JPS6251026B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for reading and transmitting calligraphic information in facsimile machines and the like.

Conventionally, in facsimile recording and reproducing images, characters in Mincho fonts, that is, characters whose horizontal strokes are thin and vertical strokes are thick, have had the disadvantage of poor reproducibility. Reproducibility was poor not only with Mincho typeface characters, but also with thin lines extending horizontally and single-shot images consisting of combinations of these lines. This is because the thickness of the line is often smaller than the resolution of the reading scan. Conventionally, therefore, the solution to this problem has been to reduce the aperture size in the optical system of the reading head to increase the scanning resolution, or to increase the linear scanning density. However, in the former method, the amount of light from the light source must be increased, leading to an increase in cost, and in the latter method, the signal transmission time increases.

Therefore, in order to improve image reproducibility without increasing the linear density of scanning and therefore without increasing the signal transmission time, image signals have conventionally been processed as shown in FIG. 1.

That is, in FIG. 1, the recording image reading head 1
It is assumed that eight photoelectric conversion elements (1a to 1h) are arranged in a line, and the arrangement pitch of each element is 1/8 mm. Adjacent photoelectric conversion elements are logically connected to each other. That is, the respective outputs of the photoelectric conversion elements 1a and 1b are input into the OR circuit _OR1 as one set, and the logical sum output A is obtained. Similarly, an OR circuit _OR2 is connected to the pair of photoelectric conversion elements 1c and 1d to obtain an OR output B. Hereinafter, in the same manner, photoelectric conversion elements 1e and 1f
The logical sum output C of , and the logical sum output D of 1g and 1h are obtained, respectively. In this way, when an image signal is detected from at least one of the elements of each set, the output from the OR circuit is obtained, and the channel A, which is scanned by the element set where the image signal was detected,
Output signals are obtained from B, C or D. OR circuit
The outputs A, B, C and D of OR ₁ , OR ₂ , OR ₃ and OR ₄ are appropriately processed as output signals of each sub-scanning channel and transmitted to the receiving side. However, it is assumed that the number of sub-scanning channels in this case is 4 lines/mm. If such a reading head 1 is used, it is possible to read out even a thin line having a width of 1/2 of 1/8 mm without changing the sub-scanning line density, and the frequency of reading of thin lines is reduced. However, if the image line width that crosses the element width is 1/2 or more, reading by the photoelectric conversion element is possible.

However, in such a conventional example, the required number of logic circuits (OR circuits in this example) is high, resulting in high costs, and when using a reading head in which photoelectric conversion elements are arranged in the main scanning direction, at least one line is required. It also had the disadvantage of requiring a large amount of memory, which also led to high costs.

The present invention was made in order to overcome the drawbacks of the conventional examples as described above, and achieves a reduction in the frequency of missed reading of thin lines in an image at a low cost, and also enables high-speed transmission of image read information. The purpose is to provide a method for reading and transmitting calligraphic information.

Embodiments of the present invention will be described below with reference to FIGS. 2 to 5.

FIG. 2 is a block diagram showing an embodiment of the present invention, and 2 is a self-scanning photoelectric conversion element array (hereinafter referred to as PDA) in which a plurality of photoelectric conversion elements are arranged in the sub-scanning direction.

3 is a reading start pulse generator that generates a reading start pulse a for each main scanning position as the PDA 2 moves in the main scanning direction; 4 is a self-scanning clock pulse for scanning with each photoelectric conversion element of the PDA 2; 5 is a driver for driving the PDA 2;

Therefore, the PDA 2 outputs a video signal in synchronization with the self-scanning clock pulse b for each main scanning position. After this output is amplified by amplifier 6,
The signal is binarized by a binarization circuit 7 and output as an image signal c.

Reference numeral 8 denotes a frequency divider which reduces the frequency of the self-scanning clock pulse b inputted after generation of the reading start pulse a to 1/2. Therefore, the frequency divider 8 generates a pulse synchronized with the odd or even picture signal of the picture signal output from the binarization circuit 7, and this is used as the sampling pulse d to extract the odd or even picture signal in the circuit 9. used for

That is, the circuit 9 is constituted by a D flip-flop, and the image signal c outputted from the binarization circuit 7 is input to the D terminal, and the sampling pulse d is input to the C terminal. Therefore, an odd or even picture signal e synchronized with the sampling pulse d is output from the Q terminal.

The binarized image signal c and its sampled image signal e are sent out from the OR gate 10 as an image signal f.

Next, the operation will be explained with reference to the time chart of FIG.

As shown in FIG. 3, the pulse generator 4 constantly generates a self-scanning clock pulse b of a predetermined frequency.

When the PDA 2 reaches a predetermined main scanning position, the pulse generator 3 generates a reading start pulse a.

These pulses a and b are input to the driver 5, and the PDA 2 is driven according to the reading start pulse a. Self-scanning clock pulse b from PDA2
Video signals are output sequentially in synchronization with This video signal is amplified by an amplifier 6 and binarized by a binarization circuit 7, and then sequentially receives image signals D1, D2, D3...
The signal is input to the circuit 9 and the OR gate 10 as follows.

When the reading start pulse a is input, the frequency divider 8 outputs a sampling pulse d having a frequency 1/2 of the self-scanning clock pulse b. The circuit 9 samples the image signal c using the sampling pulse d, and produces odd-numbered image signals D1 and D as shown in FIG.
3, D5... is output.

Therefore, the OR gate 10 outputs the logical sum of the odd-numbered picture signal and the even-numbered picture signal D1+D2, D3+D.
4, D5+D6... are sent out.

