JPS61285262A - Equal magnification image-pickup sensor - Google Patents

Abstract

PURPOSE:To provide the titled equal magnification sensor having high response speed, excellent photocurrent/dark current characteristics and long length, by placing individual electrodes, a common electrode and a photo-conductive material containing a specific hydrazone compound and a specific azo dye as active components on an insulating substrate. CONSTITUTION:The objective equal magnification sensor can be produced by attaching individual electrodes and a common electrode to the surface of an insulating substrate (e.g. glass plate) and covering the insulating substrate with a photo-conductive material containing a hydrazone compound of formula I (R1 is methyl, ethyl, etc.; R2 is methyl, ethyl, phenyl, etc.; R3 is H, Cl, Br, 1-4C alkyl, etc.) and one or more azo dyes of formula II [A is group of formula III (Ar2 is benzene ring, naphthalene ring, etc.), etc.], formula IV, formula V (Ar is phenyl, pyridyl, etc.), formula VI (X is benzene ring, indole ring, etc.), formula VII, etc., as main components by dipping method, etc.

Description

[Detailed Description of the Invention] The present invention relates to a photoelectric conversion element (same-magnification sensor), and more specifically to a photoelectric conversion element equipped with a photoconductive film containing an azo pigment and a hydrazone compound as main components. The present invention relates to an image reading equal-magnification sensor having the following features.

Conventional technologies include CdS, photoelectric conversion elements using amorphous-5i, JP-A No. 59-54373 (Electronic Corporation), JP-A No. 59-112651 (Fujitsu), and JP-A No. 59-Sho.
9-110177 (Toshiba), etc., and a photoelectric conversion element using P-C-3L is JP-A-58-118161.
(Cannon) is raised. In addition, "Nikkei Electronics J (April 26, 1982) introduces photoelectric conversion elements using Cd5a, 5e-As-Te, etc. in addition to the above-mentioned CdS and amorphous-3i. However, none of these have been successfully developed. Due to the limitations of the membrane method, it is unsuitable for use as a long (meter-sized) full-scale sensor.

We have been investigating a photoelectric conversion element with an azo pigment/binder resin dispersion system as an advantageous photoelectric conversion element material for long, same-size sensors (patent applied for). However, this system had a problem with carrier mobility, and the desired response speed could not be obtained.

The present invention aims to improve the response speed of the above-mentioned dispersion type photoelectric conversion element.

(2) An object of the present invention is to provide an image reading 1-magnification sensor having a photoelectric conversion element having a photoconductive film mainly composed of an azo pigment and a hydrazone compound, which overcomes the drawbacks of the conventional sensor.

As a result of intensive research to achieve the above object, the present inventors have developed an image reading 1x image sensor comprising individual electrodes, a common electrode, and a photoconductor disposed on an insulating substrate. The conductor has the following general formula [wherein R1 represents a methyl group, ethyl group, 2-hydroxyethyl group, or 2-chloroethyl group, R2 represents a methyl group, ethyl group, benzyl group, or phenyl group, and R1 represents hydrogen.

Chlorine, bromine, alkyl group having 1 to 4 carbon atoms, 1 to 4 carbon atoms
represents an alkoxy group, dialkylamino group or nitro group];
[However, in the general formulas (1) to (10), the above general formula is an aromatic ring such as a benzene ring or a naphthalene ring, an indole ring, or a carbazole ring.

represents a hetero ring such as a benzofuran ring or a substituted product thereof; Ar represents an aromatic ring such as a benzene ring or a naphthalene ring; or a hetero ring such as a dibenzofuran ring; or a substituted product thereof; Ar2 represents a benzene ring or a substituted product thereof; Represents an aromatic ring, naphthalene ring, etc. or a substituted product thereof,
R represents hydrogen, a lower alkyl group, a phenyl group, or a substituent thereof, and R2 represents a lower alkyl group, a phenyl group, a carboxyl group, or an ester thereof.] In 11) to (24).

