JPS62163459A - Picture information reader - Google Patents

Abstract

PURPOSE:To suppress an influence exerted on the resolution, to the minimum, even if an optical path length is varied, by always positioning a focusing rod lens array in the center of the optical path length. CONSTITUTION:In a contact type sensor unit 100, a focusing rod lens array 29 is attached so as to be slidable to a groove part 10a of a unit base 10. As for the array 29, when it has been positioned in the center TC/2 of an optical path length, as an optical path length TC, an image of an original 31 can be formed in a sensor 22 in the best state. In order to always position the array 29 in the center of the optical path length TC, the array 29 is moved automatically in accordance with a relative movement of the sensor unit 100 and an original platen 30. According to such a constitution, even if the optical path length is varied, an influence exerted on its resolution can be suppressed to the minimum, therefore, deterioration of the quality of read picture information can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an image information reading device and a contact type sensor unit that read an original image in a 1=1 ratio using a converging rod lens array.

Conventional technology In recent years, a focusing rod lens array has been used to image a document one-to-one.
Close-contact type reading sensor units or reading devices are being developed.

Conventional technologies include, for example, PCI, PO2, PD3 (Kekishita Densen Co., Ltd.) as a contact image sensor.
), CI PS216MS1, CIPS256MS
1. CIPS304S1 (@Toshiba) etc. have been developed and commercialized. These contact type sensors are configured by integrating a light source consisting of an LED array, a focusing rod lens array, and a line sensor.

In the configuration of the contact type sensor unit, the focusing rod lens arrays were all completely fixed. According to the above-mentioned conventional configuration, as shown in FIG. 9, the original 1 moves and the focusing rod lens array 2 forms an image of 1=1 on the line sensor 3 to perform reading scanning. In this case, since the optical path length TC does not change, no problem will occur if the focusing rod lens array 2 is adjusted and fixed when assembling the contact type sensor unit. However, as shown in Fig. 1Q, when the document 1 is placed on the document table 4 made of glass or the like and scanning is performed while the contact type sensor unit and the document table 4 move relative to each other, the document It is difficult to maintain a constant distance between the mounting table 4 and the close-contact type sensor unit, resulting in blurred fish collection. This is because the focusing rod lens array has a small depth of focus with respect to changes in optical path length, and resolution deteriorates significantly if the focusing rod lens array is not located in the middle of optical path length TC. This is because the change occurs only on the 21 side, resulting in a deviation of the focusing lens array from the center of the optical path length. An image information reading device using a contact type sensor unit as shown in FIG. 9 has already been commercialized for FAX and the like (for example, Panafax UF-3, Matsushita Densen@), etc.). An image information reading device in which a close-contact sensor unit and a document table move relative to each other as shown in FIG. 10 is currently being developed and commercialized (for example, Nikkei Electronics, September 10, 1984, P161 ~19
4).

Problems to be Solved by the Invention In such conventional devices, the focusing rod lens array is used to adjust the optical path length in response to changes in the optical path length due to relative movement between the contact type sensor unit and the document table. It was difficult to always position it in the center, and the quality of read image information deteriorated significantly.

The present invention has been made in view of the above points, and has a simple configuration, and the converging rod lens array is always positioned at the center of the optical path length even when the optical path length changes, thereby minimizing the deterioration in the quality of read image information. The object of the present invention is to provide a contact type sensor unit and an image information reading device that can perform the following steps.

Means for Solving the Problems In order to solve the above problems, the present invention provides a detection means for detecting a change in optical path length, and a focusing rod lens that moves a focusing rod lens array by the angle H of the change in optical path length. By providing an array position adjustment means, the converging rod lens array can always be positioned at the center of the optical path length (distance between the document surface and the contact type sensor surface) even when the optical path length changes.

Function The present invention has the above-described configuration, and by always positioning the convergent rod lens array at the center of the optical path length, even if the optical path length changes, the influence on the resolution can be minimized. The quality of image information is prevented to a minimum.

