JPH01125167A - Reader - Google Patents

Abstract

PURPOSE:To improve accuracy and to prevent deviation of a picture element by fixing a mount member to one side face of an optical split member or a holding member by adhesion based on a picture element line direction of a solid-state image pickup element. CONSTITUTION:A lens barrel 21 is contained in a V-shaped receiving part opened upward at a right angle in a lens holder member 21a, fixed by a tightening metallic fixture 21c and fitted to a prescribed position of a base 40. A mount face 21b adhering the front face of a prism 22 is formed to a rear end face of the lens barrel 21 and the prism 22 is fixed by adhesion to the mount face 21b. In this case, the CCDs 25, 27 are adhered to one side face of the prism 22 via the mount members 24, 26 with a prescribed interval with respect to the prism 22 in a form of cunti-lever through adhesion and the photodetection face is placed to the image forming face of a read unit. Thus, the picture element deviation is prevented and the accuracy is improved.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a reading device for reading images of image forming devices such as facsimiles, copiers, and printers, and imaging devices such as television cameras. Using an optical member such as a dichroic prism, the original image is COD
The present invention relates to a reading device equipped with an image reading section that reads an optical image using a solid-state image sensor such as the above.

[Background of the invention]

For example, a color image forming apparatus, particularly a digital color image forming apparatus, is generally constituted by a color image geographical device such as an image reading section and an image writing section. The image reading section passes the light image of the document surface obtained by exposure scanning, for example, through a reading imaging lens system and separates it into a plurality of lights using a light splitting means behind it.
) etc., and then images are formed on a line image sensor consisting of a solid-state image sensor that receives light in each channel. The axial position and perpendicularity of each spectral optical axis must be adjusted sufficiently to ensure proper image formation. That is, unless the optical images of each line image sensor are made to match each other as accurately as possible, the reproduced image reproduced by the writing section will be adversely affected. The solid-state image sensor, for example, the line image sensor Toshiba TCD 106C, is composed of an array of pixels with each pixel being about 7 μm, so in the example shown in FIG. If the value exceeds 1/4 pixel (approximately 2 μII), other colors such as black text or
Color ghosts of red, blue, etc. appear around the edges of figures.

In particular, when the above correspondence causes a deviation of one pixel (approximately 7 μm) or more, this effect is significant. Electrical correction is generally performed to prevent this color ghost. However, if most of the color ghosts are removed by electrical processing, the memory capacity required would be extremely large, and problems such as variations in line thickness would occur in the image, resulting in technical difficulties. Therefore, it cannot be said to be perfect, and it can be said that it is unresolved from a commercialization perspective.

The present applicant has made a proposal in Japanese Patent Application No. 60-239174 as a means for preventing pixel misalignment between image sensors. In this proposal, as shown in FIG. 15, each solid-state image sensing device 51a, 51b is connected to a base 52a.

52b to form a unit, and as shown in FIG.
It is possible to adjust the two axis directions of y and the rotation direction of the X and y axes, and the adjustment and installation are performed mechanically. The above proposal allows for fine adjustment of the mounting of each solid-state image sensor, and immediately after adjustment, the correspondence between the elements almost matches each other. However, as shown in FIG.
1b are each attached to a frame, between which many holding members, such as supports, are adjusted with adjustment screws, and these members are subject to thermal expansion and contraction due to temperature changes, poor adjustment of the screws, and screws. It is easy to cause positional misalignment due to play and errors in the device itself, or misalignment between multiple elements due to optical and aberrations in the optical member, and it is not easy to eliminate pixel misalignment, including in terms of restorability. . In particular, when holding and fixing a solid-state imaging device using precision screws, which have a mechanical structure, it is necessary to tighten the solid-state imaging device using the screws and perform fine adjustment work on the micron order, making it extremely difficult to achieve precision. . Also, even if the solid-state image sensor is set up in a jig quite firmly, the final tightening of screws, etc. will be done by torque, and if removed from the jig after tightening, the distortion will return by a few μm.
In many cases, displacement of more than 100 m is caused, and even if it is set accurately within 1 μm, for example, due to the stress strain inside the part, it is recognized that a shift of several μm or more will occur in impact tests etc. Furthermore, there is a drawback that the temperature test results may have installation errors due to the thermal expansion coefficient of the support member.

