JPS63279235A - Information observation and reading device - Google Patents

Abstract

PURPOSE:To decrease the burden of an observer by providing a means for reading the picture of an information recording medium by scanning and a means for detecting the environmental illumination intensity on a screen setting position and using the data of both means so as to control the illumination intensity of a projected picture in the optimum. CONSTITUTION:If a card is inserted at a certain speed with an aperture card insertion command signal from a main control circuit 34 the picture of a microfilm is scanned by a CCD 6 and stored in a storage circuit 44. Meanwhile, a photoelectric transducer 25 detects the environmental illumination intensity on the screen setting position and transmits it to the circuit 34. The circuit 34 computes the voltage impressed on a lamp for illumination which gives the optimum illumination intensity of picture to the screen from the picture information stored in the circuit 44 and the environmental illumination intensity of the screen so as to control a lamp power source circuit 36. Thus, the illumination intensity of the projected picture can be properly controlled and the burden of the eyes of the observer can be decreased.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an information observation/reading device that can enlarge and project an image of an information recording medium such as a microfilm or an aperture card onto a screen for observation.

(Prior art) Traditionally, as a device for storing images such as documents and figures,
Microfilms have been used to reduce and record these images on film, and microfilm reader printers have been used to optically enlarge the microfilm images to obtain hard copies as needed. Also,
In addition to such purely optical reader printers, CCD
Microfilm scanners, which scan an image on a microfilm using an image reading means such as a charge-coupled device (charge-coupled device) and send an electrical signal corresponding to the image information to an optical disk, laser beam printer, etc., are also commonly used.

The above-mentioned device is equipped with a monitor screen to check whether the searched microfilm image is the desired one or to set an area to print only a specific area within the desired image. is normal.

(Problems to be Solved by the Invention) However, in the conventional device described above, the screen is used as auxiliary equipment for monitoring, and the illuminance of the image projected on the screen is limited from the viewpoint of cost. Generally, there was no Ja-ba to make adjustments. On the other hand, images on microfilm have various differences in film base density and image density due to differences in the state of the original document, photographing conditions, or development conditions. Therefore, the quality of the image projected on the screen is
Depending on the finished state of the microfilm, each image is often too light, too dark, or too low in contrast, making it difficult to observe, which poses a problem in that it imposes a significant burden on the observer. .

Therefore, in the above microfilm scanner, C
Automatic exposure adjustment that pre-scans the image using OD and adjusts the exposure light based on this image information! (AE) may be considered, but since the visibility of the projected image on the screen is affected by the illuminance of the environment where the screen is installed, the optimal illuminance for the projected image that is easiest to see can be determined only by the image information from the COD mentioned above. It was difficult to make a decision, and the problem of imposing a burden on the observer could not be resolved.

Therefore, the present invention has been made to solve the above-mentioned problems of the prior art.The purpose of the present invention is to observe the illuminance of an image projected on a screen using a simple configuration that minimizes cost increases. An object of the present invention is to provide an information observation/reading device that can automatically adjust illuminance to an appropriate level that is easy for a person to see.

(Means for Solving the Problems) In order to achieve the above object, an information observation and reading device according to the present invention irradiates an information recording medium with light from a light source and displays an image of the information recording medium on a screen. An information observation/reading device for projecting information onto the information recording medium includes a reading means for scanning and reading an image of the information recording medium, and a light detection means for detecting the environmental illuminance at the screen installation position, The illuminance of the projected image on the screen is controlled based on the detection result of the optical width inspection means.

(Function) In the present invention having the above configuration, the image of the information recording medium is scanned and read by the reading means, and the environmental illuminance at the screen installation position is detected by the light detection means, and the information read by the reading means is Based on the detection result of the light detection means, the illuminance of the image projected on the screen is automatically adjusted to an appropriate illuminance that takes into account both the brightness of the screen installation location and the image condition of the information recording medium.

(Example) The present invention will be explained below with reference to the illustrated embodiments.

FIG. 1 is a schematic perspective view showing an embodiment of an information observation and reading device according to the present invention, and FIG.

l is an aperture card, 2 is a microfilm as an information recording medium affixed to the aperture card l, 3
is a lighting lamp as a light source, 4 is a condenser lens,
5 is a projection lens; 6 is a CCD (charge coupled device) as a reading means for reading the image on the microfilm 2;
7 and 8 are scanning rails for guiding the CCD 6 to scan; 9 is a guide for holding the CCD 6;
CC that is movable along the scanning rail 7.8.
D holding base, 12 and 13 are pulleys installed rotatably around shafts 10 and 11, and 15 is the pulley 12;
．． This is a driving pulley that transmits the driving force from the driving motor 14 to the driving wire 16 connected to the CCD holding stand 9 via the driving pulley 13 . Furthermore, 17 is a position sensor of a set of photo interpolators including a light emitting part and a light detecting part for detecting the scanning start position of the CCD 8, and 18 is an index member for operating the position sensor 17.

Furthermore, the observation device section for enlarging and projecting the image on the microfilm 2 is configured as follows. That is,
As shown in the figure, 19 is a first mirror that can be switched between a horizontal position (broken line position in the figure) and an inclined position (solid line position in the figure) that bends the image light from the microfilm 2 downward; a projection lens for enlarging and projecting the image light from the mirror 19; a second mirror 22 for bending the image light from the projection lens 20 and projecting it onto the screen 24;
Reference numeral 25 denotes a photoelectric conversion element as a light detection means for detecting the environmental illuminance at the installation position of the screen 24.

In this embodiment having the above-described configuration, g-sensing and reading of an image are performed in a normal procedure. That is, first, the illumination lamp 3 illuminates the microfilm 2 by inserting the aperture card l into the predetermined position shown in FIG. Projecting image light by lens 2
0, the image is enlarged and projected onto the screen 24 via the second mirror 22. The observer observes this projected image W1 and determines whether or not the image is the desired image to be read. and,
When the projected image is the target image, the observer instructs reading of the image using a button (not shown) or the like. Then, the first mirror 19 is switched to the position indicated by the broken line in which it does not reflect the image light, and the image light is guided to the CCDB side via the projection lens 5. As the drive motor 14 rotates, the CCD 6 reads the image and sends electrical signals corresponding to the image information to a printer, storage means, etc. (not shown).

In this embodiment, when observing the projected image on the screen, the photoelectric conversion element 25 detects the ambient illuminance at the position where the screen 24 is installed, as described above, in order to adjust the image to the appropriate illuminance of 3J that is easiest for the viewer to see. It is equipped with In this embodiment, the illuminance of the projected image on the screen 24 is controlled based on the output signal of the photoelectric conversion element 25 and the image signal output from the CCD 6 described above.

Illuminance control of the projected image on the screen 24 will be explained below based on the block diagram of FIG. 2.

In the same figure, 6 is the CCD already explained.

31 is an amplifier (hereinafter referred to as AMPI) that amplifies the image signal from the CCD 6; 32 is an A/D converter that converts the analog signal amplified by AMPI into a digital signal; 3
3 is a gate [11
A clock control circuit 35 sends a clock pulse signal to the CCD 6 and the A/D converter 32.

On the other hand, as a configuration for detecting the environmental illuminance at the installation position of the screen 24, 25 is the already explained photoelectric conversion element,
45 # converts the illuminance signal from the photoelectric conversion element 25 by ¥1@
ff@device (hereinafter referred to as AMP II), 46 is AM
This is an A/D converter that converts the analog signal amplified by P■ into a digital signal, and the digital signal from the A/D converter vA46 is sent to the main control circuit 34 via the data bus 40.
sent to.

Further, the lamp power supply circuit 36 for adjusting the amount of light emitted from the illumination lamp 3 converts the control signal sent as a digital signal from the main control circuit 34 into an analog signal.
The voltage control circuit 38':g controls the voltage applied to the illumination lamp 3 by the power supply circuit 39 based on the signal from the D/A converter 37 and the D/A converter 37.

Here, the power supply circuit 39 is connected to the AC 100V power supply by D″C1.
An output of about 2 to 24 V and 150 W is supplied to the illumination lamp 3.

The operation of this embodiment having the above configuration will be explained below based on FIGS. 1 and 2. First, when you turn on the device power,
The CCD holding stand 9 moves to a position 2t (hereinafter referred to as home position) where the index member 18 activates the position sensor 17 and stops. The first mirror 19 is in an inclined position shown by a solid line in FIG. 1, and the image light obtained when the light beam from the illumination lamp 3 passes through the microfilm 2 is projected onto the screen 24 to display an image. The image illuminance at this time is set to an illuminance suitable for a standard finished microfilm with a base density of around 1.

