JPH02141060A - Adhesive type color picture reader - Google Patents

Abstract

PURPOSE:To make a color picture reader smaller by using plural EL light emitting elements for the light source to irradiate an original surface, and making unnecessary an image formation system such as a rod lens array. CONSTITUTION:An EL light emitting element 4 and a light receiving element 2 where light emitting layers 41 to 43 to project light at plural different wavelengths are laminated are provided. The EL light emitting element 4 and the light receiving element 2 are provided through a transparent insulating layer 3, and an incident light window 52 to guide the reflected light from the original surface arranged on the counter-light receiving element side of the EL light emitting element 4 to the light receiving element 2 is provided at the EL light emitting element 4. Consequently, by using the EL light emitting element 4 where the light emitting layers 41 to 43 to project the light at the plural different wavelengths are laminated for the light source, the image formation system is made unnecessary. Thus, the whole color reader can be miniaturized.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a color image reading device, and particularly to a fully contact type color image reading device that does not require an optical system and can be miniaturized.

(Prior art) Color image reading devices used in color scanners, etc.
There has been a device that separates a color image using a prism or the like, and forms a reduced image on a light-receiving element dedicated to each color to read the color image. This device requires a light-receiving element array for each color, and also requires a human-friendly optical system, making it expensive and difficult to miniaturize the entire device.

Therefore, we constructed a three-color light source such as an LED array or a fluorescent panel, a same-magnification erect imaging system such as a rod lens array, and a light receiving element, and by sequentially switching the plurality of light sources, the three-color light source On the other hand, there was a system in which a color image was read using a single light-receiving element.

This type of close-contact color image sensor uses, for example, a fifth
As shown in the figure, a long sensor section 52 of a sandwich structure is formed on a substrate 51 by sandwiching a photoconductive layer (amorphous silicon) between an individual type fli (chromium) and a common electrode (TTO). Three fluorescent lamp light sources 54a and 54b emit light of different wavelengths to illuminate the document 53.
, 54c, and a Selfoc lens 55 that images the reflected light from the original vU 53 on the sensor section 52.

Then, each of the fluorescent light sources 54a, 54b, and 54c is turned on in synchronization with the drive cycle of the sensor section 52 to read image information. At this time, image information of the complementary color of the emitted light is output from the sensor unit 52. Therefore, each fluorescent light source 54a.

If 54b and 54c are selected to emit red, blue, and green light, if they are turned on in sequence and image information is read, cyan, yellow, and magenta image information can be output in sequence, and these can be output in sequence. Can be combined to obtain a color image.

(Problem to be Solved by the Invention) However, according to the above conventional example, a plurality of fluorescent light sources 5
4a, 54b, 54c and the SELFOC lens 55, the size of the color image reading device as a whole is increased due to the limitations of the geometrical arrangement, and the optical path length between the light source 54 and the sensor section 55 becomes long, so the use of light becomes difficult. The problem was that it was inefficient.

In addition, since the image information is read by sequentially lighting up each fluorescent light source 54a, 54b, and 54c, the sensor unit 52 needs to scan three times for each line of the document, but the lighting of the fluorescent light source 54 corresponds to the light emission pulse. On the other hand, there were problems in that the responsiveness was poor and it took time to read the image information.

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a contact type color image reading device that can improve the efficiency of light use and reduce the size of the entire unit.

(Means for Solving the Problems) In order to solve the problems of the conventional example described above, the color image reading device of the present invention includes an EL light emitting element in which a plurality of light emitting layers that emit light of different wavelengths are laminated, and a light receiving element. Equipped with:

The EL light emitting element and the light receiving element are disposed with a transparent insulating layer interposed therebetween.

Further, the EL light emitting element is provided with a light entrance window that guides reflected light from the surface of the document placed on the gray light receiving element side of the EL light emitting element to the light receiving element.

(Function) According to the present invention, an EL light emitting element in which a plurality of light emitting layers that emit light of different wavelengths are laminated is used as a light source, and an imaging system is not used, so that the entire color reading device can be miniaturized. can be achieved.

(Example) An example of the present invention will be described with reference to the drawings.

FIGS. 1(a) and 1(b) show cross-sectional explanatory views of a contact type color image reading device according to an embodiment.

The contact type color image reading device of the embodiment includes a substrate 1 made of glass epoxy, ceramic, etc., a light receiving element array 2 made up of a plurality of pixels on the substrate 1, and a light receiving element array 2 formed to cover the light receiving element array 2. The multicolor EL light emitting element 4 is formed on the transparent insulating layer 3, and the transparent insulating protective layer 5 is formed on the multicolor EL light emitting element 4.

The light receiving element array 2 includes, for example, a plurality of individual electrodes (chrome patterns) corresponding to pixels and a band-shaped transparent TFFI (IT
The sensor has a sandwich structure in which amorphous silicon (a-3i) is sandwiched between O> and O>. The transparent insulating layer 3 is formed of SlO□, 5lNa+polyimide, etc., and electrically insulates the light receiving element array 2 and the multicolor EL light emitting elements 4. The transparent insulating protective layer 5 prevents the multicolor EL light emitting elements 4 from being worn out due to direct contact between the multicolor EL light emitting elements 4 and the surface of the original 100 read by this contact type color image reading device. It is made of polyimide or the like.

