JPH01309588A - image transmission device - Google Patents

Abstract

PURPOSE:To simplify a hardware configuration at a transmitting side and to reduce power consumption by providing a picture signal reading means and a transmission carrier sending means to send a transmission carrier intensity- converted based on a read picture signal at the transmitting side and providing a detecting and amplifying means and a demodulating and reproducing means at a receiving side. CONSTITUTION:The transmission carrier is directly intensity-converted and sent with transmission carrier sending means 16 and 30 by the picture signal read from a recording medium 10 by a picture reading means 14 at a transmitting side 22. At a receiving side 24, this transmission carrier is detected and amplified by a detecting and amplifying means 40, and the transmission carrier is demodulated based on a demodulating format, and the picture signal reproduced from the recording medium 10 is reproduced with recording demodulating and reproducing means 18 and 20. Thus, a circuit at the transmitting side 22 can be simplified, and the power consumption can be reduced for that amount.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image transmission device, and particularly to an image transmission device suitable for viewing images reproduced from an information recording medium on a monitor at a remote location.

[Prior Art] Conventionally, a device as shown in FIG. 3 is known as an image reproducing device, for example, a device for viewing a reproduced image from a still image reproducing device on a remote monitor. This converts the still image signal recorded on the video floppy 4 to the still image reproduction unit 6 and converts it into a continuous standard television signal (for example, NTSG).
signal (hereinafter referred to as video signal) and play it back.
It is output to the monitor television 2.

However, the video floppy 4 is a well-known still image recording medium that has the ability to record 50 still image video signal field images on 50 concentric tracks, and the number of still images that can be recorded is limited. . That is, at present, there are 25 frame images and 50 field images. However, the time for viewing still images is limited, so when viewing multiple videos or floppy disks,
It is necessary to replace the floppy disk frequently. For this reason,
If the playback unit 6 is close to the monitor television 2 and you are watching from a distance, replacing the video floppy 4 becomes very troublesome.

In order to eliminate such troubles, it is conceivable to use the still image reproduction unit 6 at hand, but there is a problem that wiring work is troublesome unless it is installed permanently.

In order to solve this problem, a still image reproducing apparatus using an image transmission apparatus as shown in FIG. 4 has been proposed.

This is still image playback unit 6 and monitor/television 2
The image signal is optically transmitted from the image sending unit 8 provided on the still image reproduction unit 6 side to the image receiving unit 24 provided on the monitor/television 2 side using an optical signal of 8 s, and the image signal is optically transmitted from the image receiving unit 24 provided on the monitor/television 2 side. The image signal is viewed on a monitor television 2.

In this device, the still image playback unit 6 performs video playback.
When the floppy disk 4 is played back, the still image video signal is first read out as a modulated signal through the magnetic head. This signal is amplified by a preamplifier, demodulated and filtered based on the recording format by a demodulator, and converted to an NTSC video signal, which is a standard television signal, by an NTSC encoder.

This NTSC signal is then transferred to the image transmission unit 8, modulated by a modulation section in a format suitable for optical transmission, and given to the light transmission element through the light transmission element drive section. The light transmitting element transmits this modulated still image image signal toward the image receiving unit 24 as an optical signal Bs.

On the other hand, in the image receiving unit 24, the light receiving element receives a modulated signal of a still image signal sent as an optical signal BS from the light transmitting element of the image transmitting unit 8. This received signal is filtered and amplified according to the modulation frequency in the preamplifier section, and the modulated signal extracted here is demodulated in the demodulator section and converted into NTS
It is returned to a C video signal. This NTSC video signal is then applied to the monitor television 2, and the image reproduced by the still image reproduction unit 6 is displayed.

[Problems to be Solved by the Invention] However, since such a conventional image transmission device is configured as described above, there are problems as described below.

That is, although FM transmission is generally used for optical transmission using a light transmitting element and a light receiving element, FM modulation recording is also used when recording an image signal on a video floppy. Moreover, the modulation frequency of both is video floppy,
Although it depends on the performance of the light transmitting element and the light receiving element, very similar frequencies can be used.

However, the signal reproduced by the still image reproduction unit is once modulated and returned to an NTSC signal, and then modulated again by the image transmission unit for optical transmission.

Now, when adopting the configuration shown in FIG. 4 and transmitting the image reproduction signal wirelessly to the monitor/television side, the still image reproduction unit side should be as compact as possible and battery-powered.

This is extremely important in improving the usability of the still image reproduction unit. On the other hand, having both an image demodulation system and a transmission modulation system has the problem that it is difficult to miniaturize the device and is not desirable from the standpoint of reducing power consumption.

Therefore, an object of the present invention is to provide an image transmission apparatus which solves the problems of the prior art described above and which enables a simplified hardware configuration on the transmitting side and a reduction in power consumption.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention provides an image signal reading means for reading out an image signal modulated and recorded on a recording medium, and a method based on the read image signal. a transmission carrier transmitting means for transmitting the transmission carrier whose intensity has been converted by the transmission carrier; and a detection amplification means for detecting and amplifying the transmission carrier;
The present invention is characterized by comprising demodulation/reproduction means for demodulating the amplified transmission carrier signal based on the modulation format of the recording medium to reproduce an image signal.

[Function] According to the present invention, the transmission carrier transmitting means directly converts the intensity of the transmission carrier according to the image signal read from the recording medium by the image reading means on the transmitting side and transmits it. On the receiving side, this transmission carrier is detected and amplified by the detection amplification means, and the recording, demodulating and reproducing means performs demodulation based on the modulation format and reproduces the image signal reproduced from the recording medium. Therefore, the circuit on the transmitting side is greatly simplified, and power consumption can be reduced accordingly.

