JPH0210965A - Image sensor and input/output device - Google Patents

Abstract

PURPOSE:To simplify the structure of a image sensor, to prevent dispersion, to make the image sensor to various resolution, to incorporate the input and output section and to make the device small in size by providing a laser light scanning system and a beam splitter. CONSTITUTION:A sensor element 102 is provided on a transparent board 101 made of glass or the like, a laser beam 104 is scanned on an original 103 in the broadwise direction of the original, the reflected light 105 of the light 104 reflected in the original 103 is read by the element 102. Moreover, in the case of separating a laser beam into two, the laser beam radiated from a laser 901 is divided into two by a beam splitter 902, one of the split laser beams is given to a lens system 905 via an optical modulator 904 and the other beam is inputted to the lens system 905 via a mirror 903 and scanning is applied. Since the photoelectric conversion section is formed by a single element, the structure of the image sensor is simplified to prevent the dispersion in the light source and the laser beam is split into two to allow the device to cope with various resolutions. Moreover, since the laser scanning section is used in common with a laser beam printer or the like, the I/O is made small in size.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an image sensor used as an input section of a facsimile machine, an image scanner, etc., and an input/output device using the image sensor as an input section.

(Prior Art) Contact image sensors using photoconductive materials such as COD, amorphous silicon, and CdS are currently used in input units of facsimiles, image scanners, and the like.

As an example, FIG. 10 shows the structure of a contact type image sensor. In the sensor section, a sensor array 1002 made of a photoconductor such as amorphous silicon or CdS is provided on a glass substrate 1001, and a scanning IC 1003 for scanning these sensor arrays is connected to each sensor. A light source 1004 consisting of an LED array
06 is illuminated, and an image of a document 1006 is formed on a sensor array 1002 by a rod lens array 1005. The 1004 LED array is made by arranging multiple LEDs and condensing the light with a semicircular lens.For example, an A4 size contact image sensor has 1004 LED arrays.
Approximately 0 LEDs are used.

Also, in the case of COD, it consists of a light source made of a fluorescent lamp, a charge conversion section for each pixel, and a scanning system.

(Problem to be Solved by the Invention) These image sensors use multiple LEDs or fluorescent lamps as light sources, so there are variations in the intensity of the LEDs and variations in the light source due to uneven light intensity of the fluorescent lamps, causing bright signals to fluctuate. There was a problem. Furthermore, since the sensor array and the like are separated for each pixel, there is a problem in that variations in dark current from element to element directly result in variations in dark signals. This includes a scanning IC 100 regardless of whether the signal is bright or dark.
3 switching noise occurs.

Another drawback is the complexity of the structure of the image sensor itself. As shown in Figure 10, a contact image sensor requires many scanning ICs and bonding to connect them to the sensor array, and the optical system is also a special type that uses many fiber-shaped lenses called rod lens arrays. , and the light source is quite complex, as explained earlier. COD is charging conversion section,
It is an IC that consists of a charge transfer section and a signal reading section, and is not complicated as there is only one part, but it requires many manufacturing processes and has a low manufacturing yield due to its operating principle, making it more expensive than other ICs. It has become.

Next, as described above, these conventional image sensors are devices in which each pixel is independent, and have the disadvantage that the pixel density is constant.

In other words, different image sensors must be prepared for applications with different pixel densities.

Finally, from the viewpoint of human output and equipment, there is a limit to the miniaturization of equipment in the prior art. There is a laser or L in the output section.
There are electrophotographic type using ED head, liquid crystal head, inkjet type, and thermal or thermal transfer type using thermal head, but the human power section and output section are independent, and contact type image sensor Even if it is used, there is a limit to the miniaturization of the device.

An object of the present invention is to eliminate the drawbacks of the prior art described above, and to provide an image sensor that has a simple structure, no signal variation, and can be applied to various resolutions, and an input/output section using this image sensor, which is compact and compact. The objective is to provide a standardized input/output device.