In addition, in order to fix the solid-state image sensor,
There is also a proposal for fixing using an adhesive according to No. 70, but this proposal is about fixing a single solid-state image sensor, and is not about fixing the solid-state image sensor to an optical member. It is intended to be adjusted and fixed.
Fixation was done by filling adhesive with the adjustment amount, and it was not applicable to image reading that requires high precision holding without positional deviation using multiple image sensors. .

[Problem that the invention seeks to solve]

There is a need to provide a high-resolution reading device for a color image processing device, particularly a color image reading device in which a plurality of solid-state imaging devices are arranged and the image formed by each solid-state imaging device is read and signal processing is performed. Further, it is required that the images formed by each solid-state image sensor correspond to each other accurately. SUMMARY OF THE INVENTION An object of the present invention is to provide a color image reading device that prevents mutual positional deviation between solid-state image sensors and can perform the most stable image reading under all conditions such as temperature fluctuations, changes over time, vibrations, and shocks. shall be.

[Structure of the invention]

The above purpose is to use the light splitting member, the imaging lens, or the light splitting member of a reading device that reads a light image by a plurality of solid-state image sensors provided at the imaging position of an optical system consisting of an imaging lens and a light splitting member. In the reading device in which the solid-state imaging device is fixed to a holding member of an optical member via a mounting member, the mounting member is attached to one side of the light splitting member or the holding member in a pixel column direction of the solid-state imaging device. This is achieved by a reading device characterized in that it is fixed by adhesive as a reference.

〔Example〕

First, an image forming apparatus equipped with a color image reading device of the present invention will be explained with reference to FIG.

In the figure, A is an image reading device having a reading section, B is a writing unit, C is an image forming section which constitutes a color image processing device, and D is a paper feeding section.

In the image reading device A, l is a platen glass, and the original 2 is placed on this platen glass l.

The document 2 is carried by a carriage 4 that moves on a slide rail 3.
It is illuminated by fluorescent lamps 5 and 6 installed in the area. The movable mirror unit 8 is provided with mirrors 9 and 9', which move on the slide rail 3, and in combination with the first mirror 7 provided on the carriage 4 read the optical image of the document 2 on the platen glass l with a lens. Derived to unit 20.

The carriage 4 and the movable mirror unit 8 are driven by pulleys 11, 12, 13, and 14+, which are driven by a stepping motor IO via a wire 15, to provide V and 1/1, respectively.
They are driven in the same direction at a speed of 2V. Standard white plates 16 and 17 are provided on the back side of both ends of the platen glass l, and are configured so that a standard white signal can be obtained before the start of original reading scanning and after the end of scanning.

The lens reading unit 20 includes a lens barrel 21 that houses an imaging lens as a reading lens system. Prism 22 as a light decomposition means, red channel (hereinafter referred to as R-ch) CC as a line image sensor of a solid-state image sensor
D25, cyan channel (hereinafter referred to as C-ch) CC
Consists of D27. The original optical image transmitted by the first mirror 7, mirror 9, and mirror 9' is focused by a lens 21, and separated into an R-ch image and a C-Ch image by a dichroic mirror provided in a prism 22. The light images are formed on the light receiving surfaces of the R-ch CCD 25 and the C-ch CCD 27, which are fixed to the prism 22, which is a light splitting member.

The fluorescent lamps 5 and 6 are commercially available warm white fluorescent lamps in order to prevent emphasis or attenuation of specific colors based on the light source when reading color documents;
It is powered by a KHz high-frequency power source and kept warm by a heater using a POSISTOR to maintain a constant temperature of the tube wall or to increase the ohm.

The image signals output from the R-ch CCD 254 and C-Ch CCD 27 are processed through a signal processing section (not shown), and color signals separated according to the toner color are output and input to the writing unit B. Then, images by each laser beam generated by a semiconductor laser are sequentially projected onto the circumferential surface of the photoreceptor drum 31, and for each projection, images are developed by the developing rollers I, II', I[[ A color image is formed using three color toners.

Next, the color image on the circumferential surface of the photoreceptor drum 31 is transferred to a recording paper conveyed by a paper feed section at a transfer separation pole 32, and then the recording paper is separated and ejected to the outside of the apparatus via a fixing device 33. , to finish copying the color image.

The configuration of the lens reading unit 20 in the reading device A, that is, the lens barrel 21. Fixation of R-ch CCD 25 and C-ch CCD 27 to the prism 22,
The holding is performed as follows.

