JPH0846760A - Reader printer - Google Patents

Abstract

PURPOSE:To attain proper recording density even from an information recording medium in which sizes of characters are small with respect to a light receiving area of photodetector and the characters are allocated densely. CONSTITUTION:When a copy button 20 is depressed, a support 11 is reciprocated in a direction of the arrow B1 integrally with mirrors 9, 10 (back scanning) under the control of a CPU 18. In this case, a zoom magnification of a projection lens 5 is varied increasingly by motor drive to allow photodetector 15 to receive a light representing the density of an information recording medium. The density of the background with respect to characters is read accurately by increasing magnification of the projection lens (home lens) when the photodetector reads the density even from an information recording medium in which sizes of characters are small with respect to a light receiving area of photodetector and the characters are assigned densely.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a function of projecting image information on an information recording medium such as a microfilm on a screen, and a function of guiding image light to a photosensitive drum or the like for recording.
The present invention relates to a reader printer capable of electrically changing the zoom magnification of a projection lens, and more particularly to a reader printer having a function of reading the density of an information recording medium such as a microfilm with a light receiving element and adjusting the recording density according to the information.

[0002]

2. Description of the Related Art Conventionally, an apparatus of this type is shown in FIG. That is, in the reader printer 100, the light of the lamp 102 reflected by the reflecting mirror 101 is condensed by the condenser lens 103 to illuminate the microfilm 104, and the image light thereof is formed by the imaging lens 105 and the mirror 106. , 107 through the screen 10
8 and the information on the microfilm 104 is read.

On the other hand, when recording this information on a recording paper or the like, two mirrors 110 and 111 supported by a support 109 and forming an angle of 90 degrees are moved in the direction of arrow P1 so that the mirror 110 is a leader. It is positioned in the optical path (back scan), and then the mirrors 110 and 111 are scanned in the opposite arrow P2 direction to deflect the image light and to the photosensitive drum 113 via the slit 112a formed by the slit plate 112. It will be recorded and recorded by a known electrophotographic technique.

By the way, in this type of reader printer, when used as a printer, the photosensitive drum 11 is caused by the difference in the type and density of the microfilm 104.
In order to deal with the change in illuminance on 3 in order to reduce the troublesomeness of density adjustment and the running cost due to miscopying, a substrate 114 having a plurality of light receiving elements arranged on a slit plate 112 is arranged as shown in FIG. The density of the background portion of the information recording medium is read from the output value obtained by back scanning, and the light emission amount of the lamp 102 or the bias amount at the time of development is controlled based on the information to obtain an optimum recorded image. I am trying.

[0005]

However, in such a conventional example, in the case of an information recording medium in which characters are small in size with respect to the light receiving area of the light receiving element and the characters are dense, the light receiving element is In some cases, the information of only the background portion of the information recording medium cannot be received, and the correct density of the background portion of the information recording medium may not be recognized. Especially in the case of negative film, it is necessary to recognize the correct base density of the information recording medium in order to obtain a recording paper of appropriate density.
This was very difficult.

The present invention has been made in order to solve the above-mentioned problems of the prior art. The object of the present invention is to reduce the size of characters relative to the light receiving area of the light receiving element.
Moreover, it is possible to obtain an appropriate recording density even for information recording in which characters are dense.

[0007]

In order to achieve the above object, in the present invention, a display means for displaying image light obtained by illuminating an information recording medium with a light source and an optical path of the image light are provided. Means for guiding the image light to the image carrier for recording by switching, a zoom lens for varying the magnification of the image on the display means or the image carrier in the optical path, and the information via the image light. A light receiving means for reading the density of the storage medium; a density adjusting means for adjusting the recording density of the image carrier according to information from the light receiving means; and a means for enlarging the magnification of the zoom lens during prescanning. Is characterized by.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below.