(Means for Solving the Problems) The present invention has a thin film photoelectric element formed on a substrate slightly longer than the sub-scanning direction of the original and having the same length as the sub-scanning direction of the original. It consists of a charging conversion unit installed parallel to the charging conversion unit and a laser beam scanning system, which scans the document one-dimensionally with laser light parallel to the charging conversion unit, and reads the reflected light with the charging conversion unit. Provides an image sensor with characteristics.

The present invention also provides an input/output device comprising the image sensor, a document guide provided with a slit in a portion corresponding to the position scanned by the laser beam, and a photosensitive drum provided immediately after the slit.

Further, the image sensor and a document guide provided with a slit in a portion corresponding to a position scanned by the laser beam;
To provide an input/output device characterized in that an inkjet device is added immediately after the slit, which generates bubbles in the ink using a heating element that absorbs laser light and sprays the ink with the bubbles.

In the two input/output devices, there is a means for dividing the laser beam into two beams, one of the two divided laser beams is scanned to form a laser beam scanning system of the image sensor, and the other laser beam is used as a laser beam scanning system for the image sensor. After passing through a modulator, it can be scanned and manually applied to the photoreceptor drum or the inkjet device.

(Function) In conventional image sensors, the light source always illuminates the entire surface of the document, and the sensor side scans and reads it. However, in the present invention, the sensor side consists of a single element, and information is read by scanning light. reading.

In other words, the light source is one laser beam, and since it is a single light source, there is no bright signal variation due to variations in the light source as in conventional image sensors. Furthermore, since there is a single sensor element, there is no possibility of variation in dark current. Furthermore, since scanning is performed with light, there is no switching noise caused by an electrical scanning circuit. Moreover, the charging conversion section has a much simpler structure than conventional image sensors. The resolution depends on the resolution of the laser beam, and the same charge conversion unit can be used even if the resolution changes.

Further, the input/output device of the present invention combines a conventional output device and the image sensor of the present invention to provide input/output functions without increasing the overall size of the device. Claim 2
In the case of the described input/output device, it is a combination of a so-called laser beam printer and a charge conversion section of the image sensor of the present invention. Therefore, by adding only a few parts to a conventional laser beam printer, it is possible to turn what was previously only an output device into an input/output device without changing its size.

Similarly, the input/output device according to claim 3 has a configuration in which the charge conversion section of the image sensor of the present invention is simply inserted in the middle of the laser scanning path of a conventional inkjet device. Therefore, it is possible to convert a conventional inkjet device into an input/output device without changing its size.

Furthermore, in the invention as claimed in claim 4, in the input/output device as claimed in claim 3 or 4, the laser beam, which is a basic component, is divided into two parts.
It is divided into books, each with its own image sensor and output unit for scanning. With such a configuration, input and output can be performed simultaneously. Therefore,
It is also possible to copy the original.

(Embodiment) FIG. 1 does not show a first embodiment of the image sensor of the present invention, but shows a cross-sectional view of the vicinity of the charging conversion section. A sensor element 102 is provided on a transparent substrate 101 made of glass or the like, and a laser beam 104 is scanned across a document 103 in the width direction of the document, and the sensor element 102 reads reflected light 105 of the laser beam 104 reflected by the document 103. An arrow shown at the upper left of the original 103 indicates the direction in which the original is fed. Substrate 101 and sensor element 1
02 has a length slightly longer than the width of the document 103 in the direction perpendicular to the plane of the paper. Furthermore, although the sensor elements 102 are shown in two rows in the figure, in reality they are connected in parallel and used, so they are one element, and one row may be sufficient.