Here, aromatic rings such as benzene rings and naphthalene rings, hetero rings such as indole rings, carbazole rings, and benzifuran rings, or substituted products thereof, and Ar are benzene rings,
Aromatic rings such as naphthalene rings, heterocyclic rings such as dibenzofuran rings, or

Those substituents, Ar, and Ar3 are benzene rings,
Aromatics such as naphthalene rings or substituted products thereof, R1
and R3 represents hydrogen, a lower alkyl group, a phenyl group, or a substituted product thereof; R2 represents a lower alkyl group, a carboxyl group, or an ester thereof] [However, in the general formulas (25) to (27), Ar in the formula represents a substituted or unsubstituted phenyl group, a substituted or unsubstituted naphthyl group, anthryl group, pyrenyl group, pyridyl group, chenyl group, furyl group, or carbazolyl group] 29), or an aromatic ring such as a benzene ring or a naphthalene ring, a hetero ring such as an indole ring, a carbazole ring, or a benzifuran ring, or a substituted product thereof, R1 is an aromatic ring such as a benzene ring or a naphthalene ring, or a dibenzofuran ring A heterocycle such as a carbazole ring or a substituted product thereof; R2 represents hydrogen, a lower alkyl group, a phenyl group, or a substituted product thereof] [However, in the general formulas (30 to 31), X is a substituted or unsubstituted Represents an aromatic ring or a petro ring,
Ar represents a substituted or unsubstituted aromatic ring or a petro ring.] The above object is achieved by providing an image reading 1-magnification sensor characterized by containing as an active ingredient at least one azo pigment represented by the following: I found out what I can do.

That is, the present invention relates to a 1-size sensor for image reading equipped with a photoelectric conversion element formed by providing individual electrodes, a common electrode, and a photoconductive film containing an azo pigment and a hydrazone compound as main components on an insulating substrate. It is.

Figures 1, 2-a, 2-b, and 3 show an example of the overall configuration, circuit configuration, and photoelectric conversion element structure of the same-size sensor.
- Shown in Figure a and Figure 3-b.

FIG. 1 shows an example of the configuration of a 1-magnification sensor for image reading. This image sensor is composed of an illumination light source, a rod lens array as a light guiding system, and a photosensor array consisting of a photoelectric conversion film.In addition, a readout circuit and a scanning circuit are required to drive the sensor.

There are two readout methods: a real-time method and a charge accumulation method.

Figure 2-a shows an example of a real-time readout circuit. The real-time method is a method in which a blocking diode is provided in series with each element, and one individual electrode is sequentially switched, and the resistance change of each element is converted into an external current change and taken out as a photoelectric conversion output signal. FIG. 2-b shows an example of a charge accumulation type readout circuit. This method uses signal light to discharge the charges accumulated in the photodiode, detects the current of charge flowing into the photodiode at every accumulation time (scanning time), and converts the optical signal into an electrical signal.

The structure of the photoelectric conversion element is shown in FIGS. 3-a and 3-b. The device structure is planar type (third-stage) due to the arrangement of electrodes.
It is roughly divided into the sandwich type (Figure 3-b) and the sandwich type (Figure 3-b). In the sandwich type, the thickness of the photosensitive layer corresponds to the electrode spacing, so the electrode spacing can be controlled easily and with high precision, but it requires transparent electrodes and has the disadvantage that pinholes in the photosensitive layer can be fatal.

Although the prescription planar type has better pinhole resistance than the sandwich type and allows electrodes to be made in one process, it has a difficulty in controlling the electrode spacing.

Next, the materials and formulation constituting the photoelectric conversion section, which is the main focus of the present invention, will be described.

The insulating substrate in the present invention is, for example, a translucent ceramic when receiving light from the substrate side.

Use glass, plastic, or a combination of these. On the other hand, when irradiating light from the side of the photosensitive layer formed on the substrate, the substrate may be a non-light-transmitting insulating substrate, or it may be an insulating substrate on a non-insulating substrate such as a metal. good.