As described above, in this embodiment, with a simple configuration using the 1/2 frequency divider 8, flip-flop 9, and OR gate 10, it is possible to process the image signal obtained from the reading head 2 two bits at a time and send it out. Therefore, the number of elements can be reduced compared to the conventional example, and costs can be reduced.

By the way, the method described above, in which image signals of 2 bits each in the sub-scanning direction are simply ORed and sent out, is effective when the manuscript is written in Mincho font or handwritten. If the original is a typeface printed in Gothic font, the "black" information is emphasized so much that when it is reproduced on the receiving side, the thin white lines are lost and the characters are painted black. Therefore, in such cases, it may be better to simply send out the image signal of the sampled length. Furthermore, it may be better to process the image signal to be sent this time taking into account the image signal sent last time.

Therefore, a method for reading and transmitting calligraphy information, which can change the processing method of calligraphy and drawing information as appropriate depending on the written state of the document and sending it out, will now be described with reference to FIGS. 4 and 5.

That is, FIG. 4 is a block diagram showing another embodiment of the present invention, in which the same reference numerals as in FIG. 2 indicate the same or corresponding parts. The difference from the configuration shown in FIG.
1, 12, OR gate 13 and flip-flop 14, E _j =D _i-1 +D
_i・_j-1 (However, E _j is the image signal g to be sent this time, E
_j-1 is the image signal h sent out last time, that is, 1 bit earlier, and D _i
is the image signal c, D _i-1 obtained from the reading head this time.
performs logical processing on the image signal e) obtained from the previous reading head, that is, one bit earlier, inputs the obtained image signal g to the image signal sending output selection circuit 15, and outputs the logical signals SO, S1 according to the manuscript writing condition. The structure is such that these image signals e, f, and g can be appropriately selected and sent out depending on the combination of the following.

Therefore, as in the case of the embodiment described above, the binarized image signal c, the sampled image signal e, and the image signal f obtained by ORing these image signals are obtained at the timings shown in FIG. 5, respectively. Occurs in

By the way, when the image signal output selection circuit 15 selects and outputs the image signal g output from the OR gate 13, the image signal g is fed back to the flip-flop 14 of the logic processing circuit L.

At this time, if the flip-flop 14 is triggered by the write or send pulse i generated in synchronization with the even-numbered image signal, the flip-flop 14 will read the send-out image signals E0, E of the previous bit at the timing shown in FIG.
1, E2... are held. We will use this for our logical processing. That is, if the previously output image signal h is logic "1", the AND gate 12 is opened and the sampled image signal e is output from the OR gate 13. Further, when the image signal h outputted last time is logic "0", the AND gate 11 is opened and the logically summed image signal f is output. That is, the logic processing circuit L performs the logic processing of E _j =D _i-1 · _j-1 and sends out the image signal g.

As a result, when the image signal output selection circuit 15 selects the image signal g output from the logic processing circuit L, the image signal h output from the circuit 15 at the timing shown in FIG. The sampled image signal e or the ORed image signal f is obtained. This is effective for manuscripts containing a mixture of handwritten and Gothic type characters.

In this way, depending on the writing condition of the manuscript, for example, if the manuscript is mainly written in Mincho font or handwritten, the logical sum signal f is sent, and if the manuscript is printed in Gothic type, the logical sum signal f is sent. Sampling image signal e
In addition, if both are mixed, if the logic processing image signal g is selected and sent by the circuit 15, even if the line density is coarsened and sent, information will not be lost on the receiving side and will be good. Images can be reproduced.

Note that the logic processing circuit L is not limited to the above-mentioned logic processing, but can be configured to perform any logic processing depending on the written state of the manuscript.

As described above, according to the present invention, even if calligraphy information is sent with a coarse scanning line density, a good image can be reproduced on the receiving side, and high-speed transmission of calligraphy information is possible at low cost. Become.

[Brief explanation of the drawing]

Fig. 1 is a photoelectric conversion element array and its processing circuit diagram for explaining the conventional method, Fig. 2 is a block diagram showing an embodiment of the present invention, and Fig. 3 is a time chart for explaining its operation. FIG. 4 is a block diagram for explaining another embodiment of the present invention, and FIG.
The figure is a time chart for explaining the operation. 2... Self-scanning photoelectric conversion element array (PD
A) 3...reading start pulse generator, 4...self-scanning clock pulse generator, 5...driver, 6
... Amplifier, 7 ... Binarization circuit, 8 ... Frequency divider,
9...Sampling circuit, 10...OR gate,
15... Image signal sending output selection circuit, L... logic processing circuit.

Claims (1)

[Claims] 1. A calligraphy information reading means equipped with a self-scanning photoelectric conversion element array in which a plurality of photoelectric conversion elements are arranged in the sub-scanning direction, and a calligraphy information reading means equipped with a self-scanning photoelectric conversion element array in which a plurality of photoelectric conversion elements are arranged in the sub-scanning direction; means for generating a reading start pulse; means for generating a scanning clock pulse for scanning the self-scanning photoelectric conversion element array and extracting an image signal; and means for dividing the frequency of the scanning clock pulse and outputting a sampling pulse. and means for sampling, with the sampling pulse, a plurality of bits in the sub-scanning direction at each of the main-scanning positions, which is output from the document and image information reading means in synchronization with the scanning clock pulse in response to the reading start pulse; means for calculating the logical sum of the sampled image signal and the image signal output from the above-mentioned calligraphy information reading means; the above-mentioned sampled image signal, the image signal output from the above-mentioned calligraphy information reading means, and the previously sent image signal; a means for performing predetermined logical processing based on the above, and selecting the sampled image signal, the image signal obtained by performing the logical sum, and the image signal subjected to the predetermined logical processing according to the written state of the calligraphic information. 1. A method for reading and transmitting calligraphy information, comprising: