JPH04111664A - Contact type image sensor and position adjustment method for short focus image forming element array - Google Patents

Abstract

PURPOSE:To bend an element array at each adjustment and fixing and to make adjustment and fixing at a succeeding fixing point by adjusting and fixing a short focus image forming element array at a face other than a lens aperture at 3 >= fixing points to a frame. CONSTITUTION:Jigs 34,35 are moved so that actual image forming lines 32,33 are made coincident with ideal image forming lines 30,31 in the middle of a short focus image forming element array 5 and then the middle part of the short focus image forming element array 5 is fixed by using a lens tightening screw 6 arranged in the middle. Then the jigs 34,35 are moved and the short focus image forming element array 5 is bent to make the lines 32,33 coincident with the lines 30,31 at both ends of the element array 5. Then both ends of the element array 5 are fixed by lens tightening screws 7,8. When the element array 5 is fixed, the fixing is implemented under the judgement that the actual image forming lines 32,33 are made coincident with ideal image forming lines 30,31 at the position of the element array 5 maximizing the MTF near the fixing points.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for adjusting the position of a contact type image sensor and a short focus imaging element array, and relates to a contact type image sensor and a short focus image sensor used in image readers, facsimiles, etc. The present invention relates to a method for adjusting the position of a focusing imaging element array.

[Prior Art] The structure of a conventional contact type image sensor will be described below. Note that here, for the purpose of simplifying the explanation, only the portion related to the position adjustment of the short focus imaging element array will be explained.

FIG. 6(a) is a partial configuration diagram for explaining the configuration of a conventional contact type image sensor, and FIG. 6(b) is a partial configuration diagram of a conventional contact type image sensor.
It is an enlarged view of part A in figure (a).

As shown in both figures, the short focus imaging element array 51 is attached to the side plate 5.
3, 54 (consisting of a bent leaf spring) attached to the lens pressing spring 57.58 and lens adjustment screw 59.6
The position is adjusted and fixed by sandwiching the lens aperture surfaces at both ends using position adjustment means built into a contact type image sensor such as the 0. Note that 52 is a reading glass, and 55 and 56 are reading glass adhesive layers.

[Problem to be solved by the invention] However, in the above-mentioned conventional contact type image sensor,
Fixation is achieved by pressing the lens aperture,
In principle, only both ends can be fixed. Therefore, due to vibrations, shocks, etc., the central part of the short focus imaging element array 51 is easily deflected, and the adjustment position is likely to shift.
There was a problem in that there was a risk that 1 itself would be damaged.

Further, if the short focus imaging element array 51 is warped and the focal length at the reading line is not constant, there is a problem in that the amount of warpage directly reduces the depth of focus and adversely affects the image. This problem will be explained below using FIGS. 7(a) and 7(b).

In both figures, if 62.63 is the ideal reading line and imaging line, and 64.65 is the actual reading line and imaging line, respectively, then when warpage occurs in the short focus imaging element array 51, Due to the warpage, a deviation occurs between the ideal reading line or imaging line and the actual reading line or imaging line, as shown in FIGS. 7(a) and 7(b). As shown in FIGS. 6(a) and 6(b), in the conventional contact type image sensor, the short focus imaging element array 51 is fixed only at both ends, so no matter how the position is adjusted, A large deviation occurs in the center or the end of the reading line or imaging line.

In addition, when adjusting the short focus imaging element array 51, the lens adjustment screw 59 continues to rotate while adjusting the contact surface with the short focus imaging element array 51, so that the short focus,
There is a problem in that the imaging element array 51 is scraped, and dust 61 is generated and adheres to the lens aperture surface, the back surface of the reading glass, the sensor element, etc., and adversely affects the image. This problem becomes more serious as the reading resolution of the contact image sensor increases, because small dust particles have a negative effect on the image.

[Means for Solving the Problems] The contact image sensor of the present invention includes an illumination unit that illuminates the image information surface of a document, a short focus imaging element array that forms an image of the reflected light from the document surface at the same magnification. , a light receiving element that is located on the image plane of the reflected light and that photoelectrically converts the reflected light and reads image information;
At least the illumination means, the short focus imaging element array,
In a close-contact image sensor comprising a frame that integrally holds the light-receiving element, the short-focus imaging element array is attached to the front frame at three or more fixed points so that the lens aperture of the short-focus imaging element array is fixed to the front frame. It is characterized by having means for adjusting and fixing on a surface other than the surface.