As shown in FIG. 2(a), the lens barrel 21 is housed in a 7-shaped receiver that opens upward at a right angle to the lens holding member 21a, and is secured by a fastener 210 serving as a lens barrel supporting member. After being fixed, it can be attached to a predetermined position on the device board 40.

In this embodiment, a mounting surface 21b that can be joined to the front surface of the prism 22 is formed on the rear end surface of the lens barrel 21, and the prism 22 can be fixed to the mounting surface 21b by adhesive. It has become.

Since the mounting surface 21b is formed by a simple turning process, the distance to the imaging lens accommodated in the lens barrel 21 and the perpendicularity to the optical axis are extremely accurate, and the prism 22 attached to it has extremely high accuracy. R mentioned above through
A predetermined optical image can be correctly formed on the light receiving surfaces of the -ah CCD 25 and the C-ah CCD 27 without being affected by optical aberrations.

As shown in FIG. 2(b), the amount of deviation (
The degree of inclination of the right angle RL%RL' of the prism surface A with respect to the lens optical axis can be checked using a synchroscope shown in FIG. The check procedure will be described later.

As shown in the CRT display of FIG. 11, if the respective levels of the black line portion and the white line portion with respect to the white background are P and Q, the MTF is determined by the following equation.

The higher the MTF value, the better the resolution.

The MTF value is 30%, which is based on the influence of the amount of deviation in resolution.
As an example, if the amount of inclination is about IO minutes in angle, the MTF value will be 21%, which is a decrease of about 9%,
Furthermore, when the amount of inclination becomes about 30 minutes, the MTF value increases to 15%.
This represents a decrease rate of approximately 50%. Since this will interfere with the extraction of black and white discrimination signals, by maintaining this surface precision and fixing the lens barrel 21 and prism 22 together in advance, a drop in the defective rate in the later stages of production can be prevented. However, not only is there a cost advantage, but the influence of the material of the lens holding member 21a, the mounting member 24, etc. on pixel misalignment after COD mounting is also reduced, and further effects are exhibited.

In addition to the adhesive method described above, the prism 22 can be fixed by using a prism holding member 22b in close contact with the mounting surface 21b using the mounting screws 23 as shown in FIG. 2(c). There is also. These methods of fixing the prism 22 are applied to each embodiment described below.

For adhesion of the prism 22 to the lens barrel 21, an adhesive that can withstand various environmental tests in addition to adhesion is selected and used. In this embodiment, the CCD 25 and Since the same adhesive is used for bonding the CCDs 25 and 27, the characteristics of the adhesive will be summarized in the section explaining the fixing of the CCDs 25 and 27.

The mounting positions of the R-ch CCD 25 and the C-ch CCD 27 with respect to the focal plane of the imaging lens are set as follows.

In the first method, the R-chccD 25 and the C-chCCD 27 are fixedly attached to the prism 22 at a predetermined distance.
As shown in FIG. 2(d) or FIG. 2(e), the prism 22 is mounted in a cantilever manner with adhesive through the prism 22 as shown in FIG. 2(d) or FIG. 2(e).
0 image plane.

According to this method, each COD is adhesively fixed based on the end of each mounting member 24 (26) or 24a (26a), so the standard of thermal expansion due to cantilever is clear, and multiple CODs
Even if D is supported in the same way, no pixel shift will occur between them.

Furthermore, in the above example, each COD is fixed to the imaging section using its respective mounting member.
FIG. 3(a) shows that the mounting member 24b is bonded and fixed to the prism 22 by a common mounting member 24b, and the mounting member 24b
A CCD 25 and a CCD 27 are respectively glued and fixed to the holder.

As for the material of the mounting member, a material with a small coefficient of linear expansion is desired for two reasons. One is to prevent pixel misalignment due to temperature fluctuations, and the other is to prevent internal distortion of the mounting member bonded to the prism due to the difference in linear expansion coefficient between the two, resulting in cracks in the prism. This is to prevent The above-mentioned problem of pixel misalignment due to temperature fluctuations can be reduced by making the fixing conditions of each COD to the mounting member exactly the same, but the linear expansion coefficient needs to be small. be.

