no need to perform another operation, and the white reference can be set within one scanning time. Accordingly, the image reading process can be quickly performed while setting the white reference for each operation.

  In addition, since the white reference plate 14 in which the transparent glass formed in the shape of frosted glass is coated with white is illuminated by the shading correction lamp 15 from below, the brightness of the white reference plate 14 can be made constant, and the white level Can always be kept constant.

  Further, the image reading surface 3a of the article 3 is directly irradiated with the light from the illumination lamp 16 and reflected by the reflection plate 17, and the light from the shading correction lamp 15 is also reflected by the reflection plate 18. Since the light is reflected and irradiated, the lamps 16 and 15 can be efficiently used for illumination, and the brightness of the image reading surface 3a can be sufficiently secured.

  In this embodiment, the translucent glass formed in the shape of ground glass is applied with white coating to form a white reference plate, but the present invention is not necessarily limited thereto. Further, although a CCD sensor is used as an image pickup device, the present invention is not limited to this.

1 is a diagram illustrating a main configuration of an image reading apparatus according to an embodiment of the present invention. FIG. 3 is a block diagram showing a configuration of a control unit of the image reading apparatus according to the embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 3 ... Article, 3a ... Image reading surface, 6 ... CCD sensor, 7 ... Lens mechanism, 8, 10, 11 ... Reflection mirror, 9 ... 1st carriage, 12 ... 2nd carriage, 14 ... White reference board, 15 ... Shading correction lamp, 21... CPU (central processing unit), 24... Sensor controller, 25.

Claims (3)

  An imaging device, a reflection mirror mechanism and a lens mechanism for guiding reflected light from the image reading surface to the imaging device, and at least a part of the reflection mirror mechanism are incorporated in a movable carriage, and the carriage is moved from a predetermined position. Driving means for controlling and reading and scanning the image reading surface, and a white reference plate for image density correction, and before the carriage reads and scans the image reading surface, the white reference plate is scanned to scan the white reference plate. An image reading apparatus that sets a value and performs image density correction.   When the carriage is moved from a predetermined position and the image reading surface is read and scanned, a white reference plate with a white coating on the glass plate is disposed at the movable position of the carriage, and the carriage is used for image scanning. The image reading apparatus according to claim 1, wherein the white reference value is set within one scanning time that can be moved in a straight line.   3. The image reading apparatus according to claim 2, wherein the image reading surface is illuminated with an illumination lamp and the white reference plate is illuminated with a shading correction lamp.

Images