JPS5937763A - Original and original width detector of picture reader - Google Patents

Abstract

PURPOSE:To detect an original and its width accurately at low cost through a small-sized constitution, by providing a solid-state image pickup element with two couples of sensers, and deciding the presence of the original and its size on the basis of their outputs. CONSTITUTION:Original sensors 9a and 9b are provided near the solid state image pickup device 6 and original sensors 11a and 11b are provided inside of it; they correspond to the widths of sizes B4 and A4. Further, a back plate 3 facing the read end of an optical fiber 4 is painted in black into a beltlike shape at part of the white ground, and this black part 16 is arranged corresponding to the fiber read end extending from the sensors 9a and 11b. Then, the sensors 9a and 9b correspond to the white ground, so the presence of the original is detected regardless of whether the original is white or black. An original of size B4 is detected by all the sensors, but that of size A is not detected by the sensors 9a and 9b. Thus, the original size is identified.

Description

Detailed Description of the Invention Technical Field - The present invention relates to a document and a document in an image reading device that reads an image of the document using a solid-state imaging device equipped with a plurality of photoelectric conversion elements arranged in the main scanning direction. The present invention relates to a width detection device.

BACKGROUND OF THE INVENTION The above-mentioned image reading device is disposed, for example, in a facsimile transmitting device, and in that case functions to read the contents of a document image to be transmitted. At that time, the series of sending/receiving operations performed based on the read image information must be started after confirming that the original has been fed into the reading device, so the sending/receiving operations are It is an essential task to detect that the document has been fed as described above. In addition, in the above series of sending and receiving operations performed by facsimile, it is necessary to know in advance whether the size of the manuscript to be processed is as large as the original, so for this purpose, it is necessary to read the manuscript, It is also necessary to detect the width of the manuscript before starting the manual work (normally, the size of the manuscript is determined by its width and length, so it is only necessary to detect the width). The length of the bar is uniquely determined].

Conventionally, the above-mentioned document and document width detection work has been performed using a photosensor consisting of a pair of light emitting elements and a light receiving element, a microswitch equipped with an actuator, and the like.

However, these require a large amount of space for installation, which hinders miniaturization of facsimile reading devices.

SUMMARY OF THE INVENTION In view of the above points, it is an object of the present invention to provide a document and document width detection device that is small, operates accurately, and is inexpensive.

EXAMPLES Hereinafter, the present invention will be explained based on drawings showing examples thereof.

FIG. 1 shows the main parts of a facsimile reading device.

In the figure, a document l whose image is to be read is sent to the left in the figure by a pair of feed rollers 2 with its image side facing downward, and its leading edge faces the back plate 3 and is approximately Optical fiber 4 extending downward in a straight line
(hereinafter referred to as the reading position).The document 1 thus fed is illuminated by a fluorescent light 5 as a light source placed below.The image of the illuminated document L is reflected. The light is guided onto the solid-state imaging device 6 via the optical fiber 4.

As shown in FIG. 2, the solid-state imaging device 6 includes a plurality of photoelectric conversion elements 8 linearly arranged in a main scanning direction on a substrate 7.
(hereinafter referred to as line sensor) and two sets of document sensors arranged in the sub-scanning direction BB' perpendicular to the main scanning direction, static, ', namely, a first document sensor pair 9α, 9b and a second document sensor pair] 1a.

11b.

Now, suppose that the reading device according to this embodiment is A4 size (width 21
6ia) and B4 size (width 256 ttm).
Assuming that the setting is such that documents of different sizes can be read, of the two sets of document sensors described above, sensors 9α and 9b are placed at positions corresponding to the width of B4 size, while 11a and llb are the above sensors 9
a, 9b, and is placed at a position corresponding to the width of A4 size paper. In addition, licensor 8, document sensor 9α
, 9b and the original sensor 11 (L, llb) are formed as so-called equal-size sensors using amorphous silicon, CdS, or the like.

