JPS61195075A - Original reader - Google Patents

Abstract

PURPOSE:To arrange an image pick-up element at the most appropriate position by adjusting so as to coincide the effective reading width of an original in the image- forming of a test chart to a solid state image pick-up element with the width of a gate signal that fetches a share of the effective reading width of the original from the output of the image-forming of the solid state image pick-up element. CONSTITUTION:A light beam that is come out from a fluorescent lamp 32 is irradiated on an original on an original table 1 and a reflecting light 3 is image-formed on a solid state image pick-up element 22 by a lens 21 through mirrors 33, 35 and 35. For the adjustment of the positions of movable bodies 31 and 34 to arrange the element 22 at the most appropriate position, a test chart main body 50 that represents an original effective width D is used. For the adjustment of the position, a start signal generating part 50 that makes the light receiving operation of the element 22 to start and a gate signal generating part are provided and they make all output signals and gate signals of the element 22 to display on a synchroscope 52. A chart main body 50 is placed on the original table 1 and the positions of the movable bodies 31 and 34 are adjusted so as to coincide the reading width D that the output signal A of the element 22 represents with the pulse width of a signal G. Thus, the image pick-up element is arranged at the most appropriate position.

Description

DETAILED DESCRIPTION OF THE INVENTION B) Field of Industrial Application The present invention relates to a document reading device that reads a document by forming an image of the document on a solid-state image sensor.

(b) Conventional technology In a document reading device that reads a document by illuminating the document and using a lens to image the reflected light onto a solid-state image sensor through a plurality of mirrors, it is possible to The solid-state image sensor must be placed in the correct position.

Japanese Utility Model Publication No. 59-21577 discloses an adjustment mechanism configured to place a solid-state image pickup device in the correct position, and this adjustment mechanism has an adjustment mechanism that allows the effective reading of the original to be placed near both ends of the original reading window. A pair of notches are formed at approximately the same interval as the width,
The relative positional relationship between the document reading window and the solid-state image sensor can be adjusted.

(c) Problems to be Solved by the Invention By the way, when the light-receiving width of the solid-state image sensor is larger than the effective reading width of the document, in the above-mentioned prior art, the output of the solid-state image sensor has the above-mentioned pair of notches. Since the range in which two output peaks occur depending on the area is wide, it is difficult to arrange the solid-state image sensor with sufficient accuracy.

Furthermore, the optical path distance between the document surface and the solid-state image pickup device and the object-to-image distance also need to be arranged at optimal positions, but this is not disclosed at all in the above-mentioned prior art.

SUMMARY OF THE INVENTION An object of the present invention is to provide a structure that allows a solid-state image sensor to be disposed at an optimal position with a simple operation.

B) Means for Solving the Problems The present invention provides a document reading device configured to illuminate a document and form an image of the reflected light onto a solid-state image sensor via a plurality of mirrors. It has a first adjustment section that is movable in the light receiving pixel arrangement direction, and a second adjustment section that can change the object-image distance by moving the relative positions of the plurality of mirrors, and has a second adjustment section that can change the object-image distance. The above-mentioned first! The present invention is characterized in that the adjustment section and the second adjustment section are configured to be adjustable.

(E) Function The present invention adjusts the solid-state image sensor to an appropriate position while monitoring the output of the solid-state image sensor and the gate signal for extracting the effective reading width of the document from this output.

(f) Embodiment FIGS. 1 to 3 show an embodiment of the present invention. FIG. 1 is a schematic side view, in which (1) is a document table made of glass or the like, 121 is a presser lid that covers the document placed on the document table, and C11) is a fluorescent lamp 63 and a first mirror C33. (b) is a second movable body that holds a second mirror (to), (2) is a lens, @ is a solid-state image sensor consisting of a CCD, and (b) is a second movable body that holds a second mirror. Light receiving pixel is m-
are arranged in

The light emitted from the fluorescent lamp illuminates the document (not shown) on the document table (1), and the reflected light (3) is reflected by the first mirror (to) and the second mirror (to). ) to the lens (2
), the image is formed on the solid-state image sensor. At this time, the first
By moving the movable body 01) at a speed V and the second movable body (b) at a speed V/2 in the directions of the arrows in the figure, the optical path length of the reflected light (3), that is, the distance between objects It is possible to read the entire surface of a document while keeping it constant.

FIG. 2 is a perspective view showing the mounting mechanism of the solid-state image sensor (a) in FIG. 1. The handle is the substrate that holds the lens, <
24 is a solid-state image sensor (2) facing the lens (2).
), and (E) has L-shaped parts (25
a) (25b) A second mounting plate having T- and holding the first mounting plate (to) (2) ... cooperates with the board plate to attach the L
Hold the letter parts (25a) and (25b) and attach the second mounting plate (E).
The guide piece that slidably holds the
an L-shaped piece fixed to the substrate (e) close to and opposite to 5a);
(to) is an adjustment screw rotatably held by one L-shaped portion (25a) and screwed into the L-shaped piece (b).

Then, by rotating the adjusting screw (to) so as to tighten it to the L-shaped piece (b), the second mounting plate (c) moves to the right, and conversely, tightening the adjusting screw @ to the L-shaped piece (b) By rotating to loosen, the second mounting plate (2) moves to the left.

That is, as the adjustment screw (2) rotates, the solid-state image sensor (
A) is movable in the direction of the double arrow in the figure (the direction in which the light-receiving pixels of the solid-state image sensor (A) are arranged).

