JPH01185068A - Color image reading and printing device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a color image reading and printing device for reading color image information written on a color original or a board.

2. Description of the Related Art A first example of a conventional color image reading device will be described with reference to FIG. First, an LED red light source 2, an LED green light source 3, and a blue light source 4 formed of a fluorescent panel or the like are provided as light sources for illuminating the color original 1. A rod lens array 5 is arranged in a direction perpendicular to the color original l, and an image sensor 7 including photoelectric conversion elements 6 arranged in an array is provided on the output side of the rod lens array 5. .

In such a device, the LED red light source 2 and the LED
The green light source 3 and the blue light source 4 are turned on in a time-division manner, and their reflected light is detected as a red signal, a green signal, and a blue signal.

Next, a second conventional example will be explained based on FIGS. 11 and 12. First, a white light source 9 illuminates the color original 8.
and a rod lens array 10 for controlling reflected light from the color original 8.
An image sensor 13 having photoelectric conversion elements 12 arranged in an array through a color mosaic filter 11 is provided on the output side 1 of the sensor 0. The color mosaic filter 11 includes a red filter R1 and a green filter G.
, blue filters B are alternately arranged in 1:1 correspondence to the photoelectric conversion elements 12. In this case, 3 of R2O,H
Each element reads one pixel.

Problems to be Solved by the Invention In the first conventional example, multiple light sources are required, which complicates the device, and scanning is repeated for the number of light sources to read one line in the sub-scanning direction. Therefore, there is a problem that it takes a long time to read.

In the second conventional example, since a color mosaic filter is used, one pixel consists of multiple color components,
There is a problem that the resolution decreases. In addition, since the light passes through the filter, the amount of light incident on the sensor decreases, resulting in S/N
There is a problem that the ratio becomes low.

Means for solving the problem: A white light source that illuminates the multicolored characters or images on the reading surface, and a charging conversion that photoelectrically converts the reflected light from the reading surface to obtain electrical signals of different levels for each color. and a reference signal section in which a threshold level for each color is set, and a signal from the photoelectric conversion section is compared with the threshold level set in the reference signal section to generate an output signal for each color. The signal processing circuit constitutes a color reading device.

Furthermore, a color printing device is constructed by providing a thermal printer that performs two-color printing by obtaining red and black output signals from a signal processing circuit.

Even if the active light source is a type of white light source and the photoelectric conversion element has only the same function as in the case of black-and-white reading, it is possible to detect multiple A color output signal is obtained, the reading speed is fast, and there is no filter, etc.
It is designed to improve the S/N ratio and provide high resolution.

Embodiment An embodiment of the present invention will be explained based on FIGS. 1 to 9. First, on the top of the unit case 14, there is a reading surface 15.
An opening 16 is formed opposite to. A long white light source 18 surrounded by one reflecting plate 17 is disposed inside the unit case 14, and a rod lens array 19 is disposed parallel to the white light source 18. An image sensor 21 having photoelectric conversion elements 20 arranged in an array is provided on the output side of the rod lens array 19. A printed wiring board 22 constituting a drive circuit is provided below the image sensor 21.

The unit case 14 formed in this manner is attached so as to be movable left and right on the surface of the whiteboard unit 23. The surface of this whiteboard unit 23 becomes the reading surface 15.

Next, the light irradiated from the white light source 18 irradiates the reading surface 15, and the reflected light 24 reaches the photoelectric conversion unit 20, where it is converted into an electrical signal, and the analog signal is converted to an AMP/ADC. The signal is amplified and converted into a digital value by the circuit 25, and then input to the signal processing circuit 26. A reference signal section 27 is connected to this signal processing circuit 26, and the output signal from the signal processing circuit 26 is output to a printer 28. This printer 28 is a thermal printer that performs two-color printing by receiving red and black output signals.

In such a configuration, what is shown in FIG. 5 is a spectral sensitivity curve of the photoelectric conversion element 20 of the image sensor 21. In this embodiment, an amorphous silicon film is used as the photoelectric conversion element 20. Its peak sensitivity is 580-600 nm.

