JPH04142861A - Contact type image sensor - Google Patents

Abstract

PURPOSE:To keep a prescribed picture signal intensity regardless of a change in the storage time by adjusting a light quantity of a light source to read an original with a sensor chip depending on a size of an original. CONSTITUTION:An original size read section 14 reading a size of an original by means of a guide frame sends a data to a line sensor selection circuit 11 provided to a line sensor arrangement circuit board 10 with line sensors mounted thereon to decide line sensors to be started or stopped with a reset signal. Simultaneously, the original size read section 14 sends a signal to a light quantity adjustment circuit 13, which adjusts the light intensity of a light source 7 to light the original depending on the length of the original. Thus, an incident light quantity to each picture element is adjusted to keep a prescribed picture signal intensity regardless of a change in the storage time.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a contact type image sensor used mainly in information processing apparatuses for reading originals such as facsimile machines and copying machines.

[Prior Art] A contact type multi-dip image sensor is employed in a conventional document reading information processing apparatus using a short focus imaging element array. For example, in an original reading device as shown in FIGS. 10 to 15, a transparent glass plate 201 that is in contact with the original surface is attached to the top surface of a box 200, and the output light 212
The LEDs 211 are arranged in the case 200 on the substrate 210 at a predetermined angle such that the LEDs 211 are reflected by the surface of the document in contact with the upper surface of the transparent glass plate 201, and An optical system 209 that passes the reflected light 213 of the transparent glass plate 201 and a substrate 19 corresponding to this optical system.
A box 200 includes a plurality of line sensors 1 provided at two sides. The above-mentioned optical system employs, for example, the above-mentioned short-focus imaging element array represented by the product name "Serpoc Lens Array" (manufactured by Kuchimoto Sheet Glass Co., Ltd.).

The line sensor 1 is covered with a protective film 206 on the substrate 19, and the substrate 19 is supported via a rubber plate 207 by a bottom plate 205 engaged with a box.

Note that end plates 203 are attached to screws 20 at both ends of the box 200.
It is installed in 4. Further, the box 200 is provided with a connector 202 for human output such as a power supply and control signals external to the facsimile body, for example.

As shown in FIG. 16, the line sensor 1 is provided with human output pads 4.5 at both ends, and is arranged on the substrate 19 in a straight line from the first to the Nth, respectively.
By inputting a star signal through the input pad 4 and outputting an end signal through the output pad 5, they are sequentially activated in accordance with the arrangement order and read optical information. In this case, when outputting the end signal via the output pad 5, the end signal can be input to the input pad 4 as a start signal for the next line sensor. As shown in FIG. 17, each line sensor 1 is
The light receiving windows 2 are provided at a pitch of 127+1 m (for 200 DPT) or 63.5 μm (for 400 DPI) (where DPI is Dot per 1 nc).
In addition to this, an area 3 is prepared on the substrate 1 in which a line sensor drive circuit, a shift register, a power supply pad, a sensor output pad, etc. are arranged.

As shown in FIGS. 18 and 19, such a contact type multi-chip image sensor (indicated here by reference numeral 110) is disposed, for example, at a document reading position of a facsimile via a fixture 109. Here, a document insertion slot 103 is provided at the front edge of the facsimile body 100, and a slit 105 is formed in parallel to the guide stage 104 of this document insertion slot 103, and the slit IO2 determines the insertion position of the document. A guide piece 106 is a slidable device. In addition, the facsimile main body 100
A keyboard panel 101 and an operation message display section 107 are arranged on the front upper surface of the printer, and a document ejection port 102 is provided immediately behind the keyboard panel 101 and an operation message display section 107.

Then, the original 118 inserted from the original insertion slot 103
reaches the feeding roller 10g via the separation piece 117, and from there the platen roller 116 and the image sensor 11
0, and is discharged to the document take-out port 102.

A roll of recording paper 114 is stored in the rear of the facsimile main body IQ[l, and the end thereof is taken out to the outside via a platen roller 115. At the position of the platen roller 115, Record 1
11, information is recorded. In addition, in the figure, the code 1
12 is a facsimile system control board, and 113 is a power supply unit.

