JPS61198222A - Slit scanning type copying machine - Google Patents

Abstract

PURPOSE:To take an anamorphic variable power copy excellent by varying the width of a slit in the 2nd image formation mode to less than in the 1st image formation mode and increasing electric power supplied to an exposure lamp. CONSTITUTION:When the magnification of an image forming device 1 is denoted as beta1, a scanning speed (v) is set to v=v2 (=V/beta1.beta2) for the moving speed V of a photosensitive body 6 in the 2nd image formation mode and then the magnification is set to beta1.beta2 times in the scanning direction of an original M and beta1 times in the direction perpendicular to the scanning direction. Namely, what is called the anamorphic variable power copy is taken. In this case, a silt width control means SC is provided to make the width (d) of a slit 3 less in the 2nd image formation mode than in the 1st image formation mode. Further, a controller performs controls so that the electric power supplied to the exposure lamp 2 is less than in the 1st image formation mode, thereby compensating a decrease in the quantity of light projected on a photosensitive drum 6 due to a decrease in the slit width (d) for reflected light L.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a method for scanning a document scanned by a slit exposure method.
The present invention relates to a slit scanning type copying machine capable of performing so-called anamorphic variable-magnification copying, in which copies are enlarged or reduced to arbitrary sizes by varying the vertical and horizontal change rates.

More specifically, it includes a scanning device that moves an exposure lamp and a document relative to each other, and projects the image of the document scanned by the scanning device onto a photoreceptor that moves in a direction corresponding to the scanning direction through a slit. A first imaging mode configured to form an image at the same magnification in the scanning direction and in a direction perpendicular to the scanning direction, and a ratio between the scanning speed of the scanning device and the moving speed of the photoreceptor. A slit scanning type copying machine provided with an imaging mode selection means for switching between a second imaging mode in which images are formed at different magnifications in both directions by making the image formation mode different from the first imaging mode. Regarding.

[Prior Art] In the second imaging mode, the above-mentioned slit scanning copying machine predicts in advance the elongation of the base paper when it is set in the printing machine, for example, when producing base paper for printing by copying. It is used to anamorphically change the magnification of the original paper for a manuscript, or to perform anamorphic magnification copying to form a margin as a binding margin on the copied paper. be.

In the first imaging mode, the magnification by the imaging device is set to (1, 0), and the scanning speed (v) and the moving speed (V) of the photoreceptor are made equal to each other, so that the size is the same as that of the original. You can make copies of In this mode, the magnification by the imaging device is set to (βI), and the photoconductor is moved in proportion to the length of the image projected onto the photoconductor by (β1) times by this imaging device. , moving speed of photoreceptor (v)
By setting the scanning speed (v) to v = vt (V, ``V/A), it is possible to copy the original document by multiplying it by (βl) in both the vertical and horizontal directions.

In addition, in the second imaging mode, the magnification by the imaging device is set to (
β1) and the scanning speed (v) with respect to the moving speed (V) of the photoconductor is set to V=-(ζ=V/A-^), so that the original is moved in the scanning direction (β, Copying can be performed by β2) times and (β1) times in the direction perpendicular to the scanning direction.

However, in the second imaging mode, the moving speed of the original image projected onto the photoreceptor by the imaging device and the moving speed of the photoreceptor are different, so the image is not formed on the photoreceptor. There is a risk that the image of the original document will be misaligned and the resolution will be reduced.

This will be explained using a schematic diagram of a state in which an original image is projected onto a photoreceptor shown in FIG. 11. Note that the width of the slit (3) is (d), the magnification by the imaging device ([) is (β,), and the scanning speed (v) is (v= V/β1β2), and the exposure lamp is not shown.

A certain point (80) on the original (M) is located at the point (A) relative to the photoreceptor (6) when one end of the slit (3) approaches.
). As the scanning device (S) moves, when the other end of the slit (3) approaches a certain point (80) on the document (M), this point (80) becomes a point relative to the photoreceptor (6). (Ao). In other words, the photoreceptor (6)
The image of the point (Ao) projected onto the point (Ao) is
) to point (Ao), and the moving distance (
0+) is the length of the slit width (d) projected with the magnification (β, ), that is, D, = fi−d.

Meanwhile, during this time, the point (B) corresponding to the point (8) on the photoreceptor (6) moving at the speed (V) moves to the point (Bo). That route of travel! (Dn) is D o = (d/v)・V − (d/(V/8・A))・V −8・^・d − [1], and the moving distance of the projected image (D+) different from. Then, the difference (Δ) between the re-movement distances CD+) and (Do), that is, Δshih−D□=to・爲・d−8・d−8・d・(A−1)−[2] As a result, the resolution of the image formed on the photoreceptor (6) is reduced.

Therefore, by interposing an anamorphic optical element such as a cylindrical lens that has refractive power (β) only in the scanning direction in the projection optical path to the photoreceptor, the distance that the image projected on the photoreceptor moves A method has been proposed in which is made equal to the moving distance of the portion corresponding to the image on the photoreceptor (see, for example, Japanese Patent Publication No. 53-28087).

