JPH03113433A - reader printer - Google Patents

Abstract

PURPOSE:To automatically set the focal distance of a projecting optical system at a position where the maximum value of amplitude can be obtained by disposing a means for varying the focal distance of a image forming optical system so that the maximum amplitude is detected by an amplitude detecting means. CONSTITUTION:The reader/printer is provided with a screen position amplitude detecting means 8 for detecting the amplitude in the spatial frequency of a projected light beam at the screen position and a reading position amplitude detecting means 6 for detecting the amplitude in the spatial frequency at the reading position. And the reader/printer is provided with the means for varying the focal distance of the image forming optical system 5 so that the maximum amplitude is detected at a mode position by the amplitude detecting means corresponding to respective modes for projecting the light beam on the screen 4 or for reading the projected light beam. Thus, in the case of performing the switching of the time of projecting on the screen and the time of reading, the focal distance of the projecting optical system automatically is set so as to conform with the screen position or the reading means position.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention is configured to project an information image recorded on a recording medium such as a microfilm, and to read the information image for hard copy. Regarding reader printers.

(Prior Art) Conventionally, this type of reader printer has an imaging optical system that projects an information image recorded on a recording medium such as a microfilm onto a screen. Such reader printers are equipped with a photoelectric conversion element (sensor) as a reading means that reads the projected light from the imaging optical system and converts it into an electrical signal. The device is configured to be able to output a hard copy (copy) based on the projected light.

(Problem to be Solved by the Invention) However, in the case of the above-mentioned prior art, there are some in which the screen position and the reading position by the reading means are configured to be different, and in such a reader printer, when projecting onto the screen, Alternatively, when performing reading, it is troublesome to manually adjust the focal length of the imaging optical system so that the image is in focus at each position.

In addition, while the focus adjustment during screen projection can be confirmed on the screen, the focus adjustment during reading must be done while looking at a separate monitor screen, which makes it difficult to focus and not only makes it difficult for the operator to operate. The design of the optical path length and the optical path correction require a large number of mechanical and electrical parts, which makes it difficult to achieve compactness and increases costs.

The present invention has been made to solve the above problems of the prior art, and its purpose is to change the focal length of the projection optical system to the screen position or the reading means position when switching between screen projection and reading. Another object of the present invention is to provide a reader printer that automatically configures settings.

(Means for Solving the Problem) In order to achieve the above object, the present invention includes an imaging optical system that projects an information image recorded on a recording medium onto a screen, and a projection optical system that projects an information image recorded on a recording medium onto a screen. A reader printer equipped with a reading means for reading light and converting it into an electrical signal, a screen position amplitude detection means for detecting the amplitude at the spatial frequency of the projection light at the screen position, and a screen position amplitude detection means for detecting the amplitude at the spatial frequency of the projection light at the reading position. a reading position amplitude detecting means for detecting the amplitude; and the imaging optical system so that the maximum amplitude is detected by the amplitude detecting means at the mode position according to each mode of projecting onto a screen or reading the projected light. It is characterized by comprising a variable means for varying the focal length of the system.

Note that it is effective to configure so that the operation corresponding to each mode is started after the setting of the focal length according to each mode by the variable means is completed.

Further, it is desirable that the screen position amplitude detection means be provided on the front side of the screen, and the reading position amplitude detection means be provided on the back side of the screen.

(Function) In the present invention having the above configuration, the focal length of the projection optical system is automatically set depending on the screen projection mode or the reading mode.

Note that the operation corresponding to each mode is performed after the focal length is set by the variable means.

Further, a screen position amplitude detection means is provided on the front side of the screen, and a reading position amplitude detection means is provided on the back side of the screen, and the amplitude at the spatial frequency is detected at each position.

(Example) The present invention will be explained below based on illustrated embodiments.

FIG. 1 is a schematic configuration diagram showing a reader printer according to an embodiment of the present invention.

In the figure, the light emitted from lamp 1 is reflected by mirror R
The information image (
For example, in B) shown in the figure, the projection lens 3 allows mirrors R2 to
An image is focused on the screen 4 via R5. screen 4
Use a ground glass type one with fine irregularities on one side.

