JPS5853854B2 - Shikichiyoukenshiyutsusouchi - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a color tone detection device for detecting the presence or absence of a printed stamp and its color in an automatic postal sorting and stamping machine for conveyed items such as private postcards and sealed letters.

In recent years, as the mechanization of postal services has progressed, various automatic mail handling machines have been introduced and put into practical use. The automatic postal sorting and stamping machine that operates is one such type.

The machine is equipped with a color tone detection device that detects the color and size of a stamp printed in a predetermined color and size to determine whether there is a stamp or not, and whether it is regular delivery or express delivery.

Therefore, a conventional color tone detection device will be explained with reference to FIG. 1. A mail item 1 is conveyed in the direction of the arrow by a belt (not shown), and a color tone detector 2 installed on the conveyance path detects the presence or absence of the stamp. Also, it is now possible to distinguish between regular and express delivery.

That is, when the mail 1 is irradiated by the illumination lamp 3 of the detector 2, the reflected light is imaged through the condenser lens 4 on the plate 5 having a through hole 5a of a certain size.

The light passing through the plate 5 is divided into three wavelengths by a dichroic mirror 6 reflecting the red wavelength region, a dichroic mirror 7 reflecting the blue wavelength region, a red wavelength transmission filter 8, a blue wavelength transmission filter 9, and a green wavelength transmission filter 10. After being further photoelectrically converted by photoelectric conversion elements 11, 12.degree. 13, the signals are amplified by amplifiers 14, 15.degree. 16, respectively.

The three-wavelength decomposed signals thus decomposed are respectively introduced into the color tone discrimination circuit 17, and their color and size are detected to determine whether there is a stamp or not, and whether the mail is regular or express delivery.

However, since the detector 2 uses a dichroic mirror 6.7 that separates into three wavelengths, the device becomes large, and it takes a long time to adjust the optical system and photoelectric conversion system. It had drawbacks such as being expensive.

The present invention was made in view of the above circumstances, and its purpose is to eliminate the need for using an expensive dichroic mirror as a three-wavelength resolving means of the light receiving optical system in a color tone detector.
Moreover, by adopting a three-wavelength decomposition method with a simple structure, the present invention aims to provide a color tone detection device that can reduce the cost in terms of both parts and adjustment man-hours.

An embodiment of the present invention will be described below with reference to FIGS. 2 to 4.

1 in the figure is a mail item, which is carried by a belt (not shown) in the direction of the arrow (
It is transported from the front side of the drawing to the back side).

Thus, the reflected light from the mail 10 irradiated by the illumination lamp 3 of the detector 20 is imaged through the condenser lens 4 onto the plate 5 having a through hole 5a of a certain size.

A photoelectric element block 21 is installed at a predetermined position where the light is diffused by passing through the through hole 5a.

The photoelectric element block 21 includes, for example, three silicon photocells 22, 23, 2jl arranged in close contact with each other,
In front thereof, a green wavelength transmission filter 22a, a blue wavelength transmission filter 23a, a red wavelength transmission filter 24a, and an infrared cut filter 24b are arranged.

Therefore, the sizes of the three silicon photocells 22, 23, and 24 forming the photoelectric element block 21 are determined by the wavelength characteristics of the energy of the illumination lamp 3, the transmittance wavelength characteristics of the optical filter, and the sensitivity of the photocell. is set according to the wavelength characteristics of

In other words, the above-mentioned silicon photocell generally has high sensitivity in the red wavelength region, and has decreased sensitivity in the blue wavelength region.Furthermore, when an incandescent lamp is used as an illumination lamp, the energy of the blue wavelength component is higher than that of the red wavelength component. It is quite small compared to the ingredients.

Therefore, if the above three photocells are made to have the same shape, the photoelectric output of each photocell will be calculated by multiplying each wavelength by the energy of the illumination lamp, the sensitivity of the photocell, and the transmittance of the optical filter, as shown in Figure 4. Because it is the integral value, the photoelectric output in the red wavelength region is the maximum, followed by the green wavelength region,
Finally, the blue wavelength region is the minimum.

Therefore, the shape of the photocell for the blue wavelength region is set to the maximum dimension, followed by the photocell for the green wavelength region and the photocell for the red wavelength region to the minimum dimension.

