JPH0319571A - Picture reader - Google Patents

Abstract

PURPOSE:To attain highly accurate reading by devising a Fresnel base having a Fresnel lens to be turned on an original platen so as to uniformize the read density of picture information of an original placed on the face of the original platen and the picture information projecting the face of the original platen. CONSTITUTION:A Fresnel lens 2 is fixed to a Fresnel base 16, one end of the Fresnel base 16 is provided with a hole for a hinge, a hinge dowel 162 is inserted to the hole and one end of a mirror base 15 is turned as a support member. Moreover, the mirror 3 is fixed to the mirror base 15 and when the Fresnel base 16 is turned, the Fresnel lens 2 is always arranged to a prescribed position optically. Thus, the optical axis of a projection means 41, a center shaft of the Fresnel lens 2 and the optical axis of a read means 42 are made coincident to eliminate the uneven density in the case of reading a picture and highly accurate reading is attained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an image copying and scanning device, and particularly to a copying and scanning device for placing a transmissive type document such as a 35 mm slide film or an OHP (overhead projector) on a document table. The present invention relates to an image reading device suitable for projecting image information using a projection device and reading image information based on the document using a reading device provided in the image reading device IN (?1 copying machine body) Ill. (Conventional RI Technique) Conventionally, an original such as an OHP is placed on the original table on the side of the main body of a copying machine, the original is illuminated with an illumination means, and image information based on the original is read with a reading means, or Various image reading apparatuses have been proposed in which a projection means enlarges and projects an original, such as a slide film, onto the surface of the original, and a reading means reads image information based on the original.
Figure 6 is a schematic diagram of the main parts of a conventional image reading device of this type. In the figure, a transmissive original F such as a slide film is illuminated by a light beam from a light source 6 using a concave mirror 8 and a condenser lens 9, and is projected onto the original platen 7 by a projection lens 4 via a mirror 3 and a Fresnel lens 2. It is enlarged and projected. Here, light source 6, concave ta8, condenser lens,
The projection lens etc. constitute a part of the 1,000-stage 4L projection system. Then, the image information based on the original projected onto the 7th surface of the Haraakidai is transferred to the first mirror FfAI+. The second mirror portion 12 is moved and scanned, and the image is read by a reading stage 42 having an imaging lens 14, CCl) 13, etc. Here, the Fresnel lens 2 has the function of deflecting the light beam so that the projection stage 4l or Rano light beam is efficiently incident on the reading means 42. This allows image information to be read with uniform density. In the case of a large transmissive type original such as an OHP as the original for image reading, place the IQ original on the 7th surface E of the original platen, and place a Fresnel lens on the original 7 or cut it with a slight air gap. Place. and t2 shadow means (in this case, there is no film original F, so it simply acts as an illumination means).
The original is illuminated with a beam of light from the mirror 3 and the Fresnel lens 2. As described above, image information based on the MR draft is read with 42 reading stages. (Problems to be Solved by the Invention) In conventional image reading devices, a Fresnel lens is used near the document table surface in order to increase illumination efficiency, or the light of the projection means (illumination means) is There were cases where the axis, the central axis of the Fresnel lens, and the light beam of the reading means did not match and shifted. Therefore, when reading the image information of the original projected onto the original table or the original placed on the original table, the light beam incident on the reading means 42 becomes uneven over the entire screen, and the density of the read image is not constant. However, there was a problem in that the reading accuracy deteriorated. For this reason, in the past, the Fresnel lens 2 was adjusted each time by moving the document table L to avoid uneven density, but there was a problem in that such adjustment was very troublesome. The present invention makes a Fresnel table that uses a Fresnel lens rotatable with respect to a document table surface using a support member,
