JPH0530352A - Hand scanner - Google Patents

Abstract

(57) [Summary] According to the present invention, in a hand scanner device in which an operator manually moves a reading unit on a document to convert the description content of the document into image data, when a reference plate is scanned by the reading unit. A storage unit (corresponding to the RAM 4) that stores the obtained reference data, and a correction unit that performs a shading correction by comparing the image data of the document obtained by the reading unit with the reference data stored in the storage unit. (Corresponding to the calculation circuit 5) and an informing means (equivalent to the lamp 72) for informing the operator of the update timing of the reference data in the storage means when a predetermined condition is satisfied. An object of the present invention is to provide a hand scanner device capable of performing shading processing and improving image quality without imposing a burden on an operator who operates the hand scanner.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hand scanner device which is connected to a facsimile device or the like and converts a transmission original or the like into image data.

[0002]

2. Description of the Related Art Conventionally, a hand scanner device of this type has a function of reading image data in units of one line when an operator holds it by hand and scans an original. This hand scanner device irradiates the surface of a document to be read with light emitted by an LED element or the like, collects reflected light obtained as a result on a CCD element by a lens array or the like, photoelectrically converts this, and converts the original document. To obtain the image data of.

As described above, in the image data of the original obtained by the hand scanner device, even if the density level of the image to be read is uniform in one line, the variation in the light amount of the light source such as the LED element or the lens system may occur. There is distortion due to the so-called optical system, which is caused by distortion of the amount of condensed light that is caused and variations in sensitivity between elements of the photoelectric conversion element.
The distortion of the image data is, for example, an error on the image data side with respect to a reference level for discriminating white / black of the image data when the image data is finally output as binary data of white or black. Appears, which causes the quality of the read image to deteriorate.

Therefore, in order to solve the above problems, there is a correction processing method called shading processing for correcting image data obtained by reading a document with respect to the distortion of the optical system. In this shading process, a certain density reference (usually a white plate) is read before reading the original, and this is stored internally, and then the image data obtained by reading the original and the density reference are compared for each pixel. It is a method of calculating and correcting the distortion of the optical system.

By the way, since the image reading device incorporated integrally with the facsimile device is not used by removing it, the positional relationship between the white reference plate for obtaining the density reference and the reading sensor is constant. Therefore, the above-described shading processing can be performed for each page of the read document, and image data subjected to shading correction based on the latest density standard can always be obtained.

However, in the above hand scanner device, the positional relationship between the white reference plate and the reading sensor on the hand scanner side cannot be made constant due to its nature. Therefore, if the above-mentioned shading processing is to be performed in the hand scanner device, for example, a white reference plate is prepared in another place, and the white reference plate is scanned by the hand scanner device before reading one page of a document. However, an operation of obtaining the density standard for shading processing must be performed every time, and there is a disadvantage that the operation of the operator is troublesome and it takes time and effort to read the document.

[0007]

As described above, since the hand scanner device has an indefinite positional relationship between the reading sensor and the white reference plate due to its nature, the hand scanner device is not compatible with the white reference plate provided at another place. It is necessary to obtain the density reference data for shading correction by moving to the position and reading this white reference plate. For this reason,
Even with the hand scanner device, the operation load for obtaining the density reference data is imposed on the operator in order to carry out the shading process, and there is a drawback that it takes time and time to read the document. However, if the shading process is omitted, the image quality deteriorates.

Therefore, the present invention eliminates the above-mentioned drawbacks, and provides a hand scanner device capable of improving the image quality by performing shading processing without imposing a burden on an operator who operates the hand scanner. Has a purpose.

[0009]

According to the present invention, in a hand scanner device in which an operator manually moves a reading unit on a document to convert the description content of the document into image data, a reference plate is used by the reading unit. Storage means for storing reference data obtained at the time of scanning; correction means for performing a shading correction by comparing the image data of the document obtained by the reading portion with reference data stored in the storage means; And a notification means for notifying the operator of the update timing of the reference data in the means when a predetermined condition is satisfied.

[0010]

In the hand scanner device of the present invention, the storage means stores the reference data obtained when the reference plate is scanned by the reading unit. The correction unit compares the image data of the document obtained by the reading unit with the reference data stored in the storage unit to perform shading correction. The notifying means notifies the operator of the update timing of the reference data in the storage means when a predetermined condition is satisfied.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a hand scanner device of the present invention. Reference numeral 1 is a reading unit, which is a document 100.
A lamp (light source) 11 that illuminates the surface of the document, a lens 12 that collects the reflected light from the original 100 on a CCD 13, a CCD 13 that converts an optical image into an electrical signal, sample and hold the image data, and adjust to a predetermined DC level. The sample hold clamp circuit 14 is provided. Reference numeral 2 is an A / D converter that converts the image data output from the reading unit 1 into digital data. Reference numeral 3 is a switch circuit that switches between reading white reference data and normal image data. Reference numeral 4 stores white reference data. RAM,
5 is a division circuit for dividing the input image data by the white reference data read from the RAM 4, 6 is a post-image processing unit for binarizing the shading-corrected image data input from the division circuit 5, Reference numeral 7 denotes an operation unit of the hand scanner device, a switch 71 for starting reading and a lamp 72 for prompting the operator to read white reference data.
have. Reference numeral 8 is a control timing generation circuit for generating a switching control signal and a read start signal for the switch circuit 3 and for checking the presence or absence of data in the RAM 4.