In this state, a 7 batch 7 card insertion command signal from the main control circuit 34 is sent to the clock control circuit 35 via the signal line 41, and this clock control circuit 35
By sending a predetermined clock signal to CCD 6 through signal line 43, CCD 8 is brought into operation. Also, the first mirror 1
9 is changed from the tilted position l to the horizontal position iI by a switching means (not shown) in response to a command from the main control circuit 34! 1 (dashed line position l). In this state, the aperture card l is inserted from the right side in FIG. 1 in the direction of the arrow at a constant speed by an insertion mechanism (not shown). When this aperture card l is inserted, the image on the microfilm 2 is displayed on the CCD.
6. The images are sequentially projected onto L-, and the image is scanned (pre-scanned) by inserting the aperture card 1 without performing normal scanning of the image by moving the COD holding table 9. The scanning speed during this pre-scanning is set faster than the normal reading scanning speed, and image information necessary for adjusting the light amount of the illumination lamp 3 is stored in the storage circuit 44 while thinning out the image data at a certain rate. Thereafter, the image information stored in the storage circuit 44 according to a command from the main control circuit 34 is stored again in a predetermined storage area of the storage circuit 44 for each density of the image, and is composed of the image density and the appearance frequency of that density. Memorize the histogram.

3 to 5 are graphs schematically representing the histograms stored in the memory circuit 44. FIG. 3 shows an example in which the base density of the microfilm 2 is as low as about 0.7; FIG. 4 shows an example where the base density is appropriate, about 0.9 to 1, and FIG. 5 shows an example where the base density is too dark, about 1.5. Note that an actual histogram is not a smooth curve as shown in the figure, but has many step-like ups and downs, but for the sake of simplicity, the explanation will be made using a graph of the curve shown in the figure.

In the figure, the peak on the left side of the graph indicates the image portion of the microfilm 2, and the peak on the right side of the graph indicates the base density. The distance a between the two peaks and the difference between the two peaks and the valley (the depth of the valley) are mainly indicators of the contrast of the image on the microfilm 2. In addition, when the image on the microfilm 2 contains image information with different spatial frequencies, such as when large characters, symbols, and figures are mixed, as well as small characters, symbols, and figures,
The mountain on the left side of the figure has an uneven shape with a plurality of vertices.

On the other hand, the photoelectric conversion element 25 detects the environmental illuminance at the installation position of the screen 24, and amplifies this detection signal with AMP II.
The A/D converter 46 converts the signal into a digital signal and sends it to the main control circuit 34 via the data bus 40. The main control circuit 34 is equipped with equipment that varies depending on the device, such as differences in the brightness (F-number) of the screen projection lens, differences in the color of the screen's constituent materials, differences in the reflectance of the projection surface, and differences in projection magnification. under the conditions. The relationship between the histogram, the environmental illuminance, and the voltage applied to the illumination lamp 3 that provides appropriate image illuminance is experimentally determined for each type of device, and reference data based on this data is applied to the main control circuit 3.
With this configuration, the distance a between the peak indicating the base density and the peak indicating the image portion appearing in the histogram based on the image information read by the CCD 6 can be stored in advance in the memory cell 4. The voltage applied to the illumination lamp 3 that provides the most visible image illuminance on the screen 24 can be determined by taking into account not only the environmental illuminance at the installation position of the screen 24, but also the environmental illuminance at the installation position of the screen 24.
The power supply control circuit 38 is operated in accordance with the control signal from the power source 4, and the power supply circuit 39 can apply a voltage to the illumination lamp 3 to optimize the illuminance of the projected image.

In this example, for example, the base density is about 0.98, the distance a between both peaks, which affects the contrast, is about 0.87,
The supply voltage of the power supply circuit 39 is configured to be 20 VDC when the environmental illuminance at the screen installation position is 5001 ux, and the supply voltage is changed from 20 VDC based on the change in the environmental illuminance, the change in the base concentration, and the change in the interval a. It's changing.

After setting the supply voltage as described above, the first mirror 19
The image light is switched to the tilted position shown by the solid line in the figure, and the image light is
It is bent by a mirror 19 and guided to a screen 24 to project an image. At this time, the illuminance of the projected image is set to a suitable level that is comfortable for the observer to observe, so even if the observer observes the image for a long time while exchanging a large number of 7-part cards, the viewer will not feel eye fatigue. This can be kept as low as possible, and the burden on the observer can be reduced.

Further, after observing the image on the screen 24, if the viewer wishes to print this image, the viewer issues a print command using a button or the like, and this command causes the first mirror 1 to
9 switches to horizontal position.

CC which moves the COD holding table 9 in the direction of the arrow by the rotation of the drive motor 14 and reads the image by the CCD 6.
The image signal read by D6 is amplified by AMPI, digitized by A/D converter 32, sent to main control circuit 34 via gate circuit 33, and sent to signal line 41 as a serial binary code by main control circuit 34. The information is then input to a storage means (not shown) such as a laser beam printer or an optical disk device. The image density histogram stored in the memory circuit 44 used to determine the illuminance of the image projected onto the screen 24 is sent from each element of the CCD 6 to the main control circuit 6 in 6 to 8 bits. It is also possible to use it as data for determining the threshold value when converting the image signal into a serial binary code, and furthermore, the histogram in the memory circuit 44 can be used to control the light intensity of the illumination lamp 3 during reading. Good too.

