JPS60227564A - Picture reader of multi-color original - Google Patents

Abstract

PURPOSE:To attain reading with high reliability by means of a small-sized device by irradiating light of an LED array generating different color light on a multi-color original and leading the reflected light to a contact long image sensor via a SELFOC lens. CONSTITUTION:A light emitting diode array 32 is formed by arranging plural multi-color diodes 36 on an aluminum base 35 by a width of original reading in a pitch of 0.5-2.5mm.. Each diode 36 is formed by mounting red/blue LEDs 37, 38 on one package or one chip and connected to power supplies E1, E2. A current I1 flows to the LED37 and a current I2 flows to the blue LED38 respectively by the power supplies E1, E2. The reading by the contacting long-sizing image sensor 34 is started after the light emitting operation of the LEDs is finished, a storage time TS of the sensor 34 corresponds to the light emitting time of the LEDs and the read time T of each color line consists of the sum of the time TS and the read time TR. Thus, the read time Tt of one line is the sum of the line read times of blue, green and red color lines.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a multicolor original placed on a platen, which is illuminated with light and whose reflected light is incident on an image sensor through a lens to read an image. The present invention relates to an image reading device.

(Prior Art) There are various types of image reading devices for multicolor originals of this type, and typical examples are shown in FIGS. 1 to 4.
As a method, as shown in FIG.
~3D, there is a method of arranging the reading elements 48~4D in parallel. In addition, as a second method, the sea urchin shown in Figure 2,
One lens 5 and reading element 6 and the required number of filters 7
There is a method in which filters A to 7C are provided and the filters are sequentially inserted into the optical path connecting the original 8, the lens 5, and the reading element 6. Furthermore, as a third method, as shown in FIG.
There is a method in which A to IIC are provided to perform color separation of the optical image of the original 12, and the required number of reading elements 13A to 13D read the image.

Furthermore, as a fourth method, as shown in FIG.
Green and blue light sources 14A to 14. Blink C and select original 15
, and each light image is sent to the reading element 1 through the lens 16.
7 and read element 1 in synchronization with the blinking of each light source.
There is a method of reading by driving 7.

As described above, there are various types of conventional multicolor original image reading devices, but each method has the following problems. That is, since the first to third methods use filters, they have the disadvantage of reducing the amount of light, especially in the first method.
The third method has the disadvantage of requiring image alignment for each color. Further, in the first to fourth methods, a plurality of lenses, filters, reading elements, or light sources are each required, which makes the configuration complicated. Therefore, it is impossible to realize miniaturization, high reliability, and low cost of the device. Furthermore, the second
The method requires mechanical movement of the filters 7A to 7C and is unreliable.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned objects, and it is unnecessary to provide a large number of light sources, reading elements, lenses, filters, etc. for each color, and it is not necessary to adjust the image alignment of each color, and the reading operation of each color can be switched at high speed. An object of the present invention is to provide a multicolor original image reading device that is small, low cost, and highly reliable.

[Structure of the invention]

In order to achieve the above object, the multicolor original image reading device of the present invention uses a contact type elongated image sensor as an image sensor, and a plurality of light emitting diodes that generate different colors as a light source for illuminating the multicolor original. The present invention is characterized by using a light emitting diode array having a plurality of light emitting diodes, and further comprising a driving means for controlling the driving current of the plurality of light emitting diodes to generate light of a desired color.

〔Effect of the invention〕

According to the present invention, a light emitting diode array having a plurality of light emitting diodes that generate different colors is used as a light source for illuminating a multicolor original, and the driving currents of the plurality of light emitting diodes are controlled by a driving means so that different colors can be generated. Can generate colored light. Therefore, it is no longer necessary to provide a large number of light sources, image sensors, lenses, filters, etc. for different colors as in the past. Further, there is no need to adjust the image alignment of each color. Furthermore, since the structure is simplified by using a contact type elongated image sensor, it is possible to make the device smaller, lower in cost, and higher in reliability. Furthermore, since the reading operation for each color is switched electrically, high-speed operation can be achieved.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 5A to 5C show the structure of a contact type elongated image sensor of the present invention. In the figure, 20 is a light sensor, 21 is a switch, 22 is a shift register, 23
is a signal line, and 24 is a differential amplifier. The optical sensor 20 is
As shown in FIG. 5B, it consists of an amorphous silicon layer 28 grown between a split electrode 26 and a transparent electrode 27 deposited on a substrate 25 and connected to a subsequent circuit 29.