Embodiment FIG. 1 is a side view of a contact type sensor unit showing an embodiment of the present invention. In FIG. 1, 10 is a unit base, 11 is a rotating roller, 12 is a rotating roller 11 rotatably mounted on a shaft 13, and a shaft 14 is attached to the unit base 1.
This is a rotating arm rotatably attached to the 0. The rotation arm 12 is connected to the rotation center of the rotation roller 11 and the rotation fulcrum (axis 1
An eccentric pin/12A is provided in the center between the 15 is a sliding arm with elongated holes 16 and 17, elongated hole 1
At part 6.17, it is attached to the unit base 1o by a shaft 18.19 so as to be slidable vertically. The sliding arm 15 comes into contact with the eccentric pin 12A, and due to the rotation of the rotating arm 12,
The rotating roller 11 is slid in the vertical direction by % of the vertical movement amount. The sliding arm 16 also engages with the engaging pin 20. Reference numeral 21 is a mounting metal fitting, 22 is a line sensor, and 23 is a drive circuit for the line sensor 22. The line sensor 22 is fixed to the unit base 1o by a metal fitting 24. The drive circuit 23 is attached to the unit base 10 via a spacer 25. Reference numeral 26 denotes a tension spring, which is attached between the metal fitting 21 and the rotating arm 12;
The rotating arm 12 is urged in the direction of arrow A.

FIG. 2 is a sectional view parallel to the side view of FIG. 1 of the contact type sensor unit, in which 27 and 28 are light sources, and 29 is a focusing rod lens array. The light sources 27 and 28 are a plurality of LEDs.
are arranged on a P board in a direction perpendicular to the cross section, and a cylindrical lens is provided to condense the light from the LED.
As a D array light source, it is fixedly attached to the unit base 1o.

As shown in FIG. 3, the focusing rod lens array 29 is
Rod lenses 29a each having a diameter of about 1 mm are arranged in two rows, surrounded by two resin plates 2sb and a resin plate 29c at the end, and the space between them is molded with resin, and the reinforcing plate 29
d, and a retaining pin 2o is attached to this end.

The focusing rod lens array 29 is slidably attached to the groove 10a of the unit base 1o, as shown in FIG.
A cross-sectional view in a direction perpendicular to the cross-sectional view in the figure. ), both ends are biased in the direction of arrow B by compression springs 30. In addition, the retaining pin 2o is attached to a long portion 1 provided on the side surface of the unit base 1o.
It is configured to protrude to the side from 0b and engage with the sliding arm 15.

The compression spring 3o is sufficiently stronger than the tension spring 26, and the compression spring 30 causes the sliding arm 15 to move in the direction of arrow C, and the rotation arm 12 to move in the direction of arrow A against the tension spring 26. It is biased in the opposite direction. The configuration shown in the side view of FIG. 1 is similarly configured on the opposite side.

In FIGS. 1, 2, and 3, reference numeral 3o denotes an original plate made of glass, and 31 an original. The image of the original 31 placed on the original plate 30 is captured by a focusing rod lens array 29.
The 0 line sensor 22, which is imaged one-to-one on the line sensor 22, photoelectrically converted by the line sensor 22, and output as an electrical signal, has a plurality of photoelectric converters in a direction perpendicular to the cross-sectional direction in FIG. The element 22a is reading linearly (
The drive circuit 23 self-scans the originals in the main scanning direction, and the contact type sensor unit or document mounting table moves in a direction perpendicular to the main scanning direction (sub-scanning direction) to sequentially scan the originals. Convert it into an electrical signal and read it - pP et al? As shown in Figure 5, the optical path length TC is located at the center TC/2 of the optical path length (11
and 12 are equal. ) The original image can be best formed on the sensor when the contact sensor 100 and the original table 3o move relative to each other. It is difficult to keep the distance (optical path length TC) constant. If this optical path length TC changes, only the length shown in FIG. 5 will change if the focusing rod lens array is fixedly attached to the contact type sensor unit as in the conventional case. At this time, the change in resolution is 6th for the amount of change Δ11 in l.
The result will be as shown in the figure. On the other hand, even if the optical path length TC changes, the amount of change ΔTC! By moving the focusing rod lens array 29 by A to set it at the TO/2 position and making 11 and 12 the same, the change in angular image power can be reduced as shown in FIG. For example, if we use a focusing rod lens array 5LA20 series manufactured by Nippon Sheet Glass Co., Ltd. with an optical path length of 16.7 wm and a light source with a wavelength of 665 nm, and look at the resolution (MTF) of 41 P/run,
Fixing the focusing rod lens array as before, Δ11
When the optical path length changes by 0.3 mm, the MTF drops to about 50% (when Δa1 is zero, the resolution is approximately 70-751/2). However, as the change in optical path length TC, ΔTC, If you adjust the array to the TC/2 position,
When the light exposure length change is ΔTCO03, the resolution (MTF) can be maintained at about 65 coefficients. In other words, the conventional method reduces the resolution by about 20 to 25%, but it can be reduced to 5 to 10 inches.