Next, the operation of this embodiment will be described. The white reference data is not stored in the RAM 4 immediately before the power supply to the hand scanner device is turned on. Therefore, immediately after the power of this hand scanner device is turned on, the control timing generating circuit 8 detects that there is no white reference data in the RAM 4 and turns on the lamp 72 of the operation unit 7,
Prompt the operator to enter white reference data. As a result, the operator moves the reading unit 1 to a separately provided white reference plate (not shown), and the switch 71 of the operation unit 7 is moved.
After pressing to turn it on, the reading unit 1 is scanned along the white reference plate.

The control timing generation circuit 8 has a switch 71.
When it is detected that is turned on, the contact of the switch circuit 3 is switched to the terminal b side, and the lamp 11 of the reading unit 1 is turned on to start the control of reading the white reference plate.
The reflected light from the white reference plate irradiated by the lamp 11 is condensed on the CCD 13 by the lens 12 and is converted into image data for one line here. The image data is sampled for each pixel by the sample and hold circuit 14, the data level is stabilized, and then the direct current level is adjusted to a predetermined value and then output to the A / D converter 2. The A / D converter 2 digitizes the input image data (the same as the white reference data) and stores it in the RAM 4 via the switch circuit 3. When at least one line of white reference data is stored in the RAM 4, the control timing generation circuit 8 turns off the lamp 72 of the operation unit 7 to notify the operator that the document reading is ready, and at the same time, the switch circuit. 3 is switched to the terminal a side.

After that, when the operator moves the reading unit 1 on the original 100 in the sub-scanning direction, the reflected light from the original 100 irradiated by the lamp 11 is focused on the CCD 13 by the lens 12, and the light is optically reflected here. Connect the statues. This optical image is converted into image data by the CCD 13 and input to the sample hold clamp circuit 14.
The sample and hold clamp circuit 14 samples and holds the input image data to stabilize its level, and then adjusts its DC level to a predetermined value.
Output to the A / D converter 2. The A / D converter 2 converts the input image data into digital data and outputs it to the division circuit 5.

The division circuit 5 stores the image data for one line, which is input through the switch circuit 3, in the RAM for each pixel.
Shading correction is applied to the input image data by dividing the white reference data for one line stored in No. 4 by the data corresponding to the pixel. FIG. 2A shows an example of image data input to the division circuit 5. The image data is subjected to shading correction in the division circuit 5, and the image data of the optical system as shown in FIG. The image data will have the distortion corrected. The image data thus shading-corrected is binarized and output by the post-image processing unit 6.

According to this embodiment, once the white reference data for shading correction is read immediately after the power of the hand scanner device is turned on, the white reference data is used thereafter to perform the shading at the time of reading an original. In order to perform the correction, the operator can eliminate the time and effort required to read the white reference data, and since the shading correction of the read image is performed by the white reference data updated every time the power is turned on, The image quality of the read image data can be improved. In this example, the white reference data is updated each time the power to the apparatus is turned on, but the white reference data may be updated every predetermined time or every time a predetermined number of originals are read.

[0017]

As described above, according to the hand scanner device of the present invention, it is possible to improve the image quality by performing the shading process without imposing a burden on the operator who operates the hand scanner.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a hand scanner device of the present invention.

FIG. 2 is a diagram showing a waveform example of input data and output data of the division circuit shown in FIG.

[Explanation of Codes] 1 ... reading unit 2 ... A / D converter 3 ... switch circuit 4 ... RAM 5 ... division circuit 6 ... post-image processing unit 7 ... operation unit 8 ... control timing generation circuit

Claims (1)

Claim: What is claimed is: 1. In a hand scanner device in which an operator manually moves a reading unit on a document to convert the description content of the document into image data, a reference plate is scanned by the reading unit. Storage means for storing the reference data obtained at the time, and a correction means for performing a shading correction by comparing the image data of the document obtained by the reading section with the reference data stored in the storage means, and the storage means. A hand scanner device for notifying an operator of the update timing of the reference data therein when a predetermined condition is satisfied.