JPH02192359A - Facsimile equipment - Google Patents

Abstract

PURPOSE:To use the storage content of a pseudo SRAM assuming it as effective when it is held by deciding whether or not the storage content of the pseudo SRAM is effective, and erasing the storage content of the pseudo SRAM based on a judged result. CONSTITUTION:When a power source is applied and a detecting signal is added by a power source monitoring circuit 19, an initial processing at the time of applying the power source is executed. Namely, it is checked first whether or not one or more pieces of file managing information FM are stored in an SRAM 3. When it is stored, the present time is read out from a timepiece circuit 7, and the time difference of the present time and power source disconnection information SP and power source disconnection time are calculated, and it is checked whether or not the power source disconnection time elapses over a time t1 stored in a ROM 2 and possible to perform backup. When a result shows YES, it shows that effective image information is stored in an SRAM 10 just before disconnecting the power source and also, the power source is disconnected exceeding the time possible to perform the backup by a capacitor 11 for backup, therefore, all the storage contents of the pseudo SRAM 10 are cleared, and a power disconnection report is generated, then, it is recorded and outputted from a plotter 6.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a facsimile machine that uses a pseudo SRAM whose power is backed up by a capacitor as an image storage means.

[Prior Art] Generally, in facsimile machines, a storage device using DRAM (dynamic random access memory) is used as a small capacity image memory.
This DRAM has the disadvantage that the stored contents are erased in the event of a power failure such as a momentary power cut or a power outage.

To solve this problem, it is possible to configure a non-volatile image memory using, for example, SRAM (static RAM) with power backup using a battery, but SRAM has a complicated configuration. Therefore, it is more expensive than a DRAM, resulting in an inconvenience that the cost of the facsimile machine increases.

For this reason, in recent years, facsimile machines have been put into practical use in which a nonvolatile image memory is constructed using a pseudo SRAM whose power is backed up using a capacitor.

This pseudo SRAM has memory cells with the same configuration as DRAM and a self-refresh circuit that refreshes the memory contents.When the power is turned on, the memory contents are refreshed by an external circuit, and when the power is turned off, the power is supplied from a backup capacitor. A self-refresh circuit is activated by the power source to refresh the memory contents, so the memory contents are retained even in the event of a momentary power outage or short power outage, and it is cheaper than SRAM. Therefore, the cost of image memory is also reduced.

[Problems to be Solved by the Invention] However, such conventional devices have the following disadvantages.

For example, when a facsimile machine is malfunctioning and needs to be repaired, the power may be temporarily turned off.

When such a repair is performed, the time required for it is short and the backup capacitor is used to create a pseudo SR.
Even if the memory contents of the AM are sufficiently retained, the service personnel who repaired the AM will erase the memory contents of the image memory, resulting in the inconvenience of having to store the image information again. was.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a facsimile apparatus which solves the problems of the conventional apparatus and can retain the contents of an image memory when the contents are completely retained.

[Means for Solving the Problems] The present invention provides a method for comparing the backup possible time of a backup capacitor with a power-off time, comparing a terminal voltage of a backup capacitor with a reference value, or comparing a pseudo SRA.
Based on a comparison of the sum value calculated based on the memory contents of M before and after the power is turned off, it is determined whether the memory contents of the pseudo SRAM are valid, and based on the determination result, the pseudo SR
This is to erase the memory contents of AM.

[Operation] Therefore, if the storage contents of the pseudo SRAM are retained, the storage contents can be used as valid ones, so that the effort of re-reading the original can be reduced to some extent.

[Embodiments] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows a facsimile machine according to an embodiment of the present invention.

In the figure, a CPU (central processing unit) 1 is for controlling the operation of this facsimile machine and for predetermined facsimile transmission procedure processing, and a ROM 2 is for controlling the operation of the facsimile machine and for predetermined facsimile transmission procedure processing.
The SRAM 3 is used to store the control program executed by the PUI and various information necessary when executing the control program, and the SRAM 3 stores information specific to this facsimile machine and images stored in the image memory (described later). It stores information management information and the like. This SRAM 3 is backed up by a battery 4.

The scanner 5 is for reading original images at a predetermined resolution, the plotter 6 is for recording and outputting images such as received images at a predetermined resolution, and the clock circuit 7 is for reading current time information. It is for output.

The operation display section 8 is for operating this facsimile machine, and is composed of various operation keys and various display devices.

The encoding/decoding unit 9 is for encoding and compressing the image signal and decoding the encoded and compressed image information into the original image signal.

The pseudo SRAM 10 constitutes an image memory that stores encoded and compressed image information, and is backed up by a backup capacitor 11 as a power source. The voltage detector 12 is for detecting the terminal voltage of the backup capacitor 11.