Next, we will discuss the adjustment of the optical path length TC of the contact type sensor unit and the focusing rod lens array 29. First, we will discuss the adjustment of the optical path length TC of the contact type sensor unit and the focusing rod lens array 29. Place the original with the pattern formed thereon, use a jig (not shown) so that the original and the line sensor 22 have a predetermined optical path length TC, and rotate the eccentric pin 12A with the rotary row 211 in contact with the glass. Then, the sliding arm 16 is moved to move the locking pin 2o in the optical axis direction, and the focusing Rondre/Zuarray 29 is positioned at the position with the best resolution (ie, TC/2) to complete the adjustment. When removed from the jig, the compression spring 30
The sliding arm is connected to the elongated hole 16,1 through the engagement pin 20.
7 is moved until it comes into contact with the shaft 18, 19, the rotating arm 12 is rotated via the eccentric pin 12A, and when the rotating roller 11 is attached to the apparatus, it is in a state where it can come into contact with the document mounting table 3o. do. As described above, a close-contact type seven unit 1oo is constructed.

FIG. 8 is a side view of the image information reading device, in which 100 is a contact type sensor unit, 30 is a document placement table, 31 is a document, and 20 is a side view of the image information reading device.
1 is a sliding bearing, 202 is a guide shaft, 203 is a wire, 2
04.205 is a pulley, and 206 is a substrate.

In the close contact type senna unit 1o○, the rotating roller 11 is in contact with the document mounting table 11, and the sliding bearing 20 is attached by the mounting bracket 21.
1 (In the side view of the contact type sensor unit, parts other than the rotating roller 11 and the mounting bracket 21 are omitted to make the drawing easier to understand, but it has the configuration shown in Fig. 1. ). The sliding bearing 201 is a wire 20
3 is fixed on the side with a screw 207, and the pulley 204 and pulley 205 are rotated to move in the direction of the arrow, and in the opposite direction.

Although the Boo I7204 is omitted, it is rotated forward and backward by a driving means such as a motor, and moves the sliding bearing and contact type sensor unit 1oo via the wire 203. The guide shaft 202 is attached to the substrate 20 so that it is approximately parallel to the original table 30.
It is installed on 6. The original table 3o is attached to the substrate 206 with metal fittings 208.

While the contact type sensor unit is self-scanning in the main scanning direction, rotating the Boo I7204 in the direction of arrow E and moving the contact type sensor unit in the direction of the arrow (sub-scanning direction) can sequentially read the document surface. It is. The guide shaft 204 and the document table 30 are installed approximately parallel to each other, but due to processing errors or adjustment errors during installation, they are completely parallel to each other and the seam - 1 - opening is 4 inches h ffl + dot +
Zhan Xiaojia murmurs and becomes small. Furthermore, if the document surface is pressed down to make it come into close contact with the document table (particularly when trying to read a book, etc.), the document table may be deflected and the light exposure length may change.

However, this device has a mechanism that positions the converging rod lens array at the center of the optical path length, which minimizes the decrease in resolution due to changes in light exposure length, and reduces the decrease in reading quality. It is possible to minimize the In this embodiment, the contact type sensor unit is moved in the sub-scanning direction, but it goes without saying that the original table may be moved.