Examples of sensor drive electrodes installed on an insulating substrate include Al, Ti, V, Cr, Mn, Fe, Go, and Ni%.
Cu, Zn, Pb, Sn, Ag, Au.

Mo, W, etc., alloys of these metals, and multilayer films of two or more of these metals and alloys may be used.

Alternatively, a translucent electrode such as NESA, ITOlIn, 02, etc. may be used as required.

These conductive materials can be produced by sputtering, vapor deposition, or CVD.
After that, these metal films can be photoetched to obtain an electrode having a desired shape.

It is also possible to form the electrodes by a mask vapor deposition method, a screen printing method, a lift-off method, etc. which are well known in industry.

The thickness of the electrode film is 0.05 μm to 5.0 μm, preferably 1 to 4 μm.

In the case of a so-called planar type sensor (FIG. 3-a) in which the individual electrodes and the common electrode are installed flatly on a substrate, a photoconductive layer is installed after electrodes are formed on an insulating substrate, and a full-size sensor is completed. On the other hand, in the case of a so-called sandwich type (Figure 3-b) in which an upper electrode, a photoconductive layer, and a lower electrode are laminated on a substrate, the lower electrode is formed, then the photoconductive layer is formed, and then the upper electrode is layered with the above-mentioned material. and method of installation. The materials of the upper and lower electrodes do not need to be the same, and are preferably materials that do not interfere with the properties of the photoconductive layer.

The photoconductive film is mainly composed of an insulating resin, an azo pigment having the general formula described in the claims, and a hydrazone compound. Examples of insulating resins include epoxy resins, acrylic resins, polyamide resins, polyimide resins, butyrol resins, polyester resins, and polycarbonate resins, which are selected based on the film formability of the photoconductive layer, electrical properties, etc. It is also possible to use two or more types of insulating resins in order to compensate for the characteristics specific to these resins.

The mixing weight ratio of the azo pigment and hydrazone compound and the insulating resin used in the present invention is as follows.

Azo pigment/Insulating resin: 173-3/1 Hydrazone compound/Insulating resin: 1/3-1/1 If the mixing ratio of the azo pigment and hydrazone compound to the insulating resin is too high, the photoconductive film and electrode and insulation Adhesiveness to the substrate decreases and reliability is impaired. Also, if it is too small, the photoconductivity σP becomes small and S
It is not possible to increase the N ratio (σP/σd).

The thickness of the photoconductive film is generally 0.1 to 5 μm, preferably 0.2 to 2 μm. The photoconductive layer can be easily formed by a coating method such as a dipping method, a doctor blade method, a spray method, or a roll coating method.

It is also possible to mix a plurality of the above azo pigments and hydracine compounds in the photoconductive film of the present invention to complement each other's properties. Further, other additives may be added in order to improve and stabilize various properties. Further, a protective layer for protecting the photoconductive layer from the environment and external forces, a light blocking layer having a function of separating bits, etc. can be provided on the photoconductive layer. It is also possible to install a new layer between the electrode, the insulating substrate, and the photoconductive layer in order to improve the adhesion between the insulating substrate and the electrode and to improve the electrical properties between the photoconductive layer and the electrode. .

Specific examples of the azo pigment and hydrazone compound used in the present invention are illustrated below.

(Left below) One-faced tooth Pigment & Pigment & (2) General formula (-@-ai-CH4N=N-A')2 Pigment blood
Pigment teeth materials (3) General formula pigments & Pigment Arashi (4) General formula % formula % (5) General formula pigment teeth Pigment teeth General formula % formula % Pigment tooth - (8) General formula % formula % (9) General formula pigment tooth Pigment & pigment tooth (1 general formula island 1 ゛ (11) General formula.

