JPH0126977B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD The present invention relates to a transport mechanism for a photosensitive film sheet in an image recording apparatus that forms an image on a photosensitive film sheet using a laser beam method.

BACKGROUND ART Conventionally, as this type of image recording apparatus, one shown in FIG. 1, for example, has been provided.

This photosensitive film sheet S is taken out one by one from the magazine 1 by the suction means 2.
is dropped between the sub-scanning drum 4 and the nip rollers 5, 5 via the nip roller pair 3, the stopper 6 is retracted, and the nip rollers 5, 5 are moved toward the sheet S.
The sheet S is brought into pressure contact with the sub-scanning drum 4 via the sub-scanning drum 4, and is conveyed downward by the rotational force of the sub-scanning drum 4 which is constantly driven to rotate. An image is formed on the sheet S by scanning the signal.

Incidentally, the sheet conveyance mechanism in this type of image recording apparatus is required to eliminate conveyance unevenness as much as possible and convey the sheet with accurate positioning in order to prevent scanning deviation caused by the laser beam.

However, since the image recording device shown in Figure 1 uses a method in which the photosensitive film sheet S is dropped by its own weight, accurate positioning is difficult due to variations in the weight of the sheet itself and bending. In addition, since the nip rollers 5, 5 are brought into contact with and separated from the sub-scanning drum 4, even if an attempt is made to prevent uneven rotation of the drum 4 itself by connecting and rotating the sub-scanning drum 4, torque fluctuations may occur when the nip rollers 5, 5 are pressed against each other. This causes uneven rotation, resulting in uneven conveyance.

Particularly, when reproducing documents with gradation such as X-ray film, even subtle conveyance unevenness greatly affects image reproducibility, so eliminating conveyance unevenness is an important issue.

OBJECT OF THE INVENTION The present invention has been made in view of the above-mentioned drawbacks, and its object is to be able to feed a photosensitive film sheet onto a sub-scanning drum with accurate positioning;
It is an object of the present invention to provide a conveyance mechanism for a photosensitive film sheet that does not cause uneven conveyance on a sub-scanning drum.

SUMMARY OF THE INVENTION In order to achieve the above objects, the present invention provides a sub-scanning drum that is driven to rotate continuously at a constant speed, a nip roller that is driven and rotates in constant contact with the sub-scanning drum, and a photosensitive film sheet supply section. The photosensitive film sheet is installed in a substantially horizontal state on the path leading from the main scanning drum to the sub-scanning drum, and the photosensitive film sheet is installed on the sliding holding plate and on the supply part side of the holding plate, and is movable into the conveying path and can be moved back and forth. A push lever is provided on the sub-scanning drum side of the holding plate to urge the rear end of the sheet forward, and a stopper is installed on the sub-scanning drum side of the holding plate and is movable into the transport path and positions the leading end of the sheet at the entry position. After the sheet fed onto the holding plate is positioned so that the leading edge of the sheet comes into contact with the stopper by the first advancing operation of the push lever, the push lever is released to place the sheet on the holding plate, and the stopper is retracted. The leading edge of the sheet is sandwiched between the sub-scanning drum and the nip roller by the second advancing operation of the push lever.

In other words, by sliding the photosensitive film sheet on a holding plate placed in a substantially horizontal state, the difficulty in positioning due to variations in the sheet's own weight and flexure is eliminated, and the leading edge of the sheet is moved by a stopper just before the sub-scanning drum. The accurately positioned sheet is inserted between the sub-scanning drum and the nip roller, which are in constant contact and in a continuously rotating state, by the biasing force of the push lever, and while the sheet is being conveyed by the sub-scanning drum, the sheet is held at the stopper. By configuring the drum so that it does not come into contact with a push lever or the like, fluctuations in the load on the sub-scanning drum are prevented and uneven conveyance is eliminated.

Embodiment FIG. 2 shows the overall configuration of an image recording apparatus, in which a photosensitive film sheet S is loaded in a supply cassette 10 with the photosensitive side facing upward, and an air cylinder 11 is connected above the leading end of the sheet S. A suction cup 12 is installed. The suction cup 12 is movable in the vertical direction together with the air cylinder 11 using the shaft 13 as a fulcrum, and when descending, the air cylinder 1
The sheet S is sucked in the air suction operation 1, and the leading edge of the sheet S on the top layer is lifted.

The conveying roller pair 14 is installed so as to be movable in the front and back direction at approximately the same height as the leading edge of the sheet paper S lifted by the suction cup 12, and is rotated by a sheet conveyance start signal while moving toward the right side in the figure. , the leading end of the sheet S which has already been lifted is pinched, and the sheet S is immediately conveyed onto the holding plate 15 . Note that the rotation of the pair of transport rollers 14 is stopped when the sheet S is sent out onto the holding plate 15. This is to prevent uneven conveyance of the sheet S due to vibrations caused by driving by stopping other drives as much as possible when the sheet S is conveyed over the sub-scanning drum 20 in the following process.

The holding plate 15 is installed horizontally on the path from the transport roller pair 14 to the sub-scanning drum 20, and has a slightly longer overall length than the sheet S, and its surface is finished so that the sheet S can slide thereon. There is. Further, a push lever 16 and a stopper 18 are installed on the side of the conveyance roller pair 14 of the holding plate 15 and the stopper 18 on the side of the sub-scanning drum 20, respectively, which are rotatable around shafts 17 and 19, that is, movable back and forth in the sheet conveyance path. There is. The push lever 16 has a function of urging the rear end of the sheet S forward when the sheet S enters the conveying path (rotating clockwise in the figure). The stopper 18 has a hook-shaped tip, and has the function of accurately positioning the sheet S on the holding plate 15 by abutting the tip of the sheet S when the stopper 18 enters the conveyance path.