In such a configuration, when reading a document, the line sensor 1 sequentially reads from the first to the Nth document, and during this time, read data other than the document separated by the guide pieces 106 is sent to the system controller of the facsimile machine. processed and truncated.

[Problems to be Solved by the Invention] However, in the conventional example described above, when reading a document shorter than the detection area of the image sensor, reading is performed until the area where there is no document is read as described above. This results in driving the sensor l, which wastes power. Further, there is wasted time in reading the document, and furthermore, a data processing program or a data processing circuit is required to discard data in areas where the document does not exist.

Therefore, the present inventor separately proposed a contact type multi-chip image sensor having a configuration to solve this problem. In the configuration of this image sensor, the 1st to Nth line sensors each having input/output pads at both ends are arranged in a straight line on a board, and a start signal is input through the input pads, and a start signal is input through the output pads. In a contact type multi-chip image sensor configured to read optical information, the line sensors are sequentially activated in accordance with their arrangement order by outputting an end signal. As such, a control circuit is provided so that a start signal can be selectively input from the outside to the input pad of the line sensor.

In this case, when outputting the end signal via the output pad, the end signal can be manually applied to the input pad as a start signal for the next line sensor.

In addition, for the selected line sensor manual pad,
A selection circuit is also provided between the output pad of the preceding line sensor and the manual pad of the next line sensor so as to input the external start signal instead of the end signal.

Therefore, since the start signal from the control circuit can be selectively supplied to the input pad of each line sensor,
The line sensor can be driven so as not to read areas outside the document, thereby saving power and time, and also not complicating the data processing system.

However, when such a control method is adopted for the above-mentioned contact type multi-chip image sensor, the following new problems arise. That is, when all of the above line sensors read a document shorter than the corresponding length document,
The output of the image signal decreases. This point will be explained below.

As shown in FIG. 20, when the total number of pixels of the contact multi-chip image sensor is n, the image signal is divided into n pixels according to the clock after the start signal is input.
Output. The image signal output here is actually the image signal from one cycle before, and while the image signal for n pixels is currently being output, the image signal to be output with the next start signal is accumulated in the buffer. will be done. That is, the time t from a start signal to the next start signal is the accumulation time.

However, when the document is shorter than the length of all line sensors, a start signal is manually input to the line sensor corresponding to the beginning of reading the document, and a reset signal is output to the line sensor at the position of the line sensor after the document ends. In this case, only the licensor having the m-th to β-th pixels out of the total number of pixels n is driven. This state is shown in FIG. Here, one clock cycle corresponds to the number of clocks, which is kin. In other words, when a signal enters a line sensor consisting of (the first pixel of that line sensor is m
According to the above clock, image signals are output sequentially from the m-th pixel, and at the k-th clock, that is, the last line sensor to be driven (the last pixel of this line sensor corresponds to the β-th pixel). ), a signal to stop driving is inputted immediately after the input of the clock to output the image signal of the last pixel, and immediately after that, a start signal is inputted to the line sensor that started driving, and driving starts again. The accumulation time t1 from this start signal to the start signal is shorter than the accumulation time t mentioned above. It is well known that the output of the image signal becomes smaller as the storage time becomes shorter, and this solution is necessary.

[Means for Solving the Problems] The present invention has been made based on the above circumstances, in which N sensor chips having a plurality of photoelectric conversion elements are arranged in the main scanning direction, and each of the N sensor chips is operated. It has an input terminal into which a start signal is input and an output terminal which outputs an operation end signal, and is electrically connected so that the operation end signal output from the i-th sensor chip is input as an operation start signal to the 1+1th sensor chip. (In the image sensor, the image sensor has a signal generating means for generating an operation start signal that is selectively applied to each of the input terminals of the N sensor chips.) , is equipped with a light amount adjustment circuit that adjusts the light amount of the light source for reading the document with the sensor zip.

[Function] Therefore, the light intensity of a light source such as an LED can be adjusted depending on the length of the document, or the amount of light incident on the line sensor can be adjusted depending on the length of the document and the number of line sensors selected by the selection circuit. , it is possible to maintain a constant image signal intensity regardless of changes in the length of the accumulation time.

[Example] Hereinafter, an example of the present invention will be described with reference to FIGS. 1 to 9. Note that the same reference numerals are given to the parts having the same configuration as those of the above-mentioned conventional example, and the description thereof will be omitted.

In the first embodiment shown in FIG.
The pixel bits, that is, the spacing between the photoelectric conversion elements is, for example, 127
μm (200DPI). The length in the longitudinal direction of the line sensor 1 at this time is 19.73 mm, and when a plurality of line sensors 1 are arranged approximately in a straight line, the length of the line sensor 1 in the longitudinal direction is 127 μm in order to correct the gap between each line sensor 1.
It is a value that is not divisible by m. This line sensor
If you line up 13 pieces, the maximum size is B4 (256mm
) can be read.

However, code 1. From the line indicated by , a start signal is inputted as an operation start command to the start human power pad 4 of the first line sensor l, and thereafter, signals 28 and 2 □
Starting signals can be input to the scoot input pads 4 of the second and third line sensors 1 from the lines indicated by . Furthermore, in this embodiment, the end signal pad 5 of the preceding line sensor 1 is the star of the next line sensor 1! - When connected to the signal pad 4 and no start signal is input from the outside via the line, the end signal of the line sensor 1 in the previous stage is input to the start signal pad 4 of the line sensor 1 in the next stage. The next line sensor is now working.

Now, for example, when reading a B4 size document, all 13 line sensors l need to be driven in the first embodiment. Therefore, an external start signal is input to the line IS, and no start signals are input to the other lines. Therefore, the end signal from the end signal output pad 5 of the preceding line sensor 1 is input as a start signal to the start signal input pad 4 of the second and subsequent line sensors 1. The above end signal is at the end of line sensor 1 reading.
Or it is output just before the reading is finished.

In addition, when reading a document smaller than B4 size, for example, an A4 size (214 mm) document, the guide pieces 106 are operated symmetrically to read the second to first documents corresponding to the above size.
Only the second line sensor l is driven. Therefore, no start signal is supplied to the first line sensor l. Then, a start signal is input from the outside to the start signal human power pad 4 of the second line sensor l. In order to prevent the STAR 1~ signal from being input to the 13th line sensor 1, in this embodiment, the signal power pad (not shown) is sent to the reset 1 of the 12th line sensor 1 at a predetermined timing. It is preferable to configure the control circuit so that a reset signal is input to (1). At this time, the end signal is not output from the 12th line sensor,
The 13th line sensor is not driven. In the above usage mode, the 3rd to 12th line sensors]
As in the case of the above-mentioned B4 size, the end signal from the line sensor 1 at the previous stage is input to the start signal input pad 4 as a start signal.

Naturally, when reading a document smaller than A4 size, a start signal is input to the line sensor 1 that should be started, and a reset signal is input to the line sensor reset signal input pad of the line sensor 1 that should be finished. Then, the next line sensor 1 will not be driven.

In this way, according to the present invention, by providing a signal generating means for generating an operation start signal that is selectively input to the N sensor chips, it is possible to drive only any continuous line sensor 1. .

In the above embodiment, since the document insertion position is set at the center, the guide pieces 106 operate symmetrically, but if the document insertion position is set with the last line sensor 1 side as a reference, All you need to do is consider which line sensor should input only the start signal (and the reset signal does not need to be used).

In the second embodiment shown in FIG. 4, when the previous end signal is input as a start signal to the start signal input pad of the line sensor after the first driven line sensor, an external start signal is input there. Since there is a risk of malfunction due to manual input of the signal, the selected line sensor 1
A switching circuit is provided between the output pad 5 of the previous line sensor and the manual pad 4 of the next line sensor so that the start signal from the outside is input to the input pad 4 of the input pad 4 instead of the end signal. There are 6. For the switching operation of the switching circuit 6, the lines 2SW and 3S
This is so that a switching control signal can be input to W.

