JPS6225803Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an optical reading device for reading characters and marks on a form.

Traditional OCR (optical character reader) and
In an OMR (optical mark reader), in order to make it easier to detect forms (usually white paper), the part of the form transport table that is the background for photoelectric conversion is plated or painted black. It was often painted. However, when a thin paper form is inserted into a structure like this, the black color underneath is visible through the form, reducing the contrast of characters and marks written on the form.
As a result, a problem arises in that the SN ratio of photoelectric conversion decreases.

The present invention was developed in light of these circumstances, and its purpose is to develop an optical reader that can detect documents without error even when handling thin documents and can perform photoelectric conversion with a high signal-to-noise ratio. The goal is to provide equipment.

FIG. 1 is a block diagram of an embodiment of the present invention.
In the figure, reference numeral 16 denotes a sheet conveyor table, on which the sheet 17 is sent by a feed roller 15. Reference numeral 19 denotes a part of the conveyor table, and patterns such as characters and marks written on the form 17 are photoelectrically converted here.
18 represents the feeding direction of the form 17, 11 is a photoelectric conversion element of the optical system, 12 is a mirror, 14 is a light source,
13 indicates the optical path of the reflected light from the form 17.

FIG. 2 shows a state in which the form 17 is about to enter the reading section. FIG. 3 shows a state in which the pattern on the form 17 is photoelectrically converted. In addition, dotted line 2
1 indicates the scanning position of the photoelectric conversion element 11. Also,
The color of the surface of the conveyor table 19 can be switched between dark and bright by an electric signal.

FIG. 4 shows the structure of the conveyance table 19 in the case of FIG. 2, where 41 is the incident light, 42 is a liquid crystal plate in a darkened state, and 43 is a white plate. FIG. 5 shows the structure of the conveyance table 19 in the case of FIG. 3, and unlike the state shown in FIG. 4, the liquid crystal display plate 42 is colorless and transparent.

Now, in FIG. 1, when the form 17 approaches the reading section, in preparation for reading,
It is necessary to accurately grasp the position of the form 17. Therefore, the photoelectric conversion element 11 (or a solar cell dedicated to detecting the form provided nearby) can detect the form 1.
It is necessary to detect that the tip of 7 has entered the reading section. The detection method in this case is that the conveyance table 19 is black, and when the form 17 enters, the output of the photoelectric conversion element 11 changes due to the white color of the form 17, so detection is performed. There must be a control part of the device (not shown)
sends out an electric signal so that the conveyance table 19 becomes dark in color.

Also, in the state of reading in Figure 2, the form 17
If the color of the conveyor table 19 is too light, the color of the conveyor table 19 will be visible through the paper, and the brightness of the paper will appear to be lowered.As a result, the contrast of the pattern on the form 17 will be reduced, which will have an adverse effect.
Sends an electrical signal to make the color brighter.

As a specific example of the structure of the conveyor table 19, FIG.
The configuration shown in FIG. 5 can be considered, and if the conveyor table 19 has one liquid crystal display plate 42 made transparent by an electric signal, the incident light 41 will be transmitted to the white reflective plate 43 on the back side.
On the other hand, if the liquid crystal display panel 42 is made dark, the incident light 41 is absorbed and can be treated as a dark-colored transport platform 19.

Thus, according to the present invention, the color of the conveyor table 19 corresponding to the reading section can be freely controlled from the control section to bright or dark, thereby making it easier to handle thin forms 17. , document detection, character reading, etc., it is possible to almost eliminate the adverse effects caused by the color of the conveyor table, which could not be eliminated using conventional methods.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of a reading section of an embodiment of the present invention.
Figure 2 is a state diagram where a form is about to enter the reading unit, Figure 3 is a state diagram where the pattern on the form is being photoelectrically converted, Figure 4 is a configuration diagram of the conveyance platform in the case of Figure 2, and FIG. 5 is a configuration diagram of the conveyance table in the case of FIG. 3. 11 is a photoelectric conversion element, 12 is a mirror, 13 is an optical path of reflected light, 14 is a light source, 15 is a roller, 16 is a conveyor table, 17 is a form, 18 is a form feeding direction, 1
Reference numeral 9 indicates a conveyance table of the reading section, 41 indicates incident light, 42 indicates a liquid crystal display panel, and 43 indicates a white plate.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. An optical type characterized in that in a reading unit that scans a pattern on a form and converts it photoelectrically, the conveyance table on the back side of the form can be electrically switched between bright and dark colors. reading device. 2. An optical reading device according to claim 1 of the utility model registration claim, characterized in that a liquid crystal is applied thereto.