(12) General formula % formula % N=NA (14) General formula % formula % (15) General formula pigment & (16) General formula % formula % (17) General formula pigment bile Pigment bile pigment blood
Gankai Arashi Pigment Arashi (18) General Formula % Formula % Pigment Blood Pigment Blood (19-C) (19-D) Pigment Feng (20) General Formula % Formula % (21) General Formula Pigment Part Pigment Arashi Pigment Teeth Pigment Teeth (22) General formula % Formula % (23) General formula pigment & Pigment & Pigment & (24) General formula pigment Pigment teeth
111 (25) General formula (26) General formula and H5 (28) General formula Pigments & Pigments & Pigments
Pigment & (30) General formula pigment & Pigment & pigment blood
Pigment Arashi Pigment &
Pigment Arashi Pigment Arashi Pigment Blood Pigment & (31) General Formula % Formula % Pigment Arashi Pigment Arashi Pigment Arashi
Pigment blood M-Examples of hydrazone A products 2-1-C)1. <H, -82-2
-CH3-C2H, -H 2-3-CH, -CH, -@ -H2-4-
CH3-@-82-5-C2H,-CH
, -H 2-6-C2Hs - et H, -H2-7-C2
H, -CH2 barrel -H 2-8-CqHs-o-H 2-9 ring 0H-CH3-H 2-10-C2) +401 (-raH, -H2-11-C
,H,OH-CH2-@-H2-12
-C2H,OH- @ -H2-
13-C2H4CQ-ω,
-H2-14-C2H,CQ -et al.H,
-82-15-C2H,CQ -CH2-@
-H2-16-14) 14CΩ
R◇ -H2-17-CH, -C
H,-(,Q:' 18-CH3-C2Hs-
Br2-19 -CH, -C2H, -OCH.

2-20 -CI(,-(4H,-war2-2l-
CH3-CH, -@ -CH2-24 ring H
, -CH, I1 2-25 -C2H, -CH, -0CH32-2
6 ring H, -CH, -No2 2-27 -C2H,<H, -◎ (
Q2-28 -C2)1. -CH,
-◎ Parrot H52-29-C2H, -CI, -
@-CH.

2-30 (4H, -CH, -◎
-Br2-32-(4)t,0H-CH3-Q
c2H.

2-33 E(,OH-CI,
-C,H.

2-35 -C2H40H-C2H, -Br2-
36 -C,H40H- et al H6-Tsuru 2-37
-ra l(,0)1 -CH,-◎
Naki H12-38-(4)1. OH-CH2-@
-0CII(.

2-41 -C, H2CO-CH, -CH2-4
2-C21(4CQ-CzHs
-Br2-43 Naruru CQ-C2H5
-No□2-45 -C,H,CQ
-◎ -QC) 13 (hereinafter blank) Next, in order to explain the present invention in more detail, Examples and Comparative Examples are shown below, but the present invention is not limited to these.

Example 1 Polyamide (CM-8000; manufactured by Toshi Co., Ltd.) 0.4
Prepare a solution containing 7 parts by weight of methanol and 3 parts by weight of butyl alcohol61 Then, apply this solution to a glass substrate having an A1 electrode pattern shown in FIG. 4 to a dry film thickness of 0.3 μm. It was applied using a dipping method to achieve the desired results. Thereafter, it was dried for 30 minutes in a constant temperature bath at 100°C.

Next, 2.7 parts by weight of a hydrazone compound represented by the structural formula (compound Na2-8), 3 parts by weight of polycarbonate resin (Panlite-1300; manufactured by Teijin Kasei Ltd.), 77 parts by weight of tetrahydrofuran solution, and a solution of the structural formula (azo pigment Nα
2 parts by weight of the azo pigment shown in 1) was sufficiently ground in a ball mill.

Next, this pulverized mixture was taken out, and tetrahydrofuran was added while stirring slowly to prepare a photoelectric conversion layer forming liquid (1) having a solid content concentration of 2% by weight. After that, 0.
On a substrate on which a polyamide layer with a thickness of 3 μm has been formed, a naked photoelectric conversion layer forming solution (I) that can obtain a film thickness of 1 μm when dried is applied by a dipping method, and then dried at 100° C. for 30 minutes. A photoelectric conversion element (1) of the invention was obtained.