Image information projected onto the document table and I! The purpose of the present invention is to provide an image reading device that can read image information with high precision by making the reading density of the image information of the RII4 placed on the image sensor uniform. (Means for Solving the Problems) The image reading device of the present invention uses an illumination means to illuminate a document placed on a document table, and when reading image information about the document with a reading device, or When the reading means reads the rain image information regarding the document projected by the projection stage f, a Fresnel table is rotated via a support member on the surface of the document table. It is characterized in that the image information is read through the Fresnel lens. (Embodiment) FIG. 1 is a schematic diagram of the main parts of the first embodiment of the present invention. In the figure, F is a transmissive original such as a slide film, which is supported by an original supporting part t45. Reference numeral 6 denotes a light source, which condenses one of the light beams emitted from the light source 6 with a condenser lens 9, and condenses the light beam emitted to the other side with a concave surface vA8. Each illuminates manuscript F. Reference numeral 4 denotes a projection lens, which enlarges and projects the image of Hara Tsuyoshi F onto the 7th surface of the document table via a mirror 3 and a Fresnel lens 2. The mirror 3 is attached to a mirror stand 15, and the Fresnel lens 2 is fixed to a Fresnel stand 16 which can rotate +jJ. In this example, each of these elements 4, 5, 6, 8,
9 constitutes a part of the projection 1,000 steps 41. 10 is a projection table, which is provided as a part of the main body 50 of the copying machine, and has 1,000 projection stages 4L arranged thereon. 7 is a manuscript table;
Post the manuscript FB of OHP etc. which will be mentioned later! It's on. ] 1 is number 1! The mirror portion 12 is the second mirror portion, and by moving these mirror portions 11 and 12 along the 7th surface of the original platen, the 7th surface of the draft F projected on the 7th surface of the document table is changed. Image information and manuscript table 7-L! ! The image information based on the permitted large-sized 011P or other transparent type document is scanned and read by a reading means 42, which will be described later. The reading means 42 has an imaging lens 14 supported on a lens stand 131 and an image reading element l3 such as a CCD attached to a mounting member 132. still. IIa is a light source and is used when a reflective original is placed on the original platen 7. Mirror 3 is fixed to mirror stand l5. mirror stand l
A positioning bin 153 is provided at one end of 5.
It fits into a hole formed in a part of the copying machine main body 50. When the Fresnel table l6 is rotated, the Fresnel lens 2 is always optically placed at a constant position. A magnet 151 is provided at the other end of the mirror stand 15, so that when the Fresnel stand l6 is rotated, it comes into contact with a magnet 16+ provided on a part of the Fresnel stand l6. As a result, the Fresnel stand 16 is rotated and adsorbed to the mirror stand 15. In this embodiment, the hinge position of the Fresnel table l6 is provided such that the document table 7 and the Fresnel table l6 touch in parallel. The Fresnel lens 2 is fixed to a Fresnel stand 16,
A hole for a hinge is provided at the - end of the Fresnel stand 16, and a hinge dowel 162 is fitted into the hole to attach the mirror stand l5.
It is constructed so that it can move simultaneously using one end as a support member. In this embodiment, when reading image information based on a transmissive type F such as a 35 mm slide film using the f-stage 42, the F is held on the document support stand 15 with 1,000 stages of projection and the projection lens is used. 4, the image is projected near the 7th surface of the document table. In addition, when reading image information based on a large transmissive type original such as an OHP "H", the Fresnel table 16 is rotated around the hinge dowel 162 as a support member, and the original FB is placed on the surface of the original table 7. After placing it, add 2 Fresnel lenses on top of it.
is placed at a. Then, the projection means 41 (at this time, the document F is removed, and the projection means 4l has a function as an illumination means) illuminates the image via the mirror 3 and the Fresnel lens 2. R projected onto manuscript table 7 with 4l of 1,000 steps
The reading means 4 reads the image information of the stack F or the image information based on the document FB placed on the document table 7 surface-E and illuminated by the illumination means.