In addition, in FIG. 8, a mechanism for positioning the focusing rod lens array at the center of the light exposure length in response to changes in the optical path of the contact type sensor is formed integrally with the sliding bearing 201 on the device side, and a retaining pin is installed on the device side. The same effect can be obtained even if the focusing rod lens array is moved by engaging with the rod lens array 19.

Effects of the Invention As described above, according to the present invention, with a simple configuration, in reading scanning using a focusing rod lens array, the focusing rod array is always kept at the center of the optical path length even when the optical path length changes. It is extremely useful in practice because it allows good reading scanning to be carried out with minimal deterioration in resolution.

[Brief explanation of drawings]

FIG. 1 is a side view of a main part of an image information reading device according to an embodiment of the present invention, FIG. 2 is a cross-sectional side view of the same, FIG. 3 is a partial perspective view showing a focusing rod lens array of the same device, and FIG. 4 is a cross-sectional view of the same device, Fig. 6 is a side view of the optical system using a focusing rod lens, Fig. 6 is a characteristic diagram showing the relationship between Δ11 and MTF, and Fig. 7 is a graph showing the relationship between optical path length change ΔTC and MTF. FIG. 8 is a side view of an image information reading device according to an embodiment of the present invention, and FIGS. 9 and 10 are side views of essential parts of a conventional image information reading device. 1o...Unit base, 11...Rotating roller, 12...Rotating arm, 15...
・Sliding arm, 29... Focusing rod lens array, 22... Line sensor 27.28...
...Light source, 30...Document mounting table, 31...
...Manuscript, 100 contact type sensor unit, 201
...Sliding bearing, 202 ...Guide shaft, 20
3...Wire, 204,205...
Name of Pulley O agent Patent attorney Toshio Nakao and one other person
--, Kano La Kuttoren 7:7 Rebun Komahachi 4 Fig. 5 Fig. 6 Pupil F Fig. 7 Hcho F Fig. 8 Fig. 9 Fig. 10 Kenno-'' -]

Claims (3)

[Claims] (1) A line sensor that arranges multiple photoelectric conversion elements in a line and reads the original image on a one-to-one basis, a light source that illuminates the original surface, and a focusing rod that focuses the original image on the line sensor on a one-on-one basis. a contact type reading means comprising a lens array; a document mounting table that moves relative to the contact type reading means in a direction perpendicular to the arrangement direction of photoelectric conversion elements of the contact type reading means; The focusing rod lens array is moved in the optical axis direction in response to changes in the optical path length between the document surface and the line sensor surface that occur due to relative movement with the document mounting table, and the focusing rod lens array is moved to the center of the optical path length. An image information reading device comprising a focusing rod lens array adjusting means for positioning a rod lens array. (2) The focusing rod lens array is connected to a rotating roller in contact with the document mounting table, and a first lens having one end rotatably supporting the rotating roller and the other end rotatably attached to the contact type reading means. an arm, the arm contacts the first arm at the center of the length of the rotating roller fulcrum of the first arm and the attachment fulcrum to the contact type reading means, and is slidably attached to the contact type reading means in the optical axis direction. When attached, the first arm engages with the focusing rod lens array, and the rotation of the first arm causes the focusing rod lens array to move approximately 1/1 of the amount of movement of the rotating roller in the optical axis direction.
2. The image information reading device according to claim 1, further comprising a second arm that moves the focusing rod lens array by an amount of 2 in the same direction as the moving direction of the rotating roller. (3) Multiple photoelectric conversion elements are arranged in a row to convert the original image into one image.
a line sensor that reads in a one-to-one ratio; a light source that illuminates the reading position of the line sensor; a convergent rod lens array that forms an original image on the line sensor in one-to-one ratio; a unit base on which the line sensor and the light source are fixedly attached, and a detection means for detecting a change in the distance in the optical axis direction between the document mounting table; and a detection means interlocked with the detection means. 1/2 of the amount of change in the distance in the optical axis direction from the original table
and a focusing rod lens array position adjusting means for displacing the focusing rod lens array by an amount of .