The modem 13 performs predetermined modulation/demodulation processing so that digital data can be transmitted using an analog line, and the network control unit 14 is used to connect a facsimile device to an analog line network such as a public telephone line network. belongs to. Furthermore, the network control device 11 has an automatic call origination/reception function.

These CPU1. ROM2, SRAM3, scanner 5
, plotter 6, clock circuit 7, operation display section 8, encoding/decoding section 9, pseudo SRAM101 voltage detector 12, modem 1
3 and the network control device 14 are connected to a system bus 15, and exchange of various information between these elements is mainly performed via this system bus 15.

Further, the AC type g16 is connected to a power supply section 18 and a power supply monitoring circuit 19 via a main switch 17, and the power supply section 18 forms a power supply necessary for the internal circuit of the facsimile machine based on the AC power supply 16. , and outputs the power to each part. In addition, the power supply monitoring circuit 19 is an AC type g16
It detects that the facsimile is connected to the facsimile machine, and outputs a detection signal to the CPUI when the power is turned on.

The ROM2 also stores the time t during which the backup capacitor 11 can back up the pseudo SRAM 10, the date/time information when this facsimile machine started operating, the lifespan t5 of the backup capacitor 11, and the memory contents of the pseudo SRAM 10. The terminal voltage value L of the backup capacitor 11 that can be backed up is stored.

Now, when the facsimile device sets, for example, time-specific transmission, the image signal read by the scanner 5 is encoded and compressed by the encoder/decoder 9, and the image information obtained thereby is stored in the pseudo SRAM 10. Also, file management information FM for accessing the image information accumulated at that time.
For example, the file management information FM is formed in the format shown in FIG. 2(a), and the file management information FM is stored in a predetermined storage area of the SRAM 3.

File management information FMi, file number to identify each image information, destination information that stores each destination information and transmission result for one or more destinations, transmission mode when transmitting the image information. It consists of transmission mode information and image storage area information indicating the storage area occupied by the image information in the pseudo SRAM10.

This kind of file management information F old, pseudo SRAM10
It is formed and stored in the SRAM 3 when image information is accumulated. For example, it is formed when a memory transmission mode other than the above is set and transmission image information is stored, or when reception image information is stored during confidential reception or proxy reception, and the transmission operation ends. When the extraction of the received image information is completed, the respective transmitted image information and received image information are erased from the pseudo SRAM10, and the corresponding file management information FM is also erased from the SRAM3.

In addition, when the CPUI stores new image information in the pseudo SRAM 10 or deletes image information that has been processed and changes the memory contents of the pseudo SRAM 10, the CPU
All the memory contents of AM10 are accumulated in byte units, and the lower two bytes of the result are stored in SRAM3 as the reference sum value S2.
Along with remembering.

During operation, the current time information is input from the clock circuit 7 at intervals of a fixed time Ti, and the time information is inputted as shown in FIG. 2(b).
As shown in FIG. 3, the power-off time information sp is stored in the SRAM 3. Here, the time Ti is set to a value smaller than 1 second.

Now, in this way, when the facsimile machine is powered on and operating, image information is stored in the pseudo SRAM10.
When the image information is accumulated in , file management information FM of the image information is formed and stored in SRAM3, a reference sum value S1 is calculated, and S
The time information is stored in RAM 3 and sampled at time intervals of 1 hour Ti as power-off time information SP.
It is stored in RAM3.

Then, the power is turned on and f! When a detection signal is applied from the power source monitoring circuit 19, initial processing at the time of turning on the lt power source as shown in FIG. 3 is executed.

That is, first, it is checked whether one or more file management information FM is stored in the SRAM3 (determination 10).
1).

When the result of judgment 101 is YES, clock circuit 7
102), the time difference between the current time t and the power-off time information SP, that is, the power-off time t2 from when the power is turned off until it is turned on again.
(processing 103), the power off time t2 is
It is checked whether the backup possible time t□ stored in No. 2 is greater than or equal to the backup possible time t□ (determination 104).

When the result of judgment 104 becomes '10S, valid image information is stored in the pseudo SRAMl0 immediately before the power is turned off, and the power has been turned off for a period exceeding the time during which the backup capacitor 11 can be backed up. ,
Since the storage contents of the pseudo SRAM10 at that point cannot be treated as valid image information, the pseudo SRAM
All memory contents of l0 are cleared (processing tOS
), a power outage report in the format shown in FIG. 4 is formed and recorded and output from the plotter 6 (process 106).