Normally, the coefficient of linear expansion of a prism is medium, around 7.4 x 10-' (optical glass BK-7), so glass or ceramic materials (7.0 to 8.4 x 10-') are used as mounting members.
) and low thermal expansion alloys (e.g. Invar alloy (1~3X 1
0-'), Niregis 1-cast iron (4~IOX 10-')
) etc. are suitable, and aluminum material (25 x 10-') is not so suitable.

The present inventors conducted tests using various materials as mounting members, but no image shift due to thermal expansion was detected when glass materials, other ceramic materials, and low thermal expansion alloys were used.

In the above embodiment, the prism and the mounting member, the mounting member and the CC
An adhesive was used to fix the COD to D, and after adjusting the relative position of each COD in the divided optical image, the COD was fixed in close contact with the adhesive.

In particular, in Fig. 2(d), even if iron (12X 10-') with a large coefficient of linear expansion is used as the mounting member, it is practically impossible to
Since the dimension in the direction is short, the elongation due to heat is not affected much, and since the direction is the direction in which the line sensors are arranged, and the prism material and the line sensor package material are ceramic materials, the coefficient of linear expansion is approximately The results were the same, and no pixel misalignment occurred in this configuration.

The present inventors conducted comparative studies using many available adhesives. As a result, it was concluded that among two-component type adhesives and photocurable adhesives, especially ultraviolet curable adhesives are most preferable as adhesives to be used in the present invention.

Adhesives include epoxy and acrylic adhesives, and are further divided into one-liquid type and two-liquid type.・Liquid type products usually have a hardening agent mixed into them during manufacture, and when used, they gradually harden and dry when exposed to air, etc., and harden and harden for a long time, and the degree of hardening and time of hardening vary. Due to irregular shrinkage, etc., it is necessary to use special equipment for adhesive fixation. Therefore, it is not suitable from the viewpoint of the purpose of use and productivity of the present invention. In this regard, the two-component type and immediate-acting type cures in a few minutes at most by kneading the curing agent and the main ingredient during adhesion, shortening the curing time and stabilizing the degree of curing. It is effectively suited for this purpose. Although there are 1-liquid type cyanoacrylate-based products that are quick-acting, they may cause adhesive peeling upon impact or deformation of the adhered object due to shrinkage of the adhesive when it dries, so this is not necessarily the preferred form of application. I can't say that. The present inventors used Hardlock E5 as a two-component type adhesive.
When bonding was carried out at room temperature using 10K (trade name), good results were obtained in the environmental tests described later. At the time of bonding, an attempt was made to shorten the bonding time by significantly changing the temperature conditions, but as a result, pixel misalignment during bonding was observed, albeit slightly, which was clearly undesirable. On the other hand, photocurable adhesives can speed up the curing time of the adhesive simply by changing the intensity of light, improving workability, reducing costs, and stabilizing the product. Among photo-curable adhesives, ultraviolet-curable adhesives in particular have almost no change in heat even when exposed to ultraviolet rays, and can provide stable effects. The present inventors used ThreeBond TB3060B (product name), Denka 1045K (product name), Norland 65 (product name), etc. as photocurable adhesives, and irradiated ultraviolet light with a high-pressure mercury lamp to achieve bonding in a short time. We were also able to obtain good results in environmental tests, etc., which will be described later. Furthermore, using UV-curable urethane-based Three Bond 3062B (trade name), LT350 (trade name), etc., it was possible to obtain an adhesive that was even more effective in moisture resistance and had guaranteed strength. In the adhesive bonding method described above, the opposing surfaces of the adhesive members of each part are pressed together, and a small amount of adhesive is extruded from the sides of the pressed surfaces using an appropriate extrusion means. Since the adhesive has fluidity, it flows into the slight gap created between the pressing surfaces and firmly fixes the adhesive members to each other. The bonding method may be such that the adhesive is extruded so as to adhere to the entire surface of the opposing surface of the bonding member, and may flow into the gap. Alternatively, the adhesive may be introduced at appropriate intervals. Further, if the device is capable of arranging the adhesive members with appropriate positional accuracy, the adhesive may be applied in advance to the adhesive portion of each adhesive member in spots or areas, and the adhesive surfaces of the adhesive members may be immediately pressed and bonded.

A preferred embodiment of the bonding method will now be described. Figure 3(b) and Figure 3(c) are C in Figure 3(a).
CD25, C0D27 and their common mounting member 24
b. When bonding the mounting member 24b to the prism 22 shown in FIG. 3(a), after fixing the mounting member 24b to a predetermined position on the prism 22, apply adhesive to the end of the mounting member 24b as shown in FIG. 3(b). One possible method is to pot it and allow it to penetrate into the mounting surface.