Moreover, what is shown in FIG. 6 shows the spectral energy distribution of the white light source 18. Furthermore, what is shown in FIG. 7 shows the spectral reflectance of each color of the red marker, blue marker, and black marker used on the whiteboard 23. These are shown as relative outputs when the reflectance of the whiteboard 23 is set to 100.

Looking at the output signal level output from the AMP/ADC circuit 25 when reading red and black on the whiteboard 23, as shown in FIG. The level of the red signal of the red marker is about 50, and the level of the black signal of the black marker is about 20. Therefore, threshold level 1 and threshold level 2 are set at positions where these divisions can be clearly made. These threshold levels 1 and 2 are stored in the reference signal section 27.

Therefore, in the signal processing circuit 26, the output signal from the AMP/ADC circuit 25, which is input every moment, is compared with the threshold levels 1 and 2 stored in the reference signal section 27,
It is determined whether the signal is white, red, or black. Based on this determination result, when a print signal is given to the printer 28, two-color printing of red and black is performed.

Also, as shown in Figure 9, if three types of threshold levels are set for the red marker, blue marker, and black marker,
Each color signal is obtained.

Effects of the Invention As described above, the present invention includes a white light source that illuminates multicolored characters or images on a reading surface, and photoelectric conversion of reflected light from the reading surface to generate electrical signals of different levels for each color. A photoelectric conversion section to obtain an output signal, a reference signal section in which a threshold level for each color is set, and an output signal for each color by comparing the signal of the photoelectric conversion section with the threshold level set in the reference signal section. Since the color reading device is configured with a signal processing circuit that generates By comparing the threshold levels of each color, output signals of multiple colors can be obtained.The reading speed during this reading is fast, and since there is no intervening filter etc., the S/N ratio can be improved. The resolution is high, and color printing can be easily performed by configuring a color printing device by installing a thermal printer that performs two-color printing by obtaining red and black output signals from the signal processing circuit. It has the effect of

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an embodiment of the present invention, Fig. 2 is a longitudinal side view of the reading device, Fig. 3 is a partially cutaway perspective view, and Fig. 4 is a case in which it is used as a whiteboard. Fig. 5 is a characteristic diagram showing the spectral sensitivity curve of the charge conversion element, Fig. 6 is a characteristic diagram showing the spectral energy distribution curve of a white light source, and Fig. 7 is a characteristic diagram showing the spectral reflectance of each color marker. 8 is an explanatory diagram showing the setting state of the threshold level for the output signal level in the case of two colors, and FIG. 9 is an explanatory diagram showing the setting state of the threshold level for the output signal level in the case of three colors. 10 is a vertical side view showing the first conventional example, and FIG. 11 is a vertical side view showing the second conventional example.
FIG. 2 is a plan view of the color mosaic filter. 15... Reading surface, 18... White light source, 20... Photoelectric conversion element, 26... Signal processing circuit, 27... Reference signal section, 28... Thermal printer Applicant: Tokyo Electric Co., Ltd. Company JJ Figure JIZ Figure J5 Stomach O Country (Spider) ``U JZ Sae'' 3, JJ Figure (Spider)

Claims (1)

[Claims] 1. A white light source that illuminates multicolored characters or images on a reading surface, and photoelectric conversion that photoelectrically converts the reflected light from the reading surface to obtain electrical signals of different levels for each color. and a reference signal section in which a threshold level for each color is set, and a signal from the photoelectric conversion section is compared with the threshold level set in the reference signal section to generate an output signal for each color. A color image reading device comprising a signal processing circuit. 2. A white light source that illuminates the multicolored characters or images on the reading surface, a photoelectric conversion unit that photoelectrically converts the light reflected from the reading surface to obtain electrical signals of different levels for each color, and a reference signal section in which a threshold level is set; a signal processing circuit that compares the signal of the photoelectric conversion section with the threshold level set in the reference signal section to generate an output signal for each color;
A color image printing device comprising a thermal printer that performs two-color printing by obtaining red and black output signals from the signal processing circuit.