JP2003337385A - Image reader and illuminator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a means for infrared ray reading at a high speed in the case of using the infrared rays for removing dirt and flaw on a transmitted original and reading a black-and-white reflected original at the high speed. <P>SOLUTION: A dedicated read sensor is provided to read with the infrared rays, is a black-and-white sensor and is used to read a black-and-white reflected image at high speed when reading the black-and-white reflected original. <P>COPYRIGHT: (C)2004,JPO

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 for reading image information of a transparent original such as a photographic film and an illuminating device used therein.

[0002]

2. Description of the Related Art Conventionally, there is an image reading apparatus which irradiates a transparent original and reads the image as shown in US Pat. No. 5,038,227. A conventional image reading apparatus will be described with reference to FIG.

There is an image reading apparatus proposed in Japanese Patent Laid-Open No. 2001-298593, and the contents of the proposal will be described below.

FIG. 5A is a sectional view of the image reading apparatus, and FIG.
(B) is a perspective view. The light guide plate 701 has a rod-shaped fluorescent tube 700 attached to its end, and is arranged so as to be horizontal with respect to the platen glass 702 on which a document is placed. The light guide plate 701 is a resin light diffusion panel, and is configured to diffuse the light emitted from the fluorescent tube 700 and emit the light in a planar manner.

The platen glass 702 is an original table on which a transparent original such as a photographic film is placed. The transparent original placed on the platen glass 702 is sandwiched between the light guide plate 701 and the platen glass 702. Fixed. The CCD 703 is a line-shaped image sensor and is for converting image information into an electrical image signal. The image pickup optical system 704 is for optically guiding the image information of the transparent original to the CCD 703.

A carriage 705 has a CCD 703 and an image pickup optical system 704 mounted thereon and is configured to be movable in the sub-scanning direction along guides 706 and 707. Then, when the entire transparent original is illuminated in a plane by the light guide plate 701,
The image information of the transparent original is transferred to the CCD via the image pickup optical system 704.
Read by 703. And the carriage 705
By moving in the sub-scanning direction, the entire image of the transparent original is sequentially read.

However, in the above-mentioned conventional image reading apparatus, when dust such as dust is present on the transparent original or there is damage (scratch) on the film surface, the dust or even scratches are read. Therefore, it was not possible to prevent deterioration of the image due to dust or scratches.

In order to solve the above-mentioned problems, the transmitted light from the transparent original is imaged on the solid-state image pickup device by the image forming optical system,
In an image reading apparatus for reading image information of the transparent original, a first light source that mainly emits light in a visible region, a second light source that mainly emits light in an infrared region, and the first light source.
And a light guide plate having a second light source arranged on an end face, for guiding incident light from the end face in a planar shape to emit light substantially uniformly, and light from the first light source guided by the light guide plate. An image reading unit that reads image information recorded on the transparent original based on an image signal obtained by making the transmitted light that illuminates the transparent original incident on a solid-state image sensor, and is guided by the light guide plate. Defect information reading means for reading defect information on the transmissive original obtained by illuminating the transmissive original by illuminating the transmissive original with light from the second light source, and the image information reading An image reading apparatus comprising: a correction unit that removes the defect information read by the defect information reading unit from the image information.

[0009]

However, in the above configuration, the first light source in the visible light region is turned on, the visible light is read first, and then the second light source emitting infrared light is turned on. Then, the infrared light reading is performed and the reading is performed twice.

Further, the above infrared light uses an infrared LED, but the amount of light emitted is small, so that the exposure time of a solid-state image pickup tube (hereinafter referred to as CCD) such as CCD is lengthened,
You have the required infrared output.

Usually, the exposure time is three to four times that of visible light, and therefore the infrared light reading time is very long.

Further, when reading a black-and-white reflective original, one color of the reading sensor of each color of red, green and blue is used for reading.

[0013]

In order to solve the above problems, the CCD sensor for reading each color is added to a normal red reading sensor, a green reading sensor, and a blue reading sensor, and is used for infrared reading. The infrared light reading time is shortened by using a CCD having a configuration in which the CCD sensor is arranged.

Further, since the infrared reading CCD sensor is for black and white reading, it is not necessary to use a color filter, and the sensitivity of the CCD can be increased about twice.
The storage time can be halved.

When a black and white image is read on a reflective original, the sensitivity is low and the reflective black and white image cannot be read at high speed because the color sensor using the color filter is used for reading. Therefore, by using the black-and-white reading sensor, it becomes possible to read a reflected black-and-white image at high speed.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION (First Embodiment) An image reading apparatus of the present invention will be described with reference to FIGS.