A method for adjusting the position of a short-focus imaging element array according to the present invention includes: an illumination means for illuminating the image information surface of a document; a short-focus imaging element array for forming an image of reflected light from the document surface at the same magnification; A close-contact image comprising a light-receiving element that is located on an image plane of light and that photoelectrically converts the reflected light and reads image information, and a frame that integrally holds at least the illumination means, the short-focus imaging element array, and the light-receiving element. In a method for adjusting the position of a short focus imaging element array of a sensor, adjusting the short focus imaging element array at three or more fixed points on the frame at a plane other than the lens aperture plane of the short focus imaging element array; having a fixing means, when fixing the short focus imaging element array, each time one position is adjusted and fixed, the short focus imaging element array is moved and the short focus imaging element array is deflected; It is characterized by adjustment and fixation at fixed points.

[Function] The contact image sensor of the present invention adjusts and fixes the short focus imaging element array to the frame at three or more fixed points on a surface other than the lens aperture surface of the short focus imaging element array. By providing a means, it is possible to prevent the short focus imaging element array from deflecting due to vibrations, shocks, etc., and also to correct the warpage of the short focus imaging element array at each fixed point of three or more fixed points. This is to adjust the deviation of the imaging line. In addition, the contact type image sensor of the present invention adjusts the position of the short focus imaging element array by changing the fixing point using the adjustment and fixing means. The contact surface with the imaging element array does not continue to rotate during adjustment, and the short focus imaging element array will not be scraped.

A method for adjusting the position of a short focus imaging element array according to the present invention uses the above-mentioned contact type image sensor, in which the short focus imaging element array is fixed to the frame at three or more fixed points. It has a means for adjusting and fixing the imaging element array at a surface other than the lens aperture surface, and when fixing the short focus imaging element array, the short focus imaging element array is moved each time one position is adjusted or fixed. By deflecting the short focus imaging element array and adjusting and fixing it at the next fixed point, the warpage of the short focus imaging element array is corrected and the misalignment of the reading line and the imaging line is adjusted. It is something to do.

L Embodiment Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram of one embodiment of the contact type image sensor of the present invention, and FIG. 1(a) is a partial block diagram.
FIG. 1(b) is an enlarged view of section A in FIG. 1(a).

FIG. 2 is an overall configuration diagram of the contact type image sensor viewed from the side.

In FIGS. 1(a) and (b) and FIG. 2, 1 is a frame, 2 is a reading glass, 3 is a sensor substrate, 4 is a sensor element, 5 is a short focus imaging element array, and 6, 7.8 are Lens fixing screws, 9 and 1o are side plates, 11.12 are side plate fixing screws, 1
3, 14. 15 is the reading glass adhesive layer, 16 is the bottom plate, 17
．． 18 is the bottom plate fixing screw, 19.20 is the sensor board fixing rubber shaft, 21 is the LED array, 22 is the LED array fixing screw, 23 is the mounting plate, 24 is the mounting plate fixing screw, 25 is the document guide on the mounting plate side, and 26 is the mounting plate fixing screw. A lens side document guide, 27 is the main body of the apparatus, 28 is a contact type image sensor fixing screw, and 29 is a document (indicated by an arrow in the figure).

The frame l has its final shape by cutting an extruded aluminum alloy material, and is black alumite-treated to avoid adverse effects on the internal optical system and change in surface condition.

The reading glass 2 is chamfered on the document inflow side to prevent the document from getting caught.

A sensor element 4 is mounted on the sensor substrate 3.

The short focus imaging element array 5 is fixed to the frame 1 with lens fixing screws 67.8.

The side plates 9 and 10 are leaf springs, and each side plate fixing screw 1
1.12 to the frame 1.

The reading glass 2 is fixed to the central part of the frame 1 and to the side plates 9 and 10 by reading glass adhesive layers 13, 14 and 15, respectively.

The bottom plate 16 has its final shape by cutting an extruded aluminum alloy material, and is anodized to avoid changes in the surface condition, and is fixed to the frame 1 with bottom plate fixing screws 17 and 18. The sensor board fixing rubber shafts 19 and 20 fixed to the bottom plate 16 by adhesive or the like are pressed, and the sensor board 3 is fixed by the pressing force.

The LED array 21 has LED chips, cylindrical lenses, etc. mounted on a substrate, and is fixed to the frame 1 with LED array fixing screws 22.

