JPH01303424A - Image reader - Google Patents

Abstract

PURPOSE:To satisfactorily red images on a sheet or a cube by providing a lens body with a diaphragm mechanism and permitting a diaphragm instructing means to instruct the diaphragm of the lens body. CONSTITUTION:The diaphragm mechanism 14 is assembled in the lens body 15. When an original is a sheet, the diaphragm instructing means 4 gives instructions that the diaphragm of the lens body is greatly opened, and on reception of the instructions, a diaphragm control means 13 adjusts the diaphragm mechanism provided on the lens body to open it greatly. When an original is a cube such as a book, the diaphragm instructing means 4 gives instructions to close the diaphragm of the lens body. Receiving the instructions, the diaphragm control means 13 adjusts and stops the diaphragm mechanism provided on the lens body. Thus, an image on a cube can be read, the moreover an image on a sheet is read at high quality.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image reading device used in a copying machine or the like.

[F,' is the technology of the past] In the image reading device of the conventional copying machine, the original is placed on the original plate, the original is irradiated with light from a light source, and the reflected image is captured by an optical moving body. leads to the lens body through the
The lens body immediately directs the condensed image light onto the photoreceptor 1- to form a latent image of the image.

By the way, the so-called depth of field of the lens body is generally shallow <10 mm or so.

[Problems to be Solved by the Invention] However, although image reading devices usually copy sheet objects, they often copy three-dimensional objects. If such a σ-object is read by an image reading device with a shallow depth of field, the object will be out of focus and will be blurred.

SUMMARY OF THE INVENTION In view of the problems of conventional image reading apparatuses as described in E, an object of the present invention is to provide an image reading apparatus that can read images of three-dimensional objects and can also read images of sheet objects with high quality.

[Means for Solving the Problems] The present invention provides a document placement plate on which a document is placed, and a P! A light source that illuminates the A-stripe, an optical movable body that guides the reflected image yt reflected by the original, and a lens body that collects image light that has passed through the optical movable body and irradiates the image light to a photoreceptor. In an image reading device equipped with
By providing an aperture mechanism provided on the lens body, an aperture instruction means for instructing the aperture of the lens body, and an aperture control means for adjusting the aperture mechanism according to instructions from the aperture instruction stage, Achieve your purpose.

[Operation] In the present invention, when the document is a sheet, the aperture instruction means instructs the aperture of the lens body to be wide open, and the aperture control means receives the instruction and controls the aperture mechanism provided on the lens body. Adjust the aperture to slightly open it. In addition, if the original is a σ object or a book, the aperture instruction means instructs the aperture of the lens body to become smaller, and the aperture control means receives the instruction and controls the aperture provided on the lens body. Adjust the mechanism to narrow the aperture.

[Examples] The present invention will be explained below based on drawings showing examples thereof.

FIG. 1 shows an embodiment of an image reading device according to the present invention (
FIG.

In the same figure, the upper surface 1a of the copying barrel main body l has an original (high 2
An original fA mounting plate 2 is provided on which a copying machine is placed; Side 1a
A document holding cover 5 for holding the document 24 is attached to the rear of the document. 21 is a print key for starting copying.

FIG. 2 is a schematic longitudinal sectional view of the image reading device according to the present invention.

ytlf! 7 G is Hara! Original 2 placed on A placement plate 2
Light to 4! 1r: There is a lamp for opening and opening.

The reflecting mirror 7 is an L stage that reflects the image light of tJ-1 due to the light R6t, and the first optical moving body 8 is an F stage that holds and moves the reflecting mirror 7 and the light source 6. Yes (see the double-dashed line). The second optical moving body 9
This is a means for holding and moving the reflecting mirrors 10, 10, etc., which reflect the image light reflected from the transfer body 8 and guide it to the lens body 15 (see the two-dot chain line).

The lens body 15 collects the image light reflected from the reflection mirror 10, and directs it to the photoreceptor tram 1 via the reflection mirror 11.
The method is a lens that illuminates the area.