The image formed on the screen 4 by the imaging optical system or the projection optical system 5 is an enlarged image of the image on the microfilm 2, and its magnification can be determined by using a projection lens 3 with a different focal length, or by using a microfilm 2. Film 2 and projection lens 3
distance from the projection lens 3 to the screen 4 (
It can be freely changed by changing the optical path length).

A photoelectric conversion element (e.g., a long sensor such as a CCD, hereinafter referred to as a sensor) 6 serving as a reading means and a reading position amplitude detecting means is disposed in a position close to the screen 4 and converts the projection from the projection optical system 5. The light (information image) is read and converted into an electrical signal, and the amplitude at the spatial frequency (described later) of the projection light is detected at the reading position. The sensor 6 is sub-scanned in the direction of the arrow by a drive device and a drive circuit (not shown). The electrical signal obtained by this sub-scanning is sent to a predetermined signal processing circuit (for example, a CPU) or a printer section through a signal line 7. Here, an example of signal processing will be given. Since the information image on the microfilm 2 is usually negative, the image formed on the screen 4 is also negative. however.

A positive image can be obtained by inverting the image signal that has been converted into an electric signal by the sensor 6 and further converted into a digital signal using a logic inversion circuit for electric signal processing. Therefore, both negative and positive hard copies can be easily obtained.

Now, as a matter of course, from the operator's perspective, the focus of the microfilm image is designed to match the screen surface. Therefore, for the sensor 6 installed inside the screen 4, an image is formed with the focal plane (focal length) out of alignment. Therefore, when reading,
It is necessary to adjust the focal length to this sensor 6.

The automatic setting of the focal length according to the present invention will be described below.

In the reader printer of the present invention shown in FIG. 1, an elongated sensor 8 as a screen position amplitude detecting means is provided on the front surface of the screen 4 in addition to the above-mentioned sensor 6 (on the back side of the screen). Since the light-receiving surface of the sensor 8 faces the screen surface and substantially coincides with the screen position, it is possible to capture projection light having the same focal length during screen projection.

By the way, the light that has passed through the microfilm 2 has a specific spatial frequency in which a periodic pattern like a sine wave is repeated.In the present invention, the amplitude at this spatial frequency is read by each sensor 6. , it is detected as the voltage of the video signal (projection light).

Hereinafter, the principle of varying the focal length of the imaging optical system 5 according to the present invention based on the detection voltage will be explained with reference to FIGS. 2 and 3.

FIG. 2 shows the detected voltage waveforms by each sensor 6.8, and the waveform I shown by the solid line is the detected voltage waveform of sensor 8, ! The waveform (■) indicated by a good edge is the detected voltage waveform of the sensor 6. Note that the illustrated waveform is a waveform in a projection mode in which projection onto the screen 4 is performed.

In the figure, A is the voltage (amplitude) at the spatial frequency of the screen position, and B is the voltage (amplitude) at the spatial frequency of the reading position.As shown in the figure, both voltages have a relationship of A>H, and the focal length Voltage A at a position where the focal lengths match has a higher output than voltage B at a position where the focal lengths are shifted.

When the focal length is varied to match the reading position, the values of A and B change during that time and are reversed such that A<B. In other words, A or B, that is, the difference voltage E between the positive peak value and the negative peak value of the detected voltage waveform, is, as shown in FIG. In the figure, the lens position 1, where the peak value (maximum amplitude) of the differential voltage E is detected, is the focal length of each mode in which the focal length is projected onto a screen or the projected light is read. This is the lens position when adjusted. That is, the lens is focused at the lens position 11 where the differential voltage E is maximum.

Next, the focal length variable processing procedure according to the present invention will be explained according to the flowchart of FIG.

First, step 1ot waits for the mode switching instruction.
), if there is a switching instruction, it is determined whether or not to switch to the reading mode (step 102), and if it is the reading mode, the position of the projection lens 3 is moved (step 103), and the screen position shown in FIG. The amplitude A at the spatial frequency at the reading position and the amplitude B at the spatial frequency at the reading position are detected (step 104).