FIG. 2 (aXb) shows perspective views of two embodiments of the charge conversion section of the image sensor of the present invention. In the figure 2
01 is a glass substrate, 202 is a transparent electrode such as indium tin oxide or tin oxide, 203 is a photoconductive film, 204 is an upper electrode such as chromium, and 205 prevents contact between the electrodes 202 and 204; 206 is a substrate, 207 is a slit made in the substrate, 208 is a photoconductive film, 209 is a transparent electrode similar to 202, 210 is an insulating film similar to 205, and 211 is the same as 204. It is a similar lower electrode. Figure 2(a) uses a transparent substrate,
This is an example of inputting signal light (laser reflected light from an original) to a sensor element through a substrate. Figure 2 (b) uses an opaque substrate, illuminates the original with laser light through a slit, and transmits a signal from the top of the sensor. This is an example of inputting light. The photoconductive film can be, for example, an undoped amorphous silicon film produced by decomposing silane gas using a glow discharge method, an amorphous silicon film such as a PIN-type amorphous silicon film with doped layers on top and bottom, or amorphous silicon film produced by vapor deposition, sputtering, etc. There are those formed of CdS, CdSe, or arsenic selenide. Which photoconductive film to select depends on the spectral sensitivity of the photoconductive film and the oscillation wavelength of the laser beam.

The laser beam scanning system is detailed in Wanho and Aida, "Technical Trends in Laser Printers", Laser Research 12 (1984), pp. 478-498. Also, as shown in Figure 2, the sensor elements are arranged in two rows purely to increase sensitivity.
There is no problem with one row. Furthermore, although the sensor substrate is perpendicular to the laser beam in FIG. 1, there is no problem even if the substrate is tilted when the sensor elements are arranged in one row. In any case, it is possible to read the brightness and darkness of the document using a simple sensor element as shown in FIG.

(Embodiment 2) FIG. 4 shows a configuration diagram of a conventional laser beam printer. In the figure, 401 is a laser, 402 and 405 are lens systems, 403 is a motor for rotating the polygon mirror 404, and 406 is a photosensitive drum. Laser light emitted from a laser 401 is focused by a lens system 402 onto a polygon mirror 404, and as the polygon mirror rotates, the photosensitive drum 406 is scanned one-dimensionally as shown in the figure, and information is transferred to the photosensitive drum. Write.

Next, FIG. 5 shows one embodiment of the input/output device of the present invention. The input/output device of the present invention has a structure in which a document guide 507 and the above-mentioned charging conversion section 506 are inserted between the photosensitive drum 406 and the laser scanning system of the conventional laser beam printer shown in FIG. Figure 6 (a) explains this operation.
Xb). In the figure, 601 is a substrate, 602 is a sensor element, and 601 and 602 correspond to the charging conversion section 506. 603 is a document, 604 is a laser beam, and 605 is a reflected light. The document guide 507 has a slit cut in the portion through which the laser beam passes, as shown in the figure, or is made of two plates. When used as an input device, see Figure 6 (
As shown in a), a document 603 runs on a document guide 507, is scanned by a laser beam 604, and reflected light 605 is received by a sensor element 602 and read as a signal. When used as an output device, since there is no document 603, the laser beam 604 passes through the sensor board 601, and
It passes through the slit in the document guide 07 and reaches the photosensitive drum 508, allowing it to perform the same operation as a conventional laser beam printer.

In this way, by adding only a few parts to a conventional laser beam printer, it is possible to turn what was previously only an output device into an input/output device without changing its size. Strictly speaking, 506 charging conversion unit and 507
In addition to the document guide, a document feed mechanism and a signal processing circuit are required, but these do not make the device too large. In any case, it can be much smaller than a conventional input/output device that combines a COD or contact type image sensor and a laser beam printer.

FIG. 3 shows another example of the laser scanning system. 30 in the figure
1 is a charging conversion unit, 302 is a document, 303 is a laser, 30
4 is a lens system, 305 is a polygon mirror, and 306 is a mirror. Laser light emitted from a laser 303 is focused by a lens system 304 and hits a polygon mirror 305.
It is swung at an angle as shown in the figure, is reflected by a mirror 306, and enters the original. In this example, as shown in the figure, the image sensor is made smaller by folding the optical path with a mirror, and the height from the original to the mirror is approximately several centimeters for an A4 size paper. In this case, the angle of the laser beam incident on the document 302 changes depending on the curvature of the mirror, etc., but in the image sensor of the present invention, the charging conversion section is a single element and moreover, it is capable of capturing almost all of the light reflected from the document. Therefore, there is no dependence on the angle of incidence.

