JPS6113768A - Screen size detector - Google Patents

Abstract

PURPOSE:To attain the mixture of original pictures different in size and to improve the operability by discriminating the picture plane size according to the number of picture elements in an extracted screen area and separating the picture signal corresponding to the screen area from the photoelectric conversion signal. CONSTITUTION:A communication control part exchanges the desired control procedure signals prior to the electric transmission of picture planes to the reception side in a preparatory stage of transmission. Thus the matching of the device standard is secured between the transmission and the reception. This matching operation includes the picture plane size and the communication control part collates the indication of screen size given from a screen size deciding circuit 3 with the information on the screen size given from the reception side. When the communication control procedure is through with the reception side, a facsimile equipment transmits pictures. A switch 5 supplies a photoelectric conversion signal D given from a CCD1 to a binary coding circuit 6 and sends the black/white binary signal to a gate 7. While a line memory 4 reads out the stored picture plane area signal F for each start of a scan and sends it to the gate 7. The gate 7 sends the picture element data on the signal D to a picture processing part when the signal F is set at ''1''.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of the Invention] The present invention relates to a screen size detection device, and more particularly to a screen size detection device in an automatic paper feeder used in facsimile machines.

[Prior art]

The screen size detection device in the automatic paper feeder used in conventional facsimile machines moves a guide plate that regulates the original image setting position according to the original image size, and detects a detection signal from a size detection switch for each screen size that is activated by the guide plate. Specify one screen size according to
By extracting the output signal of a fixed area specified in advance according to the screen size from the main scanning width of the dimensional image sensor.

Cutting out the screen signal.

However, in such a configuration, the size of original images that can be set simultaneously is fixed, and it is impossible to perform size detection when original images of different sizes are loaded together.

That is, the conventional screen size detection device has a drawback in that original images of different sizes cannot be mixed at the same time.

[Purpose of the invention]

An object of the present invention is to provide a screen size detection device that can simultaneously load original images of different sizes.

That is, one object of the present invention is to eliminate the above-mentioned drawbacks,
By identifying the photoelectric conversion signal consisting of signals from the non-screen area and the screen area corresponding to one scanning line, extracting the screen area, and determining the screen size based on the number of pixels in the extracted screen area. An object of the present invention is to provide a screen size detection device file that specifies one screen size and cuts out a screen signal, thereby making it possible to mix original images of different sizes.

[Structure of the invention]

The screen size detection device of the present invention includes a one-dimensional image sensor that self-scans a predetermined main scanning width with a predetermined scanning clock; A photoelectric conversion signal composed of an output voltage for each of the scanning clocks of the non-screen area and the screen area that is generated is compared with a preset reference voltage for each of the scanning clocks, and based on the comparison result, a corresponding one is applied to the screen area. A screen area detection means that generates a screen area signal, counts the screen area signal, and sequentially compares the counting results with a plurality of preset screen size values to select the screen size of the original image and instruct the original image size. and screen size determination means.

The output voltage corresponding to the screen area is extracted from the photoelectric conversion signal according to the screen area signal.

[Explanation of Examples]

The present invention scans an original image having a screen width less than or equal to the nuclear main scanning width with a one-dimensional image sensor having a predetermined main scanning width, and detects the difference between the screen area and the background based on the voltage value of each pixel in the photoelectric conversion signal generated. By identifying the screen area, extracting the screen area, determining the screen size from the number of pixels corresponding to one screen area, and extracting the image signal from the photoelectric conversion signal, it is possible to mix different sizes in automatic paper feeders. This is to realize a screen size detection device t' that makes it possible.

Embodiments of the present invention will be described in detail below with reference to one drawing.

FIG. 1 is a schematic diagram showing an embodiment of the present invention.

Screen size pressure detection device consists of CCDI and 1 screen area detection circuit 2
, a screen size determination circuit 3 , a line memory 4 , a switch 5 , a binarization circuit 6 , and a gate 7 .
' Below, the operation of the embodiment shown in FIG. 1 will be explained in detail with reference to FIGS. 2 and 3. FIG. 2 is a detailed block diagram of the screen area detection circuit 2, and FIG. 3 is a conceptual diagram showing an example of a screen area signal.

As shown in FIG. 1, the CCDI is a one-dimensional image sensor in which a plurality of optical sensors are arranged in a line at approximately equal intervals, and performs self-scanning using a scanning clock S to main-scan the scanning area. In the following explanation, the main scanning width f of CCDI is A3 size (297 mm).
).

Right now, I'm using the automatic paper feeder of my facsimile to load all the original drawings in A3 size, smaller 34 size, A4 size, and 85 size, in random order.

The explanation will be based on a case where an A4 size (210ml) original image is supplied to the original image reading section of the facsimile.

When the facsimile apparatus is in the preparation stage for transmission before sending out all image signals, the leading edge of the supplied document is stopped at the scanning area of the original image reading section. In this state, the CCDI main-scans the scanning area and generates a photoelectric conversion signal Dt corresponding to A3 size.
- Output. Therefore.

The photoelectric conversion signal is composed of output signals from the scan area background, which is a non-screen area, and the screen area of the original image.

Here, the background of the scanned part is set so that if the original drawing is written in black, the background is black, and if the original drawing is written in white on a black background, the background is white. . In the explanation below, the original drawing is written in black on a white background.

At the preparatory stage for transmission, the switch 5 switches the photoelectric conversion signal to
- Supplied to the screen area detection circuit 2. Screen area detection circuit 2
As shown in FIG. 2, there are an A/D converter 21, a comparator 22, and a change point detector 23.

A run length converter 24 is provided.

The A/D converter 21 has a judgment level divided into a total of 256 levels between the upper and lower limit voltages, with the output voltage for white on the screen as the upper limit reference voltage and the output voltage for black as the total lower limit reference voltage. The pixel voltage for each scanning clock S is converted into an 8-bit digital pixel voltage according to its determination level.

The comparator 22 compares the supplied digital pixel voltage with an 8-bit reference voltage set in advance for each full scan clock S, and when the digital pixel voltage is large, it is "1", which is equal to 1, or when it is small, it is the rOJ judgment signal Et-. Output. However, the reference voltage is set to a value higher than the output voltage corresponding to the background, taking into account variations in the background density of the scanned region.

The change point detector 23 first detects that the supplied judgment signal E is "0".
” becomes “1” at the first change point, and “1” at the end
Detect second change points from rOJ and feed them to run length converter 24.

The run-length converter 24 converts the judgment signal E supplied from the comparator 22 into "1" for all values from the first change point to the second change point, and converts the judgment signal E supplied from the comparator 22 into "1" values before the first change point and before the second change point. The rest is all ruJ, and a screen area signal Pi, an example of which is shown in FIG. 3, is output.

In FIG. 3, areas with reference symbols M and N correspond to non-screen areas of the background, and areas with reference symbol H correspond to screen areas. If the resolution in the main scanning direction is 1mmmm, then rM+N
The number of pixels corresponding to +HJ is r297X8=2376J,
The number of pixels corresponding to rHJ is r210X8=1680J
become.

In FIG. 1, one screen area signal F is supplied to a screen size determination circuit 3. The screen size determination circuit 3 includes a count comparator 31 and a ROM 32. 'R,0M32 stores pixel values corresponding to screen sizes to be selected in advance. -To give an example.

r1680+4 for A4 size. OJ is stored.

However, r40J is a value for preventing erroneous judgments due to dimensional errors in the original image.

The counting comparator 31 counts "1" of the screen area signal F, and converts the counting result into the screen size value from 0M32 and 85 size, A4 size.
The screen size is compared in the order of size, B4 size, and A3 size, and when the counted value becomes smaller, that screen size is determined to be the screen size of the original image at the scanning site.

In the case of the example, since the count value is [1680J], it is larger than 85 size by -1-le I-zsooJ x D, and smaller than [1720J compared to A4 size, so it is determined that the original size is A4 size, An A4 size instruction is given to a communication control section and an image processing section (not shown).

At the same time, the one screen area signal F is stored in the line memory 4.

On the other hand, in the communication control section 1, in the preparation stage for transmission.

Necessary control procedure signals are exchanged with the receiving side prior to the transmission of the screen, and the device standards between the transmitting and receiving sides are matched.

The harmonization of this standard also includes screen size.

The communication control unit verifies the screen size instruction from the screen size determination circuit 3 against the notification of the screen size from the receiving side, and responds to the receiving side with the verification result.

After the communication control procedure with the receiving side is completed, the facsimile apparatus returns to the image sending state, and the switch 5 supplies the photoelectric conversion signal from the CCD 1 to the binarization circuit 6.

The photoelectric conversion signal is converted into white and black binary signals by a binary conversion circuit 6 and supplied to a gate 7.

The line memory 4 reads out the stored screen area signal F at each start of one scan and supplies it to the gate 7. When the screen area signal F is "1", the gate 7 supplies the corresponding pixel data in the photoelectric conversion signal to an image processing section (not shown). Therefore, only the image signal portion corresponding to one screen area H is cut out.

Thereafter, the image processing section performs necessary enlarging/reducing processing and encoding processing, but since these are not directly related to the present invention, their explanations will be omitted.

〔Effect of the invention〕

As described above, the screen size detecting device of the present invention includes a screen area detecting means, a screen size determining means, and a total of four automatic tln14
' 1 *K%E+X
kll b By extracting from all the photoelectric conversion signals, one screen size can be specified and the screen signal can be extracted, and original images of different sizes can be loaded together in an automatic paper feeder, which has the effect of completely improving operability.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a detailed block diagram of a screen area detection circuit in the embodiment shown in FIG. 1, and FIG. 3 is a conceptual diagram showing an example of a screen area signal. be. In the figure, ■... COD, 2... screen area detection circuit, 3... one screen size discrimination circuit,
4...Line memory, D...Photoelectric conversion signal, K...Reference voltage. F... Screen area signal, S... Scanning clock. Agent Patent Attorney Susumu Uchihara 1st Session 2 Figure

Claims (1)

[Claims] Self-scanning a predetermined main scanning width with a predetermined scan clock 1
a dimensional image sensor and a photoelectric conversion signal composed of output voltages generated from the one-dimensional image sensor for each of the scanning clocks in each of the non-screen area and the screen area when scanning an original image having a screen width equal to or less than the main scanning width; a screen area detection means for comparing a predetermined reference voltage with a preset reference voltage for each of the scanning clocks and generating a screen area signal corresponding to the screen area based on the comparison result, and counting the screen area signal and setting the counting result in advance. screen size determination means for selecting the screen size of the original image by sequentially comparing it with a plurality of screen size values, and instructing the original image size, and corresponding to the screen area from the photoelectric conversion signal according to the screen area signal. A screen size detection device characterized by cutting out an output voltage.