[Problem that the invention seeks to solve]

However, in the case of the above-mentioned conventional configuration, since an expensive anamorphic optical element is used, there is a vibration that increases the cost of the copying machine.

In view of the above-mentioned circumstances, an object of the present invention is to provide a structure for suppressing a decrease in resolution of an image formed on a photoreceptor when performing anamorphic variable magnification copying with different vertical and horizontal magnifications, in a cost-effective manner. The purpose is to make it advantageous.

[Means for solving problems]

The characteristic structure of the slit scanning copying machine according to the present invention is a first imaging mode in which images are formed at the same magnification in the scanning direction and in a direction perpendicular to the scanning direction, and the scanning speed by the scanning device and the movement of the photoreceptor. The image forming mode selected by the imaging mode selection means switches between a second imaging mode in which images are formed at different magnifications in each of the two directions by changing the ratio to the speed from the first imaging mode. A slit width control means that changes the width of the slit in the second imaging mode to be smaller than that in the first imaging mode according to the imaging mode, and an exposure lamp in the second imaging mode. The present invention is provided with an exposure lamp control means for changing the power supplied to the image forming apparatus to be greater than that in the first imaging mode.

[For production]

That is, as is clear from equation [2], in the first imaging mode where the vertical and horizontal magnifications are the same, &=1, Δ=0, and no image shift occurs.

On the other hand, in the second imaging mode for performing anamorphic variable magnification copying, the speed ratio between the scanning speed (V, ) in the first imaging mode and the moving speed of the photoreceptor (v), r+ -V/Vl
-V/(V/IA) = Speed ratio rt different from IA = V/*= V/(V/A・A) = A・A, which is set by changing the value of (β2) Accordingly, looking at equation [2], it is clear that the slit width (d) is a factor in reducing the resolution of the image.

Therefore, in the second imaging mode, the width of the slit (
It can be seen that the smaller d) is, the more the reduction in resolution can be suppressed.

However, simply narrowing the slit width will not
There is a possibility that another inconvenience may occur. In other words, because the amount of light projected onto the photoreceptor decreases, image formation on the photoreceptor may not be performed well, or the copy speed may decrease in order to project a sufficient amount of light onto the photoreceptor. This means that the

Therefore, it is conceivable to set the light amount of the exposure lamp to be large in advance. However, even in the first imaging mode, which does not require a particularly large amount of light, the amount of light from the exposure lamp is always large, which tends to cause problems such as increased power consumption and the temperature of the glass on the document table. It is.

By the way, copying machines are generally equipped with a means for adjusting the amount of light emitted by the exposure lamp in order to always make good copies regardless of the brightness of the original, or to compensate for deterioration of the exposure lamp itself. It is something that exists. Therefore, focusing on this, in the copying machine according to the present invention, the width of the slit in the second imaging mode is changed to be smaller than that in the first imaging mode, and the width of the slit in the second imaging mode is changed. By increasing the power supplied to the exposure lamp in the first imaging mode than in the first imaging mode, it is possible to suppress the reduction in resolution in the anamorphic variable magnification copying state, even though the configuration is simple, and to improve the overall performance of the copying machine. This is to minimize the increase in power consumption and the temperature of the platen glass.

〔Example〕

The present invention will be described in detail below based on the drawings.

FIG. 4 is a sectional view schematically showing a slit scanning type copying machine according to the present invention.

A manuscript (M
) is irradiated by the exposure lamp (2), and the reflected light from the original (original) passes through the slit (3) and passes through the imaging lens (4).
The image is projected onto the photoreceptor drum (6) via an imaging device (1) comprising a plurality of mirrors (5a) to (5d) and the like. The exposure lamp (2), the slit (3) and the first mirror (5a), which are examples of the scanning device (S), have a speed (
v), it is configured to move to the left in the figure by a DC motor (not shown) and scan the original (M). Also,
The second mirror (5b) and the third mirror (5c) move at a speed ( v/2) and is configured to move to the left in the figure by the same DC motor. The image of the document (M) scanned by this scanning device <S> is then transferred to a photosensitive drum (6) which is rotated counterclockwise in the figure by a motor (not shown) separate from the scanning device (S). ) to form an electrostatic latent image.

Around the photoreceptor drum (6), there is a main charger (7) that uniformly charges the surface of the drum, and a toner attached to an electrostatic latent image formed by projection imaging by an imaging device (I). A developing device (8) that forms an image, a transfer separation device (9) that transfers the developed image onto a transfer paper and separates the transfer paper from the photoreceptor drum (6), and adheres to the surface of the photoreceptor drum (6) after transfer. Cleaning device (1) to remove excess toner
0), and an eraser (11) for erasing the charge on the photosensitive drum (6) after transfer.

On the other hand, two types of transfer paper of different sizes are stored in separate paper feed cassettes (12a) and (12b), and the designated size of recording paper is transferred to the pink up roller (13a). ) or (13b), the sheets are taken out one by one and sent to the transfer separation device (9). The transfer paper separated after the developed image on the photoreceptor drum (6) has been transferred by the transfer separation device (9) is sent to the fixing device (14), and the toner forming the transferred developed image is transferred to the fixing device. (14)
After being melted and fixed by heating, it is carried out onto a tray (15) outside the copying machine.

In this copying machine, two imaging modes can be selected during copying.

That is, in the first imaging mode, the magnification of the imaging device (I) is set to (1, 0), and the scanning speed (v) is set equal to the moving speed (V) of the photoreceptor (6). So, the manuscript commercial
) can make copies of the same size. In this mode, the magnification of the imaging device (1) is changed by changing the conjugate length by moving the imaging lens (4) and the fourth mirror (5d) in the horizontal direction in the figure using a stepping motor. By (β
, ), and by this imaging device (I), (β
The scanning speed (v) is adjusted relative to the moving speed (v) of the photoreceptor (6) so that the photoreceptor (6) moves in proportion to the length of the image projected onto the photoreceptor (6) by a factor of I). ) by setting v = Vl (Vt = V/A) to 1
．． It is possible to copy the original (M) by multiplying it by (βl) both vertically and horizontally.

In the second imaging mode, when the magnification of the imaging device (1) is (βI), the scanning speed (v) is set as v = Vg ( By setting v2 = v, /β, ・A), the original (M) is multiplied by (β1β2) in the scanning direction and (β1) in the direction perpendicular to the scanning direction, so-called anamorphic variable-magnification copying. It is now possible to do so.

However, when performing anamorphic variable magnification copying, there is a risk that the image of the original (M) formed on the photoreceptor (6) may be misaligned, resulting in a decrease in resolution.

This will be explained using FIG. 11. In addition, the width of the slit (3) is (d), and the magnification of the imaging device (I) is (β,).
, the moving speed (V) of the photoreceptor (6), and the scanning speed (v) are (
v = V/β, β2).

A certain point (80) on the document (M) is projected onto a point (A) on the photosensitive drum (6) when one end of the slit (3) approaches. By moving the scanning device (S), the other end of the slit (3) moves to a certain point (A) on the document CM).
When approaching point o), this point (A6) is projected onto the point (Ao) with respect to the photosensitive drum (6). In other words,
The image of the point (A,) projected onto the photoreceptor drum (6) is
It moves from point (A) to point (Ao) as it scans, and its moving distance (DI) is the length of the slit width (d) projected at the magnification (βl), that is, DI==昂・It is d.

Meanwhile, during this time, the photoreceptor drum (6
), the point (B) corresponding to the point (A) is the point (B'
). The moving distance (D,) is D D =
(d/v)・V = (d/(V/β1・A))・■ =8・^・d −[1 piece,
It is different from the moving distance (Or) of the projected image. Then, the difference (Δ) between the moving distances (DI) and (DO), that is, Δ=Do D+=8・bird・d−8・d=8・d・(ordinary−1)−[2 As a result, the resolution of the image formed on the photosensitive drum (6) is reduced.

In other words, in the first imaging mode, (β2) is (1, 0), so no image shift occurs, but in the second imaging mode, (
It can be seen that the resolution decreases depending on the value of β, ).

Therefore, in this copying machine to which the present invention is applied, the second
In the imaging mode, the width (d) of the slit (3) in the second imaging mode is made smaller than in the first imaging mode in order to reduce the value of (Δ) shown by the equation 2. A slit width control means (SC) is provided to change the width as shown in FIG. Next, this slit width control means (SC) will be explained.

As shown in Figures 1 (A) and (El), reflected light (L) from the original (M) irradiated by the exposure lamp (2)
) A fixed slit member (3a) having a constant aperture width (d, ) for the reflected light (L), and a fixed slit member (3a) having an aperture width smaller than that of the fixed slit member (3a). At (d2), it is attached to a rotating shaft (3x) that can freely rotate around the axis (P) between a position where it acts on the reflected light (L) and a position where it does not act on the reflected light (L). second
It is composed of a rotating slit member (3b) as shown in the figure.

In the first imaging mode, as shown in FIG.
The fixed slit member (3a) has an aperture width (d) to allow the reflected light (L) to pass through the fixed slit member (3a). In addition, in the second imaging mode, as shown in FIG.
As shown in I), the rotary slit member (3b) is positioned in the optical path of the reflected light (L), and the structure is such that the reflected light (L) passes through its opening width (dz).

The operation of changing the position of the rotary slit member (3b) between the above-mentioned repositions is performed using the imaging mode selection key (65), which will be described later.
) is automatically performed depending on the status of
Next, the configuration and operation for this purpose will be explained.

As shown in Figure 3 (a) to 2), the scanning device (S
), which constitute the exposure lamp (2), slit (3), first mirror (5a), etc., are attached to the support frame (16). On the other hand, on the scan start end side and the scan end side of the frame (17) on the copying machine main body side that supports the document table (1),
Protrusions (17a) and (17b) are formed to abut on the free end side of the rotating slit member (3b), respectively. Also,
On the scanning start end side of this frame (17), two photosensors (18a) and (1
8b) are provided, and the detection portion (16a) formed on the scanning device support frame (I6) is connected to the photosensor (18a).
, (18b), the position of the scanning device (S) can be detected.