As described above, the reason why the optical fibers 4 are arranged in a straight line is to make the distance between the reading position and the solid-state imaging device 6 as close as possible.

Due to the above-mentioned linearity of the optical fiber 4, the array position of the tip (reading end) of the fiber 4 at the reading position is the photoelectric conversion element 8.9a, 9b, on the solid-state imaging device 6,
The sequence position is the same as that of 11α and llb.

Therefore, the original sensors 9a19b and 11(Z,
The reading ends of the fibers extending from the licensor 8 are arranged apart from the reading ends of the fiber array extending from the licensor 8 in the sub-scanning direction.

The reflected light guided to the solid-state imaging device 6 by the optical fiber 4 is photoelectrically converted by the line sensor 8 into a video signal. This video signal is generated from the main scanning clock HC! from the timing signal generation circuit 2 (FIG. 1) as shown in the timing chart in FIG. The video signal Sv thus extracted is sequentially extracted in time series by the drive circuit 13 (FIG. 1) according to LK.The video signal Sv thus extracted is sent to the binarization circuit 15 via the amplifier 14 in FIG. The circuit 15 outputs binary image information Svpf of "1" for the white level and "0" for the black level, and this binary image information is transmitted to a facsimile receiving device (not shown).

As mentioned above, the work of reading an image of a document is performed by the line sensors 8 arranged in the main scanning direction of the solid-state imaging device 6. the first document sensor pair 9a, 9b and the second document sensor pair 11α, llb
is for detecting whether or not a document whose image is to be read has been sent to the reading device, and also detecting what size the width of the sent document is. below,
The document detection work and document width detection work will be explained as follows.

First, on the back plate 3 (Fig. 1) facing the reading end of the optical fiber 4, as shown in Fig. 4, a part of the white material is coated with black paint in the form of a band. 16
are arranged so as to correspond to the reading ends of the fibers extending from the front first document sensor 9b (FIG. 2) and the front second document sensor ], ]b (FIG. 2). Since the aforementioned fiber is straight, making the black portion 16 correspond to the document sensor 9b and the reading end of the fiber extending along the length of the moon means that
This is the same as making the black portion J6 correspond to the document sensors 9b and llb without any modification. 4, the other document sensors, namely the rear first document sensor 9α and the rear second document sensor 11 (the reading end of the fiber extending from Z corresponds to the white area. Also, the broken line 17 in FIG. 4 indicates the line sensor 8 The position corresponding to the fiber array extending from (i.e., main scan position) is shown.

Document sensors 9α, 9b, 11a of the solid-state imaging device 6
, llb and the rear plate 3 in the above relationship, when there is no original at the reading position, "black" is output from the front first original sensor 9 and the front second original sensor llb. ,
Then, the rear first document sensor 9α and the rear second document sensor 11
α or olfactory “white” is output. Please check these document sensors 9.
The outputs of a, 9b, 11α, and llb are sent to the drive circuit 13.
Otherwise, 11α, llb, 9α and 9b are inserted in the order of time division after the video signal. Therefore, the number of clocks from the timing signal generation circuit 12 is four more than the number of clocks for main scanning of the line sensor 8. For example, when reading a document with a width of JIS B4 size, the second document sensor 11α, ll is activated after a clock corresponding to the 2048-bit line sensor.
Two clocks for the number b are output, and then two clocks for the first document sensors 9a and 9b are output.

In FIG. 1, a timing signal generation circuit 12 outputs a necessary timing signal to a drive circuit 13 at the same time.
The main scanning clock HOLKI is sent to the first D-type flip-flop FF1, the fl'E1 sensor pulse Ps1 is sent to the second D-type free-lag frog FF2, and the second senna pulse PS2 is sent to the third D-type free-lag frog FF3. '5I: Send. The first sensor pulse Ps1 is
The timing at which the output of the front second document sensor llb appears, for example, when reading a B4 size document, the HOLK 2
Generated in time with the 050th pulse. Further, the second sensor pulse Ps2 is generated at the timing when the output of the lif[gl document sensor 9b appears, for example, at the 2052nd pulse in the upper case.