Example 2 A photoelectric conversion element of the present invention was produced in the same manner as in Example 1 except for using a hydrazone compound represented by the structural formula (compound k2-5) and an azo pigment represented by the structural formula (azo pigment Nα6). (n) was obtained.

Comparative Example 1 Similar to Example 1, 0.3
A polyamide layer with a thickness of μm was formed. Next, azo pigment 2 shown by the structural formula (Azo pigment list 1) used in Example 1
Part by weight, polycarbonate resin (Panlite, K-13
00; manufactured by Teijin Kasei Ltd.) and 50 parts by weight of tetrahydrofuran were sufficiently ground in a ball mill. The resulting dispersion was taken out, and while slowly stirring, tetrahydrofuran was added to prepare a photoelectric conversion layer forming solution (III) with a solid content concentration of 2% by weight, and photoelectric conversion layer forming solution (III) with a dry film thickness of 1 μm was prepared in the same manner as in the example. A comparative photoelectric conversion element (m) was obtained by providing a layer.

Comparative Example 2 A comparative photoelectric conversion element (IV) was obtained in exactly the same manner as in Comparative Example 1, except that the azo pigment represented by the structural formula (azo pigment Nα6) used in Example 2 was used.

Photoelectric conversion elements (1), (II) obtained in this way,
Table 1 shows the SN ratio (photocurrent/dark current) and photoresponse speed (rise time; Tr, fall time; Td) of (m) and (IV).
．． 2. However, the element structure adopted in the examples and comparative examples is a planar type, and the distance between the Al electrodes is 5 μm.
, the electrode film thickness is 1 μm (FIG. 4). Furthermore, for the purpose of separating bits, a light blocking layer was provided as shown in FIG. 4.5, and device characteristics were evaluated.

The SN ratio was expressed as the photocurrent (σr)/dark charge (σd) ratio for each electric field strength when a DC voltage was applied to the element. In addition, the photoresponse speed is 1 x 10'V/■ under an electric field of photocurrent source type (
Tr and Td were determined from (see FIG. 6). The definitions of Tr and Td are shown in FIG.

The amount of irradiated light when measuring both the SN ratio and the optical response speed was 1701 ux (color density: 2850'K) using a tungsten lamp.

Table-1 Table-2 Table 1.2. When the electric field strength is lX10'V/■, the photoelectric conversion elements (1) and (II) according to the present invention are compared to the photoelectric conversion element (nlL (■)) which is a comparative product that uses the same azo pigment but does not contain a hydrazone compound. Better than 103 S
It was found that the N ratio could be obtained. In addition, the improvement effect in response speed Tr and Td when compared with the comparative product of the present invention is obvious, and by adding a hydrazone compound to the azo pigment and binder resin, carrier mobility in the photoconductive layer is improved. This can be judged to be an effect of the present invention aimed at improvement. Moreover, the characteristics of the SN ratio, Tr, and Td in each bit show almost the same values, and it can be judged that there is no problem with the separation between bits, and it is possible to provide a stable photoelectric conversion element with little variation between bits.

As mentioned above, according to the present invention, it is possible to form a large-scale film, making it possible to create a long (meter-sized) sensor of the same size. By doing so, an organic photoelectric conversion element with excellent response speed and signal-to-noise ratio (photocurrent/dark current) characteristics can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing an example of the overall configuration of a contact type image reading equal-magnification sensor. FIGS. 2a and 2b are readout circuit diagrams showing examples of circuit configurations. FIGS. 3a and 3b are schematic diagrams showing the element structure of the photoconductive film. FIG. 4 is a schematic plan view of a photoelectric conversion element used in the present invention, and FIG. 5 is a schematic cross-sectional view of the photoelectric conversion element. FIG. 6 shows a photocurrent waveform under an electric field of I x 10'V/m, and the photoresponse speed is indicated by the rise time Tr and fall time Td. 1... Original 2... Light source 3... Photo sensor array