FIG. 6 shows one embodiment of the image reading device of the present invention. In FIG. 6, 30 is a platen for placing a multicolor original 31, 32 is a light emitting diode array that irradiates a multicolor light source, and 33 is a contact type long image sensor 34 that directs the light reflected by the multicolor original 31. It is an extremely powerful lens for projection. The light-emitting diode array 32, as shown in FIG.
They are arranged at a pitch of about 2.5 mm. The individual multicolor light emitting diodes 36 are composed of red and blue light emitting diodes 37 and 38 mounted on one package or one chip, as shown in FIG. has been done. A current 11 flows through the red light emitting diode 37 and a current I2 flows through the blue light emitting diode 38 by the power supplies E1 and E2.

FIG. 9 shows the relationship between the driving current 11+12 of the light emitting diode and the emission wavelength. In the figure, the supply current ratio on the vertical axis is the actual current value expressed as a percentage when the standard supply current value IS of the diode is set to 100. That is, I+ −Is m^.

When Iz=OmA, the light emitting diode 36 generates red light and therefore the light emitting diode array 35 generates red light. Similarly, II-OmA, Iz = IG
mA produces blue light, I, = G + mA
, I2 = G2 inA produces green light.

This shows the timing. As shown in the figure, the reading operation by the contact type long image sensor 34 is started after the light emitting operation of the light emitting diode is completed. Contact type long sensor 34
The accumulation time Ts corresponds to the light emitting time of the light emitting diode,
The sum of the accumulation time TS and the reading operation time TR constitutes each color line reading time T. Therefore, the reading time T for one line is the sum of the line reading times T for each color of red, green, and blue.

FIG. 11 shows a multicolor light emitting diode drive circuit that controls the current flowing through the red light emitting diode 37 and the blue light emitting diode 38 by switching the switch 39. In this case, two colors of light, red and blue, are emitted, but the on time of each color light emitting diode 37, 38 needs to be sufficiently shorter than the storage time of each color.

Although the embodiments of the present invention have been described above, the contact type long image sensor is not limited to amorphous silicon;
It may be made of ds or other substances.

[Brief explanation of the drawing]

1 to 4 are schematic diagrams showing an example of a conventional image reading device, and FIGS. 5A to 5C are external perspective views and internal configurations of a contact type elongated image sensor used in an embodiment of the present invention. 6 is a schematic diagram of an embodiment of the present invention, FIG. 7 is an enlarged view of a light emitting diode array used in the image reading device of FIG. 6, and FIG. Drive circuit diagram of individual multicolor light emitting diodes, 1.8.12.15.31...Multicolor manuscript, 2A-2
D, 5.9.16... Lens, 3A-3D, 7A-7
C, IIA-IIC...Filter, 4A-4D16
．． 13A to 13C, 17... Reading element, 10... Trapezoidal prism, 14A to 14C... Light source, 30... Platen, 32... Light emitting diode array, 33...
Selfoc lens, 34... Contact type long image sensor, 36... Multicolor light emitting diode, 31... Red light emitting diode, 38... Blue light emitting diode, 39
···switch. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5B Figure 50 Figure 8 Figure 9

Claims (1)

[Claims] In an image reading device for a multicolor original that illuminates a multicolor original placed on a platen and makes the reflected light enter an image sensor through a lens to read an image, a contact type long image sensor is used as the image sensor, Furthermore, an image reading apparatus for a multicolor original uses a light emitting diode array having a plurality of light emitting diodes that generate light of different colors as a light source for irradiating the multicolor original.