In this case, a light-curing adhesive is used as the adhesive, and the mounting member 24
By using a light-transmitting substance as b, the use of a photocurable adhesive becomes more effective. That is, by utilizing transmitted light to cure the adhesive which has become thinner inside due to penetration during the end potting, adhesive curing can be promoted. Furthermore, as shown in FIG. 3(c), the mounting member 2
4b or the general adhesive method of dropping adhesive onto the surface of the mating member facing the prism 22 and pressing both together, the adhesion of the adhesive is better than the potting method shown in Fig. 3(b). By using the light-curing adhesive and the mounting member 24b on the light-transmitting side, in addition to natural drying, curing can be accelerated by transmitted light and time can be controlled, making it stable for mass production and adhesion. It can be said that this is a very preferable solution as it allows us to obtain products without any variation. As a light transmitting mounting member, BK-7 (7゜4X 10-'), blue plate glass (9,
OX 10-'), white plate glass (9,3X 10-')
etc. are almost equally preferable, corresponding to the elongation of the ceramic of the solid-state image sensor packaging material. Furthermore, as a photocurable adhesive, the above-mentioned ultraviolet curing adhesive is preferable due to its quick curing time and resistance to deformation and moisture during curing. However, the yield is 20 to 30% or more, including processing method and material thickness variations, and this can be said to be a preferable solution, especially from the standpoint of mass production and cost. In addition, special glass that matches the ultraviolet component light distribution characteristics of the ultraviolet curable adhesive can be selected as the mounting component, making it possible to improve mass production during adhesion, the required adhesion strength, and the stability of adhesion such as curing degree and curing time. By bringing the value closer to the optimum value, it is possible to obtain a value that is more suitable for the device in use.

By the way, as mentioned above, it is difficult to say that a self-liquid type of quick-drying adhesive is a preferable application form because the adhesive shrinks and deforms the adhered object when it dries, but the present invention According to a preferred embodiment of the present invention, it has been found that a quick-drying one-liquid type adhesive can also be effectively used by improving the procedure for attaching objects to be adhered.
.

That is, when attaching the COD to an optical member (such as a prism) via an attaching member, first, the position of the solid-state image sensor is adjusted relative to the optical member using a positioning method according to the present invention, which will be described later. Next, apply a quick-drying instant adhesive (cyanoacrylate adhesive, one with a primer effect, etc.) to the mounting surface of the mounting member to the light splitting member, and apply Hardlock ESIO (product name), etc. to the joint with the solid-state image sensor. The light splitting member and the solid-state image sensor are bonded and fixed with the mounting member by applying the above-mentioned preferred type of adhesive, such as a two-component type adhesive or a light-curing adhesive such as Threepond TB3062B (trade name). . In this adhesive fixing process, after the light splitting member and the mounting member are fixed with a quick-drying adhesive, fine adjustment of the positioning of the solid-state image sensing device is continued using an adjustment tool to achieve accurate positioning. After the curing of the adhesive that joins the solid-state image sensor and the mounting member is accelerated to some extent (temporary fixing step), the light splitting member and the mounting member are further potted with a suitable adhesive such as the above-mentioned photocuring type. Added by etc.
Harden and fix the entire area. (Final fixed adhesion) After performing the above temporary fixing step and fine-tuning the alignment, the final fixed adhesion is performed to adjust the positioning to the desired characteristics. Compared to the method of gluing and fixing the two, it has become possible to improve the yield by more than 50%, and it has been recognized that there is a significant improvement effect in terms of workability, cost reduction, etc.

Prism 22 of CCD 25 and CCD 27 according to the invention
For adhesion to, prepare a mounting jig TC in advance.

The mounting jig holds the sides of the CCD 25 and CCD 27, respectively, and attaches the spectra A and B as shown in FIG.
As shown in Fig. 14, each optical axis can be adjusted in the two directions x and y perpendicular to the optical axis, and in the rotational direction regarding the x and y axes, allowing fine adjustment of the mounting jig TC. Adjust so that there is no pixel shift.

As a mounting jig, for example, the adjustment table can be used in three axial directions (X.

y, z) and also rotatable about the respective axes (e.g. CHUO5EIKIC)
By using parts manufactured by O., Ltd., it is possible to perform precise positioning between a plurality of CCDs, which is the object of the present invention.