2, digital reading and digital image processing are performed. FIG. 2 shows that the image of Hara F at this time is projected by the projection lens 4 onto the surface E of the document table 7 via the Fresnel lens 2, and the image information based on the document F is transmitted to the surface 13 of the light receiving element such as a CCD using the imaging lens 141. This shows how the image is focused and read. In Figure 3, a lens array +42 using a SELFOC lens (trade name) is used in place of the imaging lens 14 in Figure 2 to form an equal-magnification imaging relationship, and the Fresnel lens 2 transforms the passing light into a parallel light. A case is shown in which image information based on the document F is imaged and read on the two sides of the photodetector T-12. In this embodiment, as shown in E below, the Fresnel stand 16 is positioned using a positioning bin etc. provided in a part of the copying machine body on the side of the image reading means, and the M Fresnel lens rotates around the support member. We are making it possible. This allows the optical axis of the projection means 4l to be aligned with the optical axis of the projection means 4l. The center axis of the channel lens 2 and the optical axis of the 1,000-stage reading stage 42 are aligned to eliminate density unevenness when reading an image, making highly accurate reading possible. In this example, when performing analog copying, a Fresnel lens with different characteristics is used compared to digital copying. FIG. 4 is a schematic diagram of the second embodiment of the present invention. In this embodiment, the mirror stand 15 is made up of a part of 1,000 projection stages 4l. Then, the projection f stage 41 is positioned with respect to the image reading device using a positioning bin (not shown) or the like to prevent the Fresnel lens 2 from coming out of a predetermined position when the Fresnel table 16 is moved. In this embodiment, a reflective original is placed on the original platen 7.
If the mirror stand 15 becomes an obstacle when reading is performed, the mirror stand 15 is folded using a part P of the mirror stand 15 as a hinge and is evacuated from the main body 5o of the four-image reading device. It is good. FIG. 5 is a schematic diagram of the main parts of the third embodiment of the present invention. In this embodiment, the projection means 4l is arranged above the surface of the document table 7, and projects the document directly onto the document table 7 and 12 without using a mirror. This facilitates the alignment of the optical axis of the projection means 41, the central axis of the Fresnel lens, and the nine axes of the reading means. or. In this embodiment, when the Fresnel stand 16 is rotated, the magnet +61 of the Fresnel stand l6 comes into contact with the magnet 151 provided on a part of the U-shaped upper member 5l of the projection means 4l, thereby moving the Fresnel stand l6 into the U-shaped member 5l. It is adsorbed to the concave part of 51. The other configurations are the same as the first embodiment shown in FIG. <Effects of the Invention> According to the present invention, the Fresnel table having a Fresnel lens is made rotatable with respect to the document table via the support member, so that the optical axis of the projection means, the central axis of the Fresnel lens, and The nine axes of the reading means can be easily aligned, and the image information projected onto the document table and IffiL. , it is possible to achieve an image reading device that can read images with high accuracy by making the reading density of the sm information of the original document uniform.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of the main parts of the first embodiment of the present invention, the second and third embodiments of the present invention, and FIG.
The figure is an explanatory diagram of a part of FIG. 1, FIGS. 4 and 5 are schematic diagrams of main parts of second and third embodiments of the present invention, and FIG. 6 is a schematic diagram of a conventional image reading device. In the figure, 41 is a projection means, 42 is a reading means, 2 is a Fresnel lens, 3 is a mirror, 4 is a projection lens, 5 is an original support stand, 6 is a light source, 7 is an original stand, 8 is a concave chisel, and 9 is a condenser lens. , 10 is the projection table,! 1 is a part of the first mirror, l2 is a part of the second mirror, 13 is a reading element,
14 is an imaging lens, 15 is a mirror stand, l6 is a Fresnel stand, 151 and 161 are magnets 2, l53 is a positioning bin, and 5o is the main body of the image reading fil1. Figure 2 Figure 3 Figure 5

Claims (1)

[Claims] (1) When a document placed on a document table is illuminated by an illumination device and image information about the document is read by a reading device, or image information about the document projected by a projection device onto the document table is read by the reading device. When reading, a Fresnel stand having a Fresnel lens positioned on the side of the reading means is configured to be rotatable on the surface of the Harako stand via a support member, and the image information is read through the Fresnel lens. An image reading device characterized in that: