JPS6278537A - Printer - Google Patents

Abstract

PURPOSE:To prevent forming of a black border by making a shading member movable back and forth by a wire stretched at an angle not parallel to the direction of scanning of a photosensitive body in a projecting light path. CONSTITUTION:When a light quantity sensor 36 in which photodetecting elements are arranged in a line parallel to a slit detects, light quantity near the slit 14 in the state of exposure and outputs a boundary detection signal that indicates position of largely different light receiving quantity existing in the direction of axial line of a photosensitive drum 15, a motor 32 rotates in the direction to wind a wire 18, and moves a shading sheet 17 to a position where light receiving quantity is largely different existing in the direction of axial line of the photosensitive drum 15, and then locks the shaft of an hourglass reel 13 by a brake 33 to prevent winding of the sheet 17 by a reel 30. Then, mirrors 12, 13 are returned in the direction of arrow mark W, and copying operation iis performed. Thus, the cause of a black border on a copied image can be eliminated.

Description

Detailed Description of the Invention A. Purpose of the Invention [Field of Industrial Application] The present invention projects a negative image recorded on a microfilm onto a moving photoreceptor through a slit, and makes a copy of it by reversal development. About the printer you get.

[Conventional technology]

Generally, most of the images recorded on microfilm are negative images, and a so-called reversal development type electrophotographic copying method is used to obtain a copy of a positive image from this negative image.

On the other hand, with negative image microfilm, generally, as shown in Figure 4, a negative image is recorded within each frame of microfilm F, and the periphery of each frame is transparent, and this peripheral transparent area is An opaque search mark 2 and a frame number 3 are each recorded.

In addition, the reader 7'I which generally uses microfilm
In the printer, since an area larger than one frame of microfilm is projected onto the photoreceptor, the transparent periphery is also exposed and the photoreceptor is unloaded.

Therefore, due to reversal development, toner particles may be present in the surrounding area.
However, a completely black so-called black frame is recorded around the image on the photoreceptor, and search mark 2 and frame number 3 are recorded within the black frame, resulting in an unsightly appearance and a decrease in the commercial value of the copied product. Furthermore, in the case of electrophotographic copying, there are problems such as increased consumption of toner.

To solve this problem, a mask with an opening corresponding to the size of one frame of the microfilm can be placed on the surface of the microfilm, but the mask must be changed every time the frame size changes. It is rather inconvenient. Also, when viewing the projected image of Screen Hi, search mark 2 and frame number 3 are no longer projected, so this mark and frame number? You will no longer be able to use it to search for information.

Therefore, there is a light-shielding mechanism that erases the black frame by moving and stopping a light-shielding member (or self-lighting sheet) 17 provided in the projection optical path in a direction perpendicular to the movement of the photoreceptor.6 [Problems to be Solved by the Invention] ] The above-mentioned light-shielding mechanism moves the light-shielding member 17.As shown in FIG. ing. The pair of wires 18 are connected to the light shielding plate 23
It is arranged at a position away from above the slit 14 of.

However, in the above configuration, a pair of parallel wires 18
If the diameter of the reel for winding is not set to the same size, the light shielding member 1
7 moves at an angle from the axial direction of the photosensitive drum 15. Therefore, the light shielding member 17
In order to prevent tilting and twisting from occurring in the axial direction of the wire, the pair of wires had to be aligned to have the same length, and the positioning accuracy of the axis of the reel for winding the wire had to be improved, which was a hassle.

An object of the present invention is to provide a printer that solves the above problems.

Structure of the Invention [Means for Solving the Problems] Unreleased Lsu 1 projects a negative image recorded on a microfilm onto a moving photoreceptor through a slit, and obtains a copy by reversal development. In the printer, an optical hk sensor for detecting the area boundary of an image frame and a C optical member movable back and forth in the moving direction of the photoreceptor are symmetrically placed in the projection optical path,
The light shielding member was constructed with a wire stretched so that the angle was not parallel to the scanning direction of the photoreceptor within the projection optical path, and the light fastness sensor detected the area boundary of the image frame. A.-1 is a printer characterized in that the light shielding member is moved and stopped at a predetermined position to block light outside the area of the image frame.

[For production]

The light-shielding member is made of a wire stretched at an angle that is not parallel to the scanning direction of the photoreceptor so that it can be retracted, so that it is possible to prevent a black frame from being formed when a negative image is copied using the reversal development method. This can be reliably prevented and the light shielding member does not move tilted from the axial direction of the photoreceptor.

〔Example〕

FIG. 1 shows a schematic configuration of the league printer of the present invention. A microfilm F is illuminated by an illumination means consisting of a lamp, four spherical mirrors, and a condenser lens 5. The image is projected onto the screen 11 at a predetermined magnification by the lens 6 by the league optical system consisting of the following. In this case, the scan mirrors 12 and 13 for the printer are moved in the direction of arrow W to a position where they do not block the projection optical path a to the screen.

When copying an image on microfilm, first place mirror 12 on the optical path between mirror 8 and mirror 9 as shown in the figure.
swell. Next, the mirror 12 and the mirror 13 are integrated into a drive device (not shown) in the direction of arrow W at the circumferential speed of a drum-shaped photoreceptor (hereinafter referred to as photoreceptor drum) 15 which is supported rotatably in the direction of the arrow. to scan the image light of the microfilm on the mirror 8-. The scanning image light passes through the mirrors 12 and 13, passes through the slit 14, and is projected onto the exposure position of the photosensitive drum 15.