The mounting plate 23 is made of sheet metal, and is fixed to the frame 1 with mounting plate fixing screws 24. The contact type image sensor is fixed to the device main body 27 via the mounting plate 23 with contact type image sensor fixing screws 28 .

In the configuration of this embodiment, the mounting plate-side document guide 25 is a guide plate for causing the document to flow smoothly into the reading glass 2, and is fixed to the main body 27 of the apparatus.

In the configuration of this embodiment, the lens-side document guide 26 is a guide plate that allows the document to flow out smoothly from the reading glass 2, and is fixed to the main body 27 of the apparatus.

The original 29 smoothly flows into the reading glass 2 along the mounting plate side original guide 25, and smoothly flows out from the reading glass 2 along the lens side original guide 26. At this time, the light beam emitted from the LED array illuminates the reading glass 2 side of the document 29 on the reading glass 2, and the image is formed on the sensor element 4 by the short focus imaging element array 5.

The image photoelectrically converted by the sensor element 4 is sent to the sensor board 3
The signal is amplified at the top and output to the outside of the contact image sensor.

The short focus imaging element array 5 is adjusted and fixed before the side plates 9 and 10 are fixed.

Adjustment of the short focus imaging element array 5 is generally performed as follows. First, a ladder chart with a pitch slightly different from the pixel density of the contact image sensor is placed on the reading glass 2 as the original 29, and the contact image sensor is operated to read, and the MTF is maximized by the moiré waveform of the output signal, etc. The position of the short focus imaging element array 5 is searched. Adjustment is completed by fixing the short focus imaging element array 5 in this state.

An example of adjustment in this embodiment will be explained with reference to FIGS. 3 and 4.

FIG. 3 is an explanatory diagram showing the state of the short focus imaging element array before adjustment, and FIG. 4 is an explanatory diagram showing the state of the short focus imaging element array after adjustment.

In both figures, 30 and 31 are an ideal reading line and an ideal imaging line, respectively, and correspond to the document surface of the reading glass 2 and the sensor element array 4. 32 and 33 are actual reading lines and imaging lines, respectively, and correspond to the focal point on the reading and imaging side of the short focus imaging element array 5. Short focus imaging element array 5
If there is a warpage, the ideal reading line, image forming line and actual reading line, as shown in Figure 3, are
A deviation occurs between the image formation line and the image formation line.

In this embodiment, the short focus imaging element array 5 is supported at both ends by jigs 34 and 35, and the short focus imaging element array 5 is moved by moving the jigs up and down.

First, as shown in FIG. 3, the jigs 34 and 35 are moved so that the actual imaging line 32, 33 coincides with the ideal imaging line 30, 31 at the center of the short focus imaging element array 5, and then the The central portion of the short focus imaging element array 5 is fixed by the arranged lens fixing screw 6.

Next, as shown in FIG. 4, by moving the jigs 34 and 35 and deflecting the short focus imaging element array 5, an actual imaging line 32. is formed at both ends of the short focus imaging element array 5.
33 to coincide with the ideal imaging line 30.31. Here, both ends of the short focus image forming element array 5 are fixed with lens fixing screws 78 (which can be placed in either order since they are equidistant from the center of the short focus image forming element array 5).

When fixing the short focus imaging element array 5, the actual imaging line 3233 and the ideal imaging line 30.31 are determined at the position of the short focus imaging element array 5 where the MTF is maximum near the fixed point. Fixation is performed assuming that they match.

Here, the fixing point by the lens fixing screw 6 at the center of the short focus imaging element array 5 is first fixed because the adjustment can be made by independently moving the jigs 34 and 35 supporting both ends;
Furthermore, when deflecting the short-focus imaging element array, the amount of movement of the jig required to obtain the required amount of deflection can be minimized. Therefore, it is preferable that the fixed points be arranged symmetrically on both sides with the center of the short focus imaging element array 5 as a reference. Therefore, it is preferable that the fixed points be an odd number rather than an even number.

By adjusting and fixing the short focus imaging element array 5 as described above, it is possible to reduce the deviation between the actual imaging line 32.33 and the ideal imaging line 30.31.

Further, even if the ideal imaging lines 30, 31 are not ideally straight, the deviation can be absorbed to some extent by the adjustment described above.

Below, we will explain with specific numerical values.

