JPS59187332A - Image forming and leading-out method of copying machine - Google Patents

Abstract

PURPOSE:To form an image of the same size as an image formed on a photosensitive drum in a copying machine having variable magnification, by guiding luminous flux which travels from an original image support to the photosensitive drum or the way to a screen and forming an image thereupon. CONSTITUTION:The luminous flux traveling from the original image support 4 to the photosensitive drum 5 is deflected on the way to a transparent screen 17 which extends in parallel to the axial line of the photosensitive drum 5 and has width 9 more than the width (b) of a slit and <=3 times as large as the width (c) of a final mirror 10, and guided to the screen 17 which is installed at such a position that its optical path length to the original support 4 is equal to that from the photosensitive drum 5 to the image support body 4, thereby forming the image thereupon. In such a constitution, the image of the same size as the image formed on the photosensitive drum is formed on the screen, so the magnification is varied while the size of the image on the screen is directly read on a scale.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for taking out an image in a copying machine whose magnification can be changed so that an image formed on a photosensitive drum can be viewed directly on a screen.

Conventionally, in copying machines that can change copy magnification, for example, copying machines that make enlarged copies from microfilm,
The light beam transmitted through the microfilm is guided to a screen via a fixed focus lens for monitoring and a fixed mirror, and is formed into an image on the screen. However, since these two lenses, mirrors, and screens are simply used for monitoring, the image formed on this screen is completely unrelated to the magnification of the image formed on the photosensitive drum during copying, and is always constant. It is a magnification.

Therefore, when you want to obtain a copy of a design drawing, etc., which is 8 dimensions by multiplying the dimension A on the microfilm by The screen cannot be used at all. As a result, in the case described above, the magnification ratio is determined using the reduction ratio of the microfilm as a clue.
Because errors occur in the shooting distance etc. when photographing microfilm, the reduction rate of the microfilm itself may not be as described, and furthermore, the microfilm may expand or contract due to changes over time or due to surrounding environmental conditions. Therefore, if an enlarged copy is made using the reduction ratio of the microfilm as the only clue, the above-mentioned errors will be compounded and it will not be possible to obtain a copy of the desired size. For this reason, conventionally,
You can make multiple copies through trial and error to obtain a copy of the desired dimensions, or you can make one experimental copy, measure and calculate the dimensions of this copy, and then determine the magnification. I was able to obtain a copy of the desired size. However, such a method has problems in that it is extremely inefficient and requires a great deal of labor and time. Incidentally, such problems occur not only when copies are obtained from microfilm, but also when copies are obtained using reflected light from an original.

This invention was made in view of the above-mentioned problem, and an object thereof is to form an image on a screen that has exactly the same size as the image formed on the photosensitive drum.

For this purpose, in a copying machine with variable magnification,
A translucent film that transmits the light beam from the original image support to the photosensitive drum in the middle, extends parallel to the axis of the photosensitive drum, and has a width that is greater than or equal to the width of the slit and less than or equal to three times the width of the final mirror. The light is directed toward the screen, and the optical path length from the photosensitive drum to the original image support is equal to the optical path length from the photosensitive drum to the original image support. This can be achieved by doing this.

The ability to change the magnification here means that it is possible to enlarge or reduce or both, and this can be done by moving the mirror of the optical system, using a zoom lens, or by using the optical system. There is something that moves the lens. The change in magnification may be continuous or stepwise (discontinuous). The original image support is something that supports the original image to be copied; for example, in the case of transmitted light, it is a microfilm, and in the case of reflected light, it is an original. The light beam transmitted through the original image support or the light beam reflected by the original image support is guided to the photosensitive drum through a well-known optical system consisting of lenses and mirrors. ).If the existing optical system is used as it is, it will be cheaper and will not increase in size, so the closer the position is to the photosensitive drum, the better. It is preferable to change the direction between the last mirror and the photosensitive drum, and between the last mirror and the mirror immediately before the last mirror.The range in which the screen can be installed can be expanded. The number of directions required is at least 1, but 2
The direction may be changed more than once. As for the direction change method,
Rotate the final mirror to remove it from the optical path, remove the final mirror to the outside of the copying machine, or rotate a separately provided deflection mirror to position the deflection mirror on the optical path. Alternatively, there is a method in which the final mirror is a mirror that reflects only in one direction and transmits in the other direction, and the final mirror is rotated about half a turn, or the final mirror is rotated while reflecting the light beam on the optical path. The light flux deflected as described above is guided to a screen that extends parallel to the axis of the photosensitive drum and forms an image, but this screen is semitransparent, such as ground glass, and its width is the same as the slit. and less than or equal to three times the width of the final mirror.

The reason is that if the width of the screen is less than the width of the slit installed in the optical system, the width of the image formed on the screen will be too narrow, making it difficult to determine which part of the image is formed on the screen. Also, if the width exceeds three times the width of the final mirror in the optical system, the interior of the copier becomes too bright due to the outside light that passes through the screen and enters the copier, causing an image to be formed on the screen. This is because the contrast of the resulting image decreases, making it impossible to distinguish. This screen is installed at a position where the optical path length from the photosensitive drum to the original image support is equal to the optical path length from the photosensitive drum to the original image support.
It is ensured that the size of the image formed on the screen is equal to the size of the image formed on the photosensitive drum.

Since the present invention can be configured as described above, by changing the direction of the light beam when necessary, a clear image of the same size as the image formed on the photosensitive drum is formed on the screen. For this reason, for example, when enlarging or reducing the size of the image on the original image support to 8 dimensions, it is only necessary to change the magnification while directly reading the size of the image on the screen with a ruler, and then return it to the original size. In this case, the scale can be photographed together with the original on microfilm, and the magnification can be changed by applying a ruler to the scale imaged on the screen.

Next, an embodiment of an apparatus for carrying out the present invention will be described based on the drawings.

Figure 1.2 shows an example in which the present invention is applied to a copying machine that enlarges and copies microfilm. In the figure, (1) is a frame of the copying machine, and this frame (
A Norogen lamp (2) as a light source is attached to the upper part of the lamp (1). A condenser lens (3) is provided below the lamp (2), and the light from the lamp (2) is condensed by the condenser lens (3).

(4) is a microfilm as an original image support placed on the frame (1), and this microfilm (
4) supports the original image to be copied.Then, this microfilm (4) can be moved in its longitudinal direction at a constant speed determined by the magnification and the rotational speed of the photosensitive drum (5). Along with condenser lens (3)
This allows the light to be focused and the light beam to pass through. (6) is a projection lens attached to the frame (1) below the microfilm (4), and the light beam passing through this projection lens (6) is reflected by the first mirror fixed directly below the projection lens (6). (7) and is deflected at right angles. (81(9)
Reference numeral 1 indicates second and third mirrors arranged to intersect at right angles;
It is reflected so that it travels parallel to the light beam incident on the mirror (8) and in the opposite direction. These second and third mirrors (81f91
' is caused to enter the second mirror (81) between the position shown by the solid line and the position shown by the imaginary line in FIG. It moves parallel to the light beam. (10) is the fourth mirror (final mirror) installed directly below the first mirror (7), and this fourth mirror (io) is reflected by the third mirror (9). The reflected light flux is guided to the photosensitive drum (5), and an image is formed on the photosensitive drum (5).In this way, the light flux that has passed through the microfilm (41) is transmitted through the projection lens (6) and a plurality of 1st, 2nd, 3rd, 4th mirror (7) (81f
91 (enlarged by the optical system (11) including 101,
An image is formed on the photosensitive drum (5), and its magnification changes continuously due to the movement of the second and third mirrors (81 (91). Note that (] 2+ <131 means that the fourth mirror (10) Photosensitive drum (5) installed between the drum (5)
A pair of slit plates parallel to the axis of rotation of the slit plate (12) (14
1 is formed. The frame il+ on the extension line of the light beam incident on the fourth mirror (10) has a window (
A light-shielding cover (1, fil) that can be opened and closed is attached to the inner end of this window (I5).A light-shielding cover (1, fil) that can be opened and closed is attached to the inner end of this window (I5). and its width (al is the sulin) (width of 1,4+ (
The screen (171 is attached, this screen χ17) is made of a translucent material such as ground glass, for example. and the fourth mirror (1
0) is equal to the distance 11+ between the photosensitive drum (5) and the fourth mirror (10). As a result, the optical path length from the microfilm (4) to the fourth mirror (10) is the same, so the optical path length from the microfilm (4) to the screen (171) and the microfilm (
4) to the surface of the photosensitive drum (5) are equal. As shown in Figure 2, the fourth mirror (10)
A sprocket 11191 is fixed to a rotating shaft (18) parallel to the photosensitive drum (5), which is located at one end of the photosensitive drum (5).

(20) is a motor that can rotate in forward and reverse directions, and this motor (
A sprocket (22+) is fixed to the rotating shaft "21) of the sprocket 20).