The multicolor EL light emitting element 4 includes a green light emitting layer 41 made of ZnS:TbF, etc., a red light emitting layer 42 made of CaS:En, etc., and a blue light emitting layer 43 made of SrS:Ce, etc.
It is configured to emit three colors of light, each with a different wavelength. That is, an opaque metal type made of metal such as aluminum @51, Y20s, S is N
a, an insulating layer 61 made of BaTxOl, etc., a green light-emitting layer 41, a transparent electrode 71a sandwiched between an insulating layer 61 made of ITO, In 20), Sn02, etc., a red light-emitting layer 42, sandwiched by an insulating layer 61. transparent electrode 71b,
The multicolor EL light emitting element 4 is formed by sequentially stacking the blue light emitting layer 43, the insulating layer 61, and the transparent electrode 71c.

The metal electrode 51 has an area larger than the pixel on each pixel of the light-receiving element array 2 so that the light emitted from the light-emitting layer 41, 42, 43 is reflected by the original 100 and the reflected light is irradiated onto the light-receiving element array 2. A rectangular light entrance window 52 with a small diameter is opened. In addition, each transparent mold @71 has the light entrance window 52.
Openings 72a, 72b, 72 at positions corresponding to
c. This is because when a voltage is applied between each electrode, the light emitting layer portion sandwiched between the transparent electrodes 71 or between the transparent i#171 and the metal electrode 51 emits light. In order to prevent the light emitted from the layer from directly irradiating the light receiving element array 2 and reducing the sensitivity of the light receiving elements, and also to prevent the reflected light from the document surface from transmitting through the transparent electrode 71 and attenuating the light receiving element array 2. This is to prevent it from being guided to array 2.

Furthermore, the blue light-emitting layers 43. Red light emitting layer 42. A green light emitting layer 41 is provided,
By changing the optical path length up to the original vJ100 for each color, the illuminance of each light irradiated onto the document surface is made uniform.

When a drive signal for emitting light from the EL element is applied between the metal electrode 51 and the transparent electrode 71a, the green light emitting layer 41 in the area sandwiched between these electrodes emits light, and the light emitted upward is emitted from the original 100. The reflected light forms an image on the light receiving element array 2 from the light incidence window 52 and is converted into an electric signal to obtain an image signal for green. In addition, the drive signal for the EL element to emit light is transmitted to the electrode 71a and transparent! @71b, the portion of the red light emitting layer 42 sandwiched between these electrodes emits light.

Similarly, if a drive signal is applied between the transparent electrode 71b and the transparent electrode 71c, the portion of the blue light emitting layer 43 sandwiched between these electrodes emits light. Therefore, by selecting the electrode to which the drive signal is input, each color can be emitted independently, and an image signal for each color can be obtained.

Next, a method of manufacturing the above-mentioned color image reading device will be explained.

A light receiving element array 2 is formed on a substrate 1 made of glass epoxy, ceramic, or the like. The light-receiving element array 2 is constructed by, for example, depositing chromium on a substrate 1 and patterning it by photolithography to form a plurality of individual electrodes, and then depositing amorphous silicon to cover the individual electrodes to form a band-shaped photoconductive layer. A band-shaped transparent electrode is formed by depositing an indium tin oxide film on the photoconductive layer.

Next, Si0. ,
A transparent insulating layer 3 is formed by depositing Sis Na, polyimide, etc.
form.

A metal such as aluminum is deposited on the transparent insulating layer 3 and patterned by photolithography to form the light receiving element array 2.
A metal electrode 51 having a light entrance window 52 located above the pixel of
form.

An insulating layer 61 is formed by depositing ITO, In2O, 5nO7, etc. on the metal electrode 51, and then Z is deposited by sputtering or the like.
A strip-shaped green light-emitting layer 41 is formed by depositing nS: TbFs or the like.

An insulating layer 61 is formed on the green light emitting layer 41, and then Y, O
,, Sis Na, BaTiO3, etc. are deposited by sputtering or the like to form a transparent mold 171a, and this transparent t[71a
is patterned by photolithography to form the light entrance window 5.
An opening 72a corresponding to 2 is formed, and an insulating layer 61 similar to that described above is formed again.
A red light emitting layer 42 made of En or the like, an insulating layer 61, a transparent type @71b having an opening 72b, and an insulating layer 61 are formed in this order. Furthermore, a blue light emitting layer 4 made of SrS:Ce, etc.
3. Insulating layer 61, transparent electrode 71c having opening 72c
A multicolor EL light emitting element 4 which emits light of three colors is obtained.

A transparent insulating protective layer 5 is formed by coating polyimide or the like on the multicolor EL light emitting element 4.

FIG. 2 shows another embodiment of the present invention, in which transparent electrodes 71a, 71b, and
Among the transparent electrodes 71c, an opening 72 is provided only in the central transparent electrode 71b.
b.

