JPH0431464B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a photographic original reading device used in newspaper companies and the like.

BACKGROUND ART FIG. 3 is a perspective view showing an example of a conventional photo original reading device.

In the figure, reference numeral 1 denotes a rotatable drum holding a photo original 4, which is rotationally driven by a motor 2 provided at one end of the drum 1. Further, a gear 1a is provided as a shaft on the other end side of the drum 1, and an optical device 3 for reading the original 4 is provided in conjunction with the gear 1a. This optical device 3 includes an optical system 3a for reading the document 4 on the drum 1, and a movable table 3b on which the optical system 3a is mounted. A so-called half nut 6 having a shape obtained by dividing the nut in half is provided. A bar-shaped feed screw 7 parallel to the axis of the drum faces the thread groove formed in the half nut 6.
is provided. By manually operating the knob 5 with respect to the feed screw 7, it is possible to engage and disengage the half nut 6. On the other hand, a gear 7a is provided as a shaft at the end of the feed screw 7, and the gear 7a is connected to the gear 1 via a drive transmission gear 8.
It is connected to a.

When reading a photo original with this photo original reading device, the optical device 3 is at the sub-scanning end position (the left end position in FIG. 3) due to the previous original reading, so the knob 5 is moved in the direction of arrow B one by one. When pressed, the half nut 6 is removed from the feed screw 7. continue,
When knob 5 is pushed in the direction of arrow A, optical device 3
is moved to a white portion of the document, and the white level is read and set at that portion. moreover,
The knob 5 is continued to be pushed in the direction of arrow A, and the optical device 3 is returned to the document reading starting position (approximately the rightmost position in FIG. 3), and the half nut 6 is set in engagement with the feed screw 7. . Then, the optical device 3 is moved by the arrow C by the rotation of the drum 1.
During this movement, the document is read. Document reading ends when the optical device 3 reaches the end of the drum 1, thereby stopping the rotation of the drum 1 and the lateral movement of the optical device 3, so that the optical device 3 remains stationary.

Problems to be Solved by the Invention However, in this photographic original reading device, the optical device must be manually removed from the feed screw each time after reading the original in order to read the white level.
After moving and reading and setting the white level at a predetermined location, the optical device must be manually returned to the document reading starting position, which is cumbersome to operate.

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, it is an object of the present invention to provide a photographic original reading device that can automatically read and set the white level.

Means for Solving the Problems In order to achieve the above-mentioned object, the present invention provides a photo original reading device with a second optical device that operates when a reading optical device is moved back and forth and when a white spot is read at high speed when the reading optical device is moved backward. It is characterized by comprising a feed screw, and a first feed screw that acts when the document is subsequently moved forward to read the document.

Operation The reading optical device is at the reading end position. When the next original is set and reading starts, the transmission means is engaged with the second feed screw by the switching means, and while the reading optical device returns to the original reading start position, the white part of the original is read and the white level is adjusted. Detect and set the
After that, reading of the photo original begins.

Embodiment FIG. 1 is a perspective view of an embodiment of the present invention, and FIG. 2 is a sectional view of the main part of FIG.

In the figure, reference numeral 1 denotes a rotatable drum holding a photo original 4 to be transmitted, which is rotationally driven by a motor 2 provided at one end of the drum 1. A reading optical device 13 is provided with respect to the drum 1 and is capable of reciprocating in the axial direction of the drum. The reading optical device 13 includes an optical system 13a for reading the photographic original 4 on the drum 1 and a movable table 13b on which the optical system 13a is mounted. A device 15 is provided.

As shown in FIG. 2, the half-nut 14 has a shape in which two so-called half-nuts, each of which has a threaded part of the nut divided in half, are placed on the outside, and a protrusion to which the actuator of the solenoid 15a is fixed is provided in the center of the half-nut. We are prepared. A document reading feed screw 16, which is a rod-shaped first feed screw that faces each threaded portion of the half nut 14 and selectively engages with each threaded portion, and a document reading feed screw 1.
A pre-scanning feed screw 17, which is a rod-shaped second feed screw having a winding direction opposite to that of the drum 6 and having a thread with a large pitch, is arranged parallel to the drum 1.

A gear 1 is installed at each end of the original reading feed screw 16, the pre-scan feed screw 17, and the drum 1.
6a, 17a, 1a are provided as shafts, and these gears 16
Gears 16a, 17 are located near a, 17a, 1a.
A transmission gear 18 that meshes with each of the drums 1a and 1a is provided, and the gears 16a, 17a, 1a and the transmission gear 18 form a gear train 20 for transmitting rotational force from the drum 1 to the feed screws 16 and 17. . The transmission gear 18 has a large-diameter gear portion 18a and a small-diameter gear portion 18b, and the large-diameter gear portion 18a meshes with the gear 17a, and the small-diameter gear portion 18b meshes with the gear 16a.

