JPH05183703A - Picture reader - Google Patents

Abstract

PURPOSE:To easily execute the skew adjustment of a linear picture reading element by detecting skew by a first and a second reference members. CONSTITUTION:A reference plate 7 is constituted of a white reference plate 7a as the first reference member having a first reflection factor and a white plate 7b arranged so as to form a gap in uniform width along the longitudinal direction of the white reference Plate 7a, and is provided with shade formed in this gap as a black line 7c different from the white reference plate 7a as the second reference member in the reflection factor. In the case of adjusting the optical axis 1 skew of a line sensor 6, a stepping motor 13 is started, and an operating arm 16 is driven clockwise, and the surface of the reference plate 7 supported by a moving member 8 is turned into a state that it faces an original reading surface. The black line 7c is moved to a position where it becomes the standard of the optical axis of an optical system 2 by rotating the stepping motor 13 by the prescribed number of pulses. The line sensor 6 is adjusted so that the reading line of the line sensor 6 coincides with the black line 7c.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading device,
More specifically, it relates to improvement of an image reading device used as an image input device such as a facsimile or a printer.

[0002]

2. Description of the Related Art In a document moving type image reading apparatus, a paper on which a pattern for adjustment is printed is used for optical adjustment of focus and magnification. Since there is a skew or the like in itself, the adjustment is performed based on a reference plate provided in the apparatus as a reference for adjustment.

A conventional adjusting method using the reference plate 30 will be described with reference to FIGS. 13 to 19.

The conventional reference plate 30 has a black-and-white pattern composed of a white reference pattern a2 and a black reference pattern a1 for shading correction, and the boundary between them is parallel to the main scanning direction.

14 to 16 show the positional relationship between the reading line 31 by the line sensor and the reference plate 30, and FIGS. 17 to 19 show the outputs of the line sensor corresponding to FIGS. 14 to 16, respectively. Signal G is shown.

FIG. 14 shows a state in which the reading line 31 read by the line sensor is skewed with respect to the reference line of the reference plate 30. In such a state, the output signal G of the line sensor is in the state shown in FIG.

In such a case, as shown in FIG.
The position of the line sensor may be adjusted as shown in FIG. 15 so that the level of the output signal G moves in parallel from the bright signal level “100” to the dark signal level “0”.

However, when the line sensor after adjustment is fixed with a screw or the like, the position of the line sensor may be displaced due to tightening of the screw or the like. When the shift is as shown in FIG. 14, it can be judged by the change of the output signal G, but when the shift is made in the black or white region as shown in FIG. 16, the output signal G does not change as shown in FIG. There is a problem that the skew (positional deviation) of the sensor is unknown.

[0009]

As described above, the conventional apparatus has a problem that even if the position of the adjusted line sensor is displaced, the skew cannot be recognized depending on the direction of displacement.

Therefore, it is an object of the present invention to provide an image reading apparatus capable of easily adjusting the skew of a linear image reading element.

[0011]

SUMMARY OF THE INVENTION The present invention is an image reading apparatus for optically reading an image on an original by moving the linearly arranged image reading element relative to the original. A first reference member having a first reflectance and arranged in the length direction, and a position where the first reference member is divided into two in a direction orthogonal to the length direction of the image reading element. And a second reference member having a reflectance different from that of the first reference member, and the skew of the image reading element is detected by the first and second reference members. is there.

[0012]

According to the image reading apparatus having the above-described structure, the first reference member having the first reflectance and arranged in the length direction of the image reading element, and the first reference member in the length direction of the image reading element are provided. And a second reference member which is arranged at a position where the first reference member is divided into two in a direction orthogonal to each other and which has a reflectance different from that of the first reference member, and detects the skew of the image reading element. Therefore, the skew adjustment of the linear image reading element can be easily performed regardless of the direction.

[0013]

Embodiments will be described below with reference to the drawings.

FIG. 1 is a schematic configuration diagram of an image reading apparatus 1 according to this embodiment.

The image reading apparatus 1 shown in FIG. 1 includes a pair of not-shown conveying rollers for conveying a document, which are vertically arranged via a document conveying path 20, an optical system 2 for reading an image, and an optical axis / skew adjustment. Adjusting means 34 for the main body frame 11
It has been configured in.

The optical system 2 is composed of a pair of fluorescent lamps 3 as light sources, a reflection mirror 4, a lens 5, and a line sensor 6 as a linear image reading element.

The adjusting means 34 arranged below the optical system 2 has a reference plate 7 serving as a reference for optical axis / skew adjustment, and the reference plate 7 from below the original conveying path 20. A reference member drive unit 40 for displacing to the original reading surface of the system 2 is provided.

The reference member drive unit 40 is a stepping motor 13 as a drive source fixedly arranged below the document conveying path 20 of the main body frame 11, and a drive shaft 14 arranged directly below the document reading surface of the optical system 2. And a belt 15 stretched around the driving shaft of the stepping motor 13 and the pulley 19.

Further, the reference member driving section 40 includes a parallel section 12a, a curved section 12b, and a curved section 12b formed in the body frame 11.
The slide hole 12 connecting the vertical portions 12c and the reference plate 7
A moving member 8 for supporting the drive shaft 14 of the pulley 19
Operation arm 16 with fan-shaped slot 17 attached to
And a guide plate 18 as a conveyance guide member attached to the drive shaft 14.

The moving member 8 is formed in a substantially rectangular shape, and the reference plate 7 is attached to one end of the moving member 8 in an orthogonal arrangement, and the elongated hole 17 of the operating arm 16 is provided.
A pair of drive pin 9 and driven pin 10 that engage with are projectingly provided.