For example, when reading a B4 size document, the output of the second document sensor lla following the output of the line sensor 8 is H
The trailing edge of the 2049th pulse of QLK is latched to 1i''Fl and outputted from the FFI with a delay of one main scanning clock. The output of the sensor llb is inverted by the inverter INVI and input to the NAND game AI.On the other hand, the other input of the NAND game AI is connected to the Q output of the above FFI.The Q output at the time of output of the sensor llb is: Since the signal is from the rear second document sensor 11 (It, the front and rear sensors llb and 11α
A logical operation is performed on the output of . For example, if there is no document at the position corresponding to the second document sensor 11α, llb, the Q output of FF1 is "1" (white) and the output of sensor llb before entering INV] is [OJ (black, white).
) Therefore, the output of Nando game) Al is "0". The "0" output of this NAND game) Al is latched by the second flip-flop I"F2 by the first sensor pulse Ps1, and as a result, the document detection signal DD is sent to the Q terminal of FF2.
Output as ET. That is, if DDET is "0", there is no document at the position of the second document sensor 11a, llb.

On the other hand, in a manner similar to the above operation, the document detection signal WDET from the first document sensors 9α, 9b latched by the second sensor pulse Ps2 is obtained at the Q terminal of the third flip-flop FF3. In this case as well, when there is no document at the position of the first document sensor 9α, 9b, Wl)ET is 1
0".

First document sensors 9α, 9b and second document sensor 11α.

If there is a document in the position corresponding to 11b, DD+,
Both ET and WDET have a force of 11''; in this embodiment, of the two document sensor pairs, the front sensors 9b and llb are set to ``black'', and the rear sensors 9α and '' are facing each other, so even if the original is white or black, it can be detected reliably. If the manuscript is white, then the previous Senna 9b, llb
(When the original is white and the document is black, the rear sensor 9α, ]1a becomes "0" (black), so the output of the Nantes gate Al is 11" in any case. In addition, the sensitivity of the front sensors 9b and llb facing the black part 16 (Fig. 4) is compared with the sensitivity of the rear sensors 9a and 11 (
If the sensitivity is set higher than the fl sensitivity, even if a document with an intermediate color is sent to the core, the front sensor 9b
, The document that has been determined as "black" and "medium" in llb is sent to the rear sensor 9α.
, 11α can be prevented as much as possible from being determined as "white" (same as the sensor output state when there is no document in the core), so the document can be detected reliably even for neutral-colored documents. can be done.

In this way, the first document sensor pair 9a, 9b and the second document sensor pair 11α, 11b can each independently detect the document, and the first document sensor pair 9a.

9tu B4 size width, and the second document sensor lla and llb are placed at the A4 size width position, so when a B4 size document is fed, the first document sensor pair and the second document sensor pair are placed at the A4 size width position. Both document sensor pairs detect the document, and when an A4 size document is fed, the first document sensor pair does not detect the document, but the second document sensor pair detects the document. In other words, the width of the document can be detected by detecting the presence or absence of the document in each pair. In this example, the sensor pair is placed at the B44 size position and the A4 size width position to determine the B4 or A4 document size, but if the sensor pair positions are set variously, it is possible to It is also possible to distinguish between documents of various sizes.

As described above, in this embodiment, the document sensor pair 9α, 9b and 11α, 11b provided on the solid-state imaging device 6 detect the document and document width.
There is no need to prepare a special document detection device other than the solid-state imaging device 6, and as a result, the entire reading device can be made smaller. Also, a document sensor 9α.

Since the sensors 9b, lia, and llb can be formed simultaneously with the manufacturing process of the Hall line sensor 8, the cost increase due to the addition of these sensors 9ct, 9b, 11α, and 11b can be ignored.