Claims (1)

[Scope of Claims] 1. In an image reading equal-magnification sensor comprising individual electrodes, a common electrode, and a photoconductor disposed on an insulating substrate, the photoconductor has the following general formula ▲ mathematical formula, chemical formula, table etc. ▼ [In the formula, R_1 represents a methyl group, ethyl group, 2-hydroxyethyl group, or 2-chloroethyl group, R_2 represents a methyl group, ethyl group, benzyl group, or phenyl group, R_3 represents hydrogen, chlorine, bromine, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a dialkylamino group, or a nitro group] and at least one hydrazone compound represented by the following general formula (1) ▲ Formula, There are chemical formulas, tables, etc. ▼ (2) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (3) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (4) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (5) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (6) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (7) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (8) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (9 ) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (10) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [However, in the above general formulas (1) to (10), A is ▼ or ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ Here, X represents an aromatic ring such as a benzene ring or a naphthalene ring, a hetero ring such as an indole ring, a carbazole ring, or a benzifuran ring, or a substituted product thereof. Ar
_1 is an aromatic group such as a benzene ring or naphthalene ring. Alternatively, it represents a hetero ring such as a dibenzofuran ring or a substituted product thereof, Ar_2 represents an aromatic ring such as a benzene ring or a naphthalene ring or a substituted product thereof, and R_
1 represents hydrogen, a lower alkyl group, a phenyl group, or a substitute thereof, and R_2 represents a lower alkyl group, a phenyl group, a carboxyl group, or an ester thereof] (11) ▲ Contains mathematical formulas, chemical formulas, tables, etc. ▼ ( 12) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (13) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (14) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (15) ▲There are mathematical formulas, chemical formulas, tables, etc. ▼ (16) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (17) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (18) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (19) ▲ Mathematical formulas, chemical formulas, tables, etc. ▼ (20) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (21) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (22) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (23) ▲ Mathematical formulas, chemical formulas, There are tables, etc. ▼ (24) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [However, in the general formulas (11) to (24) above, A is ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ or ▲ Mathematical formulas, There are chemical formulas, tables, etc. ▼ or ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ Here, Ar_1 is an aromatic ring such as a benzene ring or a naphthalene ring, a hetero ring such as a dibenzofuran ring, or a substituted product thereof; Ar_2 and Ar_3 are an aromatic ring such as a benzene ring or a naphthalene ring or a substituted product thereof; R_1 and R_3 represents hydrogen, a lower alkyl group, a phenyl group, or a substituent thereof, and R_2 represents a lower alkyl group, a carboxyl group, or an ester thereof] (25) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (26) ▲Mathematical formulas, chemical formulas, and tables (27) ▲ There are mathematical formulas, chemical formulas, tables, etc. Represents a naphthyl group, anthryl group, pyrenyl group, pyridyl group, chenyl group, furyl group, and carbazolyl group] (28) ▲ Contains mathematical formulas, chemical formulas, tables, etc. ▼ (29) ▲ Contains mathematical formulas, chemical formulas, tables, etc. ▼ [ However, in the above general formulas (28) to (29), , an aromatic ring such as a naphthalene ring, a hetero ring such as a dibenzofuran ring, a carbazole ring, or a substituted product thereof; R_2 represents hydrogen, a lower alkyl group, a phenyl group, or a substituted product thereof] (30) ▲ Numerical formula, chemical formula, table, etc. ▼ (31) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [However, in the above general formulas (30 to 31), X represents a substituted or unsubstituted aromatic ring or a hetero ring,
Ar represents a substituted or unsubstituted aromatic ring or a heterocycle.] An image reading 1-magnification sensor comprising at least one azo pigment represented by the following as an active ingredient.