This power outage report records a title at the top, records the date/time information obtained from the clock circuit 7 in column R1, and
! In l1R2, the contents of the power-off time information sp are recorded as the date/time of the power-off, and in columns R3, R4, R5, and R6, based on the contents of the file management information FM,
The file number, transmission mode, and destination information are displayed in a list.

When the recording output of such a power outage report is finished, the file management information F stored in SRAM3 at that time is
A process 107) for deleting all M is started, and a system process for operating the facsimile machine is activated (process 108).

After this, a process of reading the current time information from the clock circuit 7 and updating the contents of the power-off time information sp is performed at regular intervals Ti (processing loop of process 109 and determination 110).

Further, if the file management information FM is not stored in the SRAM 3 at power-up and the result of the determination 101 is No, the process moves to process 108 and system processing is started. Further, when the result of judgment 104 is No,
Since the storage contents of the pseudo SRAM 10 can be handled as valid image information, the process moves to step 108 and system processing is started.

In this way, when the power is turned on, if one or more pieces of image information are stored in the pseudo SRAMl0 immediately before the power is turned off, and if the power off time is longer than a certain period of time, the image information is stored in the pseudo SRAMl0. The image information is determined to be invalid and its contents are erased, and a power-off report is recorded and output to alert the operator.

In addition, if the memory contents of pseudo [SRAM10 are valid,
Since the stored contents are retained and can be used, there is no need to read the transmitted document again.

Incidentally, the backup capacitor 11 has a limited lifespan, and therefore, as the operating period of the facsimile machine passes, its discharge characteristics change and the backup possible time is considered to decrease.

Therefore, it is necessary to set a backup possible time in consideration of the lifespan of the backup capacitor 11, and an example of the process executed at power-on in this case is shown in FIG.

In this process, first, the life t5 of the backup capacitor 11 is extracted from the backup available time t and operation start date/time information stored in the ROM2, and the time tL is corrected based on the following equation (1). and the correction time t1'
is obtained (process 201).

ti'= (((SP)-t4)・t□)/l, ・
...(Then, processing 202 to judgment 211 similar to processing 101 to judgment 110 in FIG.
Compare with 1'.

As a result, the pseudo SR
It is possible to determine whether the image information stored in AM10 is valid or invalid.

FIG. 6 shows another example of initial processing when power is turned on.

In this case, first, the detected value of the voltage detector 12, that is,
Process 301) to input the terminal voltage value L2 of the backup capacitor 11, and check whether one or more file management information FM is stored in the SRAM 3 (Judgment 3)
02).

When the result of judgment 302 is YES, the terminal voltage value L of the backup capacitor 11 capable of backing up the storage contents of the pseudo SRAM 10 is extracted from the ROM 2, and it is determined whether the terminal voltage value L2 is greater than or equal to the terminal voltage value L0. A judgment is made (judgment 303).

When the result of the judgment 303 is YES, since the storage contents of the pseudo SRAM 10 at that point cannot be treated as valid image information, all the storage contents of the pseudo SRAM 10 are cleared (process 304), and the same process as described above is performed. Process 305) to form a power-off report and output it from the plotter 6, and at that time, process 306) to delete all file management information FM stored in SRAM 3.
, starts a system process for operating the facsimile machine (process 307).

Further, when the result of judgment 302 is NO, and when the result of judgment 303 is NO, the process moves to process 307 and system processing is activated.

In this way, in this embodiment, by inspecting the terminal voltage of the backup capacitor 11, the pseudo SRAM
Since it is determined whether the image information stored in l0 is appropriate, a more accurate determination can be made.

FIG. 7 shows still another example of initial processing at power-on.

In this case, first, it is checked whether one or more file management information FM is stored in the SRAM3 (determination 401).
), when the result of the judgment 401 is YES, the storage contents of the pseudo SRAM 10 at that time are accumulated in byte units, and the lower two bytes of the accumulated value are calculated as the current sum value S2 (process 402).

Next, it is checked whether the reference sum value S1 stored in the SRAM3 and the current sum value S2 do not match (determination 403).
, when the result of judgment 403 is YES, the pseudo SR
If the image information stored in AM3 is destroyed,
Since the storage contents of the pseudo SRAM10 at that point cannot be treated as valid image information, the pseudo SRAM
All memory contents of l0 are cleared (processing 404
), generate a power outage report similar to the above and print it to plotter 6.
Processing for better recording output (405), at that time SRAM3
All file management information FM stored in the FM is deleted (process 406), and system processing for operating the facsimile machine is activated (process 407).

Further, from then on, each time the storage contents of the pseudo SRAM 10 are updated, the reference sum value S of the pseudo SRAM 10 is calculated and stored in the SRAM 3 (processing loop of judgment 408 and processing 409).