FIG. 1 is a schematic perspective view of the image reading apparatus of this embodiment. As shown in FIG. 1, the image reading device 1 includes
A transparent illumination unit 2 for illuminating a transparent original such as a developer photographic film is rotatably attached by a hinge portion 18 for illuminating the transparent original. A planar light source 3 to be described later is attached to the transillumination unit 2 by being fixed on the unit lower cover 5 with screws or the like. The planar light source 3 is protected by a light source transparent protection member.

A platen glass 13 for placing a document to be read is provided on the main body of the image reading apparatus 1. When reading a photographic film, a light shielding sheet 4 is placed on the platen glass 13. The shading window 4a provided in the light shielding sheet 4 is a window for measuring the shading, and the transparent original placing portion 4b is a place for placing a transparent original.

FIG. 2 is a schematic perspective view of the transillumination unit 2, and FIG. 3 is a sectional view of the planar light source 3. Surface light source 3
Is composed of a light guide plate 19, a transparent original reading lamp 6 such as a fluorescent lamp or a xenon lamp, and a dust and scratch detection LED substrate 7 having emission intensity only in the infrared region. The transparent original reading lamp 6 and the dust flaw detection LED substrate 7 are arranged on different sides of the light guide plate 19 which are orthogonal to each other.

Here, the dust and scratch detection LED substrate 7 is composed of a plurality of infrared LED chips 7a and an LED substrate 7b having a light emitting opening 7c at a position corresponding to the infrared LED chips 7a. The outer LED chip 7a is connected to the infrared LED from the side opposite to the surface of the LED substrate 7b facing the light guide.
The light emitting portion of the chip 7a is arranged so as to be inside the light emitting opening portion 7c of the LED substrate 7b, and the light guide facing surface of the LED substrate 7b is formed flat. Also the LED
It is possible to improve the brightness of the entire planar light source 3 by reflecting the light more efficiently by printing the surface of the substrate 7b facing the light guide body in white.

Next, the LED substrate 7 for detecting dust spots is covered with a reflection sheet 10 which is bent at a predetermined position as shown in FIG.
It is closely fixed to the end face and can efficiently guide infrared light to the light guide.

The light guide plate 19 guides the illumination light L in the two-dimensional longitudinal direction by internal reflection, and the light guide section 11.
It is composed of a reflection sheet 10 for reflecting the light guided by the reflection sheet 10 toward the original and a diffusion sheet 12 for uniformizing the light reflected by the reflection sheet 10. It is a light guide diffusion panel made of resin.

The light L emitted from the transparent original reading lamp 6 and the dust flaw detection LED board 7 is reflected by the reflection sheet 1.
The light guide portion 11 advances in the two-dimensional longitudinal direction while being reflected between 0 and the diffusion sheet 12. And diffusion sheet 12
A part of the light incident on is diffused, and the entire light guide plate 19 uniformly emits light in a planar manner.

LE is extended by extending the end of the light emitting surface of the light guide of the reflection sheet 10 to the vicinity of the image reading area.
By preventing the direct light of D from directly entering the image reading area, the entire light guide body 19 can more uniformly emit light in a planar shape.

FIG. 4 is a sectional view of the image reading apparatus of this embodiment. The carriage 9 provided in the image reading apparatus 1 includes a reflection original illumination lamp 20, a CCD line sensor 1
06, the lens 105 and the reflection mirror 16 are mounted respectively. The CCD line sensor 106 converts an image into an electric image signal, and has a plurality of image pickup elements arranged in a straight line. The carriage 9 is fitted to the carriage guide shaft 8 and is movable in the sub scanning direction.

Next, the reading operation of the transparent original will be described.

First, the illumination lamp 20 for the reflective original and the LED board 7 for detecting the dust flaw are turned off, and the lamp 6 for the transparent original is used.
By turning on, the entire surface light source 3 is made to emit light,
By moving the carriage 9 in the sub-scanning direction, the image information on the transparent original is projected onto the CCD 106 via the reflection mirror 16 and the lens 105.

Then, the reflection original illumination lamp 20 and the transmission original illumination lamp 6 are turned off, and the dust and scratch detection LED substrate is turned on to cause the entire surface light source 3 to emit light.
By moving the carriage 9 in the sub-scanning direction, dust on the transparent original through the reflection mirror 16 and the lens 105,
A scratch or the like is projected on the CCD 106. Since the light from the LED substrate for detecting dust and scratches is only the infrared component,
A transparent original such as a positive one transmits this infrared component regardless of the image (photosensitive image), and an image of dust, dust, scratches, or the like that physically blocks the optical path is projected on the CCD 14 as a shadow, which is excellent. It is possible to detect dust scratches.