FIG. 3(a) shows the scanning bag W in the first imaging mode.
(S) indicates the home position. Stopping of the scanning device (S) at this home position after a certain scanning operation is performed by the detection unit (16a) of the support frame (16).
is detected by the first photo sensor (18a) on the left in the figure, thereby stopping the DC motor for the scanning device (S). The first protrusion (17a) formed on the scanning start end side of the frame (17) is arranged so as not to contact the free end side of the rotation slit member (3b) in this state. Therefore, the rotating slit member (3b
) remains in a position retracted out of the optical path of the reflected light (L), and the opening width (d, ) of the fixed slit member (3a) is
[Acts as a slit width (d) for reflected light (L) shown in the 2-column formula.

Thereafter, the scanning device (S) moves from this home position to the left in the figure by driving the DC motor, and scans the original (M).
is scanned. In the first imaging mode, when the copy size is maximum and the scanning amount is maximum, the moving direction of the scanning device (S) is reversed in the state shown in FIG. 3(B). This inversion operation is performed as follows.

That is, the DC motor for the scanning device (S) is provided with an optical encoder that digitally detects its rotational speed. Then, at the same time as scanning starts, a control device as described later starts counting pulse signals output from this optical encoder, and when the counted number of pulses reaches a set value, it is determined that the reversal position has been reached. Then, the inversion operation is performed.

The second protrusion (
17b) is arranged so as not to touch the free end side of the rotating slit member (3b) shown by the broken line in the figure in this state. Therefore, the position of the rotating slit member (3b) does not change.

FIG. 3(8) shows the scanning device (
S) is at the home position. When the second imaging mode is selected by the imaging mode selection key (65), preliminary scanning is performed only once before scanning for copying, and the scanning device (S) ,
Only during this preliminary scanning, the apparatus is configured to return to the home position shown in FIG. 3(C) 6. Thereafter, when the copying machine is operated multiple times in the second imaging mode, the scanning device (S) returns to the home position shown in FIG. 3(A) after scanning for copying. It looks like this.

The scanning device (S) is stopped at this home position after the preliminary scan by the detection part (If) a) of the support frame (16).
is detected by the second photo sensor (18b) on the right side in the figure, thereby scanning device 1! DC for f (S)
This is done by stopping the motor.

The scanning device (S) shifts from the home position in the first imaging mode explained earlier in FIG. 3(A) to the home position in the second imaging mode shown in FIG. 3(C). During the process, the rotating slit member (3b)
By hitting the first protrusion (17a), the position is changed from the position shown by the dashed line in the figure to the position shown by the solid line in the figure, and the receiver is configured to be stopped by the pin (19).

Therefore, the opening width (d2) of the rotating slit member (3b) acts as the slit width (d) for the reflected light (L), as shown in equation [2].

In other words, the slit width (d=a
Z) is the slit width (d=d
, ), and the image is caused by the difference (Δ) between the moving distance of the projected image relative to the photosensitive drum (6) and the moving distance of the photosensitive drum (6), which is determined by equation [2]. As a result, the deviation of the images is reduced, and a decrease in resolution can be suppressed.

Although it cannot be illustrated, in this second imaging mode, as will be described later, the control device controls the power supplied to the exposure lamp (2) to be greater than in the first imaging mode. The photoreceptor drum (6
) is configured to compensate for a decrease in the amount of projected light.

Thereafter, by driving the DC motor, the scanning device (S) moves from this home position to the left in the figure, and the original (M) is moved to the left in the figure.
) is scanned. When the copying operation is performed multiple times in the second imaging mode, when the scanning amount is maximum, the scanning device is operated in the state shown in FIG. 3 (El), as in the first imaging mode. The direction of movement of (S) is reversed. The second protrusion (17b) of the frame (17) is
Even in this state, the rotating slit member (3b) shown by the solid line in the figure
Since it does not hit the free end side of the rotating slit member (3b
) position does not change.

On the other hand, even when the selection is switched from the second imaging mode to the first imaging mode by operating the imaging mode selection key (65), the preliminary scan described earlier is performed only once. It has become. Then, only during this preliminary scanning, as shown in Fig. 3 (=
), the direction of movement of the scanning device (S) is reversed. The configuration for performing the reversal operation in this state is the same as that described in the explanation of FIG. 3(0), and it is only necessary to change the set value of the counter. While the scanning device (S) is moving from the reversal position described earlier with reference to FIG. 3(0) to the reversal position shown in FIG. 3(d), the rotating slit member (3b) (1
7b), the position is changed from the position shown by the dashed line in the figure to the position shown by the solid line in the figure, and the configuration is such that it returns to the state suitable for the first imaging mode described earlier.

The specific configuration of the slit width control means <SC> is shown in FIG.
In place of what is shown in FIG. 2 and FIG. 3 (a) to 2), changes can be made as appropriate, and some examples will be listed below.

<A> Modified example of the structure of the slit (3) itself.

<1> As shown in Fig. 12, the rotating slit member (3b
) is attached with a coil spring (20) to form an unstable switching mechanism. In this case, the position of the rotary slit member (3b) can be reliably changed according to the re-imaging mode, and the rotary slit member (3b) can
It is possible to reduce vibrations due to the influence of vibrations of (S), etc.

