JP2529794Y2 - Transmission type reader - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a transmissive reading apparatus, and in particular, scans a transmissive original by an optical scanning system that receives scanning light by a photoelectric conversion element and holds the original on which the original is placed. The present invention relates to a transmissive reading device in which a part moves.

[Conventional technology]

6 and 7 are a plan view and a side perspective view showing an example of a conventional transmission type reading apparatus.

In a conventional transmissive reading device 21, a light source unit 22 that irradiates a line on a top surface of the device with a laser as a light source, and a transparent original 23
And a transmissive reading unit 25 that scans the transmissive original 23 with a light beam emitted from the light source unit 22 and detects transmitted light. Covered.

A transparent document 23 is set by a document table 27 of the document holder 24 and a document pressing plate 28 pivotally supported at one end of the document table 27 so as to be openable and closable. The original mounting table 27 and the original pressing plate 28 are made of a transparent glass body so that light is transmitted when the transparent original 23 is set. The document holding unit 24 is moved in the direction of the arrow a by a drive system 30 driven by a motor 29, and scans the transparent document 23 with a light beam emitted from the light source unit 22 in a line.

The transmission reading unit 25 includes a diffusion plate 31 for diffusing the scanning light.
, A cylindrical lens 32 for condensing light, a group of optical fibers 33 for transmitting light, and a photoelectric conversion element 34, and reads scanning light. When reading is completed, motor 29
Is reversed, and the document holding unit 24 moves in the direction of arrow b and returns to a predetermined position.

[Problems to be solved by the invention]

In the above-described conventional transmissive reading apparatus, since the document holding unit is formed of a transparent body and moves, disturbance light (for example, sunlight or a fluorescent lamp) easily enters the inside of the apparatus. The output electric signal has a disadvantage that the S / N ratio is reduced due to the influence of the fluctuation of the offset voltage and the disturbance light noise.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a transmission type reading device that can scan without being affected by disturbance light.

[Means for solving the problem]

According to the present invention, a document holding unit for mounting a transparent document, a light source unit for irradiating the transparent document with light from a light source from above the document holding unit, and a light source unit opposite to the light source unit with the document holding unit interposed therebetween are mounted. And a transmissive reading unit having a photoelectric conversion element for reading the transmissive document, wherein the light source is a laser beam and the document holding unit is covered at a position other than the light source unit. A color transparent plate having a spectral characteristic that does not transmit the wavelength of the light source, and a color filter that is placed in front of the light receiving surface of the photoelectric conversion element and has a spectral characteristic that transmits only a wavelength near the wavelength of the light source. I have.

〔Example〕

 Next, the present invention will be described with reference to the drawings.

1 and 2 are a plan view and a side perspective view showing an apparatus configuration of an embodiment of the present invention, and FIG. 3 is a cross-sectional view showing an optical fiber group, a color filter, and a coupling portion of a photoelectric conversion element in the embodiment. 4 and 5 are graphs respectively showing the spectral characteristics of the color transparent plate and the color filter of this embodiment.

In the transmission type reading apparatus 1 of the present embodiment, a light source unit 2 for irradiating a line with a laser as a light source, an original holding unit 4 for setting a transparent original 3, and a transmission reading unit 5 for detecting transmitted light are arranged on the upper surface of the apparatus. And is covered with a device cover 6. The document placing table 7 and the document holding plate 8 of the document holding unit 4 are made of a transparent glass material.

A transparent color plate 17 (for example, an acrylic plate) is pivotally supported at one end of the apparatus cover 6 so as to be openable and closable, and covers the glass of the document holding section 4. The transmission reading unit 5 includes a diffusion plate 11 for diffusing scanning light, a cylindrical lens 12 for condensing light, and an optical fiber group 13 for transmitting light.
A color filter 18 is provided between the photoelectric conversion element 13 and the photoelectric conversion element 14.
As shown in the figure, they are connected via a light shielding member 16. Color transparent board 17
As shown in FIG. 4, has a spectral characteristic which is not transparent to the light source wavelength lambda _o, also the color filter 18, as FIG. 5, a spectral characteristic of transmitting only near the light source wavelength lambda _o I have.