In the above embodiment, it is desirable that the switching circuit 6 be placed immediately before each line sensor. This is because the start signal human power pad 4 of the second and subsequent line sensors 1 becomes farther away in order, and the length of the wiring pattern on the circuit board becomes longer, which increases the capacitance and makes it easier for noise to appear. be.

In the third embodiment shown in FIG. 5, only a wiring pattern is provided on the board 15 on which the line sensor l is mounted, and another board H is provided with the switching circuit, the transmission circuit for the start signal and the end signal, and the selection circuit. Control circuit 17 including circuits etc.
is provided. Note that the substrate 16 is provided with lines 8 corresponding to the lines 11+, 2°, and lswv 2sw· described above. Here, an example has been given in which the line sensor dips are arranged in a straight line, but of course they may be arranged in a staggered manner.

When the substrate 16 is provided separately as in the above embodiment, the configuration of the document reading device (contact type multi-dip image sensor) may be as shown in FIGS. 6 and 7. here,
The substrate 16 is attached to the bottom plate 205 via screws 23, and necessary electronic components are mounted thereon. Note that, as a matter of course, a connector 202° for external signals and power is provided below the board 16.

In addition, line sensors are described in U.S. Pat. A type of optical sensor in which a capacitive load is provided to the emitter of a bipolar transistor such as the one shown in FIG.

As the recording means used in the information processing device of the present invention,
For example, U.S. Pat. No. 4,723,129, U.S. Pat.
Preferably, the typical configuration and principle thereof are disclosed in the specification of No. 0796. This method uses an electrothermal transducer placed in correspondence with the sheet holding the liquid (ink) and the liquid path to generate a small amount of heat that corresponds to recorded information and causes a rapid temperature rise exceeding nucleate boiling. By applying one drive signal, the electrothermal transducer generates thermal energy and causes film boiling on the heat-active surface of the recording head, resulting in a one-to-one correspondence with this drive signal. This method is effective because bubbles can be formed. The growth and contraction of the bubbles causes the liquid (ink) to be ejected through the ejection opening to form a small droplet (at least one droplet).

Furthermore, as a full-line type recording head having a length corresponding to the width of the maximum recording medium that can be recorded by the recording apparatus, the length can be increased by combining multiple recording heads as disclosed in the above-mentioned specification. Either a configuration that satisfies the above requirements or a configuration as a single recording head formed integrally may be used.

In addition, there are also replaceable chip-type recording heads that can be installed on the device body to enable electrical connection to the device body and supply of ink from the device body, or an ink tank integrated into the recording head itself. The present invention is also effective when a cartridge type recording head is used.

Further, the document reading device is attached to a facsimile machine as indicated by the reference numeral 119 in FIG. The other configurations are the same as those in the conventional explanation, so the explanation will be omitted.

In the embodiment shown in FIG. 9, the switching circuit 2 on the circuit board 22
Reference numeral 5 is a multi-stage type, in which the number of line sensors to start driving is determined simply by inputting a switching control signal S from the outside. Such a configuration does not require a plurality of start signal input sections unlike the first embodiment, and the structure is simplified.

The contact type multi-chip image sensor constructed in this manner includes a control system as shown in FIGS. 1 and 2. That is, from the original size reading unit 14 that reads the size of the original using the guide piece 106, etc., the line sensor selection circuit 11 (for example, the switching circuit 6 in FIG. 4) provided on the board 10 on which the line sensor l is mounted is sent. Send data, decide which line sensor to start, and
Decide which line sensor to stop driving with the reset signal. At the same time, the original size reading section 14 sends a signal to the light amount adjustment circuit 13, and the light amount adjustment circuit 13 adjusts the light intensity of the light source 7 (for example, the above-mentioned LED) for illuminating the original.