<2> The effective slit width (d
) is configured to be changeable. In this case, the fixed slit member (3a) can be omitted.

3) The slit (3) is composed of two plate pieces, and by sliding the two plate pieces in conjunction with each other in opposite directions with respect to the scanning direction, the distance between the two plate pieces can be adjusted. The determined slit width (d) is changed.

4) The slit (3) is constructed from two plate pieces as in the modification example 3>, and by rotating these two plate pieces in conjunction with each other around different axes, a drawing board can be created. The slit width (d) determined as the distance between the free ends of the pieces is varied.

5) In the structure of the slit (3) in the above-mentioned embodiment or the structure of the slit (3) according to the above-mentioned modifications 2) to 4), the slit width (d) is set to 3.
Change the type in more than one step. In this case, an appropriate slit width (d) can be obtained in accordance with the ratio of the vertical and horizontal copying magnifications in the second imaging mode.

Also, at this time, the light amount of the exposure lamp (2) also changes to the slit width (
It is preferable to make the change stepwise in conjunction with the change in d).

(6) In the structure of the slit (3) in the embodiment described above, or in the structure of the slit (3) according to the above-mentioned modifications (2) to (4), the slit width (d) can be changed steplessly. Let them do it. In this case, the slit width (d) can be changed more accurately in accordance with the ratio of the vertical and horizontal copying magnifications in the second imaging mode.

Moreover, at this time, as in the case of modification 5>, it is preferable that the light amount of the exposure lamp (2) is changed steplessly in conjunction with the change in the slit width (d).

(B) A modified example of the structure in which the width (d) of the slit (3) is changed.

Due to the contact with the pair of protrusions (17a) and (17b) formed on the frame (17) as described in the previous embodiment,
The configuration for changing the position of the rotating slit member (3b) is (
Modification example 1 of the structure of the slit (3) explained in A>
It can be applied in or 4).

(7) Stopping the scanning device (S) at the home position after preliminary scanning in the second imaging mode is performed using an optical encoder attached to the DC motor. That is, at the home position of the first imaging mode shown in FIG. When the value reaches the set value, it is determined that the home position in the second imaging mode shown in FIG. 6 has been reached, and the scanning device (S) is configured to be stopped.

In this case, the second photo sensor (18b) can be omitted. This configuration is modified example 1〉or 4〉.
It can also be applied to

8〉Modification Example 7〉 has substantially the same configuration as above, but a timer is used instead of the pulse count. That is, the timer is started when the scanning device (S) starts moving, and the scanning device (S) is stopped when the timer expires after a preset time.

This configuration also has the second photo sensor (
18b) can be omitted. Also, modification examples 1〉or 4〉
It is also applicable to

<9> All position control of the scanning device (S) is performed using the optical encoder described above. In other words,
When the scanning device (S) moves, pulse counting is always performed, and the position is controlled by converting it into a displacement amount from a reference home position.

In this case, the first and second photosensors (18a)
, (18b) can be omitted. This configuration is also applicable to Modifications 1> to 4>.

<10> Modification Example It has almost the same configuration as 9>, but the modification example (
Similar to 8), use a timer instead of pulse counting. In other words, a plurality of time-up times are predetermined corresponding to each control position, and timers necessary for control are operated as appropriate.

In this configuration as well, the two photosensors (18a) and (18b) can be omitted, similar to modification (9).

It is also applicable to Modifications N) to 4>.

<11> A pair of protrusions (17a) and (17b) formed on the frame (17) on the side of the copying machine main body are respectively configured to be movable in and out of the movement path of the scanning device (S), and the slit (3 ) only when it is necessary to change the width (d) of the protrusions (17a) and (17b) using the scanning device (S).
so that it protrudes into the movement path of the

In this case, in any imaging mode, there is no need to change the scanning amount as explained in the previous embodiment, and the copying speed can be increased by minimizing the scanning amount. can. According to this configuration, the modified example
Even if it does not comply with 7> or <8>, the photosensor is 1
It may be one piece.

(12> The scanning device (S) is always positioned at the home position shown in Fig. 3 (a), and when the second imaging mode is selected, the scanning device (S)
It is moved to the position shown in Figure (C) to change the width (d) of the slit (3), and then reversed to perform scanning for copying. Furthermore, after scanning the original (M), the reversal is always performed at the position shown in FIG. 3 (D),
The width (d) of the slit (3) is returned to its original value. That is, in the second imaging mode, the slit width (d) is changed for each copying operation.

In other words, since the rate of copying operations in the second imaging mode is extremely small compared to the first imaging mode, such a configuration does not cause any particular inconvenience. On the other hand, with this configuration, the preliminary scanning described in the previous embodiment can be omitted, and the copy speed can be increased.

In this configuration, modifications 7> to 10> can be applied. Furthermore, this configuration can be modified as modified example <1> or 4>
It can also be applied to

<13> A spring is provided to bias the rotating slit member (3b) toward the position in one imaging mode, a solenoid is provided opposite to the free end side of this member (3b), and the solenoid is energized. Rotating slit member (3b
) is configured to be rotated to the position in the other imaging mode by attracting the free end side of the lens.