By subjecting both the dust-scratch detection image thus obtained and the above-described transparent original read image to image processing, the original region around the dust-scratch detection region recognized by the dust or scratches recognized on the dust-scratch detection image is read. By interpolating from the image, it is possible to read a good transparent original image from which the effects of dust and scratches have been removed.

Next, the sixth shows the structure of a conventional 2400 dpi three-color CCD.

The pixel size of this CCD is 4 um * 4 um
At 1200 dpi (A4 size 10680 pixels)
Are arranged for 6 lines, 2 lines per color are used, the second line is shifted by a half image (2 um) and 16 um is arranged, and the data of these 2 lines are combined to 240
0 dpi optical resolution is obtained.

The distance between the respective colors is 64 nm, and this physical distance is corrected by a delay circuit or the like and processed by the control board shown in FIG. 8 or software on the personal computer side so as to match the same reading position.

FIG. 6 shows three types of conventional red, green and blue colors.
The structure of a color reading CCD is shown.

FIG. 7 shows a configuration in which a black-and-white line is added, which is arranged at a distance of 80 μm from the red line.

Next, a method of reading a reflective original using a black and white sensor will be described with reference to FIG.

In FIG. 8, 201 is a CCD, 203 is a cold cathode lamp dimming circuit, 204 is an AMP for amplifying the CCD output, 205 is an A / D conversion circuit for converting an analog signal into a digital signal, and 206 is an image for shading. A shading RAM 207 for storing data, a shading correction circuit 207 for shading, a peak detection circuit 208 for detecting a white peak of a main scanning white reference, 209
Is a gamma conversion circuit that performs gamma conversion. G. 210 is for converting B into 16-bit input, 16-bit output or 16-bit input, 8-bit output. Reference numeral 210 is an offset RAM for adjusting the offset of the CCD and a buffer RAM 21 also serving as a communication buffer.
Reference numeral 1 is a buffer RAM control and call packing control circuit, 212 is an interface circuit, a USB 2.0 interface circuit, 213 is an external device such as a personal computer, 214 is a timing signal generation circuit, 215 is a ROM for controlling the scanner, It is a microprocessor with built-in RAM.

Next, the actual signal flow will be described. The document illuminated by the cold cathode lamp 4 passes through the reflection mirror and the lens and projects a document image on the CCD. The projected image is converted into an analog signal by the CCD. The signal is 20
It is converted into a digital signal through the amplifier of No. 4 and the A / D conversion circuit of 205. Shading correction is performed on the digital signal by the shading circuit, and the digital signal enters the gamma conversion circuit 209 for gamma conversion. The peak detection circuit 208 detects the white reference in the main scanning direction at the peak when the shading data is acquired, and the CPU 215 confirms whether or not the light quantity value of the cold cathode lamp is stable. Further, the lamp is dimmed by the cold cathode lamp dimming circuit 203 to compensate for the fluctuation.

At this time, when the shading RAM 206 stores the shading data in a stable state and the non-calibration mode is selected, the read start signal is received from the external device 213 using the stored data. If you do not calibrate,
The image reading is controlled by using the shading data recorded in advance. The gamma-converted data is offset-adjusted by the buffer RAM 210 in the buffer control circuit 211 and converted to the same position, and also operates as the buffer RAM of the interface circuit 212. Image data is sent from the US2.0 interface circuit to an external device.

The interface circuit of 212 is USB
In 2.0, the image data of the host computer of the external device is transmitted, the instruction of the host computer is accepted,
The CPU at 215 receives the command.

Reference numeral 215 denotes, for example, a CPU in the form of a microcomputer, which has a ROM 215A storing a processing procedure and a work RAM 215B, and controls each part according to the procedure stored in the ROM.

Next, when the external device gives an instruction to read the black-and-white reflective original, the reflective original light source 202 is turned on, and the black-and-white image is read by the black-and-white reading sensor. The signal flow in FIG. 8 is set, for example, so that the single color mode only of the red mode is selected and each circuit can be read at high speed. Since the black-and-white sensor has high sensitivity, the same CCD output can be stored in a shorter time as compared with the case of reading with a color sensor, so that a black-and-white image can be read at high speed.

Next, the control flow of FIG. 8 will be described.

In step S1, a reading start instruction from the host, an instruction for each parameter, a resolution reading mode, and the like are given via the I / F. In step S2, it is determined whether the reading of the reflective original or the reading of the transparent original is performed according to the above instruction.