The black and white striped chart image provided at the original position is C0D25.
and the images are formed on the CCD 27, and the output signals thereof are recorded on a synchroscope vertically juxtaposed. If the black and white stripe spacing is set based on the designed reduction magnification of the imaging lens and the size of the COD pixel, and a chart is created in which one stripe corresponds to one pixel, the recorded signal superimposed on the synchroscope can be The amount of pixel shift can be easily read. For example, the synchroscope CR7 plane shown in FIG. 11 illustrates a situation where there is a pixel misalignment between the CCD 25 and the CCD 27. In addition, by adjusting the mounting jig TC while checking with a synchroscope, it is possible to find the relative position between the CCDs without pixel shift, and at this position, the CCD 25 and CCD are connected with adhesive.
27 to the prism surface of the prism 22 respectively.
4 (26) at the imaging position.

The image reading section has a plurality of solid-state image sensing devices fixed to a prism, which is an optical member, using an adhesive corresponding to FIG. 3 via a mounting member made of a ceramic material, and Various comparison tests were conducted on the image reading section that holds the image sensor. The test was carried out by placing the striped chart at the original position and superimposing and comparing the output signals from a plurality of attached solid-state image sensors using a synchroscope, paying particular attention to pixel misalignment.

(1) Vibration resistance test A vibration resistance test with variable frequency was conducted for 30 minutes, and the state of pixel misalignment before and after the test was compared. Some of the screws due to mechanical structure had sagging, and a pixel shift equivalent to about 4 pixels (C30p i) was observed. No pixel shift was observed in the case of this example.

(2) Shock Test A drop test was conducted on the I-40G, and the pixel misalignment before and after was compared. Among the mechanical structures, pixel misalignment equivalent to about 3 pixels (20 μm) was observed. No pixel shift was observed in the case of this example.

(3) Temperature test First, the environmental temperature was set to 20°C for 2 hours.
The temperature was raised from °C to 70 °C and the situation of pixel misalignment was compared. In the case of mechanical structure, a pixel shift equivalent to about 4 pixels (30 μm) was observed. The ambient temperature was then restored from 70°C to 20°C over a period of 2 hours. Even in the restored state, it was observed that a pixel shift equivalent to about 2 pixels (15 μm) remained due to the mechanical structure. - No pixel misalignment was observed from beginning to end in the case of the strength wood embodiment.

In the present invention, the COD is fixed to the prism via a mounting member, but the present invention also includes fixing the COD via a separately fixed mounting auxiliary member. FIG. 4 shows an example of this. Since it is not easy to process unevenness on a prism, a mounting auxiliary member 28 made of ceramic material, for example, with a slightly complicated shape is prepared and bonded to the prism 22 in advance. By fixing the mounting member 24C (26C) to the auxiliary mounting member 28, the auxiliary member 2
8 and the mounting member 24C (26C) by a slide guide corresponding to the entry direction and a rotational movement in the direction B, it becomes easy to fix the C0D 25 (27) at the adjusted position. FIG. 4(a) shows a front view, and FIG. 4(b) shows a side view.

However, directly adhesively fixing the COD to the light splitting member is not only costly due to manufacturing defects, but also requires maintenance in the event that the COD breaks down for some reason. You will also have no choice but to discard or replace everything that has been glued to the surface.

For this reason, a second method is to attach a COD to each holding member of an optical component, which is cheaper than a light splitting member, and each case will be explained below.

FIG. 5 shows an example in which an integrated mounting member 224a, in which the R-ChCCD 25 and c-chCCD 27 are bonded and fixed in advance, is fixed to the side surface of the rear end of the lens barrel 21 with adhesive, and FIG. 6 shows a similar type. Mounting member 224b of prism 2
2 is fixed to the side surface of the prism holding member 22b to which the prism holding member 22b is attached using an adhesive, and both are mounted in a cantilevered manner on one side surface of the lens barrel 21 or the prism holding member 22b. In this embodiment, especially in the event of a process defect or maintenance/service, it is easy to separate the lens and prism from the COD, and the effect of regenerating expensive optical components can be improved. A lot. These advantages are of course effective means for the various embodiments described in this specification, and are the gist of the present invention.