A chain (23) is passed between the sprocket l-Q91 and the sprocket +221, and the fourth mirror (10) rotates around @Ilf+8+ by the rotation of the motor (2) (sword rotation axis (21)). It rotates between the copying position shown by a solid line in FIG. plate and this play)
(A pair of position sensors C251 (26+) are attached to the sides of 241, separated by about 135 degrees. Each position sensor 125) (26i has a light emitter and a light receiver (not shown), and these emitters, A light blocking plate (2η) fixed to the rotating shaft (18) is inserted between the light receivers to block light, thereby detecting the rotating position of the rotating shaft (18), that is, the fourth mirror (101). The fourth mentioned above
Mirror (10), rotation axis (I8), sprocket (t9)
1 (221, motor ('10i, position sensor - +25
1 (26+, the light-shielding plate (2'O) as a whole constitutes a direction changing means (28) that changes the surface of the light beam traveling from the microfilm (4) to the photosensitive drum (5) so that it goes toward the screen 07 on the way. Note that the fourth mirror (10) constitutes a part of the deflection means (28) and also constitutes a part of the optical system (11), and is a component common to both. During copying, the light beam from the third mirror (9) is reflected by the fourth mirror (10) located at the copying position (fl) and heads substantially downward; When it rotates to 9+, it changes direction (changes the direction of travel) and goes straight to the screen (17), which leads to the screen (17).
7). The dimensions of the image formed on the screen 07) at this time are such that the fourth mirror (101 is at the copying position (
Since the size of the image formed on the photosensitive drum (5) when the photosensitive drum (5) is on the screen 171 is the same as the size of the image formed on the photosensitive drum (5), the size of the image to be copied can be actually measured by measuring the size of the image on this screen (171) with a ruler or the like. Fourth mirror (10) of the slit plate (12)
A light receiving element (29) is attached to the side surface,
This light-receiving element (29) receives the peripheral portion of the light beam directed from the fourth mirror (20) toward the photosensitive drum (5). Power from 25 volts to 15 volts is supplied to the light receiving element (29), and a lead wire (3t+
An analog output signal (current) is taken out via +. A normally open first switch (31) is connected to the lead wire (30).
), a resistor (32) and an ammeter (33) are connected in series, and a voltage dividing wiring (3) is connected in parallel with the ammeter (33).
4) is connected. This voltage dividing wiring (34) is normally closed by the first switch (31) and has a variable resistor (35) interposed therebetween. In addition (3G
) is a normally open second switch interposed between the voltage dividing wiring (34), the first switch (31), and the lead wire (30) between the ammeter (33).As mentioned above, The reason why the connection between the first and second switches (31) (361, voltage dividing wiring C, 341, and variable resistor) is provided is that the amount of light emitted by the lamp (2) depends on whether the microfilm (4) is a dimazo film or a silver halide film. Although different, this is to ensure that the current flowing to the ammeter (33) is almost the same regardless of which film is used.When the light receiving element (c) receives light, an output signal is output and the current flows through the ammeter (33). The total needle (33) oscillates, and by observing the oscillation of this needle, the illuminance of the image formed on the photosensitive drum (5) can be determined.The installation position of the light receiving element (29) is (5) Since it is necessary to obtain almost the same illuminance as the surface, the optical path must be on the downstream side of the fourth mirror (1o). (1o) reflective surface, light-shielding cover (1o)
6) 4th mirror (10) side surface, screen (17)
The inner surface on the fourth mirror (10) side may also be used.

Next, the operation of one embodiment of this invention will be explained.

If you want to enlarge the size A of the original image on the microfilm (4) to size B and copy it, or use the microfilm (4)
If you want to enlarge the above original image to its original size and make a copy, place the microfilm (41) on the frame ill and turn on the lamp (2).Next, decide the appropriate magnification by intuition and make a second , the third mirror f81 (91) is moved synchronously.Next, the light shielding cover °-(Ilit) is rotated to the position shown by the imaginary line to open the window (I5).At this time, the motor (2o) is The rotation shaft (18) is rotated together with the fourth mirror (10).When the fourth mirror (1,0) rotates to the direction change position (,9+), the light shielding plate (27) moves to the position It is inserted between the emitter and receiver of the sensor (25), and the light from the emitter is blocked, thereby stopping the driving of the motor (20).The rotation of this fourth mirror (1o) As a result, the light beam from the third mirror (9) is directed from the photosensitive drum (5) to the screen (17).