Further, when the result of judgment 401 is NO, and when the result of judgment 403 is NO, the process moves to process 407 and system processing is activated.

In this way, in this embodiment, since the storage contents of the pseudo SRAM 10 are actually inspected, the pseudo SRAM 10
The memory contents of can be inspected more strictly.

Note that the calculation operation of the reference sum value S in the above-mentioned explanation of the operation of the facsimile apparatus needs to be performed only when the initial processing of the embodiment shown in FIG. 7 is executed. In addition, the voltage detector 12
needs to be provided only when executing the initial processing of the embodiment shown in FIG.

Further, in the above description, only the parts directly related to the present invention are described in detail, and the description of other parts is omitted.

[Effects of the Invention] As explained above, according to the present invention, it is possible to compare the backup capacitor's possible backup time with the power-off time, compare the terminal voltage of the backup capacitor with a reference value, or compare the backup capacitor's terminal voltage with the reference value, or compare the Based on the comparison of the sum value calculated based on the memory contents before and after the power is turned off, the pseudo SR
It is determined whether the memory contents of the AM are valid or not, and based on the determination result, the memory contents of the pseudo SRAM are erased, so if the memory contents of the pseudo SRAM are retained, the memory contents are Since the contents can be used effectively, the effect of greatly reducing the effort required to re-read the manuscript is obtained.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a facsimile device according to an embodiment of the present invention, FIG. 2(a) is a schematic diagram showing an example of file management information, and FIG. 2(b) shows an example of power-off time information. Schematic diagram, FIG. 3 is a flowchart showing an example of initial processing executed when power is turned on, FIG. 4 is a schematic diagram showing an example of a power-off report, and FIG. 5 is a flowchart showing a modification of the process in FIG. 3. , FIG. 6 is a flowchart showing another example of the initial processing executed when the power is turned on, and FIG. 7 is a flowchart showing still another example of the initial processing executed when the power is turned on. 1... CPU (Central Processing Unit), 2... ROM (Read Only Memory), 3... SRAM (Static RAM (Random Access Memo January), 4...
... Battery, 7... Clock circuit, 10... Pseudo SR
AM, 11...Backup capacitor, 12...
・Voltage detector. L → Fig. (a) (b) Fig. Fig.

Claims (4)

[Claims] (1) In a facsimile machine equipped with an image storage means using a pseudo SRAM to which a capacitor for power backup is added, a non-volatile storage means stores in advance the backup possible time of the capacitor, and a power supply that detects the time when the power is cut off. The power-off time detection means compares the power-off time detected by the power-off time detection means with the possible backup time stored in the non-volatile storage means when image information is stored in the pseudo SRAM at the time of power-on. A facsimile apparatus comprising image information control means for erasing image information stored in a pseudo SRAM based on the comparison result. (2) In a facsimile machine equipped with an image storage means using a pseudo SRAM to which a capacitor for power backup is added, a non-volatile storage means that stores in advance the backup possible time of the capacitor and a time when the power is cut off are detected. A power-off time detection means; a correction means for correcting the possible backup time based on the operating time when the power is turned on; and the power-off time detection means detects when image information is stored in the pseudo SRAM at the time of the power-on. The power outage time is compared with the backup possible time corrected by the correction means, and based on the comparison result, the pseudo S
A facsimile apparatus comprising an image information control means for erasing image information stored in a RAM. (3) In a facsimile machine equipped with an image storage means using a pseudo SRAM to which a capacitor for power backup is added, a non-volatile memory means that stores in advance the operable power supply voltage value of the pseudo SRAM, and a terminal voltage of the capacitor. and when image information is stored in the pseudo SRAM when the power is turned on, the detection value of the voltage detection means is compared with the operable power supply voltage value stored in the nonvolatile storage means. A facsimile apparatus comprising image information control means for erasing image information stored in a pseudo SRAM based on a comparison result. (4) In a facsimile machine equipped with an image storage means using a pseudo SRAM with a capacitor added for power backup, a reference sum value is calculated based on the stored contents of the pseudo SRAM every time the storage contents of the pseudo SRAM are updated. a reference sum value calculating means for calculating the reference sum value, a non-volatile storage means for storing the reference sum value calculated by the reference sum value calculating means, and a non-volatile storage means for storing the reference sum value calculated by the reference sum value calculating means; A comparison sum value is calculated, the comparison sum value is compared with the reference sum value stored in the non-volatile storage means, and a pseudo SR is generated based on the comparison result.
A facsimile device comprising an image information control means for erasing image information stored in an AM.