In addition, FIGS. 7(a) and 8(a) show the mounting member 124.
This shows an example in which the lens 126 or 324 is attached to one side of the lens holding member 21a. That is, the seventh
In the case shown in the figure, the lens holding member 21a extends to a portion where one side surface covers the side surface of the prism 22, and the supporting portion 21a
1d and a relatively short mounting member 124.1.
Each COD is adhesively fixed via 26.

On the other hand, in the case of FIG. 8, the lens holding member 21a is cut off at a portion corresponding to the rear end surface of the lens barrel 21, but there are two protruding portions 324 extending close to each exit surface of the prism 22.
The lens holding member 21a is directly adhesively fixed to one side surface of the lens holding member 21a by a relatively long attachment member 324 having portions a and 324b.

Note that the support portion 21d, the protrusion portions 324a, 324b
As shown in FIG. 7(b) or FIG. 8(b), each COD is supported in a cantilevered manner at a distance from the prism 22.

Further, in FIG. 9, the lens barrel 21 is attached to the lens holding member 21a.
This is an example in which the mounting member 224C is adhesively fixed to one side of the fastener 21c used for fixing, and in this case as well, each COD is cantilevered from the same direction to the fastener 21c as in each survey described above. Supported.

In each of the above embodiments, the means for fixing the mounting members are all adhesives, especially adhesives using specific adhesives, but the means for fixing each COD is not limited to this, and for example, the first O. As shown in the figure, the prism 22 can also be clamped from both sides by two mounting members 224d made of a low thermal expansion alloy and fixed by tightening with screw members 29.

In this embodiment, there is internal stress due to tightening in the COD 25 (27) and other members, which has the disadvantage of being susceptible to deterioration over time, but on the other hand, the COD can be easily removed and replaced.

As shown in the above examples, in the present invention, each COD
By fixing the COD in a cantilever manner to the same surface of the prism or other holding member with one side edge in the direction of the pixel row as a reference, each COD can be fixed even if the environmental temperature changes.
Since the CCDs extend in the same direction, so-called pixel misalignment does not occur, and even if the CCD generates heat and reaches a high temperature, the cantilever type does not apply stress due to expansion to the mounting member. As a result, a highly durable and reliable lens reading unit 20 is realized, which is free from fatigue due to the repeated stress of COD expansion and contraction, and is resistant to peeling or damage at the bonded portion.

In addition, since it is a cantilever type, the mounting members that fix each COD are of the same shape and have the same heat capacity, and if materials with the same coefficient of linear expansion are used, there will be no positional fluctuation in the pixel rows between each CCD. It is also possible to do so.

In the embodiments described above, the light is divided into two colors using the illustrated prism, and a COD is attached to each image formation position, but the present invention is of course not limited to such light dividing means. For example, Fig. 812 uses a Kester prism type light splitting means, and two right triangular prisms 122a are pasted together behind a lens 121 that forms an object image.
122b, the first right triangular prism 122a
A surface 123 with a dichroic characteristic that has an inclined surface perpendicular to the optical axis and forms a semi-transparent mirror for the light beam incident from this surface.
The image is divided into an R-ah image and a C-ah image, and after being totally reflected on the slopes of the triangular prisms 122a and 122b, the image is emitted to the R-ah CCD located nearby.
125 and C-ah CCD 127, respectively. FIG. 12(a) shows two CCDs 125 attached to a mounting member 1240 glued to the side surface of the prism.
．． This is an example in which the CCD 127 is adjusted to have one side as a reference, and then glued and fixed in a cantilevered state using adhesive.No. 121m (b) is a CCD 125 that is attached to a mounting member 124Qa glued to the side surface of the prism with one side as a reference. This is an embodiment in which the CCD 127 is adjusted in position and then glued and fixed, and the CCD 127 is glued and fixed in a cantilevered state to the mounting member 1240b which is also glued to the side surface of the prism.

Moreover, what is shown in FIG. 13 is a side view of a reading device using a light splitting means described in Japanese Patent Application No. 157005/1988 filed by the present applicant, and shows a lens 221 for forming an object image. The above laminated prism 2 is attached to the rear of the
The prism 22 is used to divide the color into three colors: blue, green, and red.
CC0225B, 225G, located close to 2
The images are respectively formed on the 25R light receiving surface.