(Example 3) FIG. 7 (aXb) is a diagram showing the principle of an inkjet device. In the figure, 701 is printing paper, 702 is
703 is a slit, 704 is ink, 705 is a heat generating plate, 706 is a substrate, 707 is a laser beam, 708 is a bubble, and 709 is an ink droplet. As shown in FIG. 7(a), this inkjet device is equipped with 705 heat generating plates.
It has a structure in which ink 704 is sandwiched between a substrate 06 and an upper plate 702 provided with slits 703. When this is irradiated with a laser beam 707 as shown in FIG. 7(b), the heat generating plate 705 absorbs the laser beam, converting the energy of the laser beam into heat and generating bubbles 708 in the ink 704.

With the power of this bubble, the ink droplets 709 are blown away as shown in the figure.
Ink is deposited on the printing paper No. 01.

Next, FIG. 8 (aXb) shows one embodiment of the input/output device of the present invention. In the figure, 801 is the inkjet device, 802 is a document guide with an open portion for laser light to pass through, 803 is a document, 804 is a substrate, 805 is a sensor element, 806 is a laser beam, 807 is reflected light from the document, 808 809 is an ink droplet, and 809 is a printing paper. The laser beam scanning system is the same as that shown in claim 2, so its explanation will be omitted here. As is clear from the figure, the input/output device of the present invention has a structure in which the charge conversion section of the image sensor of the present invention is simply inserted in the middle of the laser scanning bus of a conventional inkjet device. When used as an input device, a document 803 is sent along a document guide 802 as shown in FIG. Read it with When used as an output device, see Figure 8(b)
As shown in the figure, the laser beam 806 is transmitted to the substrate 805 and 802.
The paper passes through the document guide 801 and reaches the inkjet device 801, which serves to eject ink droplets 808 onto printing paper 809 in the same way as in the past. In this way, by simply adding a few parts to an output device consisting of a conventional inkjet device, it is possible to use it as an input/output device without increasing the size of the device.

(Embodiment 4) In the invention described in claim 4, the laser beam is divided into two beams, and the output portion of each beam is scanned by the image sensor.

FIG. 9 shows an example of a method of dividing laser light into two beams. In the figure, 901 is a laser, 902 is a beam splitter, 903 is a mirror, 904 is an optical modulator, 905 is a lens meter, 906 is a motor, and 907 is a polygon mirror.

Laser light emitted from a laser 901 is split into two beams by a beam splitter 902. One of the divided laser beams is modulated by a light modulator 904, passes through a lens system 905, hits a polygon mirror 907, and scans a photosensitive drum or an inkjet device. Already - the book is 903
The light is reflected by the mirror 905, passes through a lens system 905, hits a polygon mirror 906, and scans the original to be read.

The image sensor does not include a light modulator because it only needs to be exposed to a certain amount of light.

By appropriately positioning the mirror 903, scanning by the photosensitive drum or inkjet device and scanning by the image sensor can be performed separately and simultaneously. Image sensors do not require the intensity of laser light that is required for photosensitive drums and inkjet devices, so the intensity of the two laser beams can be dominated by the one used for the output device, and is usually used as an output device. performance will not be degraded. By directly inputting the output signal of the image sensor to the optical modulator 904, the original can be copied. Of course, it can also be used on both sides.

(Effects of the Invention) By implementing the image sensor of the present invention, it has been found that the image sensor of the present invention has the following distinct effects over conventional image sensors.

1) Since the charge conversion section is a single element, the dark signal is always constant, and the correction of the dark signal level, which was necessary in the past, is no longer necessary.