In the above embodiment, the first document sensor pair and the second document sensor pair are arranged by aligning two document sensors in the 1iitlJ scanning direction of the solid-state imaging device 6, and the document is read by the action of these sensors and the back plate. However, apart from this, the first document sensor and the second document sensor are configured with one document sensor 18 and 19, respectively, as shown in FIG. 5, and these sensors are configured as shown in FIG. The light emitting diode 21 may be disposed opposite the reading end of the fiber 4 extending from the original sensor 18, 196-. In this case, when the original reaches the position of the first original scanner 18 or the second original scanner 19, the light from the light emitting diode is blocked by the original, and as a result, the light from the light emitting diode is blocked by the original scanner 18 or the second original scanner 19. 18 or the second original sensor 19 changes. This change in the light amount is detected by the comparator C1 or C2, and finally the DDET or WDE
Output as T. At this time, the amount of fluorescent light as a light source is 5
The light from the original is reflected by the original l and is transmitted to the first and second original sensors 3.
8 and 19, it is desirable to block the reflected light to prevent the S/N from decreasing.

In FIG. 6, as a determination circuit for determining the presence or absence of a document and the width of the document, the circuit configuration takes out and processes the output of the first document sensor 18 and the output of the second document sensor 19 separately. This is different from the circuit in which data is taken out in a time-division serial manner as in the previous embodiment shown in FIG. Of course, in the example shown in Fig. 1, a method of separately extracting the document sensor output may be adopted, but it is said that time-division norial extraction can simplify the circuit configuration for processing the sensor output. There are advantages.

As is clear from the above description, according to the present invention, at least one photoelectric conversion element is arranged at a position away from the plurality of photoelectric conversion elements raised and lowered in the main scanning direction in the sub-scanning direction and corresponding to the document width. one first document sensor, at least one second document sensor disposed at a position inside the document sensor with respect to the document width direction, and a light emitting means for inputting light to the first document sensor and the second document sensor. and a determination circuit that determines the presence or absence of a document and the width of the document based on the outputs of the first document sensor and the second document sensor, thereby determining whether or not the document whose image is to be read has been sent to the reading device. (This eliminates the need to provide a special detection device. Therefore, the entire device can be made compact. Also, the first and second document sensors are Since it can be formed simultaneously with the manufacturing process of photoelectric conversion elements in the scanning direction, the entire device can be manufactured at low cost.

[Brief explanation of the drawing]

FIG. 1 is a side view and circuit diagram of a main part of a facsimile reading device showing an embodiment of the present invention, FIG. 2 is a perspective view of the solid-state imaging device 6 shown in FIG. 1, and FIG. 3 is the same as shown in FIG. 1. 4 is a perspective view of essential parts of the back plate 3 in FIG. 1, FIG. 5 is a perspective view showing a modification of the solid-state imaging device 6, and FIG. 6 is a diagram showing the solid-state imaging device in FIG. 5. It is a figure which shows the other Example of this invention used. 8... Line sensor (photoelectric conversion element) 6... Solid-state imaging device 1... Document 9α, 9b, 18... First document sensor] lα,
llb, 19...Second original sensor 3...Back plate (light emitting means) 21...Light emitting diode (light emitting means) 15...Binarization circuit 01.02...Comparator

Claims (2)

[Claims] (1) In a document and document width detection device in an image reading device that reads an image of a document using a solid-state imaging device including a plurality of photoelectric conversion elements arranged in the main scanning direction, the photoelectric conversion elements are arranged in the main scanning direction. at least one first document center located at a position away from the plurality of photoelectric conversion elements in the sub-scanning direction and corresponding to the width of the document;
at least one second document sensor disposed at an inner position of the first document sensor in the document width direction; and a light emitting unit that enters light into the first document sensor and the second document sensor;
A detection device comprising: a determination circuit that determines the presence or absence of a document based on outputs of a first document sensor and a second document sensor. (2) The first document characterized in that the outputs of the first document sensor and the second document sensor are taken out in a time-division serial manner with respect to the outputs of the plurality of photoelectric conversion elements arranged in the main scanning direction. Detection device described in section.