FIG. 1 is a diagram showing the basic construction of a reader printer to which the present invention is applied. In the figure, a microfilm 1 as an information recording medium is illuminated by an illuminating means consisting of a lamp 2 as a light source, a spherical reflecting mirror 3 and a condenser lens 4, and the image light of the film 1 is projected above it at the time of a reader. It passes through the lens 5, is reflected by the plane mirrors 6 and 7 located further above, and is projected on the screen 8 as a display means. When the copy button 20 is pressed, the CP
Under the control of U18, the projection lens 5 can electrically change the zoom magnification via the motor driver 21 by the zoom magnification changing motor 5a. The mirrors 9 and 10 are fixedly supported on the lower surface of the support 11 in a relationship intersecting at a right angle.
Move forward in the direction of arrow B1 together with 0 (back scan),
The mirror 9 advances while crossing the leader optical path. afterwards,
It moves back in the direction of arrow B2 from the exposure start point (main scan). At this time, the image light passing through the projection lens 5 is reflected by the plane mirrors 9 and 10, and the slit 13 of the slit plate 13 provided immediately above the photosensitive drum 12 as an image carrier.
The photosensitive drum 12 is exposed through a. Photosensitive drum 1
Around the periphery of 2, a developing device (not shown), the other primary charging device by electrophotography, a transfer charging device, and the like are provided.
This photosensitive drum 12 rotates at a constant speed in the direction of arrow A during image exposure, and the mirrors 9 and 10 move at a speed that is 1/2 the cycle of the photosensitive drum 12. The support 11
After the exposure is completed, it returns to the initial position where it can be used as a reader and stops. The above components are controlled by the CPU 18.

In such an optical system, the slit plate 1
3 corresponds to the change in the transmittance of the replaced projection lens 5 or the change in illuminance on the photosensitive drum 12 due to the difference in the type and density of the microfilm 4, so that the trouble of density adjustment and the so-called running cost are reduced. In order to reduce the number, a substrate 1 in which a plurality of light receiving elements are arranged on the slit plate 13
4 is arranged and the amount of light emitted from the lamp 2 or the amount of bias at the time of development is controlled based on the output value obtained by prescanning so that an optimum recorded image can be obtained.

FIG. 2 is a top view of a substrate 14 having a plurality of light receiving elements arranged on a slit plate 13. In this embodiment, the number of light receiving elements is 6, but this may be any number or a single number. The light receiving element 15 reads the transmitted light of the information recording medium during the back scan. Figure 3
FIG. 4 is a schematic diagram showing a position where a light receiving element 15 receives light during back scanning as shown in FIG. 3B for a certain micro film (negative film) as shown in FIG.
As shown in FIG. 4, the density information received by the light receiving element 15 is amplified by the amplifier 17 via the multiplexer 16 and sent to the CPU 18. The CPU 18 recognizes the density of the background portion of the information recording medium based on the data obtained by receiving the transmitted light of the information recording medium.

FIG. 5 is a histogram of the density information of the information recording medium read during the back scan. The X-axis is 255-level density data AD-converted by the CPU 18 in 8 bits. The Y-axis is the frequency of appearance of each concentration. In this embodiment, the most frequent density (henceforth PK value) of the histogram is recognized as the background portion of the information recording medium.

In the case of the negative film of microfilm, there is also a method of using the data having the highest density as the density data of the background portion, but since it is easily affected by dust, P
The method using the K value was adopted.

The CPU 18 obtains the lamp light amount information (lamp lighting data) that can obtain an appropriate recording density based on the background density information / lamp light amount voltage conversion table (FIG. 6), and sends this to the lamp regulator 19 as information. (Fig. 7). The background density information / lamp light quantity voltage conversion table of FIG. 6 is a table for selecting a lamp light quantity voltage such that the density of the background portion is not recorded as fog on the recording paper. Accordingly, the lamp regulator 19 sends to the lamp 2 a voltage for lighting the lamp with a light amount that can obtain an appropriate recorded image.

