JP2505453Y2 - Light blocking device for optical scanning device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is an optical scanning device that scans and exposes light of an original image on a photosensitive member so that light other than scanning light is incident on the photosensitive member. The present invention relates to a shading device for preventing.

[Conventional technology]

2. Description of the Related Art An optical scanning device for scanning and exposing an image of a document onto a photosensitive sheet is used in a copying machine or the like for making a hard copy. This scanning moves the slit through which the light from the original image is transmitted in time series,
This is performed by exposing the photosensitive sheet with light from the slit. As an optical scanning device for performing such scanning, there is a case where an optical scanning device having a structure in which an optical member having a slit is made to travel between a document and a photosensitive sheet is used. By the way, in the optical scanning device, it is not preferable that the scanning light from other than the slit is incident on the photosensitive sheet. Therefore, it is indispensable to incorporate a light shielding device for preventing this. This light-shielding device needs to shield the entire photosensitive sheet except for the portion corresponding to the slit, following the traveling of the optical member.

A conventional shading device is provided with a flexible shading sheet having flexibility and a take-up reel for winding the shading sheet, as seen in a so-called guillotine shutter or a focal plane shutter, which is a similar technique, The light shielding sheet has one end connected to the optical member and the other end connected to the take-up reel. A pair of light shielding sheets are provided so as to be located on both sides of the optical member.The light shielding sheet on the upstream side in the traveling direction of the optical member is pulled out from the take-up reel following the traveling of the optical member, while the light shielding sheet on the downstream side in the traveling direction is shielded. The sheet is wound on a take-up reel. With such a storage structure by winding, the storage space for the light-shielding sheet is reduced, and the device can be downsized.

By the way, such a light shielding sheet needs to be smoothly wound on a take-up reel and needs to maintain a good flat state on the photosensitive sheet. Therefore, the take-up reel has a structure in which it is urged to rotate in the winding direction by a spring.

[Problems to be solved by the device]

As described above, in the conventional device, since the winding reel is rotationally biased in the winding direction, the structure of the winding portion is complicated. In addition, it is necessary to adjust the rotation biasing force of the take-up reel and the traveling driving force of the optical member in harmony. That is, if these adjustment balances are lost, the light-shielding sheet is loosened and the planar state is lost, so that not only the light-shielding cannot be performed well, but also the traveling speed of the optical member fluctuates and uniform exposure cannot be performed. This is because. by the way,
This adjustment is difficult, which is a difficulty during assembly.

The present invention has been made in consideration of such circumstances, and an object thereof is to provide a light shielding device of an optical scanning device having a simple structure and requiring no difficult adjustment.

[Means for solving the problem]

In order to achieve the above-mentioned object, the present invention has an original image means for emitting light of an image and a photosensitive member which are arranged at opposite positions, and an optical member runs between the original image means and the photosensitive member. An optical scanning device that travels and exposes light from an original image means onto a photosensitive member, which has flexibility of winding and a restoring property of restoring a flat state from a wound state, and accompanies traveling of the optical member. And a light-shielding member whose one end is connected to the optical member so as to move so as to cover the photosensitive member and the other end is a free end, and both ends of the light-shielding member in the moving direction are slidable and light-shielded. A guide groove for holding the member in a flat state, and a storage means for inserting the free end of the light shielding member and winding the light shielding member along with the movement and storing the light shielding member in a wound state are characterized.

[Action]

In the above configuration, the light shielding member is automatically wound and accommodated in the accommodating means due to its flexibility as the optical member travels. Further, when traveling in the opposite direction, the light blocking member is pulled out from the housing means, but since both ends of the light blocking member are inserted into the guide groove, a good flat state is maintained in combination with the restoring property. Acts to cover the photosensitive member.

〔Example〕

1 to 4 show the overall structure of an optical scanning device to which the present invention is applied.

This optical scanning device has an original image means 1 having an image.
Then, the photosensitive member 2 on which an image is recorded is fixed at a facing position, and the optical member 3 travels in a parallel direction between the original image means 1 and the photosensitive member 2 (second). (See Figure and Figure 4).

The original image means 1 has a structure for displaying an image to be recorded and emitting light from the image toward the photosensitive member 2. For example, a self-luminous panel such as a transmissive liquid crystal panel or a CRT display. Alternatively, an appropriate combination such as a combination of a negative film and a light source for emitting light to the negative film can be selected and used. On the other hand, as the photosensitive member 2, a photosensitive film having sensitivity to the light from the original image means 1, a photosensitive photographic paper, or a solid-state image pickup device for outputting an electric signal by exposure is appropriately used. The original image means 1 and the photosensitive member 2 are arranged so as to face each other, but both are fixed so as to maintain a planar state.