2) Since the light source is a single element, the light intensity with respect to the document surface is always constant, making it unnecessary to correct the bright signal level, which was conventionally necessary. Combined with the first effect above, I for signal processing
It became possible to omit a considerable amount of C.

3) Since a scanning IC is no longer required, there is no switching noise at all.

4) The structure of the charge converter is very simple, so the manufacturing yield is high, and the cost of the charge converter is less than 1110 yen compared to conventional products, making it possible to realize an image sensor with the same performance at 1/2 to 1/3 of the total cost. .

5) When this image sensor was applied to image sensors with two resolutions, 8 lines/nm and 16 lines/mm, it worked without any problems. This confirms that the same image sensor can support various resolutions.

The effects obtained by the input/output device according to the second or third aspect of the invention are as follows.

1) Since the laser scanning section can be shared with a laser beam printer or an inkjet device, the volume required for the manual section of conventional input/output devices can be saved.

2) Considering laser beam printers and inkjet devices as a standard, the only image sensor required for the input section is the charging conversion section, so the cost of the input section is about 1110 yen compared to conventional devices, making it possible to manufacture the device at low cost. .

The effect obtained by the input/output device of the invention claimed in claim 4 is that the copying function, which is difficult to achieve with the input/output device of claim 2 or claim 3, can be achieved by adding only a few parts. That's true.

As explained above, according to the image sensor and the input/output device using the image sensor of the present invention, the image sensor has a simple structure and does not require signal correction;
A small, low-cost input/output device with an integrated input/output section can be obtained, which is very useful industrially.

[Brief explanation of the drawing]

FIG. 1 shows the charge conversion section of the image sensor of the present invention. FIG. 4 shows the configuration of a conventional laser beam printer. FIG. Figures 6 (a) and (b) are diagrams showing examples of input and output operations of the input/output device, and Figure 7 (aX
b) is a sectional view of a conventional inkjet device; FIG.
Xb) is a configuration diagram of one embodiment of the input/output device of the present invention, No. 9
The figure shows one embodiment of a laser beam scanning system of an input/output device according to the present invention. iytolfJtytHgt vine invitation (7'-
The 7th the φma. In the figure, 101...Substrate, 102...Sensor element, 103...Original, 104...Laser light, 105
...Reflected light, 506... Charging conversion section, 507...
Manuscript guide, 801. ...Inkjet device, 802
... Document guide, 803 ... Document, 804 ... Substrate, 805 ... Sensor element, 806 ... Laser light,
807...Reflected light 808...Ink droplet, 809.0
．． Printing paper, 901...Laser, 902...Beam splitter, 903...Mirror, 904...Light modulator, 905...Lens system, 906...Motor, 90
7... It is a polygon mirror.

Claims (1)

[Claims] 1) A thin film charging element having the same length as the sub-scanning direction of the original is formed on a substrate slightly longer than the sub-scanning direction of the original, and is installed parallel to the sub-scanning direction of the original. An image sensor comprising a photoelectric conversion section and a laser beam scanning system, which scans a document one-dimensionally with laser light in parallel to the photoelectric conversion section, and reads the reflected light with the charging conversion section. . 2) an image sensor according to claim 1;
An input/output device comprising: a document guide provided with a slit in a portion corresponding to a position to be scanned by a laser beam; and a photosensitive drum provided immediately after the slit. 3) an image sensor according to claim 1;
It is characterized by a document guide with a slit in a part corresponding to the position where the laser beam is scanned, and immediately after the slit, a heating element that absorbs the laser beam generates bubbles in the ink and the bubbles scatter the ink. An input/output device characterized by adding an inkjet device. 4) In the input/output device according to claim 2 or 3, there is provided a means for dividing a laser beam into two beams, and scanning one of the two laser beams to scan the image sensor. An input/output device characterized in that it is a laser beam scanning system, and the other laser beam is scanned after passing through an optical modulator and is input to the photosensitive drum or the inkjet device.