JPS5980059A - Multi-color original reader - Google Patents

Abstract

PURPOSE:To avoid the effect of variance in flash tubes and to obtain the picture color information having faithful color reproducibility, by using the monitor information on the light emission quantity of the flash tube of an optical system to normalize the color information of read pictures. CONSTITUTION:A multi-color original is put on an original reading board and then illuminated by a flash illumination means containing xenon tubes XR, XG and XB which serve as flash tubes. The reflected light given from the original is read by a CCD image sensor 4 serving as a picture reading means. The picture color information read synchronously with lighting of the tubes XR, XG and XB is stored individually to a storage means 5 for picture color information. At the same time, a monitor means 6 monitors the light emission quantity of the tubes XR, XG and XB respectively. Then the monitor information given from the means 6 is stored individually to a storage device 7 for monitor information. Based on the monitor information given from the means 7, an information processing means 8 processes each picture color signal stored in the means 5. Thus it is possible to prevent the effect of variance in tubes XR, XG and XB respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a multicolor document reading device used in facsimiles, copying machines, and the like. .

BACKGROUND ART A conventionally known technique is disclosed in Japanese Patent Application Laid-Open No. 164658/1983. Here, a technique is disclosed in which a flash tube is used as a light source and the flash tube is turned on for a short period of time in order to increase the speed at which a precision image reading element reads a document. It has been suggested that in addition to two-color reading, which separates and reads the red and black parts of a document, it can also be applied to multi-color reading devices, which sequentially turn on multiple illumination lights to separate and read multiple types of colors. There is.

However, in general, there is variation in the amount of light emitted from a flash tube (D), and even if it is not a problem in reproducing a simple black or original document, the above-mentioned variation in the amount of light emitted from a multicolor original requires uniformity in the separated color information. There is a drawback that it is not possible to faithfully reproduce a multicolor image exactly as in the missing original.

OBJECT OF THE INVENTION Therefore, it is an object of the present invention to provide a multicolor original reading device using a flash tube, which can obtain image color information with faithful color reproducibility even if there are variations in the amount of light emitted from the flash tube. It is an object.

SUMMARY OF THE INVENTION A first method for individually storing image color information from an integral type image reading means such as a CCD according to lighting of each flash tube.
a storage means for monitoring the amount of light emitted from the Fra-Souille tube, a second storage means for individually storing monitor information from the monitor means, and a monitor information based on the monitor information from the second storage means. and information processing means for processing the image color information from the first storage means, the information processing means for processing the image color information from the first storage means, and normalizing each image color information with the monitor information of the light emission amount of each flash tube, thereby determining the light emission amount of the flash tube. It is characterized by avoiding the influence of variations in

Example FIG. 1 is a schematic diagram of an optical system according to an embodiment.

(1) shows a multicolor original (6) placed on a transparent original table (2).
) flash illumination means for illuminating (4) in a flash-like manner;
) is an integral type image reading means for reading a reflected light image from the original (6). The flash illumination means (1) is equipped with six white light xenon tubes (XR), (XG), (XB) as flash tubes for exposure, and a red filter (FR) is installed at the light emission position of each xenon tube. , green filter (F
G), a blue filter (FB) is provided. Above these filters, there is a condenser lens (CLl), a diffuser plate (D) consisting of a lenticular lens, for example, which magnifies the linear light source into a planar shape, and a diffuser plate (D), which makes the light beam directional toward the original (6). For example, condenser lenses (CL2) made of Fresnel lenses are sequentially arranged.

A condenser lens (CLl) and a diffuser plate (D) are provided on the lower surface of the condenser lens (CL2) (111) so that the illuminance is uniform regardless of its position. Tube (XR), (XG), (
A monitoring light-receiving element for monitoring the amount of light emitted by XB), which is made of, for example, a photodiode, and is provided on the lower surface side of the condenser lens (CL2).

With this configuration, each xenon tube (XR).

When (X, G) and (XB) are lit, the lens (CL2
) emits flash lights of different colors, red (R), green (G), and blue (B), illuminating the multicolor original (or the like). This reflected light image is from a xenon tube (XR).

It is read by the CCD image sensor (4) in synchronization with the lighting of (XG) or (XB).

FIG. 2 shows a block diagram of the circuit section of the embodiment.

FIG. 3 is a time chart of the circuit section. In Fig. 2, ζVH) is a power supply line to which a DC high voltage, for example 600V, is supplied, and the switch (R8) of the control terminal material,
It is connected to xenon tubes (XR), (XG), and (XB) via (GS) and (B'S'), respectively.

(5) is a first storage means that individually stores image information read from the CCD image sensor (4) according to the lighting of each xenon tube, and is a digital memory (ME), (ME
') + (ME6). (6) is a monitoring means for monitoring the amount of light emitted from the xenon tube, which includes a monitoring light receiving element (MO), an analog switch (As 1), and a capacitor (C3').