In this case, since the width (d) of the slit (3) can be changed instantaneously using electrical means, there is no need for preliminary scanning, and moreover, the scanning amount can be changed depending on the imaging mode. There's no need. Therefore, it is possible to further increase the copy speed. As mentioned earlier, considering that copying is rarely done in the second imaging mode,
Power consumption can be reduced by urging the rotating slit member (3b) toward the position in the first imaging mode using a spring.

Modifications <9> or <10> of this configuration can also be applied. Further, this configuration can be applied to Modification Example 2), and can also be applied to Modification Examples <3> and <4> by configuring the interlocking mechanism appropriately.

<14> A stamping motor is interlocked and connected to the rotation shaft (3x) of the rotation slit member (3b), and the rotation slit member (3b) is configured to be rotated by the drive of this motor.

In this case, reliable slit width (
d) switching can be performed. Further, preliminary scanning can be omitted, and there is no need to change the scanning amount depending on the imaging mode, so that the copying speed can be increased.

In variations 5> and 6), the slit width (d
) It is preferable to apply this configuration for precise control. Further, it can be applied to Modifications 1) and 2>, and can also be applied to Modifications 3> and 4> by appropriately configuring the interlocking mechanism.

Next, a control device for a copying machine equipped with the slit width control means (SC) described above and its operation will be explained.

FIG. 5 shows the operation panel (50) of the copying machine.
(51) is a print button, and (52) is a display device that digitally displays the number of copies and copy magnification. (53
) is the copy density setting operation section, which has two keys (53a),
, (53b), the copy density can be set. (53c) is a group of LEDs that display the set copy density.

(54) is a numeric key, and by pressing any key,
It is possible to set the number of copies, copy magnification, etc. (55) is an interrupt key, and (56) is a clear stop key for canceling the input by the numeric key (54) and interrupting the copying operation.

(57) is a paper selection operation section, (57a) is a selection key,
(57b) is a group of LEDs that display the selected paper type.

(60) is the standard magnification setting operation section, with four keys (61)
By pressing any one of (64) to (64), the original (M) can be made into a copying state in which the original (M) can be equally enlarged or reduced both vertically and horizontally at three preset magnifications, and when the original (M) is the same size as the original (M). It is possible to set the copy state to a state where the copy can be made.

(61a) to (64a) are LED groups that display respective set magnifications.

(65) is an imaging mode selection key which is an example of imaging mode selection means. As described later, each setting value is initialized when the power is turned on, but at this time the imaging mode is
Copy the original (M) at the same magnification in both the vertical and horizontal directions.
The first imaging mode is set. In the first imaging mode, each key (dl
) to (64) can be selected. In this state, press the imaging mode selection key (65
) is pressed once, the imaging mode is switched to the second imaging mode. In the second imaging mode, anamorphic copying can be performed by setting different magnifications in the vertical and horizontal directions of the document (M) by operating the numeric key (54) described above. If the imaging mode selection key (65) is further pressed from this state, the imaging mode returns to the first imaging mode. (65a) is an LED that indicates that the second imaging mode has been selected.

FIG. 6 is a block diagram of a control device for a copying machine.

Microcombiner C that constitutes the main part of the control device
The PU (70) is configured to determine a copy mode based on input from each key on the operation panel (50) and display the copy mode. Also, this CP IJ (7
0) is a regulator (71) for the exposure lamp (2).
), a controller (72) for the driving DC motor of the scanning device (S), and a controller (73) for the driving stepping motor for changing the conjugate length of the imaging device 1gF (1), respectively. are doing.

A lamp regulator (which is an example of an exposure lamp control means)
71) changes the voltage applied to the exposure lamp (2) in response to the voltage control signal and lighting/smoke signal from the CPU (70), and adjusts the slit width ( In conjunction with the changing operation d), the amount of light irradiated onto the document (M) by the exposure lamp (2) is appropriately set in accordance with the slit width (d).

DC motor controller (7) for driving the scanning device (S)
2) is configured to receive drive control signals from the CPU (70) in the forward and reverse directions to control operations such as movement, reversal, and stopping of the scanning device (S). Also,
This controller (72) is configured so that a signal obtained by shaping a pulse signal from an optical encoder attached to the drive DC motor is input to the CPU (70).

The controller (73) of the stepping motor for driving the imaging device (1) receives the drive control signal in the forward and reverse directions from the CPU (70), and controls the imaging lens (4) and the fourth
The mirror (5d) is configured to be moved to a position that has a conjugate length that provides a set magnification.

In the figure, the same numbers as in FIG. 5 indicate keys and LEDs on the operation panel (50), respectively. Also,
(18a) and (18b) are shown in Figure 3 (a) and (18b).
These are the two photosensors in c).

Next, the operation of the copying machine according to the present invention will be explained in FIGS.
This will be explained based on the flowchart shown in FIG.

FIG. 7 shows the main routine that controls the overall flow of the copy operation.

1! When this main routine starts with input of '/8, etc., initial settings of each parameter are first performed (1101).
, after setting the internal timer (1102),
It is determined whether a copy operation is possible (11103).