A charging device, a developing device, a transfer device, and a cleaning device (not shown) are arranged around the photosensitive drum 15, and copies can be obtained by a known process.

The above is a known configuration, and the present invention improves the light shielding mechanism of the slit 14. FIG. 2 is a perspective view showing the structure of the light-shielding mechanism, in which the light-shielding sheet 17 wound around the reel 30 is directed in a direction perpendicular to the projection optical path and in the axial direction of the photosensitive drum 15. It is disposed immediately in front of the slit 14 so as to be movable in a direction perpendicular to the rotation of the slit.

The wires 18 attached to both sides of the tip of the light-shielding sheet 17 form one tree at the apex of the triangle, and this one wire is connected to the slit 1.
4, and is wound around a drum-shaped reel 31 connected to a motor 32 and a brake 33. Further, the reel 30 is arranged so that a force is always applied in the direction of the arrow 34 by a spring (not shown), and the stopper 35 receives a protrusion 37 attached to the tip of the light-shielding sheet, so that the reel 30
It is arranged so as to limit the winding range.

”: The light shielding mechanism is connected to the photosensitive drum 15 as shown in FIG.
Light-shielding sheets 17 are provided at both ends of the photosensitive drum 15 to block light entering the slit 14 so as to advance and retreat in the axial direction of the photosensitive drum 15, and are arranged in upper and lower stages.

Since the light shielding mechanism of the slit 14 has a two-leg structure, as shown in FIG. scans forward in the direction of arrow R, and the photosensitive drum 15 is exposed.

In this exposure state, a light amount sensor 36 in which light receiving elements are arranged in a row parallel to the slit 14 detects the amount of light near the slit 14, and the amount of light received in the axial direction of the photosensitive drum 15 differs greatly. When a boundary detection signal indicating (the boundary position of the black frame in the axial direction of the photosensitive drum 15) is output, the motor 32 rotates in a direction to wind up the wire 18, and the motor 32 rotates in the direction to wind up the wire 18, and the light shielding sheet 17 is moved onto the photosensitive drum 1.
After moving the sheet 17 to a position where the amount of received light differs greatly in the axial direction of the sheet 17, the brake 33 locks the shaft of the drum-shaped reel 31 to prevent the sheet 17 from being wound onto the reel 30 by the force of a spring (not shown). do.

Next, the mirrors 12 and 13 are returned to the direction of the arrow W to perform a normal copying operation, and the transparent portion of the microfilm F outside the image area boundary in the axial direction of the photosensitive drum 15 is shielded from light by a pair of light-shielding sheets 17 and exposed. Because it won't be done,
The cause of the black frame in the copy image is removed.

After the exposure, the brake 33 is released, and the light shielding sheet 17 is moved by the force of a spring (not shown) until the reel 3 reaches the position where the protrusion 37 attached to the tip of the light sheet 17 hits the stopper 35.
It is wound up to 0.

Hereinafter, since the sequence control of the sequential operations of H is performed by known means, the details thereof will be omitted.

In addition, in the rotational direction of the photosensitive drum, areas unnecessary for copying the microfilm (the transparent parts on the left and right sides of the frame in FIG. 4) are exposed to light on the photosensitive drum by opening and closing the movable light-shielding plate 23a that moves in the circumferential direction of the photosensitive drum 15. By controlling the start time and the end time of exposure, exposure can be prevented.

In the above embodiment, a sheet-shaped material wound around a reel is used as the light-shielding member, but a plate-shaped material may also be used.
Although the pair of light shielding sheets 17 are provided in the lower two stages of -1-, they may be provided on the same surface.

C1 Effects of the Invention Since the present invention is configured as described above, the light that has passed through the transparent area around the negative image on the microfilm is not projected onto the photoreceptor, so when the negative image is copied by the reversal development method. A positive image copy with high commercial value can be obtained without forming a black frame on the image.

Furthermore, since search information such as search marks and frame numbers are projected on the screen, there is no problem in searching for information.

Furthermore, the light-shielding member is constructed so that it can move forward and backward using a wire stretched at an angle that is not parallel to the scanning direction of the photoreceptor, so it does not move tilted from the axial direction of the photoreceptor drum, and can be reliably secured with a simple mechanism. Can move and stop,
There is no need to adjust the length of the wire or make the diameter of the reel for winding the wire the same on both sides with high precision. Even if the shaft of the reel for winding the wire is tilted to some extent due to poor positioning accuracy, the light shielding member is advantageous in that it does not cause major twisting.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing the main components of the printer of the present invention;
3 is a perspective view of a light shielding mechanism of the printer of the present invention, FIG. 3 is a perspective view of a conventional light shielding mechanism, and FIG. 4 is a front view of a microfilm. F is a microfilm, 14 is a slit, 15 is a photoreceptor (photosensitive drum), 17 is a light shielding member (light shielding sheet), 18
is a wire, and 36 is a light amount sensor. Figure 4

Claims (1)

[Claims] (1) In a printer that projects a negative image recorded on a microfilm onto a moving photoreceptor through a slit and obtains a copy through reversal development, a light sensor and a photoreceptor are used to detect the area boundaries of image frames in the projection optical path. A light-shielding member that can move forward and backward in the direction of movement of the body is provided symmetrically, and the light-shielding member is configured to be movable forward and backward using a wire stretched so as to form an angle that is not parallel to the scanning direction of the photoreceptor within the projection optical path. . A printer characterized in that the light amount sensor moves and stops a light shielding member at a predetermined position in response to a signal that detects a region boundary of an image frame, thereby blocking light outside the region of the image frame.