An operational amplifier (OAl) (hereinafter referred to as an operational amplifier) is provided. (7) is a second storage means for individually storing the monitor information from the monitor means (6), and is composed of capacitors (C4), (C5), and (C6). (8) is
This information processing means performs arithmetic processing on each image color information given from the first storage means (5) based on the monitor information input from the second storage means (7). and,
(9) is a digital control circuit that controls the operation of the entire circuit shown in FIG. ).

The operation of the circuit shown in FIG. 2 will be explained together with the time chart shown in FIG. 6.

The terminal (, JR) of MPU (9) is High//
(hereinafter abbreviated as "H"), the switch (R8) becomes conductive, and the output of the OR circuit (oRl) becomes rHJ. After a certain period of time [1], the output of the delay circuit (DLl) becomes “H”.
”, the one-shot circuit (O81) outputs a pulse of I”HJ, the trigger circuit (TR) operates, and the red xenon tube (XR) starts emitting light. On the other hand, the delay circuit (DLl) When the output reaches 1B, the delay circuit (DL2
) output becomes “H” and the one-shot circuit (O82)
outputs a 'Low' pulse with a time width t6 longer than the time required for the xenon tube to fully emit light (temporarily selected within a certain range depending on the characteristics of the CCD (4)). (<Low' is hereinafter abbreviated as rLJ).

On the other hand, an "H" pulse from the one-shot circuit (O81) is transmitted to the CCD image sensor (4), and the light-receiving charge of the CCD is reset by this pulse.

Immediately after reset, charge accumulation of the reflected light image starts. At the same time, the "L" signal from the one-shot circuit (O82) is given to the analog switch (ASl), the analog switch (ASl) becomes non-conductive, and the capacitor (O6
), the integration of the output type four streams from the monitor light receiving element (MO') is started.

Here, integration is not performed while the trigger circuit (TR) is operating, but this is because the trigger circuit (TR) is connected to a transformer (a high voltage of, for example, 3KV is instantaneously supplied to the xenon tube).
This is to avoid the influence of noise generated from the inductance component. Now, when the trigger circuit (TR) operates, the xenon tube (xR) is low in B.D. Then, resistor (R3:), capacitor (C1), capacitor (C2)1. Resistance (R4
), a differential circuit consisting of
conducts, and the light emitting state of the xenon tube (XR) is maintained.

When the integrated voltage of the capacitor (C6) in the monitoring means (6) overlaps with the output voltage of the variable voltage source (VE), the output of the comparator (ACl) is inverted to rHJ. As a result, an rHJ pulse is output from the one-shot circuit (os4). When the thyristor (SC2) is made conductive by this pulse, the thyristor (SC2) is turned on by the capacitor (C1).
The anode of 01) is lowered below Alsumi level. Cyrisk (S01) becomes non-conductive. Xenon tube (XR)
When the capacitor (C1) is charged through the diode (Dl), the xenon tube (XR) stops emitting light. In this way, the monitor 8 (6) also has an exposure control function that controls the light emission of the xenon tube based on the monitor information.

On the other hand, when the rHJ inversion signal from the comparator (ACl) is applied to the input terminal (11) of MPU (9), an "H" pulse is output to the output terminal (02) after a predetermined time C4. This "H" pulse is used on the one hand to store monitor information, and on the other hand to the CCD (4).
The transfer signal is used to transfer the accumulated charge to the transfer gate. As shown in Figure 6, a xenon tube (XR
) is delayed by the amount of time () after the light emission stops in order to sufficiently cover the afterglow (Z).Also, even if the time (C3) required for the full emission of the xenon tube (XR) has elapsed, the input When the rHJ signal is not input to terminal (11),
Signal after a certain period of time (based on time monitoring by MPU9)
It is designed to output an "H" pulse to the output terminal (02).

Now, the "H" pulse from the output terminal (O2) of the MPU (9) is input to one input of the AND circuit (, ANl), and the other input is FH and J of the terminal (JR), so rH
J pulse is output and flip-flop (FF1)
Set. Riki Okayama becomes "L" and turns off the analog switch (Ac1).

As a result, the integrated voltage of the capacitor (C6) is held in the capacitor (C4). On the other hand, CCU (4) K terminal (0
) after the rHJ pulse of M P U (9
) Transfer layer signal (CCD
(If 41 is a 6-phase drive, a 6-bit l- signal) is used to output the accumulated weight of the CCD (4).

The output data is passed through a low-pass filter (ME
l) given. Of course, as shown in FIG. 4, the input section of the storage area (ME1) includes an analog switch that is turned on/off by the shift pulse φ8H of the CCD (4), an operational amplifier for amplification, and an input section from the shift pulse φ8H. It is equipped with an A/D converter to which a slightly delayed trigger pulse φAD for A/D conversion is input, and converts an analog signal into a digital signal. The pixel information converted into digital signals is regularly stored in a memory section (MC) having a predetermined capacity. When output, it passes through the output buffer (13).

When the recording of image information by the light emitted from the red xenon tube (XR) is completed, the MPU (9) then sets the terminal (JR) to rLJ, and after a predetermined time, sets the terminal (JC) to rHJ. , switch circuit (C81).