In the embodiment shown in FIG. 2, the signal from the original size reading unit 14 is sent only to the line sensor selection circuit 12, and the line sensor selection circuit 12 outputs the number of line sensors to be driven. The data is sent to the light amount adjustment circuit 13 as data. by this,
The driving of the line sensor and the driving of the light source can be controlled with the same signal, and the possibility of generating an erroneous signal in the output of the image signal can be eliminated.

[Effects of the Invention] The present invention has been described in detail above, and since the start signal from the control circuit can be selectively supplied to the input pad of each line sensor, areas outside the document are not read. The above-mentioned line sensor can be driven in such a way that it can eliminate wasted power and time, and the data processing system does not need to be complicated.Moreover, the light intensity of a light source such as an LED can be adjusted according to the length of the document. The amount of light incident on each pixel is increased or decreased, and a constant image signal intensity is maintained regardless of changes in the length of the accumulation time. can be maintained.

[Brief explanation of the drawing]

1 and 2 are block diagrams of different embodiments showing the configuration of a control device according to the present invention, and FIGS. 3 to 5 are respective embodiments of a contact type multi-dip image sensor according to the present invention. FIG. 6 is a perspective view showing an embodiment of the document reading device according to the present invention, and FIG.
A cross-sectional view taken along line A, FIG. 8 is a vertical cross-sectional side view of a facsimile machine showing an embodiment of the document reading device of the present invention, and FIG. 9 is another implementation of the contact type multi-chip image sensor of the present invention. A schematic configuration diagram showing an example, FIG. 10 is a perspective view of a document reading device showing a conventional example, FIG. 11 is a perspective view showing the configuration of a line sensor on a board, and FIG. 12 is a C--
13 is a sectional view taken along line C, FIG. 13 is a perspective view of a board equipped with LEDs, FIG. 14 is a sectional view taken along line BB in FIG. 17 is a schematic configuration diagram of a conventional contact type multi-chip image sensor, FIG. 17 is a schematic configuration diagram of a conventional line sensor, FIG. 18 is a perspective view showing the configuration of a conventional facsimile machine, and FIG. 20 and 21 are vertical cross-sectional views taken along line D-D of
The figure is a timing diagram regarding the accumulation of image signals. l11. Line sensor 291. Light receiving window 39, 6 area 4°5. 6. 7゜8～9゜11, 12゜14, . 15, 16 17, . 18, . 19, 22° Start signal input pad End signal output pad switching circuit Light source for document illumination, circuit board, line sensor selection circuit Light amount adjustment circuit Document size reading section, circuit board area line 91 circuit board

Claims (4)

[Claims] (1) N sensor chips each having a plurality of photoelectric conversion elements are arranged in the main scanning direction, and each of the N sensor chips has an input terminal to which an operation start signal is input and an output terminal to which an operation end signal is output. and the N sensor chips are electrically connected so that an operation end signal output from the i-th sensor chip is input as an operation start signal to the i+1-th sensor chip. a light amount adjustment circuit having a signal generating means for generating an operation start signal selectively input to each of the input terminals of the device, and adjusting the amount of light of a light source for reading the document with the sensor chip according to the size of the document; A close-contact image sensor characterized by: (2) N sensor chips having a plurality of photoelectric conversion elements are arranged in the main scanning direction, and each of the N sensor chips has an input terminal to which an operation start signal is input and an output terminal to output an operation end signal. and the N sensor chips are electrically connected so that an operation end signal output from the i-th sensor chip is input as an operation start signal to the i+1-th sensor chip. has a signal generating means for generating an operation start signal that is selectively input to each of the input terminals of the input terminal, and depending on the number of line sensors selected by the selection circuit, the number of light sources for reading the document with the line sensors is controlled. A close-contact image sensor characterized by being equipped with a light amount adjustment circuit that adjusts the amount of light. (3) An information processing device comprising the contact type image sensor according to claim 1 and a recording head for recording image information. (4) The information processing apparatus according to claim 3, wherein the recording head is an inkjet recording head that discharges ink using thermal energy.