The optical member 3 horizontally reciprocates between the original image means 1 and the photosensitive member 2 and scans the photosensitive member 2 with image light from the original image means 1 in the outward direction travel.
In order to perform this scanning, an elongated slit 4 is formed in the optical member 3 in a direction orthogonal to the traveling direction, and as the optical member 3 travels, the light from the original image means 1 passes through the slit 4 and is photosensitive. It reaches the member 2.

The photosensitive member 2 is required to prevent exposure to light from other than the slits 4, and therefore the light shielding sheets 5 and 6 which are light shielding members that move so as to cover the photosensitive member 2 as the optical member 3 travels are the optical members. Connected to four.

FIG. 5 shows the optical member 3 in which the guide shaft 9 is inserted and the slider 7 reciprocates along the guide shaft 9.
And a lens array 8 mounted in a through hole 7a penetrating the slider 7 in the vertical direction, and the slit 4 is provided so as to face the upper part of the through hole 7a. Reference numeral 14 is a slit plate in which the slit 4 is formed, and is fixed to the upper portion of the slider 7 by screwing or the like. The lens array 8 is configured so that the light entering from the slit 4 is imaged on the photosensitive member 2. As shown in FIG. 1, a pair of guide shafts 9 are arranged in parallel with the traveling direction of the optical member 3.

The optical member 3 starts traveling in the forward direction from the position A shown in FIGS. 1 and 2, and stops traveling when it reaches the position B. The scanning of the image light of the original image means 1 starts at the C position between the A position and the B position, and the scanning ends at the D position. The optical member 3 reaching the position B travels in the backward direction, but the slit 4 is closed during the backward travel,
The photosensitive member 2 is prevented from being exposed to light.

In FIG. 1, FIG. 2 and FIG. 4, 10 is this slit 4
The shutter shafts are attached to both sides of the optical member 3 in order to open and close. The shutter shaft 10 is pulled out in the front-back direction of the traveling of the optical member 3, and the opening and closing of the slit 4 is switched at the end of the reciprocating traveling of the optical member 3. A shutter plate 17 is in contact with the lower surface of the slit plate 14 for switching the opening and closing of the slit 4, as shown in FIG. The shutter plate 17 is engaged with the shutter shaft 10, and when a pressing force in the traveling direction is applied to the shutter shaft 10, the shutter plate 17 slides in the forward and reverse directions on the lower surface of the slit plate 14, and this slide opens and closes the slit 4 of the slit plate 14. Is supposed to do.

In FIG. 1, reference numerals 11 and 12 denote stoppers provided at both ends of the traveling of the optical member 3. The shutter shaft 10 contacts the stoppers 11 and 12 and the shutter plate 17 slides to open and close the slit 4. Switching is performed. In addition, this stopper 1
Reference numerals 1 and 12 are formed integrally with the chassis portion 13 by raising and bending a predetermined position of the chassis portion 13 which constitutes the machine frame of the apparatus.

The reciprocating movement of the optical member 3 is performed by driving a motor 20 (see FIGS. 3 and 4). In the example shown,
The motor 20 is inserted and mounted in a storage drum 16 (described later) which is a storage means in which the light shielding sheet 6 is wound and stored, and the motor 20 can be mounted by effectively using the space in the storage drum 16. Space is no longer needed.

A reduction gear 22 is meshed with an output gear 21 of the motor 20, and a gear portion 23a of a drive pulley 23 is meshed with the reduction gear 22. A driven pulley 25 is provided at the end of the chassis portion 13 in the longitudinal direction with respect to the drive pulley 23, and an endless belt 24 is stretched around these pulleys 23, 25. The optical member 3 is connected to the belt 24, and is rotated in the forward and reverse directions by the motor 20 so that the belt 24 travels in the forward and reverse directions, thereby traveling in the reciprocating direction.

In this case, the driven pulley 25, as shown in FIG.
The belt 24 is attached to the tension arm 26 which is urged to rotate by 27, and acts so that the belt 24 maintains a predetermined tension. In FIG. 2, 28 is a guide roller provided on the drive pulley 23 side, and a second guide roller 28 is provided near the guide roller 28.
As shown in FIGS. 3 and 4, an origin sensor 29 including a photo sensor is provided. The origin sensor 29 is fixed to the chassis portion 13 on the belt 24 side and detects the origin of the traveling of the optical member 3, whereby the optical member 3 can start traveling from an accurate position.

The traveling of the optical member 3 needs to be performed at a constant speed in order to uniformly expose the photosensitive member 2. In order to perform this constant speed control, a DC motor or a stepping motor equipped with a detector such as an encoder or a frequency generator is used as the motor 20.

