JPH0715236Y2 - Scanner device - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a scanner device used for recording images of color originals such as printed matter and photographs.

[Conventional technology]

The image information of the color original is separated into the RGB three primary colors, and the CCD
Line-sequential reading with a self-scanning image sensor such as
2. Description of the Related Art A color scanner of the type that obtains an image corresponding to each color separation image of RGB and reproduces color information of a color original by combining three types of image signals has been known.

FIG. 2 is a schematic configuration diagram of a color scanner device using a general reduction optical system. A panel provided with color separation filters 6 for each of the RGB colors, in which the light source A for illumination of the subject 22 such as a document or the like controls the amount of light of the document 22 on the image sensor 8 by the lens 2 for forming an image of the document on the diaphragm 3. The motor of the color filter driving unit 9 switches the RGB filter. The image sensor 8 performs photoelectric conversion and sends out as a signal. In this case, image switching in the horizontal direction is performed by the image sensor driving unit 10, and line sequential in the vertical direction is performed by the motor 21. After passing through the RGB relative sensitivity adjustment amplifier 23, it is converted into a digital signal by the A / D converter 16 and becomes a host side by a recording means such as an electric storage circuit 17 or a floppy disk, and the scanner does not include a control signal. FIG. 3 shows two examples I and II of the spectral sensitivity characteristic of a general image sensor. FIG. 4 is a relationship diagram of the output voltage with respect to the exposure amount (lx · s) of the image sensor. Also, FIG. 5 shows the color separation characteristics used in a color television, and the color signals separated according to this curve become white when input to the color monitor at the same prescribed level.

[Problems to be solved by the device]

When the original is white, the transmitted light image of the dichroic filter having the characteristics shown in FIG. 5 is photoelectrically converted by the image sensor 8 shown in FIG. 2, and the characteristics are defined by, for example, I in FIG. That is, if the peak is in the R band, the white saturation level is set to the fourth
The light amount of the illumination A is adjusted immediately before the saturation voltage in the figure to record an image. After that, the illumination light 1 and the lens diaphragm 2 perform the GB image recording in the same manner as when R is set, but as is clear from the characteristics of FIG. By comparing the peaks, a value which is smaller by about 35% is taken out as the voltage of the color saturation level, and the signal level is adjusted by the amplifier 23 in FIG. Although the level can be adjusted electrically, the S / N of the color signal in the entire system is poor in B, and noise becomes clearly visible especially in the dark part. On the contrary, when B is used as a reference, the saturation voltage becomes a problem in R, and the photoelectric conversion characteristics of the image sensor 8 are the same in the visible range in FIG. 3 II as well. It is necessary to change. In this case, although manual recording is possible, recording and adjustment are not efficient because they are the result of adjusting the level of each color.

[Means for Solving the Problems]

The photoelectric conversion voltage color-separated into RGB in a white original is recorded in an average value voltage recording circuit, and the output level of each RGB color signal is made equal by this voltage. Therefore, a control means is provided for determining the cycle of the clock drive pulse for controlling the scan speed of each image sensor of RGB for each color separation of RGB when recording a color original.

[Action]

Since the cycle of the clock drive pulse is controlled for each of the RGB separated colors to make the output levels of the respective color separated signals equal, it is possible to shorten the control time until the proper values are set. In addition, it is possible to improve the SN ratio of the B color due to the photoelectric conversion color characteristics of the image sensor and make the SN ratio of each of the RGB colors the same to record a high quality image.

〔Example〕

An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of an embodiment of the present invention. When first recording a white image, light 1 from the subject passes through lens 2 and lens diaphragm 3
First, manually set to a position empirically known from the relation of lighting, and switch the switch 11 to H as the initial setting mode and connect the switch 13 to the contact N to drive the image sensor 8 with the color filter 6 and the switch 12 as R. Let As a result, the average value voltage storage circuit 14 stores the R proper exposure time voltage. The same operation is performed for GB thereafter, and the appropriate exposure time voltage of GB is stored in the average value voltage storage circuit 14 as the initial mode. Next, at the time of shifting to the recording mode in the overall control circuit 20, the recorded image 22 is placed, the switch 11 is switched to S, the color filter 6, the switch 12 and the switch 13 are switched for each color, and the output from the average value voltage storage circuit 14 is output. Voltage and its R voltage are 10
The period of the clock driving pulse for controlling the scan speed of the image sensor 8 is controlled by the image sensor driving unit 10 so that the output voltage of G or B corresponds to 100 when 0 is set.
The controllable range by the normal clock drive pulse is the range of 600 ns to 4.8 μs, and when control is not possible within this range, the lens diaphragm drive control circuit 5 drives the diaphragm drive unit 4 to control the diaphragm 3. Take an image. First
As is apparent from the figure, each color is memorized by the image storage circuit 17 through the amplifier 15 and the A / D conversion circuit 16 through the switch 11. As a result, the amplifier 15 and the A / D conversion circuit 16 are
Only one system is required, and images with the same SN ratio can be recorded from recording to image memory.

[Effect of device]

According to the present invention, when recording a color original, a high-quality image of each color can be obtained by eliminating the difference in the spectral energy of illumination in each color of RGB and the difference in the transmittance of the optical filter.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a diagram showing a conventional example, and FIGS. 3 to 5 are diagrams showing characteristics of respective portions. 1 …… Light 2 …… Lens 3 …… Aperture 4 …… Aperture drive unit 5 …… Lens aperture drive control circuit 6 …… Color filter 8 …… Image sensor 9 …… Color filter drive unit 10 …… Image sensor drive unit 11,12,13 …… Switch 14 …… Average value voltage storage circuit 15 …… Amplifier 16 …… AD conversion circuit 17 …… Image storage circuit 18 …… Image sensor 19 …… Color filter drive circuit 20 …… Overall control circuit 21 …… Motor 22 …… Recorded image.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display area H04N 9/04 Z

Claims (1)

[Scope of utility model registration request] 1. When a still image is recorded, an image signal which is separated by a color filter of R (red) G (green) B (blue) three primary colors and a lens arranged oppositely to the image sensor and switched is taken. In the scanning device, put out a white original
The light exchange voltage separated into each RGB color is recorded in the average value voltage recording circuit, and the scanning speed of each RGB image sensor is controlled when recording a color original in order to equalize the output level of each RGB color signal by this voltage. A scanner device provided with a control means for determining a cycle of a clock driving pulse for each RGB separated color.