As shown in FIGS. 2 and 3, the reference plate 7 has a first reflectance having a first reflectance for shading correction.
White reference plate 7a as a reference member of the white reference plate 7a
The white plate 7b is arranged so as to form a gap with a uniform width along the longitudinal direction of the
The white reference plate 7a as a reference member of the above is provided with a black line 7c having a different reflectance.

The width of the black line 7c is set to be larger than one pixel (line) on the document surface.

As shown in FIG. 4, the line sensor 6 of the optical system 2 is used to adjust the black line 7c of the reference plate 7 by the adjusting mechanism (not shown) in the directions a, b (rotating directions) and c, d. It is arranged to be adjustable in the direction (vertical direction).

Next, the operation of the image reading apparatus 1 described above will be described.
Mainly the optical axis / skew adjustment operation, and FIGS.
It will be described with reference to FIGS.

The following description will be given assuming that the reference plate 7 is in the position shown in FIG. 1 in the initial state.

When adjusting the optical axis / skew of the line sensor 6, the stepping motor 13 is started and the operating arm 16 is driven to rotate clockwise. This allows
The moving member 8 connects the drive pin 9 and the driven pin 10 to the parallel portion 12a, the curved portion 12b, and the vertical portion 12c of the slide hole 12.
Then, the surface of the reference plate 7 supported by the moving member 8 faces the document reading surface as shown in FIG.

The reference plate 7 is moved to a position where the black line 7c becomes a reference of the optical axis of the optical system 2 by rotating the stepping motor 13 by a predetermined number of pulses.

From this state, the surface of the reference plate 7 is irradiated with light, and the reflected light from the reference plate 7 is reflected by the reflecting mirror 4 and the lens 5.
It is incident on the line sensor 6 via. The reading line 6a of the line sensor 6 and the black line 7 of the reference plate 7 at this time
FIG. 6 shows a state in which c and c match.

Further, FIG. 7 shows a state in which the reading line 6a of the line sensor 6 is inclined with respect to the black line 7c. At this time, the line sensor 6 is rotated in the b direction by an adjustment mechanism (not shown), and the output signal G is changed to that shown in FIG.
By adjusting the waveform from E1 to E2 during 0, the read line 6c of the line sensor 6 can be positioned from B1 to B2 in FIG. 7, and the read line and the black line 7c can be matched. ..

FIG. 8 shows the line sensor 6 for the black line 7c.
The reading line 6c of 1 is shifted in parallel. At this time, the line sensor 6 is moved in parallel in the c direction by an adjusting mechanism (not shown) so that the output signal has a waveform from F1 to F2 in FIG. 11, so that the read line 6c of the line sensor 6 is changed to C1 in FIG. To C2, the read line and the black line 7c can be aligned.

Further, when the line sensor 6 after the optical axis / skew adjustment is fixed with a screw or the like, the position of the line sensor 6 may shift due to tightening of the screw or the like.

In this case, according to the present embodiment, when the read line 6c of the line sensor 6 is displaced as shown in FIG. 9, the output signal G changes as shown in FIG. 12 so that the line sensor 6 can be easily displaced. Can be detected.

The present invention can be variously modified within the scope of the gist other than the above-mentioned embodiment.

[0034]

According to the present invention described in detail above, due to the above-mentioned configuration, the skew can be easily detected even when the image reading element is skewed in any direction, and the skew at the time of reading the image is obtained. It is possible to provide an image reading device capable of performing accurate adjustment.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an image reading apparatus that is an embodiment of the present invention.

FIG. 2 is a side view of a reference plate of the apparatus of this embodiment.

FIG. 3 is a front view of a reference plate of the apparatus of this embodiment.

FIG. 4 is an explanatory diagram of an adjusting method of the image reading apparatus of the present invention.

FIG. 5 is a schematic configuration diagram showing an adjusting operation of the image reading apparatus according to the embodiment of the present invention.

FIG. 6 is a front view of a reference plate of the apparatus of this embodiment.

FIG. 7 is an explanatory diagram showing a positional relationship between a reference plate and a reading line of the apparatus of this embodiment.

FIG. 8 is an explanatory diagram showing a positional relationship between a reference plate and a reading line of the apparatus of this embodiment.

FIG. 9 is an explanatory view showing the positional relationship between the reference plate and the reading line of the apparatus of this embodiment.

10 is a waveform diagram showing an output signal of the line sensor corresponding to FIG.

11 is a waveform diagram showing an output signal of the line sensor corresponding to FIG.

12 is a waveform diagram showing an output signal of the line sensor corresponding to FIG.

FIG. 13 is a front view of a reference plate of a conventional device.

FIG. 14 is an explanatory diagram showing a positional relationship between a reference plate and a reading line of a conventional device.

FIG. 15 is an explanatory diagram showing a positional relationship between a reference plate and a reading line of a conventional device.

FIG. 16 is an explanatory diagram showing a positional relationship between a reference plate and a reading line of a conventional device.

FIG. 17 is a waveform diagram showing an output signal of the line sensor corresponding to FIG.

FIG. 18 is a waveform diagram showing an output signal of the line sensor corresponding to FIG.

FIG. 19 is a waveform diagram showing an output signal of the line sensor corresponding to FIG.

[Explanation of symbols]

 1 Image Reading Device 2 Optical System 6 Line Sensor 7 Reference Plate 7a White Reference Plate 7c Black Line 40 Reference Member Drive Unit

Claims (1)

[Claims] 1. An image reading device for optically reading an image on a document by moving a linearly arranged image reading device relative to the document, the image reading device being arranged in a length direction of the image reading device. The first reference member having a first reflectance and the first reference member are arranged in a position that divides the first reference member in a direction orthogonal to the length direction of the image reading element. An image reading apparatus comprising: a second reference member having a reflectance different from that of the member, and detecting the skew of the image reading element by the first and second reference members.