The light flux guided to the screen (1γ) forms an image on the screen 07). Then this screen (
17) Continuously change the magnification while directly reading the dimensions of the image above using a ruler to make fine adjustments. As a result, the size of the copied image becomes exactly B. Next, install the light-shielding cover (1
6) to close the window (■5) to prevent external light from entering the copying machine, and drive the motor (20) to move the fourth mirror (I OJ to the changing position (g+ As a result, the light beam that has passed through the microfilm (4) is guided to the photosensitive drum (5) and forms an image on this photosensitive drum (5).At this time, the light receiving element □□ □ receives the light, measures the illuminance of the image formed on the photosensitive drum (5), and outputs an output signal.Next, when the microfilm (4) is a diazo film, turn on the second switch (36). When the silver halide film is used, the first switch (31
) and send the output signal only to the lead wire (30). As a result, the output signal from the light receiving element 09) flows through the ammeter (33), and the needle of the ammeter (331) swings.Next,
In this state, move the microfilm (4) appropriately and find the position where the needle of ammeter C (3+) has the minimum deflection. The light beam that has passed through the background of the film (4) is received by the light receiving element (29).Next,
Rotate the knob that adjusts the amount of light emitted from the lamp (2) to change the amount of light emitted from the lamp (2) so that the deflection of the needle of the ammeter (33) becomes the specified value. As a result, even if the background densities of the microfilms (4) are different, the background illuminance when an image is formed on the photosensitive drum (5) can be easily made constant, and the background density is always constant. You can obtain a copy of Next, after returning the microfilm (4) to the starting position, press the copy button and rotate the photosensitive drum (5), and move the microfilm (4) to the position determined by the magnification and rotation speed of the photosensitive drum (5). move at speed. As a result, the light beam transmitted through the microfilm (4) is magnified by the optical system (11), and then sent to the photosensitive drum (5).
, and forms an electrostatic latent image on the photosensitive drum (5).

In this example, the amount of light received by the light receiving element (29) was displayed using an analog display, that is, the ammeter (33), but the output signal (analog amount) from the light receiving element (29) was displayed using an A/D display. It may be converted into a digital quantity by a converter and displayed by a digital display.

FIG. 4 is a diagram showing an embodiment of the present invention. In this embodiment, the amount of light emitted from the lamp (2) is automatically controlled. In the same figure, (4υ is the slit plate (12
), and these light receiving elements (41) are arranged spaced apart from each other on a straight line parallel to the axis of the photosensitive drum (5). There is. The lead wire (42) drawn out from each light receiving element (4I) is connected to a switch circuit (twice as many as the number of switches and voltage dividing resistors as the number of light receiving elements (41)), and the switch of this switch circuit (43) is The microfilm is switched at the same time depending on whether it is a diazo film or a silver salt film, and the voltage dividing resistor through which the output signal passes is selected so that the output value from the switch circuit (43) does not vary significantly depending on the type of film. (see) is the switch circuit (A/D where multiple outputs from 431 are input)
The A/D converter (44) converts each output from an analog quantity to a digital quantity. This is a comparator into which the output from the A/D converter (44) is input. It outputs to the phase control circuit (4fi) including the triac.This phase control circuit (46) accepts only the output from the comparator (451) at the moment when the copy button is pressed. The set value is added or subtracted to find the deviation between the two, and this deviation value is supplied to the triac as a gate signal.

Thereby, the triac performs phase control of the power supplied to the lamp (2). In this way, the comparator (45) compares the output signals from the plurality of light-receiving elements (41) separated from each other, and selects the output signal of the smallest value among these output signals (of the microfilm (4)). The amount of light emitted from the lamp (2) is controlled by taking out the light receiving element that receives the light flux that has passed through the background (output signal from the sensor), so the amount of light emitted from the lamp (2) is controlled by the amount of light emitted from each microfilm (4). ), and as a result, it is possible to instantaneously and automatically make the background density of the copy constant. It is also necessary to keep the ground density constant in copying machines that guide the reflected light from the original to the photosensitive drum, but in this case, it is necessary to keep the ground density constant. The deviation is correct so as to extract the output signal of the value.Other configurations and effects are the same as those of the above-mentioned embodiment, so a detailed explanation will be omitted.

As explained above, according to the present invention, an image having the same size as the image formed on the photosensitive drum can be formed on the screen, so that by directly reading the size of the image on the screen, , a copy with an image of a desired size can be easily obtained in a short time.

[Brief explanation of the drawing]

FIG. 1 is a schematic front view showing one embodiment of an apparatus for carrying out the present invention, FIG. 2 is a perspective view of the direction change means, FIG. 3 is a circuit diagram of an exposure adjustment device, and FIG. 4 is an exposure adjustment device. FIG. 4 is a circuit diagram of another embodiment of the device. (4) Original image support (microfilm) (5)
・Photosensitive drum (10)...Final mirror (4th mirror) (1,1+...Slit (171...Screen (28)...Direction changing means patent applicant Patent attorney representing Shashin Kogyo Co., Ltd. 1) Toshio

Claims (1)

[Claims] In a copying machine with variable magnification, a beam of light traveling from the original image support to the photosensitive drum is extended parallel to the axis of the photosensitive drum along the way, and its width is twice the width of the slit and the width of the final mirror. 3 times or less, and guide the light to the screen installed at a position where the optical path length to the original image support is equal to the optical path length from the photosensitive drum to the original image support; 1. A method for taking out an image in a copying machine, characterized in that an image is formed in a copying machine.