(C82) is made conductive. Commutation capacitor (C1)
is rapidly charged via the resistor (R2). and,
When charging is completed, the terminal (JC) is set to "L" to prepare for the next light emission, that is, light emission from the green xenon tube (XG).

When the terminal (JG) of MPU (9) rises to "H", the xenon tube (XG) starts emitting light in the same way as the process described above, and the condenser 'J' (C3) receives the integral for monitoring. Then, charges corresponding to the green reflected light image are accumulated in the CCD (4). Then, the monitor information is stored in the capacitor (C5) in the same manner as the timing control described above, and the recorded image information is transferred to the storage area (C5) via the analog switch (Ac1).
M'E 2 ).

After setting the terminal (JC) to rHJ for a predetermined time to prepare for the next light emission, the terminal (JB) of MPU (9) goes to rHJ.
Stand up to J. The blue xenon tube (XB) emits light. Similar to the previous process, monitor information is transferred to the capacitor (C6
), and the blue image information is stored in the analog switch (Ac
7) is stored in the storage area (VE6).

In FIG. 6, the light emitting time of the edge xenon tube (XG) is shorter than the others, but this is because visibility is taken into consideration.

When the last blue light is emitted, the terminal of MPU (9) (
04) provides four pulse signals to the information processing device (8).

The processing unit is activated by this pulse signal and receives R, , G, which are input from capacitors (C4), , (C5), and (C6) via buffers (OA2), (OA6), and (OA4), respectively. B monitor information and each storage area (MEL
), (VE2), and (VE6) to output the original image signal based on the R, G, and B image information. That is,
As shown in the block diagram of FIG. 5, the monitor information is once A/D converted and then stored in a separate digital memory.

Based on the contents of each memory, the digital image information of R, a, and 13 is divided, that is, normalized. The image information normalized using the monitor information does not include any error information due to variations in the light emission of the xenon tubes.

This normalized R, G, and B image information is further subjected to appropriate processing and then output to another device to which this reading device is applied. Other devices include fax machines, color copiers, and laser printers.

It is also possible to use a file data storage bag ft using a magnetic disk or an optical disk, or even a color television monitor. Depending on the purpose of use, it can be output in the form of divine signals.

Note that the signal applied from the processing device (8) to the input terminal (=2) of the MPU (9) may be at an inappropriate signal level or when the amount of light emitted is inappropriate for signal processing (e.g., the amount of light emitted is excessive or This is for automatically optimizing the size of the data (including cases where it is too small). When the MPU (9) receives this signal, the MPU (9) changes the output data from the output terminal (ol) in the desired direction and outputs the variable voltage source (VE).
change the voltage. Using this signal, MPU (+;+) invalidates the previous reading and controls the xenon tubes (XR), (XG), and (XB) to emit light again to perform correct reading.

In the above embodiments, the main control means may be a discrete digital control circuit, but it is preferable to use a microcomputer MPU because the circuit configuration can be simplified. Furthermore, the information processing device (8) in FIG.
It is also possible to replace all or part of the functions of the M or PU.

Also, in the above embodiment, a xenon tube was used as the flash tube, but a different type of flash tube with a thin tube inserted would be used.

Further, although a C'CD image sensor is used as the image reading means, it is better to use a MOS image sensor, and these sensors can of course be one-dimensional or two-dimensional.
- Effects As described above, according to the present invention, since the sensual portion of the read image is normalized using the monitor information of the amount of light emitted from the flash tube, the influence of variations in the amount of light emitted from the flash tube can be avoided. Faithful color reproduction 1
You can get dark information and dark news.

[Brief explanation of drawings]

Fig. 1 is a schematic configuration diagram showing an optical system according to an embodiment of the present invention, Fig. 2 is a block diagram of a circuit section according to an embodiment of the present invention, Fig. 6 is a time chart of the circuit section, and Fig. 4 is an example of a red FIG. 5 is a block diagram showing an example of the information processing apparatus. XR, XG, XB,... Xenon tube as a flash tube, 1... Flash illumination means, 6... Multicolor original, 4... CCD image sensor as image reading means, 5... Image color Information storage means, 6... Monitoring means, MO... Monitor light receiving element, 7... Monitor information storage means, 8... Information processing means. Patent applicant Minolta Camera Co., Ltd. Agent
Patent attorney Aoyama Aoyama and 2 others Figure 1

Claims (1)

[Claims] (1) A flash illumination unit including a plurality of flash tubes, which emits a different colored light beam to illuminate the document when each flash tube is turned on, and a counter light image from the document 1 in synchronization with the lighting of each flash tube. A document reading device including a dipping-type image reading means for reading, a first storage means for individually storing image color information from the image reading means in accordance with lighting of each of the flash tubes; a second storage means for individually storing monitor information from the second storage means; and an image stored in the first storage means based on the monitor information from the second storage means. 1. A multicolor original reading device, comprising: information processing means for processing color information.