The specifications of the contact type image sensor are a reading pixel density of 400d.
pi, reading width B 4 (257) mm, the warpage is 0.0 due to manufacturing variations in the short focus imaging element array 5.
Approximately 5 mm to 0.1 mm may occur. In addition, the linearity of the reading line of the reading glass 2, which is the actual image forming line 32, 33, and the sensor element 4 is that of the frame 1 and the reading glass 2.
, is approximately 0.1 mm due to manufacturing variations in the sensor substrate 3. When the reading pixel density is 400 dpi, the practical focus margin of the short focus imaging element array 5 is ±0.1 m.
m to about 0.2 mm. The warpage of the short-focus imaging element array 5, the reading line, and the linearity of the sensor element 4 are convenient (they do not necessarily complement each other, so conventional adjustment and fixing methods reduce the focus margin during actual use. On the other hand, if the short focus imaging element array 5 is adjusted and fixed as in this embodiment, the decrease in the focus margin can be considerably suppressed.

Also, the more fixed points there are, the smaller the deviation between the image forming line 3233 and the ideal image forming line 30.31 can be. Also, the more fixed points there are, the shorter the span between the fixed points can be. , vibration, and impact resistance.

In the above embodiment, a reading glass is provided, but a configuration that does not use a reading glass may also be used.

Further, the number of fixed points may be 3 or more (it may be even more, such as 5, 7, etc.).

Further, the fixing method is not limited to screw fixing, and other fixing methods such as adhesion and press-fitting of fixing pins may be used.

A facsimile machine using the contact type image sensor of the present invention will be described below.

FIG. 5 is a schematic configuration diagram showing an example of a facsimile having a communication function as an image information processing apparatus configured using the sensor unit according to this embodiment.

Here, 102 is a feeding roller serving as a feeding means for feeding the original 6 toward the reading position, and 104 is a feeding roller for feeding the original 6 toward the reading position.
This separation piece is used to reliably separate and feed one sheet at a time. 1
A platen roller 06 is provided at a reading position with respect to the sensor unit to regulate the surface of the document 6 to be read and serves as a conveying means for conveying the document 6.

In the illustrated example, P is a recording medium in the form of a roll paper,
Image information read by the sensor unit or, in the case of a facsimile device, image information transmitted from the outside is reproduced here.

Reference numeral 110 denotes a recording head as a recording means for forming the image, and various types such as a thermal head and an inkjet recording head can be used. Further, this recording head may be of a serial type or a line type.

Reference numeral 112 denotes a platen roller serving as a conveying means for conveying the recording medium P to the recording position by the recording head 110 and regulating the recording surface thereof.

Reference numeral 120 denotes an operation panel on which are arranged switches and messages for receiving operation input as input/output means, and a display section for notifying the status of the apparatus.

Reference numeral 130 denotes a system control board as a control means, and is provided with a control section (controller) for controlling each section, a drive circuit (driver) for the photoelectric conversion element, an image information processing section (processor), a transmitting/receiving section, and the like. 1
40 is a power source for the device.

As the recording means used in the information processing device of the present invention,
For example, U.S. Pat. No. 4,723,129, U.S. Pat.
Preferably, the typical configuration and principle thereof are disclosed in the specification of No. 0796. In this method, at least one electrothermal transducer that corresponds to the recorded information and that causes a rapid temperature rise exceeding nucleate boiling is applied to an electrothermal transducer placed corresponding to the sheet holding the liquid (ink) or the liquid path. By applying a drive signal, the electrothermal transducer generates thermal energy, causing film boiling on the heat-active surface of the recording head, resulting in bubbles in the liquid (ink) corresponding one-to-one to this drive signal. It is effective because it can form . The growth of this bubble,
The contraction causes liquid (ink) to be ejected through the ejection opening to form at least one drop.

Furthermore, as a full-line type recording head having a length corresponding to the width of the maximum recording medium that can be recorded by the recording apparatus, the length can be increased by combining multiple recording heads as disclosed in the above-mentioned specification. Either a configuration that satisfies the above requirements or a configuration as a single recording head formed integrally may be used.

In addition, a replaceable chip-type recording head that is attached to the device body enables electrical connection to the device body and ink supply from the device body, or an ink tank integrated into the recording head itself. The present invention is also effective when a cartridge type recording head is used.

[Effects of the Invention] As explained above, according to the contact type image sensor and the position adjustment method of the short focus imaging element array of the present invention, the following effects can be obtained.

(1) The short focus imaging element array can be fixed at more points than before, and the distance between the fixed points can be shortened, making it resistant to vibrations and shocks.