Since the light-emitting layer emits light only in the portion sandwiched between the electrodes, in order to prevent light from being emitted from the light-emitting layer directly above the pixels of the light-receiving element array 2, an opening may be formed in one of the electrodes that sandwich the light-emitting layer. Since the metal electrode 51 requires a light entrance window 52 in order to guide the reflected light from the original to the light receiving element array 2, the light receiving element array 2 does not need to have an opening in the transparent electrode 71a.
The light-emitting layer 41 located directly above the pixel does not emit light, and if the opening 72b is formed in the transparent electrode 71b, the light-emitting layer 41 located directly above the pixel will have an opening on one side of the transparent electrode that sandwiches the light-emitting layer. 42.43 light emission can be prevented.

According to this embodiment, the transparent electrode 71a and the transparent electrode 71c
Since there is no need to form an opening in the photolithography process, the multicolor EL light emitting element 4 can be easily formed.

FIGS. 3(a) and 3(b) show another embodiment of the present invention.

In the embodiments described above, the light-receiving element array and the multicolor BL light emitting element were integrally fabricated on the same substrate by a thin film process, but in the embodiment shown in FIGS. 3(a) and 3(b), the light receiving element array and the multicolor EL The light emitting elements are manufactured on separate substrates.

That is, in FIG. 3<a), a multicolor EL light emitting element 4 is formed by forming M layers of a light emitting layer 431, a light emitting layer 421, and a light emitting layer 41 on a transparent substrate 11 made of hard plastic or the like, in the reverse order of the above embodiment. The entire structure is covered with a transparent insulating layer 12 made of polyimide or the like. In the figure, the same components as in FIGS. 1 and 2 are designated by the same reference numerals. The light-receiving element array 2 is formed with a chrome pattern 21 in the same process as in FIGS. 1 and 2.
゜Photoconductive layer 22. A transparent electrode 23 is sequentially formed, a light shielding M25 for regulating the light receiving portion is formed via an insulating layer 24, the whole is covered with a transparent insulating layer 3, and a multi-color E is formed.
The light incident window 52 of the L light emitting element 4 and each pixel of the light receiving element array 2 are bonded together so that they correspond to each other.

In FIG. 3(b), the order of deposition of the multicolor EL light emitting element 4 is reversed from that in FIG. 3(a), so after forming the metal electrode 51 on the transparent substrate 1 made of hard plastic or the like, A multicolor EL light emitting element 4 is formed by sequentially stacking light emitting layers 41, 42, and 43, and the whole is covered with a transparent insulating layer 12 made of polyimide or the like.
cover with

According to this embodiment, since the multicolor EL light emitting device 4 and the light receiving device array 2 are manufactured separately, it is possible to improve the yield of the color image reading device obtained by joining them together.

According to the color image reading device configured as described above, light from the multicolor EL light emitting element 4 is transmitted through the antimetallic electrode 51.
11! It irradiates the reading section of the document 100 arranged in the gray light receiving element array 2fFI of the multicolor F and L light emitting elements 4. The light irradiated onto the reading unit of the original 100 is reflected from the original surface and reaches the pixels of the light receiving element array 2 through the light entrance window 52, where it is converted into an electrical signal corresponding to the darkness of the original.

As shown in FIG. 4, for the reading section of one line of the original, the sensor start signal
3 Lighting signal B1 Light emitting layer 42 Lighting signal R1 Light emitting layer 41 Lighting signal G is set, and the multicolor EL light emitting element 4 is synchronized with the driving of the light receiving element array 2 for the reading section of one line of the original, and the light emitting layer 42, 43 is activated. If you switch the lights on in the order of .41,
The accumulated signals from the pixels of the light-receiving element array 2 for each color are read out in chronological order by scanning three times to obtain each color image signal Sr.

Sg and Sb can be obtained.

(Effects of the Invention) According to the present invention, a plurality of EL light emitting elements are used as a light source for illuminating the document surface, and an imaging system such as a rod lens array is not required, so that the color image reading device can be miniaturized. be able to. Furthermore, since the optical path length between the document surface and the light receiving element can be shortened, the light usage efficiency can be improved.

[Brief explanation of the drawing]

FIG. 1(a) is an explanatory longitudinal cross-sectional view of a color image reading device according to an embodiment of the present invention, FIG. 1(b) is an explanatory cross-sectional view taken along line A-A'' in FIG. ) is an explanatory cross-sectional view taken along the line B-B' of FIG. FIG. 4 is a sectional view of a color image reading device showing another embodiment of the present invention, FIG. 4 is a timing chart for reading by the color image reading device, and FIG. 5 is an explanatory view of a conventional color image reading device. 1... Substrate 2... Light receiving element array 3... Transparent insulating layer 4... Multicolor EL light emitting element 5...
・Transparent insulation protective layer 2... Light entrance window Figure 1 (C) Figure

Claims (1)

[Claims] It has a light receiving element and an EL light emitting element in which a plurality of light emitting layers that emit light of different wavelengths are laminated, and the EL light emitting element and the light receiving element are disposed via a transparent insulating layer, and the E
A contact type color image reading device characterized in that an EL light emitting element is provided with a light entrance window that guides reflected light from a document surface disposed on the side opposite to the light receiving element of the L light emitting element to the light receiving element.