[Example] Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram of an image transmission device according to an embodiment of the present invention. As shown in the figure, on the still image reproduction image transmission unit 22 side, an image signal is modulated and recorded from a floppy disk IO driven by a motor 12 which is rotated at a constant speed by a servo controller 56. is read out through the magnetic head 14 and preamplifier 16. This image signal is directly given to the light transmitting element driving section 3o without being demodulated, and drives the light transmitting element 32 for intensity conversion.

As a result, the image signal before demodulation is sent out from the light sending element 32 as an optical signal Bs.

This optical signal Bs is received by the light receiving element 38 of the image receiving unit 24 and amplified by the preamplifier 40. The image signal obtained in this state is completely equivalent to the output signal of the preamplifier 16 of the still image reproduction image transmission unit 22. This signal is subjected to processing such as filtering in the demodulator 18, and then demodulated based on the recording format of the image signal stored on the floppy disk 10 to obtain a luminance signal and a color difference signal. This signal is converted to NT by the NTSC encoder 20.
The signal is converted into an SC video signal and sent to the monitor television 2 for display.

Now, on the floppy disk 10, the luminance signal Y is FM modulated, the color difference signal 1t-Y and the color difference signal B-Y are subjected to line-sequential FM modulation, and each is frequency-multiplexed and recorded. It is assumed that an image signal is recorded in a recording format as shown in the frequency allocation in FIG. 2.

That is, the luminance signal Y is from 6 Mllz to 7.5M1l
The color difference signals R-Y and n-Y are FM modulated with a deviation of z, and the center frequencies are 1.2MIIZ and 1.3M, respectively.
FM modulation is recorded on the low frequency side in line sequential order of 1lz.

The image signal read from the floppy disk 10 through the magnetic head 14 and preamplifier 16 is applied to the light transmitting element 32 through the light transmitting element driving section 30 without being demodulated. As a result, an image signal is sent out from the light sending element 32 as an optical signal Bs, but at this time, the signal form of the optical signal BS is the second one.
It remains an FM modulated signal with the frequency allocation shown in the figure. This signal is received by the light receiving element 38 on the side of the image receiving unit 24 and is applied to the demodulating section 18 through the preamplifying section 40, but this signal has a signal form almost the same as the signal reproduced from the floppy disk 10. This signal is subjected to demodulation and filter processing based on the recording format by the demodulator 18, and is returned to a luminance signal Y and a color difference signal RY/B-Y. The luminance signal Y and color difference signal R-Y/B-Y are converted into an NTSC video signal, which is a standard television signal, by an NTSC encoder 2o.

The NTSC signal obtained by the NTSC encoder 2o is given to the monitor television 2 and displayed as an image.

According to the above configuration, the signal processing circuit on the side of the still image reproduction image transmission unit 22 includes the preamplifier 16 and the light transmission element drive section 3.
0 is sufficient, eliminating the need for a demodulation system, NTSG encoder section, and modulation system that require large circuits and high power consumption, making it possible to realize a system that is extremely compact and suitable for battery operation.

In the above embodiment, a well-known infrared light emitting diode can be used as the light transmitting element 32. Furthermore, if the distance is long, sufficient performance can be obtained by using a laser diode.

Further, in the above embodiments, a case where an optical signal is used as a transmission carrier is exemplified, but it goes without saying that carriers such as radio waves can also be applied.

Further, the recording modulation method of the recording medium is not limited to FM modulation, and it goes without saying that other modulation methods can be applied as long as they match well with the transmission carrier.

In addition, although the above-mentioned embodiment illustrated the case where the image signal is handled based on the NTSC Hasbede signal, the implementation of the present invention is not limited to this, and the image signal is handled based on the PAL, 1-ID signal,
Of course, it is also possible to use RGB or color difference signals.

Further, in the above embodiment, a still image video player was used as an example of the transmitting side, but the present invention can be applied to any device that modulates and records images, such as a VTR or a video disk.

[Effects of the Invention] As described above, according to the present invention, when configuring a reproduction transmission system for image signals using optical signals etc., the circuit configuration on the transmission side can be simplified and power consumption can be further reduced. This makes it possible to make the transmission side more compact and battery powered.
Since it becomes possible to have a very compact image reproduction section at hand, it is possible to obtain an inexpensive image transmission device that can realize excellent operability.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an image transmission device according to an embodiment of the present invention, FIG. 2 is a frequency allocation diagram for explaining a still image recording format in an embodiment of the present invention, and FIG. 3 is a conventional FIG. 4 is a schematic external view of a still image reproducing apparatus using an image transmission apparatus according to a conventional image transmission apparatus and an embodiment of the present invention. 2... Monitor television, 4... Video floppy, 10... Floppy disk, 12... Sheet motor, 14... Magnetic head, 18... Demodulator, 20... - NTSC encoder, 22... still image reproduction image sending unit, 24... image receiving unit, 32... light transmitting element, 38... light receiving element. ward, sound, sound

Claims (1)

[Claims] 1) Image signal reading means for reading out an image signal modulated and recorded on a recording medium, and a transmission carrier sending out a transmission carrier whose intensity has been converted based on the read image signal. A detection and amplification means for detecting and amplifying the transmission carrier; and a demodulation and reproduction means for demodulating the amplified transmission carrier signal based on the modulation format of the recording medium to reproduce an image signal. image transmission device.