A diaphragm mechanism 1='L is incorporated into the lens body 15 as shown in FIG. The structure of the aperture mechanism 14 is that used in conventional cameras. 1 B
is a driving means such as a motor that drives the aperture mechanism 14.

The aperture instruction means 1 is a means for instructing the aperture of the lens body 1L. An example is the aperture control key 4a provided on the operating section 3 of FIG. That is, this key is used by the operator himself to indicate whether the document 24 is in the form of a sheet or a three-dimensional object.

Alternatively, the aperture instruction means 4 is a circuit that detects whether or not the document holding cover 5 is completely closed, and if it is completely closed, determines that the document 24 is a sheet object and outputs a signal. There may be. As shown in Figure 1,
Mac 7 on the surface 1a of the copying machine body, and a close ta switch 4 on the copier body.
b, attach the magnet 4C to the corresponding position on the other original holding cover 5, and then
Close completely (proximity switch, 111 is magnetic) 4
The circuit detects c and outputs No. 18.

Historically, the aperture instruction means 4 automatically adjusts the original 1. It may be a means for determining whether the object 24 is a sheet object or a three-dimensional object. I
! 11. As shown in FIG. 2, the first optical moving body 8
The means/Ld is attached to the side wall of. Inside the storage box of this means 4d are as shown in FIG.
Aim the laser beam at the manuscript! V! A light emitting device 22 and a receiver 23 for receiving the original light emitted from the light emitting device 22 and reflected by a height 24 are provided. The number of light-receiving elements a as shown in the figure is set in such a direction that seven parts of the light can be received even if the light is greatly different from q=.
-m is arranged.

In FIG. 2, the diaphragm controller means 13 is a means for adjusting the diaphragm mechanism 14 via the moe drive f stage 16 in accordance with the diaphragm instruction [stage 11].

Further, a developing device 17, a paper feed roller 18, a transfer separator 19, a cleaning device 20, and the like are arranged around the photosensitive drum 12.

The operation of the first embodiment of the present invention will be explained again.

When the operator manually indicates whether the object is a sheet object or a three-dimensional object, the operator presses the key 4a, which is the aperture instruction means 4. The diaphragm sensor 1ilfl<i13 operates the diaphragm 11114 based on the signal from the key 4a. That is, if the original 24 is a sheet, the aperture is opened (see I) 1 in Fig. 7) and the peripheral speed of the light source [5'#: all or photoconductor tram 12] becomes normal. do it like this. In this case, as usual, the photosensitive drum 12
The focus can be adjusted normally (see the solid line in Figure 7).
Note that in the same figure, the line VI indicates a state in which when the aperture is enlarged even though there is a three-dimensional object C, the object is greatly out of focus. On the other hand, if the document 2/L is a three-dimensional object, the aperture is closed down as shown in FIG. 8 (D2).

irt, four original documents 24 are placed at a distance of Δ" from the document placement plate 2.
Even if the mouth is tilted, the out-of-focus on the photosensitive drum 12h will be small (d2).

In addition, in FIGS. 7 and 8, each dimensional relationship is exaggerated in order to simplify the explanation. Note that when the aperture is narrowed down in this way, the amount of transmitted light decreases, so at the same time, the voltage of the light source 6 should be increased or the slit 25 should be widened (thereby increasing the amount of light (see FIG. 2)).

Alternatively or in addition to this, an optical movable body 8.9
, the circumferential speed of the photoreceptor tram 12, the paper feeding speed, etc. are reduced.

Also, by closing the document holding cover 5, the document 2
When determining type 4, the procedure is as follows.

That is, when the original 24 is a sheet, the original holding cover 5 is completely closed, so that the magnet 4c comes into contact with the proximity switch 4b, and this is detected. On the other hand, if the original 24 is a three-dimensional object, the original holding cover 5 cannot be completely closed, so the proximity switch 4b does not output a signal. Therefore, if the proximity switch 4b does not output a signal even though the print key 21 is pressed, it is determined that the document 24 is a four-piece object. The aperture control means 13 controls the aperture mechanism 14 based on the presence or absence of a signal from the proximity switch 4b. The control process is as described above.

When automatically determining the type of document 24, the process is as follows. That is, as shown in FIG. 4, when the N document 24 is a sheet material, the light emitted from the light emitter 22 is reflected by the document 24 and enters the light receiver 23. At this time, since it is a sheet material, the expected reflected light is incident on the light receiving element g. On the other hand, when the original 211 consists of seven objects, as shown in FIG. And that reflected light is
The light is incident on the light receiving element d or the light receiving element m. That is, Hara 11
%24, the reflected light will not enter the predetermined light-receiving element g if it is floating above the document placement plate 2. This makes it possible to determine the type of document 211.

The aperture indicating means 4d, which includes the light emitter 22 and the light receiver 23, is attached to the first optical movable body 8, and by moving the first optical movable body 8 by a conventionally known method, The document placement plate 20F side can be moved. Therefore, even in the case of a hook original as shown in FIG. 6, reflected light no longer enters the light receiving element g as it is pre-scanned and moved. Therefore, even in such a case, the type of document 24 can be recognized as seven objects and detected reliably. In addition, during scanning, the sheet part and the three-dimensional part are recognized according to the scanning position, and this is stored in memory, and when copying, the aperture is adjusted according to the information stored in the memory. You can also strain it. This allows for sharper copying. It goes without saying that the #, amount, circumferential speed, etc. are controlled as described above in accordance with the adjustment of the aperture.

Note that the present invention can be implemented not only when copying at the same size, but also when copying at variable magnification.

Historically, in the above explanation, copies of sheet objects are considered to be "normal", but this is relative; the state of copies of seven objects is considered to be "normal", and the state of copies of sheet objects is considered to be "normal". In the case of sheet materials, it may be considered as an "exception" to reduce hanging from overcrowding and increase circumferential speed.

[Effects of the Invention] As is clear from the above explanation, the image reading device according to the present invention includes a diaphragm mechanism provided in the lens body,
By instructing the aperture of the lens body using the aperture instruction means ζJ, the aperture of the lens body can be adjusted appropriately according to the type of patronage, so even in the case of a sheet object, the aperture of the lens body can be adjusted appropriately.
Even in the case of a physical object, excellent image reading can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of the -L section of a copying machine incorporating an embodiment of an image reading device according to the present invention, FIG. 2 is a schematic vertical sectional view of the same, and FIG. FIG. 4 is a front view of the lens body of the copying machine, and FIG. 4 is a front view of the light emitting device and light receiver for explaining the operation of the same embodiment. FIG. , a front view of the light receiver, etc., FIG. 6 is an IF view of the light emitting device, light receiver, etc. for explaining the operation of the same embodiment, and FIG. 7 is a front view showing the optical path of light in the same embodiment. ,
FIG. 8 is an IF plane view (C) showing the optical path of the light passing through ζ in the same embodiment. ! ...? U manuscript main body 2... Manuscript placement plate; 3
...Operation unit 11.4a, /1))...Aperture instruction means 5...Document holding cover 8.9...Optical movable body l; (...Aperture control means 1 /l...・
Aperture mechanism 15... Lens body 24... J

Claims (1)

[Claims] (1) A document placement plate on which a document is placed, a light source that irradiates light onto the document placed on the document placement plate, an optical moving body that guides reflected image light reflected by the document, and an optical In an image reading device equipped with a lens body that collects image light that has passed through a moving body and irradiates the image light onto a photoreceptor, an aperture mechanism provided on the lens body and an aperture of the lens body are specified. What is claimed is: 1. An image reading device comprising: an aperture instruction means for controlling the aperture; and an aperture control means for adjusting the aperture mechanism according to instructions from the aperture instruction means.