When a scanning command signal is input to the transmission type reading apparatus 1 of this embodiment having such a configuration, a driving system driven by a motor 9 is used.
The movement of the document holding unit 10 is controlled to move the document holding unit 4 in the direction of arrow A. The transparent original 3 is irradiated with a line by the light source unit 2 at a position deviated from the color transparent plate 17, and the scanning light reaches the photoelectric conversion element 14 through the transmission reading unit 5 and becomes an image signal. When the reading is completed, the motor 9 rotates in the reverse direction, and the document holding unit 4 moves in the direction of arrow B and returns to a predetermined position. During this time, color transparent plate
Reference numeral 17 does not move together with the document holder 4, and only the document holder 4 moves below the light source unit 2 when reading the transparent document 3 by line irradiation of laser light, and the color transparent plate 17 is fixed at the initial position. Left.

Color transparent plate 17 which covers the document holder 4, as shown in FIG. 4, has a spectral characteristic which is not transparent to the light source wavelength lambda _o, whereas, prior to the color filter 18 of the photoelectric conversion element 14, the fifth
As shown, it has a spectral characteristic of transmitting only near the light source wavelength lambda _o. By adopting such a structure, a color transparent plate
Disturbance light 15 passing through 17 enters the apparatus with a wavelength component other than near the light source wavelength due to the optical filter effect, and propagates from optical fiber group 13 through light diffusion plate 11 and cylindrical lens 12 of transmission reading unit 5. Then, the light does not reach the photoelectric conversion element 14 due to the color filter 18.

Since the color filter 18 passes only near the light source wavelength lambda _o, in the scanning light having passed through the transmitting original 3 is diffused by the optical diffusion plate 11 of the transmission reading unit 5, a cylindrical lens
The light is condensed by 12 and guided by the optical fiber group 13, passes through the color filter 18, reaches the photoelectric conversion element 14, and becomes an image signal.

[Effect of the invention]

As described above, according to the present invention, by providing the color transparent plate covering the document holding unit and the color filter inserted in front of the photoelectric conversion element, the color filter is not affected by disturbance light from outside the apparatus, and the color filter is not affected. The use of the transparent plate has the advantage that the transparent document set in the document holder can be visually checked by the operator after setting the document and during scanning. In addition, there is an effect that the glass of the document holder can be protected and dust can be removed. . In addition,
In the present invention, a laser beam is used as a light source for irradiating the line, but a similar effect can be obtained by using an LED (emitting diode) instead.

[Brief description of the drawings]

1 and 2 are a plan view and a side perspective view showing an apparatus configuration of an embodiment of the present invention, and FIG. 3 is a cross-sectional view showing an optical fiber group, a color filter, and a coupling portion of a photoelectric conversion element in the embodiment. 4 and 5 are graphs respectively showing the spectral characteristics of the color transparent plate and the color filter of the present embodiment, and FIGS. 6 and 7 are plan views and an apparatus configuration of an example of a conventional transmission system reading apparatus. It is a side see-through view shown. 1,21 ... Transmissive reading device, 2,22 ... Light source unit, 3,23 ... Transparent document, 4,24 ... Document holding unit, 5,25 ... Transparent reading unit, 6,26 ... Device cover, 7,27 ... Document loading table, 8,28… Document holding plate, 9,29…
Motor, 10,30 drive system, 11,31 diffusion plate, 12,32 cylindrical lens, 13,33 optical fiber group, 14,34 photoelectric conversion element, 15 disturbance light, 16 light shielding member, 17 ... Color transparent plate, 18 ... color filter.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazuaki Takahashi 3-20-4 Nishi-Shimbashi, Minato-ku, Tokyo Japan Electric Engineering Co., Ltd. Examiner Hideo Taguchi (56) References JP-A-63-40449 (JP, A)

Claims (1)

(57) [Scope of request for utility model registration] An original holding unit for mounting a transparent original, a light source unit for irradiating the transparent original with light from a light source from above the original holding unit, and a light source unit opposite to the light source unit with the original holding unit interposed therebetween. In a transmission type reading apparatus having a transmission reading unit equipped with a photoelectric conversion element that reads the transmission original, the light source is a laser beam, and the original holding unit is located at a position other than the light source unit. A color transparent plate that is provided to cover and has a spectral characteristic that does not transmit the wavelength of the light source, and a color filter that is placed in front of the light receiving surface of the photoelectric conversion element and has a spectral characteristic that transmits only a wavelength near the wavelength of the light source. A transmission type reading device, comprising: