JPH02266659A - Read circuit for facsimile equipment - Google Patents

Abstract

PURPOSE:To decrease the nonoperating period of a picture processing section while a CCD is operated with a shift clock having a frequency corresponding to the storage time in response to the luminous quantity of the light source by not making the frequency of the shift clock of the CCD identical to the frequency of a drive clock of the picture processing section but giving a proper ratio to the frequencies. CONSTITUTION:A frequency conversion section 13 comprising of a frequency conversion memory is inserted between a picture processing section 14 and an A/D converter 12 which converts an analog data output of an image sensor section 11 using a charge coupled device(CCD) 10 used as a solid-state image pickup element into a digital multi-value data. Then the ratio of the frequency of a shift clock CLK 1 of the CCD 10 and the frequency of a drive clock CLK 2 of the picture processing section 14 is selected to be a proper value. Thus, the nonoperating period of the picture processing section 14 is reduced while the CCD 10 is operated at the frequency corresponding to the storage time in response to the luminous quantity of the light source.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a facsimile apparatus, and more particularly to a reading circuit for a facsimile apparatus in which the processing efficiency of a reading section that reads a document and performs image processing is improved.

(Prior Art) The reading section of the conventional facsimile machine is a charge-coupled device (hereinafter referred to as 000) used as a solid-state image sensor.
D5) and an analog-to-digital converter (hereinafter referred to as A) that converts the analog signal output from the OOD into digital multi-value data.
/l) converter) and 001) output i A/L
) The driving lines of the image processing unit, which inputs the digital multi-single-channel data converted by the conversion unit and processes the image signal, were all clocked at the same frequency.

(Problem to be solved by the invention) The groove removing portion H,oo of the above-mentioned conventional facsimile machine
Since the frequency of the shift clock of u and the drive clock of the A/D converter and image processing section is the same, it is necessary to match the faster one to the part with lower processing capacity.

Generally, either the original or O(ID) moves and scans at a certain relative speed to perform reading, but the ratio of the number of read lines of 00D to the number of lines adopted as an image (hereinafter referred to as sample ratio) is:

It is said that the image quality is better when the ratio is 2:l or more than when the ratio is 1:l. However, if the ratio of sample dead money is 2 to 1 or more, the image processing section is apparently driven at a frequency that is one-half or less of the original driving clock frequency of the image processing section. Therefore, if [ ]OD shift clock frequency is 1:, the image processing drive frequency is the same, and the reading method of the conventional device is butterfly, if the sample ratio is 2:1 or more than 2:1, 0OL) will output the line that is not adopted. The disadvantage is that the image processing section cannot be used effectively during this period.

The object of the present invention is to eliminate all of these drawbacks, and to provide a reading facsimile device that can operate at a frequency corresponding to the accumulation time corresponding to the light intensity of the 00Df% light source and reduce the non-operating period of the image processing section. The purpose is to provide circuits.

(Means for Solving the Problems) In order to achieve the above object, the reading method of the facsimile apparatus of the present invention is to use an image sensor section 11 using %0OD10t- and digital multiplication of analog data output from the image sensor section 11. A/D converter 1 converting into value data
2, in a reading method of a facsimile machine having an image processing unit 14 that performs image processing on the digital multivalued data, the facsimile apparatus has a frequency conversion unit 13 that converts a driving clock frequency of input data and uses it as a driving clock of output data. ,
A frequency conversion section 13 is inserted between the A/D converter 12 and the image processing section 14.

When the digital multivalued data inputted to the frequency conversion section 13 is outputted, the circuit configuration is such that the clock frequency is changed to the frequency of the image processing section driving clock and outputted.

(Example) Next, the present invention will be explained with reference to the drawings.

Figure m1 is a schematic circuit diagram showing one embodiment of the present invention.

As shown in FIG. 1, in this embodiment, an image processing unit 14 is provided between an A/L converter 12 that converts the analog data output of an image sensor unit 11 using 001) 10 into digital multi-value data, and an image processing unit 14. A frequency conversion section 13 consisting of a frequency conversion memory is inserted in the .

In FIG. 1, shift clock 1 of C0D10! :, A
The sample clock of the /D converter 12 is:

The same frequency (0LKI frequency in the figure) t' exists.

Data t-%A/Dlj converted by A/D converter 12
It is written into the frequency conversion memory 13 at the same frequency as the sample clock of the Jk device 12. This frequency conversion memory 1
The data written in the first image processing section 14 is read out at the same frequency as the driving clock (0LK2 in the figure) of the first image processing section 14 and inputted to the first image processing section 14.

In this way, the efficiency of the image processing section 14 can be increased by setting the frequency ratio of the 0ODIO shift clock (OLK) and the driving clock (OLK2) of the image processing section 14 to an appropriate value.

(Effects of the Invention) As explained above, the present invention can shift the OOD by inserting a frequency conversion section that converts the clock frequency between the A/D converter of the reading section and the image processing section. Since the frequency of the clock and the frequency of the driving clock of the image processing unit can be set to an appropriate ratio instead of being the same, image processing can be performed while operating OOD with a shift clock of a frequency corresponding to the accumulation time according to the % light intensity of the light source. This has the effect of reducing the period during which the part is not movable.

[Brief explanation of drawings]

FIG. 1 is a schematic circuit diagram showing one embodiment of the present invention. 10...001) 11... Image sensor section 12... A/L) Converter 13... Frequency conversion section (frequency conversion memory) l4.
・Image processing section

Claims (1)

[Claims] A facsimile machine having an image sensor section using a charge-coupled device, an analog-to-digital converter that converts analog data output from the image sensor section into digital multi-value data, and an image processing section that performs image processing on the digital multi-value data. The reading circuit of the device includes a frequency converter that converts a drive clock frequency of input data to use as a drive clock of output data, and the frequency converter is inserted between the analog-to-digital converter and the image processing unit. . A reading circuit for a facsimile apparatus, characterized in that when outputting the digital multi-value data input to the frequency conversion section, the clock frequency is changed to the frequency of the image processing section drive clock before outputting.