In other words, each photocell is formed so that the photoelectric output is equal, and 22 in the figure is a photocell for green wavelength, 23 is a photocell for blue wavelength, and 24 is a photocell for red wavelength.

Further, 25, 26, and 27 are amplifiers made of the same components, and the outputs of each amplifier 25, 26, and 27 are connected to the color tone discrimination circuit 17.
After the presence or absence of stamps and whether it is regular or express delivery are determined, the terminal 18a is input.

18b.

Next, the operation of the present invention will be explained based on the above configuration.

Now, when the mail item 1 is conveyed along the conveyance path in the direction of the arrow and is irradiated with the illumination lamp 3, the reflected light is reflected by the condenser lens 4.
The image is formed on the through hole 5a of the plate body 5 through.

The diffused light then enters the photoelectric element block 21.

That is, green is transmitted to the silicon photocell 22 through the green wavelength transmission filter 22a, blue is transmitted to the silicon photocell 23 through the blue wavelength transmission filter 23a, and red is transmitted to the silicon through the red wavelength transmission filter 24a and the infrared cut filter 24b. The light is separated into spectra by the photocell 24.

Furthermore, the photoelectric outputs passing through the silicon photocells 22, 23, 24 are equal, and the same amplifiers 25, 26, .
27, and each output is input to the color tone discrimination circuit 17.

Therefore, it is possible to determine whether the postal item 1 has a stamp or not, and whether it is regular mail or express delivery, and output the result to the terminal 18a18b.

Although one embodiment of the present invention uses an incandescent bulb as the illumination lamp and a silicon photocell as the photoelectric element, the present invention is not limited to this, and other lamps and photoelectric elements may be used. Of course it's a good thing.

In addition, if a large photoelectric element is used and it is not possible to arrange three photoelectric elements close to each other as shown in the above embodiment, a light guide may be installed at the position of the diffused light as shown in FIG. Place the block 31 and place the light guide block 310
The incident light side has the shape shown in FIG. 6, and the output light side is branched into three directions.

Then, it may be made to enter the photoelectric elements 32, 33° 34 through an optical filter consisting of the green wavelength transmission filter 22a, the blue wavelength transmission filter 23a, the red wavelength transmission filter 24a, and the infrared cut filter 24b for photoelectric conversion. .

As explained above, the present invention does not use a dichroic □ mirror as a means for separating the light receiving optical system of a color tone detector into three wavelengths, but instead separates the light receiving optical system of a color tone detector from a fixed distance from a plate having a transparent hole arranged on an image forming surface. A photoelectric element block consisting of eight photocells or a light guide block having three entrance ports is placed at the position of the diffused light that has passed through the through hole, and each shape of the entrance port of the photocell or light guide is adjusted. By appropriately distributing the dimensions of each photocell so that the photoelectric output is constant with respect to the spectral sensitivity of the 7-photocell, the energy distribution of the illumination light source, and the transmittance of the 3-wavelength separation filter, the amplifier can also be made the same. The present invention has practical effects such as being able to be used easily, making electrical and optical adjustment easier, and making it smaller and cheaper.

[Brief Description of the Drawings] Fig. 1 is a plan view showing a conventional color tone detection device, Fig. 2 is a plan view of a color tone detection device showing an embodiment of the present invention, and Fig. 3 shows the main parts of the device. 4 is a wavelength characteristic diagram showing the photoelectric output of each photocell in the same device, FIG. 5 is a plan view of a color tone detection device showing a modification of the present invention, and FIG. FIG. 6 is a front view of the light guide in FIG. 5 when viewed from the incident light side. 3...Lamp for illumination, 4...Condensing lens, 5a...Through hole, 5...Plate body, 21
. . . Photoelectric element block, 31 . . . Light guide block, 22a. 23a, 24a, 24b-optical filter, 32°3
3.34...Photoelectric element.

Claims (1)

[Claims] 1. An illumination lamp that illuminates the transported object, a condensing lens that forms an image of the reflected light of the irradiated transported object, and a plate that has a through hole of a certain size arranged on the image formation surface of the reflected light. an optical filter disposed at a position where the diffused light passes through the through hole and is diffused into three wavelengths, and a photoelectric element that receives the transmitted light of each of the filters, and the photoelectric element has a photoelectric output. A color tone detection device characterized in that the size of at least one of the photoelectric element and the light guide is selected so as to be constant.