FIG. 13(a) shows the three mounting members 2240B, 2240G, and 2240R glued to the side surfaces of the prism, respectively, after adjusting the positions of C0D225B, 225G, and 225R so that they serve as one side reference, and then using adhesive to connect them in a cantilevered state. This is a fixed and fixed example. In addition, FIG. 13(b) shows that the mounting member 224B attached to the side surface of the prism has a COD
After adjusting the position so that 225B becomes the reference on one side, glue and
fixed and the same (mounting member 22 glued to the side of the prism)
This is an example in which two COD 225G and 225R are glued and fixed to the 4GR after adjusting their positions so that one side serves as a reference. In addition, in Fig. 13' (c), a CCD 225B,
This is an example in which the positions of 225G and 225R are adjusted so that each side serves as a reference, and then glued and fixed in a cantilevered state.

Figures 12 and 13 both show an example of a COD fixing method when using different light splitting members, and both are examples in which the mounting member is adhered to the side surface of the prism. It is not limited to this.

〔Effect of the invention〕

Adopting a method of fixing each solid-state image sensor at the imaging position of the reading optical system via a cantilever type mounting member as in the present invention results in eliminating many factors that cause pixel misalignment. Thus, a clear and excellent color image can be reproduced and obtained by the color image reading device of the present invention,
Image quality does not deteriorate due to the pixel misalignment due to changes in the environment or the passage of time, and there is no need for complex electrical correction circuits for the pixel misalignment and color ghost correction, resulting in improved durability. Sex also has excellent effects. In addition, as explained in the examples, the present invention uses filling adhesive, but since it uses a method similar to close contact adhesive, shrinkage when the adhesive hardens is smaller than in the case of commonly used filling adhesive. By making the lens barrel and prism integral in advance, it is possible to achieve highly accurate and stable image reading without any problems such as noises, etc., and it is cheaper and has even better stability. It is possible to obtain a device that is also effective in preventing pixel misalignment after fixing.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a color image forming apparatus equipped with a color image reading device of the present invention. Figure 2(a), Figure 2(c), Figure 2(d), Figure 2(
e), Figure 3, Figure 4, Figure 5, Figure 6, Figure 7, Figure 8
Figure, Figure 9, 1st Or! 1J is an explanatory diagram showing an example of mounting a solid-state image sensor according to the present invention. FIG. 2(b) is a perspective view showing a combination of a lens barrel and a prism. FIG. 11 is an explanatory diagram of a method for adjusting the position of a solid-state image sensor. 12 and 13 are detailed explanatory views of the present invention for other types of light splitting members. FIG. 14 is a perspective view showing the adjustment direction of the solid-state image sensor. FIG. 15 is a sectional view of a conventional reading unit. 20-m-reading unit 21---lens barrel 21a---lens holding member 21cm-one clamp 22---prism 22b
--- Prism holding member 25 (27) -4-ch (C-ch) CCD 24, 2
4a, 24b, 24c, 124.224a, 2
24b, 224c. 224d--Mounting member 26, 26a, 26c, 126--Mounting member 40
---Device board

Claims (9)

[Claims] (1) The light splitting member, the imaging lens, the light splitting member, etc. of a reading device that reads a light image with a plurality of solid-state photographing elements provided at the imaging position of an optical system consisting of an imaging lens and a light splitting member. In the reading device in which the solid-state image sensor is fixed to a holding member of an optical member via a mounting member, the mounting member is attached to one side of the light splitting member or the holding member in a pixel column direction of the solid-state image sensor. A reading device characterized in that it is fixed by adhesive as a reference. (2) The reading device according to claim 1, wherein the holding member for the optical member is a lens barrel of an imaging lens. (3) The reading device according to claim 1, wherein the holding member for the optical member is a prism holding member for a light splitting member. (4) The reading device according to claim 1, wherein the holding member for the optical member is a lens holding member to which an imaging lens is attached. (5) The reading device according to claim 1, wherein the holding member for the optical member is a lens barrel support member used for attaching the imaging lens to the lens holding member. (6) The reading device according to any one of claims 1 to 5, wherein the solid-state image sensor is attached to the attachment member using an adhesive. (7) The reading device according to any one of claims 1 to 6, wherein the mounting member is fixed to the light splitting member or the holding member using an adhesive. (8) The reading device according to any one of claims 1 to 7, wherein the material of the holding member is a ceramic material. (9) The reading device according to any one of claims 1 to 8, wherein the material of the mounting member is a ceramic material.