(2) Even if the short-focus imaging element array is warped, the warp can be corrected by sequentially adjusting and fixing one location at a time, and an adverse effect on the image can be prevented.

(3) Since lens adjustment screws are not used to adjust the short-focus imaging element array, the short-focus imaging element array will not be scraped by the lens adjustment screws during adjustment (and will prevent harmful effects on images due to the generation of dust). I can do it.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of the contact type image sensor of the present invention, FIG. 1(a) is a partial block diagram, and FIG. 1(b) is a section A of FIG. 1(a). This is an enlarged view. FIG. 2 is an overall configuration diagram of the contact type image sensor viewed from the side. FIG. 3 is an explanatory diagram showing the state of the short focus imaging element array before adjustment, and FIG. 4 is an explanatory diagram showing the state of the short focus imaging element array after adjustment. FIG. 5 is a schematic configuration diagram showing an example of a facsimile having a communication function as an image information processing apparatus configured using the sensor unit according to this embodiment. FIG. 6(a) is a partial configuration diagram for explaining the configuration of a conventional contact type image sensor, and FIG. 6(b) is a partial configuration diagram of a conventional contact type image sensor.
It is an enlarged view of part A in figure (a). FIGS. 7(a) and 7(b) are explanatory diagrams showing adjustment deviations of a conventional short focus imaging element array. 1 is a frame, 2 is a reading glass, 3 is a sensor board, 4 is a sensor element, 5 is a short focus imaging element array, 6.7.8 is a lens fixing screw, 9.10 is a side plate, 11.12 is a side plate fixing 13.14.15 is the reading glass adhesive layer, 16 is the bottom plate, 17.18 is the bottom plate fixing screw, 19.20 is the sensor board fixing rubber shaft, 21 is the LED array, 22 is the LED array fixing screw, 23 is the installation 24 is a mounting plate fixing screw, 25 is a mounting plate side document guide, 26 is a lens side document guide, 27 is an apparatus main body, 28 is a contact type image sensor fixing screw, and 29 is a document. Agent Patent Attorney Minoru Yamashita Figure 2 (Otsu) Figure (k) 3 Figure 6 and d2 Figure (b) Figure 4 (42)

Claims (7)

[Claims] (1) An illumination device that illuminates the image information surface of the document, a short-focus imaging element array that forms an image of the reflected light from the document surface at the same magnification, and a short-focus imaging element array that is located on the image plane of the reflected light and photoelectrically converts the reflected light. A contact image sensor comprising a light-receiving element for reading image information, and at least the illumination means, the short-focus imaging element array, and a frame that holds the light-receiving element together, the short-focus imaging element array comprising: A close-contact image sensor, comprising means for adjusting and fixing the short focus imaging element array at three or more fixing points on a surface other than the lens aperture surface of the short focus imaging element array. (2) The contact image sensor according to claim 1, wherein the number of fixed points is an odd number. (3) The contact image sensor according to claim 1, wherein the contact image sensor itself does not have means for adjusting the position of the short focus imaging element array. (4) An illumination device that illuminates the image information surface of the document, a short-focus imaging element array that forms an image of the reflected light from the document surface at the same magnification, and a short-focus imaging element array that is located on the image plane of the reflected light and photoelectrically converts the reflected light. A method for adjusting the position of a short focus imaging element array of a contact type image sensor, comprising a light receiving element for reading image information, and at least the illumination means, the short focus imaging element array, and a frame that holds the light receiving element together. The short focus imaging element array is provided with means for adjusting and fixing the short focus imaging element array at three or more fixed points on the frame at a plane other than the lens aperture plane of the short focus imaging element array, and the short focus imaging element array When fixing the array, each time one point is adjusted and fixed, the short focus imaging element array is moved to deflect the short focus imaging element array, and the next fixing point is adjusted and fixed. A method for adjusting the position of a short focus imaging element array. (5) The short focus imaging element array according to claim 4, wherein the adjustment and fixing of the short focus imaging element array is performed sequentially from a fixed point close to this reference point toward both ends, using an initially fixed position as a reference point. A method for adjusting the position of a focusing imaging element array. (6) The method for adjusting the position of a short focus imaging element array according to claim 4, wherein the fixed points are arranged symmetrically with respect to the center of the entire length of the short focus imaging element array. (7) The reference point is a fixed point closest to the center of the entire length of the short focus imaging element array.
A method for adjusting the position of the short focus imaging element array described above.