In the above embodiment, a case has been described in which the image on the microfilm is read by scanning the CCD, but the present invention is not limited to this, and the image may be read by scanning the aperture card.

FIG. 6 is a schematic perspective view showing another embodiment of the information observation and reading device according to the present invention, and the same components as in the embodiment shown in FIG. In the embodiment, a roll-shaped microfilm 53 having a large number of images 52 is used instead of an aperture card, and pre-scanning for obtaining a histogram from image information is performed either by running the microfilm 53 or by moving the CCD 6. In addition, in order to secure a movement area for the microfilm 53, the arrangement of the illumination lamp 3 and the screen 24 is changed, and the first mirror 'l 9 is used as a mirror for turning back.
, has a configuration in which mirrors 21 and 23 are added in addition to the second mirror 22.

It should be noted that the configuration and operation other than those described above are basically the same as those of the embodiment shown in FIG. 1, so the explanation thereof will be omitted.

In the above embodiments, an explanation has been given of an apparatus that reads an image using a COD and prints or records the image based on an electrical signal from the COD. It can also be applied to devices that form images by irradiating image light onto a photoreceptor.
In this case, a photoelectric conversion element for forming an image histogram may be provided separately, and a pre-scan may be performed before image formation.

Further, in the above embodiment, the photoelectric conversion element 25 is connected to the screen 2 in order to measure the environmental illuminance at the screen installation position.
Although it is installed at the end where the image of No. 4 is not projected, it is not limited thereto, and may be installed at other positions near the screen 24.

Furthermore, in the embodiment shown in FIG. 6 described above, the seventh
As shown in the figure or FIG. 8, the image 52 on the microfilm 53 is detected using blip marks such as file marks m and frame marks n, but the CCD 6 for image reading may also be used for this detection.

Furthermore, in the above embodiment, the illuminance of the projected image on the screen is adjusted by controlling the voltage applied to the illumination lamp; however, the invention is not limited to this, and the luminous flux can be varied in the optical path from the illumination lamp. The illuminance of the projected image may be adjusted by means including a regulating member.

In addition, in the above embodiment, AMP I, AMP■, A
Although the case where the /D converters 32 and 45 are provided separately for the CCD 6 and the photoelectric conversion element 25 has been described, the present invention is not limited to this, and by making it possible to switch each signal, the amplifier and A/D converter can be It is also possible to share each unit as one unit.

Incidentally, since the optimum image illuminance may vary depending on the color of the microfilm or the individual differences of the observer, it is preferable to provide a manual fine adjustment mechanism for the image illuminance.

(Effect of emitting j) The present invention has the above-described configuration and operation, and includes a light detection means for detecting the environmental illuminance at the screen installation position in addition to the reading means for scanning and reading the image of the information recording medium. The illuminance of the projected image can be controlled to the appropriate illuminance for easy viewing based on both single image information and environmental illuminance data, so the viewer does not feel significant eye fatigue and can easily view multiple images. This has the effect of keeping the burden on the observer low even when observing for a long time.

[Brief explanation of the drawing]

FIG. 1 is a schematic perspective view showing an embodiment of the information observation and reading device according to the present invention, FIG. 2 is a block diagram showing the control system of the same embodiment, and FIGS. 3 to 5 are the base density of the image. FIG. 6 is a schematic perspective view showing another embodiment of the information observation/reading device according to the present invention; FIGS. 7 and 8 are explanatory diagrams each showing the state of the microfilm. Explanation of symbols 2... Microfilm (information recording medium) 3... Illumination lamp (light source) 6... CCD (reading means) 24... Screen 25... Photoelectric conversion means (light detection) Means) Patent applicant: Canon Co., Ltd., 3rd party, 1': Agent: Patent attorney Yoshikazu Shin □ ゛('
Agent Patent Attorney Oku 1) Noriyuki, Pa)゛,
'1 ゛・1j) thing゛, l

Claims (1)

[Claims] An information observation and reading device that projects an image of the information recording medium onto a screen by irradiating light from a light source onto the information recording medium, comprising a reading means for scanning and reading the image of the information recording medium, and a screen installation position. and a light detection means for detecting the environmental illuminance of the screen, and the illuminance of the projected image on the screen is controlled based on the reading information of the reading means and the detection result of the light detection means. Observation reader.