Next, the peak value of the amplitude @B as the differential voltage E shown in FIG. 3 is detected (step 105).

When the peak value is detected, check A<B in the lens position statement 1 at that time (step 106); if YES, set the projection lens 3 to statement 1 (step 107).
, then starts reading (step 108). Note that if the determination in step 105 or 106 is NO, the process returns to step 103.

On the other hand, if the determination in step 102 is NO, in other words, if the screen projection mode is selected, the position of the projection lens 3 is moved (step 109), and the amplitude A at the spatial frequency at the screen position shown in FIG. and detect the amplitude B at the spatial frequency at the reading position (step 1
10).

Next, the peak value of the amplitude A as the differential voltage E shown in FIG. 3 is detected (step 111).

When the peak value is detected, check A>B in the lens position statement 1 at that time (step 112), and if YES, set the projection lens 3 to 1 again (step 113).
,, followed by screen projection (step 114).
), it should be noted that if the judgment in step 111 or 112 is No.
If so, return to step 109.

It should be noted that the detection of the peak value of the differential voltage E according to the present invention does not need to be performed every time, but may be performed, for example, when replacing the sensor, changing the lens magnification, or replacing the lamp, and storing the lens position at that time.

In this way, the voltage can be measured with a very simple electric circuit configuration, and thereafter, the lens position Ml can be set by selecting several buttons corresponding to the memorized lens position.

Furthermore, since the image on the screen can be directly confirmed with the naked eye, the focal length setting during screen projection may be set manually using several volumes instead of automatic setting.

(Effects of the Invention) The present invention has the above-described configuration and operation, and the spatial frequency of the projection light that has passed through the recording medium is read by the amplitude detection means, and the projection optical system is positioned at a position where the maximum value of the amplitude is obtained. The focal length of the system can be automatically set, eliminating the need for the operator to make adjustments one by one.

Additionally, there is no need for a monitor screen, half mirror, attachment lens, etc. for setting the focal length of the reading means, which were previously required, and the number of parts is relatively reduced, and a long optical path length is required for accurate focusing. Therefore, it is possible to make the device smaller and more compact, and furthermore, to reduce costs.

Note that since the operations corresponding to each mode are performed after the focal length is set by the variable means, projection on the screen or reading of projected light in an out-of-focus state is not performed.

In addition, by providing the screen position amplitude detection means on the front side of the screen and the reading position amplitude detection means on the back side of the screen, it is possible to measure the amplitude at the spatial frequency at each digit without increasing the size of the conventional device. can be detected.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing a reader printer according to an embodiment of the present invention, FIG. 2 is a diagram showing the detected voltage by the sensor shown in FIG. 1, and FIG. 3 is a diagram showing the detected voltage shown in FIG. 2. FIG. 4, which is a diagram showing the relationship between the amplitude and the projection lens position, is a flowchart showing the focal length variable processing procedure according to the present invention. Explanation of symbols 2...Micro film (recording medium) 4...Screen 5...Imaging optical system 6...Sensor (reading means, reading position amplitude detection means) 8...Sensor (screen position amplitude detection means) Detection means) Figure 2 Figure □p Figure 4

Claims (3)

[Claims] (1) In a reader printer equipped with an imaging optical system that projects an information image recorded on a recording medium onto a screen, and a reading means that reads the projected light from the imaging optical system and converts it into an electrical signal, the screen screen position amplitude detection means for detecting the amplitude at the spatial frequency of the projection light at the position; reading position amplitude detection means for detecting the amplitude at the spatial frequency at the reading position; and projection on the screen or reading of the projection light. and a variable means for varying the focal length of the imaging optical system so that the maximum amplitude is detected by the amplitude detecting means at the mode position according to each mode in which the image forming optical system is operated. printer. (2) The reader printer according to claim 1, wherein the reader printer is configured to start the operation corresponding to each mode after the setting of the focal length according to each mode by the variable means is completed. (3) The reader printer according to claim 1 or 2, wherein the screen position amplitude detection means is provided on the front side of the screen, and the reading position amplitude detection means is provided on the back side of the screen.