FIG. 3 is a perspective view showing the movable mechanism of the first movable body l31) and the second movable body (b) in FIG. 1. @ is one end of the first movable body c31) and the second movable body (goods) through tit,
@1 guide rod that holds these slidably, 6? ) is arranged parallel to the first guide shaft, and the first movable body 09 and the second
Rotating roller CIC provided at the other end of the movable body (b)
(The second guide bar on which 9 is placed, (40 is the first guide bar (
The first movable pulley, I, inserted in Moving pulley (421,
Wire stretched between 0'3 piles 1 movable pulley + 4
It is a removable fixture that fixes the wire (4D) between the 0 and 2nd movable pulleys (4D).

When reading a document, by moving the first movable pulley (40) to the left by a drive unit (not shown), the first movable body 0
1) moves to the left at a speed of V, and the second movable body (goods) moves to the left at a speed of V/2.

On the other hand, when adjusting the distance between objects and images, by removing the fixing bracket (43) and moving the wire (41),
And the interval between the second movable parts 0a can be changed.

This allows the distance between objects and images in FIG. 1 to be changed.

Hereinafter, a method for adjusting the position of the solid-state image sensor in the document reading device having a refusal configuration will be described in detail.

FIG. 4 is a plan view showing the test chart used for this position adjustment, 5G is the chart body, (51a) (
51h), (52a), and (52b) are a pair of marks respectively provided at both ends of the chart body. Each mark (51
a) (51b) (52a) The distance between the centers of (52b) indicates the effective document reading width, but the pair of marks (51a) (
The distance d between 51b) and 52a and 52b provides a permissible range for the effective reading width of the document.

The position adjustment method of the present invention has the following characteristics: the effective reading width of the document when the image is formed on the solid-state image sensor of the test chart; and the gate signal width for extracting the signal corresponding to the effective reading width of the document from the total output signal of the solid-state image sensor. The purpose is to match.

FIG. 5 is a block diagram for performing such position adjustment. The mark is a start signal generation section that generates a start signal to start the light receiving operation of the solid-state image sensor @, 5υ is a gate signal generation section that generates the above gate signal, and r52 is the entire output signal of the solid-state image sensor (a) and This is a synchroscope that displays gate signals.

Then, the above-mentioned position adjustment is performed while observing the total output signal and gate signal of the solid-state image sensor (a) shown in the synchroscope 65.

In the adjustment method of the present invention, the chart body (
5at and start by reading the test chart. FIG. 6 shows the output signal A of the solid-state image sensor 4 when reading such a test chart when the solid-state image sensor holder is placed at an appropriate position. Signal Atf chart body SO marks (51a) (51b) (52a)
It has a signal drop part at a position corresponding to (52b),
The effective document reading width Dt can be easily recognized. Further, the gate signal G shown by a broken line in the same figure is a signal for extracting a signal of a portion of the effective document reading width from the output signal A of the solid-state image sensor (a), and has a predetermined nine pulse width.

As shown in FIG. 6, when the solid-state image pickup device is placed at a proper position, the effective reading width of the document indicated by the output signal A of the solid-state image pickup device matches the pulse width of the gate signal G.

FIG. 7 and FIG. GA show the relationship between the signals A and G when the solid-state image sensor 4 is not placed at the proper position.

Figure 7 shows a case where the object-image distance is inappropriate, specifically, the object-image distance is too long, and the effective document reading width DI indicated by signal A is narrower than the pulse width of gate signal G. Become. In this situation, as shown in Figure 3, the fixing fittings (43
By removing the wire (4υ) and reducing the distance between the first movable part 01 and the second movable part (b), the object-image distance is optimized, and the document effective reading width 1 indicated by the signal person is ) t and the pulse width of the gate signal G may be made to match. Conversely, the effective document reading width indicated by signal A is gate signal G.
The distance between the pulse it portion 0υ and the second movable portion (to) may be increased.

After completing the adjustment, attach the wire (41) to the fixing bracket (43).
It is natural to fix it.

FIG. 18 shows a case where the solid-state image sensor (a) is misaligned in the pixel arrangement direction, and the effective document reading width indicated by the signal A and the gate signal G are misaligned. In this case, in Figure 2, rotate the adjustment screw (C) to move the solid-state image sensor in either direction of the double arrow in the figure, and adjust the effective reading width of the document indicated by the signal person and the gate signal. All you have to do is match the position with G.

(G) Effects of the Invention According to the present invention, it will be possible to easily arrange the solid-state image sensor at an appropriate position.

[Brief explanation of the drawing]

The figures show an embodiment of the invention, with Figure 1 being a schematic side view;
FIG. 2 is a perspective view showing a solid-state image sensor mounting machine M, FIG. 3 is a perspective view showing a movable mechanism of the first movable body and the second movable body,
Figure 4 shows the plane 11M1! which is the test chart. i! Lzu is 760. ,．． Figure 8 shows signal waveforms in different states. @...Solid-state image sensor, C11)...First movable body, (
Goods)...Second movable body, ■...Chart body.

Claims (1)

[Claims] (1) In a document reading device configured to irradiate a document and form an image of the reflected light onto a solid-state image sensor via a plurality of mirrors, a first device is configured to move the solid-state image sensor in the direction in which the light-receiving pixels are arranged. an adjustment section and a second adjustment section that can change the object-to-image distance by moving the relative positions of the plurality of mirrors; The first adjusting section and the second adjusting section are configured to match the effective document reading width in the image with the width of a gate signal for extracting the effective document reading width from the output from the imaging of the solid-state imaging device. A document reading device characterized by having an adjustable configuration.