Such an optical scanning device is housed in the housing 30 as shown by the chain line in FIG. An upper surface of the housing 30 has an opening, and the original image means 1 is fitted and fixed in this opening. Portions other than the opening on the top surface are blocked, so that external light is prevented from entering the housing 30.

As shown in FIG. 5, the light-shielding sheets 5 and 6 are screwed at their one ends to both sides of the lower surface of the slider 7 of the optical member 3, and from this end in the traveling direction of the optical member 3. It extends in a flat state. As a result, as shown by the broken line in FIG. 3, the upper side of the photosensitive member 2 is covered in the forward and backward areas of the optical member 3 in the traveling direction.

The other end of each of the extended light-shielding sheets 5 and 6 is a free end, and storage drums 15 and 16 are provided at both ends in the longitudinal direction of the chassis 13 corresponding to the free ends. ing. The free end of each shading sheet 5 and 6 is the storage drum 1
Inserted within 5,16. As shown in FIG. 8, the storage drums 15 and 16 are formed such that the inner surfaces thereof are circular curved surfaces, and the light shielding sheets 5 and 6 are formed by the traveling of the optical member 3.
When moving in the direction of the corresponding storage drums 15 and 16, the free end 5
a, 6a (6a is not shown) slides on the inner surfaces of the storage drums 15 and 16, whereby the light shielding sheets 5 and 6 are stored while being wound along the inner surfaces of the storage drums 15 and 16. It is supposed to be.

In order to smoothly slide along the inner surfaces of the storage drums 15 and 16, the free ends 5a and 6a of the light shielding sheets 5 and 6 are tapered. FIG. 7 shows the free end 5a of the light-shielding sheet 5, and a tapered surface 5b is formed at the tip portion, and the tip end of this tapered surface 5b is cut to form a cut surface 5c. The edge part is not generated. This shape is similarly applied to the free end of the light-shielding sheet 6, so that the light-shielding sheets 5 and 6 have their free ends 5a,
The curve of 6a is guided to smoothly slide on the inner surfaces of the storage drums 15 and 16.

In the structure in which the light-shielding sheets 5 and 6 are wound and housed in the housing drums 15 and 16 as the optical member 3 travels in this way, a take-up reel and a spring for urging the reels are not necessary, and the structure is eliminated. Will be easier. Further, since the light shielding sheets 5 and 6 are stored only by the traveling driving force of the optical member 3, it is not necessary to adjust the driving force and the winding force, and the assembling becomes easy.

Since the light-shielding sheets 5 and 6 are housed in the storage drums 15 and 16, they have flexibility in a wound state, and are pulled out from the storage drums 15 and 16 while following the traveling of the optical member 3. In some cases, it is necessary to have a restoring property such that the flat state is maintained above the photosensitive member 2. In order to have such characteristics, the light-shielding sheets 5 and 6 are preferably molded from a plastic film such as polyester resin. In addition to such a configuration, in order to reliably maintain the planar state of the light shielding sheets 5 and 6, both sides of the light shielding sheets 5 and 6 are held by the chassis portion 13.

FIG. 6 shows this structure on the light-shielding sheet 5 side, and the chassis portion 13 is formed by superimposing three plate materials. Light-shielding sheet 5 in this chassis 13
Guide grooves 31 are formed in the longitudinal direction on both side surfaces of the side, and both side portions of the light shielding sheet 5 are slidably inserted into the guide grooves 31. In the figure, reference numeral 32 denotes a raised material stretched on the upper and lower inner surfaces of the guide groove 31, and acts so as to sandwich the side portion of the light shielding sheet 5 from the vertical direction. Further, the raised material 32 is also planted at both front and rear ends of the chassis portion 31, and is continuously provided along with both side portions of the chassis portion 31 at its inner edge in the circumferential direction. This raising material 32 is the light shielding sheet 5
The side portions are closely contacted with each other in the vertical direction to prevent light from leaking from the guide groove 31. The light-shielding sheets 5 and 6 have both side portions inserted into the guide groove 31, and thus the flat state of the light-shielding sheets 5 and 6 can be maintained in a good condition, and the light-shielding to the photosensitive member 2 is prevented. Is surely done.

 Next, the operation of the above configuration will be described.

As shown in FIG. 4, the original image means 1 and the photosensitive member 2 are fixed at opposing positions, and the optical member 3 is stopped at the traveling start position A with the slit 4 opened. The photosensitive member 2 is fixed so as to be in a flat state, and its flatness is maintained well. On the other hand, the photosensitive member 2 emits light from the image to the photosensitive member 2.