Here, in the conventional example, as shown in FIG.
For information recording media in which the size of the characters is smaller than the light receiving area of the light receiving element and the characters are densely packed, the light receiving element may not be able to receive the density information of only the background portion, and therefore, it is appropriate. The recording density could not be obtained in some cases. In FIG. 8, a mark 80 indicates a light receiving position (and a light receiving area) of the light receiving element. That is, in such a case, if the density information of the information recording medium read during the back scan is made into a histogram, it becomes as shown in FIG. 9, and it becomes impossible to read the density of the background portion by the PK value.

Therefore, in the present invention, the copy button 2
When 0 is pressed, under the control of the CPU 18, when the support body 11 moves forward in the direction of arrow B1 integrally with the mirrors 9 and 10 (back scan), the zoom magnification of the projection lens 5 is electrically changed in the enlargement direction. The density of the information recording medium and the light receiving element 15
To receive light. At this time, the illuminance change on the light receiving element 15 due to the change of the zoom magnification by the CPU 18 is corrected by changing the light amount of the lamp 2 which is the light source. Also,
During the main scan, the CPU 18 returns the zoom magnification to the original magnification and the light quantity of the lamp 2 to the original light quantity.

FIG. 10 shows the light receiving position (light receiving area) 1 of the light receiving element when the zoom lens is enlarged during back scanning.
01 is shown. When the density information at this time is made into a histogram, it becomes as shown in FIG. 11, and it becomes possible to accurately recognize the density of the background portion by the position of the PK value.

As described above, even when the size of the characters is smaller than the light receiving area of the light receiving element and the information recording medium in which the characters are dense, the projection lens (home By increasing the magnification of the lens), the density of the background portion can be read accurately. Then, based on the density information of the background portion, it becomes possible to obtain an appropriate recording density.

[0019]

According to the present invention, the size of the character is smaller than the light receiving area of the light receiving element by increasing the zoom magnification during the prescan and automatically adjusting the density based on the information obtained at that time. Moreover, it is possible to obtain an appropriate recording density even on an information recording medium in which characters are densely arranged.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an embodiment of an information recording apparatus according to the present invention.

FIG. 2 is a top view of a substrate in which a plurality of light receiving elements are arranged on the slit plate of the embodiment.

FIG. 3A is a diagram showing an example of a microfilm, and FIG. 3B is a schematic diagram showing a position where a light receiving element 15 receives light during back scanning.

FIG. 4 is a block diagram showing a density adjusting circuit for recording paper.

FIG. 5 is a diagram in which density data of a certain document is formed into a histogram.

FIG. 6 is a diagram showing a background density information / lamp light quantity voltage conversion table.

FIG. 7 is a block diagram showing a density adjusting circuit for recording paper.

FIG. 8 is a diagram showing a light receiving position of a light receiving element when the zoom lens is not changed during back scanning.

FIG. 9 is a diagram in which density information of the information recording medium read without changing the magnification of the zoom lens during back scanning is formed into a histogram.

FIG. 10 is a diagram showing a light receiving position of a light receiving element when a zoom lens is enlarged during back scanning.

FIG. 11 is a diagram in which density information of an information recording medium read by enlarging a magnification of a zoom lens during back scanning is formed into a histogram.

FIG. 12 is a schematic diagram showing an example of a conventional information recording device.

[Explanation of symbols]

 1 Micro Film (Information Recording Medium) 2 Lamp (Light Source) 3 Screen (Display Means) 4 Photosensitive Drum (Image Carrier)

Claims (1)

[Claims] 1. A display unit for displaying image light obtained by illuminating an information recording medium with a light source, and a unit for guiding the image light to an image carrier for recording by switching an optical path of the image light. A zoom lens for varying the magnification of an image on the display means or the image carrier in the optical path, a light receiving means for reading the density of the information storage medium via the image light, and a light receiving means for reading information according to information from the light receiving means. A reader printer comprising: density adjusting means for adjusting a recording density by an image carrier, and means for enlarging a magnification of the zoom lens during a prescan.