When the scanning device (S) is performing preliminary scanning (described later) or when the imaging device (1) is moving,
Copy operation is not possible and will wait. On the other hand, if the above-mentioned conditions are not met, the copy operation is possible, and the next (1104)
). At step (+1104),
Determine whether a copy operation is in progress. If a copy operation is in progress, the process advances to step (11109), and if a copy operation is not in progress, the process advances to steps (11105) to (110B) to set each parameter.

In the step (1105), as will be described later, parameters are set according to the selected imaging mode based on the determination of the state of the imaging mode selection key (65).
In step 1106), as will be described later, a lamp voltage control table is set to apply an appropriate voltage to the exposure lamp (2) based on the selected imaging mode. In step (1107), preliminary scanning is performed only immediately after the imaging mode is switched, as will be described later. In step (11108), other copy mode settings are made. The setting operations performed in step (#108) include setting of enlargement, reduction, magnification such as same size, and setting of copy paper.

The toner setting operation for color copying is also performed in this step (11108).

After setting each of the parameters described above, processing related to the copy operation is performed (1109). For example, a print key press operation is detected in this step (1109), and a copy operation is started. Subsequently, after waiting for the internal timer to end (11110), the process returns to step (1102), and thereafter the above-described operation is repeated. This loop (11102~1
In steps 1110 to 1102), if it is determined that a copy operation is in progress at step (+1104), the copy process (1109) is performed without setting the above-mentioned parameters.

FIG. 8 shows a subroutine for setting the imaging mode in step (1105) described earlier.

In this subroutine, first, the imaging mode selection key (6
5) ON edge is detected (*201). This key (
If there is no ON edge (65), the process returns to the main routine, and if there is an ON edge, the process advances to step (1202). In step (11202), this key (65
). If the key (65) is not “ON”, the process returns to the main routine, and if it is “ON” (11
Proceed to step 203) and set the imaging mode flag (IMF
) status. This flag (IMF) is “
θ″ indicates the first imaging state, and “1” indicates the second imaging mode.

If the imaging mode flag (IMF) is "0", the imaging mode will be changed from the first to the second by operating the imaging mode selection key (65), and the flow will proceed from step (1204) onward. move on. Further, if the imaging mode flag (IMF) is "1", the imaging mode will be changed from the second to the first by operating the imaging mode selection key (65), and (1
The process proceeds to the flow after step 207).

In step (1204), the imaging mode display LE
Turn on D (65a). Next, set the imaging mode flag (IMF) to 1” (+1205) and set the scanning device (S
) of the scanning speed (v) of the photoreceptor drum (6) (V
) and the value (V/β1) determined by the preset magnification (β, ) and the aspect ratio (V/β1) set to anamorphic.
1/βt) (1206), (1
Proceed to step 210).

On the other hand, in step (120?), the imaging mode display LED (65a) is extinguished. Next, set the imaging mode flag (IMF) to "03" and set the scanning speed (v) of the scanning device (S) to the above value (V/βl).
After setting (1209), the process proceeds to step ($210).

In step (1210), a flag (SRF) requesting preliminary scanning is set to "1". In other words, when the imaging mode is changed by operating the imaging mode selection key (65), it is necessary to change the width of the slit (3) as described above, and the rotating slit member (3b ), it is necessary to perform preliminary scanning only once.

FIG. 9 shows a subroutine for setting the exposure lamp control table in step (1106) described earlier.

In this subroutine, first, the imaging mode flag (IMP
) is checked (1301). If the imaging mode flag (IMP) is 'l', that is, if it is the second imaging mode, proceed to step (+1302).
If this flag (IMF) is “0”, that is, the first
If it is the imaging mode, the process proceeds to step (1303). In step (1302) or step (1303), an appropriate applied voltage (EL) to the exposure lamp (2) is set in accordance with the selected imaging mode.

This applied voltage (Et) will be explained next.

Applied voltage (Et) and light from exposure lamp (2)! (LL)
There is the following relationship between:

EL”=LL [3] Therefore, the applied voltage ([EL) and the amount of light received on the photosensitive drum (6) (
between the slit (3) and the imaging device (I)
If the conditions are constant, then the following relationship exists.

EL"=k-Ln-[4]Now,[4
] is the relationship in the first imaging mode, then in the second imaging mode where the slit width (d2) is smaller than the slit width (d, ) at this time, the photoreceptor drum (6)
The amount of light received at the top (Lyu°) is t, e = (dx/a+)・
L.

Therefore, in the second imaging mode, the amount of light received on the photoreceptor drum (6) (L
The applied voltage (1!L') for providing ゎ) is given by the following relational expression.

(EL')” −(d+/dx) −k−Ll) −
[5] In other words, in step (1302), formula [4] is satisfied, and in step (1303), [5]
] A table of appropriate applied voltages (EL) that provides the required amount of light is set so as to satisfy the equation.

FIG. 10 shows a subroutine for preliminary scanning of step (1107) described earlier.

The preliminary scan performed by this subroutine is performed by rotating the rotating slit member (3b) around its axis CP to change the width (d) of the slit (3) to the imaging mode, as described above. This is done to make changes accordingly, and as mentioned earlier, immediately after the imaging mode is switched, 1.
It is supposed to be held only once.

In this subroutine, first, the state of the flag (SRF) requesting preliminary scanning is checked (11401).

If this flag (SRF) is not set to "1", the process returns to the main routine, and if it is set to "1", then the state of the imaging mode flag (IMP) is checked.Ca2O3>.

If “1” is set in the imaging mode flag (IMP),
This is a case where the imaging mode is switched from the first to the second imaging mode. In this case, in order to return the scanning device (S) to the home position shown in FIG. 6 after the preliminary scan, the second photo sensor (
18b) is opened (1403), and in order to reverse the scanning device (S) to the position shown in FIG. A counter setting value is set in response to a pulse signal from an optical encoder attached to a DC motor for driving the device (S) (#404). After that, (14
Proceed to step 07).

If "1" is not set in the imaging mode flag (IMF), this means that the imaging mode has been switched from the second to the first. In this case, after the preliminary scan, the scanning device (S)
Return to the home position shown in the figure (open the input gate from the first photo sensor (18a) (11405
). Then, in order to reverse the scanning device (S) to the position shown in FIG. (11406), and then proceeds to step (1407).

In step (14G?), the preliminary scanning speed is set. In order to shorten the time for preliminary scanning, the scanning speed is set to the highest speed, that is, the copy magnification is set to the lowest reduction state.

Subsequently, scanning and inversion are performed by moving the scanning device (S) (+1408), and then the imaging mode flag (IM
Depending on the state of F) (1409), wait for the input signal from the second photo sensor (18b) or the input signal from the first photo sensor (18a) to become "ON" (1410) or (1410). 1411), stopping the DC motor for driving the scanning device (S) (1412), and
After resetting the flag (SRF) requesting preliminary scanning (1412), the process returns to the main routine.

As a driving device for the scanning device (S), a stepping motor or various other motors can be used instead of the DC motor described in the previous embodiment. When a stepping motor is used, the position of the scanning device (S) can be controlled even if the optical encoder in the previous embodiment is omitted by configuring the motor to count pulses for driving the motor. be able to.

Instead of the photoreceptor drum (6), a belt-shaped photoreceptor stretched between a pair of rollers may be used, and they are connected to the photoreceptor (6).
6).

Furthermore, in the previous embodiment, the exposure lamp (2) and the slit (3) were configured to move while the original (M) was fixed in position on the original platen (1). Alternatively, a copying machine implementing the present invention may be a copying machine in which the exposure lamp (2) and slit (3) are fixed in position and the document table (1) is moved. good.

[Effects of the Invention] As described above, the slit scanning copying machine according to the present invention changes the width of the slit in the second imaging mode to be smaller than that in the first imaging mode, and By increasing the power supplied to the exposure lamp in the second imaging mode than in the first imaging mode, the high resolution in the anamorphic variable magnification copying state can be achieved while omitting the expensive anamorphic optical elements required in the past. In addition to suppressing the power consumption of the copying machine as a whole and the rise in document glass temperature, it is possible to provide a cost-effective copying machine that can perform anamorphic variable-magnification copying well. Became.

[Brief explanation of drawings]

The drawings show embodiments of the present invention, and FIGS.
) are cross-sectional views showing the states of the slit in the first imaging mode and the second imaging mode, respectively, FIG. 2 is a perspective view of the rotating slit member, and FIG. 3 (a) or =) is a scanning diagram. 4 is a schematic sectional view of the copying machine, FIG. 5 is a plan view of the operation panel, FIG. 6 is a block diagram of the control device, and FIG. 7 is a flowchart showing the operation of the copying machine. , FIG. 8 is a flowchart of the subroutine for setting the imaging mode, FIG. 9 is a flowchart of the subroutine for setting the exposure lamp control table, FIG. 10 is a flowchart of the preliminary scanning subroutine, and FIG. 11 is a flowchart of the subroutine for setting the exposure lamp control table. FIG. 12 is a sectional view showing another embodiment of the slit structure. (2)...Exposure lamp, (3)...
Slit, (6)...Photoreceptor, (M)...
...Original, (S)...Scanning device, (65)...
...Imaging mode selection means, (SC)...Slit width control means, (71)...Exposure lamp control means, (v)...Scanning speed, (V)...
...The moving speed of the photoreceptor.

Claims (1)

[Claims] Equipped with a scanning device that moves the exposure lamp and the document relative to each other,
The image of the document scanned by this scanning device is projected and formed through a slit onto a photoreceptor that moves in a direction corresponding to the scanning direction, and also in a direction perpendicular to the scanning direction. A first imaging mode in which images are formed at the same magnification, and a ratio between the scanning speed of the scanning device and the moving speed of the photoconductor is different from the first imaging mode. In a slit scanning copying machine provided with an imaging mode selection means for switching between a second imaging mode in which images are formed at different magnifications,
slit width control means for changing the width of the slit in the second imaging mode to be smaller than that in the first imaging mode according to the imaging mode selected by the imaging mode selection means; A slit scanning type copying machine provided with an exposure lamp control means for changing the power supplied to the exposure lamp in the second imaging mode to be higher than that in the first imaging mode.