In this state, the light-shielding sheet 6 is wound and stored in the storage drum 16, while the light-shielding sheet 5 is pulled out from the storage drum 15, and both side portions thereof are guided by the guide groove 31 of the chassis portion 13.
It is inserted inside and the flat state is maintained. When the start switch (not shown) is turned on in this state, the motor 20
Is activated and the belt 24 starts running. As a result, the optical member 3 travels from the A position in the forward direction (direction toward the B position). When the slit 4 of the optical member 3 reaches the position C in this traveling, the light from the original image means 1 passes through the slit 4 and enters the photosensitive member 2, and the photosensitive member 2 is exposed to light. The optical member 3 runs at a constant speed, and the light from the original image means 1 scans the photosensitive member 2 by this running. Then, when the position D is reached, the scanning of the photosensitive member 2 is finished, but the optical member 3 further continues to reach the position B. At this B position, the shutter shaft 10 stops
Since it hits 12, the shutter plate 17 slides to close the slit 4.

In the above traveling of the optical member 3, the light shielding sheet 6 is pulled out from the storage drum 16 in accordance with the traveling of the optical member 3, while the light shielding sheet 5 is gradually wound and stored in the storage drum 15.

FIGS. 8 (a) and 8 (b) show the operation of the light-shielding sheet 5. At the beginning of the traveling of the optical member 3, the free end 5a of the optical member 3 is inserted into the storage drum 15, and the photosensitive member is kept in a flat state. The upper part of the member 2 (not shown) is covered (Fig. 8 (a)). When the optical member 3 travels, the traveling force of the optical member 3 causes the free end 5a to be wound while sliding on the inner surface of the storage drum 15. As a result, the light shielding sheet 5 is wound and stored in the storage drum 15 (FIG. 8 (b)).

In this case, it is not preferable that the light-shielding sheet 5 is wound many times in the storage drum 15 in order to maintain good restoration to a flat state, and the number of windings is 1-3 times, preferably about 1.5 times. The number of times is good. In contrast to such a light-shielding sheet 5, the light-shielding sheet 6 is pulled out from the storage drum 16 and covers the photosensitive member 2 with the guide groove 31 of the chassis 13 maintaining a good flat state. For this reason, the photosensitive member 2 is not exposed to light from other than the slit 4.

Since the motor 20 is driven in the reverse direction after the optical member 3 reaches the position B, the slit 4 is closed by the shutter plate 17 in this backward traveling in which the optical member 3 travels in the backward direction. The exposure of the photosensitive member 2 is prevented. Then, when the optical member 3 reaches the position A, the shutter shaft 10 abuts on the stopper 11, so that the shutter plate 17 slides in the direction opposite to the above to open the slit 4, and the waiting state for the next scanning is set. Become. It should be noted that the traveling time in the backward direction can be saved at high speed to reduce the loss time to the waiting state.

[Effect of device]

As described above, according to the present invention, the light-shielding member that covers the photosensitive member is housed in the housing means in a wound state as the optical member travels, so that the structure is simple and the traveling driving force of the optical member is Also, it is not necessary to adjust the winding force of the light shielding member, and since the light shielding member keeps a good flat state by the guide groove, it is possible to surely shield light.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of the present invention, FIGS. 2, 3, and 4 are front views, rear views and rear views thereof, respectively. FIG. 5 is a sectional view showing an optical member, and FIG. Is a sectional view showing a guide groove, FIG. 7 is a sectional view showing a free end of a light shielding sheet, and FIGS. 8 (a) and 8 (b) are sectional views showing an operation. 1 ... Original image means, 2 ... Photosensitive member, 3 ... Optical member,
4 …… Slit, 5,6 …… Shading sheet, 7 …… Slider, 13 …… Chassis part, 15,16 …… Storage drum, 20 ……
motor.

Claims (1)

(57) [Scope of utility model registration request] 1. An original image means for emitting light of an image and a photosensitive member are arranged at opposite positions, and an optical member travels between the original image means and the photosensitive member. An optical scanning device that scans and exposes light onto a photosensitive member, which has flexibility of winding and has a restoring property of restoring a rolled state to a flat state, and the photosensitivity according to traveling of the optical member. A light-blocking member having one end connected to the optical member so as to move in a state of covering the member and the other end being a free end, and both ends of the light-blocking member in the moving direction are slidable,
Further, it is provided with a guide groove for holding the light shielding member in a flat state, and a storage means for inserting the free end of the light shielding member and winding the light shielding member along with the movement and storing the light shielding member in a wound state. A light shielding device for an optical scanning device.