In step S3, the visible light lamp is turned on when the transparent original is read. In S4, a color reading operation is performed using the R, G, B reading sensors. In S5, the visible light lamp is turned off. In S6, the infrared LED is turned on and the infrared long optical path correcting glass 107 is removed from the optical path using a solenoid (not shown).

In step S7, an infrared image is read using the monochrome reading sensor. In step S8, the infrared LED is turned off, and the correction glass 107 is returned to the optical path. In S9, the visible light lamp is turned on. In S10, the host corrects the dust information of the visible light information based on the infrared light information. In S11, the reflection original reading lamp is turned on.

In step S12, it is determined whether color reading or monochrome reading is performed. In S13, the reading scanning of the reflection original is performed using the R, G, and B lines. In step S14, the black-and-white sensor is used to read the black-and-white reading of the reflection original.

[0047]

As described above, according to the present invention, infrared image reading can be performed at high speed.

Further, by using a black-and-white sensor installed for infrared light for the reflection original, the black-and-white image of the reflection original can be read at high speed.

[Brief description of drawings]

FIG. 1 is a schematic perspective view of an image reading apparatus according to this embodiment.

FIG. 2 is a schematic perspective view of a transillumination unit according to the present embodiment.

FIG. 3 is a schematic sectional view of a transillumination unit according to the present embodiment.

FIG. 4 is a schematic cross-sectional view of the image reading apparatus according to the present embodiment.

FIG. 5 is a schematic sectional view and a perspective view of a conventional image reading device.

FIG. 6 is a diagram showing a configuration of a conventional CCD of the CCD line sensor 106.

FIG. 7 is a diagram showing a configuration in which a monochrome line of the CCD line sensor 106 is added.

FIG. 8 is a diagram showing a control unit.

FIG. 9 is a diagram showing a control flow.

[Explanation of symbols]

1 Image reading device 2 Transmission illumination unit 3 surface light source 4 light-shielding sheet 5 unit lower cover 6 Transparent original irradiation lamp LED dust detection board 7a Infrared LED chip 7b LED board 7c Luminous aperture 8 Carriage guide shaft 9 carriage 10 reflection sheet 11 Light guide 12 diffusion sheet 16 Reflective mirror 17 Light source protection member 18 hinge 19 Light guide plate 202 Light source for reflective original 13 Platen glass 105 lens 106 CCD line sensor 107 Infrared optical path correction glass

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H04N 1/04 101 H04N 1/04 101 1/19 102 103E F term (reference) 2H106 AA01 AA33 AA41 AB81 2H109 AA02 AA13 AA26 AA51 AB41 AB61 5B047 AA01 AB04 BB03 BC05 BC09 BC12 BC14 BC30 CA19 CB22 DC09 5C051 AA01 BA03 DA03 DB01 DB07 DB22 DB24 DB28 DC02 DC04 DC05 DC07 DE13 DE29 EA01 FA07 DA02 FA10 DA21 FA21 DA21 DA21 DA21 DA02 DA16 DA21 DA02 DA04 DA11 DA02 DA11

Claims (3)

[Claims] 1. An image reading device for reading original information by forming an image of transmitted light from a transparent original recording medium on a solid-state image pickup device by an imaging optical system, wherein a transparent original illumination unit emits light at least in a visible region. And at least one second light source in which a plurality of infrared LEDs that emit light only in the infrared region are arranged in series on the infrared LED substrate, and these light sources are arranged on the end face. A light guide plate for reflecting the incident light from the end face substantially uniformly over the entire plane and a reflection sheet, and transmitting from the transparent original recording medium based on the light from the first light source. Based on light from the second light source, an image reading unit that guides light to the solid-state imaging device, reads image information recorded on the transparent recording medium based on a signal obtained from the solid-state imaging device, and light from the second light source. The transparent original recording medium Defect information reading means for guiding the transmitted light from the solid-state image sensor to defect information of the recording medium itself existing in the transparent original recording medium other than the recorded image information based on the signal obtained from the solid-state image sensor. An image reading apparatus having a correction unit for removing the defect information read by the defect information unit from the image information read by the image information reading unit, wherein the solid-state imaging device includes a plurality of reading sensors for reading a visible light region. An image reading apparatus having a read sensor dedicated to reading infrared information from the infrared LED and installed on the solid-state imaging device. 2. The image reading apparatus according to claim 1, wherein the infrared information reading sensor in the fixed image pickup device is a monochrome image reading sensor. 3. The light source for reading a reflective original according to claim 1, wherein the reflective original is provided in the image forming optical system.
An image reading apparatus, wherein an image is formed on a reading sensor of the solid-state imaging device, and a black-and-white image of a reflective original is read by using the black-and-white reading sensor when reading a reflective original.