JP2000299758A - Method for detecting white paper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a cost increase and a complicated configuration due to addition of a white paper detection function by detecting white paper by means of existing circuits and configuration without having a special black dot count circuit. SOLUTION: An image scanner reads and binarized image data, which are stored once in a line buffer (S1) for each line and in a SAF as compressed data at the same time (S3). After the data compression corresponding to one page is finished, an RTC bit denoting a page end is added to the compressed data and reading by one page is finished (S4). A CPU measures the compressed data quantity by one page every time one page of data are compressed (S5). When the compressed data quantity is obtained, the CPU compares the quantity with a prescribed quantity to discriminate whether the paper sheet is a white paper sheet (S6). When the compressed data quantity is smaller than the prescribed quantity, the original is discriminated to be a white paper original (S7), and when the data quantity is greater than the prescribed quantity, the paper sheet is discriminated to be a page of an original and the processing continues to a succeeding page (S8).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a blank page detection method, and more particularly, to a blank page detection method for detecting a blank page in a facsimile, a copying machine, a scanner, or the like.

[0002]

2. Description of the Related Art A blank page is detected in Japanese Patent Application Laid-Open Nos. 5-300313 and 6-261168. If the page is blank, the user is informed that the page is blank, or a transmission is made. Although a facsimile apparatus that performs measures such as stopping is described, the blank sheet detection method in that case is the measurement of the number of black dots as described in the embodiments and the like.

[0003]

In a facsimile apparatus or the like, there is a problem that a document to be transmitted is mixed upside down in a document to be transmitted, or that a blank page is transmitted by mistakenly turning upside down a document set of all pages. is there. In order to avoid this, the operator is warned with a sticker or the like about the orientation of the document set, but this is not perfect. Therefore,
If there is a possibility that the image data is blank than the read image data, a blank sheet detection function is provided to notify the operator of the fact that the image is blank.

[0004] JP-A-5-300313 and JP-A-6-300313
In the blank sheet detection method proposed in, for example, Japanese Patent Application Publication No. -261168, the number of black dots of read image data is counted for one page, and the count value is compared with a predetermined value to determine a blank sheet. However, this method requires a separate black dot counting circuit, and has a problem of increasing costs.

In addition, since the black dots for reading white paper change depending on how to insert the original, the material of the paper, the contamination of the scanner glass and the change with the diameter, there is a possibility that an erroneous determination may occur.

[0006]

According to the present invention, there is provided image information reading means for reading an original, compression means for compressing the read image data, and a compressed data amount for one page of the compressed data compressed by the compression means. In a device comprising a measuring means for measuring the blank page, by determining the compressed data amount by comparing with a predetermined value,
Furthermore, a predetermined value for determining whether or not the page is a blank page is made variable, furthermore, the actual value of the compressed data is measured by reading the actual blank document by the predetermined value and the image information reading means, It is characterized in that it is set based on the data amount.

[0007]

FIG. 1 is a block diagram showing an embodiment of a facsimile apparatus to which a blank sheet detecting method according to the present invention is applied. In the drawing, reference numeral 1 denotes a whole facsimile, 2 denotes a CPU for controlling the whole facsimile, and 3 Is a ROM memory storing an entire control program, 4 is a RAM memory used for system control and line buffer, 5 is a DCR block for compressing / expanding image data, 6 is a DMAC block for controlling DMA, 7 is a plotter unit, and 8 is a plotter unit. An operation unit 9 is an operator I / F. A scanner 9 reads image data and binarizes the image data.
Reference numeral 0 denotes a modem that modulates and demodulates data during transmission and reception, 11 denotes an NCU that performs network control, and 12 denotes an SAF that stores image data.

FIG. 2 is a flowchart for explaining the operation of the present invention. The image data read by the image data reading scanner 9 is binarized and temporarily stored in the line buffer 4 line by line. (S1). At the same time, the image data stored in the line buffer 4
5 (S2) and compressed as SAF 12
Is stored (S3). When one page of compressed data is stored, an RTC bit indicating a page break is added to the compressed data to complete the reading operation of one page (S
4). When there are a plurality of originals, this operation is repeated. The above is a general operation.

Here, the CPU 2 of FIG. 1 stores a compressed data storage start address every time one page is compressed and measures the amount of compressed data for one page (S5). Once the compressed data amount is obtained, it is determined whether the compressed data amount is blank by comparing it with a predetermined value (S6). By the way, A4, 8 mm, MM
For a blank original in R, the number of compressed data per page is about 300
Byte. If the amount of compressed data is smaller than the predetermined value, it is determined that the document is a blank document (S7). If it is larger, it is determined that the document is a document page, and the process proceeds to the next page (S8).

The predetermined value to be compared is determined by an operator or the like.
It can be rewritten by inputting from the operation unit 8. As a method of determining the predetermined value, for example, an actual blank document is read by the scanner 9 and the amount of compressed data is measured. Determine the value. A blank document measurement mode is created, an operator sets a blank sheet, the above measurement is performed, and the CPU determines an appropriate predetermined value from the measured value.

[0011]

According to the present invention, a blank page is detected by an existing circuit and configuration without a special black dot counting circuit, thereby preventing an increase in cost and a complicated configuration due to the addition of a blank page detection function. By adopting a configuration in which the predetermined value for comparison can be made variable, it is possible to cope with an erroneous detection, and the quality is improved. Further, by determining a predetermined value for comparison with reference to an actual blank document, an appropriate predetermined value can be obtained even when there is a change in time of a scanner or the like, preventing erroneous detection and the like, Goes up.

[Brief description of the drawings]

FIG. 1 is a main part configuration diagram showing an example of a facsimile apparatus to which the present invention is applied.

FIG. 2 is a flowchart for explaining an embodiment of a blank sheet detection method according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... The whole facsimile, 2 ... CPU, 3 ... ROM memory, 4 ... RAM memory, 5 ... DCR block, 6 ... DM
AC block, 7: plotter unit, 8: operation unit, 9: scanner, 10: modem, 11: NCU, 12: SAF.

Claims (3)

[Claims] An image information reading means for reading a document;
An apparatus comprising: a compression unit for compressing read image data; and a measurement unit for measuring an amount of compressed data of one page of the compressed data compressed by the compression unit. A blank sheet detection method characterized by making a judgment by comparing with a predetermined value. 2. The blank page detection method according to claim 1, wherein the predetermined value for determining whether the page is a blank page is variable. 3. The blank paper according to claim 2, wherein the image information reading means causes an actual blank document to be read, the compressed data amount is measured, and the predetermined value is set based on the data amount. Detection method.