JPS62234460A - Picture input device - Google Patents

Abstract

PURPOSE:To reduce the production cost of a picture input device by providing an acceleration means which accelerates the roll revolving speed, a disk-shaped rotary encoder having a higher revolving speed than the roll and a detecting means which detects optically a mark and forming a mark for the detection of the secondary scanning speed to the rotary encoder in a rough pitch. CONSTITUTION:An acceleration mechanism 7 increases the revolving speed of a roll 3 and transmits this revolving speed to a rotary encoder 8. This encoder 8 uses a transparent material having high light transmissivity and a seal where a black mark 8a is printed with prescribed width and a rough pitch is pasted at the outer edge part of the encoder 8. Then the encoder 8 is revolved integrally with a small pulley 7e of the mechanism 7. A detecting means 9 detects optically the mark 8a of the revolving encoder 8. In such a way, the revolving speed of the encoder 8 is increased by the mechanism 7 and therefore an accurate secondary scanning speed is detected even in case a detecting mark for secondary scanning speed is formed in a rough pitch. Therefore the production cost of a picture input device is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an image input device that optically reads information while running and scanning a recording medium on which information is recorded, such as a manuscript. be.

[Conventional technology]

In recent years, manual image input devices have been developed.

For example, as shown in FIG. 3, this image input device includes an illumination means 102, an optical system 103, a CCD line sensor 104, etc. in a casing 101 of a scanner 100, and a recording medium 105 on which information is recorded. Sub-scanning is performed by running the scanner 100 while rotating the roller 106 attached to the casing 101, and main scanning is performed by the CCD line sensor 104, thereby scanning an area of a constant width and arbitrary length. Information can be freely selected and retrieved from.

By the way, since the scanning speed per line by the CCD line sensor 104, that is, the main scanning speed, cannot be increased indefinitely, if the sub-scanning speed is too fast, there is a risk of information being skipped. Therefore, this scanner 100 is usually provided with means (hereinafter referred to as synchronization means) for synchronizing the main scanning speed and the sub-scanning speed.

That is, as this synchronization means, for example, as shown in FIG. 4, a row encoder 108 in which marks 107 such as grooves for detecting the sub-scanning speed are formed at a constant pitch d is connected to the inner peripheral surface of the previous roller, etc. It is known that the mark 107 is formed on the outside of the casing 101 and the mark 107 is optically detected by a photo ink printer 108 or the like. It is now displayed with a red lamp etc.

[Problem to be Solved] Incidentally, in an image input device equipped with a synchronization means configured as described above, it is necessary to check whether the sub-scanning speed is appropriate or not at very short intervals when the scanner is running. Because of the need to check each time, the pitch b of the grooves formed in the rotary encoder with the above configuration is extremely fine, for example, on the order of several tens of microns, but it is difficult to form the grooves accurately. It is extremely difficult to do so.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an image input device that can accurately detect and synchronize the sub-scanning speed even though the pitch interval of marks formed on a rotary encoder is relatively coarse. be.

[Means for Solving the Problems] That is, in the present invention, a roller attached to a casing of a scanner is rotated above a recording medium, and the scanner travels and scans the recording medium, and the recording medium is moved and scanned by the scanner.
In an image input device that reads information from a recording medium on a scanning surface by a reading means, a speed increasing mechanism that increases the rotational speed while rotating together with a roller, and a synchronization between the main scanning of the reading means and the sub-scanning by the running of the scanner are provided. To achieve this.

It has marks for detecting sub-scanning speed at a predetermined pitch on the outer edge side, and is equipped with a disc-shaped rotary encoder that rotates faster than the roller by a speed-increasing mechanism, and a detection means that optically detects the marks. be.

[Effect]

The image input device of the present invention uses a speed increasing mechanism to increase the rotation speed of the roller when the scanner runs and scans, and transmits the increased rotation speed to the row reencoder side, so that the row reencoder rotates at this increased rotation speed. Therefore, marks for sub-scanning speed detection can be formed at a coarse pitch on the row encoder, and manufacturing costs can be reduced accordingly.

(Embodiment) An embodiment of the present invention will be described below with reference to the accompanying drawings.

FIGS. 1 and 2 show an image input device according to the present invention, and this image input device includes the same components as conventional ones, that is, a roller 3 in a casing 2 of a scanner 1.
In addition to the illumination means 4, the optical system 5, and the reading means 6, it also includes a speed increasing mechanism 7, a low-return encoder 8, and a detection means 9.