The sheet S is ultimately pushed to the left in the figure by the push lever 16 and is sandwiched between the sub-scanning drum 20 and the nip roller 21, but this operation will be described in detail below.

The sub-scanning drum 20 is continuously rotated counterclockwise during the recording operation, and the nip rollers 21, 21
The drum 20 is always in contact with the drum 20 and rotates as a result. When the sheet S is sandwiched between the drum 20 and the preceding nip roller 21, it is immediately conveyed to the left in the figure by the rotational force of the sub-scanning drum 20.

On the other hand, the laser beam unit 22
A laser beam generated from a beam generator 23 installed above is irradiated between the nip rollers 21 and 21 via a reflecting mirror 24, and is applied to the sub-scanning drum 20.
A predetermined image is formed by main scanning the photosensitive film sheet S being conveyed thereover.

The sheet S on which the image has been formed in this way is sent out from between the sub-scanning drum 20 and the nip roller 21 at the rear stage to the left in the figure, and is stored in the take-up cassette 25 by hanging down from the leading edge by its own weight. The take-up cassette 25 has a lid that is opened and closed upon detecting the conveyance of the sheet S, and is provided with sufficient light shielding measures.

The sheet S stored in this take-up cassette 25 is not yet developed, and is taken out from the recording apparatus while being stored in the cassette 25, and processed by development and fixing.

Next, the conveyance operation of the sheet S on the holding plate 15 will be described in detail with reference to FIG.

First, when the sheet S is conveyed onto the holding plate 15 by the conveyance roller pair 14, the push lever 16 is retracted upward from the conveyance path, and the stopper 18 is moved into the conveyance path, as shown in FIG. are doing. The sheet S is moved to the holding plate 15 by the conveying roller pair 14.
When the sheet S is conveyed upward (see Fig. 3), the push lever 16 rotates clockwise and pushes the rear end of the sheet S forward (see Fig. 3). sheet S
The central portion of the push lever 16 bends slightly upward due to the biasing force of the push lever 16.

Subsequently, the push lever 16 rotates counterclockwise to release the biasing force toward the rear end of the seat S (see FIG. 3). With this, the sheet S is attached to the holding plate 1
5, and its tip is accurately positioned by the stopper 18. Note that at this time, the push lever 16 needs to be retracted from the conveyance path relatively slowly.
That is, this is to prevent the leading end from separating from the stopper 18 when the sheet S, which has been bent by the biasing force of the press lever 16, returns to a flat state due to its own elasticity.

Next, the stopper 18 rotates clockwise to retreat from the conveyance path (see Figure 3), and the push lever 16 rotates clockwise to push the end of the sheet S (see Figure 3). ). As a result, the sheet S slides on the holding plate 15, and its leading end is sandwiched between the rotationally driven sub-scanning drum 20 and the nip roller 21, and from then on the sub-scanning drum 20
It is transported by the rotational force of

The drive of the push lever 16 and the stopper 18 is controlled by a sequence or a microcomputer in combination with a detection signal of the sheet S and a timer.
This control section is installed in the electrical equipment box 26 along with other operation control sections.

Note that the conveyance mechanism according to the present invention is not limited to the above-mentioned embodiments, and various changes can be made within the scope of the invention. For example, the push lever 16 and the stopper 18 may be movable into and out of the conveyance path from below the conveyance path.

Effects of the Invention As is clear from the above explanation, according to the present invention, since the photosensitive film sheet is slid on a holding plate provided in a substantially horizontal state, variations in positioning due to the sheet's own weight or bending are eliminated. The leading edge of the sheet can be accurately positioned in front of the sub-scanning drum by the cooperation of the push lever and the stopper.Moreover, since the sub-scanning drum is continuously rotated at all times with the nip roller in contact with it, and the sub-scanning Since the sheet does not come into contact with the stopper, push lever, etc. during conveyance by the drum, load fluctuations do not occur on the sub-scanning drum, uneven conveyance is eliminated, and high-quality images can be obtained.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing the main parts of a conventional image recording device, FIG. 2 is an overall configuration diagram of an image recording device equipped with a conveyance mechanism according to the present invention, and FIG. 3 is an operation of the conveyance mechanism shown in FIG. 2. It is an explanatory diagram. 10... Supply cassette, 14... Conveyance roller pair, 15... Holding plate, 16... Push lever, 18... Stopper, 20... Sub-scanning drum,
21... Nip roller, 22... Laser beam unit, S... Photosensitive film sheet.

Claims (1)

[Claims] 1. In an image recording device that uses a laser beam to main-scan an image signal onto a photosensitive film sheet that is conveyed at a constant speed on a sub-scanning drum,
A sub-scanning drum that is continuously rotated at a constant speed;
a nip roller that is in constant contact with the sub-scanning drum and rotates as a result of the rotation; a holding plate that is disposed substantially horizontally on a path from a photosensitive film sheet supply section to the sub-scanning drum and on which the photosensitive film sheet can slide; , a push lever that is installed on the supply section side of the holding plate and that can move forward and backward into the conveyance path and urges the rear end of the sheet forward in the advancing operation; a stopper that is movable forward and backward and that positions the leading edge of the sheet at the approach position, and the leading edge of the sheet is brought into contact with the stopper by the first advancing operation of the push lever when the sheet is supplied from the supply section onto the holding plate. After positioning, the push lever is released and the sheet is placed on the holding plate, and the leading edge of the sheet is sandwiched between the sub-scanning drum and the nip roller by the retracting action of the stopper and the second advancing action of the push lever. A transport mechanism for photosensitive film sheets.