The half-nut switching device 15 includes a latching solenoid 15a containing a permanent magnet, and a return spring 1 that is provided opposite to the solenoid 15a and has one end connected to a protrusion of the half-nut 14.
5b.

The operation of the photo original reading device configured as above will be explained.

The operation of reading a photographic original using such a photographic original reading device will be described.

The optical device 13 is at the final scan end position (near the left end in FIG. 1) due to the previous document reading, and the half nut 14 is moved by the action of the permanent magnet built into the latching solenoid 15a to read the previous document. The latching solenoid 15a is kept in the same state as when reading is completed, and the latching solenoid 15a is engaged with the pre-scan feed screw 17. When the motor 2 is driven in this state, its driving force is transmitted via the transmission gear 18, and the pre-scan feed screw 17 is rotationally driven. Then, the optical device 13 moves in the direction indicated by the arrow A in FIG.
Move back in the direction. Gear 17a is transmission gear 18
Since the pre-scan feed screw 17 is engaged with the large diameter portion 18a of the pre-scan feed screw 17, the pre-scan feed screw 17 rotates at a relatively high speed, and since its pitch is formed to be large, the optical device 13 moves at a relatively high speed in the direction of the arrow A. .
During this movement, the optical device 13 reads a white spot on the document and sets the white level. Note that by setting this white level, it is possible to record an image with high gradation when recording on paper or the like. When the optical device 13 is returned to the document reading starting position, the latching solenoid 15a
The half nut 14 is brought into engagement with the feed screw 16 by the force of the return spring 15b, and the original 4 is ready to be read. When the motor 2 is driven under this condition, the driving force of the motor 2 is transferred to the gear 1.
a, the signal is transmitted to the gear 16a via the transmission gear 18, and rotates the document reading feed screw 16. By the half nut 14 engaged with the feed screw 16,
The optical device 13 is moved forward in the direction of arrow C, and at this time the optical system 13a reads the original. Document reading ends when the optical device 13 reaches the end of the drum 1.

When the scanning of the original is completed, the latching solenoid 15a is energized. Then, a suction force against the half nut 14 is generated in the solenoid 15a. When this suction force exceeds the tensile force of the return spring 15b, the half nut 14 separates from the document reading feed screw 16 and engages with the pre-scan feed screw 17. This engaged state is maintained by the magnetic force of a permanent magnet built into the latching solenoid 15a. Furthermore, since a permanent magnet is provided, this meshing state is maintained even if the current to the solenoid 15a is cut off, which also has the effect of saving power.

Then, the optical device 13 remains in the above state and prepares for the next image reading operation.

Note that the winding directions of the two feed screws do not necessarily have to be opposite to each other. In this case, the two feed screws are rotated in opposite directions via a gear train.

Effects of the Invention According to the present invention, when reading a photographic original, the transmission means is engaged with the first feed screw, and as the drum rotates, the original reading optical device moves to read the original. After reading the original, the device remains at the original reading end position and prepares for the next image reading operation. When the next original is set, the switching means switches the transmission means to the second feed screw and engages it, and white level detection and setting are automatically performed while the reading optical device returns to the original reading starting position. Moreover, since the forward movement due to the action of the second feed screw is fast, there is an effect that the time for reading a white spot can be shortened.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a photographic original reading device according to an embodiment of the present invention, FIG. 2 is a sectional view of main parts of the photographic original reading device shown in FIG. 1, and FIG. 3 is a perspective view of a conventional photographic original reading device. It is a diagram. 1...Drum, 13...Reading optical device, 14...
...Half nut, 15...Half nut switching device (switching means), 16...Document reading feed screw (first
(feed screw), 17...Feed screw for pre-scanning (second feed screw).

Claims (1)

[Claims] 1. A rotatable drum that holds a photographic original to be sent, a reading optical device that is capable of reciprocating in the axial direction of the drum facing the drum and that reads the photographic original, and a reading optical device that is provided parallel to the drum. a first feed screw that moves the reading optical device forward when reading the photo original; a second feed screw that moves back at a higher speed than the first feed screw;
a transmission means that receives power from the first and second feed screws and transmits it to the reading optical device; a switching means that automatically switches the power from the transmission means to the first and second feed screws; and a drum. synchronous rotation means for rotating the first and second feed screws in synchronization with the rotation of the photographic original reading device.