A pair of left and right rollers 3 are rotatably provided by a support shaft 3a provided at a position off the optical path α.

The illumination means 4 is for irradiating the recording medium IO with slit light through a slit hole (enclosure) provided on the bottom side of the casing 2, and is arranged linearly at a predetermined position away from the optical path α. It is made up of light emitting diodes.

The optical system 5 is for forming image information linearly illuminated onto the recording medium 10 onto the reading means 6, and uses an imaging lens.

The reading means 6 is for optically reading the information that is linearly illuminated by the illumination means 4 and taken in through the slit hole, and converting it into an electrical signal, and is for converting the information into an electrical signal from a charge-coupled device (COD). A -dimensional line sensor is used.

The speed increase mechanism 7 is for amplifying the rotational speed of the roller 3 and transmitting the rotational speed of the roller to the rotary encoder 8 side. The drive gear 7a has a smaller number of teeth than the drive gear 7a, and the drive gear 7a has fewer teeth than the drive gear 7a.
a large pulley 7C that is coaxially supported with the speed increasing gear 7b, and a small pulley 7e to which the rotational force from the large pulley 7C is transmitted via a bell) 7d.
It is composed of. The speed increasing mechanism 7 of this embodiment is designed to increase the rotation speed of the small pulley 7e four times as much as the rotation speed of the roller 3 side.

The rotary encoder 8 is made of a material that is transparent and has good light transmittance, and is formed into a disc shape that is approximately the same shape as the previous roller 3, and the outer edge side is black with a predetermined width and coarse pitch intervals. Seal with mark 8a printed on it (enclosure)
is attached and is provided coaxially with the small pulley 7e of the speed increasing mechanism 7 so as to rotate integrally therewith. By the way, this mark is not limited to the one shown in this embodiment, and may of course be made of, for example, a disc-shaped material colored black or the like with grooves formed on the outer edge thereof. Note that the diameter of the row encoder 8 can be formed to be relatively smaller than the diameter of the roller 3.

The detection means 9 is for optically detecting marks on the rotating rotary encoder 8, and uses a photo ink labeler.

Therefore, according to the image input device according to this embodiment,
The rotary encoder 8 is connected to the roller 3 side via the speed increasing mechanism 7, and the rotational speed of the rotary encoder 8 is set to four times that of the roller 3, so it is different from, for example, a conventional rotary encoder. The pitch of the black marks 8a can be made four times coarser than those of the same shape.

〔effect〕

As explained above, according to the image input device according to the present invention, since the rotational speed of the rotary encoder is increased by the speed increasing mechanism, the marks for sub-scanning speed detection formed on the rotary encoder are arranged at a coarse pitch. Even if marks are formed at intervals, it is possible to detect the sub-scanning speed as accurately as in the conventional case where marks are formed at fine pitch intervals, and manufacturing costs can be reduced accordingly.

Further, according to the image input device according to the present invention, as described above, the marks can be formed at a coarser pitch than conventional ones, so it is possible to form the marks at a more accurate pitch. Therefore, it is possible to perform more accurate sub-scanning speed detection, and high quality can be provided.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing a scanner of an image input device according to the present invention, FIG. 2 is a schematic side view of the image input device shown in FIG. 1, and FIG. 3 is a schematic configuration diagram showing a conventional image input device. 4 are explanatory diagrams showing a conventional low reencoder. ■...Scanner. 2...Casing. 3... Laura. 10...Recording medium. 6...Reading means. 7...Speed-up mechanism. 8a...Mark 8...Low reencoder. 9...Detection means. Patent Applicant NEC Home Electronics Co., Ltd. Agent Patent Attorney Masu 1) Takeo Figure 2, 104 g3 Figure 40

Claims (1)

[Scope of Claims] 1. A means for reading from the recording medium on the running/scanning surface by causing the scanner to run/scan the recording medium while rotating a roller attached to the casing of the scanner above the recording medium. In an image input device that reads information by means of a speed increasing mechanism that increases the rotational speed while rotating together with the roller, and a speed increasing mechanism that increases the rotational speed of the roller while rotating with the roller, and a speed increasing mechanism that increases the rotational speed of the roller and synchronizes the main scanning of the reading means and the sub-scanning that is caused by the running of the scanner, a A disc-shaped rotary encoder having sub-scanning speed detection marks at a predetermined pitch and rotated faster than the roller by the speed increasing mechanism; and a detection means for optically detecting the marks. image input device.